Abstract:The transformation and upgrading of freshwater fisheries is of great significance for promoting consumption upgrading and achieving high-quality sustainable development of industry. Based on the analysis of the prominent problems faced by the transformation and upgrading of freshwater fisheries and the needs of engineering science and technology in China， this paper puts forward the specific overall ideas， the promotion paths， the main tasks and the main goals for the transformation and upgrading of freshwater fisheries. And through systematic research， the key research points of engineering science and technology innovation are put forward， such as green and efficient breeding， excellent species breeding technology and equipment， precise feeding and efficient feed utilization technology， water environment control technology under different breeding modes， efficient green technology and equipment for tailwater treatment， multi-information intelligent stereoscopic sensing technology and equipment， freshwater product fishing and high-quality freshness preservation， storage and transportation technology in cold chain logistics and equipment for aquaculture product primary processing， to provide the decision-making reference for comprehensively promoting the mechanization， establishment， and intelligence level of freshwater fishery in our country.

Abstract:Owing to the properties of low concentration and high toxicity，emerging contaminants （ECs） have become one of the major threats to water safety.Biochar has attracted extensive attention in the removal of ECs from aquatic environment due to its easy accessibility and high treatment efficiency.In order to promote the application of biochar in the removal of ECs，in this paper the pollution status of ECs ，the properties of biochar，and the research and application of biochar in the removal of ECs in aquatic environment were reviewed.The research progress of removal of ECS by biochar as absorbents，advanced oxidation catalysts and microbial immobilization carriers was summarized，and the prospect was put forward.

Abstract:To accurately design the inlet structure of the factory circular recirculating aquaculture tank， based on the computational fluid dynamics technology， fluent software was used to establish a numerical model to simulate the flow field distribution characteristics of the inlet pipe in the pond under different inlet angles θ， inlet diameter ratio d/r， and inlet height h in this study. The average velocity v_avg and uniformity coefficient U were used as the evaluation indexes， and the inlet structure was optimized and analyzed. On the basis of physical experiments that the numerical model can better simulate the flow field characteristics in the aquaculture pond， the effects of different inlet structures on the flow field were simulated. The results showed that under the same conditions， the maximum v_avg was achieved at θ=40° and the U difference between water layers was minimized； the larger v_avg and U was achieved at d/r=0.1 and the U difference between water layers was minimized； the larger v_avg was achieved at h=100~400 mm and the U difference between water layers was smallest at h=100 mm. It was shown that the flow field characteristics in the pond were in an optimal state when the inlet angle θ=40°， inlet angle d/r=0.1 and the inlet height h=100 mm.

Abstract:To investigate the growth characteristics and patterns of largemouth bass （Micropterus salmoides） during pond cultivation， various growth parameters including length， total length， snout length， eye diameter， head length， caudal peduncle length， head height， body height， caudal peduncle height， body width， and body mass were measured from individuals ranging from （16.3±4.9） g to （424.9±27.2） g.The correlations among these growth parameters were analyzed， and the predictive models for body mass were constructed using support vector regression （SVR）， radial basis function neural network （RBF）， and random forest regression （RF）.The best-fit model was determined by comparing the predicted values with the actual measured values.Optimal growth models were also developed for each growth parameter using model-fitting approach.The results revealed a highly significant correlation between body mass and growth parameters.The SVR-based predictive model exhibited the highest accuracy， with a coefficient of determination （R²） of 0.996， a root mean square error （RMSE） of 9.004， and a mean absolute error （MAE） of 6.598.A power function relationship was observed between body mass and body length， with an equation of W=0.0127×L^3.224 and a R² of 0.977.The Logistic models were the best for total length， body length， snout length， and head length.Von Bertalanffy models were the best models for head height， body height， eye diameter， and body width， while Gompertz models were most suitable for body mass， caudal peduncle length， and caudal peduncle height.The condition factor of largemouth bass fluctuated from 2.26% to 2.93% during the cultivation period.These findings suggest that growth models and body mass predictive models can be utilized to understand the growth process of largemouth bass under pond-cultured conditions.Accurate feeding based on these models can lead to optimal cultivation outcomes.

Abstract:Aquaculture of captive-pond mode has higher sewage treatment efficiency and breeding density， which is due to the benefit of frequent removals of aquaculture waste in the captive tank. However， dissolved oxygen in high density aquaculture water is a concern for farmers. When the water temperature is high in summer， air aeration is inefficient， and the bubble-based aeration method cannot meet the requirements of oxygen supply. Gas-liquid mixed pump has a great performance on increasing dissolved oxygen in sewage aeration treatment. To explore whether gas-liquid mixed pump is suitable for the oxygen enhancement in the captive-pond mode， it is necessary to explore the optimal process parameters through experiments. In this study， the performances of the pump were tested under different water temperatures， outlet pressures and gas-water volume ratios， and the field tests were carried out in the pond captive tank （diameter 4 m， height 2 m， aquaculture water volume 20 m3）. The results showed that， under the conditions of outlet pressure of 0.25 MPa and gas-water volume ratio of 0.01 to 0.05， the dissolved oxygen in outlet water was inversely proportional to the water temperature （5.6 ℃， 13.5 ℃ and 30.3 ℃）， and the dissolved oxygen varied from 47.93 mg/L to 20.60 mg/L. The oxygen absorption efficiency was inversely proportional to the gas-liquid volume ratio， and the oxygen absorption efficiency varied from 91% to 33.7%. The dynamic efficiency was proportional to volumetric gas-liquid ratio and varied from 22.32 kg/（kW·h） to 55.12 kg/（kW·h）. Field test showed that， under the condition of fish oxygen consumption density of about 13.19 to16.49 kg/m³ ， when the pump’s working power was about 3 kW， the dissolved oxygen of each captive tank can reach 11 mg/L in the daytime and keep above 8 mg/L at night. The fluctuation of dissolved oxygen in the captive tank was within 0.2 mg/L， and the uniformity was good. The pump system is simple in structure and can work efficiently under high water temperature conditions.

Abstract:In order to explore the optimal control range of water depth for Vallisneria natans type aquiculture， based on the natural distribution water depth of V. natans in the pond， four light intensity gradient groups， including 5% （L1）， 15% （L2）， 25% （L3）， and 35% （L4） of the full sunlight intensity （L1 was the suitable light intensity group， L2， L3， and L4 were the strong light groups）， were set up， corresponding to the underwater depth of 1.0-1.1， 0.6-0.8， 0.4-0.6， and 0.3-0.4 times the transparency of the pond， respectively， to study the growth， antioxidant， and purification ability of V. natans under natural light period and intensity. The results showed that under natural light period， the total biomass of V. natans increased significantly with the increase of light intensity （5%-35% full sunlight range）， and the maximum leaf length appeared in L2 group. The content of malondialdehyde （MDA） and superoxide dismutase （SOD） activity in L2， L3， and L4 groups were significantly lower than those in L1 group； the content of dissolved oxygen （DO） and pH values in water in L3 and L4 groups were significantly higher than those in L1 group， while the chlorophyll a （Chl a） content was opposite. The concentrations of ammonium nitrogen （NH₄⁺-N） and nitrite nitrogen （NO₂^--N） in each group rapidly decreased to lower levels （<0.30， <0.02 mg/L） within 3 and 2 weeks， respectively； except for group L1， the concentrations of nitrate nitrogen （NO₃^--N） and total nitrogen （TN） in other groups continued to decrease at different rates with time until the end of the experiment （<2.50， <3.00 mg/L）， which was negatively correlated with light intensity to a certain extent. The activities of glutamate synthase （Fd-GOGAT） and alkaline phosphatase （AKP） in L3 and L4 groups were significantly higher than those in L1 and L2 groups， and the removal rates of orthophosphate （PO₄^3--P） and total phosphorus （TP） in each group were more than 80%， showing good removal effects. Research has shown that the water level for V. natans type aquiculture should be controlled within a range of about 0.3 to 0.6 times transparency above V. natans.

Abstract:Filter media filtration can effectively reduce the content of suspended solids and other harmful substances in fish culture tailwater and is often used as a primary treatment technology for aquaculture tailwater. In order to investigate the effect of filter media filtration for pond captive tailwater treatment， this study used volcanic rock， activated carbon and zeolite as the filter media materials， and carried out pond captive tailwater treatment experiments with filter media type， filter media size and filter media thickness as the test factors， and total suspended solid （TSS） removal efficiency， ammonia nitrogen （NH₄⁺-N） removal efficiency and chemical oxygen demand （COD） removal efficiency as the test indexes. The results showed that all three filter media could remove TSS and COD in the tailwater， and all could reduce the concentration of NH₄⁺-N in the tailwater to a certain extent， and among the three filter media， the treatment effect of activated carbon was better than the other two， and the smaller the particle size or the larger the thickness of the filter media， the better the effect of the activated carbon in treating the tailwater. The results of the orthogonal test based on the single-factor test showed that the best overall treatment effect of the filtration device was achieved when the filter media was activated carbon， the particle size was 0.5-2 mm， and the thickness of the filter media was 80 cm. Under these conditions， the removal efficiencys of TSS， COD and NH₄⁺-N were 83.86%， 49.78% and 29.89%， respectively. The study showed that the filter media filtration has good effect on the removal of TSS and COD， but the NH₄⁺-N removal effect is not satisfactory. Therefore， in the treatment of captive tailwater， media filtration can be used as a primary treatment process for captive tailwater， but further purification of tailwater is needed for ammonia nitrogen by means of biofilter， artificial wetland or bioreactor.

Abstract:Neuronic acid （NA） is an ultra-long chain monounsaturated fatty acid，a core component of the myelin sheath of brain nerve fibers，with functions including repairing damaged brain nerve fibers and promoting regeneration of nerve cell.Therefore，more and more studies are focusing on NA.At present，NA mainly relies on extraction from natural species，which is difficult to meet market needs and limits its further development and application.In recent years，with the development of genetic engineering and synthetic biology，constructing NA metabolic pathways in existing species through multi-gene strategies can economically and sustainably obtain NA to meet the needs of fields such as nutrition，pharmaceuticals，and chemical industries.This article reviewed the biological functions，biological sources，and synthetic pathways of NA.The advantages and disadvantages of genetic engineering production of NA chassis were compared.The influencing factors of producing NA-rich seed oil using cruciferous oil crops as the chassis were further explored.It will provide some ideas and strategies for regulating NA production and obtaining renewable NA resources in the future through transgenic technology and molecular breeding.

Abstract:Rice is one of the important food crops.Lodging during the production of rice is a common phenomenon that can have a significant impact on the yield and quality of rice.Therefore，developing rice varieties with lodging-resistance is one of the main goals of rice breeding.524 rice germplasm resources were used to further mine the genes that control lodging resistance in rice.Genome-wide association analysis （GWAS） was used to identify the locus qRLG7 that is significantly associated with lodging resistance.The candidate genes regulating lodging resistance in rice were determined by analyzing the expression level and the association of candidate gene.CRISPR-Cas9 technology was used to construct mutant families of two candidate genes on the basis of analyzing the expression characteristics and natural variations of candidate genes in the promoter region.The lodging resistance of mutant families was examined.The results showed that the expression levels of two tandemly arrayed genes （LOC_Os07g37220 and LOC_Os07g37230），both encoding inositol-1-monophosphatase （IMP），were significantly higher than that of the other candidate genes in the internode at 5 cm away from the bottom of culm.The expression levels of the two IMP genes in the highly lodging resistant germplasms were significantly higher than that in the highly lodging-prone germplasms.The SNPs in the promoter regions of the two genes were significantly associated with culm diameter at 5 cm from the bottom （CD5）.The significant SNPs of candidate genes were mainly divided into two haplotypes，and the CD5 values of the two haplotypes were significantly different.The activity of the promoters of two genes had significant differences between the two haplotypes as well.The mutants of the two candidate genes had significantly reduced culm-breaking resistance，culm thickness，culm diameter，plant height，and panicle weight compared to the wild-type rice.It is indicated that the candidate gene LOC_ Os07g37220 and LOC_ Os07g37230 has a certain lodging resistance.It will provide reference for further mining and characterizing genes for the genetic improvement of lodging resistance in rice.

Abstract:The phenotype identification， microscopic observation of endosperm cells， determining the content of storage substance in endosperm， and map-based cloning of a defective maize kernel mutant named as empty pericarp35 （emp35） were conducted to study its physiological function in the development of maize kernel and map the Emp35 gene. The results showed that the development of emp35 kernels was slow and significantly smaller than that of the wild-type kernels during the same period of development， resulted in the shrunken and empty pericarp kernels. The development of embryo and endosperm in the emp35 was severely delayed， and the mitochondrial structure in endosperm cells was abnormal. The accumulation of starch and protein in the emp35 was reduced. The seeds in the F₂ population segregated in a ratio of 3 wild type to 1 empty pericarp， indicating that the defective kernel phenotype is controlled by a single recessive nuclear gene. The Emp35 gene was mapped at the interval between 127.90 Mb and 163.36 Mb on the chromosome 8 of maize with a bulked segregant analysis （BSA）. Four InDel markers were developed within this interval， and Emp35 gene was finely mapped at the interval between 139 571 117-146 176 858.

Abstract:Water is the lifeline and the largest bottleneck for the sustainable development in Xinjiang. Agriculture is the largest water consumer in Xinjiang, accounting for more than 90% of the total socioeconomic water consumption, and the proportion of agricultural water consumption in southern Xinjiang is even higher. The key to water-saving potential in Xinjiang lies in agriculture, and agricultural water saving is the fundamental way to solve the sustainable development of economy and society in Xinjiang. The development of agricultural water-saving in the irrigation areas of Xinjiang was reviewed to improve the agricultural water use efficiency and promote the high-quality development of agriculture in Xinjiang. The current status and existing problems of developing agricultural water-saving were analyzed. The countermeasures and suggestions including vigorously developing water-adapted agriculture, increasing the construction of high-efficient water-saving projects, continuously promoting salt reduction and water saving, strengthening the construction of digitalized irrigation areas, promoting water-saving publicity and training, and improving service system for agricultural water-saving were put forward based on the Central Government’s new positioning and requirements of the country for the development of agriculture in Xinjiang in the new era. It will provide strong support for promoting the sustainable development of modern agriculture and ensuring the national security of grain and cotton production in Xinjiang.

Abstract:One functional fungus strain was isolated and screened from plant rhizosphere soil with high background value of 50.187 mg/kg selenium （Se） and 50.311 mg/kg cadmium （Cd） using selective culture medium to solve the problem of co-accumulation of selenium and cadmium in crops.The fungus strain obtained was identified as Fusarium redolens.The changes in available selenium and cadmium in soil，as well as the content of Se and Cd in edible parts of plants were determined with soil simulation experiments and pot experiments.Evaluate The effects of fungus on selenium uptake and cadmium reduction based on the enrichment of selenium/cadmium and the transport coefficients.The results of soil simulation experiments showed that the rate of active selenium was positively correlated with culture time after the fungus was inoculated，while the rate of cadmium immobilization was opposite.The rate of active selenium reached its peak on the 5th day，at 60.9%.The rate of cadmium immobilization was highest at 41.2% on the third day and lowest at 27.3% on the fifth day.The results of the pot experiments showed that adding 10⁸ cfu/mL of fungi significantly reduced the soil pH by 0.35 units compared to the control.There was no adverse effect on the growth of the seedlings of Cardamine violifolia，with an average plant height，root length，and biomass of 7.4 cm，9.6 cm，and 2.9 g，respectively，all higher than that of the control.The content of available selenium in the soil significantly increased，with the highest rate of active selenium reaching 24.8%，while the content of available cadmium significantly decreased，with the rate of cadmium immobilization of 24.7%.The content of total selenium in the above ground and underground parts of Cardamine violifolia increased by 25.6% and 36.8%，respectively，while the content of total cadmium in the above ground and underground parts of Cardamine violifolia decreased by 32.7% and 11.6%，respectively.It is indicated that fungi have the ability to activate selenium and immobilize cadmium in natural soil with high background value of selenium and cadmium，and the best effect is achieved when adding a concentration of 10⁸ cfu/mL，which helps to enrich selenium and reduce cadmium in Cardamine violifolia.

Abstract:为探求抑制香菇镉富集的方法，开发镉污染防控技术，设置实验室菌丝培养和大棚袋式栽培2个阶段试验，分析培养条件及外源添加物对香菇菌丝及子实体中镉含量的影响。结果显示，在温度10~30 ℃范围内随着培养温度升高，菌丝镉含量呈现先上升后平稳的趋势；在pH 4~8范围内随着培养基pH值升高，菌丝镉含量呈现先上升后下降的趋势；在含镉的液体培养基中分别添加5 mmol/L Ca（NO₃）₂、KNO₃和 Mg（NO₃）₂，发现Mg²⁺能明显抑制菌丝对镉的富集；随着香菇子实体发育成熟，镉含量逐渐降低，不同部位镉含量呈现菌褶>菌盖>菌柄；在培养料中分别添加硫酸镁、硫酸锌、活性炭和沸石，发现添加50 mg/kg硫酸镁、60 mg/kg硝酸锌和2.5%活性炭，能使子实体镉含量下降42.8%、46.9%和50.3%。上述研究表明，培养条件和外源添加物对香菇菌丝体和子实体镉含量具有一定的影响，可通过外源添加物抑制香菇对镉的富集作用。

Abstract:The daily observation data set of the National Meteorological Station of China from 1991 to 2020 and the urban green space area data of China in 2020 were used to analyze the effects of extreme climate on major urban gardens in China with the percentile method and GIS spatial analysis technology to study the risks of urban gardens suffering from extreme climate under the background of global climate changes. The results showed that the high-risk areas affected by extreme low temperatures were located in the northern and high-altitude areas of China. High risk areas of extreme high temperature generally occurred in eastern cities with rapid urbanization. The high-risk areas of heavy precipitation were basically consistent with the distribution of rainfall belts in China， mainly located in central and southern China， with average precipitation of above 30 mm. Shigatse and Naqu in Tibet， and the northern and eastern coastal areas of China are high risk areas of gales. Urban green space in the Yunnan-Guizhou Plateau， the middle and lower reaches of the Yangtze River， parts of North and Northeast China are vulnerable to extreme drought. Designing urban gardens in the future needs to combine the characteristics of local extreme climate， improve tree species and planting structures， and enhance the adaptability of ecological systems such as landscape architecture to climate changes.

Abstract:A method suitable for identifying and classifying pepper diseases was designed to achieve precise recognition and classification of pepper diseases in complex environments including background clutter or interference.Six common diseases in the growth process of peppers were used to expand the dataset with data augmentation methods.An improved MaxViT-DF model was proposed based on MaxViT.The ordinary convolution in the MaxViT model was replaced with deformable convolution to enable the model to extract features closer to the recognition target in complex environments.A feature fusion module was introduced when applying attention to the MaxViT model to improve the model’s global perception ability.The results showed that the improved MaxViT-DF model had an identification and classification accuracy of 98.10%，and the classification accuracy for six common pepper diseases was higher than 95%.The improved model had significant advantages in convergence speed and classification accuracy compared with models including ResNet-34，EfficientNetv2，and VGG-16.It is indicated that the MaxViT-DF model can effectively identify and classify common diseases in different types of peppers.

Abstract:Accurately identifying pests and diseases in citrus can be used to timely reduce the economic losses.A common method for detecting pests and diseases in citrus based on the improved YOLOv5s model was proposed to solve the problems that the existing models of detection cannot accurately identify multiple types of pests and diseases of citrus in the natural environment.The model was improved by introducing the ConvNeXtV2 model and constructing a CXV2 module to replace the C3 module of YOLOv5s， enhancing the diversity of extracted feature.The dynamic detection head DYHEAD was added to improve the processing ability of the model for different spatial scales and task targets.The CARAFE upsampling module was used to improve the efficiency of extracting feature.The results showed that the improved YOLOv5s-CDC had a mean recall rate and average precision of 81.6% and 87.3%，4.9 percentage points and 3.4 percentage points higher than that of the original model，respectively.Compared with the detection with other YOLO serial models in multiple scenarios，it had higher accuracy and stronger robustness.It is indicated that this method can be used for detecting the diseases and pests of citrus in complex natural environments.

Abstract:The effects of genotypes and culture conditions on the microspore culture in mustard （Brassica juncea） were studied to establish an optimal system of the microspore culture and chromosome doubling in mustard.34 inbred lines of 8 different varieties of mustard were used to conduct the microspore culture.The effects of heat shock times，concentrations of activated carbon，and densities of microspore on the rate of microspore embryogenesis were analyzed.The results showed that genotypes had a significant impact on the success of microspore culture in mustard，with 11 out of 34 inbred lines successfully producing embryoids.There were significant differences in rates of producing embryo among different inbred lines，among which Brassica juncea var. megarrhiza Tsen et Lee had the highest rate of producing embryo，reaching 23.85 embryos/anther.The optimal conditions for producing microspores in mustard were 32 ℃ heat shock for 1-2 days，culture medium containing 3-5 g/L activated carbon，and the density being 1.5×10⁵ to 2.0×10⁵ microspores/mL.The results of chromosome doubling experiment showed that immersing the stem tips in 1 g/L colchicine solution for 1 hour had a high efficiency of chromosome doubling and low chimerism，which could be used to double the chromosomes in mustard.The results of chromosome doubling test showed that 1 g/L colchicine solution soaked in stem tip for 1 hour had high doubling efficiency and less mixed-ploidy formation，which could be used to double the chromosomes in mustard.

Abstract:The three citrus pulp from Zigui navel orange，Yichang mandarin，and Ponkan tangerine was treated with six methods including refrigerator thawing，natural thawing，flowing water thawing，warm water thawing，ultrasonic thawing，and microwave thawing to study the effects of thawing methods on the quality characteristicsof the quick-frozen citrus pulp.The thawing time，loss rate of juice，conventional quality indexes，color，hardness，total phenolic content，antioxidant activity，and changes in sensory of quick-frozen citrus pulp were measured.The results showed that the effects of different thawing treatments on the quality of citrus pulp from Zigui navel orange，Yichang mandarin，and Ponkan tangerine were significantly different （P<0.05）.The time of microwave thawing for Zigui navel orange，Yichang mandarin，and Ponkan tangerine was the shortest，being 0.82 min，0.89 min，and 0.81 min，respectively.The loss rate of juice in microwave thawing for Zigui navel orange，Yichang mandarin，and Ponkan tangerine was the lowest，being 0.25%，0.16%，and 0.15%，respectively.The conventional quality indexes of microwave and ultrasonic thawing were well preserved.The microwave thawing had the least effect on color with ΔE of 8.48，7.52， and 4.71，and the least loss of hardness with reductions of 36.1%，52.03%，and 36.48%，respectively.The content of total phenol and antioxidant activity in microwave thawing were relatively high，and the sensory profile was closest to that of fresh flesh samples.Compared to the other five thawing methods，microwave thawing can thaw the flesh within 1 minute，and effectively slow down the changes in color and the hardness loss of pulp，and better preserve the edible and nutritional qualities of the quick-frozen citrus pulp.

Abstract:Aquaculture is one of the most important ways of providing aquatic products， and the aquafeeds， especially for carnivorous aquatic animals， requires large amounts of fishmeal. To date， fishmeal has been recognized as the best source of protein in aquafeeds in terms of nutritional quality. However， with overfishing， anthropogenic activities and extreme weather， the production of major fish species that provide fishmeal has been decreasing globally year by year， leading to fishmeal shortage and price increase， and thus there is an urgent need for the aquaculture industry to seek for high quality alternative protein sources to fishmeal in order to achieve its sustainable development. Aquaculture is one of the most important ways of providing aquatic products. The aquatic feeds especially for carnivorous aquatic animals require large amounts of fishmeal. To date， fishmeal has been recognized as the best sources of protein in aquatic feeds in terms of nutritional quality. However， the production of major fish species that provide fishmeal has been decreasing globally year by year with overfishing， anthropogenic activities and extreme weather， leading to the shortage of fishmeal and the increase of its price， and thus there is an urgent need to seek the alternative sources of protein with high quality as fishmeal to achieve the sustainable development of aquaculture industry. Black soldier fly （BSF， Hermetia illucens） is a saprophytic insect， and its larvae have characteristics including wide feeding habits， strong reproductive ability， and rich and balanced nutrients. It is considered as a highly potential and new sources of feed protein and has broad prospects of application in the production of aquatic animals. This article reviewed the main nutritional and bioactive components of BSF larvae， as well as progress on their application in feeds for different aquaculture species such as herbivorous， omnivorous， carnivorous， crustacean， and amphibian reptiles. The optimal amount of BSF larvae in different aquatic feeds was summarized. The feasibility of using BSF larvae as a sustainable source of protein in aquatic feeds was explored. The problems and challenges in its practical application were analyzed. It will provide a basis and reference for developing and utilizing black soldier fly and studying its mechanism in aquatic animals.

Abstract:To find out the community structure of zoobenthos in five drinking water reservoirs including Guanyinge Reservoir， Baishi Reservoir， Chaihe Reservoir， Qinghe Reservoir， and Tanghe Reservoir， in Liaoning Province， and to estimate the potential fishery production according to the stock of zoobenthos， then to provide scientific guidance for the stocking and fishing of water conservation fisheries， seasonal surveys of the five reservoirs were carried out in 2019-2020. A total of 67 taxa， belonging to 3 phyla were identified. Among them， 39 species were chironomid larvae and 12 species were oligochaetes mainly Tubifex and Naididae. Only three species of mollusks were identified， including Radix swinhoei collected from Guanyinge Reservoir and Tanghe Reservoir， Bellamya purificata collected from Guanyinge Reservoir， and Cristaria plicata collected from Baishi Reservoir. The most species were detected in Tanghe Reservoir with 39 species， followed by 34 species in Guanyinge Reservoir， and the least in Baishi Reservoir with 23 species. The density was the highest in Baishi Reservoir with 1 546.89 ind/m²， followed by Guanyinge Reservoir with 658.33 ind/m²， and the lowest was Tanghe Reservoir with 481.92 ind/m². The biomass was the highest in Baishi Reservoir with 7.76 g/m²， followed by Tanghe Reservoir with 5.68 g/m²， and the lowest was Qinghe Reservoir with 2.49 g/m². The highest density of five reservoirs occurred in spring， summer and autumn， but the lowest values were all in summer. The biomass was higher in spring and winter， and lower in summer and autumn. The density and biomass of each reservoir was the highest in the still water zone. Only the highest density and biomass in Guanyinge Reservoir and biomass in Baishi Reservoir appeared in the transition zone. The density and biomass of Guanyinge Reservoir and Chaihe Reservoir were mainly composed of oligochaetes from the river zone to the front of the dam， while the reservoir entrance was dominated by chironomid larvae. The density and biomass of Qinghe Reservoir and Tanghe Reservoir were mainly composed of chironomid larvae from the reservoir entrance to the still water zone， while the front of the dam was dominated by oligochaetes. Baishi Reservoir was dominated by chironomid larvae from the reservoir entrance to transition zone， while the still water zone and the front of the dam were mainly composed of oligochaetes. The results of clustering and MDS ordination indicated that the communities of Guanyinge， Chaihe and Qinghe reservoirs were more similar. The communities of Baishi and Tanghe reservoirs were less similar and significantly different from those of Guanyinge， Chaihe and Qinghe reservoirs. Canonical correspondence analysis indicated that the density of zoobenthos were significantly correlated with the depth of water， total nitrogen， ammonia nitrogen， dissolved organic carbon and chlorophyll-a in five reservoirs. The species and composition of zoobenthos were obviously influenced by the contents of total nitrogen and ammonia nitrogen. The contents of total nitrogen and ammonia nitrogen in Tanghe Reservoir were the lowest， showing the most species and high dominance of chironomid larvae. The contents of total nitrogen and ammonia nitrogen in Baishi Reservoir were the highest， showing the least species and high dominance of tubificid worm. The fish production potential based on zoobenthos of Baishi Reservoir was the highest， followed by Tanghe Reservoir， and lowest in Qinghe Reservoir. Compared with previous surveys， the species numbers of five reservoirs increased， mainly due to the increase of chironomid larvae species. The trends of density and biomass were different from that of the number of species. The density and biomass of Guanyinge Reservoir decreased， while those of Qinghe and Tanghe Reservoirs increased. The density of Baishi Reservoir increased and the biomass decreased， while the density of Chaihe Reservoir decreased and the biomass increased. The stocking and fishing of demersal fish in five water source reservoirs should be managed in a targeted manner according to the characteristics of zoobenthos community structure.

Abstract:In order to investigate the effects of dietary supplementation of yeast chromium and dihydropyridine on physiological and biochemical indices and HSP70 mRNA expression of periparturient dairy cows under heat stress， a total of 24 periparturient Holstein‐Friesian cows with similar body weights and parity were randomly assigned to three groups. Cows were housed at high ambient temperature-humidity index（above 68）for 40 d， and the effects of yeast chromium and dihydropyridine on the heat stress response of perinatal dairy cows were observed during the experimental period. The control group was fed with basal diet， the chromium yeast group was fed with basal diet plus chromium 1‰ and the amount of chromium yeast was 8 g/d， and the dihydropyridine group was fed with basal diet plus dihydropyridine and the amount of chromium yeast was 3 g/d. The results showed as follows： ① Compared with the control group， there was no significant difference in respiratory rate of periparturient dairy cows in chromium yeast group and dihydropyridine group （P>0.05）. ② Compared with the control group， there was no significant difference in serum blood glucose and cholesterol in yeast chromium group and dihydropyridine group on the 7th day before delivery and the 3rd day after delivery （P>0.05）. Compared with the control group， the content of serum triglyceride decreased significantly in dihydropyridine group on the 7th day before delivery （P<0.05）. ③ Compared with the control group， there was no significant differences in serum Na⁺， K⁺ and Cl^- concentrations in chromium yeast group and dihydropyridine group before and after delivery （P>0.05）， and the concentrations of serum alkaline phosphatase and creatine kinase did not change significantly in the two experimental groups before and after delivery （P>0.05）. ④ There was no significant difference in the expression of heat shock protein 70 mRNA in serum between chromium yeast group， dihydropyridine group and control group （P>0.05）. In conclusion， dietary supplementation of 8 g/d yeast chromium with 1‰ chromium and 3 g/d dihydropyridine had no significant effects on physiological and biochemical indices and HSP70 mRNA expression of periparturient dairy cows under heat stress. These results indicated that supplementation of 8 g/d yeast chromium with 1‰ chromium and 3 g/d dihydropyridine had no significant effect on relieving heat stress of perinatal Holstein dairy cows.

Abstract:The mouse blastocysts were used as a model to study the expression profiles of key genes in mice during the hatching and development of blastocyst and to further analyze the mechanism of pregnancy recognition. The transcriptome of blastocysts at different stages of the hatching process was analyzed. The expression levels of key genes were detected with qPCR. The expression patterns of key proteins were studied with immunofluorescence staining. The results of analyzing the transcriptome showed that the expression of differential genes exhibited two regulatory patterns during the hatching process of mouse blastocysts from expansion， hatching to the completion of hatching. The results of GO analysis and KEGG analysis on the set of genes in the regulatory pattern showed that they were involved in biological processes including immunity and inflammation， cell differentiation， and apoptosis， etc. The results of qPCR showed that the expression of key genes Ptgs1， Lyz2， Il-1α， Cfb and Ccl9 were up-regulated， while Cd36 was down-regulated during hatching of mouse blastocysts， which was consistent with the results of transcriptome analyses. The results of immunofluorescence staining showed that Plac1， Cdx2 and C3 were down-regulated， while Lyz2 and Il-1β were up-regulated during the hatching of mouse blastocysts. It is indicated that the expression of gene exhibits specific dynamics of differentiation and the expression of abnormal gene can lead to hatching at a standstill.

Abstract:A vibration extrusion type water chestnut harvester was designed to solve the problems of high manual labor intensity， low operation efficiency， and difficulty in separating fruit and soil during dry harvesting of water chestnuts. The separated water chestnuts were scattered on the surface for easy manual picking by enhancing the effect of crushing the soil layer and improving the degree of fruit and soil separation. The key parameters affecting the separation performance were determined to be the amplitude of the vibration plate， the vibration frequency of the vibration plate， and the speed of the nail roller by analyzing the stress on the water chestnut soil block during the process of operation. The range of key parameter values was preliminarily determined according to the existing experience. Design-Expert 10.0 was used to design the CCD center combination test by using the amplitude of the vibration plate， the vibration frequency of the vibration plate， and the speed of the nail roller as the influencing factors， and the rate of soil fragmentation as the evaluation index. The results of simulating the RecurDyn-EDM coupling showed that there was a better crushing effect and the rate of soil fragmentation was 93.58% when the vibration frequency of the vibration extrusion plate， the vibration frequency of the vibration plate， and the speed of the nail roller was 33.04 mm， 6.63 Hz， and 336.72 r/min， respectively. The results of field verification test showed that the actual rate of soil fragmentation， the rate of water chestnut， and the damage rate was 93.54%， 80.33%， and 28.08%， respectively when the actual amplitude of vibration plate， vibration frequency and the speed of nail tooth was 32.41 mm， 6.5 Hz， and 330 r/min， respectively. It is indicated that the effect of crushing soil is good， and the fitting degree with the results of simulation is high.

Abstract:A seedbed belt preparation device suitable for constructing rapeseed substrate block seedling transplanters was designed based on the large cavity of the boat type furrow opener and the characteristics of constructing a wide seedbed and a flat furrow bottom through the operation of the core ploughshare furrow opener， combined with the excessive connection of the similar ploughshare surface to solve the problems of poor stability of the furrow width， low flatness of the furrow bottom， and large soil disturbance， resulting in low seedling rate and high difficulty in soil covering operations in the operation of furrow opener device of rapeseed substrate block seedling transplanter. A mechanical model for the interaction between soil and preparation device was established. The main structural parameters for constructing a stable seedbed with a seedbed belt preparation device were determined. A four-factor and three-level quadratic orthogonal combination simulation test was conducted using EDEM and taking the operating speed， working depth， front-end width of the brush type surface，and edge angle of blade as factors， the soil disturbance amount and coefficient of variation of ditch width as evaluation indicators. The results of quadratic orthogonal combination test showed that the soil disturbance amount and the coefficient of variation of the ditch width was small when the working depth， the operating speed， the front-end width of the brush type surface and the edge angle of blade was 41 mm，0.52 m/s，40 mm，and 61°， respectively. The results of bench test under the optimal parameter combination showed that the soil disturbance amount was 13.01 cm² and the coefficient of variation of the ditch width was 8.52%. The results of field comparative test showed that the seedling bed equipped with the preparation device installed on the transplanting unit increased the seedling rate of the substrate block by 2.09 percentage points， decreased the coefficient of variation of the ditch width by 13.3%， reduced soil disturbance by 20.9%， and increased the compactness of the ditch bottom by 28.7% compared to the boat type opener， meeting the requirements for the construction of the rapeseed substrate block seedling transplanter.

Abstract:It is necessary to replenish water one by one for the mushroom sticks on the multi-layer mushroom rack during the process of mushroom production.A water injection machine for mushroom sticks on rack mainly composed of six parts including a clamping device，a water injection device，a lifting device，a rotating device，a driving device，and a positioning device was designed to solve the problems of high labor intensity，low efficiency，and inability to accurately control the amount of water injected by traditional manual water replenishment.The water injection unit is composed of a clamping device and a water injection device，the clamping and water injection for a total of 15 mushroom sticks on three layers can be completed simultaneously，and the water replenishing operation of multi-layer mushroom sticks can be realized under the driving of the lifting device.The water replenishing operation of the mushroom rack on the other side can be completed by the rotating device. According to theoretical calculation，the maximum holding force F_jmax of the clamping device is 4 750 N，and the minimum thrust F_tmin of the water injection device is 2 455 N.The rotating device needs to accelerate for 2 s before rotating at a uniform speed for 3.5 s.According to the structural design and theoretical calculation，this article developed a prototype of a water injection machine for mushroom sticks on rack，and conducted a prototype test.The results showed that the damage rate of the mushroom sticks after water replenishment was 0，with the average weight ratio of 84.8% and the average working efficiency of 230 pieces/h.The water injection machine adopts the method of replenishing water with mushroom sticks on rack，which improves the working efficiency and meets the requirements of replenishing water for mushroom sticks.It will provide a theoretical basis for the development of the water injection machine for mushroom sticks on rack.

Abstract:A multi-sensor integrated positioning method for a rice transplanter supplemented with vision navigation system based on the GNSS/INS integrated positioning was proposed to improve the navigation effect of rice transplanter based on GNSS/INS integrated positioning when encountering the conditions of ambient occlusion， electromagnetic interference and sensor failure. Firstly， the improved Otsu method and the improved Hough transform algorithm were designed to extract the visual positioning information， and the relationship equation between the coordinate system of rice transplanter and camera was constructed to solve the position and pose values. Then， the federal Kalman filter algorithm with fault-tolerant function was used to fuse the visual positioning information with the positioning information output by GNSS and INS. Finally， tests were conducted in cement field and paddy field. Results showed that the accuracy of GNSS/INS/VNS combined positioning was similar to that of GNSS/INS integrated positioning in the open cement ground scene， but the average values of position error and heading error calculated by GNSS/INS/VNS combined positioning were 1.77 cm and 0.99°， respectively， which are 46.8% and 61.5% higher than those by GNSS/INS integrated positioning method. In paddy field experiment， the average values of lateral deviation and heading deviation of navigation system decreased by 45.7% and 67.9%， respectively after visual supplement， with the average values of lateral deviation of 1.97 cm and heading deviation of 0.49°. It is indicated that the multi-sensor integrated positioning method based on visual supplement can effectively reduce the positioning error and tracking deviation of navigation system， meeting the performance requirements of automatic driving operation of transplanter.

Abstract:It is extremely important to obtain accurate information of soil moisture and understand the dynamic change pattern of soil moisture. A support vector machine algorithm（SVM） was introduced for fitting analysis and regression training optimization of ultrasonic velocity-soil moisture under four different treatments of alternating wet and dry， and a prediction model of the soil moisture based on ultrasonic velocity was constructed. The prediction model was used to estimate the water content of soil in farmland tillage layer with different moisture requirements. The results showed that the average relative error of verifying soil moisture in the field with the model constructed was about 1.5% compared with the traditional drying method. It is indicated that the prediction model for ultrasonic velocity-soil moisture based on SVM model can effectively describe the soil moisture in the area studied. It will provide reference for utilizing ultrasonic characteristics to achieve continuous monitoring of soil moisture in farmland.

Abstract:The overset mesh model coupled with the VOF model in Fluent software was used to study the two-phase flow to deeply understand the spray coating process of preserved eggs and solve the problems of insufficient theoretical researches on the spray coating of preserved eggs. The liquid film wetting ratio during the coating process under different placement positions of preserved eggs was obtained. The changes of the aspect ratio of the droplets under different pipette parameters were analyzed. The optimal pipette parameters and working pressure for the removal of pendant droplets were selected by the Box- Behnken experiment using the variation index of film thickness as the response value. The results showed that the liquid film wetting ratio of the preserved eggs placed downward after spraying was 1 while the liquid film wetting ratio of the preserved eggs placed with the blunt end down after spraying was only 0.836. The optimal combination of straw parameters screened out was spacing of 14.50 mm， diameter of 12.09 mm， working pressure of 6.97 kPa， and predicted variation index of film thickness of 0.636. The experiments of simulation and the removal of pendant droplets using the air suction device were carried out under the optimal combination of straw parameters. The results showed that the relative error between the simulated value and the predicted value of the variation index of film thickness was 1.73%. The relative error between the observed value and the expected value of the variation index of film thickness was 7.55%， and the relative error between the observed value and the simulated value was 9.12%. Indicating that the coupling model in this study can be used for the simulation test of egg spray coating.

Abstract:Near-infrared spectroscopy was used to qualitatively discriminate the adulteration in whole egg powder and to analyze the concentration of adulteration quantitatively. Six different pre-processing methods were used to pre-process the raw spectral data. The competitive adaptive reweighted sampling （CARS）， successive projections algorithm （SPA） and combined CARS-SPA algorithms were used to filter the spectral data for characteristic wavelengths. Ensemble learning （EL） model was established to qualitatively discriminate the egg powder adulterated. The partial least squares regression （PLSR） model was established to quantitatively analyze the concentration of adulteration. The results showed that first order derivative was the best pre-processing method in qualitative discrimination. The CARS algorithm had the best effect of feature filtering. The EL model had an overall discrimination accuracy of 98.18% for adulterated samples， with the discrimination accuracy of differently adulterated samples of more than 97.78%.MSC was the best pretreatment method in quantitative analysis. CARS algorithm had the best effect of feature filtering. The prediction set correlation coefficient of PLSR adulteration concentration prediction models for one-component adulteration， two-component adulteration， three-component adulteration， and all adulterated samples adulteration was 0.958 5， 0.931 2， 0.945 6， and 0.955 8， respectively， with the root mean square error RMSEP of 4.689 1， 5.813 4， 4.604 1， and 3.802 9， respectively. It is indicated that the near-infrared spectroscopy can be used for detecting the adulteration in whole egg powder. It will provide a reference for regulatory agencies to detect adulteration in whole egg powder.

Abstract:Covalent attachment of ubiquitin onto lysine residues of the substrate requires the coordinated action of three classes of enzymes： the E1 ubiquitin-activating enzymes， the E2 ubiquitin-conjugating enzymes， and the E3 ubiquitin ligases. These ubiquitination-related proteins play a pivotal role in plant development and plant physiology.The APPBP1/UBA3 （E1）， UBC12 （E2）， Cullin1-Rbx1 （E3） and Nedd8 were used to reconstitute SCF E3 ligase activity in vitro to study protein ubiquitination in vitro. Ub （Ubiquitin） labeled with FITC-Cysteine green fluorescein was prepared. The ubiquitination system of SCF ubiquitin ligase in vitro was constructed. The self-ubiquitination modification of Cullin1 protein in SCF ubiquitin ligase was rapidly detected. The results showed that the autoubiquitination active reaction system of SCF E3 in vitro established has high operability and convenience.