Abstract:Utilizing reactive oxygen species(ROS),a class of oxygen free radicals or non-radical derivatives of oxygen with oxidizing ability to degrade environmental pollutants is one of the greenest and most effective chemical means for pollution control and environmental remediation. However,the formation and reaction mechanism of ROS in the degradation and transformation of environmental pollutants need to be further studied. This article reviews recent research progress on ROS(hydroxyl radical,superoxide anion,singlet oxygen and hydrogen peroxide) for environmental pollutants removal in recent years and introduces the chemical properties,generating pathways and detection methods of these common ROS. We also summarize the applications and profound reaction mechanism of ROS in air purification,organic wastewater treatment,bacterial inactivation and simultaneously prospected the development of the production technology,quantitative detection,and synergistic degradation effects of ROS in the degradation and transformation of environmental pollutants.

Abstract:Frequent events of winter haze in China have caused various health issues in large populations. It is believed that the sulfate aerosol produced by a series of physical and chemical reactions of SO2 is an important culprit of haze generation,and the heterogeneous reactions of SO2 on mineral particles is particularly important. Therefore,clarifying the formation mechanism of sulfate on mineral particles is a key scientific problem to analyze the formation of haze. In this paper,the research progresses about the typical heterogeneous reactions of SO2 on various mineral particles were reviewed,the effects of multi-pollutant coexistence system,humidity and light on heterogeneous reactions of SO2 were discussed,the future work related to heterogeneous reactions was also proposed. This paper aims to gain a deep understanding of the mechanism of mineral particles promoting the formation of sulfate and attempts to provide theoretical support for effective haze control.

Abstract:Bismuth based photocatalytic material,with the unique layered structure,suitable bandgap,and adjustable valence and conduction band position,is a new kind of unique photocatalysis material developed in recent years. Because of its high efficiency,innocuity,controllable morphology,it has a wide application prospect in the fields of solar energy conversion and environmental remediation. In this paper,the types of Bi based photocatalytic materials are introduced. The structural control methods such as morphology control and surface defect introduction,crystal face construction,surface plasma modification,element doping and heterojunction construction are systematically reviewed. The enhancing mechanism of photocatalytic performance is analyzed,and the application of Bi based photocatalytic materials in water treatment,air purification,nitrogen fixation and hydrogen production are summarized. Finally,the challenges in this field are discussed,and the future development of Bi based photocatalytic materials is prospected.

Abstract:Ammonia selective catalytic reduction of nitrogen oxides (NOx) technology with V2O5-WO3 (MoO3)/TiO2 as the core catalyst is currently widely used. But it has many problems such as narrow and high-temperature window,easy to poison by alkali inactivation,vanadium's biological toxicity and secondary pollution to the environment,which require researchers to develop new efficient and environmentally friendly catalyst systems. Due to their unique structure,good stability and environmentally friendly characteristics,perovskite materials have become a research hotspot in the field of selective catalytic reduction of NOx. We reviewd the research progress of perovskite NH3-SCR catalysts at home and abroad in recent years,and comprehensively discussed the main types,denitrification activity and structure-activity relationship of perovskite catalysts. At the same time,the research progress of perovskite in the new field of photo photo-assisted SCR technology was introduced. In addition,we summarized the research on the NH3-SCR reaction mechanism of perovskite catalysts,and prospectd the possible future development directions and research goals of this field.

Abstract:Tongcheng pig is an excellent representative of local pig breeds in China. It has the advantages of good motherhood,tolerance to roughage,and tender,juicy and delicious meat,but it also has the problems of slow growth,thick back fat and low lean meat rate. Therefore,in order to make use of the good meat quality of Tongcheng pig and improve its disadvantageous traits,the lean meat type large white pig was introduced to cultivate a new breed of Etong Two-End-Black. To evaluate the breeding effect of Etong Two-End-Black(Tongcheng pig female×lean-meat large white male),the growth traits,carcass traits(carcass length,backfat thickness,loin eye area,percentage of lean meat,etc.),meat quality traits(meat color,dripping loss,marbling and intramuscular fat content,etc.) and blood physiological and biochemical indexes were measured in Etong Two-End-Black and Tongcheng pigs. The results showed that the daily gain of the Etong Two-End-Black pig was (596.27±90.24) g/d,which was significantly higher than that of the Tongcheng pig ((513.28±90.31) g/d,P<0.01). The lean meat percentage of Etong Two-End-Black was 49.56%±2.21%,which was significantly higher than that of Tongcheng(43.47%±1.39%,P<0.01). The backfat thickness of Etong Two-End-Black was (34.73±0.94) mm,which was significantly lower than that of Tongcheng ((38.80±0.96) mm,P<0.01). The Marbling score and intramuscular fat content of Tongcheng were 3.47±1.16 and 3.45%±1.11%,respectively. There were no significant differences in other meat quality traits between the two breeds,except for intramuscular fat content (2.72%±0.87%),which was lower in Etong Two-End-Black. In addition,only part of the blood physiological and biochemical indexes between the two breeds were significant different. The results illustrated that Etong Two-End-Black has improved the growth and carcass traits while retaining the excellent meat quality traits of Tongcheng pigs. Therefore,the study can provide scientific basis for further popularization and utilization of Etong Two-End-Black.

Abstract:Tongcheng pig is the first batch of breeds to be listed on the national protection list of livestock and poultry breeds. It is a representative breed of “Huazhong Two-End-Black pig” and the meat of it tastes delicious,tender and succulent. At the same time,it is found that Tongcheng pig has special resistance to High pathogenic Porcine Reproductive and Respiratory Syndrome virus. In order to retain the advantages of disease resistance and meat quality,and improve the deficiency of slow growth and low lean ratio of Tongcheng pigs,Etong Two-End-Black was cross bred by introducing lean meat varieties. To compare the differences between Etong Two-End-Black and Tongcheng pig in nutrition and flavor compounds,amino acids,fatty acids,inosine acids and thiamine in the longissimus dorsi muscle of 30 Etong Two-End-Black and 29 Tongcheng pig were measured. The results showed that there were various kinds of amino acids in the Tongcheng pig muscle,the total content of 16 kinds of amino acids was (19.42±1.31) g/100 g,the content of essential amino acid (EAA) was (8.47±0.98) g/100 g,and the content of fresh amino acid (FAA) was (6.80±0.46) g/100 g. Tongcheng pig was rich in fatty acids and had high nutritional flavor value,the content of saturated fatty acid was 43.04%±1.84%,the content of unsaturated fatty acid was 56.96%±1.84%,in which the content of monounsaturated fatty acid (MUFA) was 47.47%±2.63% and the content of polyunsaturated fatty acid (PUFA) was 9.50%±2.50%,and the content of linoleic acid was 8.93%±2.36%. The content of flavor compounds,thiamine was 0.23±0.05 mg/100 g and inosinic acid was (3.23±0.67) mg/g,which were the material basis of Tongcheng meat quality and taste. The content of PUFA (12.08%±4.72%),linoleic acid (11.36%±4.44%) and thiamine ((0.23±0.05) mg/100 g) in Etong Two-End-Black were significantly or extremely significantly higher than those of Tongcheng,and the above other traits were not significantly different from Tongcheng pigs (P＞0.05). The above results showed that the pork of the two breeds had the characteristics of high nutritional value and unique flavor,Etong Two-End-Black pig not only retain the nutritional and flavor of Tongcheng pig,but had higher contents of PUFA and thiamine,which is worthy of further development and utilization.

Abstract:In order to evaluate the breeding effect of the hybrid combination of Barkshire and Etong Two-End-Black pig,the carcass and meat quality traits were measured in 70 Bae hybrid pigs (Barkshire× Etong Two-End-Black). The results showed that the body weight of Bae hybrid pigs was (109.10±11.01) kg,the slaughter percentage was 74.28%±1.99%,the loin eye area was (31.40±3.57) cm2,the backfat thickness was (31.65± 5.66) mm,the skin thickness was (3.32±0.74) mm,the flesh color score 1 was 3.80±0.77,and the drip loss at 48 h after slaughter was 2.07%±0.76%. Thirteen fatty acids were detected in the dorsal longest muscle,of which the saturated fatty acid content was 31.92%±7.68%,the unsaturated fatty acid content was 68.08%±6.18%,and the inosine monophosphate content detected in the longest muscle of the back was (3.71±0.42) mg/g. Correlation analysis showed that the fat percentage of the Bae hybrid pigs was significantly positively correlated with the backfat thickness (P＜0.01,r=0.69),and the inosine monophosphate content was significantly positively correlated with the carcass length (P＜0.01,r=0.4). To sum up,the results of this study showed that the slaughter performance of Bae hybrid pigs was great,the backfat thickness and skin thickness were moderate,the muscle color was bright,the line was good in hydraulic power,and the hybridization effect obtained was great.

Abstract:High pathogenic-porcine reproductive and respiratory syndrome (HP-PRRS) has caused great economic losses to pig industry in China. In order to study the changes of serum viremia and body weight gain in pigs after HP-PRRSV (HP-PRRS Virus) infection,72 healthy piglets from a large white pigs and Tongcheng pigs crossed population were selected and infected with HP-PRRSV. The clinical symptoms were observed,weight was measured,blood samples were collected,serum was separated and viremia was measured on 0,4,7,11,14,21,28,35 dpi (days post infection). The results showed that the growth rate of body weight was slow at 4 dpi,the body weight increased negatively from 4 to 21 dpi,the loss of weight reached the maximum from 7 to 11 dpi,the body weight increased positively and the growth increased gradually from 21 to 35 dpi. Viremia peaked on 4 dpi and lasted until 7 dpi,and decreased to 6.62 log10 copies/mL from 7 dpi to 35 dpi. Death occurred from 7 dpi,and the dead individuals were mainly concentrated from 7 to 14 dpi. The death peak appeared on 10 dpi,and the number of dead individuals was basically stable after 19 dpi. According to the survival on 14 dpi,the pigs were divided into two groups:disease-resistant and susceptible group. The viremia of the disease-resistant group was significantly lower than that in the susceptible group on 4,7,11 dpi (P<0.05),and the weight gain of the disease-resistant group was significantly higher than that of the susceptible group on 4-7 dpi,7-11 dpi,and 11-14 dpi (P<0.05). The above results suggested that body weight gain and viremia could be used as indicators to predict the resistance of PRRS.

Abstract:The highly pathogenic porcine reproductive and respiratory syndrome (PRRS) is the most important infectious disease of pigs. The host would respond to PRRSV by regulating different immune responses at different days post infection (DPI). The routine blood testing is the most intuitive way to detect changes of blood cell in the body. Therefore,it is necessary to detect and analyze hematological parameters for predicting the process of the disease. To investigate the changes of hematological parameters after infection with HR-PRRSV,72 Large White×Tongcheng advanced generation inter-cross piglets with an average age of 11 weeks,were used for the artificial HP-PRRSV infection experiment. The white blood cell (WBC) count,the lymphocyte percentage,the monocyte count and the granulocyte percentage were determined at 0,4,7,11,14,21,28,35 DPI,then association analysis of them with viremia were carried on. The results showed that when compared to 0 DPI,the WBC count,lymphocyte percentage and monocyte count were significantly reduced,and the granulocyte percentage was significantly increased at both 4 DPI and 7 DPI. The lymphocyte percentage was significantly reduced and the granulocyte percentage was significantly increased at both 11 DPI and 14 DPI,but there were no significant differences at the other DPI. Groups of piglets with PRRS-resistant and PRRS-susceptible were set on the basis of viremia and survive rate. It was showed that the lymphocyte and the granulocyte percentage were significantly different at 7 DPI between groups. The lymphocyte percentage of the PRRS-resistant group was significantly higher (P<0.05),and the granulocyte percentage was significantly lower (P<0.05) than the PRRS-susceptible group. For other DPI,as well as other hematological parameters,there were no significant differences. Furthermore,correlation analysis showed that the hematological parameters and viremia at all DPI in piglets were moderately correlated (P<0.01). The results demonstrated that the lymphocyte percentage and granulocyte percentage could be used as indicators of resistance to PRRS. Our current study provides basic data for further research on the changes of hematological parameters after PRRSV infection and relationship with viremia.

Abstract:Four sowing dates were set under machine transplantation and five japonica varieties were used to study the yield,growth period,quality,utilization of temperature and light resources of japonica rice varieties,clarify the ecological adaptability of japonica varieties in different japonica wheat production areas of Hubei Province and promote “transition from cultivating indica to cultivating japonica in Hubei Province” The results showed that the growth period of the varieties tested was shortened and the growth process was accelerated when the sowing date was postponed. The yield decreased to varying degrees. The utilization rate of accumulated temperature and the utilization rate of sunshine hours in the whole growing period showed a downward trend. The suitable types and sowing dates of three japonica areas in the three japonica wheat areas were preliminarily determined based on the conditions of temperature and light resource and the time of wheat stubble removal in the three japonica wheat production areas. The suitable japonica varieties in Xiangyang are early/intermediate maturing medium japonica with short growth period. The suitable varieties in Xiaochang are early/intermediate maturing medium japonica. The suitable varieties in Jiangling are early/intermediate maturing medium japonica and early maturing late japonica. They can exert the best yield potential.

Abstract:A randomized complete block (RCB) design field experiment of Ejing 403 with 2 transplanting densities (283 000 and 376 000 hills/hm2) and 5 fertilizer (N) levels (0,165,195,225 and 255 kg/hm2) was conducted to establish the high-yield cultivation techniques of two-season late japonica and promote “early indica-late japonica” plantation pattern in Hubei Province. Rice yield under different treatments was investigated and the dynamics and characteristics of leaf area index(LAI) growth and aboveground dry matter production in different populations were simulated with Gompertz equation. The results showed that the yield was significantly affected by fertilizer level but not by planting density,indicating that the populations of two-season late japonica has strong self-regulation ability. The appropriate nitrogen level for japonica tested was 225 kg/hm2. The effective panicle number and dry matter production per hectare were significantly increased at appropriate fertilizer level and thus promoted the economic yield. The high matter production depended on the higher accumulation speed and longer fast accumulation period,which were based on the rapid establishment of the appropriate LAI in the populations with high yield. The populations with higher yield had higher LAI growth speed but shorter fast growth period. The suitable population LAI and biomass production at different stages were proposed based on the modeling by quadratic equations. It will provide a guideline for establishing high-yield populations of two-season late Japonica.

Abstract:Under normal Pinellia sowing density,two intercropping methods including corn wide-narrow rows and equal rows and three corn planting distances including 35,50,and 65 cm were conducted to study the changes of Pinellia ternata growing environment,growth,yield and quality of P. ternate. The land equivalent ratio and interspecies competitiveness under the intercropping system were analyzed. The results showed that the leaf surface temperature,the soil temperature and the canopy light intensity of P. ternata were decreased with the increase of corn planting density in P. ternate/Corn intercropping system. Compared with the control,the leaf surface temperature of P. ternata decreased by 6.8 ℃,and the soil temperature decreased by 4.3℃. whereas the main leaf area,petiole length and SPAD value of P. ternata were significantly (P＜0.05) increased in the intercropping system. The growth index of corn with a 35 cm equal rows plant spacing is the best compared with the control. The main leaf area,petiole length and the SPAD value increased by 4.85 cm2,2.25 cm and 8.5,respectively. The land equivalent ratio in the intercropping system increased. Corn was more competitive than P. ternate. Intercropping corn significantly increased yield and single tuber weight of P. ternata. Under the condition of corn with a 35 cm equal rows plant spacing,the yield of P. ternata was the highest,with an increase of 44% compared with P. ternata monoculture. There is no significant difference in the medicinal quality of P. ternata under the intercropping corn,which meets the requirements of Chinese Pharmacopoeia.

Abstract:Lantibiotics attract extensive attention in the field of discovery and development of antibiotics due to its special action mode and barely observed drug-resistant mutation after being applied for decades. Lexapeptide is a type V lantibiotic recently uncovered via a functional genome mining approach (LEXAS) and has strong antibacterial activity against Gram positive bacteria including MRSA and MRSE. A gene cluster (lxm2) similar to the lexapeptide biosynthetic gene cluster was identified through screening the Streptomyces galtieri genomic DNA bacterial artificial chromosome (BAC) library via LEXAS. The BAC clone carrying lxm2 was introduced into Streptomyces lividians for heterologous expression,leading to the production of lexapeptide and a novel peak in HPLC. The production of lexapeptide and the new peak was disappeared when the lxm2 gene cluster was removed from the BAC clone. Based on NMR spectrometry and high resolution mass spectrometry,the structure of the new compound was identified to be a highly modified linear hexapeptide with sequence identical to the N-terminal six amino acids of lexapeptide,thus Lxm-N-hexapeptide was given as its name. The Lxm-N-hexapeptide did not exhibit antibacterial activity.

Abstract:The pot experiment with the soil containing pathogens of Fusarium oxysporum f. sp. was conducted to study the effects of Bacillus megaterium B213,Bacillus polymyxa B207,and Bacillus subtilis B204 alone or in combination on cucumber fusarium wilt and its mechanism. The results showed that the three microbial agents alone or in combination effectively inhibited the occurrence of cucumber fusarium wilt and significantly increased the biomass of cucumber. The effect of the two microbial agents in combination was better than that of single microbial agent. The effect of the three microbial agents in combination was better than that of the two microbial agents. Compared with the control group,the incidence of cucumber fusarium wilt in the three-agent combination group when cucumber seedlings were transplanted 35 days ago reduced by 79.99%; the dry weight of cucumber plants increased by 6.92 times; the activities of plant resistance enzymes including acid lyase,polyphenol oxidase,and peroxidase increased by 60.02%,28.90%,and 108.60% respectively; the number of rhizosphere soil Fusarium oxysporum decreased by 2 orders of magnitude. The effect of disease prevention and growth promoting may be related to the antagonism on the pathogenic bacteria,the ability to dissolve phosphorus,and the secretory ability of indoleacetic acid,protease,chitinase and ferrophilin of these three Bacillus species.

Abstract:The effects of poly-γ-glutamic acid (PGA) aqueous solution irrigation on seedlings trait and resistance-related enzymes in leaves of citrus were determined by measuring plant height,crown diameter and enzyme activity. HILIC LC-MS/MS was used to analyze the changes of 200 target metabolites in leaves after irrigation of PGA. The results showed that PGA treatment increased the height,crown diameter and branch number of seedlings. The activities of superoxide dismutase (SOD),peroxidase (POD) and polyphenol oxidase (PPO) in citrus leaves were increased after PGA treatment. The content of L-glutamate in citrus leaves decreased by 73.2%,while the content of γ-aminobutyric acid (GABA) increased by 1.6 times. The content of N6-methyl adenine increased by 2.3 times.The results of quantities of 109 metabolites analyzed by targeted metabolite showed that the difference of 13 metabolites between control and treatment was significant.

Abstract:In order to evaluate the feeding value of golden needle mushroom barn,the in vitro rumen fermentation was used to select the best feeding combination,which was further tested in the practice. Firstly,the nutrients components of golden needle mushroom barn and other roughages was measured. Next,six groups of combinations based on previous study were designed and in vitro rumen fermentation was applied to measure pH,NH3 and dry matter degradation to select the best group of combinations. Then,the beef cattle feeding trial was conducted to test the best combination. Sixteen healthy Simonthal hybrid cattle with similar bodyweight and age were selected and randomly assigned to two groups,control group and experimental group,with 8 cows in each group. The control group was fed with the basal TMR and the experimental group was fed with the optimal TMR diet. The pre-trial period was 10 days for adaption,and the experimental period was 80 days. Blood collection and body-weighting were performed at the beginning and end of the trial to evaluate the feeding effects on bodyweight gain,blood physiological parameters and serum biochemical index. The results showed that the nutrient components of golden needle mushroom barn was similar to straw and maize yellow storage; The best feeding combination was maize green storage (50%)+golden needle mushroom barn (30%)+beef grain (10%)+bean curd residue (10%); The best combination significantly increased bodyweight gain (P<0.01),reduced the feed cost and had no detrimental effects on blood physiological parameters and serum biochemical index. To sum up,golden needle mushroom barn could be used as roughage for beef cattle.

Abstract:Buffalo has outstanding characteristics of stress resistance and adoptable to poor quality roughages and is mainly used for farming service in the world.Many of the economic traits of buffaloes have not been fully utilized and are therefore considered to be the most potential livestock for development.However,buffalo breeding methods of the world is still relatively traditional,and there are few modern scale farms,which greatly limits the development of buffalo industry and utilization of economic traits of buffalo.Compared with cattle,buffalo reproductive problems are mainly manifested in the low number of follicular reserves,insignificant estrous symptoms,low breeding efficiency,and easy loss of early embryos,which also directly limits the feeding scale of buffaloes.Therefore,with the help of modern reproductive technology (such as artificial insemination,superovulation-embryo transfer,in vitro embryo production,etc.),it is an important scientific and technological guarantee for the development of buffalo breeding industry to solve the prominent problems of buffalo reproduction in a short period of time.In vitro embryo production is an important reproductive technology,which can greatly expand the source of livestock embryos,and can improve the reproductive efficiency of livestock in a short period of time in combination with embryo transfers technology.The technical efficiency of in vitro embryo production mainly depends on in vitro oocyte maturation efficiency and early embryo development efficiency.How to optimize the methods of in vitro culture is the main focus of buffalo reproduction research.Reproductive hormones play a significant role in promoting oocyte maturation,sperm-egg interaction and embryo development and widely use in oocytes maturation and embryo culture systems,such as LH,FSH,E2 and P4.In addition,like an appropriate concentration of melatonin,vitamin C,resveratrol,sodium selenite can significantly improve the maturation quality of oocytes and promote development of embryos in vitro.Though a lot of work has been done to improve the in vitro culturing system of oocytes and embryos,yet the efficiency of both in vitro maturation of oocytes and embryonic development are significantly lower than in vivo.PGF2α signaling has a pivotal role in regulating animal reproduction and PGF2α receptor (PTGFR) is highly expressed in liver,ovary,uterus,adrenal glands,fat cells,thymocytes,pancreatic islets,platelets and red blood cells.Previously research has been reported that PGF2α plays an important role to inhibit the development of rabbit and mouse embryos in vitro.In dairy cows,the PGF2α receptor PTGFR is widely distributed in the reproductive organs,and the embryo quality and pregnancy rate are negatively correlated with the increase of the concentration of PGF2α in the uterine cavity.High level of PGF2α in the peripheral circulation of dairy cows has an inhibitory effect on embryonic development,resulting in a significant decrease of pregnancy rate of dairy cows.It’s speculated that inhibiting PGF2α signaling in vitro can improve oocyte maturation efficiency and early embryo development efficiency.Therefore,this study was aimed to investigate the effects of inhibiting PGF2α signaling on the maturation oocytes and development of early embryos in vitro.The expression patterns of PGF2α receptor (PTGFR) in buffalo oocytes and early embryo development were determined by immunofluorescence staining and real-time fluorescent quantitative PCR.Subsequently,the effects of PGF2α signaling on the maturation efficiency of oocytes and the efficiency of embryonic development in buffalo was studied by different concentrations of PTGFR inhibitor AL-8810 administration in the oocyte maturation medium and embryonic development medium.The results showed that PTGFR protein was widely distributed in buffalo oocytes and embryos,and the expression level of PTGFR gene was significantly higher in 4-16 cell stage than in unfertilized oocytes and morulae (P＜0.05).Inhibiting PGF2α signaling by AL-8810 administration had no significant differences effect on the nuclear maturation efficiency of buffalo oocytes in different treatments(P＞0.05),respectively.However,the early apoptosis rate of buffalo oocytes reduced significantly in high concentration treatment (1 600 nmol/L) (P＜0.05).Embryonic development efficiency in 16 cell stage improved significantly in the treatments of concentration of 100 and 800 nmol/L,and the morula formation rate was the highest in the 800 nmol/L treatment.The above results indicated that inhibiting PGF2α signaling effectively improves in vitro maturation quality of oocytes and early embryo development potency in buffalo.The findings of this study about the above regulatory role of PGF2α signaling could provide new ideas for improving in vitro embryo production efficiency of buffalo.

Abstract:In order to study the effect of chemical inducers on the curing development and disease resistance of mechanical damaged yam,the mixture of 1 mmol/L BABA and NaHCO3 was used to treat artificially damaged yam. The callus was cultured at 35℃ for 7 days (RH 85%). The weight loss rate,decay degree,lignin,phenols and superoxide during the callus period were measured to evaluate the effect of curing treatment. The results showed that the combined treatment of BABA and NaHCO3 significantly reduced the decay degree of damaged yam,promoted the accumulation of lignin and phenolic substances in the wounded site,and significantly increased the content of superoxide. The results showed that the combination of BABA and NaHCO3 could effectively inhibit the infection of pathogens and promote the rapid formation of wound periderm of yam.

Abstract:A seed metering device with spiral tube scooping for rice and wheat was designed to improve the utilization rate of planting equipment in the middle and lower reaches of the Yangtze River and realize the dual-purpose sowing of rice and wheat. The seed metering device uses a spiral seed-scoop tube assembly to take a certain amount of seeds. The structural parameters of the key components of the seed metering device are determined. The Design-Expert software was used to analyze data and obtain the optimal parameter combination. The response surface test plan was adopted to carry out the bench verification test. The theoretical results showed that the qualified rate,the reseeding rate,the no seeding rate,the qualified rate of hole distance and the variation coefficient of hole distance was 81.3%,2.8%,2.5%,94.8% and 17.4% when the rice was sown on the 45 r/min rotational speed,3° inclination angle and 9 mm the length of seeding out hole. The qualified rate,the reseeding rate,the no seeding rate,the qualified rate of hole distance,and the variation coefficient of hole distance was 98.2%,0.2%,1.6%,93.3% and 18.3% when sowing wheat on the 60 r/min rotational speed,1° inclination angle and 9 mm length of seeding out hole. The results of bench test showed that the seeding device can meet the agronomic requirements of rice and wheat sowing under certain conditions.,The qualified rate,the reseeding rate,the no seeding rate,the qualified rate of hole distance,and the variation coefficient of hole distance was 78.2%,3.7%,1.0%,97.9%,and 16.2% when sowing rice on 45 r/min rotational speed,3° inclination angle and 9 mm length of seeding out hole. The qualified rate,the reseeding rate,the no seeding rate,the qualified rate of hole distance and the variation coefficient of hole distance was 93.4%,3.4%,3.2%,93.6%,and 25.5% when sowing wheat on 60 r/min rotational speed,1° inclination angle and 9 mm length of seeding out hole. The test results are basically consistent with the theoretical results obtained from software analyses. It will provide a reference for the designing rice and wheat dual-use planters.

Abstract:The quantities prediction is an important part of fishery resource assessment and aquaculture.Traditional active sonar and large-scale fishing gear trials and other methods have certain defects.For the quantitative assessment of freshwater fish,the hydroacoustic signals of bream and crucian carp in the same proportion and different mixed quantities were collected by hydrophone and acoustic recorder.54 characteristic parameters were extracted and used for correlation analysis.The characteristic parameters significantly correlated with the mixed quantities of freshwater fish were selected.The Rank-RS method was used to divide the samples.The multiple linear regression model was established and compared with the prediction effect of the partial least squares regression model.The results showed that the correlation between the average Mel frequency cepstrum coefficient and mixed quantity of freshwater fish was the most significant on the whole.The fitting effect of the multiple linear regression model was better.The prediction model R〖DD(-*2〗—〖DD)〗2 and the RPD was 0.950 and 4.492,indicating that the established model was suitable for predicting the mixed numbers of freshwater fish.It is feasible to apply passive underwater acoustic technology in studying quantities of freshwater fish.

Abstract:The advantages of fractional order PID algorithm compared with traditional integer order PID control algorithm were analyzed to improve the dynamic performance of farm unmanned aerial vehicle (UAV). The fractional order PID algorithm has higher control accuracy. A cascade fractional order PID control algorithm with higher update frequency is proposed based on traditional cascade integer order PID control algorithm and comprehensive implementation difficulty. It uses fractional order PID control algorithm in inner loop and integer order PID control algorithm in outer loop. The four-rotor UAV was modeled,and the parameters of the two algorithms were tuned by genetic algorithm. After obtaining the optimal control,MATLAB/SimuLink was used to simulate and analyze. The results of simulation showed that the overshoot of the two algorithms was close to zero. The regulation time of cascade fractional order PID control algorithm and cascade integer order PID control algorithm was 0.263 s and 0.386 s,respectively.The former is 31.9% less than the latter.It is indicated that effect of the cascade fractional order PID control algorithm is better than that of the cascade integer order PID control algorithm.In order to further compare the two control algorithms,a four rotor UAV is built and tested on a multi degree of freedom test bench which can test the attitude changes of multi axis aircraft.The results showed that the settling time of the cascade fractional-order PID controller was 0.24 s shorter than that of traditional algorithm.The results of simulation and experimental showed that quality of the cascade fractional order PID control algorithm was better than that of the cascade integer order PID control algorithm.The regulation time is short and the regulation process is more stable.The results of comprehensive analyses showed that the cascade fractional order PID control algorithm can further improve the operational sensitivity,optimize the flight control performance,and improve the operation efficiency of multi rotor UAV in agricultural production when applied to agriculture.It can help reduce flight accidents as well.

Abstract:Lotus seeds with different maturity have different mechanical properties. At present,shelling machinery is only suitable for lotus seeds after ripening stage. However,the crushing rate increases greatly when milk and wax ripening stages of lotus seeds are shelled. In order to improve the applicability of shelling machinery and reduce the crushing rate of fresh lotus seeds in the process of shelling and peeling,the compression,crushing and shearing characteristics of lotus seeds with different maturity were studied. In this study,the lotus seeds of space lotus No. 36 from Honghu Lake,Hubei Province were used to measure the shape dimensions and water content. The long-axis and short-axis compression and the crush test for whole lotus seed were conducted. The shear test under different speeds and depths,and the compression test in three-axis direction were carried out. The elastic modulus of lotus shell was tested. The long axis and short axis elastic modulus were analyzed and calculated based on experiments above. The ultimate failure load,the relationship between shear stress and depth,speed and maturity were obtained. The results showed that the average longitudinal and transverse ratio of the lotus seeds with milk maturity,wax maturity and maturity was 1.35,1.28,1.19,respectively. The water content was 79.84%,70.28%,57.72%,respectively. The long axis elastic moduli of lotus seeds were 1.09 MPa,1.22 MPa,and 1.85 MPa,respectively. The short axis elastic moduli were 1.33 MPa,1.42 MPa,and 2.16 MPa,respectively. The limit damage load of three maturity lotus seeds was 81.995 N,117.107 N,and 167.640 N,respectively. Under the same maturity and shear depth,the shear force did not change with shear speed and was linearly correlated with shear depth. The compression shelling force of lotus seed in the X,Y and Z directions increases with maturity. The compressive force in the three-axis direction of the lotus seed is numerically X axis

Abstract:Eggs provide various of nutrients for human beings,such as proteins,lipids,and vitamins. Besides of the processing properties from egg white,bioactive peptides obtained by the enzymatic hydrolysis method have diversiform biological functions. In this paper,biological functions such as antihypertension,anti-oxidation,prevention of cardiovascular diseases,promoting mineral absorption,anti-diabetes,and regulating intestinal health were summarized,and the structure-activity relationships of egg white peptides from duck egg and chicken egg were also reviewed. It was found that egg white-derived angiotensin-converting enzyme (ACE) inhibitory peptides could affect their ACE inhibitory activity when the C-terminal was proline,leucine,and the N-terminal was aromatic or alkaline amino acid. Hydrophobic amino acids in N-terminal,and aromatic amino acids in the primary structure of antioxidant peptides from egg white can greatly improve the antioxidant capacity of the peptides. Glutamic acid in the first C-terminal,and phosphorylation of serine in the sequence of egg white-derived calcium absorption peptides play an important in the calcium absorption. However,bioactive peptides obtained by hydrolysis were confirmed to have different bioactivities,low yield and significantly different structures,making it difficult to obtain universal structure-activity relationship conclusions. Thus,the purpose of this paper is to provide a basis for the high-valued utilization of egg white,and a certain application for the production of egg white bioactive peptides as nutritional supplements,functional nutritional health products and therapeutic drugs,as well as to put forward a new prospect for the research of bioactive peptides.

Abstract:Biomass alcoholysis is a way of high-value utilization of biomass,which can be directly converted into 5-ethoxymethylfurfural (EMF) known as a liquid fuel and fuel additives with similar combustion characteristics and energy density to gasoline and diesel.The high octane number,high boiling point and stable flash point of EMF make it a suitable transportation fuel.In this paper,the feedstock,catalytic system and solvent system for the preparation of liquid fuel by biomass alcoholysis was reviewed.The current situation and developing trend of the preparation of liquid fuels from different materials including lignocellulosic materials,fructose and glucose were summarized.The homogeneous,heterogeneous and ionic liquid catalytic systems in the process of EMF preparation from biomass were reviewed and analyzed.The advantages and disadvantages of different catalytic systems were compared.Traditional homogeneous catalysts have the advantages of easy availability and low cost with a moderate yields of EMF in general,but the recycle of the homogeneous catalysts and the corrosion of equipment are still far from satisfactory.Among them,ionic liquids have attracted wide attention due to their low toxicity,high polarity,adjustable acidity,easy separation and recovery,and high catalytic efficiency,but the cost is too high for large-scale industrial production,which is the main drawback to be solved.Heterogeneous catalysts can reduce equipment corrosion and make it much easier for the separation and recovery after the reaction.Most of the heterogeneous catalysts have the advantage of adjustable acidity,high mechanical strength,high thermal stability and high chemical stability.Heterogeneous catalysts are therefore considered to be promising.The function and effect of solvent system in the process of biomass alcoholysis were discussed.Ethanol is the most widely used solvent system in the EMF production,for it is also the necessary reactant in the alcoholysis reaction.Organic solvents including DMSO(dimethyl sulfoxide),THF(tetrahydrofuran),GVL(γ-valerolactone) and n-hexane are used together with ethanol as a solvent system to form a co-solvent system.The co-solvent can increase the yield of EMF and reduce the formation of by-products,but there are still some problems to be solved,such as difficult separation of products from solvents,high cost,low recovery rate,environmental pollution and so on.The studying trend of biomass alcoholysis to prepare EMF is prospected.