An in-depth research and practice has been conducted on vegetable diseases and pests in Shandong Province,and the principles of comprehensive and ecological control of diseases and pests are put forward,including agri...An in-depth research and practice has been conducted on vegetable diseases and pests in Shandong Province,and the principles of comprehensive and ecological control of diseases and pests are put forward,including agricultural control measures such as crop rotation,field cleaning,fertilizer and water management,physical control measures such as catching and killing,trapping,blocking,photoelectric energy treatment,biological control measures such as the use of natural enemies,pathogenic microorganisms,other beneficial organisms and metabolites,and scientific and rational chemical control measures.Comprehensive prevention and control not only controls vegetable diseases and pests effectively,but also protects the ecological environment.展开更多
Aiming at the basic and key technical problems in prevention and control of sugarcane white leaf disease(SCWL),this study systematically overcame key technical bottleneck of prevention and control of new SCWL after 10...Aiming at the basic and key technical problems in prevention and control of sugarcane white leaf disease(SCWL),this study systematically overcame key technical bottleneck of prevention and control of new SCWL after 10 years of collaborative research,and achieved several innovative achievements.SCWL phytoplasmas newly recorded in China and the new subgroup of SCWL phytoplasmas(16SrXI-D)were discovered for the first time in Yunnan,and the whole genome analysis of the epidemic subgroup was completed.The main transmission source of SCWL pathogens has been identified as infected seed canes,and Tettigoniella viridis and Clovia conifer were newly discovered as vectors for virus transmission.The disease resistance of 25 main varieties was identified,and 10 control varieties were selected.The prevention and control strategy of"emphasizing early warning,strictly carrying out quarantine,blocking the vectors and controlling residual plants"was put forward,and a comprehensive prevention technique was established through integration of various techniques,and standardized technical regulations were formulated for demonstration application.The promotion and application of these achievements have realized scientific prevention and control of SCWL,effectively curbed the spread of SCWL,and ensured the safety of sugarcane producing areas in China,achieving great economic,social and ecological benefits and providing technical support for high-quality development,loss reduction and efficiency improvement of China's sugar industry.展开更多
To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were anal...To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were analyzed on the basis of analyzing the development and protection process of foreign water sources.The results show that for the comprehensive control of water sources,it is needed to pay attention to the accurate grasp of the current environmental quality of water sources and carefully analyze the problems in the ecological environment of water sources.Besides,it is necessary to ensure the water quality and quantity of sources,focus on the implementation of environmental remediation and ecological restoration,implement regional protection of water sources,and combine engineering and non-engineering measures to take comprehensive control of environmental problems.展开更多
The paper summarizes the research progress of occurrence and comprehensive control of oriental fruit fly in the following aspects : biological and ecological characteristics, assessment of the risk and suitability, d...The paper summarizes the research progress of occurrence and comprehensive control of oriental fruit fly in the following aspects : biological and ecological characteristics, assessment of the risk and suitability, dynamic monitoring and control index, and comprehensive control methods.展开更多
The study was conducted to reduce blast damage, the use of pesticides residue, environment pollution and control costs, and to make a significant contribution to the improvement of grain production, quality and agricu...The study was conducted to reduce blast damage, the use of pesticides residue, environment pollution and control costs, and to make a significant contribution to the improvement of grain production, quality and agriculture ecological environment. Over these years, by the methods of systematical monitoring, regular surveys, field investigation, rice blast resistance identification, experiments and meteorological data analysis, the study on comprehensive prevention and control of rice blast in Nanchong City was conducted. The results showed that the rice varieties more sensitive to blast had a higher incidence of severe blast disease. Replacing,varieties with different source of resistance every three to five years and reasonable variety distribution can effectively reduce the prevalence of rice blast. Appropriate treatment of infected rice straw and pathogen, seed disinfection, seedling disinfection, and pesticide application at transplanting and etc. can delay blast occurrence and reduce the damage caused by blast. By analyzing the blast control efficiency of pesticides applied at different growth stages, we found that best control efficiency against blast was achieved by spraying pesticide twice during the whole growth stage, once 3 d before transplanting or 10 d after transplanting; and once at initial heading stage. Spraying 525 g/hm^2 75% tricyclazole was proven to be the best dosage for blast control. However, 375-450 g/hm^2 75% tricyclazole is enough if the blast incidence is not severe, or the rice varieties are slightly susceptible to blast.The control efficiency against leaf blast between 4% kasugamycin and 20% tricyclazole had no significant difference, but was significantly higher than that of 100 billion spores/g of Bacillus subtilis. The control efficiency against neck blast had no significant difference among 4% kasugamycin, 20% tricyclazole and 100 billion spores/g of B. subtilis. 450 g/hm^2 75% tricyclazole had better control efficiency against neck blast than 2 250 g/hm^2 2% 800 million spores/g Jinggangmycin-wax bud bacteria SC, 1 050 g/hm^2 41% kasugamycin-isoprothiolane WP and 900 g/hm^2 41%kasugamycin-isoprothiolane WP. The frequency of severe blast incidence in Nanchong City has reached 50% since 1997. The rice blast disease has been effectively controlled by comprehensive prevention and control technology, reducing the production loss to less than 2%, and pesticides by 4 523 t in total. In 2014, 327000 t rice grains were approved as pollution-free, green and organic agricultural products, indicating that the blast control measures produced great economic, social and ecological values.展开更多
Reproductive organ disease of geese is an endemic and multiple infectious disease in large-scale breeding of breeding geese, especially in anti-season production, which brings a great economic loss to goose production...Reproductive organ disease of geese is an endemic and multiple infectious disease in large-scale breeding of breeding geese, especially in anti-season production, which brings a great economic loss to goose production. To make effective prevention and control of reproductive organ disease of breeding geese under the anti-season breeding mode, the characteristics of control principles of infectious diseases of the poultry and the occurrence and prevalence of reproductive organ disease must be combined, so as to carry out scientific prevention and control.At the same time, according to the climate characteristics of summer, the feeding and management of breeding geese and water quality control should also be done well, and many corresponding measures should also be taken, thus obtaining better effect.展开更多
According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural c...According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural control, physical control, and chemical control and proposed specific methods and technological indices in order to provide technological references for comprehensive control on weeds of millet fields.展开更多
The paper summarizes the research progress of occurrence and comprehensive control of fall webworm on the aspeets of biological and ecological characteristics, assessment of risk and suitability, artificial survey Of ...The paper summarizes the research progress of occurrence and comprehensive control of fall webworm on the aspeets of biological and ecological characteristics, assessment of risk and suitability, artificial survey Of occurrence, dynamic monitoring and quarantine, comprehensive control methods and strategy.展开更多
A novel coaxial ducted fan structure aircraft is proposed to enable the aircraft near vertical walls at high altitudes.The state space equation of the system can be obtained by correlation deduction and identification...A novel coaxial ducted fan structure aircraft is proposed to enable the aircraft near vertical walls at high altitudes.The state space equation of the system can be obtained by correlation deduction and identification of the whole prototype model.Based on the duct test bench experiment and computational fluid dynamics(CFD)simulation analysis,the expressions between the different distances dWE from the rotor center of the prototype to the wall and the thrust,reaction torque,and tilting moment of the system under hovering conditions are obtained.The influence of the wall effect of the prototype is incorporated into the system model to analyze the relationship between distance dWE and the comprehensive controllability of the system.The results show that the system comprehensive controllability vector of other channels changes little with the decrease of the distance dWE,and only the controllability vector of the rolling channel increases significantly.At the same time,the tilting moment also increases significantly,which strengthens the tendency of the prototype to tilt towards the wall.展开更多
The tea green leafhopper Empoasca vitis Gothe, one of major tea insect pests in China's Mainland, grows concealed with small size, rapid reproduction and overlapped generations, which has become the most serious i...The tea green leafhopper Empoasca vitis Gothe, one of major tea insect pests in China's Mainland, grows concealed with small size, rapid reproduction and overlapped generations, which has become the most serious insect pest in tea garden. This paper described the morphological features, damage modes and occur- rence characteristics of E. vitis, and preliminarily summarized the main control methods in recent years. Therefore, from pollution-free and green control perspec- tive, controlling population quantity of E. vitis safely and effectively and reducing the yield loss of tea has become a hot issue in prevention and control of insect pests in tea garden. The paper provided a reference in green comprehensive prevention of insect pests in tea garden.展开更多
[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantiti...[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantities, distribution and seasonal variations of insects and wild animals in related zones were investigated from 2008 to 2010, and the collected samples of the insects and wild animals were tested in laboratory for related equine diseases. [Results] The investigations indicated that there were some mosquitoes, flies, horseflies, punkies, ticks, bats, wild birds and wild bears in equastrianism venue and peripheral regions of disease-free zone of the Guangzhou Asian Games, the laboratory results of Japa- nese encephalitis, vesicular stomatitis, Nipah virus disease, West Nile fever, and Trypanosomiasis evansi, were all negative. According to the in- vestigations and test results, the risk assessments of insect and wild animal vectors in the prevalence of related equine diseases were made to con- firm that the risk was relatively low or very low, and comprehensive prevention and control measures with prevention as major measures and insecti- cides application and environment managements as supplementary means were made on the basis of the risk assessment conclusions. [ Conclu- sions] This research has laid a solid foundation for the successful building of the first specific equine disease-free zone in our country, ensured the smooth holding of the 16th equastdan competition in Guangzhou Asian Games.展开更多
In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is close...In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is closely related to plant residues,rainfall,cultivation conditions and varieties.On the basis of understanding the symptoms and occurrence regularity of Chinese rose black spot,combination measures of agricultural and chemical prevention and control should be taken.展开更多
In recent years, pear rust sometimes occurs in eastern Hebei area, resulting in early defoliation, fruit abscission and loss of fruit commodity value. In this paper, the incidence symptoms, regularity and causes of pe...In recent years, pear rust sometimes occurs in eastern Hebei area, resulting in early defoliation, fruit abscission and loss of fruit commodity value. In this paper, the incidence symptoms, regularity and causes of pear rust are summarized, and the comprehensive prevention and control measures of pear rust in eastern Hebei are put forward.展开更多
The occurrence and comprehensive prevention and control progresses of Chilades pandava in Cycas spp. are summarized from the aspects of classification and geographic distribution, ecological characteristics, damage a...The occurrence and comprehensive prevention and control progresses of Chilades pandava in Cycas spp. are summarized from the aspects of classification and geographic distribution, ecological characteristics, damage and development rules, and comprehensive prevention and control technology, in order to provide a reference for further prevention and control against C. pandava in Cycas spp.展开更多
A comprehensive predictive strategy was proposed for the neutral-point balancing control of back-to-back three-level converters. The phase currents at both sides and the DC-link capacitor voltages were measured for th...A comprehensive predictive strategy was proposed for the neutral-point balancing control of back-to-back three-level converters. The phase currents at both sides and the DC-link capacitor voltages were measured for the prediction of the neutral-point current. A quality function was found to balance the neutral-point, and a metabolic on-times distribution factor was used as a predicator to minimize the quality function at each switching state. Simulation results show that the proposed method produces smaller ripples in tested signals compared with the established one, namely, 9.15% less in a total harmonic distortion(THD) of line-to-line voltage, 1.08% less in the THD of phase current, and 0.9 V less in the ripple of the neutral-point voltage. The obtained experimental results show that the main harmonics of the line-to-line voltage and the phase current in the proposed method are improved by 10 d B and 6 d B, respectively, and the ripple of neutral-point voltage is halved compared to the established one.展开更多
In order to effectively deal with the problems of diseases and insect pests in the growth process of strawberry and to improve the quality and yield of strawberry,the main diseases and insect pests in strawberry culti...In order to effectively deal with the problems of diseases and insect pests in the growth process of strawberry and to improve the quality and yield of strawberry,the main diseases and insect pests in strawberry cultivation such as powdery mildew,gray mold,anthracnose,red stele root rot,calcium deficiency,salt or fertilizer damage,aphids,red spiders,thrips,grubs,etc.and their identification methods were analyzed.The comprehensive pollution-free prevention and control techniques of these pests and diseases were explored,in order to provide technical guidance for high quality,efficient and harmless production of strawberry.展开更多
Through summarizing the prevalence characteristics of rice black-streaked dwarf virus disease(RBSDVD)in Linyi City of Shandong Province,this paper analyzed its prevalence is related to changes in farming and cultivati...Through summarizing the prevalence characteristics of rice black-streaked dwarf virus disease(RBSDVD)in Linyi City of Shandong Province,this paper analyzed its prevalence is related to changes in farming and cultivation systems,the increase in the population of venomous Laodelphax striatellus Fallén and its own migration and spread,the poor disease resistance of cultivated varieties,and inadequate time of prevention and control.Besides,based on the practice of local control,it came up with some comprehensive control measures including strengthening monitoring,early warning and forecasting,planting resistant(tolerant)rice varieties according to local conditions,appropriately delaying the sowing(planting)period,supplemented by insect nets to cover seedlings,and making scientific use of chemical control.It is expected to provide a reference for the prevention and control of RBSDVD.展开更多
The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic pe...The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic perspective,the seriousness of rural water quality,soil and atmospheric pollution in Xiangxiang,Xiangtan and the surrounding areas in Shaoshan irrigated area was revealed.The control measure which was 'four-dimensional pollution in the city and countryside'—— low-carbon-high-value agriculture and the technology innovation was proposed.The low-carbon-high-value technology innovation industrialization demonstration in three parts which included the pre-production,mid-production and post-production deep-processing of cultivation and breeding industry in the ecological cyclic agricultural garden in Shaoshan irrigated area was the driving force.We tried to propel the low-carbon ecological cultivation and breeding industry which included the paddy rice,grass,tree,medicinal herbs and pig,cow,chick,duck,fish.We wanted to relieve the structural unbalance of previous cultivation and breeding industry,'cheap grain hurting the farmers' and the short-leg problem of social-economic-ecological benefit.The results showed that the low-carbon-high-value agricultural system was a poly-generation technology system which promoted the multi-level and grading utilization,saved the energy,reduced the consumption and cleaned the production based on the ecology.展开更多
As a crucial economic crop in Guangxi region,chili pepper is facing increasingly severe challenges of continuous cropping obstacles.In this paper,the causes of continuous cropping obstacles in chili pepper soil are de...As a crucial economic crop in Guangxi region,chili pepper is facing increasingly severe challenges of continuous cropping obstacles.In this paper,the causes of continuous cropping obstacles in chili pepper soil are deeply analyzed,covering multiple dimensions such as the dynamic changes in soil physicochemical properties,the imbalance of soil microbial community structure,and the gradual accumulation of soil borne diseases and pests.Subsequently,a set of comprehensive prevention and control strategy is proposed:soil improvement through the application of organic fertilizers,biological fertilizers,and soil conditioners;implementing agricultural strategies of crop rotation and intercropping,flexibly adjusting planting density and methods,to optimize crop layout and improve planting management measures;actively introducing natural enemies for biological control,while promoting the use of biopesticides and microbial preparations for biological control.In response to the actual situation of continuous cropping obstacles in chili pepper soil of Guangxi,it is suggested that innovative soil improvement technologies,improved planting management measures,and promotion of biological control methods should also be considered.展开更多
[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of ...[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of M. micranthain under different habitats in Huiyang District were surveyed. [ Result] M. micrantha grew violently in the habitats of irrigation ditches, orchard, field edge and wasteland with the coverage ranging from 10% to 90%. It grew more seriously around water sources and was very likely to recur after control. The wild growth of M. micranthaln was harmful to local agriculture, forestry and fishery. The com- prehensive control measures combing artificial control, chemical control, biological control and ecological control should be adopted in different habitats. [ Conclusion] The study orovided basis for comorehensive control and invasion risk assessment of M. micranthain.展开更多
基金Supported by Major Agricultural Technologies in Shandong Province in 2023 Collaborative Promotion Plan Task Book"Demonstration and Promotion of Key Technologies for the Application of Agricultural and Animal Husbandry Organic Waste Fertilizer Fruits and Vegetables"(SDNYXTTG-2023-29).
文摘An in-depth research and practice has been conducted on vegetable diseases and pests in Shandong Province,and the principles of comprehensive and ecological control of diseases and pests are put forward,including agricultural control measures such as crop rotation,field cleaning,fertilizer and water management,physical control measures such as catching and killing,trapping,blocking,photoelectric energy treatment,biological control measures such as the use of natural enemies,pathogenic microorganisms,other beneficial organisms and metabolites,and scientific and rational chemical control measures.Comprehensive prevention and control not only controls vegetable diseases and pests effectively,but also protects the ecological environment.
基金Supported by National Natural Science Foundation of China(31760504)China Agriculture Research System of MOF and MARA(CARS-17)Special Fund for the Construction of Modern Agricultural Industrial Technology System in Yunnan Province.
文摘Aiming at the basic and key technical problems in prevention and control of sugarcane white leaf disease(SCWL),this study systematically overcame key technical bottleneck of prevention and control of new SCWL after 10 years of collaborative research,and achieved several innovative achievements.SCWL phytoplasmas newly recorded in China and the new subgroup of SCWL phytoplasmas(16SrXI-D)were discovered for the first time in Yunnan,and the whole genome analysis of the epidemic subgroup was completed.The main transmission source of SCWL pathogens has been identified as infected seed canes,and Tettigoniella viridis and Clovia conifer were newly discovered as vectors for virus transmission.The disease resistance of 25 main varieties was identified,and 10 control varieties were selected.The prevention and control strategy of"emphasizing early warning,strictly carrying out quarantine,blocking the vectors and controlling residual plants"was put forward,and a comprehensive prevention technique was established through integration of various techniques,and standardized technical regulations were formulated for demonstration application.The promotion and application of these achievements have realized scientific prevention and control of SCWL,effectively curbed the spread of SCWL,and ensured the safety of sugarcane producing areas in China,achieving great economic,social and ecological benefits and providing technical support for high-quality development,loss reduction and efficiency improvement of China's sugar industry.
基金Supported by the Innovation and Entrepreneurship Training Program for College Students of Shaanxi Province in 2022(S202211396028)Innovation and Entrepreneurship Training Program for College Students of Shaanxi Province in 2021(S202111396068).
文摘To scientifically and effectively conduct comprehensive control of water sources to achieve water safety,the importance,main steps and plan of comprehensive control of ecological environment in water sources were analyzed on the basis of analyzing the development and protection process of foreign water sources.The results show that for the comprehensive control of water sources,it is needed to pay attention to the accurate grasp of the current environmental quality of water sources and carefully analyze the problems in the ecological environment of water sources.Besides,it is necessary to ensure the water quality and quantity of sources,focus on the implementation of environmental remediation and ecological restoration,implement regional protection of water sources,and combine engineering and non-engineering measures to take comprehensive control of environmental problems.
文摘The paper summarizes the research progress of occurrence and comprehensive control of oriental fruit fly in the following aspects : biological and ecological characteristics, assessment of the risk and suitability, dynamic monitoring and control index, and comprehensive control methods.
基金Supported by Notice on the First Batch of National Modern Agricultural Demonstration Zone by the Ministry of Agriculture(Agricultural Project No.[2010]22)One of the Major Pest and Disease Early Warning and Prevention Research Programs for Main Grain and Oil Crops(N1997-ZC002)~~
文摘The study was conducted to reduce blast damage, the use of pesticides residue, environment pollution and control costs, and to make a significant contribution to the improvement of grain production, quality and agriculture ecological environment. Over these years, by the methods of systematical monitoring, regular surveys, field investigation, rice blast resistance identification, experiments and meteorological data analysis, the study on comprehensive prevention and control of rice blast in Nanchong City was conducted. The results showed that the rice varieties more sensitive to blast had a higher incidence of severe blast disease. Replacing,varieties with different source of resistance every three to five years and reasonable variety distribution can effectively reduce the prevalence of rice blast. Appropriate treatment of infected rice straw and pathogen, seed disinfection, seedling disinfection, and pesticide application at transplanting and etc. can delay blast occurrence and reduce the damage caused by blast. By analyzing the blast control efficiency of pesticides applied at different growth stages, we found that best control efficiency against blast was achieved by spraying pesticide twice during the whole growth stage, once 3 d before transplanting or 10 d after transplanting; and once at initial heading stage. Spraying 525 g/hm^2 75% tricyclazole was proven to be the best dosage for blast control. However, 375-450 g/hm^2 75% tricyclazole is enough if the blast incidence is not severe, or the rice varieties are slightly susceptible to blast.The control efficiency against leaf blast between 4% kasugamycin and 20% tricyclazole had no significant difference, but was significantly higher than that of 100 billion spores/g of Bacillus subtilis. The control efficiency against neck blast had no significant difference among 4% kasugamycin, 20% tricyclazole and 100 billion spores/g of B. subtilis. 450 g/hm^2 75% tricyclazole had better control efficiency against neck blast than 2 250 g/hm^2 2% 800 million spores/g Jinggangmycin-wax bud bacteria SC, 1 050 g/hm^2 41% kasugamycin-isoprothiolane WP and 900 g/hm^2 41%kasugamycin-isoprothiolane WP. The frequency of severe blast incidence in Nanchong City has reached 50% since 1997. The rice blast disease has been effectively controlled by comprehensive prevention and control technology, reducing the production loss to less than 2%, and pesticides by 4 523 t in total. In 2014, 327000 t rice grains were approved as pollution-free, green and organic agricultural products, indicating that the blast control measures produced great economic, social and ecological values.
基金Supported by Agricultural Science and Technology Supporting Program of Huai'an City in Jiangsu Province(No.:SN13057)~~
文摘Reproductive organ disease of geese is an endemic and multiple infectious disease in large-scale breeding of breeding geese, especially in anti-season production, which brings a great economic loss to goose production. To make effective prevention and control of reproductive organ disease of breeding geese under the anti-season breeding mode, the characteristics of control principles of infectious diseases of the poultry and the occurrence and prevalence of reproductive organ disease must be combined, so as to carry out scientific prevention and control.At the same time, according to the climate characteristics of summer, the feeding and management of breeding geese and water quality control should also be done well, and many corresponding measures should also be taken, thus obtaining better effect.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(20120304201)Hebei Province Key Technology Research and Development Program(09250307D)~~
文摘According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural control, physical control, and chemical control and proposed specific methods and technological indices in order to provide technological references for comprehensive control on weeds of millet fields.
基金Supported by Suzhou Science and Technology Plan Projects"Monitoring and Early Warning and Prevention Technology for Alien Harmful Organism of Fall Webworm"(SYN201114)
文摘The paper summarizes the research progress of occurrence and comprehensive control of fall webworm on the aspeets of biological and ecological characteristics, assessment of risk and suitability, artificial survey Of occurrence, dynamic monitoring and quarantine, comprehensive control methods and strategy.
基金Supported by the National Key Research and Development Project(2020YFC1512500)。
文摘A novel coaxial ducted fan structure aircraft is proposed to enable the aircraft near vertical walls at high altitudes.The state space equation of the system can be obtained by correlation deduction and identification of the whole prototype model.Based on the duct test bench experiment and computational fluid dynamics(CFD)simulation analysis,the expressions between the different distances dWE from the rotor center of the prototype to the wall and the thrust,reaction torque,and tilting moment of the system under hovering conditions are obtained.The influence of the wall effect of the prototype is incorporated into the system model to analyze the relationship between distance dWE and the comprehensive controllability of the system.The results show that the system comprehensive controllability vector of other channels changes little with the decrease of the distance dWE,and only the controllability vector of the rolling channel increases significantly.At the same time,the tilting moment also increases significantly,which strengthens the tendency of the prototype to tilt towards the wall.
基金Supported by Key Project on Agricultural Development by Department of Science and Technology of Guizhou Province(QKH LH[2014]3024)Key Project on Natural Science Development by Department of Education of Guizhou Province(QJH KY[2013]159)
文摘The tea green leafhopper Empoasca vitis Gothe, one of major tea insect pests in China's Mainland, grows concealed with small size, rapid reproduction and overlapped generations, which has become the most serious insect pest in tea garden. This paper described the morphological features, damage modes and occur- rence characteristics of E. vitis, and preliminarily summarized the main control methods in recent years. Therefore, from pollution-free and green control perspec- tive, controlling population quantity of E. vitis safely and effectively and reducing the yield loss of tea has become a hot issue in prevention and control of insect pests in tea garden. The paper provided a reference in green comprehensive prevention of insect pests in tea garden.
基金the help and strong support of Departments the Chinese Animal Health and Epidemic Center,Guangdong Rsearch Institute of Entomology,Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences,the Agriculture,Fisheries and Conservation Department of Hong Kong and the Hong Kong Jockey Club etc.,during the entomophily and wild animals prevention and control in the disease-free zone of Guangzhou Asian Games
文摘[ Objective] In order to construct the specific equine disease-free zone of of the Guangzhou Asian Games, to ensure that the equestrian events of Guangzhou Asian Games be smoothly held. [Methods] The species, quantities, distribution and seasonal variations of insects and wild animals in related zones were investigated from 2008 to 2010, and the collected samples of the insects and wild animals were tested in laboratory for related equine diseases. [Results] The investigations indicated that there were some mosquitoes, flies, horseflies, punkies, ticks, bats, wild birds and wild bears in equastrianism venue and peripheral regions of disease-free zone of the Guangzhou Asian Games, the laboratory results of Japa- nese encephalitis, vesicular stomatitis, Nipah virus disease, West Nile fever, and Trypanosomiasis evansi, were all negative. According to the in- vestigations and test results, the risk assessments of insect and wild animal vectors in the prevalence of related equine diseases were made to con- firm that the risk was relatively low or very low, and comprehensive prevention and control measures with prevention as major measures and insecti- cides application and environment managements as supplementary means were made on the basis of the risk assessment conclusions. [ Conclu- sions] This research has laid a solid foundation for the successful building of the first specific equine disease-free zone in our country, ensured the smooth holding of the 16th equastdan competition in Guangzhou Asian Games.
文摘In addition to conventional techniques,the prevention and control of Chinese rose black spot(Actinonema rosae)should be strengthened in the management of Chinese rose.The occurrence of Chinese rose black spot is closely related to plant residues,rainfall,cultivation conditions and varieties.On the basis of understanding the symptoms and occurrence regularity of Chinese rose black spot,combination measures of agricultural and chemical prevention and control should be taken.
基金Supported by Key Research and Development Program of Hebei Province(21326308D-1-2)Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2019-3-4-4,2020-3-4-6)Innovation Team Project of Hebei Academy of Agriculture and Forestry Sciences(F21E06-7)。
文摘In recent years, pear rust sometimes occurs in eastern Hebei area, resulting in early defoliation, fruit abscission and loss of fruit commodity value. In this paper, the incidence symptoms, regularity and causes of pear rust are summarized, and the comprehensive prevention and control measures of pear rust in eastern Hebei are put forward.
文摘The occurrence and comprehensive prevention and control progresses of Chilades pandava in Cycas spp. are summarized from the aspects of classification and geographic distribution, ecological characteristics, damage and development rules, and comprehensive prevention and control technology, in order to provide a reference for further prevention and control against C. pandava in Cycas spp.
基金Project(61074018)supported by the National Natural Science Foundation of ChinaProject(2012kfjj06)supported by Hunan Province Key Laboratory of Smart Grids Operation and Control(Changsha University of Science and Technology),China
文摘A comprehensive predictive strategy was proposed for the neutral-point balancing control of back-to-back three-level converters. The phase currents at both sides and the DC-link capacitor voltages were measured for the prediction of the neutral-point current. A quality function was found to balance the neutral-point, and a metabolic on-times distribution factor was used as a predicator to minimize the quality function at each switching state. Simulation results show that the proposed method produces smaller ripples in tested signals compared with the established one, namely, 9.15% less in a total harmonic distortion(THD) of line-to-line voltage, 1.08% less in the THD of phase current, and 0.9 V less in the ripple of the neutral-point voltage. The obtained experimental results show that the main harmonics of the line-to-line voltage and the phase current in the proposed method are improved by 10 d B and 6 d B, respectively, and the ripple of neutral-point voltage is halved compared to the established one.
基金Supported by Science and Technology Innovation Project of Hebei Province(C19C0701-03)Key Technology R&D Program of Hebei Province(16226313D-4)Natural Science Foundation of Hebei Province(C2018301047)。
文摘In order to effectively deal with the problems of diseases and insect pests in the growth process of strawberry and to improve the quality and yield of strawberry,the main diseases and insect pests in strawberry cultivation such as powdery mildew,gray mold,anthracnose,red stele root rot,calcium deficiency,salt or fertilizer damage,aphids,red spiders,thrips,grubs,etc.and their identification methods were analyzed.The comprehensive pollution-free prevention and control techniques of these pests and diseases were explored,in order to provide technical guidance for high quality,efficient and harmless production of strawberry.
基金the Genetic Breeding Post Construction Project of Rice Innovation Team for Modern Agricultural Industrial Technology System in Shandong Province of China(SDAIT-17-02).
文摘Through summarizing the prevalence characteristics of rice black-streaked dwarf virus disease(RBSDVD)in Linyi City of Shandong Province,this paper analyzed its prevalence is related to changes in farming and cultivation systems,the increase in the population of venomous Laodelphax striatellus Fallén and its own migration and spread,the poor disease resistance of cultivated varieties,and inadequate time of prevention and control.Besides,based on the practice of local control,it came up with some comprehensive control measures including strengthening monitoring,early warning and forecasting,planting resistant(tolerant)rice varieties according to local conditions,appropriately delaying the sowing(planting)period,supplemented by insect nets to cover seedlings,and making scientific use of chemical control.It is expected to provide a reference for the prevention and control of RBSDVD.
基金Supported by " Research on The Control Technology of Subtropical Agriculture Pollution System" Special Project of National Environment Protection Public Welfare Industry Science Research "Research on The Construction Strategy of Ecological Civilization" Development Plan Research Project of State Development and Reform Commission+1 种基金Xiangxiang " High-output and Efficient Cultivation of High Quality Rice and Processing Technology Industrialization Demonstration " in The Plan Test Site of National Science and Technology Enriching People and Developing County Special Project Action" Xiangxiang Middle and Long-term Development Plan of Modern Agriculture" of Subtropical Agriculture Ecology Institute in Chinese Academy of Science
文摘The comprehensive improvement strategy of intra-county environment pollution in the city and countryside was searched.By the research method which combined the microscopic view,the macroscopic view with the dynamic perspective,the seriousness of rural water quality,soil and atmospheric pollution in Xiangxiang,Xiangtan and the surrounding areas in Shaoshan irrigated area was revealed.The control measure which was 'four-dimensional pollution in the city and countryside'—— low-carbon-high-value agriculture and the technology innovation was proposed.The low-carbon-high-value technology innovation industrialization demonstration in three parts which included the pre-production,mid-production and post-production deep-processing of cultivation and breeding industry in the ecological cyclic agricultural garden in Shaoshan irrigated area was the driving force.We tried to propel the low-carbon ecological cultivation and breeding industry which included the paddy rice,grass,tree,medicinal herbs and pig,cow,chick,duck,fish.We wanted to relieve the structural unbalance of previous cultivation and breeding industry,'cheap grain hurting the farmers' and the short-leg problem of social-economic-ecological benefit.The results showed that the low-carbon-high-value agricultural system was a poly-generation technology system which promoted the multi-level and grading utilization,saved the energy,reduced the consumption and cleaned the production based on the ecology.
文摘As a crucial economic crop in Guangxi region,chili pepper is facing increasingly severe challenges of continuous cropping obstacles.In this paper,the causes of continuous cropping obstacles in chili pepper soil are deeply analyzed,covering multiple dimensions such as the dynamic changes in soil physicochemical properties,the imbalance of soil microbial community structure,and the gradual accumulation of soil borne diseases and pests.Subsequently,a set of comprehensive prevention and control strategy is proposed:soil improvement through the application of organic fertilizers,biological fertilizers,and soil conditioners;implementing agricultural strategies of crop rotation and intercropping,flexibly adjusting planting density and methods,to optimize crop layout and improve planting management measures;actively introducing natural enemies for biological control,while promoting the use of biopesticides and microbial preparations for biological control.In response to the actual situation of continuous cropping obstacles in chili pepper soil of Guangxi,it is suggested that innovative soil improvement technologies,improved planting management measures,and promotion of biological control methods should also be considered.
基金Supported by Special Fund for Scientific Research in the Public Interest(201103027)Eleventh Five-Year National Science and Technology Support Project(2006BAD32B0103)
文摘[ Objective ] The paper was to understand distribution and damage of alien weed Mikania micramhaln in Huiyang District of China. [ Method ] The coverage, nearby water sources, surrounding plants and control status of M. micranthain under different habitats in Huiyang District were surveyed. [ Result] M. micrantha grew violently in the habitats of irrigation ditches, orchard, field edge and wasteland with the coverage ranging from 10% to 90%. It grew more seriously around water sources and was very likely to recur after control. The wild growth of M. micranthaln was harmful to local agriculture, forestry and fishery. The com- prehensive control measures combing artificial control, chemical control, biological control and ecological control should be adopted in different habitats. [ Conclusion] The study orovided basis for comorehensive control and invasion risk assessment of M. micranthain.