This research focuses on the effects of migration on the TB infection rate and its prevention in Saudi Arabia, which has a large number of expatriates from TB-affected countries. Despite, based on the current global s...This research focuses on the effects of migration on the TB infection rate and its prevention in Saudi Arabia, which has a large number of expatriates from TB-affected countries. Despite, based on the current global statistics of TB occurrence, it is evident that the national incidence of TB has reduced from 10.55 per 100,000 in 2015 to 8.36 per 100,000 in 2019;despite this, there are still some difficulties because migrants bring new strains of Mycobacterium tuberculosis. Hindrances, including language barriers and perceived immigration status, hinder patients from seeking medical attention or doctors from diagnosing diseases. Each patient and each cultural group need special attention to public health, enhancing living circumstances, and health care support. Community participation, inclusion of TB control programs into functional healthcare facilities, and the functioning of TB programs need to be stressed to address TB issues. Considering the focus on social, economic, and cultural approaches, the country can make severe advancements in TB control and population protection. This holistic analysis is critical for a long-term effective strategy to combat TB in the Kingdom.展开更多
By using the precise integration method, the numerical solution of linear quadratic Gaussian (LQG) optimal control problem was discussed. Based on the separation principle, the LQG central problem decomposes, or separ...By using the precise integration method, the numerical solution of linear quadratic Gaussian (LQG) optimal control problem was discussed. Based on the separation principle, the LQG central problem decomposes, or separates, into an optimal state-feedback control problem and an optimal state estimation problem. That is the off-line solution of two sets of Riccati differential equations and the on-line integration solution of the state vector from a set of time-variant differential equations. The present algorithms are not only appropriate to solve the two-point boundary-value problem and the corresponding Riccati differential equation, but also can be used to solve the estimated state from the time-variant differential equations. The high precision of precise integration is of advantage for the control and estimation. Numerical examples demonstrate the high precision and effectiveness of the algorithm.展开更多
To fit in with the developing requirement of int and communication of protective relays, a protection egrated functions of protection measurement, control measurement and control system based on DeviceNet fieldbus is ...To fit in with the developing requirement of int and communication of protective relays, a protection egrated functions of protection measurement, control measurement and control system based on DeviceNet fieldbus is designed. The communication mechanism of DeviceNet is studied and data trigger modes, communication connection, message types and other key technologies are analyzed. The object modeling and device description of the device are realized too. Results of network test, dynamic simulation and test in the field indicate that this system can accomplish all the communication tasks in real time and can make precise response to every kind of faults of the motor, transformer, line and capacitor. Moreover, this system has higher measurement precision and better control capability.展开更多
Metal additive manufacturing(MAM)is an emerging and disruptive technology that builds three-dimensional(3D)components by adding layer-upon-layer of metallic materials.The complex cyclic thermal history and highly loca...Metal additive manufacturing(MAM)is an emerging and disruptive technology that builds three-dimensional(3D)components by adding layer-upon-layer of metallic materials.The complex cyclic thermal history and highly localized energy can produce large temperature gradients,which will,in turn,lead to compressive and tensile stress during the MAM process and eventually result in residual stress.Being an issue of great concern,residual stress,which can cause distortion,delamination,cracking,etc.,is considered a key mechanical quantity that affects the manufacturing quality and service performance of MAM parts.In this review paper,the ongoing work in the field of residual stress determination and control for MAM is described with a particular emphasis on the experimental measurement/control methods and numerical models.We also provide insight on what still requires to be achieved and the research opportunities and challenges.展开更多
The 3rd Asia-Pacfic Conference on Control and Measurement Sponsored by IEEE Shanghai Subsec-tion,Jiangsu Society of Aeronautics and Astronautics,Nanjing University of Aeronautics and Astronau-tics and the City Univers...The 3rd Asia-Pacfic Conference on Control and Measurement Sponsored by IEEE Shanghai Subsec-tion,Jiangsu Society of Aeronautics and Astronautics,Nanjing University of Aeronautics and Astronau-tics and the City University of Hong Kong will be held on August31 to September4,1998 in Dun-huang,China.APCCM Conference is the best chance for scholars,experts and engineers on control andmeasurement fields from the world to propose their academic insights,exchange their academic achieve-ments and enhance international cooperations.The purpose of of the APCCM’98 is to bring togetherscholars and experts engaging in control and measurement research to highlight new issues and contribu-tions of information technology for advances in industrial engineering.The topics of this conference arepresented as follows:control engineering,ideniification,modeling and system theory,specification andimplementation languages,controller synthesis,computer-aided design and simulation,algorithm anddeductive verification,fiber展开更多
In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and cont...In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and control system was developed. Based on the characteristics of each LIBS component, the following development steps have been performed:( 1) a summary of characteristic parameters of the component are established;( 2) the integration mechanism of multiple electrical interfaces is designed;( 3) the component control instruction library is developed. The experimental results indicate that the measurement and control system is compatible with most LIBS parts in the market.Spectrometer and laser can be compatible with at least three different types of parts. In addition,a multilayer iterative testing process is designed to improve the efficiency of optimization process of LIBS parameters. The experimental results have shown that the automatic optimization of the delay time compared to the manual testing provides significant gain in testing efficiency. The range of delay time in the experiments is 1. 28 to 10. 28 μs and the step value is 1,0. 5,0. 2 and 0. 1 μs. The gain in testing efficiency has been found to be increased by 73. 76%,75. 93%,78. 81% and 80. 42%,respectively.展开更多
Deep foundation pit excavation is a basic and key step involved in modern building construction.In order to ensure the construction quality and safety of deep foundation pits,this paper takes a project as an example t...Deep foundation pit excavation is a basic and key step involved in modern building construction.In order to ensure the construction quality and safety of deep foundation pits,this paper takes a project as an example to analyze deep foundation pit excavation technology,including the nature of this construction project,the main technical measures in the construction of deep foundation pit,and the analysis of the safety risk prevention and control measures.The purpose of this analysis is to provide scientific reference for the construction quality and safety of deep foundation pits.展开更多
Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and...Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.展开更多
In view of the fact that pine wood nematode disease is the most dominant disease in Pinus massoniana forests,which has the characteristics of strong infectivity,fast transmission speed,and great difficulty in preventi...In view of the fact that pine wood nematode disease is the most dominant disease in Pinus massoniana forests,which has the characteristics of strong infectivity,fast transmission speed,and great difficulty in prevention and control,a brief description was made to the occurrence status of pine wood nematode disease and difficulties faced with its control in the State-owned Sishibacao Forest Farm of Yunyang County,China,followed by the analysis on the prevention and control measures from aspects of strict control,epidemic situation monitoring,joint prevention and control,and clearance of infected trees,as well as the existing problems of pine wood nematode disease.Finally,reasonable suggestions including strengthening the construction of talent team were put forward,aiming to provide a beneficial reference for the scientific,efficient,and reasonable control of pine wood nematode disease in Pinus massoniana Lamb.forests of Yunyang State-owned Sishibacao Forest Farm.展开更多
Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan r...Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology.展开更多
Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,s...Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.展开更多
[ Objective] The study aimed to research the identification of Persimmon anthracnose and its controlling methods.[ Method ] The pathogen and characteristics, infection and occurrence law, damage symptoms of persimmon ...[ Objective] The study aimed to research the identification of Persimmon anthracnose and its controlling methods.[ Method ] The pathogen and characteristics, infection and occurrence law, damage symptoms of persimmon anthracnose were stated simply and the methods for con- trolling the disease were summed up. [ Result] The pathogen of Persimmon anthracnose was Gloeospor/um kaki Hod, belonging to Deuteromycotina. Germination and invasion of the conidia, sporulation and growth of mycelium all required high temperature, with the optimum temperature of 25 ℃ and the lethal temperature of 50 ℃ （10 min）. The occurrence strength of Persimmon anthracnose related with the factors including host, environment, culture circumstances, mainly doing harm to the fruits and branches. The occurrence of the disease could be controlled by such agricultur- al measures as cleaning the orchard, using the resistant varieties and planting the disease-free seedlings, adopting the balanced fertilization, improving the irrigation and drainage systems, conducting the dense planting and thin branches, building garden using the seedling that grafting on planted stock and raising the grafted parts of the stock. When the incidence was heavy, it needed to spray the fungicides or protective agent for the control of the Persimmon anthracnose. The fungicides should be mainly sprayed on the lesion of shoot, fruit surface and branches. [ Conclusion] The study provided the reference for the control of the Persimmon anthracnose.展开更多
The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and ac...The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level.展开更多
[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking...[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking an example of the artificial lakes in a campus in Xi＇an, we comparatively analyzed the present pollution situation of Xiuyuan Lake and Mingyuan Lake, and provided controlling measures against eutrophication pollution, as well as restoration measures. [Result] All the indicators （TN, TP, Chl-a, NH3-N, CODMn） of the landscape water quality in both Xiuyuan Lake and Mingyuan Lake went severely beyond the Grade IV standards, presenting a state of heavy eutrophication. Nitrogen, phosphorus and other nutrient salts carried by atmospheric precipitation and its runoff, as well as domestic garbage generated by human activities were primary exogenous pollutants of the artificial lakes. And the release of sediment pollutants was endogenous substances causing deterioration of water quality. [Conclusion] This paper presents some measures to control the pollution of artificial lakes, and provides scientific references for the construction, operation and management of artificial lakes, as well as maintenance of aquatic environment.展开更多
The sugarcane rust was the main disease causing damage on sugarcane leaves. The biological characteristics of the sugarcane rust pathogens found in Beihai were studied. The research results showed that the germination...The sugarcane rust was the main disease causing damage on sugarcane leaves. The biological characteristics of the sugarcane rust pathogens found in Beihai were studied. The research results showed that the germination of uredospores would be promoted under the dark condition or with the glucose concentration of 1.5%. The suitable temperature range for the germination of uredospore was 20 -25 ℃, 25 ℃3 was the optimum temperature. The range of relative humidity （RH） for the germination of uredospore was over 80%, the optimum relative humidity for the germination of uredospore was 100% ＋water drops with the germination rate of 28.3%. Urediospore could germinate in the pH value range of 4.1 - 11.1, the most suitable pH value was 7.0. At routine conditions, the longest survival period of uredospore was 120 days. Selection of resistant varieties and cultivation management was the key of control measures.展开更多
[Objective] The aim was to investigate pesticide use in Qujing city and explore the control measures.[Method] Surveys were made on pesticide use by farmers in five vegetable bases in Qujing city by questionnaires to s...[Objective] The aim was to investigate pesticide use in Qujing city and explore the control measures.[Method] Surveys were made on pesticide use by farmers in five vegetable bases in Qujing city by questionnaires to study pesticide use and existing problems by farmers.[Result] Some problems existed in pesticide use in Qujing,such as non-standard pesticide source,lower-recognition of pesticide and impacts of pesticide residues on environment,and without professional guidance.[Conclusion] The existing problems can be resolved by enhancing technical trainings of technicians or pesticide managers,strengthening pesticide promotion,and reinforcing examination of pesticide residues.展开更多
The alkali-atom density measurement method based on light absorption is highly suitable for a spin-exchange relaxationfree(SERF)atomic magnetometer because of its high-precision measurement and complete nonmagnetic in...The alkali-atom density measurement method based on light absorption is highly suitable for a spin-exchange relaxationfree(SERF)atomic magnetometer because of its high-precision measurement and complete nonmagnetic interference.In this study,the optical rotation angle detection system based on polarization balance detection is utilized to realize the alkali-atom density real-time measurement without affecting magnetic field measurement.We discovered that there exists an optimal frequency detuning of the probe light,which offers the highest sensitivity in alkali-atom density measurement and the lowest susceptibility to temperature fluctuations in terms of the scale factor.In contrast to conventional light absorption measurements based on pump light,this method demonstrated a threefold improvement in alkali-atom density measurement sensitivity while remaining immune to ambient magnetic fields and incident light intensity fluctuations.Furthermore,we utilized this method to achieve closed-loop temperature control with an accuracy of 0.04℃.展开更多
Pathogen and characteristics,occurrence law,damage symptom of Paulownia fortunei witches broom disease were simply described,and the control method of the disease was summarized.
Background:To analyze the epidemiological characteristics of varicella epidemics in Chongqing Municipality from 2014 to 2021,and to provide a scientific basis for the formulation of varicella prevention and control me...Background:To analyze the epidemiological characteristics of varicella epidemics in Chongqing Municipality from 2014 to 2021,and to provide a scientific basis for the formulation of varicella prevention and control measures.Methods:Data on the incidence of varicella outbreaks and vaccination data in Chongqing from 2014 to 2021 were collected through the China Disease Control and Prevention Information System and statistically analyzed using descriptive epidemiological methods.Results:From 2014 to 2021,213,715 cases of varicella were reported in Chongqing Municipality,with an average annual incidence rate of 86.26/100,000,with a statistically significant difference(χ^(2)=24,972.069,P<0.001);varicella incidence is seasonal,with peaks in May/June and October/December each year,presenting a“double-peak distribution”.The average annual incidence rate of varicella in municipal districts was 90.74/100,000,which was higher than that of counties 69.62/100,000 and autonomous counties 84.04/100,000;the average annual incidence rate of varicella in males was 89.37/100,000,and in females,82.22/100,000,with the difference not being statistically significant;the age of onset of the disease was mainly in the group of people under 15 years of age,with a total of 190,021 cases reported(88.9%),with 5-9 years old(35.7%)as the high incidence age group.The incidence occupation was dominated by students in 133,733 cases(62.6%).Conclusion:The overall varicella epidemic in Chongqing is on the rise,and has obvious seasonal,regional and population distribution characteristics.The prevention and control of varicella epidemic should be strengthened,the publicity of varicella vaccine should be increased,and it is recommended that varicella vaccine should be included in the national immunization program.展开更多
Desertification is one of the most serious environmental problems in the world,especially in the arid desert regions.Combating desertification,therefore,is an urgent task on a regional or even global scale.The Taklima...Desertification is one of the most serious environmental problems in the world,especially in the arid desert regions.Combating desertification,therefore,is an urgent task on a regional or even global scale.The Taklimakan Desert in China is the second largest mobile desert in the world and has been called the''Dead Sea''due to few organisms can exist in such a harsh environment.The Taklimakan Desert Highway,the longest desert highway(a total length of 446 km)across the mobile desert in the world,was built in the 1990s within the Taklimakan Desert.It has an important strategic significance regarding oil and gas resources exploration and plays a vital role in the socio-economic development of southern Xinjiang,China.However,wind-blow sand seriously damages the smoothness of the desert highway and,in this case,mechanical sand control system(including sand barrier fences and straw checkerboards)was used early in the life of the desert highway to protect the road.Unfortunately,more than 70%of the sand barrier fences and straw checkerboards have lost their functions,and the desert highway has often been buried and frequently blocked since 1999.To solve this problem,a long artificial shelterbelt with the length of 437 km was built along the desert highway since 2000.However,some potential problems still exist for the sustainable development of the desert highway,such as water shortage,strong sandstorms,extreme environmental characteristics and large maintenance costs.The study aims to provide an overview of the damages caused by wind-blown sand and the effects of sand control measures along the Taklimakan Desert Highway.Ultimately,we provide some suggestions for the biological sand control system to ensure the sustainable development of the Taklimakan Desert Highway,such as screening drought-resistant species to reduce the irrigation requirement and ensure the sound development of groundwater,screening halophytes to restore vegetation in the case of soil salinization,and planting cash crops,such as Cistanche,Wolfberry,Apocynum and other cash crops to decrease the high cost of maintenance on highways and shelterbelts.展开更多
文摘This research focuses on the effects of migration on the TB infection rate and its prevention in Saudi Arabia, which has a large number of expatriates from TB-affected countries. Despite, based on the current global statistics of TB occurrence, it is evident that the national incidence of TB has reduced from 10.55 per 100,000 in 2015 to 8.36 per 100,000 in 2019;despite this, there are still some difficulties because migrants bring new strains of Mycobacterium tuberculosis. Hindrances, including language barriers and perceived immigration status, hinder patients from seeking medical attention or doctors from diagnosing diseases. Each patient and each cultural group need special attention to public health, enhancing living circumstances, and health care support. Community participation, inclusion of TB control programs into functional healthcare facilities, and the functioning of TB programs need to be stressed to address TB issues. Considering the focus on social, economic, and cultural approaches, the country can make severe advancements in TB control and population protection. This holistic analysis is critical for a long-term effective strategy to combat TB in the Kingdom.
文摘By using the precise integration method, the numerical solution of linear quadratic Gaussian (LQG) optimal control problem was discussed. Based on the separation principle, the LQG central problem decomposes, or separates, into an optimal state-feedback control problem and an optimal state estimation problem. That is the off-line solution of two sets of Riccati differential equations and the on-line integration solution of the state vector from a set of time-variant differential equations. The present algorithms are not only appropriate to solve the two-point boundary-value problem and the corresponding Riccati differential equation, but also can be used to solve the estimated state from the time-variant differential equations. The high precision of precise integration is of advantage for the control and estimation. Numerical examples demonstrate the high precision and effectiveness of the algorithm.
文摘To fit in with the developing requirement of int and communication of protective relays, a protection egrated functions of protection measurement, control measurement and control system based on DeviceNet fieldbus is designed. The communication mechanism of DeviceNet is studied and data trigger modes, communication connection, message types and other key technologies are analyzed. The object modeling and device description of the device are realized too. Results of network test, dynamic simulation and test in the field indicate that this system can accomplish all the communication tasks in real time and can make precise response to every kind of faults of the motor, transformer, line and capacitor. Moreover, this system has higher measurement precision and better control capability.
基金financially supported by the National Natural Science Foundation of China(12032013,12272131)the Provincial Natural Science Foundation of Hunan(2022JJ40029)the Scientific Research Foundation of Hunan Provincial Education Department(21C0087)。
文摘Metal additive manufacturing(MAM)is an emerging and disruptive technology that builds three-dimensional(3D)components by adding layer-upon-layer of metallic materials.The complex cyclic thermal history and highly localized energy can produce large temperature gradients,which will,in turn,lead to compressive and tensile stress during the MAM process and eventually result in residual stress.Being an issue of great concern,residual stress,which can cause distortion,delamination,cracking,etc.,is considered a key mechanical quantity that affects the manufacturing quality and service performance of MAM parts.In this review paper,the ongoing work in the field of residual stress determination and control for MAM is described with a particular emphasis on the experimental measurement/control methods and numerical models.We also provide insight on what still requires to be achieved and the research opportunities and challenges.
文摘The 3rd Asia-Pacfic Conference on Control and Measurement Sponsored by IEEE Shanghai Subsec-tion,Jiangsu Society of Aeronautics and Astronautics,Nanjing University of Aeronautics and Astronau-tics and the City University of Hong Kong will be held on August31 to September4,1998 in Dun-huang,China.APCCM Conference is the best chance for scholars,experts and engineers on control andmeasurement fields from the world to propose their academic insights,exchange their academic achieve-ments and enhance international cooperations.The purpose of of the APCCM’98 is to bring togetherscholars and experts engaging in control and measurement research to highlight new issues and contribu-tions of information technology for advances in industrial engineering.The topics of this conference arepresented as follows:control engineering,ideniification,modeling and system theory,specification andimplementation languages,controller synthesis,computer-aided design and simulation,algorithm anddeductive verification,fiber
基金National M ajor Scientific Instruments and Equipment Development Special Funds,China(No.2011YQ030113)
文摘In order to improve the compatibility of laser-induced breakdown spectroscopy( LIBS) instrument for different types of parts and optimize the analysis and testing processes,a modularized automatic measurement and control system was developed. Based on the characteristics of each LIBS component, the following development steps have been performed:( 1) a summary of characteristic parameters of the component are established;( 2) the integration mechanism of multiple electrical interfaces is designed;( 3) the component control instruction library is developed. The experimental results indicate that the measurement and control system is compatible with most LIBS parts in the market.Spectrometer and laser can be compatible with at least three different types of parts. In addition,a multilayer iterative testing process is designed to improve the efficiency of optimization process of LIBS parameters. The experimental results have shown that the automatic optimization of the delay time compared to the manual testing provides significant gain in testing efficiency. The range of delay time in the experiments is 1. 28 to 10. 28 μs and the step value is 1,0. 5,0. 2 and 0. 1 μs. The gain in testing efficiency has been found to be increased by 73. 76%,75. 93%,78. 81% and 80. 42%,respectively.
文摘Deep foundation pit excavation is a basic and key step involved in modern building construction.In order to ensure the construction quality and safety of deep foundation pits,this paper takes a project as an example to analyze deep foundation pit excavation technology,including the nature of this construction project,the main technical measures in the construction of deep foundation pit,and the analysis of the safety risk prevention and control measures.The purpose of this analysis is to provide scientific reference for the construction quality and safety of deep foundation pits.
文摘Based on practical work experience,this paper analyzed the occurrence characteristics and control measures of Spodoptera frugiperda in maize.The measures including forecasting and early warning,regional prevention and control,agricultural prevention and control,physical prevention and control,chemical prevention and control,and biological prevention and control can effectively control the damage of S.frugiperda and guarantee the safety of food production.The results will provide some reference for the prevention and control of S.frugiperda.
文摘In view of the fact that pine wood nematode disease is the most dominant disease in Pinus massoniana forests,which has the characteristics of strong infectivity,fast transmission speed,and great difficulty in prevention and control,a brief description was made to the occurrence status of pine wood nematode disease and difficulties faced with its control in the State-owned Sishibacao Forest Farm of Yunyang County,China,followed by the analysis on the prevention and control measures from aspects of strict control,epidemic situation monitoring,joint prevention and control,and clearance of infected trees,as well as the existing problems of pine wood nematode disease.Finally,reasonable suggestions including strengthening the construction of talent team were put forward,aiming to provide a beneficial reference for the scientific,efficient,and reasonable control of pine wood nematode disease in Pinus massoniana Lamb.forests of Yunyang State-owned Sishibacao Forest Farm.
文摘Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology.
文摘Environmental problem is one of three major issues of common concern in the world today.Being a developing socialist country,the environmental problems in china are even more prominent,mainly in population expansion,sharp decrease of global forest areas,soil erosion,acid rain pollution,water pollution and so on.This essay is to introduce the present status,formation causes and hazardous condition of acid rain pollution in china.Some feasible and effective control measures are put forward according to the actual situation in China.
基金Supported by National"Eleventh Five-Year"Technology Support Pro-ject(2006BAD09B07,2006BAD09B09,2007BAD88B04)~~
文摘[ Objective] The study aimed to research the identification of Persimmon anthracnose and its controlling methods.[ Method ] The pathogen and characteristics, infection and occurrence law, damage symptoms of persimmon anthracnose were stated simply and the methods for con- trolling the disease were summed up. [ Result] The pathogen of Persimmon anthracnose was Gloeospor/um kaki Hod, belonging to Deuteromycotina. Germination and invasion of the conidia, sporulation and growth of mycelium all required high temperature, with the optimum temperature of 25 ℃ and the lethal temperature of 50 ℃ （10 min）. The occurrence strength of Persimmon anthracnose related with the factors including host, environment, culture circumstances, mainly doing harm to the fruits and branches. The occurrence of the disease could be controlled by such agricultur- al measures as cleaning the orchard, using the resistant varieties and planting the disease-free seedlings, adopting the balanced fertilization, improving the irrigation and drainage systems, conducting the dense planting and thin branches, building garden using the seedling that grafting on planted stock and raising the grafted parts of the stock. When the incidence was heavy, it needed to spray the fungicides or protective agent for the control of the Persimmon anthracnose. The fungicides should be mainly sprayed on the lesion of shoot, fruit surface and branches. [ Conclusion] The study provided the reference for the control of the Persimmon anthracnose.
文摘The development characteristics of Semiothisa cinerearia Bremer ＆ Grey was summarized, and we also put forward the control measures of well completing insect surveys to provide scientific basis for the control and actively carrying out comprehensive management to control the pests damage in the economic permissible level.
基金Supported by National Science Fund for Distinguished Young Scholars of China(41102107)Basic Research Program for Technology Innovation,Chang'an University(CHD2012JC080)~~
文摘[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking an example of the artificial lakes in a campus in Xi＇an, we comparatively analyzed the present pollution situation of Xiuyuan Lake and Mingyuan Lake, and provided controlling measures against eutrophication pollution, as well as restoration measures. [Result] All the indicators （TN, TP, Chl-a, NH3-N, CODMn） of the landscape water quality in both Xiuyuan Lake and Mingyuan Lake went severely beyond the Grade IV standards, presenting a state of heavy eutrophication. Nitrogen, phosphorus and other nutrient salts carried by atmospheric precipitation and its runoff, as well as domestic garbage generated by human activities were primary exogenous pollutants of the artificial lakes. And the release of sediment pollutants was endogenous substances causing deterioration of water quality. [Conclusion] This paper presents some measures to control the pollution of artificial lakes, and provides scientific references for the construction, operation and management of artificial lakes, as well as maintenance of aquatic environment.
基金Supported by Special Fund Project for Basic Research in Guangxi Sugarcane Research Institute(G2008010)Special Fund of Modern Industrial Technology System Construction(NYCYTXGXCXTD-02)~~
文摘The sugarcane rust was the main disease causing damage on sugarcane leaves. The biological characteristics of the sugarcane rust pathogens found in Beihai were studied. The research results showed that the germination of uredospores would be promoted under the dark condition or with the glucose concentration of 1.5%. The suitable temperature range for the germination of uredospore was 20 -25 ℃, 25 ℃3 was the optimum temperature. The range of relative humidity （RH） for the germination of uredospore was over 80%, the optimum relative humidity for the germination of uredospore was 100% ＋water drops with the germination rate of 28.3%. Urediospore could germinate in the pH value range of 4.1 - 11.1, the most suitable pH value was 7.0. At routine conditions, the longest survival period of uredospore was 120 days. Selection of resistant varieties and cultivation management was the key of control measures.
文摘[Objective] The aim was to investigate pesticide use in Qujing city and explore the control measures.[Method] Surveys were made on pesticide use by farmers in five vegetable bases in Qujing city by questionnaires to study pesticide use and existing problems by farmers.[Result] Some problems existed in pesticide use in Qujing,such as non-standard pesticide source,lower-recognition of pesticide and impacts of pesticide residues on environment,and without professional guidance.[Conclusion] The existing problems can be resolved by enhancing technical trainings of technicians or pesticide managers,strengthening pesticide promotion,and reinforcing examination of pesticide residues.
文摘The alkali-atom density measurement method based on light absorption is highly suitable for a spin-exchange relaxationfree(SERF)atomic magnetometer because of its high-precision measurement and complete nonmagnetic interference.In this study,the optical rotation angle detection system based on polarization balance detection is utilized to realize the alkali-atom density real-time measurement without affecting magnetic field measurement.We discovered that there exists an optimal frequency detuning of the probe light,which offers the highest sensitivity in alkali-atom density measurement and the lowest susceptibility to temperature fluctuations in terms of the scale factor.In contrast to conventional light absorption measurements based on pump light,this method demonstrated a threefold improvement in alkali-atom density measurement sensitivity while remaining immune to ambient magnetic fields and incident light intensity fluctuations.Furthermore,we utilized this method to achieve closed-loop temperature control with an accuracy of 0.04℃.
文摘Pathogen and characteristics,occurrence law,damage symptom of Paulownia fortunei witches broom disease were simply described,and the control method of the disease was summarized.
基金supported by the Center for Public Health Security Research 2022 Policy Research Project(ggwsaqyjzx202205).
文摘Background:To analyze the epidemiological characteristics of varicella epidemics in Chongqing Municipality from 2014 to 2021,and to provide a scientific basis for the formulation of varicella prevention and control measures.Methods:Data on the incidence of varicella outbreaks and vaccination data in Chongqing from 2014 to 2021 were collected through the China Disease Control and Prevention Information System and statistically analyzed using descriptive epidemiological methods.Results:From 2014 to 2021,213,715 cases of varicella were reported in Chongqing Municipality,with an average annual incidence rate of 86.26/100,000,with a statistically significant difference(χ^(2)=24,972.069,P<0.001);varicella incidence is seasonal,with peaks in May/June and October/December each year,presenting a“double-peak distribution”.The average annual incidence rate of varicella in municipal districts was 90.74/100,000,which was higher than that of counties 69.62/100,000 and autonomous counties 84.04/100,000;the average annual incidence rate of varicella in males was 89.37/100,000,and in females,82.22/100,000,with the difference not being statistically significant;the age of onset of the disease was mainly in the group of people under 15 years of age,with a total of 190,021 cases reported(88.9%),with 5-9 years old(35.7%)as the high incidence age group.The incidence occupation was dominated by students in 133,733 cases(62.6%).Conclusion:The overall varicella epidemic in Chongqing is on the rise,and has obvious seasonal,regional and population distribution characteristics.The prevention and control of varicella epidemic should be strengthened,the publicity of varicella vaccine should be increased,and it is recommended that varicella vaccine should be included in the national immunization program.
基金This work was supported by the National Natural Science Foundation of China(31971731,41771121)the Xinjiang National Key Research and Development Program(2019B00005)+1 种基金the National Key Research and Development Program(2017YFC0506705)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2017476).
文摘Desertification is one of the most serious environmental problems in the world,especially in the arid desert regions.Combating desertification,therefore,is an urgent task on a regional or even global scale.The Taklimakan Desert in China is the second largest mobile desert in the world and has been called the''Dead Sea''due to few organisms can exist in such a harsh environment.The Taklimakan Desert Highway,the longest desert highway(a total length of 446 km)across the mobile desert in the world,was built in the 1990s within the Taklimakan Desert.It has an important strategic significance regarding oil and gas resources exploration and plays a vital role in the socio-economic development of southern Xinjiang,China.However,wind-blow sand seriously damages the smoothness of the desert highway and,in this case,mechanical sand control system(including sand barrier fences and straw checkerboards)was used early in the life of the desert highway to protect the road.Unfortunately,more than 70%of the sand barrier fences and straw checkerboards have lost their functions,and the desert highway has often been buried and frequently blocked since 1999.To solve this problem,a long artificial shelterbelt with the length of 437 km was built along the desert highway since 2000.However,some potential problems still exist for the sustainable development of the desert highway,such as water shortage,strong sandstorms,extreme environmental characteristics and large maintenance costs.The study aims to provide an overview of the damages caused by wind-blown sand and the effects of sand control measures along the Taklimakan Desert Highway.Ultimately,we provide some suggestions for the biological sand control system to ensure the sustainable development of the Taklimakan Desert Highway,such as screening drought-resistant species to reduce the irrigation requirement and ensure the sound development of groundwater,screening halophytes to restore vegetation in the case of soil salinization,and planting cash crops,such as Cistanche,Wolfberry,Apocynum and other cash crops to decrease the high cost of maintenance on highways and shelterbelts.
