In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system a...In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system and reference system.This transformation aims to convert the tracking control prob-lem into a stabilization control problem.Then,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty items.Based on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is developed.Finally,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal controller.The proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety constraints.The performance of the algorithm is evaluated by the numerical simulation.展开更多
Due to the non-standardization and complexity of the farmland environment,it is always a huge challenge for tractors to achieve fully autonomy(work at Self-driving mode)all the time in agricultural industry.Whereas,wh...Due to the non-standardization and complexity of the farmland environment,it is always a huge challenge for tractors to achieve fully autonomy(work at Self-driving mode)all the time in agricultural industry.Whereas,when tractors work in the Tele-driving(or Remote driving)mode,the operators are prone to fatigue because they need to concentrate for long periods of time.In response to these,a dual-mode control strategy was proposed to integrate the advantages of both approaches,i.e.,by combing Self-driving at most of the time with Tele-driving under special(complex and hazardous)conditions through switching control method.First,the state switcher was proposed,which is used for smooth switching the driving modes according to different working states of a tractor.Then,the state switching control law and the corresponding subsystem tracking controllers were designed.Finally,the effectiveness and superiority of the dualmode control method were evaluated via actual experimental testing of a tractor whose results show that the proposed control method can switch smoothly,stably,and efficiently between the two driving modes automatically.The average control accuracy has been improved by 20%and 15%respectively,compared to the conventional Tele-driving control and Self-driving control with low-precision navigation.In conclusion,the proposed dualmode control method can not only satisfy the operation in the complex and changeable farmland environment,but also free drivers from high-intensity and fatiguing work.This provides a perfect application solution and theoretical support for the intelligentization of unmanned farm agricultural machinery with high safety and reliability.展开更多
Quality control and safety management are two very important contents in building construction project management.Once the construction quality is not up to standard or a safety accident occurs,the economic benefits o...Quality control and safety management are two very important contents in building construction project management.Once the construction quality is not up to standard or a safety accident occurs,the economic benefits of the project will be severely impacted.However,there are still some problems in the quality and safety management of the project.In this paper the problems in construction quality control and safety management are analyzed,and effective countermeasures are put forward,in hopes to help improve construction quality and safety.展开更多
The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban ...The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban centers. A subsidiary objective was to devise and implement a safety program evaluation methodology, and gain insights on the relationships between knowledge acquisition through training and trainee demographics. Salient aspects of blight elimination efforts, as well as the main facets of building demolition practices and requirements, were reviewed. Information on various related safety and health hazards was studied in depth with a focus on demolition operations dealing with blighted properties. A unique safety hazard awareness training program was created for demolition workers, contractors and inspectors based on this research. In addition to devising a curriculum of relevant training topics along with traditional and online delivery systems to be employed, effectiveness evaluation instruments were formulated. Based on the limited data collected from the trainees it was concluded that the program was well-received by them and provided effective learning. It was also found that no statistically significant associations existed between the knowledge gain of the trainees, and either their experience level or union status, after taking this training.展开更多
An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic ...An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic design,mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named "iVarious", was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the "i Various" system. This system highlighted a holistic strategy for effectiveness,security, integrity and systematization of quality and safety control standards of TCMs. The establishment of"i Various" integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards.展开更多
Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures...Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and (2) agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.展开更多
In this research,a methodology named whole-process pollution control(WPPC)is demonstrated that improves the effectiveness of process optimization.This methodology considers waste/emission treatment as a step of the wh...In this research,a methodology named whole-process pollution control(WPPC)is demonstrated that improves the effectiveness of process optimization.This methodology considers waste/emission treatment as a step of the whole production process with respect to the minimization of cost and environmental impact for the whole process.The following procedures are introduced in a WPPC process optimization:①a material and energy flow investigation and optimization based on a systematic understanding of the distribution and physiochemical properties of potential pollutants;②a process optimization to increase the utilization efficiency of different elements and minimize pollutant emissions;and③an evaluation to reveal the effectiveness of the optimization strategies.The production of ammonium paratungstate was chosen for the case study.Two factors of the different optimization schemes-namely the cost-effectiveness factor and the environmental impact indicator-were evaluated and compared.This research demonstrates that by considering the nature of potential pollutants,technological innovations,economic viability,environmental impacts,and regulation requirements,WPPC can efficiently optimize a metal production process.展开更多
Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was...Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.展开更多
Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-V...Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-VNS combined with conventional rehabilitation training promotes the recovery of neurological function of patients with acute stroke.However,these were small-sample-sized studies on the recovery of neurological function in patients after percutaneous vagus nerve stimulation in the subacute and chronic phases after stroke.This double-blinded randomized controlled trial involved 60 acute ischemic or hemorrhagic stroke patients aged 18-80 years who received treatment in the Second Affiliated Hospital of Chongqing Medical University.The subjects were randomly assigned to receive ta-VNS or sham ta-VNS combined with conventional rehabilitation training.The follow-up results over 1 year revealed that ta-VNS combined with conventional rehabilitation training greatly improved the recovery of motor and sensory functions and emotional responses compared with sham ta-VNS combined with conventional rehabilitation training.There were no obvious side effects.These findings suggest that ta-VNS combined with conventional rehabilitation training for the treatment of acute ischemic or hemorrhagic stroke patients is safe and effective.展开更多
Due to the high difficulties, high investment, and high risks in deepwater oil and gas well testing, major safety problems can occur easily. A key to prevent accidents is to conduct safety assessment and control on de...Due to the high difficulties, high investment, and high risks in deepwater oil and gas well testing, major safety problems can occur easily. A key to prevent accidents is to conduct safety assessment and control on deepwater testing and to improve the testing technology. The deepwater of the South China Sea has some special environmental features: long distance from offshore, frequent typhoons in summer and constant monsoons in winter, and the presence of sandy slopes, sandy ridges and internal waves, coupled with the complex properties of oil and gas reserves which bring more challenges to deepwater well testing. In combination with deepwater well testing practice in the South China Sea, this paper analyzes the main potential risks in deepwater well testing and concludes that there are risks of failures of testing string, tools, and ground processes. Other risks are gas hydrate blockage, reservoir stratum sanding, and typhoon impacts. Specific precautions are also proposed in response to these risks in the paper.展开更多
Most countries have expended much effort to develop food safety control systems to ensure safe food supplies within their borders. China, as one of the world's largest food producers and consumers, pays a lot of a...Most countries have expended much effort to develop food safety control systems to ensure safe food supplies within their borders. China, as one of the world's largest food producers and consumers, pays a lot of attention to food safety issues. In recent years, China has taken actions and implemented a series of plans in respect to food safety. Food safety control systems including regulatory, supervisory, and science and technology systems, have begun to be established in China. Using, as a base, an analysis of the current Chinese food safety control system as measured against international standards, this paper discusses the need for China to standardize its food safety control system. We then suggest some policies and measures to improve the Chinese food safety control system.展开更多
Despite the advantages of nuclear technology to mankind, it attendance accident is always catastrophic. In this work, the energy balance equations associated with nuclear technology are structured in parametric form t...Despite the advantages of nuclear technology to mankind, it attendance accident is always catastrophic. In this work, the energy balance equations associated with nuclear technology are structured in parametric form to form the basis of our Mathematical model solvable by the Conjugate Gradient Method (CGM).展开更多
Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction m...Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.展开更多
BACKGROUND Chiglitazar is an emerging pan-agonist of all peroxisome proliferator activated receptors(PPAR)-α,δandγ,and has therapeutic potential for type 2 diabetes(T2D).However,to date,no clinical studies or meta-...BACKGROUND Chiglitazar is an emerging pan-agonist of all peroxisome proliferator activated receptors(PPAR)-α,δandγ,and has therapeutic potential for type 2 diabetes(T2D).However,to date,no clinical studies or meta-analyses have compared the efficacy and safety of chiglitazar and traditional PPAR-γagonist thiazolidinediones(TZDs).A meta-analysis concerning this topic is therefore required.AIM To compare the efficacy and safety of chiglitazar and TZD in patients with T2D.METHODS PubMed,Medline,Embase,the Cochrane Central Register of Controlled Trials,Reference Citation Analysis and Clinicaltrial.gov websites were searched from August 1994 to March 2022.Randomized controlled trials(RCTs)of chiglitazar or TZD vs placebo in patients with T2D were included.Indirect comparisons and sensitivity analyses were implemented to evaluate multiple efficacy and safety endpoints of interest.RESULTS We included 93 RCTs that compared TZD with placebo and one that compared chiglitazar with placebo.For efficacy endpoints,the augmented dose of chiglitazar resulted in greater reductions in hemoglobin(Hb)A1c[weighted mean difference(WMD)=-0.15%,95%confidence interval(CI):-0.27 to-0.04%],triglycerides(WMD=-0.17 mmol/L,95%CI:-0.24 to-0.11 mmol/L)and alanine aminotransferase(WMD=-5.25 U/L,95%CI:-8.50 to-1.99 U/L),and a greater increase in homeostasis model assessment-β(HOMA-β)(WMD=17.75,95%CI:10.73-24.77)when compared with TZD treatment.For safety endpoints,the risks of hypoglycemia,edema,bone fractures,upper respiratory tract infection,urinary tract infection,and weight gain were all comparable between the augmented dose of chiglitazar and TZD.In patients with baseline HbA1c≥8.5%,body mass index≥30 kg/m^(2)or diabetes duration<10 years,the HbA1c reduction and HOMA-βincrease were more conspicuous for the augmented dose of chiglitazar compared with TZD.CONCLUSION Augmented dose of chiglitazar,a pan-activator of PPARs,may serve as an antidiabetic agent with preferable glycemic and lipid control,betterβ-cell function preserving capacity,and does not increase the risk of safety concerns when compared with TZD.展开更多
On a narrow warship platform,the coordinated use of shipborne weapon systems may cause firepower conflicts,which seriously endangers the ship safety.Meanwhile,with directed-energy weapons mounted on ships,firepower co...On a narrow warship platform,the coordinated use of shipborne weapon systems may cause firepower conflicts,which seriously endangers the ship safety.Meanwhile,with directed-energy weapons mounted on ships,firepower conflicts between weapons become a“high probability event”.Aiming at the problem of firepower safety control,based on the research about the collision probability model of air crafts and space targets and according to the cone of fire model of conventional weapons and directed-energy weapons,this paper solved the firepower conflict probabilities between conventional weapons as well as between conventional weapons and directed-energy weapons respectively using the methods of probability theory,and established the firepower safety control model.Then the calculation of firepower conflict probability was carried out using the dimensionality reduction method based on the equivalent conversion of polar coordinates and the power series method based on Laplace transform.The simulation results revealed that the proposed model and calculation methods are effective and reliable,which can provide theoretical basis and technical support for resolution of firepower conflicts between weapons.展开更多
In order to solve such problems as lack of dynamic evaluation system in evaluation of quality and safety trust of dairy products,and weak awareness of prevention,it is necessary to introduce the statistical process co...In order to solve such problems as lack of dynamic evaluation system in evaluation of quality and safety trust of dairy products,and weak awareness of prevention,it is necessary to introduce the statistical process control into the quality and safety trust evaluation system of dairy products,and establish quality and safety trust early warning model for dairy products,so as to determine the control limit of control chart and carry out early warning according to eight criteria. According to the empirical results,the statistical process control is helpful for finding the hidden process risks and providing the necessary basis for enterprises taking positive measures to raise the confidence of consumers.展开更多
The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying t...The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying the hidden hazard sources aregiven. Lastly, the risk pre-alarm and risk control method are confirmed, the managementstandard and management measure are used to eliminate the hidden hazard sources. Inthis study, an evaluation system is built to evaluate the result of risk management.展开更多
In order to provide a reference basis for efficient prevention and control of apple rust,apple rust(Gymnosporangium yamadai)was used as the test material,the field control effects of six triazole fungicides with diffe...In order to provide a reference basis for efficient prevention and control of apple rust,apple rust(Gymnosporangium yamadai)was used as the test material,the field control effects of six triazole fungicides with different concentrations and different application times on apple rust,and the safety of application in different periods on the crop were investigated in field trials.The results showed that the control effect and safety of myclobutanil were excellent.In the prevention test,the effects of myclobutanil 40%EC 2000 times and 4000 times dilutions in protecting apple leaves from G.yamadai infection reached more than 98%at 10 d after the second spraying in the fruitlet stage,and in the treatment test,the control effects of inhibiting the spread of leaf lesions were 90.89%and 87.17%at 16 d after the fourth spraying in the fruit expansion stage,respectively.The results of the crop safety test showed that when applying the triazole fungicides with different concentrations from the red bud stage to the fruit expansion stage of apple trees,there were no adverse effects on the leaves,branches,flowers and fruit,as well as no rust or deformity on the fruit surface.When spraying the fungicides from the red bud stage to the fruit expansion stage,except that the single fruit weights in the treatment of the 10%difenoconazole DC 2000 times and myclobutanil 40%EC 4000 times dilutions were reduced without a significant difference from the control,and the values of other treatments were all reduced by more than 9%compared with the control.When applying the fungicides during the fruit expansion period,none of the tested fungicide treatments had a significant effect on the fruit growth.展开更多
There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the d...There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the development of systems that allow automatic speed control. The first generation of automatic speed control was point-based, but in recent years a potentially more effective alternative automatic speed control method has been introduced. This method is based upon records of drivers’ average travel speed over selected sections of the road and is normally called average speed control or section control. This article discusses the different methods for automatic speed control and presents an evaluation of the safety effects of average speed control, documented through changes in speed levels and accidents before and after the implementation of average speed control at selected sites in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control.展开更多
基金supported in part by the National Science Foundation of China(62173183)。
文摘In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system and reference system.This transformation aims to convert the tracking control prob-lem into a stabilization control problem.Then,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty items.Based on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is developed.Finally,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal controller.The proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety constraints.The performance of the algorithm is evaluated by the numerical simulation.
基金supported in part by the Independent Innovation Project of Agricultural Science and Technology of Jiangsu Province(CX(20)3068)Modern Agricultural Machinery Equipment and Technology Demonstration and Promotion Project of Jiangsu Province(NJ2021-37)+1 种基金National Foreign Experts Program of China(G2021145010L)Science and Technology Project of Suzhou City(SNG2020039)。
文摘Due to the non-standardization and complexity of the farmland environment,it is always a huge challenge for tractors to achieve fully autonomy(work at Self-driving mode)all the time in agricultural industry.Whereas,when tractors work in the Tele-driving(or Remote driving)mode,the operators are prone to fatigue because they need to concentrate for long periods of time.In response to these,a dual-mode control strategy was proposed to integrate the advantages of both approaches,i.e.,by combing Self-driving at most of the time with Tele-driving under special(complex and hazardous)conditions through switching control method.First,the state switcher was proposed,which is used for smooth switching the driving modes according to different working states of a tractor.Then,the state switching control law and the corresponding subsystem tracking controllers were designed.Finally,the effectiveness and superiority of the dualmode control method were evaluated via actual experimental testing of a tractor whose results show that the proposed control method can switch smoothly,stably,and efficiently between the two driving modes automatically.The average control accuracy has been improved by 20%and 15%respectively,compared to the conventional Tele-driving control and Self-driving control with low-precision navigation.In conclusion,the proposed dualmode control method can not only satisfy the operation in the complex and changeable farmland environment,but also free drivers from high-intensity and fatiguing work.This provides a perfect application solution and theoretical support for the intelligentization of unmanned farm agricultural machinery with high safety and reliability.
文摘Quality control and safety management are two very important contents in building construction project management.Once the construction quality is not up to standard or a safety accident occurs,the economic benefits of the project will be severely impacted.However,there are still some problems in the quality and safety management of the project.In this paper the problems in construction quality control and safety management are analyzed,and effective countermeasures are put forward,in hopes to help improve construction quality and safety.
文摘The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban centers. A subsidiary objective was to devise and implement a safety program evaluation methodology, and gain insights on the relationships between knowledge acquisition through training and trainee demographics. Salient aspects of blight elimination efforts, as well as the main facets of building demolition practices and requirements, were reviewed. Information on various related safety and health hazards was studied in depth with a focus on demolition operations dealing with blighted properties. A unique safety hazard awareness training program was created for demolition workers, contractors and inspectors based on this research. In addition to devising a curriculum of relevant training topics along with traditional and online delivery systems to be employed, effectiveness evaluation instruments were formulated. Based on the limited data collected from the trainees it was concluded that the program was well-received by them and provided effective learning. It was also found that no statistically significant associations existed between the knowledge gain of the trainees, and either their experience level or union status, after taking this training.
基金financial support from National Major Scientific and Technological Special Project for "Significant New Drugs Development" (2014ZX09304307-002)Youth Development Research Foundation of NIFDC (2013WA8)the National Natural Foundation of China (81303214)
文摘An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic design,mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named "iVarious", was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the "i Various" system. This system highlighted a holistic strategy for effectiveness,security, integrity and systematization of quality and safety control standards of TCMs. The establishment of"i Various" integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards.
基金supported by the National Social Science Fund of China (13AZD079)the Zhejiang Provincial Natural Science Foundation of China (LQ14G030041 and LZ12G03003)the National Natural Science Foundation of China (71333011 and 71273234)
文摘Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and (2) agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.
基金The authors acknowledge financial support for this research from the National Key Research and Development Program of China(2017YFB0403300 and 2017YFB043305)the National Natural Science Foundation of China(51425405 and 51874269),the National Science-Technology Support Plan Projects(2015BAB02B05)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2014037).Zhi Sun acknowledges financial support from the National Youth Thousand Talents Program.The authors acknowledge constructive suggestions from Prof.Jianxin Yang.
文摘In this research,a methodology named whole-process pollution control(WPPC)is demonstrated that improves the effectiveness of process optimization.This methodology considers waste/emission treatment as a step of the whole production process with respect to the minimization of cost and environmental impact for the whole process.The following procedures are introduced in a WPPC process optimization:①a material and energy flow investigation and optimization based on a systematic understanding of the distribution and physiochemical properties of potential pollutants;②a process optimization to increase the utilization efficiency of different elements and minimize pollutant emissions;and③an evaluation to reveal the effectiveness of the optimization strategies.The production of ammonium paratungstate was chosen for the case study.Two factors of the different optimization schemes-namely the cost-effectiveness factor and the environmental impact indicator-were evaluated and compared.This research demonstrates that by considering the nature of potential pollutants,technological innovations,economic viability,environmental impacts,and regulation requirements,WPPC can efficiently optimize a metal production process.
文摘Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.
基金supported by the Medical Scientific Research Project of Chongqing Municipal Health Commission of China,Nos.2018ZDXM022,2019MSXM017 and 2020MSXM106a grant from Chongqing General Hospital of China,No.2019ZDXM03(all to LCN and JXM).
文摘Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-VNS combined with conventional rehabilitation training promotes the recovery of neurological function of patients with acute stroke.However,these were small-sample-sized studies on the recovery of neurological function in patients after percutaneous vagus nerve stimulation in the subacute and chronic phases after stroke.This double-blinded randomized controlled trial involved 60 acute ischemic or hemorrhagic stroke patients aged 18-80 years who received treatment in the Second Affiliated Hospital of Chongqing Medical University.The subjects were randomly assigned to receive ta-VNS or sham ta-VNS combined with conventional rehabilitation training.The follow-up results over 1 year revealed that ta-VNS combined with conventional rehabilitation training greatly improved the recovery of motor and sensory functions and emotional responses compared with sham ta-VNS combined with conventional rehabilitation training.There were no obvious side effects.These findings suggest that ta-VNS combined with conventional rehabilitation training for the treatment of acute ischemic or hemorrhagic stroke patients is safe and effective.
文摘Due to the high difficulties, high investment, and high risks in deepwater oil and gas well testing, major safety problems can occur easily. A key to prevent accidents is to conduct safety assessment and control on deepwater testing and to improve the testing technology. The deepwater of the South China Sea has some special environmental features: long distance from offshore, frequent typhoons in summer and constant monsoons in winter, and the presence of sandy slopes, sandy ridges and internal waves, coupled with the complex properties of oil and gas reserves which bring more challenges to deepwater well testing. In combination with deepwater well testing practice in the South China Sea, this paper analyzes the main potential risks in deepwater well testing and concludes that there are risks of failures of testing string, tools, and ground processes. Other risks are gas hydrate blockage, reservoir stratum sanding, and typhoon impacts. Specific precautions are also proposed in response to these risks in the paper.
文摘Most countries have expended much effort to develop food safety control systems to ensure safe food supplies within their borders. China, as one of the world's largest food producers and consumers, pays a lot of attention to food safety issues. In recent years, China has taken actions and implemented a series of plans in respect to food safety. Food safety control systems including regulatory, supervisory, and science and technology systems, have begun to be established in China. Using, as a base, an analysis of the current Chinese food safety control system as measured against international standards, this paper discusses the need for China to standardize its food safety control system. We then suggest some policies and measures to improve the Chinese food safety control system.
文摘Despite the advantages of nuclear technology to mankind, it attendance accident is always catastrophic. In this work, the energy balance equations associated with nuclear technology are structured in parametric form to form the basis of our Mathematical model solvable by the Conjugate Gradient Method (CGM).
文摘Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.
基金Beijing Natural Science Foundation,No.7202216National Natural Science Foundation of China,No.81970698 and No.81970708.
文摘BACKGROUND Chiglitazar is an emerging pan-agonist of all peroxisome proliferator activated receptors(PPAR)-α,δandγ,and has therapeutic potential for type 2 diabetes(T2D).However,to date,no clinical studies or meta-analyses have compared the efficacy and safety of chiglitazar and traditional PPAR-γagonist thiazolidinediones(TZDs).A meta-analysis concerning this topic is therefore required.AIM To compare the efficacy and safety of chiglitazar and TZD in patients with T2D.METHODS PubMed,Medline,Embase,the Cochrane Central Register of Controlled Trials,Reference Citation Analysis and Clinicaltrial.gov websites were searched from August 1994 to March 2022.Randomized controlled trials(RCTs)of chiglitazar or TZD vs placebo in patients with T2D were included.Indirect comparisons and sensitivity analyses were implemented to evaluate multiple efficacy and safety endpoints of interest.RESULTS We included 93 RCTs that compared TZD with placebo and one that compared chiglitazar with placebo.For efficacy endpoints,the augmented dose of chiglitazar resulted in greater reductions in hemoglobin(Hb)A1c[weighted mean difference(WMD)=-0.15%,95%confidence interval(CI):-0.27 to-0.04%],triglycerides(WMD=-0.17 mmol/L,95%CI:-0.24 to-0.11 mmol/L)and alanine aminotransferase(WMD=-5.25 U/L,95%CI:-8.50 to-1.99 U/L),and a greater increase in homeostasis model assessment-β(HOMA-β)(WMD=17.75,95%CI:10.73-24.77)when compared with TZD treatment.For safety endpoints,the risks of hypoglycemia,edema,bone fractures,upper respiratory tract infection,urinary tract infection,and weight gain were all comparable between the augmented dose of chiglitazar and TZD.In patients with baseline HbA1c≥8.5%,body mass index≥30 kg/m^(2)or diabetes duration<10 years,the HbA1c reduction and HOMA-βincrease were more conspicuous for the augmented dose of chiglitazar compared with TZD.CONCLUSION Augmented dose of chiglitazar,a pan-activator of PPARs,may serve as an antidiabetic agent with preferable glycemic and lipid control,betterβ-cell function preserving capacity,and does not increase the risk of safety concerns when compared with TZD.
文摘On a narrow warship platform,the coordinated use of shipborne weapon systems may cause firepower conflicts,which seriously endangers the ship safety.Meanwhile,with directed-energy weapons mounted on ships,firepower conflicts between weapons become a“high probability event”.Aiming at the problem of firepower safety control,based on the research about the collision probability model of air crafts and space targets and according to the cone of fire model of conventional weapons and directed-energy weapons,this paper solved the firepower conflict probabilities between conventional weapons as well as between conventional weapons and directed-energy weapons respectively using the methods of probability theory,and established the firepower safety control model.Then the calculation of firepower conflict probability was carried out using the dimensionality reduction method based on the equivalent conversion of polar coordinates and the power series method based on Laplace transform.The simulation results revealed that the proposed model and calculation methods are effective and reliable,which can provide theoretical basis and technical support for resolution of firepower conflicts between weapons.
基金Supported by Program of Chongqing University of Arts and Sciences(Z2014JG14)Young Scholar Project of Humanities and Social Science Foundation of Ministry of Education(15XJC790002)
文摘In order to solve such problems as lack of dynamic evaluation system in evaluation of quality and safety trust of dairy products,and weak awareness of prevention,it is necessary to introduce the statistical process control into the quality and safety trust evaluation system of dairy products,and establish quality and safety trust early warning model for dairy products,so as to determine the control limit of control chart and carry out early warning according to eight criteria. According to the empirical results,the statistical process control is helpful for finding the hidden process risks and providing the necessary basis for enterprises taking positive measures to raise the confidence of consumers.
基金Supported by the National Natural Science Foundation of China(70533050)the Eleventh Five-year Science & Technology Support Plan of China(2006BAK03B0703)the Ministry of Education Humanities and Social Science (08JA630083)
文摘The new type of risk management is process management. First, the hazardsources are identified before coal mine accidents occur, and then the pre-control measureand information monitoring method based on classifying the hidden hazard sources aregiven. Lastly, the risk pre-alarm and risk control method are confirmed, the managementstandard and management measure are used to eliminate the hidden hazard sources. Inthis study, an evaluation system is built to evaluate the result of risk management.
基金National Key R&D Program of China(2016YFD0201100)China Agriculture Research System of MOF and MARA(CARS-27)+2 种基金Key Common Technology Research Project for the High-quality Development of Agriculture in Hebei Province(19226508D)Special Fund for Science and Technology Development of Xinjiang Production and Construction Corps(2018AB035)Science and Technology Research Fund of the Second Agricultural Division of Xinjiang Production and Construction Corps(2019NYGG01).
文摘In order to provide a reference basis for efficient prevention and control of apple rust,apple rust(Gymnosporangium yamadai)was used as the test material,the field control effects of six triazole fungicides with different concentrations and different application times on apple rust,and the safety of application in different periods on the crop were investigated in field trials.The results showed that the control effect and safety of myclobutanil were excellent.In the prevention test,the effects of myclobutanil 40%EC 2000 times and 4000 times dilutions in protecting apple leaves from G.yamadai infection reached more than 98%at 10 d after the second spraying in the fruitlet stage,and in the treatment test,the control effects of inhibiting the spread of leaf lesions were 90.89%and 87.17%at 16 d after the fourth spraying in the fruit expansion stage,respectively.The results of the crop safety test showed that when applying the triazole fungicides with different concentrations from the red bud stage to the fruit expansion stage of apple trees,there were no adverse effects on the leaves,branches,flowers and fruit,as well as no rust or deformity on the fruit surface.When spraying the fungicides from the red bud stage to the fruit expansion stage,except that the single fruit weights in the treatment of the 10%difenoconazole DC 2000 times and myclobutanil 40%EC 4000 times dilutions were reduced without a significant difference from the control,and the values of other treatments were all reduced by more than 9%compared with the control.When applying the fungicides during the fruit expansion period,none of the tested fungicide treatments had a significant effect on the fruit growth.
文摘There is considerable safety potential in ensuring that motorists respect the speed limits. High speeds increase the number and severity of accidents. Technological development over the last 20 years has enabled the development of systems that allow automatic speed control. The first generation of automatic speed control was point-based, but in recent years a potentially more effective alternative automatic speed control method has been introduced. This method is based upon records of drivers’ average travel speed over selected sections of the road and is normally called average speed control or section control. This article discusses the different methods for automatic speed control and presents an evaluation of the safety effects of average speed control, documented through changes in speed levels and accidents before and after the implementation of average speed control at selected sites in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control.