Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital i...Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital initiated an emergency plan involving multi-departmental defense and control. It adopted a series of nosocomial infection prevention and control measures, including strengthening pre-examination and triage, optimizing the consultation process, improving the hospital’s architectural composition, implementing graded risk management, enhancing personal protection, and implementing staff training and supervision. Descriptive research was used to evaluate the short-term effects of these in-hospital prevention and control strategies. The analysis compared changes in related evaluation indicators between January 24, 2020 and February 12, 2020 (Chinese Lunar New Year’s Eve 2020 to lunar January 19) and the corresponding lunar period of the previous year. Results: Compared to the same period last year, the outpatient fever rate increased by 1.85-fold (P P Conclusion: The nosocomial infection prevention and control strategies implemented during this specific period improved the detection and control abilities for the COVID-19 source of infection and enhanced the compliance with measures. This likely contributed significantly to avoiding the occurrence of nosocomial infection.展开更多
Osteoporosis is a common bone disease in women worldwide, leading to decreased bone density and an accelerated risk of fractures. The causes of osteoporosis in women include age (senile osteoporosis), menopause-associ...Osteoporosis is a common bone disease in women worldwide, leading to decreased bone density and an accelerated risk of fractures. The causes of osteoporosis in women include age (senile osteoporosis), menopause-associated hormonal changes, deficiencies in calcium and vitamin D, genetics, lifestyle factors, medical conditions, and some type of medications. The consequences of osteoporosis are colossal, consisting of fractures, decreased quality of life, psychological impacts, and economic burden. To effectively control the menace of osteoporosis in women, numerous strategies are advocated. Adequate calcium and vitamin D consumption through diet or supplements is vital. Regular weight-bearing activities and strength training that promote bone density. Maintaining a healthy life-style through avoiding smoking, limiting alcohol in-take and maintaining a wholesome body weight is essential. Hormone replacement therapy and some medications may be recommended in certain cases. Early detection through regular bone density and blood tests is crucial to lowering its impact. Creating a supportive network through educational programs and resources fosters awareness and empowerment. By engaging these strategies, women can be empowered to combat osteoporosis, reduce fracture risk, and build stronger bones for their overall well-being.展开更多
Sugarcane red rot caused by Colletotrichum falcatum Went. is an important epidemical fungal disease. The outbreak of large-scale epidemics would cause huge losses to sugarcane production. At present,the pesticide cont...Sugarcane red rot caused by Colletotrichum falcatum Went. is an important epidemical fungal disease. The outbreak of large-scale epidemics would cause huge losses to sugarcane production. At present,the pesticide control effect is not ideal. Moreover,due to long-term continuous cropping and changeable climate in recent years,favorable conditions for the occurrence of red rot have been created. The disease was often prevalent in various sugarcane areas,caused serious damage and seriously affected the sugarcane production. With the rapid spread of the disease worldwide,the control of sugarcane red rot has become the hot spot in the field of sugarcane production and research. In this paper,the epidemic characteristics of sugarcane red rot were analyzed in combination with the field investigation. To provide theoretical basis for prevention and control of red rot in China and effective control the widespread occurrence of the disease,combined with the latest research results at home and abroad,we proposed to select resistant varieties mainly,use biological control agents such as Trichoderma spp.,Pseudomonas spp.and Bacillus spp. to treat the seed cane and soil,timely apply chemical pesticide in critical periods and strengthen scientific and effective comprehensive coordinated prevention and control measures such as field management against red rot.展开更多
In recent years,the conditions of continuous warm winter,more rain and high humidity are very beneficial to the breeding and survival of sugarcane diseases and pests.Coupled with the degradation of single varieties,mo...In recent years,the conditions of continuous warm winter,more rain and high humidity are very beneficial to the breeding and survival of sugarcane diseases and pests.Coupled with the degradation of single varieties,more attention on new plants and less on ratoon cane and the unscientific and unreasonable use of chemical pesticides,the types of sugarcane diseases and pests in the Menglian sugarcane area are increasing day by day,and the damage is increasing year by year,resulting in a substantial reduction in production and sugar,and a serious disaster threat to sugarcane production.Based on the field survey and the current sugarcane production practice in Menglian,this paper systematically reviewed the occurrence and damage dynamics and outbreak reasons of catastrophic diseases and pests that seriously influence sugarcane production,and proposed corresponding prevention and control strategies and integrated prevention and control technology according to the occurrence and damage characteristics of catastrophic diseases and pests.展开更多
With most countries paying attention to the environment protection, hybrid electric vehicles have become a focus of automobile research and development due to the characteristics of energy saving and low emission. Pow...With most countries paying attention to the environment protection, hybrid electric vehicles have become a focus of automobile research and development due to the characteristics of energy saving and low emission. Power follower control strategy(PFCS) and DC-link voltage control strategy are two sorts of control strategies for series hybrid electric vehicles(HEVs). Combining those two control strategies is a new idea for control strategy of series hybrid electric vehicles. By tuning essential parameters which are the defined constants under DClink voltage control and under PFCS, the points of minimum mass of equivalent fuel consumption(EFC) corresponding to a series of variables are marked for worldwide harmonized light vehicles test procedure(WLTP). The fuel economy of series HEVs with the combination control schemes performs better compared with individual control scheme. The results show the effects of the combination control schemes for series HEVs driving in an urban environment.展开更多
The main diseases and pests in the major growing area of jujube in Shanxi Province in recent years are investigated and studied,and several main diseases and pests are described.Based on the green prevention and contr...The main diseases and pests in the major growing area of jujube in Shanxi Province in recent years are investigated and studied,and several main diseases and pests are described.Based on the green prevention and control concept of crop diseases and pests proposed by the Ministry of Agriculture of China,the prevention and control of jujube diseases and pests are expounded from the perspectives of strengthening forecast,agricultural management,biological control and chemical control,in order to provide scientific basis for green development of jujube industry.展开更多
This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle ...This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle air pollutants in downtown Beijing in 2021 was established,and the impact of these emissions on air quality was simulated and quantified,and different emission reduction control scenarios were proposed to evaluate their environmental improvement effects and explore measures to mitigate the impact of pollution emissions.The results show that the high traffic flow and the structure of the motor vehicle emissions in downtown Beijing are the main causes of severe motor vehicle pollution.Monitoring data shows that traffic flow in central Beijing is dominated by small passenger vehicles,while the vehicle mix is better than in other regions,with 72.0%of vehicles meeting"National V"or higher emission standards.However,to achieve higher air quality goals,further reducing vehicle emissions is necessary.Based on dynamic traffic flow,the average daily emissions of nitrogen oxides(NOX),particulate matters(PM_(2.5))and volatile organic compounds(VOC)from motor vehicles in central Beijing are 17.7 tons,0.6 tons and 14.0 tons,respectively,accounting for 23.0%of the city’s average daily motor vehicle emissions.If a zero-emission zone for motor vehicles were implemented in central Beijing,the annual average emission level of pollutants will be reduced by 10.4%to 21.0%.The designation of ultra-low emission zones for motor vehicles could be effective in improving the air quality in the center of Beijing.展开更多
Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system t...Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system technologies,focusing specifically on electrical motor topologies and control strategies is presented.In terms of motor topology,this study outlines the mainstream servo motors used across different periods,as well as the latest theories and technologies surrounding contemporary servo motors.In terms of control strategies,two well-established approaches are presented:field-oriented control and direct torque control.Additionally,it discusses advanced control strategies employed in servo systems,such as model predictive control(MPC)and fault tolerance control,among others.展开更多
Orthopoxviruses(OPXVs)belong to a group of nucleo-cytoplasmic large DNA viruses.Human pathogenic OPXVs(hpOPXVs)include at least five viruses,among which smallpox virus and monkeypox virus are the most dangerous viral ...Orthopoxviruses(OPXVs)belong to a group of nucleo-cytoplasmic large DNA viruses.Human pathogenic OPXVs(hpOPXVs)include at least five viruses,among which smallpox virus and monkeypox virus are the most dangerous viral pathogens.Both viruses are classified as category-one human infectious pathogens in China.Although smallpox was globally eradicated in the 1980 s,it is still a top biosecurity threat owing to the possibility of either being leaked to the outside world from a laboratory or being weaponized by terrorists.Beginning in early May 2022,a sudden outbreak of monkeypox was concurrently reported in more than 100 disparate geographical areas,representing a public health emergency of international concern,as declared by the World Health Organization(WHO).In this review,we present the reasons for hpOPXVs such as monkeypox virus presenting a potential threat to public health.We then systematically review the historical and recent development of vaccines and drugs against smallpox and monkeypox.In the final section,we highlight the importance of viromics studies as an integral part of a forward defense strategy to eliminate the potential threat to public health from emerging or re-emerging hpOPXVs and their variants.展开更多
High-frequency resonance can occur when a modular multilevel converter(MMC)is inserted into an AC grid.Additional damping control is a relatively low-cost resonance suppression strategy compared to passive damping str...High-frequency resonance can occur when a modular multilevel converter(MMC)is inserted into an AC grid.Additional damping control is a relatively low-cost resonance suppression strategy compared to passive damping strategies.This paper analyzes the influences of a feed-forward voltage filter and feedback current filter for the inner controller for the high-frequency impedance characteristics of the MMC based on a model.Moreover,the mechanism,influencing factors,and limitations of the existing strategy including an additional lowpass filter in the voltage feed-forward stage are investigated.Secondly,a resonance suppression strategy for the inclusion of additional cascaded notch filters in the voltage feed-forward stage is proposed,and its parameter design method and applicable scenarios are analyzed.In addition,this paper analyzes the effects of the inclusion of an additional control in other stages for the inner controller of the MMC.Finally,the correctness of the theoretical analysis and the proposed strategy is verified based on the simulation of an actual project on PSCAD/EMTDC.展开更多
This paper develops a novel hierarchical control strategy for improving the trajectory tracking capability of aerial robots under parameter uncertainties.The hierarchical control strategy is composed of an adaptive sl...This paper develops a novel hierarchical control strategy for improving the trajectory tracking capability of aerial robots under parameter uncertainties.The hierarchical control strategy is composed of an adaptive sliding mode controller and a model-free iterative sliding mode controller(MFISMC).A position controller is designed based on adaptive sliding mode control(SMC)to safely drive the aerial robot and ensure fast state convergence under external disturbances.Additionally,the MFISMC acts as an attitude controller to estimate the unmodeled dynamics without detailed knowledge of aerial robots.Then,the adaption laws are derived with the Lyapunov theory to guarantee the asymptotic tracking of the system state.Finally,to demonstrate the performance and robustness of the proposed control strategy,numerical simulations are carried out,which are also compared with other conventional strategies,such as proportional-integralderivative(PID),backstepping(BS),and SMC.The simulation results indicate that the proposed hierarchical control strategy can fulfill zero steady-state error and achieve faster convergence compared with conventional strategies.展开更多
Parking in a small parking lot within limited space poses a difficult task. It often leads to deviations between the final parking posture and the target posture. These deviations can lead to partial occupancy of adja...Parking in a small parking lot within limited space poses a difficult task. It often leads to deviations between the final parking posture and the target posture. These deviations can lead to partial occupancy of adjacent parking lots, which poses a safety threat to vehicles parked in these parking lots. However, previous studies have not addressed this issue. In this paper, we aim to evaluate the impact of parking deviation of existing vehicles next to the target parking lot(PDEVNTPL) on the automatic ego vehicle(AEV) parking, in terms of safety, comfort, accuracy, and efficiency of parking. A segmented parking training framework(SPTF) based on soft actor-critic(SAC) is proposed to improve parking performance. In the proposed method, the SAC algorithm incorporates strategy entropy into the objective function, to enable the AEV to learn parking strategies based on a more comprehensive understanding of the environment. Additionally, the SPTF simplifies complex parking tasks to maintain the high performance of deep reinforcement learning(DRL). The experimental results reveal that the PDEVNTPL has a detrimental influence on the AEV parking in terms of safety, accuracy, and comfort, leading to reductions of more than 27%, 54%, and 26%respectively. However, the SAC-based SPTF effectively mitigates this impact, resulting in a considerable increase in the parking success rate from 71% to 93%. Furthermore, the heading angle deviation is significantly reduced from 2.25 degrees to 0.43degrees.展开更多
Residential air conditioning(RAC)loads have great potential to be included in demand response(DR)programs.This paper studies large-scale RAC loads participating in DR programs,such as modeling,parameters identificatio...Residential air conditioning(RAC)loads have great potential to be included in demand response(DR)programs.This paper studies large-scale RAC loads participating in DR programs,such as modeling,parameters identification,DR characteristics and control strategies.First,an aggregate model of large-scale RAC loads are established based on the buildings’performance with heat storage and insulation,avoiding the calculation of a single RAC model.Then,parameters of the aggregate model are identified based on the RACs’power and outdoor temperatures.Based on the aggregate model,DR characteristics of RAC loads are analyzed,including the dynamic relationship between power,outdoor and indoor temperature,and the potential of DR combined with the users’comfort.Next,the DR control strategies adapted for large-scale RAC loads are established by adjusting the temperature set-points.The DR strategies consider users’comfort and calculate the control signals of each RAC load according to the DR power,including adjustment temperature and adjustment time,which are sent to each RAC load for execution.In the DR process,the control center does not need to obtain the users’indoor temperature,which is conducive to protecting the users’privacy.DR strategies of RAC loads when the control degree within/beyond the DR potential are both proposed,and a load recovery control strategy is also introduced.Finally,the effectiveness and accuracy of the proposed model and DR control strategies are verified by simulation results.展开更多
Background:The 2014 Ebola epidemic is the largest in history,affecting multiple countries in West Africa.Some isolated cases were also observed in other regions of the world.Method:In this paper,we introduce a determi...Background:The 2014 Ebola epidemic is the largest in history,affecting multiple countries in West Africa.Some isolated cases were also observed in other regions of the world.Method:In this paper,we introduce a deterministic SEIR type model with additional hospitalization,quarantine and vaccination components in order to understand the disease dynamics.Optimal control strategies,both in the case of hospitalization(with and without quarantine)and vaccination are used to predict the possible future outcome in terms of resource utilization for disease control and the effectiveness of vaccination on sick populations.Further,with the help of uncertainty and sensitivity analysis we also have identified the most sensitive parameters which effectively contribute to change the disease dynamics.We have performed mathematical analysis with numerical simulations and optimal control strategies on Ebola virus models.Results:We used dynamical system tools with numerical simulations and optimal control strategies on our Ebola virus models.The original model,which allowed transmission of Ebola virus via human contact,was extended to include imperfect vaccination and quarantine.After the qualitative analysis of all three forms of Ebola model,numerical techniques,using MATLAB as a platform,were formulated and analyzed in detail.Our simulation results support the claims made in the qualitative section.Conclusion:Our model incorporates an important component of individuals with high risk level with exposure to disease,such as front line health care workers,family members of EVD patients and Individuals involved in burial of deceased EVD patients,rather than the general population in the affected areas.Our analysis suggests that in order for R0(i.e.,the basic reproduction number)to be less than one,which is the basic requirement for the disease elimination,the transmission rate of isolated individuals should be less than one-fourth of that for non-isolated ones.Our analysis also predicts,we need high levels of medication and hospitalization at the beginning of an epidemic.Further,optimal control analysis of the model suggests the control strategies that may be adopted by public health authorities in order to reduce the impact of epidemics like Ebola.展开更多
About 80% of plant viruses are transmitted by specific insect vectors, especiallyhemipterans with piercing-sucking mouthparts. Many virus-transmitting insectsare also important crop pests that cause considerable losse...About 80% of plant viruses are transmitted by specific insect vectors, especiallyhemipterans with piercing-sucking mouthparts. Many virus-transmitting insectsare also important crop pests that cause considerable losses in crop production.This review summarizes the latest research findings on the interactions betweenplant viruses and insect vectors and analyzes the key factors affecting insecttransmission of plant viruses from the perspectives of insect immunity, insectfeeding, and insect symbiotic microorganisms. Additionally, by referring to thelatest applications for blocking the transmission of animal viruses, potentialcontrol strategies to prevent the transmission of insect-vectored plant virusesusing RNAi technology, gene editing technology, and CRISPR/Cas9 + gene-driventechnology are discussed.展开更多
Foodborne pathogen poses a threat to the food industries as many outbreaks have been found to be associated with biofilm formation.The formation of biofilm is a self-protection growth pattern of bacteria,which increas...Foodborne pathogen poses a threat to the food industries as many outbreaks have been found to be associated with biofilm formation.The formation of biofilm is a self-protection growth pattern of bacteria,which increases post-processing contamination and risk to public health.It is difficult to eliminate the biofilm in the food industries,since the biofilm cells have a barrier preventing or lessening the contact with environmental stresses,antimicrobial agents and the host immune system.Bacterial biofilm formation is a complex process,including initial attachment stage,irreversible attachment stage,biofilm development stage,biofilm maturation stage,and biofilm dispersion stage.The genetic mechanism,substratum and bacterial cell surface properties involve in the biofilm formation.The biofilm inhibition methods studied are physical treatment,chemical and biochemical treatment.The potential green and safe biochemical method attracts more attention,especially,the novel strategies using the safe biochemical agents(essential oils,enzymes,biosurfactants,others)constantly emerged.The review emphasized on effective strategies for inhibiting biofilm formation in different stages(initial irreversible attachment,formation,and maturation)by use of biochemical agents,aiming to provide new insight into biofilm control in food industry thus improving food quality and safety.展开更多
COVID-19 is the most severe pandemic globally since the 1918 influenza pandemic.Effectively responding to this once-in-a-century global pandemic is a worldwide challenge that the international community needs to joint...COVID-19 is the most severe pandemic globally since the 1918 influenza pandemic.Effectively responding to this once-in-a-century global pandemic is a worldwide challenge that the international community needs to jointly face and solve.This study reviews and discusses the key measures taken by major countries in 2020 to fight against COVID-19,such as lockdowns,social distancing,wearing masks,hand hygiene,using Fangcang shelter hospitals,large-scale nucleic acid testing,close-contacts tracking,and pandemic information monitoring,as well as their prevention and control effects.We hope it can help improve the efficiency and effectiveness of pandemic prevention and control in future.展开更多
THE BASIC SITUATION The Chinese govemment has always been devoting a great deal of attention to the research of diarrhoea prevention and control. Early in 1950’s we wiped out the classical cholera which had been epid...THE BASIC SITUATION The Chinese govemment has always been devoting a great deal of attention to the research of diarrhoea prevention and control. Early in 1950’s we wiped out the classical cholera which had been epidemic over a century in old China, brought typhoid fever and dysentry under control by preventing them from spreading in large areas, and reduced to different extents the incidence and mortality of other types of diarrhoea. Since China is a country with a vast territory and a large population, and is greatly varied展开更多
Control strategies play a key role for operation of electric machines,which would directly affect the whole system performance.In fact,different control strategies have been executed and explored for electric machines...Control strategies play a key role for operation of electric machines,which would directly affect the whole system performance.In fact,different control strategies have been executed and explored for electric machines,which bring great impacts to industrial development and human society.This paper investigates and discusses the advantages control strategies for electric machines,including the field oriented control(FOC),direct torque control(DTC),finite control set model predictive control(FCS-MPC),sensorless control,and fault tolerant control(FTC).The corresponding control principles,control targets,fundamental approaches,advanced approaches,methodologies,merits and shortcomings are revealed and analyzed in detail.展开更多
Heating,Ventilation,and Air-Conditioning(HVAC)control strategies are set arbitrarily in many commercial buildings by operators,who sometimes lack relevant skills and professional training.It is acknowledged that impro...Heating,Ventilation,and Air-Conditioning(HVAC)control strategies are set arbitrarily in many commercial buildings by operators,who sometimes lack relevant skills and professional training.It is acknowledged that improving the control strategy of HVAC is feasible and valid,which as a consequence can improve the overall HVAC performance of existing buildings.However,it is quite difficult for an outsiders or a commissioning agent to tell what the HVAC control strategies are and whether they are implemented appropriately in existing buildings.This paper is intended to carry out analysis on the data about Building Automation System(BAS),as well as the data about building energy,for the purpose of identifying the control strategies of HVAC in a given building by using data mining algorithm.Then the results can be adopted by us to determine whether the building is under faulty operation or is running under suboptimal conditions.In this paper,what are proposed are algorithms of data mining identification for some specific HVAC control strategies,including DR on/off strategy,DR reset strategy and temperature reset strategy of chilled water.On the basis of data mining algorithms,a framework is then developed so as to identify these strategies,and the main scenario of this identification framework is known as analyzing many commercial buildings on an energy monitoring platform of a public building.This framework takes the sensor data obtained from HVAC,including temperature,flowrate,and electricity usage,as input,which is followed by the application of Image Segmentation and PCA algorithm for preprocessing.Then,based on these input variables,XGBoost algorithm is employed to determine whether these strategies have been implemented in buildings or not.In order to get the data for training and testing the framework,EnergyPlus Runtime Language is adopted for the application of different strategies.t is finally shown by the result that the identification algorithm can achieve the accuracy rate of 92.5%in the case studies by using one-day operation data,and the identification algorithm can arrive at the accuracy rate of 100%by using three-day operation data.展开更多
文摘Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital initiated an emergency plan involving multi-departmental defense and control. It adopted a series of nosocomial infection prevention and control measures, including strengthening pre-examination and triage, optimizing the consultation process, improving the hospital’s architectural composition, implementing graded risk management, enhancing personal protection, and implementing staff training and supervision. Descriptive research was used to evaluate the short-term effects of these in-hospital prevention and control strategies. The analysis compared changes in related evaluation indicators between January 24, 2020 and February 12, 2020 (Chinese Lunar New Year’s Eve 2020 to lunar January 19) and the corresponding lunar period of the previous year. Results: Compared to the same period last year, the outpatient fever rate increased by 1.85-fold (P P Conclusion: The nosocomial infection prevention and control strategies implemented during this specific period improved the detection and control abilities for the COVID-19 source of infection and enhanced the compliance with measures. This likely contributed significantly to avoiding the occurrence of nosocomial infection.
文摘Osteoporosis is a common bone disease in women worldwide, leading to decreased bone density and an accelerated risk of fractures. The causes of osteoporosis in women include age (senile osteoporosis), menopause-associated hormonal changes, deficiencies in calcium and vitamin D, genetics, lifestyle factors, medical conditions, and some type of medications. The consequences of osteoporosis are colossal, consisting of fractures, decreased quality of life, psychological impacts, and economic burden. To effectively control the menace of osteoporosis in women, numerous strategies are advocated. Adequate calcium and vitamin D consumption through diet or supplements is vital. Regular weight-bearing activities and strength training that promote bone density. Maintaining a healthy life-style through avoiding smoking, limiting alcohol in-take and maintaining a wholesome body weight is essential. Hormone replacement therapy and some medications may be recommended in certain cases. Early detection through regular bone density and blood tests is crucial to lowering its impact. Creating a supportive network through educational programs and resources fosters awareness and empowerment. By engaging these strategies, women can be empowered to combat osteoporosis, reduce fracture risk, and build stronger bones for their overall well-being.
基金Supported by Sugar Crop Research System (CARS-170303)the Yunling Industry and Technology Leading Talent Training Program "Prevention and Control of Sugarcane Pests"(2018LJRC56)the Yunnan Province Agriculture Research System (YNGZTX-4-92)。
文摘Sugarcane red rot caused by Colletotrichum falcatum Went. is an important epidemical fungal disease. The outbreak of large-scale epidemics would cause huge losses to sugarcane production. At present,the pesticide control effect is not ideal. Moreover,due to long-term continuous cropping and changeable climate in recent years,favorable conditions for the occurrence of red rot have been created. The disease was often prevalent in various sugarcane areas,caused serious damage and seriously affected the sugarcane production. With the rapid spread of the disease worldwide,the control of sugarcane red rot has become the hot spot in the field of sugarcane production and research. In this paper,the epidemic characteristics of sugarcane red rot were analyzed in combination with the field investigation. To provide theoretical basis for prevention and control of red rot in China and effective control the widespread occurrence of the disease,combined with the latest research results at home and abroad,we proposed to select resistant varieties mainly,use biological control agents such as Trichoderma spp.,Pseudomonas spp.and Bacillus spp. to treat the seed cane and soil,timely apply chemical pesticide in critical periods and strengthen scientific and effective comprehensive coordinated prevention and control measures such as field management against red rot.
基金Supported by Sugar Crop Research System(CARS-170303)the Yunling Industry and Technology Leading Talent Training Program(2018LJRC56)+1 种基金Menglian and Changyu Science and Enterprise Cooperation Projectthe Yunnan Province Agriculture Research System.
文摘In recent years,the conditions of continuous warm winter,more rain and high humidity are very beneficial to the breeding and survival of sugarcane diseases and pests.Coupled with the degradation of single varieties,more attention on new plants and less on ratoon cane and the unscientific and unreasonable use of chemical pesticides,the types of sugarcane diseases and pests in the Menglian sugarcane area are increasing day by day,and the damage is increasing year by year,resulting in a substantial reduction in production and sugar,and a serious disaster threat to sugarcane production.Based on the field survey and the current sugarcane production practice in Menglian,this paper systematically reviewed the occurrence and damage dynamics and outbreak reasons of catastrophic diseases and pests that seriously influence sugarcane production,and proposed corresponding prevention and control strategies and integrated prevention and control technology according to the occurrence and damage characteristics of catastrophic diseases and pests.
基金supported in part by the National Natural Science Foundation of China(61773382,61773381,61533019)Chinese Guangdongs S&T projects(2016B090910001,2017B090912001)+1 种基金2016 S&T Benefiting Special Project(16-6-2-62-nsh)of Qingdao Achievements Transformation ProgramDongguan Innovation Talents Project(Gang Xiong)
文摘With most countries paying attention to the environment protection, hybrid electric vehicles have become a focus of automobile research and development due to the characteristics of energy saving and low emission. Power follower control strategy(PFCS) and DC-link voltage control strategy are two sorts of control strategies for series hybrid electric vehicles(HEVs). Combining those two control strategies is a new idea for control strategy of series hybrid electric vehicles. By tuning essential parameters which are the defined constants under DClink voltage control and under PFCS, the points of minimum mass of equivalent fuel consumption(EFC) corresponding to a series of variables are marked for worldwide harmonized light vehicles test procedure(WLTP). The fuel economy of series HEVs with the combination control schemes performs better compared with individual control scheme. The results show the effects of the combination control schemes for series HEVs driving in an urban environment.
基金Sponsored by Young and Middle-aged Innovative Talents Training Program of Universities and Colleges in Tianjin (J01009030709)Enterprise Science and Technology Commissioner Project of Tianjin (20YDTPJC01330)+1 种基金Agricultural Science and Technology Project of Baodi District (201918)Cultivation Project of Hetian Polytechnic Horizontal Joint Project of Yisheng Orchard in Hetian City。
文摘The main diseases and pests in the major growing area of jujube in Shanxi Province in recent years are investigated and studied,and several main diseases and pests are described.Based on the green prevention and control concept of crop diseases and pests proposed by the Ministry of Agriculture of China,the prevention and control of jujube diseases and pests are expounded from the perspectives of strengthening forecast,agricultural management,biological control and chemical control,in order to provide scientific basis for green development of jujube industry.
基金supported by the National Key Research and Development Program of China (No.2022YFC3800403)the Foundation of Beijing Municipal Research Institute of EcoEnvironmental Protection (No.Y2022-007)。
文摘This study combined the real-time monitoring and investigation of traffic flows to comprehensively analyze the road traffic flow and vehicle structure in downtown Beijing.A dynamic emission inventory of motor vehicle air pollutants in downtown Beijing in 2021 was established,and the impact of these emissions on air quality was simulated and quantified,and different emission reduction control scenarios were proposed to evaluate their environmental improvement effects and explore measures to mitigate the impact of pollution emissions.The results show that the high traffic flow and the structure of the motor vehicle emissions in downtown Beijing are the main causes of severe motor vehicle pollution.Monitoring data shows that traffic flow in central Beijing is dominated by small passenger vehicles,while the vehicle mix is better than in other regions,with 72.0%of vehicles meeting"National V"or higher emission standards.However,to achieve higher air quality goals,further reducing vehicle emissions is necessary.Based on dynamic traffic flow,the average daily emissions of nitrogen oxides(NOX),particulate matters(PM_(2.5))and volatile organic compounds(VOC)from motor vehicles in central Beijing are 17.7 tons,0.6 tons and 14.0 tons,respectively,accounting for 23.0%of the city’s average daily motor vehicle emissions.If a zero-emission zone for motor vehicles were implemented in central Beijing,the annual average emission level of pollutants will be reduced by 10.4%to 21.0%.The designation of ultra-low emission zones for motor vehicles could be effective in improving the air quality in the center of Beijing.
基金Supported by the National Natural Science Foundation of China under Major Project 51991380.
文摘Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system technologies,focusing specifically on electrical motor topologies and control strategies is presented.In terms of motor topology,this study outlines the mainstream servo motors used across different periods,as well as the latest theories and technologies surrounding contemporary servo motors.In terms of control strategies,two well-established approaches are presented:field-oriented control and direct torque control.Additionally,it discusses advanced control strategies employed in servo systems,such as model predictive control(MPC)and fault tolerance control,among others.
基金This work was supported by the National Science and Technology Major Project of China(2018ZX10711001-006).
文摘Orthopoxviruses(OPXVs)belong to a group of nucleo-cytoplasmic large DNA viruses.Human pathogenic OPXVs(hpOPXVs)include at least five viruses,among which smallpox virus and monkeypox virus are the most dangerous viral pathogens.Both viruses are classified as category-one human infectious pathogens in China.Although smallpox was globally eradicated in the 1980 s,it is still a top biosecurity threat owing to the possibility of either being leaked to the outside world from a laboratory or being weaponized by terrorists.Beginning in early May 2022,a sudden outbreak of monkeypox was concurrently reported in more than 100 disparate geographical areas,representing a public health emergency of international concern,as declared by the World Health Organization(WHO).In this review,we present the reasons for hpOPXVs such as monkeypox virus presenting a potential threat to public health.We then systematically review the historical and recent development of vaccines and drugs against smallpox and monkeypox.In the final section,we highlight the importance of viromics studies as an integral part of a forward defense strategy to eliminate the potential threat to public health from emerging or re-emerging hpOPXVs and their variants.
基金supported in part by Science and Technology Project of State Grid Corporation of China,“Research on Harmonic Oscillation ProblemsSuppression Strategies of Flexible DC Connected to AC Grid”,(No.SGTYHT/17-JS-199).
文摘High-frequency resonance can occur when a modular multilevel converter(MMC)is inserted into an AC grid.Additional damping control is a relatively low-cost resonance suppression strategy compared to passive damping strategies.This paper analyzes the influences of a feed-forward voltage filter and feedback current filter for the inner controller for the high-frequency impedance characteristics of the MMC based on a model.Moreover,the mechanism,influencing factors,and limitations of the existing strategy including an additional lowpass filter in the voltage feed-forward stage are investigated.Secondly,a resonance suppression strategy for the inclusion of additional cascaded notch filters in the voltage feed-forward stage is proposed,and its parameter design method and applicable scenarios are analyzed.In addition,this paper analyzes the effects of the inclusion of an additional control in other stages for the inner controller of the MMC.Finally,the correctness of the theoretical analysis and the proposed strategy is verified based on the simulation of an actual project on PSCAD/EMTDC.
文摘This paper develops a novel hierarchical control strategy for improving the trajectory tracking capability of aerial robots under parameter uncertainties.The hierarchical control strategy is composed of an adaptive sliding mode controller and a model-free iterative sliding mode controller(MFISMC).A position controller is designed based on adaptive sliding mode control(SMC)to safely drive the aerial robot and ensure fast state convergence under external disturbances.Additionally,the MFISMC acts as an attitude controller to estimate the unmodeled dynamics without detailed knowledge of aerial robots.Then,the adaption laws are derived with the Lyapunov theory to guarantee the asymptotic tracking of the system state.Finally,to demonstrate the performance and robustness of the proposed control strategy,numerical simulations are carried out,which are also compared with other conventional strategies,such as proportional-integralderivative(PID),backstepping(BS),and SMC.The simulation results indicate that the proposed hierarchical control strategy can fulfill zero steady-state error and achieve faster convergence compared with conventional strategies.
基金supported by National Natural Science Foundation of China(52222215, 52272420, 52072051)。
文摘Parking in a small parking lot within limited space poses a difficult task. It often leads to deviations between the final parking posture and the target posture. These deviations can lead to partial occupancy of adjacent parking lots, which poses a safety threat to vehicles parked in these parking lots. However, previous studies have not addressed this issue. In this paper, we aim to evaluate the impact of parking deviation of existing vehicles next to the target parking lot(PDEVNTPL) on the automatic ego vehicle(AEV) parking, in terms of safety, comfort, accuracy, and efficiency of parking. A segmented parking training framework(SPTF) based on soft actor-critic(SAC) is proposed to improve parking performance. In the proposed method, the SAC algorithm incorporates strategy entropy into the objective function, to enable the AEV to learn parking strategies based on a more comprehensive understanding of the environment. Additionally, the SPTF simplifies complex parking tasks to maintain the high performance of deep reinforcement learning(DRL). The experimental results reveal that the PDEVNTPL has a detrimental influence on the AEV parking in terms of safety, accuracy, and comfort, leading to reductions of more than 27%, 54%, and 26%respectively. However, the SAC-based SPTF effectively mitigates this impact, resulting in a considerable increase in the parking success rate from 71% to 93%. Furthermore, the heading angle deviation is significantly reduced from 2.25 degrees to 0.43degrees.
基金supported by the Major State Basic Research Development Program of China under Grant No.2016YFB0901100the National Science Foundation of China under Grant No.51577051the Science and Technology Project of SGCC“Research on the system for friendly supply-demand interaction between urban electric power customers and power grid”.
文摘Residential air conditioning(RAC)loads have great potential to be included in demand response(DR)programs.This paper studies large-scale RAC loads participating in DR programs,such as modeling,parameters identification,DR characteristics and control strategies.First,an aggregate model of large-scale RAC loads are established based on the buildings’performance with heat storage and insulation,avoiding the calculation of a single RAC model.Then,parameters of the aggregate model are identified based on the RACs’power and outdoor temperatures.Based on the aggregate model,DR characteristics of RAC loads are analyzed,including the dynamic relationship between power,outdoor and indoor temperature,and the potential of DR combined with the users’comfort.Next,the DR control strategies adapted for large-scale RAC loads are established by adjusting the temperature set-points.The DR strategies consider users’comfort and calculate the control signals of each RAC load according to the DR power,including adjustment temperature and adjustment time,which are sent to each RAC load for execution.In the DR process,the control center does not need to obtain the users’indoor temperature,which is conducive to protecting the users’privacy.DR strategies of RAC loads when the control degree within/beyond the DR potential are both proposed,and a load recovery control strategy is also introduced.Finally,the effectiveness and accuracy of the proposed model and DR control strategies are verified by simulation results.
文摘Background:The 2014 Ebola epidemic is the largest in history,affecting multiple countries in West Africa.Some isolated cases were also observed in other regions of the world.Method:In this paper,we introduce a deterministic SEIR type model with additional hospitalization,quarantine and vaccination components in order to understand the disease dynamics.Optimal control strategies,both in the case of hospitalization(with and without quarantine)and vaccination are used to predict the possible future outcome in terms of resource utilization for disease control and the effectiveness of vaccination on sick populations.Further,with the help of uncertainty and sensitivity analysis we also have identified the most sensitive parameters which effectively contribute to change the disease dynamics.We have performed mathematical analysis with numerical simulations and optimal control strategies on Ebola virus models.Results:We used dynamical system tools with numerical simulations and optimal control strategies on our Ebola virus models.The original model,which allowed transmission of Ebola virus via human contact,was extended to include imperfect vaccination and quarantine.After the qualitative analysis of all three forms of Ebola model,numerical techniques,using MATLAB as a platform,were formulated and analyzed in detail.Our simulation results support the claims made in the qualitative section.Conclusion:Our model incorporates an important component of individuals with high risk level with exposure to disease,such as front line health care workers,family members of EVD patients and Individuals involved in burial of deceased EVD patients,rather than the general population in the affected areas.Our analysis suggests that in order for R0(i.e.,the basic reproduction number)to be less than one,which is the basic requirement for the disease elimination,the transmission rate of isolated individuals should be less than one-fourth of that for non-isolated ones.Our analysis also predicts,we need high levels of medication and hospitalization at the beginning of an epidemic.Further,optimal control analysis of the model suggests the control strategies that may be adopted by public health authorities in order to reduce the impact of epidemics like Ebola.
基金This study was supported by the National Natural Science Foundation of China(31801734)the National Key R&D Program of China(2016YFD0200804)the Ningbo Science and Technology Innovation 2025 Major Project(2019B10004).
文摘About 80% of plant viruses are transmitted by specific insect vectors, especiallyhemipterans with piercing-sucking mouthparts. Many virus-transmitting insectsare also important crop pests that cause considerable losses in crop production.This review summarizes the latest research findings on the interactions betweenplant viruses and insect vectors and analyzes the key factors affecting insecttransmission of plant viruses from the perspectives of insect immunity, insectfeeding, and insect symbiotic microorganisms. Additionally, by referring to thelatest applications for blocking the transmission of animal viruses, potentialcontrol strategies to prevent the transmission of insect-vectored plant virusesusing RNAi technology, gene editing technology, and CRISPR/Cas9 + gene-driventechnology are discussed.
基金the Science and Technology Project of Henan Province(212102110320)the Science Foundation of Henan University of Technology(Grant Nos.2020BS013,2019BS029)
文摘Foodborne pathogen poses a threat to the food industries as many outbreaks have been found to be associated with biofilm formation.The formation of biofilm is a self-protection growth pattern of bacteria,which increases post-processing contamination and risk to public health.It is difficult to eliminate the biofilm in the food industries,since the biofilm cells have a barrier preventing or lessening the contact with environmental stresses,antimicrobial agents and the host immune system.Bacterial biofilm formation is a complex process,including initial attachment stage,irreversible attachment stage,biofilm development stage,biofilm maturation stage,and biofilm dispersion stage.The genetic mechanism,substratum and bacterial cell surface properties involve in the biofilm formation.The biofilm inhibition methods studied are physical treatment,chemical and biochemical treatment.The potential green and safe biochemical method attracts more attention,especially,the novel strategies using the safe biochemical agents(essential oils,enzymes,biosurfactants,others)constantly emerged.The review emphasized on effective strategies for inhibiting biofilm formation in different stages(initial irreversible attachment,formation,and maturation)by use of biochemical agents,aiming to provide new insight into biofilm control in food industry thus improving food quality and safety.
基金funded by the Advisory Research Project of the Chinese Academy of Engineering(No.2020-XZ-37)the National Natural Science Foundation of China(No.81871738)the Mega-projects of Science and Technology Research(No.2018ZX10711001).
文摘COVID-19 is the most severe pandemic globally since the 1918 influenza pandemic.Effectively responding to this once-in-a-century global pandemic is a worldwide challenge that the international community needs to jointly face and solve.This study reviews and discusses the key measures taken by major countries in 2020 to fight against COVID-19,such as lockdowns,social distancing,wearing masks,hand hygiene,using Fangcang shelter hospitals,large-scale nucleic acid testing,close-contacts tracking,and pandemic information monitoring,as well as their prevention and control effects.We hope it can help improve the efficiency and effectiveness of pandemic prevention and control in future.
文摘THE BASIC SITUATION The Chinese govemment has always been devoting a great deal of attention to the research of diarrhoea prevention and control. Early in 1950’s we wiped out the classical cholera which had been epidemic over a century in old China, brought typhoid fever and dysentry under control by preventing them from spreading in large areas, and reduced to different extents the incidence and mortality of other types of diarrhoea. Since China is a country with a vast territory and a large population, and is greatly varied
基金Supported by the general program of National Natural Science Foundation of China under Grant 51677159a grant(Project No.CityU 21201216)from the Research Grants Council of HKSAR,China.
文摘Control strategies play a key role for operation of electric machines,which would directly affect the whole system performance.In fact,different control strategies have been executed and explored for electric machines,which bring great impacts to industrial development and human society.This paper investigates and discusses the advantages control strategies for electric machines,including the field oriented control(FOC),direct torque control(DTC),finite control set model predictive control(FCS-MPC),sensorless control,and fault tolerant control(FTC).The corresponding control principles,control targets,fundamental approaches,advanced approaches,methodologies,merits and shortcomings are revealed and analyzed in detail.
基金This work was supported by the National Science&Technology Pillar Program during the thirteenth Five-year Plan Period(No.2017YFB0903404).
文摘Heating,Ventilation,and Air-Conditioning(HVAC)control strategies are set arbitrarily in many commercial buildings by operators,who sometimes lack relevant skills and professional training.It is acknowledged that improving the control strategy of HVAC is feasible and valid,which as a consequence can improve the overall HVAC performance of existing buildings.However,it is quite difficult for an outsiders or a commissioning agent to tell what the HVAC control strategies are and whether they are implemented appropriately in existing buildings.This paper is intended to carry out analysis on the data about Building Automation System(BAS),as well as the data about building energy,for the purpose of identifying the control strategies of HVAC in a given building by using data mining algorithm.Then the results can be adopted by us to determine whether the building is under faulty operation or is running under suboptimal conditions.In this paper,what are proposed are algorithms of data mining identification for some specific HVAC control strategies,including DR on/off strategy,DR reset strategy and temperature reset strategy of chilled water.On the basis of data mining algorithms,a framework is then developed so as to identify these strategies,and the main scenario of this identification framework is known as analyzing many commercial buildings on an energy monitoring platform of a public building.This framework takes the sensor data obtained from HVAC,including temperature,flowrate,and electricity usage,as input,which is followed by the application of Image Segmentation and PCA algorithm for preprocessing.Then,based on these input variables,XGBoost algorithm is employed to determine whether these strategies have been implemented in buildings or not.In order to get the data for training and testing the framework,EnergyPlus Runtime Language is adopted for the application of different strategies.t is finally shown by the result that the identification algorithm can achieve the accuracy rate of 92.5%in the case studies by using one-day operation data,and the identification algorithm can arrive at the accuracy rate of 100%by using three-day operation data.
