期刊文献+
共找到5,531篇文章
< 1 2 250 >
每页显示 20 50 100
Controlling the dynamic behavior of decentralized cluster through centralized approaches
1
作者 袁大明 王培龙 +6 位作者 王鹏 马星宇 汪楚云 王璟 陈怀城 王高 叶方富 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期46-54,共9页
How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation... How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation of group patterns. Centralized systems excel in precise control over individual behavior within a group, ensuring high accuracy and controllability in task execution. Nevertheless, their sensitivity to group size may limit their adaptability to diverse tasks. In contrast, decentralized systems empower individuals with autonomous decision-making, enhancing adaptability and system robustness. Yet, this flexibility comes at the cost of reduced accuracy and efficiency in task execution. In this work, we present a unique method for regulating the centralized dynamic behavior of self-organizing clusters based on environmental interactions. Within this environment-coupled robot system, each robot possesses similar dynamic characteristics, and their internal programs are entirely identical. However, their behaviors can be guided by the centralized control of the environment, facilitating the accomplishment of diverse cluster tasks. This approach aims to balance the accuracy and flexibility of centralized control with the robustness and task adaptability of decentralized control. The proactive regulation of dynamic behavioral characteristics in active matter groups, demonstrated in this work through environmental interactions, holds the potential to introduce a novel technological approach and provide experimental references for studying the dynamic behavior control of large-scale artificial active matter systems. 展开更多
关键词 self-organizing system centralized control dynamics regulation
下载PDF
Analysis of the Effect of Quality Control Circle on the Central Sterile Supply Department 被引量:1
2
作者 Xiaoxiao Kong 《Journal of Clinical and Nursing Research》 2023年第6期89-94,共6页
Objective:To analyze the effect of quality control circle on the central sterile supply department(CSSD).Methods:The control group and the observation group each consisted of 180 instruments received by the sterilizat... Objective:To analyze the effect of quality control circle on the central sterile supply department(CSSD).Methods:The control group and the observation group each consisted of 180 instruments received by the sterilization supply center from January to March 2023 and 11 CSSD staff.The control group underwent routine management while quality control circle was implemented in the observation group.The quality of work,disinfection and sterilization qualification rates,disinfection and sterilization of various instruments,cleaning indicators,and management satisfaction of both groups were compared.Results:The observation group scored higher in terms of work quality,the qualification rate of disinfection and sterilization in each link,the disinfection and sterilization of instruments,and cleaning indicators compared to the control group.Besides,the management satisfaction of the observation group was higher than that of the control group(P<0.05).Conclusion:A quality control circle ensures the quality of work,improves the cleaning,disinfection,and sterilization of instruments of the CSSD,and improves the management satisfaction of the CSSD staff. 展开更多
关键词 Quality control circle central sterile supply department Nursing quality Disinfection and sterilization
下载PDF
An application-layer based centralized information access control for VPN 被引量:2
3
作者 欧阳凯 周敬利 +1 位作者 夏涛 余胜生 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第2期240-249,共10页
With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality... With the rapid development of Virtual Private Network (VPN), many companies and organizations use VPN to implement their private communication. Traditionally, VPN uses security protocols to protect the confidentiality of data, the message integrity and the endpoint authentication. One core technique of VPN is tunneling, by which clients can access the in- ternal servers traversing VPN. However, the tunneling technique also introduces a concealed security hole. It is possible that if one vicious user can establish tunneling by the VPN server, he can compromise the internal servers behind the VPN server. So this paper presents a novel Application-layer based Centralized Information Access Control (ACIAC) for VPN to solve this problem. To implement an efficient, flexible and multi-decision access control model, we present two key techniques to ACIAC—the centralized management mechanism and the stream-based access control. Firstly, we implement the information center and the constraints/events center for ACIAC. By the two centers, we can provide an abstract access control mechanism, and the material access control can be decided dynamically by the ACIAC’s constraint/event mechanism. Then we logically classify the VPN communication traffic into the access stream and the data stream so that we can tightly couple the features of VPN communication with the access control model. We also provide the design of our ACIAC prototype in this paper. 展开更多
关键词 Virtual private network Access control TUNNELING centralized management STREAM
下载PDF
Can the Glucose Central Control System Dysfunctions Induce Diabetes Mellitus?
4
作者 Altair S. de Assis João Luiz P. da Nobrega 《Open Journal of Endocrine and Metabolic Diseases》 2023年第12期244-255,共12页
We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art... We study afresh how the glucose control system anomalies impact the organicity of the glucose homeostasis and build up events of persistent hyperglycemia and diabetes mellitus. We have used critically the state of art literature related to the subject, in order to cross, to compare, and to organize the relevant contents to create a logical and consistent support to the finds. We show that it is consistent to assume that persistent hyperglycemia and diabetes mellitus can have precursors not only in pancreas, but also in brain, mainly induced by noxious dysfunctions of hypothalamus sensor neurons circuits and external noxious elements, causing pancreas overload, and the consequent exhaustion—overburden. 展开更多
关键词 Brain HYPOTHALAMUS CNS—central Nervous System Sensor Neuron Circuits Glucose central control System External Noxious Elements Juvenile Persistent Hyperglycemia Diabetes Mellitus Homeostasis Euglycemia
下载PDF
Application of metagenomic next-generation sequencing in the diagnosis of infectious diseases of the central nervous system after empirical treatment 被引量:1
5
作者 Ying-Ying Chen Yan Guo +1 位作者 Xin-Hong Xue Feng Pang 《World Journal of Clinical Cases》 SCIE 2022年第22期7760-7771,共12页
BACKGROUND The diagnostic value of metagenomic next-generation sequencing(mNGS)in central nervous system(CNS)infectious diseases after empirical treatment has not been reported.AIM To investigate the diagnostic value ... BACKGROUND The diagnostic value of metagenomic next-generation sequencing(mNGS)in central nervous system(CNS)infectious diseases after empirical treatment has not been reported.AIM To investigate the diagnostic value of mNGS of cerebrospinal fluid(CSF)in the empirically treated CNS infectious diseases.METHODS A total of 262 CSF samples from patients with suspected CNS infections were collected between August 2020 and December 2021.Both mNGS and conventional methods were used for testing.The conventional methods included microbial culture,smear,polymerase chain reaction,etc.RESULTS Among 262 suspected cases,183 cases(69.84%)were diagnosed as CNS infection,including 86 cases of virus infection(47.00%),70 cases of bacterial infection(38.25%)and 27 cases of fungal infection(14.76%).The sensitivity and specificity of mNGS were 65.6%(95%CI:58.2%-72.3%)and 89.6%(95%CI:79.1%-95.3%),respectively.The PPV of mNGS was 94.5%(95%CI:88.6%-97.6%),and the NPV was 48.8%(95%CI:39.7%–57.9%).The pathogen detective sensitivity and accuracy of mNGS were higher than those of conventional methods(Sensitivity:65.6%vs 37.2%;P<0.001;Accuracy:72.0%vs 50%,P<0.001).The results showed that compared with conventional methods,mNGS technology was a more sensitive method for the diagnosis of CNS infection after empirical treatment.CONCLUSION mNGS can be a better method applied in the diagnosis of CNS infection after empirical treatment. 展开更多
关键词 Metagenomic next-generation sequencing Cerebrospinal fluid central nervous system infection Pathogenic culture
下载PDF
Joint Centralized Power Control and Cell Sectoring for Interference Management in CDMA Cellular Systems in a 2D Urban Environment 被引量:1
6
作者 Mohamad Dosaranian Moghadam Hamidreza Bakhshi Gholamreza Dadashzadeh 《Wireless Sensor Network》 2010年第8期599-605,共7页
The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In t... The interference reduction capability of cell sectoring and power control algorithms have been considered separately as means to decrease the interference in Code Division Multiple Access (CDMA) cellular systems. In this paper, we present Switched-Beam (SB) and Rotatable Equal Sectoring (RES) techniques for CDMA cellular systems in a 2D urban environment. In the SB technique by using a number of fixed, independent, or directional antennas we increase the downlink capacity of the CDMA systems. Also in the RES method, the equal sectors of the base stations are rotating together to decrease the inter-cell and intra-cell interferences. Also in this paper we use centralized power control to overcome the near-far problem. Simulation results indicate that the proposed techniques considerably increase the capacity of the CDMA cellular systems compared to ordinary Equal Sectoring (ES) method. 展开更多
关键词 CDMA centralized Power control Equal Sectoring FORWARD Link Rotatable Equal Sectoring Switched-Beam
下载PDF
Practice of Centralized Control over Cascade Hydropower Stations
7
作者 Jin Zehua General Manager, Guizhou Wujiang Hydropower Development Ltd. 《Electricity》 2010年第1期44-47,共4页
Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem,... Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem, centralized control over cascade hydropower stations is practiced with a considerable economic benef it gained. 展开更多
关键词 RATE Practice of centralized control over Cascade Hydropower Stations OVER
下载PDF
Centralized Solar PV Systems for Static Loads Using Constant Voltage Control Method
8
作者 S. Alagammal N. Rathina Prabha I. Aarthy 《Circuits and Systems》 2016年第13期4213-4226,共14页
The alternative energy resources, like solar, are always complementary due to environmental changes. Energy generation with the sources such as solar and wind is gaining importance and of that photovoltaic conversion ... The alternative energy resources, like solar, are always complementary due to environmental changes. Energy generation with the sources such as solar and wind is gaining importance and of that photovoltaic conversion is the main focus of researches due to its promising potential as the electrical source. This paper presents the constant voltage method of control where the output of the converter is maintained constant irrespective of the variations in the irradiance with the high step-up isolated efficient single switch DC-DC converter for the solar PV systems. Constant voltage method of control uses the array of photovoltaic systems as its energy source. The output of the Solar PV systems is nonlinear and has its dependency on temperature and irradiance by which the panel voltage and current varies with the variation in irradiance. Constant voltage control method always operates in such a way that the converter voltage is tried to be maintained constantly to the reference voltage which is set by the user. The system used here utilizes high step single switch isolated DC-DC converter and monitors the voltage continuously by varying the duty cycle to maintain the converter voltage always constant. As a way of improving the performance, both the open and closed loop analysis is done where the closed loop analysis uses the PI controller for its performance. The model is implemented in MATLAB and it accepts the irradiance as the input and outputs the constant voltage from the converter and the feasibility of the proposed converter topology is confirmed with experimental results of the prototype model. 展开更多
关键词 Photovoltaic System centralized System Constant Voltage control Method Proportional-Integral controller
下载PDF
Facilities for Centralized Isolation and Quarantine for the Observation and Treatment of Patients with COVID-19 被引量:5
9
作者 Xianliang Wang Jiao Wang +10 位作者 Jin Shen John SJi Lijun Pan Hang Liu Kangfeng Zhao Li Li Bo Ying Lin Fan Liubo Zhang Lin Wang Xiaoming Shi 《Engineering》 SCIE EI 2021年第7期908-913,共6页
The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient uti... The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical space.While few studies discussed the efficient utilization of medical resources and physical space so far.Therefore,this study aimed to summarize experiences related to facilities used for centralized isolation for medical observation and treatment during the COVID-19 pandemic in China and to provide suggestions to further improve the management of confirmed cases,suspected cases,and close contacts.In China,three types of facilities for centralized isolation(Fangcang shelter hospitals,refitted non-designated hospitals,and quarantine hotels)underwent retrofitting for the treatment and isolation of confirmed and suspected cases.These facilities mitigated the immediate high demand for space.Moreover,in order to minimize infection risks in these facilities,regulators and governmental agencies implemented new designs,management measures,and precautionary measures to minimize infection risk.Other countries and regions could refer to China’s experience in optimally allocating social resources in response to the COVID-19 pandemic.As a conclusion,government should allocate social resources and construct centralized isolation and quarantine facilities for an emergency response,health authorities should issue regulations for centralized isolation facilities and pay strict attention to the daily management of these facilities,a multidisciplinary administration team is required to support the daily operation of a centralized isolation facility,in-depth studies and international collaboration on the centralized isolation policy are encouraged. 展开更多
关键词 centralized isolation Risk control Infectious patients Close contacts Coronavirus disease
下载PDF
Main Controls on Hydrocarbon Accumulation in the Paleozoic in Central Saudi Arabia 被引量:2
10
作者 Bai Guoping (Key Laboratory for Hydrocarbon Accumulation under Ministry of Education, China University of Petroleum, Beijing 102249, China) 《Petroleum Science》 SCIE CAS CSCD 2007年第2期10-17,共8页
Sandi Arabia is renown for its rich oil and gas Mesozoic. However, the discovery of Paleozoic fields in resources with the bulk of the reserves reservo/red in the the late 1980s has encouraged further exploration in t... Sandi Arabia is renown for its rich oil and gas Mesozoic. However, the discovery of Paleozoic fields in resources with the bulk of the reserves reservo/red in the the late 1980s has encouraged further exploration in the Paleozoic. This paper reviews the salient features of the Paleozoic petroleum geology in central Saudi Arabia and discusses the main factors controlling hydrocarbon accumulation in the Paleozoic. The Lower Silurian Qusaiba hot shale is the principal source rock for the hydrocarbons discovered in the Ordovician to Permian reservoirs. Of them, the Permo- Carboniferous Unayzah and Upper Ordovician Sarah Formations have the best exploration potential. The key factors controlling hydrocarbon accumulation in the Unayzah Formation are migration pathways and reservoir petrophysics. The key factors controlling hydrocarbon accumulation in the Sarah Formation are reservoir petrophysics and the development of structural traps. 展开更多
关键词 Paleozoic oil and gas accumulations central Saudi Arabia main controls Qusaiba hot shale Unayzah play Sarah play
下载PDF
Control strategy of central pattern generator gait movement under condition of attention selection 被引量:2
11
作者 Wei WANG Rubin WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第7期957-966,共10页
As a typical rhythmic movement, human being's rhythmic gait movement can be generated by a central pattern generator (CPG) located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by g... As a typical rhythmic movement, human being's rhythmic gait movement can be generated by a central pattern generator (CPG) located in a spinal cord by self- oscillation. Some kinds of gait movements are caused by gait frequency and amplitude variances. As an important property of human being's motion vision, the attention selection mechanism plays a vital part in the regulation of gait movement. In this paper, the CPG model is amended under the condition of attention selection on the theoretical basis of Matsuoka neural oscillators. Regulation of attention selection signal for the CPG model parameters and structure is studied, which consequentially causes the frequency and amplitude changes of gait movement output. Further, the control strategy of the CPG model gait movement under the condition of attention selection is discussed, showing that the attention selection model can regulate the output model of CPG gait movement in three different ways. The realization of regulation on the gait movement frequency and amplitude shows a variety of regulation on the CPG gait movement made by attention selection and enriches the controllability of CPG gait movement, which demonstrates potential influence in engineering applications. 展开更多
关键词 gait movement attention selection central pattern generator (CPG) movement control strategy
下载PDF
Enrichment of tight oil and its controlling factors in central and western China 被引量:5
12
作者 SONG Yan LUO Qun +2 位作者 JIANG Zhenxue YANG Wei LIU Dongdong 《Petroleum Exploration and Development》 CSCD 2021年第2期492-506,共15页
Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,mo... Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,modeling experiment and comprehensive analysis,this study reveals that the tight oil accumulates at start-up pressure,advances under differential pressure,diffuses at alternating fast and low speeds,charges in stepped large area and migrates rapidly through fractures,and enriches in dominant fractures and pores.The root cause of ladder-like charge is the multiple scales of pores.The widespread source rock with high hydrocarbon generation intensity is the material basis for tight oil enrichment;the dominant source reservoir assemblage is the basic unit for tight oil enrichment;fractures and beddings are conducive to local rapid migration of tight oil;fractures and pores work together to control the enrichment of tight oil.Two typical accumulation models of tight oil are established,namely"source reservoir in coexistence,four optimal factors controlling enrichment around central area,and large-scale continuous distribution"for a large freshwater lake clastic rock basin and"source reservoir integration,four optimal factors controlling enrichment,central area distribution,small in size but high in enrichment degree"for a small saline lake diamictite depression. 展开更多
关键词 tight oil enrichment mechanism main control factor enrichment model central and western China
下载PDF
Scope of machine learning applications for addressing the challenges in next-generation wireless networks 被引量:1
13
作者 Raj Kumar Samanta Bikash Sadhukhan +3 位作者 Hiranmay Samaddar Suvobrata Sarkar Chandan Koner Monidepa Ghosh 《CAAI Transactions on Intelligence Technology》 SCIE EI 2022年第3期395-418,共24页
The convenience of availing quality services at affordable costs anytime and anywhere makes mobile technology very popular among users.Due to this popularity,there has been a huge rise in mobile data volume,applicatio... The convenience of availing quality services at affordable costs anytime and anywhere makes mobile technology very popular among users.Due to this popularity,there has been a huge rise in mobile data volume,applications,types of services,and number of customers.Furthermore,due to the COVID-19 pandemic,the worldwide lockdown has added fuel to this increase as most of our professional and commercial activities are being done online from home.This massive increase in demand for multi-class services has posed numerous challenges to wireless network frameworks.The services offered through wireless networks are required to support this huge volume of data and multiple types of traffic,such as real-time live streaming of videos,audios,text,images etc.,at a very high bit rate with a negligible delay in transmission and permissible vehicular speed of the customers.Next-generation wireless networks(NGWNs,i.e.5G networks and beyond)are being developed to accommodate the service qualities mentioned above and many more.However,achieving all the desired service qualities to be incorporated into the design of the 5G network infrastructure imposes large challenges for designers and engineers.It requires the analysis of a huge volume of network data(structured and unstructured)received or collected from heterogeneous devices,applications,services,and customers and the effective and dynamic management of network parameters based on this analysis in real time.In the ever-increasing network heterogeneity and complexity,machine learning(ML)techniques may become an efficient tool for effectively managing these issues.In recent days,the progress of artificial intelligence and ML techniques has grown interest in their application in the networking domain.This study discusses current wireless network research,brief discussions on ML methods that can be effectively applied to the wireless networking domain,some tools available to support and customise efficient mobile system design,and some unresolved issues for future research directions. 展开更多
关键词 machine learning network control next-generation wireless networks
下载PDF
An Energy-Saving Control Strategy on Central Air-Conditioning System 被引量:1
14
作者 Sheng Xing 1 , Yin Juan 2 , Shang Jingfu 3 , Yu Yang 4 , Wu Zhangxian 5 1. State Grid Information & Telecommunication Co., Ltd. 2. China Huadian Finance Corporation Limited 3. State Grid AC Engineering Construction Company 4. Northeast China Electric Power Dispatching & Communication Center 5. North China Electric Power University 《Electricity》 2011年第4期62-66,共5页
An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature con... An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy. 展开更多
关键词 central air-conditioning predictive control energy saving time-delay system simulated annealing
下载PDF
Design of Fuzzy Controller for Central Air Conditioner
15
作者 谢娟 耿庆波 《Journal of Beijing Institute of Technology》 EI CAS 2003年第S1期20-24,共5页
A structure of central air conditioning system in building and its running pattern are proposed in order to perform optimum energy saving strategy. The design of room temperature controller is taken as an example to d... A structure of central air conditioning system in building and its running pattern are proposed in order to perform optimum energy saving strategy. The design of room temperature controller is taken as an example to discuss the design of fuzzy controller using common microprogrammed control unit (MCU) in detail. Based on fuzzy theory the query control tables fixed in read only memory (ROM) of MCU are established to realize the energy saving in the room temperature controller and the reasoning procedure is analyzed. The diagram of hardware design and the flow chart of software of room temperature controller are presented. The results show that the proposed method is practical and effective to achieve the energy saving goal. 展开更多
关键词 central air conditioning system room temperature controller fuzzy control energy saving
下载PDF
Study on the Elman Neural Network Operation Control Strategy of the Central Air Conditioning Chilled Water System
16
作者 Jianwei Li Qingchang Ren +1 位作者 Hai Long Zengxi Feng 《World Journal of Engineering and Technology》 2019年第2期73-82,共10页
The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time de... The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time delay characteristics, presented use feed forward coupling compensation method, to eliminate the coupling effect between temperature and pressure. In this paper, the Elman neural network controller is designed for the first time, and the simulation results show that the response time of Elman neural network controller is shorter, the system is more stable and the overshoot is small. 展开更多
关键词 FEED Forward Coupling Compensation central Air CONDITIONING Water System ALWAYS Temperature DIFFERENCE control Pressure DIFFERENCE control ELMAN Neural Network
下载PDF
Factors That Affect the Centrality Controllability of Scale-Free Networks
17
作者 胡栋 孙先 +2 位作者 李平 陈雁 张捷 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第12期174-177,共4页
The influence of a node in a network can be characterized by its macroscopic properties such as eigenvector centrality. An issue of significant theoretical and practical interest is to modify the influence or roles of... The influence of a node in a network can be characterized by its macroscopic properties such as eigenvector centrality. An issue of significant theoretical and practical interest is to modify the influence or roles of the nodes in a network, and recent advances indicate that this can be achieved by just controlling a subset of nodes: the socalled controllers. However, the relationship between the structural properties of a network and its controllability, e.g., the control of node importance, is still not well understood. Here we systematically" explore this relationship by constructing scale-free networks with a fixed degree sequence and tunable network characteristics. We calculate the relative size (nc*) of the minimai controlling set required to controi the importance of each individual node in a network. It is found that while clustering has no significant impact on nc*, changes in degree-degree correlations, heterogeneity and the average degree of networks demonstrate a discernible impact on its controllability. 展开更多
关键词 NET Factors That Affect the centrality controllability of Scale-Free Networks
下载PDF
Occurrence and Control of Weeds in Abandoned Fields in Central Hunan
18
作者 Yunyun ZHOU Shunli XIAO +4 位作者 Chenzhong JIN Xiu LIU Jun PAN Kuojie XIAO Qiuyuan DUAN 《Agricultural Biotechnology》 CAS 2021年第2期31-33,36,共4页
[Objectives]This study was conducted to clarify the occurrence of weeds,and give relevant comprehensive control suggestions accordingly.[Methods]The species and community characteristics of weeds in abandoned rice fie... [Objectives]This study was conducted to clarify the occurrence of weeds,and give relevant comprehensive control suggestions accordingly.[Methods]The species and community characteristics of weeds in abandoned rice fields in central Hunan were investigated and analyzed.[Results]There were 75 species of weeds in the abandoned farmland in central Hunan,belonging to 66 genera,27 families.Among them,22 species had a relative abundance of more than 5%.According to the different water environments of abandoned fields,there were differences in the types and structures of weeds.They succeeded to wetland vegetation types and dryland vegetation types respectively.Species grown in the original farmland still exist in abandoned fields,but they were mainly invaded by field weeds,such as Digitaria sanguinalis,Eleusine indica,Panicum acroanthum,Bidens pilosa,and Xanthium sibiricum.[Conclusions]This study lays a foundation for fully guaranteeing the actual results of re-cultivation of abandoned land in rural areas. 展开更多
关键词 central Hunan Abandoned fields WEEDS Integrated control
下载PDF
Centralization and perceived control of COVID-19 during the pandemic:A cross-sectional study
19
作者 Çiğdem SamancıTekin Selmaİnfal Kesim 《Journal of Acute Disease》 2022年第6期228-235,共8页
Objective:To uncover the impact of centralization of COVID-19 and perceived control of COVID-19 on society during the pandemic.Methods:We recruited a total of 1041 people in this cross-sectional study.The data were co... Objective:To uncover the impact of centralization of COVID-19 and perceived control of COVID-19 on society during the pandemic.Methods:We recruited a total of 1041 people in this cross-sectional study.The data were collected using a questionnaire booklet covering demographics,a COVID-19-related information form,the Centrality of Event Scale,and the Perception of Control of COVID-19 Scale.We utilized independent samples t-test,chi-square test,and one-way analysis of variance to analyze the data.Results:1041 questionnaires were collected and no questionnaire were excluded from our study.Slightly more than half of the participants(51.2%)stated that social isolation impaired public mental health,while 30.1%reported adverse impacts of the pandemic on their sleep quality.Participants with changes to their sleep patterns were found to centralize COVID-19 more.Moreover,measures against COVID-19 and constant announcements of the daily number of cases in the media brought both positive and negative effects on people and further contributed to the participants’centralization of COVID-19.Individuals with low centralization scores were concluded to perceive COVID-19 as a minor disease.Healthcare professionals without a relative diagnosed with COVID-19 and those satisfied with treatment opportunities had a higher perceived control of COVID-19,while those who were not interested in statistical data on COVID-19 and who had difficulty complying with the rules had a lower perceived control of COVID-19.Besides,poorer perceived control of COVID-19 was found to adversely affect sleep quality.Furthermore,healthcare professionals scored higher on the inevitability subscale of the Perception of Control of COVID-19 Scale.Finally,among the participants,most COVID-19 survivors thought COVID-19 to be an avoidable disease.Conclusion:In addition to its physical impacts,COVID-19 adversely impacts on mental health,and these effects are closely linked to a society’s centralization of COVID-19 and perceived control of COVID-19. 展开更多
关键词 COVID-19 Public health centrality of events Per­ception of control of COVID-19 TURKEY
下载PDF
The Control of Population Growth Is the Function of the Central Government 
20
《China Population Today》 1994年第2期2-3,1,共3页
Mr.Jiang Zcmin,Gencral-Seerctary of the Cen-tral Committee of the Chincse Communist Party and.Chairman of the People's Republic of China,in a rC-ccnt spcech cm phasized that the family planning pro-gramme should b... Mr.Jiang Zcmin,Gencral-Seerctary of the Cen-tral Committee of the Chincse Communist Party and.Chairman of the People's Republic of China,in a rC-ccnt spcech cm phasized that the family planning pro-gramme should be strictly and effectively im plemented in 1994,a year of crucial importance for promoting re-form and opening and thc drive lowards.modernization.To makc continucd contributions to the sociocconomic development in the country,we must fulfil the plan for controlling population growth..The spcech was delivcred at the anua!National Fo-rum on Family Planning Work convened jointly by the Party's Central Committcc and the Statc Council. 展开更多
关键词 The control of Population Growth Is the Function of the central Government
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部