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The Interventional Capacity of Community Health Volunteers for Screening and Linkages of Non-Communicable Diseases in Nyeri County, Kenya
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作者 Kenneth Mugambi Jackline Nyaberi Elizabeth Echoka 《Open Journal of Preventive Medicine》 2024年第4期61-78,共18页
Non-communicable diseases (NCDs) account for 63% of mortalities. Approximately 80% of these NCD-related deaths occur in LMICs. A quasi-experimental study utilizing a non-equivalent pre-and post-test was conducted from... Non-communicable diseases (NCDs) account for 63% of mortalities. Approximately 80% of these NCD-related deaths occur in LMICs. A quasi-experimental study utilizing a non-equivalent pre-and post-test was conducted from May 2022 to March 2023 with 370 study participants. Multistage cluster and random sampling were used to select ten community units, and therefore, 150 CHVs were chosen for the control unit, and 150 were used to form the interventional group. Data was collected from the KOBO app. Six (6) homogenous FGDs comprised ten members, and 10 KII were conducted across study sites. Quantitative data was analyzed using SPSS version 28.0, and qualitative data was audio-recorded, transcribed, and analyzed via N-Vivo 12. The study shows that 59.3% of respondents have minimal information, and 92.7% (n = 139) have no clear understanding of NCDs, with a pre-intervention capacity of 48.8%. Independent sample t-test showed a significant difference in capacity from a pre-intervention average of 48.75 (SD ± 5.7)%, which increased to 68.28 (SD ± 7.6)%, p < 0.001. A well-designed community interventional model plays a pivotal role in grassroots healthcare delivery but requires optimization for NCD management. 展开更多
关键词 inTERVENTION community Health Volunteers Non-Communicable Disease SCREENinG linkages
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Element cycling in the dominant plant community in the Alpine tundra zone of Changbai Mountains, China 被引量:5
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作者 LIUJing-shuang YUJun-bao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第3期521-525,共5页
Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate th... Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains. 展开更多
关键词 element cycling ECOSYSTEM dominant plant community alpine tundra zone Changbai Mountains
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A Study of Dynamic Analysis Method for the Rigid-Flexible Coupled Bar Linkage System 被引量:1
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作者 陆念力 张广芸 《Journal of Donghua University(English Edition)》 EI CAS 2011年第6期616-620,共5页
In order to present a dynamic analysis method for the rigid-flexible coupled bar linkage system(RFCBLS),the flexible element motion equation was gotten by Lagrange Equation and the rigid element motion equation was go... In order to present a dynamic analysis method for the rigid-flexible coupled bar linkage system(RFCBLS),the flexible element motion equation was gotten by Lagrange Equation and the rigid element motion equation was gotten based on rigid constraint conditions.The multi-body system(MBS) is a complex mechanism and its components have quite different rigidities.If it is considered as a rigid MBS(RMBS) to do its dynamic analysis,elastic deformation's ignorance will lead to inaccurate analysis.If it is considered as a flexible MBS(FMBS) to establish,analyze,and solve the model,quite large system equations make it difficult to solve.The better method is as follows:the complex mechanism system is regarded as a rigid-flexible coupled system(RFCS) to make dynamic characteristic of rigid components be equivalent,system equation is established by FMBS' way,and system equation dimensions are reduced by transition matrices' introduction.A dynamic analysis method for rigid element and flexible element coupling was presented based on the FMBS.The analyzed crank slide-block mechanism results show that the dynamic analysis method for RFCBLS is quick and convenient. 展开更多
关键词 rigid-flexible coupled linkage system flexible element rigid element transition matrices dynamic analysis
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THE EXTENDING OF JOUKOWSKY'S LEVER METHOD AND ITS APPLICATIONS IN LINKAGE PROBLEMS
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作者 陈人哲 章文俊 《Journal of Donghua University(English Edition)》 EI CAS 1989年第Z1期37-45,共9页
Joukowsky’s Lever Method is the method used to find out the equilibrant and balancingmoment of various mechanisms.The advantage of this method is to save the complicated processof finding out the reactional forces in... Joukowsky’s Lever Method is the method used to find out the equilibrant and balancingmoment of various mechanisms.The advantage of this method is to save the complicated processof finding out the reactional forces in kinematic pairs.But,the method is only limited to thosemechanisms composed of rigid bar linkages and with negligible friction.In practical cases,hydropneumatic elements and spring constraints may be included in the mechanism;and alsowith the development of high load,high speed and high accuracy of mechanism,the friction maynot be neglected.So,the authors have tried to develop the Generalized Joukowsky’s LeverMethod,which can be used to find out the equilibrant and balancing moment of the mechanismwhen the hydropneumatic elements and spring constraints are included and the friction inkinematic pairs has to be considered.Three examples are here analyzed to show the applicationsof this method. 展开更多
关键词 linkage equilibrant frictional FORCE SPRinG ELEMENT hydropneumation ELEMENT balancing MOMENT linkage mechanism
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CHINA’S URBAN RESIDENTIAL COMMUNITY IN THE COURSE OF TRANSFER OF SOCIAL PATTERN
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作者 Zhang Jingxiang(The Department of Geo-Ocean Science, Nanjing University, Nanjing 210093, PRC) 《Chinese Geographical Science》 SCIE CSCD 1996年第4期332-341,共10页
CHINA’S URBAN RESIDENTIAL COMMUNITY IN THE COURSE OF TRANSFER OF SOCIAL PATTERNCHINA’SURBANRESIDENTIALCOMMUN... CHINA’S URBAN RESIDENTIAL COMMUNITY IN THE COURSE OF TRANSFER OF SOCIAL PATTERNCHINA’SURBANRESIDENTIALCOMMUNITYINTHECOURSEOFT... 展开更多
关键词 URBAN RESIDENTIAL community functional elements
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Back propagation artificial neural network for community Alzheimer's disease screening in China 被引量:6
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作者 Jun Tang Lei Wu +6 位作者 Helang Huang Jiang Feng Yefeng Yuan Yueping Zhou Peng Huang Yan Xu Chao Yu 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第3期270-276,共7页
AIzheimer's disease patients diagnosed with the Chinese Classification of Mental Disorders diagnostic criteria were selected from the community through on-site sampling. Levels of macro and trace elements were measur... AIzheimer's disease patients diagnosed with the Chinese Classification of Mental Disorders diagnostic criteria were selected from the community through on-site sampling. Levels of macro and trace elements were measured in blood samples using an atomic absorption method, and neurotransmitters were measured using a radioimmunoassay method. SPSS 13.0 was used to establish a database, and a back propagation artificial neural network for Alzheimer's disease prediction was simulated using Clementine 12.0 software. With scores of activities of daily living, creatinine, 5-hydroxytryptamine, age, dopamine and aluminum as input variables, the results revealed that the area under the curve in our back propagation artificial neural network was 0.929 (95% confidence interval: 0.868-0.968), sensitivity was 90.00%, specificity was 95.00%, and accuracy was 92.50%. The findings indicated that the results of back propagation artificial neural network established based on the above six variables were satisfactory for screening and diagnosis of Alzheimer's disease in patients selected from the community. 展开更多
关键词 neural regeneration clinical practice artificial neural network Alzheimer's disease MAtheMATICALMODEL community trace elements NEUROTRANSMITTERS grant-supported paper NEUROREGENERATION
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Simulation and Analysis of Spatial Weft Insertion Mechanism Considering Flexibility and Clearance 被引量:1
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作者 张雷 贺虎 雷炳杰 《Journal of Donghua University(English Edition)》 EI CAS 2017年第2期221-228,共8页
A 3D model of the spatial four-bar weft insertion mechanism was built with unigraphics NX(UG) according to the actual requirement,and dynamics simulation was carried out by importing the model into ADAMS.Without consi... A 3D model of the spatial four-bar weft insertion mechanism was built with unigraphics NX(UG) according to the actual requirement,and dynamics simulation was carried out by importing the model into ADAMS.Without considering the clearance,the motion characteristic curve of the sword belt was generated through ADAMS combined with MATLAB.In this paper the hinge between the rod and the sector gear was selected as an example with different values of clearance,outputting the motion characteristic curve of the sword belt.Finite element analysis(FEA)was conducted,the flexible body was generated by importing the forked frame into ANSYS,and flexible dynamics simulation was carried out by importing the flexible body into ADAMS to replace the rigid rod.A comprehensive comparison of the output characteristics of the sword belt was conducted in the consideration of the clearance or flexible.Analysis of the force on the left hinge of the rod was carried out with the ADAMS post processing module.With the same clearance,considering the flexibility,amplitude of fluctuation of the force on the hinge increased obviously. 展开更多
关键词 spatial four-bar linkage weft insertion mechanism CLEARANCE FLEXIBILITY finite element analysis(FEA) ANSYS ADAMS
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Characterization of organic-rich mineral debris revealed by rapid glacier retreat, Indren Glacier, European Alps 被引量:1
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作者 FREPPAZ Michele WILLIAMS Mark W. +5 位作者 GABRIELI Jacopo GORRA Roberta MANIA Ilaria ASCHER-JENULL Judith EGLI Markus CELI Luisella 《Journal of Mountain Science》 SCIE CSCD 2021年第6期1521-1536,共16页
In the summer of 2003 and 2004, characterized by a rapid glacier retreat, a stony surface covered by well-structured organic-rich mineral debris was observed very close to the Indren glacier terminus(Monte Rosa Massif... In the summer of 2003 and 2004, characterized by a rapid glacier retreat, a stony surface covered by well-structured organic-rich mineral debris was observed very close to the Indren glacier terminus(Monte Rosa Massif, NW Italy, 3100 m ASL), on an area covered by the glacier tongue till the year before. The origin and type of this organicrich material were investigated, in order to detect their characteristics, potential sources and fate within the foreland system. The deposits were dated using Carbon-14 and analyzed for the chemical characteristics of the organic component, the elemental composition of the mineral fraction and presence of microbial markers. The material, granular and dark in color, had a total organic carbon(TOC) content ranging between 17.4 ± 0.39 and 28.1 ± 0.63 g kg^(-1) dry weight(dw), significantly higher than the surrounding glacial till(~ 1.4 g kg^(-1) dw), although only 0.33% of it was in water soluble form. Microbial carbon(C) and nitrogen(N) accounted for 10.6% and 3.13% of TOC and total N, respectively. Dissolved nitrogen(N), mainly present as ammonium, represented 2.40% of the total N. The low aromatic component and large presence of nitrogen(N)-derived compounds suggested that most of the organic carbon(OC) in these organic-rich mineral deposits was derived from microbial cells, although the high average radiocarbon age of about 2900 years may also point to the contribution of aeolian depositions of anthropogenic or natural origin. Elemental composition and the crustal enrichment factor of trace elements in the mineral fraction of the aggregates corroborated the hypothesis that most part of the accumulated material derived from ice meltwater. Some indicators of the colonization of these deposits by microbial communities were also reported, from the abundance of DNA and phylogenetic markers, to the presence of bacterial taxa commonly able to thrive in similar habitats. All these elements suggested that such kind of deposits may have a potential role as energy and nutrient sources in recently deglaciated areas, highlighting the necessity to better understand the processes underlying their formation and their evolution. 展开更多
关键词 Glacier foreland Dissolved organic carbon Organic matter q PCR Microbial community Trace elements
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Seasonal variations of microbial community and antibiotic resistome in a suburb drinking water distribution system in a northern Chinese city 被引量:1
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作者 Yanchu Ke Wenjun Sun +2 位作者 Zibo Jing Zhinan Zhao Shuguang Xie 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第5期714-725,共12页
Antibiotic resistance genes(ARGs)are an emerging issue for drinkingwater safety.However,the seasonal variation of ARGs in drinking water distribution systems(DWDS)is still unclear.This work revealed the tempo-spatial ... Antibiotic resistance genes(ARGs)are an emerging issue for drinkingwater safety.However,the seasonal variation of ARGs in drinking water distribution systems(DWDS)is still unclear.This work revealed the tempo-spatial changes of microbial community,ARGs,mobile genetic elements(MGEs)co-occurring with ARGs,ARG hosts in DWDS bulk water by means of metagenome assembly.The microbial community and antibiotic resistome varied with sampling season and site.Temperature,ammonia,chlorite and total plate count(TPC)drove the variations of microbial community structure.Moreover,environmental parameters(total organic carbon(TOC),chlorite,TPC and hardness)shifted antibiotic resistome.ARGs and MGEs co-occurring with ARGs showed higher relative abundance in summer and autumn,which might be attributed to detached pipe biofilm.In particular,ARG-bacitracin and plasmid were the predominant ARG and MGE,respectively.ARG hosts changed with season and site and were more diverse in summer and autumn.In winter and spring,Limnohabitans and Mycobacterium were the major ARG hosts as well as the dominant genera in microbial community.In addition,in summer and autumn,high relative abundance of Achromobacter and Stenotrophomonas were the hosts harboring many kinds of ARGs and MGEs at site in a residential zone(0.4 km from the water treatment plant).Compared with MGEs,microbial community had a greater contribution to the variation of antibiotic resistome.This work gives new insights into the dynamics of ARGs in full-scale DWDS and the underlying factors. 展开更多
关键词 Drinking water distribution system Seasonal change Microbial community Antibiotic resistance genes Mobile genetic elements
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Dynamic analytic model of mechanism with links fabricated from symmetric laminates
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作者 蔡敢为 常平平 +2 位作者 马存志 王汝贵 李兆军 《Journal of Central South University of Technology》 EI 2006年第6期624-630,共7页
A four-bar linkage mechanism with links fabricated from symmetric laminates was studied. The mass matrix of the beam element was obtained in light of the mass distribution characteristics of composite materials. The s... A four-bar linkage mechanism with links fabricated from symmetric laminates was studied. The mass matrix of the beam element was obtained in light of the mass distribution characteristics of composite materials. The stiffness matrix of the beam element was derived from the constitutive equations of each layer and the relationship between the strain distribution and the node displacement of the beam element. The specific damping capacity of the beam element was analyzed according to the strain distribution of the beam element and the strain energy dissipation caused by vibration in each direction of each layer; and the damping coefficients were obtained according to the principle that the total energy dissipation of the beam element was equal to the work done by the equivalent damping force during a cycle of vibration, from which the damping matrix of the dynamic equations was obtained. Using the finite element method, the dynamic analytic model of the mechanism was obtained. The dynamic responses and natural frequency of the mechanism were obtained by simulation, respectively, and those of the simulation obtained by the proposed model were analyzed and compared with the results obtained by the conventional model. The work provides theoretical basis to a certain extent for the further research on nonlinear vibration characteristics and optimum design of this kind of mechanism. 展开更多
关键词 四杆联接机构 有限元 阻尼性质 复合材料 对称层板 动力学分析模型
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数据要素市场体系建构与价值实现路径探索 被引量:1
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作者 孙建军 巴志超 夏义堃 《情报学报》 CSCD 北大核心 2024年第1期1-9,共9页
数据要素市场体系的顶层设计是加快推进数字要素市场化配置、推动我国数字经济高质量发展的前提基础与关键部署。通过剖析当前全国数据要素统一大市场建设面临的瓶颈与挑战,本文分析数据要素市场建设的特殊性,提出全国统一数据要素市场... 数据要素市场体系的顶层设计是加快推进数字要素市场化配置、推动我国数字经济高质量发展的前提基础与关键部署。通过剖析当前全国数据要素统一大市场建设面临的瓶颈与挑战,本文分析数据要素市场建设的特殊性,提出全国统一数据要素市场体系“一体两翼”“三基”“七要点”的总体架构思路,以及战略布局、结构布局和空间布局相统一的总体布局方案,并从市场体系建设新特征、内在结构与运行模式解析、数据要素市场与传统要素市场一体化联动机理揭示与场景应用示范等方面探索促进数据要素市场价值升级与高质量发展的实现路径,从而为推动数据资源化、资产化和资本化的可持续运营提供参考借鉴。 展开更多
关键词 数据要素 市场体系架构 价值实现路径 运行模式 联动机制
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基于知识元的科学-技术知识关联指标与测度方法研究
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作者 唐晓波 陈俭静 +1 位作者 周禾深 杜鑫 《数字图书馆论坛》 2024年第2期58-69,共12页
通过科学-技术知识关联指标与测度方法研究,能够细粒度分析科学与技术的互动关系,为科技评价奠定基础。提出一种基于知识元的科学-技术知识关联指标与测度方法。以论文和专利为数据来源,在知识元抽取基础上,基于科技术语在不同类型知识... 通过科学-技术知识关联指标与测度方法研究,能够细粒度分析科学与技术的互动关系,为科技评价奠定基础。提出一种基于知识元的科学-技术知识关联指标与测度方法。以论文和专利为数据来源,在知识元抽取基础上,基于科技术语在不同类型知识元中的共现情况实现科学-技术知识关联指标测度。以糖尿病领域为例开展实证研究,结果验证提出的科学-技术知识关联指标与测度方法能够在高质量论文识别中有效发挥作用,所提指标和方法对于完善科技评价体系、促进创新驱动发展战略实施有参考意义。 展开更多
关键词 知识元 知识关联 科学-技术关联 指标 测度方法
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基层治理“五社联动”机制:实践运作、治理限度与优化路径 被引量:1
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作者 邱国良 李静 王松阳 《社会工作与管理》 2024年第1期70-78,共9页
打造“社区为平台、社会组织为载体、社会工作者为支撑、社区志愿者为辅助、社会慈善资源为补充”的基层治理“五社联动”机制,有利于推动实现社区共建共治共享目标。在基层治理实践中,形成了以党建为引领的社区组织框架、社区内生力量... 打造“社区为平台、社会组织为载体、社会工作者为支撑、社区志愿者为辅助、社会慈善资源为补充”的基层治理“五社联动”机制,有利于推动实现社区共建共治共享目标。在基层治理实践中,形成了以党建为引领的社区组织框架、社区内生力量的激发动员以及社会慈善资源的外部供给等经验做法,但受全能治理的路径依赖等因素影响,“五社联动”机制的有效性未能充分发挥。为此,亟须从政府层级体制、社会志愿参与、社区协商平台以及居民主体意识等多方面入手,推动完善基层治理“五社联动”机制。 展开更多
关键词 基层治理 五社联动 治理限度 优化路径 多元协同
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Impact of different organic matters on the occurrence of antibiotic resistance genes in activated sludge
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作者 Xiuwen Zhang Suwan Liu +2 位作者 Haohao Sun Kailong Huang Lin Ye 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第5期273-283,共11页
The occurrence of antibiotic resistance genes(ARGs)in various environments has drawn worldwide attention due to their potential risks.Previous studies have reported that a variety of substances can enhance the occurre... The occurrence of antibiotic resistance genes(ARGs)in various environments has drawn worldwide attention due to their potential risks.Previous studies have reported that a variety of substances can enhance the occurrence and dissemination of ARGs.However,few studies have compared the response of ARGs under the stress of different organicmatters in biologicalwastewater treatment systems.In this study,seven organic pollutantswere added into wastewater treatment bioreactors to investigate their impacts on the ARG occurrence in activated sludge.Based on high-throughput sequencing,it was found that the microbial communities and ARG patterns were significantly changed in the activated sludge exposed to these organic pollutants.Compared with the non-antibiotic refractory organic matters,antibiotics not only increased the abundance of ARGs but also significantly changed the ARG compositions.The increase of Gram-negative bacteria(e.g.,Archangium,Prosthecobacter and Dokdonella)carrying ARGs could be the main cause of ARG proliferation.In addition,significant co-occurrence relationships between ARGs and mobile genetic elements were also observed in the sludge samples,which may also affect the ARG diversity and abundance during the organic matter treatment in the bioreactors.Overall,these findings provide new information for better understanding the ARG occurrence and dissemination caused by organic pollutants in wastewater treatment systems. 展开更多
关键词 Organic pollutants Antibiotic resistance genes Metagenomic sequencing Mobile genetic elements Microbial community
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Inhibition mechanisms of ammonia and sulfate in high-solids anaerobic digesters for food waste treatment: Microbial community and element distributions responses
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作者 Likui Feng Weixin Zhao +5 位作者 Yu Liu Yan Chen Shufei He Jing Ding Qingliang Zhao Liangliang Wei 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第2期342-348,共7页
The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digesti... The horizontal flow anaerobic digester indicated that high ammonia (2923 mg/L) and SO42-(3653 mg/L)would influence the performance of methane production with food waste as substrates.Therefore,bottle anaerobic digestion reactors were carried out to investigate the effect of ammonia/sulfate concentrations on the methane production.Experimental results manifested that the anaerobic digesters with an ammonia concentration of 3500 mg/L or sulfate of 1600 mg/L showed the best performance of methane production,with an average methane yield of 0.32 and 0.33 L (g VS)^(-1)d^(-1),respectively.Specifically,a higher ammonia (6500 mg/L) or sulfate (1600-3500 mg/L) level hindered the bioconversion of C from liquid to gas phase (2.68%or 1.73%CH_(4)-Gas,respectively),while insignificantly for the hydrolyzation of C and N from solid to liquid phase.Similar to sulfate,high ammonia nitrogen seriously inhibited the methanation process,leading to a significant carbon accumulation in the anaerobic reactor,especially for propionic acid.The predominant archaea Methanosarcina at genus level indicated that aceticlastic methanogenesis was the major methanogenic pathway.Meanwhile,high ammonia level suppressed the activity of Methanosarcina,while modest sulfate improved H_(2)-consuming methanogens activity.A large fraction of unclassified bacteria within the Firmicutes (43.78%-63.17%) and Bacteroidetes (24.20%-33.30%) phylum played an important role in substrates hydrolysis. 展开更多
关键词 Anaerobic digestion Ammonia/sulfate inhibition Element transformation Food waste Microbial community
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基于Ansoft的直驱DSPM发电机设计与仿真 被引量:3
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作者 刘华 王维俊 +1 位作者 王彭伟 张国平 《微电机》 北大核心 2013年第2期13-15,19,共4页
设计了一台适用于低速运行的直驱式双凸极永磁发电机,利用有限元电磁场分析软件Ansoft建立了电机的二维模型。对电机在空载和负载条件下的磁链特性、转矩特性和绕组感应电势进行了仿真,重点阐述了绕组电枢反应对永磁磁链的影响,分析了... 设计了一台适用于低速运行的直驱式双凸极永磁发电机,利用有限元电磁场分析软件Ansoft建立了电机的二维模型。对电机在空载和负载条件下的磁链特性、转矩特性和绕组感应电势进行了仿真,重点阐述了绕组电枢反应对永磁磁链的影响,分析了感应电势正负幅值不同的原因,并利用仿真结果验证了理论分析的正确性和有效性,对研究减小转矩脉动有一定的参考价值。 展开更多
关键词 DSPM ANSofT 有限元分析 磁链
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Application of phosphate-containing materials affects bioavailability of rare earth elements and bacterial community in soils 被引量:3
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作者 JIN ShuLan HU ZhongJun +3 位作者 MAN BaiYing PAN HuaHua KONG Xiao JIN DeCai 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2019年第9期1616-1627,共12页
The exploitation and smelting of rare earths can cause serious pollution to the farmland around the mining area. The rare earth elements(REEs) are absorbed by crops and enter the human body through the food chain, whi... The exploitation and smelting of rare earths can cause serious pollution to the farmland around the mining area. The rare earth elements(REEs) are absorbed by crops and enter the human body through the food chain, which threatens people’s health. The effects of four phosphorus-containing materials-calcium superphosphate(SSP), phosphate rock(PR), calcium magnesium phosphate(CMP) and bone charcoal(BC) on rice growth and bacterial community structure in REE mining area of Xinfeng County were studied by pot experiment. The soil solution was collected during rice transplanting and harvest periods respectively, the rice and soil samples were collected and sequenced. The concentrations of water-soluble REEs were measured by inductively coupled plasma mass spectrometry(ICP-MS), and bacteria in soil was deeply sequenced by the Illumina Miseq sequencing platform. PR, CMP and BC promoted the growth of rice, improved the biomass of rice roots, shoots and grains, and significantly reduced absorption and accumulation of REEs in rice roots, shoots and grains. SSP treatment reduced the pH value of soil, significantly improved the concentration of REE solution in soil and improved biomass of rice roots, shoots and grains,and significantly improved the concentration of REEs in grain. The effects of phosphorus-containing materials on the absorption and accumulation of 15 REEs in rice roots, shoots and grains were very different, and significantly influenced the soil bacterial community. SSP reduced richness and diversity of bacteria. CMP improved the diversity of soil bacteria, but reduced their richness. PR and BC treatment improved the richness and diversity of soil bacteria, and significantly increased the abundance of Bacillus. The results showed that adding PR, CMP and BC to soil in the REE mining area of Xinfeng can improve food security and eco-environmental quality, and hence, are potential restorative materials;SSP is not recommended for use in acidic soils. 展开更多
关键词 CALCIUM SUPERPHOSPHATE PHOSPHATE rock CALCIUM magnesium phosphorus bone charcoal rare earth elements rice bacterial community
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Simultaneous Biological Removal of p-Cresol, Sulfide and Nitrate by Denitrification 被引量:2
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作者 Liu Chunshuang Li Wenfei +4 位作者 Zhao Dongfeng Li Wei Li Xuechen Zhao Chaocheng Liu Fang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2017年第4期89-94,共6页
Biological removal of sulfide, nitrate, and p-cresol at a loading rate of 340 gS/(m^3 · d), 340 gN/(m^3 · d) and600 gC/(m^3 · d), respectively, was achieved in an upflow anaerobic sludge blanket(UASB) r... Biological removal of sulfide, nitrate, and p-cresol at a loading rate of 340 gS/(m^3 · d), 340 gN/(m^3 · d) and600 gC/(m^3 · d), respectively, was achieved in an upflow anaerobic sludge blanket(UASB) reactor. The ratio of C/S could affect the elemental sulfur(S^0) accumulation, and the C/S ratio of 1.75:1 was optimal for S^0 accumulation. Strains Pseudomonas sp., Simplicispira sp., and Rhizobium sp. could likely yield heterotrophs. Strains Arcobacter sp.,Sulfurimonas sp., Sulfurovum sp., and Sulfurospirillum sp. are the autotrophics required for the proposed UASB system. At high loading rate, the autotrophic denitrification pathway declined faster than the heterotrophic pathway. 展开更多
关键词 SULFIDE P-CRESOL MICROBIAL community ELEMENTAL sulfur
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Unravelling the linkages of cryosphere and mountain livelihood systems:A case study of Langtang,Nepal 被引量:1
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作者 Sabamee TULADHAR Binaya PASAKHALA +1 位作者 Amina MAHARJAN Arabinda MISHRA 《Advances in Climate Change Research》 SCIE CSCD 2021年第1期119-131,共13页
Globally,mountains are often characterized as fragile and hazardous terrains,with vast areas covered by the cryosphere.The livelihoods of communities in the Hindu Kush Himalayan region are closely linked with the cryo... Globally,mountains are often characterized as fragile and hazardous terrains,with vast areas covered by the cryosphere.The livelihoods of communities in the Hindu Kush Himalayan region are closely linked with the cryosphere.But over the past few decades,communities in the region have experienced multiple changes,including those driven by climat e change,with direct and immediate impacts on their lives and livelihoods.In this study,we explore linkages between the cryosphere and high-mountain livelihoods using a social-ecological system approach.It examines how the complex social-ecological system in villages in Langtang Valley,Nepal,has evolved in response to both cryospheric and socioeconomic changes.The local communities perceive gradual but significant changes in the cryospheric system,such as receding and thinning glaciers,changing snowfall patterns,changes in temperature and precipitation patterns,and a growing incidence of cryosphere-related hazards,such as avalanches and landslides.Communities in the Langtang Valley are also facing a number of socioeconomic changes,resulting in changing aspirations,particularly among the youth.The growing disconnection between society and the surrounding cryosphere,with direct impacts on the transfer and growth of local knowledge systems,are discussed.These simultaneous changes in the cryosphere and the socioeconomic domain have also resulted in a homogenization of livelihood sources,with tourism emerging as the dominant source of livelihood.This has resulted in a dependence of the local population on food imported from outside the valley.A growing dependence on tourism for livelihoods,dependence on imports for food and other basic needs,and the lack of a risk reduction strategy might pose great risks for local lives and livelihoods in the long run.Interventions pertaining to diversifying livelihoods,harmonizing social capital,and hazard risk assessment are essential for strengthening linkages between cryosphere and the socioeconomic system. 展开更多
关键词 Cryosphere-livelihood linkages Social-ecological systems Climate change High-mountain communities Hindu Kush Himalaya Langtang Valley
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棉纺精梳机分离罗拉连杆驱动机构动力学仿真及有限元分析
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作者 冯清国 巫鳌飞 +1 位作者 任家智 陈宇恒 《纺织学报》 EI CAS CSCD 北大核心 2023年第9期197-204,共8页
为提高棉纺精梳机的使用寿命及生产运行可靠性,避免精梳机在长期高速运转条件下各零件的疲劳、磨损、断裂等造成的生产事故问题。利用Solid works软件建立分离罗拉驱动机构三维模型并导入Adams软件分别进行运动学与动力学仿真,得出了不... 为提高棉纺精梳机的使用寿命及生产运行可靠性,避免精梳机在长期高速运转条件下各零件的疲劳、磨损、断裂等造成的生产事故问题。利用Solid works软件建立分离罗拉驱动机构三维模型并导入Adams软件分别进行运动学与动力学仿真,得出了不同速度条件下分离罗拉驱动机构各零件铰接点在一个运动周期内的受力分布曲线;利用Ansys Workbench软件对各零件赋予材料属性并进行有限元仿真,得到各零件在一个运动周期内不同速度下的最大应力。结果表明:当精梳机速度为500钳次/min及以下时,一个运动周期内的分离罗拉驱动机构各零件的最大应力均小于材料的许用应力(400 MPa),材料强度满足生产条件;当精梳机速度依次提高到600和700钳次/min后,定时调节盘的最大应力(415.98 MPa)较500钳次/min时分别增大40.55%和79.1%,超过材料的许用应力(400 MPa),该零件有疲劳、磨损、断裂的风险,易故障停车并造成生产事故。在JSFA588型精梳机上按照零件设计要求进行了制造、装配及生产试验,进一步验证了仿真结果的有效性。 展开更多
关键词 棉纺 精梳机 分离罗拉连杆驱动机构 铰接点受力 零件强度 动力学仿真 有限元分析
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