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从交易费用的角度探讨我国农地流转的困境
农地流转作为推动我国农业规模经营的有效方式,一直以来得到政府的大力支持,然而长期以来我国农村土地流转率仍然偏低.分析了农地流转中交易费用的存在对农户土地流转行为的影响.从农地产权安排、搜寻交易对象和价格发现、合约谈判以及合约执行4个方面探讨了农地流转中存在的交易费用,并针对流转中不同方面的交易费用提出降低交易费用的相关举措.陈平南 - 广东农业科学文章来源: 万方数据 -
大型物流配送中心的运营管理策略
论述了大型物流配送中心的基本构成,运营管理主要环节及要素,提出了提高大型物流配送中心运营管理效率和降低物流成本的主要方面和主要方法策略.侯凌燕,尹军琪 - 物流技术文章来源: 万方数据 -
Metapopulation approach for landscape level management of western tarnished plant bug,Lygus hesperus,in Texas (Hemiptera,Miridae)
Insect source-sink dynamics are vital to ecologically intensive pest management. Maintaining sink plant hosts,or "trap crops",and destroying alternate hosts or breeding places adjacent to the field crop are effective pest management strategies for some arthropods. However,determining whether a host acts as a source or a sink is challenging, especially when the pest species is highly mobile and polyphagous. The western tarnished plant bug,Lygus hesperus,is highly polyphagous,and can utilize >300 hosts. Its presence has been documented in 26 roadside weed hosts in the Texas High Plains.Previous studies demonstrated that L. hesperus prefer alfalfa over cotton and several alternate weed hosts.A four-year project involved surveying and sampling for L. hesperus in the agricultural landscapes of several sub-regions of the southwestern United States,including the Texas High Plains. In Texas,geographic information of the landscape vegetation complex was compiled from a 150 km radius in the Texas High Plains. In one study,fifty irrigated cotton fields representing the crop diversity within this region were sampled via sweep-net for 10 weeks. This effort also included sampling of up to six noncotton insect habitats within a 3 km radius of each field. Seasonal average L. hesperus abundance data were regressed with 27 field characteristics( variables),including habitat-specific land cover,distance between focal cotton fields and non-cotton habitats,longitude,latitude,elevation,habitat heterogeneity index,and several environmental / ecological variables. Significant variables were selected using a stepwise regression at 15% probability rate. A 10-parameter linear model explained 93% of the variation in the data. Major parameters contributing significantly to variation in L. hesperus abundance in cotton were corn and sunflower acreages,focal cotton field distances from several non-cotton hosts,and habitat heterogeneity index. In addition,field marking-and-capture studies were conducted using protein markers and enzyme-linked immunosorbent assays to characterize L. hesperus intercrop movement behavior. The field marking-and-capture approach can be used to study the effects of various crop management practices on L. hesperus intercrop movement and can potentially be applied to other pests and cropping systems.Parajulee Megha N.,Shrestha Ram B. - 植物保护学报文章来源: 万方数据 -
物流公司IPO过程盈余管理行为研究
物流行业的飞速发展迫使物流公司有强烈的愿望通过上市进行资本融资,进而产生盈余管理的行为.首先对物流公司IPO过程中盈余管理的手段进行分析,进而又分析了其进行盈余管理的特点、识别方法及测度其盈余管理幅度的模型.石雪梅 - 物流技术文章来源: 万方数据 -
含在线处理的熔盐堆源项计算
熔盐堆是第四代国际核能论坛推荐的6种先进四代堆之一,具有良好的中子经济性、固有安全性、可在线后处理等特点.基于熔盐燃料和冷却剂的流动性,熔盐堆可对堆内产生的放射性气体进行在线移除,周期性地从熔盐泵中除去135Xe和85Kr等中子毒物,以提高燃料循环过程中的中子经济性.目前主要的源项计算软件并不完全适用于熔盐堆在线除气情况下的源项计算,为了解熔盐堆在线处理情况下的源项分布,为熔盐堆辐射防护设计提供参考依据,并验证熔盐堆在线处理情况下源项计算方法的可行性和计算结果的可靠性,采用实际运行过的美国橡树岭国家实验室熔盐实验堆(Molten Salt Reactor Experiment,MSRE)参数,应用自主开发的PostTRITON程序计算了含在线处理情况下的源项,分析了熔盐堆裂变产物产额及氚的产生情况,并应用SCALE5.1软件包中TRITON模块计算了无在线处理情况下的源项,分析了数据偏差的原因,并与橡树岭国家实验室的计算数据进行了比较,计算结果在土8%的范围内符合一致.通过本研究,验证了在线处理下熔盐堆源项计算方法的可行性和结果的可靠性,可为熔盐堆的辐射防护设计提供重要的参考.张志宏,夏晓彬,朱兴望,蔡军 - 核技术文章来源: 万方数据 -
工作家庭冲突及其在护理管理领域的研究现状
文章对工作家庭冲突的定义、常用测量工具和国内外研究现状进行综述,并总结了工作家庭冲突的影响因素,结合我国护理专业特点提出平衡工作家庭关系的措施.赵雪 - 护理管理杂志文章来源: 万方数据 -
浅谈项目管理预算在南水北调工程项目管理中的作用
项目管理预算是项目管理投资控制的重要环节,结合南水北调天津干线工程建设管理工作实践,从编制方法和编制原则方面论述了概算和项目管理预算不同的编制过程,从南水北调投资价差编制和投资控制考评及奖惩等不同的角度反映了项目管理预算的重要性.事实证明,有效的利用项目管理预算与项目工程价款结算对比,能够对投资有效控制,减少投资风险.有利于提高管理水平,加强成本控制,提高经济效益.张雅绵,韩平 - 南水北调与水利科技文章来源: 万方数据 -
强化液体管理对重症肺部感染患者心肺保护作用的临床研究
目的 探讨严格液体管理对重症肺部感染患者心肺保护作用及其可能的机制.方法 将157例重症肺部感染患者随机分为液体管理组和对照组,用脉搏指示连续心输出量监测(PiCCO)的方法检测血流动力学变化指标[心输出量(CO)、心指数(CI)、胸腔内血管容量( ITBVI)、血管外肺水(EVLWI)]并指导液体管理;实验前后测定患者血浆脑型利钠肽(BNP),评估液体管理对患者心功能的影响;测定纤支镜肺灌洗液中白细胞介素(IL)-6的浓度,以评估肺组织局部炎症情况,监测动脉血气分析;实验前后行胸部CT检查评价肺部病变恢复情况.结果 与对照组比较,液体管理组血浆脑型利钠肽、血流动力学指标( CO、CI、EVLWI)和肺组织局部IL-6水平均明显下降(P<0.05),动脉血气氧分压升高(P<0.05),肺泡-动脉氧分压差下降(P<0.05),肺部病变和肺功能明显改善.结论 积极液体管理可保护重症肺部感染患者的心肺功能,其原因可能与降低炎症反应及改善氧合有关.方志成,郑翔,刘伯毅,陈黎,黄云飞,盛春风,刘培 - 临床内科杂志文章来源: 万方数据 -
Cyber physical systems(CPS)recently emerge as a new technology which can provide promising approaches to demand side management(DSM),an important capability in industrial power systems.Meanwhile,the manufacturing center is a typical industrial power subsystem with dozens of high energy consumption devices which have complex physical dynamics.DSM,integrated with CPS,is an effective methodology for solving energy optimization problems in manufacturing center.This paper presents a prediction-based manufacturing center self-adaptive energy optimization method for demand side management in cyber physical systems.To gain prior knowledge of DSM operating results,a sparse Bayesian learning based componential forecasting method is introduced to predict24-hour electric load levels for specific industrial areas in China.From this data,a pricing strategy is designed based on short-term load forecasting results.To minimize total energy costs while guaranteeing manufacturing center service quality,an adaptive demand side energy optimization algorithm is presented.The proposed scheme is tested in a machining center energy optimization experiment.An AMI sensing system is then used to measure the demand side energy consumption of the manufacturing center.Based on the data collected from the sensing system,the load prediction-based energy optimization scheme is implemented.By employing both the PSO and the CPSO method,the problem of DSM in the manufacturing center is solved.The results of the experiment show the self-adaptive CPSO energy optimization method enhances optimization by 5%compared with the traditional PSO optimization method.- 中国机械工程学报文章来源: 万方数据

