水平井产能预测相关式研究

针对水平井的稳态产能预测误差较大的问题,通过半解析耦合模型计算对比,发现在不同泄油体形态、水平垂直渗透率各向异性条件下,Joshi公式的误差变化规律：在厚油层、低垂向渗透     

Modelling of Energy Flow, Rotational Grazing and Potential Productivity in an Alpine Meadow Grazing Ecosystem

An eight-compartment model of the energy dynamics of an alpine meadow-sheep grazing ecosystem was proposed based on SHIYOMI's system approach. The compartments were the above-ground plant portion, the underground live portion including roots, the underground dead portion including roots, the above-ground litter Ⅰ (degradable portion), the above-ground litter Ⅱ (undegradable portion), the sheep intake, the sheep liveweight, and the faeces. Energy flows between the eight compartments were described by eight simultaneous differential equations. All parameters in the model were determined from paddock experiments.The model was designed to provide a practical method for estimating the effects of the number of rotational grazing subplots, grazing period, and grazing pressure on the performance of grazing systems for perennial alpine meadow pasture. The model provides at least 28 different attributes for characterizing the performance of the grazing system. Analyses of 270 simulated rotational grazing systems of summer-autumn meadow pasture (grazing from 1st June to 30 October each year) provided an inference base to support two recommendations concerning management variables. First, with a three-paddock, 29-day grazing period and 30.14kJ·m-2·day-1 grazing pressure scheme, the system has the highest total grazing intake, 4250.44 kJ·m-2, during the grazing season. Secondly, with a three-paddock, 7-day grazing period and 28.89kJ·m-2·day-1 grazing pressure scheme, the accumulated graze is 4073.34kJ*m-2.The potential productivity of the alpine meadow under grazing is defined in this paper as the maximal dry biomass of herbage grazed by the grazing animals over the whole growing season. It has been analysed by applying optimal control theory to the model. The productivity is regarded as the objective function to be maximized through optimization of the time course of the grazing pressure, the control variable. The results show that: (1) under constant grazing pressure, the optimal grazing pressure is f16=25.90kJ·m-2·day-1 (f46=f56=0) with the highest accumulated intake of J(1)=3268.17kJ·m-2; and (2) the optimal grazing pressure is f16=25.94kJ·m-2·day-1 (f46≠0, f56≠0) with the maxial accumulated intake J(145)=3500.39kJ·m-2. Under variable grazing pressure, the dynamics of optimal grazing pressure is shown in Fig.6(a) and Eqs. (9)(11), while the potential productivity (the highest accumulated intake) is J(145)=8749.01kJ·m-2, 2.5 times the constant grazing pressure.     

考虑要素替代弹性时技术进步影响劳动生产率变动的测定

从要素替代弹性的角度推导了技术进步影响劳动生产率变动的不同测定模型,并在此基础上进行了模型的应用及比较分析。     

基于非期望产出的机场运营效率评价

传统的机场运营效率评价模型忽视了机场运营过程中航班延误、噪音及有害排放物等非期望产出带来的负面效应. 采用非参数方向距离函数法，构建基于非期望产出的机场运营效率评价模型. 针对我国长江三角洲多机场区域10个主要机场，对引入非期望产出前后运营效率进行对比分析，验证基于非期望产出的机场运营效率评价模型的有效性. 结果显示，非期望产出是评价机场运营效率不可缺少的关键因素之一；其次，非期望产出要素对机场运营效率产生非常显著的影响. 引入非期望产出后，我国机场运营效率和运营规模之间并不存在正相关性；最后为机场及航空公司管理者在权衡机场吞吐量和服务质量方面提供了相关建议和理论依据.     

西藏经济增长中的全要素生产率分析

全要素生产率的增长是反映经济增长效率的重要注解,对全要素生产率增长源泉的分解随着人们对经济增长的认识深化和经济计量分析工具的发展在不断深入。文章从经济增长源泉、全要素生产率分解和计量方法等层面对全要素生产率增长进行了理论分析,并以西藏经济总量和产业结构为例进行了实证研究,认为西藏经济维持长期持续增长的一个重要政策取向应该是进一步加强人力资源的积累。     

放牧对荒漠草原群落多样性的影响

退化草地生态系统中物种多样性的严重丧失及其后果,至今仍缺乏有代表性的实验结论.放牧是人类施加于草原生态系统最主要的干扰因素,从荒漠草原群落多样性、植物功能群多样性以及物种多样性与生产力的关系3个方面综述相关研究进展.提出不同放牧制度对荒漠草原群落多样性、植物功能群多样性的影响过程和作用机制是研究荒漠草原利用与保护平衡的...     

考虑井筒变质量流动的砾石充填水平井产能预测

应用质量守恒和动量守恒原理推导砾石充填水平井井筒内变质量流动压降方程,并采用拟三维思想,将地层内流体在三维空间的流动分为水平面内的向垂直裂缝流和近井区域垂直平面内的径向流,建立油藏渗流模型.提出将井筒变质量流与油藏渗流耦合的数学模型及求解方法.结果表明:利用该模型计算的水平井产能与实测结果平均误差仅为3.79%,沿井筒...     

全要素生产率与福建省三大主导产业产出增长的源泉分解——基于非参数生产前沿分析

在DEA-Malmquist指数的基础上,考虑能源要素,进一步把福建省三大主导产业产出的增长分解为全要素生产率的增长以及要素投入的增长效应.研究发现,考虑能源要素后, 2002-2009年间: 1)福建省三大主导产业产出的平均增长率为21.48%,主要依靠要素投入的增长; 2)全要素生产率的提高平均每年带动产出增长7.48个百分点,其中技术进步贡献2.98个百分点,技术效率改善贡献4.5个百分点,要素投入平均每年对产出增长的贡献为14个百分点; 3)要素投入增长在经济增长中占主导地位的条件下,福建省三大主导产业的发展速度呈现逐年下降的趋势.因此,为了维持福建省三大主导产业的持续高速发展, 必须进一步提高全要素生产率,包括技术进步和技术效率的改善.     

Impact of acidification on phytoplankton and zooplankton communities

Summary Literature concerning the impacts of acidification on the phytoplankton and zooplankton composition has been reviewed. Available data on the species richness and composition of phytoplankton, attached algae and zooplankton of acidifying systems have been summarized. The effects of water acidification on the primary productivity and biomass of zooplankton have been discussed.     

论社会主义本质论中的"解放生产力,发展生产力"

解放生产力，发展生产力是实现社会主义本质的物质保证。把解放生产力，发展生产力作为社会主义本质论的首要内容，是对马克思主义的继承和发展。要坚持解放生产力和发展生产力的统一，始终把发展生产力作为社会主义的根本任务。