央递服务网络结构演变趋势分析——以长三角为例

针对快递服务网络规划问题中的两类网络物理结构形态的优劣评估问题,在动态环境下分析了网络结构变化的影响因素及其演变趋势,发现网络节点城市之间业务量的大小对于基于集中规模经济效应的轴辐式网络的成本节约优势是否成立有主要影响。这说明纯轴辐式与全连通这两个网络结构并不存在必然的优劣之分,各自的成本节约优势取决于所有城市之间业务量等参数的变化。最后结合国内有关标杆企业的数据,对长三角区域的快递服务网络结构演变趋势进行了实例分析,结果验证了所得出的结论。     

宠物生理实验教学中增强学生实践能力和创新意识探讨

宠物生理实验教学是培养宠物专业学生实践动手能力和创新意识的重要教学环节。针对目前高职毕业生动手能力和创新意识很难满足社会需求的问题,本文就如何增加高职院校宠物专业生理学的实验教学,全面提高学生动手能力和创新意识进行了探讨,为高职院校宠物专业教学的进一步完善提供了一定的指导作用,并使其毕业后更能满足社会的需求。     

The crowding-out effect of elderly support expenditure on household consumption from the perspective of population aging: Evidence from China

The pace of aging in China is accelerating, from the introduction of family planning to the liberalization of the two-child policy, with a growing proportion of families in the 4–2-1 structure. With filial piety in mind, most adult children will live with their elderly parents and share income and expenditure. Concurrently, due to the inadequacy of the social security system, a heavy supplementary burden of supporting the elderly has been placed on adult children. Based on data from the 2011, 2013, 2015, and 2017 Chinese Social Survey (CSS) of the Chinese Academy of Social Sciences (CASS), this study analyzes the objective factors affecting household elderly support expenditure using the ordinary least squares (OLS) estimation method. It also examines the crowding-out effect of elderly support expenditure on the consumption of different types of households through a panel generalized method of moments (GMM) approach. Finally, the crowding-out effect of elderly support expenditure is discussed in a sub-sample according to the number of households needing to support the elderly aged 60 and above. The empirical results illustrate that there is a crowding-out effect of elderly support expenditure on household consumption, and the magnitude of the crowding-out effect varies for diverse consumption. Our study reveals that the crowding-out effect of elderly support expenditure on core consumption is the largest in a sample with different numbers of elderly persons in families. The empirical results for the sub-sample show that the larger the elderly population, the stronger the crowding-out effect of elderly support expenditure on core consumption and the less pronounced the effect on marginal consumption.     

财政支持粮食主产区农业发展现存问题与对策思考

<正>粮食主产区是确保我国粮食安全的核心和支撑,加入WTO 后,我国粮食主产区的农业发展面临巨大压力,由于种粮比较效益低机会成本高,农民种粮增产不增收,粮食生产连年滑坡,严重影响我国粮食安全。要想解决粮食主产区农民增收问题,确保国家粮食安全,必须各项影响因素通力配合、共同作用,其中,积极     

西气东输工程用钢管的质量控制

简要阐述了西气东输工程钢管生产质量控制的重要性、选材及钢管技术条件确定、质量控制方案、质量控制模式，着重介绍了全过程质量控制和全过程驻厂监督的思路和方法。     

INTERTEMPORAL ASSET PRICING WITHOUT CONSUMPTION DATA: EMPIRICAL TESTS

In this paper I conduct tests of an intertemporal asset pricing model using variables that forecast stock returns as the risk factors. I document that the forecasting variables are priced so that expected excess returns are related to their conditional covariances with the forecasting variables. The variability in the covariance risk fails to explain the cross-sectional and time-series variation in expected stock returns. Evidence rejects restrictions on the prices of covariance risk imposed by the model with constant volatilities. I also find that an extended model that allows time-varying conditional volatilities is misspecified.     

石油物资供应部门如何降低物流成本

一、石油企业物资供应部门物流现状分析 　　近年来,随着我国石油企业物资供应管理改革的持续推进,各油田物资供应系统已经建立了较为完备的运行机制,拥有相对稳定的石油物流市场和较强的物流发展实力,但与现代物流管理的要求相比,还处于起步阶段,还有许多不足之处和值得改进的地方。     

The optimal level of corporate social responsibility based on the duopoly model

This paper constructs a duopoly model considering corporate social responsibility (CSR) and market's sensitivity to CSR (e) and analyzes the equilibrium results, the condition of CSR implementation and the optimal CSR level (β^* ) of Model CC (two enterprises implement CSR) and Model CN (only one enterprise implements CSR). The results show that β^* is affected by competitors and e. e, marginal cost (c) and cost difference affect the equilibrium results and the comparative results. Reducing c and improving e can promote social welfare. Consumer surplus under Model CC is highest. CSR has a negative effect on social welfare under certain conditions.     

论中小企业的留才策略

"人才是企业最重要的资本"。流失人才就意味着要付出巨大的补偿费用,意味着资产的损失,许多中小企业已为此付出了巨大代价。通过分析中小企业人才流失的现状,人才流失给中小企业带来的不利影响,以及中小企业人才流失问题的原因,从而提出了解决人才流失问题的相应对策。     

HF／VHF／UHF航空数据传输链路规约综述

描述了国外６种典型的ＨＦ／ＶＨＦ／ＵＨＦ航空数据传输链,并结合我国航空通信的现状提出一些建议。