浅谈增量型编码器在侧式刮板取料机中的应用

编码器是电感元件,具有精度高、测量准确、抗干扰能力强等特点。侧式刮板取料机中应用了编码器,使得取料量恒定这一工艺要求得到完美实现。     

区域产业群落形成的生态位与聚集势

本文从复杂性系统自组织理论及生态物理学的视角,考察和研究了区域产业群落形成过程中产业生态位、产业集聚核、区域产业场、产业聚集势的作用和重要性,导出了产业聚集势及其势曲线随产业场的变化情况,在一定程度上分析和揭示了区域产业群落的生成机理和发展演化规律.     

一类变质性物品的最优生产-库存策略

讨论了需求是时间的连续函数、允许缺货且缺货完全回补、变质率为常数、补货率有限的变质性物品在有限计划期内的生产-库存策略。同时证明了最优生产-库存策略的存在和唯一性,并给出了求最优策略的算法和算例。     

试论农业科技发展的规律性

本文从逻辑和历史相结合的角度,论述了农业科技发展作为一个过程所具有的三个方面的规律性,即：①生活资料需求、生产资料需求、生态环境需求和社会文化需求等多样化的社会需求是推动农业科技发展的主要动力;②清除或缓解生产要素配置中的“瓶颈”制约,是农业科技发展的突破口;③提高由社会生产力和自然生产力构成的农业生产力的整体水平,是它业科技发展的落脚点。     

渝台农业合作的现状、问题与发展路径

目前,两岸经济合作框架协议（ECFA）已经正式签署,国家高度重视农业问题并对于重庆农业发展提出了具体要求和目标,同时也给予了一系列的优惠政策,渝台农业合作面临前所未有的发展机遇。本文在实地调研的基础上就渝台农业合作的现状、存在的问题进行了总结和分析,分析表明渝台农业合作处于起步阶段,发展势头良好,但在相关政策的制定、实施方面存在不少问题;就这些问题,本文从资源整合、财政和土地政策扶持、政策的针对性和可操作性以及任何解决农民创业园失地农民的就业和收入问题等方面提出了一些政策建议,并对渝台农业合作的模式进行了探讨。     

Study on agricultural structure and non-point source pollution： a case in Dapu Town of Yixing City

The water body of Taihu Lake has been eutrophicated because of area-source pollution. 83% of the total nitrogen and 84% of the total phosphorus of the pollutant that have washed into Taihu Lake originated from the fertilizer of crop land, rural animal husbandry and living sewage and rubbish in rural area. The goal of adjusting agricultural structure is to improve agricultural development, and to increase the peasants＇ income by planting non-grain crop, centralizing animal husbandry, and intensifying aquaculture, etc. It is necessary to research on the influences of agriculture industrial structure on area-source pollution. This paper studies a case of Dapu Town in Yixing City, which is a typical drainage place beside Taihu Lake. On the basis of the analysis on the status quo of area-source pollution and agriculture industrial structure in Dapu Town, the conflicts between them are discussed. Non-grain crop production with a great deal of fertilizer and developing aquaculture with a great deal of organic pollutant, which are directly discharged, make area-source pollution more serious and accelerate the eutrophication in Taihu Lake. This paper suggests taking corresponding technological measures and policies, which have been tested in Dapu Town and demonstrated in Taih, Lake area.     

青岛海滨度假旅游产品深度开发研究

本文结合度假旅游的特点、我国旅游度假区的客源市场情况及世界旅游度假区的发展趋势,针对青岛海滨度假旅游资源特点和开发现状,提出了深度开发青岛地区海滨度假旅游产品的设想。其主要的开发对象为4个国家级、省级旅游度假区及市区的几处海水浴场。     

Micro-foundation for a constant elasticity of substitution production function through mechanization

We consider an increase in the range of capital use as a form of mechanization. A constant elasticity of substitution (CES) production function is dynamically derived from Leontief production functions through the endogenous complementary relationship between capital accumulation and mechanization. This implies that a CES production function can be resolved into technological change that does not involve changes in total factor productivity. Furthermore, using the normalizing procedure of the CES production function developed by de La Grandville [de La Grandville, O., 1989. In quest of the Slutsky diamond. American Economic Review 79, 468–481], we investigate how mechanization is related to the elasticity of substitution in our endogenous growth model.     

Sensitivity analysis of efficiency rankings to distributional assumptions: applications to Japanese water utilities

This article examines the robustness of efficiency score rankings across four distributional assumptions for trans-log stochastic production-frontier models, using data from 1221 Japanese water utilities (for 2004 and 2005). One-sided error terms considered include the half-normal, truncated normal, exponential and gamma distributions. Results are compared for homoscedastic and doubly heteroscedastic models, where we also introduce a doubly heteroscedastic variable mean model, and examine the sensitivity of the nested models to a stronger heteroscedasticity correction for the one-sided error component. The results support three conclusions regarding the sensitivity of efficiency rankings to distributional assumptions. When four standard distributional assumptions are applied to a homoscedastic stochastic frontier model, the efficiency rankings are quite consistent. When those assumptions are applied to a doubly heteroscedastic stochastic frontier model, the efficiency rankings are consistent when proper and sufficient arguments for the variance functions are included in the model. When a more general model, like a variable mean model is estimated, efficiency rankings are quite sensitive to heteroscedasticity correction schemes.