长城铁矿最佳生产规模分析论证

本文在对拟扩建的长城铁矿调整生产规模的必要性和可行性进行分析的基础上,根据经济盈利性分析原则,以长城铁矿为例,对矿山扩大生产规模的方法进行了探讨,并用盈利曲线法对长城铁矿最佳生产规模进行了分析论证。     

一种镀锌板生产线电气传动控制系统

介绍了镀锌板生产线的工艺流程及其对电气传动的要求，采用PLC对镀锌板生产线的张力和带速进行协调控制，对电气传动控制系统的活套带重补偿和控制算法作了论述。本系统在实际使用中可靠性高，经济效益好，是一种适用的镀锌板生产线电气传动控制系统。     

基于GASA算法的提前或拖期问题优化

针对企业生产的提前 /拖期问题,提出了提前 /拖期问题的数学模型,在此基础上,利用GASA混合优化策略优化之,既保留了传统遗传算法能很快达到最优值领域的优点,又通过结合模拟退火算法大大改善传统遗传算法在后期的收敛性。     

风险投资与孵化器结合初探

建立孵化器，是促进科技成果转化、培育科技型中小企业的有效途径,是被实践证明了的加速高新技术产业化的重要经验，也是建设国家创新体系的重要组成部分。对孵化器和风险投资结合的初步研究，可以更好地把两相融合，更好地培育科技型中小企业，从而加速高新技术产业化进程。     

从内控视角分析制药企业完善财务管理的措施

新时期,企业的财务管理模式发生了巨大改变,为提升企业的核心竞争力,必须加强财务内部控制,不断完善财务管理,对于制药企业来说同样如此。在现代化经济发展进程中,制药企业要想长远发展,则需要立足于内控视角,结合制药企业财务管理现状,科学调整并优化创新财务管理,在此基础上,应用各种有效措施,逐步完善制药企业财务管理。     

Wood Fuel or Carbon Sink? Aspects of Forestry in the Climate Question

This paper discusses and contrasts two mainroles of forestry in light of the debate on theglobal climate. As the main problem is relatedto the increases of the CO₂-concentrationin the atmosphere, forests may be viewed aspart of the alleviation of the problem throughtheir function as (i) a source of biomass forenergy production, which may replace fossilfuels and thus indirectly reduceCO₂-emissions, and as (ii) carbon storage,since a growing forest extracts atmosphericCO₂ and fixes it as carbon in biomass. Inthe Scandinavian forestry, logging residues areincreasingly being used for energy production.In this paper the value of forests as a sourceof bioenergy is added to the traditional timbervalue. Formulated as a joint production modelwithin the Faustmann framework, the effect ofthis addition on the optimal rotation length isdiscussed. Based on data for spruce, thedominant species in the Scandinavian forestry,it is demonstrated that the rotation length isshortened compared to the standard Faustmannmodel. Shorter rotation length implies lesscarbon storage. Therefore, in this modelwithout explicit regard to the social carbonstorage value of the forest, the gains in termsof the climate problem from utilisation offorest biomass for energy production are beingdiminished by the value of reduced carbonstorage. The carbon value of the forest is thenadded to complete the model, with the effect ofincreasing the rotation length, a result thatis well known in the literature. Finally, theempirical effects of the interaction of thesetwo climate-related value elements of theforest are discussed.     

中国粮食生产区域分化特征和成因的实证研究

对中国在1990年和2002年粮食生产的区域分化状况进行统计分析的结果表明,工业化和城市化的发展,以及农产品市场形成条件下,稻米生产的区域分散特征、小麦生产的区域集中特征以及玉米播种面积的集中和生产产量的分散特征日益明显。计量检验显示,人均承包经营耕地面积和种植业收入比率是影响粮食生产区域分化的最主要的两个因素。     

中国国内生产总值与教育之间关系的实证分析

本文从柯布-道格拉斯生产函数入手,将劳动力按受教育程度划分为四类分别进行处理。主要就中国国内生产总值(GDP)与各等教育程度劳动力和投资之间关系进行单整和协整检验,并建立误差修正模型(ECM),然后在协整条件下对各等教育程度劳动力与GDP的长、短期关系进行分析。文章的实证结果将为我国有关部门的政策决策提供有力依据。     

A Stochastic Frontier Production Function with Flexible Risk Properties

This paper considers a stochastic frontier production function which has additive, heteroscedastic error structure. The model allows for negative or positive marginal production risks of inputs, as originally proposed by Just and Pope (1978). The technical efficiencies of individual firms in the sample are a function of the levels of the input variables in the stochastic frontier, in addition to the technical inefficiency effects. These are two features of the model which are not exhibited by the commonly used stochastic frontiers with multiplicative error structures.An empirical application is presented using cross-sectional data on Ethiopian peasant farmers. The null hypothesis of no technical inefficiencies of production among these farmers is accepted. Further, the flexible risk models do not fit the data on peasant farmers as well as the traditional stochastic frontier model with multiplicative error structure.     

Embedded industrial production systems: Lessons from waste management in zinc production

To meet the sustainability challenge private companies must implement corporate strategies and adopt novel technologies. The technical and social embeddedness of industrial production systems, however, complicates these systems' transition towards sustainability. In the paper, mechanisms and conditions are reported for the development and implementation of waste management options in embedded industrial production systems. The focus is on the Dutch zinc production industry, which had to deal with a major waste problem; the generation of jarosite. The industry's options were to increase the jarosite waste storage capacity, to develop a jarosite treatment process or to switch to a zinc-ore of low-iron content whereby no jarosite waste would be generated anymore. Required conditions appeared to be a combination of technological capability and technical embedding and favourable economics. Case study research, however, revealed that adequate stakeholder management is crucial to address social pressure exerted and to obtain external acceptance for any transition strategy. Whilst appropriate, internal technological capabilities are important, effective interactions with and enrolment of various firm-external actors are crucial. In the case of zinc, access to the heterogeneous external actor network was critical for the development of the jarosite treatment solution direction. In conclusion, both the technical, organizational and social embedding of new technologies are crucial for successful implementation.