碳强度目标:演进、理由与实现

碳强度目标是关于未来要达到的温室气体排放强度的国家承诺。研究碳强度目标对于认识和实现中国气候承诺具有重要意义。严格性、约束力和覆盖范围是碳强度目标的关键要素。碳强度目标具有坚实的理论基础和深刻的现实背景,至少具有与温室气体数量目标同等重要的地位。降低碳强度需要降低温室气体的边际弹性或国民生产总值的边际碳强度,需要将国家碳强度目标分解到行业和企业,还要建立碳排放交易制度。     

浅议修辞格中的会话含义

修辞格的使用和理解往往离不开语境 ,我们应该从语用的角度去理解那些不合理语句中所隐含的合理性 ,找出修辞格中的会话含义     

Line balancing techniques as used for just-in-time ( JIT) product line optimization

This paper looks at the optimization of a production line similar to a just-in-time ( JIT) production flow line. It discusses the planning process, the types of products that can be ff e ectively processed on a JIT line, and the presently available procedures that should be followed when trying to optimize the production line. The article discusses the shortcomings of these techniques, then, based on research investigations, proceeds to recommend a process that will help assure optimization of a JIT process.     

加入WTO我国工程造价管理的改革和发展

加入WTO后我国工程造价从计价方式到管理模式都必须进行根本性的改革。改革的治本之策是按照市场价值规律发挥“竞争”和“价格”的作用 ,要建立政府宏观调控 ,部门动态监管 ,企业自主报价的运行机制。引进国际惯例 ,推行“工程量清单计价” ,以市场形成价格 ,是改革的根本方向     

The supplier selection problem with quantity discounts and truckload shipping

To minimize procurement expenditures both purchasing and transportation costs need to be considered. We study a procurement setting in which a company needs to purchase a number of products from a set of suppliers to satisfy customer demand. The suppliers offer total quantity discounts and transportation costs are based on truckload shipping rates. The goal is to select a set of suppliers so as to satisfy product demand at minimal total costs. The resulting optimization problem is strongly NP-hard. We develop integer programming based heuristics to solve the problem. Extensive computational experiments demonstrate the efficacy of the proposed heuristics and provide insight into the impact of instance characteristics on effective procurement strategies.     

中国失业阶段性转换特点及对策研究

近20多年,中国的失业经历了由隐性失业向显性失业的转化,为此,中国承受了巨大的总量失业的压力。而从发展趋势看,中国总量失业将会逐渐减压,而结构性失业将日益突显,同时外生性失业弱化,内生性失业强化。因此,在政策层面上,必须对中国失业阶段性转换特点给予密切的关注,并不失时机地将总量控制为主的就业政策转向结构控制为主的就业政策。     

基于双层夹缝微量润滑MQL装置的混粉准干式电火花加工研究

针对目前混粉准干式电火花加工中气、液、固三相流稳定雾化困难的缺点,提出新的双层夹缝混粉准干式电火花微量润滑装置的应用,并对其促进稳定雾化机理进行试验研究。结果表明采用双层夹缝混粉准干式电火花微量润滑装置能提高三相流稳定性,改善雾化状态,进而改变放电间隙及放电通道位形,从而提高工件表面质量。     

生产能力储备模式下应急物资储备与采购定价模型

为更好地促进政企双方开展应急物资生产能力储备合作,政府和协议企业需对物资的采购定价及生产能力的储备数量进行合理决策。基于此,文章从供应链的角度出发,利用供应链契约中的数量柔性契约建立了生产能力储备模式下的应急物资储备与采购定价模型,并进一步考虑了协议企业存在储备约束的情况。在利用逆序归纳法求解出合作下企业的生产能力储备量及相应的政府采购定价决策后,文章进一步分析了储备周期内灾害事件的发生概率与企业最大储备量约束对双方决策及各自成本收益的影响,为政府的采购定价及企业的储备策略提供了科学依据。此外,文章还给出了约束双方决策时的参数条件,因而也为政府在目标企业的选择方面提供了参考。     

西藏的汉族人口及相关问题研究

中国西藏的汉族人口及其变化既是一个学术问题,又是一个比较敏感的政治问题,多数的关注者通过中国政府颁布的人口普查结果寻求答案,但少数海外学者、尤其是流亡藏人对其结果存有异议,其中对拉萨市汉族人口的数量分歧最大。本报告将通过在拉萨市进行的一个独立的抽样调查,力图真实地揭示拉萨市乃至西藏自治区汉族人口的数量状况。     

The natural index and the divisia index on the straight line as well as the divisia index on the exponential line

In earlier papers the Divisia index on the straight line was called natural index. Representing the index problem in the 2n-dimensional quantity-price-space, it is now proposed to call natural index the limit of stepwise products of Laspeyres' , Paasche's or Edgeworth-Marshall s indices, if the steps approximate the straight line between the base point and the observed point. The numerical results of successive finer approximations of the natural index are illustrated by some examples. As expected these approximations converge to the value of the Divisia index on the straight line. The same approximation procedure is applied to the Divisia index on the exponential line.