面向消费者低碳偏好的供应链减排成本分摊与协调北大核心CSSCI

消费者低碳偏好和碳交易制度下,探讨供应商主导投资减排的低碳供应链协调问题。研究发现,单一成本分摊契约能改善单一批发价契约的"搭便车"现象,却无法解决"双重边际化"问题实现低碳供应链减排量和利润最优。为此,提出零售商分摊减排成本的数量折扣契约进行协调,给出了最优数量折扣策略组合。最后,通过数值仿真分析了碳交易价格和市场需求关于减排量的敏感系数对低碳供应链协调的影响。     

面向消费者低碳偏好的供应链减排成本分摊与协调

消费者低碳偏好和碳交易制度下,探讨供应商主导投资减排的低碳供应链协调问题。研究发现,单一成本分摊契约能改善单一批发价契约的"搭便车"现象,却无法解决"双重边际化"问题实现低碳供应链减排量和利润最优。为此,提出零售商分摊减排成本的数量折扣契约进行协调,给出了最优数量折扣策略组合。最后,通过数值仿真分析了碳交易价格和市场需求关于减排量的敏感系数对低碳供应链协调的影响。     

面对价格敏感性突变的供应链协调应对策略研究北大核心CSSCI

研究突发事件造成需求的价格敏感性突变时,供应链的协调应对问题。采用线性函数的形式衡量突发事件造成的额外成本,分析得到供应链的最优生产计划调整策略和最优价格调整策略,从而获得突发事件后供应链的最优利润。并设计了全单位数量折扣契约和限值线性价格契约,激励供应商和零售商实现协调应对,并满足按批量进行数量折扣的运营需求。此外,还对比分析了供应链在市场规模突变与价格敏感性突变下应对规律的异同。最后,通过数值仿真计算,展示结论的应用。     

面对价格敏感性突变的供应链协调应对策略研究

研究突发事件造成需求的价格敏感性突变时,供应链的协调应对问题。采用线性函数的形式衡量突发事件造成的额外成本,分析得到供应链的最优生产计划调整策略和最优价格调整策略,从而获得突发事件后供应链的最优利润。并设计了全单位数量折扣契约和限值线性价格契约,激励供应商和零售商实现协调应对,并满足按批量进行数量折扣的运营需求。此外,还对比分析了供应链在市场规模突变与价格敏感性突变下应对规律的异同。最后,通过数值仿真计算,展示结论的应用。     

生产成本依赖规模经济效应的供应链需求扰动管理

分析了一个供应商和一个零售商组成的供应链中,供应商单位生产成本依赖规模经济效应,需求发生扰动带动单位生产成本随之发生变化时,集中控制下供应链的扰动管理策略和分散决策下供应链的协调机制;也探讨了供应商对扰动没有反应时的供应链协调机制.研究发现,扰动幅度不大时,原生产计划具有一定的鲁棒性;当扰动幅度较大时,需要同时调整价格和订货量,即采用不同的数量折扣策略协调供应链.同时,引入算例进行数值分析,结果表明,只要供应商能够对扰动作出反应,就能够使自身利润增加、供应链得到协调.     

两个供应商和单个零售商组成的供应链成本信息共享和协调契约研究

研究两个供应商和单个零售商构成的供应链的成本信息共享策略和协调契约,两个供应商的商品为可替代的同质商品且成本不同,零售商关于两种产品的市场需求与两者的零售价格线性相关。首先利用Stackerberg博弈和Betrand博弈模型计算了完全信息下的各方分散决策;其次探讨了信息不对称条件下两个供应商的利润变化及两个供应商之间的产品成本信息分享策略;最后将完全信息下的供应链分散决策和集中决策进行对比,证明了双重边际效应的存在,并提出了协调该供应链的价格折扣契约。研究结果可以为成本信息不对称条件下两个供应商和单个零售商组成的供应链的成本信息分享策略和协调契约签订提供理论和方法指导,具有重要的理论和现实意义。     

基于差异化物流服务的供应链决策与数量折扣协调

针对一个具有差异化物流服务的供应链,设计了基于数量折扣合同的协调策略以优化供应链定价决策,提高供应链及链上各方企业的利润。首先基于效用函数分析了消费者选择行为,并由此获得每种配送服务的需求函数。然后基于Stackelberg博弈模型求解了分散决策下的供应链均衡策略并与集中决策情形进行对比,发现分散决策下过高的产品销售定价及过低的快速配送附加运费导致消费者效用减少并使供应链总利润降低25%。为了达到集中决策下的最优绩效,基于物流企业视角提出数量折扣定价合同并对相关参数进行设计,发现促使供应链达到协调的数量折扣合同有无数多个,且在一定范围内这些合同能够实现双方企业利润的改善。最后基于数值分析模拟了部分数量折扣合同,并分析了零售企业还价能力对双方利润的影响。     

产品停产后服务备件供应链的决策分析与协调契约研究

以产品停产后服务备件供应中断问题为背景,研究了由产品制造商、备件供应商和后市场制造服务商构成的服务备件供应链决策问题和基于回购契约的协调机制。首先针对产品制造商采取末次订购和后市场应急采购策略的情形,构建Stackelberg博弈模型并分析均衡下各企业的最优决策,发现制造商在同时选择末次订购和应急采购时的期望利润低于仅选择末次订购的情形,因而不具有主动选择应急采购的意愿。随后探究了该供应链系统的协调问题,发现回购契约能实现供应链协调,且各企业利润均为回购价格的线性单调函数。通过数值试验进一步展示了实现各成员企业利润帕累托改进的契约组合,并分析了其受成本参数变化的影响。     

基于供应链金融的数量折扣成本控制模型研究——基于存货质押融资模式

基于供应链金融这一新型融资模式,研究信息不对称条件下供应链整体成本控制模型.以一条由单个核心制造商和存在资金约束的单个中小零售商组成的二级供应链为研究对象,在供应链金融模式下设计数量折扣成本控制模型,研究其对供应链整体成本和利润的影响.研究结果表明,该模型充分考虑了供应链物流、信息流和资金流的特点,在利用供应链金融缓解供应链资金失衡问题的同时,运用数量折扣对供应链企业的生产决策进一步协调,从而对供应链成本起到了良好的控制效果.最后通过实例研究验证了该模型的效果和可操作性.     

易变质品供应链的协调策略

采用数量折扣作为激励机制,考虑已变质品的处理成本,研究了易变质品供应链在批量对批量(lot-for-lot)假设下的协调策略问题,得到了最优订购策略.通过数值算例和敏感性分析,比较了供应商与零售商在协作前后的成本,验证了在最优价格合同下,协作集成的易变质品供应链能够实现总成本最低.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.