Evaluation of a palladinized Nafion™ for direct methanol fuel cell application

Palladinized Nafion™ was prepared via ion-exchange and chemical reduction method. Palladium precursors and solvent systems determined the efficiency of the incorporation and distribution of nanoparticles. The tortuous thin Pd film was formed on the surface of membrane when Na⁺-Nafion™ and water were used. Pd nanoparticles enhanced the water uptake of Nafion™ and reduced its methanol uptake. And dispersed Pd nanoparticles in Nafion™ disturbed the proton conduction and methanol permeation simultaneously in Nafion™ cluster. In order to reduce methanol permeation of Nafion™ and keep its high conductivity, it was more efficient for Pd nanoparticles to distribute near the surface of membrane. Palladinized Nafion™ improved the performance of DMFC single cell operation by reducing the methanol permeation.     

Optimization of decision rules for hydroelectric operation to reduce both eel mortality and unnecessary turbine shutdown: A search for a win–win solution

Worldwide populations of freshwater eels have declined with one of the contributing causes related to mortality during passage through hydropower turbines. An inherent trade‐off underlies turbine management where the competing demand for more hydropower comes at the expense of eel survival. A win–win solution exists when an option performs better on all competing demands compared to other options. A predictive model for eel migration based on a recent telemetry study was used to develop decision rules for turbine management in the Shenandoah River system. The performance of alternative decision rules was compared to the status quo policy to search for win–win solutions. Decision rules were defined by the probability of eel movement and were evaluated by the probabilities of false positive and false negative errors. The exact value of the cut‐off probability used in the decision rule will need to be determined through negotiation between stakeholders, but a range of cut‐off probabilities resulted in a win–win situation with both reduced eel mortality and increased turbine operation relative to the current shutdown strategy. Monitoring the implementation is needed to evaluate and update the predictive model and to refine the decision rule. Although the decision is framed for the Shenandoah River system, the analytical approach could be used to develop decision rules for turbine shutdown policy in other areas.     

“入关”对部分化工矿产品的销售影响与对策(磷、硫、钾部分)

为了适应我国“入关”后国内外市场的形势,对化学矿山行业磷、硫、钾矿的国内外有关资料进行了分析研究。认为我国的磷矿和硫铁矿在国际市场上有相当的竞争力,而出口方向应是我国的周边国家和地区,钾矿将长期依靠进口。     

对国际原油价格持续走高的几点看法

分析了2005年上半年国际原油价格持续走高的原因，对下半年油价走势进行了预测。     

技术价值评估方法的研究与应用

技术价值的评估一直都没有固定的标准和方法,如何公平、合理地确定技术价格,不仅关系着技术交易双方的利益,而且对促进产学研的合作,提高我国技术成果转化率至关重要。文章主要针对一些评估方法进行研究,并将其中的拍卖法应用于技术交易在线系统,实现技术定价,完成技术的在线交易。     

跨国公司抢滩中国化工呈多方位多领域态势(续1)

报道跨国化工公司投资中国,以收购、技术转让方式涉足中国的石化原料、中间体、塑料和树脂、橡胶和轮胎、化纤、有机硅、氟化物、涂料染料、精细和特种化学品、日用化工、医药、电子材料、煤化工等领域的情况。     

跨国公司抢滩中国化工呈全方位多领域态势(续完)

报道跨国化工公司投资中国,以收购、技术转让方式涉足中国的石化原料、中间体、塑料和树脂、橡胶和轮胎、化纤、有机硅、氟化物、涂料染料、精细和特种化学品、日用化工、医药、电子材料、煤化工等领域的情况.     

油价临界点理论、方法及应用初探

提出油价临界点概念,解决如何在波动油价下,选择具有一定规模的石油项目。通过油价临界点的应用,石油公司能够准确判断石油项目的投资机会,科学调整石油项目的经营规模,合理把握国际油价波动的影响,为提高项目抗风险能力提供科学依据。     

油价临界点理论、方法及应用初探

提出油价临界点概念,解决如何在波动油价下,选择具有一定规模的石油项目.通过油价临界点的应用,石油公司能够准确判断石油项目的投资机会,科学调整石油项目的经营规模,合理把握国际油价波动的影响,为提高项目抗风险能力提供科学依据.     

Three stage trade credit policy in a three-layer supply chain–a production-inventory model

The main purpose of this paper is to investigate the optimal replenishment lot size of supplier and optimal production rate of manufacturer under three levels of trade credit policy for supplier–manufacturer–retailer supply chain. The supplier provides a fixed credit period to settle the accounts to the manufacturer, while the manufacturer gives a fixed credit period to settle the account to the retailer and the retailer, in turn, also offers a credit period to each of its customers to settle the accounts. We assume that the supplier supplies the raw material to the manufacturer and sends back the defective raw materials to the outside supplier after completion of inspection at one lot with a sales price. The system always produces good items in the model. Also, we consider the idle times of supplier and manufacturer. Finally, numerical examples are provided to illustrate the behaviour and application of the model with graphical simulation.