靖边气田水平井钻井液技术

靖边气田水平井施工中存在长裸眼入窗井壁稳定性差;121/4″大尺寸井眼入窗岩屑的悬浮携带能力不理想;为防塌提高斜井段钻井液密度造成刘家沟等中上部地层发生漏失;大斜度井段需穿越多层易坍塌煤层等难题。针对性研制出具有防塌性好、悬浮携带能力强、流变性稳定等特点的三磺盐水钻井液,现场应用表明:该体系对储层低伤害及现场维护简单。     

上海4号线弓网拉弧现象分析及改善措施研究

结合城市轨道交通工程现场实施情况,对接触网安装条件进行系统论述,提出改善措施,与国内同行共同探讨。     

The Performance of a Project Life Cycle Methodology in Practice

In a deliberate attempt to shift the analytical focus away from critical examination of the underlying ideological assumptions of project management standards, this study focuses on the performativity of a specific project life cycle methodology. Through a case study, the article analyzes the effects and usages of the methodology in practice. This article proposes to think of project methodologies as fluid objects, creating shifting and adaptable relationships between methodology and practice.     

肉牛养殖循环经济项目环境风险和清洁生产分析

本文根据肉牛养殖循环经济项目的特点,分析此类项目存在的环境风险和清洁生产潜力,提出相应措施以降低环境风险、提高资源利用水平、减少污染物排放。     

关于电力变压器局部放电问题的研究

本文作者结合自己多年的工作实践,首先针对电力变压器中局部放电问题产生的原因进行分析,进而阐述了局部放电的种种危害,最后谈及了预防降低局部放电危害的相关措施以及局部放电监测技术在变压器的应用,以供同仁参考。     

排污费与可转让排污许可证的比较——基于社会福利和制度实施层面的分析

排污费和可转让许可证制度是基于市场化环境规制的两种手段,这两种手段从理论上讲均能实现外部成本内部化,但可能在执行过程中带来不同的交易成本,对社会环境福利形成不同的收益。由于在制度设计上要获得厂商的边际收益函数和边际控制成本函数,但这种信息的获得很困难。对边际收益函数和边际控制成本函数的不同估计,造成的社会福利扭曲不同。在制度的实施层面,两种制度设计运作机理的不同,在现实的操作层面也会带来不同的排污结果。     

抽油机井井下功率损失计算方法的优化

为了有效的降低有杆抽油系统井下功率损耗及提高抽油机井系统效率,对抽油机井井下功率损失的计算方法进行优化,建立了计算井下功率损耗的新的机制。该机制将抽油杆柱与液柱的摩擦损失划分到液柱与油管摩擦损失一类,组成液柱粘滞摩擦损失功率,以液柱为研究对象,采用丹斯若斯方法在得到微元段摩阻压差的基础上计算出整体液柱粘滞摩阻损失。同时利用静力有限元方法计算出油管对杆柱的支反力,在满足工程误差许可的条件下,采用简化计算的方法求得杆管滑动摩擦功率损失。上述两个关键功率损失的计算既能满足能耗计算精度要求,又进行了适当的近似简化,为井下能耗损失的计算提供了明确的理论支持。     

Employee firing costs and accounting conservatism: Evidence from wrongful discharge laws

This paper identifies the causal effect of a firm's employee firing costs on its conditional conservatism, using the staggered adoption of US state wrongful discharge laws (WDLs) that increase a firm's cost of firing employees. We find that the adoption of WDLs leads to a significant increase in conditional conservatism. This result is greater for firms that are more labor-intensive, have higher propensities to fire employees, make more firm-specific investments and have greater risk. Overall, our findings support the view that higher firing costs lead to greater demand for conditional conservatism to decrease investment inefficiencies because higher firing costs make inefficient investments (including overinvestment in negative-net present value (NPV) projects and delays in disinvesting poorly performing projects) costlier for the firm.     

On the Use of Exchange Rates as Trading Rules in a Bilateral System of Transferable Discharge Permits

The use of a system of transferable discharge permitsto control the harmful effects of non-uniformly mixedpollutants requires the application of trading rulesin order to prevent permit trading among sources fromviolating environmental standards. The elements andproperties of bilateral trading rules can be analyzedmore easily once formulated as exchange rates, whichwould convert, in a cost-effective way, the emissionright potentially given up by the seller into an offsetting emission right acquired by the buyer. Inthis article, a new expression for such exchange ratesis proposed and then analyzed to infer someunexplored properties of the system.     

印刷线路板回收工艺与方法研究

印刷线路板的回收由于其结构和组成材料的复杂性,被认为是电子电器产品回收中的难点之一。介绍了印刷线路板回收的背景和意义,总结了现有的几种线路板回收的工艺和方法并分析了它们的优缺点,在此基础上提出了利用超临界流体技术来回收印刷线路板的工艺及方法,并同传统的回收方法进行了比较,说明了其优越性。