西霞院水利枢纽工程泄洪闸振冲碎石桩基础处理

通过西霞院水利枢纽工程泄洪闸振冲碎石桩基础处理施工方法论述,给出了加砂层振冲碎石桩施工造孔水压、水量、成孔速度、填料级配、填料方法以及振密电流值、留振时间等施工控制参数。     

石油工程项目管理机制

为了妥善处理石油工程项目中的委托-代理关系,研究了委托-代理模型和石油工程项目管理中的激励约束机制,分析了激励机制、监督机制和选择机制在石油工程项目运行管理中的重要性.只有用有效的契约去激励技术服务公司,才能使服务公司在追求自身效益最大化的同时也为实现石油公司的最大效益而尽最大努力;只有对技术服务公司的作业实施监督,才能形成对技术服务公司的有效约束;采用激励性承包方式、实施综合性评标和组建工程项目动态联盟能够防止逆向选择.分析表明,在最优激励安排下,激励强度与项目面临的不确定性、承包商的边际成本及其风险规避系数负相关,与承包商的边际生产率正相关,还与其他可观测变量相关.在最优监督水平下,作业公司的边际生产率越高,边际成本越低,越容易监督,监督带来的边际收益越高.对于那些监督比较困难的项目,可以通过加强惩罚力度的方式弥补难以有效监督的不足.激励性承包方式可以减小逆向选择造成的危害,组建动态联盟可以进一步加强激励作用,降低道德风险,解决逆向选择问题.参8     

Corrosion Inhibition Mechanism with Spilt Cell Technique of Rare Earth Metal on LC4 Al Alloy

A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl₃, the influence of corrosive performance of CeCl₃ on LC4 super-power aluminum alloy in the 0.1 mol·L⁻¹ NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl₃ solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al.     

真空制盐蒸发结晶器的设计与实践

真空蒸发制盐外热式强制逆循环轴向出料蒸发结晶器，经多个厂家生产应用实践证明是成功的，具有生命力的。这种新型结构，作为一项新技术新设备应加强研究，总结提高，推广应用。不断完善。文章从流体力学、结晶机理角度要求，到具体工程设计参数和材质选用。论述了该罐的特点。     

黄河下游河道萎缩致灾机理探讨

本文基于水力学原理，结合实体模型试验及原型实测资料分析，探讨了黄河下游河道萎缩的概念、致灾效应和致灾机理。分析表明，河道萎缩是造床过程中河道排洪输沙功能衰退的一种演变现象，其致灾效应是使洪水涨率增大，同流量下洪水水位不断抬升。致灾的现象主要表现在畸型河势增加、工程险情增多、直接造成工程损失及滩区经济损失等。试验研究揭示，主河槽宽度缩窄造成洪水水位涨幅增大，河底平均高程抬升和过水断面面积减小造成洪水水位起涨的基准面抬升是河道萎缩致灾的主要原因。河道萎缩致灾效应的大小与萎缩模式有关，其中以“集中淤槽”模式所形成的致灾效应尤为明显。     

Reaction scheme and kinetic modelling for the MTO process over a SAPO-18 catalyst

A kinetic model for simulation of the MTO process over SAPO-18 catalyst in a wide range of operating conditions has been proposed. The kinetic model predicts the experimental evolution of reaction products with time on stream, which follows three consecutive periods: initiation (where olefin production increases), a period of maximum olefin production and a period in which this production decreases. The kinetic scheme takes into account these three steps that evolve with time on stream: formation of active intermediate compounds, an step where olefins are formed by reaction of oxygenates (methanol/DME) with these intermediates and deactivation of intermediates by degradation to coke. The presence of water in the reaction medium attenuates the reaction rate of these steps. Discrimination of kinetic equations and calculation of the parameters of best fit have been carried out by solving the mass conservation equations of the individual components of the kinetic scheme together with the kinetic equation for deactivation and taking into account the effect of water on the kinetics of each step.     

论剪切质量的提高

通过对飞剪剪切长度，精度，剪刃间隙和压板机构等参数的优化，来提高钢板的剪切质量。     

论我国大学不良竞争的形成及控制

大学在办学资源、办学过程、办学质量、办学形象的竞争中出现大量的不良倾向。大学的不良竞争是由于政府主导资源配置、资源和制度供给不足、大学系统重构等因素导致。必须通过控制主体、控制手段的转变和控制对象的发展形成新的控制机制，以保证大学竞争的秩序化和规范化。     

Operation of superconducting fault current limiter using vacuum interrupter driven by electromagnetic repulsion force for commutating switch

Using conventional high‐temperature superconducting wire, a model superconducting fault current limiter (SFCL) is made and tested. Solenoid coil using Bi2223 silver sheath wire is so made that inductance is as small as possible and a vacuum interrupter is connected in series to it. A conventional reactor coil is connected in parallel. When the fault current flows in this equipment, superconducting wire is quenched and current is transferred into the parallel coil because of voltage drop of superconducting wire. This large current in parallel coil actuates magnetic repulsion mechanism of vacuum interrupter. Due to opening of vacuum interrupter, the current in superconducting wire is broken. By using this equipment, current flow time in superconducting wire can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of parallel coil. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(1): 52–61, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20315     

Formation of composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system

The formation of aluminum matrix composites fabricated by exothermic dispersion reaction in A1-TiO2-B2O3 system was investigated. The thermal analysis results show that the reactions are spontaneous and exothermic. The Gibbs free energy of α-Al2O3 is the lowest among all the combustion products, followed by TiB2 and Al3Ti. It is noted that when the B2O3/TiO2 mole ratio is below 1, the reaction products are composed of particle-like α-Al2O3, TiB2 and rod-like Al3Ti. The α-Al2O3 crystallites, resulting from the reaction between A1 and TiO2 or B2O3, are segregated at the grain boundaries due to a lower wettability with the matrix. SEM micrographs show that rod-like Al3Ti phase distributes uniformly in the matrix. When the BEO3/TiO2 mole ratio is around 1, the Al3Ti phase almost disappears in the composites, and the distribution of α-Al2O3 particulates is improved evidently.