小浪底排沙洞和孔板洞偏心铰弧形闸门的安装

小浪底水利枢纽工程排沙洞，孔板洞工作闸门选用偏心铰弧门型式，突扩跌坎门槽，压紧式主止水，辅助及预压转铰双重止水装置，较好地解决了小浪底工程中高水头，大流量，高含沙量等复杂水力学条件下泄洪孔口工作闸门容易产生的振动，空蚀及泥沙磨损等问题，排沙洞和孔板洞经过一年多的运行，证明偏心铰弧形工作闸门的运行是安全可靠的。其安装程序和安装方法对类似工程有参考价值。     

底流消能的跌坎型消力池再附长度的试验研究

再附长度是衡量坎后底滚回流区水流特征的一个重要参数,再附长度随水流入射角度、跌坎深度的变化而变化。根据平面紊动射流理论,建立淹没紊动射流的扩散方程,推导出再附长度计算的半经验公式,并结合水力学试验,对公式进行验证。结果表明,通过试验观测所得观测值与通过半经验公式计算所得理论值吻合较好。     

不同堆煤工况下的落煤塔结构静力特性研究

针对GB50583-2010国标出台之前,落煤塔结构的布置规则、设计标准无参考依据可循以及结构的赋存条件在时空域的复杂多变性等因素,从而导致结构的设计施工通常以工程经验值为参考、常规理论计算无法反映结构真实受力状态等现象。本文以山西阳泉某矿3#落煤塔为工程背景,利用ANSYS软件对结构在25.0 m最大堆煤高度下360°、270°、180°、90°扇形堆煤角和无堆煤的5种作用荷载工况进行了有限元计算,通过对结构的径向位移和应力等参数的对比分析,得出了静力特性的变化规律、最不利荷载工况、最大应力区域、皮带机水平拉力导致结构产生最大位移等重要结论,希望对该结构的理论研究和工程设计工作起到理论指导作用。     

降低立堵截流难度的措施研究

分析了影响立堵截流难度的各种因素;水力因素包括截流落差Z、截流流量Q,截流水深h等,非水力因素包括抛投材料的物理力学性质和河床面的粗糙程度等;基于各种影响因素介绍了降低立堵截流难度的各项措施,包括提高导流建筑物分流能力、采用双戗堤截流、增强截流块体抗冲稳定性、运用宽戗堤截流、平抛垫底减小水深预防堤头坍塌提高截流安全度等。     

ZP6000A/8500V整流管的研制

本文针对PIN型整流管模型,全面优化了整流管设计制造过程,成功研制了世界上先进的ZP6000A/8500V特高压整流管。     

初期续流影响分析

本文给出了考虑续流影响的理论模型，并利用拉普拉斯积分变换得到拉氏空间无量纲井底压力解，可以准确地解释有续流影响的测试资料获得地层及井筒的有关参数。     

阿图什市工业园区供水工程利用管道水压发电的可行性研究

本文介绍了阿图什市工业园区供水工程可研阶段,研究利用管道分段末端存在的水压进行发电的可行性,并通过不同的供水方案进行经济收益率比较,通过实例分析及经济数据说明,在大力发展小水电中,除降低单位电成本外,还必须适当提高小水电的上网单价占售电单价的比重。     

INFLUENCE OF SURFACTANT ON TWO-PHASE FLOW REGIME AND PRESSURE DROP IN UPWARD INCLINED PIPES

The influence of a surfactant on the two-phase flow regime and the pressure drop in upward inclined pipes is investigated for various gas/liquid flow rates.The air/water and air/100 ppm sodium dodecyl sulphate aqueous solution are used as the working fluids.The influence of the surfactant on the two-phase flow regime in upward inclined pipes is investigated using the electrical tomographic technique.For 0o,2.5o and 5o pipe inclinations,the surfactant has obvious effect on the transition from the stratified wavy flow to the annular flow,and the range of the stratified smooth flow regime is also extended to higher gas velocities.For 10o pipe inclination,no stratified flow regime is observed in the air/water flow.In the air/surfactant solution system,however,the stratified flow regime can be found in the range of and.For all inclination angles,the changes of the pressure gradient characteristics are accompanied with the flow pattern transitions.Adding surfactant in a two-phase flow would reduce the pressure gradient significantly in the slug flow and annular flow regimes.In the annular flow regime,the pressure gradient gradually becomes free of the influence of the upward inclined angle,and is only dependent on the property of the two-phase flow.     

低渗气藏产水水平井井筒压降规律研究

利用水平井开发低渗透气藏过程中,产水使得水平井筒压降规律异于井筒单相压降,因此分析产水水平井井筒压降规律至关重要。该文基于气水两相渗流原理以及水平井周围椭圆形渗流场,考虑启动压力梯度、应力敏感性、滑脱效应以及高速非达西流动等因素的影响,定义气水两相广义拟压力,得到了低渗气藏中气水同产水平井地层渗流模型,并考虑水平井筒变质量流动,建立了地层两相渗流与井筒两相管流的耦合模型。实例分析发现:低渗气藏水平井井筒压降约为0.01 MPa,远远大于气藏单相井筒压降。由敏感性分析可知,随着水气体积比和滑脱因子的逐渐增大,井筒压降不断增大,而随着启动压力梯度和应力敏感指数的增大,井筒压降则不断减小。该文为低渗气藏气水同产水平井井筒压降规律的研究提供了新的思路。     

The Ex-Dividend Day Stock Price Behavior: The Case of Portugal

This paper examines the ex-dividend day behavior of stock prices in the Lisbon Stock Market over the period 1990–1998, extending on international evidence and discussing the adequacy of competing theories, considering the Portuguese institutional environment. We find that on the ex-day stock prices fall by less than the dividend, which is in line with the findings of several studies based on US and non-US data. The main contributions of this paper are: (1) the rejection of a tax explanation for the stock price drop, because it is inconsistent with the Portuguese tax regime; (2) considering the very small stock price tick and the fact that dividends are always integer multiples of tick size, the discreteness hypothesis of Bali and Hite (Journal of Financial Economics 47(2):127–159, 1998) is also ruled out as a possible explanation for ex-day price movements. We find no evidence of tax related clientele effects. We propose that ex-day price behavior may be an anomaly, reflecting a less than efficient market with low liquidity levels, price stickiness, and insipid arbitrage trading.