电路的任意节点状态的机助分析

文中介绍了一种直接求解任意一节点电压的方法,并讨论了其机助分析问题,给出了两种实现方案.     

国际营销思考题(之一)参考答案

<正> (一)为什么在国际营销中,在渠道策略上,正确对待国外中间商具有关键意义?在这方面需要注意哪些问题? 在从事国际营销的全过程中,在发展了适销产品并订定了有竞争性的价格之后,企业选择推行的渠道策略对于能否成功地进入目标市场拓开销售具有关键的意义。而在渠道策略上如何正确选择运用中间商可说是首要问题。这是因为:第一,就世界范围来看,由出口厂商控制、左右市     

EFFECT OF DRILLPIPE ROTATION ON BOREHOLE CLEANING FOR EXTENDED REACH WELL

Wellbore cleaning is a key technology for the Extended Reach Drilling (ERD). The success of drilling extended reach wells depends directly upon the quality of wellbore cleaning. The rotation of the drillpipe, and hydraulic and rheological parameters, are the key factors for wellbore cleaning. In this study, Computational Fluid Dynamics (CFD) is applied to simulate solid-liquid two-phase flows in wellbore annulus. The annual flow field with the presence of drillpipe rotation is described through analyzing various rotation conditions. The results indicate that the quasi-spiral flow is the main flow pattern for liquid-solid transport in the horizontal annulus. The influence of rotation on the cuttings transport is also investigated, as the rotation of drillpipe increases the disturbance of liquid to solid in annulus. As a result, the solid flow becomes favorable and the solid volume is reduced. Comparisons with previously published results are also performed to prove the importance of drillpipe rotation in the wellbore clearing for the ERD.     

Politics, Insurance Regulation, and Unfunded Pension Liabilities

ABSTRACT: Insurance regulators operate in an environment in which resources are scarce and issues are most often complex and not salient to affected persons. Consequently, regulatory agencies, such as the Pension Benefit Guaranty Corporation (PBGC), need to use resources efficiently by making issues salient and not complex if regulatory goals are to be attained. To further its goal of full funding of defined benefit pension plans, the PBGC annually published a list of the Top Fifty Companies With the Largest Underfunded Pension Liability (LIST). This article investigates the issue of the economic effects of pension plan disclosure by measuring the share price response of the companies included on the LIST; then policy implications are drawn. The event study findings show that, on average, publication of the LIST did not have a negative effect on firm value. However, cross-sectional analysis provides some support for the contention that publication of the LIST had an economic cost on LISTed firms. The authors' results show that the value of large firms on the PBGC's list is less negatively affected at arrival (ARRIVAL) than smaller LISTed firms. Conversely, when firms leave the list (DEPARTURE), the value of large growth-oriented firms is more negatively affected than the value of other firms that reduce their unfunded pension liability. From a policy perspective, as hypothesized by Meier (1991), the PBGC used its scarce resources effectively by publishing the LIST. The issue of unfunded pension liability became less complex and more salient to interested parties. Consequently, consumer groups and political elites provided their support to further the regulatory agency's stated goal, which was the full funding of defined benefit pension plans. Furthermore, increased awareness of the underfunding problem contributed to the passage of the Retirement Protection Act of 1994.     

THE DYNAMIC EQUATION FOR A SPHERICAL BUBBLE IN UNIFORM SIZED SOLID PARTICLE-LIQUID HOMOGENEOUS SUSPENSION

The momentum equation for solid-liquid two-phase flow proposed by Elghobashi and Abou-Arab is taken as the governing equations for the liquid phase,and the Lagrangian dynamic equation for a spherical particle moving in the liquid flow as the basic equation for the relative motion of the particle in the liquid phase in the paper.The dynamics equation for a bubble in solid-liquid twophase flow is proposed,as well as the simplified equations under two extreme conditions with the relationship between the bubble collapse characteristic time τ_C~* and particle response time τ_(rel)~* being τ_C~*>> τ_(rel)~* and τ_C~* <<τ_(rel)~*.     

省网公司：加强资金流管控

省级电网公司可以通过集团化、市场化两种运行方式和资金流管理实时信息系统，加强资金运行管理，提高资金综合使用率，节约资金运作成本，达到资金流管控的目的     

MODEL STUDY ON PREVENTING SEDIMENT DEPOSSITION IN WATER INTAKE SYSTEM

The hydraulic and sediment deposition problems in the water intake system of a pumping house were studied by physical model.The experimental results of different working cases indicate that the sediment depositions at the gates,stilling basin and culverts are very few when the system was normally operated,but in the forebay of pumping house,especially in the pumping house for living water,the amount of sediment deposition sometimes is considerably large.At the front of the entry of pumping house forliving water,installing a set of oblique pipes can prevent the coarse grains to enter it,the deposition amount will obviously decrease.     

NUMERICAL ANALYSIS OF WATER SURFACE PROFILE IN RIVER AFFECTED BY TIDE FLUCTUATION

A Finite Difference Method with four points weighted implicit scheme and Newton-Raphson iteration method are introduced to complete the flood routing in the tidal river. The problems related to normalization of cross-sectional area and optimization of weighting factor α are discussed and α = 0. 5 - 0. 7 is suggested. With such a α, high accuracy, stable and convergence results and flexible time step will be expected. The computational example of a tidal river in Liaoning Province shows the good agreement with the measuring data on prototype.     

建管结合 无缝链接 平稳过渡 水电厂建设与生产管理新模式

贵州乌江水电开发有限责任公司（以下简称乌江公司）是国有大型水电企业，负担着乌江流域水电开发与生产运行管理的使命。公司坚持以发展为主线，认识到“大发展小困难，小发展大困难，不发展更困难”，迎着困难上。在“十五”期间的2000年至2002年的3年时间里，公司先后宣布乌江渡扩建工程、洪家渡和索风营水电站开工建设。