横流均匀环境中三维线源型正负浮力射流特性研究

本文利用混合有限分析法及交错网格。对横流均匀环境中三维线源型正负浮力射流及负浮力射流的特性进行研究，分析了不同工况下流速，温度和湍动能在断面上的分布及影响射流轨迹线的因素，讨论了轨迹线上温度的变化及浮力射流的贴壁现象。对三维长线源型负浮力射流，分析了流速比，喷口弗汝德数对负浮力射流的影响。     

再论“用离心机作静力结构模型试验”

 本文通过最近所作的两个离心模型试验,进一步探讨了用离心机作静力结构模型试验的有关问题,试验结果进一步证明用离心机作静力结构模型试验,无论在理论上和试验技术上都是可行的,最后将有关问题作了进一步的讨论。     

正交曲线坐标下三维代数应力通量模型

针对弯曲及不规则明渠的水动力及物质输运特性，本文建立了曲线坐标系下的三维代数应力通量数学模型，对平面上弯曲及不规则复杂边界情形，采用Poisson方程进行正交曲线坐标变换，各向异性的湍流代数应力通量模型被引用于本文的模拟计算中，以体现复杂边界条件引起的水动力及物质输运特性的变化。通过180度强弯曲明渠水槽及贵溪电厂不规则边界河段物理模型试验两个实例计算表明，实测值与计算吻合良好，效果令人满意。     

对加拿大货币需求的数量分析

在特定的经济条件下，全社会货币需求量以及这个量的变动规律，是一国政府制定并执行货币政策和财政政策时所要考虑的重要参数。战后以来，西方国家政府一般是通过货币政策和财政政策的执行，最终影响产出量和就业水平。分析影响货币需求变动的因素及其变量之间的数量关系，是正确地预测货币需求变动的关键。加拿大的货币需求与其相关的经济因素之间的关系；加拿大货币供求与经济增长之间的关系。     

Pricing practices and firms' market power in international cellular markets, an empirical study

Previous studies on international marketing have typically asked the question: “how is the demand characterized across countries?” Such analysis is then used to provide guidelines for firms to enter new markets and/or to allocate marketing resources across countries. To provide such normative guidelines, however, one also needs to analyze the supply-side of the problem, i.e., ask: “what is the likely market power that firms will be able to command in different countries?” Building on the New Empirical Industrial Organization (NEIO) framework, recent research in marketing provides marketers with a variety of models to explore competitive interactions among firms in the context of a single market. The goal of this paper is to extend this literature to a multimarket/multinational context to help international marketers assess the likely market power they face when entering new countries. We illustrate the proposed method on the mobile telecommunications industry, using price and quantity data from 10 countries around the world, estimating firms' market power as a function of a number of country characteristics.The results indicate that, while the simple presence of competition diminishes firms' market power, it does not lead to perfect competition. Interestingly, a higher number of competitors in a country does not seem to have significant incremental effect on market power. In contrast, the country's commitment to a severe antitrust policy has a significant negative effect, while the monopolist's lead-time before competition is allowed has a significant positive effect on market power. These findings, together with a change in price elasticities as a result of competition, suggest that market power in different countries may originate from two sources: (i) collusive pricing among cellular operators and (ii) consumers' switching costs across service providers. For international marketers, the findings imply that the attractiveness of wealthier countries (with usually faster diffusion rates and larger market potential) may be mitigated by higher levels of competition (as a result of developed antitrust regulation and more consumer exposure to competitive marketing practices). From a policy point of view, it suggests that (in contrast to the conventional wisdom) simple deregulation may not be enough to reduce prices to competitive levels. In addition, a severe antitrust policy is crucial to achieve this goal.     

On Measuring the Value of a Nonmarket Good Using Market Data

We use line integral theory to lay out in a more general theoretical framework the conditions under which it is possible to measure with market data the welfare effects of a change in a nonmarket good. We present in detail a numerical method of measuring the value of nonmarket goods using market data, under either weak neutrality or weak complementarity. Our numerical method is more flexible than the existing analytical method because it can be used with any well-behaved Marshallian demand function, and can be used even when the willig condition does not hold.     

Price-maker型水电厂策略性报价

用古诺模型研究了Price-maker型水电厂在电力市场下的策略报价问题.将系统中各厂商的竞争简化为己方和虚拟对手组成的双人博弈,提出一种基于历史数据、分析对手行为的可行方法.该方法通过分析历史可获得数据,求取对手成本函数参数及系统的逆需求函数,由此获得合理的对手策略估计,并求取在此可能对手策略下的己方最优策略,从而达到己方收益最大的目标.     

Simulation of water and nitrogen dynamics in soils during wastewater applications by using a finite-element model

A mathematical model was developed to simulate water movement, mass transport, and nitrogen transformations in soils during wastewater applications. The model is one-dimensional and based on the Galerkin finite-element method. The submodel of mass transport of nitrogen incorporates the convection-dispersion processes of ammonium and nitrate nitrogen, nitrification, denitrification, ammonium exchange and uptake of ammonium and nitrate ions. The accuracy and validity of the proposed model was examined by comparison with an explicit-implicit finite-difference model results. The model was used for simulation of water and nitrogen dynamics during wastewater application in homogeneous and multi-layered soils under different N concentration, rate, duration and scheduling of application.     

多级泵站老化的模糊评价模式

多级泵站是一个包括各级泵站及泵站内各种设施的复杂系统，系统内各个泵站的老化直接影响整个泵站系统的正常运行，采用单元化方法将多级泵站系统单元伦，引和泵站老化评价指标，建立了多级泵站老化的模糊评价模式，并对甘肃省景泰高扬程提水灌区多级泵站系统进行分析，提出了评价多级泵站老化程度的排序方法。     

基于神经网络的河道浅滩演变预测模型

河道浅滩演变是一个复杂的非线性动力学过程, 作者借助神经网络处理非线性问题的优势, 在分析影响河道浅滩演变因素的基础上, 建立了预测河道浅淮演变的BP网络模型, 并对模型中的输入因子和样本的提取进行了探讨. 以闽江竹岐至侯官河段为实例,用“试控法”给出了BP网络模型的建模方案, 用正交设计原理选取相应的训练样本集, 利用该样本集对网络进行学习和训练, 并用训练好的BP网络模型预测浅滩上年内最小水深和年平均淤积厚度. 计算结果表明: 模型预测结果与实际值吻合良好. 这为河道浅滩演变预测研究提供了新方法.