Market microstructure in a global B2B network

On‐line marketplaces raise several interesting issues, among them the relevance of location when content is digitized, and the assessment of a supplier's capabilities when buyers worldwide only have electronic contact with sellers. In global B2B on‐line marketplaces, market microstructures, i.e. which firms compete for the same customers, are thus likely to be influenced by how customers value location and firm capabilities in their decisions to do business with different suppliers on‐line. We suggest that both these sets of attributes will continue to matter on‐line—firms possessing similar capabilities, as well as firms that are similar in location by country, time zones or clusters, will compete for business from the same customers. We model the similarity in competitive positions between pairs of firms based on the overlap in their customer networks, using data on actual interactions between supplier and customer banks on an electronic trading system. Using QAP network regression techniques on the 100 largest banks in this industry, we find that similarity in capabilities influences who competes with whom, and that location still matters in a global B2B exchange. Interestingly, location influences who a firm's competitors are, but not where its customers are from. Copyright © 2001 John Wiley & Sons, Ltd.     

What Determines Real Exchange Rates? The Nordic Countries

The model derived in this paper yields testable implications concerning the long‐run co‐movements of real exchange rates, relative labor productivity, the trade balance and terms of trade. Countries with relatively higher output growth, trade deficits or improved terms of trade are found to have more appreciated real exchange rates, with the main channel of transmission working through the relative price of nontraded goods. Exogenous terms‐of‐trade shocks are found to be the most important determinant of long‐run movements in the real exchange rate for Denmark and Norway, while demand shocks account for most of the long‐run variance in the real exchange rate for Finland and Sweden.     

浅析勘察设计企业的经济效益问题

简要的分析了勘察设计企业的经济效益问题 ,初步探索了该类企业提高经济效益的方法与途径     

关于长江重大问题的思考

长江流域横跨我国华东、华中、西南三大经济区,地理位置优越,水资源得天独厚,是我国最重要的经济区域之一。新中国成立后,党和政府高度重视长江治理开发工作,组建了流域机构,开展了流域综合利用规划,初步建立了长江防洪、灌溉、水力发电、航运、水土保持和水资源保护体系,在保护     

20世纪的泥沙运动力学

在20世纪，泥沙运动力学的研究取得了不少突出的成绩，但与其他学科同时期的进展相比，发展还是比较缓慢的。按取得的进展来看，20世纪可分为两个阶段；在上半叶，有6项突破性进展，逐步积累，到1950年，Einstein集大成，提出了第1 个泥沙运动力学理论体系。在下半叶，进入了百家争鸣的时代，一些研究者提出了自己的泥沙运动理论体系，作者列举了8个有代表性的理论体系。受计算机时代的影响，从20世纪70年 代开始出现了根据大量实测资料，利用计算机进行回归分析而得出的阻力和输沙率公式，而不拘泥于发展新的理论。与此同时，一些与实际偏离较远的理论逐渐被淘汰。在21世纪，要搜集系统完整的资料，特别是近底层的资料，并拓宽研究领域到环境，生态等学科。     

西津电站对南宁及贵港防洪的作用

江河中的闸坝、电站等水利工程的调度运行对其上下游城市防洪有着重要的作用。郁江上的西津电站在洪水期如何调度可减轻上游南宁及下游贵港的洪水压力?通过分析"2001 7"洪水的调度,论述调度过程的作用和效果,为以后的防洪调度提供决策参考。     

Regionalization, public spending and growth: a stylized model dealing with ‘predatory states’

In this paper, a micro-founded model analyzing the effects of ‘regionalization’ on economic activity is developed. It shows that the spatial division of public competencies can have an impact on the growth rate via the efficiency of governmental choices: initially advantageous for weak levels, decentralization (/reduction of regional size) becomes limited due to the risk of underestimation of the real profitability of public expenditure by local governments (non-internalized cross-border effects). In accordance with the theory, a transversal estimation for a sample of 51 countries for the 1990s establishes a ‘bell-shaped’ relation between indicators of regionalization and the quality of governance.     

黄河黑山峡河段大柳树水库比小观音水库原始库容多40亿m3的作用

一级开发大柳树高坝原始库容比二级开发小观音高坝多 4 0亿m3 ,库容大带来的好处体现在 5～ 7月可多向下游增供水量 ,缓解下游河道断流 ;延长泄放清水时间 ;增加发电效益 ;满足宁蒙河段防凌要求 ;增加汛期集中泄水 ,减缓下游河道淤积萎缩 ;满足南水北调西线工程水量调节要求等。为了更好优化配置黄河水资源 ,从全局和长远利益考虑 ,应采用一级开发方案 ,修建大柳树高坝大库     

明渠水流泥沙运动水深平均及力矩方程的理论和验证

首次提出了水流泥沙运动水深平均及其力矩方程的概念 ,并从理论上推导出这套方程组。提出水流泥沙运动力矩方程的目的有两个 ,一是在不增加空间维数的情况下可以有效地恢复水流泥沙因子沿水深分布信息 ,克服目前普遍使用的水深平均方程过多地忽略沿水深分布信息的缺点 ;二是增强模型的模拟能力。针对这两个目的是否能真正得到体现 ,分别从理论和实验室资料两个方面对新推导的力矩方程进行了全面的检验。理论验证结果表明 ,一维的力矩方程除了能模拟水深平均的流速和含沙量 ,还能够较好地模拟水流泥沙因子沿水深分布信息 ,这充分说明了一维力矩方程的二维特性。为了检验力矩方程的模拟能力 ,特别选取了一些极端的水流泥沙运动实验 ,如清水冲刷、点源加沙和深槽回淤等。模拟结果表明 ,力矩方程对于这些极端的水沙运动具有较好的模拟能力     

海河流域河道外生态需水研究

水土流失是海河流域较为突出的生态环境问题之一。经对比研究发现，植被覆盖度的变化会通过影响洪充量，土壤侵蚀量等因子，进而改变水土流失的状况。从提高植被覆盖度尤其是低覆盖度草地植被的角度出发，定量研究了为改善流域水土流失状况河道外生态需水的具体数额，得出海河流域现状年河道外生态耗水（降水）385亿m^3。另外，为改善河道外生态环境状况将低覆盖度草地提高地提高至中等覆盖度水平，则需要增加生态需水12．5亿m^3。