凉水河污染对土壤和地下水的影响

在凉水河下游取河床底泥及河床下部土样,分析其NH3-N、磷和有机物的变化,发现底泥对NH3-N和磷的去除发挥了很大作用,分别是下部土壤吸附量的10倍和1倍多;土中5种氯代烃均有检出,是河水长期渗漏积累的结果。凉水河流域内的野外试验结果表明,凉水河对地下水存在污染,污染组分主要是CODCr,NH3-N也有一定污染,其他无机污染组分如NO3-N,Cr6+,TP和Pb2+对地下水的影响较小,氯代烃对地下水也有一定影响。据推测,凉水河污染对地下水的影响范围大概在河两侧80 m范围内。     

Exploring the interaction between incubators and industrial clusters: the case of the itri incubator in Taiwan

This article aims to explore the interaction between incubators and industrial clusters, which is an important linkage for local development but has not been analyzed in the literature. A model is proposed to describe this interaction. The Industrial Technology Research Institute (ITRI) Incubator within the Hsinchu industrial cluster, the core of Taiwan's technology industries, is considered to be an empirical case. This case is investigated with the proposed model and methods including data analysis, in–depth interviews, manager surveys and stakeholder analysis. It was found that the clustering effect in the Hsinchu industrial cluster is main factor in the ITRI Incubator's development. The ITRI Incubator in turn reinforces the cluster in some aspects as feedback. This result confirms the existence and importance of this interaction in local development. It is recommended that government officials and incubator managers take account of this interaction in operating an incubator program and utilize the proposed model to analyze the incubator's contributions to its industrial cluster.     

The price adjustment and lead-lag relations between stock returns: microstructure evidence from the Taiwan stock market

This paper investigates the price adjustment and lead-lag relations between returns on five size-based portfolios in the Taiwan stock market. It finds evidence that the price adjustment of small-stock portfolios is not slower than that of large-stock portfolios. Additionally, limited evidence supports a positive leading role of large-stock portfolio returns over small-stock portfolio returns. These two findings are substantially different from the results of previous research on developed markets.     

Modelling the effects of dam removal on migratory walleye (Sander vitreus) early life‐history stages

Many dams in the USA have outlived their intended purpose and an increasing number are being considered for removal. Yet, quantitative studies of the potential physical, biological and ecological responses are needed to assess dam removal decisions. In this paper, the responses of migratory walleye (Sander vitreus) to increased spawning habitat availability as a result of dam removal was studied by comparing scenarios with and without a high‐head dam in the Sandusky River (Ohio), a major tributary to Lake Erie. A conceptual, ecological model was proposed to define the relationship between hydrodynamics and walleye spawning, egg hatching, larval drift and survival. A mathematical, ecological model of the early life‐history stages was then developed and coupled with time series of depth and velocity predictions over the spawning grounds from a 1‐D hydrodynamic model. Model simulations were run for 1984–1993 for both the with‐ and without‐dam scenarios to assess the potential benefit of dam removal. The simulation results demonstrated that velocity, depth and water temperature are major factors influencing adult walleye spawning success. Without the dam, 10 times the amount of spawning habitat would be available for walleye to spawn. This increase in spawning habitat area resulted in up to five times the total egg deposition and seven times the larval output to the nursing grounds, based on the assumption that 5% of the walleye population of Lake Erie migrated up the Sandusky River to spawn. We concluded that the spawning habitat in the current condition (with the dam) is limiting and additional spawning habitat upstream could significantly increase the number of larval walleye drifting to Lake Erie. The model sensitivity analysis showed that the number of walleye migrating up the river in spring is the dominant factor for larval recruitment to the lake. Copyright © 2006 John Wiley & Sons, Ltd.     

WASP6水质模型在渭河流域水环境容量解析中的应用

将WASP6水质模型应用于渭河流域陕西片,分析流域水环境的污染现状,并采用模型试错法模拟计算渭河陕西段水环境容量,并对比分析节水增流前后水质变化,根据分析结果提出节水增流减污的水污染控制方案,为渭河的污染治理提供依据。     

基于PSR模型的水电工程生态效应评价指标体系构想

从水电工程生态效应评价指标体系研究的意义出发,通过分析水电工程生态效应评价的内涵,确立了评价指标的选取原则,基于压力(Pressure)-状态(State)-响应(Response)概念模型,构建了以科学、实用和可操作为目标的评价指标体系的框架。     

潮州供水枢纽坝下游河床下切对水位流量关系的影响研究

采用一维河网水动力数学模型,计算分析了潮州供水枢纽坝下游河床在不同下切幅度下水位流量关系的变化趋势和规律。结果表明坝下游水位流量关系随河床的下切而下降,水位下降幅度随流量的增大而增大;随着河床的继续下切,在相同下切幅度下,水位流量关系下降的幅度呈不断减小的趋势;河床再下切6m后,水位流量关系将基本趋于稳定。该文的研究可供相关规划设计人员参考。     

近代职官制度总理衙门研究综述

作为中国近代职官制度研究的重要组成部分，近年来，学界关于总理衙门的研究取得了一定的成绩，其中包括对总理衙门设立的背景、过程、影响、历史地位等。通过对近15年来总理衙门的研究情况作一个简单小结，阐述了其中的主要观点及分歧，并提出了总理衙门研究的不足与展望。     

UNIT MANAGEMENT BUYOUTS, STOCKHOLDER WEALTH, AND SELLING FIRMS' CHARACTERISTICS

Previous research on unit management buyouts, UMBs, has shown that selling firms benefit from the selloff transaction. The current research demonstrates that when the selling firm has either poor liquidity or poor earnings, selling firm shareholders do not benefit as much. We hypothesize that the unit managers have knowledge about the selling firm's difficulties so they do not pay as large a premium for the assets. Since the unit managers technically are employed by the selling firm shareholders, their bargaining to achieve a better price is an agency cost. Finally, selloff frequency does not affect seller abnormal returns.     

灌溉水库水资源优化调度

以榆社云簇水库为例、以水库灌区多种作物所能达到的最大产值为目标函数，本文研究了一套灌溉水库用水优化调度模型。它包括计划调度模型和实时调度模型两部分，适用于干旱半干旱地区灌溉水量不足的水库的用水调度。