土工实验中的液、塑限测定浅议

文章分析了当前土工实验中的液、塑限测定过程中应当注意的问题及其存在的问题,并论述了如何对其实验数据进行处理和分析的方法。     

Ambient Taxes Under m-Dimensional Choice Sets, Heterogeneous Expectations, and Risk-Aversion

We consider the design of ambient taxes forrisk-neutral and risk-averse polluters whenpolluters and the regulatory agency haveasymmetric information about environmentalrelationships and probabilities associatedwith random events. Unlike prior work, we showthat under these conditions, optimal ambienttaxes must be firm-specific, and accompaniedby additional incentives to influencepolluters' choices of abatement techniques.     

辽宁东部水源涵养林计量指标体系及其效益评估

对辽东山区水源涵养林产生的各种效益进行计量评价研究,制定了水源涵养林计量效益评价指标体系,包括3级结构、16项指标、49项因子;依各功能因子的重要性并经测算,对各项指标赋予权重和排序,森林的蓄水、减少径流、改善水质功能的权重值较高;采用条件价值法,估算辽东山区水源涵养林的各种功能价值,森林的林副产品和木材收益的功能价值较高。辽东山区水源涵养林按整体处在一般经营状态下计算,年均创造功能价值约为30.2亿元。     

Prevention versus Treatment under Precautionary Regulation: A Case Study of Groundwater Contamination under Uncertainty

Policy discussions on agricultural pollution problems characterize prevention as more cost effective and precautionary than ex post treatment. We derive conditions under which treatment alone is more cost effective in situations involving multiple sources of emissions, multiple sites affected, and a commonly used precautionary approach to uncertainty. We also show that a greater degree of precaution can result in less reliance on prevention. An empirical case study indicates that treatment alone is the most cost-effective means of dealing with nitrate in most Maryland community water system wells. The use of leaching prevention measures is restricted to the most intensive poultry producing areas. The incremental cost of precaution is substantial.     

Estimating Willingness to Pay for Improved Water Quality in the Presence of Item Nonresponse Bias

This article deals with the problem of item nonresponse in contingent valuation surveys using a payment-card method, by applying a grouped-data sample-selection estimation technique that is capable of imputing the missing values conditional upon a respondent's decision to answer a willingness-to-pay question. The advantage of the technique lies in its ability to utilize all of the information in the sample, permitting a more efficient estimation in the presence of item nonresponse bias. The major determinants of willingness to pay appear to be household income, number of children, education, perception of existing water quality, and identification with environmental issues.     

小氮肥清洁生产实践

文章介绍了沅江市氮肥厂废水闭路循环、尾气回收、废渣综合利用等工程,并介绍了该厂的生产工艺、污染源分布及排污特点。     

Provision of Human Resources for Water Resources and Hydropower Projects——A case of CGGC

1.Management of Human Resources in ChinaGezhouba Construction Group Corporation1.1Brief Introduction of CGGCChina GeZhouBa Construction Group Corporation(hereinafterreferred to as CGGC)is a super huge enterprise subordinatedto StateAssets Supervision and Administration Commission of PRC.It main-ly conducts water conservancy project,hydropower project,thermalelectric power project,nuclear electric power station,industrial andcivil works,as well as other works state-ratified.It is fa…     

钢板桩围堰在水位变动区和软弱地基中的应用

利用钢板桩作围堰,在水位变动区和软弱地基条件下,采取一定刚度的围护设施来满足深基坑的施工需要;成功地运用了一种既施工简便、节约材料又确保安全的围护结构。根据软土的特点和钢板桩的柔性特征,通过采用模拟基坑开挖过程,按照板桩墙围护结构的设计计算方法进行围堰设计,并通过实际施工中一定的控制措施和对围堰内力、变形监测,确保相邻建筑物和自身结构施工的安全。根据实际运用的效果监测表明,采用的钢板桩围堰,是可行而又较优的一种方案。     

河北省水利工程正效益分析

分析了河北省建国以来水利工程总体正效益，包括城市供水效益、农业灌溉效益、节水灌溉效益、治理盐碱土地效益、防止水土流失效益、防汛抗旱效益等。