环境砷污染与健康

本文论述了环境砷污染对健康的影响,包括砷中毒、机理、危害及分析方法。     

Experimental study on the effect of fly ash content in cemented paste backfill on its anti-sulfate erosion

ABSTRACT

In order to study the effect of fly ash content in cemented paste backfill (CPB) on its anti-sulfate erosion, the apparent phenomenon, strength development, and hydration products change the law of CPB with different fly ash content under long-term soaking of 5% sodium sulfate solution were studied by the macrotest and microanalysis, in addition, the mechanism of CPB anti-sulfate attack was analyzed by combining with a scanning electron microscope (SEM). The results indicated that the effect of sulfate environment on the strength of fly ash cemented paste backfill (FCPB) was mainly determined by the hydration products in the FCPB at different soaking times. In the early soaking stage, the formation of ettringite (AFt) in FCPB could improve its compactness, which was conducive to improving the strength of FCPB. In the late soaking stage, there were ettringite-type erosion damage and gypsum erosion-type damage internal of the FCPB with low content fly ash, resulting in microfracture, cracking of the FCPB, and reducing the strength. CPB with an appropriate content of fly ash could improve the internal structure of the FCPB to achieve the purpose of anti-sulfate erosion.     

流域水资源可持续开发利用中激励机制的应用

本文分析了流域水资源开发利用中存在的问题及原因，并根据可持续发展的理论，提出了流域水资源可持续开发利用的原则及相应的激励机制：①水价机制；②宏观调控机制；③水权机制；④相应的流域管理机制。     

NEW STRATEGIES FOR AGRICULTURAL DEVELOPMENT IN CHINA''''S MOUNTAIN AREAS

Ｂｙｔｈｅｅｎｄｏｆｔｈｅ 2 0ｔｈｃｅｎｔｕｒｙ ,ｔｈｅｍａｊｏｒｉｔｙｏｆｍｏｕｎｔａｉｎｒｅｇｉｏｎｓｉｎＣｈｉｎａ ,ｅｓｐｅｃｉａｌｌｙｔｈｏｓｅｐｏｖｅｒｔｙ ｓｔｒｉｃｋｅｎａｒｅａｓ,ｈａｄｓｏｌｖｅｄｔｈｅｐｒｏｂｌｅｍｓｏｆｆｏｏｄａｎｄｃｌｏｔｈｉｎｇ .Ｔｈｅｙａｒｅｎｏｗｍａｒｃｈｉｎｇｔｏｗａｒｄｔｈｅｇｏａｌｏｆｌｉｖｉｎｇａｗｅｌｌ ｏｆｆｌｉｆｅ .Ｎｅｗｃｈａｌｌｅｎｇｅｓｔｈａｔｔｈｅｍｏｕｎｔａｉｎｒｅｇｉｏｎｓａｒｅｆａｃｅｄｗｉｔｈｉｎｔｈｅ 2 1ｓｔｃｅｎｔｕｒ…     

化工装置爆炸事故模式及预防研究

对建国以来我国已经发生的典型化工装置爆炸事故原因进行了统计分析 ,总结了爆炸危险性的影响因素。结合对已经发生的事故案例的剖析 ,提取并建立了装置内爆炸事故模式 ,对各种模式的爆炸机理和发生条件进行了初步的研究分析 ,并提出事故的预防措施 ,以期指导安全生产     

浅析我国城市土地的储备问题

通过对城市土地储备制度的运作过程与运转机理的简要阐述，形成了一个较为完整的理论框架，侧重分析了我国现行的城市土地储备制度尚存的一些问题，提出了相应解决对策，以求进一步完善我国城市土地储备制度。     

广州市地面塌陷的形成原因与时空分布

地面塌陷是珠江三角洲城市地质灾害的主要类型之一。广州市地面塌陷灾害频繁发生,近10年来呈波动式上升趋势。其塌陷类型分为岩溶塌陷和工程地面塌陷两种,岩溶塌陷主要分布在广花盆地的花都区、白云区,工程地面塌陷主要分布在中心城区。地面塌陷灾害孕灾环境复杂、致灾因子多样,承灾体脆弱,灾害后果严重。人为因素是地面塌陷的主要诱发因素。岩溶塌陷主要是由于过量抽取地下水或矿山疏干排水、地下采空、暴雨触发所致;工程塌陷主要是人类工程行为所致,其主要致灾因子包括排水疏干与突水(突泥)作用、人工加载、人工振动、人工开挖桩基、地表渗水、地铁等地下工程盾构掘进等。     

发电设备可靠性研究现状与发展

通过对国内外发电设备可靠性研究的分析,提出了我国发电设备可靠性研究大体经历了可靠性指标统计分析、传统可靠性模型分析以及电力市场下可靠性分析3个阶段。在比较各阶段研究特点的基础上,指出了建立发电设备可靠性成本与可靠性效益之间的平衡,设定反映二者关系的新的可靠性指标是电力市场下发电设备可靠性研究的新特点。笔者认为,所提出了数据挖掘技术,是发电设备可靠性管理实现实时化、智能化与预测化的一种有效方法。     

商贸市场火灾风险评估方法

通过对典型商贸市场的实地调研,依据历年商贸市场火灾事故统计数据,采用将统计方法与专家评分相结合的方法,运用系统安全及模糊数学的相关理论,提出了商贸市场火灾风险评估方法,从而为商贸市场的安全管理及火灾风险评价提供了切实可行的参考依据。     

IMPROVING IRRIGATION RETURN FLOW QUALITY WITH A WATER RENTAL MARKET1

ABSTRACT: Current policies for correcting the problem of irrigation return flow pollution tend to attack the symptoms of the problem, rather than its cause. The present institutional arrangement for allocating irrigation water is seen as the source of the problem. This paper examines the water quality benefits of altering the institutional arrangement to allow for irrigation water transfers through a rental market. It is conceptualized that by creating a water rental market an opportunity cost would be associated with the use of irrigation water such that profit maximizing farmers would be induced to use his water supply more efficiently and rent the surplus to other irrigators, thus reducing return flow pollution. It is shown that a water rental market could increase water quality in the Yakima River in southcentral Washington by 31 percent as well as increase farm incomes and crop production.