Optimal production scale of open pit mining operations with uncertain metal supply and long-term stockpiles

An open pit mining operation consists of various stages, and the calculation of the production capacities of these stages depends upon the available supply of ore (mineralized material of economic value) and waste material. Cutoff grade is the criterion that specifies the amount of ore and waste. The material with grade equal to or higher than the cutoff grade is classified as ore. The material with grade less than the cutoff grade is considered waste. While this explains the link between cutoff grade theory and the calculation of production capacities, the majority of optimization models for finding production capacities not only disregards this relationship but also ignores expected variations and uncertainty in metal content or the available supply of ore and waste material.     

氨氮在线自动监测仪的现状与问题

氨氮在线自动监测仪已在国内水质自动监测系统中得到广泛应用。现在该仪器的生产厂家生产日趋成熟、相关标准逐步出台、仪器性能基本达标。但在实际应用过程中,该仪器仍有许多问题需要进一步认识与改进。因此从方法选择、干扰排除、国家标准、比对、质量控制等方面,分析了该仪器存在的问题,并提出了相关建议。     

我国博物馆陈列文物防震技术现状研究

为保护我国博物馆陈列文物,基于文献查阅及现场勘查相结合的方法,从博物馆、陈列台座、陈列文物三方面出发,以陈列文物为重点,研究了我国博物馆在陈文物的防震技术现状,分析了不足之处,提出了改进建议。结果表明:我国博物馆在陈文物目前以传统防震技术为主,虽然它们能在一定程度上减轻文物震害,但也存在破坏文物、影响外观、无参照标准等问题,应进行合理改进和完善;另一方面,对文物防震具有重要作用的防震博物馆及文物隔震台座在我国应进一步推广。     

Direct use values of communal resources in Bokong and Tsehlanyane in Lesotho: whither the commons?

SUMMARY

This paper presents a comprehensive assessment of the contribution of communal resources to households in Bokong and Tsehlanyane in Lesotho. It argues that communal resources are an extremely important element in the livelihoods of people in the study area. It uses households as units of analysis in order to gain an understanding of the role that communal resources play at the micro level before any extrapolations are made to the regional and national levels. A household survey, guided by a detailed semistructured questionnaire, was used. Ten newly constructed houses and vegetable garden enclosures were sampled to categorize and count all poles used to build them. The amount of thatch grass used in building those houses was also estimated. The results indicated that communal resources play a central role in the livelihoods of people in the area with firewood ($1492), crops ($1363) and wild vegetables ($774) recording the highest annual use values per household^?1 yr^?1. The total present value was estimated at $3899 household^?1 yr^?1 with firewood, crops and wild vegetables constituting 93% of that value. The study further demonstrated that communal resources are used across the entire income spread in the area, thereby negating the general belief that they are a preserve of the poor. Finally, the results demonstrated that very little value is derived through trading of resources both within and outside the area but through direct consumption within households invariably escaping national economic accounting. With declining employment rates in Lesotho due to continued retrenchments in the South African mining industry, communal resources in the country remain an indispensable resource that must be carefully managed for the common good.     

府河双流段水污染现状及控制对策

本文对府河双流段九三年至九八年连续六年的水质监测数据进行了总结,分析了府河双流段水质污染的现状和特点。提出了控制府河双流段水污染的对策建议。     

吉林省工业危险废物资源现状与循环利用

吉林省2007年工业危险废物总量为559．31万t,全省工业危险废物贮存总量为489．23万t,占全省工业危险废物总量的87．47％。吉林地区工业危险废物产生量最高,为123．02万t。全省工业危险废物综合处理指数为12．51,工业危险废物处理量很低。辽源地区工业危险废物综合处理指数最高,为100．00,长春地区工业危险废物综合处理指数亦较高,为98．54。长春地区现又有全省较大的工业危险废物处理厂。综合考虑,建立以长春和吉林地区为核心的工业危险废物循环利用和处置中心,加强工业危险废物的循环利用,不仅能合理地利用再生资源、增加社会经济效益,还能从根本上有效地防止工业危险废物对环境的污染。     

沭阳县生活垃圾现状调查及处理方案的优化选择

通过对沭阳县生活垃圾的现状调查与监测,并对国内外垃圾处理技术进行比较和优化,重点介绍垃圾处理新技术ITAD垃圾处理的方法,实现垃圾完全资源化利用,具有良好的经济效益和环境效益。     

国内外土壤种子库研究情况对比分析

摘要：土壤种子库是植被更新和生态恢复的自然来源。对生物多样性维护和植被的演替过程具有重要作用。通过查阅近年来国内外发表的关于土壤种子库的代表性文献,运用文献分析与管理软件EndnoteX3、Refviz和Excel数据处理软件对该领域的国内外研究情况进行了分析。同时,对国内外研究领域的扩展、土壤种子库的鉴别方法、土壤种子库的个体特征及群落结构的变化、土壤种子库的研究内容进行了系统对比,最后提出国内外对土壤种子库研究存在的问题,并就这些问题提出展望,为今后土壤种子库的研究工作提供了参考策略。     

全国环境规划院（所）建设现状、问题及思考分析

通过对全国各省环境规划院所的建设情况,如机构设立情况和业务领域及主要工作内容的了解,在此基础上,对比分析了城市规划和土地规划院所的建设与发展情况,并对环保系统的规划院所建设存在的问题进行了分析,认为现阶段中国环境规划院所能力建设存在职能定位尚不清晰、全国建设未形成规模效应、人员队伍力量薄弱、资质等硬件水平竞争力差以及基础保障不足等问题。结合中国环境保护工作面临的形势,提出中国环境规划院所的建设与完善的可行性建议。     

辽宁省环境服务业现状与发展建议

介绍了辽宁省环境服务业现状,对发展环境服务业过程中存在的问题与推进措施进行了探讨,并提出了相关建议。