首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1014篇
  免费   158篇
  国内免费   14篇
安全科学   355篇
废物处理   19篇
环保管理   192篇
综合类   389篇
基础理论   107篇
污染及防治   31篇
评价与监测   37篇
社会与环境   36篇
灾害及防治   20篇
  2025年   8篇
  2024年   24篇
  2023年   41篇
  2022年   52篇
  2021年   50篇
  2020年   33篇
  2019年   46篇
  2018年   45篇
  2017年   64篇
  2016年   37篇
  2015年   49篇
  2014年   45篇
  2013年   62篇
  2012年   52篇
  2011年   75篇
  2010年   42篇
  2009年   59篇
  2008年   34篇
  2007年   54篇
  2006年   54篇
  2005年   38篇
  2004年   29篇
  2003年   34篇
  2002年   28篇
  2001年   20篇
  2000年   25篇
  1999年   15篇
  1998年   20篇
  1997年   6篇
  1996年   5篇
  1995年   2篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   4篇
  1984年   2篇
  1983年   6篇
  1982年   2篇
  1981年   3篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1971年   1篇
排序方式: 共有1186条查询结果,搜索用时 0 毫秒
991.
Human mercury (Hg) exposure in two contrasting areas of mining and mineral processing activity on the Philippine islands of Mindanao and Palawan was evaluated using hair analysis. On Mindanao, samples were collected from residents of Apokon, a major regional centre for gold beneficiation. On Palawan, a former cinnabar mine and mine-waste disposal site in Honda Bay formed the focus of investigation. Relatively high hair Hg burdens (up to 13mg Hg kg–1 at Apokon and 18.5mg Hg kg–1 in Honda Bay) were observed in both populations, with occupational factors apparently constituting a first-order exposure control. At Apokon, hair burdens in excess 2mg Hg kg–1 were recorded in 90% of Au processing plant workers, compared with 21% of other sectors of the population. In Bay, ex-mineworkers, although possibly subject to occupational Hg exposure in the past, now display no evidence of this influence. Fishermen, however, systematically yielded hair Hg concentrations a factor of 2.5 higher than those of the remaining population. Approximately 7% of the Apokon and Honda Bay residents sampled presented hair Hg concentrations equal to or in excess of the World Health Organisation (WHO) reference dose. There is little evidence to indicate that residential factors significantly influence Hg exposure in either area. Hazard mitigation strategies involving the isolation of resident populations from perceived contaminant sources such as ore processing plant and sites of mine-waste disposal are, therefore, unlikely to prove beneficial.  相似文献   
992.
Health risks of gold miners: a synoptic review   总被引:1,自引:0,他引:1  
Health problems of gold miners who worked underground include decreased life expectancy; increased frequency of cancer of the trachea, bronchus, lung, stomach, and liver; increased frequency of pulmonary tuberculosis (PTB), silicosis, and pleural diseases; increased frequency of insect-borne diseases, such as malaria and dengue fever; noise-induced hearing loss; increased prevalence of certain bacterial and viral diseases; and diseases of the blood, skin, and musculoskeletal system. These problems are briefly documented in gold miners from Australia, North America, South America, and Africa. In general, HIV infection or excessive alcohol and tobacco consumption tended to exacerbate existing health problems. Miners who used elemental mercury to amalgamate and extract gold were heavily contaminated with mercury. Among individuals exposed occupationally, concentrations of mercury in their air, fish diet, hair, urine, blood, and other tissues significantly exceeded all criteria proposed by various national and international regulatory agencies for protection of human health. However, large-scale epidemiological evidence of severe mercury-associated health problems in this cohort was not demonstrable.  相似文献   
993.
Source of lead in humans from Broken Hill mining community   总被引:3,自引:0,他引:3  
This paper documents the first precise lead isotope measurements for men, women and children from the same family in an attempt to determine the source of lead in their blood. The subjects reside in one of the world's largest lead mining cities, Broken Hill, NSW, Australia. Biological and environmental samples have been compared using isotopic compositions and lead contents. Adult males have isotopic profiles (or compositions) which appear to be related to their occupations. Adult females have low blood leads (<10 g dL–1) and their main source of lead is not from the mine dumps around which the city is built but probably from a mixture of petrol, food and perhaps water. The blood lead contents in children from 1 to 14 years old vary and are partly dependent on age. There is a moderate correlation of blood lead and isotopic compositions (r = 0.73) indicating that a significant component of blood lead derives from the mine dumps in children with elevated blood leads. Some children with blood leads <20 g dL–1, however, also have a dominant component of mine lead in their blood  相似文献   
994.
    
Systematic reviews are an increasingly popular decision‐making tool that provides an unbiased summary of evidence to support conservation action. These reviews bridge the gap between researchers and managers by presenting a comprehensive overview of all studies relating to a particular topic and identify specifically where and under which conditions an effect is present. However, several technical challenges can severely hinder the feasibility and applicability of systematic reviews, for example, homonyms (terms that share spelling but differ in meaning). Homonyms add noise to search results and cannot be easily identified or removed. We developed a semiautomated approach that can aid in the classification of homonyms among narratives. We used a combination of automated content analysis and artificial neural networks to quickly and accurately sift through large corpora of academic texts and classify them to distinct topics. As an example, we explored the use of the word reintroduction in academic texts. Reintroduction is used within the conservation context to indicate the release of organisms to their former native habitat; however, a Web of Science search for this word returned thousands of publications in which the term has other meanings and contexts. Using our method, we automatically classified a sample of 3000 of these publications with over 99% accuracy, relative to a manual classification. Our approach can be used easily with other homonyms and can greatly facilitate systematic reviews or similar work in which homonyms hinder the harnessing of large text corpora. Beyond homonyms we see great promise in combining automated content analysis and machine‐learning methods to handle and screen big data for relevant information in conservation science.  相似文献   
995.
矿冶区周边水稻对不同来源重金属污染的指示作用   总被引:4,自引:1,他引:4  
有色金属开采与冶炼可对周边环境造成严重的重金属污染,查明重金属污染来源对于矿冶周边重金属污染管理与控制具有重要意义.为探索利用矿冶周边水稻对As、Cd、Pb、Zn和Cu的富集与水稻体内元素的含量平衡特征指示重金属污染来源的可行性,选择了我国著名的水口山Pb-Zn矿山开采与冶炼周边区,根据重金属污染排放和迁移扩散特征,结合当地气象和地貌条件,确定了3个典型采样区,其中两个采样区分别邻近冶炼厂和尾砂库,另一处为位于两者之间的过渡区.采用蛇形采样法在稻田内采集33个成熟水稻及土壤样品,分析水稻不同部位(包括根、茎叶、籽粒)及土壤中As、Cd、Pb、Zn、Cu5种重金属和其他16种元素的含量.结果表明,3个采样区之间土壤中的As、Cd、Pb、Zn和Cu含量均存在显著性差异;各采样区水稻中除根际和籽粒中Cd含量外,各部位重金属含量也均有显著差异.靠近冶炼厂的水稻茎叶中As、Pb含量高于离冶炼厂较远的采样区水稻茎叶.尽管As、Pb在靠近尾砂库采样区土壤中含量最高,但在该区水稻茎叶中的含量却最低;在除As、Cd、Pb、Zn、Cu5种重金属以外的其他16种元素中,水稻根部仅有5种元素含量在各采样区之间存在差异,指示相同的土地利用类型及土壤母质条件;而在茎叶和籽粒中则分别有多达11和10种元素含量出现采样区差异,指示重金属污染来源影响水稻茎叶及籽粒中元素的含量平衡.多元统计分析结果显示,3个采样区水稻茎叶中元素含量平衡存在显著的分异,显示出明显的采样区属性.结合采样区域空间位置、污染物来源、水稻对重金属的富集与转运特征分析,3个采样区重金属主要污染特征可分别确定为水-气混合来源型、大气来源型和尾砂来源型.论文结果证明利用水稻茎叶指示矿冶周边重金属污染来源是可行的.  相似文献   
996.
    
Abstract

Small-scale miners often engage in environmentally damaging activities, are subject to poor safety conditions, and utilize inefficient mineral extraction technologies. Here, we explore environmental impacts to surface waters from regional artisanal small-scale gold placer mining operations conducted in iron and aluminum-rich saprolites found within the lateritic, interior Amazon rainforest of Suriname. Heavy equipment was utilized to release gold from its host material followed by amalgamation and gravity separation. In contrast with background tributary recordings, streams adjacent to these gold mining operations consistently contained turbidity measurements that exceeded United States’ EPA guidelines for aquatic species of 50 nephelometric turbidity units and were typically in the hundreds to thousands of units. Turbidity was further heightened in association with precipitation events. Mercury played a prominent role in whole ore amalgam concentration practices. Freshwater fish from the region were found to harbor mercury that encroached upon public health criteria. Dissolved phase metals present further ecotoxicological challenges to the region, but their association with mining activities was less clear. These findings collectively reveal that small-scale placer gold mining practices in the Surinamese rainforest result in an increase of suspended sediments and release of mercury into waterways that could impact communities that depend upon local fisheries.  相似文献   
997.
通过介绍在德兴铜矿应用MPS-2型抑尘剂,建造现场抑尘加工站,并在矿山采场道路喷洒抑尘剂,测试分析了抑尘剂的抑尘效果,并对其经济成本指标进行了测算,确认在该矿应用MPS-2型抑尘剂可创造显著的社会环境效益和经济效益。  相似文献   
998.
根据滇东南矿区河流底泥重金属数据,应用HANKANSON潜在生态危害指数法对重金属的潜在生态风险进行评价。结果表明:①该地区河流底泥中产生生态危害的主要重金属是Cd和As;②从上游到下游A~G 7个断面多重金属潜在生态风险指数(R I)从小到大排列依次为:A相似文献   
999.
以广东梅州明山煤矿尾矿区土著先锋植物鬼针草(Bidens bipinnata)为研究对象,开展3种黄土与煤矸石基质配比条件下根内球囊霉(Glomus intraradices BGC BJ09)(A1)、摩西球囊霉(G.mosseae BGC NM01A)(A2)、摩西球囊霉(G.mosseae BGC HEB07B)(A3)和地表球囊霉(G.versiforme BGC GD01C)(A4)这4种丛枝菌根真菌接种对土壤重金属的吸收对比研究。结果表明,从宿主生物量、菌根侵染率及侵染强度、孢子密度、根系活力来看,A4是最适合鬼针草的菌种。与对照(4种菌剂混合后灭菌)相比,A1可显著促进地上部Cd吸收;4种菌根对Cu和Mn的吸收-排斥效应均不显著,但接种A3对地下部Cu和Mn以及接种A4对地下部Mn的移除量显著增加;接种4种菌根处理的Ni移除量均显著增加。接种菌根且覆土少(2 cm厚黄土覆于9 cm厚煤矸石上)的处理植株生物量均高于不接种且覆土厚(7 cm厚黄土覆于4 cm厚煤矸石上)的处理,说明接种菌根具有抵消由于覆土少而导致的植株生物量降低的潜力,极大地节约复垦费用。  相似文献   
1000.
以安太堡露天煤矿生态复垦区0.8 hm2刺槐+油松混交林样地为研究平台,基于样地内320个1 m×1 m草本样方的调查数据,对复垦17年后草本层的物种组成、基本数量特征和空间分布等进行研究.结果表明:样地内草本层物种组成丰富,共调查到44种植物,隶属于16科30属,其中禾本科和菊科为优势科,黄花蒿、披碱草和大籽蒿为优势种,初期种植种无芒雀麦等退化严重;重要值、多度和频度在各科和各种之间差值较大;优势科和优势种分布广泛,但物种分布呈现出明显的空间异质性.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号