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   1066篇
  免费   53篇
  国内免费   57篇
安全科学   140篇
废物处理   19篇
环保管理   216篇
综合类   460篇
基础理论   142篇
污染及防治   48篇
评价与监测   69篇
社会与环境   49篇
灾害及防治   33篇
  2024年   1篇
  2023年   10篇
  2022年   16篇
  2021年   28篇
  2020年   33篇
  2019年   27篇
  2018年   19篇
  2017年   40篇
  2016年   36篇
  2015年   37篇
  2014年   53篇
  2013年   76篇
  2012年   52篇
  2011年   92篇
  2010年   64篇
  2009年   68篇
  2008年   54篇
  2007年   64篇
  2006年   32篇
  2005年   51篇
  2004年   33篇
  2003年   46篇
  2002年   39篇
  2001年   26篇
  2000年   42篇
  1999年   28篇
  1998年   20篇
  1997年   17篇
  1996年   11篇
  1995年   12篇
  1994年   7篇
  1993年   6篇
  1992年   5篇
  1991年   1篇
  1990年   4篇
  1989年   3篇
  1988年   1篇
  1987年   5篇
  1985年   4篇
  1984年   2篇
  1983年   3篇
  1982年   3篇
  1978年   2篇
  1972年   2篇
  1971年   1篇
排序方式: 共有1176条查询结果,搜索用时 140 毫秒
801.
根据主体特征,将污染转嫁分为涉外污染转嫁和内部污染转嫁。其法律责任包括行政责任,民事责任和刑事责任。分别就这三种责任的构成要件及责任分担,作了具体分析,并提出了作者的见解。  相似文献   
802.
我国胭脂鱼资源现状及其资源恢复途径的探讨   总被引:19,自引:0,他引:19  
胭脂鱼为我国特有鱼类 ,已知仅分布于长江和闽江。目前胭脂鱼在长江水系中的资源量明显减少 ,数量已较国家一类水生野生保护动物中华鲟和达氏鲟为少 ;闽江胭脂鱼种群几近绝迹。造成胭脂鱼资源下降的原因主要与其自身繁殖力低 ,发育时间长 ,以及过度捕捞和水域污染等因素有关。人工放流是恢复长江胭脂鱼资源的重要手段。  相似文献   
803.
本文对散打比赛中散打运动员合理的运用技战术稳定的心理状态及散打运动员不良的心理状态的分析,提出有效的心理调节的训练方法。  相似文献   
804.
环境(非关税)贸易壁垒判析及其对策探讨   总被引:6,自引:0,他引:6  
卜欣欣 《上海环境科学》2000,19(2):50-52,55
WTO中有关环境的,国际环境公约、ISO14000、等有关条款,本身并非绿色贸易壁垒,基于此,分析了绿色贸易壁垒的起因特征,对其相模糊的条款与规定,有可能成为绿色贸易壁垒的误区作了判析,提出了绿色贸易壁垒的5种形式:环境税、市场准入、环境技术标准、环境标志和贸易制裁,以及我国的对策思路。  相似文献   
805.
简要介绍了环境权理论及其法律实践,指出应当同时从实体意义和程序意义两个方面来理解和把握环境权;明确和界定了“救济”的含义,并进一步指出环境权救济法律制度包括 环境民事救济法和环境行政救济法两大部分。而前者又可分为环境侵害的民事排除和环境侵权损害的民事赔偿法;后者又可分为环境侵害的行政排除法、环境侵权损害的行政补偿法、环境民事纠纷行政处理法、环境行政权损害的国家赔偿法等。  相似文献   
806.
Abstract:  Priority setting is an essential component of biodiversity conservation. Existing methods to identify priority areas for conservation have focused almost entirely on biological factors. We suggest a new relative ranking method for identifying priority conservation areas that integrates both biological and social aspects. It is based on the following criteria: the habitat's status, human population pressure, human efforts to protect habitat, and number of endemic plant and vertebrate species. We used this method to rank 25 hotspots, 17 megadiverse countries, and the hotspots within each megadiverse country. We used consistent, comprehensive, georeferenced, and multiband data sets and analytical remote sensing and geographic information system tools to quantify habitat status, human population pressure, and protection status. The ranking suggests that the Philippines, Atlantic Forest, Mediterranean Basin, Caribbean Islands, Caucasus, and Indo-Burma are the hottest hotspots and that China, the Philippines, and India are the hottest megadiverse countries. The great variation in terms of habitat, protected areas, and population pressure among the hotspots, the megadiverse countries, and the hotspots within the same country suggests the need for hotspot- and country-specific conservation policies.  相似文献   
807.
808.
Abstract:  Endangered species lists are important tools in conservation. It is essential that these lists be prepared using categorization systems that objectively assess species extinction risk. To determine which threatened species categorization system is the most appropriate and the virtues and limitations of systems used on the American continent, we evaluated 25 categorization systems from 20 countries. These systems included examples of international lists, most national systems used on the American continent, and some systems independently proposed by academics. We based our assessment on 15 characteristics that categorization systems should have, in terms of categories, criteria, and other relevant issues, in order to evaluate species conservation status objectively. Of all evaluated systems, the current World Conservation Union system is the most suitable for assessing species extinction risk. Most categorization systems, but particularly national systems, have serious deficiencies and need to be improved substantially. We recommend governments use three types of lists: (1) threatened species lists constructed following a sound categorization system, (2) lists of species of conservation priority, and (3) lists that serve as normative tools (e.g., Convention on International Trade in Endangered Species of Wild Fauna and Flora). Additionally, the information used to categorize species should be explicit and available to the public. To make the most of threatened species lists in conservation, it is imperative that all countries use the same categorization system.  相似文献   
809.
The Consistency of Extinction Risk Classification Protocols   总被引:1,自引:0,他引:1  
Abstract:  Systematic protocols that use decision rules or scores are seen to improve consistency and transparency in classifying the conservation status of species. When applying these protocols, assessors are typically required to decide on estimates for attributes that are inherently uncertain. Input data and resulting classifications are usually treated as though they are exact and hence without operator error. We investigated the impact of data interpretation on the consistency of protocols of extinction risk classifications and diagnosed causes of discrepancies when they occurred. We tested three widely used systematic classification protocols employed by the World Conservation Union, NatureServe, and the Florida Fish and Wildlife Conservation Commission. We provided 18 assessors with identical information for 13 different species to infer estimates for each of the required parameters for the three protocols. The threat classification of several of the species varied from low risk to high risk, depending on who did the assessment. This occurred across the three protocols investigated. Assessors tended to agree on their placement of species in the highest (50–70%) and lowest risk categories (20–40%), but there was poor agreement on which species should be placed in the intermediate categories. Furthermore, the correspondence between the three classification methods was unpredictable, with large variation among assessors. These results highlight the importance of peer review and consensus among multiple assessors in species classifications and the need to be cautious with assessments carried out by a single assessor. Greater consistency among assessors requires wide use of training manuals and formal methods for estimating parameters that allow uncertainties to be represented, carried through chains of calculations, and reported transparently.  相似文献   
810.
The work-conflict hypothesis (Reeve 1992) postulates that in eusocial naked mole-rat (Heterocephalus glaber) colonies there is potential conflict between the breeding female and her non-breeding colony mates over how much aid they provide in support of her reproduction. Non-breeders may withhold aid either because they are hopeful reproductives and/or because they have less to gain in terms of inclusive fitness. Breeding females should, therefore, preferentially direct aggression in the form of shoving (prolonged pushes usually involving nose-to-nose contact) towards large (hopeful reproductives) and less related non-breeders to incite them to provide aid. This study tested the following predictions of the work-conflict hypotheses. (1) There is kin bias in the shove rate of breeding females and work rates of non-breeders; (2) Shoving activates work in non-breeders. We found no evidence to suggest that the breeding female shove rate and the amount of colony maintenance activities performed by non-breeders is influenced by relatedness. Body size was a better predictor of work rate and shove rate; large animals were shoved more and worked less. Furthermore, shoving did not affect the work rate of non-breeders and rarely incited activity in inactive mole-rats. Individual mole-rats were also more likely to be shoved when already active than when resting in the nest. These results suggest that shoving by the breeding female may have functions other than the incitement of activity, such as the reproductive suppression of non-breeders. Received: 17 January 1996 / Accepted after revision: 21 September 1996  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