全文获取类型
收费全文 | 769篇 |
免费 | 38篇 |
国内免费 | 311篇 |
专业分类
安全科学 | 50篇 |
废物处理 | 45篇 |
环保管理 | 57篇 |
综合类 | 464篇 |
基础理论 | 152篇 |
环境理论 | 1篇 |
污染及防治 | 239篇 |
评价与监测 | 37篇 |
社会与环境 | 38篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 36篇 |
2021年 | 29篇 |
2020年 | 14篇 |
2019年 | 26篇 |
2018年 | 28篇 |
2017年 | 33篇 |
2016年 | 34篇 |
2015年 | 37篇 |
2014年 | 48篇 |
2013年 | 68篇 |
2012年 | 62篇 |
2011年 | 65篇 |
2010年 | 52篇 |
2009年 | 51篇 |
2008年 | 53篇 |
2007年 | 42篇 |
2006年 | 63篇 |
2005年 | 36篇 |
2004年 | 25篇 |
2003年 | 35篇 |
2002年 | 46篇 |
2001年 | 29篇 |
2000年 | 38篇 |
1999年 | 32篇 |
1998年 | 19篇 |
1997年 | 23篇 |
1996年 | 19篇 |
1995年 | 15篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有1118条查询结果,搜索用时 703 毫秒
301.
302.
An improved implementation of distributed multiplier/fictitious domain method is presented for the direct numerical simulation of particulate flow. The key improvement is to replace a finite-element triangulation for the velocity and a “twice-coarser“ triangulation for the pressure with a rectangular discretization for the velocity and pressure. For code validation, the sedimentation of a single particle in a twodimensional channel was simulated. The results showed that the simulation is independent of the mesh size as well as the time step. The comparison between experimental data and this simulation showed that our code can give a more accurate simulation on the motion of particlesthan previous DLM code. The code was then applied to simulate the sedimentation of 600 particles in a rectangular box. The falling course ispresented and discussed. At the same time, this simulation also demonstrates that the method presented in this paper can be used for solving the initial problems involving a lager number of particles exaclly with computing durations kept at acceptable levels. 相似文献
303.
化学沉淀法去除水中氨氮的试验研究 总被引:17,自引:0,他引:17
研究进行了用Mg2 + 、Mn2 + 分别与PO4 3- 作用去除NH4 + N的试验研究 ,探讨其化学反应机理 ,确定了最佳投药比、反应pH和Mg2 + 、Mn2 + 的协同效应 ,并对广州李坑垃圾填埋场渗滤液中NH4 + N进行了处理 ,其中最大NH4 + N去除率达 96 .1 %。 相似文献
304.
根据在北京市道路路面附近颗粒物 (TSP)的实测数据 ,分析了道路峡谷内 TSP的粒径分布 ,以及粒径分布与峡谷结构、距地面距离的关系 ,说明了影响粒径分布的主要因素。 相似文献
305.
306.
307.
308.
煤矿矿区环境污染现状及控制对策 总被引:10,自引:1,他引:10
随着可持续发展研究的深入,在煤炭开采中的环境保护越来越受人们的重视,分析了煤矿环境污染的现状,提出了响应的控制对策。 相似文献
309.
310.
Laurent M. Lapierre Yanhong Li Ho Kwong Kwan Jeffrey H. Greenhaus Marco S. DiRenzo Ping Shao 《组织行为杂志》2018,39(4):385-401
This study meta‐analytically examined theoretically derived antecedents of both directions of work–family enrichment (sometimes labeled facilitation or positive spillover), namely, work–family enrichment and family–work enrichment. Contextual and personal characteristics specific to each domain were examined. Resource‐providing (e.g., social support and work autonomy) and resource‐depleting (e.g., role overload) contextual characteristics were considered. Domain‐specific personal characteristics included the individuals' psychological involvement in each domain, the centrality of each domain, and work engagement. Results based on 767 correlations from 171 independent studies published between 1990 and 2016 indicate that several contextual and personal characteristics have significant relationships with enrichment. Although those associated with work tend to have stronger relationships with work–family enrichment and those associated with family tend to have stronger relationships with family–work enrichment, several antecedent variables have significant relationships with both directions of enrichment. Resource‐providing contextual characteristics tend to have stronger relationships with enrichment than do resource‐depleting characteristics. There was very little evidence of gender being a moderator of relationships between contextual characteristics and enrichment. Lastly, meta‐analytic structural equation modeling provided evidence that a theoretical path model wherein work engagement mediates between several contextual characteristics and enrichment is largely generalizable across populations. 相似文献