全文获取类型
收费全文 | 2314篇 |
免费 | 295篇 |
国内免费 | 770篇 |
专业分类
安全科学 | 399篇 |
废物处理 | 43篇 |
环保管理 | 205篇 |
综合类 | 1731篇 |
基础理论 | 344篇 |
环境理论 | 1篇 |
污染及防治 | 182篇 |
评价与监测 | 188篇 |
社会与环境 | 182篇 |
灾害及防治 | 104篇 |
出版年
2024年 | 18篇 |
2023年 | 74篇 |
2022年 | 122篇 |
2021年 | 139篇 |
2020年 | 168篇 |
2019年 | 111篇 |
2018年 | 142篇 |
2017年 | 146篇 |
2016年 | 150篇 |
2015年 | 141篇 |
2014年 | 149篇 |
2013年 | 196篇 |
2012年 | 212篇 |
2011年 | 217篇 |
2010年 | 178篇 |
2009年 | 168篇 |
2008年 | 93篇 |
2007年 | 161篇 |
2006年 | 150篇 |
2005年 | 104篇 |
2004年 | 90篇 |
2003年 | 92篇 |
2002年 | 72篇 |
2001年 | 49篇 |
2000年 | 51篇 |
1999年 | 26篇 |
1998年 | 27篇 |
1997年 | 19篇 |
1996年 | 17篇 |
1995年 | 18篇 |
1994年 | 24篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有3379条查询结果,搜索用时 125 毫秒
951.
952.
A cross-validation of safety climate scale using confirmatory factor analytic approach 总被引:4,自引:0,他引:4
PROBLEM: Given the lack of a consistent factor structure of safety climate, this study tested the stability of a factor structure of a safety climate scale developed through an extensive literature review using confirmatory factor analytic approach and cross-validation. METHODS: A cross-sectional sample of 722 U.S. grain industry workers participated in the questionnaire survey. RESULTS: The safety climate scale developed through the generation of an item pool based on a table of specifications, subsequent scientific item reduction procedures, reviews from experts, and pilot test yielded adequate reliabilities for each dimension. Each item showed proper discriminative power based on both internal and external criteria. Criterion validity was manifested by the significant positive correlation of the scale with five criteria. Evidence of construct validity was provided by both exploratory and confirmatory factor analyses. Both calibration and validation samples supported a consistent factor structure. Management commitment and supervisor support were found to influence other dimensions of safety climate. DISCUSSION: This study provides an insight into the primary reason why previous attempts have failed to find a consistent factor structure of safety climate: No specification of the influence of management commitment and supervisor support on other dimensions of safety in their models. IMPACT ON INDUSTRY: The findings of this study provide a framework upon which accident prevention efforts can be effectively organized and underscore the importance of management commitment and supervisor support as they affect employee safety perceptions. 相似文献
953.
Declines in salmon stocks and general watershed health in Washington State, USA, have led to an increase in stream restoration
and enhancement projects initiated throughout the state. The increasing number of projects has also raised questions regarding
the monitoring of these efforts. Project managers receiving hydraulic project approvals (HPAs) were surveyed to determine
whether monitoring was taking place on their projects. About half the project managers surveyed reported the collection of
baseline data and the use of biological, physical, chemical, or other water quality measures for their projects. Of those
who reported collection of monitoring data, only 18% indicated that monitoring was required. Respondents were also asked to
rank the importance of various project goals on a Likert scale. Project managers with projects focusing on “engineering” goals
(e.g., roadbed stabilization) were less likely than other project managers to collect baseline monitoring data. Project managers
with projects focusing on “restoration/ecological” or “fisheries” goals were more likely than other project managers to collect
monitoring measures. Although monitoring appears to be taking place in slightly more than half of the projects surveyed, the
nature of the data collected varies widely across projects, and in most cases the monitoring effort is voluntary. This suggests
that project sponsors, funders, and managers must consider the issues involved in requiring appropriate monitoring, establishing
standardized monitoring guidelines, the time frames in which to monitor, providing other incentives for conducting monitoring,
and ensuring adequate funding for monitoring efforts. 相似文献
954.
不锈钢板卷生产过程中的危险因素及对策 总被引:1,自引:0,他引:1
根据国内的不锈钢板卷生产工艺状况 ,分析并指出了生产过程中可能出现的危险和有害因素 ,同时对生产性粉尘、噪声和高温进行了劳动条件分级 ,从而提出了相应的对策。 相似文献
955.
956.
中国区域可持续发展水平的时空分异初探 总被引:19,自引:2,他引:17
本文通过因子分析,建立了中国可持续发展的因子结构模型,指出:(1)社会经济发展呈现“丁”字型格局;(2)环境污染东、中部严重,西部较轻;(3)生态退化西重东轻,北重南轻;(4)中国“环境与发展”时序上大致呈现“U”字型规律,29个省市分别与“U”曲线的逆向非同速(加速)阶段、同向非同速(加速)阶段、同向非同速(减速)阶段在地域上联系起来。 相似文献
957.
958.
959.
河流水质预测的因素状态网络模型研究 总被引:6,自引:0,他引:6
建立了一种河流水质预测的因素状态人工神经网络模型,其算例的计算结果表明,这一种方法有着极大的研究意义和广阔的应用前景。 相似文献
960.