全文获取类型
收费全文 | 1275篇 |
免费 | 10篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 1093篇 |
废物处理 | 4篇 |
环保管理 | 50篇 |
综合类 | 69篇 |
基础理论 | 19篇 |
环境理论 | 1篇 |
污染及防治 | 11篇 |
评价与监测 | 6篇 |
社会与环境 | 12篇 |
灾害及防治 | 30篇 |
出版年
2023年 | 17篇 |
2022年 | 4篇 |
2021年 | 52篇 |
2020年 | 58篇 |
2019年 | 22篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 23篇 |
2015年 | 29篇 |
2014年 | 37篇 |
2013年 | 39篇 |
2012年 | 59篇 |
2011年 | 30篇 |
2010年 | 23篇 |
2009年 | 32篇 |
2008年 | 26篇 |
2007年 | 29篇 |
2006年 | 28篇 |
2005年 | 80篇 |
2004年 | 119篇 |
2003年 | 81篇 |
2002年 | 56篇 |
2001年 | 38篇 |
2000年 | 72篇 |
1999年 | 73篇 |
1998年 | 68篇 |
1997年 | 35篇 |
1996年 | 36篇 |
1995年 | 55篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1295条查询结果,搜索用时 15 毫秒
731.
按照《标准化伙食团管理评估考核表》4个类别18项工作任务,对某铁路辖区申报创建标准化伙食团的单位进行验收.结果显示,统一综合管理、设备卫生清洁、人员健康管理、场所卫生清洁工作较为到位,扣分较多集中在控制油盐食品、严格进货查验、统一资料台账和设备容器标识.结合考核验收情况,提出应进一步加强标准化伙食团创建工作、加强各部门... 相似文献
732.
Rothley KD 《Environmental management》2006,38(3):327-337
Many reserve selection tools have been created to solve the minimum representation problem, selecting the least costly set
of sites such that all conservation surrogate targets are met. However, there are practical problems and risks associated
with this method for finding reserve network alternatives, including the treatment of persistence-promoting design considerations
as secondary objectives. Here, reserve networks are generated for a hypothetical landscape where the objectives are to maximize
representation and to maximize conformance with persistence-promoting design principles, subject to a constraint on the number
of sites in the networks. The efficiency of potential networks is calculated as the total number of species captured in the
included sites. Effectiveness is measured as a function of the size of individual patches, total reserve size, and extent
of interpatch connectivity. A series of tradeoff curves are produced showing the nondominated compromise alternatives between
representation and design for organisms with varying dispersal capabilities. Each alternative comprises a list of selected
sites and covers species, as well as the identities and locations of the interpatch edges connecting the sites. Potential
ways to use the results are discussed. 相似文献
733.
This paper offers an interpretation of the precautionary principle in terms of a safety target that a decision-maker has to
reach at a minimal cost in a robust way. A two-period model is used. The precautionary principle corresponds to a situation
in which the decision-maker, facing an ex ante indecision, is not able to reach a safe target from the initial condition in a worst-case framework. However, he can efficiently
succeed whenever the uncertainty at the second period is revealed to him. An example coping with the management of a renewable
resource illustrates the general results of the paper.
相似文献
Jean-Christophe PereauEmail: |
734.
735.
736.
慧星试验对水体安全性分析研究 总被引:1,自引:0,他引:1
利用彗星试验检测苏南某湖泊湖心区、长江某取水口及其给水处理厂出水水样的遗传毒性,并对结果进行分析研究.结果表明,各水样均能引起DNA损伤,在丰水期致DNA损伤作用的大小顺序为给水厂出水水样>湖泊水样>长江取水口水样;在枯水期致DNA损伤作用的大小顺序为湖泊水样>长江取水口水样>给水厂出水水样.随着染毒剂量的加大,细胞损伤率增加,细胞受损的程度也在加重,并向3、4级损伤集中,呈明显的剂量-效应关系. 相似文献
737.
Joachim G. Frommen Meike Hiermes Theo C. M. Bakker 《Behavioral ecology and sociobiology》2009,63(8):1141-1148
Many animals live in groups most of their life. One function of this behaviour is an increased predator protection whereas
larger groups provide better protection than smaller ones. A causal explanation is that due to a higher number of shoal members
the individual risk of being predated will decrease (“dilution effect”). Additionally, shoaling leads to increased predator
confusion. This “confusion effect” can be strengthened by an increased group density, which often correlates with group size.
Many studies found that individuals prefer the larger of two groups. However, whether this preference is due to a larger group
size or because of an increased density of the larger group remained unclear. To disentangle these factors we gave three-spined
sticklebacks (Gasterosteus aculeatus) the choice between shoals of (1) different group size and density, (2) different group size, but equal density and (3) equal
group sizes, but different densities. As expected, test fish preferred the larger and denser shoal over the smaller, less
dense one. This preference was lost when shoal size differed but density was kept constant. When shoal size was equal but
density differed, test fish preferred the less dense shoal. However, this was only the case when test fish chose between two
relatively dense shoals. On the other hand, when overall density was low, test fish did not discriminate between shoals of
different densities. This result may be explained in terms of predator avoidance. The results show that shoaling preferences
might not always be influenced by a higher number of group members but also by the density and cohesiveness of the respective
groups.
An erratum to this article can be found at 相似文献
738.
Infrastructure planning very often underestimates safety issues in the early design phase. The reason for this is not necessarily the overwhelming importance of other aspects, such as functionality and economic considerations. Rather, the controversial views on safety held by different safety experts accounts for the major reason for not attributing safety the importance it deserves. In this paper we propose a seven-step methodology that allows multiple decision makers to evaluate infrastructure alternatives using safety and other indicators in early project phases. The methodology is based on analytic risk assessments, where the decision makers are asked to make ordinal tradeoffs among different safety, economic, and subjective aspects. The methodology allows multiple decision makers to aggregate preferences for different alternatives evaluated by different decision makers in a participative fashion. The proposed methodology was implemented in the Multimedia Group Decision Support Room at Delft University of Technology. The methodology was validated using real decision makers to show its realism and potential for participative decision making in safety planning. 相似文献
739.
从安全生产标准化建设的内容、制定方法、体系及效果,结合实际经验进行了探讨.安全生产标准化建设的实施为职工创造了一个安全舒适的工作环境,制约了生产过程中的不安全因素,避免了因环境因素引起的违章作业,是传统安全管理迈向科学安全管理的必由之路. 相似文献
740.