全文获取类型
收费全文 | 1149篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 33篇 |
废物处理 | 13篇 |
环保管理 | 86篇 |
综合类 | 791篇 |
基础理论 | 78篇 |
污染及防治 | 109篇 |
评价与监测 | 34篇 |
社会与环境 | 5篇 |
灾害及防治 | 3篇 |
出版年
2022年 | 8篇 |
2021年 | 6篇 |
2019年 | 6篇 |
2018年 | 15篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 69篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 17篇 |
2002年 | 10篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1995年 | 56篇 |
1994年 | 50篇 |
1993年 | 41篇 |
1992年 | 33篇 |
1991年 | 26篇 |
1990年 | 32篇 |
1989年 | 25篇 |
1988年 | 34篇 |
1987年 | 30篇 |
1986年 | 21篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1979年 | 5篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1974年 | 4篇 |
1973年 | 10篇 |
1971年 | 4篇 |
1919年 | 47篇 |
1918年 | 44篇 |
1917年 | 36篇 |
1916年 | 53篇 |
1915年 | 37篇 |
1914年 | 71篇 |
1913年 | 106篇 |
排序方式: 共有1152条查询结果,搜索用时 46 毫秒
991.
992.
Prior to a prospective application of amniotic fluid (AF) cell filtration to early amniocentesis, we tested the technique on a surplus from mid-trimester samples. By using the same sample size of 5 ml in experiments with a filter and in routine diagnostic procedures (control), we evaluated an optimal filter system. The prolonged culture time of filtered cells and the reduced number of clones are most probably due to mechanical stress (filtration pressure), whereas loss of the cells by adhesion to the filter system, and an AF-free culture medium (growth factors) are suggested to be less important. The AF cells are very sensitive to mechanical stress. Slow filtration (⩽3 ml AF/min) through filters with a high porosity and the largest possible pore size should be preferred. A mixed cellulose ester filter membrane with a pore size of 5·0 μm proved to be the most efficient, allowing harvest of the filtered cells after only a slight prolongation of the culture time (+2·4 days) compared with unfiltered aliquots. A filter set with a bypass connected by three-way taps allows cell filtration during either aspiration or reinjection of the AF. Cell filtration after amniocentesis and consecutive reverse flushing of the membrane with the appropriate amount of culture medium proved to be the best with regard to easy handling and reducing the risk of bacterial contamination. 相似文献
993.
Ewa Beck-Krala Katarzyna Klimkiewicz 《International journal of occupational safety and ergonomics》2016,22(4):523-531
Occupational safety and health (OSH) plays a significant role in today’s organizations, because it helps in attracting and retaining employees as well as molding their attitudes and behaviors at work. This is why the issue of OSH is stressed in a comprehensive approach to employee rewards: the total reward concept. This article explains how OSH may be included in a complex evaluation process of the compensation system. Although the literature on the effectiveness of employee compensation refers mainly to financial and non-financial components, there is a need for inclusion of working conditions in such analyses. An evaluation of the compensation system that incorporates OSH can drive many benefits for both the organization and employees. Obtaining such benefits, however, requires systematic evaluation of the reward system, including OSH. Incorporation of OSH issue within the comprehensive analysis of compensation systems promotes responsible behavior of all stakeholders. 相似文献
994.
Mariusz Dąbrowski Jarosław Górski 《International journal of occupational safety and ergonomics》2019,25(2):278-286
One of the most serious causes of accidents in furniture making is kickback of machined material. The aim of this study was to determine the influence of the milling tool setup on hazards associated with kickback in furniture making. The speed of kickback was accepted as the measure of these hazards. The experiment involved controlled changes in milling tool setup, projection of cutting knives over the body of the milling tool, number of cutting knives and clearance angle. Multifactor analysis of variance was applied to the results of individual experiments, showing statistically significant factors and their interactions. Inspection and analysis of traces left by the cutting knives of the tools on the test pieces made of wood materials supported inferential statistics. The obtained results verified some common opinions and ideas on the impact of the milling tool setup on the hazards resulting from kickback in furniture making. 相似文献
995.
996.
997.
998.
999.
Ewa Szpyrka Anna Kurdziel Magdalena Słowik-Borowiec Magdalena Grzegorzak Aneta Matyaszek 《Environmental monitoring and assessment》2013,185(11):8873-8878
The production of apples in Poland is the largest among the countries of the European Union, and therefore, the consumption of these fruits is high in our country. The aim of this study was to determine the presence of pesticide residues in Polish apples and to assess if these residues pose a risk to the health of the consumer. Furthermore, compliance with legal regulations concerning the use of plant protection products in crop cultivation was ascertained. Pesticide residues were found in 192 samples (61.5 % of tested samples). In six samples (1.9 %), residues exceeded maximum residue limits. Violations concerned the insecticides: indoxacarb, diazinon and fenitrothion. The highest long-term consumer exposure was found in the case of consumption of apples with diazinon residue for both groups, adults and toddlers [4 % acceptable daily intake (ADI), adults; 21 % ADI, toddlers]. The highest values of short-term exposure were obtained in the case of consumption of apples with indoxacarb [5 % acute reference dose (ARfD), adults; 27 % ARfD, toddlers] and fenitrothion (4 % ARfD, adults; 23 % ARfD, toddlers). Although fungicides are the pesticides found most often in apples, the consumption of apples with insecticide residues constitutes the greatest hazard to human health. 相似文献
1000.
A territorial male can shift the location of its territory from year to year in order to increase its quality. The male can
base its decision on environmental cues or else on its breeding experiences (when territory shift is caused by breeding failure
in previous seasons). We tested these possible mechanisms of territory choice in the sedge warbler (Acrocephalus schoenobaenus), a territorial migrating passerine that occupies wetlands. This species bases its territory choices on an environmental
cue: tall wetland vegetation cover. We found that the magnitude of territory quality improvement between seasons (measured
as the area of tall wetland vegetation) increased throughout the early stages of a male's breeding career as a result of territory
shifts dependent on the earliness of arrival. The distance the territory was shifted between seasons depended negatively on
the previous year's territory quality and, less clearly, on the previous year's mating success. On the other hand, previous
mating or nesting success had no influence on territory quality improvement between seasons as measured in terms of vegetation.
The results imply that tall wetland vegetation is a long-term, effective environmental cue and that a preference for territories
in which this type of landcover prevails has evolved into a rigid behavioral mechanism, supplemented by short-term individual
experiences of breeding failure. 相似文献