全文获取类型
收费全文 | 31767篇 |
免费 | 392篇 |
国内免费 | 268篇 |
专业分类
安全科学 | 1095篇 |
废物处理 | 1531篇 |
环保管理 | 4586篇 |
综合类 | 4687篇 |
基础理论 | 8199篇 |
环境理论 | 9篇 |
污染及防治 | 7765篇 |
评价与监测 | 2236篇 |
社会与环境 | 2105篇 |
灾害及防治 | 214篇 |
出版年
2023年 | 145篇 |
2022年 | 274篇 |
2021年 | 341篇 |
2020年 | 207篇 |
2019年 | 268篇 |
2018年 | 475篇 |
2017年 | 493篇 |
2016年 | 767篇 |
2015年 | 571篇 |
2014年 | 897篇 |
2013年 | 2675篇 |
2012年 | 1104篇 |
2011年 | 1447篇 |
2010年 | 1195篇 |
2009年 | 1237篇 |
2008年 | 1527篇 |
2007年 | 1434篇 |
2006年 | 1307篇 |
2005年 | 1157篇 |
2004年 | 1091篇 |
2003年 | 1058篇 |
2002年 | 990篇 |
2001年 | 1134篇 |
2000年 | 807篇 |
1999年 | 503篇 |
1998年 | 397篇 |
1997年 | 403篇 |
1996年 | 426篇 |
1995年 | 502篇 |
1994年 | 415篇 |
1993年 | 372篇 |
1992年 | 399篇 |
1991年 | 363篇 |
1990年 | 345篇 |
1989年 | 333篇 |
1988年 | 312篇 |
1987年 | 254篇 |
1986年 | 263篇 |
1985年 | 265篇 |
1984年 | 285篇 |
1983年 | 274篇 |
1982年 | 293篇 |
1981年 | 249篇 |
1980年 | 196篇 |
1979年 | 199篇 |
1978年 | 182篇 |
1977年 | 141篇 |
1975年 | 141篇 |
1973年 | 170篇 |
1972年 | 150篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
Studies in the vicinities of copper smelters and in undisturbed areas of the Middle Urals have been performed to evaluate the effect of industrial pollution with heavy metals on macro- and micromorphological parameters of kidneys (weight, weight index, the spectrum and frequency of histopathologies) in the bank vole (Clethrionomys glareolus Schreber, 1780) and on the accumulation of Cu, Zn, Cd, and Pb in this organ. It has been found that the kidneys of voles from polluted areas accumulate considerable amounts of heavy metals, with their concentrations increasing with age and/or sexual maturation. The kidney weight, index, and the frequency and severity of the majority of observed nephropathies also increase upon change in the reproductive-age status of animals. These parameters show no dependence on the degree of industrial pollution: at individual level, none of the heavy metals accumulated in the kidneys has produced any effect on the frequency and severity of nephropathies. These results contradict the prevailing opinion that toxicants play the determinant role in the development of nephropathies in small mammals inhabiting polluted areas. Therefore, the causes of nephropathies should be sought among other factors, not related to pollution. 相似文献
973.
974.
The relationship between the principle of free trade and nature conservation is one of the most acute and multifaceted problems in international business. The diversity of WTO activities implies the necessity of interdisciplinary studies utilizing the expertise and experience of specialists in international law and ecologists. In this paper, provisions of the WTO set of agreements and procedures for dispute settlement within the WTO framework are considered as applied to environmental protection. 相似文献
975.
976.
Richard Grossman 《Environment, Development and Sustainability》2012,14(6):973-977
Human population growth challenges efforts toward sustainability. People who are concerned about the environment, development, and sustainability are in a position to stress the importance of human population and to encourage people to choose small family size (Grossman, in Conserv Biol, 24(6), pp 1435–1436, 2010). Nevertheless, this vital subject has been treated infrequently in this journal. Of more than 500 articles published since its inception, only 15 have touched on human population, few have had population as a primary subject and only three have suggested that readers of this journal can and should have influence over population growth. This article concludes by suggesting ways that we who are concerned about sustainability should promote education about family planning and the advantages of small family size. 相似文献
977.
To restore food security to a traditional African cropping system following a sudden loss of seed, genetic diversity must be re-established. This study examines the extent to which Cowpea diversity was reinstated two years after a flood disaster in Gaza Province, Mozambique. The contribution that seed from various sources made to the recovery was assessed using semi-structured interviews and morphological and molecular data. Data suggest that diversity had recovered to some extent yet there was evidence of a narrowing of the genetic base, with fewer rare alleles and differences in the distribution of allele frequencies. Although the main channels for accessing seed after the flood were seed relief and markets, these sources contributed to minimal and different diversity. It appears that diversity was regained primarily through social networking in the form of loans or gifts of seed from friends and relatives. The results of the study are discussed in relation to seed relief approaches. 相似文献
978.
M. A. Potapov I. V. Zadubrovskaya P. A. Zadubrovskii O. F. Potapova V. I. Evsikov 《Russian Journal of Ecology》2012,43(1):40-44
A comparative analysis of reproductive behavior has been performed in the steppe lemming (Lagurus lagurus) and narrow-skulled vole (Microtus gregalis). The results show that the species are similar in certain behavioral features indicative of the stability of mating pairs.
However, in the narrow-skulled vole, unlike in the steppe lemming, mature males in olfactory tests show preference for receptive
sibling females versus non-kin females. Probably, it is the absence of the incest taboo that allows the involvement of young
of the year in reproduction within growing family groups and accounts for “coloniality” of the species. 相似文献
979.
Walter W. Heck John A. Dunning 《Journal of the Air & Waste Management Association (1995)》2013,63(2):112-114
The sensitivity of tobacco and/or pinto bean to ozone, as an air pollutant, is increased by growing plants in a shortened photoperiod under reduced light intensity and in a light potting mix. Sensitivity also is influenced by carbon dioxide concentration, time of day, and age of plant at time of exposure. Plants are more severely injured by a given dose under continuous exposure than when the exposure is split into two time periods. Tobacco shows cumulative development of injury when exposed to low concentrations intermittently over several days. 相似文献
980.
J. B. Koogler R. S. Sholtes A. L. Danis C. I. Harding 《Journal of the Air & Waste Management Association (1995)》2013,63(4):211-214
In conjunction with a 15-month air quality survey of Jacksonville, Fia., a mathematical model has been developed to describe the dispersion of atmospheric pollutants. The source inventory used with the model was compiled, in part, from the data obtained from the sampling of all major sources within the area. The major sources were considered separately from the one-mile square area sources which accounted for the remainder of the emissions. Meteorological data was recorded continuously in the city including vertical temperature observations to 750 ft. The model was compiled in FORTRAN and can be used for both gaseous and particulate pollutants, by utilizing proper decay rates. The variant nature of meteorological parameters and emission rates are considered. The ground level concentrations of several pollutants which were determined for 24 hr periods at 11 sites and continuously at two other sites were used to check the model. A limited tracer study was carried out in conjunction with the project. 相似文献