全文获取类型
收费全文 | 19024篇 |
免费 | 192篇 |
国内免费 | 148篇 |
专业分类
安全科学 | 522篇 |
废物处理 | 744篇 |
环保管理 | 2709篇 |
综合类 | 3927篇 |
基础理论 | 4383篇 |
环境理论 | 13篇 |
污染及防治 | 4656篇 |
评价与监测 | 1208篇 |
社会与环境 | 1127篇 |
灾害及防治 | 75篇 |
出版年
2022年 | 128篇 |
2021年 | 146篇 |
2019年 | 133篇 |
2018年 | 237篇 |
2017年 | 246篇 |
2016年 | 386篇 |
2015年 | 300篇 |
2014年 | 429篇 |
2013年 | 1486篇 |
2012年 | 523篇 |
2011年 | 755篇 |
2010年 | 575篇 |
2009年 | 669篇 |
2008年 | 774篇 |
2007年 | 840篇 |
2006年 | 717篇 |
2005年 | 612篇 |
2004年 | 628篇 |
2003年 | 634篇 |
2002年 | 579篇 |
2001年 | 678篇 |
2000年 | 453篇 |
1999年 | 338篇 |
1998年 | 236篇 |
1997年 | 237篇 |
1996年 | 275篇 |
1995年 | 282篇 |
1994年 | 288篇 |
1993年 | 259篇 |
1992年 | 237篇 |
1991年 | 239篇 |
1990年 | 232篇 |
1989年 | 197篇 |
1988年 | 204篇 |
1987年 | 181篇 |
1986年 | 186篇 |
1985年 | 179篇 |
1984年 | 197篇 |
1983年 | 199篇 |
1982年 | 214篇 |
1981年 | 188篇 |
1980年 | 155篇 |
1979年 | 150篇 |
1978年 | 157篇 |
1977年 | 144篇 |
1976年 | 115篇 |
1975年 | 115篇 |
1974年 | 128篇 |
1971年 | 103篇 |
1967年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
J. B. Harcum Jim C. Loftis Robert C. Ward 《Journal of the American Water Resources Association》1992,28(3):469-478
ABSTRACT: The use of nonparametric tests for monotonic trend has flourished in recent years to support routine water quality data analyses. The validity of an assumption of independent, identically distributed error terms is an important concern in selecting the appropriate nonparametric test, as is the presence of missing values. Decision rules are needed for choosing between alternative tests and for deciding whether and how to pre-process data before trend testing. Several data pre-processing procedures in conjunction with the Mann-Kendall tau and the Seasonal Kendall test (with and without serial correlation correction) are evaluated using synthetic time series with generated serial correlation and missing data. A composite test (pre-testing for serial correlation followed by one of two trend tests) is evaluated and was found to perform satisfactorily. 相似文献
12.
13.
14.
E Enan I G Berberian S el-Fiki M el-Masry O H Enan 《Journal of environmental science and health. Part. B》1987,22(2):149-170
Male Baladi rabbits were acutely and sub-chronically intoxicated with cyanofenphos and profenophos. The levels of cholesterol, triglycerides, B-lipoproteins and total proteins were determined in the serum, brain, spinal cord and sciatic nerve of rabbits. Moreover, the activities of alkaline phosphatase, acid phosphatase and glutamic-pyruvic transaminase were determined in the liver of the animals. The whole studies revealed that the biochemical constituents were highly affected by the tested insecticides. Also, the liver function suffered from adverse effects of the tested insecticides. 相似文献
15.
Collections made in the course of long-term field studies on ecology of the northern mole vole Ellobius talpinus Pall. in the Ural Region and neighboring areas (more than 2000 individuals from 24 points of the species range) were used
to analyze geographic variation in its coat color (color morphs). On the basis of long-term observations (1985–1999) on marked
animals from a polymorphic population (Kurtamyshskii raion, Kurgan oblast), the life spans of males and females and the dependence
of life span on population density and structure were estimated in animals of different color morphs. Each color morph of
E. talpinus was shown to have specific features of the seasonal dynamics of age structure and migrations. 相似文献
16.
F. Rincón-León G. Zurera-Cosano R. Moreno-Rojas M. Amaro-López 《Environmental monitoring and assessment》1993,27(3):193-200
The importance of eating habits and the number of fish sampled in the estimation of mercury environmental contamination through biological indicators was studied. The species used were one with piscivorous habits (Anguilla anguilla) and another with omnivorous habits (Ciprinus carpio). From one original sample for each species, randomized samples were generated using the subroutine GGSRS from the mathematics library IMSL, and later the statistical significance of Pearson's correlation coefficient for the relationship between fish weight and mercury concentrations in muscle was obtained for each random sample. The results show that the use of omnivorous species such as Ciprinus carpio as a biological indicator of contamination enables us to carry out estimations with a greater degree of confidence than when piscivorous species such as Anguilla anguilla are used. 相似文献
17.
18.
19.
Progress in Restoration of the Mauritius Kestrel 总被引:1,自引:0,他引:1
In the 1970s, the Mauritius Kestrel ( Falco punctatus ) was the most endangered bird of prey in the world, at one time with only two known pairs surviving in the remnant native forest of the Black River Gorges (ca. 4,000 ha). At the end of the 1991–1992 breeding season, a minimum of 30 nesting pairs and more than 170 individuals were distributed in four separate forested areas, thanks mainly to manipulation of the reproductive potential of the wild pairs, to captive propagation, and to reintroduction (restocking). Since 1984, 139 young have been reared from 618 eggs laid by captive kestrels, and 147 from 265 wild eggs incubated and hatched in the laboratory; 235 young kestrels have been released on Mauritius by hacking and fostering. Adjustments in feeding and nesting habits of kestrels hacked and released outside the Black River Gorges in areas dominated by exotic vegetation and agriculture have allowed these kestrels to survive and reproduce in an array of previously unused habitats. Now that the kestrels have been released from dependence on the remnant and dying native forest, a viable population of more than 100 nesting pairs should be achievable in a few more years. 相似文献
20.