全文获取类型
收费全文 | 17263篇 |
免费 | 143篇 |
国内免费 | 114篇 |
专业分类
安全科学 | 406篇 |
废物处理 | 652篇 |
环保管理 | 1906篇 |
综合类 | 5330篇 |
基础理论 | 3571篇 |
环境理论 | 2篇 |
污染及防治 | 4095篇 |
评价与监测 | 880篇 |
社会与环境 | 617篇 |
灾害及防治 | 61篇 |
出版年
2018年 | 200篇 |
2017年 | 188篇 |
2016年 | 287篇 |
2015年 | 216篇 |
2014年 | 319篇 |
2013年 | 1154篇 |
2012年 | 370篇 |
2011年 | 517篇 |
2010年 | 494篇 |
2009年 | 555篇 |
2008年 | 573篇 |
2007年 | 596篇 |
2006年 | 529篇 |
2005年 | 466篇 |
2004年 | 501篇 |
2003年 | 457篇 |
2002年 | 436篇 |
2001年 | 616篇 |
2000年 | 412篇 |
1999年 | 283篇 |
1998年 | 203篇 |
1997年 | 195篇 |
1996年 | 193篇 |
1995年 | 230篇 |
1994年 | 242篇 |
1993年 | 206篇 |
1992年 | 223篇 |
1991年 | 231篇 |
1990年 | 253篇 |
1989年 | 229篇 |
1988年 | 181篇 |
1987年 | 180篇 |
1986年 | 180篇 |
1985年 | 180篇 |
1984年 | 199篇 |
1983年 | 187篇 |
1982年 | 195篇 |
1981年 | 207篇 |
1980年 | 169篇 |
1979年 | 181篇 |
1978年 | 147篇 |
1977年 | 139篇 |
1974年 | 147篇 |
1973年 | 146篇 |
1968年 | 156篇 |
1967年 | 184篇 |
1966年 | 156篇 |
1965年 | 149篇 |
1964年 | 151篇 |
1963年 | 139篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
Daniel H Zitomer Prasoon Adhikari Craig Heisel Dennis Dineen 《Water environment research》2008,80(3):229-237
Codigestion of five wastes and municipal wastewater sludge was evaluated using full-scale testing. Synergistic, antagonistic, and neutral outcomes were observed depending on codigestate identity and concentration, highlighting the value of careful blending. Yeast waste resulted in notable synergism, increasing biogas production by over 50%, whereas aircraft deicing waste resulted in antagonism at high loadings and neutral outcomes at lower loadings. Restaurant waste codigestion resulted in neutral outcomes. The synergisim with yeast codigestates may have resulted from trace nutrients (i.e., iron, nickel, and cobalt) in the wastes that increased microbiological activity. Antagonist outcomes with deicing waste may have been the result of organic overload or inhibitory deicer constituents. Codigestion of wastes at the feed rates investigated was estimated to produce 0.50 ML/d of methane having an energy equivalent of 17 500 MJ/d. This was estimated to reduce net carbon dioxide emissions by 560 tonnes/y. 相似文献
4.
Cornus stolonifera, Salix petiolaris, and Spiraea alba
clones already located within the corridor of an electrical power line. To
establish the efficiency of treatments, we examined the statistical
differences of growth traits between species and treatments.
An analysis of the effects of layering shows, after the first growth season,
differences for all growth traits in only one species, Spiraea alba.
After the second growth season, we observed the development of new aerial
stems. Layering favors horizontal expansion of shrubs over height
development. The third year after treatment, the effect of layering is
reduced except for Cornus stolonifera, which continuously increases,
as shown by the significant progression of the clone issued from the layer
even five years after treatments. With the cutting back technique, we
expected a distinct vertical growth of the shrubs at the expense of
increasing the crown diameter. This technique would be best associated with
the rejuvenation of clones, followed by a layering of new shoots to allow a
horizontal expansion of the shrubs. Therefore, the formation of a dense shrub
community by layering should be considered a valuable approach for the
biological control of undesirable trees in powerline rights-of-way. 相似文献
5.
D Heinevetter H J Lewerenz R Plass R Macholz 《Journal of environmental science and health. Part. B》1985,20(5):539-558
In vitro investigations of the influence of lindane and its metabolites were performed on microsomal and mitochondrial ATPases from liver, kidney and brain of rat and mouse. The microsomal Na+-K+-ATPases in rat liver were inhibited by the tested substances. An increase of activity was observed only with 2.5 X 10(-5) M gamma-HCH. Effects on the microsomal Na+-K+-ATPase from kidney and brain of rat were also indicated. The mitochondrial enzyme in rat liver was stimulated by all the compounds tested at concentrations of 10(-4) M - 10(-2) M. The effects on mitochondrial enzymes from kidney and brain varied in dependence on the tested substances. In the microsomes and mitochondria of mouse an influence on the Na+-K+-ATPases similar to the effects on the preparations from organs of rat was evident. 相似文献
6.
7.
8.
9.
10.
Ontogenetic change of habitat depths of Nautilus pompilius in the Philippines (Tañon Strait) and Fiji is considered by comparing 18O/16O ratios in septa and cameral fluid of live-caught specimens and ambient sea-water. 18O values of cameral liquid become heavier with decreasing volume within a chamber, which may be due to isotopic fractionation during discharge across the siphuncular wall. All of the seven Philippine and Fiji specimens analyzed show a distinct change in 18O from light values in the first seven septa to heavier values in the succeeding septa. Two different isotopic temperature scales are obtained for the Fiji and Philippine populations, suggesting a differential vital effect of metabolism between them. Sightly light 18O values in Septa 1 to 7 and hatching at relatively high temperatures in aquaria both suggest that N. pompilius hatch at the shallowest depths within their inhabitable vertical range. Depths of postembryonic animals in the Philippines and Fiji waters estimated from the isotopic temperature-depth diagrams range from 120 to 160 m and from 440 to 520 m, respectively, both of which correlate well with capture records. More than several tens of small-scale 18O cycles are detected in the sequence of nacreous layers within the single septum of a submature Philippine specimen. This can be interpreted as reflecting daily vertical migration. 相似文献