全文获取类型
收费全文 | 1366篇 |
免费 | 7篇 |
国内免费 | 8篇 |
专业分类
安全科学 | 50篇 |
废物处理 | 48篇 |
环保管理 | 109篇 |
综合类 | 275篇 |
基础理论 | 338篇 |
环境理论 | 2篇 |
污染及防治 | 393篇 |
评价与监测 | 92篇 |
社会与环境 | 68篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 7篇 |
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 15篇 |
2019年 | 8篇 |
2018年 | 27篇 |
2017年 | 43篇 |
2016年 | 38篇 |
2015年 | 32篇 |
2014年 | 37篇 |
2013年 | 67篇 |
2012年 | 69篇 |
2011年 | 78篇 |
2010年 | 56篇 |
2009年 | 52篇 |
2008年 | 78篇 |
2007年 | 85篇 |
2006年 | 68篇 |
2005年 | 42篇 |
2004年 | 44篇 |
2003年 | 49篇 |
2002年 | 43篇 |
2001年 | 34篇 |
2000年 | 33篇 |
1999年 | 16篇 |
1998年 | 12篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 16篇 |
1994年 | 23篇 |
1993年 | 21篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 16篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 17篇 |
1978年 | 10篇 |
1977年 | 13篇 |
1976年 | 12篇 |
1975年 | 9篇 |
1972年 | 5篇 |
排序方式: 共有1381条查询结果,搜索用时 15 毫秒
951.
952.
Precision-cut tissue slices of the anterior kidney from Atlantic cod (Gadus morhua) were prepared with a Krumdieck tissue slicer and exposed to 2-(2-chlorophenyl)-2-(4-chloro-(14C)phenyl)-1,1-dichlorethane (o,p(')-[14C]DDD) in vitro. Microautoradiography revealed irreversible o,p(')-DDD-derived binding confined to the glucocorticoid producing interrenal cells (adrenocortical analogues). This cell-selective binding was confirmed by means of autoradiography at different levels of resolution on Atlantic cod administered o,p(')-[14C]DDD intragastrically. The results provide evidence for a site-specific metabolic activation and irreversible binding of o,p(')-DDD in the interrenal cells, which, in turn, may modify glucocorticoid homeostasis. 相似文献
953.
Alternately operated wastewater treatment plants (WWTPs) are fundamentally different compared to conventional activated sludge WWTPs with respect to flow patterns and aeration in the biological reactors. Several model applications exist for conventional WWTPs, e.g. SimpleTreat, and in this study the effect of substituting a complex discontinuous operation, involving alternating degradation and flow conditions between two reactors, with one single bioreactor with continuos flow (SimpleTreat) has been investigated by setting up two models representing the respective operation schemes. The discontinuous operation induces fluctuations in the outlet concentrations that are not modelled with the single bioreactor model, however, the fluctuations and the associated uncertainties were found to be insignificant compared to the influence of the input parameter uncertainties on the model results. An empirical relationship between an aggregate pseudo-1st order degradation rate for the single bioreactor model and realistic aerobic and anoxic 1st order degradation rates, respectively, has been established. When using this aggregate degradation rate in the single bioreactor model an outlet concentration can be calculated that deviates no more than 2% from the mean outlet concentration from the alternating operation model. For substances with aerobic half-lives longer than approximately 2 h, which is valid for many chemical substances, the aggregate 1st order degradation rate can be set equal to the aerobic 1st order degradation rate. 相似文献
954.
Dr C. K. Høgdall E. V. S. Høgdall J. Arends B. Nørgaard-Pedersen S. Smidt-Jensen S. O. Larsen 《黑龙江环境通报》1992,12(3):223-227
CA-125, alpha-fetoprotein (AFP), and human chorionic gonadotropin (HCG) were determined in maternal serum in the first trimester from 14 women with a Down's syndrome fetus and 61 women with a healthy fetus. In the second trimester, 15 and 60 serum samples were determined from women with a Down's syndrome and a healthy fetus respectively. In both trimesters, maternal serum CA-125 was found to be elevated in Down's syndrome pregnancies compared with controls. Using discrimination functions, our preliminary results indicate that CA-125 is a better marker than AFP and HCG respectively for a Down's syndrome fetus in the first trimester and improves the detection rate in the second trimester. 相似文献
955.
956.
957.
Linda Sygna Jan S. Fuglestvedt H. Asbj?rn Aaheim 《Mitigation and Adaptation Strategies for Global Change》2002,7(4):419-421
Volume Contents
Contents Volume 7 相似文献958.
959.
Karl-Gerhardt Børlum 《黑龙江环境通报》1984,4(4):311-314
The Possibility of severe fetal malformations, including neural tube defects, secondary to early amniotic rupture followed by formation of fibrous bands (amniotic band syndrome) is a well-known entitity. The fact that these pregnancies are usually uneventful makes prenatal diagnosis difficult, but routine determination of serum alphafetoprotein, followed by ultrasound scanning, may detect some of the malformations. We present a case, where detection of a neural tube defect led to induced second trimester abortion of a fetus severely affected by this syndrome. There appeared to be a causal relationship between maternal trauma and the amniotic rupture. 相似文献
960.
The concentration of trace elements within cephalopod statoliths can provide a record of the environmental characteristics at the time of calcification. To reconstruct accurately the environmental characteristics at the time of calcification, it is important to understand the influence of as many factors as possible. To test the hypothesis that the elemental composition of cuttlefish statoliths could be influenced by diet, juvenile Sepia officinalis were fed either shrimp Crangon sp. or fish Clupea harengus under equal temperature and salinity regimes in laboratory experiments. Element concentrations in different regions of the statoliths (core–lateral dome–rostrum) were determined using laser ablation inductively coupled plasma mass spectrometry (LA- ICPMS). The ratios of Sr/Ca, Ba/Ca, Mn/Ca and Y/Ca in the statolith’s lateral dome of shrimp-fed cuttlefish were significantly higher than in the statolith’s lateral dome of fish-fed cuttlefish. Moreover, significant differences between statolith regions were found for all analysed elements. The fact that diet adds a considerable variation especially to Sr/Ca and Ba/Ca must be taken into account in future micro-chemical statolith studies targeting cephalopod’s life history. 相似文献