全文获取类型
收费全文 | 1609篇 |
免费 | 14篇 |
国内免费 | 23篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 73篇 |
环保管理 | 218篇 |
综合类 | 306篇 |
基础理论 | 311篇 |
环境理论 | 2篇 |
污染及防治 | 441篇 |
评价与监测 | 141篇 |
社会与环境 | 89篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 19篇 |
2022年 | 36篇 |
2021年 | 37篇 |
2020年 | 19篇 |
2019年 | 27篇 |
2018年 | 40篇 |
2017年 | 34篇 |
2016年 | 57篇 |
2015年 | 40篇 |
2014年 | 65篇 |
2013年 | 88篇 |
2012年 | 86篇 |
2011年 | 103篇 |
2010年 | 79篇 |
2009年 | 87篇 |
2008年 | 81篇 |
2007年 | 100篇 |
2006年 | 76篇 |
2005年 | 72篇 |
2004年 | 76篇 |
2003年 | 47篇 |
2002年 | 48篇 |
2001年 | 33篇 |
2000年 | 22篇 |
1999年 | 21篇 |
1998年 | 23篇 |
1997年 | 15篇 |
1996年 | 18篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 16篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 4篇 |
1968年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有1646条查询结果,搜索用时 125 毫秒
21.
B. Sikkema-Raddatz R. H. Sijmons M. B. Tan-Sindhunata A. Y. Van Der Veen R. Brunsting B. De Vries J. R. Beekhuis D. J. Bekedam B. Van Aken B. De Jong 《黑龙江环境通报》1995,15(5):467-473
We report two cases of apparently balanced complex de novo chromosomal rearrangements (BCCR) detected prenatally at 17 weeks and 10 weeks of gestation, respectively. Chromosomes were studied using GTG-banding and fluorescent in situ hybridization (FISH). In one case four chromosomes and in the other case three chromosomes were involved in the rearrangements. One of the pregnancies was terminated and no external or internal abnormalities were detected at autopsy. The other pregnancy continued to term. Level III ultrasound examination showed no abnormalities. The child is now 3 years old and has neither congenital anomalies nor evidence of delayed psychomotor development. 相似文献
22.
Frans J. Los MD PhD Diane Van Opstal Martin P. Schol Johannes L. J. Gaillard Helen Brandenburg Ans M. W. Van Den Ouweland Peter A. In 'T Veld 《黑龙江环境通报》1995,15(12):1155-1159
A prenatally detected case of a rare mosaic tetrasomy 12p/trisomy 12p is reported, presenting as the well-known accessory isochromosome 12p and a supernumerary single 12p marker in 17/24 and 6/24 clones of cultured amniotic fluid cells, respectively. The chromosomal nature of both marker chromosomes was investigated in cultured amniotic fluid cells by fluorescent in situ hybridization with various probes: the 12-centromeric probes pa12H8 and D12Z3, a whole chromosome 12 paint, and the chromosome 12p-specific paint M28. DNA analysis revealed a maternal origin of the extra 12p material. After counselling, the parents requested termination of pregnancy. Inspection and autopsy of the fetus revealed many of the dysmorphisms and internal structural abnormalities of the Pallister–Killian syndrome. 相似文献
23.
M. Van Blerk MD J. Smitz L. De Catte C. Kumps J. Van Der Elst A. C. Van Steirteghem 《黑龙江环境通报》1992,12(12):1062-1066
This study explores if assay of cancer antigen 125 (CA 125) in maternal serum might aid the detection of Down's syndrome in the second trimester of pregnancy. CA 125 levels were determined retrospectively in stored maternal serum samples from ten Down's syndrome pregnancies and 78 controls matched for gestational and maternal age. In addition, second-trimester amniotic fluid samples from nine Down's syndrome and 109 unaffected pregnancies were analysed for CA 125. Maternal serum CA 125 values for Down's syndrome pregnancies were lower, with the median being 0.72 multiples of the unaffected population median. The medians for affected and unaffected pregnancies did not differ significantly and there was a considerable overlap in the range of values of cases and controls. The distribution of amniotic fluid CA 125 levels for Down's syndrome pregnancies resembled that for controls. From our present results, we could not find an association between Down's syndrome and second-trimester maternal serum or amniotic fluid CA 125 levels. 相似文献
24.
25.
The larvae and pupae of the ladybird Thalassa saginata develop inside colonies of the dolichoderine ant Dolichoderus bidens. This association is the first specific and obligatory relationship recorded between ants and ladybirds. The ants provide shelter and protection to the larvae but the diet of the latter remains unclear. The integration of T. saginata larvae into the ant colonies is achieved by mimicking the cuticular patterns of the ants brood. Moreover, the larvae secrete substances from their hairs and anal gland that are likely to enhance their attractiveness. 相似文献
26.
27.
28.
John Van Sickle 《Journal of the American Water Resources Association》2003,39(3):717-726
ABSTRACT: Bivariate correlation analysis has been widely used to explore relationships between stream and watershed attributes that have all been measured on the same set of watersheds or sampling locations. Researchers routinely test H0: ρ= 0 for each correlation in a large table and then go on to discuss only those that are declared “significant.” Such test results are inaccurate because no allowance is made for multiple testing, and also because the tests are not mutually independent. This paper reviews the Bonferroni approach to controlling the overall error rate in multiple testing and shows how the approach becomes impractical for large correlation tables. The Hotelling/Williams test is introduced for comparing two dependent correlations that share a variable, and numerical constraints for two such correlations are illustrated. References are also given for testing other hypothesized patterns among dependent correlations, and links to dependent correlation software are provided. The methods are illustrated for watershed and stream variables sampled in 23 small agricultural watersheds of the Willamette Valley, Oregon. 相似文献
29.
30.
Aviva Savelson Robert Van Wynsberghe James Frankish Harmony Folz 《Local Environment》2005,10(6):629-647
The future of human health and that of all other species depends on the viability and sustainability of a host of environments and ecosystems. Human behaviours have profound effects (both positive and negative) on such ecosystems. Despite the obviousness of these statements, there remains a lack of clarity around the mechanisms for altering specific behaviours related to sustainability and their impact on environments. This paper offers a conceptual framework for identifying relations between human behaviour and ecosystem health and sustainability. We also discuss strategies for changing target behaviours in the context of a programme or policy planning. Finally, we draw on research that applies this adaptation to a small island community near Vancouver, Canada. 相似文献