全文获取类型
收费全文 | 7113篇 |
免费 | 50篇 |
国内免费 | 37篇 |
专业分类
安全科学 | 144篇 |
废物处理 | 307篇 |
环保管理 | 613篇 |
综合类 | 1019篇 |
基础理论 | 1499篇 |
环境理论 | 3篇 |
污染及防治 | 1758篇 |
评价与监测 | 636篇 |
社会与环境 | 1191篇 |
灾害及防治 | 30篇 |
出版年
2023年 | 35篇 |
2022年 | 116篇 |
2021年 | 117篇 |
2020年 | 51篇 |
2019年 | 66篇 |
2018年 | 138篇 |
2017年 | 154篇 |
2016年 | 195篇 |
2015年 | 124篇 |
2014年 | 247篇 |
2013年 | 586篇 |
2012年 | 270篇 |
2011年 | 319篇 |
2010年 | 265篇 |
2009年 | 286篇 |
2008年 | 342篇 |
2007年 | 375篇 |
2006年 | 296篇 |
2005年 | 281篇 |
2004年 | 258篇 |
2003年 | 240篇 |
2002年 | 226篇 |
2001年 | 253篇 |
2000年 | 201篇 |
1999年 | 94篇 |
1998年 | 70篇 |
1997年 | 74篇 |
1996年 | 63篇 |
1995年 | 82篇 |
1994年 | 69篇 |
1993年 | 56篇 |
1992年 | 61篇 |
1991年 | 60篇 |
1990年 | 71篇 |
1989年 | 56篇 |
1988年 | 42篇 |
1987年 | 38篇 |
1986年 | 46篇 |
1985年 | 46篇 |
1984年 | 51篇 |
1983年 | 36篇 |
1982年 | 46篇 |
1981年 | 36篇 |
1980年 | 45篇 |
1979年 | 44篇 |
1974年 | 31篇 |
1973年 | 34篇 |
1972年 | 40篇 |
1971年 | 30篇 |
1969年 | 31篇 |
排序方式: 共有7200条查询结果,搜索用时 15 毫秒
941.
942.
Sudhirendar Sharma 《生态毒理学报》2002,(4):71-72
当 1974年提出雄心勃勃的国家生物气体开发计划时 , 它被欢呼为样板的适用气体技术 .可是预 测的 1200万个家庭规模的生物气体工厂中有四分之三没有建成 .在印度 , 生物气体技术没有能 够在大量可获得的牲畜粪便巨大潜力之上化为投资 .检讨了这个失败的原因 , 并为复兴此计划 提出了建议 . 相似文献
943.
D. Molina-Gomes V. Nebout F. Daikha-Dahmane F. Vialard Y. Ville J. Selva 《黑龙江环境通报》2006,26(3):239-241
We report a case of prenatal diagnosis of trisomy 20p resulting from a maternal pericentric inversion. The diagnosis was confirmed on both chorionic villi and amniotic cells. This case underlines the fact that prenatal ultrasound diagnosis of this structural anomaly is difficult. The only early sonographic feature was increased nuchal translucency. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
944.
M. Dassenakis F. Botsou V. Paraskevopoulou C. Chikviladge K. Kachiasvili 《Chemistry and Ecology》2006,22(5):379-393
The aim of the present study was to examine the distribution of pollutants in two coastal systems in Georgia: (1) Kubitskali river which flows into the Black sea through the city of Batumi and is polluted mainly from the effluents of an oil refinery; (2) Paliastomi lake, which is a shallow water body at the south-east of the city of Poti. During 2000-2001, two samplings took place in each system, one in the low-flow period and one in the high-flow period. During these samplings, pH, temperature, dissolved oxygen, and salinity were measured in situ, whereas water samples were collected for the analysis of trace metals, nutrients, and organic pollutants with standard methods. The results of the measurements indicate the significant pollution of both systems by ammonia and in the case of Kubitskali River also by oil products. The need for a sustainable management plan of the activities taking place in the river basin is urgent. 相似文献
945.
946.
The dominant use of coal in power sectors has been associated with adverse environmental impacts. Ambient air monitoring for the two size fractions of particulate matter, respirable suspended particulate matter (RSPM) and non-respirable suspended particulate matter (NRSPM) in the downwind and upwind directions of a large coal-fired power station in central India, was carried out. Collected samples of ambient particulate matter were analysed atomic absorption spectrophotometrically for 15 elements. Spatial variability in elemental composition of RSPM and NRSPM and the degree of enrichment of these toxic metals in RSPM were investigated. A significant spatial variability for the elements in RSPM and NRSPM and higher degrees of enrichment of the elements were observed. 相似文献
947.
Mal'kova M. G. Pal'chekh N. A. Yakimenko V. V. Kuz'min I. V. 《Russian Journal of Ecology》2004,35(1):27-34
The spatial structure of populations has been studied in two rodent species inhabiting the subzone of meadow steppes of the steppe zone of Omsk oblast: the narrow-sculled vole (Microtus gregalis Pall.) and steppe lemming (Lagurus lagurus Pall.). Their populations are represented by combinations of territorial family groups whose structure and spatial distribution vary by season depending on population density, the phase of the population cycle, and the status of their members in the population. In the areas cohabited by M. gregalis and L. lagurus, the pattern of territory use and the rhythm of animal activity during the day depend primarily on their total density: under conditions of low density, the population groups of both species are spatially separated; at increased density, they are distributed with respect to the pattern of daily activity. Both species jointly use part of the territory but at different times of day: M. gregalis, mainly at night and in the morning; L. lagurus, in the daytime. 相似文献
948.
949.
Reproductive output, as the percentage of the mother weight devoted to egg production, was estimated for the burrowing shrimp
Callianassa tyrrhena in wet, dry and ash-free dry weight. Three biometrical approaches were used. First, the relationship between the egg mass
and the mother weight was determined. A second approach was to estimate the weight loss of the female caused by oviposition.
Similar results were obtained from these methods for dry and ash-free dry weight (about 20 and 35%, respectively), but not
for the wet weight estimation. The third approach, based on the weight loss of the ovary, did not reveal a constant value
for reproductive output throughout the female size range, although it was found that the ovary loses a constant percentage
of its weight during oviposition. This discrepancy is due to the fact that the ovary weight shows positive allometry to the
weight of the female body. The comparison of the three methods offers insight into the biological events that are related
to ovary maturation and oviposition. It is suggested that molting just before oviposition and its inhibition during the yolk
accumulation in the ovary play dominant roles in the expression of the reproductive output in the different approaches used.
Received: 17 July 1996 / Accepted: 11 September 1996 相似文献
950.
E. Marchina G. Piovani L. Vezzola D. Bellotti V. Cerri C. Groli Prof. S. Barlati 《黑龙江环境通报》2003,23(12):959-963
A 40-year-old woman underwent amniocentesis at 15.3 weeks of gestation. Chromosome analysis performed using QFQ, DA-DAPI and CBG banding revealed two de novo extra-chromosomal markers (ESACs) in 11 of the 16 colonies analysed. Fluorescence in situ hybridization (FISH) showed that both chromosomes came from the Yq11.22.1 region of the Y chromosome. PCR analysis of genes and STS localized on the Y chromosome excluded the Yp presence specifically of the SRY gene, and most of the euchromatic region of Yq. After extensive genetic counselling and considering both laboratory and second-level ultrasound data, the couple decided to continue the pregnancy. At 37.4 weeks of gestational age, a girl weighing 2750 g was born with an Apgar score of 9/10. A blood sample taken from the umbilical cord showed three cellular lines:mos47,XX, +mar1 ish.der (Y)(wcpY+) [21%]/48,XX, +mar1 ish.der (Y)(wcpY+), +mar2 ish.der (Y)(wcpY+) [41%]/46,XX [38%]. One year after birth, the baby was developing normally and had normal psychomotorial activity. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献