首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   664篇
  免费   12篇
  国内免费   3篇
安全科学   24篇
废物处理   48篇
环保管理   31篇
综合类   125篇
基础理论   149篇
环境理论   1篇
污染及防治   187篇
评价与监测   82篇
社会与环境   25篇
灾害及防治   7篇
  2023年   11篇
  2022年   24篇
  2021年   19篇
  2020年   10篇
  2019年   11篇
  2018年   33篇
  2017年   27篇
  2016年   41篇
  2015年   22篇
  2014年   44篇
  2013年   75篇
  2012年   42篇
  2011年   45篇
  2010年   37篇
  2009年   23篇
  2008年   16篇
  2007年   19篇
  2006年   20篇
  2005年   10篇
  2004年   15篇
  2003年   12篇
  2002年   23篇
  2001年   8篇
  2000年   9篇
  1999年   5篇
  1997年   4篇
  1995年   3篇
  1994年   2篇
  1993年   5篇
  1986年   2篇
  1982年   2篇
  1980年   2篇
  1972年   1篇
  1971年   2篇
  1970年   6篇
  1969年   2篇
  1968年   1篇
  1967年   4篇
  1966年   3篇
  1965年   2篇
  1964年   1篇
  1961年   1篇
  1960年   4篇
  1959年   4篇
  1958年   10篇
  1957年   4篇
  1956年   3篇
  1955年   1篇
  1931年   1篇
  1930年   2篇
排序方式: 共有679条查询结果,搜索用时 989 毫秒
421.
Bioremediation potential of bacteria and fungi isolated from sludge samples has been investigated (Danube alluvium, Pančevo, Serbia). Total isolated microorganisms were divided into three parts. One part was added with actidione antifungicide. The second part was added with streptomycin antibiotic. The third part was without additives. Paraffinic type of crude oil was a substrate for assessment of bioremediation potential. The simulated oil biodegradation lasted 30, 60 and 90 days. Parallel with that, the experiments with blind trial were conducted. Extracts were isolated from the samples with chloroform in a separate funnel. They were assayed for the group composition (alkanes, aromatics, alcohols and fatty acids) by column chromatography. Alkane fraction was analysed by gas chromatography—mass spectrometry (GC–MS). The most intense oil degradation was achieved in the experiments with bacteria, somewhat weaker with consortium of fungi and bacteria, and the weakest bioremediation potential in these experiments was shown by fungi.  相似文献   
422.
This study focused on the responses of soil microorganisms to different management regimes on disturbed windthrow areas. Microbial parameters potentially serving as indicators of environmental changes within a long-term monitoring of forest development after large-scale disturbance events were assessed. Basal and substrate-induced respiration, N mineralisation, catalase activity, microbial biomass as well as functional diversity based on Biolog assay were determined in soil samples from three disturbed plots and an undisturbed reference plot in the Tatra National Park (Slovakia) since 2006. A relative congruence of inter-annual trends of microbial activity indicators at all plots results from a common response of microbiota to changes of climate at the landscape level after forest stands were destroyed. While catalase activity and functional diversity proved to be useful indicators of temporal trends, microbial biomass seems to reflect different management regimes at the disturbed plots.  相似文献   
423.
This work has been developed to examine the level of non-dioxin-like (ndl) PCBs (28, 52, 101, 138, 153 and 180) in (a) ten different freshwater fish species from the Danube river, (b) two sampling points: up and downstream of the industrial zone of the city of Pancevo (ecological hot spot in Serbia) and (c) two time points i.e., in 2001 and 2006. Obtained results would serve to analyse spatial, temporal and congener profile characteristics of ndl PCBs cumulated in fish tissues due to environmental pollution. Sixty-four samples of the following species were collected: wels (Silirus glanus), pike (Esox lucius), bream (Abramis brama), crucian carp (Carassius carassius), pike pearch (Stizostedion lucioperca), barbel (Barbus barbus), tench (Tinca tinca), sterlet (Acipenser ruthenus L.), common carp (Cyprinus carpio) and bighead carp (Hypophthalmichthys nobilis). Gas chromatography coupled with electron capture detector was used for analysis of ndl PCBs. Total ndl PCBs content in upstream samples ranged from 2.7 to 98.1 ng/g and from 4.9 to 68.3 ng/g in 2001 and 2006, respectively. During the 5 years, ndl PCBs content increased significantly in downstream samples i.e., ndl PCBs varied from 13.7 to 46.1 ng/g and from 14.4 to 107.2 ng/g in 2001 and 2006, respectively. PCBs 138 and 180 were predominant congeners in 2001, while in 2006 the most abundant PCB congeners were 138 and 153. In 2006, the presence of PCB 28 and PCB 52 has indicated a recent contamination event. Data on continual monitoring of PCBs in all relevant environmental compartments together with appropriate biomonitoring data are expected to give comprehensive insight into the fate and behaviour profile of these contaminants.  相似文献   
424.
Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.  相似文献   
425.
The preen gland is a holocrine sebaceous gland of the avian integument which produces an oily secretion that is spread on the plumage during preening. It has been suggested that birds may defend themselves against feather-degrading bacteria (FDB) and other potential pathogens using preen gland secretions. However, besides some in vitro studies, the in vivo bacterial inhibitory effects of the preen oil on the abundance of feather-associated bacterial species has not yet been studied in passerines. Here we tested the effect of gland removal on the abundance of FDB and other-cultivable bacterial loads (OCB) of male house sparrows (Passer domesticus). Our results did not support earlier results on in vitro antibacterial activity of preen oil against FDB since the absence of the preen gland did not significantly affect their loads related to the control birds. In contrast, we found that preen gland removal led to higher loads of OCB. This result suggests that the antimicrobial spectrum of the preen oil is broader than previously thought and that, by reducing the overall feather bacterial loads, the preen gland could help birds to protect themselves against a variety of potentially harmful bacteria.  相似文献   
426.
Environmental Science and Pollution Research - The investigation conducted in the Vojvodina Province, as a typical European and one of the biggest agricultural regions in the Balkans, offers the...  相似文献   
427.
Environmental Geochemistry and Health - Identifying a suitable geochemical background level (GBL) and an appropriate normalizer is imperative for ensuring soil quality, health, and security. The...  相似文献   
428.
Environmental Geochemistry and Health - The oil pollutant in the Sava River aquifer in the residential area of Belgrade, Serbia was investigated in order to analyze the extent, origin and spatial...  相似文献   
429.
Environmental Science and Pollution Research - Current artificial soils for ecotoxicological studies contain non-renewable materials that must be mined, and their production and processing consume...  相似文献   
430.
Environmental Science and Pollution Research - Water pollution is a constant challenge for humanity. Sustainable economic development and environmental protection through a green economy structure...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号