全文获取类型
收费全文 | 335篇 |
免费 | 7篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 15篇 |
环保管理 | 102篇 |
综合类 | 30篇 |
基础理论 | 95篇 |
环境理论 | 1篇 |
污染及防治 | 47篇 |
评价与监测 | 23篇 |
社会与环境 | 15篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 19篇 |
2011年 | 22篇 |
2010年 | 14篇 |
2009年 | 11篇 |
2008年 | 17篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 17篇 |
2004年 | 14篇 |
2003年 | 20篇 |
2002年 | 11篇 |
2001年 | 12篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有343条查询结果,搜索用时 639 毫秒
241.
Juliette G. C. Omtzigt Frans J. Los Adriana M. Hagenaars Patricia A. Stewart Eva S. Sachs Professor Dr Dick Lindhout 《黑龙江环境通报》1992,12(11):893-897
In the context of a prospective study on the adverse effects of anti-epileptic drugs on fetal outcome, we evaluated our experience with prenatal diagnosis by ultrasonography and α- fetoprotein (AFP) determination in amniotic fluid. We compared these results with AFP values in maternal serum obtained prior to amniocentesis. From November 1985 to July 1990, amniocentesis at 16–18 weeks of gestation was performed in 267 pregnancies of 237 different women using anti-epileptic drugs. Among 92 pregnancies with maternal valproic acid use, five (including one concordantly affected monozygotic twin-pair) were terminated because of a spina bifida aperta, all prenatally diagnosed by AFP determination and acetylcholinesterase electrophoresis in amniotic fluid. The maternal serum AFP level was raised (⩾ 2.5 multiples of the median (MOM) for singleton pregnancies and ⩾ 4.5 MOM for twin pregnancies) in only two of these five affected pregnancies. We emphasize that maternal serum AFP levels may be unreliable for prenatal screening for fetal neural tube defects in women taking valproate and recommend that amniocentesis and fetal ultrasound examination should be offered directly. 相似文献
242.
A. Reuss J. W. Wladimiroff R. J. Scholtmeijer M.D. Ph.D. P. A. Stewart P. J. J. Sauer M. F. Niermeijer 《黑龙江环境通报》1988,8(2):93-102
Between January 1982 and January 1986, 76 pregnant women between 15 and 40 weeks of gestation were referred because of suspected fetal obstructive urinary tract pathology. A total of 14 high-level (ureter) and 17 low-level (urethral) obstructions were diagnosed. High-level obstructions were at the uretero-pelvic level in 11 and at the uretero-vesical level in 3 cases. Increased amniotic fluid volume was observed in 28 per cent. The survival rate was 86 per cent. In the 17 cases of urethral obstruction, oligohydramnios was present in 70 per cent, associated structural defects in 30 per cent, and an abnormal karyotype in 6 per cent. Pregnancy was terminated because of progressive massive hydronephrosis in 41 per cent; intrauterine or neonatal death occurred in 47 per cent, resulting in a survival rate of only 12 per cent. 相似文献
243.
Muir DC Ford CA Grift NP Stewart RE Bidleman TF 《Environmental pollution (Barking, Essex : 1987)》1992,75(3):307-316
Organochlorine pesticides (DDT, chlordane, polychlorinated camphenes (PCCs), dieldrin, hexachloroheclohexanes (SigmaHCH), mirex), polychlorinated biphenyl congeners (PCBs) and chlorobenzenes (SigmaCBz) were determined in blubber and liver of narwhal (Monodon monoceros) collected during 1982-1983 from Pond Inlet on northern Baffin Island in the Canadian Arctic. PCCs were the predominate organochlorines in narwhal blubber, ranging in concentration from 2990 to 13 200 ng g(-1) (wet wt) in males and from 1910 to 8390 ng g(-1) in females. PCCs consisted of two major components, an octachlorobornane and a nonachlorobornane with gas chromatographic retention times of 1.05 and 1.22, relative to 4,4'-DDE. SigmaPCB concentrations in blubber ranged from 2250 to 7290 ng g(-1) in males and from 894 to 5710 ng g(-1) in females. Seven PCB congeners (tetra-, penta- and hexachlorobiphenyls) accounted for 45% of total PCB (SigmaPCB) in narwhal blubber. Narwhal had 1.4- to 8.6-fold higher ratios of tetra- and pentachlorobiphenyls to PCB-153 (2,2',4,4',5,5'-hexachlorobiphenyl), lower 4,4'-DDE/SigmaDDT ratios and lower proportions of trans-nonachlor to total chlordane components than reported for odontocetes living in more contaminated environments. Mean SigmaPCB concentrations in narwhal were 6- to 15-fold lower than in dolphins from the Canadian east coast and belugas from the St Lawrence River estuary, respectively, while PCC levels were from 4- to about 2-fold lower, and SigmaHCH, dieldrin and SigmaCBz differed by <2-fold. The pattern of organochlorines in narwhal tissues suggests they are exposed to proportionally more volatile compounds, and may have less capacity to metabolize some of these compounds, relative to odontocetes living nearer sources of these contaminants. 相似文献
244.
A population model is presented that accounts for spatial structure within habitat patches. It is designed for social species of wildlife that form social group home ranges that are much smaller than patch size. The model represents social group home ranges by Voronoi regions that tessellate a patch to form a Voronoi diagram. Neighbouring social groups are linked with habitat-confined shortest paths and form a dispersal network. The model simulates population dynamics and makes use of Voronoi diagrams and dispersal networks as a spatial component. It then produces density maps as outputs. These are maps that show predicted animal densities across the patches of a landscape. A construction procedure for the particular Voronoi diagram type used by the model is described. As a test case, the model is run for the squirrel glider (Petaurus norfolcensis), a small arboreal marsupial native to Australia. A time series of density maps are produced that show squirrel glider density changing across a landscape through time. 相似文献
245.
James B. McClintock Robert A. Angus Christina Ho Charles D. Amsler Bill J. Baker 《Marine Biology》2008,154(6):1077-1084
The circumpolar sea star Odontaster validus is ubiquitous in the nearshore marine benthos of Antarctica. Despite its ecological importance, little is known of its behavioral
interactions with other common sympatric sea stars. To examine these interactions we employed time-lapse video analyses conducted
in a large laboratory tank (1.8 m diameter circular tank, 1,629 L). In each experimental trial, 34 adult O. validus were placed in a tight circular grouping on one side of the tank, and one adult individual of one of three common sympatric
species of predatory sea star (Labidiaster annulatus, Diplasterias brandti, or Perknaster aurorae) was placed on the opposite side of the tank. Digital images of sea star movements were then captured at one min intervals
over a 24 h period and aspects of sea star movements subsequently analyzed. Each 24 h treatment was replicated three times,
as was a control treatment consisting only of O. validus. O. validus had significantly elevated levels of activity in the presence of P. aurorae when compared with the other two sea stars (potential chemically mediated response), and displayed a distinct “flight response”
(change in direction and twofold to sixfold increase of speed) upon tactile contact with this species. Moreover, an “alarm
response” was detected when individuals of O. validus that encountered a fleeing conspecific also fled the vicinity. In contrast, our results indicated that O. validus displays virtually no chemical or tactile behavioral responses to the large multi-armed L. annulatus and only weak tactile responses to D. brandti. 相似文献
246.
Effects of sheltering fish on growth of their host corals 总被引:1,自引:0,他引:1
Sally J. Holbrook Andrew J. Brooks Russell J. Schmitt Hannah L. Stewart 《Marine Biology》2008,155(5):521-530
Stony corals are the foundation species of tropical reefs, and their structures can harbor a diverse range of mutualist taxa
that can confer important benefits, including provision of nutrients. Prominent among the associates of branching coral in
the genus Pocillopora are groups of zooplanktivorous damselfishes that take refuge in the coral to avoid their predators. In field and laboratory
experiments, we explored the effects of colonies of resident damselfishes on growth of their host corals. Laboratory studies
revealed a positive relationship between biomass of fish and output of ammonium. In the field, levels of ammonium were significantly
elevated in the water surrounding the branches of Pocillopora occupied by colonies of damselfish, particularly in time periods following active feeding by the fish. Experimental manipulation
of the presence of fish on host corals during a month-long field experiment revealed that corals hosting fish grew significantly
more than those that lacked fish, and coral growth was positively correlated with the biomass of resident fish. The Pocillopora colonies in the field experiment varied in the degree of openness of their branching structure, and dye studies indicated
that this affected their ability to retain waterborne nutrients. Together with biomass of resident fish, colony openness explained
76% of the variation in coral growth rate during the experiment. Corals can exhibit considerable morphological variability,
and mutualistic fish respond to colony architecture during habitat selection, with some species preferring more open-branched
forms. This makes it likely that corals may face tradeoffs in attracting resident fish and in retaining the nutrients they
provide. 相似文献
247.
Angus H. H. Macdonald Eugenia M. Sampayo Tyrone Ridgway Michael H. Schleyer 《Marine Biology》2008,154(2):209-217
Studies on latitudinal gradients in Symbiodinium diversity on scleractinian corals are largely restricted to warm-water low latitude locations, and it appears that there
is a shift in symbiont distributions with increasing latitude. The Symbiodinium assemblages of high latitude coral communities have largely been undocumented despite occupying an important transitional
zone between tropical and temperate regions. Using a combination of the internal transcribed spacer region 2 (ITS2) and denaturing
gradient gel electrophoresis (DGGE), we assessed the cladal and subcladal variability of Symbiodinium in the widely distributed species Stylophora pistillata along a latitudinal transect in southeast African waters which extended into high latitude locations. All colonies examined
belonged to clade C. Six unique ITS2-DGGE banding profiles (designated Cspa to Cspf) were observed, which showed a latitudinal distribution from north to south, most likely a result of a gradient in water
temperature and irradiance driven by riverine input in the southern regions. Sequence analysis revealed that all sequences
except one did not match previously identified clade C sub-types, probably due to the lack of regional information in the
Western Indian Ocean when compared to the Caribbean and Pacific. This study further supports the applicability of ITS2-DGGE
in studies on Symbiodinium diversity, and highlights that potentially ecologically informative biogeographic patterns may be overlooked when only cladal
designations are employed. 相似文献
248.
Climate change influences populations by reducing or extirpating local populations, by disrupting patterns of migration and by shifting geographical distributions. These events can affect genetic population structure in several ways. Molecular markers have been used in numerous population genetic and phylogeographical studies of marine species and have detected population responses to climate change in the last few decades, such as range expansions, adaptative shifts and declines or increases in abundance. Little is known, however, about the molecular and physiological basis of adaptive responses to climate change in marine Mediterranean species. The Mediterranean Sea ecosystem is a ‘living laboratory’ with native species that are challenged by environmental change and by invasive species and a ‘gene-climate’ approach should be adopted as a way of focusing on the relationship between climate warming and genetic diversity. 相似文献
249.
K. Fajčíková V. Cvečková A. Stewart S. Rapant 《Environmental geochemistry and health》2014,36(5):973-986
We undertook a quantitative estimation of health risks to residents living in the Slovak Republic and exposed to contaminated groundwater (ingestion by adult population) and/or soils (ingestion by adult and child population). Potential risk areas were mapped to give a visual presentation at basic administrative units of the country (municipalities, districts, regions) for easy discussion with policy and decision-makers. The health risk estimates were calculated by US EPA methods, applying threshold values for chronic risk and non-threshold values for cancer risk. The potential health risk was evaluated for As, Ba, Cd, Cu, F, Hg, Mn, NO3 ?, Pb, Sb, Se and Zn for groundwater and As, B, Ba, Be, Cd, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se and Zn for soils. An increased health risk was identified mainly in historical mining areas highly contaminated by geogenic–anthropogenic sources (ore deposit occurrence, mining, metallurgy). Arsenic and antimony were the most significant elements in relation to health risks from groundwater and soil contamination in the Slovak Republic contributing a significant part of total chronic risk levels. Health risk estimation for soil contamination has highlighted the significance of exposure through soil ingestion in children. Increased cancer risks from groundwater and soil contamination by arsenic were noted in several municipalities and districts throughout the country in areas with significantly high arsenic levels in the environment. This approach to health risk estimations and visualization represents a fast, clear and convenient tool for delineation of risk areas at national and local levels. 相似文献
250.
Yahya Thamrin Author Vitae Author Vitae Sasha Stewart Author Vitae 《Journal of Safety Research》2010,41(1):59-63