全文获取类型
收费全文 | 1054篇 |
免费 | 14篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 68篇 |
环保管理 | 114篇 |
综合类 | 137篇 |
基础理论 | 192篇 |
污染及防治 | 341篇 |
评价与监测 | 98篇 |
社会与环境 | 81篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 11篇 |
2022年 | 42篇 |
2021年 | 55篇 |
2020年 | 26篇 |
2019年 | 25篇 |
2018年 | 37篇 |
2017年 | 33篇 |
2016年 | 56篇 |
2015年 | 27篇 |
2014年 | 59篇 |
2013年 | 98篇 |
2012年 | 37篇 |
2011年 | 89篇 |
2010年 | 41篇 |
2009年 | 47篇 |
2008年 | 47篇 |
2007年 | 52篇 |
2006年 | 60篇 |
2005年 | 39篇 |
2004年 | 35篇 |
2003年 | 31篇 |
2002年 | 26篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1961年 | 2篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1955年 | 3篇 |
1949年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有1086条查询结果,搜索用时 15 毫秒
241.
Maria João Gonçalves Ana Catarina Calado Santos Carlos Fernando Dias Rodrigues Pedro Coelho André Nuno Costa António Jorge Guiomar 《毒物与环境化学》2013,95(6):1202-1211
In the 1920s, Otto Warburg reported a striking metabolic shift in solid tumors: contrary to their normal counter parts, which exhibited a nearly pure respiratory metabolism, where cancer cells relied strongly on lactic fermentation for energy production, even in the presence of ample oxygen. This metabolic shift, later named the Warburg effect, is now viewed as a nearly universal cancer phenotype. To investigate whether it is operating in hexavalent chromium (Cr(VI))-induced carcinogenesis, PC-12 cells were exposed to low Cr(VI) concentrations and effects determined on the rates of glucose uptake, lactate production and oxygen consumption, critical indicators of the type of energy metabolism adopted by the cells. Further, the influence on the cells’ energy charge, an important parameter in the evaluation of the cellular physiological state was assessed. In the presence of ample oxygen, concentration-dependent, statistically significant decreases in the energy charge were detected, which were accompanied by an increased glucose uptake rate. This enhanced uptake may constitute the first step in a compensatory mechanism aimed at counteracting the decrease in energy charge. Although these changes may be too small to exert an impact in the cellular functions, they may provide insight into the initial steps of Cr(VI)-induced carcinogenesis. 相似文献
242.
Jean Rouchaud Marc Metsue Fabrice Gustin Frans van de Steene Christian Pelerents Frans Benoit 《毒物与环境化学》2013,95(1-4):215-226
For the protection of early and summer cauliflower and brussels sprouts crops against root fly, the insecticide chlorpyrifos was applied at planting onto soil around the stem of the plant, or in the planting line. In the soil, chlorpyrifos (1) was transformed into the insecticide metabolites oxon, 0,0‐diethyl‐0‐(3,5,6‐tri‐chloro‐2‐pyridinyl) phosphate (2), and 3,5,6‐trichloro‐2‐pyridinol (3). The soil half life time of chlorpyrifos could be 2.8 times greater (42 days relative to 15 days) when the field history as to cauliflower monoculture and insecticide treatments was short (1 year), than when it was long (8 years). Rains and season also had cumulative effects on the chlorpyrifos soil half life times. In the leaves of cabbage, chlorpyrifos and compound 3 were observed at concentrations which were higher, especially when their soil concentrations were high. Chlorpyrifos and compounds 2 and 3 however were not detected in the “flower” of cauliflower, nor in the brussels sprouts itself, the limit of sensitivity being 0.02 ppm of fresh weight. 相似文献
243.
244.
Sophie Arnaud-Haond V. Vonau C. Rouxel F. Bonhomme Jean Prou E. Goyard P. Boudry 《Marine Biology》2008,155(2):147-157
In order to study further the genetic structure of the pearl oyster Pinctada margaritifera in French Polynesia with a special consideration for the sampling scale, we analyzed or re-analyzed sets of data based on
nuclear DNA markers obtained at different spatial scales. At a large scale (several 1,000 km), the remote Marquesas Islands
were confirmed to be significantly differentiated from Tuamotu–Gambier and Society archipelagos, with a marked difference
however for the two main islands that are different from each other. At a medium scale (several 10 to several 100 km), overall
homogeneity was observed within and between these two archipelagos, with some exceptions. This could be attributed both to
large-scale larval dispersal and to human-driven spat translocations due to pearl oyster cultivation. These results contrast
with those observed (1) at a small scale (less than 10 km) in a lagoon heavily impacted by translocation and cultural practices,
where significant genetic differentiation was detected among three laying beds, and (2) at a micro scale where we detected
an important variability of the genetic composition of young spat recruited on artificial collectors. Such patterns could
result from a high variance in the number of genitors at the origin of each cohort, or from pre- or post-settlement selection
on linked loci. Altogether, our data support the hypothesis that under certain conditions populations of bivalves may exhibit
patterns of chaotic genetic patchiness at local scale, in line with the increasing report of such patchiness in marine benthic
organisms. This underlines the importance of sampling scale that should be rigorously defined depending on the questions to
be answered. Nevertheless, a survey of about 80 articles dealing with population genetics of marine invertebrates showed that
only 35% of those studies disclosed details about the sampling strategy (particularly the area explored). These results emphasize
the need for cautious interpretation of patterns of genetic structure at medium scale when rigorous sampling strategies are
not deployed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
245.
Roger L. Hothem David G. Lonzarich Jean E. Takewaka Harry M. Ohlendorf 《Environmental monitoring and assessment》1998,50(1):67-84
Organochlorines, metals, and trace elements were measured in liver, kidney, or whole-body tissues of canvasbacks (Aythya valisineria), lesser scaups (A. affinis), and greater scaups (A. marila) collected from San Francisco Bay and three coastal areas of California during the winter of 1986–1987. Potentially toxic concentrations of mercury (mean 10.4 µg/g, dry weight) and selenium (mean 32.7 µg/g, dry weight) were found in livers of scaups and canvasbacks from several San Francisco Bay sites. These elements varied spatially, temporally, and between species, with the highest concentrations found in late winter. Mean concentrations of mercury, selenium, and cadmium were generally higher in scaups than in canvasbacks. Of all the organochlorines included in the analyses, only p,p'-DDE and total PCBs were detected in all samples in this study. Mean whole-body concentrations of DDE and PCBs from San Francisco Bay ducks collected in late winter varied spatially and between species, but the concentrations were not considered toxic. Causes for inter-specific differences are unclear, but may be attributable to differences in diet, movement, or physiology. 相似文献
246.
247.
E. P. dos Santos 《Marine Biology》1968,1(4):348-350
This paper presents a method of investigating the distributional pattern of a biological population, using a technique of simulation. The method consists of the comparison of the empirical frequency curve of a population, obtained using the Method of Quadrats, with a simulated one, since the pattern of the simulated curve depends on the simulated distribution. An example is given. 相似文献
248.
249.
Anne-Catherine Bénard Vincent Darcos Christian Drakides Claude Casellas Jean Coudane Michel Vert 《Journal of Polymers and the Environment》2011,19(1):40-48
Water-soluble synthetic polymers are extensively used in cosmetics, detergents and paints. Many end up in wastewater and,
later on, in wastewater-treatment plants. In order to gain an insight into their fate in such plants, fluorescence and radioactivity
labelings were compared using a lab-scale reactor designed to mimic industrial conditions. Two fermentation media were considered,
namely a mixture of E402 and E204 micro-organisms and an activated sludge collected from a water-treatment plant located in
the south of France. A sample of low molar mass commercial poly(acrylic acid) (PAA) was labeled by radioactivity with tritium
and by coupling the 6-aminofluorescein fluorescent dye. Labeled PAA-containing sludges were allowed to ferment. To monitor
the fate of the polymers, aliquots of the fermented mixtures were withdrawn at selected times and centrifuged. Liquid and
solid phases were analyzed by scintigraphy or UV spectrometry, depending of the labeling techniques. Both techniques led to
similar distributions, c.a. 75% in the supernatant and 25% in the solid phase. Distributions remained constant during the
biological tests. There was no degradation of the commercial PAA after aqueous size exclusion chromatography (SEC), in agreement
with literature. These features showed that fluorescence-labeling can be used instead of the complex and expensive radiolabeling.
The validated fluorescence-based method was then applied to a linear poly(acrylic acid) synthesized by ATRP and labeled with
6-aminofluorescein. There was no significant difference between the commercial and the linear poly(acrylic acid)s. In contrast,
a linear PAA with 5% of tert-butyl ester repeating units was predominantly found in the solid phase although adsorption or absorption by micro-organisms
could not be demonstrated. The method based on fluorescence labeling should be applicable to other water soluble polymers
provided that the dye remains attached to the polymer as it was the case for the studied poly(acrylic acid)s. 相似文献
250.
Wamba Alfred G. N. Lima Eder C. Ndi Sylvere K. Thue Pascal S. Kayem Joseph G. Rodembusch Fabiano S. dos Reis Glaydson S. de Alencar Wagner S. 《Environmental science and pollution research international》2017,24(27):21807-21820
Environmental Science and Pollution Research - Natural pozzolan is an amorphous silicate-based material of volcanic origin. In this work, the natural pozzolan was modified by using... 相似文献