全文获取类型
收费全文 | 953篇 |
免费 | 8篇 |
国内免费 | 17篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 54篇 |
环保管理 | 96篇 |
综合类 | 171篇 |
基础理论 | 208篇 |
环境理论 | 2篇 |
污染及防治 | 304篇 |
评价与监测 | 56篇 |
社会与环境 | 58篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 2篇 |
2022年 | 15篇 |
2021年 | 19篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 29篇 |
2017年 | 36篇 |
2016年 | 36篇 |
2015年 | 31篇 |
2014年 | 30篇 |
2013年 | 94篇 |
2012年 | 47篇 |
2011年 | 74篇 |
2010年 | 56篇 |
2009年 | 58篇 |
2008年 | 66篇 |
2007年 | 53篇 |
2006年 | 49篇 |
2005年 | 31篇 |
2004年 | 30篇 |
2003年 | 31篇 |
2002年 | 20篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 9篇 |
1997年 | 10篇 |
1996年 | 5篇 |
1995年 | 12篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1981年 | 3篇 |
1965年 | 7篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 12篇 |
1961年 | 11篇 |
1959年 | 3篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1955年 | 3篇 |
1954年 | 7篇 |
1953年 | 2篇 |
1941年 | 2篇 |
1932年 | 1篇 |
1914年 | 1篇 |
排序方式: 共有978条查询结果,搜索用时 31 毫秒
801.
802.
803.
Anne-Marie Boulay Christian Bouchard Cecile Bulle Louise Deschênes Manuele Margni 《Mitigation and Adaptation Strategies for Global Change》2002,7(4):417-418
Subject Index
Subject Index 相似文献804.
805.
Christian Hoffmann 《Die Naturwissenschaften》1965,52(14):436-437
806.
Stem cells for regenerative medicine: advances in the engineering of tissues and organs 总被引:2,自引:0,他引:2
The adult bone marrow stroma contains a subset of nonhematopoietic cells referred to as mesenchymal stem or mesenchymal progenitor cells (MSC). These cells have the capacity to undergo extensive replication in an undifferentiated state ex vivo. In addition, MSC have the potential to develop either in vitro or in vivo into distinct mesenchymal tissues, including bone, cartilage, fat, tendon, muscle, and marrow stroma, which suggest these cells as an attractive cell source for tissue engineering approaches. The interest in modern biological technologies such as tissue engineering has dramatically increased since it is feasible to isolate living, healthy cells from the body, expand them under cell culture conditions, combine them with biocompatible carrier materials and retransplant them into patients. Therefore, tissue engineering gives the opportunity to generate living substitutes for tissues and organs, which may overcome the drawbacks of classical tissue reconstruction: lacking quality and quantity of autologous grafts, immunogenicity of allogenic grafts and loosening of alloplastic implants. Due to the prerequisite for tissue engineering to ensure a sufficient number of tissue specific cells without donor site morbidity, much attention has been drawn to multipotential progenitor cells such as embryonic stem cells, periosteal cells and mesenchymal stem cells. In this report we review the state of the art in tissue engineering with mesenchymal stem and mesenchymal progenitor cells with emphasis on bone and cartilage reconstruction. Furthermore, several issues of importance, especially with regard to the clinical application of mesenchymal stem cells, are discussed. 相似文献
807.
Deep-sea hydrothermal vent ecosystems host both symbiotic and non-symbiotic invertebrates. The non-symbiotic vent fauna is
generally assumed to rely on free-living chemoautotrophic bacteria as their main food source but other sources such as detritus
have recently been suggested to be a part of the invertebrate diets. Little is known about how food availability influences
the distribution of vent organisms on a small scale. In addition, the feeding ecology and role of small, often numerically
dominant invertebrates, the meiofauna is poorly understood at vents. In this study, we used stable carbon and nitrogen isotopic
analysis to investigate the role of particulate detritus in the diets of macro- and meiobenthic invertebrates within three
vent assemblages at Axial Volcano, Juan de Fuca Ridge, and Northeast Pacific. Particulate organic matter of a detrital origin
became more important in the diet of invertebrates in assemblages typically associated with low-hydrothermal flow intensities.
Meiobenthic species occupied several different feeding guilds and trophic levels in the assemblages investigated. We conclude
that small-scale spatial variability in food sources is an important feature of vent food webs and that spatial patterns observed
here and elsewhere are shaped by variations in hydrothermal discharge. 相似文献
808.
The luminescence inhibition test was applied to contaminated soils. Two different methods were used: The standard sediment elutriate test and the so-called “solid-phase test”. Cadmium sulfate, p-cresol and o-nitroanisole were used as model substances for the contamination of two different soils that show significant differences in grain size. While five of six elutriates acted toxically in the standard elutriate test, the solid-phase test detected only the heavy metal clearly. The interpretation of the solid-phase test results, unlike those of the standard sediment test, is problematic because of the high and varied ground inhibitions of the uncontaminated soils. This suggests that the rate of adsorption of the bacteria depends on the type of soil. An interpretation without an uncontaminated reference seems impossible. A good correlation between the portion of elutriated contaminants and the values of inhibition was only obtained by using the standard elutriate test. 相似文献
809.
Christian Schlatter Alfred Steinegger Urs Rickenbacher Christian Hans Andrea Lengyel 《Environmental geochemistry and health》1990,12(1-2):59-64
Due to the exposure to alumina in the air, workers in the primary aluminium industry are expected to exhibit a higher aluminium exposure than the general population. The additional daily intake will be less than 20 mg. The determination of aluminium in blood plasma of electrolysis-workers by flameless atomic absorption spectrometry revealed levels before shift in the range of 20–30 g/L compared to levels of less than 3 g/L in a non-occupationally exposed group. These levels refer to work in old plants with unhooded pots. The plasma levels can rise up to 60 g/L during the shift. A similar rapid change of the levels during work is seen in the urine values. Due to the delay in excretion the maximal values in the range of 5 g/h are found four hours after cessation of work. It seems therefore that only preshift samples give a reliable measure of the body burden. Compared to the much higher levels in dialysis patients the observed values in aluminium workers are not considered to be of relevance to health. 相似文献
810.
William O'Neil Martin David Christina Moore Erhard Joeres 《Journal of Environmental Economics and Management》1983,10(4):346-355
Recent emphasis on reforms of environmental regulation has led to suggestions for strategies which maintain environmental standards but allow the needed flexibility and cost effectiveness. The transferable discharge permit (TDP) is one such strategy for water pollution control recently adopted in Wisconsin. In this article, the potential for substantial cost savings from trading TDPs is demonstrated using data on the Fox River in Wisconsin. A simulation model of water quality (Qual-III) and a linear programming model of abatement costs determine the optimum pattern of discharge. Reaching that optimum from proposed pollution abatement orders is shown to be feasible. Varying conditions of flow and temperature can be accommodated using trade coefficients which can be accurately estimated through interpolation. The calculations demonstrate the value and feasibility of flexible regulations governing water pollution abatement. 相似文献