全文获取类型
收费全文 | 16115篇 |
免费 | 173篇 |
国内免费 | 133篇 |
专业分类
安全科学 | 402篇 |
废物处理 | 694篇 |
环保管理 | 1891篇 |
综合类 | 2630篇 |
基础理论 | 4443篇 |
环境理论 | 5篇 |
污染及防治 | 4151篇 |
评价与监测 | 1091篇 |
社会与环境 | 1005篇 |
灾害及防治 | 109篇 |
出版年
2022年 | 135篇 |
2021年 | 119篇 |
2020年 | 119篇 |
2019年 | 116篇 |
2018年 | 222篇 |
2017年 | 250篇 |
2016年 | 349篇 |
2015年 | 286篇 |
2014年 | 463篇 |
2013年 | 1248篇 |
2012年 | 520篇 |
2011年 | 728篇 |
2010年 | 637篇 |
2009年 | 611篇 |
2008年 | 691篇 |
2007年 | 738篇 |
2006年 | 612篇 |
2005年 | 533篇 |
2004年 | 533篇 |
2003年 | 526篇 |
2002年 | 515篇 |
2001年 | 651篇 |
2000年 | 479篇 |
1999年 | 262篇 |
1998年 | 176篇 |
1997年 | 213篇 |
1996年 | 208篇 |
1995年 | 241篇 |
1994年 | 236篇 |
1993年 | 183篇 |
1992年 | 200篇 |
1991年 | 186篇 |
1990年 | 209篇 |
1989年 | 196篇 |
1988年 | 157篇 |
1987年 | 165篇 |
1986年 | 162篇 |
1985年 | 161篇 |
1984年 | 150篇 |
1983年 | 144篇 |
1982年 | 129篇 |
1981年 | 123篇 |
1980年 | 117篇 |
1979年 | 127篇 |
1978年 | 101篇 |
1977年 | 114篇 |
1975年 | 88篇 |
1974年 | 87篇 |
1973年 | 96篇 |
1972年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
J. Altenburger Th. Dielacher P. Eder H. Ferner M. Fegerl J. Fresner O. Gelinek A. Kogler J. Jantschgi M. Nussbaumer B. Russegger H. Schnitzer K. Schauer B. Sebesta J. Seiler F. Sprenger H. Widenmeyer 《Journal of Cleaner Production》1994,2(3-4)
The paper focuses upon the organization of a federal state-funded pollution prevention project in the Styrian industry. The project includes 13 companies from the textile, pulp and paper, machine building, wood working and printed circuit board manufacturing industries, covering most of the sectors and sizes in the Styrian industry. It started in January 1994 and will last for one year. It will demonstrate the possibilities of pollution prevention and the need for further research work. This project will make use of the methods and tools that were refined in the Austrian Prepare project. As a first step, a systematic balance of all the inputs and outputs of a company is made, after which the weak points and inefficiencies of material and energy use are identified and the options for improvements, both economical and ecological, are defined. Consequently, modifications in products and production lead to a situation with less waste and emissions. The preliminary lessons from these projects are presented: as a rule, the utilities (consumption of process materials and water, cleaning, energy, preparatory and finishing steps) are treated as black boxes and usually represent a considerable optimization potential. In these areas especially there is usually a lack of information and coordination as well as a need for a systematic and comprehensive approach. Leadership in the company and creative consultants are needed for starting lasting successful pollution prevention projects. 相似文献
52.
Distribution of actinomycetes in oil contaminated ultisols of the Niger Delta (Nigeria) 总被引:1,自引:0,他引:1
J.P.Essien 《环境科学学报》2000,12(3):296-302
The distribution of actinomycetes in oil contaminated sandy loam ultisols of the Niger Delta region of Nigeria was studied to aid in understanding the effect of hydrocarbons on indigenous microbial population in tropical soils. The average total counts of actinomycetes in all the oil samples analysed was 103 cfu/g. Higher counts of actinomycetes were observed during the dry season than during the wet season. The counts of hydrocarbonoclastic actinomycetes correlated positively with the total count of actinomycetes.The actinomycetes were generally restricted to the top soil(0-10 cm soil depth) although a seemingly deeper(down to 40 cm soil depth) distribution was noticed in the dry season. The isolates included oil degrading species of Actinoplanes, Norcadia,Streptomyces and Streptosporangium. Their high oil utilization ability indicates their positive potential and role in the bioremediation of oil-spilled soils. 相似文献
53.
54.
55.
Chemical process simulation (CPS) software has been widely used by chemical (process) engineers to design, test, optimise, and integrate process plants. It is expected that industrial ecologists to bring these same problem-solving benefits to the design and operation of industrial ecosystems can use CPS. This paper provides industrial ecology researchers and practitioners with an introduction to CPS and an overview of chemical engineering design principles. The paper highlights recent research showing that CPS can be used to model industrial ecosystems, and discusses the benefits of using CPS to address some of the technical challenges facing companies participating in an industrial ecosystem. CPS can be used to (i) quantitatively evaluate and compare the potential environmental and financial benefits of material and energy linkages; (ii) solve general design, retrofit, or operational problems; (iii) help to identify complex and often counter-intuitive solutions; and (iv) evaluate what-if scenarios. CPS should be a useful addition to the industrial ecology toolbox. 相似文献
56.
57.
Plasticity of honeybee castes 总被引:1,自引:0,他引:1
58.
Fibroblasts from a fetus with the prenatal diagnosis of mosaic trisomy 20 were cloned by dilution plating. Adenosine deaminase (ADA), a biochemical marker for chromosome 20, was assayed in trisomic clones and normal clones as control. The cytogenetic diagnosis was substantiated by demonstration of a triplex gene dosage effect for ADA in the trisomic cells. 相似文献
59.
60.
Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals 总被引:2,自引:0,他引:2
Pörtner HO 《Die Naturwissenschaften》2001,88(4):137-146
Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed. 相似文献