全文获取类型
收费全文 | 464篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 10篇 |
环保管理 | 20篇 |
综合类 | 113篇 |
基础理论 | 128篇 |
环境理论 | 1篇 |
污染及防治 | 156篇 |
评价与监测 | 18篇 |
社会与环境 | 13篇 |
灾害及防治 | 2篇 |
出版年
2018年 | 4篇 |
2016年 | 5篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 13篇 |
2011年 | 20篇 |
2010年 | 14篇 |
2009年 | 28篇 |
2008年 | 16篇 |
2007年 | 27篇 |
2006年 | 23篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 13篇 |
2001年 | 7篇 |
2000年 | 18篇 |
1999年 | 23篇 |
1998年 | 16篇 |
1997年 | 18篇 |
1996年 | 18篇 |
1995年 | 13篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1970年 | 2篇 |
1967年 | 2篇 |
1965年 | 3篇 |
1964年 | 2篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1958年 | 3篇 |
1955年 | 3篇 |
1952年 | 3篇 |
1931年 | 3篇 |
1930年 | 6篇 |
1929年 | 2篇 |
1923年 | 6篇 |
1922年 | 3篇 |
1921年 | 2篇 |
1913年 | 2篇 |
排序方式: 共有468条查询结果,搜索用时 31 毫秒
181.
With special filter materials it is possible to eliminate the heavy metals lead, copper and nickel and arsenic from water by sorption resp. chemical bounding. After a reaction time of 24 hours the reduction rates were between 97% and >99,9%. 相似文献
182.
183.
Manuela Baumgarten Christian Huber Patrick Büker Hans-Peter Dietrich Christian Heerdt Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2091-2107
Exposure and flux-based indices of O3 risk were compared, at 19 forest locations across Bavaria in southern Germany from 2002 to 2005; leaf symptoms on mature beech trees found at these locations were also examined for O3 injury. O3 flux modelling was performed using continuously recorded O3 concentrations in combination with meteorological and soil moisture data collected from Level II forest sites. O3 measurements at nearby rural open-field sites proved appropriate as surrogates in cases where O3 data were lacking at forest sites (with altitude-dependent average differences of about 10% between O3 concentrations). Operational thresholds of biomass loss for both O3 indices were exceeded at the majority of the forest locations, suggesting similar risk under long-term average climate conditions. However, exposure-based indices estimated higher O3 risk during dry years as compared to the flux-based approach. In comparison, minor O3-like leaf injury symptoms were detected only at a few of the forest sites investigated. Relationships between flux-based risk thresholds and tree response need to be established for mature forest stands for validation of predicted growth reductions under the prevailing O3 regimes. 相似文献
184.
The complexity of ecosystems urges that the evaluation process should avoid an aggregation of information. The reason is that although mathematical modelling has made enormous progress (object oriented programming) there is still no ecologically reasonable function of quality. The technique to compare chemicals for example, even if they are characterized by many properties, is based on the generalization of the concept of order and the method of visualization by the using Hasse diagrams. By the example of six chemicals the procedure will be explained and it will be shown that a high hazard potential of chemicals is related to different properties, which cause different ecotoxicological consequences. 相似文献
185.
2-Chlorovinylarsine dichloride (Lewisite I) react by room temperature quickly with alcohols in an equilibrium reaction to yield 2-Chlorovinylarsine chloride ether and 2-Chlorovinylarsine bisether. The reactions are not quantitative. The ethyl- and propylether are not stable. The ether were identified with mass spectrometry. 相似文献
186.
Response patterns in adult forest trees to chronic ozone stress: identification of variations and consistencies 总被引:1,自引:0,他引:1
Nunn AJ Reiter IM Häberle KH Langebartels C Bahnweg G Pretzsch H Sandermann H Matyssek R 《Environmental pollution (Barking, Essex : 1987)》2005,136(3):365-369
The responsiveness of adult beech and spruce trees to chronic O(3) stress was studied at a free-air O(3) exposure experiment in Freising/Germany. Over three growing seasons, gas exchange characteristics, biochemical parameters, macroscopic O(3) injury and the phenology of leaf organs were investigated, along with assessments of branch and stem growth as indications of tree performance. To assess response pattern to chronic O(3) stress in adult forest trees, we introduce a new evaluation approach, which provides a comprehensive, readily accomplishable overview across several tree-internal scaling levels, different canopy regions and growing seasons. This new approach, based on a three-grade colour coding, combines statistical analysis and the proficient ability of the "human eye" in pattern recognition. 相似文献
187.
Growth of Lygeum spartum in acid mine tailings: response of plants developed from seedlings, rhizomes and at field conditions 总被引:3,自引:0,他引:3
Conesa HM Robinson BH Schulin R Nowack B 《Environmental pollution (Barking, Essex : 1987)》2007,145(3):700-707
Lygeum spartum is a native species in semiarid Mediterranean areas that grows spontaneously on acid mine tailings. We aimed to study the suitability of this plant for phytostabilization. L. spartum was grown from both seeds and rhizomes in acid mine tailings with various fertilizer and lime treatments. Untreated soils had a solution pH of 2.9 with high concentrations of dissolved salts (Electrical Conductivity 25 dS m(-1)) and Zn (3100 mg L(-1)). Plants grown on untreated soil had high shoot metal concentrations (>4000 mg kg(-1)Zn). Liming increased the solution pH to 5.5 and reduced the dissolved salts by more than 75%, resulting in lower shoot metal accumulation. Plants grown from rhizomes accumulated less metal than those grown from seeds. Plants collected in the field had metal concentrations an order of magnitude less than plants raised in the growth chamber. These differences may be due to the higher moisture content and homogeneous nature of the soils used in the pot experiment. 相似文献
188.
Effects of the 2008 flood on economic performance and food security in Yemen: a simulation analysis
下载免费PDF全文
![点击此处可从《Disasters》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Extreme weather events such as floods and droughts can have devastating consequences for individual well being and economic development, in particular in poor societies with limited availability of coping mechanisms. Combining a dynamic computable general equilibrium model of the Yemeni economy with a household‐level calorie consumption simulation model, this paper assesses the economy‐wide, agricultural and food security effects of the 2008 tropical storm and flash flood that hit the Hadramout and Al‐Mahrah governorates. The estimation results suggest that agricultural value added, farm household incomes and rural food security deteriorated long term in the flood‐affected areas. Due to economic spillover effects, significant income losses and increases in food insecurity also occurred in areas that were unaffected by flooding. This finding suggests that while most relief efforts are typically concentrated in directly affected areas, future efforts should also consider surrounding areas and indirectly affected people. 相似文献
189.
The relationship between the polymeric composition of hemocyanin and environmental conditions could be described more thoroughly if there were a simple method for separating the dodecameric and hexameric forms of the protein. Such a method for the separation of these two forms of hemocyanin from Callinectes sapidus Rathbun using size-exclusion high performance liquid chromatography has been developed. The method uses columns with an exclusion limit of 1x106 daltons and monitors the binuclear copper moiety by its absorbance at 337 nm. The application of the method was demonstrated by obtaining the dodecamer to hexamer ratios for 20 hemocyanin samples from freshly caught adult intermolt male C. sapidus. The ratios ranged from 1.9:1 to 7.3:1 and appeared to be normally distributed. This variation in the polymeric composition of hemocyanin (much greater than that attributable to the reproducibility of the assay) is apparently occurring in nature, contrary to previous reports that have indicated the ratio to lie within a narrow band for a given species.New address effective May 1, 1992: Department of Chemistry, University of California, Irvine, California 92717, USA 相似文献
190.
Kristina Voigt Gerhard Welzl Rainer Brüggemann Stefan Pudenz 《Environmental Sciences Europe》2002,14(1):58-64
Comprehensive data on environmental monitoring programs concerned with air pollutants like ozone (O3), nitrogen dioxide (NO2), nitrogen oxide (NO), carbon dioxide (CO2) und carbon monoxide (CO), and occassionally suspended dust, benzene and other environmental chemicals, are available on the free Internet. As different monitoring information systems exist in most states or big cities of the Federal Republic of Germany, a comparison of these systems with their pros and cons is of great interest to the public. Environmental air pollutant monitoring systems in 16 states of Germany are listed and evaluated by applying 5 evaluation criteria for the differentiation of these systems. Different data-analysis methods will be applied, the Hasse diagram technique, a method derived from discrete mathematics and the partially Ordered Scalogram Analysis with Coordinates (POSAC) method, a multivariate statistical approach. The important objects, the so-called maximal or minimal objects, are detected in both methods. The Internet-based environmental monitoring systems of the states of Berlin, Bremen, Saxony-Anhalt, Baden-Wurttemberg are rated good in the evaluation approaches, whereas the information systems of the states of Brandenburg, North Rhine-Westphalia, Saxony received a rather poor ranking. The attributes of DA, way of data presentation on the Internet, and ME, type and length of measurements, were pointed out in the data-analysis methods. Multivariate explorative statistical methods offer a comprehensive tool for the graphical analysis of data-matrices. The ranking of objects is given in an effective and graphically comprehensible manner using the Hasse diagram technique. The choice and preference of the methods is problem-driven. A combination of these different methods is envisaged in the authors’ future research. 相似文献