全文获取类型
收费全文 | 617篇 |
免费 | 2篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 2篇 |
环保管理 | 17篇 |
综合类 | 372篇 |
基础理论 | 100篇 |
污染及防治 | 92篇 |
评价与监测 | 19篇 |
社会与环境 | 16篇 |
灾害及防治 | 3篇 |
出版年
2018年 | 9篇 |
2017年 | 9篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 22篇 |
2012年 | 11篇 |
2011年 | 13篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 15篇 |
2007年 | 18篇 |
2006年 | 10篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 11篇 |
2000年 | 7篇 |
1999年 | 19篇 |
1998年 | 6篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1992年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1967年 | 6篇 |
1966年 | 8篇 |
1965年 | 7篇 |
1964年 | 8篇 |
1961年 | 9篇 |
1960年 | 6篇 |
1955年 | 7篇 |
1952年 | 6篇 |
1950年 | 5篇 |
1942年 | 6篇 |
1941年 | 8篇 |
1940年 | 9篇 |
1939年 | 5篇 |
1938年 | 6篇 |
1937年 | 12篇 |
1936年 | 12篇 |
1935年 | 10篇 |
1934年 | 12篇 |
1933年 | 8篇 |
1931年 | 7篇 |
1929年 | 9篇 |
1922年 | 6篇 |
1921年 | 7篇 |
1920年 | 5篇 |
排序方式: 共有625条查询结果,搜索用时 281 毫秒
491.
Robert S. Wright Edward L. Tew Clifford E. Decker Darryl J. von Lehmden William F. Barnard 《Journal of the Air & Waste Management Association (1995)》2013,63(4):384-385
Air pollution abatement policies must be based on quantitative information on current and future emissions of pollutants. As emission projections uncertainties are inevitable and traditional statistical treatments of uncertainty are highly time/resources consuming, a simplified methodology for nonstatistical uncertainty estimation based on sensitivity analysis is presented in this work. The methodology was applied to the “with measures” scenario for Spain, concretely over the 12 highest emitting sectors regarding greenhouse gas and air pollutants emissions. Examples of methodology application for two important sectors (power plants, and agriculture and livestock) are shown and explained in depth. Uncertainty bands were obtained up to 2020 by modifying the driving factors of the 12 selected sectors and the methodology was tested against a recomputed emission trend in a low economic-growth perspective and official figures for 2010, showing a very good performance.Implications:?A solid understanding and quantification of uncertainties related to atmospheric emission inventories and projections provide useful information for policy negotiations. However, as many of those uncertainties are irreducible, there is an interest on how they could be managed in order to derive robust policy conclusions. Taking this into account, a method developed to use sensitivity analysis as a source of information to derive nonstatistical uncertainty bands for emission projections is presented and applied to Spain. This method simplifies uncertainty assessment and allows other countries to take advantage of their sensitivity analyses. 相似文献
492.
Persistent toxic substances in soils and waters along an altitudinal gradient in the Laja River Basin, Central Southern Chile 总被引:5,自引:0,他引:5
In this study the levels and distribution of some persistent toxic substances (PTS) were investigated in soils, superficial water, and snow along an altitudinal gradient in the Laja River Basin (South Central Chile). The principal objective was to establish the basin's contamination status. The working hypothesis was that PTS levels and distribution in the basin are dependent on the degree of anthropogenic intervention. Fifteen PAHs, seven PCBs congeners, and three organochlorine pesticides were studied in superficial soil and water samples obtained along the altitudinal gradient and from a coastal reference station (Lleu-Lleu River). Soil samples were extracted using accelerated solvent extraction with acetone/cyclohexane (1:1) for PAHs and organochlorine compounds. Contaminants were extracted from water and snow samples by liquid-liquid extraction (LLE). PAH and organochlorine compound quantification was carried out by HPLC with fluorescence detection and GC-MS, respectively. PCBs in soils presented four different profiles in the altitudinal gradient, mainly determined by their chlorination degree; these profiles were not observed for the chlorinated pesticides. In general, the detected levels for the analyzed compounds were low for soils when compared with soil data from other remote areas of the world. Higher summation operator PAHs levels in soils were found in the station located at 227 masl (4243 ng g-1 TOC), in a forestry area and near a timber industry, where detected levels were up to eight times higher than the other sampling sites. In general, PAH levels and distribution seems to be dependent on local conditions. No pesticides were detected in surface waters. However, congeners of PCBs were detected in almost all sampling stations with the highest levels being found in Laja Lake waters, where 1.1 ng/l were observed. This concentration is two times higher than values reported for polluted lakes in the Northern Hemisphere. The presence of organochlorine compound in snow sampled at the highest elevation point of the basin is indicative of the transport and atmospheric deposition phenomena of alpha-HCH, gamma-HCH and PCB 52, with values being similar to the levels reported in Canadian snow samples. We conclude that environmental PTS substance levels are in general relatively low, although PAHs may be of concern in some areas of the basin. 相似文献
493.
Pharmaceuticals in the river Elbe and its tributaries 总被引:13,自引:0,他引:13
Wiegel S Aulinger A Brockmeyer R Harms H Löffler J Reincke H Schmidt R Stachel B von Tümpling W Wanke A 《Chemosphere》2004,57(2):107-126
Medicinal drugs were found to be ubiquitous in the river Elbe, its tributary the river Saale and in other tributaries at their points of entry into the Elbe. The distribution of concentration peaks along the investigated river stretches provides an indication that they are mainly due to the emission of treated waste water from municipal sewage treatment works. This leads to the conclusion that medicinal substances can be regarded as faecal indicators for water pollution caused by human activity. The main substances found in the Elbe in 1998 were diclofenac, ibuprofen and carbamazepine as well as various antibiotics and lipid regulators in the concentration range of <20-140 ng/l. The more thorough investigations carried out in 1999 and 2000 show that in addition to the drugs (phenazone, isopropyl-phenazone and paracetamol) metabolite concentrations contributed significantly to the total concentration of pharmaceuticals in the Elbe. The metamizole metabolites N-acetyl-4-aminoantipyrine (AAA) and N-formyl-4-aminoantipyrine (FAA) were found in concentrations from <20 to 939 ng/l. A multivariate statistical analysis revealed a high correlation in respect of the distribution of persistent substances. The metoprolol distribution throughout the Saale demonstrated that the tributaries cause either an increase (Weisse Elster, Unstrut, Ilm) or a reduction (Wipper, Bode) in the concentration, depending on the respective load of waste water. Wide scale sampling in Saxony during 2002 showed the ubiquitous occurrence of carbamazepine in surface waters. The ecotoxicological effects of this contamination cannot be assessed at present. This is due to the fact that no legal framework in respect of these medicinal drugs for human consumption has been established and therefore little research and no risk assessment has been carried out. Therefore it is urgently necessary to include at least the quantitatively most significant substances in the new assessment concept of the EC White Paper. 相似文献
494.
B. Wehner U. Uhrner S. von Löwis M. Zallinger A. Wiedensohler 《Atmospheric environment (Oxford, England : 1994)》2009,43(6):1235-1245
A new setup has been developed and built to measure number size distributions of exhaust particles and thermodynamic parameters under real traffic conditions. Measurements have been performed using a diesel and a gasoline passenger car driving with different speeds and engine conditions. Significant number of nucleation mode particles was found only during high load conditions, i.e. high car and engine speeds behind the diesel car. The number concentration of soot mode particles varied within a factor of two for different engine conditions while the concentration of nucleation mode particles varied up to two orders of magnitude. The results show that roadside measurements are still quite different from those behind the tailpipe. Beside dilution transformation processes within the first meter behind the tailpipe also play an important role, such as nucleation and growth. Emission factors were calculated and compared with those obtained by other studies. Emission factors for particles larger than 25 nm (primary emissions) varied within 1.1 × 1014 km?1 and 2.7 × 1014 km?1 for the diesel car and between 0.6 × 1012 km?1 and 3.5 × 1012 km?1 for the gasoline car. The advantage of these measurements is the exhaust dilution under atmospheric conditions and the size-resolved measurement technique to divide into primary emitted and secondary formed particles. 相似文献
495.
Virological Quality of Irrigation Water in Leafy Green Vegetables and Berry Fruits Production Chains
P. Kokkinos I. Kozyra S. Lazic K. Söderberg P. Vasickova M. Bouwknegt S. Rutjes K. Willems R. Moloney A. M. de Roda Husman A. Kaupke E. Legaki M. D’Agostino N. Cook C.-H. von Bonsdorff A. Rzeżutka T. Petrovic L. Maunula I. Pavlik A. Vantarakis 《Food and environmental virology》2017,9(1):72-78
This study condenses data acquired during investigations of the virological quality of irrigation water used in production of fresh produce. One hundred and eight samples of irrigation water were collected from five berry fruit farms in Finland (1), the Czech Republic (1), Serbia (2), and Poland (1), and sixty-one samples were collected from three leafy green vegetable farms in Poland, Serbia, and Greece. Samples were analyzed for index viruses of human or animal fecal contamination (human and porcine adenoviruses, and bovine polyoma viruses), and human pathogenic viruses (hepatitis A virus, hepatitis E virus, and noroviruses GI/GII). Both index and pathogenic viruses were found in irrigation water samples from the leafy green vegetables production chain. The data on the presence of index viruses indicated that the highest percentage of fecal contamination was of human origin (28.1 %, 18/64), followed by that of porcine (15.4 %, 6/39) and bovine (5.1 %, 2/39) origins. Hepatitis E virus (5 %, 1/20) and noroviruses GII (14.3 %, 4/28) were also detected. Samples from berry fruit production were also positive for both index and pathogenic viruses. The highest percentage of fecal contamination was of human origin (8.3 %, 9/108), followed by that of porcine, 4.5 % (4/89) and bovine, 1.1 % (1/89) origins. Norovirus GII (3.6 %, 2/56) was also detected. These data demonstrate that irrigation water used in primary production is an important vehicle of viral contamination for fresh produce, and thus is a critical control point which should be integrated into food safety management systems for viruses. The recommendations of Codex Alimentarius, as well as regulations on the use of water of appropriate quality for irrigation purposes, should be followed. 相似文献
496.
K. Theo von der Trenck Joachim Ruf Manfred Flittner 《Environmental science and pollution research international》1994,1(4):253-261
The treatment of hazardous sites in Baden-Württemberg is based on three legal documents: the state waste disposal art (LAbfG, 1990), the assessment committee directive (KommissionsVO, 1990), and the guide values directive (UM & SM B-W, 1993). The guide values directive was commonly issued by the Ministry of Labor, Health and Social Affairs and the Ministry of the Environment of the state of Baden-Württemberg (UM & SM B-W, 1993) and contains a three-level hierarchy of numerical criteria and rules which serve as both screening levels during the investigation and as remediation objectives. The decision for the appropriate level of remediation is based on feasibility and environmental balance considerations. The levels are ordered as follows: ? Level 1 (Background-Values) On principle, all remediations have to be based first on background levels. In the case of lack of feasibility or negative environmental balance for level-1 objectives use-specific requirements are considered next. ? Level 2 (Assessment-Values for Worst Case Exposure Conditions) The generic requirements underlying level 2 afford appropriate protection for humans regarding the most sensitive uses of the environment. At least four resources are considered on this level: Ground-water as such and its use, the health of humans on contaminated sites, and soil with respect to growth and quality of plants. Barriers against migration of the contaminants, the effect of dilution, and abandonment of certain uses, etc., are not taken into consideration on level 2. ? Level 3 (Site-Specific Requirements) Lack of feasibility or a negative environmental balance of level-2 objectives lead to consideration of site-specific circumstances which may alleviate the requirements. With respect to groundwater, the distinction is again necessary between groundwater as a resource and the use of groundwater. On level 3 the guideline gives rules of how to derive site-specific remediation objectives for groundwater in the form of concentrations and fluxes of contaminants after taking into account barriers, dilution, and the abandonment of uses. The guideline is the only directive of its kind in the world that regulates both concentrations and fluxes of contaminants into groundwater. 相似文献
497.
498.
499.
J. Eichler H. Preuss W. Döring H. Volkmann J. Giesecke R. Lüst F. L. Boschke L. Horner W. Klemm H. Runge John M. Harkin H. Wagner L. Jaenicke Horst Eichler W. Föllmer F. Henschen M. Wiesendanger R. Schenkel G. H. R. von Koenigswald M. Runge J. Jung D. Schmähl G. Böttger 《Die Naturwissenschaften》1969,56(1):42-48
500.