全文获取类型
收费全文 | 2212篇 |
免费 | 16篇 |
国内免费 | 16篇 |
专业分类
安全科学 | 63篇 |
废物处理 | 154篇 |
环保管理 | 140篇 |
综合类 | 252篇 |
基础理论 | 434篇 |
环境理论 | 3篇 |
污染及防治 | 802篇 |
评价与监测 | 245篇 |
社会与环境 | 142篇 |
灾害及防治 | 9篇 |
出版年
2023年 | 21篇 |
2022年 | 74篇 |
2021年 | 67篇 |
2020年 | 44篇 |
2019年 | 57篇 |
2018年 | 77篇 |
2017年 | 82篇 |
2016年 | 120篇 |
2015年 | 69篇 |
2014年 | 120篇 |
2013年 | 246篇 |
2012年 | 152篇 |
2011年 | 181篇 |
2010年 | 118篇 |
2009年 | 100篇 |
2008年 | 98篇 |
2007年 | 120篇 |
2006年 | 88篇 |
2005年 | 68篇 |
2004年 | 56篇 |
2003年 | 42篇 |
2002年 | 38篇 |
2001年 | 22篇 |
2000年 | 24篇 |
1999年 | 15篇 |
1998年 | 11篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1987年 | 4篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1979年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1967年 | 4篇 |
1966年 | 2篇 |
1965年 | 2篇 |
1964年 | 3篇 |
1961年 | 3篇 |
1960年 | 5篇 |
1959年 | 10篇 |
1958年 | 12篇 |
1957年 | 5篇 |
1956年 | 9篇 |
排序方式: 共有2244条查询结果,搜索用时 15 毫秒
1.
María L. Pignata Martha S. Cañas Hebe A. Carreras Liliana Orellana 《Environmental management》1997,21(5):793-801
Ligustrum lucidum Ait. f. tricolor (Rehd.) Rehd. in relation to atmospheric pollutants in Córdoba city, Argentina. The study area receives
regional pollutants and was categorized taking into account traffic level, industrial density, type of industry, location
of the sample point in relation to the street corner, treeless condition, and topographic level. Dried weight/fresh weight
ratio (DW/FW) and specific leaf area (SLA) were calculated, and concentrations of chlorophylls, carotenoids, total sulfur,
soluble proteins, malondialdehyde (MDA), and hydroperoxy conjugated dienes (HPCD) were determined in leaf samples. Sulfur
content correlates positively with traffic density and SLA correlates negatively with some combinations of the categorical
variables; MDA correlates positively with topographic level and total protein concentration correlates negatively with treeless
condition. On the basis of our results, traffic, location of trees, type of industry, situation of a tree with respect to
others, and topographic level are the environmental variables to bear in mind when selecting analogous sampling points in
a passive monitoring program. An approximation to predict tree injury may be obtained by measuring DW/FW ratio, proteins,
pigments, HPCD, and MDA as they are responsible for the major variability of data. 相似文献
2.
CO concentrations were measured in five kindergartens, one children's hospital and two homes for aged, practically without indoor sources, all situated in the city centre, for ten random days in winter and ten in summer. The indoor CO concentrations were the result of the distance from and the traffic density in the nearest street, of general pollution level, seasonal differences, day-to-day variations and daily cycle of air pollution, the vicinity of traffic having a dominant influence. Therefore location of institutions for sensitive population groups in old city centres within a block of houses seems to be a suitable solution as far as exposure to CO is concerned.Revised version of a paper presented as poster at the VIth World Congress on Air Quality, Paris 1983. 相似文献
3.
4.
Pavle I. Premović 《Die Naturwissenschaften》1982,69(10):479-482
The Middle Precambrian chert of Gunflint formation contains an exceptionally high amount of bitumen free radicals. The Gunflint chert appears to be the oldest formation in which the presence of these radicals has been found. Their presence in this deposit constitutes evidence for the existence of primitive protovascular plants in the early Proterozoic environment of the Lake Superior Region of Canada. 相似文献
5.
6.
7.
8.
Recycled blocks with improved sound and fire insulation containing construction and demolition waste
Carlos Leiva Jaime Solís-Guzmán Madelyn Marrero Celia García Arenas 《Waste management (New York, N.Y.)》2013,33(3):663-671
The environmental problem posed by construction and demolition waste (C&D waste) is derived not only from the high volume produced, but also from its treatment and disposal. Treatment plants receive C&D waste which is then transformed into a recycled mixed aggregate. The byproduct is mainly used for low-value-added applications such as land escape restoration, despite the high quality of the aggregate. In the present work, the chemical composition properties and grading curve properties of these aggregates are defined. Furthermore, the resulting recycled concrete with a high proportion of recycled composition, from 20% to 100% replacement of fine and coarse aggregate, is characterized physically and mechanically. An environmental study of the new construction material when all aggregates are substituted by C&D waste shows a low toxicity level, similar to that of other construction materials. The new material also has improved properties with respect to standard concrete such as high fire resistance, good heat insulation, and acoustic insulation. 相似文献
9.
María Pía Areal M. Lorena Arciniegas Fernanda Horst Verónica Lassalle Francisco H. Sánchez Vera A. Alvarez Jimena S. Gonzalez 《Journal of Polymers and the Environment》2018,26(8):3129-3138
Scientific and technological researches are devoted to obtain materials capable of retaining different kinds of pollutants, contributing to contamination solutions. In this context, hydrogels have emerged as great candidates because of their excellent absorption properties as well as good mechanical, thermal and chemical properties. More specifically, ferrogels (magnetic gels) present the extra advantage of being easily manipulated by a permanent magnet. Here, we present the results derived from the application of ferrogels as efficient tools to extract heavy metal pollutants from wastewater samples. The gels were prepared following the method of freezing and thawing of a polyvinyl alcohol aqueous solution with magnetic nanoparticles coated with polyacrylic acid. Ferrogels were fully characterized and their ability to retain Cu2+ and Cd2+, as model heavy metals, was studied. Thus kinetics and mechanisms of adsorption were evaluated and modeled. The concentration of MNPs on the PVA matrix was key to improve the adsorption capability (approximately the double of retention is improved by the MNPs addition). The adsorption kinetics was determined as pseudo-second order model, whereas the Langmuir model was the most appropriate to explain the behavior of the gels. Finally reuse ability was evaluated to determine the real potential of these materials, the ferrogels demonstrated high efficiency up to about five cycles, retaining about 80–90% of their initial adsorption capability. All the results indicated that the materials are promising candidates able to compete with the commercial technology regarding to water remediation. 相似文献
10.
Agricultural fire for land preparation is central in the livelihoods of subsistence farmers practicing shifting cultivation. Achieving a good agricultural burn, one in which the biomass is thoroughly consumed within the chosen area, depends on specific weather conditions. Fire use decisions are also shaped by institutions that define the timing and rules for fire use but also constrain the alternatives and shape adaptive capacities. Global and regional climate changes interact with the institutional framing of fire management affecting local fire use and burn outcomes. These effects are documented and analyzed to suggest adaptations to existing governance systems. We examined subsistence farmers’ socio-ecological vulnerability in the Calakmul municipality, located in southeastern Mexico. Using interviews with farmers and government agents, as well as participatory mapping and observation of agricultural burns, we studied fire management knowledge, practices and burn outcomes. Our results describe a continuum of burn outcomes covering good agricultural burns, uncontrolled burns leading to wildfires and “malquemados” literally poorly burned areas. Malquemados represent unsuccessful combustion associated with excess moisture that results in scorched vegetation. We discuss how unexpected early rains trigger effects that cascade through space and the ecological, economic and cultural domains. We argue that fire management has been historically approached from a conservation standpoint yet agricultural fire use and wildfire prevention should also be addressed from a rural development perspective. This shift in fire management would lead to the proper inclusion of the entire array of burn outcomes in studies and policies addressing farmers’ vulnerability amplified by synergistic effects between climate variability and institutional change. 相似文献