全文获取类型
收费全文 | 2203篇 |
免费 | 21篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 51篇 |
废物处理 | 156篇 |
环保管理 | 141篇 |
综合类 | 262篇 |
基础理论 | 484篇 |
环境理论 | 1篇 |
污染及防治 | 761篇 |
评价与监测 | 215篇 |
社会与环境 | 156篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 26篇 |
2022年 | 59篇 |
2021年 | 63篇 |
2020年 | 33篇 |
2019年 | 39篇 |
2018年 | 68篇 |
2017年 | 77篇 |
2016年 | 117篇 |
2015年 | 70篇 |
2014年 | 117篇 |
2013年 | 214篇 |
2012年 | 136篇 |
2011年 | 166篇 |
2010年 | 94篇 |
2009年 | 69篇 |
2008年 | 145篇 |
2007年 | 149篇 |
2006年 | 108篇 |
2005年 | 86篇 |
2004年 | 56篇 |
2003年 | 49篇 |
2002年 | 56篇 |
2001年 | 36篇 |
2000年 | 21篇 |
1999年 | 18篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 11篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1983年 | 3篇 |
1967年 | 4篇 |
1966年 | 2篇 |
1964年 | 8篇 |
1963年 | 7篇 |
1962年 | 7篇 |
1960年 | 5篇 |
1959年 | 3篇 |
1958年 | 8篇 |
1957年 | 3篇 |
1956年 | 4篇 |
1955年 | 2篇 |
1943年 | 2篇 |
排序方式: 共有2230条查询结果,搜索用时 31 毫秒
961.
Growth, age and somatic production of the benthic predator Adelomelon brasiliana were studied at the southern limit of its distribution on the South American Atlantic shelf. Stable oxygen isotope ratios confirmed annual formation of internal shell growth marks. Modal shell length of the population was 140 mm, while modal shell-free wet mass was 255 g. A logistics growth function (SL=186.28 mm, K=0.185, t0=4.601) fitted 131 pairs of size-at-age data (25 shells) best. A. brasiliana is a very long-lived species, reaching up to 20 years of age. The maximum individual somatic production of 46 g shell-free wet mass year–1 is attained at 145 mm shell length, which corresponds to about 12 years of age.Communicated by O. Kinne, Oldendorf/Luhe 相似文献
962.
Santos FJ López-Gutiérrez JM García-León M Suter M Synal HA 《Journal of environmental radioactivity》2005,84(1):103-109
In this work we present results of the (129)I/(127)I ratio in aerosols of Seville, Southwest of Spain (37.4 degrees N,6 degrees W). A radiochemical method is applied to extract the iodine from the aerosols and prepare samples to be measured by accelerator mass spectrometry (AMS) at the ETH facility in Zürich. We have found the possibility of monitoring the (129)I/(127)I isotopic ratio on a two-days basis with sensitivities in the order of 10(4)-10(5) atoms (129)I/m(3), and values of 10(-8)-10(-9) for the isotopic ratio. 相似文献
963.
Safety assessment is a tool which, by means of an iterative procedure, allows the evaluation of the performance of a disposal system and its potential impact on human health and the environment. Radionuclides from a deep geological disposal facility may not reach the surface environment until many tens of thousands of years after closure of the facility. The BIOMASS Programme on BIOsphere Modelling and ASSessment developed Examples of "Reference Biospheres" to illustrate the use of the methodology and to demonstrate how biosphere models can be developed and justified as being fit for purpose. The practical examples are also intended to be useful in their own right. The Example Reference Biosphere 2B presented here involves the consideration of alternative types of geosphere-biosphere interfaces and calculation of doses to members of hypothetical exposure groups arising from a wide range of exposure pathways within agricultural and semi-natural environments, but without allowing for evolution of the corresponding biosphere system. The example presented can be used as a generic analysis in some situations although it was developed around a relatively specific conceptual model. It should be a useful practical example, but the above numerical results are not intended to be understood as prescribed biosphere 'conversion factors'. 相似文献
964.
Schifter I Díaz L López-Salinas E 《Journal of the Air & Waste Management Association (1995)》2005,55(9):1289-1297
Environmental agencies are currently in the process of implementing a new air management program, which includes the improvement of fuel quality. In this work, exhaust emissions data and estimated relative risk for various fuels testing in-use vehicles, equipped with three different exhaust emission control technologies, are presented. Aromatics, sulfur, and olefins contents; type of oxygenated compound; and Reid vapor pressure were varied. The aim also includes calculating the ozone (O3) forming potential and a relative cancer risk of emissions from current and formulated gasoline blends in Mexico. The proposed gasoline decreases carbon monoxide, total hydrocarbons (THC), and nitrogen oxides emissions by 18 and 14%, respectively, when compared with gasoline sold in the rest of the country and within ozone nonattainment metropolitan areas in Mexico, respectively. 相似文献
965.
This article summarises the abatement of NO(x) pollution by using sorbing catalytic materials with special relevance to the challenge presented in fixed installations sources. A general vision of the origins of the different pollutants, with emphasis on nitrogen oxides formation, is presented as introduction. The impact of NO(x) pollution comprises additionally a quick view of its toxicity and environmental effects. Actual solutions are presented especially the case of the selective catalytic reduction (SCR) process with its advantages and difficulties. The new concepts for NO(x) abatement are also analysed. In such a way, updated information on solid sorbents for NO(x) removal is provided by including metal oxides, spinelles, perovskites, double-layered cuprates, zeolites, carbonaceous materials, heteropolyacids (HPAs), and supported heteropolyacids. The possibility of reducing those sorbed NO(x) is also underlined. Sorption mechanisms are analysed and clarified by emphasising convergence and disagreement points. 相似文献
966.
Miranda M López-Alonso M Castillo C Hernández J Benedito JL 《Environment international》2005,31(4):543-548
This study evaluated the contribution of anthropogenic pollution to toxic metal residues (Cd, Pb and As) in cattle in an industrialized area of Asturias (northern Spain), and investigated possible implications of toxic metal exposure for metabolism of essential metal elements (Cu, Zn, Fe, Mn). Samples of liver, kidney, muscle and blood from animals aged 9-12 months were obtained from an industrialized area (78 calves) and from a rural area (92 calves). Samples were acid-digested, and levels of metals determined by atomic absorption spectrophotometry. Cadmium and lead contents in the liver and kidney were moderately and significantly higher in calves from the industrialized area (Cd: liver 29.6, kidney 161; Pb: liver 38.1, kidney 38.3 microg/kg wet weight) than in calves from the rural area (Cd: liver 22.9, kidney 96.4; Pb: liver 20.7, kidney 15.9 microg/kg kg wet weight). Although these toxic metals were only moderately raised, our results suggest that they may nevertheless have interfered with trace element metabolism, as reported previously for severely polluted regions. Notably, copper levels in calves from the industrialized area were generally low, and nearly half of these animals showed tissue copper levels indicating risk of copper deficiency. 相似文献
967.
968.
Food and Environmental Virology - Survival of tick-borne encephalitis virus was studied from pasteurized and unpasteurized goat milk and from salted/unsalted and spiced/unspiced cheese made from... 相似文献
969.
970.
Pilar?LópezEmail author Pedro?Aragón José?Martín 《Behavioral ecology and sociobiology》2003,55(1):73-79
Female mate choice based on visual traits appears to be rare in lizards. Field observations suggest that females of the lizard Lacerta monticola preferred to mate with larger/older males. Although older males are usually green and larger, and younger males brown and smaller, there is some overlap in size and coloration between age classes. Thus, visual cues may not always be reliable indicators of a male's age. We hypothesized that female mate-choice preferences may be based on males' pheromones, which might transmit information about characteristics such as age. In a laboratory experiment, we analyzed the effect of age of males on attractiveness of their scents to females. When we offered scents of two males of different age, females associated preferentially with scents of older males. This suggested that females were able to assess the age of males by chemical signals alone, and that females preferred to be in areas scent-marked by older males. Thus, females may increase their opportunities to mate with males of high quality, or may avoid harassment by sneaking young males. This result agreed with field observations on females mating with old males, and rejection of advances by young males. Our results also suggested that female preference for older males may depend on their own body size. Large females showed a strong preference for older males, whereas smaller females were not so selective. This, together with males' preference for large females, might lead to size-assortative matings. We suggest that the quality and/or quantity of male pheromones could communicate to the female heritable male genetic quality (i.e. age) and thereby serve as the basis of adaptive female choice in lizards.Communicated by W.E. Cooper 相似文献