首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2371篇
  免费   15篇
  国内免费   25篇
安全科学   131篇
废物处理   154篇
环保管理   134篇
综合类   229篇
基础理论   412篇
环境理论   2篇
污染及防治   932篇
评价与监测   259篇
社会与环境   150篇
灾害及防治   8篇
  2023年   27篇
  2022年   79篇
  2021年   74篇
  2020年   42篇
  2019年   70篇
  2018年   92篇
  2017年   103篇
  2016年   144篇
  2015年   73篇
  2014年   138篇
  2013年   288篇
  2012年   156篇
  2011年   182篇
  2010年   111篇
  2009年   94篇
  2008年   108篇
  2007年   125篇
  2006年   83篇
  2005年   72篇
  2004年   69篇
  2003年   61篇
  2002年   50篇
  2001年   28篇
  2000年   25篇
  1999年   18篇
  1998年   11篇
  1997年   7篇
  1996年   6篇
  1995年   7篇
  1994年   2篇
  1993年   3篇
  1992年   6篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1984年   2篇
  1982年   3篇
  1979年   2篇
  1967年   2篇
  1965年   3篇
  1963年   4篇
  1962年   5篇
  1961年   4篇
  1960年   3篇
  1959年   2篇
  1958年   2篇
  1915年   1篇
排序方式: 共有2411条查询结果,搜索用时 0 毫秒
941.
The feasibility of modeling municipal waste generation (MWG) for countries at different levels of development using artificial neural networks (ANN) and selected generic indicators of sustainability was investigated. The main goals of this research were to develop ANN-based models for predicting MWG, to overcome the problem of incomplete MWG data, which is notable in developing countries, and to provide a new method for the planning of municipal solid waste management systems as well as for the simulation of various other scenarios. Data from 26 European countries was used in this study as training, test and validation datasets for the developing of ANN models. Since this kind of modeling is particularly important for developing countries where MWG data is missing or incomplete, emphasis was placed on modeling of MWG for Bulgaria and Serbia. Based on a comparison of actual MWG data with predictions given by the model, we show that ANNs can be applied successfully to modeling and forecasting MWG on a national scale. Moreover, the scope for possible application of the model is broad, since it uses generic indicators of sustainability such as gross domestic product, domestic material consumption and resource productivity, and performs well for countries with highly diversified levels of economic development, industrial structure, productivity and output.  相似文献   
942.
Environmental Modeling & Assessment - The São Francisco River Basin plays a critical role in the hydroelectrical operational planning of Brazil. Understanding the hydroclimatic dynamic...  相似文献   
943.
Journal of Polymers and the Environment - High-amylose maize starch (AS) was modified by graft copolymerization with sodium acid maleate and disodium maleate, using the KMnO4-NaHSO3 redox system,...  相似文献   
944.
Environment Systems and Decisions - Early warning systems for weather events are becoming widespread as technological capacities develop. For warnings to be effective, they must allow enough lead...  相似文献   
945.
This contribution determines the coastal erosion risk of Necochea and Quequén cities, Necochea Municipality, Buenos Aires Province (Argentina). Both risk components, hazard and vulnerability, were assessed by the construction of indices. The hazard index is composed of four indicators: the erosion or accretion rate, coastal geomorphology, storm waves effects, and sediment supply. The vulnerability index is comprised of land use/cover, demographic, life conditions, and work and consumption indicators, and includes population census data such as demographic, education, health, sanitary, economic, production, work and population exposure aspects. The analysis concluded that coastal erosion risk ranges from very low to high along the study area, Quequén yielding the highest values. Risk levels vary in both cities based on the uneven spatial distribution of hazard. The risk assessment developed herein constitutes a practical and adequate tool that can be utilized with other elements and tasks in the elaboration of a coastal management program.  相似文献   
946.
947.
The environment provides many necessary services for a plethora of human activities related to that are being acknowledged as our ecosystems degrade; therefore, ecosystem-based solutions are becoming increasingly more important. Hydrologic restorations (HRs) apply this type of ecosystem approach; there are multiple examples around the Mediterranean area executed since the beginning of the twentieth century. One good example of these restoration-type solutions can be seen in the badlands of Saldaña (Palencia, Spain). This case has been particularly successful in stopping gully erosion from badlands. Despite its importance for the well-being of the inhabitants of Saldaña and surroundings, the economic effects of these services which were put into place by this HR have never been assessed. In the present study, four different and compatible ecosystem restored services have been valued in monetary terms. For their aggregation, an innovative approach has been taken using the analytic hierarchy process methodology, so the weight of each ecosystem service (ES) can be determined. The economic flow of these ESs has been calculated in terms of annual income and updated values, from which natural capital increase in the population of Saldaña can be assessed. After analysing the results, it can be concluded that the village has earned more than seven million euros, which, in turn, generates important benefits to its inhabitants.  相似文献   
948.
Aposematic (warning) signals of prey help predators to recognize the defended distasteful or poisonous prey that should be avoided. The evolution of aposematism in the context of predation has been in the center of modern ecology for a long time. But, the possible roles of aposematic signals in other ecological contexts have been largely ignored. Here we address the role of aposematic signals in competition between prey and predators. Bumblebees use visual and auditory aposematic signals to warn predators about their defenses. For 2 years, we observed competition for nestboxes between chemically defended insects, Bombus ardens (and possibly also Bombus ignitus), and cavity nesting birds (Parus minor and Poecile varius). Bumblebees settled in 16 and 9 % of nestboxes (in 2010 and 2011 breeding seasons, respectively) that contained bird nests at the advanced stage of nest building or at the stage of egg laying. Presence of bumblebees prevented the birds from continuing the breeding activities in the nestboxes, while insects took over the birds’ nests (a form of kleptoparasitism). Playback experiments showed that the warning buzz by bumblebees contributed to the success in ousting the birds from their nests. This demonstrates that aposematic signals may be beneficial also in the context of resource competition.  相似文献   
949.
Several factors such as smoking habits, diet, occupational, and environmental exposure to chemical carcinogens influence the overall level of DNA damage. In 69 healthy adult volunteers’ polymorphisms of glutathione S-transferase (GST), an enzyme which participates in the metabolism of a broad range of carcinogens and endogenous compounds were determined. The level of DNA damage was assessed by comet assay and classified according to GSTT1/M1 genotype and smoking habits. GSTM1 null genotype was recognized in 48% of studied subjects and GSTT1 null genotype in only two cases (3%). In subjects carrying GSTT1/M1 alleles a significantly lower degree of DNA damage, determined as % DNA in the comet's tail, than in null individuals was noted. However, the results obtained did not indicate that in studied subjects an elevated endogenous level of DNA damage may be significantly related to smoking habits.  相似文献   
950.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号