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   130篇
  免费   2篇
  国内免费   1篇
安全科学   9篇
废物处理   13篇
环保管理   12篇
综合类   12篇
基础理论   18篇
环境理论   1篇
污染及防治   56篇
评价与监测   7篇
社会与环境   5篇
  2023年   2篇
  2021年   3篇
  2019年   5篇
  2018年   5篇
  2017年   5篇
  2016年   6篇
  2015年   5篇
  2014年   9篇
  2013年   6篇
  2012年   12篇
  2011年   7篇
  2010年   2篇
  2009年   3篇
  2008年   7篇
  2007年   6篇
  2006年   8篇
  2005年   8篇
  2004年   7篇
  2003年   7篇
  2002年   4篇
  2001年   1篇
  1998年   2篇
  1997年   2篇
  1995年   1篇
  1993年   3篇
  1992年   1篇
  1990年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
排序方式: 共有133条查询结果,搜索用时 250 毫秒
101.
We assess the physical potential to reduce nutrient loads from waste water treatment plants in the Baltic Sea region and determine the costs of abating nutrients based on the estimated potential. We take a sample of waste water treatment plants of different size classes and generalize its properties to the whole population of waste water treatment plants. Based on a detailed investment and operational cost data on actual plants, we develop the total and marginal abatement cost functions for both nutrients. To our knowledge, our study is the first of its kind; there is no other study on this issue which would take advantage of detailed data on waste water treatment plants at this extent. We demonstrate that the reduction potential of nutrients is huge in waste water treatment plants. Increasing the abatement in waste water treatment plants can result in 70 % of the Baltic Sea Action Plan nitrogen reduction target and 80 % of the Baltic Sea Action Plan phosphorus reduction target. Another good finding is that the costs of reducing both nutrients are much lower than previously thought. The large reduction of nitrogen would cost 670 million euros and of phosphorus 150 million euros. We show that especially for phosphorus the abatement costs in agriculture would be much higher than in waste water treatment plants.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-013-0435-1) contains supplementary material, which is available to authorized users.  相似文献   
102.
The most important driver for management is successful business that increases its value to shareholders. The adoption of environmentally responsible business practices can open up an additional range of opportunities for companies, for example by improving material efficiency. The choice to improve environmental performance of a company tends to also improve its financial performance. In this paper, our aim is to study the value of sustainability in process and mining industry from the perspective of interest groups such as investors, customers and the public, by using case examples. Interviews and workshops were employed to investigate whether or not investors and customers are interested in sustainability in the process and mining industries. We also illustrate how easy it can be to jeopardize corporate reputation through. The present situation and challenges faced in bringing sustainability into everyday business practices are summarized and proposals made concerning ways to achieve increased sustainability.  相似文献   
103.
104.
Sustainable development as the leading global development paradigm and sustainability as a cornerstone of modern industrial development have guided this development work on social metrics in the process industry. This study addresses the development of social metrics in the process industry and for metal production, in particular, at the plant level. The developed social indicators are one part of the overall sustainability index that aims to present a balanced and holistic view of plant-level sustainability performance, encompassing information on all different dimensions. This development work was preceded by the benchmarking and review of existing global reporting frameworks, initiatives and the literature. Current indicators of industrial sustainability mainly satisfy the needs of corporate-level management and capital investors. Therefore, plant-level indicators are critically needed to support and fill potential gaps in corporate-level assessments and management with a special emphasis on plant-level sustainability. The purpose of our development work for social indicators was to operationalise the concept of sustainability and associated performance measurement at the plant level. The development of social indicators was carried out through workshops with industry partners. As a joint effort, eight core social indicators and their associated sub-indicators were developed. We also report the results of our benchmarking and review of existing frameworks, initiatives and the literature. The social part of the overall sustainability index provides the information on both in-plant sustainability performance and the direct and indirect impacts of plant-level operations on the surrounding society including various stakeholders, interest groups and citizens.  相似文献   
105.
Summary. Many studies investigating effects of plant chemicals on herbivore performance have reported contradictory results, perhaps because of possible interaction between different chemicals. Also, a herbivore’s performance is not necessarily consistent with its food or oviposition preference. Our aim was to investigate simultaneously antibiosis (larval growth and survival) and antixenosis (oviposition and feeding preferences) responses in herbivore to three plant chemicals, of which one is expected to have positive and two are expected to have negative effects. Antibiosis was measured by correlating the nitrogen and glycoalkaloid levels in host plants to the survival and adult size of Leptinotarsa decemlineata, by rearing larvae on whole plants of three potato varieties. Although host plants differed in their glycoalkaloid levels, survival rate and adult body size did not differ among beetles reared on different potato varieties. This suggests that beetles are quite robust for differences in both foliar α-chaconine and foliar α-solanine content. However, differences in antixenosis were found although they could not be directly predicted from the leaf chemistry. Females preferred to lay their eggs on the variety with high α-solanine content (Nevsky) towards which males showed a tendency to feeding preference. Overall, our results confirm that beetles are well adapted to the chemical defences of potato plants as potato varieties did not significantly affect beetle performance, but differences in oviposition preference may still result in major differences in the amount of damage inflicted on plants in the fields.  相似文献   
106.
Summary The roles of sexes in the nest defence behavior of monogamous willow tit (Parus montanus) were studied near Oulu, northern Finland, in 1988–1990. The relative roles of the sexes changed during the breeding cycle: females defended their nests more vigorously before hatching and males defended more after hatching. This sexual asymmetry was studied by means of the cost/benefit model of optimal parental investment (PI). Because of the monogamous breeding system, sexual differences in future benefits were not a likely explanation for the asymmetry. This was also supported by preliminary results of DNA-fingerprinting analyses. Behavioral observations — sex-role reversal, high correlation between the mates, and equal variations in male and female behavior — indicated the same. In the beginning of the breeding cycle, higher female defence was related to renesting potential. The extra costs of renesting are considerably higher for females than for males, and therefore, females appeared to benefit more than males in keeping the first clutch alive while renesting was still possible. Such a female strategy was possible in this northern population, since the time for renesting was rather short and never lasted beyond the hatching of the first nests. After this point, the male can only invest in the present clutch. By the end of the breeding cycle, increased defence of the nest by males may be a consequence of males being larger and/or in better condition than females. Therefore, in the latter half of the breeding cycle, the sexual differences in nest defence did not indicate any sexual difference in PI. The asynchronous arrival of the parents at the nest also affected individual responses, indicating that defending the nest is a dynamic process.  相似文献   
107.
Fetal male cells from maternal venous blood were detected by a non-radioactive in situ hybridization method using the biotinylated Y-specific DNA probe pY431. The hybridizations were performed on Ficoll-Paque-isolated nucleated blood cells obtained from 11 pregnant women in the seventh to 31st week of gestation. A Y-specific signal was detected in both granulocytes and lymphocyte-like cells in seven of the 11 women studied. These women gave birth to boys. In one of the four remaining cases, a Y-specific signal was detected in the lymphocyte-like cells but not in the granulocytes. This woman gave birth to a girl. The other three women had no cells with a Y-specific signal and all three gave birth to girls. Altogether, 83 500 nucleated cells were analysed. One hundred and three cells showed a Y-specific signal. Of these Y-specific cells, 62 per cent were granulocytes and 38 per cent lymphocyte-like cells. Our results suggest that fetomaternal transfer of granulocytes is common and that it occurs as early as in the seventh week of gestation. None of the ten non-pregnant female control samples showed positive cells with the Y-chromosome-specific probe; approximately 97 per cent of the cells from the five adult male controls showed a Y-specific signal. Our results indicate that in situ hybridization using a Y-specific DNA probe performed on granulocytes in maternal blood can be used for fetal male sex determination.  相似文献   
108.
The conversion of municipal sludge and poultry manure to activated carbon results in a significant ash fraction that contains several different anions and cations. The objectives of this study were to determine whether the select ions are released or leached from virgin carbon into the sorption medium at different pH values. Activated carbon was placed in solutions of pH 1, 5, or 7, and the leaching of six cations (cadmium, chromium, copper, nickel, lead, and zinc) and two anions (arsenate and selenate) was recorded. Considerable quantities of zinc and copper were removed at pH 1 from all carbon sources. However, the amounts leached at pH 5 and 7 were small or undetectable. Our results indicate that leaching or desorption from carbons made from municipal sludge or poultry manure is pH-dependent and occurs readily under highly acidic conditions but minimally under pH conditions typically seen in contaminated water or wastewater.  相似文献   
109.
Environmental manipulation experiments showed that species respond individualistically to each environmental-change variable. The greatest responses of plants were generally to nutrient, particularly nitrogen, addition. Summer warming experiments showed that woody plant responses were dominant and that mosses and lichens became less abundant. Responses to warming were controlled by moisture availability and snow cover. Many invertebrates increased population growth in response to summer warming, as long as desiccation was not induced. CO2 and UV-B enrichment experiments showed that plant and animal responses were small. However, some microorganisms and species of fungi were sensitive to increased UV-B and some intensive mutagenic actions could, perhaps, lead to unexpected epidemic outbreaks. Tundra soil heating, CO2 enrichment and amendment with mineral nutrients generally accelerated microbial activity. Algae are likely to dominate cyanobacteria in milder climates. Expected increases in winter freeze-thaw cycles leading to ice-crust formation are likely to severely reduce winter survival rate and disrupt the population dynamics of many terrestrial animals. A deeper snow cover is likely to restrict access to winter pastures by reindeer/caribou and their ability to flee from predators while any earlier onset of the snow-free period is likely to stimulate increased plant growth. Initial species responses to climate change might occur at the sub-species level: an Arctic plant or animal species with high genetic/racial diversity has proved an ability to adapt to different environmental conditions in the past and is likely to do so also in the future. Indigenous knowledge, air photographs, satellite images and monitoring show that changes in the distributions of some species are already occurring: Arctic vegetation is becoming more shrubby and more productive, there have been recent changes in the ranges of caribou, and "new" species of insects and birds previously associated with areas south of the treeline have been recorded. In contrast, almost all Arctic breeding bird species are declining and models predict further quite dramatic reductions of the populations of tundra birds due to warming. Species-climate response surface models predict potential future ranges of current Arctic species that are often markedly reduced and displaced northwards in response to warming. In contrast, invertebrates and microorganisms are very likely to quickly expand their ranges northwards into the Arctic.  相似文献   
110.
Summary We studied how age, body size and prior residency affected social dominance in the willow tit (Parus montanus) groups. The contribution of each variable was experimentally tested in unisexual two-bird trials, in which the birds were matched for all variables except the one studied. Large birds were dominant over smaller ones (Fig. 1). The effect of body size was more prominent in males than in females. Age had no influence on dominance. Residents became dominant more often than newcomers (Fig. 2). Adulthood or larger body size did not override the advantage of prior residency (Fig. 2). Therefore, the proximate reason for the age-dependent dominance seen in natural willow tit flocks is most likely the prior residency advantage of the adults. Factors connected with fighting ability (body size and age) seem to be less important than the time of establishment of rank, which may reflect the importance of resource value differences between residents and newcomers in this context. The advantage of residency might make it advantageous to be a member of a flock even as a subordinate, rather than being solitary.  相似文献   
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