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   77篇
  免费   0篇
  国内免费   1篇
废物处理   3篇
环保管理   6篇
综合类   3篇
基础理论   49篇
污染及防治   13篇
评价与监测   1篇
社会与环境   3篇
  2022年   1篇
  2021年   1篇
  2019年   2篇
  2017年   1篇
  2015年   1篇
  2013年   6篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   5篇
  2008年   3篇
  2007年   7篇
  2006年   5篇
  2005年   3篇
  2004年   2篇
  2003年   2篇
  2002年   3篇
  2001年   3篇
  2000年   3篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1989年   3篇
  1985年   1篇
  1967年   2篇
排序方式: 共有78条查询结果,搜索用时 15 毫秒
61.
A water footprint (WF) measures the total water consumed by a nation, business or individual by calculating the total water used during the production of goods and services. This paper extends the existing methods for WF to more localised levels for crops grown partly in open systems and partly in plastic-covered houses with multi-seasonal harvesting, such as the horticulture industry in Spain. This improvement makes it possible to visualise the links of EU tomato consumption to precise production sites in Spain and opens a debate to the usefulness of such findings. This paper also compares existing ecological methodologies with WF and argues that both life cycle analysis (LCA) and ecological footprint (EF) models could benefit from WF methods. Our results show that the EU consumes 957,000 tons of Spanish fresh tomatoes annually, which evaporates 71 Mm(3)/yr of water and would require 7 Mm(3)/yr of water to dilute leached nitrates in Spain. In Spain, tomato production alone evaporates 297 Mm(3)/yr and pollutes 29 Mm(3)/yr of freshwater. Depending upon the local agro-climatic character, status of water resources, total tomato production volumes and production system, the impact of EU consumption of fresh tomatoes on Spanish freshwater is very location specific. The authors suggest that business now seek to report and address negative impacts on the environment. WF opens the door to complex water relationships and provides vital information for policy actors, business leaders, regulators and managers to their draw, dependence and responsibilities on this increasingly scarce resource.  相似文献   
62.
Abstract

The biological effects of clofibrate (ethyl p‐chlorophenoxy‐isobutyric acid) on the growth and metabolism of the soil‐borne wheat pathogen Fusarium culmorum, were examined.

In mid log phase (16 hr) cultures both phenylalanine uptake and secondary spore production were stimulated at 0.1 μM concentration; the net sterol content was reduced 50% at 0.35 μM; oxygen uptake was stimulated at 0.1 mM; growth was inhibited 50% at 0.1 mM concentration. Both phenylalanine and oxygen uptake were inhibited at 1.0 mM and pyruvate dehydrogenase activity was reduced 50% at 50 mM concentration of clofibrate.

The data indicate that clofibrate affects a number of biological and enzyme systems. The inhibitory effect on the growth of the pathogen suggest a potential use of hypolipidemic agents like clofibrate as an antifungal agent for seed protection.  相似文献   
63.
BACKGROUND, AIMS AND SCOPE: Laboratory studies were conducted with the aim of defining the leaching potential of some phenylureas and their metabolites. A first study was performed for calculating their leaching index (as GUS) on the base of intrinsic properties: persistence (as DT50) and mobility (as Koc) in soil. Another study consisted of aged column leaching experiments whose meaning was to semi-quantify the occurrence of the tested compounds in the leachates, so simulating in field conditions. METHODS: The tested compounds were: diuron, linuron and monolinuron (parents); 3,4-dichloroaniline (DCA), 4-chloroaniline (CLA), 1-(3,4-dichlorophenyl)-3-methylurea (DCPMU), 1-(3,4-dichlorophenyl)urea (DCPU), 1-(4-chlorophenyl)urea (CPU) and monuron, this latter considered both as a metabolite and parent compound. The Koc values of the examined substances were determined by the HPLC screening methods, according to the OECD TG 121. DT50 determinations and aged column leaching experiments were carried out according to SETAC procedures. RESULTS AND DISCUSSION: The examined compounds showed a rather wide range of persistence in soil, with DT50 values less than 2 days for DCA and CLA, close to 8 days for DCPU and CPU and from 16 (diuron) up to 24.8 (DCPMU) days for the others. Their mobility was generally high, based on their Koc values, which ranged from 33 (CPU) to 406 (linuron). The GUS indices indicated that monuron has a clear potential to contaminate groundwater (> 2.8); DCPMU, monolinuron, CPU and diuron are intermediate contaminants (1.8-2.8). Linuron, DCPU, CLA and DCA exhibited a non-leaching behaviour (< 1.8). The aged leaching column experiments showed that parents were found in the leachates at very high percentages respect to the doses applied. The metabolites reached much less percentages, the highest values were observed for monuron from diuron (5.7), CPU (7.2) and DCPMU (8.2%). CONCLUSION: Diuron, Monuron, CPU and DCPMU on the basis of their intrinsic properties, formation from their parents and occurrence in leachates from aged column leaching studies, seem to possess the characteristics of groundwater contaminants. The methodological approach of this study is relatively easy and rapid, hence it can represent a tool for a first screening of compounds such as pesticide metabolites (generally available only in small quantities and for which a field study is not conceivable) or other compounds for which not adequate environmental data are available.  相似文献   
64.
Alkylphenols (APs) and AP ethoxylated compounds (APEs) were screened in human subcutaneous adipose tissue samples from Italy. The samples were collected during bariatric surgery from 16 subjects (three men and 13 women) and a total of seven alkylphenol compounds (APs) was detected. Nonylphenol (NP) was the compound found at the highest level (mean 122 ng g−1 fresh weight; range 10-266 ng g−1 fw). Several nonylphenol ethoxylates (NPEOs) were found in all the sample analysed though the frequency of detection decreased with the increasing number of ethoxylic groups. NP4EO was found only in four patients ranging from trace amounts to 41.3 ng g−1 fw. Total nonylphenols (NPEs) ranged between 45 and 1131 ng g−1 fw, whereas the concentration of total octylphenols (OPEs) was at least 10 times lower (range 6-80 ng g−1 fw). Our findings show that the average concentration of NP is about two times higher than that found in women from Southern Spain and up to three times that of people from Switzerland. Similarly, OP mean level is two times that reported in Finland and Spain populations. This is the first study that reports the presence of alkylphenols in the Italian population adipose tissue and it draws a baseline for further researches in order to depict a trend in human exposure to these compounds and to investigate possible consequences for human health.  相似文献   
65.
66.
The goal of restoring ecological integrity in rivers is frequently accompanied by an assumption that a comparative reference reach can be identified to represent minimally impaired conditions. However, in many regulated rivers, no credible historical, morphological or process-based reference reach exists. Resilient restoration designs should instead be framed around naturalization, using multiple analytical references derived from empirically-calibrated field- and model-based techniques to develop an integrated ecological reference condition. This requires baseline data which are rarely collected despite increasing evidence for systematic deficiencies in restoration practice. We illustrate the utility of baseline data collection in restoration planning for the highly fragmented and regulated lower Merced River, California, USA. The restoration design was developed using various baseline data surveys, monitoring, and modeling within an adaptive management framework. Baseline data assisted in transforming conceptual models of ecosystem function into specific restoration challenges, defining analytical references of the expected relationships among ecological parameters required for restoration, and specifying performance criteria for post-project monitoring and evaluation. In this way the study is an example of process-based morphological restoration designed to prompt recovery of ecosystem processes and resilience. For the Merced River, we illustrate that project-specific baseline data collection is a necessary precursor in developing performance-based restoration designs and addressing scale-related uncertainties, such as whether periodic gravel augmentation will sustain bed recovery and whether piecemeal efforts will improve ecological integrity. Given the numerous impediments to full, historical, restoration in many river systems, it seems apparent that projects of naturalization are a critical step in reducing the deleterious impacts of fragmented rivers worldwide.  相似文献   
67.
A Response     
  相似文献   
68.
69.
70.
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