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   124篇
  免费   2篇
  国内免费   2篇
安全科学   3篇
废物处理   4篇
环保管理   11篇
综合类   15篇
基础理论   35篇
污染及防治   41篇
评价与监测   14篇
社会与环境   4篇
灾害及防治   1篇
  2023年   1篇
  2022年   3篇
  2021年   6篇
  2020年   2篇
  2019年   2篇
  2018年   5篇
  2017年   5篇
  2016年   11篇
  2015年   2篇
  2014年   7篇
  2013年   13篇
  2012年   14篇
  2011年   11篇
  2010年   9篇
  2009年   7篇
  2008年   3篇
  2007年   6篇
  2006年   7篇
  2005年   2篇
  2004年   3篇
  2003年   2篇
  2002年   3篇
  2000年   1篇
  1998年   1篇
  1997年   2篇
排序方式: 共有128条查询结果,搜索用时 31 毫秒
101.
The fate of the three environmentally relevant β-blockers atenolol, metoprolol and propranolol has been studied in batch experiments involving aquifer material and nitrate reducing conditions. Results from the about 90 d long tests indicate that abiotic processes, most likely sorption, jointly with biotransformation to atenololic acid were responsible for the 65% overall removal observed for atenolol. Zero order kinetics, typical of enzyme-limited reactions, controlled the transformation of this beta blocker to its corresponding carboxylic acid. The mass balance evidences that no mineralization of atenolol occurs in the biotic experiment and that atenololic acid is more stable than its parent compound under the studied conditions. This finding stresses the importance of considering atenololic acid as target compound in the environmental studies on the fate of atenolol. For metoprolol and propranolol the results from the experiment suggest a slower sorption to be the dominant removal process, which led to final decreases in concentrations of 25-30% and 40-45%, respectively. Overall, the removals observed in the experiments suggest that subsurface processes potentially constitute an alternative water treatment for the target beta-blockers, when compared to the removals reported for conventional wastewater treatment plants.  相似文献   
102.
The synthesis of the BONUS+ research is introduced. The HELCOM Baltic Sea Action Plan is examined as a case to illustrate the potentials and challenges in building the science–policymaking interface on a macroregional level. The projects address environmental challenges in the Baltic Sea as defined by the Baltic Sea Action Plan, or consider the environmental governance and decision making within the Baltic Sea context in general. Eutrophication, biodiversity, hazardous substances, maritime activities, and the environment governance are addressed, as are crosscutting issues, such as the impact of climate change, maritime spatial planning and impacts of future development on ecosystem services. The projects contributed to relevant policy developments: 37 consultations carried out at EU level, 49 modifications to policy documents and action plans, 153 suggestions for the efficacy of pertinent public policies and governance, and in 570 occasions, scientists working in BONUS+ projects served as members or observers in scientific and stakeholder committees.  相似文献   
103.
Environmental Science and Pollution Research - Solar-driven photocatalysis is a promising water-cleaning and energy-producing technology that addresses some of the most urgent engineering problems...  相似文献   
104.
Environmental Science and Pollution Research - Three sampling campaigns were performed in the Lis River (Leiria, Portugal) in February of 2018, November of 2018, and May of 2019. River water and...  相似文献   
105.
The paper proposes an imprecise Fault Tree Analysis in order to characterize systems affected by the lack of reliability data. Differently from other research works, the paper introduces a classification of basic events into two categories, namely Initiators and Enablers. Actually, in real industrial systems some events refer to component failures or process parameter deviations from normal operating conditions (Initiators), whereas others refer to the functioning of safety barriers to be activated on demand (Enablers). As a consequence, the output parameter of interest is not the classical probability of occurrence of the top event, but its Rate of OCcurrence (ROCOF) over a stated period of time. In order to characterize the basic events, interval-valued information supplied by experts are properly aggregated and propagated to the top. To this purpose, the Dempster–Shafer Theory of evidence is proposed as a more appropriate mathematical framework than the classical probabilistic one. The proposed methodology, applied to a real industrial scenario, can be considered a helpful tool to support risk managers working in industrial plants.  相似文献   
106.
Fetal cerebral ventriculomegaly (VM) is diagnosed when the width of one or both ventricles, measured at the level of the glomus of the choroid plexus (atrium), is ≥ 10 mm. VM can result from different processes: abnormal turnover of the cerebrospinal fluid (CSF), neuronal migration disorders, and destructive processes. In a high percentage of cases, it is associated with structural malformations of the central nervous system (CNS), but also of other organs and systems. The rate of associated malformations is higher (≥60%) in severe VM (>15 mm) and lower (10–50%) in cases of borderline VM (10–15 mm). When malformations are not present, aneuploidies are found in 3–15% of borderline VM; the percentage is lower in severe VM. The neurodevelopmental outcome of isolated VM is normal in > 90% of cases if the measurement of ventricular width is between 10 and 12 mm; it is less favorable when the measurement is > 12 mm. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
107.
This research proposes a methodology for defining greenways via sustainable planning. This approach includes the analysis and discussion of culture and natural processes that occur in the landscape. The proposed methodology is structured in three phases: eco-cultural analysis; synthesis and diagnosis; and proposal.An interdisciplinary approach provides an assessment of the relationships between landscape structure and landscape dynamics, which are essential to any landscape management or land use. The landscape eco-cultural analysis provides a biophysical, dynamic (geomorphologic rate), vegetation (habitats from directive 92/43/EEC) and cultural characterisation. The knowledge obtained by this analysis then supports the definition of priority actions to stabilise the landscape and the management measures for the habitats. After the analysis and diagnosis phases, a proposal for the development of sustainable greenways can be achieved.This methodology was applied to a study area of the Azambuja Municipality in the Lisbon Metropolitan Area (Portugal). The application of the proposed methodology to the study area shows that landscape stability is crucial for greenway users in order to appreciate the landscape and its natural and cultural elements in a sustainable and healthy way, both by cycling or by foot. A balanced landscape will increase the value of greenways and in return, they can develop socio-economic activities with benefits for rural communities.  相似文献   
108.
Transfer of maternal hormones to the eggs is a major source of offspring phenotypic variation. The developmental and organizational effects of egg hormones can extend into adulthood and affect behavioral and morphological traits involved in sexual and reproductive behavior, with important consequences for offspring fitness. In this study, we injected testosterone (T) in egg albumen of captive ring-necked pheasant (Phasianus colchicus) eggs. We then assessed the consequences for chick growth, cell-mediated immunity, and multiple male secondary sexual traits at maturity by comparison with a control group. We also compared the covariation between traits in the two experimental groups. We found that control males had redder wattles than males from T-injected eggs, suggesting that attractiveness and reproductive success of the offspring might vary depending on maternal transfer of T to the eggs. T treatment also modified the covariation between cell-mediated immunity and wattle coloration and between the area of the wattle and the expression of another secondary sexual trait, the ear tufts. These effects are likely to translate into fitness differences among the offspring if mate acquisition depends on the simultaneous expression of several traits that are differentially affected by the same maternal contribution. Maternal effects mediated by egg hormones might affect the fitness of the offspring not only by directional modification of phenotypic traits, but also by facilitating or inhibiting their covariation. This suggests the possibility that female choice based on the relative expression of multiple secondary sexual traits exerts a pressure on how maternal transfer of androgens contributes to developmental programs.  相似文献   
109.
A totally protected di-O-benzyl derivative of triacetonlactose dimethyl acetal was transformed into a 4'-hexeno disaccharide by elimination of acetone with t-BuOK in DMF and subsequently in 5'-C-methoxy derivative by oxidation with MCPBA in methanol as a solvent. The hydrolysis of this latter compound affords 2,6-di-O-benzyl-L-arabino-aldohexosos-5-ulose, which by intramolecular aldol condensation with DBU gives an inosose that was stereoselectively reduced to epi-inositol. Therefore our synthetic strategy offers a new and simple method to transform lactose into carbocyclic monosaccharide analogues.  相似文献   
110.
Reproduction is a demanding activity, since organisms must produce and, in some cases, protect and provision their progeny. Hence, a central tenet of life-history theory predicts that parents have to trade parental care against body maintenance. One physiological cost thought to be particularly important as a modulator of such trade-offs is oxidative stress. However, evidence in favour of the hypothesis of an oxidative cost of reproduction is contradictory. In this study, we manipulated the brood size of wild barn swallows Hirundo rustica soon after hatching of their nestlings to test whether an increase in nestling rearing effort translates into an increased oxidative damage and a decreased antioxidant protection at the end of the nestling rearing period. We found that, while plasma oxidative damage was unaffected by brood size enlargement, females rearing enlarged broods showed a decrease in plasma non-enzymatic antioxidants during the nestling rearing period. This was not the case among females rearing reduced broods and among males assigned to either treatment. Moreover, individuals with higher plasma oxidative damage soon after the brood size manipulation had lower plasma non-enzymatic antioxidants at the end of the nestling rearing period, suggesting that non-enzymatic antioxidants were depleted to buffer the negative effects of high oxidative damage. Our findings point to antioxidant depletion as a potential mechanism mediating the cost of reproduction among female birds.  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