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   70篇
  免费   0篇
安全科学   1篇
环保管理   3篇
综合类   45篇
基础理论   6篇
污染及防治   7篇
评价与监测   1篇
社会与环境   1篇
灾害及防治   6篇
  2023年   2篇
  2021年   2篇
  2017年   3篇
  2016年   3篇
  2015年   2篇
  2014年   4篇
  2013年   1篇
  2012年   3篇
  2011年   3篇
  2010年   4篇
  2009年   6篇
  2008年   3篇
  2007年   3篇
  2006年   5篇
  2005年   1篇
  2004年   2篇
  2003年   2篇
  2002年   8篇
  2001年   4篇
  1995年   1篇
  1993年   1篇
  1992年   3篇
  1990年   1篇
  1983年   1篇
  1979年   1篇
  1978年   1篇
排序方式: 共有70条查询结果,搜索用时 46 毫秒
61.
62.
63.
64.
Perceptions, knowledge and mitigation are factors that might play a role in preventing injury and loss of life during a major earthquake.2 Little is known about the relationships between different demographic and educational parameters and these factors. A national representative sample of 495 adults was investigated in order to determine the relationship between demographic and educational parameters in terms of the perceived threat, perceived coping, knowledge and mitigation of earthquakes in Israel. Compared to females, males perceived the threat of earthquakes to be lower (t=3.183, p=0.002), manifested higher levels of perceived coping (t=2.55, p=0.011), and had higher levels of earthquake related knowledge (t=2.047, p=0.041). We conclude that there are gender differences in perceptions and knowledge regarding earthquakes.  相似文献   
65.
66.
To date, the field of contaminant geochemistry—which deals with the study of chemical interactions in soil and aquifer environments—has focused mainly on pollutant toxicity, retention, persistence, and transport and/or on remediation of contaminated sites. Alteration of subsurface physicochemical properties by anthropogenic chemicals, which reach the land surface as a result of human activity, has been essentially neglected. Contaminant-induced changes in subsurface properties are usually considered as deviations from a normal geological environment, which will disappear under natural attenuation or following remediation procedures. However, contaminants may in many cases cause irreversible changes in both structure and properties of the soil–subsurface geosystem between the land surface and groundwater. The time scales associated with these changes are on a “human time scale”, far shorter than geological scales relevant for geochemical processes. In this review, we draw attention to a new perspective of contaminant geochemistry, namely, irreversible changes in the subsurface as a result of anthropogenic chemical pollution. We begin by briefly reviewing processes governing contaminant–subsurface interactions. We then survey how chemical contamination causes irreversible changes in subsurface structure and properties. The magnitude of the anthropogenic impact on the soil and subsurface is linked directly to the amounts of chemical contaminants applied and/or disposed of on the land surface. This particular aspect is of major importance when examining the effects of humans on global environmental changes. Consideration of these phenomena opens new perspectives for the field of contaminant geochemistry and for research of human impacts on the soil and subsurface regimes.  相似文献   
67.
68.
Belmaker J  Ziv Y  Shashar N  Connolly SR 《Ecology》2008,89(10):2829-2840
The size of the regional species pool may influence local patterns of diversity. However, it is unclear whether certain spatial scales are less sensitive to regional influences than others. Additive partitioning was used to separate coral-dwelling fish diversity to its alpha and beta components, at multiple scales, in several regions across the Indo-Pacific. We then examined how the relative contribution of these components changes with increased regional diversity. By employing specific random-placement null models, we overcome methodological problems with local-regional regressions. We show that, although alpha and beta diversities within each region are consistently different from random-placement null models, the increase in beta diversities among regions was similar to that predicted once heterogeneity in coral habitat was accounted for. In contrast, alpha diversity within single coral heads was limited and increased less than predicted by the null models. This was correlated with increased intraspecific aggregation in more diverse regions and is consistent with ecological limitations on the number of coexisting species at the local scale. These results suggest that, apart from very small spatial scales, variation in the partitioning of fish diversity along regional species richness gradients is driven overwhelmingly by the corresponding gradients in coral assemblage structure.  相似文献   
69.
A field hospital overseas requires various types of communication equipment. This study presents the communications equipment used by three Israeli field hospital delegations to earthquake sites at Adapazari, Turkey, in 1999, Port‐au‐Prince, Haiti, in 2010 and Minamisanriku, Japan, in 2011. The delegations to Turkey and Haiti were relatively large (105–230 personnel) and were on the site early (three to four days after each event). The 55‐person delegation to Japan arrived later and was established as an outpatient community hospital. Standard military VHF radios were the only effective tool up to 5 km, until cellular coverage was regained (1–2 weeks after each event). International communication was good. While short‐wave communication (telephone and Internet) was used in Turkey, a direct satellite channel was set up in Haiti. In Japan, BGAN Inmarsat provided efficient Wi‐Fi for all needs. Motorola walkie talkies were not efficient beyond the immediate vicinity. This paper recommends continued use of military‐specification equipment alongside newer modalities, particularly in situations where infrastructure is damaged.  相似文献   
70.
Combined first trimester screening using pregnancy associated plasma protein-A (PAPP-A), free β-human chorionic gonadotrophin, and nuchal translucency (NT), is currently accepted as probably the best combination for the detection of Down syndrome (DS). Current first trimester algorithms provide computed risks only for DS. However, low PAPP-A is also associated with other chromosome anomalies such as trisomy 13, 18, and sex chromosome aneuploidy. Thus, using currently available algorithms, some chromosome anomalies may not be detected. The purpose of the present study was to establish a low-end cut-off value for PAPP-A that would increase the detection rates for non-DS chromosome anomalies. The study included 1408 patients who underwent combined first trimester screening. To determine a low-end cut-off value for PAPP-A, a Receiver–Operator Characteristic (ROC) curve analysis was performed. In the entire study group there were 18 cases of chromosome anomalies (trisomy 21, 13, 18, sex chromosome anomalies), 14 of which were among screen-positive patients, a detection rate of 77.7% for all chromosome anomalies (95% CI: 55.7–99.7%). ROC curve analysis detected a statistically significant cut-off for PAPP-A at 0.25 MoM. If the definition of screen-positive were to also include patients with PAPP-A<0.25 MoM, the detection rate would increase to 88.8% for all chromosome anomalies (95% CI: 71.6–106%). This low cut-off value may be used until specific algorithms are implemented for non-Down syndrome aneuploidy. Copyright © 2001 John Wiley & Sons, Ltd.  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