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   196篇
  免费   0篇
  国内免费   2篇
安全科学   2篇
废物处理   2篇
环保管理   10篇
综合类   81篇
基础理论   36篇
环境理论   1篇
污染及防治   47篇
评价与监测   12篇
社会与环境   7篇
  2022年   6篇
  2021年   3篇
  2019年   2篇
  2018年   6篇
  2017年   2篇
  2016年   3篇
  2015年   4篇
  2014年   4篇
  2013年   3篇
  2012年   8篇
  2011年   6篇
  2010年   4篇
  2009年   7篇
  2008年   6篇
  2007年   9篇
  2006年   8篇
  2005年   2篇
  2004年   2篇
  2003年   3篇
  2002年   5篇
  2001年   2篇
  2000年   4篇
  1999年   3篇
  1998年   3篇
  1997年   4篇
  1996年   4篇
  1993年   3篇
  1981年   2篇
  1980年   2篇
  1978年   2篇
  1975年   2篇
  1973年   2篇
  1972年   3篇
  1971年   3篇
  1970年   7篇
  1969年   2篇
  1966年   3篇
  1964年   6篇
  1961年   4篇
  1960年   2篇
  1959年   4篇
  1943年   1篇
  1940年   2篇
  1938年   5篇
  1936年   1篇
  1935年   3篇
  1934年   3篇
  1932年   1篇
  1925年   2篇
  1920年   2篇
排序方式: 共有198条查询结果,搜索用时 15 毫秒
111.
112.
113.
In this narrative review, we provide an overview of the self‐monitoring literature as it applies to the workplace context. Our starting point to the review is a meta‐analysis of self‐monitoring literature published in 2002 by Day, Schleicher, Unckless, and Hiller. After providing an overview of the theoretical basis of self‐monitoring and its measurement, we present a summary of the broad literature on self‐monitoring to examine the implications of self‐monitoring for employees and organizations. Based on our review, we identify the main outcomes of self‐monitoring as well as findings of the literature treating self‐monitoring as a moderator. We provide evidence that self‐monitoring has potential downsides, which would benefit from further investigation. We conclude our review by identifying important potential future research directions.  相似文献   
114.
Environmental Geochemistry and Health - Organic matter (OM) and enzymes activity can act as indicators of the time and level of soil contamination with heavy metal. The goal of this study is...  相似文献   
115.
The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols.  相似文献   
116.
117.
The nests of European honeybees (Apis mellifera) are organised into wax combs that contain many cells with a hexagonal structure. Many previous studies on comb-building behaviour have been made in order to understand how bees produce this geometrical structure; however, it still remains a mystery. Direct construction of hexagons by bees was suggested previously, while a recent hypothesis postulated the self-organised construction of hexagonal comb cell arrays; however, infrared and thermographic video observations of comb building in the present study failed to support the self-organisation hypothesis because bees were shown to be engaged in direct construction. Bees used their antennae, mandibles and legs in a regular sequence to manipulate the wax, while some bees supported their work by actively warming the wax. During the construction of hexagonal cells, the wax temperature was between 33.6 and 37.6 °C. This is well below 40 °C, i.e. the temperature at which wax is assumed to exist in the liquid equilibrium that is essential for self-organised building.  相似文献   
118.
119.

Many studies have been devoted to investigation of toxic benzo(a)pyrene (BaP) compound, but studies involving changes at the cellular level are insufficient to understand the mechanisms of polycyclic aromatic hydrocarbons (PAHs) effect on plants. To study the toxicity of BaP, a model vegetation experiment was conducted on cultivation of spring barley (Hordeum sativum distichum) on artificially polluted BaP soil at different concentrations. The article discusses the intake of BaP from the soil into the plant and its effect on the organismic and cellular levels of plant organization. The BaP content in the organs of spring barley was determined by the method of saponification. With an increase in the concentration of BaP in the soil, its content in plants also rises, which leads to inhibition of growth processes. The BaP content in the green part of Hordeum sativum increased from 0.3 µg kg?1 in control soil up to 2.6 µg kg?1 and 16.8 µg kg?1 under 20 and 400 ng/g BaP applying in soil, as well as in roots: 0.9 µg kg?1, 7.7 µg kg?1, 42.8 µg kg?1, respectively. Using light and electron microscopy, changes in the tissues and cells of plants were found and it was established that accumulation of BaP in plant tissues caused varying degrees of ultrastructural damage depending on the concentration of pollutant. BaP had the greatest effect on the root, significant changes were found in it both at histological and cytological levels, while changes in the leaves were observed only at the cytological level. The results provide significant information about the mechanism of action of BaP on agricultural plants.

  相似文献   
120.
Environmental Geochemistry and Health - Nowadays, nanotechnology is one of the most dynamically developing and most promising technologies. However, the safety issues of using metal nanoparticles,...  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