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   186篇
  免费   1篇
  国内免费   2篇
安全科学   1篇
废物处理   13篇
环保管理   17篇
综合类   12篇
基础理论   53篇
污染及防治   45篇
评价与监测   31篇
社会与环境   16篇
灾害及防治   1篇
  2023年   4篇
  2022年   14篇
  2021年   8篇
  2020年   1篇
  2019年   3篇
  2018年   8篇
  2017年   5篇
  2016年   3篇
  2015年   6篇
  2014年   5篇
  2013年   18篇
  2012年   13篇
  2011年   12篇
  2010年   6篇
  2009年   5篇
  2008年   11篇
  2007年   5篇
  2006年   11篇
  2005年   9篇
  2004年   11篇
  2003年   4篇
  2002年   5篇
  2000年   3篇
  1999年   2篇
  1998年   3篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   3篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
排序方式: 共有189条查询结果,搜索用时 31 毫秒
31.
Few other policy zones are as complex as the issue of climate change. If the more pessimistic projections of climate change doom are correct, then the failure to address the issue is likely to be catastrophic and irreversible. The Inter-governmental Panel on Climate Change has predicted the potential extinction of many species and that the existence of small-island and other vulnerable countries will be threatened if business-as-usual greenhouse gas emissions continue. Climate change is a transboundary problem and requires unprecedented levels of cooperation between states and serious and sustained responses from major emitters. However, the growing demand and consumption of natural resources for continued energy security and cornucopian economic growth have undermined the outcomes of international climate change negotiations. It is argued here that there is a strong connection between the major emitters’ positions at United Nations’ climate talks, their possessions, dependence and consumption of natural resources, and the continued undermining of international climate change policy for unsustainable growth. This paper assesses the resource politics of the US, China, India, Canada, Russia, and Saudi Arabia and their positions at climate talks to show the link between lack of climate change policy progress and the positions of these main players.  相似文献   
32.
Environmental Chemistry Letters - Water contamination by emerging contaminants is increasing in the context of rising urbanization, industrialization, and agriculture production. Emerging...  相似文献   
33.
Environmental Science and Pollution Research - Research on phase change material (PCM) for thermal energy storage is playing a significant role in energy management industry. However, some hurdles...  相似文献   
34.
Environmental Science and Pollution Research - Increasing petroleum consumption and a rise in incidental oil spillages have become global concerns owing to their aquatic and terrestrial toxicity....  相似文献   
35.
Environmental Science and Pollution Research - Climate change and global warming are the visible consequences of the increased amount of carbon dioxide (CO2) in the atmosphere. Among the various...  相似文献   
36.
Effect of cumulative doses of estradiol -17beta (E2-7, 14 and 28 mg/kg body weight) and 17alpha, 20beta-dihydroxy-4-pregnen-3-one (17alpha,20betaP-7, 14 and 28 mg/kg body weight) on total phospholipids (TP) and various phospholipids- phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE) on liver plasma and ovary were investigated during the reproductively active preparatory and prespawning phases of the annual reproductive cycle in the freshwater female catfish, H. fossilis. The effect of E2 on TP was generally stimulatory and has pronounced effect than 17alpha,20betaP during both the phases. The levels of PC was promoted high during prespawning phase by E2 comparatively very less than by 17alpha, 20betaP in studied tissues during both the phases. The levels of PS after E2 treatments was maximum in all tissues during prespawning phase whereas 17alpha,20betaP was effective only in liver during this phase. The PI was elevated in liver during preparatory phase but its elevation was in all studied tissues during prespawning phase after E2 treatments. The levels of PI was most effective in ovary during preparatory phase in response to 17alpha,20betaP. The levels of PE was declined in liver but elevated in ovary after E2 treatments during both the phases. Treatments of E2 during preparatory phase showed greater number of vitellogenic oocytes as compared to 17alpha,20betaP treatments. The present finding has demonstrated that estradiol-17beta has more pronounced effects than the 17alpha,20beta P in regulation of different phospholipids and ovarian recrudescence during reproductively active phases and among the phospholipids the PC is the main phospholipids of vitellogenin/ovarian lipids in H. fossilis.  相似文献   
37.
Journal of Material Cycles and Waste Management - Decades have passed, facing the energy crisis and environmental pollution and researching various possible solutions to tackle them. The use of...  相似文献   
38.
We describe the effect of inorganic mercury on the emergence, hatching and growth ofArtemia franciscana (commercially obtained). At concentrations as low as 0.01µmol 1–1, mercury delays development of the organism, but the effect on the final number of developed brine shrimp is small. At higher concentrations, mercury has a dramatic effect, inhibiting the developmental process at the emergence and hatching stages. As recorded by light and scanning electron microscopy, organisms stalled at emergence are not immediately killed. Their eye spots continue to darken and some may hatch although partially enclosed in the cyst shell. Completely emerged prenauplii in the presence of mercury often have an abnormal oval shape while hatched organisms may display shortened and deformed bodies and exhibit restricted movement. The results demonstrate that emergingA. franciscana are very sensitive to inorganic mercury and the potential usefulness of this organism for the study of metal effects upon physiological processes is indicated.  相似文献   
39.
40.
Light microscopic and ultra-structural studies of the lymphoid tissues such as blood immunocytes, spleen and pronephros of the freshwater catfish, Clarias batrachus, were carried out. The peripheral blood showed nucleated erythrocytes, total leucocytic count (TLC) more than that observed in mammalian blood and leucocytes with morphological appearance similar to the mammalian white blood cells (WBCs). The spleen and pronephros showed presence of numerous lymphocytes, monocytes and nucleated red blood cells (RBCs) along with hemosiderin-containing macrophages. The morphology of lymphoid organs of the catfish has been discussed in light of the evolution of the immune system in this class of vertebrates.  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