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   6篇
  免费   0篇
教育   4篇
科学研究   2篇
  2013年   1篇
  2012年   1篇
  2003年   2篇
  1972年   1篇
  1956年   1篇
排序方式: 共有6条查询结果,搜索用时 171 毫秒
1
1.
2.
The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×108m3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×108m3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: fi rstly, water transfer project will bring to the Basin 60×108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low-income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.  相似文献   
3.
4.
5.
BOOK REVIEWS     
S OVEREIGN R EASON . By Ernest Nagel.
T HE S OCIOLOGY OF E DUCATION AND E DUCATIONAL S OCIOLOGY . A Sociology of Education by Wilbur B. Brookover. New York: American Book Company, 1955; and Applied Principles of Educational Sociology and Educational Sociology, A Resource Book . Edited by Harold R. Bottrell.
W HY J OHNNY C AN ' T R EAD AND W HAT Y OU C AN D O A BOUT I T . By Rudolf Flesch.
T HE F LEXIBLE S CHOOL : A R EPORT OF THE C OMMITTEE FOR THE S TUDY OF F LEXIBILITY IN THE E LEMENTARY S CHOOL .  相似文献   
6.
科技创新促进四川经济发展:问题与对策   总被引:2,自引:0,他引:2  
陈光  雷叙川  张略  王永杰 《软科学》2003,17(5):71-75
在对四川省区域创新能力进行数据分析和区位比较的基础上,进一步对四川工业大中型企业技术创新能力进行了深入的讨论。归纳出科技创新实践中存在的主要问题,从观念、体制、机制和运作等四个层面提出应对之策。  相似文献   
1
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