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671.
672.
1954年12月26日-1955年1月18日湖北省遭遇了120年一遇的历史罕见持续低温冰雪灾害。2008年1月13日-2月3日,湖北省再次出现了一次持续低温冰雪过程,严重程度仅次于1954年,为70年一遇。利用常规天气图和数值预报产品资料,应用天气学和波谱分析方法,对比分析了两次过程的环流形势特征及能谱特征。结果表明:两次过程具有基本一致的长波系统背景场、水汽条件、地面冷空气条件;在低温冰雪过程中,850~700hPa存在明显逆温层;中高纬度、中低纬度能量谱强度、输送和转换有明显的变化,并且与天气系统的变化相对应。但是,两次天气过程的表现形式有明显差异,而且前者的主要影响系统,如阻塞高压、低涡、副高和地面冷高压等的强度均明显比后者强。 相似文献
673.
贵阳市生活垃圾处理存在公众环保意识不强、垃圾处理方式单一、设施落后和资金不足等问题,可从加强宣传与垃圾处理技术研究、推进管理体制建设和制定法律法规等方面改善贵阳市生活垃圾处理现状,以全面落实各项政策,推进城市生活垃圾处理工作,促进城市可持续发展。 相似文献
674.
One year has passed since the Advice on Solving the Problems of Rural Migrant Workers by the State Council was put into practice. The status for rural migrant workers has been improved effectively. Especially, their wages have been increased notably, the problem of default on wage payments has been alleviated, and the services offered to them by governments have been improved. However, some essential problems, such as low income and bad living conditions, have not been changed ultimately. Their strong wishes to become legal urban residents are still far from being realized. Therefore, we should carry out the current policies, make further institutional innovations, increase relevant investments, gradually eliminate institutional barricades, and fund shortage problems that prevent rural migrant workers from becoming legal urban residents, and solve the problems of rural migrant workers thoroughly. 相似文献
675.
Ammonium and nitrate concentrations have been investigated in water samples from the wells in the island of Vulcano, (Italy). Systematic observations, extended over a period of five years, have verified different trends in the changing concentrations of both species. Nitrate ion is considered as contributed to the unconfined upper ground aquifer by the surface environment, while for ammonium ion a deep origin appears more likely. Significant changes in the activity of the volcanic system appear to affect the distribution of ammonium only, while nitrate levels do not display any important variation. 相似文献
676.
V. Gordeev 《Regional Environmental Change》2002,3(1-3):88-98
The great remote region of the Arctic, which even recently has been considered pristine, has during the last few decades
become an object of pollution impact from local and distant sources. The major atmospheric, riverine, and marine pathways
result in the long-range transport of contaminants into and within the Arctic. Over the last few years, very comprehensive
programs were carried out, the major goal of which was to assess the present state of the Arctic environment (Arctic Monitoring
and Assessment Programme and Canadian Arctic Contaminants in 1997). Recent studies on Arctic estuaries and river–coast interaction
have been conducted as a contribution to the global IGBP/LOICZ project. New data from Russian research over the last few decades
were also received. All kinds of contaminants were taken into consideration, including artificial radionuclides, heavy metals,
persistent organic pollutants, and petroleum hydrocarbons. Many localities were found with significant levels of pollution.
However, the general conclusion is that, in comparison with most other areas of the world, the Arctic remains a relatively
clean environment.
Electronic Publication 相似文献
677.
阐述了摩托车发动机污染控制技术的发展趋势,分析了不同摩托车的工作原理和结构特点,有针对性地提出了减少在用车污染的对策,根据实践经验和摩托车发动机的排放特点,探讨了如何使用催化净化技术控制排放的问题。 相似文献
678.
C. Biney D. Calamari H. Naeve T. W. Maembe B. Nyakageni M. A. H. Saad 《Chemistry and Ecology》1987,3(1):49-74
The awareness of the harm caused by pollutants to natural environments has led the political and legislative authorities of industrially-developed countries to introduce or review regulations to protect the environment. However, in recent years, all over the world and particularly in many countries in Africa, there has been a remarkable population growth, accompanied by an intense urbanization, an increase of industrial activities and a higher exploitation of cultivable land. These transformations have brought about a huge increase in the quantity of discharges and a wide diversification in the types of pollutants that reach river waters and have undesirable effects on fish and on the potential for fishery exploitation. 相似文献
679.
调查发现,盐城海涂环境的污染物主要是工业废水中的化学需氧量,氨氮和硫化物。射阳和东台两地区是主要的污染区域。 相似文献
680.
21世纪中国城市化方式转变与对策研究 总被引:2,自引:0,他引:2
孙宏霞 《中国人口.资源与环境》2002,(5)
21世纪之初 ,中国的城市化发展正面临一些新形势 ,必须重新定位城市化战略。本文指出加快城市化步伐 ,重视发展大城市 ,促进城市群的形成与发展 ,有重点地发展小城市 ,是未来中国城市化战略的正确选择 相似文献