首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
This paper traces the gradual opening up to foreign investment of the rich mineral endowment of the vast territory of the former Soviet Union, containing the world's largest mineral industry. It analyzes the current status of mineral joint ventures in some of the new Republics, including Russia, Kazakhstan, Tajikistan and the Ukraine, including new legislation and other measures taken by individual states to facilitate foreign investment, as well as prospects, risks and uncertainties associated with investment in FSU mining activities that may be encountered by foreign companies. A successful gold joint venture in Tajikistan is described and evaluated to provide an understanding of the many aspects of an operational FSU project.  相似文献   

2.
Samples of the slime mold Fuligo septica (L.) Wiggers were collected from an ecologically diverse selection of sites across the former USSR and in North Korea to determine their Zn concentrations. Plasmodia were collected from trees, rocks, soils, the walls of buildings and a variety of other materials and structures from 1990 to 1996. The biomass collected ranged from 305 to 968 mg, whereas Zn concentrations in plasmodia of F. septica ranged from 8400 to 23,000 mg kg(-1) dry wt. (mean and standard error = 14,200 +/- 860 mg kg(-1) dry wt.). No clear trend as to which areas produced F. septica with the highest Zn concentrations was discernable. Nor was it possible to identify any particular substrate on which F. septica grew that produced noticeably high Zn concentrations. For example, forest litter on which F. septica was found had Zn concentrations of only 25 to 130 mg kg(-1) dry wt. Our data confirm the only other study showing hyperaccumulation of Zn in F. septica, which was carried out in Finland. This ability seems to be unique to this species, but how or why it does this, or why such high Zn concentrations are not toxic to F. septica, are questions requiring future research.  相似文献   

3.
The prevailing system of environmental management strongly depends on the economic and political structures of a country and is influenced by the current condition of them. Environmental degradation in the Soviet Union has been caused mainly by the political and economic misconceptions listed in this article. With the transformation of its state order to the model of Western democracies, the Soviet Union is experiencing a deep economic crisis of restructuring, reflected in a parallel crisis in its system of environmental management, which is manifest in the form of rapid transformation. This is characterized by the contradiction of the state’s old administrative institutions, which still exist, with the efforts to use market mechanisms of environmental control. Such methods include various fees and payments for the use of natural resources or for pollution and creation of specialized regional funds and banks to finance environmental programs. All these occur in the context of the strengthening of regional sovereignty, the introduction of self-accounting for economic units, the adoption of comprehensive legal enactments, and the setting up of an efficient administrative system of their enforcement. Public activism, as one of the principal actors in this structure, also has undergone quick maturation. Nevertheless the future development of the new Soviet system of environmental control remains uncertain because of the present unpredictability of the overall situation in the short run.  相似文献   

4.
Contemporary analysis of the food sector has failed convincingly to link production to consumption, and it has not provided a sociological account of such links. This paper makes a provisional attempt to begin such an analysis and does so by examining the case of the market for organic food in Tuscany. It proposes that the ‘pioneers’ of organics in this region constituted a new food movement that succeeded in opening up a new market. However, this market could only be successfully expanded once other actors were enrolled in the market-making process, notably state agencies and supermarkets. The regional government, through new regulations and specific initiatives, integrated organic foods into rural development policy, thereby assisting producers in the process of conversion. Supermarkets co-operated in the implementation of these policies and made space for Tuscan organic products in their stores. So while the ‘pioneers’ began the process of market building, these later entrants were crucial to the stabilization and expansion of the organic sector in Tuscany. Thus, it can be concluded that the emergence of these new ‘markets’ for nature can only be adequately explained by analysing the full range of actors. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

5.
In 1998 the Minister for the Regions, Regeneration and Planning issued a statement which argued that the European context for planning had been largely missing from the planning system in England. This paper explores the impact of European Union (EU) membership on the practice of local authority planning in the UK. The research was based on nine local planning authorities in England, Scotland and Wales. The results indicate that EU membership has exerted a direct and indirect influence on planning at the local level. A classification of EU influences on local planning activities is developed. The research also indicates that the scope and structure of the UK planning system are being influenced by EU membership. There is considerable emphasis on the role of planning as a tool for sustainable development, and the development of environmental quality standards, coupled with existing policies in the sphere of nature conservation, present a challenge to the traditional approach of the UK planning system of balancing all material considerations.  相似文献   

6.
Summary This study evaluates the impact of intensive market gardening on the nutrient status of hydromorphic soil in the Ojo area of Lagos metropolis. Following 15–20 years of continuous market gardening, the organic matter content of the 0–10 cm layer of the hydromorphic soil has been reduced to 75 percent of the level found in a swamp forest soil used as a control. The extent of the organic matter decline in the cultivated soil is slight compared with the degree of organic matter diminution in well-drained soil used for shifting or continuous cultivation. This is due to the low degree of humus mineralisation in water-logged soil and the application of organic manure.In spite of regular application of both organic and inorganic fertilisers, the levels of exchangeable calcium, magnesium, potassium and sodium are lower in the 0–10 cm and 10–20 cm layers of the intensively cultivated hydromorphic soil used for market gardening than in the swamp forest control areas. The mean level of extractable manganese is lower in the 10–20 cm layer of the cultivated soil. These differences are due to nutrient immobilisation and removal in harvested vegetables, and to nutrient loss from the market gardening plots through erosion. There is, however, a build-up of available phosphorus in the surface layer of the market garden soil due to the application of inorganic phosphate fertilisers.The levels of mineral nutrients in the surface layers of the cultivated soil are within the optimal ranges for most arable crops, suggesting that the soil is not impoverished. This is due to the judicious application of both organic and inorganic fertilisers, and is indicative of the fact that hydromorphic soils can support continuous cultivation under proper management.Dr A.O. Aweto is a Senior Lecturer in the Department of Geography, and Mr G.M. Ogurie was until recently a geography student in the same department.  相似文献   

7.
The author describes a futures study which looked at the long term supply of raw materials and resources for Sweden. The study involves the construction of a number of possible scenarios of Swedish and world development and an examination of their implications for resource supply. The conclusion is that there are unlikely to be any physical limits to growth over the next 25 years or so but that there may well be political obstacles. In any event, ideas of development are largely conditioned by historical and social circumstances and new paradigms may well produce new models of development.  相似文献   

8.
从温度对振动模态频率和温度对振动响应两方面分析温度对振动特性的影响,在此基础上针对典型电路板组件研究制定振动响应特性试验方案,利用激光测振系统开展不同温度下的模态频率和振动响应测试。试验结果表明,电路板组件的固有频率、加速度响应和位移响应均随着温度的升高而降低,且温度越高,振动响应的降幅越大。因此,在对产品进行振动分析时应充分考虑温度的影响,尤其是在温度较高时不应忽略温度对振动响应特性的影响,否则会造成较大的偏差。  相似文献   

9.
The current European Directive for the quality of drinking water was originally proposed in 1975 and adopted in 1980. With improved scientific knowledge and a desire to simplify, consolidate and update existing legislation, the commission is currently revising the Directive. Proposed changes include a significant reduction in the value of the lead parameter, which will involve countries such as the UK with considerable expenditure related to the removal of lead pipes and fittings in the water systems. Water quality will in future be measured and expected to comply at the tap. Other proposed changes are also outlined.  相似文献   

10.
双锥形管接头角度参数对管路密封的影响分析   总被引:3,自引:0,他引:3  
根据金属密封的基本条件,应用非线形有限元分析软件Msc.Marc,针对联接导管位置不同的两种双锥形管接头密封管路联接结构,计算分析双锥形管接头锥角和锥角差对管路密封性能的影响。计算结果表明,轴向预紧力随锥角或锥角差的增大而增大,密封系统承载内压能力随之下降。  相似文献   

11.
为探讨原油伴生卤水对农作物的影响,进行了种子发芽率试验和田间试验,确定了土壤氯化物含量影响棉花生长的临界值。结果表明,当土壤中氯离子含量大于306.7 mg/kg时,可明显影响棉花的正常生长,使产量明显下降,并污染土壤环境。  相似文献   

12.
随着科技的飞速发展,传统美术手工技艺逐渐被计算机和数字影像所取代,其实用价值已经退出了历史的舞台。但是应该看到,传统美术并非消亡,原有的那种探索、启发、冥想、创造依然在新的美术设计和艺术表现形式中发挥作用,从而体现了其存在价值。美术的概念在被一种新的艺术概念所取代,变的是称谓和形式,不变的是灵魂和精神,而这种技术的改变正是美术的未来。  相似文献   

13.
当前在我国海洋油气开发过程中已开展了相应的后评价工作,而在开展这些后评价工作中,也未有相应的技术规程和行业标准作为支撑,评价质量参差不齐。文章分析了海洋石油开发工程环境影响后评价标准化的制定、开展环境影响后评价的情形、工作程序、评价过程。为进一步落实《海洋石油开发工程环境影响后评价管理暂行规定》要求,从而为海洋油气开发工程环境问题提供标准化和科学化的管理依据。  相似文献   

14.
如何调动广大教师的积极性,已成为非常重要的课题。本文通过对教师激励因素的探讨,阐明在市场经济体制下,高等学校如何调动教师工作的积极性、主动性和创造性,更好地完成教育、教学任务。  相似文献   

15.
In 1988 I published a paper “Electromagnetic fields—a new ecological factor” (Markov 1988). There was no internet and very few cell phones were available. It was not even fear from the hazard of the power lines. However, I want to cite the beginning of this paper: “The contemporary conditions of life put man in dependence of the complex of physical influences on the environment and in the first place—of the electromagnetic fields. The rapid development of science and technology has resulted in the introduction of many new devices and technologies in industry, agriculture, and everyday life. On the other hand, during their phylogenetic and ontogenic development, the living organisms are continuously exposed to the influence of different biotic and abiotic factors. The physical factors are included in the first group, and the entire evolution of life is connected with an adaptation to the action of these factors.” Could I repeat this statement nearly a quarter of century later? Sure, I will. The only difference would be that I will speak not only for electromagnetic fields, but for green-house effects, global warming, volcano eruption, and radiation disasters. I would also discuss the noise and vibration to which people are exposed from early days to the very end of their life traveling with private vehicles or public transport.  相似文献   

16.
环评有效性问题的制度思考   总被引:1,自引:0,他引:1  
从我国环评的现状出发,探讨了我国环评在环评启动时间、建设项目分类环境管理、建设项目环境影响评价分级审批、环评报告内容和结论、公众参与等方面存在的问题,提出了明确环评启动时间、环评报告审批与稽查分离、环评机构和环评工程师市场化、提高公众参与的专业化程度的制度性建议。  相似文献   

17.
A study was carried out to evaluate the interaction effect of sewage and duration of consumption on the production traits of pullets. Intake of the test waters was a function of their degree of acceptability when intake was voluntary at periods of low ambient temperatures. The intiation of egg production in all groups began after five weeks of treatment and differences in egg weight of the groups was slight and not significant (P > 0.05). The effect of the sewage waters on growth was pronounced only when the birds were in lay and the alum-treated sewage promoted higher body weight gain. The feed conversion ratio and the feed intake were not affected significantly (P > 0.05) by the interaction, and both had the same trend. The eggshell thickness was sensitive to changes in ambient temperature.  相似文献   

18.
19.
在现有环境污染严重的背景下绿色转型成为经济发展的必要,为解决发展中的污染问题政府采取环境规制政策进行干预,环境规制政策的评价标准不仅要保护环境同时也要兼顾经济发展。目前关于检验排污权交易政策对绿色发展的影响研究较少。本文基于中国2004—2018年30个省份面板数据,通过双重差分法(DID)等实证检验排污权交易政策的实施效果和作用机制,并且采用PSM-DID等方法进行稳健性检验。研究发现:排污权交易政策的实施不仅减少了污染物SO2的排放,而且对工业绿色创新效率具有显著促进作用,有效推动经济可持续发展;通过作用机制分析可知,排污权交易政策提高绿色创新效率的作用途径是加大研发投入,并没有通过调整产业结构提高绿色创新效率;异质性分析表明在强环境规制下排污权政策的实施效果更好。中国政府有必要继续推动建设排污权交易政策的全国化,发挥政府激励作用,促使企业加大研发投入,提升绿色创新效率,推动经济可持续发展。本文从绿色创新效率的新视角检验了排污权交易政策的实施效果,有助于区域绿色发展的同时也为制定和完善排污权交易政策提供借鉴和参考。  相似文献   

20.
In this paper, we investigate whether people's knowledge of the past influences their preferences and values towards future landscape change. "Knowledge of the past" is one aspect of the information set held by individuals, and a well-established finding in economics is that changes in information can change preferences and values. The particular aspects of knowledge of the past we work with here are: (i) awareness of past landuse, as represented by woodland cover and (ii) awareness of differing and sometimes contradictory literary impressions of this past landscape. The case studies used here relate to prospective changes in woodland cover in two UK national parks, the Lake District and the Trossachs. We find that people who are made aware that the landscape has changed over time, or that perceptions of the landscape have changed over time, are more likely to favour changes to the current landscape (are less likely to favour the status quo). Knowledge of the past therefore seems to have an impact on preferences for future landscapes. We also investigate the impacts on preferences of how "special", how "wild" and how "worked in" people perceive the landscapes of these two national parks to be.  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