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31.
我国森林资源产品流动及其变化特征分析   总被引:6,自引:1,他引:5  
论文运用物流分析的基本思想,基于我国森林资源产品产量、贸易量统计资料,采用统一单位“原木当量”(m3),估算了1981~2000年森林资源采伐和产品加工环节的资源流量,进而分析我国森林资源产品流动的变化特征。结果表明,我国从“六五”(1981~1985年)到“九五”(1996~2000年)期间,消耗森林资源量分别为10230×104、11678×104、13444×104和16962×104m3/a,呈加速增长趋势。其中,来自国外的资源流量占总流量的比重呈增加趋势,“六五”期间占19.1%,到“九五”期间上升为48.3%。流入资源以原木、木浆、纸及纸板、胶合板为主,它们主要来自北美、东亚、东南亚地区,有来源多地区化的变化趋向。森林资源在“六五”期间主要流向原木锯材类产品加工,随着产品流向结构的逐步改善,更多的资源流向人造板类产品的生产消费;纸类产品生产消费的资源流量增加迅速,但主要来自国外。  相似文献   
32.
Background, Aims and Scope When joining the European Union on 1st May 2004, Estonia had to conform its legislation to the European Union legislation. In relation with that, also the treatment requirements on end-of-life vehicles proceeding from Directive 2000/53/EC of the European Parliament and of the Council of 18 September 2000 were established in Estonia for the first time. Since this area was not regulated with law beforehand, there was not any information available about it. The aim of the current survey was to ascertain the condition of scrap yards in mid 2004. In addition to that, also to identify the number of scrap yards operating in Estonia, to classify these by the number of dismantled vehicles and the potential environmental hazard, and to map the locations of car dismantling companies and evaluate their compliance with the valid requirements. Methods The companies that have been registered in the Commercial Registry under the activity code 503090-end-of-life vehicle dismantling were visited and visually reviewed. During the visits, the compliance of scrap yards with the existing requirements was evaluated and it was also attempted to identify how environmentally sound the dismantling technology of every scrap yard owner is. Results and Discussion Altogether, 63 scrap yards operated in Estonia by mid 2004. Twelve of them dismantled more than 100 vehicles, 13 of them 51-99 vehicles and 38 up to 50 vehicles a year. The total annual market capacity on dismantling of vehicles in Estonia is considered to be approx. 10,000 units. There are very few companies dealing only with car dismantling as the main business. Most scrap-yard owners also offer side services, e.g. haulage, car repair and maintenance. The dismantlers are interested in the selling of second-hand spare parts and scrap metal. Only one company out of 63 complied with all the requirements enacted by the relevant decision of the Estonian Minister of Environment. The rest of the scrap yards did not meet the requirements on the site on storage and treatment nor did they have the hazardous waste handling licence or the waste permit. Of the requirements established for the site for storage of end-of-life vehicles, 97% of the scrap yards were surrounded with a fence, 67% had a 24-hour guard, 45% had covered the areas with waterproof cover, but only 3% had an oil trap. Sites for treatment were in a somewhat better condition, these were mostly situated inside the buildings, where floors were covered with waterproof covers. Most of the dismantlers collected the waste oil and waste fluids into separate vessels, but there were a number of dismantlers who did not know of existence of polychlorinated biphenyls (PCB) in car air conditioning systems and the availability of mercury in sensors belonging in passenger safety systems. Proceeding from the general condition of the scrap yard, the rest of 62 scarp yards were distributed between two empirical parameters - 'rather environmentally hazardous' or 'rather not environmentally hazardous'. As a matter of fact, 17% of scrap yards turned out 'rather environmentally hazardous'. Conclusion Out of the scrap yards operating in Estonia, only one is compliant with the requirements set up by Directive 2000/53/EC. Another 62 appeared during the review to be sites of potential environmental pollution. In order to comply with environmental requirements and get the hazardous waste treatment license, the scrap yard owners have to invest into state-of-the-art dismantling and environment protection equipment. The main obstacle to reach the environmentally sound scrap-yard is the high investment cost and the black market for spare parts. Recommendation and Outlook As the correction of the market in end-of-life vehicle treatment started after the adoption of Directive 2000/53/EC, the environmental authorities have to look after the ongoing correction. It is because there is still a demand for cheap spare parts and it makes it attractive to dismantle the vehicles out of scrap-yards by licensees.  相似文献   
33.
Estimates of terrestrial Broad Habitat cover for Wales from the Countryside Survey 2000 stratified sample field mapping programme in Britain are compared with the findings of a full census field mapping project, the Habitat Survey of Wales. The Countryside Survey sampling regime comprised a stratified random sample of 1 km squares [corrected] covering <0.5% of the land surface. Comparative assessment indicates that although few of the sample-derived estimates for individual Broad Habitats are within 30% of the full census survey results, relative extents accord with data from the complete census survey for all Broad Habitats apart from Arable & Horticultural. The accuracy of this estimate is improved when the national boundary of Wales is taken into account in the sample stratification scheme. It is suggested that cultural land-use differences between countries render cropland habitat extent less predictable from physical environmental parameters than semi-natural habitat extent. It is also shown that the precision of sample-derived cover estimates is influenced by habitat pattern: the error term associated with habitats of broadly equal extent is greater for those with the most clumped distributions.  相似文献   
34.
收集Carrousel 2000型氧化沟工艺启动过程中活性污泥样品,直接提取微生物的基因组DNA并纯化,然后对细菌16S rDNA的V3高变区进行PCR扩增和DGGE分离,通过比较DGGE图谱的相似性来研究工艺调试过程中微生物种群的变化情况.研究表明,活性污泥中具有非常丰富的微生物种群.调试初期水质波动对氧化沟中微生物种群的影响非常明显,但接种的成熟活性污泥中微生物种群能够很快适应新型氧化沟工艺的结构及水力特性.调试从4月开始,4月氧化沟中微生物种群相似性Cs最大值为68.9%,5~6月Cs最大值为70.8%,8月Cs最大值为73.0%,可见氧化沟中微生物种群相似性逐渐增加,直至稳定.在此过程中,系统对COD、氨氮的处理效果同步提高并趋于稳定.综合分析好氧活性污泥在氧化沟中驯化期为2个月.图4表4参12  相似文献   
35.
Recently, the European Commission adopted a new strategy to halt the loss of biodiversity. Member states are expected to favor a more effective collection and redistribution of European Union (EU) funds under the current Multiannual Financial Framework for 2014–2020. Because of the large spatial variation in the distribution of biodiversity and conservation needs at the continental scale, EU instruments should ensure that countries with higher biodiversity values get more funds and resources for the conservation than other countries. Using linear regressions, we assessed the association between conservation investments and biodiversity values across member states, accounting for a variety of conservation investment indicators, taxonomic groups (including groups of plants, vertebrates, and invertebrates), and indicators of biodiversity value. In general, we found clear overall associations between conservation investments and biodiversity variables. However, some countries received more or less investment than would be expected based on biodiversity values in those countries. We also found that the extensive use of birds as unique indicators of conservation effectiveness may lead to biased decisions. Our results can inform future decisions regarding funding allocation and thus improve distribution of EU conservation funds.  相似文献   
36.
采用传统档案分类管理的思想,应用ASP+SQL server2000设计出开放的软件结构,实现了装备腐蚀资料的分类存储和集中管理,为装备腐蚀科研人员腐蚀控制工作提供了信息支撑。对软件实现的功能、逻辑结构和所采用的开发技术进行了详细的介绍。  相似文献   
37.
航天动力学环境的最新进展与技术展望   总被引:6,自引:6,他引:0  
总结了近年来航天动力学分析、试验方面的最新成果。按照航天飞行器寿命期不同阶段的特点,对动力学试验与理论建模、分析预示、试验技术、测量方法,特别是地面气候复合以及高速飞行热结构动力学分析与试验方面的工作进行归纳,并指出存在的不足,以及未来发展的方向。通过工程研制中的分析与数据积累修正,在建模分析预示、条件制定以及测量技术等方面取得显著成果,但由于飞行器复杂,在准确精细预示方法、热结构预示与试验技术方面以及气候复合状态下的分析与试验方面尚需大量研究。应坚持理论与试验、工程研制与研究相结合的方式,不断完善持续改进,实现动力学精细化预示与天地一致性试验。  相似文献   
38.
Many recent developments in coastal science have gone against the demands of European Union legislation. Coastal dune systems which cover small areas of the earth can host a high level of biodiversity. However, human pressure on coastal zones around the world has increased dramatically in the last 50 years. In addition to direct habitat loss, the rapid extinction of many species that are unique to these systems can be attributed to landscape deterioration through the lack of appropriate management. In this paper, we propose to use of an ecosystem classification technique that integrates potential natural vegetation distribution as a reference framework for coastal dune EU Habitats (92/43) distribution analysis and assessment. As an example, the present study analyses the EU Habitats distribution within a hierarchical ecosystem classification of the coastal dune systems of central Italy. In total, 24 land elements belonging to 8 land units, 5 land facets, 2 land systems and 2 land regions were identified for the coastal dunes of central Italy, based on diagnostic land attributes. In central Italy, coastal dune environments including all the beach area, mobile dunes and all the fixed-dune land elements contain or could potentially hold at least one EU habitat of interest. Almost all dune slack transitions present the potentiality for the spontaneous development of EU woodlands of interest. The precise information concerning these ecosystems distribution and ecological relationships that this method produces, makes it very effective in Natura 2000 European network assessment. This hierarchical ecosystem classification method facilitates the identification of areas to be surveyed and eventually bound, under the implementation of EU Habitat directive (92/43) including areas with highly disturbed coastal dune ecosystems.  相似文献   
39.
This article reviews the influence of two specific European Union (EU) laws, the Birds and Habitats Directives, on the choice of national policy instruments by Member States. Both Directives leave the choice for policy instruments to manage the sites designated under the Directives to the Member States. Using path dependency as a leading concept, this article analyses the continuity or changes in policy instruments due to the implementation of the Directives in 15 countries. This article shows that the tendency to use existing instruments to implement EU policy is limited, as in almost all countries new instruments were developed. Yet, states do tend to choose instruments from their predominant policy instrument mix and preferred implementation style to address the management requirements of the Directives. Additionally, in Central and Eastern European countries where the implementation of EU policy coincided with a process of transition to a market economy, new instruments were introduced outside the existing implementation style. The introduction of new policy instruments is the result of historical turns, domestic pressure and a shift to new modes of governance. National case studies are needed to shed more light on the interaction between EU policy and domestic factors during the process of instrument choice.  相似文献   
40.
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