盾构隧道的开挖模拟及地震反应数值分析

由于盾构隧道掘进的特殊施工工艺,使开挖模拟的数值计算存在着诸多难以量化的因素。采用应力释放法模拟盾构隧道的开挖,在衬砌和土体之间设置等代层单元模拟盾构施工的影响,求得竣工期的应力场和位移场。在静力计算基础上运用动力有限元时程分析法,采用粘性人工边界条件,分析了隧道衬砌在地震过程中的最大响应。其结果和规律可为一般的盾构隧道地震反应分析提供借鉴。     

燃煤锅炉湿式脱硫除尘一体化设备的综合分析

本文对湿式脱硫除尘一体化设备的结构和性能进行了较为全面的分析,指出了该设备存在的诸多弊病,提出了解决方案--脱硫、除尘分体组合式的思路.     

土壤锑污染对桑树的影响初探

运用盆栽实验和实验分析方法,研究了土壤锑(Sb)污染对桑叶品质的影响,揭示了桑树对土壤锑的耐性机制。在土壤中分别添加三价锑15mg/kg、40mg/kg、80mg/kg、120mg/kg、160mg/kg和300mg/kg,以植物生长指标及生理指标为测试指标,实验周期60d。实验结果表明,低浓度Sb处理(<40mg/kg)对桑树生长有促进作用;随着土壤Sb浓度增高(40—300mg/kg),它对桑树产生抑制效应。但当土壤锑浓度不超过160mg/kg时,桑树对土壤锑污染有一定的耐性,其耐性指数>0.8。土壤锑污染对桑叶叶绿素含量、淀粉含量和可溶性糖含量影响不显著,桑叶中的锑含量随土壤锑含量的增加而增多。     

山东省在全国的区际地位及区域内部分工格局研究

区域分工对区域经济发展具有重要作用。山东地处我国东部沿海,是全国人口大省、经济大省,在全国经济发展格局中占有举足轻重的地位。根据区域分工理论,对山东省在全国和区域内部分工进行了分析,揭示了山东省在全国的区际地位以及所辖17个市之间的区域分工与合作格局,为山东省强化区域分工和联系,提高区域竞争力提供决策依据。     

旅游循环经济理念下的珠江源旅游区建设初探

旅游循环经济是发展旅游业一种新的指导思想,是实现旅游业可持续发展的新范式。针对珠江源旅游区的现状,根据旅游循环经济资源循环利用和保护并重的理念,探讨其在旅游区的林地系统利用建设、湿地系统利用建设、岩溶地貌系统利用建设、旅游服务设施系统利用建设方面的应用。     

Watershed Evapotranspiration Increased due to Changes in Vegetation Composition and Structure Under a Subtropical Climate1

Abstract: Natural forests in southern China have been severely logged due to high human demand for timber, food, and fuels during the past century, but are recovering in the past decade. The objective of this study was to investigate how vegetation cover changes in composition and structure affected the water budgets of a 9.6‐km² Dakeng watershed located in a humid subtropical mountainous region in southern China. We analyzed 27 years (i.e., 1967‐1993) of streamflow and climate data and associated vegetation cover change in the watershed. Land use/land cover census and Normalized Difference of Vegetation Index (NDVI) data derived from remote sensing were used to construct historic land cover change patterns. We found that over the period of record, annual streamflow (Q) and runoff/precipitation ratio did not change significantly, nor did the climatic variables, including air temperature, Hamon’s potential evapotranspiration (ET), pan evaporation, sunshine hours, and radiation. However, annual ET estimated as the differences between P and Q showed a statistically significant increasing trend. Overall, the NDVI of the watershed had a significant increasing trend in the peak spring growing season. This study concluded that watershed ecosystem ET increased as the vegetation cover shifted from low stock forests to shrub and grasslands that had higher ET rates. A conceptual model was developed for the study watershed to describe the vegetation cover‐streamflow relationships during a 50‐year time frame. This paper highlighted the importance of eco‐physiologically based studies in understanding transitory, nonstationary effects of deforestation or forestation on watershed water balances.     

Impacts on industry of Europe's emerging chemicals policy REACh

For Europe, a new regime in chemicals regulation is about to start. After the proposal of the European Commission concerning the Registration, Evaluation and Authorization of Chemicals (REACh) passed its readings in the European Parliament and some differences with the European Council of Ministers were resolved, the regulation will come into force in June 2007. This paper is focused on the question how serious the cost burdens for industry induced by REACh will be, and whether the New European Member States (NMS) which joined the European Union in May 2004 will be able to cope with the regulation. This evaluation has been done by assessing the legislative, administrative and economic framework in New Member States and by analysing real business cases in companies. The empirical showcase business impact studies are at the same time of interest for companies of EU-15 states, other European countries who may implement the regulation, and even for exporters of raw materials and chemicals outside Europe, who will also have to comply with REACh if they market in the European Community. The results give no indications that REACh adoption will bring significant drawbacks to companies in the NMS. The emerging regulation will bring challenges for individual companies, especially for small and medium-sized ones, but for the European chemical industry as a whole, there is no question that it will be able to cope with REACh burdens without losing its global competitiveness.     

RETRACTED ARTICLE: Environmental Impact Assessment of Industrial Structure Change in a Rural Region of China

As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global environmental change. Consequently, the research on the change of regional industrial structure and associated effects on the environment is one of the key issues of researches on sustainable development, human–environment relationship, and regional response to global environment change. However, compared to the flourish of researches on environmental impact assessment of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure. In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental impact coefficient of industrial department associated with the index of environmental impact of industrial structure was constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure. And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure.     

柚园间种作物及施用不同有机肥对土壤与柚果的影响

柚树间种短期经济作物在提高柚园经济效益的同时,还可提高土壤的有机质和N、P、K养分质量分数,改善柚园小区气候,增加有机肥来源。间种物残余体作为绿肥,可显著地提高柚果产量和质量。