糯扎渡电站溢洪道边坡稳定分析及系统锚固方法     

张发明  庞正江  陈祖煜  贾志欣  汪小刚 《岩土力学》2005,26(Z1):255-259

糯扎渡水电站位于云南省思茅市境内,是澜沧江流域开发中具有十分重要意义的工程。设计土石坝方案的溢洪道开挖边坡的稳定性关系到该方案的合理选择。通过对溢洪道附近的平硐与露头的野外调查,获得了1 400余条结构面的详细信息,在岩体结构面统计基础上,运用随机网络模拟的方法得到了溢洪道开挖边坡的裂隙网络图像,分析了岩体结构面的连通率,采用Hoek和Brown提出的GSI体系,对岩体质量进行综合定量评价,在此基础上,提出各高边坡岩体力学参数的综合指标。应用模拟退火算法,搜索出边坡潜在的最危险滑裂面的位置,并运用Sarma法分析了开挖边坡的稳定性,提出各个边坡稳定性的分析评价成果以及建议的边坡系统锚固措施。  相似文献   

干旱区主要陆表过程与人类活动和气候变化研究进展   总被引：24，自引：23，他引：1  

王涛 《中国沙漠》2007,27(5):711-718

分析了国内外水、土、气、生主要陆表过程的相互作用以及干旱、半干旱区主要陆表过程与气候变化和人类活动互为响应机制的一系列研究成果,提出了未来该研究领域的发展方向应集中在地球表层系统各要素相互作用的综合研究,同时突出人类活动在陆表过程中的主导地位;在研究手段上应基于国家野外科学观测站、生态网络站的长期定位观测,开展干旱、半干旱区不同尺度水、土、气、生过程相互作用机理及其联网对比、集成研究。最终通过深刻理解研究区陆表过程及其调控机理,丰富陆地表层系统科学研究的内涵,带动相关学科在交叉集成研究上的理论创新。  相似文献   

依靠科技创新发展地勘经济     

管志炜 《江西地质》2000,14(3):237-240

本文论述了科技创新及其重要性,指出地勘行业目前科技创新存在的一些问题和认识误区。提出加强科技创新工作,进一步提高对科技创新重要性认识;加快创新机构和创新服务机构的建设;为科技创新提供良好的政策和社会环境;依靠科技创新,调整、优化经济结构,逐步形成具特色的支柱产业和主导产业等建议。  相似文献   

地质创造学及其在知识创新中的意义     

庄寿强 《江苏地质》2000,24(1):11-13

地质创造学根据创造学中的综合原理 ,将地质学与创造学结合成一门交叉性学科。地质创造学主要研究地学领域中的理论和实践的创造活动 ,探索地学的创造过程、创造原理及其思维的特点、规律和方法。  相似文献   

知识经济时代的区域地理学创新   总被引：3，自引：0，他引：3  

刘锋  张军涛 《地域研究与开发》2000,19(2):17-20

区域地理学研究充分体现了地理学的地域性和综合性,并不断将自然科学与社会科学结合起来综合研究区域中出现的务种实践问题。知识经济的来临将从多方面影响区域地理不研究,也将为其提供新的研究领域。因此,区域地理学需要创新、扩展自身的研究领域并不断提高解决实际问题的能力,以适应知识经济时代的要求。文章探索性地提出了知识经济时代区域发展的四大驱动力和区域地理学的创新方向。  相似文献   

粤港澳大湾区协同创新的综合测度与演化特征     

吴康敏  张虹鸥  叶玉瑶  陈奕嘉  岳晓丽 《地理科学进展》2022,41(9):1662-1676

理解粤港澳大湾区协同创新的网络结构及其演化特征对于新时期大湾区的创新化发展转型至关重要。论文通过构建包括技术创新、知识生产、创新资本3个维度的协同创新测度指标体系,基于城市群流空间网络构建与社会网络分析方法,系统性研究了多创新维度下粤港澳大湾区协同创新的网络结构及其演化特征。结果表明：(1)粤港澳大湾区创新流空间结构呈现出显著的极化特征,且随着时间推移,极化效应不断强化,深圳、香港、广州在创新流空间网络中占据绝对核心地位;(2)多维度创新流要素网络结构呈现出显著差异性,技术创新与创新资本维度中,香港、深圳占据了城市群网络的核心,知识生产维度的核心城市则是广州与香港,广州在各维度网络中均扮演了重要的“枢纽型”城市角色,深圳在各维度网络中的创新层级随着时间推移在不断增长;(3)综合多维度指标的测度结果显示,香港与深圳分别是早期与新时期粤港澳大湾区协同创新网络的核心,当前大湾区整体呈现为穗深港三核心并立的城市群网络空间结构。研究可为新时期粤港澳大湾区创新资源的合理化配置提供理论与实证支撑。  相似文献   

测定天文大气折射和建立电磁波折射延迟实测模型(Ⅱ)-采用依巴谷星表作为工作星表   总被引：1，自引：0，他引：1  

铁琼仙  杨磊  李彬华  张捍卫  冒蔚 《天文研究与技术》2005,2(4):246-251

叙述了测定大气折射对工作星表的要求和星表系统误差的影响,并通过FK5星表相对于依巴谷星表的系统误差,来说明以往的各种基本星表都不适用的原因;文章说明了依巴谷星表所列星位置不含随天区而异的系统误差的特性,分析了该星表问世时的精度和十多年后的今天仍能达到的精度,说明它可以作为这种测定的工作星表,从而为直接测定天文大气折射值和折射率差提供了一个重要的条件;文章还介绍了依巴谷星表的星等分布,认为只需选用亮于6mag的依巴谷星,这一星等范围,为制定专用测量仪器终端的设计方案提供了依据。  相似文献   

Accuracy of tretyakov precipitation gauge: Result of wmo intercomparison     

Daqing Yang  Barry E. Goodison  John R. Metcalfe  Valentin S. Golubev  Esko Elomaa  Thilo Gunther  Roy Bates  Timothy Pangburn  Clayton L. Hanson  Douglas Emerson  Voilete Copaciu  Janja Milkovic 《水文研究》1995,9(8):877-895

The Tretyakov non-recording precipitation gauge has been used historically as the official precipitation measurement instrument in the Russian (formerly the USSR) climatic and hydrological station network and in a number of other European countries. From 1986 to 1993, the accuracy and performance of this gauge were evaluated during the WMO Solid Precipitation Measurement Intercomparison at 11 stations in Canada, the USA, Russia, Germany, Finland, Romania and Croatia. The double fence intercomparison reference (DFIR) was the reference standard used at all the Intercomparison stations in the Intercomparison. The Intercomparison data collected at the different sites are compatible with respect to the catch ratio (measured/DFIR) for the same gauge, when compared using mean wind speed at the height of the gauge orifice during the observation period. The Intercomparison data for the Tretyakov gauge were compiled from measurements made at these WMO intercomparison sites. These data represent a variety of climates, terrains and exposures. The effects of environmental factors, such as wind speed, wind direction, type of precipitation and temperature, on gauge catch ratios were investigated. Wind speed was found to be the most important factor determining the gauge catch and air temperature had a secondary effect when precipitation was classified into snow, mixed and rain. The results of the analysis of gauge catch ratio versus wind speed and temperature on a daily time step are presented for various types of precipitation. Independent checks of the correction equations against the DFIR have been conducted at those Intercomparison stations and a good agreement (difference less than 10%) has been obtained. The use of such adjustment procedures should significantly improve the accuracy and homogeneity of gauge-measured precipitation data over large regions of the former USSR and central Europe.  相似文献   

应变分析法与GPS网优化设计     

张勤 《地球科学与环境学报》1995,(4)

本文借助于弹性力学应变分析理论，提出ＧＰＳ网应变强度分析法，建立了对应于椭球微分坐标系的“位移－应变”数学模型，分析了ＧＰＳ模拟网应变强度的分布情况，得出一些有益的结论。  相似文献   

Could fiscal policies induce green innovation in developing countries? The case of Brazilian manufacturing sectors     

Camila Gramkow  Annela Anger-Kraavi 《Climate Policy》2018,18(2):246-257

Brazil is the first major developing country to pledge for absolute reductions in greenhouse gas emissions. This article explores the extent to which fiscal policies could contribute to this reduction and to greening the Brazilian economy. It was found that the use of green fiscal policies is at an early stage in Brazil, but a growing number of measures have been adopted in recent years led by subnational-level policies. An econometric analysis of 24 Brazilian manufacturing sectors for the years 2001–2008 shows that some fiscal instruments, such as low-cost (subsidized) finance for innovation and fiscal incentives for sustainable practices, have been effective in inducing green innovation. However, less than 14% of more than 100 thousand companies included in the study have adopted greener technologies. Even though Brazilian green fiscal policies have been rather uncoordinated and ad hoc, their significant impact on the uptake of green technologies indicates these can play an important role in a transition to a green economy.

POLICY RELEVANCE

Faced with the challenge of reducing its greenhouse gas emissions in absolute terms, Brazil now needs to put in place policies to help deliver the country’s pledge. This article analyses which fiscal policies should be adopted and how these policies could form part of a low carbon policy framework in the country. Among our policy-relevant findings is that subnational green fiscal policies are relatively less complex to introduce and encourage uptake of green technologies. Thus, they could be an entry point to a wider green fiscal policy strategy. We also found that fiscal incentives for green innovation projects can present more than proportional impact on the uptake of green technologies owing to positive feedbacks, increasing returns to scale and spill-overs. These are attractive features of green innovations to developing countries in addition to environmental benefits, as they favour the accumulation of indigenous technological capabilities that are critical for long-term technological and economic development. These lessons learned from green fiscal policies in Brazil are applicable to other developing countries.  相似文献