国内外电气石研究进展

电气石因其特殊的物理性质而被国内外学者广泛关注,并形成了大量的研究成果和应用专利。目前国内外对电气石的研究主要集中在晶体矿物学、找矿矿物学和岩石矿物学、晶体物理化学特性、矿床资源特征4个方面。自20世纪40年代以来,围绕电气石的晶体结构和电气石物理特性的内在动因等,中外学者做了大量深入细致的基础研究,并在利用电气石的化学成分判断成矿、成岩地质环境方面取得了许多宝贵的经验。近几年,国内外利用电气石的物理特性制造环保、保健产品等获得突破,展现了电气石的良好开发前景。     

国内外电气石研究进展

电气石因其特殊的物理性质而被国内外学者广泛关注，并形成了大量的研究成果和应用专利。目前国内外对电气石的研究主要集中在晶体矿物学、找矿矿物学和岩石矿物学、晶体物理化学特性、矿床资源特征4个方面。自20世纪40年代以来，围绕电气石的晶体结构和电气石物理特性的内在动因等，中外学者做了大量深入细致的基础研究，并在利用电气石的化学成分判断成矿、成岩地质环境方面取得了许多宝贵的经验。近几年，国内外利用电气石的物理特性制造环保、保健产品等获得突破，展现了电气石的良好开发前景。     

Work practice among advanced producer service firms – project work in space-time

This article is an explorative investigation of a sample of advanced producer service (APS) companies located in Stockholm (the capital and main urban centre of Sweden). The discussion is centred on aspects of work practice and how this is conditioned by space-time constraints. These space-time constraints refer to coupling, authority and capability constraints which are concepts framed in a time-geography approach. Although time-geography is primarily engaged in mapping presence and locations in time-space, its concepts of constraints embrace physical, social and cultural factors. The article presents an empirical in-depth study of project work and work practice among a selection of APS companies. A micro-approach to work practice has been pursued using a multi-method strategy and time-geography methodology including time diaries, interviews and a questionnaire. The experiences among the investigated companies of time-geography constraints make the constant negotiations for the practice of work among these organizations intelligible. To the extent these investigated companies may be considered representative of advanced services more generally, the presence of pressing constraints helps to explain the more general structure of this industry of high labour turnover and rapid company re-structuring processes.     

综合超前地质预报方法在宜万铁路云雾山隧道施工中的应用

云雾山隧道是宜万铁路的重要控制性工程之一,针对该隧道的工程地质和水文地质条件,采取了综合超前地质预报方法,降低了隧道施工风险,加速了工程进度和保证了工程质量,对以后相似隧道的施工提供借鉴意义。     

超前帷幕注浆技术在蔡园煤矿导水断层治理中的应用

蔡园煤矿中部发育一条走向近NW向的正断层,对开采12煤层有影响,在分析断层特征及水文地质条件基础上,采用超前帷幕注浆技术对断层破碎带进行了加固,并对影响断层富水性的灰岩含水层进行了预注浆封堵,实现了对断层破碎带加固、堵水的双重效果,达到了巷道围岩加固及含水层改造的双重目的,保证了巷道的安全通过。     

高速铁路隧道塌方原因分析与施工处治技术

结合某高速铁路隧道DgK88+520～522段施工出现掌子面附近拱顶塌方的工程背景,从现场地质条件与设计支护参数等方面分析了塌方原因,并采用数值模拟对比分析了勘查设计与围岩变更后的开挖支护措施引起的围岩变形。结果表明,根据原勘查设计Ⅲa级围岩确定的开挖方法与支护参数不能有效保证实际围岩条件下的隧道稳定性,而采用围岩变更为Ⅴb级围岩、三台阶七步法开挖、Ⅴb级围岩复合式衬砌支护的设计,拱顶沉降则可大幅度降低。介绍了塌方处治措施和拱顶沉降监测结果。由于围岩表现为脆性,在塌方后拱顶沉降较小,为确保工程安全,应根据地质勘查与超前地质预报等辅助措施,更为准确地掌握隧道围岩地质赋存条件,确定合理的开挖方法与支护参数。     

矿井水预测探查及预警保障技术

阐述了矿井水灾地质保障技术的现状及发展趋势。监测预警系统以突水机理、构造预测探测及突水量预测理论为基础。为此,划分了三种突水模式:正常岩层底板突水模式、断层裂隙带突水模式、陷落柱突水模式。归纳出完整厚板整体剪切断裂导水、厚板微观压裂导升、薄板宏观整体破断导水三种基本的突水机理。在宏观预测的基础上,形成了构造及其导水性的预测探查规范程序。以微变形和破坏两种情况下流-固耦合实验结果为基础,建立了矿井涌水量预测流程,实现了区域微变形和局部采动破坏共存条件下的突(涌)水量预测。依据灾害发生的监测预警指标体系,建立了矿井水灾预警的硬件系统和识别系统。     

浙东南山丘区泥石流爆发的临界雨量分析

首先对浙东南山区泥石流的形成条件（物源、地形和降水条件）进行了研究。随后研究了本区泥石流的基本特征：在形成方式上,以谷坡或沟源地带的土动力启动方式为主;在侵蚀特征方面,主要有面蚀作用和沟谷侵蚀作用;堆积特征方面,在宏观上当规模较大时可形成堆积扇,规模较小时往往以停积于中下游沟道为主;微观上,主要表现为堆积物质结构杂乱,个别具有期次性。对本区泥石流临界雨量组合进行分析,认为采用基于区域临界雨量组合的泥石流预警预报方法较为合理。利用研究区内4次群发泥石流时的降雨特征值确定了本区泥石流爆发的临界雨量组合,并将其应用于研究区泥石流的临灾预警,分为以下步骤：①收集实时降雨资料;②绘制实时雨量组合曲线;③泥石流灾害预警;④泥石流临界雨量基准的修正。     

基于高级生产者服务业视角的成渝地区城市网络体系

基于高级生产者服务业视角,建立了成渝地区17个最小分析单元(FUR,Functional Urban Region)×149家公司的量化矩阵,进行了基于服务值、连通性和网络性特征的分析,研究了成渝地区的城市网络体系结构及其特征.其中,FUR为重庆都市发达经济圈、渝西走廊地区和绝大部分地级市.结果表明:成都市和重庆都市发...     

Evaluating the potential of a blended passive microwave‐interactive multi‐sensor product for improved mapping of snow cover and estimations of snow water equivalent

The retrieval of Snow Water Equivalent (SWE) from remote sensing satellites continues to be a very challenging problem. In this paper, we evaluate the accuracy of a new SWE product derived from the blending of a passive microwave SWE product based on the Advanced Microwave Sounding Unit (AMSU) with a multi‐sensor snow cover extent product based on the Interactive Multi‐sensor Snow and Ice Mapping System (IMS). The microwave measurements have the ability to penetrate the snow pack, and thus, the retrieval of SWE is best accomplished using the AMSU. On the other hand, the IMS maps snow cover more reliably due to the use of multiple satellite and ground observations. The evolution of global snow cover from the blended, the AMSU and the IMS products was examined during the 2006 snow season. Despite the overall good inter‐product agreement, it was shown that the retrievals of snow cover extent in the blended product are improved when using IMS, with implications for improved microwave retrievals of SWE. In a separate investigation, the skill of the microwave SWE product was also examined for its ability to correctly estimate SWE globally and regionally. Qualitative evaluation of global SWE retrievals suggested dependence on land surface temperature: the lower the temperature, the higher the SWE retrieved. This temperature bias was attributed in part to temperature effects on those snow properties that impact microwave response. Therefore, algorithm modifications are needed with more dynamical adjustments to account for changing snow cover. Quantitative evaluation over Slovakia in central Europe, for a limited period in 2006, showed reasonably good performance for SWE less than 100 mm. Sensitivity to deeper snow decreased significantly. Copyright © 2007 John Wiley & Sons, Ltd.