Isolating quartz-dominated OSL signal of rock slice by using pulsed stimulation: Implications for dating burial age of cobbles     

《Quaternary Geochronology》2022

Although the OSL signal sourced from quartz is expected to be more stable and bleached more rapidly than the IRSL signal sourced from feldspar in a general sense, the former is much less investigated than the latter for rock surface related luminescence dating. It is mainly due to the difficulty in isolating quartz-dominated OSL signals from rock slices, and the low sensitivity and non-fast component dominated OSL signals for quartz in most of rocks. In merit of the sub-conduction band transition of trapped electrons of feldspar under both green light stimulation and IR stimulation at elevated temperature (Jain and Ankjӕrgaard, 2011), it is expected that the contribution of feldspars to the green light stimulated luminescence could be substantially reduced by a prior IR stimulation at elevated temperature. Meanwhile, more fast-component dominated quartz OSL signal (if there is any) could be obtained by green light stimulation (Bailey et al., 2011). Therefore, in this study, we investigated the feasibility of using the post-IR pulsed green stimulation, which is performed at 25 °C (PGLSL₂₅) following two IR stimulations (IR₅₀IR₂₂₅), to isolate the quartz-dominated OSL signals from rock slices of granite cobbles for burial dating. The decay characteristics of stimulation curve, characteristic saturation dose and thermal stability of the pIR₅₀IR₂₂₅ PGLSL₂₅ signal suggest that this signal is quartz-dominated, but still not fast-component dominated. We tentatively validated the equivalent dose (D_e) measurement protocol by dose recovery experiment. The luminescence-depth profiles show that the bleaching depths of pIR₅₀IR₂₂₅ PGLSL₂₅ signals are slightly smaller than or close to that of the IR₅₀ signals, while they are much shallower for the pIR₅₀IR₂₂₅ signals. The pIR₅₀IR₂₂₅ PGLSL₂₅ procedure enables multiple D_e values determined from luminescence signals, with different bleachabilities and stabilities, from both feldspars and quartz in one measurement, which is of potential for buried age dating of cobbles.  相似文献   

基于SWOT分析的新形势下甘肃省地矿局发展对策研究     

郭万里  王国荣  王恒山  李瑞 《地质论评》2022,68(6):2022112002-2022112002

为适应国家发展改革的趋势,促进甘肃省地勘事业的可持续发展,探索出一套具有甘肃特色、适应当前市场经济体制的地勘业发展的“甘肃模式”。本文SWOT方法\[指分析企业在整个市场环境中的机会（Opportunities）、风险（Threats）、优势（Strengths)、劣势（Weaknesses）\]分析了甘肃省地勘事业在高质量发展道路上的现状、内外部环境和存在的优势、劣势、机遇及威胁,提出了甘肃地勘事业未来怎样顺应时代发展潮流,发挥优势、规避劣势、抓住机遇、迎接挑战的途径和策略。这对于甘肃地勘产业形成统一的有机体,产业结构相对合理、产业队伍相对稳定,产业内部协调有序运行,从而保持地勘经济持续增长具有十分重要的意义。  相似文献   

基于ENVI的高分辨率遥感影像城市绿地信息提取研究   总被引：1，自引：0，他引：1  

陈阳  赵俊三  陈应跃 《测绘工程》2015,(4):33-36

近年来众多高分辨率遥感卫星的发射为城市绿地信息提取提供了高效的手段,如何充分利用高分辨率遥感影像对现代城市进行规划和生态环境评价具有重要意义。文中介绍一个完整的遥感工程在ENVI下的实现过程,包含高分辨率数据的处理、高分辨率信息提取流程的合理安排、FX模块面向对象信息提取等内容,可全面快速掌握城市绿地总量与分布现状,为绿地系统规划与日常管理决策提供参考,对生态城市建设具有重要意义。  相似文献   

基于红绿色觉异常人群的路况地图色彩设计研究     

朱海红  夏梦 《测绘工程》2015,(12):1-6

红绿色觉异常人群对于明度变化的感受比正常视觉者更加敏感,可以弥补色相辨别的缺陷。通过针对黄色明度对比实验得出红绿色觉异常人群对明度对比各等级的视觉感受,找出对红绿色觉异常人群既可以容易识别又不会觉得刺眼的明度对比范围。实验结果引入地图设色,结合色彩象征意义,做出红绿色觉异常人群和正常人群通用的路况地图。在路况信息清晰表达前提下,尽可能保留色彩象征意义,并保证地图的观赏性。通过路况地图色彩明度对比实验制作出红绿色觉异常人群既能无障碍识别又带有警示象征意义的路况地图。  相似文献   

利用资源三号影像动态监测矿区环境复绿研究     

谢国雪  杨如军  卢远 《测绘与空间地理信息》2015,(5):46-48

选择以原地形依台阶式开采方式为主的稀土矿区为研究对象,利用国产资源三号卫星影像为主要的数据源,动态监测矿区环境复绿变化情况.首先,采用同名点自动匹配纠正影像后进行融合处理,再利用正射影像纠正技术校正融合后的影像数据;其次,采用绿色波段占0.7,近红外波段占0.3的比例合成新的绿色波段,再将新合成的绿色波段与正射纠正的影像进行波段重组处理;最后,采用面向对象的方法提取各个影像的绿地信息,精度验证通过后,将提取成果进行叠加分析,统计变化情况.研究成果表明,矿区2014年复绿成效比2013年明显,矿区复绿面积占56.35％,恢复植被任务仍需继续完成.  相似文献   

Urban green commons: Insights on urban common property systems   总被引：1，自引：0，他引：1  

Johan Colding  Stephan Barthel  Pim Bendt  Robbert Snep  Wim van der Knaap  Henrik Ernstson 《Global Environmental Change》2013,23(5):1039-1051

The aim of this paper is to shed new light on urban common property systems. We deal with urban commons in relation to urban green-space management, referring to them as urban green commons. Applying a property-rights analytic perspective, we synthesize information on urban green commons from three case-study regions in Sweden, Germany, and South Africa, and elaborate on their role for biodiversity conservation in urban settings, with a focus on business sites. Cases cover both formally established types of urban green commons and bottom-up emerged community-managed habitats. As our review demonstrates, the right to actively manage urban green space is a key characteristic of urban green commons whether ownership to land is in the private, public, the club realm domain, or constitutes a hybrid of these. We discuss the important linkages among urban common property systems, social–ecological learning, and management of ecosystem services and biodiversity. Several benefits can be associated with urban green commons, such as a reduction of costs for ecosystem management and as designs for reconnecting city-inhabitants to the biosphere. The emergence of urban green commons appears closely linked to dealing with societal crises and for reorganizing cities; hence, they play a key role in transforming cities toward more socially and ecologically benign environments. While a range of political questions circumscribe the feasibility of urban green commons, we discuss their usefulness in management of different types of urban habitats, their political justification and limitation, their potential for improved biodiversity conservation, and conditions for their emergence. We conclude by postulating some general policy advice.  相似文献   

第四纪与环境     

李秉成 《地球科学与环境学报》2001,23(2):63-64

目前最大的环境问题是由人类排放CO  相似文献   

Doppler shift measurements on the green coronal line—evidence for largescale macroscopic mass motion     

J. N. Desai  T. Chandrasekhar  P. D. Angreji 《Journal of Astrophysics and Astronomy》1982,3(1):69-77

Fabry-Perot interferometric observations on the green coronal line (λ 5303 å) carried out during the total solar eclipse of 1980 February 16 have yielded relative Doppler shift velocities with an accuracy of ± 7 km s^-1. The values show a peak in the 30–50 km s^-1 range indicating largescale macroscopic mass motion in the solar maximum corona.  相似文献   

Événements panafricains dans l'Adrar Souttouf (Sahara marocain)     

Michel Villeneuve  Hervé Bellon  Abdelkrim El Archi  Mohamed Sahabi  Jean-Pierre Rehault  Jean-Louis Olivet  Abdel M. Aghzer 《Comptes Rendus Geoscience》2006,338(5):359-367

The Adrar Souttouf belt (Western Sahara) lies in the northern part of the Mauritanide belt and was considered as a part of the Hercynian Mauritanian-Appalachian belt. Recently the presence of a Panafrican protolith (595 Ma) was evidenced by the age of inherited zircons from an eclogitic unit and led to consider complex Panafrican events included in the Hercynian belt, as in the central and southern Mauritanide belt. Our new field survey completed by ten KAr dating (whole rocks and separate minerals) confirmed that multiphased Panafrican formations outcrop within the center of the Adrar Souttouf massif. Diverse events ranged from ca. 1000 to 500 Ma, some of them being indicative of an oceanic type environment and metamorphism. The 1000 Ma metamorphic event is recorded for the first time in the West African craton. A large Hercynian remobilisation is also evidenced. To cite this article: M. Villeneuve et al., C. R. Geoscience 338 (2006).  相似文献   

基于RS的宁波市绿地空间分布的GIS初步研究     

方金林  邹逸江 《东北测绘》2012,(1):13-19

随着城市环境问题的日益突出,建立宁波市绿地空间分布信息系统有重要的意义。本文应用RS与GIS等现代技术最新理论和方法对宁波市绿地空间分布进行分析,提出宁波市绿地空间分布GIS的体系结构,详细设计了系统的实现技术路线和途径。  相似文献