On the lack of seismic discontinuities within the inner core   总被引：1，自引：0，他引：1  

F. Leyton  K. D. Koper  L. Zhu  M. Dombrovskaya 《Geophysical Journal International》2005,162(3):779-786

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Drilling-induced remanent magnetization in basalt drill cores     

Haraldur Audunsson  Shaul Levi 《Geophysical Journal International》1989,98(3):613-622

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The Geomagnetic Spectrum For 1980 and Core-Crustal Separation     

Joseph C. Cain  Zhigang Wang  Dave R. Schmitz  J. Meyer§ 《Geophysical Journal International》1989,97(3):443-447

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The effect of refreezing on the isotopic composition of melting snowpack     

Shiqiao Zhou  Masayoshi Nakawo  Shigemasa Hashimoto  Akiko Sakai 《水文研究》2008,22(6):873-882

The isotopic composition of solid and liquid portions of natural melting snowpack is investigated in detail by the separating of liquid water from snow grains at different depths of the snowpack. The slope of the δD–δ¹⁸O line for the liquid phase is found to be lower than for the solid phase. This is proved to be due to the isotopic fractionation occurring in the melt–freeze mass exchange within the snowpack. Melting of the snowpack has no clear impact on the δD–δ¹⁸O line for the solid phase, but the slope of the δD–δ¹⁸O line for the liquid shows an overall slight decrease in the melting period. When the snowpack is refrozen, the refreezing process would inevitably cause the slope of the solid phase to decrease because of the discrepancy between the slopes of the two phases. Thus the slope of the solid would become lower and lower as the diurnal melt–freeze episodes cycle throughout the melting season. This effect is then demonstrated by looking into the isotopic composition changes of glacier firn. The extent of the effect depends on the snowpack properties and environmental conditions. The slope changes also result in a decreasing trend in deuterium excess. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

基于CAN总线的自动气象监测系统中的设计   总被引：1，自引：0，他引：1  

李源鸿  敖振浪 《成都信息工程学院学报》2003,18(1):20-23

提出基于CAN总线具有很强扩展能力、能灵活配置，可满足各种不同应用和需求的自动气象监测系统。重点介绍系统的硬件和软件的设计方法。  相似文献   

Seasonal air temperature variations retrieved from a Geladaindong ice core, Tibetan Plateau     

ZHANG Yongjun  KANG Shichang  QIN Dahe  REN Jiawen  ZHANG Yulan  Bjorn GRIGHOLM  Paul MAYEWSKI 《地理学报》2007,17(4):431-441

A 70-year history of precipitation δ18O record has been retrieved using an ice core drilled from a plat portion of the firn area in the Guoqu Glacier (33o34′37.8″ N, 91o10′35.3″ E, 5720 m a.s.l.) on Mt. Geladaindong (the source region of Yangtze River) during October and November, 2005. Based on the seasonality of δ18O records and the significant positive rela-tionships between monsoon/non-monsoon δ18O values and summer/spring air temperature from the nearby meteorological stations, the history of summer and spring air temperature have been reconstructed for the last 70 years. The results show that both summer and spring air temperature variations present similar trends during the last 70 years. Regression analysis indicates that the slope of the temperature-δ18O relationship is 1.3℃/‰ for non-monsoon δ18O values and spring air temperature, and 0.4℃/‰ for monsoon δ18O values and summer air temperature. Variation of air temperature recorded in the ice core is consistent with that in the Northern Hemisphere (NH), however, the warming trend in the Geladaindong region is more intense than that in the NH, reflecting a higher sensitivity to global warming in the high elevation regions. In addition, warming trend is greater in spring than in summer.  相似文献   

基于Srtm-DEM与遥感的长白山基本地貌类型提取方法   总被引：5，自引：0，他引：5  

龙恩  程维明  周成虎  姚永慧  刘海江 《山地学报》2007,25(5):557-565

基于中国1∶100万数字地貌制图工作,以吉林省长白山区为试验区,对基于Srtm-DEM与遥感提取基本地貌类型方法进行了探讨。研究表明,基于Srtm-DEM派生的各种模型对基本地貌类型自动提取具有很大的实效性:其中坡度3.5°是实现该区平地和山地宏观地貌单元自动提取的最佳断点,高程模型及起伏度模型相结合,可初步实现基本地貌类型的自动提取,其结果可很好的反应区域地貌宏观规律;在此基础上,基于30 m空间分辨率的遥感影像,综合运用区域地质、土地利用、植被、土壤等多地理要素信息及制图综合知识,以及地貌单元的完整性特征,以山脊线、坡折线和山麓线为地貌单元的标志线,基于地貌知识的专家修正,可获得研究区完整的基本类型地貌单元,实现了基于Srtm-DEM与遥感的基本地貌类型的智能化提取;最后,以研究区内1∶50万地貌图为准,对提取结果进行定性、定量评价分析表明,其提取总体精度达76%,面积相差较小;该方法在一定程度上改进了传统手工和野外调查为主的提取方法,实现了地貌信息的数字化、定位化及定量化,为全国1∶100万数字地貌信息提取与集成奠定了基础。  相似文献   

济南市旅游产业核心竞争能力研究   总被引：1，自引：0，他引：1  

于杰  孙瑛  王兴杰 《地域研究与开发》2007,26(6):89-92

在分析济南市旅游产业发展存在问题的基础上,根据核心竞争能力理论,构建了济南市旅游产业核心竞争能力框架结构.认为核心竞争能力是济南旅游产业持续发展的源泉所在,如果济南市旅游产业要在激烈的市场竞争中荻取竞争优势,就必须识别和构建自己的核心竞争能力,因此,分别从企业家型的政府、旅游资源特色、旅游人力资源的积累和培养、旅游企业的品牌建立、旅游企业服务质量的提高、旅游危机管理的能力等因素进行了系统阐述,并就今后的发展方向提出建议和具体措施.  相似文献   

A search for the Slichter modes in superconducting gravimeter records using a new method   总被引：1，自引：0，他引：1  

J. Y. Guo  O. Dierks  J. Neumeyer  C. K. Shum 《Geophysical Journal International》2007,168(2):507-517

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应用MAPGIS制作地球化学图单元素异常图及综合异常图   总被引：1，自引：0，他引：1  

袁义生  刘应忠  罗明学  何彦南 《贵州地质》2007,24(2):156-160

利用MAPGIS离散数据网格化模型绘制地球化学图,通过四种不同的网格化方法效果对比,在元素含量分析数据极差相对较小时,采用Kring泛克立格法网格化模型绘制的地球化学图效果佳。分析数据极差相对较大时,采用距离幂函数反比加权网格化模型绘制的地球化学图效果较好。两种数据网格模型绘制的地球化学图均达到化探规范中对地球化学图的要求,因此提出了应用MAPGIS制作地球化学等含量线图,利用地球化学等含量线图的属性,绘制单元素异常图及综合异常图。  相似文献