Mobile-GIS中的数据组织模型研究   总被引：3，自引：0，他引：3  

刘召芹  谢彩香  王梅 《测绘与空间地理信息》2006,29(4):1-5

mob ile-GIS是GIS的全新发展领域,从应用的角度评述了移动服务中的数据特点和各种数据模型的原理及适用领域。不同的数据模型造成部门间数据难以共享,为此本文提出了一种集成数据模型,能使不同模型相互转化,提高数据共享程度。  相似文献   

高低空急流在闽西北大暴雨过程中的作用及数值模拟   总被引：9，自引：16，他引：9  

林毅  刘铭  刘爱鸣 《气象科学》2006,26(4):449-455

本文对2002年6月14~18日福建西北部地区的连续暴雨~大暴雨过程的诊断及模拟分析表明,在有利的环流背景条件下,高空急流的加强和动量下传,促使低空急流的建立和维持;低空急流的加强则提供了有利暴雨产生的高温高湿的大气条件;高低空急流的适宜配置,产生了动力场的耦合作用,为大暴雨的发生、发展提供了动力条件。  相似文献   

Using satellite remote sensing to survey transport-related urban sustainability: Part 1: Methodologies for indicator quantification     

Ying Zhang  Bert Guindon 《International Journal of Applied Earth Observation and Geoinformation》2006

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内核地球自转动力学理论的研究进展(Ⅳ)——内核自转动力学方程          下载免费PDF全文

张捍卫  许厚泽  王爱生 《地球物理学进展》2006,21(4):1139-1144

本文是序列文章的第四篇，其内容包括：基于连续介质力学的基本理论，给出了固体外核（SIC）自转的动力学方程，考虑了地球的自引力、液核对内核边界的压力和二阶外部引潮力位对SIC自转的影响，并在O(mε)的量级上给出了其实用的表达式.本文的理论推导更加严密和细致，改正了文献〔1〕在推导过程中的某些错误（例如：（B39）、（B44）和（B59c）式）.本文的工作是对文献〔1〕有关理论的扩展和改进，对进一步研究内核地球自转的动力学理论是非常重要的.  相似文献   

长输管道抗震研究的新进展   总被引：2，自引：0，他引：2  

陈贵清  郝婷玥  吴班  王兴国 《地震工程与工程振动》2006,26(3):193-196

本文主要从以下4个方面:地震对长输管道的危害、长输管道震害的研究方法、管道抗震分析和管道抗震的措施,介绍了近几年长输管道抗震方面的研究进展,指出了今后长输管道的研究方向。  相似文献   

Inertial theory of the mean Hadley circulation under the condition of nonstatic equilibrium     

CHAO Jiping  LIU Fei 《中国科学D辑(英文版)》2006,49(5):546-553

1 Introduction The mean meridional circulation plays an important role in the transportation and balance of heat, momen- tum, vortex and vapor between different latitudes. According to the data analysis, there are three circula- tions from the equator to the polar area: the Hadley circulation, a heat-driven circulation which rises around the equator and sinks at a certain latitude; the subpolar circulation, another heat-driven circulation around the polar area; and the Ferrel circulation, an i…  相似文献   

RFID技术在数字城市建设中的应用     

孙伟  马东洋  邹晓亮 《地理空间信息》2007,5(1):57-59

介绍了RFID的基本概念和特点,并对RFID技术进行详细地阐述,探讨了RFID技术在数字城市建设中的应用。  相似文献   

Addressing Hurricane Intensity through Angular Momentum and Scale Energetics Approaches     

T. N. Krishnamurti  L. Stefanova  L. Watson  S. Pattnaik 《Pure and Applied Geophysics》2007,164(8-9):1429-1441

This paper addresses two avenues for gaining insight into the hurricane intensity issue—the angular momentum approach and the scale interaction approach. In the angular momentum framework, the torques acting on a parcel's angular momentum are considered along an inflowing trajectory in order to construct the angular momentum budget. These torques are separable into three components: The pressure torque, the surface friction torque, and the cloud torque. All torques are found to diminish the angular momentum of an inflowing parcel, with the cloud torques having the most important role. In the scale interaction approach, energy exchanges among different scales within a hurricane are considered as a means of understanding hurricane intensity. It is found that the majority of kinetic energy contribution to the hurricane scales originates from potential-to-kinetic in-scale energy conversions. The contribution of mean-wave interactions in the kinetic energy varies with distance from the center and with the life stage of a storm. In the early stages, as the disorganized convection becomes organized on the hurricane scales, upscale energy transfers (i.e., from small to large scale) are found to take place in the outer radii of the storm. In a mature storm, the kinetic energy transfers are downscale, except for the inner radii.  相似文献   

西气东输管道工程中卫黄河穿越隧道场地工程地质条件评价     

曹兴山  卿春和 《工程地质学报》2007,15(3):338-345

西气东输工程中卫黄河穿越隧道长1197.77m,高4.3m,宽5.6m。隧道入口高于黄河水位28m,出口高于黄河水位45m。隧道顶板高程为1130m。位于黄河水下100m。隧道场地围岩为寒武系磨盘井组灰绿色、银灰色浅变质中厚层细粒长石石英砂岩、千枚状板岩、绢云母化千枚岩。围岩为弱风化Ⅲ～Ⅳ类岩石。透水率为4～67Lu,纵波波速为500～3300m.s-1。BQ为300～400。变形模量为6.11～9.22GPa。泊松比（）0.14～0.24。内摩擦角（）为42.1～44.7。地下水为基岩裂隙水。含水层为寒武系浅变质岩,受大气降水渗入补给,单井涌水量为1.0～50m3.d-1。隧道轴线穿越区岩体较完整较破碎,未有全新活动断层。隧道位置选择和开挖深度设计是可行的。施工和长期运营是安全的。  相似文献   

Diurnal atmospheric forcing and temporal variations of the nutation amplitudes     

C. Bizouard  A. Brzeziński  S. Petrov 《Journal of Geodesy》1998,72(10):561-577

A 29-year time-series of four-times-daily atmospheric effective angular momentum (EAM) estimates is used to study the atmospheric influence on nutation. The most important atmospheric contributions are found for the prograde annual (77 μas), retrograde annual (53 as), prograde semiannual (45 as), and for the constant offset of the pole (δψsinɛ₀=−86 as, δɛ=77 as). Among them only the prograde semiannual component is driven mostly by the wind term of the EAM function, while in all other cases the pressure term is dominant. These are nonnegligible quantities which should be taken into account in the new theory of nutation. Comparison with the VLBI corrections to the IAU 1980 nutation model taking into account the ocean tide contribution yields good agreement for the prograde annual and semiannual nutations. We also investigated time variability of the atmospheric contribution to the nutation amplitudes by performing the sliding-window least-squares analysis of both the atmospheric excitation and VLBI nutation data. Almost all detected variations of atmospheric origin can be attributed to the pressure term, the biggest being the in-phase annual prograde component (about 30 as) and the retrograde one (as much as 100200 as). These variations, if physical, limit the precision of classical modeling of nutation to the level of 0.1 mas. Comparison with the VLBI data shows significant correlation for the retrograde annual nutation after 1989, while for the prograde annual term there is a high correlation in shape but the size of the atmospherically driven variations is about three times less than deduced from the VLBI data. This discrepancy in size can be attributed either to inaccuracy of the theoretical transfer function or the frequency-dependent ocean response to the pressure variations. Our comparison also yields a considerably better agreement with the VLBI nutation data when using the EAM function without the IB correction for ocean response, which indicates that this correction is not adequate for nearly diurnal variations. Received: 10 September 1997 / Accepted: 5 March 1998  相似文献