SHORT COMMUNICATION THE RELATIONSHIP OF CLOSURE,MEAN CENTERING AND MATRIX RANK INTERPRETATION

This paper describes an investigation into the relationship of closure,a baseline offset and mean centeringto the interpretation of matrix rank.The equivalence of a certain type of closure to a constant baseline(i.e.a simple numerical offset which may vary between response channels but is constant over all samples)is demonstrated.A systematic approach to the interpretation of the rank of a matrix is given.     

Attitude dynamics and control of spacecraft using geomagnetic Lorentz force

Attitude stabilization of a charged rigid spacecraft in Low Earth Orbit using torques due to Lorentz force in pitch and roll directions is considered. A spacecraft that generates an electrostatic charge on its surface in the Earth's magnetic field will be subject to perturbations from the Lorentz force. The Lorentz force acting on an electrostatically charged spacecraft may provide a useful thrust for controlling a spacecraft's orientation. We assume that the spacecraft is moving in the Earth's magnetic field in an elliptical orbit under the effects of gravitational, geomagnetic and Lorentz torques. The magnetic field of the Earth is modeled as a non-tilted dipole.A model incorporating all Lorentz torques as a function of orbital elements has been developed on the basis of electric and magnetic fields. The stability of the spacecraft orientation is investigated both analytically and numerically. The existence and stability of equilibrium positions is investigated for different values of the charge to mass ratio(α*). Stable orbits are identified for various values of α*. The main parameters for stabilization of the spacecraft are α*and the difference between the components of the moment of inertia for the spacecraft.     

The mini-QSO's contribution to cosmic reionization

By employing an improved simulation of the evolution of black holes(BHs)based on the merger tree of dark matter halos,we explore the relationship between the central BH mass Mbh and velocity dispersion σflat high redshift z≥6 and quantify the mini-QSO's(with BH mass M=200-105M)contribution to cosmic reionization.The simulation demonstrates how seed BHs migrate onto the MBH-σ* relation by merging with each other and accreting gas at z≥6:1.The correlation between BHs and their host halos increases as the BHs ...     

Petroleum System of the Fula Depression at the Muglad Basin in the Central African Fault Zone

Petroleum system theory has been used to study characteristics of the Fula depression in the Central African fault zone.In this system,deep lacustrine facies mudstone in the Abu Gabra For-mation of the Lower Cretaceous is a very good source rock,thick deltaic facies sandstone of the Abu Gabra Formation and fluvial facies sandstone of the Bentiu Formation are good reservoir beds,and the mudstone in the Upper Cretaceous Darfur Group is the regional cap rock.The oil search mode and fault block trap seal-off co...     

NCAR RegCM2对1991年夏季江淮流域异常降水事件中关键物理过程的模拟能力检验(英文)

选取１９９１年夏季江淮流域发生的持续性特大暴雨洪涝个例，利用ＮＣＡＲ第二代区域气候模式ＲｅｇＣＭ２对逐日降水过程及其关键物理因子进行了数值模拟。模式的侧边界条件出ＥＣＭＷＦ的大尺度分析资料提供，模拟时间为１９９１年５－８月。模式范围包括东亚地区及相邻海域，水平分辨率为 ６０ ｋｍ × ６０ ｋｍ，垂直方向为 ２３层。试验结果显示，该模式能够合理地模拟出１９９１年夏季东亚地区的逐日降水过程，特别是在江淮流域发生的异常降水事件。对一些关键物理变量和过程时空结构的分析表明，大气垂直速度和水平散度的时间演变与江淮流域的５次降水事件一致；形成异常降水的水汽来源主要是大气的水平运动输送。西太平洋副热带高压控制着东亚夏季季风的进退，ＲｅｇＣＭ２能够模拟出西太平洋副高的南北位置移动。而且，模式能够较好地再现出对水汽输送至关重要的低空急流的逐日变化。     

Seasonal Characteristics of Surface Radiation Fluxes on the East Rongbuk Glacier in the Mt.Everest Region

Ground-based measurements are essential for understanding alpine glacier dynamics,especially in remote regions where in-situ measurements are extremely limited.Prom 1 May to 22 July 2005(the spring-summer period),and from 2 October 2007 to 20 January 2008(the autumn-winter period),surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m a.s.l.by using an automatic weather station(AWS).The...     

STABILIZING EFFECT OF BENTRIC ALGAE ON COHESIVE SEDIMENTS

I.INTRODUCTIONMOrphologicalprocessesinlotvlandriversaredond~actransportphenomenaoffineandcohesivesediments.AsthismaterialtendstobindtoxicagentsandthuSrepresentsapotentialdangerfortheaqUaticenvironmentitisofspotalinterestintennsOfwaterqualityinvestigations.BesidesthisapeOfenvironmentalprotectionfinesedimentsoftendepositinnavigationchannelsandimpedeshipping.implyingextensiveandexpensitredredging.Thesereasonsprot,e,thatthetranSPortbehal'iorOffinesedimentsshouldbeinvestigatedcarefullytogiv…     

带保温层压力管道CBS检测软件系统设计

目的 康普顿背散射扫描成像技术具有在线、单侧等优点,广泛应用于航空、航天、石油等领域。资料与方法 针对该技术在带保温层管道检测上的应用,给出了—套面向用户的检测软件。结果包括参数设置、能谱测量、扫描测量、三维显示以及保存打印等模块。结论 主控程序具有界面友好、简单易学等特点,本软件系统及应用该软件的扫描图像,显示效果良好。     

华北地区拆离滑脱带控震作用初探

华北东部盆岭区以地震多、震级大、损失惨重而称。以往地震地质研究多注重断裂交汇、拐点、分枝等部位的控震作用。但是,华北盆岭区多次大震的烈度并不呈线型展布,震源也并非沿陡倾断裂走向分布,而是在一定深度上(近水平)弥散展布,故人们开始注意深部滑脱带控震的探讨。笔依据近十余年华北地幔亚热柱的研究认为,华北断陷区之下为—强烈上隆的地幔亚热柱。地幔物质的上隆及上侵作用使上地壳裂解断陷,而中地壳在地幔、下地壳的影响下形成相间展布的低速—高导层。在地幔亚热柱热物质流向外拆离的带动下,中、下地壳亦由亚热柱顶部向外围拆离滑脱。当中、下地壳拆离到上地壳裂陷盆地边缘受到造山带的阻挡而减慢时,两之间便产生剪切作用,导致应力不断积聚并阶段性释放,从而造成亚热柱外围地震频繁发生。     

低渗透油藏薄差油水层解释方法研究

本文分析了影响永乐油田葡萄花油藏薄差油水层解释精度的因素,提出了永乐油田薄差层流体识别的有效方法,为外围油田新区钻井运行及射孔方案编制提供较为准确的基础数据。