兰州市人体舒适度预报系统开发研制   总被引：6，自引：0，他引：6  

许东蓓  王小勇  黄玉霞  杨民  何金梅 《干旱气象》2003,21(1):20-23

利用兰州市197l-2000年气象资料，统计分析各气象要素的变化规律，并探讨其对人体舒适度的影响。在国内外人体实验和有关研究方法基础上，结合本地特殊的气候状况，建立了与人体舒适度有关的8个指数的计算方法和相应的预报等级，并在预报实践中进行了效果检验和参数订正，可以满足兰州市气象指数预报业务的需要。  相似文献   

The spacetime gravitational field of a deformable body   总被引：3，自引：0，他引：3  

E. W. Grafarend  J. Engels  P. Varga 《Journal of Geodesy》1997,72(1):11-30

The high-resolution analysis of orbit perturbations of terrestrial artificial satellites has documented that the eigengravitation of a massive body like the Earth changes in time, namely with periodic and aperiodic constituents. For the space-time variation of the gravitational field the action of internal and external volume as well as surface forces on a deformable massive body are responsible. Free of any assumption on the symmetry of the constitution of the deformable body we review the incremental spatial (“Eulerian”) and material (“Lagrangean”) gravitational field equations, in particular the source terms (two constituents: the divergence of the displacement field as well as the projection of the displacement field onto the gradient of the reference mass density function) and the `jump conditions' at the boundary surface of the body as well as at internal interfaces both in linear approximation. A spherical harmonic expansion in terms of multipoles of the incremental Eulerian gravitational potential is presented. Three types of spherical multipoles are identified, namely the dilatation multipoles, the transport displacement multipoles and those multipoles which are generated by mass condensation onto the boundary reference surface or internal interfaces. The degree-one term has been identified as non-zero, thus as a “dipole moment” being responsible for the varying position of the deformable body's mass centre. Finally, for those deformable bodies which enjoy a spherically symmetric constitution, emphasis is on the functional relation between Green functions, namely between Fourier-/ Laplace-transformed volume versus surface Love-Shida functions (h(r),l(r) versus h ^′(r),l ^′(r)) and Love functions k(r) versus k ^′(r). The functional relation is numerically tested for an active tidal force/potential and an active loading force/potential, proving an excellent agreement with experimental results. Received: December 1995 / Accepted: 1 February 1997  相似文献   

新疆及邻区强震发生的深部条件与坚固体孕震模式的新证据   总被引：7，自引：0，他引：7  

梅世蓉 《内陆地震》1997,11(2):97-102

根据新疆及其邻近地区地壳，上地幔三维结构的最新研究结果，联系这个地区的强震震源分布、剖析强震孕良，发生的深部构造特征，结果表明：该区浅源强震与中原强震的震源均位于地壳或上地幔速度结构横向，纵向非均匀性较明显的地区，且位于相应层内的高速扰动区或高低速过渡带中，从而有力一证明了“坚固体孕震模式”的合理性。  相似文献   

室内土工模型试验的新方法——桩基渗水力土工模型试验     

方磊  李广信 《高校地质学报》1997,3(4):451-457

本文通过桩基渗水力工模型试验实例，介绍了一种新的室内土工模型试验方法－渗水力土工模型试验。它利用水在土体中的渗流来提供土工模型试验中必须的体积力，因而克服了常规模型试验和离心模型试验中一些缺陷。该方法在桩基研究及工程实际中具有良好的应用前景。  相似文献   

北淮阳金寨—苏仙石地区中生代花岗岩类岩石学及地球化学特征   总被引：4，自引：4，他引：4  

李家振  刘文灿 《现代地质》1997,11(1):102-110

位于大别山北麓的北淮阳金寨—苏仙石地区广泛发育花岗岩类侵入岩，同位素年龄为１４０～９７Ｍａ，时代属Ｊ３—Ｋ１。根据侵入岩的地质、岩石学和岩石地球化学特征，将本区侵入岩划分为３个超单元（包括１０个单元）和３个独立单元，分属中性岩和酸性岩两大类，岩石类型有闪长岩、二长岩和花岗岩等。根据岩石化学的判别结果，侵入岩均属亚碱性系列中的钙碱性岩石，并属于普通型和钾质型  相似文献   

略阳─石泉边界地质体特征   总被引：4，自引：0，他引：4  

王根宝  吴闻人  张升全 《陕西地质》1997,(1)

略阳─石泉构造带是一板块缝合带，经历了长期复杂的演化历史。现由不同时期、不同构造体制下的断裂构造系统，裹挟不同构造演化阶段的各类建造─蛇绿混杂岩、陆缘楔状体，岛孤岩浆岩及外来岩块等，共同组成了分隔秦岭、扬子地块的一个特殊边界地质体。  相似文献   

宝鸡岩体颜家河超单元岩浆反序演化特征     

吴宏恩 《陕西地质》1997,(1)

本文依据宝鸡岩体颜家河超单元各单元的岩石组构、矿物成分、岩石化学和地球化学等方面的资料，研究了它们由早到晚的变化特征，并将各种特征有机地联系在一起，发现该超单元岩浆从早到晚存在着反序演化的特点，即由偏酸性岩浆向偏基性岩浆演化，并建立了该超单元的岩浆演化模式。  相似文献   

The mechanisms of shallow earthquakes and the monitoring of a comprehensive test ban     

David Bowers  David A. McCormack 《Geophysical Journal International》1997,128(3):701-707

The ability of seismological criteria to identify earthquakes from underground explosions depends partly on the orientation of the earthquake source. Well-determined double-couple moment tensor solutions for a large number of earthquakes have been published in the Harvard centroid moment tensor (CMT) and United Slates Geological Survey (USGS) catalogues. Statistical analyses of these catalogues indicate that the distribution of the orientation of earthquake mechanisms is not random. The distribution of the T axes shows significant clustering around the downward vertical, indicating that a larger number of earthquake mechanisms radiate compressional P -wave energy to teleseismic distances from near the maximum of the radiation pattern than is predicted if earthquake sources are randomly oriented double couples. The clustered T axes correspond to compressional dip-slip mechanisms, and it is this type of mechanism which is believed to cause both the m _b: M _s (the ratio of body-wave to surface-wave magnitude) and first-motion criteria to misidentify an earthquake as an explosion.  相似文献   

Deconvolution of teleseismic recordings for mantle structure     

M. G. Bostock  M. D. Sacchi 《Geophysical Journal International》1997,129(1):143-152

Delineation of detailed mantle structure frequently requires the separation of source signature and structural response from seismograms recorded at teleseismic distances. This deconvolution problem can be posed in a log-spectral domain where the operation of time-domain convolution is reduced to an additive form. The introduction of multiple events recorded at many stations leads to a system of consistency equations that must be honoured by both the source time functions and the impulse responses associated with propagation paths between sources and receivers. The system is inherently singular, and stabilization is accomplished through the supply of an initial estimate of the source time function. Although alternative choices exist, an effective estimate is derived from the eigenimage associated with the largest eigenvalue in a singular-value decomposition of the suite of aligned seismograms corresponding to a given event. The relation of the deconvolution scheme to simultaneous least-squares deconvolution is examined. Application of the methodology to broadband teleseismic P waveforms recorded on the Canadian National Seismograph Network demonstrates the retrieval of effective Green's functions including secondary phases associated with upper-mantle structure.  相似文献   

Observability of the isotropic component of a moment tensor     

Hitoshi Kawakatsu 《Geophysical Journal International》1996,126(2):525-544

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