水泥粉体深层喷射搅拌桩复合地基处理及其效果     

程礼来  郜云峰  苗先文  段宗贵 《河南国土资源》1998,(1)

水泥粉体深层喷射搅拌桩与干振碎石桩〔１〕、干振灰土桩等一样,也是处理松软地基土的一种有效方法。但与干振碎石桩等其他挤密型复合地基处理方法不同,水泥粉体深层喷射搅拌桩属于摩擦桩型。由于天然地基土对桩体的侧摩擦力和端阻力的共同作用,使复合地基的承载力大幅度提高。然而人们普遍认为,水泥粉体深层喷射搅拌桩法复合地基处理不能解决场地土的液化问题。本文通过工程实例和瑞雷波检测结果,证实了该方法处理的复合地基,除了承载力有较大幅度的提高外,地基土的抗液化能力也可以得到相应的加强。  相似文献   

1976年云南龙陵7．4级地震序列分析   总被引：5，自引：0，他引：5       下载免费PDF全文

左兆荣  张国民 《地球物理学报》1996,39(5):653-659

地震成核是地震孕育过程中的一个至关重要的阶段，加速是成核过程的一个属性，也是地震失稳破裂的一个必要条件．地震加速释放是成核在脆性层中的大地震的普遍前兆，且可将该加速过程简要地概括为地震释放速率正比于失稳破裂剩余时间的负幂．基于这一原理，对１９７６年５月２９日云南龙陵Ｍ_ｓ７．４级地震序列进行回顾性分析，表明主震及后续显著地震的失稳破裂时间和震级可成功地被估算，但要求所测系数ｒ^２  相似文献   

Decrease in the mechanical energy of the solar system due to tidal friction     

Milan Burša 《Studia Geophysica et Geodaetica》1996,40(4):339-352

Summary The total decrease in the mechanical energy of the Solar System due to the tidal friction during its whole history has been estimated at 1·7 × 10³³ kg m² s^–2 which is about 0·85% of its present energy integral. The main contributions come from Sun-Jupiter (63·4%), Sun-Saturn (26·6%), Sun-Neptune (5·9%), Sun-Uranus (3·7%), all satellite systems (0·2%), Sun-Venus (0·1%).  相似文献   

Poets and narrators from Mendoza and their local perceptions     

Prof.  Dr. María E. de Civit Furlani  Prof.  Dr. María J. de Manchón Gutiérrez 《GeoJournal》1996,38(1):109-118

This article outlines three modalities of relation between literature and geography: the literary work as demonstrative element, the literary work as collective image, and the literary work as analogous process. The verification of the three modalities takes place through an approachment to the local literature using a geographical concept, namely region, and a particular area: the province of Mendoza, in western Argentina. Ten literary works of different genre were selected to which content analysis was applied. First the relevance of these representations at the initiation of geographical research is verified and then the way in which they stimulate the definition of problems and the formulation of hypotheses is addressed.  相似文献   

南极磷虾的生长与复眼直径关系的研究          下载免费PDF全文

孙松  王荣 《极地研究》1996,8(1):4-11

本文对南极磷虾复眼的直径与磷虾体长之间的关系、在负生长状态下磷虾复眼直径的变化等进行了研究。实验结果表明：在正常情况下（磷虾身体不出现负生长），磷虾复眼的直径与体长之间存在指数函数关系。雌性磷虾的眼径（ＥＤ）与体长（ＢＬ）之间的关系为：ＥＤ＝０．５８９８ｅ０．０２８２ＢＬ（ｒ＝０．９６１３，ｎ＝２４１９）；雄虾的眼径与体长之间的关系为：ＥＤ＝０．５４４ｅ０．０３０９ＢＬ（ｒ＝０．９６２２，ｎ＝１９２０）。在相同体长的情况下，雄性磷虾的复眼直径比雌虾的大。从活体培养的结果来看，当南极磷虾出现负生长时，复眼直径保持不变，即眼径不受负生长的影响。在正常情况下（不存在负生长），雌虾的体长与眼径之间的比率（ＢＬ／ＥＤ）平均为２１．３２±０．０４（ｎ＝１３４７），雄虾的体长与眼径之间的比率平均为２０．６８±０．０７（ｎ＝７４８），未成体虾的体长与复眼直径之间的比率平均为２１．５４±０．０６（ｎ＝１０７２）。利用体长与眼径之间的比率可以准确地将在实验室内活体培养后已存在负生长的磷虾与其它处于正常状态的磷虾分开。体长与眼径之间的比率也可以作为磷虾种群是否存在负生长的监测指标  相似文献   

High-Latitude Springtime Photochemistry. Part Ii: Sensitivity Studies of Ozone Production     

John a. Herring  Daniel a. Jaffe  Harald J. Beine  Sasha Madronich  Donald R. Blake 《Journal of Atmospheric Chemistry》1997,27(2):155-178

A seven-year record of surface ozone measurements from Denali NationalPark, Alaska shows a persistent spring maximum. These data, combined withmeasurements of NO_x, hydrocarbons, O₃, and PANfrom a continental site in Alaska during the spring of 1995 are used as thebasis for a sensitivity study to explore tropospheric photochemistry in thisregion. Because of the relatively high concentrations of NO_x(mean of 116, median of 91 pptv), the net tendency was for photochemicalozone production. The range of net O₃ production for averageconditions measured at this site during spring is between 0.96–3.9ppbv/day depending on the assumptions used; in any case, this productionmust contribute to the observed springtime maximum in O₃.Model calculations showed that of the anthropogenic ozone precursors, onlyNO_x had a strong effect on the rate of ozone production; themeasured concentrations of anthropogenic hydrocarbons did not significantlyaffect the ozone budget. Naturally produced biogenic hydrocarbons, such asisoprene, may also have a significant effect on ozone production, even atconcentrations of a few 10's of pptv. An observed temperature-isoprenerelationship from a boreal site in Canada indicates that isoprene may bepresent during the Alaskan spring. Measurements of isoprene taken duringthe spring of 1996 suggest that reactive biogenic hydrocarbon emissionsbegin before the emergence of leaves on deciduous trees and that theconcentrations were sufficient to accelerate ozone production.  相似文献   

Linear stability of a non-constantly stratified horizontal layer penetrated by an azimuthal magnetic field     

Ján Boďa  Gustáv Siráň  Reviewer P. Hejda 《Studia Geophysica et Geodaetica》1988,32(3):272-286

Summary The convection in a rapidly rotating, electrically conducting, horizontal fluid layer, non-constantly stratified and penetrated by an inhomogeneous magnetic field, is studied. The convection is investigated for various ratios of the thickness of the stable and unstable stratified part of the layer. The thermal model of the layer, as well as the analysis of the results have been treated with regard to the physical conditions in the liquid core of the Earth.

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Determination of tidal torques independently of densities     

Milan Burša  Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1986,30(2):118-123

Summary The components of the tidal torques along the axes of the inertia ellipsoid of a perfectly elastic Earth have been derived quite independently of the density distribution of masses within the Earth. It has been demonstrated that not only the sectorial, but also the tesseral terms in the tidal forming potential are responsible for the tidal deceleration of the Earth's rotation.

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Normal density earth models   总被引：1，自引：0，他引：1  

Zedeněk Martinec  Karel Pěč  Reviewer M. Burša 《Studia Geophysica et Geodaetica》1986,30(2):124-147

Summary Models of the Earth's density, close to thePREM model, have been derived, they reproduce the external normal gravitational field of the Earth and its dynamic flattening, and are referred to as normal density models. The Earth's surface is approximated by an ellipsoid of the order of the flattening, or of its square. Of the group of normal models sgtisfying the solution of the inverse problem, the normal density modelHME2 is recommended. The spherically symmetric density modelPREM, which was corrected in the course of solving the inverse problem, thus creating the modifiedPREM-E2 model, was used as the a priori information.

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对流运动中水平旋转气流动力作用的数值分析   总被引：1，自引：1，他引：1       下载免费PDF全文

徐文俊  马骥德  解东 《大气科学》1985,9(1):82-91

用轴对称动力方程组研究对流运动中水平旋转气流的作用,结果表明,有水平旋转气流存在时,将使对流运动中下部的上升气流明显加强,上部减弱,使调整后的垂直气流结构强度增加,强中心高度变低,对流厚度变薄.这有利于解释超级单体的稳定持续发展和对流强度大而云层并不厚的观测事实. 通过对气压场调整的分析,可以认为水平旋转气流对垂直运动的作用是通过气压场的变更而实现的.  相似文献