Central configurations of the n-body problem with a general force function (i) — fundamental equations and theoretical analysis AAnS 33/2 (1992) 186–193     

Fu Yan-ning

Sun Yi-sui 《Chinese Astronomy and Astrophysics》1992,16(4):474

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Field studies on dynamic properties of reinforced earth     

S. Boominathan

K. Senathipathi

V. Jayaprakasam 《Soil Dynamics and Earthquake Engineering》1991,10(8):402-406

The concept of reinforced earth has not become popular in the case of foundations for buildings. Presumably, the practical difficulties in application and the exorbitant cost have outweighed the beneficial aspects of ‘Reinforced Earth’ in such applications. Block foundations which are usually provided for machines to take care of the dynamic loads are small and compact and the improvement of the base with reinforcements should not be a difficult or impractical proposition. In this investigation, the feasibility of improving the dynamic properties of soil b ase by applying high modulus materials, such as steel wires and low modulus materials as geotextiles, and a combination of both have been studied in a standard forced vertical block resonance test. The feasibility and the supremacy of the ‘Reinforced Earth’ with the reinforced bases of (i) mild steel frame stiffened with high tensile wires (ii) sand coated geotextiles with the inclusion of a thin layer of frictional sand and (iii) sand coated geotextiles stiffened with welded mesh, have been brought out.  相似文献   

Quasilongitudinal approximation for whistler-mode waves in the magnetospheric plasma     

S. S. Sazhin

R. B. Horne 《Planetary and Space Science》1990,38(12):1551-1553

The range of applicability of an improved quasilongitudinal approximation for whistler-mode waves in the equatorial magnetosphere (4 L 6.6) is specified based on the direct comparison between numerical solutions of the hot electromagnetic dispersion equation with the corresponding analytical quasilongitudinal solutions. It is pointed out that this approximation can be used at frequencies ω less than but not close to the electron gyrofrequency Ω (ω 0.6 Ω) and wave normal angles θ less than but not close to the resonance cone angle θ_R. At ω = 0.8 Ω the analytical results deviate considerably from numerical ones due to the strong damping of the waves, and so the quasilongitudinal solution becomes no longer valid.  相似文献   

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廖超明  武军郦 《大地测量与地球动力学》2009,29(5):22-26

????1998??2009?????GPS?????????о???????壨18.5??25.5??104.5??112.0????ITRF2000????μ??????????????????????ο?????μ?????α????????????????????????????о????滪???????NE115?????????????????????33.5 mm/a?????????????3.5 mm/a??????????????????  相似文献   

Structural Characteristics and Formation Mechanism in the Micangshan Foreland,South China   总被引：2，自引：1，他引：1  

XU Huaming LIU Shu QU Guosheng LI Yanfeng SUN Gang LIU Kang Institute of Geology  China Earthquake Administration  Beijing  China Southwestern Division Company of SINOPEC  Deyang  Sichuan    China National Earthquake Response Support Service  Beijing  China 《《地质学报》英文版》2009,83(1)

Lying at the junction of the Dabashan,Longmenshan and Qinling mountains,the Micangshan Orogenic Belt coupled with a basin is a duplex structure and back-thrust triangular belt with little horizontal displacement,small thrust faults and continuous sedimentary cover.On the basis of 3D seismic data,and through sedimentary and structural research,the Micangshan foreland can be divided into five subbelts,which from north to south are:basement thrust,frontal thrust,foreland depression-back-thrust triangle,fore...  相似文献   

Speleogenesis of Selected Caves beneath the Lunan Shilin and Caves of Fenglin Karst in Qiubei, Yunnan   总被引：2，自引：1，他引：1  

Stanka EBELA  Tadej SLABE  Petr PRUNER 《《地质学报》英文版》2004,78(6):1289-1298

Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S  相似文献   

Cretaceous Oceanic Redbeds: Implications for Paleoclimatologyand Paleoceanography   总被引：4，自引：0，他引：4  

WANG Chengshan  HUANG Yongjian  HU Xiumian  LI Xianghui State Key Laboratory of Oil/Gas Reservoir Geology  Exploration  Chengdu Universityof Technology  Chengdu  Sichuan  College of Earth Science  Chengdu University of Technology  Chengdu  Sichuan Department of Earth Science  Nanjing University  Nanjing  Jiangsu China University of Geosciences  Beijing 《《地质学报》英文版》2004,78(3):873-877

The Cretaceous is among the most unusual eras in the geological past. Geoscience communities have been having great concerns with geological phenomena within this period, for example carbonate platforms and black shales in the Early and Middle Cretaceous respectively, during the last decades. But few people have paid any attention to the set of pelagic redbeds lying on the black shales, not to mention the applications to paleoclimatology and paleoceanography. It is shown by the sedimentary records of redbeds, that they were deposited around the CCD, with both a higher content of iron and much lower concentrations of organic carbon, which implies conditions with a  相似文献   

Intercomparison of NO_x, SO_2, O_3, and Aromatic Hydrocarbons Measured by a Commercial DOAS System and Traditional Point Monitoring Techniques   总被引：1，自引：0，他引：1  

谢品华  刘文清  付强  王瑞斌  刘建国  魏庆农 《大气科学进展》2004,21(2)

A field-based Intercomparison study of a commercial Differential Optical Absorption Spectroscopy (DOAS) instrument (OPSIS AB, Sweden) and different point-sample monitoring techniques (PM, based on an air monitoring station, an air monitoring vehicle, and various chemical methods) was conducted in Beijing from October 1999 to January 2000. The mixing ratios of six trace gases including NO, NO2, SO2, O3, benzene, and toluene were monitored continuously during the four months. A good agreement between the DOAS and PM data was found for NO2 and SO2. However, the concentrations of benzene, toluene, and NO obtained by DOAS were significantly lower than those measured by the point monitors. The ozone levels monitored by the DOAS were generally higher than those measured by point monitors. These results may be attributed to a strong vertical gradient of the NO-O3-NO2 system and of the aromatics at the measurement site. Since the exact data evaluation algorithm is not revealed by the manufacturer of the DOAS sys  相似文献   

滇西保山地块下石炭统的新发现及特征   总被引：1，自引：0，他引：1  

姚金昌  赵成峰 《地层学杂志》2004,28(2):173-178

在区域地质调查过程中在保山地块的东部发现了一套与原下石炭统明显不同的沉积组合,定为下石炭统张家田组,岩石以出现较多碎屑岩、凝灰岩及夹两层蚀变玄武岩为重要特征,产丰富的牙形石化石,可分为三个生物带,时代为早石炭世岩关期一大塘早期。  相似文献   

赣南大吉山五里亭岩体的锆石ELA-ICP-MS定年及其与钨成矿关系的新认识   总被引：39，自引：3，他引：36  

邱检生  McInnes BIA  徐夕生  Allen C M 《地质论评》2004,50(2):125-133

大吉山是南岭地区一个著名的大型钨多金属矿床,五里亭岩体是矿区出露规模最大的火成岩体,岩性为中粗粒似斑状黑云母二长花岗岩。锆石 ELA-ICP-MS 定年结果表明其形成年龄为 237.5±4.8 Ma,属印支期岩浆活动的产物。与南岭地区典型钨多金属矿床成矿岩体相比,五里亭岩体贫硅,富钙、镁、铁,Rb/Sr、Rb/Ba 和 U/Th 比值低,K/Rb 比值高,铕负异常不显著,分异指数低,尚未达到矿化岩体的分异演化程度,不具备矿化岩体的地球化学特征。元素—同位素综合示踪显示区内白云母碱长花岗岩为五里亭岩体经高度分异演化的产物,它与钨多金属矿成矿直接有关。矿区范围内出露的闪长岩起源于地幔,这一岩浆侵位所引起的高热场环境有利于花岗质岩石的形成与演化,对成矿具有重要的意义。  相似文献