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11.
针对牙轮钻头的滑动轴承和滚动轴承在实际工作中所存在的问题,提出一种牙轮钻头滚滑复合轴承,对滚滑复合轴承结构进行有限元对比分析、模拟对比试验和钻头现场验证实验,表明滚滑复合轴承是一种较先进的创新性轴承。  相似文献   
12.
由小震震源机制解得到的鄂尔多斯周边构造应力场   总被引:8,自引:4,他引:8       下载免费PDF全文
利用格点尝试法首先分区对鄂尔多斯地块周边的 30 0 0多个小震震源机制解进行了处理。结果显示 ,在震源机制解覆盖的时段内 ,地块周边地区的平均构造应力场有以下特征 :地块周边主要以水平构造作用力为主 ,且其主压应力轴走向以地块西南侧为中心 ,从北至东呈扇形展布。在分区基础上 ,对各区的平均主应力轴分布进行了扫描 ,得到了其随时间的变化过程。其中渭河、六盘山和银川区的构造应力场相对稳定 ,临汾和同心区的构造应力场变化复杂 ,临河、包头、呼和、大同和太原区的构造应力场变化与该区的几次中强地震有密切关系。另外 ,地块周边除个别区外大多数区域在 1992年和 1996年前后 ,主压应力轴走向有趋近于N75°E的现象  相似文献   
13.
Through numerical simulation for GPS data, aseism/c negative dislocation model for crustal horizontal movement during 1999-2001 in the northeast margin of Qinghai-Xizang block is presented, combined with the spatial distri-bution of apparent strain field in this area, the characteristics of motion and deformation of active blocks and their boundary faults, together with the place and intensity of strain accumulation are analyzed. It is shown that: a) 9 active blocks appeared totally clockwise motion from eastward by north to eastward by south. Obvious sinistral strike-slip and NE-NEE relative compressive motion between the blocks separated by Qilianshan-Haiyuan fault zone was discovered; b) 20 fault segments (most of them showed compression) locked the relative motion between blocks to varying degrees, among the total, the mid-east segment of Qilianshan fault (containing the place where it meets Riyueshan-Lajishan fault) and the place where it meets Haiyuan fault and Zhuanglanghe fault, more favored accumulation of strain. Moreover, the region where Riyueshan-Lajishan fault meets north boundary of Qaidam block may have strain accumulation to some degree, c) Obtained magnitude of block velocities and locking of their boundaries were less than relevant results for observation in the period of 1993-1999.  相似文献   
14.
Through study on trenches, analysis of recurrence characteristics and recurrence interval cluster/gap of strong earthquakes along the major active faults on the northern border of Ordos block, we found 62 paleoearthquakes that occurred in the late Quaternary, including 33 earthquakes occurring in the Holocene. The recurrence characteristics of the paleoearthquakes are different at three levels, segments, faults, and fault zones. The strong seismic sequence on the independent segments is mostly characterized by long- and short-interval recurrences, while that on the faults and in fault zone is characterized clearly by random and cluster recurrences. Results of the moving window test indicate that the probabilities of "temporal cluster or gap", caused by random coincidence as opposed to intersegment contagion, are 64% and 70% for the Serteng piedmont fault and for the south-border fault of Wula Mountains, respectively, no clear interaction among the segments of each fault; while the probability is 26.8% for the whole fault zone, suggesting a clear interaction among the faults of this fault zone. These recurrence characteristics may imply an effect of the entire block motion on the recurrence of strong earthquakes. Moreover, the elapsed time for the Wujumeng Pass-Dongfeng Village segment of Serteng piedmont fault and the Tuzuo Banner-Wusutu and the Hohhot segments of Daqingshan piedmont fault has exceeded the average recurrence interval, hence these three segments may be the possible places for future strong earthquakes.  相似文献   
15.
Two events of Tibet uplifting are revealed by detrital apatite fission track (AFT) age data from Linxia Basin. They occurred at about 14 and 5.4-8.0 MaBP respectively. We interpret the first one to be related to the uplifting of the northern Tibet, which might have resulted from convectively removing the thickened lower lithosphere. The second one is a result of Laji Mountain uplifting. Numerous studies of the Tibetan Plateau suggest that the onset time of the deformation in the northeastern margin of Tibetan Plateau and the time of Tibet attaining to its present elevation is about 8 MaBP. They are approximately coincident with the uplift of Lajishan Mountain. It suggests that the northeastern margin of Tibet propagated northeastwardly to its present site in about 8 MaBP for accommodating the sustained convergence between India-Eurasia plate and for keeping its high elevation. The active block pattern dominating the strong earthquake distribution of Chinese continent probably formed at about 8.0-5.4 MaBP.  相似文献   
16.
鄂豫皖交界地区地震地质背景与中强地震复发特征的研究   总被引:1,自引:2,他引:1  
鄂豫皖交界地区位于东大别山西部,历史中强地震(M≥43/4)主要发生在土地岭-落儿岭及商城-麻城断裂带上,且“互动”和“连动”的特征较为显著。根据这一特征,在研究东大别山区域地质、地壳结构、断裂活动及地震构造应力场特征的基础上,可将鄂豫皖交界地区的中强地震作为秦岭-大别山活动地块中的次级地块的整体活动来看待。该区历史地震活动整体表现为丛集特征,而主要发震断层(土地岭-落儿岭断裂)的历史地震活动则具有相对较好的准周期性。地震复发周期研究提示,该地块近期发生M≥5.0左右地震的危险性较大,而霍山-六安地区为未来发生中强地震的主要危险区。  相似文献   
17.
PreliminaryresultsonkinematicmodeloftectonicblocksderivedfromhighprecisionGPSobservationsinSouthwestChinaLIRENHUANG1)(黄立人)...  相似文献   
18.
The structural feature shown on a remote sensing image is a synthetic result ofcombination of the deformations produced during the entire geological history of an area.Therefore, the respective tectonic stress field of each of the different stages in the complexdeformation of an area can be reconstructed in three steps: (1) geological structures formed atdifferent times are distinguished in remote sensing image interpretation; (2) structuraldeformation fields at different stages are determined by analyzing relationships betweenmicrostructures (joints and fractures) and the related structures (folds and faults); and (3)tectonic stress fields at different stages are respectively recovered through a study of the featuresof structural deformation fields in different periods. Circular structures and related circlular and radial joints are correlated in space to con-cealed structural rises. The authors propose a new method for establishing a natural model ofthe concealed structural rises and calculating the tectonic stress field by using quantitative dataof the remote sensing information of circular structures and related linear structures.  相似文献   
19.
Introduction Both Sichuan and Yunnan are provinces with more earthquakes. Based on catalogue of strong earthquakes in China compiled by the Prediction Department of China Earthquake Administration, there are 639 M5.0 earthquakes during 26 B.C.~A.D. 2001. Among them, 475 are M=5.0~5.9 events, 124 are M=6.0~6.9 events, 39 are M=7.0~7.9 events, and one is M=8 event occurred in Sichuan and Yunnan area. Here is one of the areas where seismic activities are most active in China. Sichuan-Yun…  相似文献   
20.
程万正 《内陆地震》2004,18(1):20-28
分析了雅江地块的构造环境、地震活动和震兆异常,探讨2001年雅江6.0级地震、2002年新龙5.3级地震发生后雅江地块的强震趋势。重点对理塘-德巫断裂带,新龙、白玉、德格及贡觉一带地区的异常地震活动图像进行分析,认为该区存在强震填空的潜在危险性。  相似文献   
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