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931.
The multi-scale characteristics of wave significant height (Hss) in eastern China seas were revealed by multi-scale wavelet analysis. In order to understand the relation between wave and wind, the TOPEX/Poseidon measurements of Hs and wind speed were analyzed. The result showed that Hs and wind speed change in multi-scale at one-, two-month, half-, one- and two-year cycles. But in a larger time scale, the variations in Hs and wind speed are different. Hs has a five-year cycle similar to the cycle of ENSO variation, while the wind speed has no such cycle. In the time domain, the correlation between Hs and ENSO is unclear. 相似文献
932.
应用于地球深部物质科学研究的静态超高压实验技术 总被引:2,自引:0,他引:2
三十多年来静态超高压实验技术已发展成为实验压力、温度范围分别为1~550GPa,-256°~3500℃,主要应用于下地壳、地幔及地核物质的物理和化学性质研究,并已取得大量研究成果的一项实验技术。本文简要介绍了该项实验技术与地学领域其它高温高压实验技术的区别,以及静态超高压实验装置的两大系列——金钢石压腔装置和大腔体高压装置的特点和应用情况。并对这两大系列实验技术的发展前景和我国应有的对策进行了评述。 相似文献
933.
Toward a stepwise Kwangsian Orogeny 总被引:2,自引:0,他引:2
The Kwangsian Orogeny originated along the southeast coast of China and stepwise developed in a northwest direction. It includes two stages, a long locally varying uplift from the Late Ordovician to the early Silurian and a finally tectonic movement near the Silurian and Devonian transition. The Kwangsian uplift event shows a stepwise delay northwestwards from the southeastern coast area in Nemagraptus gracilis Biozone (Sa1) to the south side of the Xuefeng Mountains in or later than Cystograptus vesiculosus Biozone (R3) to Coronograptus cyphus Biozone (R4). In the southern of Yangtze Platform, the Yichang Uplift was droved by the Kwangsian Orogeny forming a diachronous stratigraphical break through Rhuddanian and Aeronian. The distribution of the early Telychian lower marine red beds indicates a northwestward increase of the Cathaysian Oldland. Stratigraphical evidence may explain why the Kwangsian movement was marked by an angular disconformity during the Pridoli to earliest Devonian interval. 相似文献
934.
935.
中国内陆河流域植被对气候变化的敏感性差异(英文) 总被引:1,自引:0,他引:1
Terrestrial ecosystem and climate system are closely related to each other. Faced with the unavoidable global climate change, it is important to investigate terrestrial ecosystem responding to climate change. In inland river basin of arid and semi-arid regions in China, sensitivity difference of vegetation responding to climate change from 1998 to 2007 was analyzed in this paper. (1) Differences in the global spatio-temporal distribution of vegetation and climate are obvious. The vegetation change shows a slight degradation in this whole region. Degradation is more obvious in densely vegetated areas. Temperature shows a gen-eral downward trend with a linear trend coefficient of -1.1467. Conversely, precipitation shows an increasing trend with a linear trend coefficient of 0.3896. (2) About the central tendency response, there are similar features in spatial distribution of both NDVI responding to precipitation (NDVI-P) and NDVI responding to AI (NDVI-AI), which are contrary to that of NDVI responding to air temperature (NDVI-T). Typical sensitivity region of NDVI-P and NDVI-AI mainly covers the northern temperate arid steppe and the northern temperate desert steppe. NDVI-T typical sensitivity region mainly covers the northern temperate desert steppe. (3) Regarding the fluctuation amplitude response, NDVI-T is dominated by the lower sensi-tivity, typical regions of the warm temperate shrubby, selui-shrubby, bare extreme dry desert, and northern temperate meadow steppe in the east and temperate semi-shrubby, dwarf ar-boreous desert in the north are high response. (4) Fluctuation amplitude responses between NDVI-P and NDVI-AI present a similar spatial distribution. The typical sensitivity region mainly covers the northern temperate desert steppe. There are various linear change trend re-sponses of NDVI-T, NDVI-P and NDVI-AI. As to the NDVI-T and NDVI-AI, which are influ-enced by the boundary effect of semi-arid and semi-humid climate zones, there is less cor-relation of their linear change tendency along the border. There is stronger correlation in other regions, especially in the NDVI-T in the northern temperate desert steppe and NDVI-AI in the warm temperate shrubby, selui-shrubby, bare, extreme and dry desert. 相似文献
936.
An abundance of the phenomena of tectonic deformation and paleoseismic events of different times and their recurrent interval, as well as coseismic vertical displacements is exposed in Jiuxian trenches across the Nankou-Sunhe fault zone in Changping County. The research result shows three paleoearthquakes occurring during the Holocene. They were dated as 10643 ± 250 a B.P.-9706 ± 1235 a B.P., 7894±150 a B.P.-7640 ± 650 a B.P., and 3987±100 a B.P.-3670 ± 310 a B.P., respectively. The coseismic vertical displacements are 1.0 m, 2.0 m, and 2.0 m, respectively. From a statistical formula of relation between historic earthquake magnitudes and surface seismic dislocations in North China, the magnitudes of these paleoearthquakes are inferred to be in a range from M 7.7 to M 7.9. The research shows that the Holocene fault activity in the plain can be traced in the trenches according to the micro-geomorphic features. Many micro-structural phenomena are also found in these trenches. Identification of the paleoearthquakes in the Nankou-Sunhe fault zone during the Holocene time is of significance for assessment of future seismic risk in Beijing area. 相似文献
937.
938.
A vertical 2-D water–mud numerical model is developed for estimating the rate of mud mass transport under wave action. A nonlinear semi-empirical rheology model featured by remarkable hysteresis loops in the relationships of the shear stress versus both the shear strain and the rate of shear strain of mud is applied to this water–mud model. A logarithmic grid in the vertical direction is employed for numerical treatment, which increases the resolution of the flow in the neighborhood of both sides of the interface. Model verifications are given through comparisons between the calculated and the measured mud mass transport velocities as well as wave height changes. 相似文献
939.
940.
近年来碰撞造山带研究取得了很大进展,为碰撞造山带分类奠定了基础。1992年,Sengor提出了一个三分法的分类。但是,这个分类不能涵盖所有的碰撞造山带,同时其内部还有重叠。本文主要依据参与碰撞的单元,即板块、微板块、前缘弧、残留弧和增生弧,提出一个新的分类方案,即将碰撞造山带分为陆-陆,陆-前缘弧,陆-残留弧,陆-增生弧,弧-弧,陆-弧-陆6种类型。从世界各地的碰撞造山带来看,陆-陆碰撞型是很少见的,也就是说,威尔逊旋回不论在现代还是古代地质历史上都是罕有发生的,而大多数碰撞造山带都是非威尔逊旋回型的。 相似文献