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71.
近千年来中国区域降水模拟与重建资料的对比分析 总被引:10,自引:2,他引:8
依据中国区域27年GPCP降水观测再分析资料、500年旱涝等级资料及近千年冰芯、树轮、湖芯等降水代用资料,对全球海气耦合气候模式ECHO G近千年积分模拟降水进行时空变化的对比分析,检验模式对中国地区降水的模拟性能。结果表明模拟降水较好体现了中国区域降水年平均和季节平均的分布型态,并在年代际变化上与历史记录一致。中国西部模拟降水呈现出与重建资料一致的准200年的百年际周期及20~30年左右的年代际周期,并与湖泊盐度的高低时段对应较好。总体而言,模式成功再现了观测及代用资料所体现的中国区域近千年降水的主要时空变化特征。EOF分析结果进一步揭示了3个不同气候特征时期模拟降水存在不同的区域分异特点。 相似文献
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矿体产于白垩纪马头窝单元(K1^7M^λπ)石英斑岩与石炭系上统空树河组三段二层(C2k^3-3)地层的石英砂岩、长石石英砂岩接触带上,或上述两类岩石的破碎带中,矿体与围岩界线常呈波状起伏,呈突变或渐变接触。矿区围岩蚀变明显,有进一步找矿的前景。 相似文献
75.
WU Zhenhan JIANG Wan Peter Blisniuk BI Siwen ZHANG Shukun Olaf Kuchel MAO Yi Institute of Geomechanics CAGS Minzu Xueyuan Nanlu Beijing Institut fur Geowissenschaften Universitat Potsdam Postfach D- Potsdam Germany Liu Xinzhu 《《地质学报》英文版》1999,73(3):289-293
The Shuanghu basin is a NE-trending rift basin bounded by NE-striking normal faults and NW-striking shear-extensional faults of the northern Tibetan Plateau. Four samples from calcite veins in marginal faults and one sample from mudstone (S-3) were collected for dating the evolution of the Shuanghu basin by using the ESR spectrograph of EXM-type. Ages were calculated according to the close-equilibrium model on the basis of the measured ESR signal spectra of samples, providing good chronological information. It is known from the ESR dating that the extensional faulting and rifting of the Shuanghu area began at 4.92 Ma B.P., followed by regional folding in 3.56-1.36 Ma, NW-striking faulting in 0.60 Ma and normal faulting in 0.024 Ma in the Shuanghu basin. 相似文献
76.
Vršnak B. Roša D. Božić H. Brajša R. Ruždjak V. Schroll A. Wöhl H. 《Solar physics》1999,185(2):207-225
Two large stable solar filaments were used as test tracers to determine the apparent synodic rotation rate as a function of the central meridian distance for several filaments' segments at different heights. An analytic fitting procedure was applied to determine simultaneously the real synodic rotation rate and the height of the traced filament segments. The determined heights were compared with the values obtained from the widths of filament contours on the solar disk and with the values obtained by direct measurements at the solar limb. Furthermore, the obtained rotation rates and heights of the filaments' segments close to the filaments' pivot points were compared with the values obtained using two successive central meridian passages. Finally, sources and scales of errors were investigated and possible implications on the previous studies of the solar differential rotation were considered. 相似文献
77.
ZHAO Wenzhi YANG Xiaoping Steve KERSHAW ZHANG Baomin 《《地质学报》英文版》2006,80(5):684-692
Lower Silurian mud mounds of the Shinuilan Formation, located in the southern Sichuan Basin, China, have developed in open shelf settings in deeper water than shallow-water reef-bearing limestones that occur in the region. An integration of the outcrop, drill data and seismic profiles show that contemporaneous faults have controlled the boundary and distribution of the sedimentary facies of Lower Silurian rocks in the southern Sichuan Basin. Mounds appear to have developed in the topographic lows formed by synsedimentary faulting, on the sheff of the Yangtze Platform. Average mound thickness is 20 m, maximum 35 m. Mounds are composed mainly of micrite, possibly microbially bound, and are overlain by shales. Mound tops are preferentially dolomitized, with the Mg^2+ source probably from the clay content of the mound-top carbonate. Microfacies analysis and reconstruction of the diagenetic history reveal that the mound tops have higher porosity, and are gas targets; in contrast, mound cores and limbs show pores filled by three generations of calcite cement, and therefore have a low gas potential. 相似文献
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30��N���ණ����ƽ��ĵ�Ƶ�仯������ENSO�Ĺ�ϵ 总被引:2,自引:0,他引:2
????1992??12???2007??5?μ??????????о???????????仯??????????????????14?????????????30??N??????????????????????????57.7 mm??40.9 mm??????????????????????????????о?????????????????????ζ??????SOI????????????????????????????????????????????SOI???????30??N??????SLA??SOI???????????????γ??????????SLA??SOI???к???????????????????????????糡??????????????????SLA??γ???????????????????????????????30??N ???????????????????????????????????????????????????????????????????????????????????????SLA??????????·???????u??????????????????????????30??N ?????????????????????????????u??????????????70???????23????????????u????????SLA??SOI????????????????????????????????????????е?????????????30??N ???????????????????u????SOI???????ENSO????????????????????????糡???????????糡???γ????????????????????仯???????????á?????ENSO???????????????????????????? 相似文献
80.
Terra rossa and eutric cambisol soils were surveyed in Slovenia. At both sites, 6–13 boreholes were drilled in a regular 24 m × 24 m
square grid. Soil samples from various depths were taken for gamma spectrometric analysis, and radon in soil gas was measured
at a depth of 80 cm using an AlphaGuard instrument. The following ranges of activity concentration (Bq kg−1) were obtained for 238U, 226Ra, 228Ra, 40K and 137Cs: in terra rossa, 64–74, 70–84, 45–49, 293–345, 20–30 and, in eutric cambisol, 55–80, 132–147, 50–57, 473–529, 106–272.
Radon activity concentrations in both soils ranged from about 100 kBq m−3 to 370 kBq m−3. 相似文献