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991.
The time series BT profiles and surface winds and atmospheric pressure, collected in the deep waters off Ratnagiri and Karwar
during summer monsoon were utilized to document the characteristics of internal waves (IW). Low-frequency (≤2, cycle per day
(cpd)) IW off Ratnagiri are found to propagate at 83 cm/s with wavelengths of 45 km and wave heights upto 40 m. These parameters
for high-frequency (>2 cpd) IW off Karwar correspond to 99 cm/s, 3 km and 23 m. The IW off Karwar appear to leave the station
at 70° (±10°) (measured from the horizontal). The data sets were further analysed to address the harmonic composition of the
IW and identify the possible sources for the observed IW fields. Power spectra of the IW indicated energy peaks at inertial
(0·6 cpd) and tidal (1 and 2 cpd) frequencies off Ratnagiri and in the high-frequency band of 0·5–2·0 cycles per hour off
Karwar. The coherence between the IW and wind/tide is found to be good at several frequencies within the IW spectrum. This
feature probably suggests tides as a source for the IW of tidal frequencies and winds and tides as a joint source for the
IW at the remaining frequencies. 相似文献
992.
993.
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996.
陕西双王金矿床含铁白云石的某些标型特征 总被引:2,自引:0,他引:2
含铁白云石是双王金矿床矿体和围岩中的主要矿物,按其产状可分为四类:Ⅰ.产于层状钠质岩(矿体围岩)中的含铁白云石;Ⅱ.产于含金角砾岩体钠质岩角砾中的含铁白云石;Ⅲ.产于含金角砾岩胶结物中的含铁白云石,Ⅳ.产于近矿蚀变岩石中的含铁白云石。Ⅰ,Ⅱ类为热水沉积成因,Ⅲ和Ⅳ类为热液充填交代产物;它们在化学成分、有序度及碳氧同位素等方面有许多相似之处,但又有一定的差别。研究表明,含金角砾岩胶结物中的含铁白云石主要来自层状钠质岩,为矿床的热水沉积—改造成因提供了新的证据。 相似文献
997.
998.
WANG Guixian WANG Xingkui GUO Jiachao Professor Sediment Research Laboratory Dept. of Hydraulic Engineering Tsinghua University Beijing China. Associate Professor Dept. of Hydraulic Engineering Tsinghua University. Assistant Dept. of Hydraulic Engineering Tsinghua University. 《国际泥沙研究》1993,(3)
I. INTRODUCTIONResistance to flow in alluvial streams is one of the crucial problems in fluvial hydraulics. Despite that large amount of studies have been conducted for centuries, no perfectmethod describing and calculating the resistance to flow in alluvial streams is availablehll now. Investigation on bed forms and resistance properties of light--weight bed materials is even more scarce. USWES (1936) has conducted systematic experiments onlight--weight materials in a flume & m long an… 相似文献
999.
1000.
In this paper we discuss two types of crust models with abnormal density, velocity of wave and certain geometrical structures.
The far-field synthetic seismograms of P and SH wave are calculated by the far-field vertical displacement formulas of P and
SH waves with the double couple point source and the formulas of reflection coefficient, radiation pattern and travelling
time difference derived from the models suggested in the paper. It is shown by the results that the effect of special crust
structures near focus on the far-field seismograms can be ignored if the densities and wave velocity of the special structure
are less than average those of the crust (model I). However the effect should be noticed if the densities and wave velosities
of the structure are large than average those of the crust (modelI). The effect of the special crust structure on the far-field seismograms has not been studied further before. Seismic records
of the Haicheng earthquake and the crust structure in Haicheng region are studied by the calculation method in the paper.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 1993. 相似文献