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131.
萨拉乌苏河流域150 ka BP以来的粒度旋回 总被引:18,自引:1,他引:18
萨拉乌苏河流域米浪沟湾地层剖面150kaBP以来古流动砂丘砂与河湖相和古土壤在粒度上具有多次显著的粗细韵律交替变化,粒度参数-Mz、σ、Sk、Kg和SC/D亦随之响应为多波动峰谷交替的态势,同时,粒度特征值-φ5、φ16φ、φ25、φ50、φ84、φ9相应地表现为非常有节奏地跳动,据此,将米浪沟湾剖面划分为27个粒度粗细沉积旋回,并认为其是150kaBP以来在东亚冬夏古代季风交替影响下沙漠演变的一个颇为完整的气候-地质过程记录。 相似文献
132.
滞回曲线对应力振幅和频率的响应 总被引:2,自引:0,他引:2
基于疲劳载荷对应力-应变滞回曲线的影响,作者研究了滞回曲线对应力振幅和频率的影响,获得了载荷超过屈服点后应力振幅增大,滞回曲线趋于稳定,应变硬化效应增强的结果,随着正弦波频率增加岩石的滞回圈频散效应增强,饱和液体加强了这种频散作用,随孔隙液体的粘滞系数增大,滞回曲线的频散效应更强。 相似文献
133.
本文通过对矿井地质条件分类指标进行探讨,提出“同采地质块段”作为矿井地质条件分类的唯一指标,并在廿台河矿区取得了较好的应用效果。 相似文献
134.
135.
TheQvaluevariationsinthepreparingpro┐cesofrockruptureBINWANG1)(王彬),ZHAO-YONGXU1)(许昭永),JIN-MINGZHAO1)(赵晋明)YI-LIHU2)(胡毅力)1)Sei... 相似文献
136.
本文应用孢粉分析对富蕴水磨沟探槽的地层年代和古环境进行了探讨,认为富蕴地区在新冰期第一期活动中气候干净,为寒冻荒漠植被;在大西洋期为暖干气候,生长了草原化荒漠植被;在其后的新冰期活动中为冷湿气候,发育了灌丛草原植被。结合新疆特殊的地理条件,将上述环境演变过程与国内外全新世气候波动研究结果相比较,并参考有关(14)~C数据,作者认为该探槽中发现的第一次古地震活动应晚于6000a,B.P,第二次古地震活动似应发生于2500a,B.P之后。 相似文献
137.
Using the data set of about 1 Hz Lg amplitudes from 80 stations in the six eastern provinces of China, the ratios of horizontal
to vertical amplitude of Lg waves,H/Z are determined. The mean lg(H/Z)-value is equal to 0.13. For the station bases of soft deposit,granite and sedimentary rock, lg(H/Z)-values average 0.55, 0.04 and 0.10, respectively. For the three kinds of station bases, the station terms of horizontal
amplitude,C
h
average 0.65, −0.09 and 0.00; that of vertical amplitude,C
z
average 0.32, −0.04 and 0.00, respectively. There are the relations betweenC
h
,C
z
and lg(H/Z):C
h
=0.01+2.10C
z
andC
h
=−0.15+1.46 lg(H/Z).
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 281–286, 1991.
Project sponsored by the Chinese Joint Seismological Science Foundation. 相似文献
138.
Yuru Zhuo 《地震学报(英文版)》1992,5(1):33-43
Using the WKBJ approximation method we calculate the synthetic teleseismograms of P and PP waves to match the observed ones
of six large Chinese earthquakes with known focal mechanisms: Tibet earthquake of July 14, 1973; Haicheng earthquake of February
4, 1975; Songpan earthquakes of August 16, 1976, August 21, 1976 and August 23, 1976 and Nignhe earthquake of November 15,
1976. The focal mechanism of the Tibet earthquake is discussed to examine the technique used in the calculation.
We note that the amplitude ratios of PP and P waves (A
PP/A
P) have different characteristics for dip—slip events and strike—slip events within certain epicentral distances. We calculate
the synthetic teleseismograms of P and PP waves for the strike—slip and dip—slip events with fault angles of 330°, 240° and
0°, focal depths of 8 km, 17 km and 24 km, at the assumed station with an azimuth of 310° and epicentral distances from 40°;
to 80°. The diagrams of maximum amplitude ratios of PP and P waves (A
PP/A
P) versus distances are given. The possibility to use the (A
PP/A
P) values to give an approximate estimation for the focal mechanism type is discussed. This work may be useful for determining
the focal mechanism type for those earthquakes which have only few records such as the Chinese earthquakes from the 1930s
to 1960s.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 150–160, 1991. 相似文献
139.
140.
The amplitude response of a LCR gravimeter with the SRW-E feedback was determined on a vertical vibrating platform. The ink-pen recorder was connected parallel with the digital voltmeter input to obtain an analog response of the gravimeter to the harmonic motion of the base with a peak-to-peak amplitude of 10 m and periods excited in an interval of 4 - 10 s as by the ground motion of meteorological microseisms, and in the interval 10 -100 s as by surface waves of distant strong earthquakes.
In the first interval, an unexpected maximum of the amplitude response was observed with the double amplitude of apparent 6,5 Gal (6.5 × 10
–8
m/s
2
) at a period of 4.8 s, and a baseline shift with the amplitude of–64Gal was observed at the same period. The value of this direct component cannot be separated from the effect of the Earth's gravity field. In the second interval, the amplitude response of the gravimeter displayed one expected maximum at a period of 40 s with the double amplitude of 8.1Gal. At the usual level of microseisms with a peak-to-peak amplitude of up to 2 m the fluctuation of the gravimeter on the direct baseline shifted by –4.9 Gal was estimated at 1 Gal. With typical Rayleigh surface waves with periods of 20 s and double amplitudes of up to 100 m, the fluctuation reached 67 Gal. 相似文献