青川M_S4.0级地震斜坡地震动响应监测数据分析

自从"5·12"汶川地震后,青川余震一直持续。以2015年9月23日青川M_S4.0级余震监测数据进行研究。通过对比青川东山监测点的地震动响应结果表明:在河谷部位,水平东西向最大峰值加速度大于水平南北向,而在山脊上则水平南北向最大峰值加速度强于水平东西向;相对于河谷(4#)监测点,东山山脊上6#监测点水平向PGA放大系数最大达到2.0,竖直向PGA放大系数为4.0;谱比分析(HVSR)显示,东山监测点谱比分析的地形放大系数最大可达5.6;且卓越频率多在1.5~3.5 Hz之间。研究表明,强震条件下东山斜坡存在明显的地形的放大效应;且位于地形转折处的6#监测点的放大效应最显著。     

风尘寺单薄山脊九寨沟余震频谱特征分析

研究近地震场地的地震频谱变化特征,分析其地形效应,能够为边坡支护设计提供依据。通过对九寨沟风尘寺台站实测的3次余震数据对比分析,揭示了不同监测点地震时频谱变化特征。结果表明:相对于山脚监测参考点,山脊监测点FFT主频值较小,集中在7～12 Hz;山脊监测点加速度反应谱特征周期较大,范围为0. 06～0. 12 s; HVSR分析揭示山脊监测点谱比分析的地形放大系数可达12,且存在多个卓越频率,主要在5、30以及50 Hz左右放大较为明显;山脊监测点均方根加速度在水平方向与竖直方向均具有不同程度的放大,且在水平EW向有显著的放大效应,放大系数可达12. 5倍。可见单薄山脊对地震波具有明显的地形放大效应,而且当地震波传播方向与山脊走向大角度相交时地形放大效应最为显著,同时也证实了微地貌对斜坡地震动响应的控制作用。     

“4·20”芦山地震冷竹关地震动响应监测数据分析

通过在四川省泸定冷竹关沟两岸斜坡不同部位挖掘平硐并放置强震监测仪器的方法,对"4.20"芦山地震在该峡谷两侧斜坡的地震动响应特征、地形放大效应等进行研究。根据7台地震仪器所记录的芦山主震数据,冷竹关沟右岸1#监测点PGA水平分量为1.64m/s2,竖直分量为0.67m/s2,明显高于其他监测点的PGA值(0.11～0.42m/s2)。参照康定姑咱强震台主震记录,1#监测点PGA放大系数达到6.9,其阿里亚斯强度放大数十倍。谱比分析(HVSR)显示,1#监测点谱比分析的水平分量地形放大系数达到9.0,2#监测点地形放大系数为3.5,左岸4#～7#监测点地形放大系数一般在1.0～3.0。研究表明,强震条件下冷竹关右岸单薄山梁地震动地形放大效应明显强于左岸中高山斜坡,且1#监测点的凸出地形放大效应最大。随着振幅值的放大,强震动能量以数十倍效应剧增,当短时间内积聚的振动能量超过或远远超过岩土体介质的强度时,易形成震裂、崩塌、滑坡及高陡地形的抛射效应。     

九寨沟Ms4.1级余震薛家坝场地地震动响应监测数据分析

九寨沟"8. 8"地震后余震一直持续,对灾区人民生命财产安全造成了极大地威胁,进行余震监测研究意义重大。通过对薛家坝不同地基类型、不同高程处各监测点的地震动响应分析揭示:处于深厚覆盖层场地的1#监测点记录到的峰值加速度 2#监测点参考点,说明局部范围内不同地基类型对地震波的放大效应要比地形放大效应更为显著; 1#监测点阿里亚斯强度最大值分别为2#及参考点的1. 5、5. 1倍,而处于相同地基条件的2#监测点阿里亚斯强度最大值约为参考点最大值的3. 5倍;傅氏谱分析发现:深厚覆盖层场地对地震波的放大作用强于完整基岩场地,2#监测点同一高程不同埋深对地震波具有选择放大作用,距离洞口越近放大作用越明显。     

汶川震区地震动三维地形效应的谱元法模拟

针对三维波动弹性动力方程推导了谱元法算法,并考虑三维真实地形及介质的衰减特性,基于并行计算环境采用谱元法和ASTER DEM模型对5.12汶川地震动的地形效应进行了模拟.模拟结果表明陡峻地形对地震波两个水平分量的影响要大于对竖向分量的.震中附近区域的PGA最大值为671 cm/s2,高PGA区多分布于山顶及山脊区域.与...     

堆积型滑坡地震响应的离心模型试验

基于离心振动台模型试验,采用Taft波激励,不断增大其幅值,研究不同强度地震波作用下堆积型滑坡地震响应特征,对比分析了汶川地震清溪台站基岩波结果的异同.结果表明:坡面水平向和竖直向峰值加速度放大系数均随坡高增加而增大,呈现高程放大效应;坡体内水平向峰值加速度放大系数分布与坡面不同;坡面对输入地震波有反射作用并呈现坡面浅表放大效应;基岩水平向加速度随高程增加存在增大现象,与地震动输入相比,均有缩小现象.同一高程处,坡面水平向与竖直向、坡体内及基岩水平向峰值加速度放大系数随地震波幅值的增大其变化规律不同.     

2021年5月21日云南漾濞6.4级地震强地面运动特性分析

2021年5月21日,中国云南省大理白族自治州漾濞彝族自治县苍山西镇发生6.4级强地震及多次余震。本文对此次地震中获得的20组共60条强震动记录进行了基线校正和滤波等处理,按照震中距由近及远,重点研究了地震动幅值衰减规律、持时特性和加速度反应谱特征。结果表明：此次地震记录多为中远场记录,近场记录较少,漾濞台站获得的峰值地面加速度(PGA)为720.3 cm/s²,地震动幅值随着震中距的增大而逐渐衰减。在近场范围内,台站记录体现出高幅值PGA、低幅值峰值地面速度(PGV)的特点,PGA和PGV观测值与预测值的衰减规律一致;对于中远场而言,Huo与Yu模型相比,其预测值更接近观测值,但两个模型都低估了实际地震动的最大峰值。持时随着震中距的增大而延长,符合线性规律;竖向与水平向持时的比随着震中距的增大呈现出先增大后减小的规律,符合高斯分布规律。加速度反应谱峰值随着震中距的增大而逐渐衰减,在周期大于1 s的中长周期段水平向反应谱峰值较竖向反应谱峰值衰减较快,而卓越周期逐渐向长周期偏移;反应谱峰值均位于短周期部分,不会对长周期建筑造成严重破坏;尽管漾濞地区抗震设防水准较高,...     

基于环境噪声测试表征斜坡地震动响应:以自贡西山斜坡为例

以四川省自贡市西山公园斜坡上8处强震台站场地为研究对象,通过2次环境噪声测试并采用水平/竖直向谱比法(HVSR)和标准谱比法(SSR)分析该斜坡场地效应,并与汶川地震监测数据对比,探究采用环境噪声在表征斜坡地震动响应特征上的异同。研究结果表明,环境噪声HVSR平均谱比曲线分析较好揭示了斜坡台站场地放大效应的峰值频率,且和SSR分析结果共同揭示了该斜坡顶5~#～7~#台站场地放大效应较明显;而1~#～4~#台站场地放大效应并未随海拔高度增加产生明显变化,且2种谱比分析对比显示其放大峰值频率范围相近,放大系数差异不明显。对比环境噪声和地震监测数据显示,两者HVSR平均谱比曲线在场地响应卓越频率上的拟合度较高,但在方向效应上的拟合度不具代表性,且地震数据平均谱比放大系数大于环境噪声。采用环境噪声表征斜坡的地震动放大效应,其峰值频率耦合性较好,而场地放大系数仍需参考地震监测数据或数值模拟分析。     

河漫滩-阶地复合地形场地的非线性地震反应特征

以滁州市地震小区划场地为原型,针对由河漫滩、阶地、波状起伏的低丘等组成的典型复合场地,基于ABAQUS软件显式有限元并行计算平台,建立了大尺度场地二维模型,考虑土体的非线性特征,以SH波作为输入地震动,分析了河漫滩-阶地复合场地地震动力响应特征.结果表明,(1)与基岩地震动峰值加速度相比,土层近地表范围内(15m以浅)峰值加速度均表现出明显的放大现象,15m以深土层地震动放大效应随深度增加而逐渐减弱,且随深度增大,PGA放大系数值逐渐小于1.0;(2)土层峰值加速度随着深度增加非单一递减,局部土层深度地震动出现聚集效应,这一现象在河漫滩区表现比较明显;(3)场地不同区域地震动放大效应差异较大,河漫滩区地震动放大效应要明显比阶地低丘区更大;且输入地震动峰值相同时,河漫滩区反应谱特征周期要大于阶地区域,两者差距达0.05—0.15s;(4)随着输入地震动增加,反应谱谱峰向长周期方向移动明显.     

苏州城区凹陷沉积土层对地震反应特征的影响

针对土层非均匀分布的苏州城区凹陷沉积场地,采用黏弹性人工边界模拟无限域场地的边界,基于ABAQUS建立大尺度二维有限元模型,分析了加速度峰值、位移峰值、频谱等地震动参数特征,探讨了凹陷沉积土层对地震效应的影响.结果表明:凹陷沉积地震动响应呈现较大的空间差异性,局部位置地表加速度放大效应明显;苏州城区场地敏感周期段为0.20～0.70 s,与水平均匀场地相比,凹陷沉积场地地表反应谱沿横向变化较大,越靠近地表,反应谱谱峰越向长周期方向偏移;由于地震波在局部区域聚焦,凹陷沉积场地PGA值沿深度方向呈起伏变化现象;沿水平方向的PGD随土层深度增加呈非单调递减,且与输入地震动频谱特性相关.大尺度二维模型一定程度上能合理反映微地形起伏、土层分布对地震波传播过程的影响.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that