驱动机制改变对沙堆模型行为特性的影响

慢驱动机制是自组织临界系统(SOC)的基本条件之一,若仅当驱动机制发生改变时,系统的行为特性会呈现何种变化,尚未有人研究.针对这一问题开展了快驱动机制的沙堆模型实验,通过快速倾斜沙堆底板的方式使沙堆从欠临界角快速到达临界角.实验表明,沙堆坡度保持在临界角附近时,落沙量服从幂律分布;随着沙堆坡度逐渐偏离临界角度,落沙量的统计特性将经历对数正态分布-正态分布的转变,不再呈现SOC特性.汶川实震诱发断裂带上盘的崩塌滑坡原型问题是驱动机制改变在自然界中的体现(其隆升速度与滑坡速度之间不存在巨大的时间标度分离).在对汶川地震断裂带上、下盘地区1.5km内的崩塌滑坡规模面积统计分析发现,上盘灾害服从对数正态分布,而下盘不服从对数正态分布.据此,推断汶川地震靠近断裂带上盘附近的崩塌滑坡呈现对数正态分布的规律可能是具普适性意义的现象.     

Ⅶ—Ⅸ度烈度区地震触发崩塌滑坡分布规律

利用"4·20"芦山地震Ⅶ—Ⅸ度烈度区资料翔实的有利条件,研究不同烈度区地震触发崩塌滑坡的整体分布规律,并基于自组织临界状态理论,从物理角度对其机理进行诠释.实震资料表明:Ⅸ度、Ⅷ度、Ⅶ度烈度区,崩塌滑坡面积与发生频率之间的关系均可用幂律描述,且幂指数b值相近,但随地震烈度的降低,崩塌滑坡密度单调减小;元胞自动机模拟表明:当扰动强度按0.5的比率递减时,沙堆模型的动力学特性基本服从同一幂律分布,雪崩密度呈线性关系减小;振动台沙堆模型物理实验也支持了以上结论.说明规模与发生频率之间的幂律关系是Ⅶ—Ⅸ度烈度区地震触发崩塌滑坡的统一分布规律,灾害点密度的不同是体现它们震害强度差异的主要指标.结论可为地震触发山地灾害危险性区划、地震次生灾害风险评估等提供科学依据.     

地质灾害发生频率的幂律规则

幂律规则是指某事件发生的频率与发生规模之间呈幂函数关系。本文在对向家坝水电站库岸崩滑体发育分布规律进行统计的基础上，参考前人对地震、泥石流等的研究成果，提出了地震、崩塌、滑坡、泥石流等地质灾害发育分布满足幂律规则的观点。     

汶川地震滑坡详细编录及其与全球其他地震滑坡事件对比

 汶川地震滑坡编录结果表明,2008年5月12日汶川地震触发了197481处滑坡,面积约为1160km²,大致分布在一个面积约1.1x10⁵km²的区域内,是当前汶川地震滑坡最全面详细的编录成果,也是有记录以来单次地震事件触发滑坡数量最多的记录。其中196007处滑坡(占滑坡总数量的99.25%),面积为1150.622km²(占总滑坡面积的99.19%),分布在一个面积为44031km²、以映秀—北川地表破裂为近似中心的近椭圆形区域内。分析这196007处滑坡面积与滑坡数量的幂律关系,结果表明,面积在1x10⁴—1x10⁶m2之间的滑坡,滑坡面积与滑坡数量累加之间的幂律关系式可表示为lgN(A)=-2.0745A+13,判定系数R²=0.9931,表明该滑坡面积区间内滑坡面积与滑坡数量之间具有良好的幂律关系。对比结果表明,汶川地震滑坡影响区面积略高于全球其他地震事件滑坡影响区面积的上包络线。汶川地震滑坡编录成果为后续汶川地震滑坡相关科学研究提供了重要的基础数据。     

自然沙堆积的静止角研究

以塔克拉玛干沙漠西南边缘自然沙丘的沙子为研究对象,对不同粒径的沙采用漏斗法进行沙堆积,并录像记录了沙的堆积过程。将录像处理成图片,用计算软件“CorelDraw”处理,从而得到沙堆静止角和崩塌角随时间和沙粒粒径的变化关系。得出结论：（1）沙堆的静止角随时间呈振荡变化。首先,静止角逐步变大到崩塌角,崩塌后堆积角回到静止极角,然后再增大到崩塌角,如此往复。（2）当粒径小于0.30 mm 时,沙堆崩塌角及崩塌角与静止极小角的差值随沙粒粒径的增大而增大;但当粒径大于0.30 mm 时,其差值随沙粒粒径的增大而减小。（3）崩塌角与静止极角差值的平均值为（4.6±0．6）°。（4）混合沙的崩塌角与静止极角的差值为（5.2±0.3）°。     

粒径呈幂律分布的颗粒气体中的颗粒分离行为特性

采用分子动力学方法模拟了受到边界振动的粒径呈幂律分布的颗粒气体中的颗粒分离行为特性.研究发现当系统受到振动时,模拟区域出现温度梯度,系统出现颗粒分离现象,所有的颗粒都会朝着温度低的区域移动,且大颗粒比小颗粒更趋向于聚集在低温区域;系统大颗粒和小颗粒间的粒径差越大,系统的颗粒分离行为越显著.同时,系统的子区域中的局域粒径分布函数仍然为幂律分布.     

“4·20”芦山地震地质灾害遥感快速解译与空间分析

2013年4月20日四川省芦山县发生7.0级地震,地震诱发了大量的崩塌滑坡。利用四川省测绘地理信息局和四川省地质调查院提供的芦山县城、太平镇、宝盛乡、龙门乡、清仁乡、上里镇、思延乡等重灾乡镇的震后高精度航空影像进行了地质灾害体的解译,利用GIS分析了芦山地震诱发的崩塌滑坡的空间分布关系和特征。结果表明崩塌滑坡主要受断层控制,距离发震断层3km范围内分布密度最大;坡度是影响崩滑分布的重要因素,崩滑体主要分布在坡度40°～50°范围内;在海拔高度1～1.5km范围内崩塌滑坡密度最大;距水系400m范围内的崩塌滑坡分布密度最大;白垩系泥岩、砂岩出露的地方容易产生大量崩塌滑坡;崩塌滑坡主要集中分布在Ⅸ烈度区。     

青川县重点区域地震诱发地质灾害遥感调查与分析

探讨汶川地震诱发地质灾害的发育分布特征。利用航空影像对青川县红石河区域进行遥感解译,并结合汶川地震前研究区地质灾害调查数据进行对比分析。在193km2的范围内共解译地质灾害712处,其中,滑坡209处,崩塌486处,泥石流17处,地质灾害发育密度达到了3.7km-2。汶川地震诱发的地质灾害具有明显的断层上下盘效应、坡度效应、灾害链效应及高密度发育的特点。     

震后次生山地灾害对山区道路的危害及防治体系

山区地质地貌条件复杂,使得我国山区道路沿线的山地灾害广泛发育,5.12汶川地震诱发的生山地灾害使得山区道路沿线的环境进一步恶化。分析了汶川地震震后两年多时间内崩塌滑坡、泥石流的活动特征及其对山区道路的危害,其中震后崩塌滑坡主要以小型的堆积层崩滑为主,且分布范围广,而震后的泥石流则表现为规模大、频发性、群发性、持续时间长等特点。为保证山区道路的畅通,必须采取有效的措施对威胁道路的次生山地灾害进行综合防治,提出了震后山区道路灾害防治与管理体系。     

颗粒物质内部应力分布的研究

作者介绍了颗粒物质内部应力分布的研究现状,讨论了典型的沙堆底部中心压力最小这一反常规现象及相关理论以及动态二维沙堆实验与理论分析,对这些理论进行了综述和比较。测量了探棒与颗粒相对运动情况下,颗粒重组导致滑动摩擦力增大的实验,并对结果进行了解释。     

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