淮南矿区典型冻土的力学特性试验研究

对淮南矿区3种典型人工冻结粘土力学特性的研究表明：钙质粘土力学性能最差；冻结粘土的单轴强度、变形模量和蠕变强度均随温度降低而增加，特别是当冻土温度低于-10℃时，冻结粘土强度随温度降低而剧烈增加，但温度的变化对泊松比影响较小，蠕变状态方程可用形如ε=A(T)σ^Bt^C的幂函数表示；在没有补给水源的情况下，其冻胀力可达0．8MPa，冻胀率小于5％，深层粘土的冻胀性小于浅层粘土。     

淮南弱膨胀土冻胀融沉特性

采用自行研制的冻胀融沉试验系统,对淮南弱膨胀土进行不同含水率、冷端温度等条件下的室内冻胀和融沉试验。结果表明:土体冻胀率随含水率、冷端温度和干密度的升高而增大;而随着含盐率的增加,冻胀率呈现减小的趋势,冻胀率与时间关系的可用指数函数y=a(1-e~(-bt))描述。通过温度和水分变化规律可知,距离冷端越远,温度下降速率越慢,达到稳定状态的时间越长。土体冻结深度随温度降低而增加,且与温度场发展规律一致。由于冻结过程中的水分迁移,使冻结区的含水率普遍大于初始含水率,而未冻区含水率则小于初始含水率,在冻结缘附近含水率达到最大,水分在此处集聚形成分凝冰夹层。另外,融沉试验的结果说明了土体融沉量会随含水率升高和温度降低而增大,由各级荷载下的融沉量确定融沉系数和体积压缩系数,为冻土沉降计算提供参数。     

季冻区粉质粘土路基的冻胀特性的模型试验研究

为对季冻区路基冻胀性能进行研究,以实际工程为依托,通过相似原理方法进行缩尺模型试验研究。在开敞式条件下进行单向冻融试验,分析在不同温度梯度条件下冻融循环两次过程中温度分布及冻胀特性。自行研制的冻胀设备能满足变形、温度等多项试验指标。试验测试结果表明：冻结速率随时间的增加呈现出降低趋势且具有一定的波动性;冻结深度随冻结负温的增加而增加,并且在-15℃时,最大冻深达到39cm;通过对冻结深度与时间关系进行分析提出冻结深度预测公式,通过对前人已有数据进行验证发现本文提出公式具有很好的适用性;在不同冷端温度与冻胀量关系中发现,当冻结负温在-10℃下,土体达到最大冻胀量。     

季冻区粉质黏土路基的冻胀特性的模型试验研究

为对季冻区路基冻胀性能进行研究,以实际工程为依托,通过相似原理方法进行缩尺模型试验研究。在开敞式条件下进行单向冻融试验,分析在不同温度梯度条件下冻融循环两次过程中温度分布及冻胀特性。自行研制的冻胀设备能满足变形、温度等多项试验指标。试验测试结果表明:冻结速率随时间的增加呈现出降低趋势且具有一定的波动性;冻结深度随冻结负温的增加而增加,并且在-15℃时,最大冻深达到39 cm;通过对冻结深度与时间关系进行分析提出冻结深度预测公式,通过对前人已有数据进行验证发现所提出公式具有很好的适用性;在不同冷端温度与冻胀量关系中发现,当冻结负温在-10℃下,土体达到最大冻胀量。     

单向正融粉制黏土路基的静力学特性及显著性分析

由于正融土体相较全融或全冻土体具有不稳定性,对路基土体会产生更大破坏,为了探究单向正融粉制黏土路基的静力学特性,通过改装动静三轴试验机,对不同围压、冻前含水率、顶端冻结负温、顶端融化温度进行了静三轴剪切试验,研究应力-应变曲线和静强度的变化规律,并且基于显著性分析对静强度进行探究。试验结果表明:随着围压和含水率的增加,应力-应变曲线逐渐由弹性-应变软化型变为弹性-应变硬化型;正融土静强度随顶端冻结负温的降低和融化温度的降低而升高,冻结负温比融化温度对正融土强度贡献更大;认为存在临界含水率,小于该含水率,静强度随含水率的增长而增大,大于该含水率则随含水率的增长而减小。通过显著性分析发现,围压对静强度影响最为显著,冻前含水率次之;同时,冻结和融化温度的交互作用也有较为显著的影响。     

单向冻结条件下裂隙岩体冻胀特性试验

单向冻结条件下寒区隧道围岩不均匀冻胀性是产生隧道冻胀力的主要原因之一.为研究寒区隧道含裂隙围岩不均匀冻胀特性,进行了单向冻结条件下裂隙岩体的冻胀试验,分析了裂隙岩体在单向冻结时的冻结过程及变形规律.试验表明,裂隙处冻胀与岩石自身冻胀存在明显差异,裂隙岩体在冻胀过程中表现出明显的不均匀冻胀特性.在裂隙较深的工况下,随裂隙宽度的增加,裂隙法向的线冻胀率增加.对于含裂隙饱和砂岩,岩石自身线冻胀率随冻结温度的降低明显增大,而裂隙法向的线冻胀率明显减小.凝灰岩孔隙率较小,岩体的冻胀变形以裂隙处的冻胀变形为主,岩石自身在低温条件下表现为冷缩.根据试验结果,在岩体不均匀冻胀系数中考虑了裂隙的影响,计算了含裂隙饱和砂岩的不均匀冻胀系数.裂隙平行于温度梯度方向时,随裂隙宽度的增加,含裂隙饱和砂岩的不均匀冻胀系数有所减小.随温度梯度的增加,含裂隙饱和砂岩的不均匀冻胀系数增加,且增幅相比岩石不均匀冻胀系数明显增大.试验初步反映了裂隙岩体的不均匀冻胀特性,为寒区隧道裂隙岩体冻胀变形计算提供了试验依据.     

动荷载作用下冻结黏土破坏特性试验研究

对冻结黏土进行单轴压缩试验和振动荷载试验,研究静-动荷载作用下冻结黏土的破坏强度、起始屈服强度、破坏应变、破坏时间、破坏应变比能,并进行对比分析。研究结果表明:冻结黏土破坏强度和起始屈服强度随温度降低而显著增大,振动频率的影响较小;冻结黏土破坏应变和破坏时间随温度降低呈现先增大后减小的趋势,温度的降低导致冻结黏土脆性增强;冻结黏土破坏应变比能是衡量冻结黏土抵御破坏能力的指标,随温度降低而增大,振动频率的影响规律不明显;在振动荷载作用下,破坏强度和起始屈服强度增大,破坏应变、破坏时间和破坏应变比能减小,振动荷载使得冻结黏土脆性增强,并且有利于破坏冻结黏土。     

人工冻结粘性土的冻胀特性研究

冻结法在矿山建设方面应用已越来越多,冻胀对施工的影响也不容忽视,对冻胀进行研究很有必要.通过自行研制的冻胀仪进行试验,并根据试验结果,比较分析两淮地区人工冻结粘性土在不同地层深度和土质下的冻胀特性,以及相同土样的砂质粘土在不同含水率下的冻胀特性,得出了冻胀力和冻胀率随着地层深度的增加而减小的特性.并研究了相同砂质粘土土样在不同含水量下的冻胀特性,得出了相同土样的砂质粘土冻胀率随着含水量的增大而增大,特别当含水量大于塑限时冻胀增量更大的物理特性,对工程应用具有一定的参考价值.     

水泥改良粉质粘土的冻土强度变化规律研究

对粉质粘土地层进行水泥改良后再进行冻结,可以有效减小冻结过程中产生的冻胀量,而改良后地层的冻结强度是冻结设计和施工的基础。为了获得水泥改良后粉质粘土冻结强度的变化规律,进行了不同水泥掺量条件下不同龄期改良粉质粘土的室内实验,测试了冻土的单轴抗压强度和弹性模量参数,获得了水泥掺量对改良后粉质粘土的冻土强度影响规律,建立了冻土强度、弹性模量与水泥掺量之间的线性拟合关系。通过实验发现,水泥的掺入可以有效提高冻土的力学参数,而且水泥掺量越大,冻土强度越高,同时冻土弹性模量也得到了相应提高。研究结果表明,当水泥掺量小于5%时,掺入水泥对冻土单轴抗压强度和弹性模量的提高作用不明显,实际施工中一般应控制掺入地层的水泥量超过5%。     

青藏高原多年冻土冻结强度的影响因素

对青藏高原风火山现场及室内冻胀试验进行分析的基础上,对影响青藏高原多年冻土冻结强度的土温、含水率、土质、基础桩材料等因素进行了分析,得出：土温高于-7℃范围内与负温近似成线形关系,冻结强度随含水率的增加而增大,粗颗粒土冻结强度大于细颗粒土,建筑材料越粗糙,冻结强度越大.     

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