气液相变的自聚集分析

应用分子自由程概念给出一种判别体相中活化与非活化分子的判据,基于分子自聚集理论,提出活化分子临界聚集浓度的概念,描述核心形成之前的物理图景.浓度较低时活化分子主要以单体形式存在,达到临界聚集浓度时开始聚集,但只有聚集数小于5的聚集体能够在体相中稳定存在,过剩的活化分子只能无限聚集,形成临界核心,继而产生相分离.在无外界扰动时,临界聚集浓度点对应着气-液相变的过热极限点或过冷极限点.通过定量分析聚集体浓度和聚集数的关系,确定体相处于过热(过冷)极限点时体相与新相之间的界面特性,预测体相与微小新相之间的界面张力γ,对经典理论的形核率作出合理修正.     

硝酸锌与组氨酸固液反应的热动力学

用微热量计对硝酸锌与组氨酸在水中的固液反应进行了热动力学研究。通过实验和计算得出该反应的热力学参数(活化焓、活化熵及活化自由能)、速率常数和动力学参数(活化能、指前因子及反应级数)。将温度改变对该反应的影响及配合物的合成条件进行了讨论。     

纤维粘连蛋白的AFM分析

利用原子力显微镜(AFM)分析了纤维粘连蛋白(FN)单分子及其聚集行为，对FN在壳聚糖膜表面聚集过程及FN/壳聚糖微胶粒形成过程进行了连续观察分析，并分析了微空间中“水膜”在FN分子及微胶粒形成及聚集过程中的作用.FN分子单体呈“V”型，其聚集体以头－尾的方式结合.     

绿色离子液体介质中有序分子聚集体构建

 离子液体具有很多物理、化学特性且环境友好,被广泛应用于化学、化工、材料、生物、环境等领域。评述了非质子化离子液体、质子化离子液体等作为绿色介质在构建胶束、溶致液晶、囊泡、微乳液和乳状液等有序分子聚集体方面的研究进展。简述了两亲分子和有序分子聚集体的基本概念、分类及发展,对各种离子型表面活性剂、非离子型表面活性剂及聚合物类表面活性剂在非质子化离子液体、质子化离子液体及水溶液中自组装有序分子聚集体的类型、结构、影响因素、驱动力、机制等进行对比分析,并对其应用领域和研究趋势进行展望。     

微纳液滴的凝固及熔化特性研究

金属的凝固和熔化是金属材料成形过程中的重要相变过程.当大体积的金属熔体被弥散为尺度在微米乃至纳米的微小液滴时,金属的凝固和熔化均会由于材料自身尺度的减小,而在相变过程中发生显著的变化.这一过程涉及到基础科学问题的研究、样品制备及表征技术的开发等,对金属的最终组织和使用性能,也会产生显著影响.对本研究团队近年来在微纳液滴凝固及熔化特性方面的研究进行总结,同时对该研究领域未来的发展进行展望.     

铸造速度对Al-Cu合金半固态组织影响的多尺度模拟

用多尺度模拟方法研究了半连续铸造过程与Zl201合金成分近似的5%Al-Cu合金凝固组织受铸造速度的影响。建立了温度场模型和相变模型。通过固相率的变化把温度场计算和微观组织模拟从宏观尺度和介观尺度耦合起来。将宏观尺度上计算出的稳态温度场映射到介观尺度上。利用液固相变区中原胞的平均过冷度确定半连续铸造过程中各元胞的形核,采用溶质扩散模型描述晶粒长大。针对选定对象模拟了浇铸温度为930 K,铸造速度在(1.5～3.5)mm/s时微观组织的演变。结果表明,当铸造速度在2.0 mm/s时得到的微观组织均匀、细小,模拟结果与实验结果吻合。     

蒸发与凝结现象的分子动力学研究

采用分子动力学方法研究了气液共存体系的蒸发与凝结现象,模拟验证了经典理论对界面分子碰撞流率预测的有效性,并通过对气液界面上的相变微观过程的分析统计,获得了气相分子凝结的判据,以此为依据提出了采用分子动力学方法统计凝结的新方法,模拟计算了3个不同温度下氩的凝结系数,对不同温度条件下的分子动力学模拟表明,氩的凝结系数随系统温度的升高而减小。     

基于动态相变的热轧Nb-V-Ti微合金化TRIP钢组织及性能

通过单轴热压缩试验,结合扫描电镜以及X射线衍射技术,研究了动态相变前奥氏体晶粒状态对基于动态相变的热轧Nb-V-Ti微合金化TRIP钢复相组织状态及力学性能的影响.与动态相变前奥氏体晶粒为等轴状条件下相比,动态相变前奥氏体晶粒为拉长状条件下,动态相变得到的铁素体转变量较大,最终复相组织中贝氏体含量较少且团径较小,马氏体含量较少,但对残余奥氏体含量及其含碳量影响不明显.与不含微合金化元素的基于动态相变的热轧TRIP钢相比,Nb-V-Ti微合金化TRIP钢的屈服强度和抗拉强度明显提高,而延伸率有所降低.     

表面电位对异向凝聚影响的计算机模拟

在对微细粒物料异向凝聚的动力学过程进行详细理论分析的基础上，开发了模拟异向凝聚过程及聚集体结构的程序，对聚集体形成的动力学过程及其结构等进行模拟，求得聚集体的分维数，从而更好地揭示了微细粒物料的凝聚机理及聚集体的内部结构。不同表面电位时，模拟聚集体的分维数介于１．５２￣１．７３之间。     

单液滴运动相变模型

在对汽水分离装置中液滴运动过程中的相变现象描述和物理机理解释的基础上,结合压力变化条件下静止单液滴相变模型的基础和液滴运动模型,建立了单液滴运动相变模型。该模型给出了液滴运动过程中,由于流动阻力和局部结构改变造成压力降低,打破汽液相平衡而造成液滴的快速蒸发和汽液相平衡蒸发2个阶段的机理解释和数学表述,与已有结果和理论分析结果均较符合。该模型可以用于液滴在重力分离空间、旋风和旋叶分离器、波纹板分离器等汽水分离装置中运动相变过程中的分离效率计算,衡量液滴相变对汽水分离性能的影响,指导分离装置结构的优化设计。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-