反相气相色谱法测定溶剂在PBMA中的无限稀释活度系数

用反相气相色谱方法测定了１６种溶剂在聚甲基丙烯酸丁酯（ＰＢＭＡ）中３４３￣４３３Ｋ范围内的无限稀释活度系数,并用周浩等的高分子溶液分子热力学模型对实验结果进行了关联,结果令人满意。     

离子液体的无限稀释活度系数测量过程分析

摘要：离子液体受到结构上不对称性、静电作用等多种作用影响,系数特征容易发生形变,传统的测量方法在干扰状态下,很难准确测量。提出一种新的无限稀释活度系数测量模型(MCS-SVM)。通过实验测量与无限稀释活度系数相关的溶质参数,并将它们分成为训练集和测试集;然后将训练集输入到一种最小二乘支持向量机分类模型,并进行的活度系数,完成最优的无限稀释活度系数测量消除测量误差。仿真结果表明,相对于传统测量方法,该模型可以准确描述无限稀释活度系数与溶质参数的非线性关系,提高了无限稀释活度系数的测量精度。     

萃取分离油和磷脂的研究

探讨了有机溶剂革取油脚中的中性油的机理．萃取实验结果表明；２５℃，溶剂比为１．０时，用乙酸乙脂作溶剂，磷脂在萃取相和萃余相的分配系数λｐ小于０．１，选择性系数β大于４４。     

萃取体系的热力学研究——磷-32标记分配法测定D2EHPA的活度系数

在萃取化学中,为了研究萃取机理和求得真正的热力学平衡常数,常需引用有机相各组分的活度系数。但是由于实验方法的困难,有关这方面的数据还很不完备。 二(2-乙基己基)磷酸(D2EHPA)是一种重要的萃取剂,它广泛的应用于核燃料提取、稀土元素分离和其他有色金属的水冶工艺中。曾利用蒸气压法初步测定过它在某些溶剂中的活度系数。但蒸气压法实验直接测定的是溶剂的活度系数,如求溶质的活度系数,     

气相色谱法测定无限稀活度系数——有机物 脂肪酸酯二元溶液

无限稀活度系数对于溶液理论工作者是一非常重要的物理量。无限稀释时,溶质一溶质间距离无限远,其相互作用可忽略不计,溶液中只存在溶质一溶剂、溶剂一溶剂相互作用力,使得理论处理简单化。而气相色谱因其测试周期短,准确度高,巳成为研究溶液的一种重要方法〔‘,一:」。本文报道了用气相色谱法测定的正庚烷、正己烷、环己烷、四氯化碳、苯、三氯甲烷、乙醚、异丙醇、正丙醇、乙醇、甲醇、乙酸甲醋、丙酮、丁酮等十四种溶质在丁二酸二正丁醋、丁二酸二异辛醋、癸二酸二正壬酗中的无限稀活度系数,并就实验结果作了讨论。     

采用人工神经网络方法预测烷烃的无限稀释活度系数

采用人工神经网络技术,利用改进的BP算法：Levenberg-Marquardt优化学习方法,以分子连接性指数等作为分子描述参数,对烷烃在各种溶剂中的无限稀释活度系数进行预测。计算值与实验值进行比较,表明两者结合具有良好的预测效果。     

采用人工神经网络方法预测烷烃的无限稀释活度系数

采用人工神经网络技术,利用改进的BP算法Levenberg-Marquardt优化学习方法,以分子连接性指数等作为分子描述参数,对烷烃在各种溶剂中的无限稀释活度系数进行预测.计算值与实验值进行比较,表明两者结合具有良好的预测效果.     

根据分配系数初选醇水体系的萃取溶剂

提出了根据分配系数与醇在溶剂中活度系数的关系,初选醇水体系萃取溶剂的方法。用UNIFAC模型计算了醇在溶剂中活度系数,用文献数据验证了本方法的正确性。预测苯酚、丁酸等可望作为醇水体系的萃取剂。     

气相色谱法测无限稀活度系数及超额偏摩尔函数

本文报道了用气相色谱法测定十一种溶质:正庚烷、正已烷、正戊烷、四氯化碳、乙醚、异丙醇、正丙醇、乙醇,甲醇、丙酮、丁酮在正三十六烷及角鲨烷溶剂中的无限稀活度系数γ,根据活度系数与温度的关系,计算出了超额偏摩尔函数H_1~E、S_1~E,并就实验结果进行了讨论。     

电导法测定HCl在H2O和1.2-丙二醇混合溶剂中的活度系数

对电导法测定电解质溶液活度系数的原理进行理论推导，并通过测定HCl在H2O和1，2-丙二醇混合溶剂中的活度系数，对电导法进行实验验证，讨论温度和浓度对电解质溶液活度系数的影响。     

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.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the