三相床合成气制二甲醚的宏观动力学

在温度220~265℃,压力4.0~6.0 MPa,空速1~2 L/(g.h),气体摩尔分率yH2=0.555 0~0.743 5,yCO=0.214 2~0.371 2,yCO2=0.030 0~0.044 8,搅拌转速1 000 r/min的反应条件下,于500 mL高压搅拌釜中进行了合成气在双功能催化剂上二甲醚合成过程的三相床宏观动力学研究,建立了幂函数型的动力学模型,获得了模型参数,经统计检验和残差分析证实了模型的可靠性。     

基本粒子的旋转激发态

在文章[1]里,从结构模型出发,阐明了0~-、1~-介子和(1/2)~+、(3/2)~+重子内部结构的某些特征,并成功地解释了它们的β衰变和电磁现象。在这篇文章里,将进一步处理2~+、(5/2)~+和(7/2)~+的基本粒子。我们的观点是:这些粒子分别是上述1~-、(1/2)~+和(3/2)~+粒子的空间旋转激发态。由于在我们的模型里,基础粒子间的超强作用是与自旋无关的,这些激发态的     

基于岩土广义双τ~2强度理论的弹塑性本构模型建立及程序实施

基于广义双τ~2强度理论建立非关联流动的弹塑性本构模型(文中简称Dτ~2弹塑性本构模型),并采用应力张量第一不变量I_1,应力偏张量的第二不变量J_2以及洛德角θ_σ来表达该强度理论,推导Dτ~2弹塑性本构模型的完全隐式本构积分算法,并给出相应的有限元实施步骤.广义双τ~2强度理论在数值实施方面避免了"奇异屈服面"处理困难的问题,其数值实现相对简单.基于推导的本构积分算法编制求解程序,采用Prandtl经典问题解析解进行了Dτ~2弹塑性本构模型以及实施方法的正确性验证,对比Dτ~2弹塑性本构模型、DP本构模型以及Prandtl理论解析之间的关系,该强度理论和程序可以广泛应用于土木、采矿和水利等岩土工程安全性及稳定性的分析研究.     

4,4'-二异氰酸酯二苯甲烷在超临界CO_2中溶解行为研究（英文）

测定了温度为313~353 K、压力为9.6~16.3 MPa条件下,4,4'-二异氰酸酯二苯甲烷(MDI)在超临界CO_2中的溶解度,运用Bartle和Chrastil半经验模型对溶解度数据进行了关联分析.结果表明:实验数据和理论数据吻合良好,平均值绝对相关偏差对Bartle模型在4.56%~10.68%,Chrastil模型为10.79%.根据Kumar和Johnston的理论算得MDI在该条件下的超临界CO2中的偏摩尔体积V_2.     

基于线性回归与神经网络的储层参数预测复合方法

为提高储层参数的预测精度,提出一种利用测井资料,结合多元线性回归和神经网络预测储层参数的新的复合方法,具体分两步:(1)通过多元线性回归分析建立回归值y'的计算模型,将y'作为储层参数的初步预测值;(2)通过RBF神经网络建立y'的残差Δd的预测模型,将预测结果Δd作为y'的非线性误差补偿,最终建立储层参数解释模型,y=y'+Δd。基于该方法,结合测井资料和岩心数据,建立了鄂尔多斯盆地某致密砂岩气田M3井区S_2~2、T_2~2段孔隙度和含水饱和度的测井解释模型,结果显示,新方法建立的模型预测值与S_2~2、T_2~2段实际岩心孔隙度、含水饱和度值的平均相对误差均小于17%,明显优于单独根据多元线性回归分析或RBF神经网络建立的解释模型,预测精度更高。     

超声场对超临界CO2萃取除虫菊酯的影响

在有、无超声场(20 kHz,200W-电功率)中用超临界CO2萃取除虫菊酯,结果表明,超声场能强化传质的内、外扩散过程,从而提高萃取速率.还在35~45℃,8~18 MPa下测定了有、无超声场作用下除虫菊酯在超临界CO2中的溶解度.结果表明,施加超声场能提高除虫菊酯在超临界CO2中的溶解度,用Chrastil模型和改进的Chrastil模型对超声场中的测定结果进行处理,表明用改进的Chrastil模型关联能获得较好的结果.     

除虫菊酯在超临界二氧化碳中溶解度的研究

建立了一套带预饱和釜的流动法测定固态物质在超临界CO2中溶解度的装置,测定了在35~45℃,8~17 MPa下除虫菊酯在超临界CO2中的溶解度.用Chrastil模型和改进的Chrastil模型对测定结果进行处理.表明对除虫菊酯用改进的Chrastil模型关联能获得较好的结果,该关联式为超临界CO2萃取与分离除虫菊酯提供了依据.     

无界报酬折扣模型的最优策略结构

在Harrison意义下的无界报酬函数折扣模型下,本文讨论了最优策略的几个性质和它的结构。本文证明了:若π~*=(π_1~*,π_2~*,…)是该模型的最优策略,则π_1~(*∞),(π_1~*,…,π_n~*)~∞与(π_1~*,…,π_n~*,π_1~*,π_2~*,…)(n≥1)都是最优策略;给出π_n~*也构成最优随机平稳策略的条件和修改方法;策略π~*=(π_1~*,π_2~*,…)是最优的当且仅当它在任何时刻可达的状态上都必须选取最优决策;最后指出π_0~(*∞)为最优随机平稳策略的充要条件是决策规则π_0~*是若干个最优平稳策略f_n~∞的决策函数f_n的凸组合。从而较完满地解决了Harrison无界报酬意义下折扣模型的最优策略结构问题。     

具有不正确设计阵和散布阵的随机回归系数和参数的G-M估计

考虑随机效应线性模型Y=Xβ+ε,E（β′,ε′）=0,Cov（（β′,ε′）′）=diag（б_1~2,б_2~2）,其中X,V≥o U≥0及A均为已知阵,α,б_1~2和б_2~2为参数,记此模型为 L（Xβ,Aα;б_1~2V,б_2~2U）,在 L（X_0β,Aα;б_1~2V_0,б_2~2U_0）下,假定X_0Aα和X_0β的G-M估计存在,我们求解下列问题:在什么条件下, L（X_0β,Aα; б_1~2V_0,б_2~2U_0）下的每个可估函数ω′_1α,ω′_2β及ω′_1α+ω′_2β的G-M估计也是L（Xβ,Aα;б_1~2V,б_2~2U）下相应待估函数的a）无偏估计;b）G-M估计     

原颗粒催化剂上苯胺加氢复杂反应体系的宏观动力学

采用自制的GDCH-2012圆柱状颗粒催化剂,对苯胺加氢联合制备环己胺和二环己胺反应的宏观动力学进行研究。在固定床反应器中,催化剂分3个单层,层间用石英砂均匀间隔。在高温、低苯胺流量、低苯胺与H2摩尔比的条件下消除了外扩散的影响。在温度180~240℃、压力0.3 MPa、苯胺进料流量0.013 2~0.158 mol/h、苯胺与H2摩尔比(氢胺比)(10~20)∶1条件下测定宏观动力学的实验数据,并建立宏观反应动力学模型。以苯胺的转化率、二环己胺的收率以及N-环己基苯胺收率的残差平方和为目标函数,采用Matlab软件中的非线性最小二乘法对实验数据进行拟合,估算出该模型中的各个参数,并对模型的显著性进行了检验。结果表明:模型计算值与实验测定值吻合良好,且模型是高度适定的。通过计算还得到了氢胺比(10~20)∶1、反应温度180~240℃、不同苯胺转化率下的催化剂内扩散有效因子。     

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.     

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