固体磷酸催化剂的酸强度及其分布研究

采用浸渍法制备了固体磷酸催化荆,用Hammett指示剂法研究了焙烧温度及浸渍时间对固体磷酸催化荆酸强度范围及不同酸强度下酸量的影响.结果表明,浸渍时间一定时,催化剂的总酸量及各酸强度下的酸量都随着焙烧温度的升高而降低,焙烧温度一定时,催化剂的总酸量随着浸渍时问的增加而增大.     

土壤酸、碱度含量对土抗剪强度影响

土壤酸、碱度用以表征土壤的重要物理化学性质。本文通过室内不排水直剪试验研究不同酸、碱条件下土壤的抗剪强度变化规律。实验结果表明,酸的污染会降低土壤的抗剪强度。碱污染对土壤抗剪强度的影响受法向应力大小的影响。在法向应力小的时候,土壤的抗剪强度小幅提高;法向应力大时,土壤抗剪强度降低。     

固体酸催化剂在缩醋（酮）合成中的应用

综述了硅铝酸盐类，固体超强酸，离子交换树脂，杂多酸以及多机氯化物和硫酸盐等五类固体酸催化剂在催化合成缩醛（酮（中的笔研究进展，通过活性比较发现硅铝酸盐类通过增大骨架硅铝比，可增强酸中心强度，使缩醛（酮）反应更顺利进行，无机盐的酸中心强度与电负性与离子半径之比的大小成一致关系，且酸强度越大，缩醛（酮）的催化合成越容易进行。     

固体酸催化剂在缩醛(酮)合成中的应用

综述了硅铝酸盐类、固体超强酸、离子交换树脂、杂多酸以及无机氯化物和硫酸盐等五类固体酸催化剂在催化合成缩醛 (酮 )中的应用和研究进展。通过活性比较发现硅铝酸盐类通过增大骨架硅铝比 ,可增强酸中心强度 ,使缩醛(酮 )反应更顺利进行 ;无机盐的酸中心强度与电负性与离子半径之比的大小成一致关系 ,且酸强度越大 ,缩醛 (酮 )的催化合成越容易进行。     

溶剂法与丁胺滴定法测定REY分子筛催化剂的表面酸性

利用溶剂法和丁胺滴定法对REY分子筛裂化催化剂的表面酸性进行了测定,得到了两套酸量-酸强度分布曲线。确定了溶剂的pK_a~S和Hammett指示剂的pK_a~H之间的关系,发现用两种方法测得的酸量-酸强度分布曲线的走向有很好的一致性。     

固体超强酸的合成与应用研究 Ⅰ.量热滴定法测定超强酸的酸强度

本文首次应用量热滴定法测定固体超强酸的酸强度。和Hammett指示剂法比较的结果表明:两种方法在表征固体超强酸酸强度上是一致的。     

非水溶液电位滴定法及吸附指示剂法测量一些氧化锌脱硫剂和氧化铝的表面酸、碱度

固体催化剂的表面酸度和酸强度分布测量,对于石油加工工业是一项很主要的课题。典型的表面酸催化过程有催化裂化、异构化、烃化、聚合等等。许多实验证明,对于一些催化反应、催化剂表面酸度、酸强度对反应活性、选择性等都有影响。因此,表面酸度及酸强度分布的测量对于酸催化剂活性中心等重要理论的研究及实际应用都有重要价值。     

星型尼龙6纤维的力学性能研究

采用熔融挤出的方法制备尼龙6星型聚合物纤维，对所得纤维的强度、伸长、模量和回弹率进行测试，并考察了星型尼龙6的应力松弛，结果表明，随三元酸含量减少，纤维强度逐步增加，但三元 酸含量减少到一定程度，强度基本保持一定值；三元酸含量较高的星型尼龙6纤维弹性比线型链高一些，当三元酸含量进一步提高时，弹性又能所下降；三元酸含量较高的纤维，应力松弛较慢。     

用Hammett指示剂法测定固体催化剂的酸强度及其分布

本文利用胺滴定法在H0为＋5.0－－8.2范围的环已烷溶液中观察吸附的哈迈特指示剂的颜色变化，选用PKa值不同的向种指示剂，测出不同酸强度下的酸量而作出酸强度分布曲线，探讨了其规律性。     

聚对苯二甲酸乙二酯分子振动模式的特性研究

采用拉曼光谱法对聚对苯二甲酸乙二酯纤维的拉曼光谱特性进行研究,对聚对苯二甲酸乙二酯纤维分别进行酸、碱、盐处理,获得酸、碱、盐处理前后纤维的拉曼光谱,并对拉曼光谱的特性进行了分析与比较.结果表明,与未经处理的聚对苯二甲酸乙二酯相比,Na OH处理的PET在波数大于1 750cm-1时强度低于未经处理的PET,酸性染料对聚酯纤维的亲和力比较高,H2SO4处理的PET拉曼光谱和不经任何处理的PET的拉曼光谱相比,发生明显变化,强度显著减弱.而Cu SO4处理的PET拉曼光谱峰值强度明显高于未经处理PET纤维的拉曼光谱峰值强度.表明酸处理能够抑制聚对苯二甲酸乙二酯分子的振动模式,盐处理能够激发聚对苯二甲酸乙二酯分子的振动模式.     

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