聚乙二醇促进苯乙烯-丙烯腈无规共聚物碱解行为研究

本文研究了苯乙烯-丙烯腈无规共聚物（SAN）在二氧六环（DOA）中的碱解行为.结果表明聚乙二醇（PEG）能促进SAN的碱解,尤其是促进腈基转化为酰胺基;随反应时间的增加,酰胺基进一步转化为羧基;PEG分子链长对于SAN碱解的促进作用具有重要影响.     

丙烯腈/丙烯酰胺/苯乙烯三元共聚超滤膜材料的制备和表征

以偶氮二异丁腈为引发剂,采用溶液聚合法制备了丙烯腈、丙烯酰胺、苯乙烯三元共聚物,并用红外光谱(IR)、示差扫描量热(DSC)、热重分析(TG)等手段对共聚物进行了结构和性能表征。结果表明:苯乙烯的加入使得参加环化反应的氰基和酰胺基的数目减少,保留了更多作为功能基团的酰胺基。用相转化法制备得到超滤平板膜,膜的渗透通量为2.63 mL/(cm2.h),对聚乙二醇20000(PEG 20000)的截留率为96.95%。     

3,4-二氨基呋咱的乙酰化及酰化产物的硝解

以3,4-二氨基呋咱为反应物,对其酰化反应、酰化产物的硝解反应及其产物的重排分解反应进行了研究. 在对甲苯磺酸的催化下,以3,4-二氨基呋咱为反应物,用乙酸和乙酸酐为酰化试剂分别得到了3-氨基-4-乙酰胺基呋咱和3,4-二乙酰胺基呋咱,反应时间分别为3 h和10 min时产率最大,分别为78%和89%;在硝酸-醋酐硝化体系中对3,4-二乙酰胺基呋咱进行了硝解反应,得到化合物3-乙酰胺基-4-硝酰胺基呋咱,反应温度在0~-5℃时得率较大,为54%;在微量酸存在下,在溶剂四氢呋喃中3-乙酰胺基-4-硝酰胺基呋咱可发生重排分解生成3-乙酰胺基呋咱.      

联合梯田不同海拔稻田土壤养分及其生态化学计量比分布特征

以东南丘陵区的联合梯田土壤为研究对象,探讨不同海拔土壤有机质(SOM)、碱解氮(SAN)、有效磷(SAP)、速效钾(SAK)含量及其化学计量比的分布特征.结果表明:在海拔100~299 m(Ⅰ)、300~499 m(Ⅱ)、500~699 m(Ⅲ)、700~899 m(Ⅳ)、900 m以上(Ⅴ)5个梯度,SOM含量在海拔Ⅰ~Ⅳ基本稳定,在海拔Ⅴ显著增加;SAN含量随着海拔的升高略有增加趋势;SAP和SAK含量在海拔Ⅰ较低,从海拔Ⅱ到Ⅴ呈下降趋势.SOM、SAN含量在各海拔梯度肥力总体较高,SAP和SAK肥力中等偏上(除Ⅴ外);SAN与SAP含量比无明显变化规律,SAN与SAK含量比和SAP与SAK含量比随着海拔的升高呈"Ⅴ"字型变化.此外,高海拔区(Ⅳ和Ⅴ)土壤SAN与SAP含量比较高,表明联合梯田土壤在高海拔区存在一定的磷限制,需加强施肥指导,适当增施磷肥.     

新型手性四氮镍(Ⅱ)配合物的合成、表征及催化苯乙酮不对称氢转移研究

合成了两个手性四氮配体,(S,S,S,S)-N,N’-二[2-(对甲苯磺酰胺基)-1,2-二苯基乙基]乙二胺(A)和(S,S,S,S)-N,N’-二[2-(对甲苯磺酰胺基)-1,2-二苯基乙基]丙二胺(B),及其手性镍(Ⅱ)配合物1和2,采用元素分析、1 H NMR、MS和IR对它们进行了表征.研究了手性配合物催化苯乙酮的不对称氢转移反应,考察了碱量和反应时间对催化活性的影响.     

高分子造纸助剂的设计及其作用机理Ⅰ. N-氯代酰胺基在中性条件下的反应

研究了1-丁酰胺的N-氯代衍生物与1-丙醇水溶液在弱碱性条件下的化学反应.通过对产物的定量及结构分析,发现N-氯代酰胺基的55% 转化为1-丁酰基-3-丙基尿素,15%转化为1,3-二丙基尿素,10% 转化为丙氨基甲酸丙酯.由此推论PAM的N-氯代酰胺基能形成网状结构且能和羟基形成共价键.这些都预示着N-氯代聚丙烯酰胺具有优良的纸湿增强效果.     

2,6-二乙酰吡啶缩2,6-二甲基苯胺双希夫碱的合成及其晶体结构

将2,6-吡啶二甲酸二甲酯与乙酸乙酯混合发生缩合反应,得到2,6-二乙酰吡啶(DAP)Ⅰ,将Ⅰ与2,6-二甲基苯胺发生缩合反应,获得2,6-二乙酰吡啶缩2,6-二甲基苯胺双希夫碱化合物Ⅱ.并通过元素分析和核磁共振氢谱等手段对其结构进行了表征.用X射线单晶衍射测定了Ⅱ的晶体结构.晶体结构表明,两个芳环与吡啶环没有通过两个亚甲胺基(CN)形成π键共轭体系.     

1,4-二[N-(2-(3-吡啶酰胺基)亚乙基)]氨基-5,8-二羟基蒽醌的合成与结构表征

1,4-二[N-(2-(3-吡啶酰胺基)亚乙基)]氨基-5,8-二羟基蒽醌(Ⅲ)可以作为潜在的抗癌候选化合物.本文以1,4,5,8-四羟基蒽醌隐色体为原料,通过与乙二胺反应制得1,4-二(氨基亚乙基胺基)-5,8-二羟基蒽醌(Ⅱ),然后再与烟酸酰氯反应制备1,4-二[N-(2-(3-吡啶酰胺基)亚乙基)]氨基-5,8-二羟基蒽醌(Ⅲ),化合物通过IR、NMR进行了结构表征.     

含酰胺基团过渡金属配合物红外光谱的研究

制备了聚(苯乙烯-丙烯酰胺)过渡金属配合物-SAA·MCln(M=Fe,Cu,Cr)和氯化稀土丙酰胺配合物-LnCl~3·3PA;Ln=Pr,Nd,Eu、Dy)。剖析了含酰胺基团配合物的红外光谱,结果表明,酰胺基团与金属离子的配位方式为■     

硬脂酸酰胺基二苯醚双磺酸钠的合成和性质

通过对硝基二苯醚的硝基还原反应、硬脂酸酰氯胺基酰化反应、氯磺酸磺化反应,合成了带有极性酰胺基团的双子表面活性剂硬脂酸酰胺基二苯醚双磺酸钠.通过IR,1H-NMR,MS对产品及其中间体结构进行了鉴定.用拉起圆环液膜法测定了水溶液表面张力和临界胶束浓度,结果表明其临界胶束浓度为2.42 mmol/L,水溶液表面张力可降至34.4 mN/m,与传统的表面活性剂十二烷基苯磺酸钠(SDBS)比较,具有更高的活性.     

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