单组分聚氨酯密封胶的研制

研究了单组分聚氨酯密封胶的合成，该胶由蓖麻油和聚醚二元醇分别和ＴＤＩ反应制得不同预聚体，再按不同配比进行混合，然后加入多种填料和催化剂制成．为此，讨论了催化剂用量、ＮＣＯ／ＯＨ比、不同预聚体比、有机硅含量对该密封胶的影响．     

环氧树脂的韧性固化剂的合成

用酸酐与一系列不同相对分子质量的柔性链剂聚物合成了环氧树脂的韧性固化剂。该韧性固化剂，在固化后的环氧树脂网络中，通过化学链引入了柔性链，与普通固化剂固化的环氧树脂相比，其韧性等机械强都有一定程度的提高。     

聚氨酯多元醇水分散体的合成

以异佛尔酮二异氰酸酯(IPDI),聚醚二元醇(N210),二羟甲基丙酸(DMPA),三羟甲基丙烷(TMP)为主要原料制备端-NCO聚氨酯预聚体,用二乙醇胺(DEA)封端引入羟基,合成了双组分水性聚氨酯的聚氨酯多元醇分散体组分.研究发现:DMPA,TMP的用量、羟基含量及分散体与固化剂组分的配比等因素显著影响分散体及涂膜...     

室温固化无溶剂双组份聚氨酯结构胶的研究

合成了4种相对分子质量和官能度各不相同的聚酯多元醇,并与MDI反应合成了端羟基及端异氰酸基预聚体,通过红外光谱对其结构进行了表征.研究了不同端羟基化合物与端异氰酸基化合物所构体系的粘接性能、热老化性能及热失重情况,结果表明该体系室温剪切强度为35~40 MPa,80℃,100℃和200℃剪切强度可达12~16 MPa,6~8 MPa和3~5 MPa,90°剥离强度为5~7 kN/m,T5最高为286℃,加入石棉后体系的高温剪切强度及耐热老化性能都得到提高.     

聚氨酯改性TDE-85/MeTHPA环氧树脂体系的结构表征

选用聚醚二元醇(PPG)和甲苯二异氰酸酯(TDI)为原料,合成聚醚型聚氨酯预聚体。采用该聚氨酯预聚体(PUP)、扩链剂、交联剂对TDE-85/甲基四氢邻苯二甲酸酐(MeTHPA)环氧树脂进行改性,通过扫描电镜与红外光谱分析,探讨聚氨酯(PU)改性环氧树脂(EP)体系的结构特征。结果表明:TDE-85与MeTHPA之间发生固化反应,形成环氧聚合物网络Ⅰ;1,4-丁二醇(1,4-BDO)及三羟甲基丙烷(TMP)与PU预聚体之间发生了扩链、交联反应,形成聚氨酯聚合物Ⅱ;PU改性TDE-85/MeTHPA树脂为非均相结构,PU含量是影响PU/EP材料两相相容性和相区尺寸的主要因素;当添加的PUP质量分数为15%时,PU改性TDE-85/MeTHPA体系具有互穿聚合物网络结构特征。     

可满足湿法预浸料的腈基树脂复合材料的制备与性能研究

采用含苯并噁嗪环的烯丙基腈基树脂(BCN)和环氧树脂(EP)对腈基树脂预聚体(PNP)进行改性,表征了改性树脂的固化行为、加工性能、预浸料的可加工性及其玻纤(GF)复合材料常温和老化后的力学性能、耐热性能和微观结构．结果表明,PNP/BCN/EP树脂可满足湿法预浸料工艺,预浸料可折叠,不掉粉,且有一定粘性; PNP/BCN/EP/GF复合材料的常温弯曲模量和弯曲强度分别为22.61 GPa和791.41 MPa;经300℃/72 h老化后,弯曲模量和弯曲强度保持率达98%和96%,质量保持率大于99%;可望在300℃左右的高温环境下服役．     

聚醚酰亚胺改性的环氧树脂的物理老化

用差示热分析（ＤＳＣ）方法研究了由胺端基或苯端基封端的两种聚醚酰亚胺改性的环氧树脂的物理老化，改性及未改性的环氧体系在１５０℃的热焓松弛数据表明，该体系的松弛程度及松弛速率与聚醚酰亚胺端基有密切的关系，同时发现，溶度参数及相结构是影响两组分体系物理老化的重要因素。     

聚醚砜改性环氧树脂低温力学性能研究

采用自制聚醚砜与环氧树脂反应,合成了改性环氧树脂,结合DSC,SEM及FT-IR等手段,研究了不同聚醚砜含量的改性环氧树脂在低温下(-50℃)的力学性能。研究表明:聚醚砜对环氧树脂固化温度影响不明显;低温下,聚醚砜含量升高,环氧树脂拉伸强度及弯曲强度先增加后降低,当聚醚砜含量为40%时,改性环氧树脂在低温下的拉伸强度及弯曲强度最高,分别为114.42 MPa及193.76 MPa。     

端羧基丁腈橡胶改性环氧树脂的研究

以端羧基丁腈橡胶(CTBN)作为环氧树脂(EP)的增韧改性剂,合成CTBN-EP的共混物和预聚体。通过红外光谱法(FT-IR)对共混物和预聚体进行结构表征,分析反应进程。同时,着重研究了CTBN的含量对环氧树脂力学性能的影响,评价增韧效果。FT-IR测试表明,共混过程未发生化学反应,预聚过程中EP中环氧基开环与CTBN活性端羧基发生酯化反应生成酯键。重点研究了CTBN含量对体系力学性能的影响。研究结果表明,随着CTBN含量增加,共混物和预聚体的拉伸强度均降低,断裂伸长率先上升后下降,冲击强度逐渐上升,说明CTBN对EP具有增韧效果。     

改性HTBN型聚氨酯弹性体的配方优化研究

以端羟基聚丁二烯—丙烯腈共聚物(HTBN)为软段、聚醚(酯)多元醇为改性剂,采用浇铸工艺制备聚氨酯弹性体(PUE)。研究了聚醚(酯)多元醇种类、分子量以及用量对PUE力学性能的影响,研究了二异氰酸酯、扩链剂种类对PUE力学性能的影响。实验结果表明:以HTBN与PTMG-1000混合物(质量比为1 1)为软段、PPDI为硬段、E-300作为扩链剂制备PUE,当预聚体NCO%为6.0%、NCO/NH2摩尔比为1.05,预聚体浇注固化后在115℃热处理2 h,得到的PUE力学性能最佳。PUE的拉伸强度为48.23 MPa、撕裂强度为165.26 N/mm、断裂伸长率为652.45%、硬度(邵氏A)为97。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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