增容PP/回收PET共混物的非等温结晶和熔融行为研究

双螺杆挤出机制备了相容剂PP-g-MA或PP-g-GMA增容PP/回收PET(r-PET)(质量比为80/20)共混物,DSC研究了相容剂含量、熔融温度与时间以及降温速率对共混物非等温结晶与熔融行为的影响。加入PP-g-MA或PP-g-GMA对PP结晶温度影响不明显或使其有所降低,与相容剂种类及其用量有关。PP-g-MA增容共混物中r-PET熔点比PP-g-GMA增容的低,表明相容剂PP-g-MA与共混物中r-PET的作用比PP-g-GMA的明显。熔融温度提高,共混物中PP结晶和熔点降低,r-PET熔融峰形和熔点取决于熔融温度。     

PBs/PET共混体系的制备与表征

以丁二酸、丁二醇为原料,通过直接缩聚反应合成了高分子量聚丁二酸丁二醇酯。并将聚丁二酸丁二醇酯 (PBS)同聚对苯二甲酸乙二醇酯 (PET)在不同温度下熔融共混。测定了不同组分共混物的熔点和水降解性。聚合物熔融峰随着共混时间的增加渐渐的下移。这说明PBS和PET热降解和酯交换反应随着共混温度的增加而同时发生。共混物的降解性与芳香组分的含量和链段长度都有关。     

PPS／PEEK共混物多次DSC扫描中PPS结晶行为

聚苯硫醚(PPS)及其与聚醚醚酮(PEEK)共混物DSC多次升降温扫描表明,同一PPS样品在多次扫描过程中从不同温度下降温结晶,结晶温度(θc)明显不同,归结于PPS自成核作用的存在和其分子结构的变化.共混物中PPS组分的熔点(θmp)虽然有所降低,但由于PEEK对PPS结晶有促进作用,PPS组分θc明显地比纯PPS的高,结晶热与生成结晶的熔融热(结晶度)增加,归结于PPS与PEEK界面相互作用引起高温下异相成核,可结晶部分增加,结晶加快.     

PET/LCP反应性共混物序列结构与热性能的关系

利用2H－NMR方法对聚对苯二甲酸乙二酯（PET）和热致性液晶共聚酯60PHB／PET（LCP）体系在少量扩链剂双（2－恶唑啉）BOZ存在下形成的反应性共混物的序列长度进行表征，并研究序列长度对共混物热性能的影响，研究表明PET和PHB的序列长度均随共混时间的延长和温度的提高而降低，且在相同温度下，含扩链剂BOZ的共混体系的序列长度比不含BOZ的体系小，表明BOZ对酯交换起促进作用，共混物组分中PET的熔点Tm和熔体结晶工Tmc均随序列长度（LPET)的增大而降低，而冷结晶温度Tcc却升高。     

非晶态共聚物P(VA-VP)对PVA结晶行为影响的研究

本文用DSC法研究了醋酸乙烯酯和乙烯基吡咯烷酮共聚物的水解物和聚乙烯醇(PVA)共混体系的热性能与结晶行为.结果表明,共混物的玻璃化转变温度和组成关系符合Fox方程.共混体系的熔点、熔融热效应、晶片层厚度和结晶度随非晶组分的增加而下降.结晶度还受结晶时间的影响,显示了处于非平衡状态下的结晶组分具有不同的结晶特性.还研究了共混物组成对半结晶时间、结晶速率常数及晶体的成核与生长形态的影响,非晶相组分的加入不影响PVA晶体的成核与Avrami指数.     

支化度和分子量对树枝化共聚物熔融和结晶性能的影响

从PEG10000出发合成了一系列分子量相同、支化度不同和支化度相同、分子量不同的PCL-PEG-PCL树枝化三嵌段共聚物,采用DSC测定了共聚物的熔点及结晶温度,结果表明:在相同分子量下,随支化度的提高,熔点和结晶温度都向低温方向移动;在相同支化度下两者都随分子量的增大而向高温方向移动;采用XRD观察了共聚物中不同组分的结晶情况,结果表明:在相同分子量下,支化度(G)对PEG段的结晶有非常大的影响,当G≥3时PEG段的结晶就完全被抑制了,在相同支化度(G=2)下,PCL段的聚合度对PEG段的结晶抑制作用也非常明显,当聚合度≥22时,PEG段的结晶就完全被抑制了。     

TPI与TPB共混物的非等温结晶动力学

通过WAXD和DSC研究了反式-1,4-聚异戊二烯(TPI)与反式-1,4-聚丁二烯(TPB)共混物的非等温结晶行为.WAXD数据表明了共混物中存在TPI和TPB晶体.结果表明修正的Avrami方程能较适宜的描述TPI和TPB组分的非等温结晶过程.TPI与TPB(Tp＞119℃)的结晶分为初级和次级两个结晶阶段,TPB( Tp＜ 50℃)只表现出一个结晶历程.TPB对TPI的结晶起到异相成核的作用.     

支化度和分子量对树枝化三嵌段共聚物熔融和结晶性能的影响

从PEG10000出发合成了一系列分子量相同而支化度不同和支化度相同而分子量不同的PCL-PEG-PCL树枝化三嵌段共聚物,采用DSC测定了共聚物的熔点及结晶温度。结果表明:在相同分子量下,随支化度的提高,熔点和结晶温度都向低温方向移动;在相同支化度下二者都随分子量的增大向高温方向移动。采用XRD观察了共聚物中不同组分的结晶情况,结果表明:在相同分子量下,支化度对PEG段的结晶有非常大的影响,当支化度G≥3时PEG段的结晶就完全被抑制了;在相同支化度(G=2)下,PCL段的聚合度对PEG段的结晶抑制作用也非常明显,当聚合度P_d≥22时,PEG段的结晶完全被抑制。     

尼龙1212/聚偏氟乙烯共混物的结晶行为

通过溶液共混法制备尼龙1212/聚偏氟乙烯(PVDF)共混物,采用X线衍射仪(XRD)和差示扫描量热仪(DSC)研究了尼龙1212/PVDF共混物结构、熔融和结晶行为.研究结果表明:在降温过程中先结晶尼龙1212限制了PVDF的结晶,但是这种限制作用随着尼龙1212质量分数的降低而减弱,这也影响到共混物的熔点和结晶温度.通过Avrami方程和阿累尼乌斯方程对PVDF和共混物(质量比80∶20)的等温结晶行为进行研究,结果表明由于尼龙1212结晶导致了共混物的等温结晶活化能升高,共混物的结晶速率显著降低.     

PBT/EVA共混体系相容性、相态及结晶形态的考察

讨论了PBT/EVA共混体系的相容性、相态及结晶形态。实验发现,PBT/EVA共混具有一定程度的相容性。对于不同模式的共混方法,共混相态差别较大。以双螺杆挤出机挤出共混相态分散均匀,相域较小,而单螺杆挤出机挤出共混分散较差,相域大且有包藏结构。PBT/ENA共混呈海岛结构,且相域界面有一定程度的层过渡。对共混体系的结晶度及结晶形态考察发现,结晶温度对结晶形态影响较大,而温度和组份比的影响对结晶度较小(≤10％),有趣的是在高于EVA熔点温度下EVA组份有反常结晶现象。本工作对研究PBT的复合改性有一定的指导意义。     

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.     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-