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1.
NPG-TAM/蒙脱土纳米复合贮能材料的研究   总被引:2,自引:0,他引:2  
研究了利用插层复合法将新戊二醇-三羟甲基氨基甲烷(NPG-TAM)二元体系多元醇混合物嵌插到蒙脱土的层间,制取NPG-TAM/蒙脱土复合贮能材料的方法。由实验确定了适宜的制备条件。用XRD、IR、DSC等方法对其结构及贮能性能进行了分析。实验结果表明:所得材料是一种纳米复合贮能材料,具有较适宜的相变温度和相转变焓,同时较好地解决了多元醇单独使用时存在的塑晶现象。  相似文献   

2.
脂肪酸二元体系固液相变动力学研究   总被引:2,自引:0,他引:2  
为有效地控制脂肪酸贮能材料的相变过程,用差示扫描量法(DSC)研究了癸酸(CP)与硬脂酸(SA),月桂酸(LA)与豆蔻酸(MA)、棕榈酸(PA)二元体系的热力学性能,确定了低共熔混合物的组成、相变温度和相变潜热。运用Kissinger方法计算了CP-SA、LA-MA、LA-PA低共熔混合物固液相变过程的活化能及反应级数,结果表明:反应级数为1左右,活化能为199~226 kJ/mol,为脂肪酸、二元体系在民用建筑和调温纺织中应用提供了重要依据。  相似文献   

3.
光聚合和热聚合蒙脱土插层纳米复合材料的制备   总被引:2,自引:0,他引:2  
利用光引发聚合和热引发聚合研究了单体(MMA)和蒙脱土(Mot)插层复合材料(PMMA/Mot)的制备.用X衍射技术对两种产物内蒙脱土的结构进行了表征.结果表明,蒙脱土经改性后能很好地使聚合单体插入蒙脱土层内并在光或热的作用下发生原位聚合反应生成复合材料.利用DSC、SEM研究了产物的结构和形态,并对两种聚合方法制备蒙脱土纳米复合材料的特点进行了初步讨论.  相似文献   

4.
通过聚合插层的方法制备了SPET/蒙脱土纳米复合材料,用WAXD,TEM研究了形态结构,用DSC比较了不同离子含量的SPET及其与蒙脱土纳米复合材料的结晶行为,用TGA研究了离聚物/蒙脱土的热稳定性。结果表明,离聚物中磺酸钠含量的提高有助于蒙脱土层间距的增大及在基体中的分散;另外基体中分散的蒙脱土能大大改善SPET的结晶性能并提高了其热分解温度。  相似文献   

5.
采用真空吸附法将液态的癸酸-硬脂酸(CA-SA)二元共晶相变材料封装入多孔膨胀珍珠岩(EP)中,制备颗粒定型复合相变材料CA-SA/EP,并以石膏为无机基体研制储能墙板。采用傅里叶红外光谱仪(FT-IR)、扫描电子显微镜(SEM)、差示扫描量热仪(DSC)、多路温度测试仪和热扩散系数测试仪表征材料的性能。结果表明:以质量比4∶1的CA-SA二元共晶相变材料在EP复合相变材料中的最佳吸附质量分数为75%,且在EP的多孔网络结构中均匀分布,复合过程中CA-SA二元共晶相变材料与EP间不发生化学反应,没有新产物形成;CA-SA/EP颗粒定型复合相变材料的相变温度和相变潜热分别为20.7℃和120.4 J/g,500次热循环后,颗粒定型复合相变材料的热性能基本不变。  相似文献   

6.
用原位缩聚的方法合成聚对苯二甲酸丙二酯/蒙脱土纳米复合材料(PTT/MMT),所得的材料为剥离型纳米复合材料.通过DSC等测试手段研究了PTT/MMT纳米复合材料的结晶行为和热分解过程;测定了纳米复合材料的力学性能.结果表明,随着蒙脱土含量的增加,PTT/MMT的熔融结晶温度增高,其结晶过程为异相成核;纳米复合材料的力学性能有一定的提高.  相似文献   

7.
采用真空浸润法制备一种定型复合相变材料,其中癸酸(CA)和棕榈酸(PA)低共熔物为相变工作物质,膨胀珍珠岩(EP)为载体材料。通过FT-IR、SEM、DSC和TG等手段研究定型相变材料的化学稳定性、微观结构、热性能和热稳定性。结果表明:CA-PA合金通过物理结合被均匀地吸附在膨胀珍珠岩的孔道中。膨胀珍珠岩吸附CA-PA合金的最佳质量分数为55%,熔融潜热、凝固潜热分别为81.5、79.7J/g,对应的熔融温度、凝固温度分别为27.9、19.1℃。冷热循环1 000次后,CA-PA/EP定型复合相变材料的热性能基本不变,具有很好的稳定性。  相似文献   

8.
以环氧树脂E53为研究对象,采用预剥离法制备出环氧树脂/蒙脱土纳米复合材料,并结合XRD、SEM及DMA等实验方法研究蒙脱土分散状态对环氧树脂的微观结构和性能影响.结果表明:在环氧树脂E53固化前,对蒙脱土进行预剥离处理有利于制备出剥离型环氧树脂/蒙脱土纳米复合材料;蒙脱土的加入,使环氧树脂/蒙脱土纳米复合材料的Tg比环氧树脂的升高5℃8℃,其储能模量及刚性随之增加;较低的β转变温度使其具有最好的低温韧性.对于剥离型环氧树脂/蒙脱土纳米复合材料,其均匀分散的无机纳米片层能有效地阻止裂纹的扩展,对材料起到了增强增韧效果.  相似文献   

9.
聚丙烯酸/蒙脱土高吸水性复合材料的制备及其性能   总被引:1,自引:0,他引:1  
利用高温快速反应法制备聚丙烯酸/蒙脱土高吸水性复合材料,研究反应温度及蒙脱土质量分数对聚丙烯酸/蒙脱土高吸水性复合材料吸水率的影响,所得复合材料吸水率为511 mL/g.并对其保水性能研究.结果表明,聚丙烯酸/蒙脱土高吸水性复合材料在高温条件下具有优异的保水性能.  相似文献   

10.
本文采用原位乳液聚合方法制备了聚丙烯酸丁酯-有机蒙脱土,聚(甲基丙烯酸甲酯-衣康酸)(PBA-OMMT/P(MMA-ITA)纳米复合材料.利用X-射线衍射仪(XRD)、差示扫描量热仪(DSC)、傅立叶变换红外光谱(FT-IR)和热重分析(TGA)对复合材料进行了表征.结果表明:单体已插层进入有机蒙脱土层问发生聚合反应,使有机蒙脱土片层间距由原来的0.59nm增加到0.88nm以上, 且有机蒙脱土的加入能够显著提高纳米复合材料的玻璃化转变温度(Tg)和热稳定性能.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

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