尼龙1010溶液结晶的形态结构

本文用偏光显微镜和透射电子显微镜研究了尼龙1010从溶液结晶形成的形态结构,尼龙1010的苯酚/四氯乙烷溶液根据其结晶温度可产生负球晶、正球晶、环状球晶和非常球晶结构。     

聚碳酸酯球晶的形态结构研究

利用偏光显微镜和透射电子显微镜观察了聚碳酸酯(PC)溶液结晶的形态结构,PC在苯酚-四氯乙烷溶液中根据结晶温度的不同可生成带状球晶、延伸球晶、负球晶和层状球晶结构。     

离聚物Surlyn对聚对苯二甲酸乙二醇酯/聚萘二甲酸乙二醇酯共混物结晶性能和力学性能的影响

利用差示扫描热法(DSC)和偏光显微镜(POM)研究了乙烯-甲基丙烯酸离子键聚合物Surlyn对聚对苯二甲酸乙二醇酯(PET)/聚萘二甲酸乙二醇酯(PEN)共混物的结晶性能和力学性能的影响。研究结果表明,Surlyn对PET/PEN共混物具有化学成核作用。适量添加Surlyn,能促进PET/PEN共混物的成核结晶,明显提高结晶速度、结晶温度和结晶度,减小球晶尺寸,提高球晶均匀性,并有助于改善PET和PEN相容性,从而提高PET/PEN共混材料的拉伸强度、弯曲强度、弯曲模量和缺口冲击强度等力学性能。本研究体系Surlyn的最佳用量为2 phr。     

间苯二甲酸共聚酯的结晶特性

研究了聚对苯二甲酸乙二醇酯（PET）分子链中引入间苯二甲酸（IPA）的无规共聚酯（IPET）的非等温结晶动力学和等温结晶时球晶的生长和形态。结果表明,共聚酯的结晶温度随IPA含量的增加而升高,玻璃化转变温度、熔点随IPA含量的增加而降低;IPA的引入使IPET的结晶速率及球晶生长速率明显降低,但对球晶的形态及生长机理并无明显的影响。     

用扫描电镜观察聚丙烯的球晶结构

用熔体结晶和溶液结晶两种方法获得聚丙烯的球晶样品,经过溶胀、化学刻蚀后用扫描电镜进行观察,获得了清晰的立体感强的球晶照片。由SEM照片可以看出,球晶结构相当完善,突出地显现出球晶生长的“骨骼”结构。     

PET/PC共混物配比对其高压结晶行为的影响

利用SEM及W AXD等测试手段研究了配比对PET/PC共混物高压结晶行为的影响。SEM观察表明,随PC比例的增加,共混物高压下主要结晶形态以伸直链晶体,生长成熟的立体开放球晶,大尺寸球晶的方式变化。拟合分峰法和W arren-A verbach傅氏分析法的计算结果表明,随PC含量的增加,高压结晶共混物的结晶度降低,PET的平均晶粒尺寸总体呈减小趋势,晶粒尺寸分布则变窄,而晶格畸变平均值在一定PC比例范围内达到极大值。     

多重受热历史对PLA/MWCNTs复合材料结晶和熔融行为的影响

为改善聚乳酸(PLA)的结晶性能,分别以PLA和表面包覆纳米SiO_2并接枝硅烷偶联剂的多壁碳纳米管(MWCNTs)为基体和改性剂,经溶液共混法制备PLA/MWCNTs复合材料.分别利用POM和DSC研究复合材料等温结晶、非等温结晶和冷结晶的球晶形态、结晶和熔融行为.研究结果表明:PLA/MWCNTs复合材料结晶和熔融行为强烈依赖于受热历史和改性MWCNTs含量;PLA/MWCNTs复合材料冷结晶时结晶度最高,球晶尺寸最小且熔点最低;1℃/min降温结晶时球晶尺寸最大,且熔点最高;降温速率越快,复合材料的起始结晶温度、结晶焓和结晶度越低.改性MWCNTs可作为PLA的异相成核剂,改善复合材料的结晶、熔融行为和球晶尺寸,其最佳用量为0.3%.     

SiO_2-MWNTs/聚乳酸复合材料的冷结晶动力学及球晶形态

为研究多壁碳纳米管(MWNTs)对聚乳酸(PLA)冷结晶动力学和球晶形态的影响,分别以PLA和表面包覆纳米SiO2并接枝硅烷偶联剂的纳米SiO2改性MWNTs(SiO2-MWNTs)为基体和改性剂,经溶液共混法制备了SiO2-MWNTs/PLA复合材料。采用DSC、偏光显微镜、Jeziorny模型和Johnson-Mehl-Avrami模型研究了复合材料的非等温冷结晶动力学和球晶形态。结果表明:SiO2-MWNTs可作为异相成核剂,能有效降低SiO2-MWNTs/PLA复合材料的冷结晶温度,提高晶核生成速率和晶体生长活化能。SiO2-MWNTs/PLA复合材料的冷结晶过程主要由成核作用控制,加入SiO2-MWNTs可同时提高复合材料的结晶速率和结晶度。冷结晶时,PLA球晶尺寸小于熔体冷却结晶时的,且SiO2-MWNTs含量对冷结晶球晶尺寸的影响远小于其对熔体冷却结晶球晶尺寸的。所得结论对优化PLA的结晶结构和性能、制备高性能PLA复合材料具有指导意义。     

PET/SiO2纳米复合材料的光学性能和结晶成核行为

以乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA)包覆纳米S iO2的核-壳结构复合粒子,并利用聚合法和共混法制备PET纳米复合材料。研究了复合颗粒和纳米复合材料的制备条件和方法等对复合材料光学和结晶成核行为的影响。结果表明:分散良好的纳米颗粒对PET有很强的成核作用,抑制PET球晶生长速度,提高PET总结晶速率和透明度。共混法制备的纳米复合NPET透明度提高,而聚合法制得的NPET透明度降低。NPET熔融结晶行为表明,随着纳米颗粒含量增加,NPET双熔融小峰逐步降低;纳米S iO2含量2%时,NPET的结晶速度最快,结晶半峰宽仅有5.1℃。     

高聚物的等温结晶

综述了高聚物等温结晶、球晶结构等方面的研究进展，依据熔体结晶过程中临界晶核的形成、球晶的生长和结晶／非晶组分间的相互扩散等因素讨论了高聚物温结晶动力学、形态以及分子量对球晶径向生长速率的影响。     

Infrared microspectroscopy using prism-based spectrographs and focal plane array detection

Several prism-based spectrographs employing a mercury cadmium telluride (MCT) focal plane array detector have been interfaced to an infrared microscope. In the combined system, the area-defining aperture of the microscope also served as the entrance slit to the spectrograph. This investigation considered the fundamental limits of diffraction for both the spectrograph and microscope in order to determine both the spatial and spectral resolution of the system as a whole. Experimental results for spectral resolution, spectral range, and peak-to-peak noise have been presented. Finally, the dynamic capabilities of one spectrograph/microscope combination were investigated.     

Acoustic microscopy of ferroelectric ceramics

Ferroelectric ceramics have been observed in an acoustic microscope. The images demonstrate the ability of the microscope to image elastic properties and to penetrate opaque layers.     

高强度弹簧不锈钢的强化机理研究

本文在所开发的3YC系列高强度奥氏体弹簧不锈钢材料的研究基础上,进一步研究了材料在固溶处理、冷加工变形和时效强化等3个工艺过程中的组织与性能的关系,建立了材料强度与化学成份,冷变形量之间的定量关系。     

Facile synthesis, optical and photoconductive properties of novel ZnO nanocones

Large-scale, uniform ZnO nanocones with tips about 200 nm and length about 50 μm have been synthesized by a facile hydrothermal method. The morphology and structures were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and high-resolution transmission electron microscope (HR-TEM). The effects of reaction time and PEG-400 on the morphology of ZnO nanostructures were investigated, also an oriented attachment mechanism has been briefly proposed. The optical properties were investigated by lasing confocal microscope and photoluminescence spectrum, a strong near band edge emission peak centered at 387 nm from the ZnO nanocones was observed in photoluminescence spectrum. Finally, we have fabricated UV photodetector based on single ZnO nanocone, which present good switching properties by turning the UV light on and off.     

力-磁-环境耦合作用下超磁致伸缩材料TbDyFe表面畴变的观察

就TbDyFe超磁致伸缩材料在应力、磁场和环境耦合作用下的表面畴变进行了研究。主要利用光学显微镜及其微分干涉相衬显微（Differential Interference Contrast，DIC）系统，并自行设计搭建了恒磁场试样台和环境试验箱，由此实现了对应力、磁场及环境作用下材料表面磁畴变化的原位跟踪研究。     

Micromorphological studies on the ZnSe single crystals grown by chemical vapour transport technique

Single crystals of ZnSe have been grown by chemical vapour transport technique. Microscopic observation of crystal surfaces has been carried out using optical microscope and scanning electron microscope (SEM). Different micromorphological patterns such as microsteps, spirals and kinks were observed on the surface of the grown crystals in different growth conditions. Present studies show that the formation of these microstructures on the surface of the grown crystals depends on the growth parameters such as undercooling and stability of the growth interface. The morphology and lattice parameters of the grown crystals have also been determined by X-ray analysis.     

Sonochemical synthesis of amorphous long silver sulfide nanowires

Long silver sulfide nanowires have been prepared via the thioglycolic acid (TGA)-assisted sonochemical method. The transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) images reveal that the nanowires have uniform width and length. The selected area electron diffraction (SAED) pattern indicates that the Ag₂S nanowires are amorphous. Furthermore, the mechanism for the TGA-assisted sonochemical synthesis of Ag₂S nanowires has been preliminarily presented.     

Studies of topological features of the HFCVD surface of a nanocrystalline diamond film using a scanning tunneling microscope with a diamond tip

Structural features of HFCVD nanocrystalline diamond films have been considered and a physicomathematical model of the atomic structure of its surface has been constructed. The film has been studied in air using a scanning tunneling microscope with a tip of a boron-doped semiconducting diamond single crystal. Fractal analysis of images of the film surface from scanning tunneling microscope has shown the presence of diamond single crystals of different orientations having a mean size of 31 nm with a fractal dimensionality of 2.36 and 2.73.     

Coherent surface waves generated using phased surface plasmons

Experiments on the generation of coherent optical surface waves with the participation of phased surface plasmons have been performed using a high-resolution near-field scanning microscope. Characteristics of the obtained radiation have been determined.