溶胶-凝胶法制备纳米薄膜的研究进展

溶胶-凝胶法是制备纳米薄膜的常用方法.综述了溶胶-凝胶法制备纳米薄膜的原理与特点及其最新研究进展,最后指出了溶胶-凝胶法制备纳米薄膜今后急需解决的问题.     

溶胶-凝胶法的研究和应用现状

简述了溶胶-凝胶法的基本原理,全面概述了溶胶-凝胶法的研究和应用现状,已有的研究表明,此法是一种有前途的制备新型材料的新方法,指出了今后溶胶-凝胶法研究的方向。     

柠檬酸盐凝胶自燃烧法合成超细粉体

溶胶-凝胶自燃烧法兼顾了溶胶-凝胶法与自燃烧法的优点,是一种很有应用前景的制备复合氧化物纳米材料的低温合成方法.介绍了柠檬酸盐凝胶自燃烧法的基本原理、反应配比的理论计算,分析了pH值、加水量、柠檬酸/硝酸盐、反应温度等因素对柠檬酸溶胶、凝胶的影响.综述了溶胶-凝胶自燃烧法在制备材料中的应用现状.     

溶胶-凝胶法制备太阳能薄膜的研究及展望

介绍了溶胶-凝胶法的反应机理、工艺过程,着重介绍了太阳能光电/光热转换的原理、薄膜的分类以及最新研究现状,指出采用溶胶-凝胶法可获得高效率太阳能薄膜,并展望了溶胶-凝胶法在太阳能薄膜制备方面的发展趋势及应用前景.     

溶-凝胶法制备纳米羟基磷灰石的研究进展

本文综述了溶胶-凝胶法的基本原理,以及国内溶胶-凝胶法制备纳米羟基磷灰石的研究进展,提出了有待解决的问题.     

太阳光热转换吸收薄膜制备方法:现状与发展

在简要叙述太阳光热转换吸收薄膜原理以及当前常用的电镀法和物理气相沉积法制备技术的基础上,着重阐述了作为湿化学技术的溶胶-凝胶法制备太阳光热转换吸收薄膜的进展,结合当前获得的以溶胶-凝胶法分别在甲醇和乙醇中制备Ni-Al_2O_3金属陶瓷薄膜的2个例子,讨论了溶胶-凝胶法需要注意的几个问题,提出了发展水基溶胶-凝胶法的方向.     

溶胶-凝胶法功能膜的成膜技术及其应用

1　溶胶 -凝胶法成膜技术溶胶 -凝胶法是以金属有机或无机化合物溶液为原料 ,经水解、缩合反应生成在溶液中显示分散流动性的亚微米级超微粒溶胶 ,再将其与超微粒结合 ,形成外表层固化凝胶 ,进而加热形成固体的技术。溶胶 -凝胶法最早用于制造玻璃表面反射膜和防反射膜 ,且在石英、氧化铝等纤维和板材中广泛使用。该法比熔融法操作反应温度低 ,而且能制造熔融法不能制造的成分复杂的玻璃。因此 ,倍受关注。1 1　溶胶 -凝胶法工艺溶胶 -凝胶法最基本的技术是用烷氧基硅烷制造硅玻璃。烷氧基硅烷溶胶 -凝胶变化的化学式通式Ｓｉ(ＯＲ) 4 如图…     

溶胶-凝胶法合成纳米材料研究进展

溶胶-凝胶法具有反应条件温和、结晶度好且分散度高的优点,与旋涂法、金属掺杂法等工艺配合使用可以改变纳米材料形貌,改善产品特性,克服传统方法的局限性,使纳米材料适应面更广,品质更优良。综述了溶胶-凝胶法在零维、一维、二维、三维纳米材料合成中的研究现状及发展趋势。介绍了近年来纳米材料的合成方法、阐明了作用原理并分析了溶胶-凝胶法合成纳米材料的优越性,最后对溶胶-凝胶法发展前景进行了展望。     

Sol-Gel法合成有机/无机纳米复合材料的研究进展

介绍了溶胶-凝胶法的基本过程,归纳了溶胶-凝胶法制备有机/无机纳米复合材料的方法。并指出了这种复合材料的应用前景。     

锆钛酸铅95/5纳米粉体Sol-Gel法制备与改进

以醋酸铅、硝酸锆、钛酸丁酯为原料,改进溶胶-凝胶法,制备得到锆钛酸铅95/5纳米粉体.改进溶胶-凝胶法省去溶胶加水、凝胶干燥、干凝胶研磨等步骤,采用加热蒸馏溶胶制备凝胶,蒸馏回收溶剂并干燥凝胶,凝胶分段加热处理等方法,简化了加工工艺,大大缩短了合成周期,降低了成本.XRD和TEM分析表明,用改进sol-gel法制备得到的PZT粉体煅烧温度低、晶粒细小、均匀,直径约10nm.     

圆柱形金属橡胶结构的静态力学性能

对圆柱形金属橡胶结构做静态实验,运用最小二乘法对实验数据进行拟合,得到金属橡胶材料本构方程的各系数,将由实验得到的各系数代入本构方程式中,从而得到理论拟合迟滞回线,将理论拟合迟滞回线与试验迟滞数据进行对比,发现理论拟合迟滞回线与试验迟滞数据吻合较好,同时运用ANSYS有限元软件对金属橡胶结构进行有限元建模、定义边界条件及施加载荷,最后进行应力应变分析,得到应力应变分布图,发现分析结果与实验结果吻合。     

Relationship between mechanical properties and crystal structure in cocrystals and salt of paracetamol

Abstract

Objectives were to study mechanical properties of various solid forms of paracetamol and relate to their crystal structures. Paracetamol form I (PRA), its cocrystals with oxalic acid (PRA-OXA) and 4,4-bipyridine (PRA-BPY) and hydrochloride salt (PRA-HCL) were selected. Cocrystals and salt were scaled-up using rational crystallization methods. The resulting materials were subjected to different solid-state characterizations. The powders were sieved and 90–360?µm sieve fraction was considered. These powders were examined by scanning electron microscopy (SEM) and densities were determined. Tablets were made at applied pressures of 35–180?MPa under controlled conditions and the tablet height, diameter and hardness were measured. Tensile strength and porosity of the tablets were estimated using well known models. Crystal structures of these systems were visualized and slip planes were identified. Cocrystal and salt of PRA were physically pure. Sieved powders had comparable morphologies and particle size. The apparent and theoretical densities of powders were similar, but no clear trends were observed. The tensile strengths of these compacts were increased with increasing pressure whereas tabletability decreased in the order oxalic acid?>?PRA-HCL?≈?PRA-OXA?>?BPY?>?PRA-BPY. Tablet tensile strength decreases exponentially with increasing porosity with the exception of PRY-BPY and BPY. Slip plane prediction based on attachment energies may not be independently considered. However, it was possible to explain the improved mechanical properties of powders based on the crystal structure. Cocrystallization and salt formation have introduced structural features that are responsible for improved tableting properties of PRA.     

Testing of explosive welding and welded joints. Wavy character of the process and joint quality

The basic defects occuring in explosive clad plates were properly systemized and the reasons of their formation were explained. Cases of cracks and delaminations in explosive clad plates were examined in this work. Various values of tensile stresses coming from loading and unloading waves were analysed, as they were the main reason of defects. The defects were connected with properties of welded materials in the joint area and beyond it. Some practical aspects of this process were shown as well.     

有缺陷和无缺陷量子点内应变分布的比较与分析

阐述了量子点内能级结构与应变的关系,用ANSYS7．1计算了有缺陷和无缺陷两种情况下：InAs／GaAs量子点的应变分布,通过对计算结果的比较,讨论了两种情况下不同的应变分布对量子点电子结构影响的不同结果,指出有缺陷时量子点各能级的改变量都与无缺陷时不同,无缺陷时应变的作用只是使能级平行移动;有缺陷时,缺陷将使量子点内能级结构复杂化,有缺陷时发光波长和发光光谱都比无缺陷时复杂。     

透明聚氨酯树脂材料的热性能和力学性能

以4,4′-二环己基甲烷二异氰酸酯(H12MDI)、聚醚多元醇、交联扩链剂、催化剂及助剂合成了一些透明聚氨酯树脂材料。用FT—IR对其结构进行了表征。DSC、TGA测试其玻璃转化温度为95℃～110℃,质量损失5％和10％的热分解温度为265℃、280℃～286℃。SEM对其断口形貌分析表明,其断裂为脆性断裂或韧性断裂。力学性能测试其拉伸强度49MPa～56MPa,断裂伸长率11％～16％,抗弯强度106MPa～116MPa,弹性弯曲模量2006MPa～3089MPa,冲击强度19kJ／m^2～35kJ／m^2,邵氏硬度80D。透先率91％～93％。实验结果表明,透明聚氨酯树脂材料具有卓越的光学性能,优良的力学性能和中等的热稳定性能。     

Growth and study of some gel grown group II single crystals of iodate

Single crystals of calcium iodate and barium iodate were grown by simple gel technique by single diffusion method. The optimum conditions were established by varying various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of the reactants etc. Crystals having different morphologies and habits were obtained. Prismatic, dendritic crystals of barium iodate and prismatic, needle shaped, hopper crystals of calcium iodate were obtained. Some of them were transparent, some transluscent, and few others were opaque. Both the crystals were studied using XRD, FT-IR, and thermal analysis. The crystals were doped by iron impurity. The effect of doping was studied using IR spectroscopy and thermal analysis.     

应用在食品行业中的冷封胶薄膜

概述了冷封胶薄膜的结构种类、制备工艺以及优点,接着陈述了冷封薄膜在软包装中的应用以及局限性,指出了实际生产中遇到的问题并对问题进行分析,提出改进方法.最后探讨了冷封薄膜未来的发展方向.     

基于差影技术的乳腺微钙化点检测方法

目的 协助医生进行诊断，避免医生因大量阅片引起疲劳而造成误诊，提高乳腺癌早期诊断的效率和准确率。方法 先对乳腺钼靶X线照片数字化；再对数字化的乳腺影像归一化；然后从中选取感兴趣区域；最后利用差影技术检测出微钙化点并标示于影像中。结果 对于16幅（其中13幅含有微钙化）经过病理解剖确诊的乳腺钼靶片进行实验，利用本文方法共检测出14幅钙化图像。结论 该方法检出率高，微钙化点定位准确，值得进一步研究。     

热敏CTP激光测控条及应用

根据检测要求组合棋盘格、三角形、线型、空白等形成测控条,通过CTP输出印版,采用测量仪器和人眼视觉对印版成像进行了检测,分析了成像故障原因并提出了激光调试解决方法。     

Growth and study of mixed crystals of Ca-Cd iodate

Mixed crystals of calcium-cadmium iodate were grown by a simple gel technique using diffusion method. The optimum conditions were established by varying various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactants etc. Crystals having different morphologies and habits were obtained. Prismatic, dendritic crystals of calcium-cadmium iodate and prismatic needle shaped, hopper crystals of mixed iodate were obtained. Some of them were transparent, some transluscent and a few others were opaque. The crystals were characterized using FT-IR, EDAX, XRD, TGA and DTA.