共查询到20条相似文献,搜索用时 93 毫秒
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溶胶-凝胶法功能膜的成膜技术及其应用 总被引:7,自引:0,他引:7
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… 相似文献
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Sol-Gel法合成有机/无机纳米复合材料的研究进展 总被引:1,自引:0,他引:1
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。 相似文献
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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。 相似文献
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AbstractObjectives 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. 相似文献
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Bogumi? Wronka 《International Journal of Impact Engineering》2011,38(5):309-313
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. 相似文献
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透明聚氨酯树脂材料的热性能和力学性能 总被引:5,自引:0,他引:5
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。 相似文献
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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. 相似文献
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应用在食品行业中的冷封胶薄膜 总被引:5,自引:1,他引:5
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. 相似文献
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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. 相似文献