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NdP5O14晶体的晶场参数 总被引:1,自引:0,他引:1
NdP5O14晶体是一种高钕浓度的化学计量比的新型激光材料,它在高的Nd(III)浓度下荧光几乎不发生猝灭.本效计算了它的主要晶场参数,以深入了解它的光学性质. 相似文献
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近年来, 我们在研究含氟烯烃和烷烃的红外激光诱导氧化和氯化反应的基础上, 深入研究了红外激光诱导卤代烷烃的脱卤化氢并生成: CF2卡宾和:CFCF3卡宾的反应[1-4]以往的研究往往是根据反应产物推论反应机理, 认为在反应过程中存在着卡宾中间体,但在实验中未能直接检测到. Kakimoto[5,6]曾报道过在流动体系中测到了.F+CH3F和.F+CH3Cl反应中:CHF和:CHCl的激光荧光激发谱, 但没有讨论卡宾形成的机理.Hirota[7]在讨论.F+CH3F反应时, 认为:CHF可能由攫氢过程产生而对于.F+CH3Cl反应同时生成:CHF和:CHCl未做说明. 本实验中用扩散分子束代替了流动反应体系, 从而大大减少了产物和反应物气体分子间的猝灭过程, 获得了信噪比大而清晰的图谱, 由此确证了:CHF和:CHCl的存在, 说明了.F+CH3Cl反应中自由基攫氢过程和偶合反应过程共存的反应历程. 这一结论对红外激光诱导一碳卤代宾化学反应机理研究有重要参考意义. 相似文献
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本文报道了CW-CO2激光引发的CF2HCH3与Cl2的反应.除主要产物CF2=CH2外,还有CF2ClCH3. CF2ClCH2Cl. CF2=CHCl. CF2=CCl2和CF2Cl2.为了探索应用激光方法合成CF2=CH2的可能性,研究了激光输出功率. 照射时间. 反应体系中CF2HCH3与Cl2的比例及样品压力对CF2=CH2得率的影响.同时为了探讨反应机理,还进行了TEA-CO2激光引发CF2HCH3加Cl2实验和CW-CO2激光作用下CF2=CH2. CF2=CH2加Cl2的反应研究,令人感兴趣的是在激光照射CF2=CH2时,发现了双键的断裂. 相似文献
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This paper focuses on the most relevant devices currently used in order to achieve electrically stimulated generations of colours from electroactive polymers, either as coloured light emissions from the material or as modifications of its intrinsic colour properties. For this purpose, most relevant materials, fundamental principles of operations, latest developments and current applications of organic-based electrochromic, electroluminescent and lasing devices are reviewed here. The very promising performances resulting from the analysis of state-of-the-art products, and in particular of those which are currently approaching commercial applications, suggest likely roles played by such devices for niche applications in the very near future. 相似文献
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《Composite Interfaces》2013,20(1):63-72
Interfacial structure of laminated polyethylene (PE)/polypropylene (PP) films was investigated by synchrotron X-ray microbeam. The X-ray microbeam (0.9 μm (vertical) × 1.7 μm (horizontal)) formed using a phase zone plate was irradiated on the cross-section of the laminated films. In order to irradiate X-ray microbeam in the direction perpendicular to the cross-section of the film sample, adjustment of the sample setting was performed by Thomson scattering method. The Thomson scattering intensity is proportional to the number of the irradiated electrons, so the irradiated position of the X-ray microbeam could be determined from the intensity profile with high spatial resolution. By changing the sample position, diffraction patterns could be obtained from the laminated films across the PE/PP interfacial region. The thickness of the interfacial region of the annealed laminate was estimated as 5 μm judging from the changes of the diffraction intensities from the PE crystallites to the PP ones. The interfacial thickness depended on the thermal treatment of the film. It was found that the adhesion strength of the PE/PP laminate increased with increasing the interfacial thickness. Both of PE and PP chains entangled each other during laminate processing. The entangled molecular chains play important role as anchoring effect at the PE/PP interdiffusion region. However, the phase separation progressed with further crystallization by annealing. Thus, the adhesion strength of the PE/PP laminate was considered to be influenced by the interfacial thickness. 相似文献
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《Composite Interfaces》2013,20(6):611-628
This research used Co60 γ-ray radiation to modify Armos fibers in 1,2-epoxy-3-chloropropane. After the treatment, the interlaminar shear strength (ILSS) values of aramid/epoxy composites were improved by about 20%. Surface elements of Armos fibers were determined by XPS analysis, which indicated that the oxygen/carbon ratio was increased. The surface of the fibers treated was rougher than that of the untreated fibers when examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Fourier transform infrared (FT-IR) spectra confirmed that the epoxy group was grafted onto the fibers. The wettability of the fibers' surface was also enhanced by the treatment. Nanoindentation technique analysis showed that the nanohardnesses of the various phases (the fiber, the interface and the matrix) in the composite, whose fibers were treated, were correspondingly higher than those in the composite, whose fibers were untreated. The results indicate that γ-ray irradiation grafting technique, which is a suitable batch process for industrialization, can modify the physicochemical properties of Armos fibers and improve the interfacial adhesion of its composite. 相似文献