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用INDO方法对C76BN的22种可能异构体进行较系统的理论研究,表明最稳定的两种异构体52,53-C76BN和29,28-C76BN是B和N直接相连并位于C78(C2v)椭球长轴附近的6/6键上;用INDO/SCI方法计算C76BN的电子光谱表明,其长波吸收峰与C78(C2v)相比发生红移.用AM1方法对C76BN的四种稳定异构体进行构型优化及红外光谱研究表明,BN单元的取代削弱C原子之间的共轭而使红外频率变小. 相似文献
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用半经验AM1方法对苝二酸酐与嘧啶衍生物的1∶1及1∶2氢键复合物进行理论研究,表明随着氢键数目增多,弱相互作用能变大,主体上的供电基和客体上的吸电基有利于氢键相互作用,氢键导致电子从主体流向客体。用INDO/SCI方法计算配合物的电子光谱,表明其长波吸收峰与主体相比发生兰移,各配合物的长波吸收峰位置相差不大,与实验一致。讨论吸收峰兰移的原因并对电子跃迁进行理论指认,同时得到了配合物的双质子转移势能曲线,给出了相对于N-H键的过渡态和活化能。 相似文献
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以氯丙烯为原料,季铵化一步法合成二甲基二烯丙基氯化铵后,再与丙烯酸、丙烯酰胺共聚,制得一种用途广泛的阳离子型聚季铵盐。本文探讨了反应影响因素,确定了最佳工艺条件,并在洗发香波中进行了应用实验。结果表明,该聚合物与洗发香波中常用的表面活性剂的相容配伍性极佳,能赋于头发良好的调理性能。 相似文献
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Systematic studies on eight isomers of C70O were performed by means of INDO methods It has been indicated that the O atom is mainly added to the C1-C2 or C3-C3 bond and an epoxide feature with C1 symmetry is formed.Based on the optimized geometries,the UV-Vis spectra were calculated.It has been found that the main peaks of C70O resemble those of C70 and the characteristic absorptions beyond 460 nm are produced,which is m agree ment with the experimental results.Theoretical assignments about the absorptions were carried out and the reason for the red-shift of the absorptions was discussed.C70O is probably composed of four isomers according to the calculated results. 相似文献
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用INDO系列方法对C76Si2的17种可能异构体进行系统理论研究, 表明最稳定异构体是由C78(C2V)沿X方向椭球长轴所穿过的六元环上的2个C原子(29, 30)被Si取代所形成, 异构体稳定性随2个Si原子沿Z方向距离增加而降低, 且取代场所附近易成为进一步反应中心; C76Si2(29, 30)电子光谱吸收峰与C78相比发生红移, 主要是由于其对称性降低和LUMO- HOMO能隙变小。 相似文献
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用INDO系列方法对C_(60)的阳离子自由基C_(60)~+进行几何构型优化,得到D_(5d)对称性的构型,表明C_(60)~+确实发生了Jahn-Teller结构畸变,形成7种键和4种不等同C原子,且单键变短,双键变长,键长趋于平均化,体系的正电荷和单电子主要分布在赤道附近,从而导致了赤道附近C原子的高反应活性。 相似文献
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Influence of Annealing Temperature on Structure, Optical Loss and Laser-Induced Damage Threshold of TiO2 Thin Films 下载免费PDF全文
TiO2 thin films are prepared on fused silica with conventional electron beam evaporation deposition. After annealed at different temperatures for 4h, the spectra and XRD patterns of the TiO2 thin film are obtained. Weak absorption of coatings is measured by the surface thermal lensing technique, and laser-induced damage threshold (LIDT) is determined. It is found that with the increasing annealing temperature, the transmittance of TiO2 films decreases. Especially when coatings are annealed at high temperature over 1173K, the optical loss is very serious. Weak absorption detection indicates that the absorption of coatings decreases firstly and then increases, and the absorption and defects play major roles in the LIDT of TiO2 thin films. 相似文献