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本文利用GAUSSIAN 03程序包中的密度泛函理论,在B3LYP/6-31G(d)水平下,对聚21硅烷、电荷掺杂的聚21硅烷以及杂原子(硼和磷)掺杂的聚21硅烷进行几何全优化,并对它们的几何结构和自旋密度进行了比较性理论研究.结果表明,电荷掺杂能使聚硅烷的Si—Si键长增长,其极子分布几乎遍及了聚21硅烷的整个链;而杂原子(B、P)的掺杂对聚硅烷的影响主要集中在与B、P原子相邻的Si原子上,极子分布仅局域在B、P原子附近的3~5个原子上. 相似文献
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考虑到杂质和表面粗糙的散射,运用量子统计的格林函数方法,计算金属薄膜中的电导率.计算表明:在薄膜系统中,来自杂质和表面粗糙散射的电导率都以π/kF(kF为费米波矢值)为周期随厚度d振荡. 相似文献
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合成了3A金属取代的钨错杂多化合物:α-GeW9M3(M=A1,Ga,In)。通过元素分析、红外、紫外、183WNMR以及热分析手段进行了表征。测定了电导率。结果表明:所合成的杂多化合物热稳定范围宽,不易失水,将是一类新型固体电解质。 相似文献
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简述了电荷转移型导电配位化合物的产生、发展、导电机理、研究现状、热点及其发展趋势。 相似文献
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Fu Xu Xiaolong Mo Sen Wan Changqing Jiang Hongwei Hao Luming Li 《科学通报(英文版)》2014,(29):3831-3834
Carbon nanotube yarns (CNTY) possess good specific strength and specific conductivity. As such, their potential for commercial applications is significant. Fatigue performance is a significant consideration in yarn/wire applications. In this study, the flexural fatigue performance of CNTY spun from super-aligned carbon nanotube arrays was investigated using a reversed bending test. The results showed that CNTY exhibited excellent resistance to pure flexural fatigue, significantly outperforming stainless steel wire; CNTY failed where a combination of flexural fatigue and tension-tension fatigue had special hollow fracture morphology, and CNTY resistance remained fundamentally unchanged in the combination fatigue process. 相似文献
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A dispersion-strengthened copper alloy with 1 wt% TiC for commercial electrical-contact wires was prepared by in-situ reaction casting, grain-ultrafining by equal-channel angular pressing (ECAP) and subsequent annealing with aim to obtain excellent comprehensive performance. The results showed that fine TiC particles were in-situ synthesized in the as-cast Cu matrix and aggregated in clusters, and thus mechanical properties of the as-cast alloy deemed insufficient. Continued ECAP at 473 K significantly refined the grains of the as-cast alloy and improved the distribution of TiC particles. Due to multiple strengthening mechanisms, the ECAP-processed alloys maintained good conductivity with obviously enhanced tensile strength and hardness values. After post-ECAP annealing, the elongation and conductivity of the fine-grained copper alloy increased with the adequate tensile strength. The novel combined process endows the alloy appropriate performance to serve current high-frequency electrification railway systems. 相似文献
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建立了毛细管电泳电导法快速测定西米替叮的方法.利用非涂层弹性融硅石英毛细管(50cm×75μm)为分离通道,探讨了缓冲溶液的种类、pH值、浓度,分离电压,进样时间对分离检测的影响.结果表明,在最佳条件下:30mmol/LTris(Cit调节pH=8.0)为运行缓冲介质,分离电压为10kv,西米替叮在10分钟内能得到较好的检测.标准品溶液浓度在0.5-20mg/L范围内有良好的线性关系,回归方程为y=9.0923x 15.83,相关系数r=0.9984,回收率为98.8%. 相似文献
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本文有效地将十二基硫酸钠在高岭土上的吸附等温线与溶液的导电率曲线结合起来,研究了SDS在高岭土和Na-高岭土上的吸附,发现SDS在高岭土上的吸附等温线最大值与吸附后平衡溶液的CMC、固液比、SDS的沉淀损失等因素有关,圆满地解释了吸附等温线最大值及其出现的位置。 相似文献
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本文以过氧乙酸为预氧化剂、浓硫酸为插层剂,采用化学氧化法制备了不同氧化程度的石墨层间化合物,并对其进行微波膨胀获得膨胀石墨. 本文采用SEM、XRD和FT-IR对石墨层间化合物和膨胀石墨的形貌、结构和含氧官能团的变化进行表征,研究预氧化时间对膨胀石墨膨胀容积及导电性能的影响. 结果表明,当预氧化时间为20 min时插层膨胀最好,获得的膨胀石墨膨胀容积达到275 mL/g,此时所制备的柔性石墨箔电导率达到2000 S/m,表现出极好的导电性能. 本工作为绿色制备具有高膨胀容积的膨胀石墨提供了思路. 相似文献