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图T1,1,m与Q(3,n)中有路因子的充分必要条件及T1,1,m的匹配等价类 总被引:1,自引:0,他引:1
如果一个图的匹配多项式可以被一个路的匹配多项式整除,我们就称此路是该图的一个路因子,路因子在刻画图的匹配等价类,研究匹配唯一性方面有很重要的作用.本文得到了图T1,1.m与图Q(3,n)中有路因子的充分必要条件. 相似文献
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The spectra of matching polynomials which are useful in the computations of resonance energy and grand canonical partition functions of molecular's. It also present other properties for certain classes of graphs and lattices. In [1] Balasubramanian calculates several matching polynomials and matching roots of several molecular graphs. He found that the matching polynomial of C_6, C_(10), C_(14), C_(18) and C_(22) are divided by x~2-2. In this note,we prove that x~2-2 divides MC_(4k+2)(x), k = 1, 2,..., n and obtain some other properties of matching polynomials of paths and cycles. 相似文献
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非视线散射大气光通信的光学天线 总被引:4,自引:3,他引:1
由于大气衰减的影响,非视线散射大气光通信需要使用光学天线以提高对光信号的采集能力,进而增加通信距离。针对非视线大气光通信的需求,利用ZEMAX软件对半球透镜、复合抛物面聚光器(CPC)和卡塞格伦望远镜等光学天线进行了性能分析。分析表明:半球透镜和CPC视场较大,增益值高。利用蒙特卡罗法模拟计算了一定条件下,非视线散射光通信在有无半球透镜或CPC作光学天线时到达探测元件的能量随通信距离的变化。结果表明:CPC聚光能力更强,适合作为非视线散射光通信的光学天线。 相似文献
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设计合成了一系列具有不同烷氧基尾链长度的单体4′-烷氧基-4-联苯酚甲基丙烯酸酯Mbi Cm(m=1,2,4,6,8,10,12,14,16,18),通过自由基聚合方法合成了相应的具有不同烷氧基尾链长度的无柔性间隔基侧链型液晶高分子PMbi Cm,将所得的侧链型液晶高分子和相变材料石蜡按一定质量比混合,通过"加热-冷却法"成功制备了定形相变材料.通过凝胶测试发现当尾链长度为m=12,14,16,18时,高分子对固体石蜡具有良好的凝胶定形效果,且随着烷氧基尾链的增长,聚合物和石蜡的相容性增加,最低凝胶浓度降低,得到定形相变材料的凝胶解缔温度也相应下降.通过示差扫描量热法(DSC)、热重分析法(TG)、流变(Rheology)等测试考察了定形相变材料的相变储能性能、热稳定性和流变性能,实验结果表明该定形相变材料具有相变焓值高、热稳定性好、凝胶强度高等优点.通过红外光谱(FTIR)、偏光显微镜(POM)和扫描电镜(SEM)等测试发现PMbi Cm通过非共价键作用力自聚集形成三维凝胶网络结构,对石蜡起固定支撑作用. 相似文献
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A series of side chain liquid crystalline polymers(SCLCPs) containing triphenylene(Tp) units in the side chains, denoted as PMTS(without spacer) and PMTn S(n = 2, 3, 4, 6, which is the number of the methylene units between the main chain and Tp moieties in the side chains), with different lengths of spacers were synthesized through conventional free radical polymerization. The chemical structures of the monomers were confirmed by 1H/13C-NMR, and the phase behaviors were examined by differential scanning calorimetry(DSC), polarized optical microscopy(POM) and wide-angle X-ray diffraction(1D and 2D WAXD). The molecular characterization of the polymers was performed with 1H-NMR, gel permeation chromatography(GPC) and thermogravimetric analysis(TGA). The phase behaviors of the polymers have been investigated by a combination of techniques including DSC, POM, 1D and 2D WAXD. The results showed that the length of spacer has significant effects on the LC phase behavior of polymers. For PMTS and PMT2 S, they displayed the columnar phase developed by the Tp moieties and the main chain as a whole due to the strong coupling effect of the Tp moieties and the main chain. For the PMT3 S, PMT4 S and PMT6 S, they formed the symmetry hexagonal columnar(ΦH) phase owing to the decoupling effect. All of these indicated that the "decoupling effect" or "coupling effect" depended on the length of spacers, leading to the different LC phase formation mechanism. 相似文献
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含聚碳酸酯,4—羟基苯甲酸,己二醇和1,4—苯二甲酸结构的嵌段共聚物的… 总被引:1,自引:0,他引:1
以端酰氯基因的热致液晶共聚酯HTH-6和端酚羟基的聚碳酸酯齐聚物为原料,通过溶液缩聚法制备了含PC和HTH-6的嵌段共聚物,并用IR、POM、DSC、WAXD等手段对共聚物结构,热行为和结晶行为进了表征。DSC和POM结果证明这些嵌段共聚物都属向列型热致性液晶。在280℃以睛的温度范围内无相分离,而在较高温度为两相结构,共聚物的结晶结构与HTH-6相同,结晶度随HTH-6含量增加而增加,结晶速度也 相似文献
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无线紫外光局域通信是在短距离内实现全方位信息安全传输的有效途径之一,其中数据传输速率是该类通信系统的重要技术指标。从常用的紫外收发通信系统结构出发,研究无线紫外光局域通信数据传输速率的影响因素。研究结果表明:大气信道和紫外光源的选择对系统数据传输速率影响较大;由于大气散射信道的多径时延,系统的最大调制速率受到限制,当通信距离较短或天气环境较好时,系统的最大调制速率较高;紫外光源中,低压汞灯最大调制速率20kHz,紫外LED最大调制速率为几兆赫兹左右。相关研究成果为高速紫外光局域网络的设计与应用提供了参考。 相似文献
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