【摘 要】
：
Main observation and conclusionrnTwo discotic liquid crystalline (LC) molecules consisting of a bowl-shaped corannulene core and five-fold photoactive azobenzene branches with different paraffinic side chains were developed.Their self-assembly,photo-respo
【机 构】
：
Tianjin Key Laboratory of Molecular Optoelectronic Science,Department of Chemistry,Tianjin Universit
论文部分内容阅读
Main observation and conclusionrnTwo discotic liquid crystalline (LC) molecules consisting of a bowl-shaped corannulene core and five-fold photoactive azobenzene branches with different paraffinic side chains were developed.Their self-assembly,photo-responsive behavior and charge-carrier transport properties were investigated in detail.A wider mesophase temperature range was achieved when utilizing longer and furcal flexible side chain substitution.2D XRD measurements revealed the π-packed corannulene-centered 1b (i.e.,with furcal side alkoxyl chains) exhibited helical columnar LC phase.This packing structure also led to a higher hole charge carrier mobility of 7.07 × 10-2 cm2·V-1·s-1 compared to that of the counterpart 1a with linear side chain substitutions.
其他文献
在可靠性工程中,关联系统的元件寿命相依性可能是由所运行的共同随机环境导致的.本文利用多元扭曲函数刻画系统的结构函数和元件寿命之间的相依性.在普通随机序、失效率序、反向失效率序和似然比序意义下,给出充分条件对不同随机环境下的关联系统进行了比较.
本文研究了一个带有强占优先权和非强占优先权的M/M/1排队模型,顾客分为三个优先等级,第一类顾客享有强占优先权,第二类顾客享有非强占优先权,第三类顾客无优先权.三类顾客具有不同的到达率,当第一类顾客到达后它将打断正在接受服务的第二类或第三类顾客立即接受服务;当第二类顾客到达时,若系统中只有第三类顾客,则此顾客必须等待当前服务完成,才能接受服务,否则排队等待.同一类顾客遵循FCFS的排队规则.利用补充变量法构造多维向量马尔可夫过程并对此排队系统的状态转移方程进行分析,得到三类顾客队长联合分布的概率母函数,进
几何模型是实际生活中被广泛应用的离散型概率模型,而上截断几何模型在实际生活中也有着重要的应用.本文将对上截断几何混合模型的参数及非参数方法进行系统阐述.利用高斯分布、贝塔分布和伽马分布提出了未知参数的最大条件似然估计,并结合数值模拟和实例说明上截断几何模型的应用.
由于传统多事件触发巨灾债券的触发事件之间具有一定的相关性,投资者损失的可能性和收益波动性较大.为了减小这一弊端带来的影响,本文以地震巨灾债券为例,在考虑风险反馈情况下重新构造了多事件触发巨灾债券的支付函数,并在最大化保险公司对冲效率的目标下,通过蒙特卡洛模拟给出了全部风险事件触发后债券现金流支付的最优折扣系数.研究表明,在新的支付函数下,投资者期望收益率增加,收益波动性减小,该债券更具市场吸引力.最后,本文重点分析了巨灾触发参数值对最优折扣系数的影响.
记录数是随机游动模型中的一个基础统计量.本文给出了直线上简单对称随机游动弱记录数的大偏差和中偏差.“,”Record numbers are important statistics in random walk models.Their deviation principles are unknown as far as we know.In this article,we provide the asymptotic probabilities of large and moderate deviat
股票市场的价格波动以及其带来的收益率变化备受国内外专家学者的关注.在此背景下,本文主要研究长资产收益率序列波动率的变化情况,并用于上证综合指数的实例分析中.由于最常用的GARCH模型仅在观察周期较短时才充分有效,针对长资产收益率序列的波动率往往具有长记忆性,本文提出了一种改进的时变波动率模型.为使模型更好地拟合波动率的变化,本文将波动率的方差分解为条件方差与无条件方差的乘积,通过合理的模型转化,使条件方差遵循GARCH过程,无条件方差使用非参数方法(B-spline函数)拟合,并使之随时间平滑变化.通过数
Main observation and conclusionrnBoswelliains A-E (1-5),five new cembrane-type diterpenoids,were isolated from the resin of Boswellia papyifera.Their structures,determined by using spectroscopic,computational and chemical methods,demonstrate that 2-5 are
Main observation and conclusionrnThe steric and electronic properties of N-heterocyclic carbenes (NHCs) can be modified by the exocyclic substituents at the nitrogen atoms,by 1-3 atoms\' replacements of the five-membered imidazolium skeleton and by the
The karst landform is a typical ecologically vulnerable region, and the problem of karst rocky desertification in southtern and western China has led to impoverishment and a degraded local ecological environment, which severely limits local socioeconomic
Main observation and conclusionrnHistone point mutations,including missense mutations on histone H3 at positions 27 (K27M),34 (G34R/V,G34W,G34L) and 36(K36M),were identified as potential cancer driver mutations.H3.3G34R/V mutations account for pediatric g