槲皮素及其异构体分子的结构性质研究

槲皮素是一类有着重要药理活性的黄酮类化合物。本文在B3LYP/6-31G**水平上对槲皮素及其14种异构体进行了几何优化,得到各种异构体的结构与性质。由电荷布居数分析出B环是此类多羟基化合物的活性部分,3位-OH的存在抑制了A、C环的活性。同时,表明此类化合物中必有分子内氢键形成。并给出了最稳构型、槲皮素和标准结构三类分子的振动光谱。探讨了它们的构效关系。     

Synchronization of networks with time-varying couplings

In this paper, we present a review of our recent works on complete synchro-nization analyses of networks of the coupled dynamical systems with time-varying cou-plings. The main approach is composed of algebraic graph theory and dynamic system method. More precisely, the Hajnal diameter of matrix sequence plays a key role in in-vestigating synchronization dynamics and the joint graph across time periods possessing spanning tree is a doorsill for time-varying topologies to reach synchronization. These techniques with proper modification count for diverse models of networks of the cou-pled systems, including discrete-time and continuous-time models, linear and nonlinear models, deterministic and stochastic time-variations. Alternatively, transverse stability analysis of general time-varying dynamic systems can be employed for synchronization study as a special case and proved to be equivalent to Hajnal diameter.     

激光指示器光轴调校技术

利用反射式光学系统对激光指示器的光轴进行了调校。提出了激光指示器及观瞄装置的光轴校正方案,并建立了调校装置。该装置由离轴抛物面反射镜、十字靶标、背景光源、图像采集装置及其它附件组成。对调校装置的测量精度进行了标定和计算。结果表明,该装置的测量精度可达到0.05mrad。利用该装置对激光指示器的光轴进行了调校,并给出了系统示意图和测试效果。     

反相胶束增稳荧光法测定兔血浆中痕量盐酸小檗碱的研究

本文研究了气溶胶（ＡＯＴ）／环己烷／水反相胶束介质中中草药有效成分盐酸小檗碱的荧光性质,并将该法应用于兔血浆中痕量盐酸小檗碱的测定。该法的线性范围为１．０×１０－ ７～３×１０－ ５（ｇ／ｍ Ｌ）,检出限为８．３×１０－ ８（ｇ／ｍ Ｌ）,相对标准偏差为１．１％ 。     

高光学质量,高平均功率非稳腔Nd：YAG激光器

在分析含热透镜的非稳腔固体激光器普遍特性的基础上，分别定义了几何放大率和输出曲率半径的热敏感度，结合腔镜失调敏感度而成为设计该类谐振腔的重要依据，据此，进一步改善和发展的新型的棒成像非稳腔。     

浊点萃取-胶束增稳室温燐光法测定水样中痕量α-萘乙酸

提出了用非离子表面活性剂Triton X-100作萃取剂的浊点萃取-胶束增稳室温燐光法测定痕量α-萘乙酸的新方法.就溶液pH、试剂浓度、平衡温度和时间等实验条件对浊点萃取的影响及后续使用的胶束增稳室温燐光法的测定条件进行了探讨.在最佳条件下,线性范围为3.0×10-8～2.0×10-6 mol/L;检出限1.3×10-8 mol/L;方法用于强化水样中痕量α-萘乙酸的测定,回收率95%～104%;相对标准偏差2.0%～3.5%.     

瞬态问题稳定性及弥散分析的无网格RKPM配点法研究

介绍了基于强形式的RKPM配点法求解瞬态动力问题的算法,并提出了采用RKPM配点法,配合时间域中心差分求解二阶波动方程的稳定性评价方法,并通过数值算例验证了此方法的正确性．此评价方法可以方便有效地评估出实际计算时的临界时间步长．通过数值算例比较可知,实际算例的计算临界时间步长与本评价方法,所预测的临界时间步长结果非常接近．给出了如何合理地选择RKPM形函数支撑域的建议．最后与径向基函数配点法进行了对比研究．     

Stochastic resonance in an asymmetric bistable system driven by coloured correlated multiplicative and additive noise

This paper investigates the stochastic resonance （SR） phenomenon in an asymmetric system with coupling between multiplicative and additive noise when the coupling between two noise terms is coloured. The approximate expression of signal-to-noise ratio has been obtained by applying the two-state theory and SR exhibits in the bistable system. Moreover, the potential asymmetry r and cross-correlation strength λ can weaken the SR phenomenon, while the cross-correlation time r can strengthen the SR phenomenon.     

高吸收ZnSe多晶无镜光学双稳的实验观测

本文对具高吸收的ZnSe多晶材料的增加吸收型光学双稳性进行了实验观测,发现在介质的吸收远高于过去提出的理论判据时,仍能获得双稳输出,并测定了阈值开关功率与光斑尺寸及样品厚度的关系.采用分层模型分析实验结果,定性地解释了实验现象.     

Negative Resistance in a Two-Dimensional System with Entropic Barrier

A phenomenon of negative resistance is found in two-dimensional bistable and periodic potentials via Langevin simulation, where output quantities for noise and signal driven system, such as the power-spectrum density modulus and the signal power amplification, can become minima at finite temperatures. In such a system, the curvature of the potential along non-transport degree of freedom at the barrier is larger than that at the local minima. The temperature-dependent effective barrier, i.e. entropic barrier, is introduced via integration over the non-transport variables. The system shows the negative resistance because of the competence between the signal and the entropic barrier.