高阻恒流LED产生亚泊松光的理论研究

本文研究高阻恒流源驱动的光发射二极管（ＬＥＤ）的输出光场的振幅噪声压缩与电，光量子效率，漏电流效应，泵浦残余噪声频率的关系，指出高阻恒流技术不仅使任意纵模产生振幅噪声压缩，而且由于仅在高阻恒流下各纵模间存在负量子相关，使得ＬＥＤ总输出光场的振幅噪声压缩加深。     

高分子中激子和双激子的极化率(解析计算)

高分子的电致发光是载流子在电场中的输运和复合,为了阐明它的机理,需要研究高分子中激子的极化性质,首先求得了激子和双激子的解析解,然后用线性响应的Green函数方法计 算了两者的极化率,解析地证明了一个重要的结论：激子的极化率为正,双激子的极化率为负.从激子跃迁至双激子,高分子的电偶极矩要反转方向. 关键词： 激子 双激子 解析解 负极化率     

Wigner Function of Density Operator for Negative Binomial Distribution

By using the technique of integration within an ordered product （IWOP） of operator we derive Wigner function of density operator for negative binomial distribution of radiation field in the mixed state case, then we derive the Wigner function of squeezed number state, which yields negative binomial distribution by virtue of the entangled state representation and the entangled Wigner operator.     

基于电流变液的可调谐负磁导率材料

通过把负磁导率材料SRR阵列置于高性能电流变液中,研究了电极加载方式、电流变液浓度、电流变液类型以及电场强度等因素对浸入电流变液中的SRR阵列谐振频率的影响. 实验表明,电极加载方式对SRR阵列的磁响应有重要的影响;在容器盒中充满电流变液之后SRR阵列的谐振频率往低频发生了移动,并且可以通过改变外加电场强度来调节,最大的调节范围为130MHz. 数值计算结果表明SRR阵列的有效磁导率在谐振频率附近为负值,并且有效磁导率为负的频率范围也可以通过改变外加电场强度来调节. 关键词： 负磁导率材料 谐振频率 电流变液     

Optical bistability at angular incidence in a one-dimensional photonic crystal containing single negative materials

Nonlinear wave propagation is studied theoretically in a one-dimensional photonic band gap structure containing single negative materials. It is found that Kerr nonlinearity is greatly enhanced near the lower edge of a recently explored angular gap for transverse magnetic polarized light. Consequently, optical bistability is achieved at very low values of input intensity in a periodic structure composed of only a few repeating units. The characteristics of optical bistability are affected only slightly with the variation of the incident angle and thickness ratio of the layers. The effect of losses is also found to be relatively insignificant in such a small structure.     

Enthalpic effect of polyacrylonitrile on the concentrated solutions in dimethyl sulfoxide: Strong thixotropic behavior and formation of bound solvents

The effect of dipole–dipole interaction by nitrile groups of PAN on the bound state of solvent molecules and the concentrated solution properties in DMSO was investigated. Variation of a solution viscosity exhibited three overlap concentrations, C1*, C2*, and C3*, at 2.7, 8.6, and 16.3 wt%, respectively, representing the transition of concentration regions in the order of dilute, unentangled‐semi dilute, entangled‐semi dilute, and concentrated regions. The two‐dimensional mapping of FT‐IR analysis and dielectric measurement confirmed that the intermolecular interaction of PAN was suddenly enhanced at the C*s, inducing polarization to DMSO. In the ice‐melting process of PAN solutions, two different melting peaks (T_m2 and T_m3) of DMSO newly appeared at each C2* and C3*, suggesting the different types of bound solvents. In the concentrated solutions, the saturated dielectric constant and the strongly delayed evaporation of the solvent even at the boiling point of DMSO along with strong thixotropic behavior were indicative of the stronger confinement state of bound DMSO than in the semidilute solutions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1080–1089     

An Isosteric Triaza Analogue of a Polycyclic Aromatic Hydrocarbon Monkey Saddle

Since a few years, the interest in negatively-curved fused polycyclic aromatic hydrocarbons (PAHs) has significantly increased. Recently, the first chiral negatively-curved PAH with the topology of a monkey saddle was introduced. Herein the synthesis of its triaza congener is reported. The influence of this CH↔N exchange on photophysical and electrochemical properties is studied as well as the isomerization process of the enantiomers. The aza analogue has a significantly higher inversion barrier, which makes it easier to handle at room temperature. All experimental results are underpinned by theoretical DFT calculations.