Functional and Basis Set Dependence for Time-Dependent Density Functional Theory Trajectory Surface Hopping Molecular Dynamics: Cis-Azobenzene Photoisomerization

Within three functionals (TD-B3LYP, TD-BHandHLYP, and TD-CAM-B3LYP) in combination with four basis sets (3-21g, 6-31g, 6-31g(d), and cc-pvdz), global switching (GS) trajectory surface hopping molecular dynamics has been performed for cis-to-trans azobenzene photoisomerization up to the S₁(nπ*) excitation. Although all the combinations show artificial double-cone structure of conical intersection between ground and first excited states, simulated quantum yields and lifetimes are in good agreement with one another; 0.6 (±5%) and 40.5 fs (±10%) by TD-B3LYP, 0.5 (±10%) and 35.5 fs (±4%) by TD-BHandHLYP, and 0.44 (±9%) and 35.2 fs (±10%) by TD-CAM-B3LYP. By analyzing distributions of excited-state population decays, hopping spots, and typical trajectories with performance of 12 functional/basis set combinations, it has been concluded that functional dependence for given basis set is slightly more sensitive than basis set dependence for given functional. The present GS on-the-fly time-dependent density functional theory (TDDFT) trajectory surface hopping simulation can provide practical benchmark guidelines for conical intersection driven excited-state molecular dynamics simulation involving in large complex system within ordinary TDDFT framework. © 2019 Wiley Periodicals, Inc.     

高阶非线性差分方程的导数收敛及其应用

首先研究高阶线性差分方程的整体收敛性，并证明了高阶非线性差分方程各阶导数的整体收敛；进而得到了关于高阶非线性差分方程整体收敛的一个定理，最后利用这个定理部分解决了Ladas提出的一个猜测。     

常曲率空间中的具有共形第二基本形式的子流形

以把调和态射看作等距浸入的单位法投影的问题为背景,研究了具有共形第二基本形式的子流形,论证了具有共形第二基本形式的高维子流形,一般不是由极小点和全脐点构成,这和曲面的情形形成了鲜明的对照。也给出了常曲率空间中具有平行中曲率的奇数维子流形的一个完全分类。     

A pH-driven DNA nanoswitch for responsive controlled release

An intelligent pH-responsive carrier and release system based on DNA nanoswitch-controlled organization of gold nanoparticles (AuNPs) attached to mesoporous silica (MS) has been designed and demonstrated.     

pH-Sensitive Poly(Vinyl Alcohol)/Sodium Carboxymethylcellulose Hydrogel Beads for Drug Delivery

A series of pH-sensitive hydrogel beads were prepared composed of poly(vinyl alcohol) (PVA) and sodium carboxymethylcellulose (CMC) by using Fe³⁺ crosslinking and freeze-thawing (FT) cycle techniques. The mixed solution of CMC and PVA was firstly crosslinked with Fe³⁺ to form beads and then subjected to freezing-thawing cycles for further crosslinking. The formation of hydrogel was confirmed by Fourier transform infrared spectroscopy (FTIR). The gelling rate in ferric solution and the swelling and pH-senstive properties of the hydrogel beads were investigated. The encapsulation efficiency and in-vitro release properties of beads were also evaluated using Bovine serum albumin as model drug. The pH sensitivity and the release rate increased with increasing CMC content. These results suggest that the PVA/CMC hgdrogel beads should be useful as pH-sensitive drug delivery systems for bioactive agents.     

Two-photon and Three-photon Fluorescence of Triton X-100 in the Ultraviolet Region

Journal of Fluorescence - We report, to our best knowledge, the first observation of two-photon and three-photon fluorescence of Triton X-100 (TX-100) in water and cyclohexane. The observed...     

基于半光滑牛顿法的润滑液膜有限元空化算法

针对润滑液膜中空化问题,引入Fischer-Burmeister函数,提出一种求解满足质量守恒雷诺方程的半光滑牛顿迭代算法.该算法将空化问题的非线性互补关系转化为等式约束方程,避免了迭代计算中的不等式约束识别问题.算法可将空化约束方程与雷诺方程、力平衡方程、变形方程等同时纳入牛顿迭代方程组,有效解决了传统松弛迭代算法需要多重嵌套循环带来的效率低下问题及压力与膜厚的强耦合性带来的收敛困难问题.计算实例表明,该算法计算效率高、收敛性好,且易应用于弹流润滑分析中,在滑动轴承和机械端面密封等多种物理模型下均有良好的适用性.     

基于图像块相关性分类的加密域可逆数据隐藏

考虑到不同图像块中像素的重要位(高位)具有不同的相关性,本文提出了一种基于图像块高位相关性分类的加密域可逆数据隐藏算法.在数据嵌入前,对各图像块的高位进行相关性划分,然后根据相关性强弱对加密图像的相应像素执行不同程度的低位(不重要位)取反,以达到减小嵌入失真和提高数据提取正确率的目的.同现有的两个主要方法相比,大量的实验结果表明该算法在保证解密后图像具有相同峰值信噪比的情况下,能有效减小数据提取和图像恢复的错误率.     

Thermodynamic Model for ThO<Subscript>2</Subscript>(am) Solubility in Isosaccharinate Solutions

Extensive studies on ThO₂(am) solubility were carried out as functions of a wide range of isosaccharinate concentrations (0.0002 to 0.2 mol⋅kg⁻¹) at fixed pH values of about 6 and 12, and varying pH (ranging from 4.5 to 12) at fixed aqueous isosaccharinate concentrations of 0.008 mol⋅kg⁻¹ or 0.08 mol⋅kg⁻¹, to determine the aqueous complexes of isosaccharinate with Th(IV). The samples were equilibrated over periods ranging up to 69 days, and the data showed that, in most cases, steady-state concentrations were reached in <15 days. The data were interpreted using the SIT model, and required the inclusion of mixed hydroxy-ISA complexes of Th(IV) [Th(OH)ISA²⁺, Th(OH)₃(ISA)₂^-_{2}^{-}, and Th(OH)₄(ISA)₂^2-]_{2}^{2-}] with log ₁₀ K ⁰=12.5±0.5,4.4±0.5 and −3.2±0.5 for the reactions: