Theoretical studies on the reaction path and dynamics of the reaction CH_3+H_2O→CH_4+OH

The reaction path, the dynamical properties along the reaction path and CVT rate constants are computed by the ab initio MO method, the reaction path Hamiltonian theory and the variational transition state theory. The results show that the effect of the electron correlation energy on activation barrier is large, the recrossing and tunneling effects exist in the reaction.     

气相色谱质谱法快速测定人血浆中克仑特罗

血浆样品经0.01mol·L-1盐酸和无水乙醇浸取,在碱性条件下用氯仿萃取,GG-MS-选择离子测量法测定,外标法定量。在选定的色谱条件下,盐酸克仑特罗的检出限为0.05ng,线性范围为0.1-100ng,方法的平均回收率为95.6％,RSD小于6.82％(n=6)。该法毋需衍生化,基质无干扰,简便可靠,适用于生物材料中克仑特罗的快速分析。     

三芳基膦配体的合成研究

从间溴苯酚出发, 利用新的合成方法经五步反应合成了一系列具有不同烷氧基的芳基膦配体. 改进后的方法可方便地通用于在苯环上具有各种不同基团基的膦配体衍生物的合成, 且有原料易得、操作简单、产率较高的优点.     

Advanced Current Collectors for Alkali Metal Anodes

High-energy-density batteries are in urgent need to solve the ever-increasing energy storage demand for portable electronic devices, electric vehicles, and renewable solar and wind energy systems. Alkali metals, typically lithium(Li), sodium(Na) and potassium(K), are considered as the promising anode materials owing to their low electrochemical potential, low density, and high theoretical gravimetric capacities. However, the problem of dendrite growth of alkali metals during their plating/stripping process will lead to low Coulombic efficiencies, a short lifespan and huge volume expansion, eventually hindering their practical commercialization. To resolve this issue, a very effective approach is engineering the anodes on structured current collectors. This review summarizes the development of the alkali metal batteries and discusses the recent advances in rational design of anode current collectors. First, the challenges and strategies of suppressing alkali-metal dendrite growth are presented. Then the special attention is paid to the novel current collector design for dendrite-free alkali metal anodes. Finally, we give conclusions and perspective on the current challenges and future research directions toward advanced anode current collectors for alkali metal batteries.     

A Novel, Simple and Efficient Synthesis of Ferrocenyl Enones and Alkynols

Propargylic alcohols are versatile precursors to many organic molecules including natural products and pharmaceutical compounds.[1] In our continuing interest in the development of practical methods for synthesis of ferrocene derivatives, we decided to investigate the efficiencies of ferrocenylacetylene addition to aromatic aldehydes under t-BuOKcatalyzed condition.[2] Interestingly, we found that the usually reliable coupling reaction between terminal alkyne of type 1 and aromatic aldehydes of type 2 does not furnish the expected propargylic alcohols, but that the isomeric aryl enones 3are found in high yield and very short reaction time (10～20 min). This provided a promising protocol for preparation of ferrocenyl chalcones in a practical, economical and mild sense compared with the traditional method. To the best of our knowledge, this unusual reaction was first observed for the addition of ferrocenylacetylene to aldehyde in a base-catalyzed manner (Eq. 1).     

激光通道传输热特性对远场光束质量的影响

 通过仿真计算分析了激光在光束控制系统通道内传输所产生的热效应及其对远场光束质量的影响。激光传播由近轴波方程描述，用快速傅里叶变换技术求解；激光热效应引起的流场密度变化采用完全Navier-Stokes方程计算。计算给出了不同波长、不同吸收系数条件下的远场光斑情况。计算结果表明，在典型的工作条件和状态下，较高能量激光在光束控制系统通道内产生的热效应影响不容忽视，它会明显降低远场目标处的能量集中度，增大光斑的发散。     

蝙蝠喉部发声组织建模及发声机理*

建立蝙蝠发声组织模型对超声机理研究及在智能设备的应用具有重要意义。根据蝙蝠喉部发声组织结构特点,通过有限元方法构建了蝙蝠的3种不同发声组织模型,分析了尺寸、材料力学参数、组织结构和张力4个因素对发声组织特征频率的影响。结果表明,如果用人类声带,按比例缩小构建蝙蝠喉部组织模型,蝙蝠无法发出超声波。构建组织结构含甲状软骨和声带的半鼓状模型和只含声带的条状模型,两种模型的特征频率相近且在合理的参数域内均无法达到超声范围。而含膜条状模型的特征频率可以通过张力进行超声频率的调节,这与文献的实验结果一致。因此,可基于含膜条状模型对蝙蝠喉管发声组织进行建模及其发声机理研究。     

A DIFFUSIVE SVEIR EPIDEMIC MODEL WITH TIME DELAY AND GENERAL INCIDENCE

In this paper,we consider a delayed diffusive SVEIR model with general inci-dence.We first establish the threshold dynamics of this model.Using a Nonstandard Fi...     

基于稠密变形场能量优化的非刚性在线体积重建方法

针对动态非刚性在线重建存在的重建漂移问题,提出了一种基于单个RGB-D传感器的稠密变形场在线融合策略,实现了对非刚性几何形状的动态重建.通过局部平滑和输入约束处理,将空间的最优变形转换为非线性正则变分优化问题,并使用数据并行闪存优化策略,以摄像机捕获速率,实现对非刚性场景的在线跟踪重建.通过实验表明,本文方法实现了对非...     

基于行过扫数据降低大面阵CCD图像噪声算法研究

针对全帧转移大面阵电荷耦合器件(CCD)多帧图像数据随时间漂移的现象和测试电路引入的噪声,导致无法准确评估CCD器件的参数,文章提出一种基于行过扫数据校正算法。行有效像元数据与对应行垂直过扫数据同时输出,通过有效像元数据减去垂直过扫数据均值,对图像数据漂移的现象进行抑制。测试电路中模拟模块与数字模块同时作用于单行有效像元数据与垂直过扫数据,通过有效像元数据减去垂直过扫数据均值,消除测试电路引入的噪声。实验结果表明,经过该算法校正后的器件读出噪声减小了20%,暗场差值图像中超过15 e^-和25 e^-的比例减小了25%。该算法适用于大面阵CCD器件,可校正测试系统引入的测试误差,提高全帧转移大面阵CCD器件测试效率。