Structures and spectroscopic properties of nonperipherally and peripherally substituted metal-free phthalocyanines: a substitution effect study based on density functional theory calculations

The molecular structures, molecular orbitals, atomic charges, electronic absorption spectra, and infrared (IR) and Raman spectra of a series of substituted metal-free phthalocyanine compounds with four (1, 3, 5, 7) or eight (2, 4, 6, 8) methoxyl (1, 2, 5, 6) or methylthio groups (3, 4, 7, 8) on the nonperipheral (1-4) or peripheral positions (5-8) of the phthalocyanine ring are studied by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The calculated structural parameters and simulated electronic absorption and IR spectra are compared with the X-ray crystallography structures and the experimentally observed electronic absorption and IR spectra of the similar molecules, and good agreement between the calculated and experimental results is found. The substitution of the methoxyl or methylthio groups at the nonperipheral positions of the phthalocyanine ring has obvious effects on the molecular structure and spectroscopic properties of the metal-free phthalocyanine. Nonperipheral substitution has a more significant influence than peripheral substitution. The substitution effect increases with an increase in the number of substituents. The methylthio group shows more significant influence than the methoxyl group, despite the stronger electron-donating property of the methoxyl group than the methylthio group. The octa-methylthio-substituted metal-free phthalocyanine compounds have nonplanar structures whose low-lying occupied molecular orbitals and electronic absorption spectra are significantly changed by the substituents. The present systematical study will be helpful for understanding the relationship between structures and properties in phthalocyanine compounds and designing phthalocyanines with typical properties.     

Semi-supervised locally discriminant projection for classification and recognition

Semi-supervised dimensional reduction methods play an important role in pattern recognition, which are likely to be more suitable for plant leaf and palmprint classification, since labeling plant leaf and palmprint often requires expensive human labor, whereas unlabeled plant leaf and palmprint is far easier to obtain at very low cost. In this paper, we attempt to utilize the unlabeled data to aid plant leaf and palmprint classification task with the limited number of the labeled plant leaf or palmprint data, and propose a semi-supervised locally discriminant projection (SSLDP) algorithm for plant leaf and palmprint classification. By making use of both labeled and unlabeled data in learning a transformation for dimensionality reduction, the proposed method can overcome the small-sample-size (SSS) problem under the situation where labeled data are scant. In SSLDP, the labeled data points, combined with the unlabeled data ones, are used to construct the within-class and between-class weight matrices incorporating the neighborhood information of the data set. The experiments on plant leaf and palmprint databases demonstrate that SSLDP is effective and feasible for plant leaf and palmprint classification.     

CAPPFramework工程化实施研究

ＣＡＰＰ应用框架与开发平台（ＣＡＰＰＦｒａｍｅｗｏｒｋ）是一个以面向对象ＣＡＰＰ知识库系统为核心的通用交互式ＣＡＰＰ应用支撑软件。ＣＡＰＰＦｒａｍｅｗｏｒｋ的实施已成为ＣＡＰＰＦｒａｍｅｗｏｒｋ推广应用的关键,这是由工艺设计问题的特性所决定的。文章对ＣＡＰＰＦｒａｍｅｗｏｒｋ实施的工程化管理进行研究,建立了ＣＡＰＰＦｒａｍｅｗｏｒｋ实施质量保证体系,以提高ＣＡＰＰＦｒａｍｅ－ｗｏｒｋ应用系统的工程化程度。     

构件模板动态实例化技术的研究与应用

本文介绍了构件体系结构下的模板动态实例化技术,该技术将构件模板与补充语义分离处理,引入动态实例化操作,为需求改变的动态配置提供了实用和有效的手段。     

PDUIMS--基于持久存储的用户界面管理系统的设计与应用

用户界面作为软件系统的重要组成部分,在软件整个生命周期中具有独特的地位。软件质量控制的核心在于用户界面的有效、可扩展、高适应度的管理、常规的界面管理位于源码一级,对于大规模企业级应用将带来许多弊端文中介绍了一个利用动态加载和持久存储实现的面向商务处理的用户界面管理系统ＰＤＵＩＭＳ,该系统通过功能描述数据表存储用户界面实现了集中统一的数据库工程化界面管理和发布,对于应用语义提供了分离机制实例表明了该     

二甲基硫醚与过氧化氢反应机理的研究及溶剂效应

采用密度泛函理论的B3LYP方法,在6-311+G(d,p)基组水平上研究了CH3SCH3与H2O2的微观反应机理,全参数优化了反应势能面上各驻点的几何构型,振动分析和内禀反应坐标(IRC)分析结果证实了中间体和过渡态的真实性,计算所得的键鞍点电荷密度的变化情况也确认了反应过程.结果表明,反应共分2步进行,主要经历了O对S的进攻、H转移以及O-O键断裂的历程.并分别考察了其在水中和甲苯的溶剂效应.结果表明,溶剂效应降低了反应的活化能,并使过渡态红外光谱蓝移.     

Comparison of structural and photoluminescence properties of ZnO thin films grown by pulsed laser deposition and ultrasonic spray pyrolysis

ZnO thin films have been deposited by pulsed laser deposition (PLD) and ultrasonic spray pyrolysis (USP) method, respectively. X-ray diffraction and transmission electron microscopy characterizations indicate that ZnO film grown by PLD exhibits better crystallinity than that grown by USP. Photoluminescence spectra show that the near-band edge ultraviolet emission of film grown by PLD is narrower and shifts to higher energy, compared with that of film grown by USP. In the visible range, ZnO film grown by PLD exhibits four local level emission centered at 470 nm, 486 nm, 544 nm, and 613 nm, respectively, while the film grown by USP only presents a weak broad band emission centered at 502 nm. Hall measurement shows higher carrier density and lower hall mobility in ZnO film grown by PLD than that in film grown by USP. The higher density of intrinsic defects as well as higher crystallintiy is considered to account for the difference of photoluminescence in ZnO film grown by PLD with that in film grown by USP.     

基于神经网络的GIS空间数学模型研究

文中对空间数学模型的建立方法以及不同方法的优缺点进行了分析比较,指出基于人工神经网络的建模方法是目前GIS应用领域中行之有效的方法之一,最后通过实例对该方法的有效性进行了验证。     

ICP-AES测定低合金钢中钨的含量

研究了用ICP-AES法测定低合金钢中元素钨的测定方法。选用波长239.709nm谱线,考虑共存元素之间的干扰问题,控制适当酸度,用ICP-AES法测定低合金钢中元素钨,相对标准偏差小于4%,加标回收率在95.5%～104.0%之间,分析方法快速、简便,分析结果准确。