用小波变换确定电位滴定终点

将小波变换在信号和图象处理过程中边缘检取的思想方法引入到化学中，以确定电位滴定的终点，能直接对测量的数据进行处理，不会引入人为的误差因素。计算精度可达实验精度的下限，且处理结果的判断非常简便，用本方法对实验数据进行处理，获得满意的结果。     

Determination of six aromatic compounds by using target factor analysis-UV spectrometry

The UV-spectra solutions containing mixtures of 1-naphthylamine(NAA), 1-naphthol(NAP), 2,7-dihydroxynaphthalene(DHN), 2,4-dimethoxybenzaldehyde(DMO), methyl salicylate(MSA) and dibutyl phthalate (DBP), have been measured. The numbers, identities and concentrations of the aromatic compounds in the mixtures have been determined successfully using Target Factor Analysis. Some sample mixtures have been analyzed successfully. The average recoveries are 99% for NAP, 102% for NAA, 102% for DHN, 103% for DMO, 102% for MSA, 101% for DBP.     

红外光谱数据的小波压缩和重建

介绍了小波变换及多分辨分析理论，并利用Ｄａｕｂｅｃｈｉｅｓ的正交紧支集小波基和Ｍａｌｌａｔ算法实现了对红外光谱数据的压缩和重建。计算表明，即使对原始数据压缩５倍，仍能很好地重建原有图谱，重建光谱数据与原始光谱数据之间的均方差为０．２６０。这为光谱数据的存储、检索和处理带来了方便。     

Organic Crystal Growth: Directly from Amorphous Solid Powder to Single Crystals

Preparation of organic crystals mainly depends on solution-deposition, sublimation, and melt-deposition techniques. Solid-state growth methods are generally not suitable for organic crystal growth due to the unprocurable mass transfer. Herein, we report two pyridine-substituted fluorenone compounds with extraordinary crystal-growth capacity, and these compounds can directly and quickly form single crystals from their amorphous solid powder by heating under antisolvent-assistance conditions. The novel experimental phenomenon and crystal growth mechanism were investigated in depth. The results indicate that multiple intermolecular hydrogen-bonding sites and planar aromatic structure (prone to π-π interactions) of these molecules dominate the mass transfer during crystal growth by providing enough energy. This discovery enhances our knowledge of solid-state methods for single-crystal growth.     

小波变换用于示波信号中有用信息提取的研究

示波分析是近年来在我国发展起来的一个新的电化学分析研究领域［１～４］．它根据阴极射线示波器荧光屏上示波图及其变化进行分析测试,从原理上可以将其分为示波电位法和示波计时电位法;从测定方式上可以将其分为示波滴定和示波测定．关于示波电位法的一些理论问题（如...     

Diagnosis of Senile Dementia with Compactly Supported Wavelet Neural Network

This research presents wavelet neural network, a novel class of neural network, to diagnose senile dementia by using experimental data about the trace element contents in the human serum. As a wavelet-based neural network, it adopts the scaling functions in the theory of wavelets, provides a good framework for determining the structure of ANN.     

General and Green Synthesis of C-6 Sulfonylmethyl 4-Aryl-3,4-dihydropyrimidinones in Water

A simple, inexpensive, and green reaction permitting the synthesis of new C-6 arylsulfonylmethyl 4-aryl-3,4-dihydropyrimidinones in water by S-alkylation of 6-bromomethyl 3,4-dihydropyrimidinones 2 with benzenesulfinic acid anions 3 is reported. The required 6-bromomethyldihydropyrimidone precursors 2 were readily prepared using an organic solid brominating reagent.     

栅状表面共振吸收的光声学研究

用光声学的方法首次研究了栅状表面的共振吸收问题,并观测到了栅状金属表面和栅状半导体表面对入射光的共振吸收现象,还从理论上对栅状表面共振吸收作了进一步的研究。理论和实验结果表明,对于一个给定的入射光波长,选择合适的金属栅的几何参数(栅格周期及高度)和物理参数(介电常数),可以在吸收谱上得到尖锐的共振吸收峰,在吸收峰附近金属表面的反射光强度接近为零,而金属表面场强则可达原入射光场强的上百倍。     

Synthesis and photophysical properties of three (multi)branched planar molecules

Three thiophenevinyl substituted one-, two-, and three-branched truxene π-conjugated compounds TS1, TS2 and TS3 have been prepared using a Heck reaction. Their linear absorption, single- and two-photon excited fluorescence were examined. The three analogues emit blue fluorescence at 420 nm. The number of branches has no influence on the position of the absorption maxima of the charge transfer band and fluorescence emitting maxima. However, the molar extinction coefficients of charge transfer band increase almost linearly with the number of branches. The two-photon absorption cross-section of the octupolar three-branched compound TS3 is several times that of the two-branched compound TS2 and one-branched compound TS1.     

小波神经网络在紫外光谱识别中的应用研究

介绍用于信号识别的小波神经网络的结构和算法，并将其用于酪氨酸，二羟基苯丙氨酸和色氨酸的紫外光谱识别。在波小神经网络中，采用Ｍｏｒｌｅｔ母波波和一维搜索变步长共轭梯度优化方法。结果表明，小波神经网络对于光谱间的细微结构差别具有很好的识别能力。