Ethanol/water pulp enzymatic pretreatment: Chemical and FTIR-PCA analyses

Pulps obtained from ethanol/water cooking of sugarcane bagasse were treated at different times using xylanase enzyme obtained from Thermomyces lanuginosus IOC-4145 or commercially (Cartazyme HS, Sandoz Products Ltd.). The enzyme dosage was 18 IU per g of dry pulp and the time varied from 4 h to 12 h. When xylanase from T. lanuginosus was used, the kappa number and viscosity improved independently of the processing time used (4 h, 8 h, and 12 h). After chemical evaluation, the obtained pulps were classified using Fourier Transformed Infra-Red Spectroscopy and Principal Component Analysis. The results showed that the first three principal components explained more than 90 % of the total variance of the pulp spectra.     

Filter Diagonalization with Finite Fourier Transform Eigenfunctions

Below, we briefly report on the progress in the development of the Filter Diagonalization technique when filtering is carried out with the aid of Finite Fourier Transform (FFT) eigenfunctions. During recent years interest in these functions, also known as ‘prolates’, or ‘slepians’, has increased among scientists doing research in the field of signal processing. The main explanation to this follows from the set of very special extremal and orthogonality properties exibited by the FFT eigenfunctions. Recent results of Walter and Shen on sampling with prolate spheroidal functions will necessary produce a new wave of interest. In the presented, Filter diagonalization machinery, we show that the sampling formula of Walter and Shen simplifies essentially the computation of matrix elements as certain 2D–integrals involving FFT eigenfunctions.     

中药配方颗粒红外光谱法的快速鉴别

采用红外光谱法对中药配方颗粒及其辅料进行了鉴别研究。结果表明：不同生产厂商的配方颗粒中所添加的辅料类型及用量有较大差别；不同种的配方颗粒在辅料含量较低的情况下有较明显的指纹性，而辅料含量较高时，采用差谱技术可以提高谱图的指纹性，达到中药配方颗粒--鉴别的目的。该法简便、快速、可靠，是中药配方颗粒宏观质控的一个强有力的手段。     

Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

Introduction Inorganic oxide films have attracted a lot of interest in the last several decades. Among them, silicon dioxide films are widely used in modern microelectronics, optics and mechanics. This material has been grown by various methods including thermal oxidation, chemical vapor phase deposition, plasma-enhanced chemical vapor phase deposition, and so on.1,2 Recently, Nagayama et al.3 have reported that SiO2 thin films could be produced by a new chemical method of liquid phase depos…     

离散小波变换-遗传算法-交互检验法用于近红外光谱数据的高倍压缩与变量筛选

用遗传算法(GA)与交互检验(CV)相结合建立了一种用于对近红外光谱(NIR)数据及其离散小波变换(DWT)系数进行变量筛选的方法，并应用于烟草样品中总挥发碱和总氮的同时测定。结果表明：NIR数据经DWT压缩为原始大小的3．3％时基本没有光谱信息的丢失；有效的变量筛选可以极大地减少模型中的变量个数，降低模型的复杂程度，改善预测的准确度。     

Møller-Plesset (MP2) perturbation theory for large molecules

Summary A novel formulation of MP2 theory is presented which starts from the Laplace transform MP2 ansatz, and subsequently moves from a molecular orbital (MO) representation to an atomic orbital (AO) representation. Consequently, the new formulation is denoted AO-MP2. As in traditional MP2 approaches electron repulsion integrals still need to be transformed. Strict bounds on the individual MP2 energy contribution of each intermediate four-index quantity allow to screen off numerically insignificant integrals with a single threshold parameter. Implicit in our formulation is a bound to two-particle density matrix elements. For small molecules the computational cost for AO-MP2 calculations is about a factor of 100 higher than for traditional MO-based approaches, but due to screening the computational effort in larger systems will only grow with the fourth power of the size of the system (or less) as is demonstrated both in theory and in application. MP2 calculations on (non-metallic) crystalline systems seem to be a feasible extension of the Laplace transform approach. In large molecules the AO-MP2 ansatz allows massively parallel MP2 calculations without input/output of four-index quantities provided that each processor has in-core memory for a limited number of two-index quantities. Energy gradient formulas for the AO-MP2 approach are derived.Dedicated to Prof. W. Kutzelnigg whose books on theoretical chemistry aroused my interest in this field     

Y型分子筛骨架外阳离子行为的FT-FIR研究

应用付里叶变换远红外光谱（ＦＴ－ＦＩＲ）方法研究了ＮＨ＾＋４交换、Ｎａ＾＋反交换和不同水蒸汽处理条件对ＮａＹ分子筛骨架外阳离子的影响。结果表明，在ＮＨ＾＋４、Ｎａ＾＋阳离子交换过程中，六方柱笼中Ⅰ位竞争激烈，积极参与交换。骨架外阳离子受影响较大，升温过程中分子筛空穴的吸附水被除去的同时阳离子发生了重新分布。较高温度下分子筛发生脱结构羟基，生成多种形式的铝阳离子。     

基于小波的恒电量瞬态响应信号的滤波处理

利用小波变换的阈值法对恒电量响应信号进行滤波处理, 同时与传统的时域和频域的滤波方法进行分析比较, 并且讨论了小波变换的分解层数对恒电量响应信号滤波效果的影响. 结果表明, 利用小波变换可以在时域和频域同时对恒电量响应信号取得良好的去噪效果. 这不仅能提高时域曲线拟合的精度, 还大大地提高了恒电量频谱解析的可靠性. 在实际应用中, 小波变换的分解层数取5～7层可以收到满意的效果.     

激光拉曼光谱在高分子中的应用

论述了激光拉曼光谱对高分子结构、结晶形态和表征,反应动力学过程和取向的研究,还介绍了纵向声学模、共振、高温高压、光波导和付里叶拉曼光谱在高分子研究中的最新进展。     

High-resolution Hadamard transform microscope fluorescence imaging: quantifying the DNA content in single cells

This study presents a novel miniaturized Hadamard transform fluorescence imaging microscope, by combining a conventional fluorescence microscope with Hadamard transform multiplexing encoding using a one-dimensional movable mask to realize spatial resolution and a linear CCD for multichannel detection. The microscope can provide high-resolution automatically-generated 0–255 gray level HT images for morphological analysis and visualization of a single cell, and normalized HT images for cellular quantitative measurements. The microscopes imaging capability was applied to measure the DNA content in human lymphocyte, chicken erythrocyte and eel erythrocyte, and a comparative study was performed. The results show that the calibrated DNA content in a chicken erythrocyte is 2.32 pg when human lymphocyte is used as the standard, and eel erythrocyte may be a potentially reliable and novel standard for determining DNA contents in other species because it has a stable DNA value of 2.06 pg, with a CV of 4.3% when 20 eel erythrocytes are measured. The results also demonstrate that the HT imaging microscope should be valuable in the fields of medicine and cell biology.