邻苯二酚紫催化光度法测定亚硝酸根的研究

基于亚硝酸根对溴酸钾氧化邻苯二酚紫使其褪色的催化作用,建立了一种测定痕量亚硝酸根的新方法,研究了其动力学条件,测定了反应级数和表观活化能。测定范围为０．２～３．５μｇ／１０ｍＬ。方法选择性好,迅速简便,用于水中和蔬菜中亚硝酸根的测定,结果满意     

ICP-AES测定ATO（Sb掺杂SnO2）中的Pb,Cd,Cr的含量

通过试验确定了ATO粉的最佳溶样条件及其Pb,Cd,Cr的含量测定的最佳测定条件。     

ICP-MS同时测定饮用水中23种元素的研究

本文对饮用水的测定作了研究,采用ＩＣＰ－ＭＳ法直接测定饮用水中２３种元素,结果证明,其灵敏度,精密度和准确度都很高,而且２３种元素可以同时测定,测定元素浓度范围为ｎｇ／Ｌ－ｍｇ／Ｌ,样品前处理简单,测定快速,省事省力。     

旋转坐标系同核NOE差谱

提出一种测定旋转坐标系NOE差谱的NMR技术.与通常的NOE技术相比,其特点是:应用范围较广,可节省测定时间,NOE信号为纯吸收型,可测定NOE的大小,并且可得到某些谱峰高度重叠,采用通常技术难于测定的有机化合物的NOE谱.     

原子吸收光谱法和ICP-AES测定矿物中铷的比较

比较了原子吸收光谱法(AAS)和电感耦合等离子体-原子发射光谱法(ICP-AES)测定经混酸溶解的矿物中的铷。结果表明:两种方法的准确度、精密度均较好。AAS测定铷检出限更低,但其测定范围窄,需要添加硫酸钾作为消电离剂,过程复杂;ICP-AES测定范围较宽,对于高含量样品无需稀释即可直接测定,过程简单,可多元素同时测定,更适合于分析大批量样品。     

紫外吸收光谱积分法分析蛋白质浓度-以碱性磷酸酶为例

利用矿物(针铁矿,蒙脱石)和太湖沉积物吸附碱性磷酸酶(alkaline phosphatase,APase),测定吸附后上清液中剩余碱性磷酸酶浓度时发现其紫外吸收光谱发生了变化,利用传统280nm处紫外吸收法无法直接准确测定其浓度值。基于对碱性磷酸酶252～305nm处吸收峰面积积分方法可以消除影响,并准确分析测定碱性磷酸酶浓度。其测定结果与考马斯亮蓝法测定结果进行比较,表明了该方法可以方便,快速和准确地测定此类实验中碱性磷酸酶浓度。同时,该方法还可以扩展至其他蛋白质的定量分析,甚至其他类似实验中,一定程度上克服传统方法应用单波长进行定量分析中存在的易受干扰的缺点。     

有机溶剂中水的分光光度法测定

在有机溶剂中有水存在时 ,氯醌酸发生离解 ,其最大吸收波长发生红移 ,且吸收强度显著增加。详细地研究了氯醌酸变色机理及其用于测定水的最佳条件 ,建立了一种新的测定有机溶剂中水含量的分光光度分析方法。测定了白酒、食用酒精与试剂无水酒精中的水含量 ,得到满意测定结果。测定线性范围为φ(H2 O) 0 0 2 %～ 10 % ,方法简单、灵敏度高、重现性好。对甲醇、异丙醇、丁酮、丙酮、乙腈、四氢呋喃中水的测定进行了实验 ,得到了相应的吸光度与浓度校准曲线     

测定烟花爆竹烟火药剂成分的样品预处理方法研究

为了准确分析烟花爆竹烟火药剂的成分,其前处理已成为测定的一个重要环节,很有必要研究测定烟火药剂成分含量的预处理方法。     

干燥物料水分状态研究

物料在太阳能干燥房中干燥以后 ,用水分测定仪测定其含水量进行再干燥。测定再干燥前后物料的红外光谱 ,研究其水分状态表明 ,在干燥过程后期 ,将干燥温度控制在结合水开始逸出的温度 ,可得到最好的干燥效果     

ICP-AES测定锰矿中二氧化硅含量

试样经氢氧化钠和过氧化钠混合熔剂碱熔,再用酸浸提,干过滤后定容.采用ICP-AES测定锰矿中二氧化硅含量.本法测定锰矿标样(冶金部标准样品505)中二氧化硅含量,其测定结果的相对标准偏差RSD为1.08%,测定平均值为33.93%(标样推荐值为33.58%).     

ICP-AES测定镁合金中的Zn、Mn、Zr、Ce

采用ICP－AES测定了镁合金中的Zn、Mn、Zr、Ce，进行了酸度试验，氢氟酸用量试验，分析线的选择，并研究了基体元素对待测元素的干扰。测定值与标钢值吻合较好，RSD＜5％。方法简便可靠，可获得令人满意的分析结果。     

Optical properties of heated air, carbon dioxide, and argon

Stable-plasma generators, spectroscopic measuring equipment, and methods for determining the optical properties of an extremely heated medium with a given composition have been developed. The spectral coefficients of absorption and emission of heated air, carbon dioxide, and argon were studied. A comparison with the data of other theoretical and experimental investigations has been performed. Deceased. Institute of Molecular and Atomic Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 818–826, November–December, 1997.     

Transmission properties of one-dimensional Photonic crystals containing double-negative and single-negative materials

The transmission properties of one-dimensional photonic crystals containing double-negative and singlenegative materials are studied theoretically.A special kind of photonic band gap is found in this structure.This gap is invariant with scaling and insensitive to thickness fluctuation.But when changing the ratio of the thickness of two media.the width of the gap could be enlarged.The defect modes are analyzed by inducing a linear defect layer in the structure.It is found that the number of defect modes will increase when the thickness of the defect layer becomes larger.     

Influence of substrate process tolerances on transmission characteristics of frequency-selective surface

Frequency-selective surface （FSS） is a two-dimensional periodic structure consisting of a dielectric substrate and the metal units （or apertures） arranged periodically on it. When manufacturing the substrate, its thickness and dielectric constant suffer process tolerances. This may induce the center frequency of the FSS to shift, and consequently influence its characteristics. In this paper, a bandpass FSS structure is designed. The units are the Jerusalem crosses arranged squarely. The mode-matching technique is used for simulation. The influence of the tolerances of the substrate＇s thickness and dielectric constant on the center frequency is analyzed. Results show that the tolerances of thickness and dielectric constant have different influences on the center frequency of the FSS. It is necessary to ensure the process tolerance of the dielectric constant in the design and manufacturing of the substrate in order to stabilize the center frequency.     

The effect of nature of polyions and treatment after deposition on wetting characteristics of polyelectrolyte multilayers

The sequential adsorption of oppositely charged polyelectrolytes (PE) occurs to be a powerful tool for obtaining various materials of precisely defined properties. The interfacial features of PE multilayer films are governed by the choice of polycation/polyanion pairs and the conditions of film formation. Additionally, the long time exposure to the conditions different than that encountered during formation usually affects polyelectrolyte multilayer structure.The wettability of heterogeneous surfaces produced by ‘layer-by-layer’ (LbL) adsorption of polyelectrolytes was investigated in this work. We focused on the influence of film treatment after deposition on wetting properties of obtained multilayers. The effect of the nature of the first layer was also studied. Apart from simple arrangements: (polyallylamine hydrochloride)/(polysodium 4-styrenesulfonate) (PAH/PSS) and (poly-l-lysine hydrobromide)/(poly-l-glutamic acid sodium salt) (PLL/PGA) more complicated structures were considered having as a first layer two types of polyethylene imines (PEI) of different molecular weight.Wetting properties of such polyelectrolyte films were determined experimentally by contact angle measurements using technique of direct image analysis of the shape of sessile drop.     

Lectures on the functional renormalization group method

These introductory notes are about functional renormalization group equations and some of their applications. It is emphasised that the applicability of this method extends well beyond critical systems, it actually provides us a general purpose algorithm to solve strongly coupled quantum field theories. The renormalization group equation of F. Wegner and A. Houghton is shown to resum the loop-expansion. Another version, due to J. Polchinski, is obtained by the method of collective coordinates and can be used for the resummation of the perturbation series. The genuinely non-perturbative evolution equation is obtained by a manner reminiscent of the Schwinger-Dyson equations. Two variants of this scheme are presented where the scale which determines the order of the successive elimination of the modes is extracted from external and internal spaces. The renormalization of composite operators is discussed briefly as an alternative way to arrive at the renormalization group equation. The scaling laws and fixed points are considered from local and global points of view. Instability induced renormalization and new scaling laws are shown to occur in the symmetry broken phase of the scaler theory. The flattening of the effective potential of a compact variable is demonstrated in case of the sine-Gordon model. Finally, a manifestly gauge invariant evolution equation is given for QED.     

Effect of compatibilizers on the crystallization kinetics of cellulose-filled high density polyethylene

High density polyethylene (HDPE) is a ubiquitous material with versatile properties. It is produced and used in greater volume than any other thermoplastic. HDPE is often filled with a variety of materials for various applications. Glass fiber and wood flour are two common fillers for HDPE. This study investigated microcrystalline cellulose (MCC) as a filler in HDPE. The use of compatibilizers, or coupling agents, was investigated as a means of improving the dispersion of the cellulose filler in the HDPE matrix and the mechanical properties of the resulting composites. One compatibilizer was shown to improve the strength of the resulting composite. The stiffness was unaffected, as expected. Thermal properties were measured by means of differential scanning calorimetry. Analysis of the crystallization kinetics indicated that the Avrami coefficient was altered by the filler and was also modified by the presence of the compatibilizer. The presence of cellulose and/or compatibilizer increased the matrix degree of crystallinity. The two compatibilizers studied did not behave similarly and may have different mechanisms of compatibilization.     

Matrix-Based Analytical Model of Critical Coupling Length of Titanium In-Diffused Integrated-Optic Directional Coupler on Lithium Niobate Substrate

The critical coupling length Lc is the most important design parameter of an integrated-optic directional coupler, which is the basic building block of a variety of optical integrated circuits. The existing methods of estimating Lc of a Ti in-diffused waveguide directional coupler on LiNbO3 substrate are based on the beam propaga tion method (BPM), which requires huge computing time. A considerably simpler and computationally faster analytical method involving only multiplication of 2 x 2 matrices with no iterations is described in this article. A staircase type step-index profile is generated from the one-dimensional effective index profile in the lateral direction by partitioning the latter into a large number of thin sections of different refractive indices. The overall transfer matrix of the step-index layered structure so obtained may be computed by the progressive multiplication of individual transfer matrices (2 x 2) relating the field components in adjacent layers. Hence the wave amplitude in any layer may be computed as a function of the input wave amplitude for different angles of incidence. This method has been successfully employed to compute the propagation constants for symmetric and asymmetric guided modes in the coupled region of the directional coupler and hence compute the coupling length. The values of Lc computed for a variety of devices agree closely with the published experimental results reported by several research groups. The computer program implementing the model runs reasonably fast in an ordinary PC and is versatile enough to consider arbitrary waveguide dimensions. Ti film thickness, and diffusion parameters for any wavelength of input light and for both transverse electric and transverse magnetic polarizations.     

Detecting dark energy in long baseline neutrino oscillations

In this paper, we discuss a possibility of studying properties of dark energy in long baseline neutrino oscillation experiments. We consider two types of models of neutrino dark energy. For one type of models the scalar field is taken to be quintessence-like and for the other phantom-like. In these models the scalar fields couple to the neutrinos to give rise to spatially varying neutrino masses. We will show that the two types of models predict different behaviors of the spatial variation of the neutrino masses inside the Earth and consequently result in different signals in long baseline neutrino oscillation experiments.     

Dynamic conductivity of composites of fractal structure

We have studied the dynamic conductivity of a composite consisting of well- and weak-conducting components with random fractal structure. In order to calculate effective properties of composite medium, we used hierarchic structure model and innovative iterative averaging method based on renormalization group transformations idea. Our results show, that the behavior of a composite over a magnetic field become even more complicated.Unusual peaks and oscillations appear in frequency dependencies of effective conductivity, permittivity and other properties. We discuss the influence of fractal parameters of the composite structure on such unusual behavior of effective properties.