A mixed method for measuring low-frequency acoustic properties of macromolecular materials

A mixed method for measuring low-frequency acoustic properties of macromolecular materials is presented. The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequencies, usually less than 100 Hz; then based on the Principles of Time-Temperature Superposition (TTS), these parameters are extended to the frequency range that acousticians are concerned about, usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis. To test the feasibility and accuracy, we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method. While applying the basic parameters to calculating characteristics of the sample in acoustic pipe, a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe.     

The First Eigenvalue of the Laplacian and the Conductance of a Compact Surface

We present some results whose central theme is the phenomenon of the first eigenvalue of the Laplacian and conductance of the dynamical system. Our main tool is a method for studying how the hyperbolic metric on a Riemann surface behaves under deformation of the surface. With this model, we show that there are variation of the first eigenvalue of the laplacian and the conductance of the dynamical system, with the Fenchel–Nielsen coordinates, that characterize the surface.     

The extrapolated first order method for solving systems with complex eigenvalues

An extrapolated form of the basic first order stationary iterative method for solving linear systems when the associated iteration matrix possesses complex eigenvalues, is investigated. Sufficient (and necessary) conditions are given such that convergence is assured. An analytic determination of good (and sometimes optimum) values of the involved real parameter is presented in terms of certain bounds on the eigenvalues of the iteration matrix. The usefulness of the developed theory is shown through a simple application to the conventional Jacobi method.     

SiC/SiC复合材料第一壁热工设计

以日本原子力研究所那珂研究所聚变堆设计室进行的先进稳态托卡马克聚变堆2（A－SSTR2）概念设计为基础，对SiC/SiC复合材料包层／第一壁热工设计进行了分析计算。通过选取各种几何位形和材料敏感特性参数，用有限元法进行了大量的热工计算，以最高温度、最大热应力为基础建立了包层／第一壁设计窗口，选取了满足热工要求的最佳设计方案，对今后的工程设计具有指导作用和重要的参考价值。     

Investigation of the First Mirror on Tokamak

The study progress of NNSF in 2006 has been presented in this paper. The aim and plan of this item have been described briefly. Three test mirror exposure experiments have been done in this year. The main components of the deposited materials on the first mirror are carbon and iron analyzed by AES. The first mirror is polluted easier during glow discharge and wall processing than omhic discharge.     

On the entropic regularization method for solving min-max problems with applications

Consider a min-max problem in the form of min _xX max_1im {f _i (x)}. It is well-known that the non-differentiability of the max functionF(x) max_1im {f _i (x)} presents difficulty in finding an optimal solution. An entropic regularization procedure provides a smooth approximationF _p(x) that uniformly converges toF(x) overX with a difference bounded by ln(m)/p, forp > 0. In this way, withp being sufficiently large, minimizing the smooth functionF _p(x) overX provides a very accurate solution to the min-max problem. The same procedure can be applied to solve systems of inequalities, linear programming problems, and constrained min-max problems.This research work was supported in part by the 1995 NCSC-Cray Research Grant and the National Textile Center Research Grant S95-2.     

超微柱电极上一次导数循环伏安法

本文提出一次导数循环伏安法理论,其电流、电位关系接近于对称峰形波,有益于提高方法的灵敏度和分辨率,可用于分析和电化学研究工作. 1 理论1.1 一次导数循环伏安法电流方程式利用文献方法解柱形扩散方程求得线性扫描氧化波和还原波方程式,再将其结果对t微分,即得到超微柱电极上一次导数循环伏安法氧化波和还原波方程式     

Crystal structure and cation transport properties of the layered monodiphosphates Rb6Bi4(PO4)2(P2O7)3

Single crystals of the new Bi(III) phosphates, Rb₆Bi₄(PO₄)₂(P₂O₇)₃, have been isolated and their structure has been determined by X-ray diffraction techniques. This compound crystallizes in the monoclinic space group P2₁/c with a=9.077(1)Å, b=9.268(2)Å, c=36.418(6)Å, β=95.75(1)° and Z=8. The crystal structure is made up of BiO₅ and BiO₆ polyhedra sharing the corners with PO₄ tetrahedra and P₂O₇ diphosphate groups. The structure can be described as infinite anionic layers with composition [Bi₄(PO₄)₂(P₂O₇)₃]_∞⁶⁻ parallel to the [301] plane, connected via P-O-Bi bridges to form a three-dimensional open framework. This framework delimits tunnels running along [100] and [010] directions, where the rubidium ions reside. This compound exhibits a rubidium ion conduction but with rather low conductivity value at 640 K.     

一阶导数差示脉冲极谱法测定氢氯噻嗪的研究

本研究了一阶导数差示脉冲极谱法用于氢氯噻嗪及其制剂的定量分析。在０．００２ｍｏｌ／Ｌ盐酸－０．００２ｍｏｌ／Ｌ氯化钾底液中，于０．０５０Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）处出现良好的一阶导数极谱峰，氢氯噻嗪浓度在０～６．０×１０＾－４ｍｏｌ／Ｌ范围内，与峰高呈线性关系，检测限为４．０×１０＾－９ｍｏｌ／Ｌ。方法操作简便、快速、灵敏、结果准确。     

Anticircular high performance thin-layer chromatography

The principal analytical details for the third of three possible modes in high performance thin-layer chromatography are given, namely the anticircular mode. Separation is achieved by allowing the mobile phase to enter the plate layer on a precise outer circle line, from where it flows towards the centre with nearly constant speed. This technique is theoretically and practically the fastest of all three possible in HPTLC. It permits maximum sample capacity with a minimum of time, layer and mobile phase consumption. It is therefore the most economical HPTLC technique. A new carrier-free mobile phase transfer principle is used. The conditions for qualitative and quantitative analysis are good: repeatability, reproducibility and accuracy of routine TLC analyses are superior to those achieved by the classical trough technique. The specially narrow spot-path in anticircular HPTLC facilitates automated quantitation. Compared with the linear and circular modes, the anticircular mode shows better separation and significantly increased sensitivity at higher Rf-values. The drawback, however, is that the separation power (expressed by the separation number) is lower compared with the other two modes.