四方相氧化锆纳米粉的低温合成与表征

氧化锆材料是近年来备受关注的陶瓷材料之一.它在许多不同的领域,诸如陶瓷颜料、工程陶瓷、宝石业、压电元件、离子交换器以及固体电解质方面等有着广泛的用途[1].其最常用的性质是其晶相转变时会有效改善陶瓷的脆性,因此在室温下保持其四方相是其中的关键.为此许多研究都侧重在其中加入各种添加剂,利用水热法、包裹法、形成共溶体等方法来阻止其晶格的转化[2-4].但研究也发现:在固定组成陶瓷基体中,ZrO2的相变温度随粉体颗粒直径的减小而降低,当颗粒足够小时能够提高材料强度的四方ZrO2可以保存到室温甚至室温以下.因此,减小ZrO2粉体粒度对于提高材料强度是非常有利的.本实验采用一种新的低温固相反应的方法制备氧化锆超细粉,从而使这种重要的陶瓷原料的制备有了新的思路.     

Fir laser stabilization using stark effect: Data on CH3Br and CH3Cl

Data on the influence of the Stark Effect on an optically pumped FIR laser with CH₃Cl or CH₃Br as active medium are given for various wavelengths. A very simple method for an effective FIR power stabilisation based on the Stark Effect is described. Its working is illustrated with the EPR signal of a 10% diluted DAG sphere.     

Bifurcations of Invariant Tori and Subharmonic Solutions of Singularly Perturbed System

This paper deals with bifurcations of subharmonic solutions and invariant tori generated from limit cycles in the fast dynamics for a nonautonomous singularly perturbed system. Based on Poincare map, a series of blow-up transformations and the theory of integral manifold, the conditions for the existence of invariant tori are obtained, and the saddle-node bifurcations of subharmonic solutions are studied.     

一种改进的Fuzzy-HMMS算法及其收敛性

对D at T ran和M ichae lW agner等人提出的FCM-FE-HMM S算法作了进一步的补充和改进,提出了改进的FCM-FE-HMM S算法,并给出了算法收敛性分析,得出在给定初值的情况下该算法将收敛到一个局部最优解。     

影响西安市燃气出租车发展变量的统计分析

燃气汽车规模化发展是解决城市环境污染的一个主要途径.以西安市燃气出租车发展问卷调查结果为依据,利用因子分析法对影响燃气出租车发展的变量进行分类.总结出影响燃气出租车发展的八个重要指标,覆涵了政府、加气站、司机个人等方面.     

几种基于散乱数据拟合的局部插值方法

本文首先针对散乱数据拟合的Shepard方法,结合截断多项式、B样条基函数和指数函数来构造其权函数,使新的权函数具有更高的光滑度和更好的衰减性,并且其光滑性和衰减性可以根据实际需要自由调节,从而提高了曲面的拟合质量．同时还给出一种类似的局部插值方法．另外,本文还基于多重二次插值,结合多元样条的思想,给出了两个局部插值算法．该算法较好地继承了多重二次插值曲面的性质,从而保证了拟合曲面具有好地光顺性和拟合精度．曲面整体也具有较高的光滑性．     

Enzymes immobilized on montmorillonite: comparison of performance in batch and packed-bed reactors

Summary The enzymes a-amylase, invertase and glucoamylase were immobilized on acid activated montmorillonite using two techniques, viz. adsorption and covalent binding, and their activities were tested in a batch and packed-bed reactor and were compared. The packed-bed reactor showed an improved performance for all immobilized enzymes, which was attributed to lowering of diffusional restrictions to mass transfer. Lower activity in case of batch reactor for immobilized invertase was due to a combined effect of loss of native conformation of enzyme on account of immobilization and mass transfer resistances due to improper diffusion of substrate to the active site of enzyme. For immobilized glucoamylase, the packed-bed reactor demonstrated exceptionally high activity that was very close to the free enzyme. Covalently bound glucoamylase showed higher activity than the free enzyme.     

EAST װ�ñ�Ե����ģϸ˿��ȵĸ���CCD�ɼ������ϵͳ���

The high speed CCD visible-light camera system has been installed to detect the dynamic characteristics of ELMs filaments on EAST tokamak. In order to convert the CCD video imaging coordinates into real space coordinates, the CCD system has calibrated using Tsai’s two-stage calibration technique. A raised spike in the grayscale profile, drawn by selecting the grayscale value of the image in the vertical direction of the ELMs filament in the CCD image, represents an ELMs filament structure whose positional coordinates are determined by the apex of the spike. The Sobel edge detection operator was used to examine the edge profile of the filament to obtain the width of the filament. By analyzing the characteristics of the filament width of the ELMs, it is found that the width of ELMs filaments continuously decreases outward from the outermost magnetic surface. This indicates that the filaments continue to dissipate energy and particles as they propagate outward. The width of filaments of Type-I ELMs is greater than that of Type-III ELMs.     

百万大气压下的压强校准及5.5 Mbar静压强的获得

进行了百万大气压下,静水压和非静水压条件下的压力校准,同时观察到金刚石砧容器中红宝石R线红移至830nm处,由校准公式算得对应的压强为5.5Mbar。 关键词：