不同样液制备方法电感耦合等离子体原子发射光谱测定人血清 …

３９例血清样品用酸消化和酸释制待测液,ＩＣＰ－ＡＥＳ相同条件与此同时地测定Ｆｅ,Ｚｎ、Ｃｕ、Ｃｒ、Ｃｄ和Ｐｂ。统计结果表明,消化法测得Ｆｅ、Ｚｎ和Ｃｒ显著高于稀释法,Ｃｄ低于稀释法;Ｃｕ和Ｐｂ两法测得结果无显著差异。     

不同样液制备方法电感耦合等离子体原子发射光谱测定人血清铁、锌、铜、铬、镉、铅的比较

３９例血清样品用酸消化和酸稀释制备待测液,ＩＣＰ－ＡＥＳ相同条件下同时测定Ｆｅ、Ｚｎ、Ｃｕ、Ｃｒ、Ｃｄ和Ｐｂ。统计结果表明,消化法测得Ｆｅ、Ｚｎ和Ｃｒ显著高于稀释法,Ｃｄ低于稀释法;Ｃｕ和Ｐｂ两法测得结果无显著差异。相关分析表明,两法测得Ｆｅ、Ｃｕ、Ｚｎ和Ｃｒ正相关;Ｐｂ和Ｃｄ不相关。ＩＣＰ－ＡＥＳ测定动脉粥样硬化和健康对照组间人血清六种微量元素稀释法无显著差异,而消化法测得组间不同程度存在显著性差异。建议采用消化法制备待测液较好。     

机载激光测深系统中海面波浪影响的改正

针对研制的新型机载激光测深系统的海上飞行试验数据,进行预处理、信息提取、数据同步和坐标转换后,开展波浪改正研究.对海底高程的GPS高程信息无波浪改正、GPS高程信息改正飞机航高变化计算波浪和加速度信息改正飞机航高变化计算波浪三种技术进行了分析.数据处理结果表明,采用加速度信息改正飞机航高变化计算得到的波浪信息的方法,结果较好,可满足研制的机载激光测深系统的要求.     

Preliminary study on rotary ultrasonic machining of CFRP/Ti stacks

Reported drilling methods for CFRP/Ti stacks include twist drilling, end milling, core grinding, and their derived methods. The literature does not have any report on drilling of CFRP/Ti stacks using rotary ultrasonic machining (RUM). This paper, for the first time, reports a study on drilling of CFRP/Ti stacks using RUM. It also compares results on drilling of CFRP/Ti stacks using RUM with reported results on drilling of CFRP/Ti stacks using other methods. When drilling CFRP/Ti stacks using RUM, cutting force, torque, and CFRP surface roughness were lower, hole size variation was smaller, CFRP groove depth was smaller, tool life was longer, and there was no obvious Ti exit burr and CFRP entrance delamination. Ti surface roughness when drilling of CFRP/Ti stacks using RUM was about the same as those when using other methods.     

A finite-element method using dispersion reduced spline elements for room acoustics simulation

This paper presents a finite element method (FEM) using hexahedral 27-node spline acoustic elements (Spl27) with low numerical dispersion for room acoustics simulation in both the frequency and time domains, especially at higher frequencies. Dispersion error analysis in one dimension is performed to increase the accuracy of FEM using Spl27 by modifying the numerical integration points of element stiffness and mass matrices. The basic accuracy and efficiency of the FEM using the improved Spl27, which uses modified integration points, are presented through numerical experiments using benchmark problems in both the frequency and time domains, revealing that FEM using the improved Spl27 in both domains provides more accurate results than the conventional method does, and with fewer degrees of freedom. Moreover, the effectiveness of FEM using the improved Spl27 over that using hexahedral 27-node Lagrange elements is shown for time domain analysis of the sound field in a practical sized room.     

Implementing logic gates and the Deutsch-Jozsa quantum algorithm by two-dimensional NMR using spin- and transition-selective pulses

Quantum logical operations using two-dimensional NMR have recently been described using the scalar coupling evolution technique [J. Chem. Phys. 109, 10603 (1998)]. In the present paper, we describe the implementation of quantum logical operations using two-dimensional NMR, with the help of spin- and transition-selective pulses. A number of logic gates are implemented using two and three qubits with one extra observer spin. Some many-in-one gates (or Portmanteau gates) are also implemented. Toffoli gate (or AND/NAND gate) and OR/NOR gates are implemented on three qubits. The Deutsch-Jozsa quantum algorithm for one and two qubits, using one extra work qubit, has also been implemented using spin- and transition-selective pulses after creating a coherent superposition state in the two-dimensional methodology.     

基于多元素复合空心阴极灯的土壤有效养分测试

通过修改原子吸收分光光度计操作软件使其在利用单元素空心阴极灯进行测试的同时,可以直接装备多元素复合空心阴极灯进行相关测试.针对30个在北京取样的潮土样本,利用多元素复合空心阴极灯对其有效Cu,Fe,Zn,Mg,Ca含量进行了3次重复测试,同时与基于单元素空心阴极灯的测试进行了对比.结果表明,基于多元素复合空心阴极灯测试的土壤有效Cu,Fe,Zn,Ca含量与基于单元素空心阴极灯测试的呈显著线性相关关系,其R2均大于0.9,且线性回归方程的斜率接近于1;两种方法测试的土壤有效Mg含量之间的R2为0.86,其线性同归方程的斜率为o.85;对比数据之间经方差检验呈无显著性差异.因此,利用多元素复合空心阴极灯进行土壤养分测试不仅具有与单元素空心阴极灯相当的测试精度,还可节省40%～50%的测试时间从而提高测试效率.     

基于非线性光学理论的激光防护材料近况

按照防护原理,可将激光防护材料分为基于线性光学理论的防护材料和基于非线性光学理论的防护材料。综述了基于非线性光学理论的多种激光防护方法及其防护原理,介绍了基于非线性光学理论的多种新型防护材料及其研究进展,比较了四种基于非线性光学理论的激光防护方法的优、缺点,简短地分析了激光防护材料今后发展的基本方向。     

网格单元形状对数值计算的影响

实现了二维非结构化网格上的N-S方程的离散,编制了非结构化同位网格上的SIMPLE程序,针对CFD/NHT 中几个有基准解的问题进行了试算考核。结果表明,在步长基本相同的情况下,四边形网格的收敛速度和解的精度都优于 三角形网格,尤其是收敛速度更明显;使用考虑边界贴体特性的边界层网格,解的精度优于均匀网格。     

Manipulating electromagnetic waves with metamaterials: Concept and microwave realizations

Our recent efforts in manipulating electromagnetic （EM） waves using metamaterials （MTMs） are reviewed with em- phasis on 1） manipulating wave polarization and transporting properties using homogeneous MTMs, 2） manipulating surface-wave properties using plasmonic MTMs, and 3） bridging propagating and surface waves using inhomogeneous meta-surfaces. For all these topics, we first illustrate the physical concepts and then present several typical practical real- izations and applications in the microwave regime.     

生物质气为燃料的燃料电池理论电动势计算

在以生物质气体为燃料的固体氧化物燃料电池体系中,通过热力学平衡分析编程计算出700-1200 K时气体中各物种例如H2、CO、CO2和CH4的平衡组成,从而得到以氧化钇稳定氧化锆(YSZ)为电解质的电池理论电动势．碳沉积对电动势有显著影响．通过计算可以推测比较适宜的操作温度和增湿条件．还计算了以掺杂氧化铈为电解质的电池电动势,相比氢气为燃料时,使用生物质气体导致的电动势的下降比使用YSZ为电解质的电池要小的多．     

Dynamic recording of a digital hologram with single exposure by a wave-splitting phase-shifting method

The wave-splitting phase-shifting digital holography using a pixelated microretarder array is proposed. By using four intensity images recorded by the pixelated microretarder array, Stokes parameters of the incident wave can be calculated. The fully complex amplitude distribution of the object wave can be obtained by using Stokes parameters, if the polarization states of the object and reference waves are linear and orthogonal. Two sets of experimental results are provided to verify the feasibility of the proposed method. One is the result for a movie recording using a CW laser and the other is the result for instant recording using a single pulsed laser.     

两种M~2因子实验测量方法的比较

为了从实验上分析和验证H-S传感器测量M2因子方法,对使用双曲线拟合法测量M2因子和H-S传感器测量M2因子做了详细的实验研究,且对实验结果、实验误差进行了比较与分析。研究表明:当H-S波前传感器透镜组足够多,重构误差较小,选取合适的泽尼克多项式阶数时,H-S波前传感器一次测量法得到的光束的M2因子与传统方法测得的M2因子值基本相当。与双曲线拟合法相比,H-S传感器法适用范围小,但是当满足测量条件时,H-S传感器法更便捷。     

Young's modulus of ZnO microwires determined by various mechanical measurement methods

The mechanical properties of ZnO microwires have been studied using three different methods: quasi-static flexural measurements using atomic force microscopy, static measurements using a nano indenter, and dynamic flexural measurements using optical interferometry. ZnO microwires were synthesized by chemical vapor deposition method, and the crystal structure and quality were examined using x-ray diffraction and photoluminescence spectroscopy. The Young's moduli were estimated using the measurement results from the three methods, and they showed consistent values in the range 67.5–79.4 GPa for microwires with diameters of 1.8 μm ± 100 nm.     

Inconsistence of Non-Singular Spherically Symmetric Solution and a Satisfactory Energy-Momentum Complex

Two spherically symmetric non-singular black hole solutions in Moiler tetrad theory of gravitation have been obtained. Although the two solutions have the same form of metric （spherically symmetric nonsingular black hole）, their energy contents are different. We use another method given by Gibbons and Hawking to calculate the energy content of these solutions. We also obtained different value of energy. Study the requirements of a satisfactory energymomentum complex given by Moiler we find that the second solution, which behaves as 1/√r, is not transformed as a four-vector under Lorentz transformation.     

BP神经网络与近红外光谱定量预测杉木中的综纤维素、木质素、微纤丝角

利用近红外光谱(NIR)技术结合BP神经网络定量预测了杉木中的综纤维素、木质素和微纤丝角。首先对杉木的原始近红外光谱数据进行卷积(Savitzky-Golay)平滑和二阶导数处理,然后利用小波变换压缩,将由171个数据点组成的近红外光谱压缩为86个数据点,最后用BP神经网络建模,采用Leave-n-out交叉验证法对模型进行验证,并讨论了隐含层神经元个数、学习速率、动量因子和学习次数对所建BP网络的影响。用所建的网络模型预测了测试集中杉木样本的综纤维素、木质素和微纤丝角 ,预测的相关系数R2值分别为0.91, 0.90, 0.87,预测均方根误差RMSEP分别为：0.86%, 0.33%, 4.99%。结果表明该方法快速,无损,基本能满足定量分析的要求。     

小型低温透平制冷机中电动机和发电机的应用

介绍了低温领域中小型透平制冷机应用的电动机和发电机,列举了四种主要的应用型式,即:小型制冷机中应用电机驱动压缩机;透平膨胀机中采用发电机制动;发电机吸收同轴膨胀机增压机功差以及电动机发电机两用电机.同时探讨了微型制冷机领域对低温电机的特殊要求及其发展方向.     

斜蜗舌对贯流风机内流的影响及降噪机制研究

本文提出采用一种新型的不等距蜗舌(这里统称为斜蜗舌)在提高风机的外特性性能的同时,相对降低噪声.通过试验与数值模拟,比较直叶片式,斜叶片式贯流风机分别用直蜗舌和斜蜗舌时内流、外特性及噪声频谱.采用三维Navier-Stokes方程和κ-ε两方程湍流模型对内部流场进行数值分析,发现与采用常规蜗舌的贯流风机不同的是斜蜗舌贯流风机偏心涡位置随着蜗舌间隙的变化而发生改变.本文旨在探讨斜蜗舌对贯流风机内流的影响及降噪的机制.     

Relationship between Peroxide Initiators and Properties of Styrene Grafted Polypropylene via Reactive Extrusion

To understand the relationship between the initiators and the properties of grafted polypropylene (PP), and provide guidance for designing polymers with different performance through selecting appropriate initiators, a series of styrene (St) grafted PP was prepared by modifying commercial linear PP via reactive extrusion using two different peroxide initiators, dicumyl peroxide (DCP) and benzoyl peroxide (BPO). Fourier transform infrared spectra indicated that the use of DCP led to a higher St grafting degree compared to the system using BPO. The melt flow index and rheological characteristics suggested the existence of short chain branching (SCB) structures in the St grafted PP using DCP, and long chain branching (LCB) structures in the St grafted PP using BPO. Differential scanning calorimetry and polarized optical microscopy results showed that the degradation of the PP chains and the introduction of SCB structures hindered the crystallization process of the St grafted PP using DCP, and the existence of the LCB structures accelerated the crystallization process of the St grafted PP using BPO. We suggest this research can contribute to the understanding of methods to prepare grafted PP with special properties via reactive extrusion by using proper initiators.     

Dye effluent decolourisation using ultrasonically assisted electro-oxidation

Solutions of the acidic dye, Sandolan Yellow, were subjected to sonolysis, electrolysis and sonoelectrolysis. Decolourisation did not take place using ultrasound alone but was achieved using an electro-oxidation process. The rate of electro-chemical decolourisation in the absence of ultrasound was dependent on the type of electrode used, electrolyte concentration, reaction temperature and the current density. Electro-oxidation of Sandolan Yellow using platinum electrodes was enhanced using ultrasound when carried out in a semi-sealed cell, which minimised the effects of ultrasonic degassing.