Kinetics of the process of electrocontact drying of moist materials

The method and results are presented for an experimental and analytical study of the kinetics of the process of drying of moist materials impregnated with an electrolyte by the passage through them of an electric current of commercial frequency.     

波分复用光纤象束系统成象质量研究

用成象系统象的光学信息量分析了波长复用对象束系统传象质量的影响。波长复用增加了象束中每根光纤传输的象元数,从而改善了象束的成象分辨率和信噪比。     

Some results of an experimental investigation of the structure of a turbulent stream of conducting liquid

Results are presented of an investigation, made with the aid of an induction anemometer, of some characteristics of a turbulent stream of electrically conducting liquid in an open channel. External magnetic and electric fields are applied to the flow. It has been observed that the flow structure is appreciably affected by the Lorentz force normal to the channel floor. The characteristics obtained are compared with experimental results for an ordinary liquid.     

Variation of the structure of amorphous lead titanate in the course of crystallization

The laws of formation of an equilibrium crystalline structure of lead titanate during crystallization from an amorphous state were studied. The initial thermal treatment leads to structural relaxation of the amorphous state. Subsequently, an intermediate state is formed whereby cubic phases with perovskite and pyrochlore structures coexist in the amorphous matrix. Finally, an equilibrium tetragonal phase is established at room temperature.     

Influence of safety belt usage on perception of the risk of an accident

Does the use of a safety belt increase or decrease the perception of the risk of an accident? Young and older male drivers were asked to drive an urban route and rate their perceptions of the risk of an accident. On the first driving trip all subjects were unbelted, while on the second driving trip half of the subjects wore a safety belt while half did not. Results indicated that young male drivers decrease their perception of the risk of an accident as they become familiar with a driving route if they are NOT wearing a safety belt. Young male drivers asked to wear a safety belt sustained their perception of the risk of an accident as they became familiar with the test route. Older drivers' perception of the risk of an accident was not affected by familiarity or safety belt usage.     

On the isovectors of a class of nonlinear diffusion equations

A class of nonlinear diffusion equations is expressed in terms of an ideal of exterior differential forms. The components of the associated isovector field are constructed by using its transport property under Lie's derivative. The solution of the corresponding orbital equations generate an invariant group of transformations which reduce the nonlinear diffusion equation to an ordinary differential equation. For the problem of heat propagation, in an initially cool infinite media, due to a plane source, an exact solution is derived.     

Template synthesis of arrays of nano fuel cells

A method for the construction of an array of fuel cells wherein each cell is 200 nm in diameter is presented. Electrodeposition of Pt-Cu nanowires inside the cylindrical pores of an Anodisc filter membrane and the subsequent dealloying of the Cu by soaking the filter in fuming nitric acid for several hours are used to construct an array of porous platinum electrodes. About 10(9) electrically isolated cylindrical porous electrodes, each 200 nm in diameter, are formed in this manner. Utilizing two arrays of porous electrodes with a polymer electrolyte membrane or an electrolyte support matrix sandwiched between, an array of nano fuel cells is produced. This method of producing an array of coplanar fuel cells allows for the series connection of fuel cells outside the array and eliminates the need for fuel and air manifolds, greatly reducing the overall system complexity. Initial prototypes utilizing an aqueous solution of NaBH(4) as a fuel have produced power densities of ca. 1 mW/cm(2) based on an estimate of the area of the current collectors in contact with the nano-fuel-cell array and have demonstrated the ability to wire bundles of fuel cells either in parallel or in series.     

Qualitative analysis of the possibility of ignition of controllable thermonuclear fusion

Results of a preliminary experiment on excitation of gaseous active media by hard radiation of an uncontrolled thermonuclear explosion are presented. Pulsed lasing of an HF laser with an energy output of ≈10 kJ and efficiency of ≈3% and of an excimer XeF laser with an output of ≈1 kJ and efficiency of ≈9% with a pulse duration of ≈2 nsec is obtaned. Ya. Kupala Grodno State University, Grodno, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 72, No. 4, pp. 739–740, July–August, 1999.     

侧送风气流组织设计的改进

本文以一会议室空调为计算实例，提出了利用侧送风气流组织优化算法与CFD技术相结合的侧送风气流组织设计的改进方法。     

Theory of the flow and conduction of inhomogeneous media

A basic model of an inhomogeneous medium is outlined and, by a combination of the methods of flow theory and reduction to an elementary cell, an analytic dependence is obtained for the conduction of such a medium.     

弹药元器件(PAA)正确包装的虚拟现实检测技术应用研究

利用虚拟现实技术,通过构建PAA进行包装的虚拟交互环境,采取HV分割方法对PAA包装进行测试,提出了测试PAA包装是否正确的一种新途径,从而可在包装上提高PAA这类特殊商品的安全性能。     

Control of reflectance of liquid droplets by means of electrowetting

It has recently been noted that hemispherical structures have useful reflection characteristics. We describe a new application that makes use of these characteristics by controlling the reflectance of a surface composed of an array of hemispherical liquid droplets. In this system the reflectance state is spatially controlled through the use of electrowetting to alter the shape of an array of droplets. This may have an application in the field of electronic image displays.     

The influence of coolant pH on efficiency of machining sapphire

The manifestation of Rebinder effect in abrasive machining of sapphire has been studied versus coolant pH. The change of pH from neutral to acidic results in an 1.8 times higher rate of grinding with a bound abrasive. An alkaline medium also facilitates the workpiece surface attrition by a bound abrasive. The use of an acidic solution as a coolant leads to an increase in efficiency of polishing sapphire, while an alkaline one lowers the polishing efficiency.     

Calibration method of the specific characteristic of an electronic system of a rotating-analyzer ellipsometer

In photometric ellipsometry the optical signal is transformed into an electrical signal by a photodetector, and it passes an electronic system to reduce the noise and to amplify the signal. But inherently it will induce a phase shift and an amplitude attenuation of the output signal. Such a specific characteristic of an electronic system depends on the angular frequency of the signal and gives systematic errors to the results of the measurement of rotating-analyzer ellipsometry. We propose a modified method of measurement that enables us to calibrate the electronic system in the ellipsometric measurement configuration.     

Wigner distribution function of an Airy beam

We study the Wigner distribution function (WDF) of an Airy beam. The analytical expression of the WDF of an Airy beam is obtained. Numerical and graphical results of the WDF of an Airy beam provide an intuitive picture to explain the intriguing features of an Airy beam, such as weak diffraction, curved propagation, and self-healing. Our results confirm that these novel properties of an Airy beam are attributed to the continuum of sideways contributions to the field.     

Three-dimensional display of a horizontal-parallax-only hologram

We propose a three-dimensional (3D) holographic display by converting an optically recorded complex full-parallax (FP) hologram to an off-axis horizontal-parallax-only (HPO) hologram. First, we record the complex FP hologram of an object using optical scanning holography. We then convert the complex FP hologram to an off-axis HPO hologram through fringe-matched Gaussian low-pass filtering and with the introduction of an off-axis reference. Finally, we reconstruct the off-axis HPO hologram optically using an amplitude-only spatial light modulator. Until now, only computer-generated HPO holograms have been displayed optically. To the best of our knowledge, this is the first demonstration of a 3D display of an optically recorded HPO hologram.     

传输线变压器的机理及宽带阻抗匹配的设计

传输线变压器具有频带宽、易于制作的特点，在通信领域得到了广泛的应用。但在超声换能器与超声信号源之间采用传输线变压器实现阻抗匹配的报道较少。文章对传输线变压器实现宽带阻抗匹配的机理进行了详细的分析，通过一个简单的等效电路阐明了传输线变压器如何巧妙地利用传输线间的分布电容，使其由影响高频能量传输的不利因素而转换为电磁能量转换必不可少的条件，从而达到宽频带传输的目的。以500kHz-2MHz范围内的超声换能器的阻抗匹配变压器的设计为例，具体给出了确定传输线变压器特性阻抗、线长、磁心、导线型号和匝数的方法。     

Effect of the law of distribution of image illumination on the accuracy of phase-type measuring systems

Conclusions When determining the effect of the law governing the distribution of illumination of an image on the accuracy of phase measuring systems involving raster analyzers, it is not necessary to know the two-dimensional illuminance-distribution function, but only the one-dimensional function S₀(x) describing the light flux during detection of the image. During experimental assessments of the quality of an image, this leads to the need to scan by halfplane, but there is no need to determine the two-dimensional illuminance-distribution function, which is an extremely complicated procedure in practice.Expression (9) enables the error in measuring the coordinates of the light image to be calculated, by introducing an asymmetrical law of illuminance distribution or an instability in this law.Translated from Izmeritel'naya Tekhnika, Vol. 19, No. 6, pp. 32–34, June, 1976.     

Fresnel diffraction at an opaque strip expressed by means of asymptotic representations of Fresnel integrals

The paper presents an asymptotic expression of relative intensity distribution in a Fresnel diffraction pattern at an opaque straight strip illuminated with a spherical wave. The asymptotic expression is used in an analysis showing an area of validity where the asymptotic expression reduces to an asymptotic expression of relative intensity distribution in a Fresnel diffraction at a half plane. The area of validity is defined through width of the geometrical shadow in a Fresnel diffraction pattern at an opaque straight strip and distance of a point under study to the center of the Fresnel diffraction pattern. Within this area, relative intensity in the Fresnel diffraction pattern at an opaque straight strip shows sinusoidal behavior, which can be used in easy location of maxima or minima of the relative intensity. The result of the analysis is supported by experiments realized in the area of validity and outside it.     

Impact force measurement of an actuator arm of a hard disk drive

Impact forces of an actuator arm of a hard disk drive (HDD) are measured by means of modifying the levitation mass method (LMM) whose basic concept was proposed by the first author. In the LMM, force is measured as the inertial force of a mass levitated with sufficiently small friction using an aerostatic linear bearing. The Doppler frequency shift of the laser beam reflecting from the mass is accurately calculated from the waveform recorded using a digitizer. The velocity, the position, the acceleration and the inertial force of the mass are calculated from the measured time-varying Doppler frequency shift. In the experiments, the mechanical response of an actuator arm of a HDD against an impact load and the inertial force of the actuator arm in free oscillation are measured. The importance and the problems concerning the present knowledge on the impact force of an actuator arm of a HDD are also discussed.