Precision Capacitor Ratio Measurement Technique for Integrated Circuit Capacitor Arrays

The recent development of integrated circuit capacitor arrays and the growth of their applications have resulted in a need to perform precision testing as an aid to future design improvements. For reasons discussed in this paper, laboratory instruments such as capacitance bridges are not well-suited to this need. In order to test capacitor arrays accurately, a novel technique has been developed. It is based on a special algorithm in which the capacitor array is used as a precision voltage divider. A capacitor array tester consisting of both hardware and software has been built which executes this algorithm. This system has been used to perform measurements upon a large number (thousands) of NMOS and CMOS capacitor arrays. The standard deviation of this tester's measurement error is approximately 0.0009 percent of full scale (0.0088 LSB referenced to 10 bits). In contrast with manual testing with a capacitance bridge (requiring 10 min per array), the tester requires less than 5 s to fully test an array, mark the circuit and move to the next die position.     

Dynamics of Spinor Condensates Driven by an Inhomogeneous Magnetic Field

A variational wavefunction including the breather, dipole and scissor modes simultaneously is constructed to investigate the collective-excitation dynamics of spin-1 \(^{87}\mathrm{Rb}\) condensates driven by a space- and time-dependent magnetic field. When the Dirac point never enters the condensate, it is shown that the dipole, breather and scissor modes will be all excited driven by the sinusoidal oscillation of the Dirac point, due to the coupling of different collective modes from the inhomogeneity of the magnetic field. A resonance-driving phenomenon is observed. If the Dirac point passes through the condensate, our numerical results agree with most experimental observations (Ray et al. in Nature 505:657, 2014) and find that the center of mass of the condensate does not follow the zero point of the magnetic field. Hopefully, our method can be extended to study the similar dynamics for the other spinor condensates.     

Real-Time Current of a Charge Carrier in a Strongly Correlated System Coupled to Phonons, Driven by a Uniform Electric Field

We perform a quantum time evolution of a single charge carrier doped into strongly correlated system and coupled to phonons, driven by a uniform electric field. We study a two-dimensional t?CJ-Holstein model and calculate the real-time current. At large values of electric field, the response of the system exhibits damped Bloch oscillations, and the values of the steady current decrease with increasing electric field. On the other hand, the maximal amplitude of the real-time current increase with increasing field. We discuss the appearance of the negative differential resistivity regime, observed recently in various nonequilibrium studies of interacting many-body systems.     

同一轴线上双激振器驱动的振动体同步运动状态分析

以同一轴线上双激振器驱动的振动磨机为典型研究对象,通过对其实际模型的合理简化,得到运动系统的力学模型.利用Lagrange方程建立了运动系统的动力学方程,通过对动力学方程的求解分析,得到了振动体的运动轨迹随两个激振器转角差的变化规律,振动体在运动过程中,随着两个激振器转角差的增大,振动体质心的运动幅值减小,而沿质心轴线两端的运动幅值增大,当两个激振器转角差达到180度时,质心运动幅值为零,沿质心轴线两端的运动幅值达到极大,此时振动系统产生锥形运动,使得振动设备无法正常工作.研究结果可为研究更复杂振动系统的同步运动和利用同步运动减少参振体质量提供理论基础.     

Spin Dynamics of a Fermi Liquid in an Electric Field

The influence of an external electric field on the spin dynamics of an electrically neutral Fermi liquid is considered, the mechanism of such an influence being the relativistic spin-orbital interaction. As a result, Leggett's equations for the spin dynamics of weakly polarized Fermi liquids are generalized to the case of non-zero external electric field. In addition, we obtained the transverse spin dynamics equation for strongly spin-polarized liquids in an electric field at zero temperature. In both situations covariant derivatives depending on the electric field are shown to be substituted for spatial gradients in line with the SU(2) gauge invariance of the microscopic Hamiltonian. The new equations are applied to the study of spin flow along a channel, where an electric field is found to bring about an additional phase shift of the order of magnitude of the phase shift in superfluid ³He-B but growing with time.     

便携式测量系统中彩色线阵CCD数据采集电路的设计

本文提出了将彩色线阵CCD光电传感器用于现代便携式测量系统的设计方案.针对便携式系统尺寸小、功耗低的特点,设计了彩色线阵CCD的数据采集电路.该电路的功能是获取便携式毒气测量仪中侦毒管内的化学试剂发生化学反应前后的颜色信息,从而最终使整个测量系统完成毒气种类和毒气浓度的判别.该电路包含CCD器件的驱动电路,模拟信号的数字化电路和数据存储电路,以及电源控制电路等模块.该数据采集电路具有高速,节能的特点.使用该电路对被测物模型进行实际测量,显示了该数据采集电路的有效性.该数据采集电路测量侦毒管颜色变化长度的分辨力为0.06 mm.     

Toner Jumping Phenomenon in an Electric Field

This article gives a short review on fundamentals of electrophotographic printing using dry toners with conductive or insulative characteristics. The toner jumping phenomenon, TonerJet® technology, toner cloud confinement, and toner cloud beam technology in electric fields are emphasized. Theory and comparison of advantages among toner developments and transport are briefly discussed. The purpose of this article is to advance the development of a novel printing technology, “toner cloud beam,” which has the possibility of using a highly simplified toner imaging mechanism. To clarify the characteristics of conductive toner, the difference between insulative and conductive toner were compared. Unique characteristics of conductive toner are focused on: the up-and-down motion between voltage applied electrodes and cloud formation by confinement at the dented part of the electrode. The present state of the novel printing mechanism is summarized.     

Determination of an Absolute Capacitance by a Horizontal Cross Capacitor

A cross capacitor is a calculable one whose capacitance is ideally determinable from one length measurement of its electrodes. In the Electrotechnical Laboratory of Japan (ETL), a horizontal cross capacitor was constructed. In this model, ease of checking alignment of the horizontal electrode bars, and a simple driving mechanism to move the guard electrode, were emphasized. Because the movable guard electrode rests on, and is guided by, the horizontal electrode bars no special supporting mechanism is necessary. The displacement, which defines the length of the capacitor, is observed by interference fringes using a Hg198 source. The sensitivity obtained for electrical measurement is better than 0.01 aF and for length measurement better than 1/30 fringe. The errors of this capacitor are examined in detail and confirmed by experimental tests. The absolute capacitance was determined as 0.1 pF with an accuracy better than 1 ppm.     

Effects of an Inhomogenous Electric Field on an Evaporating Thin Film in a Microchannel

In this paper, heat transfer enhancement in an evaporating thin film along the wall of a microchannel under an imposed inhomogenous electrostatic field is analyzed. The mathematical model, based on the augmented Young–Laplace equation with the inhomogenous electrostatic field taken into consideration, is developed. The 2D inhomogenous electric field with the curved liquid–vapor interface is solved by the lattice Boltzmann method. Numerical solutions for the thin film characteristics are obtained for both constant wall temperature and uniform wall heat flux boundary conditions. The numerical results show that the liquid film becomes thinner and the heat transfer coefficient increases under an imposed electric field. Both of octane and water are chosen as the working mediums, and similar result about the enhancement of heat transfer on evaporating thin film by imposing electric field is obtained. It is found that applying an electric field on the evaporating thin film can enhance evaporative heat transfer in a microchannel.     

A Method for Driving an Oscillator at a Quasi-Uniform Velocity

We describe a simple way to drive an actuator, comprising a superconducting coil moving in a static magnetic field, at a quasi-uniform velocity. The main objective is to avoid oscillations in this system with low damping, as they undermine the uniformity of the velocity. The method consists in calculating the force that should be exerted on the coil from the equation of motion and programming a waveform generator to produce the corresponding current through the coil. The method was tested on a device towing a grid through a closely fitted channel filled with superfluid ⁴He at temperatures below 100 mK. The motion of the grid over the distance of 4.3 cm at 10?cm/s resulted in oscillations of less than 50 μm in amplitude (or less than 1 mm/s in terms of velocity). The method can be applied to any oscillator.     

Intensification of the Electric Convection of Weakly Conducting Liquids by a Pulsed Electric Field

Results of an investigation of the kinematic characteristics of the electric convection of weakly conducting liquids intensified by a pulsed electric field are reported.     

射频无电极放电氮气等离子体光源研究

本文报道了一种利用射频无电极放电激励的氮气等离子体新型光源，测出了辐射光谱、光功率、工作气压等光源相关参数，优化实验条件得出的电光转换效率达22．05％。最后运用此光源成功的对一种印刷预涂感光版（pre-sensitive plate，PS版）进行了曝光，通过曝光前后PS版感光层颜色的光密度变化评价了感光效果。     

A Compact Dual-Port Multi-Band Rectifier Circuit for RF Energy Harvesting

This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth. It uses a combination of п–matching network (MN) at Port-1, with a parallel connection of three cell branch MN at Port-2. The proposed impedance matching network (IMN) is adopted to reduce circuit complexity, to improve circuit performance, and power conversion efficiency (PCE) of the rectifier at low input power. The fabricated rectifier prototype operates at 0.92, 1.82, 2.1, 2.46 and 2.65 GHz covering GSM/900, GSM/1800, UMTS2100, and Wi-Fi/2.45–LTE2600. The size of the compact rectifier on the PCB board is 0.13λ_g × 0.1λ_g. The fabricated rectifier achieved an RF-to DC (radio frequency direct current) PCE of 31.8%, 24%, 22.7%, and 15%, and 14.1% for −20 dBm at the five respective measured operating frequencies. The circuit attains a peak RF-to-DC PCE of 82.3% for an input power of 3 dBm at 0.92 GHz. The proposed rectifier realizes an ambient output dc voltage of 454 mV for multi-tone input signals from the two ports. The rectifier drives a bq25504-674 power management module (PMM) to achieve 1.21 V from the two-port connection. The rectifier has the ability to exploit both frequency domain through the multi-band operation with good impedance bandwidth and a spatial domain using dual-port configuration. Hence, it is a potential candidate for various applications in radio frequency energy harvesting (RFEH) system.     

The Movement of an Ion-exchange Microparticle in a Weak External Electric Field

The electrokinetic motion of spherical particle suspended in the electrolyte solution under influence of external electric field is studied. Due to impermeability of particle’s surface for one kind of ion species the particle exhibit behavior different to well investigated dielectric particles. Under an assumption of a weak external electric field, we derive the analytical estimation of the particle’s velocity by means of a method of matched asymptotic expansions. The analytical analysis is complemented by numerical solution, which gives the distribution of ion’s concentrations, electric potential profiles and flows streamlines. The analytical results are successfully compared with the results of numerical simulation.     

Numerical Simulation of Gasdynamic Flows Formed by an Electric Arc in an External Transverse Magnetic Field

The results of numerical investigations of an electric arc in an external transverse magnetic field are given. The effect of external controlled discharge parameters and of the magnetic field of the electrodes on the characteristics of a flow of arc-discharge plasma is treated. Some singularities of the flow formed by an electric arc in an external transverse magnetic field are revealed.