Implementation of an analogue model of a memristor based on a light-dependent resistor

In this paper,an analogue model of a memristor using a light-dependent resistor(LDR) is presented.This model can be simplified into two parts:a control circuit and a variable resistor.It can be used to easily verify theoretical presumptions about the switching properties of memristors.This LDR-based memristor model can also be used in both simulations and experiments for future research into memristor applications.The paper includes mathematical models,simulations,and experimental results.     

基于零磁通电流传感的自动电阻电桥设计

因商用直流电流比较仪(DCC)精度高、结构复杂、成本高昂,基于商用零磁通电流传感器基础上研制了一套直流比较仪自动电阻电桥,以降低成本、满足电阻测量精度要求较低应用场合的需求。围绕零磁通电流传感器的原、副边线圈安匝平衡机制下,其原、副边电流比例一定的特点,设计了自动电阻电桥电路。采用基于DSP的嵌入式数字电路实现系统控制和算法,使用自制且经过校准的24位AD采集电路读取电桥中电阻两端的压差信号,经实时处理及屏幕显示,最终得到被测电阻(Rx)和标准电阻值(Rs)的比例值。采用经校准过的标准电阻(Rs)对该电阻电桥100Ω：10Ω和10Ω：1Ω的比例进行校准,实验结果表明：该电阻电桥测量的比例准确度可达10-6 量级,测量的相对标准差为10-6 ~10-7 量级。     

基于电阻型频率选择表面的宽带雷达超材料吸波体设计

将多边开缝式电阻型频率选择表面 (frequency selective surface, FSS)与传统的磁性吸波材料(radar absorption materials, RAM)复合, 提出了一种新型吸波体模型. 在分析该模型材料结构和拓扑结构的基础上, 得到等效电路模型; 基于传输线理论获得该模型的反射率及输入阻抗. 采用CST仿真软件对电阻型FSS与无电阻型FSS进行对比仿真, 通过分析吸波效率, 结果表明电阻型FSS在8.7 GHz附近具有更加优良的吸波性能, 实物测试结果与仿真结果一致. 同时FSS复合传统的磁性吸波材料RAM 产生了拓频效果, 在8–15 GHz范围内起到全频段吸收.     

Heat generation by a ballistic Landauer resistor

Heat generation by collisionless Ohmic electric conductance in quantum nanowires is investigated. The heat generated in both contacts is the same and is spread out over the length of the electron mean free path. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 1, 61–66 (10 January 1996) Published in English in the original Russian journal. Edited by Steve Torstveit.     

无规电阻网络的等效电阻

以Y←→△、串联、并联变换为基础，介绍一种计算二维无规电阻网络的等效电阻的普适计算方法。     

Nonlinear mirror based on raman interactions

We analyze a nonlinear mirror based on Raman interactions. The mirror is a combination of a Raman-active medium and a tetrachroic mirror. The reflections of the nonlinear mirror at two input frequencies differing by the Raman shift are calculated and its properties and possible applications are discussed.     

Excess noise for a lattice gas model of a resistor

We model a resistor by a stochastic lattice gas: Charge carriers jump randomly to neighboring lattice sites and interact by the constraint of single site occupancy. In contrast to independently moving charge carriers, the excess noise to quadratic order in the driving force for this model behaves for small frequencies as ^-1/2, |log|, ^d/2-1 for dimensionsd=1,2,3,..., respectively. We show that for this model the relationship between the excess noise and the four point current correlation function in equilibrium as proposed by Stanton and Nelkin becomes exact. This supports the view that the 1/f-noise may be related to the long time tail in the four point current correlation function.     

Fluctuation-dissipation models of a nonlinear resistor and Gupta's formulas

Moscow State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 31, No. 2, pp. 222–230, February, 1988.     

Nonlinear mirror based on cross-polarized wave generation

We present a new type of nonlinear mirror based on the generation of a cross-polarized wave through a nonresonant electronic third-order process. It is characterized by a reflection coefficient that depends on the input intensity. Its behavior results from the interference between the nonlinearly generated cross-polarized wave and a pi/2 phase-retarded wave. This setup has a lot of advantages: it does not require any phase matching, it is achromatic and suitable for femtosecond pulses, linear losses are easily adjustable, and the overall behavior is predictable. The device has been experimentally tested using BaF2 and YVO4 crystals.     

Photosensitive composition based on polyvinyl alcohol

The changes in the composition of a photosensitive material composed of polyvinyl alcohol, zinc oxide, and bismuth chloride, both in the fabrication stage and under exposure (as a result of direct blackening), have been investigated. The form of the bismuth-containing compound, which is involved in photochemical transformations and can be responsible for the formation of visible image, is established.     

Infinite hierarchy of exponents in a two-component random resistor network

We have studied the voltage distribution for a two-component random mixture of conductances _a and _b. A scaling theory is developed for the moments of the distribution, which predicts, for small values ofh=_a/_b, an infinite number of crossover exponents, one for each moment, for Euclidean dimensiond >2, and only one crossover exponent ford=2. Monte Carlo results on the square lattice confirm this prediction.     

基于科尔效应的非线性自适应光学系统

本文介绍并比较了环形振荡腔式以及由一片Ｋｅｒｒ 介质与一块二维反馈镜组成的非线性光学系统的结构特点,分析了上述系统的非线性动力学过程以及对波前相位畸变的压缩方式,指出了上述系统可能的应用领域     

Nonlinear directional coupler based on Rb:KTP-waveguides

We propose the use of KTP-based waveguides for all-optical switching. The passing of subnanosecond light pulses through the Rb:KTP nonlinear directional coupler is investigated. The nonlinear switching of 40% of light power from the one channel to another is observed at 5 kW input power.     

Nonlinear free vibration of a microscale beam based on modified couple stress theory

This paper presents a nonlinear free vibration analysis of the microbeams based on the modified couple stress Euler–Bernoulli beam theory and von Kármán geometrically nonlinear theory. The governing differential equations are established in variational form from Hamilton principle, with a material length scale parameter to interpret the size effect. These partial differential equations are reduced to corresponding ordinary ones by eliminating the time variable with the Kantorovich method following an assumed harmonic time mode. The resulting equations, which form a nonlinear two-point boundary value problem in spatial variable, are then solved numerically by shooting method, and the size-dependent characteristic relations of nonlinear vibration frequency vs. central amplitude of the microbeams are obtained successfully. The comparisons with available published results show that the current approach and algorithm are of good practicability. A parametric study is conducted involving the dependency of the frequency on the length scale parameter along with Poisson ratio, which shows that the nonlinear vibration frequency predicted by the current model is higher than that by the classical one.     

Excess noise in a hopping model for a resistor with quenched disorder

We consider a model for independent charged particles, hopping on a lattice with static disorder in the waiting times. The excess current noise is calculated and shown to be related to resistance noise and arising from mobility fluctuations. It is also related to the four point super-Burnett-function. The strength of the noise is calculated at small frequencies for weak disorder (classical long time tails) and for strong disorder, when it may behave like I/f. In that case the Hooge factor equals the fraction of deep trapping centers.     

Improving the transient response of a bolt-clamped Langevin transducer using a parallel resistor

This paper suggests a parallel resistor to reduce DC time constant and DC response time of the transient response, induced immediately after an AC voltage connected to a bolt-clamped Langevin transducer (BLT) is switched off. An equivalent circuit is first expressed. Then, an open-circuit transient response at the terminals induced by initial states is derived and measured, and thus parameters for losses of the BLT device are estimated by DC and AC time constants of the transient response. Moreover, a driving and measuring system is designed to determine transient response and steady-state responses of the BLT device, and a parallel resistor is connected to the BLT device to reduce the DC time constant. Experimental results indicate that the DC time constant greatly exceeds the AC time constant without the parallel resistor, and greatly decreases from 42 to 1 ms by a 100-kOmega parallel resistor.