Memristor’s characteristics: From non-ideal to ideal

Memristor has been widely studied in the field of neuromorphic computing and is considered to be a strong candidate to break the von Neumann bottleneck. However, the non-ideal characteristics of memristor seriously limit its practical application. There are two sides to everything, and memristors are no exception. The non-ideal characteristics of memristors may become ideal in some applications. Genetic algorithm(GA) is a method to search for the optimal solution by simulating the process of biological evolution. It is widely used in the fields of machine learning, combinatorial optimization,and signal processing. In this paper, we simulate the biological evolutionary behavior in GA by using the non-ideal characteristics of memristors, based on which we design peripheral circuits and path planning algorithms based on memristor networks. The experimental results show that the non-ideal characteristics of memristor can well simulate the biological evolution behavior in GA.

Effect of spin on the instability of THz plasma waves in field-effect transistors under non-ideal boundary conditions

Terahertz(THz) radiation can be generated due to the instability of THz plasma waves in field-effect transistors(FETs). In this work, we discuss the instability of THz plasma waves in the channel of FETs with spin and quantum effects under non-ideal boundary conditions. We obtain a linear dispersion relation by using the hydrodynamic equation, Maxwell equation and spin equation. The influence of source capacitance, drain capacitance, spin effects, quantum effects and channel width on the instability of THz plasma waves under the non-ideal boundary conditions is investigated in great detail. The results of numerical simulation show that the THz plasma wave is unstable when the drain capacitance is smaller than the source capacitance;the oscillation frequency with asymmetric boundary conditions is smaller than that under non-ideal boundary conditions;the instability gain of THz plasma waves becomes lower under non-ideal boundary conditions. This finding provides a new idea for finding efficient THz radiation sources and opens up a new mechanism for the development of THz technology.

Energy-efficient data transmission with non-ideal circuit power for downlink cellular networks

The downlink energy-efficient transmission schedule with non-ideal circuit power over Wreless networks involving a single transmitter and multiple receivers was investigated. According to the special structure of the problem, a novel algorithm called OOSCPMR （the optimal offine scheduling with non-ideal circuit power for multi-receivers） is proposed, and the optimal offine solutions to optimize the energy- efficient transmission policy are found. The packets to be transmitted can be divided into two types where one type of packet is determined to be transmitted using the enrgy- efficient tansmission time, and the other type of packet is determined by the ID moveright algorithm. Finally, an energy-efficient online schedule is developed based on te proposed OOSCPMR algoriAm. Simulation results show that the optima offline transmission schedule provides te lower bound performance for the online tansmission schedule. The proposed optimal offline and online policy is more energy efficient than the existing schemes tat assume ideal circuit power.

A Non-linear Non-ideal Model of Simulated Moving Bed Chromatography for Chiral Separations

A non-linear non-ideal model, taking into account non-linear competitive isotherms, axial dispersion, film mass transfer, intraparticle diffusion, and port periodic switching, was developed to simulate the dynamics of simulated moving bed chromatography (SMBC). The model equations were solved by a new efficient numerical technique of orthogonal collocation on finite elements with periodical movement of concentration vector. The simulated SMBC performance is in accordance with the experimental results reported in the literature for separation of l,1'-bi-2-naphthol enantiomers using SMBC. This model is useful for design, operation, optimization and scale-up of non-linear SMBC for chiral separations with significant non-ideal effects, especially for high solute concentration and small intraparticle diffusion coefficient or large chiral stationary phase particle.

Numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code

Ammonium nitrate and fuel oil(ANFO)based explosive is a classic example of non-ideal high explosives.Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter,presence and characteristics of confinement,as well as incomplete consumption of explosive at the sonic point.In this work we propose a detonation model based on the Wood-Kirkwood(WK)theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate models.Our objective is to analyze the validity of the model for highly non-ideal ANFO explosives,with emphasis on effect of reaction rate models.It was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius(i.e.for D/D_(id)>~0.6).Single-step pressure-based model,with the pressure exponent equal to 1.4,proved to be the most accurate,even in the vicinity of the failure radius.The impact of the rate models is most evident on temporal(and spatial)distribution of flow parameters in detonation driving zone,especially when it comes to the conversion and width of detonation driving zone.

A novel digital control strategy of three-phase shunt active power filter under non-ideal mains voltages

A novel control strategy for three-phase shunt active power filter (SAPF) was proposed to improve its performance under non-ideal mains voltages. The approach was inspired by our finding that the classic instantaneous reactive power theory based algorithm was unsatisfactory in terms of isolating positive sequence fundamental active components exactly under non-ideal mains voltages. So, a modified ip-iq reference current calculation method was presented. With usage of the new method, not only the positive sequence but also the fundamental active current components can be accurately isolated from load current. A deadbeat closed-loop control model is built in order to eliminate both delay error and tracking error between reference voltages and compensation voltages under unbalanced and distorted mains voltages. Computer simulation results show that the proposed strategy is effective with better tracking ability and lower total harmonic distortion (THD). The strategy is also applied to a 10 kV substation with a local electrolysis manganese plant injecting a large amount of harmonics into the power system, and is proved to be more practical and efficient.

Pseudoelastic effect in autoparametric non-ideal vibrating system with SMA spring

In this paper a three degrees of freedom autoparametric system with limited power supply is investigated numerically. The system consists of the body, which is hung on a spring and a damper, and two pendulums connected by shape memory alloy （SMA） spring. Shape memory alloys have ability to change their material properties with temperature. A polynomial constitutive model is assumed to describe the behavior of the SMA spring. The non-ideal source of power adds one degree of freedom, so the system has four degrees of freedom. The equations of motion have been solved numerically and pseudoelastic effects associated with the martensitic phase transformation are studied. It is shown that in this type system one mode of vibrations might excite or damp another mode, and that except different kinds of periodic vibrations there may also appear chaotic vibrations. For the identification of the responses of the system＇s various techniques, including chaos techniques such as bifurcation diagrams and time histories, power spectral densities, Poincare maps and exponents of Lyapunov may be used.

Confinement Effect and Diameter Effect on the Non-ideal Detonation Parameters of Small Charge

An expanding model of the confinement of non-ideal detonation of small charge is established on the basis of the nozzle theory.Making use of the expanding model,the analytic relationship of small charge detonation velocity and the semi-empirical relationship of detonation pressure that both change with charge diameter and confinement condition are established.The detonation velocity and pressure of small charges are calculated and experimentally verified,and the detonation velocity deviation is less than 7% while the detonation pressure deviation is less than 9%.

Investigation of Shock Waves in Non-Ideal Gas under the Action of Magnetic Field

In present paper, certain aspect of shock wave in non-ideal gas, when magnetic field is orthogonal to the trajectories of the gas particles and electrical conductivity is taken to be infinite, is investigated. Considering one-dimensional unsteady non-planer motion, basic equations, its general solution and formation of shock-wave, conservation laws and jumps conditions, variation of area of non-uniform cross section and analytical solution of strong non planer shock is obtained.

Frequency-Concentration Dependence of Optical Activity of a Non-Ideal 1D-Superlattice

In the present work the widths of layers constituting the non-ideal superlattice are much bigger then the characteristic scales of space dispersion. In such a case the contribution of individual layers to gyrotropy can be regarded as independed. Thus the corresponding optical quantities can be expressed through the layers’ gyrotropic characteristics. This approach is applied to calculate the specific rotation angle of plane of polarization of light propagating through a nonideal 1D-superlattice, which varies in composition as well as in layers’ width. We carry out numerical calculation of the frequency dispersion of optical activity of a non-ideal superlattice, which includes impurity layers with point defects.

双清一号(珞珈三号01星)多模式成像样例数据集

针对当前多数高分辨遥感卫星面向用户服务存在获取数据种类单一问题,该文公开了双清一号(珞珈三号01星)多模式成像样例数据集,涵盖了面阵推扫、面阵推帧和视频凝视等多种成像模式,包含城市、水体、山区、机场等不同目标区域的典型数据样本。该数据集由信号数据解码、Bayer插值、相对辐射校正、几何定位、视频稳像和3维重建等步骤处理构建;同时,对在轨定标、兴趣区产品快速生产、高清视频几何稳像和多角度3维重建等关键算法做了深入探讨和研究。最后,对样本数据集从图像标准产品、凝视视频产品和实景3维产品等3个方面进行了可视化展示和定量化精度评价。

指导性案例制度的运行思路再定位

指导性案例制度旨在通过各级法院参照适用前案的方式,推进法律适用的统一。但该制度的运行存在效力不明确、供给量不足、适用范围不广等诸多问题。鉴于遵循先例以实现同案同判的运行机制与指导性案例以确保法律适用统一的运行机制具有相似性,通过分析判例法上遵循先例的运行条件,融入指导性案例的运行环境观察其运行效果,发现由于两者的法律适用逻辑存在根本性差异,指导性案例制度实现法律适用统一的效率性、稳定性、权威性和发展性等方面皆不尽如人意。指导性案例应当回归其指导示范价值而非硬性拘束,并围绕覆盖司法分歧和增加案例竞争,完善相应的遴选与退出机制。

1895-1945年日本作家凝视中国台湾的视角

中日甲午战争后,日本殖民者在中国台湾开始了长达五十年的殖民统治。在五十年的殖民历史和复杂权力演绎中,一种裹挟了殖民霸权和帝国主义殖民意识形态的看与被看的二元关系在近代日本和中国台湾之间形成。日本作家对中国台湾主要采取了三种凝视视角:傲视、盯视和卑视,这三者的形成原因和具体表现,体现了日本殖民者统治中国台湾的侵略本质,也反映了当下中国台湾右翼集团宣扬的“日本对台殖民有功”“日台一家亲”等言论的荒谬。

基于二维相控阵体制的探鸟雷达系统

随着环境的改善和航空事业的迅速发展,野生动物与航空器的冲突愈发尖锐,其中鸟击事件占野生动物袭击事件的90%以上。据统计,鸟击事件每年给全世界航空业带来超过20亿美元的损失,是影响世界航空业的头号危害。针对鸟击事件对航空器造成巨大危害的问题,必须对鸟情进行持续、全面的观察,其目的一方面是当观察到大量鸟类聚集活动时,可以及时指导飞行员进行规避、对鸟群进行驱赶;另一方面,通过长期数据积累,可以对鸟类的生物学和运动学特征进行研究,进而实施有针对性的防治措施。基于上述需求,雷达技术以其全天时、全天候、大范围、远距离、高精度等优势,在机场鸟情防治中得到了迅速的发展与应用,并发挥了重要作用。本文首先概要介绍了国内外鸟击事故整体情况及传统的鸟情探测手段,指出雷达技术在机场鸟击防范应用中的优势;其次,较为全面地介绍了探鸟雷达系统的发展历程,鸟情探测系统的体制、工作模式、探测性能等相应的发展情况;然后,对雷达在鸟情探测中的应用难点进行分析,并从系统体制、目标探测、目标识别等角度出发,对相应关键技术的研究进展进行说明;接着,对国内外典型探鸟雷达系统的技术状态和应用情况进行了对比,并对北京理工雷科电子信息技术有限公司的圆柱形二维有源相控阵探鸟雷达系统的研究进展进行了介绍;最后,对探鸟雷达技术的发展做出总结与展望。

Assessing the energy release characteristics during the middle detonation reaction stage of aluminized explosives

Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale,which prolong the release of detonation energy and the energy release at different stages also shows significant differences.However,at present,there are few effective methods for evaluating the energy release characteristics of the middle reaction stage of such explosives,which can have a duration of tens to hundreds of microseconds.The present work demonstrates an approach to assessing the midstage of an aluminized explosive detonation based on a water push test employing a high degree of confinement.In this method,the explosive is contained in a steel cylinder having one end closed that is installed at the bottom of a transparent water tank.Upon detonation,the gaseous products expand in one direction while forcing water ahead of them.The resulting underwater shock wave and the interface between the gas phase products and the water are tracked using an ultra-high-speed framing and streak camera.The shock wave velocity in water and the expansion work performed by the gaseous detonation products were calculated to assess the energy release characteristics of aluminized explosives such as CL-20 and RDX in the middle stage of the detonation reaction.During the middle stage of the detonation process of these aluminized explosives,the aluminum reaction reduced the attenuation of shock waves and increased the work performed by gas phase products.A higher aluminum content increased the energy output while the presence of oxidants slowed the energy release rate.This work demonstrates an effective means of evaluating the performance of aluminized explosives.

凝视型红外探测系统的三维噪声研究

应用三维噪声模型分析了凝视型中波红外探测系统的噪声特性,并研究了信息处理方法对各类噪声分量的抑制效果。在不同积分时间下对不同温度的面源黑体连续采集图像数据并进行分析,发现增加积分时间和黑体入射能量时,各噪声分量都先以非线性形式迅速减小再逐渐趋于恒定,且各噪声分量会呈现出各自特有的图像模式。研究发现在未经任何信息处理的原始图像中,空间噪声是系统噪声的主要成分;综合运用空间和时间噪声抑制方法后,空间噪声几乎被完全抑制,时间噪声降低约一半,瞬态像素噪声成为噪声的主要成分。

卫星对空中动态目标凝视成像姿态规划方法

针对低轨卫星面阵相机对空中动态目标凝视成像需求,提出卫星平台根据像面脱靶量进行目标位置估计和凝视姿态规划方法.基于空中动态目标飞行高度的先验知识,以目标地理经纬度和经纬度变化率为状态量,以目标中心像素值为观测量,设计扩展卡尔曼滤波器,实现目标地理经纬度的精确估计和预报.在此基础上,规划卫星姿态和角速度,避免了目标像素噪声和延时对姿态稳定度的影响,并实现了单星对目标位置估计.通过数学仿真验证了所提方法的有效性.

一种发动机低温自启动的方法

车辆长时间处于寒冷环境时,车辆的一系列启动条件会受限,故会导致发动机启动困难。为解决用户冷启动困难,无法用车的痛点,可通过加装设备实现设定发动机水温、蓄电池电压、特定时间、间隔时间等参数作为发动机启动的触发条件,以便能确保车辆处于寒冷环境时,也可以正常启动车辆。

Battlefield dynamic scanning and staring imaging system based on fast steering mirror

This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.

关于《小杜丽》中stare一词及其变体译法的商榷

查尔斯·狄更斯的小说《小杜丽》(Little Dorrit)于1855~1857年间连载了19个月。金绍禹先生于1998年出版的中译本《小杜丽》让更多中国读者了解了这部作品,对19世纪中叶的英国社会有了更深刻的认识。作者通过分析《小杜丽》译本第一章中stare一词及其变体的译法,探讨了如何更好地理解词义,以引起当代译者对语境的重视。