Long range electromagnetic field nature of nerve signal propagation in myelinated axons

The nature of saltatory conduction in myelinated axon described by equivalent circuit and circuit theory is still contentious. Recent experimental observations of action potentials transmitting through disjointed nerve fibers strongly suggest an electromagnetic wave propagation mechanism of the nerve signals. In this paper, we employ the electromagnetic wave model of the myelinated axon to describe action potential signal propagation. We use the experimental frequency-dependent conductivity and permittivity values of the nerve tissues in order to reliably calculate the electromagnetic modes by using electromagnetic mode solvers. We find that the electromagnetic waves above 10 {kHz} can be well confined in extracellular fluid—myelin sheath—intracellular fluid waveguide and propagate a distance of 7 mm without much attenuation. Our study may serve as one of the fundamental researches for the better understanding of the nervous system.     

EAST装置中70m双绞线对信号衰减的研究

为了分析EAST装置电磁测量系统中70m双绞线给测量信号带来的影响,建立了电磁线圈和双绞线的等效电路模型。设计了有双绞线模型和没有双绞线模型的两种电路模型,并对这两种模型在simolorer6.0软件中进行了仿真,通过分析这两种模型的传递函数和仿真输出的电压峰峰值,证明了70m双绞线对EAST中电磁测量系统的影响是可以忽略的。     

Development of a self-oscillating ultrasonic micro-motor and its application to a watch

We have developed an ultrasonic micro-motor for use as a micro-actuator in place of an electromagnetic motor. This ultrasonic micro-motor, which can be driven by a single signal and in which the change of the direction of the rotor movement can be made easily by selecting the electrode to apply the driving signal, can easily construct a self-oscillating circuit and simplify the driving circuit. We have also simplified the motor structure, which is easy to miniaturize and mass-produce. We applied a version of this motor with a diameter of 8 mm to a vibration alarm, and one with a diameter of 4.5 mm to a driving source of a calendar mechanism in a watch. This ultrasonic micro-motor is expected to be of use as a new driving source in a broad range of fields.     

Time dependence of the average charge and current in a dissipative mesoscopic circuit

Taking into consideration the interactions between electrons and phonons,we have studied the temporal evolution of the average charge and current in a dissipative mesoscopic RLC circuit.Our results show that a mesoscopic RLC circuit can be treated as an interactive system between an electromagnetic harmonic oscillator and many lattice harmonic oscillators;this is called the bathing of the harmonic oscillators.The results also show that the quantum equation of motion of the linear mesoscopic RLC circuit is identical in form to its classical equation of motion,the only difference between them being their respective meanings.In order to thoroughly study the quantum properties of a dissipative mesoscopic circuit,we have to consider not only the electromagnetic energy of the circuit,but also the crystal lattice vibration energy and the interactive energy between electrons and phonons.     

Transfer of quantum correlations from light to atoms in the case of irreversible evolution

We consider the irreversible dynamics of two two-level atoms that interact with a bipartite broad-band electromagnetic field in an entangled state that forms a heat bath with a quantum correlation. Using Ito’s stochastic integration technique, we have derived a kinetic equation for atoms and found their steady state, which turns out to be inseparable and leads to a violation of Bell’s inequalities. The application of the atomic state found as a quantum channel for teleportation is considered. We have calculated the channel quality or fidelity that determines the possibilities for using the channel, in particular, characterizes its security. The process of teleportation by means of a quantum channel formed by an entangled heat bath is considered. Comparison of two (atomic and light) channels has shown that they have different properties with regard to separability and identical properties with regard to nonlocality. This means that nonlocality can be completely transferred from light to atoms.     

无线电引信双源辐照效应研究

为了探索复杂电磁环境对无线电引信的作用规律,提出双辐射源电磁环境构建方法和试验方法,试验研究了无线电引信的双辐射源电磁环境效应,找到了使无线电引信意外起爆的双辐射源辐照频率组合方式和敏感阈值。发现双辐射源使无线电引信意外起爆的作用机理:引信天线及弹体接收到差频为多普勒频率的复合连续波信号,经自差机振荡器混频、检波管检波并滤波后,输出信号幅度较大的正弦波信号,经低频电路放大、信号整流积分及抗干扰惯性支路的共同作用,通过增幅速率选择电路,触发执行级电路误动作导致引信意外起爆。     

无线电引信双源辐照效应研究

为了探索复杂电磁环境对无线电引信的作用规律,提出双辐射源电磁环境构建方法和试验方法,试验研究了无线电引信的双辐射源电磁环境效应,找到了使无线电引信意外起爆的双辐射源辐照频率组合方式和敏感阈值。发现双辐射源使无线电引信意外起爆的作用机理：引信天线及弹体接收到差频为多普勒频率的复合连续波信号,经自差机振荡器混频、检波管检波并滤波后,输出信号幅度较大的正弦波信号,经低频电路放大、信号整流积分及抗干扰惯性支路的共同作用,通过增幅速率选择电路,触发执行级电路误动作导致引信意外起爆。     

电感储能加速器运行中电磁辐射的实验研究

发现了一个被普遍忽视的问题, 在电感储能加速器运行中产生很强的电磁辐射. 这种电磁辐射在一定距离范围内可以对测量仪器造成破坏. 通过多次测量, 发现此辐射主频在75MHz左右, 频谱较宽, 是一低频电磁波. 以同轴电缆作为测量仪器的替代物, 测量辐射场对同轴电缆的作用, 罗氏线圈测得电流幅值达217mA. 辐射可能是由回路LC振荡或者加速器中的电爆炸丝开关引起的. 基于LC振荡和电爆炸丝的工作原理, 分别讨论了辐射产生的物理过程. 我们更倾向于认为辐射来源于开关导通引起的回路LC振荡. 此外, 辐射强度受电流的变化率影响, 初级回路电流变化慢, 次级回路变化快, 这样产生了一弱一强的两个辐射信号. 这些为进一步研究电感储能加速器运行中的电磁辐射及防护提供实验支持.     

电子学系统强电磁脉冲干扰场路结合仿真

对设备机箱内部某串口电路受外界强电磁脉冲干扰所引起的信号完整性问题进行了研究,基于场路结合的仿真分析方法,从空间电磁耦合现象和电路信号干扰效应这两个方面对强电磁脉冲干扰进行了完整的系统分析,发现电磁干扰可导致内部电路出现逻辑电平翻转等扰乱效果,并提出了有效避免电磁干扰的措施。     

Interaction of intense laser radiation with weak electromagnetic waves in an evacuated section of a ring laser

A laboratory experiment for the study of nonlinear interaction of electromagnetic waves in vacuum is proposed. The basic idea of the experiment is as follows. If one separates a certain region of the circuit in a ring laser from the remaining part with gas-impenetrable partitions, evacuates it, and forms external electromagnetic fields there, the oscillation frequencies and the polarization states of the electromagnetic waves traveling in this ring laser in counter directions are different. A calculation is made for the oscillation frequencies of electromagnetic waves traveling in a ring laser in opposite directions in the case when they interact in an evacuated section of the ring laser circuit with intense laser radiation. It is shown that the effect can be observed in experiments using presently available pulsed lasers of ultrahigh power.     

一种传导电磁泄漏源的等效模型研究

在网络作战体系中, 电磁泄漏探测是敌对双方都十分重视的领域。电磁泄漏探测分为主动探测和被动探测两种, 其中主动探测由发射源对外发射信号, 通过检测具体位置处的信号特征, 得到被测设备、系统或网络的泄漏信息或其它特征信息。针对一种主动传导电磁泄漏发射源进行分析, 结合其工作机理和具体的试验现象, 提出了对应的等效模型。该等效模型按工作频率的高低, 分为高频等效天线模型和低频等效电路模型两类, 通过理论分析了该模型的准确性, 通过电路仿真验证了等效模型的正确性。通过该模型研究, 可以为后续电磁泄漏探测的数据分析提供有力的分析手段。     

Distributed quantum computation with superconducting qubit via LC circuit using dressed states

A scheme is proposed where two superconducting qubits driven by a classical field interacting separately with two distant LC circuits connected by another LC circuit through mutual inductance,are used for implementing quantum gates.By using dressed states,quantum state transfer and quantum entangling gate can be implemented.With the help of the time-dependent electromagnetic field,any two dressed qubits can be selectively coupled to the data bus (the last LC circuit),then quantum state can be transferred from one dressed qubit to another and multi-mode entangled state can also be formed.As a result,the promising perspectives for quantum information processing of mesoscopic superconducting qubits are obtained and the distributed and scalable quantum computation can be implemented in this scheme.     

阻尼作用下振子相图的电路模拟

电学量和力学量之间存在一一对应的关系,例如弹簧振子振动和LC电路的微分方程具有相同的形式.我们用电路系统在示波器中直接展现出电磁振荡过程,模拟了黏滞阻尼振动过程的相图.又利用稳压二极管模拟了摩擦阻力作用下弹簧振子振动的相图.将一道力学问题找到对应的电路模拟,在教学过程中具有启发意义.     

基于双层超表面的宽带、高效透射型轨道角动量发生器

提出一种宽带、高传输效率的双层超表面,其单元结构是在介质层两边对称刻蚀结构参数相同的十字型金属贴片且将两层超表面沿y方向错位半个周期长度形成.通过引入y方向的错位,双层超表面的透射带宽得到大幅度提升.同时,采用等效电路理论分析了该双层超表面的带宽展宽机理.在此基础上,进一步结合Pancharatnam-Berry相位原...     

Asymmetric Double Quantum Dots as a Subminiature Mesoscopic Cell

A subminiature mesoscopic cell,consisting of asymmetric double quantum dots capacitively coupled to a nearby mesoscopic circuit,is proposed,which can transform disordered noise energy to ordered electric energy.Two schemes,the noises originating from the nearby mesoscopic circuit and from the electromagnetic wave disturbance in external environment,are investigated.We found that the proposed cell can manifest as a good constant current source and the output current may not reach its largest value even if the circuit is shorted.     

Stimulated emission of the coherent electromagnetic radiation by superconducting film

Coherent microwave radiation has been directly detected in the frequency range of 0.15–200 MHz from superconducting thin films excited by an oscillating magnetic field directed perpendicular to the film plane. Due to pinning, a metastable state of the vortex system can be set up in the superconducting films. Vortex-jump synchronization reached via their electromagnetic interaction with external resonant circuit causes the generation of the electromagnetic radiation.     

宽带高抑制性能电磁脉冲防护电路设计与实验

强电磁脉冲易通过天线、孔缝、线缆等多种耦合途径进入电子系统内部,造成敏感电子设备出现短暂故障或永久损毁。安装电磁脉冲防护电路可有效提高电子设备抗强电磁脉冲能力。基于LC选频网络和瞬态电压抑制(TVS)二极管,设计了一种宽带高抑制性能电磁脉冲防护电路,防护电路工作带宽超过2 GHz、插入损耗低于0.6 dB。系统性研究了防护电路对频谱分布在工作带宽内多种电磁脉冲(方波脉冲、宽带高功率微波、窄带高功率微波)的防护能力。结果表明:防护电路对不同类型电磁脉冲电压抑制比大于40 dB、耐受功率超过387 kW、而响应时间仅0.7 ns。该防护电路具有工作频带宽、电磁抑制性能好、响应速度快、耐受功率高等特点,对电子信息系统电磁防护加固具有重要意义。     

Analysis of Electromagnetic Information Leakage Based on Cryptographic Integrated Circuits

Cryptographic algorithm is the most commonly used method of information security protection for many devices. The secret key of cryptographic algorithm is usually stored in these devices’ registers. In this paper, we propose an electromagnetic information leakage model to investigate the relationship between the electromagnetic leakage signal and the secret key. The registers are considered as electric dipole models to illustrate the source of the electromagnetic leakage. The equivalent circuit of the magnetic field probe is developed to bridge the output voltage and the electromagnetic leakage signal. Combining them, the electromagnetic information leakage model’s function relationship can be established. Besides, an electromagnetic leakage model based on multiple linear regression is proposed to recover the secret key and the model’s effectiveness is evaluated by guess entropy. Near field tests are conducted in an unshielded ordinary indoor environment to investigate the electromagnetic side-channel information leakage. The experiment result shows the correctness of the proposed electromagnetic leakage model and it can be used to recover the secret key of the cryptographic algorithm.     

Verifiable post-Maxwellian effect of the nonlinear electrodynamics in vacuum

The lasing frequencies of a ring laser with counterpropagating electromagnetic waves are calculated for the case when a part of the laser circuit is subjected to a constant electromagnetic field. It is demonstrated that, according to equations of the parametrized post-Maxwellian electrodynamics of vacuum, two waves with different planes of polarization and frequencies should propagate in each direction of the ring laser. The analysis has shown that, with the help of advanced ring lasers and external electromagnetic fields attainable in the laboratory, the post-Maxwellian parameters can be measured with a precision that would be sufficient to verify the most popular theoretical models of the nonlinear electrodynamics of vacuum.     

Coupling a quantum dot, fermionic leads, and a microwave cavity on a chip

We demonstrate a hybrid architecture consisting of a quantum dot circuit coupled to a single mode of the electromagnetic field. We use single wall carbon nanotube based circuits inserted in superconducting microwave cavities. By probing the nanotube dot using a dispersive readout in the Coulomb blockade and the Kondo regime, we determine an electron-photon coupling strength which should enable circuit QED experiments with more complex quantum dot circuits.