The Immediate Analgesic Effect and Impact on Gait Function of Transcutaneous Electrical Nerve Stimulation in Late-Stage Elderly Individuals with Knee Pain: Examination of Gait Function Using an IoT-Based Gait Analysis Device

Purpose: This study verified the effects of transcutaneous electrical nerve stimulation (TENS), which can be worn during walking and exercise, in elderly individuals with late-stage knee pain who exercise regularly. Methods: Thirty-two late-stage elderly individuals were evaluated for knee pain during rest, walking, and program exercises, with and without TENS. Gait analysis was performed using an IoT-based gait analysis device to examine the effects of TENS-induced analgesia on gait. Results: TENS significantly reduced knee pain during rest, walking, and programmed exercises, with the greatest analgesic effect observed during walking. The greater the knee pain without TENS, the more significant the analgesic effect of TENS. A comparison of gait parameters revealed a significant difference only in the gait cycle time, with a trend towards faster walking with TENS;however, the effect was limited. Conclusion: TENS effectively relieves knee pain in late-stage elderly individuals and can be safely applied during exercise. Pain management using TENS provides important insights into the implementation of exercise therapy in this age group.

SOLIDWORKS Electrical在通过式脚踏封口机自动化改造设计中的应用

小型企业塑封工艺中通过式脚踏封口机应用广泛,但在塑封重型工件时,工人操作非常费力且次品率高,无法保障塑封质量,为此对其进行机构优化与软硬件设计自动化改造。利用SOLIDWORKS Electrical快速建立3D虚拟电气配盘与生成各类BOM清单,大大缩短了研发周期,安装人员还可以根据虚拟电气装配路径进行准确安装。最终设计出结构合理,满足生产工艺要求的自动化装置,企业以极少改造成本提质增效,为机电一体化装置自动化设计提供了一个高效开发途径。

The action mechanism of the work done by the electric field force on moving charges to stimulate the emergence of carrier generation/recombination in a PN junction

It is discovered that the product of the current and the electric field in a PN junction should be regarded as the rate of work(power)done by the electric field force on moving charges(hole current and electron current),which was previously misinterpreted as solely a Joule heating effect.We clarify that it is exactly the work done by the electric field force on the moving charges to stimulate the emergence of non-equilibrium carriers,which triggers the novel physical phenomena.As regards to Joule heat,we point out that it should be calculated from Ohm’s law,rather than simply from the product of the current and the electric field.Based on this understanding,we conduct thorough discussion on the role of the electric field force in the process of carrier recombination and carrier generation.The thermal effects of carrier recombination and carrier generation followed are incorporated into the thermal equation of energy.The present study shows that the exothermic effect of carrier recombination leads to a temperature rise at the PN interface,while the endothermic effect of carrier generation causes a temperature reduction at the interface.These two opposite effects cause opposite heat flow directions in the PN junction under forward and backward bias voltages,highlighting the significance of managing device heating phenomena in design considerations.Therefore,this study possesses referential significance for the design and tuning on the performance of piezotronic devices.

A Novel Analytical Model for Surface Electrical Field Distribution and Optimization of TFSOI RESURF Devices

A novel analytical model for the thin film silicon on insulator (TFSOI) reduced surface field (RESURF) devices has been proposed.Based on the 2-D Poisson equation solution,the analytical expressions for the surface potential and field distributions are derived.From this analysis,the optimum design condition for the maximum breakdown voltage is obtained.The dependence of the maximum breakdown voltage on the drift region length is examined and the relationship between the critical doping concentration and the front- and back- interface oxide layer thickness is discussed.The numerical simulation performed by the advanced semiconductor simulation tool,DESSIS-ISE,has been shown to support the analytical results.

基于MATLAB的电动汽车动力电池电液固定装置抗振与密封性能实验研究

动力电池是电动汽车最重要的驱动能源,作为动力电池与整车固定连接的承载装置,其固定装置的安全性和稳定性是非常关键的性能指标,针对电动汽车动力电池总成电液固定装置的抗振和密封性能,在动力电池总成固定装置系统结构基础上,对其抗振性能和密封性能进行分析,通过MATLAB模拟壁面受力状态,注入激励信号观察固定装置的性能表现,最后在构建的模拟动力电池总成固定装置碰撞实验环境中验证其抗振和密封性能的可靠性和稳定性,实验结果表明,所设计的动力电池总成固定装置能够提高该装置的抗振和密封性能。

Electrical bistable devices using composites of zinc sulfide nanoparticles and poly-(N-vinylcarbazole)

N-dodecanethiol capped zinc sulfide（Zn S） nanocrystals were synthesized by the one-pot approach and blended with poly（N-vinylcarbazole）（PVK） to fabricate electrical bistable devices. The corresponding devices did exhibit electrical bistability and negative differential resistance（NDR） effects. A large ON/OFF current ratio of 104 at negative voltages was obtained by applying different amplitudes of sweeping voltage. The observed conductance switching and the negative differential resistance are attributed to the electric-field-induced charge transfer between the nanocrystals and the polymer,and the charge trapping/detrapping in the nanocrystals.

LOW POTENTIAL ELECTROPOLYMERIZATION OF ANISOTROPIC CONDUCTIVE POLYTHIOPHENE FILMS AND FABRICATION OF ELECTRICAL DEVICES

The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochemical polymerization potential. The positively charged metal surface of electrode in the process of electrochemical deposition enhanced the coordination interaction between pi-electrons of thiophene unit and the metal, which makes thiophene rings lie parallel to the surface of electrode, resulting in a highly ordered polymeric structure. Because of the large intra-chain transfer integrals, the transport of charge is believed to be principally along the conjugated chains, which is much greater than the inter-chain hopping. The specific electrical resistance across the polythiophene film thickness is more than 10(4) times than that along the surface plane of the film. In this paper we review the recent development of polymerization technique by low potential electrochemical method performed in our lab and several electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, and laminate film junction of undoped polythiophene derivatives were used.

Traction power substation balance and losses estimation in AC railways using a power transfer device through Monte Carlo analysis

The high dynamic power requirements present in modern railway transportation systems raise research challenges for an optimal operation of railway electrification. This paper presents a Monte Carlo analysis on the application of a power transfer device installed in the neutral zone and exchanging active power between two sections. The main analyzed parameters are the active power balance in the two neighbor traction power substations and the system power losses. A simulation framework is presented to comprise the desired analysis and a universe of randomly distributed scenarios are tested to evaluate the effectiveness of the power transfer device system. The results show that the density of trains and the relative branch length of a traction power substation should be considered in the evaluation phase of the best place to install a power transfer device, towards the reduction of the operational power losses, while maintaining the two substations balanced in terms of active power.

Electrically driven uniaxial stress device for tuning in situ semiconductor quantum dot symmetry and exciton emission in cryostat

Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stress, which enables us in situ to tune exciton optical properties at low temperature down to 15 K with high tuning precision. The design and operation of the device are described in detail. This technique provides a simple and convenient approach to tune QD structural symmetry, exciton energy and biexciton binding energy. It can be utilized for generating entangled and indistinguishable photons. Moreover, this device can be employed for tuning optical properties of thin film materials at low temperature.

Experimental Verification of Left-Handed Metamaterials Composed of Coplanar Electric and Magnetic Resonators

We verified experimentally left-handed metamaterials （LHM） composed of coplanar electric and magnetic resonators. A typical LHM sample composed of coplanar resonator unit cells was fabricated, investigated and tested. The experimental results show that the tested sample has a left-handed band of width 1.4 GHz in the X band. The experimental results agree quite well with the simulation ones. Moreover, both the simulation and experimental results show that the LHM under study can automatically achieve good impedance-matching in the left-handed band.

Polypyrrole-Coated Zein/Epoxy Ultrafine Fiber Mats for Electromagnetic Interference Shielding

To reduce the environmental pollution and meet the needs for wearable electronic devices, new requirements for electromagnetic interference(EMI) shielding materials include flexibility, biodegradability, and biocompatibility. Herein, we reported a polypyrrole-coated zein/epoxy(PPy/ZE) ultrafine fiber mat which was inherently biodegradable and skin-friendly. In addition, it could maintain its ultrafine fibrous structure after coating, which could provide the mat with mechanical compliance, high porosity, and a large specific area for high EMI shielding. With the assistance of the epoxide cross-linking, the breaking stresses of the PPy/ZE fiber mats could achieve 3.3 MPa and 1.4 MPa and the strains were 40.1% and 83.0% in dry and wet states, respectively, which met the needs of various wearable electronic devices. Along with the extension in the PPy treatment duration, more PPy was loaded on the fiber surfaces, which formed more integrated and conductive paths to generate increasing conductivities up to 401.76 S·m^(-1). Moreover, the EMI shielding performance was raised to 26.84 dB. The biobased mats provide a green and efficient choice for EMI shielding materials, which may be a promising strategy to address EMI problems in multiple fields.

Methods and Results of Assessment of the Pulse Electrical Disturbances Influence on. Digital Devices Functioning

Two methods of calculating the parameters and characterizing the degree of pulse electrical disturbances influence on digital devices functioning, both analytical and numerical, are considered here. The analytical method permits one to assess the error occurrence probability in transmitting the data packets considering the dependence on the signal pulses energies-to-pulse disturbances energies ratio and the disturbances repetition frequency-to-data transmission rate ratio and also the dependence on the bits quantity in the packet. The numerical method allows one to assess the specific effect of the repetitive pulse disturbance influence on the digital devices functioning （the number of errors in transmitted data packets, transmission rate, etc.） depending on such factors as the repetition frequency, the disturbance waveform and duration, the mode of data coding, etc..

Design of an Electrically Written and Optically Read Non-volatile Memory Device Employing BiFeO3/Au Heterostructures with Strong Absorption Resonance

Exploiting new concepts for dense, fast, and nonvolatile random access memory with reduced energy consump- tion is a significant issue for information technology. Here we design an ＇electrically written and optically read＇ information storage device employing BiFeO3/A u heterostruetures with strong absorption resonance. The electro- optic effect is the basis for the device design, which arises from the strong absorption resonance in BiFeO3/Au heterostructures and the electrically tunable significant birefringence of the BiFeO3 film. We first construct a sim- ulation calculation of the BiFeO3/Au structure spectrum and identify absorption resonance and electro-optical modulation characteristics. Following a micro scale partition, the surface reflected light intensity of different polarization units is calculated. The results depend on electric polarization states of the BiFeO3 film, thus BiFeO3/Au heterostructures can essentially be designed as a type of electrically written and optically read infor- mation storage device by utilizing the scanning near-field optical microscopy technology based on the conductive silicon cantilever tip with nanofabricated aperture. This work will shed light on information storage technology.

Engineering Geometric Electrodes for Electric Field-Enhanced High-Performance Flexible In-Plane Micro-Supercapacitors

In plane micro-supercapacitors that are miniaturized energy storage components have attracted significant attention due to their high power densities for various ubiquitous and sustainable device systems as well as their facile integration on various flexible/wearable platform.To implement the micro-supercapacitors in various practical applications that can accompany solid state or gel electrolyte and flexible substrates,ions must be readily transported to electrodes for achieving high power densities.Herein,we show large enhancement in electrochemical properties of flexible,inplane micro-supercapacitor using sharp-edged interdigitated electrode design,which was simply fabricated through direct laser scribing method.The sharp-edged electrodes allowed strong electric field to be induced at the corners of the electrode fingers which led to the greater accumulation of ions near the surface of electrode,significantly enhancing the energy storage performance of micro-supercapacitors.The electric field-enhanced in-plane micro-supercapacitor showed the volumetric energy density of 1.52 Wh L^(−1)and the excellent cyclability with capacitive retention of 95.4%after 20000 cycles.We further showed various practicability of our sharp-edged design in micro-supercapacitors by showing circuit applicability,mechanical stability,and air stability.These results present an important pathway for designing electrodes in various energy storage devices.

面向电力装备自供电传感的微纳能源收集技术

数智化电网的建设依赖于海量分布式电力装备状态监测传感器,提升传感器的供电可靠性进而实现自供电感知,对拓展设备状态感知系统的深度和广度具有重要意义。近年来,以纳米发电机为代表的微纳能源收集方法与器件被广泛关注,其能够将多元、分散的机械能、热能、电磁能等转化为电能,搭配微能量存储元件与低功耗微纳传感器实现自供电传感。该文围绕面向电力装备自供电传感的微纳能源收集方法这一主题,首先介绍了电力装备及其运行环境微能量的分布特性;其次,总结了以热电纳米发电机、摩擦纳米发电机、压电纳米发电机、磁场能收集发电机、水伏发电机为代表的微纳能源收集方法原理及特点,分析了其在电力装备场景下的适用性,同时综述了基于微纳能源器件的电力装备微能量收集与自供电传感最新研究进展,并提出了本领域目前发展面临的主要技术难点和潜在解决方案。最后,展望了微纳能源收集方法及器件的发展趋势,有望为电力装备自供电状态监测和数智化发展提供参考与指导。

运用5G通信技术远程程控心脏置入型电子设备的有效性及安全性评价

目的:探讨与技术服务人员术中现场程控、测试心脏置入型电子设备(cardiac implantable electrical devices,CIEDs)各项参数的常规方式相比,该非接触式远程程控系统在CIEDs置入过程中的的安全性和有效性。方法:本研究为回顾性研究。依照时间顺序,连续分析了自2020年8月至2021年3月,于我院接受CIEDs置入的110例患者,根据术中程控及测试方式,分为常规程控组及非接触组。入选患者中,59例常规组患者由技术服务人员术中现场程控,其余51例非接触组患者通过新型远程非接触系统程控。结果:常规组的开关门频率高于非接触组[(9.8±1.8)vs.(5.8±1.2),P<0.05]。在CIEDs置入期间和术后12个月时,常规组和非接触组之间的设备相关参数差异及手术相关不良事件差异无统计学意义。结论:基于5G通信传输技术的新型非接触性程控系统与传统的程控方法相比,是安全有效的。

水稻插秧机调平装置电气控制系统设计

为了保证秧苗入土深度一致,提升秧苗成活率,对水稻插秧机的调平装置及电气控制系统进行了设计。水稻插秧机的主要组成包括机架、电气控制系统、调平装置、秧箱、取秧和插秧部件、动力系统及传动系统。为了提升调平装置的性能,对液压装置的参数包括最大功率和作业效率进行了设计,并对横向自适应调平装置的电气控制系统进行了设计。为了验证水稻插秧机调平装置的性能,对插秧机进行了液压装置仿真试验和调平装置性能试验。试验结果表明:液压装置的参数可以满足设计要求,调平装置可以满足插秧机的作业要求。

烟草钵苗双盘对称交错式自动取苗装置设计与试验

为解决烟草半移栽作业用工量大、效益低等问题,设计一种对称交错式自动取苗装置。首先,阐述该自动取苗装置对两盘钵苗进行交错式取苗的原理,建立取投苗作业过程中的动力学和运动学模型。然后,对送盘装置、取投苗装置和自动控制系统等取苗装置关键部件进行结构设计,分析关键部件的作业过程,结合实际需求完成关键元器件的选型。最后,在已有移栽机动力底盘的基础上试制2ZY-1型烟草移栽机样机,以60天苗龄的烟草钵苗为作业对象进行田间取投苗性能试验。试验结果表明,在自动取投苗速度为20株/min时,取苗成功率为89.63%,投苗成功率为97.20%,伤苗率为3.59%。

车端侧滚减振装置对高速双层动车组动力学性能的影响分析

双层动车组设置较大的二系横向阻尼来抑制一次蛇行引起的共振,而较大的二系横向阻尼会使车辆的横向平稳性变差。针对某型高速双层动车组横向平稳性差的问题,基于车端侧滚减振装置的工作原理建立了车端侧滚减振装置在车体滚摆和摇头运动状态下的数学模型,并将AMEsim软件中建立的减振器仿真模型与台架试验进行验证。最后通过建立车端侧滚减振装置与被试车辆的联合仿真模型,在不改变车辆现有悬挂参数的基础上对车端侧滚减振装置的关键参数进行优化选取。仿真结果表明,车端侧滚减振装置可以在不影响车辆垂向平稳性、保证曲线运行安全性的前提下有效改善双层动车组的横向平稳性。

基于PLC的蔬菜移栽机器人输送装置电气控制系统

以蔬菜移栽机器人为研究对象,以准确移栽蔬菜秧苗为目的,采用PLC控制技术设计了一套蔬菜移栽机器人喂苗装置电气控制系统。试验结果表明:蔬菜移栽机器人喂苗装置正确移栽率在96%以上,运行精度满足移栽机定位要求,能够实现蔬菜的无损移栽。