Effect of power supply parameters on discharge characteristics and sterilization efficiency of magnetically driven rotating gliding arc

Plasma sterilization is a new generation of high-tech sterilization method that is fast,safe,and pollution free.It is widely used in medical,food,and environmental protection fields.Home air sterilization is an emerging field of plasma application,which puts higher requirements on the miniaturization,operational stability,and operating cost of plasma device.In this study,a novel magnetically driven rotating gliding arc(MDRGA)discharge device was used to sterilize Lactobacillus fermentation.Compared with the traditional gas-driven gliding arc,this device has a simple structure and a more stable gliding arc.Simulation using COMSOL Multiphysics showed that adding permanent magnets can form a stable magnetic field,which is conducive to the formation of gliding arcs.Experiments on the discharge performance,ozone concentration,and sterilization effect were conducted using different power supply parameters.The results revealed that the MDRGA process can be divided into three stages:starting,gliding,and extinguishing.Appropriate voltage was the key factor for stable arc gliding,and both high and low voltages were not conducive to stable arc gliding and ozone production.In this experimental setup,the sterilization effect was the best at 6.6 kV.A high modulation duty ratio was beneficial for achieving stable arc gliding.However,when the duty ratio exceeded a certain value,the improvement in the sterilization effect was slow.Therefore,considering the sterilization effect and energy factors comprehensively,we chose 80%as the optimal modulation duty ratio for this experimental device.

Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure

Brain tissue is one of the softest parts of the human body,composed of white matter and grey matter.The mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain function.Besides,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical properties.Whether white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical properties.As such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional dependence.Building a constitutive law for multiscale brain tissue using traditional function-based approaches can be very challenging.Instead,this paper proposes a data-driven approach to establish the desired mechanical model of brain tissue.We focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our approach.The matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading paths.The generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal pressures.Finally,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body forces.Compared with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling efficiency.The predictions made by our trained model demonstrate sufficient accuracy.Specifically,we find that the level of internal blood pressure can greatly influence stress distribution and determine the possible related damage behaviors.

Effects of counter-current driven by electron cyclotron waves on neoclassical tearing mode suppression

Through theoretical analysis,we construct a physical model that includes the influence of counter-external driven current opposite to the plasma current direction in the neoclassical tearing mode(NTM).The equation is used with this model to obtain the modified Rutherford equation with co-current and counter-current contributions.Consistent with the reported experimental results,numerical simulations have shown that the localized counter external current can only partially suppress NTM when it is far from the resonant magnetic surface.Under some circumstances,the Ohkawa mechanism dominated current drive(OKCD)by electron cyclotron waves can concurrently create both co-current and counter-current.In this instance,the minimal electron cyclotron wave power that suppresses a particular NTM was calculated by the Rutherford equation.The result is marginally less than when taking co-current alone into consideration.As a result,to suppress NTM using OKCD,one only needs to align the co-current with a greater OKCD peak well with the resonant magnetic surface.The effect of its lower counter-current does not need to be considered because the location of the counter-current deviates greatly from the resonant magnetic surface.

Research on the Microstructure Construction Technology of Fully Degraded Polymer Vascular Stent Based on Electric Field Driven 3D Printing

The so-called fourth-generation biodegradable vascular stent has become a research hotspot in thefield of bioengineering because of its good degradation ability and drug-loading characteristics.However,the preparationof polymer-degraded vascular stents is affected by known problem such as poor processflexibility,low formingaccuracy,large diameter wall thickness,limited complex pore structure,weak mechanical properties of radial support and high process cost.In this study,a deposition technique based on a high-voltage electric-field-driven continuous rotating jet is proposed to fabricate fully degraded polymer vascular stents.The experimental results showthat,due to the rotation of the deposition axis,the deposition direction of PCL(polycaprolactone)micro-jet isalways tangent to the surface of the deposition axis.The direction of the viscous drag force is also consistent withthe deposition direction of the jet.It is shown that by setting different rotation speeds of deposition axisωandlinear motion speeds of the nozzle V,the direction of rotation,pitch and angle of the individual printed spiralcurve can be precisely tuned.In the process of multiple spiral curves matching the deposition forming thin walltube mesh,the mesh shape and size of the thin wall tube can be accurately controlled by changing the number ofmatching spiral curves and the size of the matching position bias distance.Finally,the characteristics of a PCLtubular stent sample(with uniform-size microfibers and mesh shape),fabricated under the appropriate processparameters are described in detail.

Investigation of system parameters towards safer impact based shock-to-detonation transition in a novel laser driven flyer plate prototype

Laser driven flyer plate technology offers improved safety and reliability for detonation of explosives in industrial applications ranging from mining and stone quarrying to the aerospace and defense industries.This study is based on developing a safer laser driven flyer plate prototype comprised of a laser initiator and a flyer plate subsystem that can be used with secondary explosives.System parameters were optimized to initiate the shock-to-detonation transition(SDT)of a secondary explosive based on the impact created by the flyer plate on the explosive surface.Rupture of the flyer was investigated at the mechanically weakened region located on the interface of these subsystems,where the product gases from the deflagration of the explosive provide the required energy.A bilayer energetic material was used,where the first layer consisted of a pyrotechnic component,zirconium potassium perchlorate(ZPP),for sustaining the ignition by the laser beam and the second layer consisted of an insensitive explosive,cyclotetramethylene-tetranitramine(HMX),for deflagration.A plexiglass interface was used to enfold the energetic material.The focal length of the laser beam from the diode was optimized to provide a homogeneous beam profile with maximum power at the surface of the ZPP.Closed bomb experiments were conducted in an internal volume of 10 cm^(3) for evaluation of performance.Dependency of the laser driven flyer plate system output on confinement,explosive density,and laser beam power were analyzed.Measurements using a high-speed camera resulted in a flyer velocity of 670±20 m/s that renders the prototype suitable as a laser detonator in applications,where controlled employment of explosives is critical.

Data Driven Vibration Control:A Review

With the ongoing advancements in sensor networks and data acquisition technologies across various systems like manufacturing,aviation,and healthcare,the data driven vibration control(DDVC)has attracted broad interests from both the industrial and academic communities.Input shaping(IS),as a simple and effective feedforward method,is greatly demanded in DDVC methods.It convolves the desired input command with impulse sequence without requiring parametric dynamics and the closed-loop system structure,thereby suppressing the residual vibration separately.Based on a thorough investigation into the state-of-the-art DDVC methods,this survey has made the following efforts:1)Introducing the IS theory and typical input shapers;2)Categorizing recent progress of DDVC methods;3)Summarizing commonly adopted metrics for DDVC;and 4)Discussing the engineering applications and future trends of DDVC.By doing so,this study provides a systematic and comprehensive overview of existing DDVC methods from designing to optimizing perspectives,aiming at promoting future research regarding this emerging and vital issue.

Exploration of a New Task-driven Model for Botany Field Practice

In the present context of increasing social demands for natural science education,increasing people s awareness of environmental biodiversity protection,and ecological civilization lifting to the state strategy,it is just the time to explore a new botany field practice model.The attempt of a new task-driven model for botany field practice will greatly enhance students thinking about plants and nature,plants and environment,and plant and ecological civilization,and will inevitably enhance students initiative awareness and practical ability to protect and rationally utilize plant resources.

Object-oriented Battlefield Environment Simulation Process Object Model Based on Task-driven

Battlefield environment simulation process is an important part of battlefield environment information support, which needs to be built around the task process. At present, the interoperability between battlefield environment simulation system and command and control system is still imperfect, and the traditional simulation data model cannot meet war fighters’ high-efficient and accurate understanding and analysis on battlefield environment’s information. Therefore, a kind of task-orientated battlefield environment simulation process model needs to be construed to effectively analyze the key information demands of the command and control system. The structured characteristics of tasks and simulation process are analyzed, and the simulation process concept model is constructed with the method of object-orientated. The data model and formal syntax of GeoBML are analyzed, and the logical model of simulation process is constructed with formal language. The object data structure of simulation process is defined and the object model of simulation process which maps tasks is constructed. In the end, the battlefield environment simulation platform modules are designed and applied based on this model, verifying that the model can effectively express the real-time dynamic correlation between battlefield environment simulation data and operational tasks.

利多卡因基于TASK-3通道诱导老龄小鼠认知功能障碍研究

目的探究TASK-3通道在利多卡因(Lidoc)诱导老龄小鼠术后认知功能障碍(POCD)中的作用。方法野生型(WT)小鼠与TASK-3敲除(TASK-3^(-/-))小鼠各20只,随机分为WT组,WT+Lidoc组,TASK-3^(-/-)组,TASK-3^(-/-)+Lidoc组。取WT+Lidoc组,TASK-3^(-/-)+Lidoc组小鼠每天皮下注射40mg·kg^(-1) Lidoc麻醉,6h后分别开展水迷宫实验或者跳台实验,共7d。取小鼠脑组织分别开展免疫组化染色、苏木精-伊红染色、TUNEL染色、树突棘染色、电生理测试。结果与WT组相比,WT+Lidoc组小鼠水迷宫中逃避潜伏期明显增加,首次到达平台时间增加,穿越平台次数与平台象限停留时间明显减少,跳台潜伏期与跳台错误次数明显增加。然而,与TASK-3^(-/-)组相比,TASK-3^(-/-)+Lidoc组小鼠水迷宫实验与跳台时间指标没有明显改变。此外,与WT组相比,WT+Lidoc组小鼠脑组织中Caspase-3表达明显增加,神经元状态明显损伤,TUNEL阳性细胞数明显增加。与此同时,Lidoc造成小鼠海马神经元树突棘密度明显减少,fEPSP斜率明显减少。然而,与TASK-3^(-/-)组相比,TASK-3^(-/-)+Lidoc组小鼠Caspase-3表达并没有明显改变,神经元状态正常且TUNEL阳性细胞数没有变化。与此同时,小鼠神经元树突棘状态和fEPSP斜率没有影响。结论Lidoc诱导老龄小鼠POCD可能是激活TASK-3通道造成Caspase-3表达增加实现。

MPC-based Torque Distribution for Planar Motion of Four-wheel Independently Driven Electric Vehicles:Considering Motor Models and Iron Losses

The most critical obstacle for four-wheel independently driven electric vehicles(4WID-EVs)is the driving range.Being the actuators of 4WID-EVs,motors account for its major power consumption.In this sense,by properly distributing torques to minimize the power consumption,the driving range of 4WID-EV can be effectively improved.This paper proposes a model predictive control(MPC)-based torque distribution scheme,which minimizes the power consumption of 4WID-EVs while guaranteeing its tracking performance of planar motions.By incorporating the motor model considering iron losses,the optimal torque distribution can be achieved without an additional torque controller.Also,for this reason,the proposed control scheme is computationally efficient,since the power consumption term to be optimized,which is expressed as the product of the motor voltages and currents,is much simpler than that derived from the efficiency map.With reasonable simplification and linearization,the MPC problem is converted to a quadratic programming problem,which can be solved efficiently.The simulation results in MATLAB and CarSim co-simulation environments demonstrate that the proposed scheme effectively reduces power consumption with guaranteed tracking performance.

双孔钾通道TASK-1在心房颤动的研究进展

心房颤动(atrial fibrillation,AF)是成人最常见的持续性心律失常,随着全球人口老龄化AF的发病率和患病率正在逐年上升。AF的临床治疗手段持续改进并不断优化,但房颤发病机制仍未完全阐明。双孔钾通道家族中的TWIK相关酸敏感钾通道1(TWIK-related acid-sensitive potassium channel 1,TASK-1),其可能为一有巨大价值的AF治疗靶点。本综述系统总结了关于双孔钾通道家族中TAKS-1通道与房颤的研究进展。

新工科背景下近代物理实验教学改革与实践

以任务驱动式教学模式为核心,提高新工科创新型、应用型人才的物理实验综合素养。通过教学内容的重构、教学方法的改革、评价方式的优化等全面的教学改革与实践,将物理知识与工科相关的科学前沿相结合,充分体现物理实验是新工科研究基础的特征,使学生具备多学科交叉融合实验的能力,为未来培养多元化、创新型卓越工程人才提供支撑。同时,改革也促进了教学团队的教学水平提升,获得师生双向满意的教学效果。

“互联网+”背景下“模拟电子技术实验”教学

针对传统“模拟电子技术实验”课程教学过程中存在的问题,在“互联网+”背景下,采用“三位一体”混合式教学模式进行教学改革。教学设计过程中通过任务驱动教学法,以实验任务为载体,进行“三位一体”混合式教学。该教学模式整合SPOC在线平台、虚拟仿真平台和便携式实验微平台的教学资源,构建学生“自主学习、自主实践、自主创新”的实验教学平台,体现了“互联网+教育”思想在“模拟电子技术实验”教学中的应用。

新能源汽车动力电池及管理技术课程教学设计与实施

为培养新能源汽车后市场急需的高素质技术技能型人才,针对新能源汽车技术专业教学过程与生产过程脱节、教学内容与工作内容不匹配的问题,以新能源汽车技术专业核心课新能源汽车动力电池及管理技术课程为例,对该课程进行了整体教学设计并在新能源汽车技术专业中应用。根据岗位能力需求、课程标准、“1+X”证书考核标准确定教学目标,重构课程内容,在分析学生学情的基础上,充分利用校企优势资源因材施教。以企业真实的生产任务为教学载体,基于问题导向,采用任务驱动教学法,通过“三阶段七环节”实施教学。通过多元化、多维度、过程性评价促进学生能力全面提升。

Power Consumption Characteristics Research on Mobile System of Electrically Driven Large-Load-Ratio Six-Legged Robot

The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective utilization rate of energy is not high,which has become an important obstacle to its practical application.To research the power consumption characteristics of robot mobile system is beneficial to speed up it toward practicability.Based on the configuration and walking modes of robot,the mathematical model of the power consumption of mobile system is set up.In view of the tripod gait is often selected for the six-legged robots,the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot’s statically indeterminate problem and constructing the equal force distribution.Then,the power consumption of robot mobile system is solved under different working conditions.The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint,body height,and span.The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption.According to the walking experiments of prototype,the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in duty ratio,body height,and span.Then,the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system.The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots.

A deep learning driven hybrid beamforming method for millimeter wave MIMO system

The hybrid beamforming is a promising technology for the millimeter wave MIMO system,which provides high spectrum efficiency,high data rate transmission,and a good balance between transmission performance and hardware complexity.The most existing beamforming systems transmit multiple streams by formulating multiple orthogonal beams.However,the Neural network Hybrid Beamforming(NHB)adopts a totally different strategy,which combines multiple streams into one and transmits by employing a high-order non-orthogonal modulation strategy.Driven by the Deep Learning(DL)hybrid beamforming,in this work,we propose a DL-driven nonorthogonal hybrid beamforming for the single-user multiple streams scenario.We first analyze the beamforming strategy of NHB and prove it with better Bit Error Rate(BER)performance than the orthogonal hybrid beamforming even with the optimal power allocation.Inspired by the NHB,we propose a new DL-driven beamforming scheme to simulate the NHB behavior,which avoids time-consuming neural network training and achieves better BERs than traditional hybrid beamforming.Moreover,our simulation results demonstrate that the DL-driven nonorthogonal beamforming outperforms its traditional orthogonal beamforming counterpart in the presence of subconnected schemes and imperfect Channel State Information(CSI).

震害评估任务驱动的遥感信息服务链构建方法

地震是全球影响最大的自然灾害之一。利用遥感数据对灾区进行动态震害评估,有助于支持应急救援和恢复重建工作,并在一定程度上降低灾害损失。然而,随着Web服务和在线计算技术的快速发展,如何根据不同震害评估任务需求,选择合适的遥感数据和处理服务进行智能组合,构成遥感信息服务链,已成为亟待解决的难题。因此,本文提出了一种任务驱动的遥感信息服务链构建方法,通过分析震害评估任务与遥感服务的特点,基于本体构建统一描述语义的震害评估任务描述模型与遥感信息服务描述模型,研究逐级精化的服务多级语义匹配方法,并从服务类型、服务功能、服务质量三个方面进行服务匹配。结果表明,本方法可构建出12条可用服务链,用时均在70 min内,且最优归一化服务质量指标达到0.607。研究成果能够支持遥感信息服务链构建,可为震害服务管理提供技术支持。

面向任务的无人飞行器自组网OLSR协议

无人飞行器(unmanned aerial vehicle,UAV)自组网的路由研究多以性能指标出发、忽略无人飞行器网络的任务驱动性,与实际需求动态耦合弱、适用性不强。针对该问题基于无人飞行器多任务网络提出了面向任务的无人飞行器联盟组网架构,提出了无人飞行器联盟的任务自适应优化链路状态路由协议(task adaptive optimized link state routing,TA-OLSR)。基于模糊逻辑设计拓扑稳定度计算方法,利用拓扑稳定度实现TA-OLSR控制消息的自适应广播,同时结合稳定度设计新的多点中继选择策略。仿真结果表明,TA-OLSR算法能从宏观面向任务的角度出发,实现不同任务下的良好自适应性,提升数据包投递率,减少冗余信息传播,降低网络开销,有效提高整体网络性能。

数智时代的信息分析方法:数据驱动、知识驱动及融合驱动

数智时代,面对大数据、大知识所带来的挑战,如何创新发展信息分析方法,关乎新时代信息分析工作的开展,关乎数据资源的开发利用。本文在梳理现有信息分析方法的基础上,提出数据驱动、知识驱动,以及数据与知识融合驱动的三种数智型方法思路。首先,提出基于文本、网络、音频、图像等的数据驱动以及与之相应的文本挖掘、图挖掘、音频挖掘、图像挖掘等信息分析模式;其次,提出基于专家知识库、通用知识库、领域知识图谱、通用知识图谱等的知识驱动信息分析模式;最后,提出基于特征、模型、决策三种层面的数据与知识融合驱动的信息分析模式。通过以上三种方法,构建能够系统融合大数据、大知识的信息分析方法,实现数智融合型信息分析,促进图书情报学科方法论发展,赋能国家决策和社会治理。图3。表1。参考文献59。

高职“机械设计基础”课程混合式教学改革创新路径研究

基于“机械设计基础”这门课程的特点和高职学习者学情,探索“学做研创”专业基础课程改革路径,通过设计不同的产品结构设计主题,以机械产品设计为主线,有机融入“机械原理设计→机械结构设计→机械产品评价”教学方式,创新实施基于成果导向的“1+1+N”线上线下混合式教学模式,以宿舍为单位组建学习型组织,团队协作完成不同难易程度的机械作品以检验学习成果,实现“教与学、学与做、做与创”深度融合,让“学习者成为课堂主体”“教师成为课堂主导教练员”,打造高效优质金课堂。