Research on simulation of gun muzzle flow field empowered by artificial intelligence

Artificial intelligence technology is introduced into the simulation of muzzle flow field to improve its simulation efficiency in this paper.A data-physical fusion driven framework is proposed.First,the known flow field data is used to initialize the model parameters,so that the parameters to be trained are close to the optimal value.Then physical prior knowledge is introduced into the training process so that the prediction results not only meet the known flow field information but also meet the physical conservation laws.Through two examples,it is proved that the model under the fusion driven framework can solve the strongly nonlinear flow field problems,and has stronger generalization and expansion.The proposed model is used to solve a muzzle flow field,and the safety clearance behind the barrel side is divided.It is pointed out that the shape of the safety clearance under different launch speeds is roughly the same,and the pressure disturbance in the area within 9.2 m behind the muzzle section exceeds the safety threshold,which is a dangerous area.Comparison with the CFD results shows that the calculation efficiency of the proposed model is greatly improved under the condition of the same calculation accuracy.The proposed model can quickly and accurately simulate the muzzle flow field under various launch conditions.

Photodetachment dynamics of H^- ion in a harmonic potential plus a time-dependent oscillating electric field

The photodetachment dynamics of H^- ion in a harmonic potential plus an oscillating electric field is studied using the time-dependent closed orbit theory. An analytical formula for calculating the photodetachment cross section of this system is put forward. It is found that the photodetachment cross section of this system is nearly unaffected for the weak oscillating electric field strength, but oscillates complicatedly when the oscillating electric field strength turns strong. In addition, the frequency of the harmonic potential and the oscillating electric field （the frequency of the harmonic potential and the frequency of the oscillating electric field are the same in the paper, unless otherwise stated.） can also affect the photodetachment dynamics of this system. With the increase of the frequency in the harmonic potential and the oscillating electric field, the number of the closed orbits for the detached electrons increased, which makes the oscillatory structure in the photodetachment cross section much more complex. Our study presents an intuitive understanding of the photodetachment dynamics driven by a harmonic potential plus an oscillating electric field from a space and time dependent viewpoint. This study is very useful in guiding the future experimental research for the photodetachment dynamics in the electric field both changing with space and time.

Efficient solver for time-dependent Schrodinger equation with interaction between atoms and strong laser field

We present a parallel numerical method of simulating the interaction of atoms with a strong laser field by solving the time-depending Schr?dinger equation(TDSE) in spherical coordinates. This method is realized by combining constructing block diagonal matrices through using the real space product formula(RSPF) with splitting out diagonal sub-matrices for short iterative Lanczos(SIL) propagator. The numerical implementation of the solver guarantees efficient parallel computing for the simulation of real physical problems such as high harmonic generation(HHG) in these interaction systems.

Dynamical Properties of Two Coupled Dissipative QED Cavities Driven by Coherent Fields

When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fields. We investigate the effects of the coherent fields, the dissipation as well as the incoherent coupling on the following dynamical properties of the system： photon transfer, reversible decoherence, and quantum state transfer, etc. We find that the photons in the cavities do not leak completely into the environment due to the collective coupling between the cavities and the enviroment, and the photons are transferred irreversibly from the cavity with more photons to the cavity with less ones due to the incoherent coupling so that they are equally distributed among the two cavities. The coherent field pumping on the two cavities increases the mean photons, complements the revived magnitude of the reversible decoherence, but hinders the quantum state transfer between the two cavities. The above phenomena may find applications in quantum communication and other basic fields.

Study and Measurement of Glidarc Driven by Magnetic Field

Non-thermal plasma at atmosphere was generated through glidarc discharge driven by magnetic field and observed by using a high speed charge coupled device （CCD） and photo multiplier tube （PMT）. The arc diameter projecting in the direction of arc motion （front-viewed diameter） and the diameter projecting in the perpendicular direction of arc motion （side-viewed diameter） were measured. The effect of both the arc current and the magnetic field was analysed. The front-viewed diameter was compared with the side-viewed one. Simultaneously the electricfield intensity was measured directly and analysed by considering the effect of the external magnetic field and arc current.

Dynamic Behavior of Entanglement Between Two Spatially Separated Atoms in Two Dissipative and Driven Cavity Fields

We consider two two-level atoms, interacting with two independent dissipative cavities, each of which is driven by an external source. The two cavity fields are both initially prepared in the coherent states, and the two two-level atoms are initially prepared in the singlet state ｜ψ^-〉 =（｜eg〉 - ｜ge〉 ） / √2. We investigate the influence of the damping constant n, the intensity of the external sources F, and the relative difference of the atomic couplings r on the entanglement between the two atoms. In the dispersive approximation, we find that the entanglement between the two atoms decreases with the time evolution, and the decreasing rate of entanglement depends on the values of F/k, k/ω, and r. For the given small values of F/k and k/ω, on the one hand, the increasing of r favors entanglement decreasing of the atomic system, on the other hand, when r → 1 the entanglement decreasing becomes slower. With the increasing of the value of k/ω, the influence of r on the decreasing rate of entanglement becomes smaller, and gradually disappears for the big value of k/ω.

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.

Determination of the Velocity of a Magnetic-Field Driven Gliding Arc by Using a Photo-Multiplier

The gliding arc is an important approach to production of non-thermal plasma at atmospheric pressure, it can offer high-energy efficiency and high-electivity for chemical reactions. In this paper, the gliding arc driven by the transverse magnetic field is described and its velocity is measured by using a photo-multiplier. The mean velocity of the gliding arc increases with increasing magnetic induced-intensity, and its value varies from 7.8 m/s to 32 m/s.

气流场驱动喷射3D打印熔融聚乳酸微细纤维及表面浸润性调控

提出了一种高速气流场驱动喷射高效三维(3D)打印熔融聚乳酸微细纤维的方法,分析了高速气流致熔融材料剪切破碎原理,研究了打印工艺中供料气压、气流流速、打印高度等关键参数对微细纤维直径分布及结构孔隙率、截面尺寸的影响规律。并对所获得的聚乳酸微细纤维进行了表面浸润性测试。结果表明,该工艺相对于静电纺丝等微细纤维制造方法,加工效率提高10倍以上。通过控制不同的打印参数,可以有效实现纤维直径在6~18μm、孔隙率在55%~96%范围内的有效调控。通过3D打印工艺,可实现具有宏观路径可控、微观具有高孔隙率微纤维结构的制作。表面浸润性结果显示,打印微细纤维由于材料分子基团及高孔隙率综合作用,具有疏水性及粘附性特征,通过对微观局部进行亲水处理,实现了同一材料局部疏水和亲水共存结构的制作,证明了该方法表面浸润性调控的有效性。

建筑屋面风雨场及突出建筑立面风驱雨的实测研究

文章对某多层建筑屋面区域风驱雨(wind-driven rain,WDR)开展实测,结合3类典型降雨事件的分析,揭示大气湍流特征以及风速、风向对雨滴的影响特性,并针对突出屋面建筑,实测分析立面WDR分布特性,量化国际标准化组织(International Organization for Standardization,ISO)半经验模型对突出屋面建筑WDR预测的偏差。结果表明,在3类降雨事件中,湍流度、阵风因子和湍流积分尺度的实测值与基于地面实测建立的公式理论值之间存在较大差异;实测的雨滴数量与标准M-P谱计算的雨滴数量差值最大为125个。在风速和雨强差异较小时,建筑立面WDR分布受来流与立面夹角的影响显著。由于ISO半经验模型是基于地面实测建立的,其对突出屋面建筑WDR的预测存在偏差,在模型适用的降雨条件下实测值约为ISO预测值的2倍。

铁电效应调控的高性能p-NiO/i-BaTiO_(3)/n-ITO自供能紫外光电探测器

近年来,自供能的紫外光电探测器由于无需任何外部偏压即可工作而成为军事和民用领域的研究热点。其中,钛酸钡(BTO)作为一种宽禁带铁电材料,拥有良好的铁电、压电和热电性能,可以产生本征自发极化场来分离光生载流子,从而实现自供能紫外光电探测。到目前为止,基于BTO的自供能光电探测器已经取得了巨大进展,然而,除了使用高质量的单晶材料外,所报道的器件往往表现出低响应度(10^(-8)~10^(-7) A·W^(-1))。本文利用低成本的射频溅射技术,制造了一种高性能的NiO/BTO/ITO p-i-n异质结构自供能紫外光电探测器。通过将BTO的铁电去极化场和p-i-n结的内建电场耦合,能有效提高光生载流子的分离和迁移。因此,该器件在正极化态下255 nm波长紫外光照射下的响应度可以达到3.4×10^(-5) A·W^(-1),远远高于其他已报道的基于非晶态和陶瓷BTO制备的紫外光电探测器。此外,该器件具有0.3 s/0.4 s的快速响应时间。本工作为提高BTO光电探测器的性能提供了一种新的策略。

场驱动医疗微机器人:材料制备工艺不断优化的应用前景

背景:微机器人具有体积小、灵活、靶向性强等特点,可以在狭窄的环境下通过单体或集群的方式完成复杂的工作。随着材料、制备工艺以及驱动方式的不断优化,其在生物医学领域内显示出越来越重要的应用价值。目的:分析场驱动微机器人在生物医学领域的应用并展望其应用前景。方法:以“微机器人,纳米机器人,驱动,生物医学,医疗”为中文关键词,以“microrobots,micro-robots,nanorobots,micromachine,microswimmer,medical”为英文关键词,分别检索万方以及Pub Med数据库,检索时间范围重点为2010年1月至2024年1月,同时纳入少数远期文献。通过阅读文题、摘要初步筛选,排除重复性研究、低质量期刊以及与内容不相关的文献,阅读全文后最终纳入66篇文献进行综述。结果与结论:场驱动医疗微机器人涵盖了磁、光、热、超声及多种混合因素驱动机器人。场驱动机器人已被应用于肠道诊断、药物靶向治疗及干细胞治疗等多个领域。尽管医用微机器人在临床医学中已有少数应用,但大多数还处于理论和实验阶段。医用微机器人的未来面临诸多挑战,如实现大规模制备、进一步提升精确控制、解决回收或体内降解问题,以及所用材料是否会对人体产生不良反应等,此外微机器人还需与相应的微创医学手术相配合。

一种利用远场数据恢复Dirichlet特征值的神经网络方案

探讨了声场中利用远场数据重构具有Dirichlet边界条件的障碍物的特征值反问题,提出了一种基于数据驱动的神经网络方案。首先针对具有Dirichlet边界条件的障碍物建立内特征值问题和外散射问题的数学模型,然后构建一个具有序列对序列结构的多层前馈神经网络,该网络采用反向传播误差和自学习的方式更新网络中的超参数,最后在散射体信息未知的前提下,利用远场数据重构障碍物的Dirichlet特征值。数值实验表明该方法可以有效地重构障碍物的Dirichlet特征值。

新能源汽车现场工程师人才培育探究

针对广西新能源汽车产业对现场工程师需求快速增长,结合目前新能源汽车专业建设发展中出现的校企合作不深入、师资力量薄弱、课程体系与新能源汽车产业岗位需求不匹配等问题,文章从现场工程师的视角出发,探讨了新能源汽车技术专业人才培养的思路。提出校企协同育人,基于新能源汽车产业一线岗位技能要求重构课程体系,引入企业一线技术人员,共建校企混编教学团队。研究以新能源汽车产业为驱动,培育新能源汽车制造业现场工程师,为新能源汽车技术专业人才培养提供了新的建设思路。

基于场驱动的X波段龙勃透镜平面化设计研究

龙勃透镜天线因其多种优异属性,如多波束能力、宽角扫描、高增益等,是应用于雷达、卫星通信等电磁领域的重要器件。然而传统球形龙勃透镜因为体积、重量等问题大大限制了其在某些场景的应用。为了解决龙勃透镜的平面化、共形化等问题。文章提出并设计了一种用于X波段(8 GHz~12 GHz)应用的平面型龙勃透镜。利用超材料结构思想和场驱动设计技术实现了平面型龙勃透镜的介电常数梯度渐变和轻量化。采用12 dB增益喇叭天线对所设计的龙勃透镜进行仿真,在12 GHz的工作频率上获得高达14.1 dB的天线增益,与球形龙勃透镜相比,模型总体积减少了78%。此外,该平面型龙勃透镜模型,是基于有限元分析的透镜辐射分布电场驱动求解构建的,该方法可以为复杂结构透镜部件的开发及共形化设计提供创新思路。

功能涂层在多场多尺度仿真下的设计理论及研究进展

功能涂层设计需要考虑从纳米级到米级的多场多尺度效应,这对于功能涂层的设计理论和仿真计算仍是一项巨大挑战。梳理当前功能涂层的多尺度仿真方面存在一些问题,如多场耦合理论有待加强、多尺度数值方法计算效率有待提高、大尺度湍流数值仿真仍存在较大模型误差等。综述了功能涂层设计理论与仿真的现状与趋势,重点讨论了多场多尺度设计理论、动力学设计理论、数据驱动仿真方法以及强度与寿命评价方法等方面的最新进展。在此基础上,提出功能涂层设计理论与仿真的未来重点发展方向。指出面向工业应用的多场多尺度设计技术、动载荷性能设计、数据驱动仿真和搭建仿真软件平台是功能涂层仿真设计所面临的技术难点,并给出面向关键技术难点的研究建议,为后续多场多尺度仿真在功能涂层设计领域中的应用提供参考。

数据驱动靶场静态毁伤数字试验技术

针对静态毁伤试验成本高、周期长、数据样本量有限、边界条件无法验证的问题,开展了静态毁伤数字试验技术探索。以靶场静态毁伤试验为研究对象,基于理论公式、历史试验数据和数值仿真计算,构建了爆炸威力场预测模型及冲击波压力、破片飞散特性等毁伤分析模型。利用仿真和试验结合模型驱动及3维场景数字化显示等关键技术,建立了典型静态毁伤数字试验场景,实现了数据驱动静态毁伤数字试验。可为靶场静态毁伤传感器布设提供理论依据,为靶场开展数字试验提供技术基础。

基于电场驱动喷射微3D打印的曲面透明电加热玻璃技术

为了解决高性能曲面透明电加热玻璃制造工艺复杂和制备成本高的问题,提出了一种基于电场驱动喷射微3D打印制造曲面透明电加热玻璃的新方法,并阐述了该工艺流程;通过实验揭示了主要打印参数对制造曲面透明电加热玻璃银线线宽的影响规律;使用优化的打印参数在曲面透明玻璃上制备了有效加热面积为35 mm×40 mm,线宽为90μm,周期为3000μm,附着力为4B,透光率为90%,电阻为1.6Ω,银线为金属网栅结构的曲面透明电加热玻璃。实验结果表明,该打印方法工艺简单,利用该方法制造的曲面透明电加热玻璃具有附着力好、透光率高和加热性能良好等优点,为实现低成本、高性能的曲面透明电加热玻璃的工业化制造提供了一种全新的解决方案。

海上油气田生产污水处理新技术应用分析

海上油气田在生产过程中,会产生大量含油污水。由于生产加药等因素的影响,油气田产出的污水水质很差。深水气田在生产中会加入甲醇、乙二醇等化学药剂,使产出污水水质较油田差,气田污水未经处理直接外排,会严重污染海洋环境。针对海洋油气田不同设施的生产污水水质差异,通过对生产污水除油的工艺方法进行研究,调研海域内生产污水处理工艺及效果,借鉴原油脱水中的电破乳技术,提出了一套新的应用电驱聚结破乳原理的生产污水处理工艺,并成功应用,使得外排生产污水含油量由0.003 0%下降至0.001 5%,极大地保护了海洋环境。

基于滑膜观测的FOC无刷电机控制系统设计

针对目前全驱动型机器人的高工作精度以及高稳定性需求,设计全驱动型机器人关节驱动控制系统。基于无刷电机数学模型,电机驱动方案采用矢量电机控制算法FOC,电机角速度位置采用有感、无感相结合获取,即在启动以及低速转动下采用位置传感器,在中高速转动下切换使用滑模观测器。观测器对电机反电动势观测值进行运算处理,获得电机位置和速度。在MATLAB/Simulink搭建控制模型,验证算法可行性。仿真结果表明:在负载情况下,中低转速下,控制精度低,低成本位置传感器足以满足控制需求;在中高转速下,位置获取方法切换为滑模观测器,此时无位置传感器控制,无需使用高精度位置传感器,根据电机运行的电流观测到的位置,足以满足中高转速需求。且观测器监测内部运行状态,无视外界影响,大大提高控制系统的响应性与稳定性。