高温超导块材在旋转场中的电磁响应

高温超导(HTS)块材在旋转系统中会受到旋转磁场的影响,为此我们建立了实验装置用以模拟和反映块材在旋转场中的电磁响应,并结合实验现象从理论上初步探讨了旋转磁场中HTS内部磁通渗透过程和能量损耗机理.     

不同燃料循环方案的可持续性与经济性分析

基于核燃料循环政策技术的成熟度,选取了一次通过循环方案(OTC)、单次复用循环方案(TTC)、快堆闭式循环方案(FRC)及混合堆闭式循环方案(HRC)四种典型的核燃料循环方案进行分析。采用平衡物质流模型对不同燃料循环方案的可持续性进行研究,基于平准化电力成本计算方法对不同方案的燃料成本和乏燃料处置成本进行分析。研究结果表明:闭式燃料循环可极大减少核废料产生; 燃料可自持的FRC方案及HRC方案可使用贫铀做燃料而不消耗天然铀; 仅考虑燃料成本和乏燃料处置成本时,HRC方案的经济性最高而TTC方案的经济性最差。     

三相交流电的旋转磁场的演示

演示内容: (一)旋转磁场的产生。 (二)旋转磁场的转速。 (三)旋转磁场的旋向。仪器原理及线路: 如图一,A、B、C为三相对称低频电源[注],K甲为电源换向开关,K乙为电路切换开关,D1、D4、D2、D5,D3、D6分别为相当于三相交流电动机定子绕组各元件的首端和末端,a、b、c为变极变速用引出线. (一)当 K乙扳向 P=1位置,D1、 D2、 D3与对称三相电源A、B、C接通时,1—12各槽导体中均有按正弦规律变化的电流通过.由于发光二极管LED的整流作用.使得电流流进时只能从槽中右支路流过——LED发红光;电流流出时则只能从左支路流过——LED发兰光.…     

电动机旋转磁场是发电机旋转磁场的跟随器

三相交流发电机与三相异步电动机都采用星形连接,分析旋转磁场和三相异步电动机的正反转.结果表明:电动机旋转磁场是发电机旋转磁场的跟随器.     

Formation Process of Magnetized Fusion Target on the YingGuang 1 Device

Magnetized target fusion is an alternative method to fulfill the goal of controlled fusion,which combines advantages of both magnetic confinement fusion and inertial confinement fusion since its parameter space lies between the two traditional ways.Field reversed configuration(FRC) is a good candidate of magnetized targets due to its translatable,compressible,high β and high energy density properties.Dynamic formation process of high density FRC is observed on the YingGuang 1 device for the first time in China.The evolution of a magnetic field is detected with magnetic probes,and the compression process can be clearly seen from images taken with a high-speed multi-frame CCD camera.The process is also studied with two-dimensional magneto hydrodynamic code MPF-2D theoretically,and the results agree well with the experiment.Combining the experimental data and the theoretical analysis,the length of the formed FRC is about 39 cm,the diameter is about 2-2.7cm,the average density is 1.3×10~(16) cm~(-3),and the average temperature is 137 eV.     

电磁交互场对Al-合金凝固组织的影响研究

将在坩埚中熔融的Al-Cu合金在冷却凝固的过程中加入旋转磁场和脉冲电流的交互场,研究Al-(4～5%)Cu合金在复合场作用下的微观组织的变化.结果发现旋转磁场和脉冲电流的交互场对合金的凝固组织产生明显的细化作用.从组织细化效果来看,存在一个最佳的电磁参数配匹,100 V磁场-100A-300Hz-100μs的电脉冲使粗...     

交流电机的旋转磁场

用矢量分解和合成的方法阐明三相交流电机旋转磁场的产生 ,进而解释两组绕组旋转磁场及单相电机的起动问题。     

三相异步电动机旋转磁场显示仪

采用RC低频振荡器，通过降低交流电的频率，设计了三相异步电动机旋转磁场显示仪，实现了三相异步电动机旋转磁场的可视化．     

浅谈家用吊扇的调速方法

家用吊扇的核心部分是单相异步电动机,此绕组如图1,有一主绕组(工作绕组)与一串联电容器C的副绕组(启动绕组)相并联.这样做可使二绕组的电流在相位上相差90°,从而形成旋转磁场.转子的转动过程与三相异步电动机相似.     

单相旋转磁场演示仪

由于家用电器大多数是采用单相电容式感应电动机,而单相电容式感应电动机的驱动力是单相旋转磁场产生的,关于单相旋转磁场的基本原理可根据交流电路和垂直振动的叠加来进行解释,本文仅叙述单相旋转磁     

Enhanced confinement and stability of a field-reversed configuration with rotating magnetic field current drive

A new experiment has been constructed to study the sustainment of a field-reversed configuration (FRC) with a rotating magnetic field (RMF). FRCs were formed with cold, unmagnetized ions and thus without a kinetic ion component that was believed to provide stability to internal tilt modes. No destructive instabilities were observed for the RMF FRC. Only peripheral radial penetration of the RMF was observed. The radially inward flow arising from axial screening currents at the FRC edge reduced convective and conductive losses to the measurement limit of the diagnostics.     

Ion heating in the field-reversed configuration by rotating magnetic fields near the ion-cyclotron resonance

The trajectories of ions confined in a field-reversed configuration (FRC) equilibrium magnetic geometry and heated with a small-amplitude, odd-parity rotating magnetic field (RMF) have been studied with a Hamiltonian computer code. When the RMF frequency is in the ion-cyclotron range, explosive heating occurs. Higher-energy ions are found to have betatron-type orbits, preferentially localized near the FRC's midplane. These results are relevant to a compact magnetic-fusion-reactor design.     

Stretching instability of a two-dimensional freely rotating chain

We study the mechanical property of a two-dimensional free rotating chain (FRC). We find that at low force and with a scaled bond length, the relation between extension and applied force of a FRC obeys the same linear law as that of a free jointed chain (FJC), agreeing with the conclusion that free of applied force the end-to-end distances of two models have the same power law. But beginning from a moderate force, the two models become very different even with a scaled bond length. Especially, when the bond angle is small, the relative extension of a FRC is always smaller than that of a FJC; but with a large bond angle the relative extension of a FRC becomes larger than that of a FJC. Moreover, the extension of FJC is a smooth function of applied force, but the extension of a long FRC can subject to a first order transition when the bond angle is large.     

旋转带电球体的转动惯量

对均匀带电球体绕其自身的对称轴作变角速度旋转产生的磁场和感应电场求解，之后计算了这球体对该轴的转动惯量。     

虚光子过程对“两个二能级原子-单模光场”相互作用系统场熵演化特性的影响

利用全量子理论,研究了非旋波近似下两个二能级原子与单模光场相互作用过程中受激场场熵的演化规律,通过与旋波近似下的相应结果进行比较,进一步揭示出非旋波近似条件下虚光子过程对场熵演化特性的影响.     

Onset and saturation of ion heating by odd-parity rotating magnetic fields in a field-reversed configuration

Heating of figure-8 orbit ions by odd-parity rotating magnetic fields (RMF(O)) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances (s congruent to omega(R)/omega) of the RMF(O) frequency, omega(R), with the figure-8 orbital frequency, omega, and is proportional to s2 for s-even resonances and to s for s-odd resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude.     

对旋轴流水轮机的非定常数值模拟研究

为了研究采用对旋转轮的新型轴流式水轮机的非定常性能,应用三维非定常数值计算方法,对该新型水轮机进行了数值模拟研究.数值计算中,采用了全三维全流道的数值计算方法,基于DES(Detached Eddy Simulation)方法获得了对旋轴流水轮机的非定常流场和能量性能.计算结果显示,该新型水轮机在一个转动周期的不同时刻,其内部流场存在显著的非定常特性.     

反场构形磁化等离子体的一种解析平衡模型

反场构形（FRC）预加热磁化等离子体是磁化靶聚变（MTF）中等离子体靶的主要形成方法之一。为了从物理机理及物理本质上更好地理解反场构形磁化等离子体的平衡状态,依据FRC等离子体的经典刚性转子（RR）模型,通过对平衡状态的解析求解,获得了等离子体各主要参数在平衡状态下的分布函数,并与标准二维磁流体力学（MHD）的数值模拟结果进行对比分析,在此基础上讨论了RR模型参数对平衡状态分布函数的影响。结果表明,在FRC等离子体分界线内部,RR解析模型可以较好地描述等离子体状态分布。     

周期场作用下自旋的主方程及其稳定态

用Robertson理论推导一个在纵磁场和横周期场作用下的自旋的运动方程。得到了阻尼和自旋稳定态对外场强度、频率及与热库的耦合系数的依赖关系。讨论了自旋稳定态的结构及其形成原因。 关键词：     

THE SOUND FIELD OF A ROTOR IN A STATIONARY DUCT

A method is developed for the prediction of noise from rotors in an axisymmetric duct at rest. The technique combines a previously developed model for noise from disc sources with a boundary integral equation method for scattering from the duct surface. Recent developments in the theory of Gaussian quadrature and generalized elliptic integrals are used to simplify the implementation of the formulation. The sound field of a simplified model ducted rotor is then calculated and its structure examined in the framework of known features of the field around rotating sources. It is found that, as for an open rotor, the sonic radius plays an important role in the structure of the field.