Traveling Reaction Zone Method for Preparation of Textured Ceramic Superconductor Thick Films

Textured thick films of superconducting YBa₂Cu₃O_7−x (YBCO) have been prepared on ceramic substrates using a traveling reaction zone method. The technique utilizes the rapid reaction between Y₂Cu₂O₅ and BaCuO₂ to form YBCO as the film passes through a steep temperature gradient furnance. The films consist of a single continuous superconducting phase with strong c -axis orientation normal to the translation direction of the film.     

Superconducting Coupling Nature at Grain Boundaries in Bi2Sr2CaCu2Ox Glass-Ceramics

Superconducting coupling nature at grain boundaries in Bi₂Sr₂CaCu₂O _x glass-ceramics consisting mainly of the low- T _c phase was first examined by measuring superconducting properties and temperature or ac field dependence of ac complex susceptibility. It was found from the ac loss peaks that superconducting coupling at grain boundaries was basically characterized by three types of weak links. The weak-link behaviors at grain boundaries depended strongly on cooling conditions after annealing and annealing time and temperature. Particularly, it was found that the weak links at grain boundaries were improved by prolonged annealing at 840°C. The furnace-cooled glass-ceramics obtained by annealing at 820° or 840°C for about 200 h exhibited a critical transport current density (77 K, zero magnetic field) of about 200 A/cm².     

Preparation of Ba2YCu3O7-δ Thin Films with Preferred Orientation through an Organometallic Route

Superconducting Ba₂YCu₃O_7-δ thin films were prepared through an organometallic route. Single-phase Ba₂YCu₃O_7-δ thin films with preferred orientation were successfully prepared on SrTiO₃ (100) single-crystal substrates at 800°C by a dip coating method using partially hydrolyzed Ba-Y-Cu organometallic solutions. Preferentially oriented Ba₂YCu₃-O_7-δ thin films were also prepared on MgO (100) substrates. By controlling the partial hydrolysis conditions, a coating solution for precursor thin films was kept accurately at the stoichiometric composition. The use of ozone gas during the pyrolysis of the precursor thin films was found to suppress the formation of BaCO₃. Ba₂YCu₃O_7-δ thin films with c -axis orientation perpendicular to a SrTiO₃ (100) substrate, which were heat-treated at 900°C for 15 min, exhibited a superconductivity transition with an onset of 90 K and an end of 75 K.     

Bi2—xPbxSr2Ca2Cu3Oy系高Tc超导体相变的研究

用DSC研究了高T_e超导体B_(2-r)Pb_rSr_2Ca_2Cu_sO_v(x=0,0.2,0.4,0.6)从室温至600℃范围内的相变。在320℃和440℃附近有二个吸热蜂,每一个峰对应一个相变过程。440℃附近的相变是不可递的,其原子激活能为1.37eV,是由高T_e相向低T_e相的转变。而320℃附近的相变则与超结构的形成有关。     

证据理论在热保护火工品高温安全性评估中的应用

为了评估热保护火工品的高温安全性,根据假设的装药和保护结构失效温度分布及温升历程模型,建立了热保护火工品的安全性分析模型.采用证据理论中的专家判断方法处理模型参数确定中的不确定性问题,基于专家判断获得的参数区间分布情况,使用随机抽样方法,生成了N组模型参数,完成安全性分析并进行结果的统计表达.分析结果表明,证据理论可以成功用于热保护火工品高温安全性的量化评估.     

Comparative Study of 10-MW High-Temperature Superconductor Wind Generator with Overlapped Field Coil Arrangement

The electromagnetic characteristics and iron loss of a high-temperature superconductor wind generator (HWG) equipped with an overlapped field coil arrangement (OFCA) are studied by comparing with the one equipped with the conventional field coil arrangement (CFCA). Through a quantitative analysis, it was found that HWG with OFCA exhibits better electromagnetic characteristics than HWG with CFCA and can reduce the iron loss by eliminating the magnetic flux sag caused by the adjacent field coil sides with the same current flow direction. In addition, the OFCA topology can further reduce the volume of the wind generator.     

5000t/d水泥生产线窑尾高温风机变频改造

本文主要介绍了高压变频器在淄博鲁中水泥有限公司窑尾高温风机上的应用情况,并对节能效果进行了分析。     

Self‐Assembly of Nanostructured,Complex, Multication Films via Spontaneous Phase Separation and Strain‐Driven Ordering

Spontaneous self‐assembly of a multication nanophase in another multication matrix phase is a promising bottom‐up approach to fabricate novel, nanocomposite structures for a range of applications. In an effort to understand the mechanisms for such self‐assembly, complimentary experimental and theoretical studies are reported to first understand and then control or guide the self‐assembly of insulating BaZrO₃ (BZO) nanodots within REBa₂Cu₃O_7–δ (RE = rare earth elements including Y, REBCO) superconducting films. The strain field developed around BZO nanodots embedded in the REBCO matrix is a key driving force dictating the self‐assembly of BZO nanodots along REBCO c‐axis. The size selection and spatial ordering of BZO self‐assembly are simulated using thermodynamic and kinetic models. The BZO self‐assembly is controllable by tuning the interphase strain field. REBCO superconducting films with BZO defect arrays self‐assembled to align in both vertical (REBCO c‐axis) and horizontal (REBCO ab‐planes) directions result in the maximized pinning and J_c performance for all field angles with smaller angular J_c anisotropy. The work has broad implications for the fabrication of controlled self‐assembled nanostructures for a range of applications via strain‐tuning.     

High Tc Superconducting Materials for Strong Current Applications： Approach at the First Stage

Strong current and large-scale application is the most important prospect of high Te superconductors （HTS）. Practical HTS samples in various forms have been produced with high critical currents operated at economic cryogenic temperatures. Engineering applications of those HTS materials have been studied with various HTS prototype devices. The applicable HTS materials produced in different forms are verified in this paper with regard to their strong current characterizations, and the HTS applications are summarized along with the HTS prototypes made.     

高温超导直线感应电机的设计和电磁分析

本文介绍了高温超导直线感应电机的设计和电磁分析方法。首先,使用遗传算法得到一组优化的电机参数;然后,为了确定电机参数的准确性需要用有限元方法对得到的电机参数建模仿真;垂直穿过高温超导绕组的磁场(垂直磁场)对电机的临界电流影响很大,为了增加电机的临界电流,穿过电机初级超导绕组的垂直磁场应该尽可能地小。最后,要对建立的电机模型进行详细的电磁分析,以保证各项性能指标满足要求。