100kV直流高温超导电缆终端应力锥设计

本文提出了一种新的单直线应力锥设计方法,根据PPLP材料的绝缘特性,结合超导电缆的本体尺寸和设计电压,给出了增饶绝缘厚度和应力锥轴向长度的设计数据,其中增饶绝缘厚度为3.5 mm,应力锥轴向长度为38.5 mm,并对单直线应力锥进行电场数值分析,结果表明,所设计的单直线应力锥满足100 kV直流高温超导电缆运行要求。     

Liquid crystal aligning capabilities on surface-reformed indium-doped zinc oxide films via ion-beam exposure

We investigated the characteristics of a solution-processed indium-doped zinc oxide (In:ZnO) film formed via ion-beam (IB) irradiation as a liquid crystal (LC) alignment layer. The In:ZnO film was deposited using solution processing and cured at various temperatures. Uniform LC alignment was observed at all curing temperatures in cross-polarised optical microscopy images. A regular pre-tilt angle supported these results and showed homogeneous LC alignment. Several surface analyses were conducted to evaluate the effect of IB irradiation on the In:ZnO film surface. X-ray diffraction analysis showed an amorphous structure both before and after IB irradiation, and physical surface reformation was observed using atomic force microscopy. Root mean square surface roughness was reduced and a smooth surface was achieved after IB irradiation. X-ray photoelectron spectroscopy was used to detect chemical surface reformation. It was found that the IB irradiation broke the metal-oxide bonds and increased the occurrence of oxygen vacancies, which affected the van der Waals forces between the LC molecules and the In:ZnO film surface. Electrical performance was observed to identify the possibility of using the In:ZnO film in LC applications. Enhanced electro-optical performance was measured and zero residual DC voltage which was verified using a capacitance-voltage curve was achieved.     

Magnetization and structural studies of Mn doped ZnO nanoparticles: Prepared by reverse micelle method

Single phase Mn (2.5 at%) doped ZnO nanocrystalline samples were synthesized by reverse micelle method as characterized by Rietveld refinement analysis of X-ray diffraction data, high resolution transmission electron microscopy and selected area electron diffraction analyses. The X-ray photoelectron spectroscopy and electron paramagnetic resonance (EPR) studies indicated that manganese exist as Mn²⁺ in ZnO lattice. DC magnetization measurements as a function of field and temperature, of 2.5 at% Mn doped ZnO nanoparticles annealed at 675 K, showed room temperature ferromagnetism (RTF). This observation is further confirmed by the EPR spectrum of the sample, which shows a distinct ferromagnetic resonance signal at room temperature. These results indicate that the observed RTF in Mn-doped ZnO may be attributed to the substitutional incorporation of Mn at Zn sites.     

绒面ZnO透明导电薄膜

采用孪生ZnO (Al2 O3 ∶2 % )对靶直流磁控溅射制备高透过率、高电导率的平面ZnO薄膜 (迁移率为 5 .5 6cm2 /V·s,载流子浓度为 4 .5 7× 10 2 0 cm-3 ,电阻率为 2 .4 6× 10 -3 Ω·cm ,可见光范围 (380～ 80 0nm)平均透过率大于 85 % )。用酸腐蚀的方法 ,可以获得绒面效果 ,而反应气压对绒面效果没有影响 ,薄膜的电学特性没有变化 ,绒面对光散射作用增强 ,导致相对于平面ZnO薄膜的透过率要低一些 (可见光范围平均透过率大于 80 % )。     

Dynamical behaviors of the chaotic Brushless DC motors model

This article is concerned with the boundedness solutions of the brushless DC motor system. For this system, the global attractive set and positively invariant set are obtained based on generalized Lyapunov function stability theory and the extremum principle of function. Furthermore, the rate of the trajectories is also obtained. Numerical simulations are presented to show the effectiveness of the proposed scheme. © 2014 Wiley Periodicals, Inc. Complexity 21: 79–85, 2016     

基于神经网络模糊控制理论的转台伺服系统控制设计

针对三轴飞行仿真转台伺服系统非线性、模型不精确等特点,在分析转台系统结构的基础上,采用模糊PID控制的方法对转台伺服系统进行仿真控制,得到较好的控制效果。模糊控制控制规则的获得带有很大的人为因素,并且在控制过程中对规则采用查表法占用大量的内存。基于以上原因,设计了神经网络模糊控制器(NNSOC),利用神经网络控制自学习、自调整的能力,为模糊控制器提供自动生成控制规则的能力;同时由于神经网络具有联系记忆能力,可对未训练的样本做出决策。对NNSOC的控制效果进行了仿真。结果表明：其具有很好的动态性能和鲁棒性,对转台的控制效果良好。     

Electrical conductivity of polycrystalline films of p-sexiphenyl

In this work the results of DC conductivity measurements of polycrystalline p-sexiphenyl thin films are presented. The investigations concerned the effect of temperature, film thickness and electric field on the DC conductivity mechanism. The thickness of the investigated material varied from 0.2 to 2.5 μm. The measurements were carried out for different electrode polarities of the 0 -100 V voltage and at temperatures ranging from 15 to 325 K. Thin films of p-sexiphenyl were obtained by controlled vacuum sublimation on BK-7 glass substrate with gold and aluminium electrodes. Analyzing the obtained results we conclude that injection of the charge carrier from electrodes into the investigated material proceeds by thermionic emission and field emission and it is dependent on temperature and external electric field. The charge carrier transport is controlled by localized states (traps) in the forbidden energy gap. The activation energy calculated from formula ln I = f(1/kT) varied from kT for low temperature up to 1.0 eV.     

基于自适应斜坡补偿的双环电流模DC/DC混沌控制

提出了一种自适应斜坡补偿方法,将该方法引入到双环电流模buck DC/DC的混沌控制中,并给出实现该方法的电路结构.建立了双环电流模DC/DC系统稳定性分析的离散模型,理论分析了自适应斜坡补偿在双环控制下系统的稳定性条件,推导出了自适应因子k与系统工作的最大占空比的关系式.仿真结果表明该方法可有效控制系统的分岔和混沌现象,提高系统的工作范围和动态响应速度.     

一种改进的谐振参数扰动法及其在DC/DC变换器混沌控制中的应用

种改进的谐振参数扰动法来控制混沌，该混沌控制方法引入了基于非线性映射的调制，其控制目标可以是任意周期的轨道，而不是原混沌吸引子中的嵌入轨道。作为一个应用实例，文中描述了该方法在电流模式控制dc/dc变换器中的应用结果。     

溅射功率对直流磁控溅射Ti膜结构的影响

 采用直流磁控溅射方法制备了纯Ti膜,研究了不同功率下Ti膜的沉积速率、表面形貌及晶型结构,并对其应力进行了研究。研究表明：薄膜的沉积速率随溅射功率的增加而增加,当溅射功率为20 W时,原子力显微镜(AFM)图像显示Ti膜光洁、致密,均方根粗糙度最小可达0.9 nm。X射线衍射(XRD)分析表明薄膜的晶体结构为六方晶型,Ti膜应力先随溅射功率增大而增大,在60 W时达到最大值（为945.1 MPa）,之后随溅射功率的增大有所减小。