驱动X光二极管的级联Blumlein型脉冲网络过电压脉冲分析

为了提高装置容许的运行电压以提高辐射剂量产额, 开展了放电过程中影响脉冲形成网络过电压幅值因素的研究。在引入开关导通不同步性和导通电阻条件下, 建立了适用于任意电阻性负载的级联Blumlein型脉冲形成网络电压波过程理论模型, 基于波过程模型进一步分析了影响脉冲形成网络过电压幅值的因素。研究表明开关不同步是产生过电压的主要因素, 过电压峰值出现在开关闭合后的3倍形成网络电长度时刻。随着网络级联级数的增加, 二极管阻抗与源阻抗匹配情况下最大过电压可达到-2倍充电电压, 而二极管阻抗下降使得过电压幅值得以加强, 阻抗过早崩溃可使过电压幅值接近充电电压的-3倍。     

层叠Blumlein纳秒脉冲形成线设计与实验

研究了一种结构紧凑型的多级层叠Blumlein纳秒脉冲形成线,从理论上分析了放电时回路各分布参数对层叠Blumlein脉冲形成线输出电压的影响,并利用PSpice模拟验证了各分布参数对层叠Blumlein脉冲形成线输出结果的影响,发现开关的导通电阻是制约输出电压幅值的主要因素,开关的分布电感对输出波形的影响大于负载分布电感的影响,基于时域有限差分法原理,利用XFDTD软件模拟了两级层叠Blumlein线的电磁耦合效应。开展了多级层叠Blumlein脉冲形成线实验,结果表明,基于陶瓷固态传输线和GaAs光导开关的层叠Blumlein脉冲形成线能够实现输出电压叠加,可用于产生ns量级脉宽的脉冲高压。     

超高斯光束在片状放大器中传输的特性研究

根据非线性薛定谔方程,应用分步傅立叶算法,模拟了不同强度的入射超高斯光束在片状放大器中的传输行为。分析了超高斯光束的光束宽度参量、阶数,以及片状放大器中的自由传播空间对光传输的影响。     

Fault Diagnosis of Permanent Magnet Synchronous Motor Based on Stacked Denoising Autoencoder

As a complex field-circuit coupling system comprised of electric, magnetic and thermal machines, the permanent magnet synchronous motor of the electric vehicle has various operating conditions and complicated condition environment. There are various forms of failure, and the signs of failure are crossed or overlapped. Randomness, secondary, concurrency and communication characteristics make it difficult to diagnose faults. Meanwhile, the common intelligent diagnosis methods have low accuracy, poor generalization ability and difficulty in processing high-dimensional data. This paper proposes a method of fault feature extraction for motor based on the principle of stacked denoising autoencoder (SDAE) combined with the support vector machine (SVM) classifier. First, the motor signals collected from the experiment were processed, and the input data were randomly damaged by adding noise. Furthermore, according to the experimental results, the network structure of stacked denoising autoencoder was constructed, the optimal learning rate, noise reduction coefficient and the other network parameters were set. Finally, the trained network was used to verify the test samples. Compared with the traditional fault extraction method and single autoencoder method, this method has the advantages of better accuracy, strong generalization ability and easy-to-deal-with high-dimensional data features.     

Infusion of Variable Chemical Structure to Tune Stacking among Metal-Organic Layers in 2D Nano MOF

Thickness of two-dimensional (2D) metal-organic frameworks (MOFs) govern their intriguing functionalities. Primarily this thickness is controlled by the stacking between the metal-organic layers (MOL). It is observed that until now such modulating factors for stacking efficiency of MOL are not well studied. Here, we report a fundamental hypothesis to comprehend regulation of stacking efficiency among MOLs as a function of chemical structure of organic ligands (dicarboxylic acids and pillar linkers). This basically involves a series of isostructural three-dimensional (3D) MOFs which contain linkers of variable chemical nature that could be depillared to generate 2D stacked MOFs of different thickness. Depending on the linkers, we encountered the formation of single MOL to stacked multiple MOLs as evidenced from atomic force microscopic and other experimental analysis. The present study gives a concrete correlation between the stacking within 2D MOFs (from monolayer to multilayers), and their 3D counter parts, which may provide a thickness tuning pathway for 2D MOFs.     

基于垂直层叠结构的多光谱彩色传感器研究

基于垂直层叠的半导体结构是多光谱彩色传感器中的新技术,它具有抗色彩失真, 高空间分辨率, 无需彩色插值和低通滤波器以及更高的光能量利用率等优点。它的基本原理是利用不同波长的光在硅材料中穿透深度的非线性分布,即：短波长的蓝光主要在表面被吸收,长波长的红光则主要在更深的位置被吸收。目前国际上研究的结构中有使用标准晶态硅工艺制作的埋入式多pn结结构和使用PECVD方法制作的非晶硅系象素结构, 其中前者利用了标准的硅工艺, 而由于后者使用了光学性能更好的非晶硅系材料, 在结构设计上具有更大的灵活性。文章在综合了国际研究文献的基础上,对其光谱机理和象素结构进行了理论与实验分析,对性能做出了比较,并提出了下一步研究的主要方向。     

Synthesis and properties of poly(acrylamide)s containing both long chain alkyl groups and phosphatidylcholine analogues in the side chains

A series of new phospholipid analogous acrylamide monomers ( 4a–e ) containing long alkyl chains as hydrophobic groups and containing phosphatidylcholine analogues as hydrophilic group were synthesized in high yields. The homopolymerizations and copolymerization ( 4b with 4e ) were carried out in the presence of a radical initiator. The structures and thermal properties of these polymers were investigated by x-ray diffraction analysis, DSC, and polarizing microscopy measurements. It has been revealed that these homopolymers ( 5b, 5c , and 5d ) which bear saturated long-hydrocarbon chains in the side chains exhibited not only orderly stacked bilayer structures at room temperature but also clear liquid crystalline behavior within a wide temperature range. The viscosity behavior of all polymers was found similar to usual polyelectrolytes in porlar solvent. The polymers obtained were also characterized by ¹H-NMR, IR, and melting point, respectively. © 1996 John Wiley & Sons, Inc.     

TOPCon太阳电池发射极Al2O3/SiNx与SiO2/Al2O3/SiNx叠层膜钝化性能的比较

本文对TOPCon电池发射结的叠层钝化膜进行了研究,对比了3种不同叠层钝化膜(SiO₂/SiN_x、Al₂O₃(1.5 nm)/SiN_x、SiO₂/Al₂O₃(1.5 nm)/SiN_x)的钝化性能。结果表明:Al₂O₃(1.5 nm)/SiN_x的钝化性能优于SiO₂/SiN_x,SiO₂/Al₂O₃(1.5 nm)/SiN_x的钝化水平最佳,隐开路电压均值可达到705 mV。基于Al₂O₃/SiN_x叠层膜研究了Al₂O₃厚度(1.5 nm、3 nm和5 nm)对钝化性能和电池转换效率的影响。当Al₂O₃厚度由1.5 nm增加到3 nm时,钝化性能得到明显提升,隐开路电压均值提高了20 mV,达到707 mV,对应电池的光电转换效率升高了0.23个百分点,与SiO₂/Al₂O₃(1.5 nm)/SiN_x叠层膜电池的转换效率持平。然而,当Al₂O₃厚度继续增加至5 nm时,隐开路电压均值保持不变。因此可以使用Al₂O₃(3 nm)/SiN_x叠层膜代替SiO₂/Al₂O₃(1.5 nm)/SiN_x叠层膜,不仅简化了电池的工艺步骤,而且降低了生产成本。     

单开关调制的PFN型层叠Blumlein线发生器

采用平板线加载的陶瓷电容型脉冲形成网络（PFN）构成了单开关调制的层叠Blumlein线发生器。采用传输线理论对短路寄生传输线的短路特性进行了理论分析,结果表明,短路寄生传输线的阻抗可以等效为耦合电感在主传输线的放电频率下产生的感抗。Pspice软件模拟表明,层叠线Blumlein线的电压叠加效率随耦合电感增加而增加。提出了一种磁环增感方法,在4级层叠Blumlein线上实现了3.1倍的脉冲电压叠加。