Current–voltage characteristics of AlCdO Schottky contact on the polished and unpolished p-type Si surfaces with and without light illumination

In this study, the current-voltage characteristics of the AlCdO/unpolished p-type Si and AlCdO/polished p-type Si Schottky diodes with and without light illumination were examined. It is found that the Schottky barrier height (the series resistance) of the AlCdO/unpolished p-type Si Schottky diode is higher (lower) than that of the AlCdO/polished p-type Si Schottky diode. The power conversion efficiency of the AlCdO/p-type Si devices in the light (AM 1.5 G, 100 mW/cm²) was improved by increasing built-in potential at the AlCdO/p-type Si interfaces and reducing the device series resistance and surface reflectivity. It is shown that the device surface roughness plays an essential role in improving the device performance.     

Dieless drawing steel wires using a dielectric heating method and modeling the process dynamics

Modern industries require the production of multi-functional, inorganic, micron-sized metal wires. This study suggests a novel method that could potentially offer a highly efficient dieless drawing technology for manufacturing thin stainless steel fibers. The method is based on a hot-working principle, using microwaves as the heat source and SiC as the susceptor. Experimental trials with a laboratory rig showed that the new system worked effectively for drawing the stainless steel wires and should be able to realize the diameter attenuation with a diameter reduction of up to 21%. The theoretical model describing the deformation behavior of the stainless steel wires in the working zone along with the constitutive equation of Bingham model modified with a power law and Zener–Hollomon parameter turned out to match very good with the actual results of the experiment. The coefficient of variation of the drawn wire diameter increased, as the draw ratio increased, which could be attributed to the occurrence of the narrow necking zone.     

城中村问题调查与分析

以华北地区为主要研究对象,对秦皇岛山东堡地区进行了深入调研,从中发现城中村存在的一些共性问题,通过分析找出了症结所在并提出合理的解决方案。     

Hilbert transform based FBP algorithm for fan-beam CT full and partial scans

This paper presents a new type of filtered backprojection (FBP) algorithm for fan-beam full- and partial-scans. The filtering is shift-invariant with respect to the angular variable. The backprojection does not include position-dependent weights through the Hilbert transform and the one-dimensional transformation between the fan- and parallel-beam coordinates. The strong symmetry of the filtered projections directly leads to an exact reconstruction for partial data. The use of the Hilbert transform avoids the approximation introduced by the nonuniform cutoff frequency required in the ramp filter-based FBP algorithm. Variance analysis indicates that the algorithm might lead to a better uniformity of resolution and noise in the reconstructed image. Numerical simulations are provided to evaluate the algorithm with noise-free and noisy projections. Our simulation results indicate that the algorithm does have better stability over the ramp-filter-based FBP and circular harmonic reconstruction algorithms. This may help improve the image quality for in place computed tomography scanners with single-row detectors.     

Cell Membrane Camouflaged Hollow Prussian Blue Nanoparticles for Synergistic Photothermal‐/Chemotherapy of Cancer

Nanodrug‐based cancer therapy has been actively developed in the past decades. The main challenges faced by nanodrugs include poor drug loading capacity, rapid clearance from blood circulation, and low antitumor efficiency with high risk of recurrence. In this work, red blood cell (RBC) membrane camouflaged hollow mesoporous Prussian blue nanoparticles (HMPB@RBC NPs) are fabricated for combination therapy of cancer. The stability, immune evading capacity, and blood retention time of HMPB@RBC NPs are significantly enhanced compared with those of bare HMPB NPs. Doxorubicin (DOX), as a model drug is encapsulated within HMPB@RBC NPs with loading capacity up to 130% in weight. In addition, DOX loaded HMPB@RBC NPs show pH‐/photoresponsive release. The in vivo studies demonstrate the outstanding performance of DOX@HMPB@RBC NPs in synergistic photothermal‐/chemotherapy of cancer.     

基于关系数据库ORACLE的多媒介信息管理系统

本文介绍了一个多媒介信息管理系统的设计与实现,提出了基于关系数据库的多媒介信息一体化存取与管理方案,以及适宜的用户界面。     

利用脉冲复制环提高纳秒脉冲单次测量的动态范围

提出了一种提高纳秒光脉冲单次测量动态范围的方法,其中光纤脉冲复制环用来产生时域上幅度呈指数递减的脉冲复制串,有效环增益为0.955。经软件补偿脉冲复制串使其具有相同的幅度,然后累加平均前18个脉冲,能够将注入的单发纳秒光脉冲动态范围提高2.74倍,这样就可以实现利用光电探测管和示波器对100:1高对比度的惯性约束核聚变(ICF)脉冲测量。     

先进服务器应用的内存解决方案

内存性能对于桌上型计算机、路由器,甚至是个人数字助理(PDA)已是基本要求,对服务器与工作站而言,更为重要.由于需要处理密集运算工作置及管理大量数据,系统就必须配置最先进的内存.     

MPC在大功率交流牵引中的应用

目前由交-直-交电压型功率变换器和异步牵引电动机所构成的交流传动系统，已成为世界电力机车、电动车组和城轨车辆电传动技术的主流，而交流传动的核心单元是牵引变换器。本文对原ADtranz公司所设计的模块化功率变换器-MPC的技术特征进行了归纳和分析，最后指出随着电力电子技术和微处理器技术的发展，模块化及分布式控制系统已经成为功率变换器的发展趋势。     

250W高压钠灯电子镇流器的研究

为满足人们对绿色照明的要求,该文设计了节能、高功率因数及总谐波失真低的高压钠灯电子镇流器来替代传统的电感式镇流器,采用有源功率因数校正、恒功率控制、低频方波驱动的三级式结构的电路设计,并搭建了样机,实现了160V～265V宽电压输入,功率因数PF≥0.99,总谐波畸变因数THD≤9．1％,电路可靠工作,通过了电磁兼容传导干扰测试。