A Smart Card Based Efficient and Secured Multi-Server Authentication Scheme

Increasing popularity of the multi-server architecture has propelled the research on the multi-server authentication schemes. Current dominating authentication schemes are smartcard based, verification table free schemes with passwords. Although these schemes have developed to be robust against most of the popular malicious attacks, they still have security weaknesses and their efficiency is generally low. In this paper, we analyze and formulate security issues in previously proposed schemes. And based on the formulation, an enhanced efficient and secure scheme is proposed. In the proposal, a novel “redundant key protection” is proposed to utilize. The proposed scheme is validated and verified by Colored Petri Nets.     

全固态窄线宽钠导星激光器

研制了一台重复频率400 Hz,平均功率1.0 W的激光二极管抽运全固态窄线宽钠导星激光器.利用两路波长分别为1064 nm和1319 nm的声光(AO)调Q激光器作为基频光,在腔外通过三硼酸锂(LBO)晶体和频产生(SFG)589 nm钠导旱激光,和频效率约达20%.每路基频光均采用标准具压窄线宽,输出和频光线宽约1.8 GHz,并调节控制标准具的温度和倾斜角度将中心波长锁定于589.159 nm(偏差±1 pm),实现了激光器谱线与钠原子D2线的精确匹配.     

Low-jitter design method based on Wn-domain jitter analysis for 10 Gbit/s clock and data recovery ICs

A low-jitter design method based on vn-domain jitter analysis for the clock and data recovery (CDR) ICs using the linear phase-locked loop (PLL) is proposed. Using this method, the loop parameters of the PLL can be optimised, which makes it possible to design the CDR IC for various targets.     

Gold Nanoshell Nanomicelles for Potential Magnetic Resonance Imaging,Light‐Triggered Drug Release,and Photothermal Therapy

A novel multifunctional drug‐delivery platform is developed based on cholesteryl succinyl silane (CSS) nanomicelles loaded with doxorubicin, Fe₃O₄ magnetic nanoparticles, and gold nanoshells (CDF‐Au‐shell nanomicelles) to combine magnetic resonance (MR) imaging, magnetic‐targeted drug delivery, light‐triggered drug release, and photothermal therapy. The nanomicelles show improved drug‐encapsulation efficiency and loading level, and a good response to magnetic fields, even after the formation of the gold nanoshell. An enhancement for T₂‐weighted MR imaging is observed for the CDF‐Au‐shell nanomicelles. These nanomicelles display surface plasmon absorbance in the near‐infrared (NIR) region, thus exhibiting an NIR (808 nm)‐induced temperature elevation and an NIR light‐triggered and stepwise release behavior of doxorubicin due to the unique characteristics of the CSS nanomicelles. Photothermal cytotoxicity in vitro confirms that the CDF‐Au‐shell nanomicelles cause cell death through photothermal effects only under NIR laser irradiation. Cancer cells incubated with CDF‐Au‐shell nanomicelles show a significant decrease in cell viability only in the presence of both NIR irradiation and a magnetic field, which is attributed to the synergetic effects of the magnetic‐field‐guided drug delivery and the photothermal therapy. Therefore, such multicomponent nanomicelles can be developed as a smart and promising nanosystem that integrates multiple capabilities for effective cancer diagnosis and therapy.     

Multifunctional Upconversion Nanoparticles for Dual‐Modal Imaging‐Guided Stem Cell Therapy under Remote Magnetic Control

Stem cells have generated a great deal of excitement in cell‐based therapies. Here, a unique class of multifunctional nanoparticles (MFNPs) with both upconversion luminescence (UCL) and superparamagnetic properties is used for stem cell research. It is discovered that after being labeled with MFNPs, mouse mesenchymal stem cells (mMSCs) are able to maintain their viability and differentiation ability. In vivo UCL imaging of MFNP‐labeled mMSCs transplanted into animals is carried out, achieving ultrahigh tracking sensitivity with a detection limit as low as ≈10 cells in a mouse. Using both UCL optical and magnetic resonance (MR) imaging approaches, MFNP‐labeled mMSCs are tracked after being intraperitoneally injected into wound‐bearing mice under a magnetic field. The translocation of mMSCs from the injection site to the wound nearby the magnet is observed and, intriguingly, a remarkably improved tissue repair effect is observed as the result of magnetically induced accumulation of stem cells in the wound site. The results demonstrate the use MFNPs as novel multifunctional probes for labeling, in vivo tracking, and manipulation of stem cells, which is promising for imaging guided cell therapies and tissue engineering.     

银纳米立方体对诺丹明分子的荧光增强或猝灭效应实验研究

用乙二醇还原硝酸银,成功制备了平均边长约97 nm的银纳米立方体以用于诺丹明(RhB)分子的荧光实验。实验中,将探针分子 RhB 粉末掺杂于PMMA苯甲醚溶液中,制得不同厚度参杂有RhB探针分子的PMMA薄膜,运用光谱技术和共焦显微技术研究了银纳米立方体与荧光分子的间隔、银纳米立方体不同浓度分布对RhB分子的荧光强度的影响。荧光光谱表明,荧光强度随PMMA厚度变薄而增强,当PMMA厚度为10nm时,荧光增强因子最大,获得了56倍的荧光增强效果,而继续减小PMMA厚度时,其荧光增强因子又变小,说明发生了荧光猝灭效应。共焦荧光像则更直观地表现了银纳米立方体的浓度分布对荧光分子辐射增强的影响。因而,可通过调控银纳米立方体与荧光分子的距离及银纳米立方体的分布优化荧光增强因子以用于基于荧光的单分子探测,这一实验结果在生物成像和生物传感领域有潜在应用价值。     

Fractional order Buck–Boost converter in CCM: modelling,analysis and simulations

In this paper, the modelling, analysis and the power electronics simulator (PSIM) simulations of the fractional order Buck–Boost converter operating in continuous conduction mode (CCM) operation are investigated. Based on the three-terminal switch device method, the average circuit model of the fractional order Buck–Boost converter is established, and the corresponding DC equivalent circuit model and AC small signal equivalent circuit model are presented. And then, the equilibrium point and the transfer functions are derived. It is found that the equilibrium point is not influenced by the inductor’s or the capacitor’s order, but both these orders are included in the derived transfer functions. Finally, the comparisons between the theoretical analysis and the PSIM simulations are given for confirmation.     

A generalized EMD with body prior for pedestrian identification

In this paper, we present a generalized Earth Mover’s Distance (EMD) for pedestrian identification with body prior. (i) The general configuration of body is a valuable cue for human identification. A model of body prior about the general configuration is pursued to describe body prior for every pedestrian. In addition, the spatial incompatibility is computed by Kullback–Leibler divergence according to the pursued model and embedded into the ground distance of EMD. (ii) Furthermore, we generalize EMD by assigning different weights to regions of body, which are learned based on maximum margin criterion to boost discriminative power for pedestrian identification. The experimental results show that the generalized EMD and body prior substantially improve performance on pedestrian identification and the proposed approach is comparable to the state-of-the-art performance.     

新型智能配电仪表(YJD-344)的研制

YJD-344是一种具有自动量程转换功能、测量精度高、实现组网方便、成本低的智能仪表。本仪表是基于ATT7022B这一计量芯片而研制的,硬件部分主要由电流、电压输入电路,电能处理模块,LCD显示电路,按键输入电路,开关电源电路,时钟电路,RS485串行通讯接口电路,2路开关量输出,2路开关量输入电路等几部分组成。整个系统软件部分主要有:主程序、数据采集子程序、键盘中断服务子程序、显示子程序、串行通讯子程序。通过实验测试,本系统设计合理,电流表、电压表、功率表数据误差满足设计要求。     

基于CS1000自动反吹系统提升焦炉煤气净化质量

本项目通过开发基于多重冗余CENTUMCS1000下的5、6#焦炉外送煤气管道自动反吹系统,设计自动控制方案,制定具体安全保障方案,实现对该系统各阀门状态,整个反吹过程,反吹设定时间等参数的操作监控,从而有效提升了焦炉煤气的质量,为莱钢的一线生产和节能降耗工作提供了极大的便利。并最终通过OPC完成CS1000与IFIX4.0之间的通讯,将自动反吹系统引至远程执行中心,实现远程控制。