Image reconstruction from acoustical holograms using microprocessors

An acoustic imaging system using holographic techniques is described. Insonification of the object is achieved using a phased array scanner. Image reconstruction uses Fourier Transformations to produce a 128 × 128 pixel TV display. The system has the ability to focus in the ‘near field’ of its transducer arrays and has a frame rate of approximately 0.3 Hz.     

散射参考光法制作真彩色全息图

本文提出了用散射参考光制作2D真彩色全息图的原理,按本原理制作的全息图比用散射物光法制作的图像清晰得多,并且使记录激光能量得到充分利用,特别适用于记录大幅面彩色全息图。     

Encrypted Books: Mysteries that Fill Hundreds of Pages

Abstract

The cryptology literature and other sources mention several dozen books that are entirely or partially encrypted. However, a systematic treatise about this issue has never been made. This article aims to close this gap. The author has assembled a list of encrypted books that contains 41 entries, so far. Based on this list, an overview on encrypted books is given. Encrypted books are classified according to criteria like purpose, solved/unsolved, encryption method, and creation time. Numerous open research questions are identified. Finally, it is a goal of this article to ask readers for additional information about the books on the list and for encrypted books that are still missing.     

基于网络编码的ECC验证方案在WSN中的研究

网络编码在无线传感器网络应用,改善了无线传感器网络的性能。虽然与之前相比,其安全性有所提高,但当面临安全攻击（被动攻击和主动攻击）时,整个网络系统的安全性仍然亟待提高。提出了一种改进方案,该方案结合密码学中椭圆曲线加密算法,并基于应用网络编码的无线传感器网络,采用加密验证方案。使传感器节点在电量受限的情况下,传输更多的有效数据。同时,增强了无线传感器网络节点之间通信的安全性,以及WSN其鲁棒性和容错性。     

E-beam lithography of computer generated holograms using a fully vectorial 3D beam propagation method

A fully vectorial 3D beam propagation method (BPM) has been applied to obtain a required pattern of computer generated hologram (CGH) with a variable profile of four phase levels. The computer reconstruction of the CGH image having one and two focal spots was performed by application of the fully vectorial 3D BPM method. After transferring the CGH by EBL technique an adequate phase profile was obtained. Inter-level parameter method was developed to obtain the estimated an electron beam dose required for the even topographical patterning. Using this method, an EBL exposure dose determined to achieve the required relief amplitude of 1.29 μm was 43 μC/cm². The manufactured holograms showed that the overall proposed production process, from the 3D BPM computer simulation to e-beam lithography, can be used to obtain good quality product with reasonable time and computational resources.     

红外遥控全息底片自动处理装置

本文介绍一种新型红外遥控 全息底片自动处理装置，该装置采用红外遥控，光电识别密度，微处理器控制，自动完全全息底暗室处理工艺过程。     

细菌视紫红质膜的实时读写特性研究

对细菌视紫红质（ＢＲ）膜作为实时全息介质的读写特性作了理论和实验研究，分析了两种读出模式：连续读出模式和脉冲读出模式。结果表明连续读出模式的强度很小，而脉冲读出模式可以实现高强度的读出。对脉冲读出的技术要求作了理论上的探讨     

IP2DM: integrated privacy‐preserving data management architecture for smart grid V2G networks

With the development of battery vehicles, vehicle‐to‐grid (V2G) networks are becoming more and more important in smart grid. Although battery vehicles are environmentally friendly and flexible to use two‐way communication and two‐way electricity flow, they also raise privacy‐preservation challenges, such as location and movement privacy. On the one hand, utility companies have to monitor the grid and analyze user data to control the power production, distribution, scheduling, and billing process, while typical users need to access their data later online. On the other hand, users are not willing to provide their personal data because they do not trust the system security of the utility companies where their data stored, and it may potentially expose their privacy. Therefore, in this paper, we study data management of V2G networks in smart grid with privacy‐preservation to benefit both the customers and the utility companies. Both data aggregation and data publication of V2G networks are protected in the proposed architecture. To check its security, we analyze this architecture in several typical V2G networks attacks. We conduct several experiments to show that the proposed architecture is effective and efficient, and it can enhance user privacy protection while providing enough information for utility companies to analyze and monitor the grid. Copyright © 2016 John Wiley & Sons, Ltd.     

高精度石英全息透镜的MEMS工艺制作

通过微电子机械技术(MEMS)在抛光的熔融石英基材表面制作了平面精度达到0.4μm的超大单片面积的全息透镜。采用了分辨率达到0.2μm的步进投影式拼接光刻,适合石英基材的专用等离子耦合刻蚀(ICP)干法刻蚀技术,特殊的物理清洗方法,以及相关的多项辅助工艺。透镜理想面形横截面曲线为分段抛物线,每一片由23个柱状结构单元周期横向排列构成,采用等深度不等宽度的4台阶结构拟合,单元宽度约为2.966mm。在4in(10.16cm)圆片上,获得了单片尺寸为68mm×68mm的方形透镜。采用接触式台阶仪,扫描电子显微镜(SEM),高倍光学显微镜等方法进行不同阶段检测。结果显示:台阶平面精度为0.4μm,垂直精度为30nm,有非常好的立墙陡直度和刻蚀均匀性。此工艺方案可实现小规模批量生产,成本适中,可以直接用于制作6in(15.24cm)以上同等级要求的石英透镜,经适当改进也可用于蓝宝石等基底材料的制作。     

后处理中重铬酸铵浓度对MBG全息图衍射效率的影响

研究了后处理中重铬酸铵浓度对单纯亚甲蓝敏化的明胶（ＭＢＧ）全息图衍射效率的影响，比较了有铅和无铬两种不同后处理法所得曝光板红外与紫外可见吸收光谱图，未发现明显差异．对ＭＢＧ作了Ｘ射线能谱分析，并在此实验结果的基础上讨论了全息图形成的机理。