安全服务器的一种实现方案

随着Internet的迅猛发展,Internet上的安全性日益受到重视,而进口到中国的WWW服务器安全性和加密强度均受到限制.因此,文中介绍了一种基于Apache实现的安全服务器,用自主的密码算法替代弱化的国外密码算法.     

基于ARM11的嵌入式Web网络监控系统设计

介绍了以基于最新ARM11体系结构的S3C6410处理器为核心的嵌入式Web网络监控系统的相关理论与可行性,并且以此为基础给出了一种创新的基于S3C6410处理器实现嵌入式Web网络图像与视频传输系统的解决方案.该方案首先论述了选择ARM11处理器的原因,并且重点介绍了采用S3C6410的优势,简要介绍了各种相关的集成...     

An explicit method for construction of CTBC codes with girth 6

A cylinder-type block-circulant (CTBC) code with circulant permutation matrix (CPM) size p is presented by a binary base matrix with a cylindrical structure and a slope-vector on ${\mathbb{Z}}_p$. The slope-vector is called proper if the corresponding CTBC code is 4-cycle free. In this paper, an algorithm is presented that for a given base matrix with a cylindrical structure, explicitly generates a proper slope-vector. This proper slope-vector provides a lower-bound on the CPM-sizes of the corresponding CTBC codes required to achieve girth at least 6. Interestingly, the lower bound, minimum distance and 6-cycle multiplicity of the constructed CTBC codes are better than some masked and unmasked known explicitly constructed 4-cycle free QC LDPC codes with the same regularity. Simulation results show that the constructed CTBC codes outperform some 4-cycle free QC LDPC codes in binary and nonbinary cases.     

MSM原理及其在直线驱动器上的应用

磁控形状记忆合金（MSM）是一种新型功能材料，具有形变量大和机电能量转换效率高的特点。该文首先介绍了MSM在磁场作用下的形变机理，并测得在0．4T的磁场下其自由形变率可达3．6％。然后分析利用仿生学蠕动原理将MSM小步距的位移累加形成直线驱动器所需要的大行程的工作原理，设计出了MSM直线驱动器及其控制系统，最后给出了样机的实验结果。     

Link 11数据链干扰技术

从Link11数据链的数学模型入手，分析其在噪声干扰、单音干扰、多音干扰等下的误码性能。仿真结论表明，对Link11的干扰技术中，不论采用噪声干扰，或者是采用单音或多音干扰，只要掌握其工作原理，就可以采取适当方式对其进行干扰。从另一方面可以看出，Link11由于易损性等原因，已经暴露了许多不尽人意的缺点，一种新型的数据链——Link22产生，并对其特点作了简单分析。     

结构化P2P网络综述

结构化P2P网络使用分布式哈希表（DHT）技术将数据映射到相应的节点，以便在数据的存放与查找方面有很好的扩展性，同时P2P网络的路由表的容量和链路长度之间存在渐进曲线的关系。首先介绍现有的P2P网络拓扑类型，然后对基于DHT的结构化P2P网络进行了详细的分析比较。     

LINK11_SLEW信号的非协同解调

根据LINK11_SLEW信号的波形协议和帧结构,先对复杂信道下的LINK11_SLEW信号进行一次模拟解调,再采用相关同步算法、重构前导序列测频算法、平均自适应滤波的信道均衡( AFA)算法和最佳采样点鉴相解扰算法进行二次解调,理论推导和计算仿真表明,复杂信道下采用常规解调方式无法有效解调的 LINK11_SLEW 信号,采用新算法解调星座图在10符号之内达到收敛,在Eb/N0高于12 dB的情况下,解调误码率小于10-3。     

投影光刻机中PDP-11主控制计算机系统的替换

介绍了针对早期的投影光刻机存在PDP-11计算机速度慢,控制系统难操作的问题,利用普通PC机通过GPIB卡替换了PDP-11计算机,使用VB语言编写的程序替换了主控制系统程序。     

802.11b收发系统中的全集成低功耗发送机设计

基于SMIC 0.18μm CMOS工艺,设计了一个应用于IEEE 802.11b收发系统的全集成低功耗发送机.直接转换发送机包括两个Chebyshev Ⅰ型低通滤波器,两个可编程增益放大器(PGA),一个单边带混频器和一个功率预放大器.发送机以3dB为步长提供32dB增益,其最大输出功耗为-3.4dBm,EVM为6.8%.工作在1.8V电源电压,发送机的功耗仅57.6mW.发送机芯片面积为1.6mm×1.6mm.     

Nido-Hydroborate-Based Electrolytes for All-Solid-State Lithium Batteries

Hydroborate-based solid electrolytes have recently been successfully employed in high voltage, room temperature all-solid-state sodium batteries. The transfer to analogous lithium systems has failed up to now due to the lower conductivity of the corresponding lithium compounds and their high cost. Here LiB₁₁H₁₄ nido-hydroborate as a cost-effective building block and its high-purity synthesis is introduced. The crystal structures of anhydrous LiB₁₁H₁₄ as well as of LiB₁₁H₁₄-based mixed-anion solid electrolytes are solved and high ionic conductivities of 1.1 × 10⁻⁴ S cm⁻¹ for Li₂(B₁₁H₁₄)(CB₁₁H₁₂) and 1.1 × 10⁻³ S cm⁻¹ for Li₃(B₁₁H₁₄)(CB₉H₁₀)₂ are obtained, respectively. LiB₁₁H₁₄ exhibits an oxidative stability limit of 2.6 V versus Li⁺/Li and the proposed decomposition products are discussed based on density functional theory calculations. Strategies are discussed to improve the stability of these compounds by modifying the chemical structure of the nido-hydroborate cage. Galvanostatic cycling in symmetric cells with two lithium metal electrodes shows a small overpotential increase from 22.5 to 30 mV after 620 h (up to 0.5 mAh cm⁻²), demonstrating that the electrolyte is compatible with metallic anodes. Finally, the Li₂(B₁₁H₁₄)(CB₁₁H₁₂)  electrolyte is employed in a proof-of-concept half cell with a TiS₂ cathode with a capacity retention of 82% after 150 cycles at C/5.