New binary one-generator quasi-cyclic codes

Sixteen new binary quasi-cyclic linear codes improving the best known lower bounds on minimum distance in Brouwer's tables are constructed. The parameters of these codes are [102, 26, 32], [102, 27, 30], [142, 35, 40], [142, 36, 38] [146, 36, 40], [170, 16, 72], [170, 20, 66], [170, 33, 52] [170, 36, 50], [178, 33, 56], [178, 34, 54], [182, 27, 64] [182, 36, 56], [186, 17, 76], [210, 23, 80], [254, 22, 102] Sixty cyclic and thirty quasi-cyclic codes, which attain the respective bounds in Brouwer's table and are not included in Chen's table are presented as well.     

Short-pulse Calorimetric Load for High Power Millimeter-wave Beams

A spherical compact matched load, for high vacuum operation suited for short pulses (2 MW, 0.1 s) precise measurement has been designed to test high power gyrotrons Bruschi, Gandini, Muzzini, Spinicchia, Cirant, Gittini, Granucci, Mellera, Nardone, Simonetto, and Sozzi (Fusion Eng. Des. 56–57:649–654, 2001); Bruschi, Cirant, Gandini, Granucci, Mellera, Muzzini, Nardone, Simonetto, Sozzi, and Spinicchia (Nucl. Fusion 43:1513–1519, 2003); Bruschi, Cirant, Gandini, Gittini, Granucci, Mellera, Muzzini, Nardone, Simonetto, Sozzi, Spinicchia, Angella, and Signorelli (Development of CW and short-pulse calorimetric loads for high power millimeter-wave Beams, 23rd Symposium on Fusion Technology, September 20–24, 2004, Venice, Italy). In order to enhance the power handling capability of the load and to reduce the operation problems that may arise from an excessive reflection from the load, a ray tracing code has been written to model the power distribution on the inner surface and the pattern of the reflected radiation. The outcome of this code has been used to select a more convenient profile for the spreading mirror of the load and to optimize a pre-load specially conceived to minimize the power reflected fraction.     

最新一代系统节电器的综合介绍——G4 Speed Uni Saver

本文较全面地介绍系统节电器，包括生产，趋势，污染后果，浪涌型式，性能，特点，原理，应用场合，参数，各代区别，第四代的优点，装置方式，功率确定，动能区别，系统框图，使用结论等。     

Theoretical foundations of transform coding

Discusses various aspects of transform coding, including: source coding, constrained source coding, the standard theoretical model for transform coding, entropy codes, Huffman codes, quantizers, uniform quantization, bit allocation, optimal transforms, transforms visualization, partition cell shapes, autoregressive sources, transform optimization, synthesis transform optimization, orthogonality and independence, and departures form the standard model     

基于ASP.NET的网络选课系统的设计与实现

本设计为基于Dotnet技术开发的网络选课系统,引入学分制和竞分制的概念。提供学生、教师、管理员三个角色登陆系统。实现了学生选课、退课、竞买选课、查看成绩,查看选课结果,查看个人信息、课程信息、教室信息;教师查看教学计划,录入成绩;管理员维护学生、教师、课程、教室信息,设置系统状态等功能。在课程上进行了较细的分类,主要分为专业选修课、专业必修课、公共选修课、公共必修课。该系统具有操作简便,功能强大,可扩展性好等特点。为学生,教师,管理员提供简单快捷的选课工作环境。     

Elemental Compositions of Over 80 Cell Phones

Over the last few years, 85 cell phones have been disassembled, ground up, dissolved, and analyzed for elemental content, mainly for information about the metals present in the phones, but also for some metalloids and nonmetals. The following list of 38 elements were detected in some or all of the phones: Be, B, Mg, Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Y, Nb, Pd, Ag, In, Sn, Sb, Te, Ba, Ta, W, Pt, Au, Tl, Pb, Bi, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er. Cadmium was never detected. This paper discusses the methods used for carrying out the analysis, proposes possible sources in the telephones for the elements of interest, the reasons for the interest in most of the elements, and method repeatability.     

第七届电子封装技术国际会议(通知)

自1994年以来,两年一届的电了封装技术国际会议(ICEPT)分别在中国北京、上海和深圳等地顺利召 开。作为唯一同中国政府,权威机构,业内主导所组织和支持的电子封装技术会议,每届都吸引了大批的国内 外高校、研究机构、封装组装制造厂商、封装测试组装设备厂商、封装组装材料厂商踊跃参加,人数每次都超 过400位,包括来自近20个国家和地区的国外专家、学者和企业家等。会议议题主要集中在封装设计、封装 制造、封装测试、以及光电了封装、MEMS封装、系统及组装等领域。这是唯一由中国政府和相关业界发起 的国内最高水平、最大规模的关于电…     

视频监控标准化最新进展

关注视频监控主流国际及国内标准化组织工作，分析了ITU-T、ONVIF、IEC、ISO、PSIA、HDcctv、IEEE、3GPP、ETSI、TC100、CCSA、AVS、全国信息技术标准化技术委员会等主要标准组织的视频监控相关标准化工作进展，介绍了视频监控系统、架构、设备、编解码、安全、智能应用、大数据应用、云存储、云计算、边缘存储、边缘计算等标准化研究最新进展。在此基础上，探讨了视频监控未来的产品研发方向和标准化内容，给出了视频监控标准化路线图，提出了未来的视频监控标准化及预研方向及建议。     

三网融合产业链重构与整合

三网融合产业链是由内容提供商、网络运营商、集成服务商、设备制造商、用户等构成的具有价值增值功能的企业联盟,产业链具有立体网状、竞争合作、开放多元、相互关联的特点,三网融合产业链要加强横向、纵向和混合多元整合,建立基于规模经济、范围经济和网络经济的可竞争性市场,促进三网融合稳步发展,提高信息化服务水平。     

面向企业协作服务的新型业务架构探索与实践

系统基于自研自容器微服务架构,通过自定义轻量化协议实现终端两省一低(省电、省流量、低功耗)平台三高一低(高扩展性、高负载、高可用、低资源消耗),以办公型即时通讯录、企业融合通信、企业办公协同为基础,实现办公的移动化、平台化、社交化、业务化,全面提升员工效率,充分释放组织潜能.     

谈对电子元器件企业设计开发过程中“六性”的审核

通过对电子元器件企业＂可靠性、维修性、保障性、测试性、安全性和环境适应性＂的审核,帮助企业识别＂可靠性、维修性、保障性、测试性、安全性和环境适应性＂,认识＂可靠性、维修性、保障性、测试性、安全性和环境适应性＂在产品设计开发中的重要性,实现产品的＂可靠性、维修性、保障性、测试性、安全性和环境适应性＂指标。     

电台发射台改进设计

针对电台发射台搬迁对发射台的建立做出了改进设计,发射台播出体系由拉线塔、中波发射机、音频切换和监控、光缆、数字微波、UPS、发电机组、综合布线和安全监控、测试仪器、卫星地面站、调频发射塔、调频发射机、天馈系统、应急直播室等14部分组成.     

稀土元素对KNdP_4O_(12)激光晶体的影响

用蒸发溶液法从磷酸溶液中生长出14种KNd_(0.9)Ln_(0.1)P_4O_(12)晶体(其中Ln=La、Ce、Pr、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu或Y)。测定了它们的晶体结构、红外光谱、吸收光谱、荧光光谱和荧光寿命,计算了晶格常数,观察到掺入Ln~(3+)后对KNdP_4O_(12)晶体的影响。     

A Progress Report on Metal–Sulfur Batteries

Nonaqueous conversion‐reaction sulfur chemistry has been attracting increasing attention over the past decade for the development of next‐generation lithium‐based batteries. Li–S batteries are currently approaching a nexus stage from lab‐scale experiments to possible pragmatic applications. Inspired by the success of Li–S chemistry, other metal–sulfur batteries with a variety of metallic anodes, such as sodium, potassium, magnesium, calcium, and aluminum, have also started to attract attention. In comparison to lithium, Na, Mg, Al, K, and Ca are naturally more abundant and affordable. The Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S battery systems provide a great potential for improving the volumetric energy density of sulfur‐based batteries. The multivalent metal‐sulfur systems, Mg‐S, Al‐S, and Ca‐S, offer better safety features as well. However, the research and development on Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S batteries is far behind the Li–S system due to many critical challenges. In this progress report, the fundamental principles of various metal–sulfur chemistries are first presented and compared. Then, the historical progress, recent advances, and key challenges of the Li–S, Na‐S, Mg‐S, Al‐S, K‐S, and Ca‐S systems are summarized and discussed. Finally, future efforts and directions for both the fundamental and practical research are prospected.     

STOP, GO, and the state of the art in proposal writing

It is shown that the state of the art in proposal preparation makes available a wide array of techniques and devices to help make the proposal compliant, clear, convincing, and appealing. The techniques discussed are modular format, topical outlining, topic thesis sentences, required figures for topics, graphics oriented (GO) charts, figure enrichment, expanded figure titles, phrased topic titles, action topic titles, key issues visuals and lead topics, topic level storyboards, group wall review of storyboards, proposal manager's win strategy worksheets and customer's requirements worksheets, section level win strategy worksheets, compliance control system and worksheets, and early red team reviewing. In particular, the Sequential Topical Organization of Proposals (STOP) system, which introduced the modular format and topical storyboarding, is described     

Flash存储器技术与发展

Flash存储器是在20世纪80年代末逐渐发展起来的一种新型半导体不挥发性存储器，它具有结构简单、高密度、低成本、高可靠性和系统的电可擦除性等优点，是当今半导体存储器市场中发展最为迅速的一种存储器。文章对Flash存储器的发展历史和工作机理、单元结构与阵列结构、可靠性、世界发展的现状和未来趋势等进行了深入的探讨。     

A review of high-power switch technology

The basic operation and some of the performance parameters and limitations of various high-power switches with potential for rep-rated operation are summarized. The specific switches included are: thyratrons, ingitrons, liquid metal plasma valve, crossed field tube, vacuum tube, spark gaps (gas, liquid, vacuum, and solid), thyristors, transistors, mechanical switches, vacuum arc opening switch, electron-beam switches, dielectric surface discharge switches, thermally driven opening switches, and superconducting switches.     

On the undetected error probability of nonlinear binary constantweight codes

The undetected error probability (UEP) of binary (n, 2δ, m) nonlinear constant weight codes over the binary symmetric channel (BSC) is investigated, where n is the blocklength, m is the weight of codeword and 2δ is the minimum distance of the codes. The distance distribution of the (n, 2, m) nonlinear constant weight codes is evaluated. It is proven in this paper that the (5, 2, 2) code, (5, 2, 3) code, (6, 2, 3) code, (7, 2, 4) code, (7, 2, 3) code and (8, 2, 4) code are the only proper error-detecting codes in the (n, 2, m) nonlinear constant weight codes for n⩾5, in the sense that their UEP is increased monotonically with the channel error rate p, of course all these proper codes are m-out-of-n codes. Furthermore, it is conjectured that except for the cases of n⩽4δ, there are no proper error-detecting binary (n, 2δ, m) nonlinear constant weight codes, for n>8 and δ⩾1     

电台的安全播出保障体系设计

针对电台安全播出保障体系,对包括直播室、总控、网络、传输、电源、卫星、音频工作站、录音棚、直播车、保障记录数据库在内的10个部分进行了改进设计。     

大数据环境下的网络安全分析

随着计算机技术和互联网技术的发展,数据正以指数速度迅速膨胀,海量的数据包括敏感数据、隐私数据等。大数据网络安全是一个综合性的课题,涉及技术、管理、使用等许多方面。本文介绍了大数据的国内外发展现状;分析了大数据的网络安全,包括物理安全、数据内容安全、数据传播安全、数据管理安全等;并讨论了大数据网络安全的防护措施,包括访问控制、数据加密、网络隔离、入侵检测、病毒防治、安全审计、数据备份、增强安全意识等;最后展望了大数据网络安全的情景。