陶瓷加工中的激光技术应用研究

工程陶瓷作为２１世纪的三大应用材料之一，其有效的加工方法已成为国内外专家学者探索的热点。而激光技术由于是非接触式加工，没有切削力，加工速度快，能加工一些特殊型面等优点，在陶瓷的加工方面得到了一定的应用，并取得了一定的进展。本文介绍了应用激光技术加工陶瓷和激光技术在陶瓷磨削中的辅助应用，并阐述了各种技术的基本原理和加工质量评价，同时展望各种激光技术在陶瓷加工中的发展趋势。尽早开发应用于陶瓷加工的各种激光新技术，对推动陶瓷的应用发展和激光技术的发展应用都有着深远的意义。     

智慧建筑能源物联网冷热输送管网优化研究

在前期研究工作中,作者提出基于天然气基分布式能源系统智慧建筑能源物联网(NDES-SG)概念以及框架,而本文则重点对NDES-SG中,冷热输送管网能量耗散关键影响因素—保温层优化设计展开研究。本文以冷热物流管网输配为研究对象,研究冷热物流输送管道保温层厚度与输送距离(供冷、热半径)的协同关系,以及选取不同保温材料时,管网经济特性规律。分析结果表明,任意一种保温材料在一定约束条件下,冷热输配管网存在保温厚度与供能半径最优协同关系,即"二者协同最优"拐点值。在NDES-SG中,基于天然气基的分布式产能系统及大中型蓄能系统的位置布点、物联网总能系统效率与输送管网的损失密切相关,因此此研究成果将为智慧建筑能源物联网的冷热电管网输配优化设计以及产能系统和蓄能系统容量的选择和布点的研究提供了理论指导与研究思路。     

固态照明/显示用荧光陶瓷研究进展EI北大核心CSCD

固态照明作为第四代照明光源因其高效、环保的优势在近30年来得到了飞速发展,广泛应用于各种场景(例如汽车大灯、投影显示、工业生产和远距离照明)。而大功率、高亮度的白色发光二极管(W-LED)及激光照明技术对颜色转换材料的服役稳定性提出了新的要求,荧光陶瓷以其能承受高功率激发密度的独特优势应运而生。本文综合评述了固态照明/显示用荧光陶瓷的最新研究进展,阐明了光源的评估标准,总结了白光及几种单色发光荧光陶瓷在大功率照明和投影显示领域的发展和应用。并阐述了荧光陶瓷中光提取效率、显色指数(CRI)和相关色温(CCT)的提升策略,讨论了激光照明中的发光饱和与发光均匀性问题。最后对荧光陶瓷在固态照明/显示应用中的前景和挑战进行了展望。     

固态照明/显示用荧光陶瓷研究进展

固态照明作为第四代照明光源因其高效、环保的优势在近30年来得到了飞速发展,广泛应用于各种场景(例如汽车大灯、投影显示、工业生产和远距离照明)。而大功率、高亮度的白色发光二极管(W-LED)及激光照明技术对颜色转换材料的服役稳定性提出了新的要求,荧光陶瓷以其能承受高功率激发密度的独特优势应运而生。本文综合评述了固态照明/显示用荧光陶瓷的最新研究进展,阐明了光源的评估标准,总结了白光及几种单色发光荧光陶瓷在大功率照明和投影显示领域的发展和应用。并阐述了荧光陶瓷中光提取效率、显色指数(CRI)和相关色温(CCT)的提升策略,讨论了激光照明中的发光饱和与发光均匀性问题。最后对荧光陶瓷在固态照明/显示应用中的前景和挑战进行了展望。     

基于物联网的高效安全快递自取系统设计与实现

针对物流行业投送环节存在的“最后一公里”问题,设计并实现了一种基于物联网的高效安全快递自取系统。该系统综合利用物联网、嵌入式、传感器、GPRS等技术,快递自取箱终端以嵌入式微处理器S3C6410为主控器,实现扫码自主存件、短信自动通知客户、验证码校验自助取件、异常邮件处理以及紧急报警等功能,经过测试,该系统在实际环境中运行稳定,能够高效、安全、快捷的完成投送,可广泛布设于小区、单位等公共场所,具有十分广阔的市场应用价值。     

OBS网络中光缓存冲突配置解决方案研究

本文分别对RFID系统和EPC物联网的结构及工作原理进行分析,以某企业案例作为实例进行分析,以一批产品从生产线到分销商的物流周期对比测算了FRID系统和原流程系统的主要环节耗时、货物处理完成率、标签识别率等方面的数据,结果RFID系统表现出较大的优势。     

面向智慧城市的物联网基础设施关键技术研究

智慧城市是利用物联网等新一代信息技术实现城市智慧运行和管理的新型城市形态,是信息技术与城市发展深度融合的产物。针对当前智慧城市因碎片化、烟囱式发展模式而面临的重复建设严重、跨域资源难以共享与联动协同等突出问题,从资源汇聚和促进城市应用互联互通互操作的角度,定义了城市物联网基础设施的概念内涵,提出城市物联网基础设施是一个涵盖“网络 平台 服务”的综合体,分析总结了国内外政府与企业在城市物联网基础设施尤其是物联网平台方面的发展现状,在此基础上,研究提出了为实现城市物联资源泛在接入、网络融合、资源管理和智能服务等核心功能亟需突破的关键技术,最后给出了推动城市物联网基础设施快速发展的意见和建议。     

云平台分布式智能感知物联网应用开发

在全面分析物联网应用开发复杂性的基础上,探讨了使用全新异步非阻塞的服务器平台Node.js用于开发物联网的优点。在开源框架Zetta基础上提出了各种物联网设备的基于Node.js的统一模型法,并将物联网与云平台集成开发新型物联网应用的有益探索和运用。     

高功率激光装备小型化轻量化技术

自激光器问世以来,激光在各领域的需求和应用非常广泛,而随着高功率激光装备输出功率不断提高,重量与体积已成为制约高功率激光装备应用与发展的关键问题之一。由于当前高功率激光装备仍将提高输出功率作为其发展目标,加之高功率激光装备结构功能复杂、能量转换效率低等特点,制约了高功率激光装备小型化、轻量化的实现。本文在介绍高功率激光装备的特点及其小型化、轻量化技术约束的基础上,综述了装备常用小型化、轻量化技术应用、新型高功率激光技术应用、提高能量转换效率及散热效率等高功率激光装备小型化、轻量化实现途径,以及各种技术途径在高功率激光装备中已有的应用。根据高功率激光装备现状及特点,其在小型化、轻量化方面具有很大的发展空间及应用前景。     

湿度传感器的可靠性研究

本文详细分析了湿敏陶瓷的微观结构和感湿机理,阐述了引起陶瓷湿敏元件性能漂移的因素和机理。     

Fundamentals of Multiferroic Materials and Their Possible Applications

Materials science is recognized as one of the main factors driving development and economic growth. Since the silicon industrial revolution of the 1950s, research and developments in materials and solid state science have radically impacted and transformed our society by enabling the emergence of the computer technologies, wireless communications, Internet, digital data storage, and widespread consumer electronics. Today's emergent topics in solid state physics, such as nano-materials, graphene and carbon nano-tubes, smart and advanced functional materials, spintronic materials, bio-materials, and multiferroic materials, promise to deliver a new wave of technological advances and economic impact, comparable to the silicon industrial revolution of the 1950s.

The surge of interest in multiferroic materials over the past 15 years has been driven by their fascinating physical properties and huge potential for technological applications. This article addresses some of the fundamental aspects of solid-state multiferroic materials, followed by the detailed presentation of the latest and most interesting proposed applications of these multifunctional solid-state compounds. The applications presented here are critically discussed in the context of the state-of-the-art and current scientific challenges. They are highly interdisciplinary covering a wide range of topics and technologies including sensors, microwave devices, energy harvesting, photo-voltaic technologies, solid-state refrigeration, data storage recording technologies, and random access multi-state memories. According to their potential and expected impact, it is estimated that multiferroic technologies could soon reach multibillion US dollar market value.     

面向物联网的Sybil入侵防御系统设计与实现

设计物联网中的Sybil入侵防御系统,进行入侵检测,保障物联网的网络安全,针对当前入侵防御系统拦截准确性不好的问题,提出基于网络入侵信号检测和前馈调制滤波设计的物联网Sybil入侵防御系统设计方法;首先进行Sybil入侵防御系统总体设计描述和功能分析,然后进行Sybil入侵信号检测算法设计,最后完成面向物联网的Sybil入侵防御系统硬件设计和软件开发,实现系统的集成设计;仿真测试表明,采用该系统进行物联网中的Sybil入侵检测的准确度较高,性能较好,具有较强的兼容性和友好性。     

物联网环境下的差异网络数据库异常数据检测

当前的物联网环境下,各个智能网络的数据库的使用没有统一标准,不同生产商的数据库中的异常数据标准也不同,这就使得传统的以模式识别为基础的网络数据库异常检测方法在进行异常阀值设置时,无法形成统一标准,数据库数据量庞大且存在无序性,无法保证检测的准确性和检测效率。提出基于混沌特征分析算法的物联网环境下的差异网络数据库异常数据检测方法。依据混沌特征分析相关理论构建物联网环境下的差异网络数据库模型,构建一种异常数据的偏差函数,对不同数据库下的异常数据进行偏差统计,通过对偏差函数的统计结果进行最小值求解,根据求解描述最小化的阀值请求,实现物联网环境下的差异网络数据库异常数据的检测。实验结果表明,利用改进算法进行异常数据检测,能够提高检测的有效性与准确性。     

Photonic Integrated Circuits for Cost-Effective,High Port Density,and Higher Capacity Optical Communications Systems

Abstract

Bandwidth-hungry services, such as higher speed Internet, voice over IP (VoIP), and IPTV, allow people to exchange and store huge amounts of data among worldwide locations. In the age of global communications, domestic users, companies, and organizations around the world generate new contents making bandwidth needs grow exponentially, along with the need for new services. These bandwidth and connectivity demands represent a concern for operators who require innovative technologies to be ready for scaling. To respond efficiently to these demands, Alcatel-Lucent is fast moving toward photonic integration circuits technologies as the key to address best performances at the lowest “bit per second” cost. This article describes Alcatel-Lucent's contribution in strategic directions or achievements, as well as possible new developments.     

Laser processing integrated into machine tools — design,applications, economy

In the last few years, lasers have found new applications in production engineering as tools for surface treatment, cutting, welding, drilling and marking. So far, the laser has mainly been used in special laser processing machines (laser-only) directly integrated into a production line or serving as stand-alone stations in the workshop. By combining conventional metal cutting technologies with laser processes in one machine, complete processing of a workpiece with different technologies in one setting can be realized. The main advantages are a reduction of the material flow between the production machines, which leads to a reduction in processing time and logistics, and an enhancement of manufacturing quality due to the processing in one setting. In addition to this approach, new processing technologies such as laser-assisted machining are possible.Applications of laser caving, hardening, welding and drilling of production parts in combination with the cutting process in one setting have been investigated with the aim of adapting these technologies to the characteristics of the machines and the typical parts spectra. Furthermore, various technical solutions for the integration of lasers into milling centres and lathes have been elaborated. In both situations the laser tool is handled like a standard tool and can be exchanged automatically. The main results will be reported, together with a brief discussion of the economic aspects of laser processing integrated into machine tools.This article is based on an invited paper presented at LANE '94, Erlangen, 12–14 October 1994.     

基于串口转WiFi的物联网终端远程控制实现方法

随着物联网技术的高速发展,对同一无线局域网内的设备进行控制时,存在传输距离短、可移动性差等缺点。针对此问题,提出了一种物联网终端远程控制的实现方法,采用串口转WiFi模块,通过Socket模式下的透传机制,传统的串口设备能够无线接入到互网络中基于MQTT消息传输协议的服务器上,完成数据的接收和发送,从而使终端设备突破无线通信距离的限制,达到数据交互和远程控制的目的。实验结果表明该方法正确、可靠,可广泛应用于智能家居、工业控制等领域。     

Rumsfeld hadrons

A missing link in the Standard Model is understanding hadrons, particles that respond to the strong interactions. In this article I summarise our knowledge in three classes, which are reminiscent of Donald Rumsfeld's (in)famous: ‘things that we know we know; things that we know we don't know; and things that we don't know that we don't know'. Recent discoveries in particle physics concerning strongly interacting hadrons fall into those categories. It is of course the third category that is the most tantalising, but lessons from the first two may help resolve the third.     

Lightweight authentication scheme for massive MIMO on Internet of Things connectivity

Massive MIMO is an essential technology in developing 5G networks and a concept that may be applied to other wireless systems. However, the advantages of adopting massive MIMO for broadband communication are well-established. Recently researcher has been devoted to building communication systems sustaining high communication rates with security. While massive MIMO for Internet-of-Things (IoT) connectivity is still a developing issue, IoT connectivity has requirements and limitations that differ significantly from broadband connections. Although IoT makes people’s lives easier by allowing physical devices to flow through, the interaction of open wireless channels such as Bluetooth, ZigBee, LoRa, Narrowband-Internet of Things (NBIoT), and WiFi, has produced various security and privacy difficulties. Identity authentication is one of the effective solutions for addressing the Internet of Things security and privacy concerns. The typical point-to-point authentication technique ignores the internet of things’ massive number of nodes and limited node resources. Group authentication is an authentication method that simultaneously confirms the identity of a group of members, offering a novel approach to identity identification for the internet of things nodes. However, existing group authentication systems appropriate for the internet of things scenarios pose security issues. They cannot withstand malicious attacks such as forging and replay and cannot prevent group managers from fooling group members. Most existing group authentication schemes are computationally expensive and cannot be applied to resource-constrained IoT scenarios. At the same time, existing systems based on secret-sharing technology cannot resist forgery attacks and replay attacks. The attacker can forge a legal token by modifying the Lagrangian coefficient in the authentication token to pass the group authentication. This work employs verifiable secret sharing technology to create a lightweight verifiable group authentication method (L-IoT-GS) suitable for Internet of Things situations to resist group managers’ deceptive group behavior. Nodes in the Internet of Things scenario can frequently join and leave the network. Because of this, this article proposes a critical update link based on a verified group authentication system for updating group Member rights. According to security analysis, the suggested L-IoT-GS scheme meets accuracy and confidentiality requirements and can withstand malicious attacks such as replay, forgery, and impersonation. Furthermore, performance study and experimental simulation reveal that the L-IoT-GS technique minimizes group members’ computing costs compared to existing standard IoT group authentication schemes.