美国规范风荷载浅析及计算

美国规范作为世界主流标准之一,被越来越多的涉外工程所要求采用.以算例为基础,针对美国建筑最小荷载规范ASCE/SEI 7-05中的风荷载进行分析和研究,以期对采用美国规范的涉外工程有所帮助.     

High‐efficiency black silicon interdigitated back contacted solar cells on p‐type and n‐type c‐Si substrates

This work demonstrates the high potential of Al₂O₃ passivated black silicon in high‐efficiency interdigitated back contacted (IBC) solar cells by reducing surface reflectance without jeopardizing surface passivation. Very low reflectance values, below 0.7% in the 300–1000 nm wavelength range, together with striking surface recombination velocities values of 17 and 5 cm/s on p‐type and n‐type crystalline silicon substrates, respectively, are reached. The simultaneous fulfillment of requirements, low reflectance and low surface recombination, paves the way for the fabrication of high‐efficiency IBC Si solar cells using black silicon at their front surface. Outstanding photovoltaic efficiencies over 22% have been achieved both in p‐type and n‐type 9‐cm² cells. 3D simulations suggest that efficiencies of up to 24% can be obtained in the future with minor modifications in the baseline fabrication process. Copyright © 2015 John Wiley & Sons, Ltd.     

南京电视台十运会传输系统方案设计介绍

从十运会传输方案总体要求、传输系统方案设计遵循标准．典型光传输设备基本原理．十运会传输系统的设计四方面，洋细介绍了南京电视台十运会传输系统方案设计情况。     

Opto‐electrical modelling and optimization study of a novel IBC c‐Si solar cell

Interdigitated back contact (IBC) crystalline silicon (c‐Si) solar cells are attracting a lot of attention because of their capability to reach world record conversion efficiency. Because of the relatively complex contact pattern, their design and optimization typically require advanced numerical simulation tools. In this work, a TCAD‐based simulation platform has been developed to account accurately and in detail the optical and passivation mechanisms of front texturization. Its validation has been carried out with respect to a novel homo‐junction IBC c‐Si solar cell based on ion implantation and epitaxial growth, comparing measured and simulated reflectance, transmittance, internal quantum efficiency, external quantum efficiency spectra, and current density–voltage characteristics. As a result of the calibration process, the opto‐electrical losses of the investigated device have been identified quantitatively and qualitatively. Then, an optimization study about the optimal front surface field (FSF) doping, front‐side texturing morphology, and rear side geometry has been performed. The proposed simulation platform can be potentially deployed to model other solar cell architectures than homo‐junction IBC devices (e.g., passivated emitter rear cell, passivated emitter rear locally diffused cell, hetero‐IBC cell). Simulation results show that a not‐smoothed pyramid‐textured front interface and an optimal FSF doping are mandatory to minimize both the optical and the recombination losses in the considered IBC cell and, consequently, to maximize the conversion efficiency. Similarly, it has been showed that recombination losses are affected more by the doping profile rather than the surface smoothing. Moreover, the performed investigation reveals that the optimal FSF doping is almost independent from the front texturing morphology and FSF passivation quality. According to this result, it has been demonstrated that an IBC cell featuring an optimal FSF doping does not exhibit a significant efficiency improvement when the FSF passivation quality strongly improves, proving that IBC cell designs based on low‐doped FSF require a very outstanding passivation quality to be competitive. Deploying an optimization algorithm, the adoption of an optimized rear side geometry can potentially lead to an efficiency improvement of about 1%_abs as compared with the reference IBC solar cell. Further, by improving both emitter and c‐Si bulk quality, a 22.84% efficient solar cell for 280‐μm thick c‐Si bulk was simulated. Copyright © 2017 John Wiley & Sons, Ltd.     

添加剂颜料纤维在干粉砂浆生产线中的自动计量

目前,具有竞争力的工业规模运转的预拌干粉砂浆生产线几乎完全实现自动化,能够在砂浆主材和添加剂种类日益增加的情况下,满足更高的标准和质量要求.为使制定的要求与效率协调一致,工艺处理也必须作相应的改进.因此,在先进的现代化设备中,添加剂和颜料以中型散装容器(IBC)的形式交付,并通过专门防灰尘的上料站自动传输.着重介绍在预拌干粉砂浆生产过程中,添加剂和颜料的自动计量情况.     

基于身份的TLS协议及其BAN逻辑分析

基于身份的密码体制(IBC)轻量、高效,密钥管理方式简单,但缺乏有效安全协议的支持限制了其应用。通过增加支持IBC的加密套件,引入IBC公钥代替RSA证书公钥,减少消息交换数量,提出支持IBC的、高效的基于身份的IB_TLS协议。使用BAN逻辑对其进行形式化分析,证明IB_TLS协议是安全的。     

基于身份的密码学算法研究

为解决在有限资源下大量数字证书的管理问题,基于身份的密码学通过公钥密码仅由身份信息计算产生简化了公钥密码管理,该技术可以作为传统公开密钥基础设施的扩展安全机制以增加其便携性。     

网格环境下基于身份的跨域认证研究

在网格安全标准中,实体问的跨域身份认证采用基于证书的公钥基础设施认证框架,证书的管理过于复杂,限制了网格规模的扩大。针对上述问题,在分析网格安全需求的基础上,引入基于身份的密码体制,提出一种跨域签密方案,以解决使用不同系统参数的虚拟组织问相互认证的问题,并对其安全性和性能进行分析。     

O2O应用中二维码的混合认证服务系统

二维码作为一种信息载体,可以实现电子商务应用的线上与线下（O2O）并行互动,为消费者带来更便捷和快速的消费体验。但是,二维码不能有效应对移动互联网环境下的信息泄露、信息篡改、身份认证、抵赖性等安全挑战。文章针对二维码信息容量有限,无法在其中嵌入传统PKI体系的数字证书及证书链的问题,提出了一种结合PKI与IBC密码体制的技术方案,按照预先定义的规则为已持有数字证书的用户生成IBC密钥对,充分利用IBC密码体制中公钥信息量较少的优势。文章设计了密钥对申请及发放的协议流程,以及使用IBC密钥对来完成数字签名及验证的过程,同时借助数字证书的状态来判断用户是否有效,满足在O2O应用过程中的安全需求。该技术方案实现了在已建立PKI体系的场合下完成IBC密钥对的分发,有效解决了二维码在O2O应用中电子标签数据的认证问题,并且建立了基于数字证书的IBC数字签名信任链,满足数据传输的机密性、用户身份识别、信任关系的建立等安全目标,尤其适用于信息容量受到限制的二维码类型。     

Efficient identity-based signature scheme with batch authentication for delay tolerant mobile sensor network

Identity-based cryptography （IBC） has drawn a lot of attentions in delay tolerant environment. However, the high computational cost of IBC becomes the most critical issue in delay tolerant mobile sensor network （DTMSN） because of the limited processing power. In this paper, an efficient identify-based signature scheme with batch authentication （ISBA） is proposed for DTMSN. ISBA designs an online/offline signature with batch authentication to reduce the computational cost, and improves data delivery mechanism to increase the number of messages for each batch authentication. Simulation results show that ISBA not only realizes a lower computational cost than existed schemes, but also does not induce negative impact on the delivery performance.