Crystallization of Poly(ethylene adipate) within γ-Phase Poly(vinylidene fluoride) Matrix

The effects of PEA on the γ-phase PVDF crystal structure and the crystallization of PEA within the pre-existing γ-phase PVDF spherulites have been investigated by optical microscopy(OM), infrared spectroscopy(IR) and scanning electron microscopy(SEM). The results demonstrate that the γ-phase PVDF spherulites consist of the lamellae exhibiting a highly curved scroll-like morphology and develop preferentially in PEA-rich blend. With increasing PEA concentration, the scroll diameter increases and the scrolls are better separated from each other. PEA crystallizes first in the interspherulitic region and transcrystalline layer develops. Subsequently, the transcrystalline layer of PEA continues to grow within the γ-phase PVDF spherulites, e.g., in the region between the scrolls, until impinging on other PEA transcrystalline layers or spherulites. The crystallization kinetics results indicate that the growth rate of PEA crystals in the intraspherulitic region of γ-phase PVDF shows a positive correlation with content of PEA, but a negative one with the crystallization temperature of γ-phase PVDF.     

Mass and isotopic concentrations of water-insoluble refractory carbon in total suspended particulates at Mt.Waliguan Observatory(China)

Mass concentration and isotopic values δ¹³C and ¹⁴C are presented for the water-insoluble refractory carbon（WIRC） component of total suspended particulates（TSP）,collected weekly during 2003,as well as from October 2005 to May 2006 at the WMO-GAW Mt.Waliguan（WLG） site.The overall average WIRC mass concentration was（1183±120）ng/m³（n = 79）,while seasonal averages were 2081 ±1707（spring）,454±205（summer）,650±411（autumn）,and 1019±703（winter） ng/m3.Seasonal variations in WIRC mass concentrations were consistent with black carbon measurements from an aethalometer,although WIRC concentrations were typically higher,especially in winter and spring.The δ¹³C PDB value（-25.3 ± 0.8）%.determined for WIRC suggests that its sources are C₃ biomass or fossil fuel combustion.No seasonal change in δ¹³C PDB was evident.The average percent Modern Carbon（pMC） for ¹⁴C in WIRC for winter and spring was（67.2 ± 7.7）%（n = 29）.Lower pMC values were associated with air masses transported from the area east of WLG,while higher pMC values were associated with air masses from the Tibetan Plateau,southwest of WLG.Elevated pMC values with abnormally high mass concentrations of TSP and WIRC were measured during a dust storm event.     

基于单片机的数据采集系统设计

随着经济的发展和社会的进步,人们对物质生活与精神生活的要求也日益提高,对生产、生活场所的条件也越来越要求方便、舒适、高效、安全以及环保节能,这些需求极大地促进电子电气产品的更新换代,不断催生高效、快捷的数据采集工具的诞生。文章对基于单片机的数据采集系统的设计进行了分析。     

基于关键路径延时检测的自适应电压缩减技术

为了减小传统的最差情况设计方法引入的电压裕量,提出了一种变化可知的自适应电压缩减(AVS)技术,通过调整电源电压来降低电路功耗.自适应电压缩减技术基于检测关键路径的延时变化,基于此设计了一款预错误原位延时检测电路,可以检测关键路径延时并输出预错误信号,进而控制单元可根据反馈回的预错误信号的个数调整系统电压.本芯片采用SMIC180 nm工艺设计验证,仿真分析表明,采用自适应电压缩减技术后,4个目标验证电路分别节省功耗12.4％,11.3％,10.4％和11.6％.     

基于RRPP技术的以太网组网应用

本文阐述了一种基于RRPP技术的环网拓扑传输系统及传输方法,主要适用于以太网的环网保护应用。该传输方法为:所述环网拓扑的结构包括一个汇聚节点和所述汇聚节点下带的多个环网,所述汇聚节点由若干台汇聚设备构成,所述传输方法通过IFR2(第二代智能弹性架构技术)将所述若干台汇聚设备虚拟化为一个设备,即虚拟化设备。在不降低双汇聚设备可靠性的前提下,简化了网络架构,确保了业务的快速倒换,提高了网络的可靠性。     

基于多分辨率GPS层析技术的电离层暴时LSTID特征研究

利用GPS电离层层析技术探测电离层已经有了数十年的发展，特别在电离层暴时有着独特的优势.文章基于一种多分辨率层析算法，并结合美国东西部地区部分GPS地面数据对2015年3月16日-17日出现的电离层暴进行重构.首先，借助独立的测高仪数据验证多分辨率层析技术对电子密度反演的精度结果，同时也证实了电离层暴时多分辨率层析算法的适用性.其次，通过对美国东部地区2015年3月17日磁扰动最强烈时段的电离层重构，检验由磁暴引起的大尺度电离层行扰（large-scale travelling ionospheric disturbance，LSTID）的存在，并利用总电子含量（total electron content，TEC）数据分析此次电离层行扰的水平特征.同时，通过与非相干散射雷达（incoherent scatter radar，ISR）观测值的对比，借助反演得到的电子密度剖面信息讨论电离层行扰在垂向上的特征.结果表明:此次LSTID的波长为1 200 km左右，周期为50~60 min，以350~400 m/s的波速向西南方向传播，并且电离层行扰（travelling ionospheric disturbance，TID）的垂向电子密度具有较可靠的精度.     

Modeling Impact of ROADM Intra-Node Add/Drop Contention on a Single Node Lightpath Blocking Performance

We propose an analytical model to evaluate the lightpath blocking performance for a single ROADM node with intra-node add/drop contention,in which the number of lightpaths that can be added/dropped with the same wavelength is limited by the add/drop contention factor.Different models of traffic load per nodal degree are considered to validate the effectiveness of the analytical model.The simulation results show that the proposed analytical model is effective in predicting the performance for different values of add/drop contention factor C and for variable offered loads at the node.The add/drop contention factor shows an important impact on the lightpath blocking performance and properly raising the contention factor can significantly improve the lightpath blocking performance.When the add/drop contention factor C exceeds a certain level,the performance of a ROADM with intra-node contention is close to that of a contentionless ROADM.     

向您推荐《液晶与显示》——中文核心期刊

《液晶与显示》是中国最早创办的液晶学科专业期刊,也是中国惟一的液晶学科和显示技术领域中综合性专业学术期刊。它由中国科学院长春光学精密机械与物理研究所、中国光学光电子行业协会液晶专业分会和中国物理学会液晶分会主办,科学出版社出版。《液晶与显示》以研究报告、研究快报、综合评述和产品信息等栏目集中报道国内外液晶学科和显示技术领域中最新理论研究、科研成果和创新技术,及时反映国内外本学科领域及产业信息动态,是宣传、展示我国该学科领域和产业科技创新实力与硕果,进行国际交流的平台。本刊是英国《科学文摘》     

美国CES消费电子展中,LCD、PDP、LCoS等电视市场划分渐显

新型数字显示器技术的发展 ,使得显像 (ＣＲＴ)电视逐渐出局的态势愈见明显 ,在日前美国ＣＥＳ消费电子展中 ,从等离子电视 (ＰＤＰ)、液晶电视 (ＬＣＤＴＶ)、到数字光源处理 (ＤＬＰ)与ＬＣｏＳ等投影电视大放异彩 ,欲争夺新一代电视产品的主流地位。尤其数字电视亟力走向大尺寸化 ,价格逐步走低 ,展出规模更甚以往 ,而日商在此次展览中相当积极 ,更显示出了日本家电厂商欲进军美国电视机市场的企图心。在液晶电视方面 ,厂商均极力朝大尺寸方向走 ,较具代表性的如Ｓａｍｓｕｎｇ推出 4 6英寸与 5 4英寸 (192 0× 10 80 )ＬＣＤＴＶ ,为参…