使用EEG分析水平视差对3D图像舒适性的影响

水平视差是影响3D 图像舒适性的重要因素之一。采用不同等级水平视差的3D 图像作为刺激信号,通过记录被试者的EEG 反应信号,提取出被试者观看不同等级水平视差3D 图像的ERP 波形;同时记录被试观看这一系列3D 图像舒适性体验的行为数据,并计算其舒适性检测率。通过EEG信号分析可见,无论在交叉或者非交叉水平视差情况下,3D 图像水平视差舒适范围在45'以内;水平视差在45'~75'时,交叉视差3D 图像ERP 波形280 ms 附近的幅值与不舒适的程度相关,非交叉视差3D 图像ERP 波形250 ms 附近的幅值与不舒适程度相关;检测率曲线结果和主观评价结果显示:3D图像水平视差的舒适性范围在45'以内,水平视差在45'~75'时,3D 图像不舒适程度随着视差的增加而增大。结果表明:EEG 分析、检测率曲线和主观评价结论一致,因此,可以使用EEG 分析水平视差对3D 图像舒适性的影响。     

单壁碳纳米管和W针尖热处理时残气质谱

分别对W针尖上未组装和组装单壁纳米管理进行热处理,然后对所得残气质谱图进行记录和分析,发现在热处理过程中,脱附出一定量的原子C和原子O,然后结合成为CO和CO2被释放出来。     

Performance analysis and code optimization of low densityparity-check codes on Rayleigh fading channels

A numerical method has been presented to determine the noise thresholds of low density parity-check (LDPC) codes that employ the message passing decoding algorithm on the additive white Gaussian noise (AWGN) channel. In this paper, we apply the technique to the uncorrelated flat Rayleigh fading channel. Using a nonlinear code optimization technique, we optimize irregular LDPC codes for such a channel. The thresholds of the optimized irregular LDPC codes are very close to the Shannon limit for this channel. For example, at rate one-half, the optimized irregular LDPC code has a threshold only 0.07 dB away from the capacity of the channel. Furthermore, we compare simulated performance of the optimized irregular LDPC codes and turbo codes on a land mobile channel, and the results indicate that at a block size of 3072, irregular LDPC codes can outperform turbo codes over a wide range of mobile speeds     

Lead-free solder flip chip-on-laminate assembly and reliability

This paper examines the assembly process for flip chip die with SnAgCu solder bumps and the results of liquid-to-liquid thermal shock testing. The SnAgCu alloy required a thicker dip layer of flux to achieve good wetting compared to the SnPb eutectic alloy. A liquid spray flux yielded more consistent solder wetting with the SnAgCu alloy. With both fluxes, a nitrogen reflow atmosphere was necessary with the SnAgCu alloy. A peak reflow temperature of 246°C was used for the assembly of the SnAgCu thermal shock test vehicles. A lower peak temperature of 235°C did not yield sufficient solder wetting. Liquid-to-liquid thermal shock testing was performed from -40°C to +125°C. The SnPb alloy performed slightly better than the SnAgCu and the dip flux was better that the spray flux. The degree of delamination with the SnAgCu alloy was significantly higher than with the SnPb alloy. Cracks in the underfill between adjacent solder balls were observed. The SnPb alloy extruded into these cracks more readily than the SnAgCu and created electrical shorts     

Surface Oxygen Coordination of Hydrogen Bond Chemistry for Aqueous Ammonium Ion Hybrid Supercapacitor

Aqueous ammonium ion hybrid supercapacitor (A-HSC) combines the charge storage mechanisms of surface adsorption and bulk intercalation, making it a low-cost, safe, and sustainable energy storage candidate. However, its development is hindered by the low capacity and unclear charge storage fundamentals. Here, the strategy of phosphate ion-assisted surface functionalization is used to increase the ammonium ion storage capacity of an α-MoO₃ electrode. Moreover, the understanding of charge storage mechanisms via structural characterization, electrochemical analysis, and theoretical calculation is advanced. It is shown that NH₄⁺ intercalation into layered α-MoO₃ is not dominant in the A-HSC system; rather, the charge storage mainly depends on the adsorption energy of surface “O” to NH₄⁺. It is further revealed that the hydrogen bond chemistry of the coordination between “O” of surface phosphate ion and NH₄⁺ is the reason for the capacity increase of MoO₃. This study not only advances the basic understanding of rechargeable aqueous A-HSC but also demonstrates the promising future of surface engineering strategies for energy storage devices.     

航天发射场推进剂环境污染治理技术研究

环境保护和污染控制是建设生态型发射场的重要组成部分.分析了中国航天发射场的环境污染,针对推进剂四氧化二氮泄漏提出了采用钙基高活性粉剂处理技术,介绍了研制的系列处理装置,提出了臭氧-紫外光-活性炭联合工艺处理推进剂废水和高温燃烧处理推进剂废气废液技术,研制了移动式处理装置,解决了常规液体推进剂的发射环境污染难题,为航天发...     

基于终端的感知技术浅析

简单介绍了智能管道的产生背景,对智能管道的多维感知技术进行了详细分析,从终端入手研究了基于终端可实现的智能管道感知技术,并提出了相应的解决方案,指出基于终端的感知技术解决方案将助推智能管道的实现,最后分析了基于终端的智能管道感知技术解决方案在实现上面临的困难和挑战,为智能管道技术的进一步研究及其实际部署进行了有益探索.     

运营商播种农村市场

转型是电信运营商在新形势下的必然战略选择，开创蓝海则是该战略中的一个方向。对于我国的电信运营商们来说，农村市场拥有着巨大的潜力，他们都纷纷将其作为未来的工作重点之一。在大的战略方向明确之后，运营商们的重点也逐渐在向具体工作的执行方面转移，近日出现的“沙盘”概念似乎也在验证着这样一种趋势。当然，运营商们并不会仅限于这种纸上谈兵式的模拟，他们的农村市场开拓工作已经在进行中了。     

超大规模集成电路快速热处理技术

本文介绍了快速热处理技术的研究成果.包括:RHT设备,高剂量注入硅的RTA机理与最佳RTA条件选择,以及浅PN结制造,硅化物形成,BPSG回流和薄氧化层的快速氮化等RTP技术.     

GaAs半导体中三光子吸收的非线性光电导测量

采用非线性光电导技术测量2.06μm激光激发的GaAs本征半导体三光子吸收,观察到三光子和单光子吸收的混合光电导,测得了三光子吸收系数.测量结果与理论计算符合较好.