下一代无线业务对运营管理及计费模式的影响

下一代无线业务在帮助服务提供商创新业务模式和增强盈利能力方面发挥着十分重要的作用、而无线通信技术的推陈出新不仅为服务提供商创新收益模式提供了良好的运营环境，而且还将使运管商现有的业务运营方式得到根本性的改观。为此，服务提供商需要对运营领域中的一系列关键问题给予高度的重视。除此之外．运营商还应充分认识到在下一代无线数据业务运营中多种计费模式的并存这一主流发展趋势并根据用户的需求及时采纳和制定各种灵活的计统费模式。     

In-situ sonosynthesis of cobblestone-like ZnO nanoparticles on cotton/polyester fabric improving photo,bio and sonocatalytic activities along with low toxicity and enhanced mechanical properties

For the first time in this study, in-situ sonosynthesis and deposition of ZnO nanoparticles under ultrasound irradiation was used to prepare multifunctional cotton/polyester fabric. The process was carried out at 80 ^°C in ultrasonic bath and was free from final heating of fabrics to convert zinc hydroxide to zinc oxide nanoparticles. This was due to the physical and chemical effects of ultrasound promoting the involved reactions and facilitating the nucleation and growth of ZnO nanoparticles. Central composite design was also used to statistically analyze the process, optimizing the applied condition including zinc precursor concentration, pH and the effect of dispersing agent namely cetyltrimethylammonium bromide surfactant (CTAB). The treated samples were further characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDX). Photocatalytic activities of the treated samples were assessed based on the ability of fabrics to degrade Methylene Blue dye stain under sunlight irradiation. The effect of synthesis parameters on photocatalytic activities (self-cleaning) was statistically optimized. Moreover, for evaluating the sonocatalytic efficiencies of the samples Reactive Blue 2 was applied and the activities were studied by visible spectroscopy. The cotton/polyester samples possessed multifunctional properties including self-cleaning, sonocatalytic, antibacterial, antifungal, low cytotoxicity and enhanced mechanical properties.     

移动智能终端技术产业发展要素

移动智能终端作为移动互联网的发展载体,已经进入了快速发展期,移动智能终端引领的技术变革和产业模式创新已成为我国重要的历史性机遇。为推动我国移动智能终端产业实现跨越发展,文章对移动智能终端生态系统、操作系统、芯片、产业链四个要素进行研究,揭示其基本规律,并给出促进产业发展的若干建议。     

Boosting Piezo-Catalytic Activity of KNN-Based Materials with Phase Boundary and Defect Engineering

Although the piezo-catalysis is promising for the environmental remediation and biomedicine, the piezo-catalytic properties of various piezoelectric materials are limited by low carrier concentrations and mobility, and rapid electron-hole pair recombination, and reported regulating strategies are quite complex and difficult. Herein, a new and simple strategy, integrating phase boundary engineering and defect engineering, to boost the piezo-catalytic activity of potassium sodium niobate ((K, Na)NbO₃, KNN) based materials is innovatively proposed. Tur strategy is validated by exampling 0.96(K_0.48Na_0.52)Nb_0.955Sb_0.045O₃-0.04(Bi_xNa_4-3x)_0.5ZrO₃-0.3%Fe₂O₃ material having phase boundary engineering and conducted the defect engineering via the high-energy sand-grinding. A high reaction rate constant k of 92.49 × 10⁻³ min⁻¹ in the sand-grinding sample is obtained, which is 2.40 times than that of non-sand-grinding one and superior to those of other representative lead-free perovskite piezoelectric materials. Meanwhile, the sand-grinding sample has remarkable bactericidal properties against Escherichia coli and Staphylococcus aureus. Superior piezo-catalytic activities originate from the enhanced electron-hole pair separation and the increased carrier concentration. This study provides a novel method for improving the piezo-catalytic activities of lead-free piezoelectric materials and holds great promise for harnessing natural energy and disease treatment.     

固－液两相流中的一种湍流模式

定义了体积分数速度，并由此建立了固－液两相流中的一种湍流模式（Ｋ─ε双方程模式），模化了动量方程、Ｋ方程及ε方程。本模型中，考虑了相间的速度滑移，颗粒间的作用及相间作用，对一管湍流中固－液混合物流动的预测表示与实验结果比较一致。     

一款应用于脑活动探测的宽带天线系统设计

为利用微波传输法对大脑活动进行探测,提出了一款应用于大脑活动探测的宽带天线.该天线单元为微带单极子天线,由开槽矩形宽缝、三角形贴片极子和反射板构成,采用微带线馈电,直接与人体头组织介质匹配,经过仿真优化,该天线-10 dB回波损耗带宽覆盖了工作频率范围2.3~8 GHz.并仿真分析了大脑内的电磁能量传输特性及电场分布,结果显示介质匹配天线相比普通天线在头颅内具有更好的穿透能力,在大脑皮层和深部脑区仍存在较强的电场强度.最后对此宽带天线进行了加工测试,实测数据与仿真结果基本吻合.该天线单元尺寸小、结构简单、易加工,能够很好地满足微波传输法探测大脑活动技术中头部共形天线阵列的设计要求.     

红外成像系统性能模型的研究进展

综述了国内外红外成像系统性能模型的状况。在分析静态性能模型和动态性能模型的基础上，分别给出了其基本构想，阐述了几种静态性能模型的优缺点，讨论了动态性能模型的三种模块；目标背景模块，图像处理算法模块和目标工作平台模块。介绍了它们在预测现场性能的应用。展望了性能模型的发展趋势。     

基于双流-非局部时空残差卷积神经网络的人体行为识别

3维卷积神经网络(3D CNN)与双流卷积神经网络(two-stream CNN)是视频中人体行为识别研究的常用架构,且各有优势。该文旨在研究结合两种架构且复杂度低、识别精度高的人体行为识别模型。具体地,该文提出基于通道剪枝的双流-非局部时空残差卷积神经网络(TPNLST-ResCNN),该网络采用双流架构,分别在时间流子网络和空间流子网络采用时空残差卷积神经网络(ST-ResCNN),并采用均值融合算法融合两个子网络的识别结果。进一步地,为了降低网络的复杂度,该文提出了针对时空残差卷积神经网络的通道剪枝方案,在实现模型压缩的同时,可基本保持模型的识别精度;为了使得压缩后网络能更好地学习到输入视频中人体行为变化的长距离时空依赖关系,提高网络的识别精度,该文提出在剪枝后网络的首个残差型时空卷积块前引入一个非局部模块。实验结果表明,该文提出的人体行为识别模型在公共数据集UCF101和HMDB51上的识别准确率分别为98.33%和74.63%。与现有方法相比,该文模型具有参数量小、识别精度高的优点。     

机械设备故障规律及运行趋势预测方法综述

对于机械设备的故障运行问题,技术人员应当深入研究机械设备的故障规律,并研究出运行趋势的预测方法,从传感器的检测时间间隔与使用数量等方面加以深入的研究.本文介绍了机械设备运行状态的故障预测方法,并将机械设备运行状态的故障预测方法总结为三个步骤,分别是数据获取、处理与设备寿命预测,结合这些内容,提出了关于机械设备故障运行的...     

宏蜂窝基站与分布式基站3G建网成本对比分析

对传统的室内宏蜂窝基站与新型的分布式基站在3G建网成本上进行了详细的分析，并给出了不同应用场景下的成本对比.