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61.
数字版权保护技术已经成为网络电视中除了视频编码技术以外的又一项核心技术。它用于保护内容所有人的版权,控制客户对于内容的使用。文章在阐述OMADRM标准的基础上,提出了一种适应国内广电系统实际播控环境的TS制式节目的DRM解决方案,并根据自行开发的演示系统,就其加密效率加以论证。 相似文献
62.
63.
Wei Hong Jinxiong Zhou Zhigang Suo 《Journal of the mechanics and physics of solids》2008,56(5):1779-1793
A large quantity of small molecules may migrate into a network of long polymers, causing the network to swell, forming an aggregate known as a polymeric gel. This paper formulates a theory of the coupled mass transport and large deformation. The free energy of the gel results from two molecular processes: stretching the network and mixing the network with the small molecules. Both the small molecules and the long polymers are taken to be incompressible, a constraint that we enforce by using a Lagrange multiplier, which coincides with the osmosis pressure or the swelling stress. The gel can undergo large deformation of two modes. The first mode results from the fast process of local rearrangement of molecules, allowing the gel to change shape but not volume. The second mode results from the slow process of long-range migration of the small molecules, allowing the gel to change both shape and volume. We assume that the local rearrangement is instantaneous, and model the long-range migration by assuming that the small molecules diffuse inside the gel. The theory is illustrated with a layer of a gel constrained in its plane and subject to a weight in the normal direction. We also predict the scaling behavior of a gel under a conical indenter. 相似文献
64.
Yanqing Tian Xiaohe Xu Yingying Zhao Xinyi Tang Fengyu Su Xiaoguang Zhao Enle Zhou 《Liquid crystals》1995,19(3):295-300
The synthesis of three new series of chiral Schiff's bases containing benzilideneaniline and 2-hydroxybenzilideneaniline moieties as mesogenic cores is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements were used to study the phase transition temperatures and behaviour. The results reveal that most of these materials show chiral smectic mesomorphism. 相似文献
65.
本文根据实地考察内容,结合宽带网络技术和业务重点及实施策略,全面介绍了日本关西宽带实验网发展背景,通信与广播电视综合应用实验和B-ISDN实用化实验的进展以及NTT所起作用。文章最后就关西宽带实验网的借鉴意义提出了几方面意见。 相似文献
66.
67.
Yubin Gong Yuanlong Mo Yongdong Zhou Xiaolan Zhou 《Journal of Infrared, Millimeter and Terahertz Waves》1996,17(4):769-777
A new type of mm-wave slow wave system, double staggered ladder circuit is analyzed in this paper, by means of “average cavity field method” and three-dimensional finite element method. The influence of the electron beam channel on the dispersion characteristics is discussed. An experimental research is made, the experimental results agree well with the theoretical one. 相似文献
68.
本文根据光传输理论导出介导消光系数,折射率与介质电磁参数,光波频率,电偶极子浓度及迁移率等的关系,分析了光激发与增加气敏介质的氧吸附的规律,结合实验说明气敏薄膜的光学变化机制。 相似文献
69.
Kun-Jie Wang Zu-Cheng Zhou Yan Yao 《Electronics letters》1998,34(15):1468-1469
A new nonlinear filter structure, the minimum redundant nonlinear filter (MRNF), for combating narrowband interference in direct sequence spread spectrum systems is proposed. Analytical expressions for the signal-to-noise ratio improvement factors are derived under the condition of single tone interference. The results show that the MRNF provides significantly better performance than the minimum redundant transversal filter 相似文献
70.
A molecular dynamics method has been used to simulate the argon ion-assisted deposition of Cu/Co/Cu multilayers and to explore ion beam assistance strategies that can be used during or after the growth of each layer to control interfacial structures. A low-argon ion energy of 5–10 eV was found to minimize a combination of interfacial roughness and interlayer mixing (alloying) during the ion-assisted deposition of multilayers. However, complete flattening with simultaneous ion assistance could not be achieved without some mixing between the layers when a constant ion energy approach was used. It was found that multilayers with lower interfacial roughness and intermixing could be grown either by modulating the ion energy during the growth of each metal layer or by utilizing ion assistance only after the completion of each layers deposition. In these latter approaches, relatively high-energy ions could be used since the interface is buried and less susceptible to intermixing. The interlayer mixing dependence upon the thickness of the over layer has been determined as a function of ion energy. 相似文献