CD 媒体不仅将人类带进数字音响时代,而且也为促进视频、音频技术的结合创造了条件,可以说以 CD 媒体为基础的数字视听产品的问世是存储媒体上的一场革命。目前,人们在关注 CD 媒体发展的典型产品——VCD 时,第二代 VCD 即字数视盘——D...CD 媒体不仅将人类带进数字音响时代,而且也为促进视频、音频技术的结合创造了条件,可以说以 CD 媒体为基础的数字视听产品的问世是存储媒体上的一场革命。目前,人们在关注 CD 媒体发展的典型产品——VCD 时,第二代 VCD 即字数视盘——DVD(Digital Video Disc)已经出现。VCD 采用了 MPEG—Ⅰ视频和音频编码方式,在直径为120mm 的盘片上存储74分钟的活动图像及声音。PAL 制标准规定,其清晰度为352(V)×288(H)。从效果上看,水平分解力在300线以下,比广播电视(480线)、LD(580—展开更多
飞机电视系统哈里斯公司设计出一种专用天线和分配系统。该系统可以使飞机上的乘客能够观看到实况卫星电视广播。这项电视技术是该公司国防与空间部的研究成果。该系统可以把美国 Direc TV 台的20多个频道的电视节目传送到飞机上,供机...飞机电视系统哈里斯公司设计出一种专用天线和分配系统。该系统可以使飞机上的乘客能够观看到实况卫星电视广播。这项电视技术是该公司国防与空间部的研究成果。该系统可以把美国 Direc TV 台的20多个频道的电视节目传送到飞机上,供机上的乘客选择收看。哈里斯的天线同时能够接收到 Direc TV 台卫星传送的各种信号。展开更多
With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its u...With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its utilities in a number of academic and real environments.There are a wide range of solutions to provide image watermarking frameworks,while each one of them is attempted to address an efficient and applicable idea.In reality,the traditional techniques do not have sufficient merit to realize an accurate application.Due to the fact that the main idea behind the approach is organized based on contourlet representation,the only state-of-the-art materials that are investigated along with an integration of the aforementioned contourlet representation in line with watermarking framework are concentrated to be able to propose the novel and skilled technique.In a word,the main process of the proposed robust watermarking framework is organized to deal with both new embedding and de-embedding processes in the area of contourlet transform to generate watermarked image and the corresponding extracted logo image with high accuracy.In fact,the motivation of the approach is that the suggested complexity can be of novelty,which consists of the contourlet representation,the embedding and the corresponding de-embedding modules and the performance monitoring including an analysis of the watermarked image as well as the extracted logo image.There is also a scrambling module that is working in association with levels-directions decomposition in contourlet embedding mechanism,while a decision maker system is designed to deal with the appropriate number of sub-bands to be embedded in the presence of a series of simulated attacks.The required performance is tangibly considered through an integration of the peak signal-to-noise ratio and the structural similarity indices that are related to watermarked image.And the bit error rate and the normal correlation are considered that are related to the extracted logo analysis,as well.Subsequently,the outcomes are fully analyzed to be competitive with respect to the potential techniques in the image colour models including hue or tint in terms of their shade,saturation or amount of gray and their brightness via value or luminance and also hue,saturation and intensity representations,as long as the performance of the whole of channels are concentrated to be presented.The performance monitoring outcomes indicate that the proposed framework is of significance to be verified.展开更多
The selective precipitation of zinc from zinc-nickel sulfate solution with the Zn/Ni molar ratio of20:1was studied.Dropwise addition of0.5mol/L NaOH solution into the zinc-nickel sulfate solution containing0,0.01,0.02...The selective precipitation of zinc from zinc-nickel sulfate solution with the Zn/Ni molar ratio of20:1was studied.Dropwise addition of0.5mol/L NaOH solution into the zinc-nickel sulfate solution containing0,0.01,0.02,0.03and0.04mol/L ethylene diamine tetraacetate(EDTA)as a chelating agent was done.The equilibrium analysis of precipitation pathway was performed using Visual MINTEQ program.The equilibrium analysis showed that the presence of small amounts of EDTA can prevent nickel precipitation in alkaline conditions without any negative effect on zinc precipitation.On this basis,more than90%of zinc could be precipitated as a product with about50%Zn and only0.11%Ni at pH=9.0merely as a result of the presence of0.03mol/L EDTA in the solution.The stirring time of120min after precipitation was found to be essential for more complete separation.The X-ray diffraction studies on the precipitate revealed that the precipitated phase was Zn4(OH)6SO4.4H2O.展开更多
文摘CD 媒体不仅将人类带进数字音响时代,而且也为促进视频、音频技术的结合创造了条件,可以说以 CD 媒体为基础的数字视听产品的问世是存储媒体上的一场革命。目前,人们在关注 CD 媒体发展的典型产品——VCD 时,第二代 VCD 即字数视盘——DVD(Digital Video Disc)已经出现。VCD 采用了 MPEG—Ⅰ视频和音频编码方式,在直径为120mm 的盘片上存储74分钟的活动图像及声音。PAL 制标准规定,其清晰度为352(V)×288(H)。从效果上看,水平分解力在300线以下,比广播电视(480线)、LD(580—
文摘飞机电视系统哈里斯公司设计出一种专用天线和分配系统。该系统可以使飞机上的乘客能够观看到实况卫星电视广播。这项电视技术是该公司国防与空间部的研究成果。该系统可以把美国 Direc TV 台的20多个频道的电视节目传送到飞机上,供机上的乘客选择收看。哈里斯的天线同时能够接收到 Direc TV 台卫星传送的各种信号。
文摘With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its utilities in a number of academic and real environments.There are a wide range of solutions to provide image watermarking frameworks,while each one of them is attempted to address an efficient and applicable idea.In reality,the traditional techniques do not have sufficient merit to realize an accurate application.Due to the fact that the main idea behind the approach is organized based on contourlet representation,the only state-of-the-art materials that are investigated along with an integration of the aforementioned contourlet representation in line with watermarking framework are concentrated to be able to propose the novel and skilled technique.In a word,the main process of the proposed robust watermarking framework is organized to deal with both new embedding and de-embedding processes in the area of contourlet transform to generate watermarked image and the corresponding extracted logo image with high accuracy.In fact,the motivation of the approach is that the suggested complexity can be of novelty,which consists of the contourlet representation,the embedding and the corresponding de-embedding modules and the performance monitoring including an analysis of the watermarked image as well as the extracted logo image.There is also a scrambling module that is working in association with levels-directions decomposition in contourlet embedding mechanism,while a decision maker system is designed to deal with the appropriate number of sub-bands to be embedded in the presence of a series of simulated attacks.The required performance is tangibly considered through an integration of the peak signal-to-noise ratio and the structural similarity indices that are related to watermarked image.And the bit error rate and the normal correlation are considered that are related to the extracted logo analysis,as well.Subsequently,the outcomes are fully analyzed to be competitive with respect to the potential techniques in the image colour models including hue or tint in terms of their shade,saturation or amount of gray and their brightness via value or luminance and also hue,saturation and intensity representations,as long as the performance of the whole of channels are concentrated to be presented.The performance monitoring outcomes indicate that the proposed framework is of significance to be verified.
文摘The selective precipitation of zinc from zinc-nickel sulfate solution with the Zn/Ni molar ratio of20:1was studied.Dropwise addition of0.5mol/L NaOH solution into the zinc-nickel sulfate solution containing0,0.01,0.02,0.03and0.04mol/L ethylene diamine tetraacetate(EDTA)as a chelating agent was done.The equilibrium analysis of precipitation pathway was performed using Visual MINTEQ program.The equilibrium analysis showed that the presence of small amounts of EDTA can prevent nickel precipitation in alkaline conditions without any negative effect on zinc precipitation.On this basis,more than90%of zinc could be precipitated as a product with about50%Zn and only0.11%Ni at pH=9.0merely as a result of the presence of0.03mol/L EDTA in the solution.The stirring time of120min after precipitation was found to be essential for more complete separation.The X-ray diffraction studies on the precipitate revealed that the precipitated phase was Zn4(OH)6SO4.4H2O.
