A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by F...A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by FT IR, UV Vis, as well as TG DTA measurement. The results showed that this type of system had different properties in solution and in thin films. ESR spectra g values for the one electron blues were the characteristic of tetragonal W 5+ complex in aqueous solution and thin films. The formation of a radical signal of ESR spectra indicated that polyacrylamide was a proton donor, the reversibility for photochromism was relative to the presence and diffusion of oxygen in polymeric network.展开更多
A pendant drop tensiometry apparatus aided by video-image digitization technology was established, by which static interface or surface tension of some liquids was measured with satisfactory results.In order to study ...A pendant drop tensiometry apparatus aided by video-image digitization technology was established, by which static interface or surface tension of some liquids was measured with satisfactory results.In order to study the effect of emulsifier concentration on emulsion stability, dynamic interfacial tension was measured between toluene and water against concentration of Tween 60(Polyoxyethylene(20) stearyl-sorbitanate). As expected, higher concentration is the Tween 60 solution in toluene injected into the toluene phase, faster falls the interface tension between toluene and water.Furthermore, it reveals interestingly that two steps of diffusion occur in the system, i.e ., at low and high concentration, after the surfactant solution is injected.The characteristic process of dynamic interface tension can be ascribed to diffusion control because of linearity between interface tension and the minus second root of aging time.The discovery is correlated to the fact that much higher concentration of surfactant above its critical micelle concentration is often required when a stable emulsion is planned to prepare.展开更多
研究了多通道分布式主动噪声控制(Distributed Active Noise Control,ANC)系统的空间平滑问题.传统的分布式ANC算法通过本地控制器之间的通信,可以大大提高系统稳定性.但由于每组控制器和误差麦克风分布位置不同,引入的估计偏差影响系...研究了多通道分布式主动噪声控制(Distributed Active Noise Control,ANC)系统的空间平滑问题.传统的分布式ANC算法通过本地控制器之间的通信,可以大大提高系统稳定性.但由于每组控制器和误差麦克风分布位置不同,引入的估计偏差影响系统整体降噪性能.因此,旨在开发一种新型扩散滤波最小均方算法(Diffusion Filtered-x Least Mean Squares,Diff-FxLMS),该算法平衡了空间平滑度和信息交换强度之间的矛盾,从而减少估计偏差.通过对Diff-FxLMS算法性能进行的理论分析,揭示了扩散控制机制,为ANC算法设计提供了理论依据,并在此基础上发展出一种新型的可变平滑度的Diff-FxLMS(Varible Spatial Regularized Diff-FxLMS,VSR-Diff-FxLMS)算法.仿真结果验证了新算法的性能及理论分析的可靠性.展开更多
在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk a...在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk and node influence analysis)。综合考虑虚假信息传播特征空间的多样性和复杂性,通过自注意力机制实现用户传播虚假信息行为维度、时间维度和内容维度特征的嵌入表示,运用改进的无监督聚类K-means++算法实现不同用户传播风险等级的自动划分;设计一种自适应加权策略实现对离散粒子群优化算法的改进,进而提出一种基于离散粒子群优化的虚假信息传播关键节点选取方法,用于从具有特定传播风险等级的用户节点集合中选取若干个具有影响力的控制驱动节点,从而实现精准、高效的虚假信息传播控制;基于现实在线社交网络平台上开展试验,结果表明,所提出的DDC-UPRNI方法与现有算法相比,在控制效果和时间复杂度等重要指标上具有明显优势。该方法为社会网络空间中的虚假信息管控治理提供重要参考。展开更多
文摘A new photochromic complex of Keggin type Tungstophosphate acid/polyacrylamide system was prepared in aqueous solution, and its thin films was made by the dip coating technique. Their properties were investigated by FT IR, UV Vis, as well as TG DTA measurement. The results showed that this type of system had different properties in solution and in thin films. ESR spectra g values for the one electron blues were the characteristic of tetragonal W 5+ complex in aqueous solution and thin films. The formation of a radical signal of ESR spectra indicated that polyacrylamide was a proton donor, the reversibility for photochromism was relative to the presence and diffusion of oxygen in polymeric network.
文摘A pendant drop tensiometry apparatus aided by video-image digitization technology was established, by which static interface or surface tension of some liquids was measured with satisfactory results.In order to study the effect of emulsifier concentration on emulsion stability, dynamic interfacial tension was measured between toluene and water against concentration of Tween 60(Polyoxyethylene(20) stearyl-sorbitanate). As expected, higher concentration is the Tween 60 solution in toluene injected into the toluene phase, faster falls the interface tension between toluene and water.Furthermore, it reveals interestingly that two steps of diffusion occur in the system, i.e ., at low and high concentration, after the surfactant solution is injected.The characteristic process of dynamic interface tension can be ascribed to diffusion control because of linearity between interface tension and the minus second root of aging time.The discovery is correlated to the fact that much higher concentration of surfactant above its critical micelle concentration is often required when a stable emulsion is planned to prepare.
文摘研究了多通道分布式主动噪声控制(Distributed Active Noise Control,ANC)系统的空间平滑问题.传统的分布式ANC算法通过本地控制器之间的通信,可以大大提高系统稳定性.但由于每组控制器和误差麦克风分布位置不同,引入的估计偏差影响系统整体降噪性能.因此,旨在开发一种新型扩散滤波最小均方算法(Diffusion Filtered-x Least Mean Squares,Diff-FxLMS),该算法平衡了空间平滑度和信息交换强度之间的矛盾,从而减少估计偏差.通过对Diff-FxLMS算法性能进行的理论分析,揭示了扩散控制机制,为ANC算法设计提供了理论依据,并在此基础上发展出一种新型的可变平滑度的Diff-FxLMS(Varible Spatial Regularized Diff-FxLMS,VSR-Diff-FxLMS)算法.仿真结果验证了新算法的性能及理论分析的可靠性.
文摘在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk and node influence analysis)。综合考虑虚假信息传播特征空间的多样性和复杂性,通过自注意力机制实现用户传播虚假信息行为维度、时间维度和内容维度特征的嵌入表示,运用改进的无监督聚类K-means++算法实现不同用户传播风险等级的自动划分;设计一种自适应加权策略实现对离散粒子群优化算法的改进,进而提出一种基于离散粒子群优化的虚假信息传播关键节点选取方法,用于从具有特定传播风险等级的用户节点集合中选取若干个具有影响力的控制驱动节点,从而实现精准、高效的虚假信息传播控制;基于现实在线社交网络平台上开展试验,结果表明,所提出的DDC-UPRNI方法与现有算法相比,在控制效果和时间复杂度等重要指标上具有明显优势。该方法为社会网络空间中的虚假信息管控治理提供重要参考。
