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91.
针对耦合波导缝隙馈电时波导内电磁场复杂且不利于工程应用的问题,提出一种耦合波导缝隙有源阻抗计算方法.根据耦合波导端口处S矩阵与端口处输入阻抗矩阵的关系建立关于耦合波导缝隙有源阻抗方程,且采用牛顿法求解此非线性高阶分式方程,得到计及缝隙间互耦的耦合波导缝隙有源阻抗值.通过提取HFSS软件中耦合缝隙馈电的裂缝天线S矩阵进行仿真计算,结果表明该计算耦合缝隙有源阻抗的方法是有效的且适合大型裂缝天线耦合裂缝设计. 相似文献
92.
《Catalysis communications》2011,14(1):101-105
Well-ordered hexagonal mesoporous silicate (HMS) materials with various contents of phosphotungstic acid (HPW) were synthesized via an original direct synthesis method. The characterization results show that the samples have regular fingerprint-like mesopores and spherical morphology. Compared with the conventional wet impregnation method, the samples obtained by the original direct synthesis method have better HPW dispersion and larger specific surface area. Finally, the catalytic performance of these samples was tested through the oxidative desulfurization (ODS) of DBT in the model oil. The results indicate that the direct synthesized samples exhibit better catalytic performance than the impregnated samples. 相似文献
93.
This paper is concerned with the leader-following consensus problem of a group of au-tonomous agents with unknown parameters and unmodeled bounded additive disturbances. Under the assumption that the topology graph has symmetric weights, distributed adaptive controllers are proposed to guarantee that each agent can follow the leader in the presence of bounded disturbances. For the dynamics without disturbances, the proposed dynamic controller ensures that the states of all agents track the leader’s state, and the errors of parameters eventually converge to the compact set which can be made as small as desired by an appropriate choice of the design parameters. 相似文献
94.
Shu Yang Sun Han Sheng Gong Kun Zhao Xiao Lin Wang Xue Wang Xi Hao Zhao Bing Yu Huan Xin Wang 《International Journal of Food Science & Technology》2013,48(9):1783-1790
This study examined the effect of co‐inoculation of yeast and lactic acid bacteria (LAB) on the chemical and sensory characteristics of cherry wines, in comparison with a traditional sequential culture. Three LABs were investigated, including two O. oeni (SG26 and Viniflora) and one L. plantarum (PL18). All co‐inoculations significantly shortened the fermentation time (average 8 days earlier) to reach a stable level of residual sugar (<2 g L?1) and L‐malic acid (<0.5 g L?1), and no inhibitory effect on the yeast proliferation was observed. For volatiles determined, co‐culture with SG26 produced the greatest amount of volatile components (138.5 mg L?1), whereas sequential inoculation with PL18 had the lowest level (119.6 mg L?1). PCA result revealed that different LABs had diverse influences on the volatile profile of cherry wines, and sensory analysis confirmed that these samples presented distinct sensory profiles, and particularly, a stronger note of fruity was perceived when co‐culture was used. 相似文献
95.
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97.
Ping Yin Yucai Hu Yanzhi Sun Yingxia Yang Chunnuan Ji Qiang Xu Xiaohui Xu Wenjie Zhang 《Materials Letters》2007,61(17):3755-3757
Amorphous iron(III) phosphate has been synthesized by solid-state reaction at room temperature and was characterized by several methods. The non-crystalline sample displayed the particle size within the range of 100-200 nm, and it had a strong fluorescence emission peak centered at 306.6 nm. Moreover, its absorption properties for Hg(II) and Ag(I) heavy metal ions have been investigated. The experimental research results revealed that its excellent absorption capacity for Hg(II) and Ag(I) could reach to 1.831 mmol/g and 1.354 mmol/g, respectively, at pH = 5.98 and the absorption time t = 6 h. The absorption properties for Hg(II) were usually stronger that those for Ag(I). 相似文献
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99.
对离散时间Markov跳变系统, 当系统状态不完全可测时, 研究了一类基于输出反馈的鲁棒模型预测控制问题. 所研究系统为准线性参数时变的, 考虑在当前时刻系统的时变参数是已知的, 将来时刻未知的情况. 综合考虑系统存在多胞不确定性和有界噪声等因素, 通过运用线性矩阵不等式方法及变量变换思想, 将无穷时域性能指标的最小最大鲁棒预测控制问题转化为具有线性矩阵不等式约束的凸优化问题, 得到了系统的输出反馈控制律. 引入二次有界概念, 在满足输入输出约束的情况下, 保证闭环系统的随机稳定性. 数值算例验证了方法的有效性. 相似文献
100.
提出了基于云计算的医学图像流媒体服务传输系统,此系统将医疗设备和PACS进行整合,将来自于各个医疗设备的图像用扫描仪扫描为数码图像,并以流媒体的形式实时提交给远程服务器端。在云数据库虚拟化存储平台上,用先进的流媒体技术解决了医疗资源共享和高分辨率图像连续存储问题。实验结果表明, 与传统服务器在LAN(Local Area Network)、TANet(Taiwan Academic Network)和家庭网络中使用FTP传输相比,建立的云计算医学图像流媒体服务传输系统的网络传输率分别提高了45.6%、49.4%和8.1%。 相似文献