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991.
文章采用规范正交基作为测试函数,基于p-多重网格的思想,建立了间断Galerkin方法的二重网格格式,并以此求解了Euler方程,数值模拟了绕NACA0012和RAE2822翼型的跨音速流场。其中,在网格交界处采用Roe的迎风型数值通量。沿时间方向,高阶格式和低阶格式上分别采用Runge-Kutta方法和LUSGS方法推进。通过对残值收敛曲线的比较,认为文中的p-多重网格算法取得了非常优良的加速收敛效果。 相似文献
992.
文章针对非平稳噪声环境和低信噪比的情况,提出了一种基于低频区和高频区带噪语音特性的非平稳噪声估计,并结合人耳听觉掩蔽效应进行语音增强的算法。该算法首先通过非平稳噪声估计为加窗后的每一帧语音构造一个时变的权值实现对噪声的实时估计,然后结合人耳听觉特性计算出每一帧语音的不同Bark域的噪声掩蔽阈值,最后利用计算出的噪声掩蔽阈值自适应设定语音增强系数。仿真结果表明,该算法在抑制背景噪声,提高信噪比,减少语音失真等方面优于传统的语音增强方法。 相似文献
993.
Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of
bridge wind engineering, and the structural health monitoring system (SHMS) employed in many long-span bridges provide a research
basis for the field measurement. In order to provide reliable basis for wind resistant evaluation of Runyang Suspension Bridge
(RSB), two anemometers and 85 accelerometers were installed in the SHMS of RSB. In August 2005, Typhoon Matsa crossed over
Jiangsu, the SHMS timely recorded the typhoon and structural vibration responses. In this paper by using the time-frequency
technique and statistical theory, the recorded data were analyzed to obtain the strong wind characteristics, the buffeting
response characteristics of the cable and deck, and the variation of buffeting response RMS versus wind speed. Results obtained
in this study can be employed to validate the credibility of current buffeting response analysis theory techniques, and provide
reference values for wind resistant evaluation of other long-span bridges.
Supported by the National Hi-Tech Research and Development Program of China (“863” Project) (Grant No. 2006AA04Z416), the
Key Project of the National Natural Science Foundation of China (Grant No. 50538020) and the Outstanding Youth Fund of the
National Natural Science Foundation of China (Grant No. 50725828) 相似文献
994.
RuiLin Chen QingYuan Zeng XinGu Zhong Jun Xiang XiaoGang Guo Gang Zhao 《中国科学E辑(英文版)》2009,52(7):2037-2047
The results of numerical investigations of aerodynamic forces and moment coefficients of flow passing a simplified train geometry under different wind speeds are summarized. To compute numerically the different coefficients, the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations, combined with the k-ε turbulence model, were solved using finite volume technique. The pres-sure-velocity fields were coupled using the SIMPLE algorithm. At each iteration the pressure correction was obtained by sol... 相似文献
995.
Experiments of simultaneous removal of SO2 and NO from simulated flue gas, using NaClO2 solution as the absorbent, were carried out in a self-designed bubble reactor, and high simultaneous removal efficiencies
of SO2 and NO were obtained under the optimal experimental conditions. The mechanism of simultaneous removal based on NaClO2 acid solutions was proposed by analyzing the removal products. Possibility and limitation of the desulfurization and denitrification
using NaClO2 acid solutions were calculated by thermodynamic methods. Experimental results of reaction kinetics for simultaneous desulfurization
and denitrification indicated that the oxidation-absorption processes of SO2 and NO were divided into two zones, namely the fast and slow reaction zones. In the slow reaction zones both were zero order
reactions, and in the fast reaction zones, the reaction order, rate constant and activation energy of SO2 reaction with absorbent were 1.4, 1.22 (mol·L−1)−0.4·s−1 and 66.25 kJ·mol−1, respectively, and 2, 3.15×103 (mol·L−1) −1·s−1, and 42.50 kJ·mol−1 for NO reaction, respectively.
Supported by the National High-Tech Research and Development Program of China (“863” Project) (Grant No. 2007AA061803) 相似文献
996.
Multi-channel micro neural probe fabricated with SOI 总被引:1,自引:0,他引:1
WeiHua Pei Lin Zhu ShuJing Wang Kai Guo Jun Tang Xu Zhang Lin Lu ShangKai Gao HongDa Chen 《中国科学E辑(英文版)》2009,52(5):1187-1190
Silicon-on-insulator(SOI) substrate is widely used in micro-electro-mechanical systems(MEMS).With the buried oxide layer of SOI acting as an etching stop,silicon based micro neural probe can be fabri-cated with improved uniformity and manufacturability.A seven-record-site neural probe was formed by inductive-coupled plasma(ICP) dry etching of an SOI substrate.The thickness of the probe is 15 μm.The shaft of the probe has dimensions of 3 mm×100 μm×15 μm with typical area of the record site of 78.5 μm2.The im... 相似文献
997.
DongJie Guo HaiTao Ding Haiju Wei Qingsong He Min Yu ZhenDong Dai 《中国科学E辑(英文版)》2009,52(10):3061-3070
This paper reports a new technique to fabricate an ion-exchange polymer-metal composite (IPMC) actuator. This technique is based on a hybrid organic-inorganic composite membrane. In the fabrication course, silica oxide particles, prepared from hydrolysis of tetraethyl orthosilicate in situ with sol-gel reaction, co-crystallize with perfluorosulfonate acid (PFSA) ionomer. Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) analyses demonstrate that a highly water-saving hybrid mem... 相似文献
998.
Research on indoor experimentation of range SAL imaging system 总被引:1,自引:0,他引:1
GUO Liang XING MengDao ZHANG Long TANG Yu & BAO Zheng State Key Laboratory of Radar Signal Processing Xidian University Xi’an China Xi’an Polytechnic University Xi’an 《中国科学E辑(英文版)》2009,52(10):3098-3104
By means of advantages of both SAR and lidar, the combination of the techniques of (inverse) synthetic aperture and lidar makes it possible to obtain high resolution 2-D image. In this paper, an indoor experimental system of inverse synthetic aperture lidar imaging is given and a processing approach is presented. The given system is in the mode of lidar system with separated receiver and transmitter, which can effectively eliminate the jamming from the lens or/and the intersection between two optic fibers. ... 相似文献
999.
区域创新能力评价指标体系及实证 总被引:3,自引:0,他引:3
在考察国内外区域创新研究现状的基础上,给出了区域创新能力的概念及内容,设计了区域创新能力评价指标体系,并利用2007年的统计数据,围绕知识创造、知识流动、企业技术创新、技术创新环境和创新的经济绩效等5个方面,运用主成分和层次分析法对我国31个省市的创新能力进行了分析,东部省市的整体创新能力水平较高,东北和中部次之,西部较差. 相似文献
1000.