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Science China(Technological Sciences) 2019年第8期62卷 1349-1356页

作者： HAN XinXing XU ChengHai JIN Hua xie weihua MENG SongHe National Key Laboratory of Science and Technology for National Defence on Advanced Composites in Special Environments Harbin Institute of Technology

Ultra-high temperature ceramic(UHTC) composites are widely used in high-temperature environments in aerospace applications. They experience extremely complex environmental conditions during service, including thermal, mechanical and chemical loading. Therefore, it is critical to evaluate the mechanical properties of UHTCs subject to an environment with elevated temperature, mechanical stress and oxygen. In this paper, an experimental investigation of the uniaxial tensile properties of a ZrB_2-SiC-graphite subject to an environment with a simultaneously elevated temperature, mechanical stress and oxygen is conducted based on a high-temperature mechanical testing system. To improve efficiency, an orthogonal experimental design is used. It is suggested that the temperature has the most important effect on the properties, and the oxidation time and stress have an almost equal effect. Finally, the fracture morphology is characterized using scanning electron microscopy(SEM), and the mechanism is investigated. It was concluded that the main fracture mode involved graphite flakes pulling out of the matrix and crystalline fracture, which indicates the presence of a weak interface in the composites.

关键词： ultra-high temperature ceramics environment with elevated temperature mechanical stress and oxygen uniaxial tensile strength orthogonal experimental design

Self-assembly of lipids and nanoparticles in aqueous solution:Self-consistent field simulations

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Theoretical & Applied Mechanics Letters 2012年第1期2卷 22-26页

作者： weihua xie Guangkui Xu Xiqiao Feng Institute of Biomechanics and Medical Engineering Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

Self-assembled nanostructures of lipids and nanoparticles hold great promise for applications in such fields as nanomedicine. This paper uses the self-consistent field theory to investigate the self-assembly behavior of lipid molecules and nanoparticles with different shapes in an aqueous solution. It is found that the lipid molecules can form monolayered and bilayered nanostructures around the nanopartieles with different shapes （e.g., triangular, square, hexagonal and octangular）. With decreasing the size of nanoparticles or increasing the number of polygon edges, the shape of lipid layers will approach an approximately spherical shape. These findings may help to predict and design novel drug delivery nanocarriers.

关键词： liposome nanoparticle self-assembly self-consistent field theory drug delivery

Decentralized robust H-infinity descriptor output feedback control for value-bounded uncertain descriptor large-scale systems

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控制理论与应用（英文版） 2006年第2期4卷 193-200页

作者： Yongfang xie weihua GUI Zhaohui JIANG College of Information Science and Engineering Central South University Changsha Hunan 410083 China

For a class of value-bounded uncertain descriptor large-scale interconnected systems, the decentralized robust H∞ descriptor output feedback control problem is investigated. A design method based on the bounded real lemma is developed for a decentralized descriptor dynamic output feedback controller, which is reduced to a feasibility problem for a nonlinear matrix inequality （NLMI）. It is proposed to solve the NLMI iteratively by the idea of homotopy, where some of the variables are fixed alternately at each iteration to reduce the NLMI to a linear matrix inequality （LMI）. A given example shows the efficiency of this method .

关键词： Descriptor output feedback Value-bounded uncertainty Decentralized H-infinity control Homotopy method LMI

Design and Implementation of a Real-Time Three-Frequency COMPASS Software Receiver

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Design and Implementation of a Real-Time Three-Frequency COM...

A Stable DOA Tracking Method Using FDPM and Kalman Filter

第四届中国卫星导航学术年会

作者： weihua xie Jun Zhang Chao xie QianWang Beijing Satellite Navigation Center

GNSS software-defined receiver is of importance in satellite navigation system, especially in the fields of receiver design and satellite navigation system scheme validating. The general scheme of COMPASS software receiver has been proposed, and the main software functional modules were designed using XML language. A real-time software receiver with 12 channels on PC platform has been implemented, which can process COMPASS B1/B2/B3 C（civil） code signal. The receiver can be capable of post-processing datasets from collection hardware or real-time processing data stream through PCI bus interface. A lot of performance improvement approaches have been proposed to enhance the speed of the software receiver, which include computational platform choosing , acquisition and correlator arithmetic optimization,program code optimization with SIMD instructions on CPU and CUDA instructions on GPU. Using this methods,the software receiver can reach real-time processing capacity under 80MHz sampling rate and 2 bit quantization conditions. The positioning results show that the software receiver’s three-dimensional positioning accuracy is superior to 10m under 95% confidences.

关键词： COMPASS navigation system. Software receiver. Real time. XML language. Speed optimization

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A Stable DOA Tracking Method Using FDPM and Kalman Filter

Intelligent Recognition Technology of GNSS Interference Source Based on Electromagnetic Fingerprint

第九届中国卫星导航学术年会

作者： Gangqiang Guan Deyong Xian Zhou Yi weihua xie Beijing Satellite Navigation Center

To solve the problems that eigenvalue decomposition of the covariance matrix is computationally intensive and the target moving can cause a spatial spectrum spread in the GNSS(global navigation satellite system) interference detection and localization system using antenna array, in this paper we propose a low-complexity GNSS signal DOA tracking algorithm using a Kalman filter implementation. This method firstly utilizes an improved FDPM(fast data projection method) for noise subspace tracking, and sets the DOA estimation predicted by Kalman filter as the initial value of Newtown iteration, then using the iteration result as a new DOA observation the sate vector of the Kalman filter is updated and calibrated, therefore a stable and effective DOA tracking loop is achieved. Simulation results show that using the method the performance of DOA tracking can be significantly improved while the computational burden is reduced simultaneously.

关键词： subspace tracking DOA tracking Newton iteration Kalman filter

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Intelligent Recognition Technology of GNSS Interference Sour...

几种鲶鱼的养殖技术(之三)——水库网箱养殖杂交鲶试验

第十一届中国卫星导航年会

作者： Xinyu Yan Xin Chen weihua xie Weimin Zhen Shanghai Key Laboratory of Navigation and Location Based Services School of Electronic Information and Electrical Engineering Shanghai Jiaotong University Beijing satellite navigation center China Research Institute of Radiowave Propagation

Due to the influence of transmission path attenuation, Received Global Navigation Satellite System(GNSS) signal is weak, and extremely susceptible to suppression interference, resulting in degradation

关键词： suppression interference interference detection and identification electromagnetic fingerprint feature GoogLeNet model

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中国水产 2002年第2期 36-37页

作者：谢卫华黑龙江农垦红兴隆分局畜牧水产局 155811

杂交鲶是由黑龙江鲶鱼(♂)×六须鲶(♀)杂交而成的养殖新品种,其生长快,口味鲜美,市场销售好.2000年我们从黑龙江水产研究所引进夏花3800尾,进行了水库网箱养殖试验.现将试验情况介绍如下:

关键词：水库网箱养殖杂交鲶试验饲料成活率

高超声速飞行器热环境与结构传热的多场耦合数值研究

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航空学报 2016年第9期37卷 2739-2748页

作者：周印佳孟松鹤解维华杨强哈尔滨工业大学复合材料与结构研究所哈尔滨150080

为了准确预测高超声速飞行器面临的严峻气动热/力环境以及结构的热力响应,发展了高超声速流动与结构传热耦合框架。采用分区求解方法,通过耦合界面的实时数据传递,实现了基于Navier-Stokes方程的高超声速化学非平衡计算流体力学(CFD)求... 详细信息

为了准确预测高超声速飞行器面临的严峻气动热/力环境以及结构的热力响应,发展了高超声速流动与结构传热耦合框架。采用分区求解方法,通过耦合界面的实时数据传递,实现了基于Navier-Stokes方程的高超声速化学非平衡计算流体力学(CFD)求解器与结构的热力全耦合有限元法(FEM)求解器的多场耦合计算,建立了高超声速飞行器的多场耦合数值分析方法。首先对经典高超声速圆柱绕流实验进行了耦合计算,结果与实验值吻合良好。然后针对典型的超高温陶瓷(UHTC)材料的耦合传热问题进行了数值研究,考虑热传导效应对气动热环境和结构热响应预测的影响,结果表明对于复杂外形且热导率相对较高的UHTC材料,结构内部热传导对热环境和表面温度分布的影响不可忽略。最后针对UHTC材料热物性(比热和热导率)非线性对高超声速流动传热过程的影响进行了研究,结果表明当比热和热导率处于合理的误差范围内时,材料表面温度响应对其变化并不敏感。

关键词：高超声速飞行器多场耦合气动热数值模拟热防护

基于EFEN-SP_3方法的pin-by-pin中子动力学计算方法研究

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原子能科学技术 2019年第2期53卷 243-249页

作者：谢伟华曹良志李云召西安交通大学核科学与技术学院陕西西安710049

为能直接给出安全分析所需的最热棒功率而不引入组件均匀化近似和精细功率重构近似,本文研究了基于栅元均匀化的pin-by-pin中子动力学计算方法。通过全隐式向后差分对多群时空中子动力学方程组的时间变量进行离散,采用指数函数展开节块-... 详细信息

为能直接给出安全分析所需的最热棒功率而不引入组件均匀化近似和精细功率重构近似,本文研究了基于栅元均匀化的pin-by-pin中子动力学计算方法。通过全隐式向后差分对多群时空中子动力学方程组的时间变量进行离散,采用指数函数展开节块-SP_3(EFEN-SP_3)方法求解含裂变介质的多群中子固定源方程组,通过高阶源展开技术消除了中子源分布与缓发中子先驱核分布形状不一致的问题。采用Ks因子、LW外推和粗网再平衡等加速技术提高计算效率。三维pin-by-pin中子动力学问题的数值结果表明:pin-by-pin中子动力学计算能直接给出单棒功率密度分布;高阶源展开技术可有效抑制计算偏差随时间步的累加效应;加速技术可将SP_3动力学计算的求解速度提高134.9倍。

关键词：压水堆 pin-by-pin 中子动力学 EFEN-SP3 加速技术

复合材料多尺度分析方法与典型元件拉伸损伤模拟

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复合材料学报 2015年第3期32卷 617-624页

作者：杨强解维华孟松鹤杜善义李勇霞哈尔滨工业大学特种环境复合材料国防科技重点实验室哈尔滨150080

复合材料具有多尺度特性,多尺度模拟方法能够考虑细观损伤、演变对宏观材料性能和力学行为的影响,是复合材料响应分析的一种重要方法和手段。基于多尺度渐进展开理论,对复合材料弹性问题控制方程进行尺度分解,推导了细观尺度与宏观尺度... 详细信息

复合材料具有多尺度特性,多尺度模拟方法能够考虑细观损伤、演变对宏观材料性能和力学行为的影响,是复合材料响应分析的一种重要方法和手段。基于多尺度渐进展开理论,对复合材料弹性问题控制方程进行尺度分解,推导了细观尺度与宏观尺度的控制方程,建立了复合材料宏观和细观尺度响应之间的关联。基于协同多尺度计算策略,利用通用有限元软件的用户子程序与脚本二次开发,在宏观模型计算中实时调用细观模型进行多尺度渐进损伤模拟,实现了宏观和细观尺度的信息传递与反馈。建立的复合材料多尺度数值模拟方法可以快速集成细观损伤模型以及宏观唯象强度理论,具有良好的通用性。碳/碳复合材料拉伸模拟算例结果与试验结果吻合较好。

关键词：多尺度分析均匀化局部化渐进损伤碳/碳复合材料