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Acta Mechanica Sinica 2012年第2期28卷 291-299页

作者： yang-wei liu Bao-Jie liu Li-Peng Lu Group 404 National Key Laboratory of ScienceTechnology on Aero-Engine Aero-thermodynamicsSchool of Jet PropulsionBeihang University100191 BeijingChina

The average-passage equation system （APES） provides a rigorous mathematical framework for account- ing for the unsteady blade row interaction through multistage compressors in steady state environment by introducing de- terministic correlations （DC） that need to be modeled to close the equation system. The primary purpose of this study was to provide insight into the DC characteristics and the in- fluence of DC on the time-averaged flow field of the APES. In Part 2 of this two-part paper, the influence of DC on the time-averaged flow field was systematically studied; Several time-averaging computations boundary conditions and DC were conducted with various for the downstream stator in a transonic compressor stage, by employing the CFD solver developed in Part 1 of this two-part paper. These results were compared with the time-averaged unsteady flow field and the steady one. The study indicat;d that the circumferential- averaged DC can take into account major part of the unsteady effects on spanwise redistribution of flow fields in compres- sors. Furthermore, it demonstrated that both deterministic stresses and deterministic enthalpy fluxes are necessary to reproduce the time-averaged flow field.

关键词： Unsteady Blade row interaction Compressor Deterministic correlation Average-passage equation system CFD

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High-fidelity numerical simulation of unsteady cavitating flow around a hydrofoil

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Journal of Hydrodynamics 2023年第1期35卷 1-16页

作者： Nan Xie Yu-meng Tang yang-wei liu School of Energy and Power Engineering Beihang UniversityBeijing100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing100191China

Cavitation is a widespread and detrimental phenomenon in hydraulic machinery, therefore, it requires to be accurately predicted. In this study, large eddy simulation (LES), scale-adaptive simulation (SAS) and grid-adaptive simulation (GAS) are employed to investigate the unsteady cavitating flow around a NACA0009 hydrofoil. The prediction accuracy of GAS, SAS, both using the shear-stress transport (SST) k — ω model as baseline turbulence model, is validated by comparing with experimental and LES results. The cavity behaviors and turbulence fields are analyzed systematically. Results show that the GAS gives a more reasonable turbulent viscosity and accurately predicts the periodic evolution of typical vortical structures of cavitating flow, such as tip leakage vortex cavitation, tip separation vortex cavitation, leading-edge cavitation, and trailing-edge vortex. The time-averaged cavity volume, volume fluctuation amplitude, and characteristic frequencies of cavities predicted by the GAS are very closed to the LES, while the SAS fails to accurately capture these cavity characteristics. Furthermore, the local trace criterion is applied to extract the vortical structures and to analyze the swirling patterns of the tip leakage vortex. Multi-scale vortical structures in LES are well identified by local trace criterion. The prediction accuracy of the SAS method for small-scale vortical structures, such as the vortex shedding on the suction side and the vortex rope around the tip leakage vortex, is obviously insufficient, while the GAS has a higher accuracy in predicting vortex shedding. The tip leakage vortex and induced vortex extracted from GAS are also closer to that of LES in both swirling patterns and scale.

关键词： Tip leakage vortex cavitation leading-edge cavitation large eddy simulation(LES) grid-adaptive simulation scale-adaptive simulation

AN UNSPLIT LAGRANGIAN ADVECTION SCHEME FOR VOLUME OF FLUID METHOD

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Journal of Hydrodynamics 2010年第1期22卷 73-80页

作者： yang wei liu Shu-hong WU Yu-lin Laboratory of Hydraulic Science and Engineering Tsinghua University Beijing 100084 China

An Unsplit Lagrangian Advection （ULA） scheme for Volume Of Fluid （VOF） method is presented in this article. The ULA scheme is developed based on an algorithm of Piecewise Linear Interface Construction （PLIC）. The volume fluxes between cells are calculated through solving the new equation of the linear interfaces in cells in the ULA scheme. The fluxes flowing out from one cell is the inflow fluxes for another cell. In this way the whole fluid volume is conserved strictly without using any redistribution algorithms. The ULA scheme is based on two-dimensional structured rectangular mesh and may be extended to three-dimensional structured mesh with more geometrical efforts. The results from three widely-used benchmark tests show that the ULA scheme can achieve the accuracy higher than Split Lagaragian Advection （SLA） scheme and the Flux-Corrected Transport （FCT） algorithm.

关键词： advection schemes free surfaces fluid interfaces Volume Of Fluid (VOF) method

Facile Synthesis of 4,5-Disubstituted 2H-1,2,3-Triazoles by Catalyst-free Cycloaddition between Substituted Vinyl Sul- fones and Sodium Azide under Ambient Conditionst

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Chinese Journal of Chemistry 2012年第12期30卷 2786-2790页

作者： yang Jinjin Yin wei liu Renhua Chu Changhu School of Pharmacy Shanghai Key Laboratory of New Drug Design East China University of Science and Technology 130 Meilong Road Shanghai 200237 China

A highly efficient method for readily preparing 4,5-disubstituted 2H-1,2,3-triazoles was found. Under ambient conditions, a catalyst free cycloaddition between substituted vinyl sulfones and sodium azide could be completed in a very short time. In this cycloaddition process, sulfonyl group acts as a leaving group, while its ester group was retained.

关键词： vinyl sulfone sodium azide cycloaddition 1,2,3-triazole catalyst free

Granulosa cell proliferation differentiation and its role in follicular development

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Chinese Science Bulletin 2005年第23期50卷 2665-2671页

作者： LU Cuiling yang wei HU Zhaoyuan liu Yixun State Key Laboratory of Reproductive Biology Institute of ZoologyChinese Academy of Sciences Beijing 100080 China

Granulosa cells (GCs) are the most important cells in the ovary that undergo serious changes morphologi- cally and physiologically during the processes of follicular proliferation, differentiation, ovulation, lutenization and atresia. Oocyte (OC) directs GC proliferation and differen- tiation, while GCs influence OC maturation. Many ovarian factors are involved in the regulation of these processes via different molecular mechanisms and signal pathways. P38 MAPK can selectively regulate steroidogenesis in GCs con- trolled by FSH; Transcript factors LRH-1 and DAX-1 play an important role in this process; FSH induces GC prolifera- tion and differentiation by stimulating PCNA and StAR ex- pression and steroidogenesis. Activated ERK1/2 signal pathway may be involved in the FSH-regulated GC prolif- eration and differentiation. Therefore,GC is an ideal model for studying cell proliferation, differentiation and interaction as well as signal transduction. This review briefly summa- rizes the latest data in the literature, including the results achieved in our laboratory.

关键词：粒细胞卵母细胞细胞增殖卵泡发育信号转换

First Observation of Neoclassical Tearing Modes in the HL-2A Tokamak

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Chinese Physics Letters 2010年第6期27卷 137-140页

作者： JI Xiao-Quan yang Qing-wei liu Yi ZHOU Jun FENG Bei-Bin YUAN Bao-Shan Southwestern Institute of Physics Chengdu 610041

The m/n = 2/1 neoclassical tearing modes are first observed in HL-2A low density, low beta plasma with central electron cyclotron resonance heating. The neoclassical tearing modes （NTMs） are triggered by a sawtooth crash with m/n = 1/1 precursors, which are toroidal coupled with a small scale m/n = 2/1 mode. The time history of the island width is compared with the prediction of the NTM theory, showing a good agreement between theory and experiment.

关键词： Tears Scales Neoclassical

Relative n-widths of periodic convolution classes with NCVD-kernel and B-kernel

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Science China Mathematics 2010年第1期53卷 165-172页

作者： yang wei & liu YongPing School of Mathematical Sciences,Beijing Normal University Laboratory of Mathematics and Complex Systems,Ministry of Education,Beijing 100875,China School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing China

In this paper,we consider the relative n-widths of two kinds of periodic convolution classes,Kp(K) and Bp(G),whose convolution kernels are NCVD-kernel K and B-kernel G. The asymptotic estimations of Kn(Kp(K),Kp(K))q a... 详细信息

关键词： relative n-width periodic convolution class NCVD-kernel B-kernel

We Must De It,Do It Persistently,and Do It Well

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China's Foreign Trade 2008年第21期 10-11页

作者： yang wei liu Xinwen

The start of the sixth session of the China Auto Inter- national Exhibition Tour brings a Chinese wind that sweeps across auto markets both at home and *** strike while the iron is hot,China's Foreign Trade in-

关键词： We Must De It,Do It Persistently,and Do It Well than De

For a Safer World, For Smooth Cooperation

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China's Foreign Trade 2007年第21期 22-23页

作者： yang wei, liu Xinwen

The large trade surplus and production safety problems have tarnished China's image around the world recently. As China's first and largest trade partner, the EU has a lot of influence on its international performance, and given the current situation, increased bilateral cooperation is needed. Development of a smooth dialogue channel is a great opportunity for mutual benefit and future cooperation. Mr. Heinz Zourek, the General Director for the Enterprise and Industry of the European Union's Commission to China,

关键词：中国国际贸易合作伙伴市场竞争

Metal-film-assisted ultra-clean transfer of single-walled carbon nanotubes

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Nano Research 2014年第7期7卷 981-989页

作者： Yujun He Dongqi Li Tianyi Li Xiaoyang Lin Jin Zhang yang wei Peng liu Lina Zhang Jiaping Wang Qunqing Li Shoushan Fan Kaili Jiang State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics & Tsinghua-Foxconn Nanotechnology ResearchCenter Tsinghua University Beijing 100084 China

Transfer printing of nanomaterials onto target substrates has been widely used in the fabrication of nanodevices, but it remains a challenge to fully avoid contamination introduced in the transfer process. Here we report a metal-film- assisted method to realize an ultra-clean transfer of single-walled carbon nanotubes （SWCNTs） mediated by poly（methyl methacrylate）（PMMA）. The amount of PMMA residue can be greatly reduced due to its strong physical adhesion to the metal film, leading to ultra-clean surfaces of both the SWCNTs and the substrates. This metal-film-assisted transfer method is efficient, nondestructive, and scalable. It is also suitable for the transfer of graphene and other nanostructures. Furthermore, the relatively low temperature employed allows this technique to be compatible with nanomaterial-based flexible electronics.

关键词： metal-film-assisted single-walled carbonnanotube transfer flexible substrate Schottky barrier