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Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 2101-2110页

作者： Hui Wang biao guo Xuguang An Yu Zhang Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu 610213China School of Materials Science and Engineering Xihua UniversityChengdu 610039China Interdisciplinary Materials Research Center Institute for Advanced StudyChengdu UniversityChengdu 610106China

FeCrAl alloy is one of the most promising candidates as an accident-tolerant fuel(ATF)cladding ***,the influence of cold-rolling(CR)reduction on microstructure and tensile properties of the as-annealed FeCrAl alloys,with low Cr and Nb contents,is systematically *** the increase in CR reduction,the grain size of FeCrAl alloy is obviously refined after annealing because the increase in stored deformation energy leads to enhanced ***,the large CR reductions result in a severe mixed-grain microstructure,significantly reducing the uniform deformability of the FeCrAl *** dislocation density of the as-annealed FeCrAl alloy decreases with the increase in CR reduction,except for the excessive CR reduction of 50%.Moreover,the Laves phases are crushed and dissolved during CR and annealing,as well as large amounts of refined Laves phases are found after large CR *** pinning effect of the Laves phases can significantly improve the strength of FeCrAl ***,the strengthening mechanisms of FeCrAl alloy consist of fine-grain strengthening,dislocation strengthening and precipitation ***,the FeCrAl alloy,with a CR reduction of 30%,achieves optimal tensile *** study can provide theoretical guidance for the industrial production of the FeCrAl alloy.

关键词： FeCrAl alloy Cold-rolling reduction Tensile properties Microstructure evolution Strengthening mechanism

Microstructure and Carbides Characteristics of Spray Formed 9V High Vanadium Steels

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Journal of Wuhan University of Technology(Materials Science) 2016年第4期31卷 896-902页

作者：徐轶 guo biao GE Changchun School of Materials Science & Engineering Southwest Jiaotong University Chengdu 610031 China School of Materials Science and Engineering Xihua University Chengdu 610039 China Institute of Special Ceramics and Powder Metallurgy University of Science and Technology Beijing Beijing 100083 China

To develop advanced high speed steel with high vanadium content,a kind of vanadium content 9% high speed steel in the form of circular ring was spray formed under certain thermal *** carbides topography of as-cast and as-sprayed 9V steel were *** effects of post thermo-mechanical processing（hot isostatic pressing and hot forging） and heat treatment on the microstructure and carbides distribution were *** spray formed 9V steel typically consists of fine,homogeneous and angular-shaped MC carbides with diameters ranging from 1 to 2 μ*** formed 9V steel shows an excellent hot workability following increase of forging ratio due to fine homogeneous *** heat treatment,spray formed 9V steel is composed of MC carbides,martensite and retained *** hardness value of heat treated materials is inversely proportional to the volume fraction of residual *** dispersed MC carbides have significant influences on the dislocation motion of spray formed 9V steel.

关键词： spray martensite vanadium austenite forging hardness dispersed dislocation diameters pressing

PARTIALLY AVERAGED NAVIER-STOKES METHOD FOR TIME-DEPENDENT TURBULENT CAVITATING FLOWS

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Journal of Hydrodynamics 2011年第1期23卷 26-33页

作者： HUANG biao WANG guo-yu School of Vehicle and Transportation Engineering Beijing Institute of Technology Beijing 100081 China

Cavitation typically occurs when the fluid pressure is lower than the vapor pressure in a local thermodynamic state,and the flow is frequently unsteady and *** Reynolds-Averaged Navier-Stokes（RANS）approach has been popular for turbulent flow *** most widely used ones,such as the standard k-εmodel,have well-recognized deficiencies when treating time dependent flow *** identify ways to improve the predictive capability of the current RANS-based engineering turbulence closures,conditional averaging is adopted for the Navier-Stokes equation,and one more parameter,based on the filter size,is introduced into the k-ε*** the Partially Averaged Navier-Stokes（PANS）model,the filter width is mainly controlled by the ratio of unresolved-to-total kinetic *** model is assessed in unsteady cavitating flows over a Clark-Y *** the experimental validations regarding the forces,frequencies,cavity visualizations and velocity distributions,the PANS model is shown to improve the predictive capability considerably,in comparison to the standard k-ε model,and also,it is observed the value of1f in the PANS model has substantial influence on the predicting *** the filter width1f is decreased,the PANS model can effectively reduce the eddy viscosity near the closure region which can significantly influence the capture of the detach cavity,and this model can reproduce the time-averaged velocity quantitatively around the hydrofoil.

关键词： cavitating flow PANS model filter width unresolved-to-total kinetic energy

Techniques for Radar Imaging Based onMUSIC Algorithm

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Journal of Systems Engineering and Electronics 1999年第1期10卷 31-38页

作者： guo, biao Lu, Xiaoying Chen, Zengping Air Force Inst of Radar Beijing China

At first, the radar target scattering centers model and MUSIC algorithm are analyzed in this paper. How to efficiently set the parameters of the MUSIC algorithms is given by a great deal of simulated radar data in experiments. After that, according to measured data from two kinds of plane targets on fully polarized and high range resolution radar system, the author mainly investigated particular utilization of MUSIC algorithm in radar imaging. And two-dimensional radar images are generated for two targets measured in compact range. In the end, a conclusion is drew about the relation of radar target scattering properties and imaging results.

关键词： Algorithms Electromagnetic wave scattering Mathematical models Radar systems Radar target recognition

Investigation of the role of aziridine bonding agents on the aging of the composite solid rocket propellant(CSRP)

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航空动力学报 2008年第11期23卷 2101-2106页

作者： Amged A Ali ZHANG Jian-wei CAI guo-biao School of Astronautics Beijing University of Aeronautics and Astronautics Beijing 100191 China

The role of bonding agents on the aging characteristics is one of the important research *** program of the prepared propellant samples was conducting as follows:Five samples,two free of bonding agents,and three containing an aziridine based bonding agents(MAPO,HX-752,MAT4),four samples based on different bonding and curing agents all were aged at 70 ℃.The prepared bonding agent "MAT4" gave remarkable improvements and resulted in highly stable mechanical properties comparing with HX-752 or *** selected bonding agents family inhibited the rate of decomposition of the propellants during the aging periods and supported the propellant matrix against decomposition at the elevated temperatures.

关键词：氮丙啶黏结剂老化现象复合固体火箭推进剂航空动力系统

Pumping speed of cryopump for xenon

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航空动力学报 2015年第7期30卷 1731-1736页

作者： LING Gui-long WEI Li-jun CAI guo-biao School of Astronautics Beijing University of Aeronautics and Astronautics Unit 93469 the Chinese People's Liberation Army

The xenon pumping speed testing system of the large-diameter external cryopump was designed to meet the plume test requirements for prototype electric *** flowmeter method was utilized to measure the xenon pumping *** test results show that the averaged effective pumping speed of doublecryopumps is 52 200L/s,and that of single-cryopump is 27 100L/*** pumping speed ratio of two configurations is *** can be concluded that the pumping speed has in linear relationship with the number of cryopump,and the coefficient is irrelevant with the gas *** averaged effective pumping speed of xenon is less than its nominal pumping speed,and the averaged pumping efficiency is *** the identical inflow conditions,the averaged effective pumping speed ratio of nitrogen is 0.53,slightly less than the theoretical pumping speed ratio of ***,it can be concluded that results assessment of large-diameter external cryopump design index can guide the engineering application,showing certain reference significance.

关键词： vacuum plume large-diameter external cryopump xenon pumping speed test

Flow Behavior and Numerical Simulation of Spray-Formed FGH95 Superalloy Under Hot Compression

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Journal of Iron and Steel Research International 2013年第12期20卷 69-74页

作者： guo biao GE Chang-chun XU Yi School of Materials Science and Engineering Southwest Jiaotong University Institute of Special Ceramics and Powder Metallurgy School of Materials Science and Engineering University of Science and Technology Beijing

The flow behavior of spray-formed FGH95 superalloy （similar to Rene 95） was investigated at tempera- tures ranging from 1050 to 1 140 ℃ and strain rate ranging from 0.01 to 10 s-1. At a given temperature and strain rate, flow stress increases quickly with increasing strain and then reaches a peak, then gradual decreases until high strain, and dynamic softening is observed. Utilizing the hyperbolic sine {unction and introducing the strain with non- linear fitting, the revised constitutive equations incorporating the effects of temperature, strain rate and strain for high temperature flow stress prediction of superalloy were established. The revised constitutive equations were im- planted into finite element software by second development to simulate the hot compression process successfully, and the effective stress and load stroke curves obtained by numerical simulation are good agreement with the experimen- tal results.

关键词： spray-formed FGH95 superalloy constitutive equations numerical simulation

Recent Progress on Rice Genetics in China

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Journal of Integrative Plant Biology 2007年第6期49卷 776-790页

作者： Hua Jiang Long-biao guo Qian Qian State Key Laboratory of Rice Biology China National Rice Research Institute Hangzhou 310006 China The Agricultural College Yangzhou University Yangzhou 225006 China

Through thousands of years of evolution and cultivation, tremendously rich genetic diversity has been accumulated in rice （Oryza sativa L.）, developing a large germplasm pool from which people can select varieties with morphologies of Interest and other important agronomic traits. With the development of modern genetics, scientists have paid more attention to the genetic value of these elite varieties and germplasms, and such rich rice resources provide a good foundation for genetic research in China. Approximately 100 000 accessions of radiation-, chemical- or insertion-induced mutagenesis have been generated since the 1980s, and great progress has been made on rice molecular genetics. So far at least 16 variant/mutant genes Including MOC1, BC1, SKC1, and Rfgenes have been isolated and characterized in China. These achievements greatly promote the research on functional genomics, understanding the mechanism of plant development and molecular design breeding of rice in China. Here we review the progress of three aspects of rice genetics in China： moving forward at the molecular level, genetic research on elite varieties and germplasms, and new gene screening and genetic analysis using mutants. The prospects of rice genetics are also discussed.

关键词： functional genomics genetics germplasm resources rice (Oryza sativa).

An introduction to the novel vacuum plume effects experimental system

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Science China(Technological Sciences) 2016年第6期59卷 953-960页

作者： CAI guo biao LING Gui Long HE Bi Jiao School of Astronautics Beihang University

This paper introduces a newly developed vacuum Plume effects Experimental System(PES) used for plume effect tests of rocket engines and vacuum heat tests of satellites. The design level, manufacturing technique, and testing capabilities of the PES have reached a highly advanced level at home and abroad. The PES mainly consists of a vacuum chamber, vacuum acquisition system, nitrogen system, helium system, and parameter measurement system. A breakthrough was obtained on the Large Scale Cryo-Pumping System, which was based on a combined liquid nitrogen and liquid helium heat sink. An internal cryopump with a limiting temperature of 4.2 K and an efficient absorption area of 305 m2 was developed. The absorption capability of the cryopump was above 7×107 L/s. Vacuum plume tests were performed in the temperature ranges of ambient temperature, liquid nitrogen, and liquid helium. The experimental results showed that the plume test capability of PES is higher than that of similar foreign equipment STG and CHAFF-4. For 2 g/s and 117 N rocket engines, the dynamic vacuum degree of environment was 8.0×10?4 Pa(approximately 137 km height) and 1.1×10?2 Pa(approximately 106 km height), respectively.

关键词： vacuum plume effect liquid nitrogen heat sink liquid helium heat sink plume absorption pump

Constitutive Equations for Flow Behavior of Powder-forged Fe-0.5C-2Cu Steel under Hot Compression

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Journal of Iron and Steel Research International 2014年第3期21卷 389-395页

作者： biao guo Sui-cai ZHANG Chang-chun GE School of Materials Science and Engineering Southwest Jiaotong University Institute of Special Ceramics and Powder Metallurgy School of Materials Science and EngineeringUniversity of Science and Technology Beijing

To investigate the hot deformation behavior of powder-forged （P/F） Fe-0. 5C：-2Cu steel, the hot compres- sion tests were conducted at temperatures ranging from 900 to 1000 ℃ and strain rates from 0.1 to 10 s-1 using Gleeble-1500 thermal simulator. The true stress-true strain curves at different temperatures and strain rates of P/F steel were obtained. It is found that dynamic recovery only occurs as strain rate is 10 s 1 at 900 ℃, and the dynamic recrystallization is the main softening mechanism. The flow stress increases with decreasing temperature and increas- ing strain rate. The experimental data are employed to develop constitutive equations on the basis of the Arrhenius- type equation by introducing the strain with nonlinear fitting. The flow stresses prediel：ed by the proposed constitu- tive equations are in good agreement with the experimental values, and the correlation coefficient （R2） and the aver- age absolute relative error （AARE） are 0. 995 25 and 3.07% respectively. These results indicate the proposed consti- tutive equations can effectively describe the hot deformation behavior of the material.

关键词： powder-forged steel flow behavior constitutive equation