| 1 | CONSTITUTE EQUATIONS OF 40Cr STEEL UNDER SUPERPLASTIC COMPRESSIVE DEFORMATION显示文摘The microstructure of 40Cr steel sample and its surface is ultra-fined through saltbath cyclic quenching and high frequency hardening, then the superplasticity is studied under isothermal superplastic compressive deformation condition. The experimental results indicate that the stress-strain curves are shown to take place obvious superplastic flow characteristic at the temperature of 730-770℃ and at the initial strain rate of (1.7-5.0)× 10-4s-1. Its strain rate sensitivity is 0.30-0.38, the steady superplastic flow stress is 60-70MPa, the superplastic flow activation energy is 198-217kJ/mol,and it is close to α-Fe grain boundary self-diffusion activation energy. The superplastic compressive constitute equations of this steel are correspondingly set up. Due to the finer microstructure of high frequency hardening, it appears bigger strain rate sensitivity value, smaller the steady superplastic flow stress and the superplastic flow activation energy, so it has better superplastic deformation capability. | K.K.Zhang Y.L.Yang S.Z.Liu C.X.Han D.Xu | 2003 | Acta Metallurgica Sinica(English Letters)2003，16，6： | 3 |
| 2 | The technology for detection of gamma-ray burst with GECAM satellite显示文摘Introduction The main physical objective of the GECAM satellite is to detect gamma-ray bursts,which is related to gravitational waves of double compact object mergers.The GECAM satellite also detects and investigates various bursts of high-energy celestial bodies.Purposes and methods In this study,we designed,developed and calibrated the payload and launched it into orbit with GECAM satellite.The payload consists of the gamma ray detector(GRD,for detecting 4 keV–4 MeV X/γray),the charged particle detector(CPD,for detecting 150 keV–5 MeV charged particle),and the electronic box(EBOX).The all-sky field coverage is achieved via two 229-degree large-area satellites positioned 180 degrees apart and are on opposite sides of the geo-center.Each satellite is equipped with 25 GRDs and 8 CPDs;thus,the satellite can identify charged particle bursts in space.Gamma-ray detectors adopt lanthanum bromide crystal technology combined with silicon photomultipliers.This is the first time that this technology was used massively in space detectors.Conclusions The GECAM satellite can quickly determine the direction of gamma-ray bursts(positioning)via indexing and fitting method,while the transmit variability,energy spectrum and direction of the gamma-ray bursts guide subsequent observations through the Beidou-3 RDSS in quasi-real time.It will play an important role in the study of high energy celestial bursts. | X.Q.Li X.Y.Wen Z.H.An C.Cai Z.Chang G.Chen C.Chen Y.Y.Du M.Gao R.Gao K.Gong D.Y.Guo J.J.He D.J.Hou Y.G.Li C.Y.Li G.Li L.Li X.F.Li M.S.Li X.H.Liang X.J.Liu Y.Q.Liu F.J.Lu H.Lu B.Meng W.X.Peng F.Shi X.L.Sun H.Wang J.Z.Wang Y.S.Wang H.Z.Wang X.Wen S.Xiao S.L.Xiong Y.B.Xu Y.P.Xu S.Yang J.W.Yang Q.B.Yi D.L.Zhang Fan Zhang S.N.Zhang C.Y.Zhang C.M.Zhang Fei Zhang X.Y.Zhao Y.Zhao X.Zhou C.S.Zhang J.P.Yu L.Chang K.K.Zhang J.Huang Y.M.Chen X.B.Han | 2022 | Radiation Detection Technology and Methods2022，6，1： | 0 |
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