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| 1 | Studies of laser-plasma interaction physics with low-density targets for direct-drive inertial confinement fusion on the Shenguang III prototype显示文摘The physics of laser-plasma interaction is studied on the Shenguang III prototype laser facility under conditions relevant to inertial confinement fusion designs.A sub-millimeter-size underdense hot plasma is created by ionization of a low-density plastic foam by four high-energy(3.2 kJ)laser beams.An interaction beam is fired with a delay permitting evaluation of the excitation of parametric instabilities at different stages of plasma evolution.Multiple diagnostics are used for plasma characterization,scattered radiation,and accelerated electrons.The experimental results are analyzed with radiation hydrodynamic simulations that take account of foam ionization and homogenization.The measured level of stimulated Raman scattering is almost one order of magnitude larger than that measured in experiments with gasbags and hohlraums on the same installation,possibly because of a greater plasma density.Notable amplification is achieved in high-intensity speckles,indicating the importance of implementing laser temporal smoothing techniques with a large bandwidth for controlling laser propagation and absorption. | V.T.Tikhonchuk T.Gong N.Jourdain O.Renner F.P.Condamine K.Q.Pan W.Nazarov L.Hudec J.Limpouch R.Liska M.Krus F.Wang D.Yang S.W.Li Z.C.Li Z.Y.Guan Y.G.Liu T.Xu X.S.Peng X.M.Liu Y.L.Li J.Li T.M.Song J.M.Yang S.E.Jiang B.H.Zhang W.Y.Huo G.Ren Y.H.Chen W.Zheng Y.K.Ding K.Lan S.Weber | 2021 | Matter and Radiation at Extremes2021，6，2： | 2 |
| 2 | Improved mechanical properties of SiC fiber reinforced silica-based ceramic cores fabricated by stereolithography显示文摘Silica-based ceramic cores have been widely used to fabricate aero-engine hollow blades due to their moderate high temperature mechanical properties and excellent leachability.In this study,silica-based ceramics with SiC fiber addition were prepared via stereolithography,and the influence of SiC fiber content on mechanical properties of the obtained silica-based ceramics was investigated.With the increase of SiC fiber content,linear shrinkage gradually decreased,while room temperature flexural strength and high temperature flexural strength first increased and then decreased.As SiC fiber content increased to 4.0 wt%,linear shrinkage was reduced to 0.62%resulting from the oxidation of SiC.Furthermore,room temperature flexural strength was improved from 11.79 MPa to 23.83 MPa and high temperature flexural strength was enhanced from 15.64 MPa to 34.62 MPa with 4.0 wt%SiC fiber addition due to the reinforcement of fibers and the enhancedβ-cristobalite content,which meets the need of ceramic cores.Therefore,it demonstrates the capability of fabricating high-performance and high-precision silica-based ceramic cores reinforced by SiC fibers via stereolithography for rapid manufacturing of hollow blades. | W.Zheng J.M.Wu S.Chen K.B.Yu J.Zhang Y.S.Shi | 2022 | Journal of Materials Science & Technology2022，，21： | 2 |
| 3 | A Frequency Determination Method for Digitized NMR Signals显示文摘We present a high precision frequency determination method for digitized NMR FID signals.The method employs high precision numerical integration rather than simple summation as in many other techniques.With no independent knowledge of the other parameters of a NMR FID signal(phaseφ,amplitude A,and transverse relaxation time T_(2))this method can determine the signal frequency f_(0)with a precision of 1/(8π^(2)f_(0)^(2)T_(2)^(2))if the observation time T≫T_(2).The method is especially convenient when the detailed shape of the observed FT NMR spectrum is not well defined.When T2 is+∞and the signal becomes pure sinusoidal,the precision of the method is 3/(2π^(2)f_(0)^(2)T_(2))which is one order more precise than the±1 count error induced precision of a typical frequency counter.Analysis of this method shows that the integration reduces the noise by bandwidth narrowing as in a lock-in amplifier,and no extra signal filters are needed.For a pure sinusoidal signal we find from numerical simulations that the noise-induced error in this method reaches the Cramer-Rao Lower Band(CRLB)on frequency determination.For the damped sinusoidal case of most interest,the noise-induced error is found to be within a factor of 2 of CRLB when the measurement time T is 2 or 3 times larger than T2.We discuss possible improvements for the precision of this method. | H.Yan K.Li R.Khatiwada E.Smith W.M.Snow C.B.Fu P.-H.Chu H.Gao W.Zheng | 2014 | Communications in Computational Physics2014，15，5： | 1 |
| 4 | Formation of 0 84nm hydrated kaolinite as an environmentfriendly precursor of kaolinite intercalation显示文摘 | J.Zhou W.Zheng J.F Xu L.Chen Y.Li N.Ma P.Du | | 0，，： | 1 |
| 5 | Inflammatory cytokines inhibit ADAMTS13 synthesis in hepatic stellate cells and endothelial cells显示文摘 | X. W.ZHENG D. Z.SHANG X. L.ZHENG | 2008 | Journal of Thrombosis and Haemostasis2008，，7： | 1 |
| 6 | Inflammatory cytokines inhibit ADAMTS13 synthesis in hepatic stellate cells and endothelial cells显示文摘 | X. W.ZHENG D. Z.SHANG X. L.ZHENG | 2008 | Journal of Thrombosis and Haemostasis2008，，7： | 1 |
| 7 | Near‐infrared Raman spectroscopy for early diagnosis and typing of adenocarcinoma in the stomach显示文摘 | S. K.Teh W.Zheng K. Y.Ho M.Teh K. G.Yeoh Z.Huang | 2010 | Br J Surg2010，，4： | 1 |
| 8 | Adam revisited:a weighted past gradients perspective显示文摘Adaptive learning rate methods have been successfully applied in many fields,especially in training deep neural networks.Recent results have shown that adaptive methods with exponential increasing weights on squared past gradients(i.e.,ADAM,RMSPROP)may fail to converge to the optimal solution.Though many algorithms,such as AMSGRAD and ADAMNC,have been proposed to fix the non-convergence issues,achieving a data-dependent regret bound similar to or better than ADAGRAD is still a challenge to these methods.In this paper,we propose a novel adaptive method weighted adaptive algorithm(WADA)to tackle the non-convergence issues.Unlike AMSGRAD and ADAMNC,we consider using a milder growing weighting strategy on squared past gradient,in which weights grow linearly.Based on this idea,we propose weighted adaptive gradient method framework(WAGMF)and implement WADA algorithm on this framework.Moreover,we prove that WADA can achieve a weighted data-dependent regret bound,which could be better than the original regret bound of ADAGRAD when the gradients decrease rapidly.This bound may partially explain the good performance of ADAM in practice.Finally,extensive experiments demonstrate the effectiveness of WADA and its variants in comparison with several variants of ADAM on training convex problems and deep neural networks. | Hui Zhong Zaiyi Chen Chuan Qin Zai Huang Vincent W.Zheng Tong Xu Enhong Chen | 2020 | Frontiers of Computer Science2020，14，5： | 0 |
| 9 | Study of strain and compostion of the self—organized GE dots by grazing incident X—ray diffraction显示文摘Grazing incident X-ray diffraction at different grazing angles for self-organized Ge dots grown on Si(001) are carried out and lattice constant expansions of 1.2?parallel to the surface as compared with the Si lattice are found within the Ge dots.A 3.1?lattice expansion of the Ge dots along the growth direction is also fund by ordinary X-ray(004) diffraction.According to the Poisson equation and the Vegard law,our results infer that the Ge dot should be a partially strain relaxed SiGe alloy with Ge content of abuot 55?2001 Elsevier Science B.V.All rights reserved. | X.Jiang Z.Jiang W.Jiang Q.Jia W.Zheng D.Xian X.Wang | 2001 | Beijing Synchrotron Radiation Facility2001，，2： | 0 |
| 10 | Two Dimensional Layered Films for Electronics and Optoelectronics显示文摘Two dimensional layered films such as graphene and layered inorganic materials are promising for future nanoscale electronics and optics.We also performance of dielectric layer and metal contacts on the performces of field | P.A.Hu W.Feng J.Zhang W.Zheng X.Wang | 2016 | 功能材料信息2016，13，1： | 0 |
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