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Science China(Physics,Mechanics & Astronomy) 2020年第8期63卷 61-70页

作者： Xu-chang Zheng Chao-Hsi chang Tai-Fu Feng Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Physics Chongqing UniversityChongqing 401331China China Center of Advanced Science and Technology(CCAST)(World Laboratory) Beijing 100190China Department of Physics Hebei UniversityBaoding 071002China

To test the standard model(SM)precisely and to look for the clues deviating from SM,a proposal for determining the effective electro-weak mixing angles sin2θefff(particularly f=lept,c,b)is *** is via observing the asymmetries(the forward-backward one AFB,the left-right one ALR and the combined left-right forward-backward one ALRFB)of the doubly heavy-flavored hadrons in the production at a super Z-factory(an e+e-collider designed with a luminosity as high as possible for modernday techniques runs around the center-of-mass energy s1/2=mZ).To see the sensitivity,uncertainties as well as the event accumulation precisely,the observables for describing the asymmetries of the produced hadrons are computed numerically with varying effective mixing angles,and based on the result analyses,it is concluded that the proposal may offer an independent complement determination of the effective mixing angles.

关键词： electro-weak mixing angle production of doubly heavy-flavored hadron asymmetries super Z-factory

Nonlinear performance of classical damping

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 279-296页

作者： Shuenn-Yih chang Department of Civil Engineering Taipei University of Technology

The performance of a classical damping matrix, constructed either from the use of initial structural properties or current structural properties, in the step-by-step solution of a nonlinear multiple degree of freedom （MDOF） system is analytically evaluated. The analytical results are confirmed by numerical examples. Consequently, some conclusions are drawn from these analytical results that might be considered as rough guidelines for practical applications. It is found that a classical damping matrix constructed from initial structural properties is adequate for practical applications, since it has approximately the same damping effect as obtained by current structural properties and is more efficient in terms of computing.

关键词： classical damping nonlinear dynamic analysis integration method

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang Liu chang-jun Wang chang Liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Extensions of nonlinear error propagation analysis for explicit pseudodynamic testing

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Earthquake Engineering and Engineering Vibration 2009年第1期8卷 77-86页

作者： Shuenn-Yih chang Department of Civil Engineering Taipei University of Technology NTUT Box 2653 Chinese Taipei 106-08

Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm （chang, 2003） are presented. One extends the stability study from a given time step to a complete step-by-step integration procedure. It is analytically proven that ensuring stability conditions in each time step leads to a stable computation of the entire step-by-step integration procedure. The other extension shows that the nonlinear error propagation results, which are derived for a nonlinear single degree of freedom （SDOF） system, can be applied to a nonlinear multiple degree of freedom （MDOF） system. This application is dependent upon the determination of the natural frequencies of the system in each time step, since all the numerical properties and error propagation properties in the time step are closely related to these frequencies. The results are derived from the step degree of nonlinearity. An instantaneous degree of nonlinearity is introduced to replace the step degree of nonlinearity and is shown to be easier to use in practice. The extensions can be also applied to the results derived from a SDOF system based on the instantaneous degree of nonlinearity, and hence a time step might be appropriately chosen to perform a pseudodynamic test prior to testing.

关键词： nonlinear error propagation explicit pseudodynamic algorithm stability condition step-by-step integration procedure step degree of nonlinearity

Starting flow in a rotating parallel plate channel

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Acta Mechanica Sinica 2012年第5期28卷 1271-1276页

作者： chang Yi Wang Department of Mathematics Michigan State University

The starting flow due to a suddenly applied pressure gradient in a parallel plate channel which is rotating as a system is studied. Exact analytic series solutions to the unsteady Navier-Stokes equations are found by both the Laplace transform method and the separation of parameters method, the latter is shown to be superior. Rotation not only induces a secondary transverse flow but also alters the character of the transient flow rate and velocity profiles. Back flow and inertial oscillations occur, especially at higher rota- tion rates.

关键词： Rotating system flow - Starting

The effects of hydrogen on the helium behavior in palladium

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Nuclear Science and Techniques 2016年第5期27卷 114-119页

作者： chang-Ning Peng Electrical Engineering College Longdong University

As one candidate of tritium storage materials,palladium subjects to the damage from helium atoms introduced by the(3-decay of tritium *** mechanical properties of palladium will be greatly degraded deriving from the accumulation of helium atoms.A set of interatomic potentials has been fitted based on ab initio calculation according to the Morse *** dynamic methods are utilized to investigate the existence of H atoms on the release of helium atoms from palladium with the present fitted *** is found that hydrogen atoms play significant roles in the diffusion and release of helium *** presence of hydrogen atoms tends to obstacle the diffusion and release of helium atoms in palladium.

关键词：氦原子氢原子行为钯分子动力学存储材料机械性能莫尔斯

Nonlinear evaluations of unconditionally stable explicit algorithms

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Earthquake Engineering and Engineering Vibration 2009年第3期8卷 329-340页

作者： Shuenn-Yih chang Department of Civil Engineering Taipei University of Technology

Two explicit integration algorithms with unconditional stability for linear elastic systems have been successfully developed for pseudodynamic testing. Their numerical properties in the solution of a linear elastic system have been well explored and their applications to the pseudodynamic testing of a nonlinear system have been shown to be feasible. However, their numerical properties in the solution of a nonlinear system are not apparent. Therefore, the performance of both algorithms for use in the solution of a nonlinear system has been analytically evaluated after introducing an instantaneous degree of nonlinearity. The two algorithms have roughly the same accuracy for a small value of the product of the natural frequency and step size. Meanwhile, the first algorithm is unconditionally stable when the instantaneous degree of nonlinearity is less than or equal to 1, and it becomes conditionally stable when it is greater than 1. The second algorithm is conditionally stable as the instantaneous degree of nonlinearity is less than 1/9, and becomes unstable when it is greater than 1. It can have unconditional stability for the range between 1/9 and 1. Based on these evaluations, it was concluded that the first algorithm is superior to the second one. Also, both algorithms were found to require commensurate computational efforts, which are much less than needed for the Newmark explicit method in general structural dynamic problems.

关键词： explicit integration algorithms unconditional stability pseudodynamic algorithm nonlinear system instantaneous degree of nonlinearity

An updated constraint on the local stratigraphy at the chang'E-4 landing site

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Earth and Planetary Physics 2021年第1期5卷 19-31页

作者： YiRen chang ZhiYong Xiao YiChen Wang ChunYu Ding Jun Cui YuZhen Cai State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 999078China Planetary Environmental and Astrobiological Research Laboratory School of Atmospheric SciencesSun Yat-sen UniversityZhuhaiGuangdong 519000China Center for Excellence in Comparative Planetology Chinese Academy of SciencesHefei 230000China National Astronomical Observations of China Chinese Academy of SciencesBeijing 100000China

The chang’E-4 mission has been exploring the lunar *** scientific targets of the rover onboard are(1)resolving the possible mineralogy related to the South Pole-Aitken basin and(2)understanding the subsurface processes at the lunar *** to date that are based on the reflectance spectra and radar data obtained by the rover have shown a persistent inconsistency about the local *** explain both the abnormal surface topography at the landing site and the unexpected radargram observed by the rover,the Alder crater has been frequently reported to be older than the mare basalts at that landing ***,this argument is not supported by earlier geological mapping nor recent crater *** this controversy is critical for a full understanding of the geological history of the landing area and for correct interpretations of the scientific data *** detailed crater statistics,rigorous statistical analyses,and an updated crater chronology function,this study is determined to resolve the relative ages of the Alder crater,Finsen crater,and the mare basalts on the floor of Von Kármá*** results reveal that while background secondaries and local resurfacing have widely occurred in the study area,affecting age determinations,the statistics are significant enough to conclude that the Alder crater is the oldest among the three *** independent constraint is consistent with both the crosscutting relationships of different terrains in this area and global stratigraphic *** results exclude Alder as a possible contributor of the post-mare deposits at the landing site,appealing for a more systematic stratigraphy study to resolve the provenances of these deposits.

关键词： Moon chang'E-4 impact craters absolute model age stratigraphy

不同宿主来源产气荚膜梭菌生物被膜形成前后药物敏感性分析

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动物医学进展 2025年第1期46卷 38-42页

作者：吴莹邵长军刘文华青岛农业大学动物医学院山东青岛266109 烟台市农科院山东烟台264200

为了检测5株不同宿主来源产气荚膜梭菌形成生物被膜能力及其对抗菌药物的敏感性差异,首先用纸片扩散法药敏试验测定5株不同来源的产气荚膜梭菌对7种抗菌药物的敏感性;筛选高敏药物测定各菌株的最小抑菌浓度(MIC);利用结晶紫染色法检测... 详细信息

为了检测5株不同宿主来源产气荚膜梭菌形成生物被膜能力及其对抗菌药物的敏感性差异,首先用纸片扩散法药敏试验测定5株不同来源的产气荚膜梭菌对7种抗菌药物的敏感性;筛选高敏药物测定各菌株的最小抑菌浓度(MIC);利用结晶紫染色法检测不同来源产气荚膜梭菌生物被膜形成能力和高敏药物对生物被膜的抑制和清除能力。药敏结果显示,5株不同宿主来源产气荚膜梭菌均对氨苄西林高度敏感,对其余6种抗菌药物有不同程度耐药;氨苄西林对不同菌株的MIC值在0.031~2.000μg/mL之间;所有菌株均能生成生物被膜,但生物被膜生成能力有差异;不同菌株在各自4、2、1 MIC下生物被膜的生成受到不同程度抑制,而亚抑菌浓度的氨苄西林能刺激生物被膜的生成,氨苄西林对已经生成的生物被膜不能完全清除。结果表明,不同来源产气荚膜梭菌形成生物被膜前后对药物敏感性不同,可为产气荚膜梭菌的临床用药选择及使用剂量提供一定的参考依据。

关键词：产气荚膜梭菌生物被膜最小抑菌浓度耐药性

Néel Transition and Staggered Magnetization of La_(2-δ)Sr_(δ)CuO_(4)

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Chinese Physics Letters 2000年第12期17卷 905-906页

作者： chang Zhe Institute of High Energy Physics Chinese Academy of SciencesBeijing 100039

The doped anisotropic antiferromagnet,which is believed to describe the elementary properties of the high-temperature superconductors,is studied by making use of Green’s function theory of the t-J *** Néel transition and staggered magnetization dependence on the anisotropic parameter ς and the doping density δ in La_(2-δ)Sr_(δ)CuO_(4) are *** results are found to be in good agreement with experiments on the cuprates.

关键词： anisotropic Transition elementary