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Inhibit the Porosity with Electron Beam Scanning Method in Welding LD10 Aluminum Alloy

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稀有金属材料与工程 2011年第S4期40卷 54-57页

作者： Mo Zhonghai,Wang Yarong,Huang Wenrong Institute of Machinery Manufacturing Technology,china Academy of Engineering Physics,Mianyang 621900,china china Acad Engn Phys Inst Machinery Mfg Technol Mianyang 621900 Peoples R China

LD10 aluminum alloy is becoming widely used in aeronautics and astronautics industries for the advantages of high specific strength and good mechanical *** alloy is an active metal with low melting point and boiling *** porosity is apt to occur in the processing of electron beam *** this article,the author investigated the influence of electron beam scanning welding parameters (scanning figure,scanning frequency,focus,and welding speed) on porosity.10 mm thick LD10 aluminum alloy were welded and then tested by X-ray *** experiment results indicated that rational parameters would reduce the occurrence opportunity of *** the parameters of circle scanning,high scanning frequency,focus-out,and smaller welding speed,the porosity can be significantly reduced.

关键词： electron beam welding LD10 aluminum alloy porosity

Effects of Processing Parameters on Weld Geometries in Electron Beam Welding Based on Partial Correlation Analysis

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稀有金属材料与工程 2011年第S4期40卷 30-34页

作者： Shen X F,Huang W R,Zhang Y Z Institute of Machinery Manufacturing Technology,china Academy of Engineering Physics,Mianyang 621900,china china Acad Engn Phys Inst Machinery Mfg Technol Mianyang 621900 Peoples R China

Accelerating voltage,electron beam current,welding speed constitutes the main electron beam welding process parameters,while the penetration depth and depth-width ratio are two of the most important characteristic parameters of the weld *** complex interactions exists between the five variables,so the analysis of a single process parameter on one of weld geometries is affected by the other process parameters,and the impact of these interference parameters should be excluded to find the real relationship between the variables where partial correlation analysis provides such a *** of the accelerating voltage,electron beam current,welding speed of electron beam welding process parameters on weld geometries is analyzed by using partial correlation *** priority order of adjustment of process parameters is obtained,namely:in order to obtain a larger depth-width ratio indicators,it should be taken firstly to increase the beam current and accelerating voltage,and then to raise the welding speed;in order to obtain greater penetration depth,it is preferred to increase the beam current,followed by increasing the accelerating voltage,and reducing the welding speed finally.

关键词： electron beam welding process parameters characteristic parameters of weld morphology partial correlation analysis

Processing technique of target capsule's micro inflation hole with a scanning probe

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Science china(Technological Sciences) 2004年第1期47卷 77-84页

作者： SUN Tao, YAN Yongda, GAO Dangzhong, TANG Yongjian, FU Yibei & DONG ShenPrecision Engineering Research Institute, Harbin Institute of Technology, Harbin 150001, china Research Centre of Laser Fusion, Chinese Academy of Engineering Plysics, Mianyang 621900, china Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang 621900, china Precision Engineering Research Institute Harbin Institute of Technology Harbin China Research Centre of Laser Fusion Chinese Academy of Engineering Plysics Mianyang China Institute of Nuclear Physics and Chemistry Chinese Academy of Engineering Physics Mianyang China

To resolve inflation of inertial confinement fusion (ICF) target and encapsulation of micro inflation hole with adhesive, a scanning probe microscope (SPM) diamond microprobe was used as the cutting tool with SPM in contact mode. Some parameters influencing the quality of micro inflation hole, such as the scanning direction of the diamond tip, the scanning rate and the contact force are discussed. Accurate taper hole was achieved whose climension and precision could meet the requirements of inflation and encapsulation technique of micro hole. The experimental results show that using SPM diamond microprobe as the cutting tool and with special processing technique, the precision machining of target capsule's taper inflation hole can be realized. A novel operative technology for filling high Z gas to target is provided.

关键词： target capsule, scanning probe microscope (SPM), diamond microprobe, processing technique, brittle material.

The Influence of Temperature on the Afterglow Feature of SrAl_2O_4∶Eu,Dy Phosphors

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Journal of Wuhan University of Technology(Materials Science) 2006年第3期21卷 120-122页

作者：王兵 Materials School Southwest University of Science and TechnologyMianyang 621010China

Using a self-designed temperature testing box in which Xenon-lamp irradiation can be applied, the afterglow feature of SrAl2O4： Eu, Dy as a function of temperature has been researched. Two sorts of SrAl2O4 ： Eu, Dy phosphors, namely highest quality commercial one and the self-synthesized one by solid-state reaction process were employed. Results reveal a common phenomenon behaving as phosphorescent sudden extinguishments at a certain low temperature although their threshold temperature value （ about 223 K） has a slight difference . The general charueteristic for the influence of temperature on the afterglow feature presents, compared to the luminescent decay at room temperature （RT）, a bigger and faster decrease of phosphorescent brightness with the reduction of temperature, while decay curves still maitain the same pattern composed of a quick decline part and a platform falling part during which the phosphorescent brightness at 273 K is only aboat 1/2 as big as that at RT, and at 253 K the figure has changed to about 1/3. Finally , the reason of previous observed results has been analyzed briefly in theory.

关键词： afterglow SrAl2O4:Eu,Dy low temperature

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Science china Chemistry 2004年第6期47卷 466-479页

作者： SONG Huajie1,2, XIAO Heming1 & DONG Haishan2 1. Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, china 2. Institute of Chemical Materials, china Academy of Engineering Physics, Mianyang 621900, china Department of Chemistry Nanjing University of Science and Technology Nanjing China Institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The symmetry-adapted perturbation theory (SAPT) that has the ability in decompo- sition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the diffi- culty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2, HF2 and (N2)2 and a set of larger ni- tramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capa- ble of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially pro- vides a good means to calculate accurately intermolecular forces in larger system such as en- ergetic systems.

关键词： intermolecular interaction, density functional theory (DFT), symmetry adapted perturbation theory (SAPT), asymptotic correction, frequency-dependent density susceptibilities (FDDS).

Large-eddy simulations of the Richtmyer-Meshkov instability of rectangular interfaces accelerated by shock waves

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Science china(Physics,Mechanics & Astronomy) 2010年第12期53卷 905-914页

作者： WANG Tao,BAI JingSong,LI Ping & LIU Kun Institute of Fluid Physics,china Academy of Engineering Physics,Mianyang 621900,china Institute of Fluid Physics China Academy of Engineering Physics Mianyang China

A parallel algorithm and code MVFT(multi-viscous-fluid and turbulence) of large-eddy simulation(LES) is developed from our MVPPM(multi-viscous-fluid piecewise parabolic method),and performed to solve the multi compressible Navier-Stokes(N-S) *** effect of the unresolved subgrid-scale(SGS) motions on the large scales is represented by different SGS stress models in LES.A Richtmyer-Meshkov instability experiment of the evolution of a rectangular block of SF6,which occupies half of the height of the shock tube test section,following the interaction with a planar shock wave,is numerically and exhaustively simulated by this *** comparison between experimental and simulated images of the evolving SF6 block shows that they are *** numerical simulations reproduce the complex developing process of SF6 block,which grows *** geometric quantities that characterize the extents of SF6 block are also compared in detail between numerical simulations and experiment with good agreements between them,a quantitative demonstration of the developing law of SF6 *** is an evident discrepancy between the three numerical simulations for the maximum position of the right edge of block at the late stage,because the right interface grows complicated and the dissipation is different for different SGS *** SGS turbulent dissipation,molecular viscosity dissipation and SGS turbulent kinetic energy have been studied and *** have a similar distribution to the large eddy *** SGS turbulent dissipation is much greater than the molecular viscosity dissipation;the SGS turbulent dissipation of Vreman model is smaller than the Smagorinsky *** general,the simulated results of Vreman SGS model are better compared with the dynamic viscosity and Smagorinsky SGS *** vorticity and circulation deposition on the block interface have also been investigated.

关键词： large-eddy simulation Navier-Stokes equations subgrid-scale Richtmyer-Meshkov instability turbulent dissipation turbulent kinetic energy circulation deposition

Encapsulation of inorganic particles by dispersion polymerization through ultrasonic irradiation

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Science china Chemistry 2005年第6期48卷 545-552页

作者： ZHANG Kai1,2, FU Qiang1, HUANG Yuhong2 & ZHOU Dehui2 1. College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, china 2. Institute of Structure Mechanics, china Academy of Engineering Physics, Mianyang 621900, china College of Polymer Science and Engineering Sichuan University Chengdu China Institute of Structure Mechanics China Academy of Engineering Physics Mianyang China

The nano-silica/polystyrene composite particles were prepared and characterized according to the following steps. First, the nano-silica particles were pretreated with surfactants under ultrasonic field. Second, the dispersion polymerization of styrene in a water/ethanol (1/6, weight ratio) medium, with poly(N-vinyl pyrrolidone) (PVP) as stabilizer and 2,2’-azobisizobu- tyronitrile (AIBN) as initiator in the presence of nano-silica particles was initiated with N2 purging through ultrasonic irradiation by taking its advantages of multieffect, i.e. dispersion, crushing, activation, and initiation. Finally, the polymerization kinetics characteristics were studied, and the encapsulation of composite particles was investigated with optical microscope, SEM, TEM, FTIR, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

关键词： composite particle, dispersion polymerization, ultrasonic irradiation.

Consecutive reversible ionization-recombination reactions and ionic charge state distribution of Au plasma

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Science china(Physics,Mechanics & Astronomy) 2005年第5期48卷 575-584页

作者： ZHU Zhiyan1, ZHU Zhenghe1, TANG Changhuan1, TANG Yongjian2 & GAO Tao1 1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, china 2. china Academy of Engineering Physics, Mianyang 621900, china Institute of Atomic and Molecular Physics Sichuan University Chengdu China china Academy of Engineering Physics Mianyang China

The present work proposes kinetics of ionization-recombination to study the charge state distribution of Au plasma. The first step is to calculate the average lifetime, energy level structure, degeneracy and partition function of Au48+―Au52+ by relativistic quantum mechanics, and next to compute the equilibrium constant and the second-order recombination rate constant by statistical thermodynamics. Based on these data, the differential equations of consecutive reversible ionization-recombination reactions are solved from which the charge state distribution and its average charge are derived. Finally, the influence of electron temperature and density on average charge is given in this paper. It is called the first-principle theory, for no experimental data are needed.

关键词： Au plasma, ionization-recombination dynamics, ionic charge state distribution, average charge.

Theoretical study of aging effects on LaNi_(5) tritium storage

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 676-686页

作者： PING Feilin1,2, JIANG Gang1, ZHANG Lin2 & ZHU Zhenghe1 1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, china 2. Research Center of Laser Fusion, Mianyang 621900, china Institute of Atomic and Molecular Physics Sichuan University Chengdu China Research Center of Laser Fusion Miangyang China

The electronic structure and energy of La2Ni10H12 and La2Ni10H11He (He is at tetrahedral, octahedral or twelve-face polyhedral interstitials) double cells have been calculated using the density functional theory. Their equilibrium structure, energy bands, electronic density of states (DOS) and X-ray diffraction are presented and discussed. The results indicate the helium-3 produced due to the decay of tritium is most possibly sited at twelve-face polyhedral and octahedral interstices and changes the thermodynamic properties of LaNi5 tritide system. The changes due to aging such as the reduction in the isotherm plateau pressure, increase of the isotherm plateau slope, and appearance of deeply trapped hydrogen are caused not only by the lattice expansion, but also by modification of the electronic structure due to the presence of He.

关键词： LaNi5 alloy, density functional theory, electronic structure, aging.