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Numerical performance assessment of double-shell targets for z-pinch dynamic hohlraum

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Matter and Radiation at Extremes 2022年第3期7卷 10-19页

作者： Y.Y.Chu z.Wang J.M.Qi z.P.Xu z.H.Li Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China

A z-pinch dynamic hohlraum can create the high-temperature radiation field required by indirect-drive inertial confinement fusion.A dynamic hohlraum with peak radiation temperature over 300 eV can be obtained with a>50 MA z-pinch driver according to the scaling law of dynamic hohlraum radiation temperature vs drive *** on a uniform 300 eV radiation temperature profile with a width of 10 ns,three double-shell capsules with radii of 2,2.5,and 3 mm are proposed,and the corresponding fusion yields from a one-dimensional calculation are 28.8,56.1,and 101.6 *** implosion dynamics of the 2.5 mm-radius capsule is investigated in *** ignition,the areal density of the fuel is about 0.53 g/cm^(2),the fuel pressure is about 80 Gbar,and the central ion temperature is about 4.5 keV,according to the one-dimensional simulation.A two-dimensional simulation indicates that the double-shell capsule can implode nearly spherically when driven by the radiation field of a z-pinch dynamic *** sensitivities of the fusion performance to the radiation temperature profiles and to deviations in the capsule parameter are investigated through one-dimensional simulation,and it is found that the capsule fusion yields are rather stable in a quite large parameter space.A one-dimensional simulation of a capsule embedded in 50 mg/cm^(3)CH foam indicates that the capsule performance does not change greatly in the mimicked environment of a z-pinch dynamic *** double-shell capsules designed here are also applicable to laser indirect-drive inertial fusion,if a laser facility can produce a uniform 300 eV radiation field and sustain it for about 10 ns.

关键词： dynamic double performance

A Simplified Regular Solution Model for Solubility of Nonmetal (2) in Metal(1)-Metal(3) Alloy Systems

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Journal of Materials Science & Technology 1996年第4期12卷 281-285页

作者： Fang, z zhang, QR CHANGSHA TECH COLL DEPT METCHANGSHA 410012PEOPLES R CHINA

A simplified regular solution model for the solubility of nonmetallic element (2) in metal(1)-metal(3) alloy system has been derived and applied to the Fe-C-j, Ni-S-j and Fe-N-j (j denotes a metal) systems with satisf... 详细信息

关键词： Alloys

Current status and future directions of high-throughput ADME screening in drug discovery

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Journal of Pharmaceutical Analysis 2020年第3期10卷 201-208页

作者： Wilson z.Shou Bristol-Myers Squibb PO Box 4000PrincetonNJ08540USA

During the last decade high-throughput in vitro absorption,distribution,metabolism and excretion(HTADME)screening has become an essential part of any drug discovery effort of synthetic *** conduct of HT-ADME screening has been"industrialized"due to the extensive development of software and automation tools in cell culture,assay incubation,sample analysis and data *** HT-ADME assay portfolio continues to expand in emerging areas such as drug-transporter interactions,early soft spot identification,and ADME screening of peptide drug ***,thanks to the very large and high-quality HT-ADME data sets available in many biopharma companies,in silico prediction of ADME properties using machine learning has also gained much momentum in recent *** this review,we discuss the current state-of-the-art practices in HT-ADME screening including assay portfolio,assay automation,sample analysis,data processing,and prediction model *** addition,we also offer perspectives in future development of this exciting field.

关键词： In vitro HT-ADME Automation Bioanalysis Mass spectrometry Acoustic ejection mass spectrometry

Pinless Friction Stir Spot Welding of Mg-3Al-1zn Alloy with zn Interlayer

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Journal of Materials Science & Technology 2016年第1期32卷 76-88页

作者： R.z.Xu D.R.Ni Q.Yang C.z.Liu z.Y.Ma College of Materials Science and Engineering Shenyang Aerospace University Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

With the addition of a thin zn interlayer, 2.4 mm thick Mg-3AI-1zn alloy sheets were friction stir spot welded （FSSW） using a pinless tool with fiat, convex and concave shoulder shapes. The results showed that an alloying reaction took place between the Mg substrate and zn interlayer during FSSW, forming a discontinuous intermetallics layer composed of dispersive （α-Mg ＋ Mgzn） eutectic structure under- neath the shoulder and a Mg-zn intermetallics bonding zone at the outside of the joints. This alloying reaction increased the bonded area and eliminated the hook defects, thereby producing sound FSSWjoints with a shallow keyhole without hook defects. The increase of plunge depth was beneficial to the Mg-zn diffusion, thereby increasing the tensile-shear load of the joints. However, excessive plunge depths re- sulted in a decrease of the effective sheet thickness, reducing the strength of the joints. At a small plunge depth, the convex and concave shoulders were more beneficial to the interface reaction than the fiat shoul- der. The maximum joint load of 6.6 kN was achieved by using the concave shoulder at a plunge depth of 1.0 mm. A post-welding heat treatment promoted the dissolution of the discontinuous reaction layer in the joints; however, it led to the occurrence of void defects, influencing the bonding strength.

关键词： Friction stir spot welding Magnesium alloys zn interlayer Hook defects

Numerical investigation on the flowfield of “swallowtail” cavity for supersonic mixing enhancement

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Acta Mechanica Sinica 2009年第1期25卷 37-44页

作者： C. Wang z. Jiang z. Hu J. Lu Institute or Mechanics. Chinese Academy of Sciences 100190 Beijing China ReCAPT Gyeongsang National University JinjuKyeongnam 660-701 South Korea

A ＂swallowtail＂ cavity for the supersonic combustor was proposed to serve as an efficient flame holder for scramjets by enhancing the mass exchange between the cavity and the main flow. A numerical study on the ＂swallow- tail＂ cavity was conducted by solving the three-dimensional Reynolds-averaged Navier-Stokes equations implemented with a k-e turbulence model in a multi-block mesh. Turbu- lence model and numerical algorithms were validated first, and then test cases were calculated to investigate into the mechanism of cavity flows. Numerical results demonstrated that the certain mass in the supersonic main flow was sucked into the cavity and moved spirally toward the combustor walls. After that, the flow went out of the cavity at its lateral end, and finally was efficiently mixed with the main flow. The comparison between the ＂swallowtail＂ cavity and the conventional one showed that the mass exchanged between the cavity and the main flow was enhanced by the lateral flow that was induced due to the pressure gradient inside the cavity and was driven by the three-dimensional vortex ring generated from the ＂swallowtail＂ cavity structure.

关键词： Supersonic mixing - Flame holder "Swallowtail" cavity - Combustion ignition Numerical simulation

When joggers meet robots:the past,present,and future of research on humanoid robots

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Bio-Design and Manufacturing 2019年第2期2卷 108-118页

作者： George H.z.Liu Michael z.Q.Chen Yonghua Chen Department of Mechanical Engineering The University of Hong KongPokfulamHong KongPeople’s Republic of China School of Automation Nanjing University of Science and TechnologyNanjing 210094JiangsuPeople’s Republic of China

Spawned by fast-paced progress in new materials and integrate circuit technology,the past two decades have witnessed tremendous development of humanoid robots for both scientific and commercial purposes,*** response and daily life *** the root of this trend are the increasing research interests and cooperation opportunities across different laboratories and *** application-driven requirements of high effectiveness and reliability of humanoid robots led intensive research and development in humanoid locomotion and control *** spite of the progress in the area,challenges such as unnatural locomotion control,inefficient multi-motion planning,and relatively slow disturbances recovery set further requirements for the next generation of humanoid ***,the purpose of this work is to review the current development of highly representative bipedal humanoid robots and discuss the potential to move the ideas and models forward from laboratory settings into the real *** this end,we also review the current clinical understanding of the walking and running dynamics to make the robot more human-like.

关键词： Humanoid robot Walking dynamics Dynamic control Bio-inspired gait Robot efficiency Shock absorption

High-Speed Friction Stir Welding of T6-Treated B4Cp/6061Al Composite

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Acta Metallurgica Sinica(English Letters) 2020年第1期33卷 67-74页

作者： Y.z.Li Y.N.zan Q.z.Wang B.L.Xiao z.Y.Ma Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China University of Science and Technology of China Shenyang 110016China

T6-treated 20 wt% B4 Cp/6061 Al sheets were joined under welding speeds of 400–1200 mm/min by friction stir welding(FSW) with a threaded cermet pin. The macro-defect-free FSW joints could be achieved at high welding speeds up to 1200 mm/min, but larger plunge depth was required at the welding speeds of 800 and 1200 mm/min to eliminate the tunnel defect. In the nugget zone(Nz) of the joints, the B4 C particles were broken up and uniformly redistributed. The Nz exhibited lower hardness than the base metal(BM), and the hardness value almost did not change with increasing welding speed, attributable to the dissolution of precipitates. Compared with the BM, the joints showed lower tensile strength. As the welding speed increased from 400 to 800 mm/min, the joint efficiencies were nearly the same and up to ~ 73%. When the welding speed increased up to 1200 mm/min, the tensile strength significantly decreased, due to the occurrence of kissing bond defect at the bottom of the Nz. With increasing welding speed, the fracture location of the joints transferred gradually from the heat-affected zone to the Nz due to the kissing bond defects.

关键词： Metal-matrix composites Microstructures Mechanical properties Friction stir welding High-speed welding

Partition method and experimental validation for impact dynamics of flexible multibody system

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Acta Mechanica Sinica 2018年第3期34卷 482-492页

作者： J.Y.Wang z.Y.Liu J.z.Hong School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong University

The impact problem of a flexible multibody system is a non-smooth, high-transient, and strong-nonlinear dynamic process with variable boundary. How to model the contact/impact process accurately and efficiently is one of the main difficulties in many engineering applications. The numerical approaches being used widely in impact analysis are mainly from two fields： multibody system dynamics （MBS） and computational solid mechanics （CSM）. Approaches based on MBS provide a more efficient yet less accurate analysis of the contact/impact problems, while approaches based on CSM are well suited for particularly high accuracy needs, yet require very high computational effort. To bridge the gap between accuracy and efficiency in the dynamic simulation of a flexible multibody system with contacts/impacts, a partition method is presented considering that the contact body is divided into two parts, an impact region and a non-impact region. The impact region is modeled using the finite element method to guarantee the local accuracy, while the non-impact region is modeled using the modal reduction approach to raise the global efficiency. A three-dimensional rod-plate impact experiment is designed and performed to validate the numerical results. The principle for how to partition the contact bodies is proposed： the maximum radius of the impact region can be estimated by an analytical method, and the modal truncation orders of the non-impact region can be estimated by the highest frequency of the signal measured. The simulation results using the presented method are in good agreement with the experimental results. It shows that this method is an effec-rive formulation considering both accuracy and efficiency. Moreover, a more complicated multibody impact problem of a crank slider mechanism is investigated to strengthen this conclusion.

关键词： Partition method Impact dynamics Experimental investigation Efficiency and accuracy Partition principle

Determination of surface structure and the depth profile of silica glass by infrared spectroscopy

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光学精密工程 2005年第4期13卷 413-420页

作者： C. z. Tan Laboratory of Solid State Microstructure and Department of Materials Science and Engineering Nanjing University 210093 Nanjing China Institut für Mineralogie Freie Universitt Berlin 14195 Berlin Germany

The surface structure and properties are different from those of the bulk, depending on the substrate materials and deposition condition, and playing an important role in precise optical components. The conventional spectroscopic methods to monitor the surface structure are restricted only in several layers of molecules. It is known that the penetration depth of the incident light increases with its wavelength and decreases with the angle of incidence. Thus infrared spectroscopy provides a powerful means for determination of surface structure and the depth profile up to micrometers. By recording the reflection spectra at different angles of incidence, the surface structure and its depth profile can be monitored successively. Further, the incident field has the subcomponents parallel and perpendicular to the surface, which excite the transverse and longitudinal optic modes, respectively. Change of the polarization direction of the incident light provides a practical function to study anisotropic property of the surface and the interaction between the transverse and longitudinal optic modes. In this work, infrared spectrophotometer was applied to investigate the depth profile in microstructure of silica glass. Combining with the glass fiber system, this technique can be used for in-situ control of the deposition process. In comparing with ellipsometry, this method reveals both structural and constitutional information.

关键词：硅石光谱红外线表面结构光学材料