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Chinese Chemical Letters 1995年第11期6卷 1009-1012页

作者： Xu, PF wu, z Lanzhou Univ Dept Chem Lanzhou 730000 Peoples R China Cent Res Inst Bldg & Construct MMI Beijing 100088 Peoples R China

The preparation and characterization of some divalent metal ion M (Ⅱ)complexes derived from potassium 3-(benzotriazole-1-carbonylmethyl)-dithiocar bazate (BCDHK) is reported. Thesolid complexes of the composition ML· nH2Oand ML2·2H2O (M=Ph(Ⅱ), UO2(Ⅱ)), have been characterized on the basis of elemental analyses,IR, UV and TGA.

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Design and optimization of a longitudinal feedback kicker cavity for the HLS-Ⅱ storage ring

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Chinese Physics C 2013年第3期37卷 84-92页

作者：徐卫 W.z.wu 何多慧 Y.K.wu National Synchrotron Radiation Laboratory (NSRL) University of Science and Technology of China Department of Physics Duke University

In the Hefei Light Source （HLS） storage ring, multibunch operation is used to obtain a high luminosity. Multibunch instabilities can severely limit light source performance with a variety of negative impacts, including beam loss, low injection efficiency, and overall degradation of the beam quality. Instabilities of a multibunch beam can be mitigated using certain techniques including increasing natural damping （operating at a higher energy）, lowering the beam current, and increasing Landau damping. However, these methods are not adequate to stabilize a multibunch electron beam at a low energy and with a high current. In order to combat beam instabilities in the HLS storage ring, active feedback systems including a longitudinal feedback system （LFB） and a transverse feedback system （TFB） will be developed as part of the HLS upgrade project, the HLS-Ⅱ storage ring project. As a key component of the longitudinal bunch-by-bunch feedback system, an LFB kicker cavity with a wide bandwidth and high shunt impedance is required. In this paper we report our work on the design of the LFB kicker cavity for the HLS-Ⅱ storage ring and present the new tuning and optimization techniques developed in designing this high performance LFB kicker.

关键词： longitudinal feedback system kicker nose cone

BEHAVIOR OF SHORT FATIGUE CRACKS AT BLUNT NOTCHES IN A MEDIUM CARBON STEEL

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Acta Metallurgica Sinica(English Letters) 1997年第5期10卷 430-436页

作者： wu, z.X. Sun, X.F. Southwest Jiaotong Univ Chengdu China

The behavior of part-through and through short cracks in single edge blunt notched specimens of a medium carbon steel was investigated by a replication method. It is found that the fatigue failure of these notched specimens is caused mainly by the growth of short surface cracks originating from the surface of notch root. More than 70% of the fatigue life is spent in the regimes in which short surface cracks initiate and propagate as part-through cracks before joining up to form a single through-thickness crack. The effect of original crack profile which is formed through the coalescence of multiple part-through cracks is the main reason causing the 'anomalous' propagation behavior of the through-thickness crack in its early stage.

关键词： Carbon steel Crack initiation Crack propagation Fatigue of materials Fracture mechanics Surfaces

Regulation of thermoelastic properties of concave-packaged DNA adsorption films and its relevant microcantilever detection signals

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Acta Mechanica Sinica 2021年第4期37卷 705-711,I0004页

作者： C.X.wu N.H.zhang C.Y.zhang J.z.wu School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsShanghai 200072China

The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of *** this paper,we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films,the detection signals of microcantilevers and their temperature ***,the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders;then,the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus,prestress and thermal expansion coefficient of DNA adsorption films;finally,based on an effective macroscopic continuum model for DNA microbeam deformation,we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections,*** show that,compared with the convex-packaged,the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress,so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature *** results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors.

关键词： DNA-microbeam Packaging pattern Elastic property Thermal expansion coefficient Detection signal

Ultrahigh strength Mg-Y-Ni alloys obtained by regulating second phases

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Journal of Materials Science & Technology 2020年第10期42卷 117-124页

作者： S.z.wu X.G.Qiao M.Y.zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

Mg-Y-Ni alloys with different second phases were designed by changing Y/Ni atomic ratio from 1.5 to *** microstructure and mechanical properties of as-cast and as-extruded alloys were *** as-cast Mg-Y-Ni alloy with Y/Ni ratio of 1.5 is composed ofα-Mg and long period stacking ordered(LPSO)*** Y/Ni ratio is equal to 1,nanoscale lamellarγ’phase and eutectic Mg2Ni phase are formed in addition to LPSO *** Y/Ni ratio decreases further,the amount of eutectic Mg2Ni phase increases,while the amount of LPSO phase *** extrusion,the LPSO andγ’phases are distributed along the extrusion direction,while eutectic Mg2Ni phase is broken and dispersed in the as-extruded *** phase and Mg2Ni phase in the alloys promote dynamic recrystallization(DRX)during extrusion,whileγ’phase inhibits ***,the Mg96Y2Ni2(at.%)alloy with LPSO phase andγ’phase as the main second phases shows the strongest basal texture after *** tensile yield strength of the as-extruded Mg-Y-Ni alloys increases first and then decreases with decreasing Y/Ni *** as-extruded Mg96Y2Ni2(at.%)alloy with Y/Ni=1 exhibits excellent mechanical properties with tensile yield strength of 465 MPa,ultimate tensile strength of 510 MPa and elongation to failure of 7.2%,which is attributed to the synergistic effect of bulk LPSO phase and nanoscaleγ’phase.

关键词： Mg-Y-Ni alloys LPSO γ’Phase Mg2Ni Mechanical properties

A new model for the expansion tube considering the stress coupling:Theory,experiments and simulations

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Defence Technology（防务技术） 2022年第7期18卷 1190-1204页

作者： M.z.wu X.W.zhang Q.M.zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyHaidian DistrictBeijing10081China

Based on the two-arc profile assumption,the expansion deformation and energy absorption of circular tubes compressed by conical-cylindrical dies were ***,the deformation of the two arcs was analyzed independently and an improved model denoted as Model-I was ***,by further involving the coupling between the bending moment and membrane forces,a more elaborate model,i.e.,Model-II was ***,experiments and simulations were conducted to verify the models,which show that,compared with previous theoretical models,Model-II could not only capture the prominent features of the deformation,but also improve the prediction accuracy of the steady driving force *** means of this model,it was found that the critical semi-conical angle,which makes the driving force minimum,increases with the increase of the friction coefficient,expansion ratio as well as the radius/thickness ratio of the ***,the energy dissipation due to stretching is always greater than that of bending,while the friction dissipation can account for the largest proportion at small semi-conical angle or large friction *** a certain friction and die conditions,the specific energy absorption of expanded tubes can be much higher than that under progressive collapse mode.

关键词： Expansion Circular tube Stress coupling Strain hardening Energy absorption

On a general theory for compressing process and aeroacoustics:linear analysis

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Acta Mechanica Sinica 2010年第3期26卷 355-364页

作者： E .Mao Y. P. Shi J. z. wu State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University 100871 Beijing China University of Tennessee Space Institute Tullahoma TN 37388 USA

Of the three mutually coupled fundamental processes （shearing, compressing, and thermal） in a general fluid motion, only the general formulation for the compress- ing process and a subprocess of it, the subject of aeroacous- tics, as well as their physical coupling with shearing and thermal processes, have so far not reached a consensus. This situation has caused difficulties for various in-depth complex multiprocess flow diagnosis, optimal configuration design, and flow/noise control. As the first step toward the desired formulation in fully nonlinear regime, this paper employs the operator factorization method to revisit the analytic linear theories of the fundamental processes and their decomposi- tion, especially the further splitting of compressing process into acoustic and entropy modes, developed in 1940s-1980s. The flow treated here is small disturbances of a compressible, viscous, and heat-conducting polytropic gas in an unbounded domain with arbitrary source of mass, external body force, and heat addition. Previous results are thereby revised and extended to a complete and unified theory. The theory pro- vides a necessary basis and valuable guidance for developing corresponding nonlinear theory by clarifying certain basic issues, such as the proper choice of characteristic variables of compressing process and the feature of their governing equations.

关键词： Longitudinal (compressing) processTransversal (shearing) process Acoustic mode Entropy mode Aeroacoustics

A betatron tune measurement system based on bunch-by-bunch transverse feedback at the Duke storage ring

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Chinese Physics C 2013年第7期37卷 76-82页

作者：徐卫 W. z. wu 李京祎何多慧 Y. K. wu National Synchrotron Radiation Laboratory (NSRL) University of Science and Technology of China FEL Laboratory TUNL and Department of Physics Duke University

To combat electron beam instabilities, a digital bunch-by-bunch transverse feedback （TFB） system has been developed for the Duke storage ring. While it is capable of suppressing transverse beam instabilities for multibunch operation, the TFB system has not been needed for typical operation of the Duke storage ring. To explore the great potential of this system, we have developed beam diagnostic techniques using the TFB, in particular, the TFB based tune measurement techniques. The tune measurement technique allows us to conduct fast chromaticity measurements, compared with the existing chromaticity measurement system using a network analyzer. This new tune measurement system also enables us to measure the bunch tune for multibunch operation of the Duke storage ring. With the TFB based tune measurement system, we have studied the tune stability of the electron beam in the Duke storage ring. This tune system has also been used to calibrate the tune knob for the Duke storage ring.

关键词： transverse feedback tune chromaticity

MODELING OF ISOTHERMAL PRECIPITATION KINETICS IN HSLA STEELS AND ITS APPLICATION

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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 902-906页

作者： X.M.zhao D.wu L.z.zhang z.Y.Liu TheStateKeyLab.ofRollingandAutomation NortheastemUniversityShenyang110004China

Microalloying elements in high-strength low-alloy steels, such as Nb, Ti and V, precipitate during hot-rolling processes. On the basis of classical theory of nucleation and growth, quanti- tative modeling of isothermal precipitation was developed, which was tested by the stress rela- xation method, the calculated precipitation-time-temperature curve is in good agreements with the measured results, then the model was applied to predict the precipitation behavior during continuous cooling.

关键词： isothermal precipitation kinetics HSLA steel

THEORETICAL ANALYSIS FOR THE MOTION AND TEMPERATURE OF MELT DROPLETS IN SPRAY DEGASSING PROCESS

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Acta Metallurgica Sinica(English Letters) 2007年第3期20卷 193-198页

作者： R.z. wu z.K. Qu B.D. Sun D. Shu J. Wang College of Materials Science ＆ Chemical Engineering Harbin Engineering University Harbin 150001 China State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai 200030 China Department of Chemistry Harbin Normal University Harbin 150025 China

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process couM be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets wouM solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results,

关键词： spray degassing hydrogen removal aluminum melt motion temperature