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Dynamic Testing Technique Based on Multi-channel Photonic Doppler Velocimetry for Investigating the Dynamic Behavior of Materials

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Acta Mechanica Solida Sinica 2019年第6期32卷 725-736页

作者： Yuanyuan Ding yonggang wang Zheng Zhang Huawei Lai Key Laboratory of Impact and Safety Engineering Ministry of EducationNingbo UniversityNingbo 315211China

In the present paper,more attention is paid to develop a new optical measurement approach of split-Hopkinson pressure bar(SHPB)and wave propagation inverse analysis(WPIA)by using multi-channel photonic Doppler velocimetry(PDV).Based on the particle velocities measured by PDV,the dynamic stress-strain curve of material is obtained in SHPB *** strain is determined by the radial particle velocity of specimen,and the stress is determined by the free surface particle velocity of the transmit ted *** results obtained by the new method coincide with those obtained by the conventional strain gauge *** new method is non-intrusive and insensitive to electrical noise,making it significantly more reliable than strain *** the oblique incidence of laser beam,a series of particle velocity wave propagation signals for long rod specimen are measured *** on the measurements of particle velocity profile,the dynamic constitutive response of polymethyl methacrylate(PMMA)is det ermined by WPIA *** comparison bet ween the dynamic st ress-s train curve and the quasi-static one indicates that the strain-rate effect must be taken into account for PMMA.

关键词： Dynamic mechanical behavior Photonic Doppler velocimetry Split-Hopkinson pressure bar Lagrangian analysis

Description of squeezed surface plasmons

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Science China(Physics,Mechanics & Astronomy) 2011年第9期54卷 1583-1586页

作者： YANG LiHua wang yonggang YANG BoJun School of Science Beijing University of Posts and Telecommunications Beifing 100876 China

Surface plasmon polaritons (SPPs) are the combined electron oscillations and electromagnetic waves propagating along the interface between a conductor and a dielectric. Recently Huck et al. [Huck A, et al. Phys Rev Lett, 2009, 102: 246802] proved that SPPs can be in a squeezed state, and the squeezed surface plasmons can propagate in a gold waveguide. In this paper, we introduce a quantum mechanical description of the squeezed surface plasmons at first, and discuss the influence of the waveguide losses on the squeezed surface plasmons.

关键词： surface plasmon polaritons (SPPs) squeezed state waveguide losses

Objective array design for three-dimensional temperature and salinity observation:Application to the South China Sea

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Acta Oceanologica Sinica 2022年第7期41卷 65-77页

作者： Mengxue Qu Zexun Wei Yanfeng wang yonggang wang Tengfei Xu First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao266061China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao266061China

In this study,a moored array optimization tool(MAOT)was developed and applied to the South China Sea(SCS)with a focus on three-dimensional temperature and salinity *** of the MAOT involves two steps:(1)deriving a set of optimal arrays that are independent of each other for different variables at different depths based on an empirical orthogonal function method,and(2)consolidating these arrays using a K-center clustering *** with the assumed initial array consisting of 17 mooring sites located on a 3°×3°horizontal grid,the consolidated array improved the observing ability for three-dimensional temperature and salinity in the SCS with optimization efficiencies of 19.03%and 21.38%,*** with an increased number of moored sites showed that the most cost-effective option is a total of 20 moorings,improving the observing ability with optimization efficiencies up to 26.54%for temperature and 27.25%for *** design of an objective array relies on the ocean phenomenon of interest and its spatial and temporal *** this study,we focus on basin-scale variations in temperature and salinity in the SCS,and thus our consolidated array may not well resolve mesoscale *** MAOT can be extended to include other variables and multi-scale variability and can be applied to other regions.

关键词： optimal array design observation system simulation experiment South China Sea empirical orthogonal function K-center clustering

Microstructure, Texture, and Hardness Evolutions of Al-Mg-Si-Cu Alloy during Annealing Treatment

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Journal of Wuhan University of Technology(Materials Science) 2019年第6期34卷 1288-1296页

作者： wang Xiaofeng MA Cunqian MA Pengcheng ZHOU Songze wang yonggang Key Laboratory of Impact and Safety Engineering(Ningbo University) Ministry of EducationNingbo 315211China Capital Aerospace Machinery Company Beijing 100076China Aerospace Research Institute of Materials and Processing Technology Beijing 100076China

Microstructure, texture and hardness evolutions of Al-Mg-Si-Cu alloy during annealing treatment were studied by microstructure, texture and hardness characterization in the present study. The experimental results show that microstructure, texture and hardness will change to some extent with the increase of annealing temperature. The microstructure transforms from the elongated bands to elongated grains first, and then the grains grow continuously. The texture transforms from the initial deformation texture b fiber to recrystallization texture mainly consisting of CubeND {001} and P {011} orientations first, and then the recrystallization texture may be enhanced continuously as a result of the grain growth. Hardness decreases slowly at first, and then decreases sharply and increases significantly finally. Besides, the particle distributions also have great changes. As the annealing temperature increases, they increase firstly as a result of precipitation, and then gradually disappear as a result of dissolution. Finally, the effect of annealing temperature on microstructure, texture and hardness evolutions is discussed.

关键词： Al-Mg-Si-Cu alloy hardness microstructure texture recrystallization

Evaluation of high-resolution and depth-encoding PET detector modules based on single-ended readout with TOFPET2 ASIC

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Radiation Detection Technology and Methods 2021年第3期5卷 451-458页

作者： Mingchen wang yonggang wang Liwei wang Modern Physics Department University of Science and Technology of ChinaHefei 230026AnhuiChina

Purpose We developed a low-complexity,high-resolution depth-of-interaction(DOI)capable positron emission tomography(PET)detector and tested its performance to prove that it can be applied to practical PET *** The detector module consists of a 24×24 LYSO crystal matrix,each with dimension of 1.04×1.04×15mm^(3),optically coupled to an 8×8 SiPM photo-sensor array with TOFPET2 ASIC single-ended *** only adding a light guide at the top of the crystal to reflect scintillation light back to the SiPM array,the continuous DOI information is extracted using a light sharing and redirection encoding method without adding system *** The crystal array with 9-to-1 coupling between scintillators and photo-sensors can be clearly separated in the flood *** other detector performance in terms of DOI resolution,energy resolution and coincidence time resolution are measured on average as 4.1 mm,15.0%and 432 ps,*** The test results confirm that the light sharing and redirection DOI encoding method can provide reasonably high DOI resolution without deteriorating other performance,even for highly pixelated PET detectors readout with commercially available ASIC *** has great potential for applications in future pre-clinical and organ-dedicated PET scanners.

关键词： High-resolution Depth-of-interaction TOFPET2 ASIC PET detector

A potential approach to replace sulfurized olefins with borate ester containing xanthate group in lubricating oil

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Chinese Science Bulletin 2008年第7期53卷 992-997页

作者： wang yonggang LI JiuSheng REN TianHui School of Chemistry and Chemical Engineering Shanghai Jiaotong University Shanghai 200240 China PetroChina Lanzhou Lubricating Oil R&D Institute Lanzhou 730060 China

To develop a potential substitute for sulfurized olefins, a borate ester derivative containing xanthate group (titled BXT) was synthesized and characterized. Meanwhile, its tribological properties in rape-seed oil were evaluated using four-ball tribometer. The results indicate that BXT shows excellent tri-bological capacity such as load-carrying, friction-reducing and antiwear property. Moreover, the syn-thesized compound has no noticeable odor, shows little corrosion to copper, and exhibits better ther-mal stability compared with sulfurized olefins. In order to study the action mechanism of BXT in friction process, analysis of the worn surface was carried out using a three-dimensional non-contact surface profilometer and XPS analyzer.

关键词：势能硫化作用烯烃硼酸盐酯黄原酸盐

The annual mean sketches and climatological variability of the volume and heat transports through the inter-basin passages:A study based on 1 400-year spin up of MOM4p1

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Acta Oceanologica Sinica 2014年第9期33卷 12-24页

作者： ZHU Yaohua WEI Zexun wang yonggang GUAN Yuping wang Xinyi Key Laboratory of Marine Science and Numerical Modeling First Institute of Oceanography State Oceanic Administration State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences

The annual mean volume and heat transport sketches through the inter-basin passages and transoceanic sections have been constructed based on 1400-year spin up results of the MOM4p 1. The spin up starts from a state of rest, driven by the monthly climatological mean force from the NOAAWorld Ocean Atlas （1994）. The volume transport sketch reveals the northward transport throughout the Pacific and southward transport at all latitudes in the Atlantic. The annual mean strength of the Pacific-Arctic-Atlantic through flow is 0.63x106 m3/s in the Bering Strait. The majority of the northward volume transport in the southern Pacific turns into the Indonesian through flow （ITF） and joins the Indian Ocean equatorial current, which subse- quently flows out southward from the Mozambique Channel, with its majority superimposed on the Ant- arctic Circumpolar Current （ACC）. This anti-cyclonic circulation around Australia has a strength of 11 x 106 ms /s according to the model-produced result. The atmospheric fresh water transport, known as P-E^R （pre- cipitation minus evaporation plus runoff）, constructs a complement to the horizontal volume transport of the ocean. The annual mean heat transport sketch exhibits a northward heat transport in the Atlantic and poleward heat transport in the global ocean. The surface heat flux acts as a complement to the horizontal heat transport of the ocean. The climatological volume transports describe the most important features through the inter-basin passages and in the associated basins, including： the positive P-E＋R in the Arctic substantially strengthening the East Greenland Current in summer; semiannual variability of the volume transport in the Drake Passage and the southern Atlantic-Indian Ocean passage; and annual transport vari- ability of the ITF intensifying in the boreal summer. The climatological heat transports show heat storage in July and heat deficit in January in the Arctic; heat storage in January and heat deficit in July in the

关键词： volume transport heat transport global ocean circulation inter-basin passages climatologicalvariability

High-power and low-cost sodium-ion batteries with a wide operation temperature from -70℃ to 130℃

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SmartMat 2023年第5期4卷 99-108页

作者： Zhi Li Yu Zhang yonggang wang Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Institute of New EnergyiChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Fudan UniversityShanghaiChina

Low-cost sodium-ion batteries(SIBs)are promising candidates for grid-scale energy-storage systems,and the wide-temperature operations of SIBs are highly demanded to accommodate extreme ***,a low-cost SIB is fabricated with a Na_(4)Fe_(3)(PO_(4))_(2)P_(2)O_(7)(NFPP)cathode,a natural graphite(NG)anode,and an ether-based *** prepared NG/NFPP batteries deliver a long lifespan of 1000 cycles,high-power density of 5938 W/kg,and remarkable rate performance of 10 A/g with a high capacity retention of 60%.Benefiting from the solvent co-intercalation process of the NG anode and the high Na^(+) diffusion rate of the NFPP cathode,the NG//NFPP battery displays outstanding performance at-40℃ and even can work at an ultralow temperature of-70℃.Furthermore,the high boiling point of the electrolytes and high thermal stability of the electrode materials also enable the high-temperature operation of the full battery up to 130℃.This work will guide the design of the wide-temperature SIBs.

关键词： high-power density low cost sodium-ion battery wide-temperature operation

A study of intra-seasonal variations in the subsurface water temperatures in the South China Sea

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Acta Oceanologica Sinica 2019年第4期38卷 97-105页

作者： Zhan Lian Baonan Sun Zexun Wei yonggang wang Xinyi wang Key Laboratory of Marine Science and Numerical Modeling First Institute of OceanographyMinistry of Natural Resources Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology (Qingdao)

Through analysis of the results of a verified high-fidelity numerical model, the intra-seasonal variations(ISVs) in the depth of the 22°C isotherm(D22) in the South China Sea(SCS) basin are investigated. The results show that the ISVs in the D22 exhibit distinct seasonality in the SCS. The ISVs in the D22 are quite significant, especially within a band along the northwestern boundary of the basin and at the southern end of the basin during boreal winter. In these areas, the ratio of the standard deviations(STDs) of intra-seasonal band to the STDs of total data could exceed 0.6. Although the ISVs in the D22 are detectable in the area affected by the Vietnam Offshore Current during boreal summer and autumn, these variations are sometimes overwhelmed by oscillations with other frequencies. An analysis of the causes of the ISVs in the D22 in the SCS indicates that sea surface fluxes and wind stirring are not the dominant external driving mechanisms of the phenomena described above. The ISVs in the D22 are thought to be induced mainly by the thermodynamic adjustment of the ocean itself and the associated instabilities. The energy of the northern and southern bands that display strong ISVs in the D22 may be derived from eddy kinetic energy, rather than eddy available potential energy. The diversity of the propagation of the ISVs in the D22 is very conspicuous within these two bands.

关键词： intra-seasonal variations depth of 22°C isotherm South China Sea