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Experimental study of anti-cavitation mechanism of valve lintel natural aeration of high head lock

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Journal of Hydrodynamics 2020年第2期32卷 337-344页

作者： Xin Wang ya-an Hu Jian-min Zhang Hydraulic Engineering Department Nanjing Hydraulic Research InstituteNanjing210029China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing210029China

To study the serious valve top gap cavitation of Datengxia high head single-lift ship lock,the 1:1 scale slice experiment is carried out,to truly reveal the gap flow characteristics,as well as the valve top gap cavitation characteristics and the anti-cavitation mechanism of natural *** kinds of cavitation,namely,the throat cavitation,the mainstream inner cavitation,and the valve plate cavitation,are determined and they are found to occur step-by-step in the gap section in the development of the *** to the anti-cavitation mechanism of the natural aeration,the pressure of the gap flow through the ventilation is increased,to avoid the mainstream inner cavitation and the valve plate cavitation,and to weaken the throat *** negative pressure zone in the gap section gradually extends with the development of the cavitation until the gap section is filled with a stable−10 m water *** the natural aeration measure is employed,the pressure in the gap section approximately reaches the−2 m water head,and the cavitation *** systematic tests reveal the quadratic polynomial relationship between the pressure in the gap and the ventilation per meter *** pressure,which corresponds to the maximum value of the ventilation at the beginning of the gap,approximately reaches the−2 m water head,and the pressure and the ventilation reach the equilibrium state *** the pressure in the gap increases when the valve is opened,the ventilation gradually decreases until the natural aeration *** gap section length for the high head valves has a great effect on the natural aeration and should be long enough to maintain the stable negative pressure in the gap,whereas the throat width has a minimal *** can be used for the anti-cavitation design of the high head lock valve.

关键词： High head lock valve top gap cavitation natural aeration slice experiment

Experimental Investigation on Thermal Characteristics of Long Distance Loop Heat Pipes

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Journal of Thermal Science 2022年第3期31卷 741-750页

作者： ZHAO ya’nan yaN Tao LIANG Jingtao Key Laboratory of Space Energy Conversion Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100190China

Loop heat pipes(LHPs)are attractive two-phase thermal control devices for satellites,electronics and many other *** are capable of transporting heat efficiently for long distances up to several meters at any *** paper investigated the heat transfer characteristics of loop heat pipes with long distances and small diameter transport *** stainless steel tubes of 2 mm and 3 mm in inner diameters were chosen as liquid lines and vapor lines of the *** local thermal resistances in the evaporator of the 6 m-LHP were researched and analyzed,which indicated that the thermal resistance between the aluminum block and the vapor in the vapor channel accounted for a major proportion of the total thermal *** effect of heat sink temperatures on the performance of the 6 m-LHP were compared with 10°C,15°C,20°C and 25°C cooling water ***,the thermal characteristics of LHPs with transport distances of 2 m and 16 m were also experimentally *** 16 m-LHP could achieve a heat transfer capacity of 100 W and the 2 m-LHP could reach more than 339 W,on the premise of the evaporator temperature below 100°*** thermal resistance of the 2 m-LHP could achieve 0.125°C/W.

关键词： loop heat pipe thermal management heat transport long distance thermal resistance

Probing granular inhomogeneity of a particle-emitting source by imaging two-pion Bose–Einstein correlations

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Nuclear Science and Techniques 2021年第2期32卷 81-89页

作者： Li-ya Li Peng Ru Ying Hu School of mathematics and Economics Hubei University of EducationWuhan 430205HubeiChina Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China

Using the source imaging technique in two-pion interferometry,we study the image of the hydrodynamic particle-emitting source with the HIJING initial conditions for relativistic heavy-ion collisions on an event-by-event *** is shown that the initial-state fluctuations may give rise to bumpy structures of the medium during hydrodynamical evolution,which affects the two-pion emission space and leads to a visible two-tiered shape in the source function imaged using the two-pion Bose–Einstein *** two-tiered shape can be understood within a similar but more analytic granular source model and is found to be closely related to the introduced quantity n,which characterizes the granular inhomogeneity of the *** fitting the imaged source function with a granular source parametrization,we extract the granular inhomogeneity of the hydrodynamic source,which is found to be sensitive to both the Gaussian smearing width of the HIJING initial condition and the centrality of the collisions.

关键词： Heavy-ion collision Bose-Einstein correlations Imaging technique

Electronic properties of size-dependent moTe2/WTe2 heterostructure

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Chinese Physics B 2019年第10期28卷 490-497页

作者： Jing Liu ya-Qiang ma ya-Wei Dai yang Chen Yi Li ya-Nan Tang Xian-Qi Dai College of Physics and materials Science Henan Normal UniversityXinxiang 453007China Physics Department The University of Hong KongPokfulam RoadHong KongChina School of Physics and Electronic Engineering Zhengzhou Normal UniversityZhengzhou 450044China

Lateral two-dimensional(2D) heterostructures have opened up unprecedented opportunities in modern electronic device and material science. In this work, electronic properties of size-dependent moTe2/WTe2 lateral heterostructures(LHSs)are investigated through the first-principles density functional calculations. The constructed periodic multi-interfaces patterns can also be defined as superlattice structures. Consequently, the direct band gap character remains in all considered LHSs without any external modulation, while the gap size changes within little difference range with the building blocks increasing due to the perfect lattice matching. The location of the conduction band minimum(CBm) and the valence band maximum(VBm) will change from P-point to Γ-point when m plus n is a multiple of 3 for A-mn LHSs as a result of Brillouin zone folding. The bandgap located at high symmetry Γ-point is favourable to electron transition, which might be useful to optoelectronic device and could be achieved by band engineering. Type-II band alignment occurs in the moTe2/WTe2 LHSs, for electrons and holes are separated on the opposite domains, which would reduce the recombination rate of the charge carriers and facilitate the quantum efficiency. moreover, external biaxial strain leads to efficient bandgap engineering. moTe2/WTe2 LHSs could serve as potential candidate materials for next-generation electronic devices.

关键词： first-principles calculations electronic structures moTe2/WTe2 superlattice strain effects

Constraints on axion-like particles with different magnetic field models from the PKS 2155–304 energy spectrum

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Research in Astronomy and Astrophysics 2019年第10期19卷 152-158页

作者： Jia Bu ya-Ping Li Department of Astronomy Xiamen University Xiamen 361005 China Shanghai Astronomical Observatory Shanghai 200030 China

Axion-like particles(ALPs) are a promising kind of dark matter candidate particle that are predicted to couple with photons in the presence of magnetic fields. The oscillations between photons and ALPs traveling in the magnetic fields have been used to constrain ALP properties. In this work, we obtain some new constraints on the ALP mass ma and the photon-ALP coupling constant g with two different magnetic field models through TeV photons from PKS 2155–304. The first is the discrete-Φ model in which the magnetic field has the orientation angle Φ that changes discretely and randomly from one coherent domain to the next, and the second is the linearly-continuous-Φ model in which the magnetic field orientation angle Φ varies continuously across neighboring coherent domains. For the discrete-Φ model, we can obtain the best constraints on the ALP mass m1 = ma/(1 neV)= 0.1 and on the photon-ALP coupling constant g11= g/(10^-11 GeV^-1)= 5. The reasonable range of the ALP mass m1 is 0.08 ~ 0.2 when g11 = 5,and the only reasonable value of the photon-ALP coupling constant is g11 = 5 when m1 = 0.1. For the linearly-continuous-Φ model, we can obtain the best constraints on the ALP mass m1 = 0.1 and on the photon-ALP coupling constant g11 = 0.7. The reasonable range of the ALP mass m1 is 0.05 ~ 0.4 when g11= 0.7, and the reasonable range of the photon-ALP coupling constant g11 is 0.5 ~ 1 when m1 = *** of the results are consistent with the upper bound(g ment.

关键词： cosmology dark matter-gamma rays general-galaxies magnetic fields

Anti-corrosive and highly reversible zinc metal anode enabled by the phenolic resin coating

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Rare metals 2024年第5期43卷 2115-2124页

作者： ya-Ping Wang ya-Di yang Shu-Qi Duan Li Wang Jia-Shuo Guo An-Qiang Pan School of materials Science and Engineering Hebei University of TechnologyTianjin 300130China Key Laboratory of Special Functional materials for Ecological Environment and Information(Hebei University of Technology).ministry of Education Tianjin 300130China Key Laboratory for New Type of Functional materials in Hebei Province Hebei University of TechnologyTianjin 300130China School of materials Science and Engineering Central South UniversityChangsha 410083China

Aqueous zinc-ion batteries have attracted much attention due to their high theoretical capacity,low cost high safety,and ***,challenges such as dendrite growth and side reactions severely hinder the electrochemical performance of the Zn anode,leading to low Coulombic efficiency(CE)or even short circuits Herein,phenolic resin(PF)is used as a protective coating on the surface of the zinc metal *** PF layer can greatly improve the corrosion resistance of the Zn electrode in the ***,this artificial electrode/electrolyte interphase also elevates the nucleation barrier and restrains Zn^(2+)2D diffusion,regulating the zinc deposition/dissolution *** a result,PF@Zn symmetric cells exhibit superior performance than that of bare Zn symmetric cells,achieving a stable and dendrite-free cycle of 1400 ***,the carbon nanotube mnO_(2)||PF@Zn(CNT/mnO_(2)||PF@Zn)full cell also delivers a long cycle life with a high-capacity retention of about 180.0 m Ah·g^(-1)after 1400 cycles,far exceeding that of bare Zn *** work provides a facile strategy for achieving a dendrite-free and rechargeable zinc anode.

关键词： Rechargeable aqueous batteries Zn metal anode Phenolic resin Anti-corrosion

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Acta mathematica Sinica,English Series 2014年第10期30卷 1689-1697页

作者： Zhe DONG ya Fei ZHAO Department of mathematics Zhejiang University

In this note, we show that avon Neumann algebra m is injective if and only if the weak＊ similarity degree d.（m） ≤ 2.

关键词： Weak* similarity degree injective von Neumann algebra operator space

Adaptive mesh refinement immersed boundary method for simulations of laminar flows past a moving thin elastic structure

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Journal of Hydrodynamics 2020年第1期32卷 148-160页

作者： mohammed Suleman Aldlemy mohammad Rasidi Rasani AKAriffin TmYSTuan ya Centre for Integrated Design for Advanced mechanical Systems Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia Department of mechanical Engineering College of Mechanical Engineering TechnologyBenghaziLibya Department of mechanical Engineering Faculty of EngineeringUniversiti Teknologi Petronas31750 TronohPerakMalaysia

One of the critical issues in numerical simulation of fluid-structure interaction problems is inaccuracy of the solutions,especially for flows past a stationary thin elastic structure where large deformations *** resolution is required to capture the flow characteristics near the fluid-structure interface to enhance accuracy of the solutions within proximity of the thin deformable ***,in this work,an algorithm is developed to simulate fluid-structure interactions of moving deformable structures with very thin *** this algorithm,adaptive mesh refinement(amR)is integrated with immersed boundary finite element method(IBFEm)with two-stage pressure-velocity *** successive interpolation of the flow field by IBm,the governing equations were solved using a fixed structured mesh,which significantly reduces the computational time associated with mesh *** cut-cell IBm is used to predict the body forces while FEm is used to predict deformation of the thin elastic structure in order to integrate the motions of the fluid and solid at the *** is used to discretize the governing equations and obtain solutions that efficiently capture the thin boundary layer at the fluid-solid *** amR-IBFEm algorithm is first verified by comparing the drag coefficient,lift coefficient,and Strouhal number for a benchmark case(laminar flow past a circular cylinder at Re=100)and the results showed good agreement with those of other *** algorithm is then used to simulate 2-D laminar flows past stationary and moving thin structures positioned perpendicular to the freestream *** results also showed good agreement with those obtained from the arbitrary Lagrangian-Eulerian(ALE)algorithm for elastic thin *** is concluded that the amR-IBFEm algorithm is capable of predicting the characteristics of laminar flow past an elastic structure with acceptable accuracy(error of-0.02%)with only-1%of the computati

关键词： Immersed boundary method finite element method adaptive mesh refinement two-stage velocity-pressure correction thin deformable structures

Charged ultrafine particle filtration through vehicular cabin air filters

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Particuology 2016年第5期14卷 1-5页

作者： Bin Xu Yu Gong ya Wu Department of Environmental Engineering Tongji University 1239 Siping Road Shanghai 200092 China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Shanghai 200433 China

Understanding the effectiveness of cabin air filters is important for assessing human exposure to ultra- fine particles （UFPs） of vehicular origin. The filtration efficiency of vehicular UFPs with electric charges was investigated for different electric charge characteristics （charge state, charge polarity）. The average filtration efficiency increased ~10% as the electric charge state on the particles changed in distribution from lightly charged to highly charged. The enhancement of filtration efficiency due to electric charge was different at various filter-face air velocities. As electric charges increased, the filtration efficiency increased 12% and 9% at low air velocity （0.1 m/s） and high air velocity （0.S m/s）, respectively. The filter fiber material poses somewhat effect on the filtration efficiency change due to the electric charge. The effects of filter usage and charge polarity on filtration efficiency due to the electric charge were negligi- ble. A coefficient was empirically derived and successfully accounts for the electric charge effect on UFP filtratinn efficiency.

关键词： Particle filtration Electric charge Filtration efficiency Vehicular particle