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Microwave electrometry with Rydberg atoms in a vapor cell using microwave amplitude modulation

Chinese Physics B 2024年第5期33卷 65-74页

作者：郝建海贾凤东崔越王昱寒周飞刘修彬张剑谢锋白金海尤建琦王宇钟志萍 School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China Science and technology.on Metrology and Calibration laboratory Changcheng Institute of Metrology & MeasurementAviation Industry Corporation of ChinaBeijing 100095China CAS center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China

We have theoretically and experimentally studied the dispersive signal of the Rydberg atomic electromagneticallyinduced transparency(EIT)Autler–Townes(AT)splitting spectra obtained using amplitude modulation of the microwave(MW)electric *** addition to the two zero-crossing points interval△f_(zeros),the dispersion signal has two positive maxima with an interval defined as the shoulder interval△f_(sho),which is theoretically expected to be used to measure a much weaker MW electric *** relationship of the MW field strength E_(MW)and△f_(sho)is experimentally studied at the MW frequencies of 31.6 GHz and 9.2 GHz *** results show that△f_(sho)can be used to characterize the much weaker E_(MW)than that of△f_(zeros)and the traditional EIT–AT splitting interval△f_(m);the minimum E_(MW)measured by△f_(sho)is about 30 times smaller than that by△f_(m).As an example,the minimum E_(MW)at 9.2 GHz that can be characterized by△f_(sho)is 0.056 mV/cm,which is the minimum value characterized by the frequency interval using a vapor cell without adding any auxiliary *** proposed method can improve the weak limit and sensitivity of E_(MW)measured by the spectral frequency interval,which is important in the direct measurement of weak E_(MW).

关键词： quantum sensor Rydberg atoms electromagnetically induced transparency amplitude modulation

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Mechanism of high Li-ion conductivity in poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network based electrolyte revealed by solid-state NMR

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Journal of energy Chemistry 2024年第6期93卷 377-383,I0010页

作者： Fan Li Tiantian Dong Yi Ji Lixin Liang Kuizhi Chen Huanrui Zhang Guanglei Cui Guangjin Hou State key laboratory of Catalysis Dalian National Laboratory for Clean EnergyCollaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina university of Chinese Academy of Sciences Beijing 100049China Qingdao Industrial energy Storage Research institute Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101ShandongChina

Solid polymer electrolytes(SPEs)have become increasingly important in advanced lithium-ion batteries(LIBs)due to their improved safety and mechanical properties compared to organic liquid ***-linked polymers have the potential to further improve the mechanical property without trading off Li-ion *** this study,focusing on a recently developed cross-linked SPE,i.e.,the one based on poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network(PVCN),we used solid-state nuclear magnetic resonance(NMR)techniques to investigate the fundamental interaction between the chain segments and Li ions,as well as the lithium-ion *** utilizing homonuclear/heteronuclear correlation,CP(cross-polarization)kinetics,and spin-lattice relaxation experiments,etc.,we revealed the structural characteristics and their relations to lithium-ion *** is found that the network formation prevents poly(ethylene oxide)chains from crystallization,which could create sufficient space for segmental tumbling and Li-ion co nductio *** such,the mechanical property is greatly improved with even higher Li-ion mobilities compared to the poly(vinylene carbonate)or poly(ethylene oxide)based SPE analogues.

关键词： ssNMR Lithium-ion mobility Cross-link Solid polymer electrolyte

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new friction factor and Nusselt number equations for laminar forced convection of liquid with variable properties

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Science China(Technological Sciences) 2018年第1期61卷 98-109页

作者： ZHAO HouJian LI XiaoWei WU XinXin key laboratory of advanced reactor engineering and safety of ministry of education Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy Technology Tsinghua University

Friction factor and heat transfer coefficient of liquid flow with variable properties can significantly differ from that with constant properties. Existing equations obtained by regression analysis of experimental data use correction factors to account for variable property effect. They are limited to specific kind of fluid and low or medium temperature differences. The correction factors of the equations for heating and cooling conditions are different. new explicit friction factor and Nusselt number equations for laminar forced convection of liquid with variable properties are derived with a first order approximation of dynamic viscosity-temperature variation. The new equations are applicable to all kinds of liquids and can be used for large temperature differences. Governing equations of laminar forced convection of water and ethanol are numerically solved using computational fluid dynamics(CFD)method and the results are used to verify the derived equations. The derived equations show good predictions of friction factors and Nusselt numbers for both heating and cooling conditions and show more accurate predictions than the existing equations. A dimensionless number is also introduced based on theoretical analysis to evaluate property variation effects on friction factors and heat transfer coefficients.

关键词： laminar convection friction factor heat transfer coefficient variable property

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First-principle studies of radioactive fission productions Cs/Sr/Ag/I adsorption on chrome-molybdenum steel in Chinese 200 MW HTR-PM

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nuclear Science and Techniques 2017年第6期28卷 123-132页

作者： Chuan Li Chao Fang Chen Yang institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua University

Chrome-molybdenum steel(2·1/4Cr1Mo) is one of the main products of steam *** adsorption behaviors of radioactive fission products on2·1/4Cr1Mo surface are critical in the analysis of ***,the adsorption behavior of cesium,strontium,silver and iodine on 2·1/4Cr1Mo was investigated with first-principle calculations that the Ag and I atoms prefer to be adsorbed at the square hollow site of the face-centered cubic iron cell with a binding energy of about 1 and 3 eV,*** contrast,Cs and Sr atoms are not adsorbed on the surface of the 2·1/*** results are again confirmed via analysis of charge density differences and the densities of ***,the adsorption rates of these fission products show that only I and Ag have significant adsorption on the metal *** adsorption results explain the amount of adsorbed radionuclides for an evaluation of nuclear safety in *** micro-pictures of the interaction between fission products and materials are a new and useful way to analyze the source term.

关键词： First-principle calculation Fission product Adsorption behavior HTR-PM

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Flow fields and packing states in the discharge flow of noncircular particles-A SIPHPM simulation

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Particuology 2017年第6期15卷 10-21页

作者： Nan Gui Xingtuan Yang Jiyuan Tu Shengyao Jiang institute of nuclear and new energy technology. collaborative innovation center of advanced nuclear energy technology. key laboratory of advanced reactor engineering and safety of ministry of education. tsinghua university Beijing 100084 China School of engineering RMIT University. Melbourne VIC 3083. Australia

Although the discharge flow of spherical materials has been extensively explored, the effect of particle shape on discharge is still poorly understood. The present work explores the two-dimensional discharge flow fields of noncircular particles using the soft-sphere-imbedded pseudo-hard particle model method. Rectangular particles having different aspect ratios （Ra = 1, 1.5, 2-5） and regular polygonal particles hav- ing different numbers of sides （Ns = 3-8, 10） are discharged through hopper beds having different orifice widths （Di = 40, 70.77, 99.13, 125.74, 151.13 mm）. The discharge rates of differently shaped particles in different beds are consistent with Beverloo＇s relation. Moreover, the flow fields are computed and eval- uated to study the effects of Ra, Ns, and Di on particle discharge. The characteristics of particle-particle connections in the discharge process are evaluated according to the temporal evolution and spatial dis- tribution of the contact points. Additionally, the effect of the initial packing on the discharge profile is investigated. The findings help clarify the discharge of noncircular particles.

关键词： Non-spherical Discharge flow Hopper Particle Discrete element method

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Research on the steam–gas pressurizer model with Relap5 code

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nuclear Science and Techniques 2017年第5期28卷 1-8页

作者： Xi-Zhen Ma Hai-Jun Jia Yang Liu institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University Beijing 100084 China

Steam–gas pressurizers are self-pressurizing, and since steam and noncondensable gas are used to sustain their pressure, they experience very complicated thermal–hydraulic phenomena owing to the presence of the latter. A steam–gas pressurizer model was developed using Relap5 code to investigate such a pressurizer's thermal–hydraulic *** important thermal–hydraulic processes occurring in the pressurizer model include bulk flashing, rainout, wall condensation with noncondensable gas, and interfacial heat and mass transfer. The pressurizer model was verified using results from insurge experiments performed at the Massachusetts institute of technology. It was found that noncondensable gas was one of the important factors governing the pressure response, and the accuracy of the developed model would change with different mass fractions and types of noncondensable gas.

关键词： Relap5 code Noncondensable gas Heat and mass transfer Steam–gas pressurizer Condensation

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Thermal behavior of the HTR-10 under combined PLOFC and ATWS condition initiated by unscrammed control rod withdrawal

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nuclear Science and Techniques 2018年第9期29卷 130-138页

作者： Feng Gou Yuan Liu Fu-Bing Chen Yu-Jie Dong institute of nuclear and new energy technology Tsinghua University Collaborative Innovation Center of Advanced Nuclear Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety Ministry of Education

Two tests initiated by unscrammed control rod withdrawal were performed on the High Temperature GasCooled reactor-Test Module(HTR-10) in November 2003 after the reactor achieved its full power, and the test conditions represented a typical transient scenario of modular high-temperature reactors(HTRs), called pressurized loss of forced cooling, and anticipated transient without *** on the test parameters, the HTR-10 thermal behaviors under the test conditions were studied with the help of the system analysis code THERMIX. The combination of the test results and the investigation results makes the HTR-10 safety potential better understood. key phenomena, such as the helium natural circulation and the temperature redistribution in the reactor, were revealed. As the safety feature of most significance, there is a large margin between the maximum fuel temperature and its safety limit in each test. Temperatures of thermocouples in different components were calculated by THERMIX and compared with the test values. The applicability of the code was verified by good agreement obtained from the comparison.

关键词： HTR-10 Control rod withdrawal ATWS THERMIX

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Research on the effect of Reynolds correlation in natural convection film condensation

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nuclear Science and Techniques 2017年第6期28卷 169-178页

作者： Lei Wu Hai-Jun Jia Xi-Zhen Ma Yang Liu Xing-Tuan Yang Jun Wang institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua University engineering Physics institute University of Wisconsin Madison

Film condensation is a vital phenomenon in the nuclear engineering applications,such as the gas-steam pressurizer design,and heat removing on containment in the case of postulated *** number in film condensation can be calculated from either the mass relation or the energy relation,but few researches have distinguished the difference between them at *** paper studies the effect of Reynolds correlation in the natural convection film condensation on the outer *** general forms of the heat transfer coefficient correlation of film condensation are developed in different flow *** simultaneously solving a set of the heat transfer coefficient correlations with Re_(mass) and Re_(energy),the general expressions for Re_(mass) and Re_(energy) and the relation between the corresponding heat transfer coefficients are *** the laminar and wavefree flow regime,Re_(mass) and Re_(energy) are equivalent,while in the laminar and wavy flow regime,Re_(mass) is much smaller than Re_(energy),and the deviation of the corresponding average heat transfer coefficients is about 30% at the *** the turbulent flow regime,the relation of Re_(mass) and Re_(energy)is greatly influenced by Prandtl *** relative deviation of their average heat transfer coefficients is the nonlinear function of Reynolds number and Prandtl *** with experimental results,the heat transfer coefficient calculated from Re_(energy) is more accurate.

关键词： Film condensation Reynolds correlation Heat transfer coefficient Natural convection

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Review on active thermal protection and its heat transfer for airbreathing hypersonic vehicles

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Chinese Journal of Aeronautics 2018年第10期31卷 1929-1953页

作者： Yinhai ZHU Wei PENG Ruina XU Peixue JIANG key laboratory for Thermal Science and Power engineering of ministry of education Department of Energy and Power Engineering Tsinghua University institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Tsinghua University

Hypersonic vehicles with turbojet, ramjet, and scramjet engines are expected to be widely applied to future transportation systems. Due to high-speed flight in the atmosphere, body outer surfaces suffer strong aerodynamic heating, and on the other hand, combustion chamber inter walls are under extremely high temperature and heat flux. Therefore, more efficient and stable active cooling technologies are required in hypersonic vehicles, such as regenerative cooling, film cooling, and transpiration cooling, as well as their combinations. This paper presents a comprehensive literature review on three active cooling methods, i.e., regenerative cooling, film cooling, and transpiration cooling, and deeply analyzes the mechanism of each cooling method, including the fluids flow, heat transfer, and thermal cracking characteristics of different hydrocarbon fuels in regenerative cooling,the heat transfer and flow mechanism of film cooling under supersonic mainstream conditions, and the heat transfer and flow mechanism of transpiration cooling.

关键词： Film cooling Hypersonic vehicle Regenerative cooling Thermal protection Transpiration cooling

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Analysis and correlation of fluid acceleration with vorticity and Liutex(Rortex)in swirling jets

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Journal of Hydrodynamics 2019年第5期31卷 864-872页

作者： Nan Gui Hou-bo Qi Liang Ge Peng-Xin Cheng Hao Wu Xing-tuan Yang Ji-yuan Tu Sheng-yao Jiang institute of nuclear and new energy technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyKey Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing100084China School of engineering RMIT UniversityMelbourneAustralia

The characteristics of the acceleration a and its correlation with the vortex core in the swirling flow are analyzed in this *** swirling flows of four swirl numbers(Sn=n S 0,0.10,0.20 and 0.36)are simulated by the direct numerical simulation,and the fluid mass particles from the inlet of the swirling flow are traced as a database for the current *** correlations of the acceleration a with the vortex identification parameters of R andωare quantified,where R is the parameter of the“Liutex”-method proposed by ***,and its early version is“Rortex”.The probability density functions of the included angles of a-R and a-ωare computed,which are used to clarify the geometrical configuration between a and *** covariance coefficients between a and the parameters of various vortex core criteria(Q,λ2,ΩL,ΩR,ωand R)are computed and their relative levels of correlation are *** to the velocity,the expectation and the rms of the acceleration magnitudes and its projections on R and the plane perpendicular to R are computed for better explaining the correlation features between a and *** is found that a and R are always either perpendicular or parallel to each other with the quantized included angles of∠(a,R)=kπ/2,(k=0,1,2).This confirms the role of R which works as the axis of the vortex exclusively.

关键词： swirling flow acceleration correlation vortex Rortex Liutex direct numerical simulation

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