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Experimental Study on the Molten Salt at Micron Scale during the Melting Process

Journal of Thermal Science 2024年第1期33卷 70-85页

作者： TIAN Ziqian LIAO Zhirong XU Chao FANG Yongzhe jiang kaijun YUAN Mengdi Key Laboratory of Power Station Energy Transfer Conversion and System Ministry of Education of ChinaSchool of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

The investigation of the melting behaviors of the molten salt at micron scale during the melting process is critical for explaining the solid-liquid phase transition mechanism.In this paper,a novel experimental system and analysis method were proposed to study the melting process with three heating rates in the range of1-10℃/min of the solar salt at micron scale.The solid-liquid boundary morphology and phase transition kinetics of molten salt particles were focused on.Meanwhile,the correlations between liquid fraction,temperature and time under different heating rates were studied.The solid-liquid boundary morphology was depicted by the visualized experimental set-up,and the instantaneous liquid volume fraction during the non-isothermal phase transition was obtained.Then,the correlation between temperature and liquid volume fraction was proposed to reveal the evolution of the solid-liquid boundary with temperature at different heating rates.Furthermore,the non-isothermal phase transition kinetic equation was established by introducing a constant parameter(V_(a,b)),and more kinetic parameters such as 1g V_(a,b) and-lg V_(a,b)/b were studied.The results showed that the exponent b is not sensitive to the heating rate with a range of 3-5 for solar salt particles.However,the heating rate influences the value of V_(a,b) and presents a positive relationship.Besides,the non-isothermal phase transition kinetic equations at different heating rates in the range of 1-10℃/min can be quickly predicted by the proposed improved experimental test method.This study could fill the research insufficiency and provide significant guidance for future research on the solid-liquid transition mechanism of molten salts at micron scale.

关键词： molten salt non-isothermal phase transition solid-liquid boundary morphology liquid volume fraction micron scale melting process

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Chemical profiling of principle active and toxic constituents in herbs containing aristolochic acids

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Chinese Herbal Medicines 2024年第2期16卷 293-300页

作者： Lijun Yue kaijun Yang Feng jiang Shuai Dong Kang Yang Dan Zhu School of Pharmacy Minzu University of ChinaBeijing 100081China Key Laboratory of Ethnomedicine Ministry of Education Minzu University of ChinaBeijing 100081China Hospital of Minzu University of China Beijing 100081China

Objective:To clear the amounts of the principal active/toxic components in herbs containing aristolochic acids(HCAAs),which are still used as medicine and/or seasoning in many ethnic minority areas of China.Methods:In this study,six major active and toxic components in HCAAs were extracted with ultrasonic extraction.With 6-O-methyl guanosine as internal standard,the target compounds were analyzed qualitatively and quantitatively by using ultrahigh performance liquid chromatography-electrospray ionization-tandem mass spectrometry(UPLC-ESI-MS/MS)with multiple reaction monitoringinformation dependent acquisition-enhanced production ion scanning mode(MRM-IDA-EPI)combined with dynamic background subtraction(DBS)function.Results:The method showed good linearity in the linear range of the six analytes.The limit range of detection was from 0.01 ng/mL to 0.27 ng/mL.All of the detection repeatability,extraction repeatability and accuracy of the method were good.After extraction,the samples remained stable at 15℃ within 24 h.Six analytes were all found in samples except aristolactam(AL)in sample 2,and the contents varied greatly.The contents of these compounds decreased in fruits,leaves and stems of Aristolochia delavayi successively.Conclusion:This method has the advantages of less sample dosage,simple operation,short analysis cycle,high sensitivity,specificity and accuracy.It laid a good foundation for guiding the safety of HCAAs,the indepth study of pharmacological and toxicological effects and the scientific and standardized processing and compatibility of HCAAs.

关键词： aristolactam aristolochic acids chemical profiling herbs containing aristolochic acids ultrahigh performance liquid chromatography-electrospray ionizationtandem mass spectrometry(UPLC-ESI-MS/MS)

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Characteristics of Axial and Radial Development of Solids Holdup in a Countercurrent Fluidized Bed Particle Solar Receiver

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Journal of Thermal Science 2021年第6期30卷 2223-2240页

作者： jiang kaijun WANG Fengli KONG Yanqiang XU Chao DU Xiaoze MOE Key Laboratory of Power Station Energy Transfer Conversion and System North China Electric Power UniversityBeijing 102206China School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China

A novel particle solar receiver(PSR)with gas-solids countercurrent fluidized bed(CCFB)was proposed.The cold-mold prototype was set up to investigate the gas-solids flow structure by using optical fiber probes.The local solids holdup distribution,its evolution with various operating conditions and the fluctuations of the local flow structures were investigated experimentally.The results show that the novel CCFB can achieve much higher solids holdup(~9%)compared to the traditional downer ones(~l%).The solid particles are mainly distributed in the near-wall region and the particles are more difficult to get a fully developed state in the near-wall region.The excellent gas-solids mixing and contacting demonstrated by the standard deviation and intermittency index means a better wall-to-bed heat transfer process.The distribution of the solid particles in the CCFB transport tube is revealed,which can provide a significant reference for the structure design of the hot-mold PSR.Moreover,the research can fill in the research gap in the gas-solids counterflow field.

关键词： concentrated solar power particle solar receiver countercurrent fluidized bed optical fiber probe local solids holdup

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Experimental Investigation on the Hydrodynamic Characteristics of Fluidized Bed Particle Solar Receiver with Gas-Solid Countercurrent Flow Pattern

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Journal of Thermal Science 2021年第6期30卷 2241-2253页

To design a particle solar receiver(PSR),a vital energy conversion system,is still a bottleneck for researchers.This study presents a novel PSR based on countercurrent fluidized bed(CCFB)technology,named CCFB receiver.In this design,downward-moving particles are subjected to the action of an up-flow gas to reduce the falling speed and enhance the radial disturbance,and hence increase the residence time of particles and improve the heat transfer.A cold-mold visual experimental setup is established.The influence factors are investigated experimentally,including the superficial gas velocity,solid flux,aeration gas,particle size and transport tube diameter.The results indicate that the maximum solid holdup can exceed 9%or so with fine particles of diameter d_(p)=113.5 μm and a tube diameter of 40 mm.It is proved that the CCFB can operate stably and adjust the solid flux rapidly.The results of this study provide a new structure for PSRs in the concentrated solar power field and could fill the research insufficiency in the gas-solid counterflow field.

关键词： particle solar receiver gas-solid two-phase flow countercurrent fluidized bed solid holdup

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Radio-frequency spectroscopic measurement for pairing gap in an ultracold Fermi gas

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Science China(Physics,Mechanics & Astronomy) 2013年第3期56卷 581-587页

作者： jiang kaijun LUO Hua LI Kai ZHANG DongFang GAO TianYou PENG ShiGuo State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of Sciences

The study of ultracold Fermi gases has exploded a variety of experimental and theoretical research since the achievement of degenerate quantum gases in the lab,which expands the research range over atomic physics,condensed matter physics,astrophysics and particle physics.Using the Feshbach resonance,one can tune the attractive two-body interaction from weak to strong and thereby make a smooth crossover from the BCS superfluid of cooper pairs to the Bose Einstein condensate of bound molecules.In this crossover regime,the pairing effect plays a significant role in interpreting the interaction mechanism.Whenever the localized or delocalized pairing occurs at sufficiently low temperature,the single-particle energy will shift with respect to free atoms,due to the two-body or many-body interaction.Measuring the pairing gap can improve the understanding of the thermodynamics and hydrodynamics of the phase transition from the pseudogap to the superfluid,which will make an analogue to the high-temperature superconductivity in condensed matter.In this work,we will give a brief introduction to a novel radio-frequency(RF) spectroscopic measurement for pairing gap in an ultracold Fermi gas,which is currently widely used on the ultracold atomic table in the lab.In different interaction regimes of the BEC-BCS crossover,ultracold atoms are excited with a RF pulse and the characteristic behavior can be extracted from the spectrum.

关键词： degenerate Fermi gas Feshbach resonance Bose Einstein condensate superfluid

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厚油层注采模式对纵向波及特征影响研究

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油气地质与采收率 2024年第2期31卷 148-154页

作者：童凯军李长勇姜俊帅姜汉桥李俊键中国海洋石油国际有限公司北京100008 中国石油大学(北京)石油工程学院北京102249

注采模式优选对缓解厚油层层内矛盾,提高纵向波及效率具有重要意义。目前尚未形成油水井同时部分打开的井间解析渗流模型,无法支撑厚油层波及特征的研究。为此,采用保角变换方法,将油水井同时部分打开剖面地层依次变换为圆形边界偏心裂... 详细信息

注采模式优选对缓解厚油层层内矛盾,提高纵向波及效率具有重要意义。目前尚未形成油水井同时部分打开的井间解析渗流模型,无法支撑厚油层波及特征的研究。为此,采用保角变换方法,将油水井同时部分打开剖面地层依次变换为圆形边界偏心裂缝井地层、单位圆形边界两分支裂缝井地层、注水井全部打开采油井部分打开剖面地层,之后重复上述变换,将注水井全部打开采油井部分打开剖面地层变换为油水井全部打开剖面地层,从而将原始二维渗流过程变换为一维渗流过程,实现了不同注采模式下厚油层层内压力及流线分布的解析计算。与精细数值模拟方法的对比表明,该方法对不同井距/厚度比的情形均可获得较高计算精度。利用该方法,开展了注采模式对纵向波及特征的研究。结果表明:对于底注高采模式,注水井顶部为主力注入层段,注水井顶部1/3的井段控制超过1/2的地层,使超过2/3的采油井段受效;注水对地层的波及主要作用于注水突破前的阶段。在相同的打开厚度下,底注高采的注水突破最晚、波及效率最高,底注中采、中注高采次之,高注高采、底注底采注水突破最早、波及效率最低。采油井的打开厚度越大,注水突破时间越短,但注水突破时的波及系数增大,应综合考虑注水突破时间和波及系数两方面的因素,优选最佳打开厚度。

关键词：厚油层部分打开井注采模式保角变换纵向波及

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基于深度学习的墙式氧气吸入器检定方法

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计量学报 2024年第5期45卷 685-691页

作者：黄康孙斌吴燕娟裘凯军赵玉晓中国计量大学计量测试工程学院浙江杭州310018 金卡智能集团股份有限公司浙江杭州310018 浙江省机电产品质量检测所有限公司浙江杭州310051

针对墙式氧气吸入器检定时人工读数影响大、检定效率低等问题,提出一种基于深度学习的墙式氧气吸入器检定方法。通过工业相机拍摄墙式氧气吸入器图像,输入到改进后的残差块ResNet-18网络中,实现对浮子流量计的自动读数。残差块结构改进... 详细信息

针对墙式氧气吸入器检定时人工读数影响大、检定效率低等问题,提出一种基于深度学习的墙式氧气吸入器检定方法。通过工业相机拍摄墙式氧气吸入器图像,输入到改进后的残差块ResNet-18网络中,实现对浮子流量计的自动读数。残差块结构改进策略有:在直联通路中增加Dropout网络层;删除残差块中的1×1卷积层;使用LeakyReLU激活函数代替ReLU激活函数。将数据集按照51的比例划分为训练集和测试集,经过100批次的训练,网络模型在测试集上的准确率为98.37%。将中国计量科学研究院检定合格的墙式氧气吸入器连接至检定装置中检定,计算得到浮子流量计的最大示值误差为±0.2 L/min,误差在允许范围内,检定结果相同。结果表明,该方法可以代替人工读数,有效提高检定效率。

关键词：流量计量墙式氧气吸入器检定装置深度学习残差块 ResNet-18网络

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Radio-frequency spectroscopic measurement for pairing gap in an ultracold Fermi gas

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Science China Chemistry 2013年第3期56卷 581-587页

关键词：光谱测量费米气体无线电频率配对差距 Feshbach共振多体相互作用凝聚态物理

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生物基可降解聚氨酯材料的制备及改性研究进展

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工程塑料应用 2024年第2期52卷 187-192页

作者：杨尚科母艳潇卞军赵威李铜倪可扬江兴玉蔺海兰陈代强常凯军蔡旭光西华大学材料科学与工程学院成都610039 四川大学高分子科学与工程学院成都610065 海南古樽科技有限公司海口570100 常州源自然新材料科技有限公司江苏常州213000

利用生物质资源合成的聚氨酯材料,凭借其生物相容性和可降解性受到国内外的广泛关注。围绕近几年的文献,首先介绍了合成生物基聚氨酯常用的生物基多元醇和生物基异氰酸酯,以及它们的制备方法与结构特点,然后从不同结构的单体、不同扩链... 详细信息

利用生物质资源合成的聚氨酯材料,凭借其生物相容性和可降解性受到国内外的广泛关注。围绕近几年的文献,首先介绍了合成生物基聚氨酯常用的生物基多元醇和生物基异氰酸酯,以及它们的制备方法与结构特点,然后从不同结构的单体、不同扩链剂和复合改性等方面详细概述了生物基可降解聚氨酯的研究进展,阐述了单体的设计与合成、聚合反应原理、生物基可降解聚氨酯的结构、性能以及应用等内容。最后对未来生物基可降解聚氨酯的研究趋势进行了展望。

关键词：聚氨酯生物基高分子材料可降解性研究进展

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Breaking Mirror Circularly Polarized Luminescence of Chiral Metal-Organic Frameworks by High-Pressure Stimulation

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CCS Chemistry 2023年第10期5卷 2215-2224页

作者： Laizhi Sui Zhi-Bin Jin Guangming Niu Jutao jiang Qiao-Hong Li Li-Mei Chang kaijun Yuan Zhi-Gang Gu Jian Zhang Xueming Yang State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 110623 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 University of Chinese Academy of Sciences Beijing 100049 Marine Engineering College Dalian Maritime UniversityDalian 116026 Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108 Department of Chemistry College of ScienceSouthern University of Science and TechnologyShenzhen 518055

Understanding high-pressure-stimulated circularly polarized luminescence(CPL)of enantiomers remains a challenging but significant task in fundamental research and optical applications.Here,we combined in situ high-pressure photoluminescence with circularly polarized light to study how high pressure stimulated the CPL of crystalline enantiomers.Chiral lanthanide(Ln)-tartrate(Tar)metal-organic frameworks(MOFs;Ln=Eu,Tb)were synthesized to study their CPL from atmospheric pressure to 10 GPa.Under atmospheric pressure,D-and L-Eu(Tar)showed strong andmirror CPL.CPL intensity changes,emission wavelength shifts,and signal inversions were induced by increasing pressure.Note that the D-Eu(Tar)enantiomer showed strong CPL with a maximal dissymmetric factor(g_(lum))of 0.69 under 3 GPa,which is much higher than that under atmospheric pressure and of other reported MOF-based CPL materials.More interestingly,D-and L-Ln(Tar)enantiomers display obvious asymmetric CPL signals with increasing pressure,demonstrating that high pressure can break the mirror CPL of the MOF enantiomers.Our findings provide a critical understanding on in situ high-pressure CPL of chiral materials and establish a new optical phenomenon where high pressure can break the mirror CPL of enantiomers.

关键词： chirality metal-organic frameworks high pressure circularly polarized luminescence symmetry breaking

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