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Forced boiling of nonazeotropic immiscible mixture in a supercapillary microchannel array for ultra-high heat flux removal with chip junction temperature below 85℃

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Science China(Technological Sciences) 2024年第5期67卷 1364-1380页

作者： SUN bo BAO YuChen TIAN tong LI Ji School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Laboratory of Advanced Thermal Management Technologies School of Engineering ScienceUniversity of Chinese Academy of SciencesBeijing100049China

In this study,a structure-optimized two-phase microchannel heat sink with sintered submicron nucleation sites was developed and tested.The copper-based microchannels had a rectangular cross-section with an equivalent hydraulic diameter of 222μm.The subcooled flow boiling characteristics were comprehensively compared between pure HFE-7100 and a non-azeotropic,immiscible binary mixture of HFE-7100 and water,considering heating areas of 1 and 5 cm^(2).The total heating power input to the test section were 100–1500 and 250–3000 W for a 1 and 5 cm^(2)heat source,respectively,with a flow rate ranging from 50 to150 L/h.Compared to pure HFE-7100,the non-azeotropic immiscible binary mixture of HFE-7100/water in the sintered porous microchannels exhibited a much higher overall heat transfer coefficient and lower power consumption.To maintain the junction temperature of a high power electronic chip below 85℃,the proposed supercapillary microchannel heat sink could effectively dissipate the heat flux of 1275 W/cm^(2)over 1 cm^(2)heat source and 500 W/cm^(2)over 5 cm^(2)heat source.In addition,the volume ratio of the binary mixture strongly influence the two-phase flow heat transfer characteristics.An optimal volume ratio exist in terms of the thermal resistance–pumping power minimization(HFE-7100:water=2:8 is recommended in this study).The findings of this investigation on the flow boiling properties of non-azeotropic immiscible mixtures help fill a gap in the related field.

关键词： microchannel sintered powder coating submicron nucleation cavities nonazeotropic immiscible ultra-high heat flux

Neutron irradiation influence on high-power thyristor device under fusion environment

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Nuclear Science and Techniques 2024年第4期35卷 65-81页

作者： Wei tong Hua Li Meng Xu Zhi-Quan Song bo Chen School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

Because of their economy and applicability,high-power thyristor devices are widely used in the power supply systems for large fusion devices.When high-dose neutrons produced by deuterium–tritium(D–T)fusion reactions are irradiated on a thyristor device for a long time,the electrical characteristics of the device change,which may eventually cause irreversible damage.In this study,with the thyristor switch of the commutation circuit in the quench protection system(QPS)of a fusion device as the study object,the relationship between the internal physical structure and external electrical parameters of the irradiated thyristor is established.Subsequently,a series of targeted thyristor physical simulations and neutron irradiation experiments are conducted to verify the accuracy of the theoretical analysis.In addition,the effect of irradiated thyristor electrical characteristic changes on the entire QPS is studied by accurate simulation,providing valuable guidelines for the maintenance and renovation of the QPS.

关键词： Fusion device Neutron irradiation effects Thyristor Quench protection

Surface tension of single suspended aerosol microdroplets

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Chinese Chemical Letters 2024年第4期35卷 520-524页

作者： Yukai tong Zhijun Wu bo Zhou Min Hu Anpei Ye Key Laboratory for the Physics and Chemistry of Nanodevices School of ElectronicsPeking UniversityBeijing 100871China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China

The surface tension of troposphere aerosols can significantly influence their atmospheric processes and key properties, particularly on the morphology, the phase transition, the activation as cloud condensation nuclei, and the gas-particle partitioning. However, directly measuring the surface tension of single ambient aerosol is quite challenging, due to the limitations of their picolitre volumes and thermal motion. Here, we developed a dual laser tweezers Raman spectroscopy(DLT-RS) system to directly sense the surface tension of single airborne microdroplets(PM10particles). A pair of aerosol droplets were trapped and driven to coalesce by the laser tweezers. Meanwhile, the backscattering light intensity and brightfield images during the coalescence process were recorded to characterize the aerosol surface tension. A remarkable advantage of directly sensing aerosol surface tension is that the solutes in aerosols are often supersaturated, which is common in atmospheric aerosols but almost unavailable in bulk solutions.We experimentally measured the surface tension of aerosols composed of nitrates or oxalic acid/nitrate mixture. Besides, the variation of surface tension during aerosol aging process was also explored, which brings possible implications on the surface evolution of actual ambient aerosol during their atmospheric lifetime.

关键词： Surface tension Droplet coalescence Single aerosol Laser tweezers Aerosol aging

Continuous-wave operation of 1550 nm low-threshold triple-lattice photonic-crystal surface-emitting lasers

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Light(Science & Applications) 2024年第3期13卷 446-453页

作者： Ziye Wang Xia Liu Pinyao Wang Huanyu Lu bo Meng Wei Zhang Lijie Wang Yanjing Wang Cunzhu tong State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Central Research Institute Planning Dept 2012 LabsHuawei Technologies Company Ltd.Shenzhen 518129China

Benefitting from narrow beam divergence,photonic crystal surface-emitting lasers are expected to play an essential role in the ever-growing fields of optical communication and light detection and ranging.Lasers operating with 1.55μm wavelengths have attracted particular attention due to their minimum fiber loss and high eye-safe threshold.However,high interband absorption significantly decreases their performance at this 1.55μm wavelength.Therefore,stronger optical feedback is needed to reduce their threshold and thus improve the output power.Toward this goal,photonic-crystal resonators with deep holes and high dielectric contrast are often used.Nevertheless,the relevant techniques for high-contrast photonic crystals inevitably complicate fabrication and reduce the final yield.In this paper,we demonstrate the first continuous-wave operation of 1.55μm photonic-crystal surface-emitting lasers by using a‘triple-lattice photonic-crystal resonator’,which superimposes three lattice point groups to increase the strength of in-plane optical feedback.Using this geometry,the in-plane 180°coupling can be enhanced threefold compared to the normal single-lattice structure.Detailed theoretical and experimental investigations demonstrate the much lower threshold current density of this structure compared to‘single-lattice’and‘double-lattice’photonic-crystal resonators,verifying our design principles.Our findings provide a new strategy for photonic crystal laser miniaturization,which is crucial for realizing their use in future high-speed applications.

关键词： resonator crystal lattice

R2R3-type Lo MYB21 affects jasmonate-regulated development and dehiscence of anthers in lily(Lilium oriental hybrids)

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Horticultural Plant Journal 2024年第1期10卷 239-251页

作者： Zheng tong Tingting Dong Qiuhua Li Rui Wang Junna He bo Hong Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences&Hainan Institute for Tropical Agricultural ResourcesHaikouHainan 571101China Beijing Key Laboratory of Development and Quality Control of Ornamental Crops Department of Ornamental HorticultureChina Agricultural UniversityBeijing 100193China Beijing Garden Expo Management Center Beijing 100072China

Lilies are widely cultivated for cut flowers,but their large anthers carry a considerable amount of colored pollen that is dispersed easily.Studying the molecular mechanism of anther development and dehiscence could help solve this problem.LoMYB21,encoding a putative R2R3v-myb avian myeloblastosis viral oncogene homolog(MYB)transcription factor,was identified from oriental lilies(Lilium‘Siberia’).Real-time quantitative PCR analysis showed that LoMYB21 was mainly expressed in the anther,filament and stigma and had high expression during the late stages of lily anther development.LoMYB21 had transactivation activity and was located in the nucleus through yeast one-hybrid assays and transient expression in Nicotiana benthamiana.Suppression of LoMYB21 by virus-induced gene silencing(VIGS)in Lilium‘Siberia’led to anther indehiscence and reduced the expression of genes related to Jasmonate acid(JA)biosynthesis and signal transduction.Induction of LoMYB21 in DEX::LoMYB21 transgenic Arabidopsis caused procumbent inflorescences that became infertile,accompanied by higher expression of JA biosynthetic and signaling genes.These results demonstrated that JA content and signaling were abnormal in silenced lily and transgenic LoMYB21 Arabidopsis,which affected anther development.Our study indicated that LoMYB21 could regulate lily anther dehiscence through JA biosynthesis and signaling during the late stages of anther development.

关键词： Lilium LoMYB21 Anther dehiscence Jasmonate acid

Development of a high-repetition-rate lumped-inductance kicker magnet prototype for the beam switchyard of SHINE

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Nuclear Science and Techniques 2024年第2期35卷 20-31页

作者： Yong-Fang Liu Rui-Ping Wang Jin tong bo Zhang Si Chen Qi-Bing Yuan Hai-Xiao Deng Ming Gu bo Liu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201412People’s Republic of China

The Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility(SHINE)operates at a maximum repetition rate of 1 MHz.Kicker magnets are key components that distribute electron bunches into three different undulator lines in a bunch-by-bunch mode.The kicker field width must be less than the time interval between bunches.A lumpedinductance kicker prototype was developed using a vacuum chamber with a single-turn coil.The full magnetic field strength was 0.005 T.This paper presents the requirements,design considerations,design parameters,magnetic field calculations,and measurements of the kicker magnets.The relevant experimental results are also presented.The pulse width of the magnetic field was approximately 600 ns,and the maximum operation repetition rate was 1 MHz.The developed kicker satisfies the requirements for the SHINE project.Finally,numerous recommendations for the future optimization of kicker magnets are provided.

关键词： X-ray free-electron laser Kicker magnet Beam switchyard High repetition rate Ni-Zn ferrites

Exploring the Interplay between Local Chain Structure and Stress Distribution in Polymer Networks

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Chinese Journal of Polymer Science 2024年第6期42卷 874-885页

作者： Jin-tong Xue Yang Bai Li Peng Xian-bo Huang Zhao-Yan Sun School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China National-certified Enterprise Technology Center Kingfa Science and Technology Co.Ltd.Guangzhou510663China

The mechanical behavior of polymer networks is intrinsically correlated with the local chain topology and chain connectivity.In this study,we delve into this relationship through the lens of coarse-grained molecular dynamics(CG-MD)simulations.Our aim is to illuminate the intricate interplay between local topology and stress distribution within polymer monomers,cross-linkers,and various components with distinct cross-link connections,thereby elucidating their collective impact on the mechanical properties of polymer networks.We mainly focus on how specific local structures contribute to the overall mechanical response of the network.In particular,we employ local stress analysis to unravel the mechanics of these structures.Our findings reveal the diverse responses of individual components,such as junctions,strands,cross-linkers between junctions,and dangling chain ends,when subjected to stretching.Notably,we observe that these components exhibit varying degrees of deformation tolerance,underscoring the significance of their roles in determining the mechanical characteristics of the network.Our investigations highlight junctions as primary contributors to stress accumulation,and particles with higher local stress showing a stronger correlation between stress and Voronoi volume.Moreover,our results indicate that both strands and cross-linkers between junctions exhibit heightened stress levels as strand lengths decrease.This study enhances our understanding of the multifaceted factors governing the mechanical attributes of cross-linked polymer systems at the microstructural level.

关键词： Local chain structure Local stress Molecular dynamics simulation

Applications of gastric peroral endoscopic myotomy in the treatment of upper gastrointestinal tract disease

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 658-669页

作者： Shi-Yu Chang Guo-Hua Jin Hai-bo Sun Dong Yang tong-Yu Tang Department of Gastroenterology The First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina

Gastric peroral endoscopic myotomy(G-POME)is an emerging minimally invasive endoscopic technique involving the establishment of a submucosal tun-nel around the pyloric sphincter.In 2013,Khashab et al used G-POME for the first time in the treatment of gastroparesis with enhanced therapeutic efficacy,prov-iding a new direction for the treatment of gastroparesis.With the recent and rapid development of G-POME therapy technology,progress has been made in the treatment of gastroparesis and other upper digestive tract diseases,such as congenital hypertrophic pyloric stenosis and gastric sleeve stricture,with G-POME.This article reviews the research progress and future prospects of G-POME for the treatment of upper digestive tract gastrointestinal diseases.

关键词： Gastric peroral endoscopic myotomy Upper digestive tract diseases Gastroparesis Congenital hypertrophic pyloric stenosis Gastric sleeve stricture

Photoluminescence and ratiometric thermo-response of Eu2+ and Eu3+ in BaAl2B2O7:Eu2+,Eu3+ phosphor materials

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Journal of Rare Earths 2024年第7期42卷 1240-1249页

作者： Ziyao Wang Haitao Fu Xiufeng Zhan bo tong Guofeng Ma H.T.(Bert) Hintzen Institute of Innovative Science and Technology Shenyang University College of Mechanical Engineering Shenyang University Faculty of Applied Sciences Delft University of Technology

A novel Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state reaction.The valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and discussed.The phosphor shows high sensitivity(Sa=0.0173 K-1,Sr=0.461%/K) and superior signal discriminability(Δv～10380 cm-1).The thermo-sensitive performance is subject to the dual effects of different thermoresponses by Eu2+versus Eu3+combined with energy transfer from Eu2+to Eu3+,so that the sensitivity of the phosphor in the temperature range presents a non-monotonic trend.The development of the BaAl2B2O7:Eu2+,Eu3+phosphor is not only expected to be relevant for application in the field of temperature sensing,but also of reference significance for improving the sensitivity by means of energy transfer between co-activator ions over a wider temperature range of Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphors.

关键词： Eu2+/Eu3+ Phosphor Photoluminescence Rare earths Ratiometric thermo-response