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Turbulent Agglomeration of Microparticles in a Cylinder Wake Flow Using LES-DEM:Focusing on the Effect of the Reynolds Number

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Journal of Thermal Science 2025年第1期34卷 34-49页

作者： WANG Shuang mu Lin LI Xue xie Jun DONG Ming School of Energy and Power Engineering Dalian University of Technology School of Optical Information and Energy Engineering Wuhan Institute of Technology School of Energy and Environment Shenyang Aerospace University

Turbulent agglomeration is viewed as a promising technology for enhancing fine particle removal *** better understand particle transport,agglomeration behaviors,and fluid-particle interactions,we numerically explored these phenomena under cylindrical vortex wake influence using a coupled large eddy simulation and discrete element method（LES-DEM） *** validity of the LES approach was verified by comparison with available direct numerical simulation（DNS） *** adopted the Johnson-Kendall-Roberts（JKR） contact model for particle-particle *** particle dispersion and agglomeration characteristics of particles with different diameters（dp=2-20 μm） in the laminar and transition of shear layer（TrSL） flow regimes were *** particles were concentrated at the vortex centers,while larger particles accumulated around the *** agglomeration efficiency exhibited an M-shaped profile spanwise（y-direction）.With increasing Reynolds number,the agglomeration efficiency and turbulence intensity *** particle agglomeration efficiency peaks at a certain Reynolds ***,at higher Reynolds numbers,reducing the residence time of particles in the flow field decreases the agglomeration efficiency.

关键词： discrete element method large eddy simulation microparticle particle agglomeration

Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 140-147页

作者： Di-Chao Chen xie Liu Changqing Xu Da-Jian Wu Ying cheng Xiao-Jun Liu School of Physics and Technology Nanjing Normal University Key Laboratory of Modern Acoustics School of Physics Nanjing University

Vortex transmutation utilizes a periodic system, which not only enables the alteration of the topological charge(TC) of unstable input vortices but also facilitates their transformation into stable structures. This approach is crucial for investigating the characteristics of vortices in various wave systems. Here, we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES). The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete symmetry. Our results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures, enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

Actively tunable electromagnetically induced transparency in hybrid Dirac-VO2 metamaterials

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Optoelectronics Letters 2025年第1期21卷 13-20页

作者： DI Ke xie Meng XIA Huarong cheng Anyu LIU Yu DU Jiajia Department of Optoelectronic Engineering Chongqing University of Post and Telecommunications Chongqing Key Laboratory of Autonomous Navigation and Microsystem Chongqing University of Posts and Telecommunications Department of Automation Chongqing University of Post and Telecommunications

In this paper, we present a metamaterial structure of Dirac and vanadium dioxide（VO2） and investigate its optical properties using the finite-difference time-domain（FDTD） technique. Using the phase transition feature of VO2, the design can realize active tuning of the plasmon induced transparency（PIT） effect at terahertz frequency, thereby converting from a single PIT to a double-PIT. When VO2is in the insulating state, the structure is symmetric to obtain a single-band PIT effect. When VO2is in the metallic state, the structure turns asymmetric to realize a dual-band PIT effect. This design provides a reference direction for the design of actively tunable metamaterials. Additionally, it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship. In addition, the structure achieves superior refractive index sensitivity in the terahertz band, surpassing 1 THz/RIU. Consequently, the design exhibits encouraging potential for application in refractive index sensors and optical switches.

关键词： Transparency

热工艺对ZT4(Ti6-Al-4V)钛合金铸件残余应力的影响

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航空材料学报 2005年第3期25卷 25-27页

作者：冯芝华王红红谢成木闫渊林北京航空材料研究院精密铸造工程事业部北京100095

对两相钛合金ZT4(Ti-6Al-4V)铸件在不同的后处理工艺条件下表面的残余应力分布进行了研究。试验发现:热等静压处理后铸件表面的残余应力处于较低的应力水平状态,补焊后铸件表面的热应力呈现分散的大数值拉-压应力状态,退火可有效降低铸... 详细信息

对两相钛合金ZT4(Ti-6Al-4V)铸件在不同的后处理工艺条件下表面的残余应力分布进行了研究。试验发现:热等静压处理后铸件表面的残余应力处于较低的应力水平状态,补焊后铸件表面的热应力呈现分散的大数值拉-压应力状态,退火可有效降低铸件表面的热应力,退火后残余应力水平与退火出炉温度有关。

关键词：钛合金铸件热工艺残余应力分布铸件表面热等静压处理两相钛合金工艺条件水平状态应力状态出炉温度应力水平热应力后处理退火

Printing perovskite and graphene parallel structure-based optical-mechanical sensors for human-machine interaction

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Science China Technological Sciences 2025年

作者： Sisi CHEN Jiemin ZHANG Nan cheng Wenbo LI Jing LIU Hongfei xie Jie ZHANG Yueying cheng Xiaotong ZHAO Meng SU Yanlin SONG Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular Sciences Institute of ChemistryChinese Academy of Sciences (ICCAS) University of Chinese Academy of Sciences Weiyang College Tsinghua University Department of Cardiovascular Surgery First Medical Center PLA General Hospital AECC Beijing Institute of Aeronautical Materials Beijing Institute of Graphene Technology Beijing Engineering Research Centre of Graphene Application School of Integrated Circuit & Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University

Surgical robots are designed to provide enhanced precision and dexterity compared to manual surgical procedures,which mainly rely on multimodal sensing technologies for the surgeon to seamlessly operate the robotic arms and *** with single-mode sensors, optical and mechanical bi-modal sensors provide improved precision, enhanced safety,and robustness of human-machine interaction systems. Here, the template-guided and pneumatic printing technologies are combined to construct perovskite and graphene parallel structures with both optical and mechanical sensing capabilities. The printed uniformly crystallized perovskite microstructure exhibits fast and sensitive photoelectric response characteristics,enabling shadow recognition functionality. The combination of graphene and elastic rubber endows the great printability to prepare parallel structures near the perovskite arrays for force sensing capabilities. Thus, the printed perovskite and graphene structures possess non-contact optical sensing capabilities to detect hand position by recognizing shadows between the hand and the sensor, as well as contact mechanical sensing capabilities to detect touch force applied by the hand. It provides a synergistic platform for real-time and multidimensional feedback to improve human-machine interaction.

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Pulsed dynamic electrolysis enhanced PEMWE hydrogen production:Revealing the effects of pulsed electric fields on protons mass transport and hydrogen bubble escape

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Journal of Energy Chemistry 2025年第1期100卷 201-214页

作者： Xuewei Zhang Wei Zhou Yuming Huang Liang xie Tonghui Li Huimin Kang Lijie Wang Yang Yu Yani Ding Junfeng Li Jiaxiang Chen Miaoting Sun Shuo cheng Xiaoxiao Meng Jihui Gao Guangbo Zhao School of Energy Science and Engineering Harbin Institute of Technology China Datang Technology Innovation Co. Ltd

The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis （PEMWE） emerging as the preeminent pathway for hydrogen *** remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable *** impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles *** address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis *** to constant voltage electrolysis (hydrogen production rate:51.6 m L h-1,energy consumption:5.37 kWh Nm-3H2),this strategy (hydrogen production rate:66 m L h-1,energy consumption:3.83 kWh Nm-3H2) increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic （PV） system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 *** combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis （PDE） dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode *** such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport *** promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.

关键词： Electrolysis

FHL2 deficiency aggravates Candida albicans infection through decreased myelopoiesis

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Science China Life Sciences 2025年

作者： Rongmei Gao Kanchao Chen Yimin Wang Rongxia Guo Xiaoyu Zhang Peng Wu Weili Wang Qingxiang Huang Xuemei xie Shangda Yang Yanling Lü Qian Ren Fei Liu Song Chen Fengxia Ma Tao cheng Hui cheng State Key Laboratory of Experimental Hematology National Clinical Research Center for Blood Diseases Haihe Laboratory of Cell Ecosystem Institute of Hematology & Blood Diseases Hospital Chinese Academy of Medical Sciences & Peking Union Medical College CAMS Center for Stem Cell Medicine PUMC Department of Stem Cell and Regenerative Medicine

Hematopoiesis is a finely tuned process that generates all blood cell types through self-renewal and differentiation, which is crucial for maintaining homeostasis. Acute infections can prompt a hematopoietic response known as emergency myelopoiesis. In this study, using a Candida albicans (C. albicans) infection model, we demonstrated for the first time that disruption of Fhl2 led to increased fungal burden,heightened inflammatory response and reduced survival rates. Impaired myeloid hematopoiesis and immune cell production were evident, as proved by the decreased numbers of hematopoietic stem and progenitor cells (HSPCs) and granulocytes in the bone marrow of Fhl2-deficient mice. In conclusion, FHL2 regulated emergency myelopoiesis in response to C. albicans, affecting the host’s defense against pathogens.

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Molecular Characterization of Drug-Resistant Beijing Family Isolates of Mycobacterium Tuberculosis from Tianjin,China

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Biomedical and Environmental Sciences 2010年第3期23卷 188-193页

作者： GUI-LIAN LI DE-FU ZHAO TONG xie HAN-FANG JU cheng mu HUI ZHAO xie-XIU WANG Tianjin Medical University 300070 Tianjin China Tuberculosis Rreference Laboratory Tuberculosis Control Centers 300041 Tianjin China Tianjin Centers for Disease Control and Prevention Tianjin 300011 China

Objective Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis （M. tuberculosis） is widespread in East Asia, especially in some areas in China, like Beijing and Tianjin. This study aimed at determining the mutation patterns of drug-resistant Beijing strains of M. tuberculosis isolated from Tianjin, China. Methods A total of 822 M. tuberculosis isolates were screened for drug resistance by an absolute concentration method and the genotype was identified by PCR. 169 drug-resistant isolates of the Beijing family were analyzed for the potential mutations in the rpoB, katG, inhA promoter region and in rpsL, rrs and embB genes, which are associated with resistance to rifampin （RFP）, isoniazid （INH）, streptomycin （SM） and ethambutol （EMB） respectively by PCR and DNA sequencing. Results Fifty-eight out of 63 RFP-resistant isolates were found to carry the mutations within the 81-bp RFP resistance determining region （RRDR） of the rpoB gene and the most frequent mutations occurred at codon 531 （44.4%）, 526 （28.6%）, and 516 （7.9%） respectively. 16 mutation pattems affecting 12 different codons around the RRDR of rpoB were found. Of 116 INH-resistant isolates, 56 （48.3%） had the mutation of katG 315 （AGC→ACC）（Ser→Thr）, 3 （2.6%） carried S315N （AGC→AAC） and 27 （16.0%） had the mutation of inhA-15A→T. 84 out of 122 SM-resistant isolates （68.9%） displayed mutations at the codons 43 or 88 with AAG→AGG （Lys→Arg） of the rpsL gene and 22 （18.0%） with the mutations at positions 513A→C, 516C→T or 905 A→G in the rrs gene. Of 34 EMB-resistant isolates, 6 had mutation with M306V （ATG→GTG）, 3 with M306I （ATG→ATT）, 1 with M306I （ATG→ATA）, 1 with D328Y （GAT→TAT）, 1 with V348L （GTC→CTC）, and 1 with G406S （GGC→AGC） in the embB gene. Conelusion These novel findings extended our understanding of resistance-related mutations in the Beijing strains of M. tuberculosis and may provide a scientific basis for development of new strategies for diagnosis a

关键词： Mycobacterium tuberculosis mutation Drug-resistance Beijing family

钼铜载体与铝合金外壳的无压纳米银胶低温烧结强度

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半导体技术 2025年第1期50卷 95-100页

作者：陈澄尹红波王成倪大海谢璐曾超林扬州海科电子科技有限公司江苏扬州225001

纳米银胶的烧结温度一般为250℃及以上,而在功率模块装配过程中,多温度梯度装配工艺要求纳米银胶的烧结温度不得超过217℃。使用800HT2V纳米银胶烧结钼铜载体与铝合金外壳,观察了不同烧结温度下纳米银胶装配后的微观形貌,测试了其装配... 详细信息

纳米银胶的烧结温度一般为250℃及以上,而在功率模块装配过程中,多温度梯度装配工艺要求纳米银胶的烧结温度不得超过217℃。使用800HT2V纳米银胶烧结钼铜载体与铝合金外壳,观察了不同烧结温度下纳米银胶装配后的微观形貌,测试了其装配后剪切强度、热导率的变化,并进行了温度冲击试验。测试结果表明,烧结样品剪切强度均符合标准要求,随着烧结温度的升高,纳米银胶热导率及剪切强度明显提升,且在最高温度200℃下烧结充分,并形成致密的烧结体。在温度冲击试验后烧结样品的剪切强度均有一定程度的下降,最高温度150℃和175℃烧结的纳米银胶烧结样品剪切强度下降超过40%,而最高温度200℃烧结的样品剪切强度只下降21.2%。考虑到功率模块的长期可靠性,纳米银胶推荐使用最高温度200℃烧结。

关键词：无压纳米银胶烧结钼铜载体铝合金外壳剪切强度热导率可靠性