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China Foundry 2024年第4期21卷 360-368页

作者： Jia-ping Fu Can-xu zhou Guo-fa Mi Yuan Liu School of Materials Science and Engineering Henan Polytechnic UniversityJiaozuo 454100HenanChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent *** order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum *** effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was *** results show that the diamond/Al-12Si composites exhibit high relative density and a uniform *** thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite *** the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 *** research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size.

关键词： diamond/aluminum composites thermal conductivity electronic packaging vacuum-assisted pressure infiltration

Numerical Study on the Effect of Gap Diffraction on the Hydrodynamic Performance of A Floating Breakwater

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China Ocean Engineering 2024年第4期38卷 663-675页

作者： BIAN Xiang-qian JI chun-yan XU Sheng GUO Jian-ting HUO fa-li School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Two-dimensional(2D)flume experiments are useful in investigating the performances of floating breakwaters(FBs),including hydrodynamic performances,motion responses,and mooring *** a reasonable gap between the flume wall and the FBs is a critical step in 2D flume ***,research on the effect of the gap on the accuracy of 2D FB experimental results is *** address this issue,a numerical wave tank is developed using CFD to estimate the wave-FB interaction of a moored dual-cylindrical FB,and the results are compared to experimental data from a previously published *** is good agreement between them,indicating that the numerical model is sufficiently *** numerical model is then applied to explore the effect of gap diffraction on the performance of FBs in2D *** was discovered that the nondimensional gap length L_(Gap)/W_(Pool)should be smaller than 7.5%to ensure that the relative error of the transmission coefficient is smaller than 3%.The influence of the gap is also related to the entering wave properties,such as the wave height and period.

关键词： floating breakwater diffraction effect gap hydrodynamic performance model experiments CFD numerical simulation

Stochastic resonance of spinor condensates in optical cavity

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 80-87页

作者： Zheng-chun Li Bixuan fan Lu zhou Weiping Zhang School of Physics and Astronomy and Tsung-Dao Lee InstituteShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China Shanghai Branch Hefei National LaboratoryShanghai 201315China Shanghai Research Center for Quantum Sciences Shanghai 201315China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Stochastic resonance is a phenomenon in which adding random noise to a system enhances the detection or transmission of a weak signal. It occurs when the noise interacts with the system's nonlinearity, thus improving signal-to-noise ratio and increasing sensitivity. Although parametric resonances in an atomic spinor Bose-Einstein condensate have been investigated, the question of whether one can observe stochastic resonance in such a system persists. In this study we propose a scheme for generating stochastic resonance in a cavity-spinor Bose-Einstein condensate coupling system. We demonstrate stochastic resonance through numerical calculations using the mean-field theory and truncated Wigner approximation methods. Furthermore, the characteristics of the system's response to noise and periodic signals are studied in detail. This study unravels a new scheme for observing stochastic resonance via linking atomic many-body physics with cavity quantum electrodynamics.

关键词： spinor condensate stochastic resonance optical cavity

Anomalous response to creep deformation from dislocation density during electrically assisted creep aging

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Rare Metals 2024年第10期43卷 5268-5283页

作者： Chang zhou Li-Hua Zhan chun-Hui Liu Ming-Hui Huang College of Mechanical and Electrical Engineering Central South University Light Alloys Research Institute State Key Laboratory of Precision Manufacturing for Extreme Service PerformanceCentral South University

Adding numerous dislocations into metallic materials before the forming stage significantly enhances their deformability. However, this beneficial effect of dislocation defects may not have a simple monotonic relationship with increased dislocation density during electroplastic deformation. This is due to the complex interactions among the drifting electrons, dislocations and solute atoms. This study explores the effect of diverse initial dislocation densities on creep deformation during electrically aided creep aging of an aluminum–lithium alloy. Surprisingly, we discovered a threshold value for the dislocation density that affects electroplastic creep, i.e., an enhanced effect from dislocations weakens when exceeding this density threshold(an anomalous response to creep). Microstructural data also reveal that such an anomalous response originates mainly from differences in various dislocation density-tailored configurations, which can influence the dislocation motions and precipitation kinetics of the strengthening T1precipitates under the same action of pulsed currents. This study provides important insights into the dislocation density-mediated electroplastic creep of an aluminum–lithium alloy.

关键词： Al–Cu–Li alloy Creep aging Dislocation density Pulsed currents

Vector magnetometry in zero bias magnetic field using nitrogen-vacancy ensembles

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Chinese Physics B 2024年第10期33卷 21-29页

作者： chunxing Li fa-Zhan Shi Jingwei zhou Peng-Fei Wang CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

The application of the vector magnetometry based on nitrogen-vacancy(NV)ensembles has been widely investigatedin multiple *** has the superiority of high sensitivity and high stability in ambient conditions with microscale ***,a bias magnetic field is necessary to fully separate the resonance lines of optically detected magneticresonance(ODMR)spectrum of NV *** brings disturbances in samples being detected and limits the rangeof ***,we demonstrate a method of vector magnetometry in zero bias magnetic field using NV *** utilizing the anisotropy property of fluorescence excited from NV centers,we analyzed the ODMR spectrum of NVensembles under various polarized angles of excitation laser in zero bias magnetic field with a quantitative numerical modeland reconstructed the magnetic field *** minimum magnetic field modulus that can be resolved accurately is downto~0.64 G theoretically depending on the ODMR spectral line width(1.8 MHz),and~2 G experimentally due to noisesin fluorescence signals and errors in *** using 13C purified and low nitrogen concentration diamond combinedwith improving calibration of unknown parameters,the ODMR spectral line width can be further decreased below 0.5 MHz,corresponding to~0.18 G minimum resolvable magnetic field modulus.

关键词： vector magnetometry NV ensembles optically detected magnetic resonance(ODMR) zero bias magnetic field

Molecular Dynamics Simulation Studies on the Micromorphology and Proton Transport of Nafion/Ti_(3)C_(2)T_(x) Composite Membrane

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Chinese Journal of Polymer Science 2024年第3期42卷 373-387,I0009页

作者： Zhi-Yue Han Su-Peng Pei chun-Yang Yu Yong-Feng zhou School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry&Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Chinese Academy of SciencesXining 810008China

The perfluorosulfonic acid(PFSA) membrane doped with two-dimensional conductive filler Ti_(3)C_(2)T_(x) is a fuel cell proton exchange membrane with high application potential. Experimental studies showed that the proton conductivity of Nafion/Ti_(3)C_(2)T_(x) composite membrane is improved significantly compared with that in pure Nafion. However, the microscopic mechanism of doping on the enhancement of membrane performance is remain unclear now. In this work, molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/Ti_(3)C_(2)T_(x) composite membrane at the molecular level. The results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/Ti_(3)C_(2)T_(x) at low and high hydration levels in the nanoscale *** the increase of water content, Ti_(3)C_(2)T_(x) in membrane was gradually surrounded by ambient water molecules to form a hydration layer, and forming a relatively continuous proton transport channel between Nafion polymer and Ti_(3)C_(2)T_(x) monomer. The continuous proton transport channel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level. The current work can provide a theoretical guidance for designing new type of Nafion composite membranes.

关键词： Nafion/Ti_(3)C_(2)T_(x)composite membrane Proton transport Molecular dynamics simulation

乡村旅游地居民的日常抵抗——以徽村拆建房风波为例

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旅游学刊 2012年第2期27卷 32-36页

作者：周春发浙江师范大学文化创意与传播学院浙江金华321004

文章以场域行动者为理论视角,透过徽村一系列拆建房风波的深入分析,展现了徽村村民在徽村旅游场域中日常抵抗的行动逻辑与实践过程。研究表明,由于旅游分红的不公、村落保护制度的失效、新村建设的难产等因素的影响,徽村村民采取了拆旧... 详细信息

文章以场域行动者为理论视角,透过徽村一系列拆建房风波的深入分析,展现了徽村村民在徽村旅游场域中日常抵抗的行动逻辑与实践过程。研究表明,由于旅游分红的不公、村落保护制度的失效、新村建设的难产等因素的影响,徽村村民采取了拆旧建新这一将文化资本转换成经济资本的行动策略。此举可能导致徽村社区的迅速衰退。

关键词：行动者日常抵抗乡村旅游古村落社区变迁

川芎嗪对脓毒症诱导的急性肺损伤小鼠血管内皮生长因子水平变化的影响

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中国生物制品学杂志 2011年第2期24卷 199-202页

作者：刘丹周发春重庆医科大学附属第一医院急诊科重庆400016

目的研究川芎嗪(Tetramethylpyrazine,TMP)对脓毒症诱导的小鼠急性肺损伤(Acute lung injury,ALI)的保护作用以及对血管内皮生长因子(Vascular endothelial growth factor,VEGF)水平变化的影响。方法将小鼠随机分为假手术组(Sham组)、脓毒症组(Sep组)、治疗对照组(NS组)、TMP-A组和TMP-B组,Sep组、NS组、TMP-A组和TMP-B组采用盲肠结扎穿刺术(Cecal ligation and puncture,CLP)复制脓毒症相关性ALI模型,造模成功后,TMP-A组和TMP-B组分别经腹腔注射100 mg/kg和40 mg/kg TMP,Sham组和NS组经腹腔注射等量生理盐水,Sep组不作处理。分别于造模后0、12、24和48 h取材,HE染色观察小鼠肺组织病理学变化;ELISA检测小鼠血浆中VEGF含量变化;Western blot检测小鼠肺组织VEGF蛋白水平。结果 TMP组小鼠在造模后12 h时肺组织病理变化与Sep组相比有所减轻,24 h时肺泡水肿、肺出血及中性粒浸润均明显减轻,48 h时TMP作用最理想;TMP组小鼠血浆VEGF水平造模后24 h开始低于Sep组(P<0.05),48 h持续下降,已接近Sham组水平;TMP组小鼠肺组织VEGF蛋白水平在造模后24 h比Sep组明显升高,但低于Sham组(P<0.05);100 mg/kg TMP的效果优于40 mg/kg;小鼠肺组织VEGF水平与血浆VEGF水平呈负相关(P<0.05)。结论 TMP能够有效减轻脓毒症所致ALI,这一作用与降低血浆VEGF水平,恢复肺组织VEGF蛋白水平有关。

关键词：川芎嗪脓毒症呼吸窘迫综合征,成人血管内皮生长因子类

Imaging characteristics and treatment strategies for carotid artery occlusion caused by skull base fracture:Three case reports

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World Journal of Clinical Cases 2024年第15期12卷 2664-2671页

作者： Pei-Xin Shangguan Ke-chun zhou Department of Emergency Lishui Municipal Central HospitalLishui 323000Zhejiang ProvinceChina

BACKGROUND Traumatic internal carotid artery(ICA)occlusion is a rare complication of skull base fractures,characterized by high mortality and disability rates,and poor ***,timely discovery and correct management are crucial for saving the lives of such patients and improving their *** article retrospectively analyzed the imaging and clinical data of three patients,to explore the imaging characteristics and treatment strategies for carotid artery occlusion,combined with severe skull base *** SUMMARY This case included three patients,all male,aged 21,63,and 16 *** underwent plain film skull computed tomography(CT)examination at the onset of their illnesses,which revealed fractures at the bases of their ***,these cases were definitively diagnosed through CT angiography(CTA)*** first patient did not receive surgical treatment,only anticoagulation therapy,and recovered smoothly with no residual limb dysfunction(Case 1).The other two patients both developed intracranial hypertension and underwent decompressive *** of these patients had high intracranial pressure and significant brain swelling postoperatively,leading the family to choose to take him home(Case 2).The other patient also underwent decompressive craniectomy and recovered well postoperatively with only mild limb motor dysfunction(Case 3).We retrieved literature from PubMed on skull base fractures causing ICA occlusion to determine the imaging characteristics and treatment strategies for this type of *** For patients with cranial trauma combined with skull base fractures,it is essential to complete a CTA examination as soon as possible,to screen for blunt cerebrovascular injury.

关键词： Skull base fracture Traumatic internal carotid artery occlusion Blunt cerebrovascular injury Imaging Case report

The preface: Interplay of topological and magnetic orders in the Mn-Bi-Te family

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National Science Review 2024年第2期11卷 6-7页

作者： Fu-chun Zhang Hai-zhou Lu X.C.Xie Kavli Institute for Theoretical Sciences University of Chinese Academy of Sciences Department of Physics Southern University of Science and Technology (SUSTech) International Center for Quantum Materials School of Physics Peking University

The discovery and synthesis of MnBi2Te4in 2013 initially garnered little attention [1]. Yet, the revelation of its topological properties in 2019 [2–6] sparked a surge of research into the MnBiTe family. These extensive studies are primarily driven by two objectives:the realization of a high-temperature quantum anomalous Hall effect （QAHE） and the exploration of exotic phases born from the interplay of topological and magnetic orders,

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