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Stability analysis of a liquid crystal elastomer self-oscillator under a linear temperature field

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 337-354页

作者： Haiyang wu Jiangfeng LOU Biao ZHANG Yuntong DAI kai li School of Civil Engineering Anhui Jianzhu UniversityHefei 230601China

Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so ***,numerical methods have been widely utilized for obtaining the characteristics of self-oscillation including amplitude and ***,numerical methods are burdened by intricate computations and limited precision,hindering comprehensive investigations into self-oscillating *** this paper,the stability of a liquid crystal elastomer fiber self-oscillating system under a linear temperature field is studied,and analytical solutions for the amplitude and frequency are ***,we establish the governing equations of self-oscillation,elucidate two motion regimes,and reveal the underlying ***,we conduct a stability analysis and employ a multi-scale method to obtain the analytical solutions for the amplitude and *** results show agreement between the multi-scale and numerical *** research contributes to the examination of diverse self-oscillating systems and advances the theoretical analysis of self-oscillating systems rooted in active materials.

关键词： self-oscillation stability analysis multi-scale method liquid crystal elastomer linear temperature field

重症肺炎支原体肺炎患儿血清sCD163、NLRP3、IL-37的检测及其临床意义

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海南医学 2024年第9期35卷 1307-1311页

作者：张大新吴凯利付晨张玉文商丘市第四人民医院儿科河南商丘476000 商丘市第四人民医院医务科河南商丘476000

目的检测重症肺炎支原体肺炎(MPP)患儿血清可溶性血红蛋白清道夫受体s(sCD163)、NOD样受体蛋白3(NLRP3)、白细胞介素(IL)-37水平并探讨其临床意义。方法选取2021年1月至2023年6月商丘市第四人民医院收治的112例重症MPP患儿作为重症MPP组... 详细信息

目的检测重症肺炎支原体肺炎(MPP)患儿血清可溶性血红蛋白清道夫受体s(sCD163)、NOD样受体蛋白3(NLRP3)、白细胞介素(IL)-37水平并探讨其临床意义。方法选取2021年1月至2023年6月商丘市第四人民医院收治的112例重症MPP患儿作为重症MPP组,另选取同期收治的112例轻症MPP患儿作为轻症MPP组。比较两组患儿的血清sCD163、NLRP3、IL-37水平,以及不同临床表现重症MPP患儿和不同预后患儿的血清sCD163、NLRP3、IL-37水平。采用Spearman相关性分析血清sCD163、NLRP3、IL-37水平与重症MPP患儿预后的关系,绘制受试者工作特征曲线(ROC)评价血清sCD163、NLRP3、IL-37水平对重症MPP患儿预后的预测价值。结果重症MPP组患儿的血清sCD163、NLRP3、IL-37分别为(157.16±45.19)pg/mL、(12.96±3.41)μg/mL、(102.49±30.25)pg/mL,明显高于轻症MPP组的(114.83±37.39)pg/mL、(7.45±2.17)μg/mL、(67.42±24.83)pg/mL,差异均有统计学意义(P<0.05);有肺实变、肺不张、胸腔积液及肺外并发症患儿的血清sCD163、NLRP3、IL-37水平均分别高于无肺实变、肺不张、胸腔积液及肺外并发症患儿,差异均有统计学意义(P<0.05);治疗1个月后,重症MPP患儿中35例预后不良,77例预后良好,预后不良患儿的血清sCD163、NLRP3、IL-37分别为(194.33±58.63)pg/mL、(18.47±6.11)μg/mL、(124.83±30.45)pg/mL,明显高于预后良好患儿的(140.26±40.25)pg/mL、(10.46±3.27)μg/mL、(92.34±25.34)pg/mL,差异均有统计学意义(P<0.05);经Spearman相关性分析结果显示,血清sCD163、NLRP3、IL-37水平与重症MPP患儿预后呈正相关(P<0.05);经ROC分析结果显示,血清sCD163、NLRP3、IL-37水平预测重症MPP患儿预后不良的曲线下面积(AUC)值分别为0.796、0.765、0.737,三者联合预测预后不良的AUC值为0.923,明显高于各指标单独预测,敏感度、特异度分别为88.57%、83.12%。结论重症MPP患儿血清sCD163、NLRP3、IL-37水平升高与预后不良密切相关,三者联合有望成为预测重症MPP患儿预后的重要指标。

关键词：肺炎支原体肺炎可溶性血红蛋白清道夫受体s NOD样受体蛋白3 白细胞介素-37 病情程度预后

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Incombustible solid polymer electrolytes:A critical review and perspective

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Journal of Energy Chemistry 2024年第6期93卷 264-281,I0007页

作者： kai wu Jin Tan Zhenfang liu Chenguang Bao Ao li Qi liu Baohua li College of Materials Science and Engineering Hunan UniversityChangsha 413000HunanChina Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 055GuangdongChina

Since the advent of the solid-state batteries,employing solid polymer electrolytes(SPEs)to replace routine flammable liquid electrolytes is regarded to be one of the most promising solutions in pursing highenergy-density battery *** with superior thermal stability,good processability,and high mechanical modulus obtain increasing ***,SPE-based batteries are not impenetrable due to their decomposition and combustibility under extreme *** believe incorporating appropriate flame-retardant additives/solvents/fragments into SPEs can intrinsically reduce their flammability to solve the battery safety *** this review,the recent research progress of incombustible SPEs,with special emphasis on flame-retardant structural design,is ***,a brief introduction of flame-retardant mechanism,evaluation index for safety of SPEs,and a detailed overview of the latest advances on diverse-types SPEs in various battery systems are *** deep insight into thermal ru naway process,the free-standing incombustible GPEs,and the ratio nal design of pouch cell structures may be the main directions to motivate revolutionary next-generation for safety batteries.

关键词： Non-flammable electrolyte Solid polymer electrolyte High safety electrolyte Solid state electrolyte Solid state battery

Exploring Trade-offs in Thermal Interface Materials:The Impact of Polymer-Filler Interfaces on Thermal Conductivity and Thixotropy

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Chinese Journal of Polymer Science 2024年第7期42卷 916-925,I0006页

作者： Bin Zhang Zheng-li Dou Yong-Zheng Zhang Qiang Fu kai wu College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

Effective thermal transport across solid-solid interfaces which is essential in thermal interface materials(TIMs),necessitates both optimal thixotropy and high thermal *** role of filler surface modification,a fundamental aspect of TIM fabrication,in the influence of these properties is not fully *** study employs the use of a silane coupling agent(SCA)to modify alumina,integrating experimental approaches with molecular dynamics simulations,to elucidate the interface effects on thixotropy and thermal conductivity in polydimethylsiloxane(PDMS)-based *** findings reveal that the variations of SCAs modify both interface binding energy and transition layer *** interface binding energy restricts macromolecular segmental relaxation near the interface,hindering desirable thixotropy and bond line *** the contrary,the thickness of the transition layer at the interface positively influences thermal conductivity,facilitating the transport of phonons between the polymer and ***,selecting an optimal SCA allows a balance between traditionally conflicting goals of high thermal conductivity and minimal bond line thickness,achieving an impressively low interface thermal resistance of just 2.45-4.29 K·mm^(2)·W^(-1)at275.8 kPa.

关键词： Thermal interface material Surface modification Thermal conductivity Thixotropy Interface thermal resistance

Synergism of preintercalated manganese ions and lattice water in vanadium oxide cathodes for high-capacity and long-life Zn-ion batteries

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Journal of Energy Chemistry 2024年第9期96卷 709-717页

作者： Mengjing wu Rongrong li kai Yang lijiang Yin Weikang Hu Xiong Pu Key Laboratory of the Ministry of Education for Advanced Catalysis Material Institute of Physical ChemistryCollege of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004ZhejiangChina CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 101400China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049China Chilwee Power Co.Ltd. Changxing 313100ZhejiangChina

Aqueous Zn-ion batteries(AZIBs)are recognized as a promising energy storage system with intrinsic safety and low cost,but its applications still rely on the design of high-capacity and stable-cycling cathode *** this work,we present an intercalation mechanism-based cathode materials for AZIB,*** vanadium oxide with pre-intercalated manganese ions and lattice water(noted as MVOH).The synergistic effect between Mn^(2+)and lattice H_(2)O not only expands the interlayer spacing,but also significantly enhances the structural *** in-situ and ex-situ characterizations clarify the Zn^(2+)/H^(+)co–(de)intercalation mechanism of MVOH in aqueous *** demonstrated remarkable structure stability,excellent kinetic behaviors and ion-storage mechanism together enable the MVOH to demonstrate satisfactory specific capacity of 450 mA h g^(−1)at 0.2 A g^(−1),excellent rate performance of 288.8 mA h g^(−1)at 10 A g^(−1)and long cycle life over 20,000 cycles at 5 A g^(−1).This work provides a practical cathode material,and contributes to the understanding of the ion-intercalation mechanism and structural evolution of the vanadium-based cathode for AZIBs.

关键词： Zn-ion batteries Vanadium oxide Pre-intercalation Lattice water Manganese ion

Petroleum pitch derived hard carbon via NaCl-template as anode materials with high rate performance for sodium ion battery

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 1-10页

作者： Baoyu wu Hao Sun Xiaoxue li Yinyi Gao Tianzeng Bao Hongbin wu kai Zhu Dianxue Cao Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education College of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China Hunan Hongshan New Energy Technology Co. LtdYiyang 413000China

Sodium-ion batteries(SIBs)have garnered significant interest in energy storage due to their similar working mechanism to lithium ion batteries and abundant reserves of sodium *** facile synthesis of a carbon-based anode materials with capable electrochemical performance is key to promoting the practical application of *** this work,a combination of petroleum pitch and recyclable sodium chloride is selected as the carbon source and template to obtain hard carbon(HC)anode for *** times and temperatures are optimized by assessing the sodium ion storage behavior of different HC *** optimized HC exhibits a remarkable capacity of over 430 mAh·g^(-1) after undergoing full activation through 500 cycles at a density of current of 0.1 A·g^(-1).Furthermore,it demonstrates an initial discharge capacity of 276 mAh·g^(-1) at a density of current of 0.5 A·g^(-1).Meanwhile,the optimized HC shows a good capacity retention(170 mAh·g^(-1) after 750 cycles)and a remarkable rate ability(166 mAh·g^(-1) at 2 A·g^(-1)).The enhanced capacity is attributed to the suitable degree of graphitization and surface area,which improve the sodium ion transport and storage.

关键词： petroleum pitch hard carbon sodium-ion batteries high rate recyclable template

High-temperature stability of retained austenite and plastic deformation mechanism of ultra-fine bainitic steel isothermally treated below Ms

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Journal of Iron and Steel Research International 2024年第8期31卷 2014-2030页

作者： Ting-ting He Feng Hu Kun Wang Wen Zhou li li Serhii Yershov kai-ming wu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Collaborative Innovation Center for Advanced Steels Wuhan University of Science and TechnologyWuhan 430081HubeiChina Zhejiang Tsingshan Iron and Steel Co. Ltd.Qingtian 323903ZhejiangChina

The mechanical properties of the sample and the stability of retained austenite were studied by designing two kinds of ultra-fine bainitic steel with different heat treatment methods austempering above and below Ms(martensite start tem-perature),which were subjected to tensile tests at 20 and 450℃,*** results show that compared to room temperature(20℃)tensile properties,the uniform elongation of the sample at high temperature(450℃)significantly ***,the uniform elongation of the sample austempered above Ms decreased from 8.0%to 3.5%,and the sample austempered below Ms decreased from 10.9%to 3.1%.Additionally,the tensile strength of the sample austempered above Ms significantly decreased(from 1281 to 912 MPa),and the sample austempered below Ms slightly decreased(from 1010 to 974 MPa).This was due to the high carbon content(1.60 wt.%),high mechanical stability,low thermal stability for the retained austenite of the sample austempered below ***,the retained austenite decomposed at high temper-atures,the carbon content and transformation driving force were significantly reduced,the transformation rate increased,and the phase transformation content reduced.

关键词： Ultra-fine bainite Isothermal treatment High-temperature tensile property Retained austenite stability Plastic deformation

Unmanned Ship Identification Based on Improved YOLOv8s Algorithm

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Computers, Materials & Continua 2024年第3期78卷 3071-3088页

作者： Chun-Ming wu Jin Lei wu-kai liu Mei-ling Ren ling-li Ran Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology School of Electrical EngineeringNortheast Electric Power UniversityJilin132012China School of Biomedical Engineering Taiyuan University of TechnologyTaiyuan030600China

Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved YOLOv8 algorithm(R_YOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model *** algorithm is validated in detail on two vessel *** comprehensive experimental results demonstrate that,in the infrared dataset,the YOLOv8s algorithm exhibits improvements in various performance ***,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_YOLO ***,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%.

关键词： Unmanned ships R_YOLO EMA CSPStage YOLOv8s

Study on macro and micro shear strength of continuously graded and gap-graded sand

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Particuology 2024年第3期86卷 101-116页

作者： Peiran Zhao Songyu liu kai wu School of Transportation Southeast UniversityNanjing210096China

The particle gradation of sand has a significant influence on its shear strength,yet the similarities and differences between the effects of continuous and gap grading have yet to be fully *** this study,the discrete element method(DEM)was used to simulate biaxial tests on granular samples that were both continuously graded and *** macroscopic analysis revealed that the shear strength of continuously graded sands increases initially and then decreases as the uniformity of particle size distribution *** the other hand,the lack of medium particles in gap-graded sands amplifies the difference in particle size between coarse and fine particles,leading to a decrease in shear ***,both continuous and gap gradings affect the internal packing structure of the particle assembly,which consequently affects particle stress distributions,contact forces,coordination numbers,stress-induced anisotropies,and contact force networks,thus having an impact on the macroscopic shear *** global uniformity of particle size distribution was unidirectionally affected by continuous grading,while gap grading had a locally bidirectional *** findings provide a better understanding of the effects of particle grading on the macroscopic shear strength of sands.

关键词： Biaxial test Shear strength Particle gradation Discrete element method Micromechanics