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A non-probabilistic reliability topology optimization method based on aggregation function and matrix multiplication considering buckling response constraints

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 321-336页

作者： Lei WANG Yingge LIU Juxi HU Weimin CHEN Bing HAN Institute of Solid Mechanics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China Aircraft and Propulsion Laboratory Ningbo Institute of TechnologyBeihang UniversityNingbo 315100Zhejiang ProvinceChina State Key Laboratory of Navigation and Safety Technology Shanghai Ship and Shipping Research InstituteShanghai 200135China National Engineering Research Center of Ship&Shipping Control System Shanghai Ship and Shipping Research InstituteShanghai 200135China

A non-probabilistic reliability topology optimization method is proposed based on the aggregation function and matrix *** expression of the geometric stiffness matrix is derived,the finite element linear buckling analysis is conducted,and the sensitivity solution of the linear buckling factor is *** a specific problem in linear buckling topology optimization,a Heaviside projection function based on the exponential smooth growth is developed to eliminate the gray *** aggregation function method is used to consider the high-order eigenvalues,so as to obtain continuous sensitivity information and refined structural *** cyclic matrix programming,a fast topology optimization method that can be used to efficiently obtain the unit assembly and sensitivity solution is *** maximize the buckling load,under the constraint of the given buckling load,two types of topological optimization columns are *** variable density method is used to achieve the topology optimization solution along with the moving asymptote optimization *** vertex method and the matching point method are used to carry out an uncertainty propagation analysis,and the non-probability reliability topology optimization method considering buckling responses is developed based on the transformation of non-probability reliability indices based on the characteristic ***,the differences in the structural topology optimization under different reliability degrees are illustrated by examples.

关键词： buckling topology optimization aggregation function uncertainty propagation analysis non-probabilistic reliability

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Thermal decomposition kinetics and mechanism investigation of cumene hydroperoxide under inert gas: A novel experimental method

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Process Safety and Environmental Protection 2023年 172卷 408-416页

作者： Yu, Chang-Fei Liu, Shang-Hao Yuan, Liang Wei, Dan-Dan Key Laboratory of Industrial Dust Control and Occupational Health Ministry of Education Anhui University of Science and Technology 168 Taifeng Street HuainanAnhui232001 China Department of Chemical and Materials Engineering National Yunlin University Science and Technology 123 University Rd. Sec. 3 DouliouYunlin64002 Taiwan State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and Technology 168 Taifeng Street HuainanAnhui232001 China Coal Mining National Engineering Technology Research Institute 168 Taifeng Street HuainanAnhui232001 China School of Safety Science and Engineering Anhui University of Science and Technology 168 Taifeng Street HuainanAnhui232001 China

Organic peroxides, due to temperature manipulation failure and/or manner disturbances, had been probable to lead to the prevalence of runaway phenomena, even fire, and explosion. Cumene hydroperoxide (CHP), is a traditional liquid organic peroxide for industrial purposes and is applied as a free radical initiator for polymerization reactions in the petrochemical industry. Its utilization in the industrial processes had certain potential safety hazards. In this work, linearly ramped thermal decomposition in CHP was performed using differential scanning calorimetry under a nitrogen atmosphere. Kinetic analysis is made using data from the ramped measurements with two integral strategies (Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose). The gaseous products of thermal decomposition in CHP are investigated via thermal gravimetric evaluation coupled with Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry. Combined with the experimental results, the possible decomposition path of CHP is discussed. This makes up the gap of unclear decomposition mechanism of CHP in inert atmosphere, and has important reference significance for its industrial production and application. © 2023

关键词： Thermolysis

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Study on the critical velocity for initiation of a covered explosive by fragment impact 4

Study on the critical velocity for initiation of a covered e...

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4th International Conference on Defence technology, ICDT 2024

作者： Yu, Wanqian Zhang, Haijun Guo, Shang Shu, Qinghai School of Material Science and Engineering Beijing Institute of Technology Beijing100081 China National Key Laboratory of Land and Air Based Information Perception and Control Xi'an710065 China

This study examines the critical velocity for initiating a covered explosive via fragment impact, crucial for enhancing ammunition safety and reliability. Using numerical simulation techniques, the initiation threshold and influencing factors under non-normal impact conditions are investigated, which are more relevant to battlefield scenarios. The Jacobs-Roslund formula for NTO based insensitive explosive is calibrated, which is applicable for both flat-nosed and standard conical-nosed fragments. To account for a large range of impact angles, a correction term is introduced, and the predicted values are in good agreement with the simulation results. The effects of fragment pitch, yaw, and charge curvature on the critical velocity are found to be minimal at impact angle not exceeding 25°. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Explosives

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Excellent energy storage properties in non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3)-based relaxor ferroelectric ceramics

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Chinese Chemical Letters 2024年第7期35卷 470-472页

作者： Shunshun Jiang Ji Zhang Jing Wang Shan-Tao Zhang School of Materials Science and Engineering Nanjing University of Science&TechnologyNanjing 210094China State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China National Laboratory of Solid State Microstructures Department of Materials Science and EngineeringCollege of Engineering and Applied Science&Jiangsu Key Laboratory of Artificial Functional Materials&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The rapid development of high-power and pulsed-power techniques inspires extensive investigates on high-performance ceramic-based ***,the low recoverable energy density(Wrec)hampers their wider ***,the non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3)-based ceramics were designed and *** proper introduction of oxygen vacancies facilitated activating defect dipole,giving rise to reduced remanent ***,the optimal composition exhibited an exceptional high Wrec of 8.3 J/cm^(3),a high efficiency of 85%,and excellent anti-fatigue and thermal *** work provides an efficient approach to explore ceramic capacitors with high capacitive energy storage performances.

关键词： Non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3) Ceramic capacitor Energy density Thermal stability

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Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

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Food science and Human Wellness 2024年第1期13卷 124-136页

作者： Han Gong Tiange Li Dong Liang Jingxin Gao Xiaohan Liu Xueying Mao Key Laboratory of Functional Dairy Ministry of EducationCollege of Food Science and Nutritional EngineeringChina Agricultural UniversityBeijing 100083China Henan Engineering Technology Research Center of Food Processing and Circulation Safety Control College of Food Science and TechnologyHenan Agricultural UniversityZhengzhou 450002China Applied Nutrition I China National Center for Food Safety Risk AssessmentBeijing 100022China

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and *** aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice *** was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body *** demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula ***,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A *** increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain *** summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of *** findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

关键词： Cow’s milk allergy Milk fat globule membrane Gut microbiota Short-chain fatty acid G protein-coupled receptor Regulatory T cell

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Fe/BC co-conditioners with environmental and economic benefits on composting:reduced NH_(3)emissions and improved fertilizer quality

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Biochar 2024年第1期6卷 50-65页

作者： Jixiang Wang Huifang Xie Jun Wu Weijiang He Xi Zhang Junxia Huang Yanfang Feng Lihong Xue Key Laboratory of Agro-Environment in Downstream of Yangtze Plain Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and EnvironmentJiangsu Academy of Agricultural SciencesNanjing 210014China. Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science and TechnologyNanjing 210094China. Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes Ministry of EducationCollege of EnvironmentHohai UniversityNanjing 210098China.

The significant volatilization of NH_(3)during aerobic composting causes nitrogen(N)losses and environmental *** iron(Fe)and biochar(BC)can influence the N conversion process in *** application can delay the maturation of materials,while biochar can enhance the quality of organic *** combination of these two conditioners may help decrease NH_(3)emissions and improve organic fertilizer ***,this study investigates the effects of different doses of FeCl_(3)and BC on NH_(3)emissions and organic fertilizer quality during *** results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH_(3)emissions during composting by 11.1-48.2%,increased the total nutrient content by 0.6-15.3%,and enhanced economic and environmental benefits by 0.1-23.6$t^(−1).At the high-temperature stage of composting,Fe/BC co-conditioners decreased the pH by 0.3-1.2,but there was no significant difference compared to the control at the end of composting,and they did not affect compost *** structural equation model analysis suggested that the reduction in NH_(3)emis-sions was related to ammonia-oxidizing bacteria(AOB),NH_(4)^(+)-N,and total nitrogen(TN).As a result,the Fe/BC co-conditioners reduced NH_(3)emissions by lowering the pH at the beginning of composting and increasing the content of NH_(4)^(+)-*** study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH_(3)emissions and improve the quality of organic fertilizers.

关键词： Aerobic composting Biochar Organic fertilizer NH_(3)emissions FeCl_(3)

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120 ppm Quality Factor Thermal Stability from -40 to +60 of a Dual-Axis MEMS Gyroscope Based on Joule Effect Dynamic control 36

120 ppm Quality Factor Thermal Stability from -40 to +60 of ...

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36th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2023

作者： Cui, Jian Zhao, Qiancheng Peking University National Key Laboratory of Science and Technology on Micro/Nano Fabrication School of Integrated Circuits Beijing China Beijing Advanced Innovation Center for Integrated Circuits Beijing China

ISBN: (纸本)9781665493086

This paper presents a novel calibration method to improve the thermal stability of the quality factor of a MEMS gyroscope based on Joule effect dynamic control for the first time to the knowledge of the authors, which adjusts the dissipation energy of a resistive element connected to the mechanical structure with closed loop control by monitoring the driving voltage. The results show that the relative variation of the Q-factor dramatically reduced by more than 30000× down to ∼120ppm from -40 to +60 after applying the proposed means to a dual-axis gyroscope, which achieves only 30ppm of driving voltage stability over 100 range with 3600× reduction. This technique is promising for enhancing the anti-shock performance and alleviating the bias thermal drift caused by the electrical coupling of the MEMS gyroscopes. © 2023 IEEE.

关键词： Thermodynamic stability

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Impact of Evaporation Duct on Electromagnetic Wave Propagation During a Typhoon

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Journal of Ocean University of China 2022年第5期21卷 1069-1083页

作者： WANG Shuwen YANG Kunde SHI Yang YANG Fan ZHANG Hao School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Ocean Acoustics and Sensing Northwestern Polytechnical UniversityMinistry of Industry and Information TechnologyXi’an 710072China National Key Laboratory of Underwater Information Processing and Control Xi’an 710072China

The evaporation duct,a result of evaporation from the ocean,is a region above the sea surface in which radio waves are refracted *** duct has strong effects on microwave *** cause huge anomalies in marine meteorological parameters that influence the evaporation duct distribution and structure,which in turn affects the propagation of electromagnetic(EM)***,EM wave propagation under the typhoon process has seldom been ***,taking Typhoon Phanfone(201929)as an example,this study uses a dataset from the European Centre for Medium-Range Weather Forecasts,combined with the Naval Atmospheric Vertical Surface Layer Model and the parabolic equation model,to study the evaporation duct’s impact on EM wave propagation during a *** spatial and temporal path loss distributions reveal that large amounts of EM wave energy are emitted from the evaporation duct when the EM wave passes through a typhoon *** average,a typhoon eye causes an approximately 20 dB increase in path loss for EM wave propagation at low antenna ***,the effects of a typhoon eye on EM wave propagation at different signal frequencies and antenna heights are *** results show that a typhoon has a larger impact on EM wave propagation with low signal frequency and high antenna height.

关键词： evaporation duct typhoon ECMWF wave glider electromagnetic wave propagation

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Multivariate Multiscale Sample Entropy for Multi-Channel Underwater Acoustic Signal Analysis 7

Multivariate Multiscale Sample Entropy for Multi-Channel Und...

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7th IEEE Information technology, Networking, Electronic and Automation control Conference, ITNEC 2024

作者： Zhou, Jing Li, Yaan Wang, Mingzhou Shi, Lei School of Marine Science and Technology Northwestern Polytechnical University Xi'an China Xi'an Precision Machinery Research Institute National Key Laboratory of Underwater Information and Control Xi'an China

ISBN: (纸本)9798350370782

Multi-channel time series collected by arrays are prevalent in underwater acoustic signal processing and are crucial for uncovering the intrinsic characteristics of the observed system. This paper introduces the multivariate multiscale sample entropy (MMSE) to assess the complexity information in multi-channel underwater acoustic signals. Simulation analysis is employed to validate the effectiveness of the MMSE algorithm in extracting both within-channel and cross-channel information from multi-channel signals. Various types of simulated ship-radiated noise are generated to illustrate the MMSE algorithm's capability to differentiate between signals. Additionally, we employ MMSE to analyze various real-world signals, including ship-radiated noise, ambient noise, and interface reverberation. The MMSE results demonstrate its proficiency in differentiating various underwater acoustic signals compared to traditional frequency domain methods. © 2024 IEEE.

关键词： Frequency domain analysis

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Composition-dependent catalytic performance of Au_(x)Ag_(25-x) alloy nanoclusters for oxygen reduction reaction

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Nano Research 2024年第11期17卷 9490-9497页

作者： Chuan Mu Biao Wang Qiaofeng Yao Qian He Jianping Xie Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Fuzhou 350207 China Department of Chemical and Biomolecular Engineering National University of Singapore 4 Engineering Drive 4 Singapore 117585 Singapore School of Physical Science and Technology Southwest University Chongqing 400715 China Key Laboratory of Organic Integrated Circuits Ministry of Education and Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of Chemistry School of Science Tianjin University Tianjin 3700072 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China Department of Materials Science and Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117575 Singapore

Oxygen reduction reaction(ORR)occurs at the cathode of electrochemical devices like fuel cells and in the Huron-Dow process,reducing oxygen to water or hydrogen *** the past years,various electrocatalysts with enhanced activity,selectivity,and durability have been developed for ***,an atomic-level understanding of how materials composition affects electrocatalytic performance has not yet been achieved,which prevents us from designing efficient catalysts based on the requirements of practical *** is partially because of the polydispersity of traditional catalysts and their unknown structure dynamics in the electrocatalytic *** we establish a full-spectrum of atomically precise and robust Au_(x)Ag_(25-x)(MHA)18(x=0–25,and MHA=6-mercaptohexanoic acid)nanoclusters(NCs)and systematically investigate their composition-dependent catalytic performance for ORR at the atomic *** results show that,with the increasing number of Au atoms in Au_(x)Ag_(25-x)(MHA)18 NCs,the electron transfer number gradually decreases from 3.9 for Ag25(MHA)18 to 2.1 for Au25(MHA)18,indicating that the dominant oxygen reduction product alters from water to hydrogen *** functional theory simulations reveal that the Gibbs free energy of OOH adsorption(ΔGOOH*)on Au25 is closest to the idealΔGOOH*of 4.22 eV to produce H_(2)O_(2),while Ag alloying makes theΔGOOH*deviate from the optimal value and leads to the production of *** study suggests that alloy NCs are promising paradigms for unveiling composition-dependent electrocatalytic performance of metal nanoparticles at the atomic level.

关键词： metal nanoclusters synthesis electrocatalysis structure-property relationship

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