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A comprehensive fluid-solid coupling dynamic simulation for spatiotemporal distribution of regression rate in hybrid rocket motors

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Chinese Journal of Aeronautics 2024年第9期37卷 100-112页

作者： Tianfang WEI Guobiao CAI Hui TIAN xiangyu meng Xianzhu JIANG Xiaoming GU School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of Education Beijing 100191China

The spatiotemporal distribution characteristics of the regression rate are crucial aspects of the research on Hybrid Rocket Motor(HRM).This study presents a pioneering effort in achiev-ing a comprehensive numerical simulation of fluid dynamics and heat transfer in both the fluid and solid regions throughout the entire operation of an *** accomplish this,a dynamic grid tech-nique that incorporates fluid-solid coupling is *** validate the precision of the numerical simulations,a firing test is conducted,with embedded thermocouple probes being used to measure the inner temperature of the fuel *** temperature variations in the solid fuel obtained from both experiment and simulations show good *** maximum combustion temperature and average thrust obtained from the simulations are found to deviate from the experimental results by only 3.3%and 2.4%,***,it can be demonstrated that transient numerical simu-lations accurately capture the fluid-solid coupling characteristics and transient regression *** dynamic simulation results of inner flow field and solid region throughout the entire working stage reveal that the presence of vortices enhances the blending of combustion gases and improves the regression rate at both the front and rear ends of the fuel *** addition,oscillations of the regression rate obtained in the simulation can also be well corresponded with the corrugated surface observed in the ***,the zero-dimension regression rate formula and the for-mula describing the axial location dependence of the regression rate are fitted from the simulation results,with the corresponding coefficients of determination(R°)of 0.9765 and 0.9298,*** research serves as a reference for predicting the performance of HRM with gas oxygen and polyethylene,and presents a credible way for investigating the spatiotemporal distribution of the regression rate.

关键词： Hybrid Rocket Motor(HRM) Transient numerical simulation Fluid-solid couplingheat transfer Spatiotemporal distribution of regression rate Dynamic grid

Engineering Thermoelectric Performance of α-GeTe by Ferroelectric Distortion

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Energy & Environmental Materials 2024年第2期7卷 171-179页

作者： Yuting Fan Chenghao Xie Jun Li xiangyu meng Jinchang Sun Jinsong Wu Xinfeng Tang Gangjian Tan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The rhombohedralα-GeTe can be approximated as a slightly distorted rock-salt structure along its[111]direction and possesses superb thermoelectric ***,the role of such a ferroelectric-like structural distortion on its transport properties remains ***,we performed a systematic study on the crystal structure and electronic band structure evolutions of Ge_(1-x)Sn_(x)Te alloys where the degree of ferroelectric distortion is continuously *** is revealed that the band gap is maximized while multiple valence bands are converged at x=0.6,where the ferroelectric distortion is the least but still *** undistorted,the band gap is considerably reduced,and the valence bands are largely separated ***,near the ferro-to-paraelectric phase transition Curie temperature,the lattice thermal conductivity reaches its minima because of significant lattice softening enabled by ferroelectric *** predict a peak ZT value of 2.6 at 673 K inα-GeTe by use of proper dopants which are powerful in suppressing the excess hole concentrations but meanwhile exert little influence on the ferroelectric distortion.

关键词： electronic band structures ferroelectric distortion lattice softening thermoelectric α-GeTe

Review of the application of in-situ sensing techniques to address the tea growth characteristics from leaf to field

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 1-11页

作者： Qiong Cao Chunjiang Zhao Ze Xu Ping Jiang Haibin Yang xiangyu meng Guijun Yang Information Technology Research Center Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China College of Machnical and Electrical Engineering Hunan Agricultural UniversityChangsha 410125China Tea Research Institute of Chongqing Academy of Agricultural Sciences Chongqing 400000China

The tea plant is a valuable and evergreen crop that is extensively cultivated in China and many other ***,there is growing research interest in this *** the tea industry,it is crucial to develop rapid and non-invasive methods to evaluate tea plants in their natural *** article provides a comprehensive overview of non-invasive sensing techniques used for in-situ detection of tea *** topics covered include leaf,canopy,and field-level assessments,as well as statistical analysis techniques and characteristics specific to the ***-invasive testing technology is primarily used for monitoring and predicting tea pests and diseases,monitoring quality,and nutrients,determining tenderness and grade,identifying tea plant varieties,automatically detecting,and identifying tea buds,monitoring tea plant growth,and extracting tea garden areas through remote *** also helps to evaluate planting suitability,assess disasters,and estimate ***,the article examines the challenges and prospects of emerging techniques aimed at resolving the in-situ detection problem for tea *** can assist researchers and producers in comprehensively understanding the tea environment,quality characteristics,and growth process,thereby enhancing tea production quality,and fostering tea industry development.

关键词： non-destructive in-situ detection tea plants growth characteristics sensors

基于政策工具视角的我国政府购买公共体育服务政策研究

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当代体育科技 2024年第2期14卷 157-161页

作者：孟祥宇西南大学体育学院重庆400715

该文采用政策文本量化分析法,对我国现有的90个与政府购买公共体育服务紧密相关的政策文本进行分析。构建政策工具二维分析框架,基于政策工具Y维度的政府相关部门、社会组织、公民个人3个参与主体,与X维度的经济型、政治型、行政型、管... 详细信息

该文采用政策文本量化分析法,对我国现有的90个与政府购买公共体育服务紧密相关的政策文本进行分析。构建政策工具二维分析框架,基于政策工具Y维度的政府相关部门、社会组织、公民个人3个参与主体,与X维度的经济型、政治型、行政型、管理型、社会型5类政策工具,剖析我国政府购买公共体育服务政策,揭示我国政府购买公共体育服务政策作为政府职能转变的具体表现,发现政策文本部分政策工具运用不足、管理体系需进一步完善等问题,并提出相应建议,以期为政策完善提供理论参考。

关键词：政府购买公共体育服务政策文本政府职能转变

花生壳生物炭负载钙钛矿材料对亚甲基蓝吸附性能研究

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广东化工 2024年第4期51卷 27-30,57页

作者：孟祥雨西南交通大学四川成都610031

本文通过溶胶凝胶法在超声辅助下成功合成了复合材料BC@LF。通过SEM、XRD以及BET表征了材料的表面形貌、成分、晶型以及吸附参数。测试了BC@LF对亚甲基蓝(MB)的吸附能力,实验结果表明BC@LF可以快速吸附MB,并且其吸附能力与溶液pH以及温... 详细信息

本文通过溶胶凝胶法在超声辅助下成功合成了复合材料BC@LF。通过SEM、XRD以及BET表征了材料的表面形貌、成分、晶型以及吸附参数。测试了BC@LF对亚甲基蓝(MB)的吸附能力,实验结果表明BC@LF可以快速吸附MB,并且其吸附能力与溶液pH以及温度呈正相关性。同时还测定了BC@LF的PZC结果表明pH低于6.9时BC@LF表面电位为正,p H高于6.9时BC@LF表面电位为负。根据实验结果分析了BC@LF在吸附MB过程中的吸附动力学和热力学,其中吸附动力学符合Elovich模型为化学吸附行为,吸附热力学符合Freundlich模型表明BC@LF为非均匀吸附。此外,选取了五种有机污染物对BC@LF进行吸附测试,得到了不错的吸附效果证明了BC@LF具有对有机污染物吸附的普适性。

关键词：生物炭 LaFeO_(3) 复合材料亚甲基蓝吸附作用

基于TCN-LSTM模型的电网电能质量扰动分类研究

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电力系统保护与控制 2024年第17期52卷 161-167页

作者：王义国林峰李琦刘钰淇胡贵洋孟祥宇广东省能源集团有限公司广东广州510620 广东粤电青溪发电有限责任公司广东梅州514200 西南交通大学电气工程学院四川成都610000

随着新能源发电和众多电动汽车充电桩等非线性设备并网运行,电网电能质量问题日渐凸显。现有解决方案在电能质量扰动分类上流程复杂,且在处理扰动信号时分类准确率偏低。为应对这一挑战,引入了TCN-LSTM混合模型,融合了时域卷积网络(temp... 详细信息

随着新能源发电和众多电动汽车充电桩等非线性设备并网运行,电网电能质量问题日渐凸显。现有解决方案在电能质量扰动分类上流程复杂,且在处理扰动信号时分类准确率偏低。为应对这一挑战,引入了TCN-LSTM混合模型,融合了时域卷积网络(temporal convolutional network,TCN)和长短时记忆网络(longshort-term memory,LSTM)。其中,TCN专注于捕捉时序数据的局部特性,而LSTM负责挖掘长期依赖关系,两者结合能够有效捕捉信号的局部特征和全局关系。为验证模型性能,对14种加入不同信噪比白噪声的电能质量扰动信号进行分类测试。结果表明,TCN-LSTM模型展现出较强的抗噪性能,并在与现有深度网络模型的对比中展现了更高的分类准确度。

关键词：电能质量扰动分类 TCN-LSTM模型时序数据抗噪性能

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地被物对祁连山青海云杉林土壤呼吸的影响

内蒙古师范大学学报（自然科学版） 2024年第2期53卷 111-119页

作者：孟祥宇王阳内蒙古师范大学生命科学与技术学院内蒙古呼和浩特010022 内蒙古自治区高等学校蒙古高原生物多样性保护与可持续利用重点实验室内蒙古呼和浩特010022 无穷维哈密顿系统及其算法应用教育部重点实验室内蒙古呼和浩特010022

土壤呼吸是陆地生态系统碳循环的重要组成部分,对环境变化响应的敏感性受地被物强烈影响,并显著影响生态系统的碳源/汇功能。应用Li-8100A土壤碳通量自动测量系统,对祁连山青海云杉林下土壤呼吸进行野外测定,研究环境因素和不同地被物(... 详细信息

土壤呼吸是陆地生态系统碳循环的重要组成部分,对环境变化响应的敏感性受地被物强烈影响,并显著影响生态系统的碳源/汇功能。应用Li-8100A土壤碳通量自动测量系统,对祁连山青海云杉林下土壤呼吸进行野外测定,研究环境因素和不同地被物(苔藓和凋落物)对土壤呼吸动态变化的影响。将去除苔藓和凋落物的样地与对照组进行对比,并收集0~<20 cm、20~<40 cm、40~60 cm土壤温度和土壤含水量、光合有效辐射、风速风向、相对湿度和大气温度等数据。在日尺度上,土壤温度和空气温度是影响该地区土壤呼吸日变化的主要驱动因子,但与土壤含水量的变化没有显著相关性。在季节尺度上,20~60 cm土壤温湿度的变化是土壤呼吸季节变化的主要影响因素。研究区日均CO_(2)排放量约为311.66~728.61 mg·m^(-2)·h^(-1),去除苔藓生长季土壤碳排放减少约12%,而去除凋落物土壤碳排放减少约32%。移除苔藓或者凋落物可以显著增加土壤呼吸的温度敏感性(Q_(10))。研究结果表明青海云杉林下的苔藓和凋落物对土壤呼吸有显著影响,在估算区域土壤碳排放时应区分考虑。

关键词：青海云杉土壤呼吸 Q10 土壤温度 Van’t Hoff模型

Fuzzy Set-Membership Filtering for Discrete-Time Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2022年第6期9卷 1026-1036页

作者： Jingyang Mao xiangyu meng Derui Ding Department of Control Science and Engineering University of Shanghai for Science and TechnologyShanghai 200093China Division of Electrical and Computer Engineering Louisiana State UniversityBaton RougeLA70803 USA IEEE School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

In this article,the problem of state estimation is addressed for discrete-time nonlinear systems subject to additive unknown-but-bounded noises by using fuzzy set-membership ***,an improved T-S fuzzy model is introduced to achieve highly accurate approximation via an affine model under each fuzzy ***,compared to traditional prediction-based ones,two types of fuzzy set-membership filters are proposed to effectively improve filtering performance,where the structure of both filters consists of two parts:prediction and *** the locally Lipschitz continuous condition of membership functions,unknown membership values in the estimation error system can be treated as multiplicative noises with respect to the estimation ***-time recursive algorithms are given to find the minimal ellipsoid containing the true ***,the proposed optimization approaches are validated via numerical simulations of a one-dimensional and a three-dimensional discrete-time nonlinear systems.

关键词： Affine model membership functions set-membership filtering stability Takagi-Sugeno fuzzy modeling

基于网络药理学和分子对接技术对三物黄芩汤治疗肝癌的机制分析及实验观察

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世界科学技术-中医药现代化 2024年第3期26卷 819-828页

作者：王华真何磊孟祥宇谢圆魁驻马店市第二人民医院驻马店463000

目的通过网络药理学和分子对接技术分析三物黄芩汤治疗肝癌的潜在作用机制,并通过动物实验进行初步验证。方法运用TCMSP数据库筛选三物黄芩汤的有效化合物,运用Drug bank、Pharm mapper、Uniport、PubMed等数据库获得三物黄芩汤的作用靶... 详细信息

目的通过网络药理学和分子对接技术分析三物黄芩汤治疗肝癌的潜在作用机制,并通过动物实验进行初步验证。方法运用TCMSP数据库筛选三物黄芩汤的有效化合物,运用Drug bank、Pharm mapper、Uniport、PubMed等数据库获得三物黄芩汤的作用靶点,运用Gene cards和TCGA数据库获得肝细胞癌相关靶点,与上述三物黄芩汤作用靶点取交集后得到“药物-疾病”靶点,运用String数据库构建蛋白相互作用网络,运用David和KEGG数据库进行GO、KEGG富集分析,运用Cytoscape软件构建相应网络。运用Discovery studios软件进行分子对接,对上述网络药理学结果进行验证。采用C57小鼠肝脏原位荷瘤模型,观察三物黄芩汤干预对肝癌细胞增殖、转移的影响,并观察肝癌细胞IL-6分子表达的变化。结果三物黄芩汤有效成分81个,核心成分10个,作用靶点249个,肝癌样本与正常样本差异靶点1420个,两者交集59个。蛋白相互作用网络频数分析显示,三物黄芩汤治疗肝细胞癌的机制与ESR1、MYC、JUN、IL-6、MMP9、EGF等靶点有关。GO和KEGG富集分析表明以IL-6为核心的IL-17 signaling pathway、TNF signaling pathway、Toll-like receptor signaling pathway等多条信号通路可能发挥重要作用。分子对接结果显示,药效分子Acacetin、Wogonin、Baicalein、Oroxylina、Beta-sitosterol、8-Isopentenylkaempferol、Formononetin、Luteolin、Quercetin、Stigmasterol可与IL-6蛋白结合,进一步证实了上述结果。动物实验表明,三物黄芩汤可抑制肝种植瘤的大小和肺部转移,癌细胞IL-6含量降低,初步验证了三物黄芩汤的抗肝癌作用和机制。结论本研究通过网络药理学和分子对接技术发现IL-6是三物黄芩汤治疗肝癌的关键靶点,进一步通过动物实验表明三物黄芩汤可降低肝癌组织IL-6表达量发挥治疗肝癌作用,为三物黄芩汤的抗肝癌应用提供理论依据。

关键词：三物黄芩汤肝癌网络药理学分子对接 IL-6