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季戊四醇固固相变材料导热性能的分子动力学研究

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陕西科技大学学报 2024年第4期42卷 126-132页

作者：崔柳景照硕张卫潮祝朝阳陈栓俊王士星华北电力大学新能源电力系统国家重点实验室北京102206 国网能源和丰煤电有限公司新疆塔城834700

火力发电中余热耗散现象不可避免,有效地利用电厂余热不仅带来直接的经济效益,而且也是实现双碳目标的重大举措。季戊四醇具有稳定性好、安全性高,并且在一定温度时会发生体心立方结构(α相)与面心立方结构(γ相)相互转化的优点,因而在... 详细信息

火力发电中余热耗散现象不可避免,有效地利用电厂余热不仅带来直接的经济效益,而且也是实现双碳目标的重大举措。季戊四醇具有稳定性好、安全性高,并且在一定温度时会发生体心立方结构(α相)与面心立方结构(γ相)相互转化的优点,因而在固固相变领域具有良好的应用场景.研究季戊四醇在不同温度时的导热性能对工业余热回收利用十分必要.本文利用分子动力学模拟方法,分别对季戊四醇相变前后的两种相态的导热性能开展了研究.为了揭示季戊四醇热导率变化的物理机理,进一步对X射线衍射图谱、声子态密度、不同频率的声子贡献以及不同类型的作用力贡献开展分析.研究结果表明,随着体系温度升高,α相季戊四醇的热导率逐渐下降.当温度超过相变温度,季戊四醇由α相转变为γ相,热导率大幅下降.相比于α相,γ相季戊四醇热导率的降低归因于:(1)γ相季戊四醇晶胞结构发生了变化,分子间氢键遭到破坏;(2)γ相季戊四醇晶体内声子散射增强;(3)主导声子频率的不同导致了α相和γ相季戊四醇热导率差异;(4)γ相季戊四醇晶体中对热导率贡献最大的键拉伸作用力占比较小.研究结果可为工业余热回收利用发展及固固相变材料的开发和设计提供理论指导.

关键词：电厂余热利用固固相变分子动力学模拟季戊四醇热导率

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红色旅游资源与思想政治教育的有机融合——以江苏红色旅游资源为例

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闽西职业技术学院学报 2024年第3期26卷 102-107页

作者：章云霞王懿张超伟苏州健雄职业技术学院江苏苏州215400 江苏省太仓高级中学江苏苏州215400

由于多元经济、多元文化的冲击,部分大学生出现信仰危机,导致人生观、世界观、价值观模糊,提高大学生的思想道德修养刻不容缓。通过对江苏红色旅游地大学生红色文化感知情况问卷调查,了解到大学生红色文化旅游地区活动范围较小且主动性... 详细信息

由于多元经济、多元文化的冲击,部分大学生出现信仰危机,导致人生观、世界观、价值观模糊,提高大学生的思想道德修养刻不容缓。通过对江苏红色旅游地大学生红色文化感知情况问卷调查,了解到大学生红色文化旅游地区活动范围较小且主动性较低,他们对红色文化了解后兴趣度则会大幅度提高。基于大学生对红色文化的感知情况,依托红色文化资源,构建高校思想政治教育服务体系,加强红色文化宣传,切实提升大学生思想道德素养。

关键词：红色文化大学生旅游感知思想政治教育

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某公路边坡及边坡挡墙稳定性分析

内蒙古公路与运输 2024年第3期 18-22页

作者：曹虎奇张超伟徐利梅榆林市公路工程试验检测中心陕西榆林719000 西安科技大学建筑与土木工程学院陕西西安710054 榆林市公路局绕城公路段陕西榆林719000

边坡及边坡挡墙稳定性对于公路工程安全建设及运营具有重要意义。目前针对边坡稳定性分析已有较多研究,而边坡挡墙稳定性分析计算很少有实际工程案例可供参考。文章以陕西省榆林市府谷老高川至郭家湾公路的两段边坡为例,依据土力学和相... 详细信息

边坡及边坡挡墙稳定性对于公路工程安全建设及运营具有重要意义。目前针对边坡稳定性分析已有较多研究,而边坡挡墙稳定性分析计算很少有实际工程案例可供参考。文章以陕西省榆林市府谷老高川至郭家湾公路的两段边坡为例,依据土力学和相关规范中的理论基础,通过库伦土压力理论计算,对自然放坡的边坡和设置仰斜式挡墙的边坡分别进行稳定性分析研究,为两段边坡的设计提供有力的支撑。结果表明:在一定的条件下,文中涉及的自然放坡和设置仰斜式挡墙的边坡均能满足规范要求,所提出的计算方法具有一定的参考价值,可为同类工程的设计提供理论计算参考。

关键词：公路工程稳定性分析理论计算边坡仰斜式挡墙

High-resolution tsunami hazard assessment for the Guangdong-Hong Kong-Macao Greater Bay Area based on a non-hydrostatic tsunami model

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Science China Earth Sciences 2024年第7期67卷 2326-2351页

作者： Yifan ZHU chao AN Houyun YU wei zhang Xiaofei CHEN Key Laboratory of Hydrodynamics(Ministry of Education) School of Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Earth and Space Sciences Southern University of Science and Technology Shenzhen 518055China

The Guangdong-Hong Kong-Macao Greater Bay Area(GBA)is threatened by potential tsunami hazards from the Littoral Fault Zone(LFZ)and the Manila subduction zone(MSZ),and may suffer huge damage because of its dense population,concentrated infrastructure,and low-lying *** tsunami studies for the GBA made simple assumptions on the mechanisms of LFZ earthquakes,and used coarse bathymetry data in tsunami simulation,which limited the prediction of detailed tsunami hazard *** this paper,we develop a parallel dispersive tsunami model PCOMCOT to efficiently simulate dispersive,nonlinear,and breaking tsunami *** also construct large-scale and high-resolution bathymetry models for the GBA by correcting and integrating various data *** rupture simulation is performed for the LFZ to obtain a more reliable earthquake source *** propose several representative earthquake scenarios for the LFZ and MSZ,and use PCOMCOT to calculate the resulting tsunami waves,currents,and inundation in the *** results indicate that if an M_(w)7.5 oblique-slip earthquake occurs in the LFZ off the Pearl River Estuary(PRE),the subsequent tsunami will primarily impact Hong Kong,causing maximum positive and negative waves of around 1 m and -2 m,respectively,along with slightly destructive currents(≥1.5 m/s).An M_(w)9.0 MSZ megathrust earthquake can lead to widespread inundation with>1 m depth on the outlying islands of Macao and in the urban areas of Hong Kong around the Victoria ***,it will also cause catastrophic tsunami currents along the narrow waterways in Hong Kong and Macao,and the spatial distribution of strong currents(≥3 m/s)shows a considerable discrepancy from the areas of serious ***,more attention should be paid to the potential impacts of tsunami currents on the GBA.

关键词： Tsunami hazards Inundation Tsunami currents Non-hydrostatic model Guangdong-Hong Kong-Macao Greater Bay Area

Physics-based battery SOC estimation methods:Recent advances and future perspectives

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Journal of Energy Chemistry 2024年第2期89卷 27-40,I0003页

作者： Longxing Wu Zhiqiang Lyu Zebo Huang chao zhang Changyin wei College of Mechanical Engineering Anhui Science and Technology UniversityChuzhou 233100AnhuiChina Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle Hubei University of Arts and ScienceXiangyang 441053HubeiChina School of Internet Anhui UniversityHefei 230039AnhuiChina School of Mechanical and Electrical Engineering Guilin University of Electronic TechnologyGuilin 541004GuangxiChina

The reliable prediction of state of charge(SOC)is one of the vital functions of advanced battery management system(BMS),which has great significance towards safe operation of electric *** far,the empirical model-based and data-driven-based SOC estimation methods of lithium-ion batteries have been comprehensively discussed and reviewed in various ***,few reviews involving SOC estimation focused on electrochemical mechanism,which gives physical explanations to SOC and becomes most attractive candidate for advanced *** this reason,this paper comprehensively surveys on physics-based SOC algorithms applied in advanced ***,the research progresses of physical SOC estimation methods for lithium-ion batteries are thoroughly discussed and corresponding evaluation criteria are carefully ***,future perspectives of the current researches on physics-based battery SOC estimation are *** insights stated in this paper are expected to catalyze the development and application of the physics-based advanced BMS algorithms.

关键词： Lithium-ion batteries State of charge Electrochemical model Battery management system

Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline

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Petroleum Science 2024年第4期21卷 2723-2733页

作者： Ao-Yang zhang Meng Cai Na wei Hai-Tao Li chao zhang Jun Pei Xin-wei Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Research Institute of Production Engineering Daqing Oilfield Co.Ltd.

During the operational process of natural gas gathering and transmission pipelines, the formation of hydrates is highly probable, leading to uncontrolled movement and aggregation of hydrates. The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines, resulting in production reduction, shutdowns, and pressure build-ups. Consequently, a cascade of risks is prone to occur. To address this issue, this study focuses on the operational process of natural gas gathering and transmission pipelines, where a comprehensive framework is established. This framework includes theoretical models for pipeline temperature distribution, pipeline pressure distribution, multiphase flow within the pipeline, hydrate blockage, and numerical solution methods. By analyzing the influence of inlet temperature, inlet pressure, and terminal pressure on hydrate formation within the pipeline, the sensitivity patterns of hydrate blockage risks are derived. The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate, potentially mitigating pipeline blockage during natural gas transportation. Furthermore, an increase in inlet temperature and terminal pressure, and a decrease in inlet pressure, results in a displacement of the most probable location for hydrate blockage towards the terminal station. However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system, contradicting the operational goal of energy efficiency and reduction of energy consumption. Consequently, for high-pressure gathering pipelines, measures such as raising the inlet temperature or employing inhibitors, electrical heat tracing, and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation. Moreover, considering abnormal conditions such as gas well production and pipeline network s

关键词： Natural gas hydrates Gathering pipeline Temperature variation Hydrate formation rate Sensitivity analysis

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

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Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng Sheng-Jie wei Guang-Qing zhang Da-wei Zhou Chuang-chao Xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 10 Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1) this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01%.(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 100 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Comparative analysis of thermodynamic and mechanical responses between underground hydrogen storage and compressed air energy storage in lined rock caverns

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International Journal of Mining Science and Technology 2024年第4期34卷 531-543页

作者： Bowen Hu Liyuan Yu Xianzhen Mi Fei Xu Shuchen Li wei Li chao wei Tao zhang State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Large Structure Health Monitoring and Control Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China

Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar ***,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage *** study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock *** thermodynamic responses are validated using additional simulations and the field test *** and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation *** reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and *** steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing *** CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same *** present research can provide references for the selection of energy storage methods.

关键词： Underground hydrogen storage Compressed air energy storage Mechanical response Thermodynamic response Lined rock caverns

A data-driven approach to RUL prediction of tools

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Advances in Manufacturing 2024年第1期12卷 6-18页

作者： wei Li Liang-Chi zhang Chu-Han Wu Yan Wang Zhen-Xiang Cui chao Niu Department of Mechanical Engineering University College LondonLondonWC1E 7JEUK Shenzhen Key Laboratory of Cross-Scale Manufacturing Mechanics Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China SUSTech Institute for Manufacturing Innovation Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen518055GuangdongPeople’s Republic of China School of Mechanical and Manufacturing Engineering The University of New South WalesKensingtonNSW2052Australia Baoshan Iron&Steel Co. Ltd.Shanghai200941People’s Republic of China

An effective and reliable prediction of the remaining useful life(RUL)of a tool is important to a metal forming process because it can significantly reduce unexpected maintenance,avoid machine shutdowns and increase system *** study proposes a new data-driven approach to the RUL prediction for metal forming processes under multiple contact sliding *** data-driven approach took advantage of bidirectional long short-term memory(BLSTM)and convolutional neural networks(CNN).A pre-trained lightweight CNN-based network,WearNet,was re-trained to classify the wear states of workpiece surfaces with a high accuracy,then the classification results were passed into a BLSTM-based regression model as inputs for RUL *** experimental results demonstrated that this approach was able to predict the RUL values with a small error(below 5%)and a low root mean square error(RMSE)(around 1.5),which was more superior and robust than the other state-of-the-art methods.

关键词： Remaining useful life(RUL) Bidirectional long short-term memory(BLSTM) Data-driven approach Metal forming