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Machine learning aided investigation on the structure-performance correlation of MOF for membrane-based He/H2 separation

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Green Chemical Engineering 2024年第4期5卷 526-532页

作者： Shitong zhang Yanjing He zhengqing zhang Chongli Zhong State Key Laboratory of Separation Membranes and Membrane Processes Tiangong University School of Chemical Engineering and Technology Tiangong University School of Textile Science and Engineering Tiangong University

The separation of He/H2using membrane technology has gained significant interest in the field of He extraction from natural gas. One of the greatest challenges associated with this process is the extremely close kinetic diameters of the two gas molecules, resulting in low membrane selectivity. In this study, we investigated the structure-performance relationship of metal-organic framework（MOF） membranes for He/H2separation through molecular simulations and machine learning approaches. By conducting molecular simulations, we identified the potential MOF membranes with high separation performance from the Computation-Ready Experimental（Co RE）MOF database, and the diffusion-dominated mechanism was further elucidated. Moreover, random forest（RF）-based machine learning models were established to identify the crucial factors influencing the He/H2separation performance of MOF membranes. The pore limiting diameter（PLD） and void fraction（φ）, are revealed as the most important physical features for determining the membrane selectivity and He permeability, respectively. Additionally, density functional theory（DFT） calculations were carried out to validate the molecular simulation results and suggested that the electronegative atoms on the pore surfaces can enhance the diffusion-based separation of He/H2, which is critical for improving the membrane selectivities of He/H2. This study offers useful insights for designing and developing novel MOF membranes for the separation of He/H2at the molecular level.

关键词： He/H 2 Membrane separation Molecular simulation Machine learning DFT calculation

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双差模非屏蔽线缆回路的电磁串扰研究

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强激光与粒子束 2024年第2期36卷 119-126页

作者：彭宁杨勇张明饶波张正卿华中科技大学电气与电子工程学院磁约束聚变与等离子体国际合作联合实验室强电磁技术全国重点实验室武汉430074 武汉第二船舶设计研究所武汉430205

随着电气化的发展,电气与电子系统中的电磁兼容问题越来越被重视,为了消除或抑制电磁耦合的影响,实现设备或元件电磁兼容的工作,有必要对线缆间的串扰进行研究。但目前少有相关研究关注独立的发射回路与接收回路构成的双差模回路间的电... 详细信息

随着电气化的发展,电气与电子系统中的电磁兼容问题越来越被重视,为了消除或抑制电磁耦合的影响,实现设备或元件电磁兼容的工作,有必要对线缆间的串扰进行研究。但目前少有相关研究关注独立的发射回路与接收回路构成的双差模回路间的电磁串扰问题。提出了一种基于多导体传输线理论的五导体传输线模型,并基于此研究了双差模非屏蔽线缆回路间的串扰问题。该方法根据耦合机理,首先建立单位长度五导体传输线等效模型,然后根据有限差分的方法列写基尔霍夫方程组,最后补充边界条件后求解得到串扰的频域解。将串扰计算结果与CST软件仿真结果进行对比,验证了该模型和计算方法的可行性与有效性,经计算分别研究了感性耦合与容性耦合,分析得到了不同因素对线束间串扰的影响规律,可为实际工程中采取措施抑制线缆间串扰提供指导,体现出该模型的先进性。

关键词：传输线理论五导体双差模回路串扰有限差分法

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电动车车身骨架静态特性多目标优化

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汽车实用技术 2024年第3期49卷 58-63页

作者：张正晴张春梅长安大学汽车学院陕西西安710064

针对微型电动车交通事故频发、车身骨架现有研究不足等问题,根据某款微型电动车车身骨架的有限元模型采取了工程设计中的计算机辅助工程(CAE)分析和多目标优化设计的概念对其车身骨架进行静态特性多目标优化。采取三组方案进行对比,在... 详细信息

针对微型电动车交通事故频发、车身骨架现有研究不足等问题,根据某款微型电动车车身骨架的有限元模型采取了工程设计中的计算机辅助工程(CAE)分析和多目标优化设计的概念对其车身骨架进行静态特性多目标优化。采取三组方案进行对比,在模型精度和计算效率之间做出取舍,得到最优的优化方案,在最终的优化结果对比和计算效率之间,方案三采用移动最小二乘法的方案在精度和效率上最佳。优化后,在车身质量没有大幅度变化的情况下,车身的扭转刚度增加了410.75 N·m/°,弯曲刚度增加了1 041.2 N/mm,该车身骨架静态性能明显提升。

关键词：车身骨架有限元多目标优化静态刚度分析电动车

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金属-有机骨架离子凝胶膜的制备及其在C_(3)H_(6)/C_(3)H_(8)分离中的应用

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膜科学与技术 2024年第2期44卷 19-28页

作者：高云硕孙玉绣刘丽娟耿晨旭张政清乔志华天津工业大学省部共建分离膜与膜过程国家重点实验室化学工程与技术学院天津300387 PPG涂料(天津)有限公司天津300457

通过调节反应时间合成出3种不同颗粒大小金属-有机骨架(ZIF-8),并将其与离子液体1-丙基-3-甲基咪唑双三氟甲磺酰亚胺盐(PmimTf_(2)N)和聚醚共聚酰胺(Pebax 1657)混合制得ZIF-8/IL/Pebax离子凝胶膜,用于对丙烯/丙烷混气体系的分离.通过ZI... 详细信息

通过调节反应时间合成出3种不同颗粒大小金属-有机骨架(ZIF-8),并将其与离子液体1-丙基-3-甲基咪唑双三氟甲磺酰亚胺盐(PmimTf_(2)N)和聚醚共聚酰胺(Pebax 1657)混合制得ZIF-8/IL/Pebax离子凝胶膜,用于对丙烯/丙烷混气体系的分离.通过ZIF-8颗粒与离子液体在Pebax膜中的协同作用,实现了金属-有机骨架(MOF)填料在聚合物基质中高达70%的质量掺杂量,C_(3)H_(6)/C_(3)H_(8)体系的气体分离性能也得到明显提升.研究表明,ZIF-8/IL/Pebax离子凝胶膜相比于Pebax纯膜,C_(3)H_(6)渗透通量提高了385%,达到了227.1 Barrer;同时,C_(3)H_(6)/C_(3)H_(8)的选择性也从3.04提高到了25.11.此外,在不同温度和压力条件下(10~40℃,0.15~0.3 MPa),ZIF-8/IL/Pebax离子凝胶膜均表现出优异的气体分离性能,并表现出了良好的应用前景.

关键词：金属-有机骨架混合基质膜离子凝胶高掺杂量 C_(3)H_(6)/C_(3)H_(8)分离

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Predicting of Covalent Organic Frameworks for Membrane-based Isobutene/1,3-Butadiene Separation:Combining Molecular Simulation and Machine Learning

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Chemical Research in Chinese Universities 2022年第2期38卷 421-427页

作者： CAO Xiaohao HE Yanjing zhang zhengqing SUN Yuxiu HAN Qi GUO Yandong ZHONG Chongli State Key Laboratory of Separation Membranes and Membrane Processes Tiangong UniversityTianjin 300387P.R.China School of Material Science and Engineering Tiangong UniversityTianjin 300387P.R.China School of Textile Science and Engineering Tiangong UniversityTianjin 300387P.R.China School of Chemical Engineering and Technology Tiangong UniversityTianjin 300387P.R.China College of Mathematics Science Bohai UniversityJinzhou 121013P.R.China

Efficient separation of C4 olefins is of critical importance and a challenging task in petrochemical industry. Covalent organic frameworks(COFs) could be used as promising candidates for membrane-based isobutene/1,3-butadiene(i-C4H8/C4H6) separation. Owing to large amounts of COFs appearing, however, the rapid prediction of optimal COFs is imperative before experimental efforts. In this work, we combine molecular simulation and machine learning to study COF membranes for efficient isolation of i-C4H8 over C4H6. Using molecular simulation, four potential COF membranes, which possess both high membrane performance score (MPS) value and moderate membrane selectivity were screened out and the mechanism of membrane separation further revealed is an adsorption dominated process. Further, random forest(RF) model with high prediction accuracy(R2>0.84) was obtained and used for elucidating key factors in controlling the membrane selectivity and i-C4H8 permeability. Ultimately, the optimal COF features were obtained through structure-performance relationship study. Our results may trigger experimental efforts to accelerate the design of novel COFs with better i-C4H8/C4H6separation performance.

关键词： Covalent organic framework Isobutene/1 3-butadiene separation Molecular simulation Machine learning

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Pore engineering of ZIF-8 with ionic liquids for membrane-based CO_(2)separation:bearing functional group effect

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Green Chemical Engineering 2021年第1期2卷 104-110页

作者： zhengqing zhang Xuemeng Jia Yuxiu Sun Xiangyu Guo Hongliang Huang Chongli Zhong State Key Laboratory of Separation Membranes and Membrane Processes and School of Chemistry and Chemical Engineering Tiangong UniversityTianjin300387China

CO_(2)separation performance of polymer membranes can be significantly enhanced by selecting porous fillers with high CO_(2)*** liquids incorporation has been recognized as an effective strategy for improving the separation ability of pristine porous ***,the influence of the specific functional groups of ILs in IL@MOF composites on separation performance of MMMs still remains ***,we designed three microenvironment-tuned IL@ZIF-8 composites in which the three ILs contain different functional groups(-CH3,–SO3H,and–NH2).Molecular simulation results showed that the NH2-IL@ZIF-8 has a commendable CO_(2)adsorption capacity and CO_(2)/CH4 adsorptive selectivity,and the results were well confirmed by the following experimental *** importantly,the prepared NH2-IL@ZIF-8 based MMMs also exhibit superior CO_(2)separation performance among the three IL@ZIF-8 based MMMs owning to its high CO_(2)***,this work can provide guidance for designing IL@MOF composites for MMMs fabrication towards gas separation,and the research mode combining molecular simulation prediction and experimental verification can afford valuable reference for material development in membrane separation field.

关键词： Molecular simulation Gas separation Ionic liquids ZIF-8 Mixed-matrix membranes(MMMs)

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Development and Application of a Power Law Constitutive Model for Eddy Current Dampers

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2403-2419页

作者： Longteng Liang Zhouquan Feng Hongyi zhang zhengqing Chen Changzhao Qian School of Civil Engineering and Architecture Xiamen University of TechnologyXiamen361024China Hunan Provincial Key Laboratory ofWind and Bridge Engineering Hunan UniversityChangsha410082China Fujian Provincial Key Laboratory ofWind Disaster and Engineering Xiamen University of TechnologyXiamen361024China State Key Laboratory of Bridge Engineering Safety and Resilience Hunan UniversityChangsha410082China

Eddy current dampers (ECDs) have emerged as highly desirable solutions for vibration control due to theirexceptional damping performance and durability. However, the existing constitutive models present challenges tothe widespread implementation of ECD technology, and there is limited availability of finite element analysis (FEA)software capable of accurately modeling the behavior of ECDs. This study addresses these issues by developing anewconstitutivemodel that is both easily understandable and user-friendly for FEAsoftware. By utilizing numericalresults obtained from electromagnetic FEA, a novel power law constitutive model is proposed to capture thenonlinear behavior of ECDs. The effectiveness of the power law constitutive model is validated throughmechanicalproperty tests and numerical seismic analysis. Furthermore, a detailed description of the application process ofthe power law constitutive model in ANSYS FEA software is provided. To facilitate the preliminary design ofECDs, an analytical derivation of energy dissipation and parameter optimization for ECDs under harmonicmotionis performed. The results demonstrate that the power law constitutive model serves as a viable alternative forconducting dynamic analysis using FEA and optimizing parameters for ECDs.

关键词： Eddy current damper constitutive model finite element analysis vibration control power law constitutive model

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Microscopic defects formation and dynamic mechanical response analysis of Q345 steel plate subjected to explosive load

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Defence Technology（防务技术） 2024年第2期32卷 430-442页

作者： zhengqing Zhou Zechen Du Yulong zhang Guili Yang Ruixiang Wang Yuzhe Liu Peize zhang Yaxin zhang Xiao Wang Research Institute of Macro-Safety Science University of Science and TechnologyBeijing100083China School of Civil and Resource Engineering University of Science and TechnologyBeijing100083China China North Industry Advanced Technology Generalization Institute Beijing100089China College of Field Engineering PLA Army Engineering UniversityNanjing210007China School of Mechanical Engineering Nantong UniversityNantong226019China

As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope(SM) and scanning electron microscope(SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0-3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler(ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models(MGFM) and Logistic fitting models(LFM), the relationship can be better expressed by cubic polynomial fitting model(CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response.

关键词： Explosive load Q345 steel Micro defect Finite element simulation Dynamic response Data fitting

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智能机器外观形象的伦理问题——从拟人化到环境假设的道德图像

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自然辩证法通讯 2019年第10期41卷 24-30页

作者：张正清北京航空航天大学马克思主义学院

智能机器的外观设计存在拟人化倾向,拟人化设计背后是一种对自我的内在假设,认为智能机器想要合乎道德共同体的道德标准,就必须具有与共同体内部成员相似的道德图像。本文认为这种对道德图像的认识导致了一种自我谬误。这种错误理解会... 详细信息

智能机器的外观设计存在拟人化倾向,拟人化设计背后是一种对自我的内在假设,认为智能机器想要合乎道德共同体的道德标准,就必须具有与共同体内部成员相似的道德图像。本文认为这种对道德图像的认识导致了一种自我谬误。这种错误理解会在个体层面导致道德身份同一的问题,在群体层面产生中心化的问题。而自我谬误反映到智能机器的道德自我上,表现为自我与他者混淆、绝对对象化和道德图像的不对称;反映到外观设计上就是内在假设的自我主导机器的道德图像。而环境假设的自我可以克服自我谬误带来的问题,其在设计上主张客体图像的独立性、它者行为的差异性和互动关系的去道德化,从而构建一种承认它者性道德的设计路径。

关键词：智能机器道德图像设计伦理

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图象小波域的水印嵌入方法

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计算机工程 2002年第1期28卷 70-72页

作者：张郑擎莫玉龙上海大学通信与信息工程学院通信工程系上海200072

图象小波变换后获得的低频尺度子图携带了较多的信号能量,在这一分量上嵌入水印,可保证水印稳健性较好,也能提高图象对水印的容量。作者应用小波提升算法基础上获得的非线性小波变换方法来提高尺度子图系数的值,增强这些系数的感觉容量... 详细信息

图象小波变换后获得的低频尺度子图携带了较多的信号能量,在这一分量上嵌入水印,可保证水印稳健性较好,也能提高图象对水印的容量。作者应用小波提升算法基础上获得的非线性小波变换方法来提高尺度子图系数的值,增强这些系数的感觉容量,实验结果表明使用这种方法可以获得稳健性更强的小波水印嵌入算法。

关键词：图像水印嵌入对策非线性小波变换水印嵌入方法图像处理小波域

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