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Nonlinear frequency analysis of buckled nanobeams in the presence of longitudinal magnetic field

Acta Mechanica Solida Sinica 2017年第5期30卷 465-473页

作者： Xi-ping Sun Yuan-zhuo Hong Hu-Liang Dai Lin Wang Tianjin Research Institute Water Transport Engineering M.O.TTest Detection Center of Water Transport EngineeringTianjin 300456China Department of Mechanics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Wuhan 430074China

The nonlinear free vibration around the postbuckling configuration of nonlocal nanobeams with pinned-pinned boundary conditions are analytically investigated, considering the ge- ometric nonlinearity arising from the mid-plane stretching and particularly the effect of a longitudinal magnetic field. When the applied axial force is small, the nanobeam is stable and its free vibration is around the straight equilibrium position. As the axial force becomes large and is beyond a certain critical value （critical axial force）, however, either positive or negative non-trivial equilibrium configuration occurs and the free vibration is around the buckled configuration. The governing equation for the nanobeam before buckling exhibits a cubic nonlinearity while for a buckled nanobeam it contains both cubic and quadratic non- linearities. Based on the nonlinear governing equations, approximate analytical solutions for the postbuckling configuration in terms of the applied axial force are evaluated, show- ing that the magnetic field parameter has a great effect on the critical axial force, buckled displacement and linear frequencies of the nanobeam system. More interestingly, the non- linear frequency is found to be generally higher than the linear frequency in the case of prebuckling regime while it could be lower than the linear one in the case of postbuck- ling regime. The nonlinear frequency can be significantly influenced by the magnetic field, the nonlinear coefficient associated with the mid-plane stretching, and the initial vibration amplitude.

关键词： Nonlocal nanobeamPostbucklingNonlinear frequencyMagnetic fieldVibration

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Quasi-Classical Trajectory Calculations of Reaction Stereodynamics of H+OH(v=0,j=0)→H2+O(^(3) P)

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Chinese Physics Letters 2011年第8期28卷 68-71页

作者： ZHAO Li SUN ping LIU Chao-zhuo School of Science China University of Petroleum(East China)Dongying 257061 School of environmental science Dalian Jiaotong UniversityDalian 116028

In order to study the vector properties,especially the correlation between the reagents and the products,of the title reaction,the quasi-classical trajectory calculations on the ^(3)A'and ^(3)A"potential energy surfaces(PESs)have been *** results indicate that the product rotational angular momentum j'is aligned and oriented perpendicular to the scattering plane on both *** rotational polarization behaviors of the product H2 with different collision energies are shown for the two *** alignment effect tends to become weaker with the increasing collision *** product H2 mainly tends to the backward scattering on the two PESs at low collision ***,there exists a switch from backward scattering to the sideways one on the ^(3)A"PES with increasing collision *** differences are reasonably explained with the characteristics of the two PESs.

关键词： energy collision backward

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Synthesis of novel chiral phosphine-triazine ligand derived fromα-phenylethylamine for Pd-catalyzed asymmetric allylic alkylation

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Chinese Chemical Letters 2008年第3期19卷 261-263页

作者： Jia Di Huang Xiang ping Hu zhuo Zheng Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 PR China Graduate School of Chinese Academy of Sciences Beijing 100039 PR China

A novel chiral phosphine-triazine ligand was synthesized from chiral α-phenylethylamine through a three-step procedure. In a model reaction of Pd-catalyzed allylic alkylation of rac-1,3-diphenylprop-2-en-1-y1 pivalat... 详细信息

关键词： Synthesis α-Phenylethylamine Phosphine-triazine ligand Pd-catalyzed allylic alkylation

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基于BIM的智慧农业温室大棚建模分析

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农机化研究 2025年第3期47卷 217-221页

作者：李祯庄卓河南工业职业技术学院河南南阳473000

智慧农业是当前农业发展的趋势,而温室大棚作为重要的农业生产设施,对其进行建模分析具有重要意义。为此,基于BIM技术,对Venlo智慧农业温室大棚进行了建模分析。首先,对温室大棚的设计流程进行分析;然后,对BIM工作流做介绍和分析,并对... 详细信息

智慧农业是当前农业发展的趋势,而温室大棚作为重要的农业生产设施,对其进行建模分析具有重要意义。为此,基于BIM技术,对Venlo智慧农业温室大棚进行了建模分析。首先,对温室大棚的设计流程进行分析;然后,对BIM工作流做介绍和分析,并对建筑结构和节点进行深化分析;最后,设计了一栋智慧农业温室大棚,并利用BIM软件对其进行三维建模和分析。实例设计表明:基于BIM技术的智慧农业温室大棚建模分析具有较高的准确性和可操作性,可为农业生产提供重要支持。

关键词：智慧农业 Venlo温室大棚 BIM技术建筑结构三维建模

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Improving oil recovery in the CO2 flooding process by utilizing nonpolar chemical modifiers

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Chinese Journal of Chemical Engineering 2016年第5期24卷 646-650页

作者： Yong Yang Xiangliang Li ping Guo Yayun zhuo Yong Sha Research Institute of Exploration and Development Shengli Oilfield CompanySINOPEC Dongying 257000China College of Chemistry and Chemical Engineering Xiamen University Xiamen 361000China

By means of experiments of C02 miscibility with crude oil, four nonpolar chemicals were evaluated in order to enhance the miscibility of C02 with crude oil. Through pre-slug injection and joint injection of toluene in CO2, crude oil displacement experiments in the slim-tube were conducted to investigate effects of the toluene- enhanced C02 flooding under simulated subterranean reservoir conditions. Experimental results showed that toluene can enhance extraction of oil into C02 and dissolution of C02 into oil with the increment of 251% and 64% respectively. Addition of toluene can obviously improve the oil recovery in either pre-slug injection or joint injection, and the crude oil recovery increased with the increase of the toluene concentration. The oil recov- ery can increase by 22.5% in pre-slug injection with the high toluene concentration. Pre-slug injection was recom- mended because it can consume less toluene than joint injection. This work could be useful to development and application of the CO） flooding in the oil recoverv as well as CO2 emission reduction.

关键词： Carbon dioxide Petroleum Vapor liquid equilibria Enhanced oil recovery C02 flooding C02 emission reduction

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面向联邦大语言模型训练的传输优化技术综述

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计算机科学 2025年第1期52卷 42-55页

作者：顿婧博李卓网络文化与数字传播北京市重点实验室(北京信息科技大学) 北京100101 北京信息科技大学计算机学院北京100101

随着人工智能技术的快速发展,各类大型语言模型不断涌现.但是专用大语言模型的用户及数据集大多具有隐私性和安全性要求,数据安全隐私问题亟待解决.在此背景下,联邦大语言模型应运而生并得到越来越多的关注.由于大型语言模型庞大的数据... 详细信息

随着人工智能技术的快速发展,各类大型语言模型不断涌现.但是专用大语言模型的用户及数据集大多具有隐私性和安全性要求,数据安全隐私问题亟待解决.在此背景下,联邦大语言模型应运而生并得到越来越多的关注.由于大型语言模型庞大的数据量以及联邦学习的分布式架构,海量的参与节点与云服务器间进行大量的模型交换会产生较高的通信成本.为提升模型收敛速率,研究人员对面向联邦大语言模型训练的传输优化技术展开了研究.文章分析了联邦大语言模型所面临的挑战;综述了基于模型微调的传输优化方法、基于模型压缩的传输优化方法以及基于分布式并行处理的传输优化的优化问题;介绍了已有的开源联邦大语言模型以及所用到的传输优化技术,并对未来研究方向进行了展望.

关键词：联邦学习大语言模型传输优化通信开销模型压缩

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Tuning the porosity of {Co12IICo8III（μ3-OH）24（X）}11+ supramolecular frameworks by reaction time for D2/H2 separation

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Science China Chemistry 2025年

作者： zhuozhou Xie Zhu zhuo Zi-Ang Nan Qing Li Xiufang Li Zi-Xiu Lu Linzhe Lü Jin Liu Luyao Liu Wenjing Wang Wei Wang Daqiang Yuan You-Gui Huang State Key Laboratory of Structure Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences University of Chinese Academy of Sciences Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth Materials Haixi InstitutesChinese Academy of Sciences State Key Laboratory of Physical Chemistry of Solid Surfaces Department of Chemistry College of Chemistry and Chemical EngineeringXiamen University

Systematicly tuning the porosities of porous materials is crucial for targeted gas mixture separation,yet it remains a longstanding *** a common strategy,altering the phenylene ring count in the organic building units has been exploited to adjust pore apertures in metal organic frameworks （MOFs） and covalent organic frameworks （COFs）,resulting in only a stepwise pore size variation of approximately 2.8?.Unlike MOFs and COFs,the porosities for supramolecular assembly frameworks are highly dependent on the packings of the molecular building units in the *** above strategy cannot be applied to supramolecular assembly frameworks and other strategies are required to adjust pore apertures in supramolecular frameworks,especially to achieve porous materials with the optimal pore size for D2/H2separation （～3?）.Here,we successfully modulate the porosity of supramolecular frameworks of[CoII1+12CoIII8L12（μ3-OH）24（X）]1clusters （L=mono-deprotonated 1-iminoisoindole-3-amine,X=ClO?4or Cl?） by controlling the duration of self-assembly *** simply adjusting the reaction time,we obtain three[CoII12CoIII8L12（μ3-OH）24（X）]11+supramolecular frameworks:[CoII12CoIII8（μ3-OH）24（ClO4）L12)]·（Cl）4·（HCO2）7（1）,[CoII12CoIII8L12（μ3-OH）24（Cl）]·（ClOI4）4·（Cl）6·（HCO2）·（H2O）10（2）,and[CoI12CoIII8L12（μ3-OH）24（Cl）]·（Cl）11·（H2O）12（3）.The different stacking patterns of the[CoII12CoIII8L12（μ3-OH）24（X）]11+clusters in these frameworks lead to significantly varied stabilities and *** 1 exhibits permanent porosity with interconnected channels and maintains stability under harsh *** contrast,compound 2 is nearly nonporous,and compound 3 becomes unstable upon *** pores of compound 1 show higher affinity to D2than H2,and the pore aperture diameter of compound 1 （～3.06?） meets the optimal porosity for D2/***,compound 1 demonstrates moderate D2/H2separation at 77 K (retention time:～7 min/g for D2/H2/Ne （10/10/80 vol%） in a flow of 5 mL

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Evolution of the Lagrangian drift and vortex added-mass of a growing vortex ring

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Journal of Hydrodynamics 2021年第4期33卷 725-735页

作者： shu-jia Lin Yang Xiang zhuo-qi Li Fu-xin Wang Hong Liu School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China

The vortex-based propulsive systems’ enhanced performance greatly contributes to the vortex added-mass effect, which was initially developed to explain the added drag when a solid body accelerates in fluids. However, the solution of the instantaneous vortex added-mass coefficient is still remaining a question because vortices always do not have a stable geometric shape like solid bodies. In this paper, the formation of a canonical vortex ring is performed to investigate the nature of vortex added-mass and explore a solution for estimating the vortex added-mass coefficient. The vortex ring is generated by a piston-cylinder apparatus, and the time-dependent flow fields are recorded by particle image velocimetry technique. The ridges of finite-time Lyapunov exponent are applied to identify the Lagrangian boundary of the vortex ring. It is found that a part of the ambient fluids is entrained by the vortex ring when it propagates downstream, resulting in the growth of the vortex ring. Besides, a significant drift of the ambient fluid is observed to bypass the Lagrangian boundary of the vortex ring and reveals the nature of the vortex added-mass. Thus, the added-mass coefficient of the vortex is redefined as the ratio of the volume of the Lagrangian drift fluids in finite time interval step to the vortex volume at that instant. By referring to McPhaden’s method to estimate the added-mass of a solid body, a method based on the multiple material lines with relative-timestep is developed to estimate the volume of Lagrangian drift fluids induced by the vortex added-mass. Then, an empirical criterion for determining the material line number and the finite time interval step is suggested for the vortex ring flow, and the eventual vortex added-mass coefficient calculated by the volume of Lagrangian drift fluids is found to well agree with the results of Brennen. Moreover, the method based on multiple material lines for calculating Lagrangian drift fluids’ volume suggests a poten

关键词： Added-mass Lagrangian coherent structure(LCS) finite-time Lyapunov exponent(FTLE)

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基于改进标签传播算法的舆情社交网络社区发现

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计算机应用研究 2025年第1期42卷 48-55页

作者：钱晓东王卓兰州交通大学经济与管理学院兰州730070 兰州交通大学电子与信息工程学院兰州730070

通过改进的标签传播算法研究了舆情社交网络中的社交主题发现。针对传统算法容易陷入局部最优的问题,依据节点间相似度选择标签传播时的邻居节点;针对传统算法标签更新时的随机性问题,通过结合舆论动力学模型HK的观点交互过程,依据节点... 详细信息

通过改进的标签传播算法研究了舆情社交网络中的社交主题发现。针对传统算法容易陷入局部最优的问题,依据节点间相似度选择标签传播时的邻居节点;针对传统算法标签更新时的随机性问题,通过结合舆论动力学模型HK的观点交互过程,依据节点影响力的大小更新标签。实验结果表明,该方法在最好情况下(k=0.9)相较于原算法,在稳定性和模块度指标两方面分别提高了31%和78%,并且优于其他几种改进算法。由此可见,该算法相较于原算法及其他改进算法在舆情社交网络的主题社区发现中表现更好。

关键词：标签传播算法舆情社交网络 HK模型主题社区发现

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Phosphate-induced differences in stabilization efficiency for soils contaminated with lead, zinc, and cadmium

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Frontiers of Environmental Science & Engineering 2018年第2期12卷 97-105页

作者： Jie Ren zhuo Zhang Mei Wang Guanlin Guo ping Du Fasheng Li College of Water Sciences Belling Normal Unive~ity Beijing 100875 China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100012 China

Phosphates can cost-effectively decrease the mobility of Pb in contaminated soils. However, Pb always coexists with other metals in soil, their competitive reactions with phosphates have not been tested. In this study, the abilities of KHzPO4, K2HPO4, and K3PO4 to stabilize Pb, Zn, and Cd in soils contaminated with a single metal or a ternary metal for different phosphorus/metal molar ratios were investigated. Results indicated that the stabilization efficiency of KH2PO4, K2HPO4, and K3PO4 for Pb, Zn, and Cd in single metal contaminated soil （P/M ratio 0.6） was 96.00%-98.74%, 33.76%-47.81%, and 9.50%-55.79%, respectively. Competitive stabilization occurred in the ternary system, Pb exhibited a strong competition, the stabilization efficiency of Zn and Cd reduced by 23.50%- 31.64%, and 7.10%--39.26%, respectively. Pyromorphite and amorphous lead phosphate formed with excess KH2PO4 or K2HPO4 addition, while K3PO4 resulted in the formation of a hydroxypyr- omorphite precipitate. Amorphous Zn and Cd phosphates and hydroxides were the primary products. The immobilization rate of Zn and Cd depends on pH, and increased significantly in response to the excess phosphate application. This approach provides insight into phosphate-induced differences in stabilization efficiency in soils contaminated with multiple metals, which is of theoretical and engineering significance.

关键词： Heavy metals Metal-contaminated soil Phosphate Competitive stabilization

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