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Enhanced photothermal dehydration of methanol over W_(18)O_(49)/Au/SAPO-34 catalysts with broadened light absorption

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Rare Metals 2024年第3期43卷 1139-1152页

作者： Ya-Qin Tang Meng-Xia Yan Chang-Qian Lu Shao-Yuan Li Kui-Xian Wei Tao Qu Wen-HuiMa Yong-Nian Dai Kong-Zhai Li Da-Jun Luo xue-liang zhang Yi-Ke Liu Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming650093China School of Materials and Energy Engineering Guizhou Institute of TechnologyGuiyang550003China

Methanol-to-olefins(MTO)process is one of the most critical pathways to produce low carbon ***,the reaction is driven by thermal catalysis,which inevitably needs to consume large amounts of fossil *** a new technique to substitute for the fuel burning is urgent for MTO process to improve the industry prospects and ***,we report a novel W_(18)O_(49)/Au/SAPO-34(W/Au/S),a multifunctional photothermal catalyst for the MTO reaction.A high methanol conversion was achieved under xenonum(Xe)lamp irradiation,yielding methyl ether(ME)and ethylene as the main *** optimized W/Au/S catalysts showed ethylene yield as high as 250μmol in 60 min,which was 2.5 times higher than that of Au/*** physiochemical characterization revealed that the SAPO-34 molecular sieves were surrounded by Au and W_(18)O_(49)nanoparticles,which exhibited a strong localized surface plasmon resonance excitation around 540 nm and light absorption beyond 500 *** multifunctional catalysts showed a strong photothermal effect,arising from the broadened light absorption of Au and W_(18)O_(49)nanoparticles,leading to a temperature as high as 250℃on the surface of the *** study showed that the superior ethylene selectivity of W/Au/S catalysts was attributed to the moderating acidic sites of W_(18)O_(49)for methanol dehydration to *** research may provide new insight for designing heterostructures to improve photo-to-chemical conversion performance and is expected to accelerate progress toward the excellent multifunctional photothermal catalysts with broad light absorption for methanol activation and C-C bond formation.

关键词： Methanol conversion Ethylene Photothermal catalysis W_(18)O_(49) BrΦnsted-acid

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Synchronization of three homodromy coupled exciters in a non-resonant vibrating system of plane motion

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Acta Mechanica Sinica 2012年第5期28卷 1424-1435页

作者： xue-liang zhang Bang-Chun Wen Chun-Yu Zhao School of Mechanical Engineering and Automation Northeastern University

In this paper, the synchronization problem of three homodromy coupled exciters in a non-resonant vibrating system of plane motion is studied. By introducing the average method of modified small parameters, we deduced dimensionless coupling equation of three exciters, which converted the problem of synchronization into that of the existence and stability of zero solutions for the average differential equations of the small parameters. Based on the dimensionless coupling torques and characteristics of the cor- responding limited functions, the synchronization criterion for three exciters was derived as the absolute value of dimensionless residual torque difference between arbitrary two motors being less than the maximum of their dimensionless coupling torques. The stability criterion of its synchronous state lies in the double-condition that the inertia coupling matrix is positive definite and all its elements are positive as well. The synchronization determinants are the coefficients of synchronization ability, also called as the general dynamical symmetry coefficients. The double-equilibrium state of the vibrating system is manifested by numeric method, and the numeric and simulation results derived thereof indicate the indispensable and crucial role the structural parameters of the vibrating system play in the stability criterion of synchronous operation. Besides, by adjusting its structural parameters, the elliptical motion of the vibrating system successfully met the requirements in engineering applications.

关键词： Synchronization Vibrating system Stability Coupling dynamic - Vibratory synchronization transmission

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Temperature-dependent evolution of oxide inclusions during heat treatment of stainless steel with yttrium addition

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International Journal of Minerals,Metallurgy and Materials 2020年第6期27卷 754-763页

作者： xue-liang zhang Shu-feng Yang Jing-she Li Jin-qiang Wu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Department of Material Science and Engineering Missouri University of Science and TechnologyRollaMO 65409USA Center for Innovation through Visualization and Simulation Purdue University NorthwestHammondIN 46323USA

The evolution of oxide inclusions during isothermal heating of 18Cr–8Ni stainless steel with yttrium addition at temperatures of 1273 to 1573 K was investigated *** spherical Al–Y–Si(–Mn–Cr)oxide inclusions were observed in as-cast *** heating,most of the homogeneous inclusions were transformed into heterogeneous inclusions with Y-rich and Al-rich parts,even though some homogeneous oxide particles were still observed at 1273 and 1573 *** the increase in heating temperature,more large-sized inclusions were *** shape of the inclusions also changed from spherical to *** maximum transformation temperature of inclusions was determined to be 1373 *** evolution mechanism of inclusions during heating was proposed to be the combined effect of the(i)internal transformation of inclusions due to the crystallization of glassy oxide and(ii)interfacial reaction between inclusions and steel ***,the internal transformation of inclusions was considered to be the main factor at heating temperatures less than 1473 K.

关键词： stainless steel rare earth metals oxide inclusions heating temperature

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Reliability Evaluation of QFN Devices Soldered Joints with Creep Model

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Chinese Journal of Mechanical Engineering 2011年第3期24卷 428-432页

作者： JI Feng xue Songbai zhang liang GAO Lili SHENG Zhong DAI Wei College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

The solder joint reliability of quad flat non-lead （QFN） package,which has become very popular over the past few years,has received intense *** finite element method （FEM） is essential to evaluate the reliability of QFN *** this paper,Garofalo-Arrheninus model was implemented to simulate the deformation of QFN soldered *** creep strain of the soldered joints was calculated by means of finite element analyses,and was used to evaluate the reliability of QFN *** is found that the critical soldered joint of QFN is located the package corner while the maximum creep strain is obtained at the top interface of peripheral soldered *** creep strain is provided with periodicity and additivity as the thermal *** analysis of QFN package with different lead counts was presented as well,in which the phenomenon that the value of induced creep strain arise as the package size decreasing is ***,SnPb and two lead-free solders,namely,Sn3.5Ag/Sn3.8Ag0.7Cu,were both taken into *** results indicate that the creep strain value of lead-free soldered joints is lower than that of SnPb soldered joints,which can be attributed to the difference of stiffness and coefficient of thermal expansion among three ***-Arrheninus model is used to calculate the creep strain of the QFN device for the first time in this *** results provide an important basis for evaluating the reliability of QFN package.

关键词： finite element analyses reliability lead-free solder creep strain

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Interfacial reaction between oxide inclusion and steel matrix deoxidized by Si and Mn at 1473 K

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Journal of Iron and Steel Research International 2018年第1期25卷 1-8页

作者： xue-liang zhang Shu-feng Yang Cheng-song Liu Jing-she Li Qing Liu Gang Liu School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083 China Beijing Key Laboratory of Special Melting and Preparationof High-End Metals Beijing 100083 China The State Key Laboratory of Refractories and MetallurgyWuhan University of Science and Technology Wuhan 430081 Hubei China

An improved diffusion couple method was used to simulate the dynamic process of the solid-state reaction at the interface between oxide inclusions and a steel matrix deoxidized by Si and Mn during heat treatment at 1473 K. Experimental results indicated that good contact between the oxide and steel matrix was attained after pre-treatment at 1673 K. In addition, the reaction between the oxide and steel matrix at 1673 K was suppressed, and the effect of this reaction on the diffusion couple experiments at 1473 K was minimized. In the diffusion couple experiments, the diffusion of oxygen from the oxide to the steel matrix resulted in the precipitation of fine oxide particles and a decrease in the Mn content in the steel matrix near the interface after heat treatment at 1473 K. With increasing heat treatment time, the widths of the particle precipitation zone （PPZ） and Mn-depleted zone （MDZ） gradually increased. In addition, the solid-state reaction at the interface between the oxide and steel matrix was intense, and the widths of the PPZ and MDZ increased rapidly during the 0-20 h stage of heat treatment, especially during the 0-5 h stage. The interfacial reaction was retarded, and the rates of width expansion of PPZ and MDZ decreased with increasing heat treatment time.

关键词： Oxide inclusion Diffusion couple Heat treatment Solid-state reaction Interfacial reaction

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A stable implicit nodal integration-based particle finite element method(N-PFEM)for modelling saturated soil dynamics

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2172-2183页

作者： liang Wang xue zhang Jingjing Meng Qinghua Lei Department of Earth Sciences ETH ZürichZürich8092Switzerland Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolL693BXUK Department of Civil Environmental and Natural Resources EngineeringLuleåUniversity of TechnologyLuleå97187Sweden Department of Earth Sciences Uppsala UniversityUppsala75105Sweden

In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated *** approach incorporates the nodal integration technique into a generalised Hellinger-Reissner(HR)variational principle,creating an implicit PFEM *** mitigate the volumetric locking issue in low-order elements,we employ a node-based strain smoothing *** discretising field variables at the centre of smoothing cells,we achieve nodal integration over cells,eliminating the need for sophisticated mapping operations after re-meshing in the *** express the discretised governing equations as a min-max optimisation problem,which is further reformulated as a standard second-order cone programming(SOCP)***,pore water pressure,and displacements are simultaneously determined using the advanced primal-dual interior point ***,our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM *** experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy,obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM *** work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics.

关键词： Particle finite element method Nodal integration Dynamic saturated media Second-order cone programming(SOCP)

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Combining unscented Kalman filter and wavelet neural network for anti-slug

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Petroleum Science 2023年第6期20卷 3752-3765页

作者： Chuan Wang Long Chen Lei Li Yong-Hong Yan Juan Sun Chao Yu Xin Deng Chun-Ping liang xue-liang zhang Wei-Ming Peng School of Mechanical Engineering Southwest Petroleum UniversityChengdu610500SichuanChina Energy Equipment Institute Southwest Petroleum UniversityChengdu610500SichuanChina CNPC National Engineering Research Center for Oil and Gas Drilling Equipment Co.LTD Baoji721000ShaanxiChina Oil Production Service Co. CETS LTD.Tianjin300000China

The stability of the subsea oil and gas production system is heavily influenced by slug flow. One successful method of managing slug flow is to use top valve control based on subsea pipeline pressure. However, the complexity of production makes it difficult to measure the pressure of subsea pipelines, and measured values are not always accessible in real-time. The research introduces a technique for integrating Unscented Kalman Filter (UKF) and Wavelet Neural Network (WNN) to estimate the state of subsea pipeline pressure using historical data and a state model. The proposed method treats multiphase flow transport as a nonlinear model, with a dynamic WNN serving as the state observer. To achieve real-time state estimation, the WNN is included into the UKF algorithm to create a WNN-based UKF state equation. Integrate WNN and UKF in a novel way to predict system state accurately. The simulated results show that the approach can efficiently predict the inlet pressure and manage the slug flow in real-time using the riser's top pressure, outlet flow and valve opening. This method of estimate can significantly increase the control effect.

关键词： State estimation Stable control Method fusion Wavelet neural network Unscented Kalman filter

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Fully sprayed MXene-based high-performance flexible piezoresistive sensor for image recognition

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Nano Materials Science 2024年第1期6卷 77-85页

作者： Zhi-Dong zhang xue-Feng Zhao Qing-Chao zhang Jie liang Hui-Nan zhang Tian-Sheng zhang Chen-Yang xue Key Laboratory of Instrumentation Science&Dynamic Measurement of Ministry of Education North University of ChinaTaiyuan030051People's Republic of China State Key Laboratory of ASIC and System Shanghai Institute of Intelligent Electronics&SystemsSchool of MicroelectronicsFudan UniversityShanghai200433People's Republic of China Shanxi Hosipital of Acupuncture and Moxibustion Taiyuan030006People's Republic of China

High-performance flexible pressure sensors provide comprehensive tactile perception and are applied in human activity monitoring,soft robotics,medical treatment,and human-computer ***,these flexible pressure sensors require extensive nano-architectural design and complicated manufacturing and are ***,a highly sensitive,flexible piezoresistive tactile sensor is designed and fabricated,consisting of three main parts:the randomly distributed microstructure on T-ZnOw/PDMS film as a top substrate,multilayer Ti_(3)C_(2)-MXene film as an intermediate conductive filler,and the few-layer Ti_(3)C_(2)-MXene nanosheetbased interdigital electrodes as the bottom *** MXene-based piezoresistive sensor with randomly distributed microstructure exhibits a high sensitivity over a broad pressure range(less than 10 kPa for 175 kPa^(-1))and possesses an out-standing permanence of up to 5000 ***,a 16-pixel sensor array is designed,and its potential applications in visualizing pressure distribution and an example of tactile feedback are *** fully sprayed MXene-based pressure sensor,with high sensitivity and excellent durability,can be widely used in,electronic skin,intelligent robots,and many other emerging technologies.

关键词： Piezoresistive sensor Ti_(3)C_(2)-MXene T-ZnOw/PDMS film Randomly distributed microstructure

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Effect of dopant valence on the oxygen desorption and oxygen permeability of SrCo_(0.4)Fe_(0.5)M_(0.1)O_(3-δ)(M=Ni, Al and Zr) mixed-conducting oxides

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Chinese Chemical Letters 2008年第6期19卷 725-729页

作者： Yan Jun He Xian Feng Chang xue liang Dong Chun zhang Wan Qin Jin Nan Ping Xu State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing 210009 China

The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ （M = Ni, Al and Zr） mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement. The SrCo0.4Fe0.5M0.1O3-δ for M = Fe, Ni, Al and Zr were denoted as SCF, SCFN, SCFA and SCFZ, respectively. O2-TPD analysis revealed that the amount of α oxygen desorption decreased with increasing the valance of doped metal elements （SCFN 〉 SCFA SCF 〉 SCFZ）. The oxygen permeation flux at the temperature ≈igher than 1148 K decreased in the order of SCFN 〉 SCF 〉 SCFZ 〉 SCFA. Single activation for oxygen permeation was observed for SCFZ oxide and the activation energies of SCF and SCFA change at around 1073 K, while the change temoerature of SCFN was about 1173 K.

关键词： Valence Mixed-conducting oxide Oxygen desorption Oxygen permeability

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LAGRANGE REPRESENTATION OF MULTIVARIATE INTERPOLATION

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Science China Mathematics 1989年第4期32卷 385-396页

作者：梁学章 Institute of Mathematics Jilin University Changchun.

This paper gives a set of linearly independent interpolating functionals and a correspon-ding set of fundamental Lagrange polynomials for the multivariate extension (the liftedmultivariate map) of univariate generaliz... 详细信息

关键词： multivariate extension interpolation properly posed set of nodes Lagrange representation.

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