检索结果-南通市图书馆

A dual-site Fe-based catalyst for efficient ammonia synthesis under mild conditions

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Shiyong Zhang Mingyuan Zhang Tianhua Zhang Jizhen Sun Jiaxin Li Kailin Su Ruishao Mao Yanliang Zhou Xuanbei Peng Yangyu Zhang Jun Ni Bingyu Lin Xiuyun Wang Lilong Jiang national Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou University Qingyuan Innovation Laboratory

Achieving green ammonia （NH3） synthesis requires developing effective catalysts under mild ***,the competitive adsorption of N2and H2,as well as the strong binding of N-containing intermediates on the catalyst,greatly inhibits the active sites for efficient ***,we constructed a series of ZrH2-modified Fe catalysts with dual active sites to address these issues and realized efficient NH3synthesis under mild *** study shows that ZrH2can not only provide active sites for H2activation but also transfer electrons to Fe sites for accelerating *** interaction between Fe and ZrH2over 40ZrH2-Fe leads to a decrease in work function and a downward shift of the d-band center,which is conducive to N2activation and NH3desorption,*** utilization of distinct sites for activating different reactants can avoid the competitive adsorption of N2and H2,leading to excellent NH3synthesis activity of the 40 wt.%ZrH2-mediated Fe *** a result,40ZrH2-Fe exhibits a high NH3synthesis rate of 23.3 mmol g-1cath-1at 400°C and 1 MPa and robust stability during100 h time-on-stream.

关键词：

Efficient photocatalytic H2 evolution over tubular mesoporous carbon nitride with N-vacancy by microwave-assisted synthesis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Yuanlong Pan Qiang Zhang Guangzheng Huang Yannan Luo Honglin Gao School of Materials and Energy National Center for International Research on Photoelectric and Energy MaterialsYunnan University

Modifying the microstructure of photocatalysts while simultaneously introducing vacancies has shown significant potential in enhancing their performance for hydrogen production. Herein, a novel tubular mesoporous carbon nitride（TMCN） with nitrogen vacancies was fabricated using a microwave-assisted synthesis strategy, employing melamine-cyanuric acid supramolecular（MC-S） as the precursor. The optimized TMCN exhibited an outstanding H2production rate, approximately 29 times higher than that of pristine g-C3N4. The N-vacancies serve as sites for reactant adsorption and activation, leading to enhanced delocalization of HOMO-LUMO. Furthermore, the porous structures of TMCN facilitate the reactant diffusion, while its tubular architectures promote the oriented transfer of charge carriers. Crucially, the markedly improved photocatalytic performance of TMCN can be predominantly attributed to the synergistic effects arising from its superior structure and N-vacancy defects. This work opens new possibilities for the simultaneous formation of surface defect states as photocatalytic reaction sites and distinctive structures conducive to charge carrier transport.

关键词：

16.48% Efficient solution-processed CIGS solar cells with crystal growth and defects engineering enabled by Ag doping strategy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 59-65页

作者： Mengyu Xu Shaocong Yan Ting Liang Jia Jia Shengjie Yuan Dongxing Kou Zhengji Zhou Wenhui Zhou Yafang Qi Yuena Meng Litao Han Sixin Wu Key Laboratory for Special Functional Materials of MOE National & Local Joint Engineering Research Centre for High-efficiency Display and Lighting Technology School of Nanoscience and Materials Engineering Henan University

Solution-processed Cu（In,Ga）Se2（CIGS） solar cells suffer from serious carrier recombination and power conversion efficiency（PCE） loss because of the poor film properties and easy formation of ***, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved opencircuit voltage（VOC） of 662 m V and fill factor（FF） of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.

关键词： Cell engineering

Design of a cationic accelerator enabling ultrafast ion diffusion kinetics in aqueous zinc-ion batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 377-384页

作者： Yawei Xiao Qianqian Gu Haoyu Li Mengyao Li Yude Wang national Center for International Research on Photoelectric and Energy Materials School of Materials and Energy Yunnan University Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources School of Chemistry and Chemical Engineering Hainan University College of Chemical Engineering Fuzhou University Yunnan Key Laboratory of Carbon Neutrality and Green Low-carbon Technologies Yunnan University

Aqueous zinc-ion batteries are highly favored for grid-level energy storage owing to their low cost and high safety,but their practical application is limited by slow ion *** address this,a strategy has been developed to create a cation-accelerating electric field on the surface of the cathode to achieve ultrafast Zn2+diffusion *** employing electrodeposition to coat MoS2on the surface of BaV6O16·3H2O nanowires,the directional built-in electric field generated at the heterointerface acts as a cation accelerator,continuously accelerating Zn2+diffusion into the active *** optimized Zn2+diffusion coefficient in CC@BaV-6O16·3H2O@MoS2(7.5×10～8cm2s-1) surpasses that of most reported V-based ***,MoS2serving as a cathodic armor extends the cycling life of the Zn-CC@BaV6O16·3H2O@MoS2full batteries to over 10000 *** work provides valuable insights into optimizing ion diffusion kinetics for high-performance energy storage devices.

关键词： Zinc alloys

A Computational Study of Thrust Vectoring Control Using Dual Throat Nozzle

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第6期19卷 486-490页

作者： Choon Sik Shin Heuy Dong Kim Toshiaki Setoguchi Shigeru Matsuo Department of Mechanical Engineering Andong National University Department of Mechanical Engineering Saga University

Dual throat nozzle (DTN) is fast becoming a popular technique for thrust vectoring. The DTN is designed with two throats, an upstream minimum and a downstream minimum at the nozzle exit, with a cavity in between the upstream throat and exit. In the present study, a computational work has been carried out to analyze the performance of a dual throat nozzle at various mass flow rates of secondary flow and nozzle pressure ratios (NPR). Two-dimensional, steady, compressible Navier-Stokes equations were solved using a fully implicit finite volume scheme. The present computational results were validated with available experimental data. Based on the present results, the control effectiveness of thrust-vectoring is discussed in terms of the thrust coefficient and the coefficient of discharge.

关键词： Compressible Flow Dual Throat Nozzle Thrust Vector Control Shock Wave Supersonic Flow

Unsteady Shock-Flow Characteristics in an Over-Expanded Rocket Nozzle

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第4期19卷 332-336页

作者： Jong Sung Lee Huey Dong Kim Toshiaki Setoguchi Shigeru Matsuo School of Mechanical Engineering Andong National UniversityAndong760-749Korea Department of Mechanical Engineering Saga University1HonjoSagaJapan

A numerical investigation of transient side-loads in an axisymmetric over-expanded thrust optimized contour nozzle is *** nozzles experience side-loads during start-up and shut-down operations,because of the flow separation at nozzle *** types of flow separations such as FSS and RSS shock structure occur.A two-dimension numerical simulation has been carried out over an axisymmetric TOC nozzle to validate present results and investigate oscillatory flow characteristics for start-up *** Averaged Navier-Stokes equations are numerically solved using a fully implicit finite volume *** equations are solved by coupled implicit *** Stress turbulence model is *** computed pressure at the nozzle wall closely matched with experiment data.A hysteresis phenomenon has been observed between these two shock *** transition from FSS to RSS pattern during start-up process has shown maximum nozzle wall *** wall pressure and shear stress values have shown fluctuations during the FSS to RSS transition. The oscillatory pressure has been observed on the nozzle wall for high pressure *** results have shown that magnitude of the nozzle wall pressure variation is high for the oscillatory phenomenon.

关键词： Free shock separation Over-expansion flow Restricted shock separation Side-loads Supersonic nozzle

Theoretical and Computational Analyses of LNG Evaporator

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2017年第2期26卷 132-137页

作者： Palani Kumar Chidambaram Yang Myung Jo Heuy Dong Kim FMTRC Daejoo Machinery Co Ltd Department Mechanical Engineering Andong National University

Theoretical and numerical analysis on the fluid flow and heat transfer inside a LNG evaporator is conducted in this work. Methane is used instead of LNG as the operating fluid. This is because; methane constitutes over 80% of natural gas. The analytical calculations are performed using simple mass and energy balance equations. The analytical calculations are made to assess the pressure and temperature variations in the steam tube. Multiphase numerical simulations are performed by solving the governing equations(basic flow equations of continuity, momentum and energy equations) in a portion of the evaporator domain consisting of a single steam pipe. The flow equations are solved along with equations of species transport. Multiphase modeling is incorporated using VOF method. Liquid methane is the primary phase. It vaporizes into the secondary phase gaseous methane. Steam is another secondary phase which flows through the heating coils. Turbulence is modeled by a two equation turbulence model. Both the theoretical and numerical predictions are seen to match well with each other. Further parametric studies are planned based on the current research.

关键词： LNG Evaporator Analytical Calculation Numerical Simulation

Numerical Study of the Effects of the Face Velocity onCeramic Filter

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1998年第4期7卷 226-230页

作者： Seo, Taewon(School of Mechanical Engineering, andong national university, 388 Songchun-Dong, andong,760-749, South Korea) School of Mechanical Engineering Andong National University Andong South Korea

Time-averaged explicit Navier-Stokes equations with the modified Darcy’s law for the threedimensional cylindrical flow field were formulated to the problem. Numerical investigation of the effects of the face velocity on ceramic candle filter was executed in three-dimensional turbulent flow field. It is found that the flow in the vessel is pushed toward the filter region by the pressure difference between inside and outside of the filter due to the viscosity and inertial resistance. It is also found that the pressure drop is directly proportional to the flow rate and the slope of the pressure drop will be mitigated when the thickness of the filter cake (8) is larger than 10 mm.

关键词： 3D turbulent flowfield N-S equations with Darcy's law

Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 439-449页

作者： Jia Zhao Taixi Feng Guimin Lu national Engineering Research Center for Integrated Utilization of Salt Lake Resource East China University of Science and TechnologyShanghai 200237China Joint International Laboratory for Potassium and Lithium Strategic Resources East China University of Science and TechnologyShanghai 200237China

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies.

关键词： magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation