检索结果-内蒙古大学图书馆

Regulating Surface Terminals and Interlayer Structure of Ti3c2tx for Superior Nh3 Sensing

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Li, Jiazheng Li, Yanqiong Zeng, Wen Bai, Bofeng Ren, Shan College of Materials Science and Engineering Chongqing University Chongqing400030 China School of Electronic information & Electrical Engineering Chongqing University of Arts and Sciences Chongqing400030 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China

MXene materials have exhibited potential in electrochemistry, particularly in gas sensing, due to their excellent conductivity, large specific surface area of layered materials, and unique functional groups. However, the gas sensing performance of intrinsic 2D MXene materials is often limited by their fluorine-containing terminals and interfacial structure. In this study, based on intrinsic Ti3C2Tx, we employed alkali treatment and annealing to prepare oxygen-rich Ti3C2(OH)x/Ti3C2Ox with expanded interlayer spacing, achieving enhanced gas sensing performance for NH3. By utilizing the intercalation effect of layered materials and the synergistic effect of regulating MXene unique surface terminations, the sensing materials prepared have achieved optimization of surface chemistry and structural. Compared to intrinsic Ti3C2Tx, the interlayer spacing of oxygen-rich Ti3C2(OH)x/Ti3C2Ox increased from 9.1 Å to 12.1 Å. The surface terminations of oxygen-rich Ti3C2(OH)x/Ti3C2Ox have been defluorinated and oxygenated. The maximum response value of oxygen-rich Ti3C2(OH)x/Ti3C2Ox to NH3 was 35.66, approximately twice that of the original Ti3C2Tx at an NH3 concentration of 200 ppm. DFT (Density functional theory) calculations and DRIFT (In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy) tests explained the interaction between the surface terminals and NH3, indicating good selectivity and sensitivity of oxygen-rich Ti3C2(OH)x/Ti3C2Ox to NH3. The results of this study demonstrate that the synergistic effects of surface chemistry and structural engineering are crucial for MXene to optimize the electrochemical performance, particularly the gas sensing performance. This provides a feasible approach for the performance optimization of intrinsic MXene materials. © 2024, The Authors. All rights reserved.

关键词： Oxygen

Investigation of the Solar-Driven Chemical Looping Methane Dry Reforming on Rh-Doped LaCeO3.5 Oxygen Carrier

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Li, Peng Gai, Zhongrui Zhang, Jinrui Rao, Qiong Tang, Sanli Shen, Yuanhui Pan, Ying Jin, Hongguang Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China University of Chinese Academy of Sciences Beijing100049 China

The feasibility of a solar-driven chemical looping dry reforming of methane (DRM) process, which converts solar energy and methane into syngas via a looping material oxygen carrier is investigated experimentally. Thermogravimetric analysis (TGA) experiments were firstly carried out to verify the effect of the Rh-doped LaCeO3.5 which were synthesized via modified Pechini method and incipient wetness method and the result shows that Rh greatly improved the reaction kinetics. Photo-TGA experiments were conducted to evaluate the light effect in chemical looping DRM. Under the light condition, the Rh-doped LaCeO3.5 shows higher methane conversion, oxygen extraction rate and CO selectivity compared with the undoped one, decreasing the apparent activation energy of the reaction at the same time. Insights obtained from the UV-Vis spectroscopy verified that the surface Rh under the light could promote the activation of surface methane species and increase the light absorbance. Meanwhile, the FEM methods were used to obtain the distributions of the temperature fields of the photo-TGA reactor through the calculation of the coupling of the fluid, reaction and temperature fields. In this way, the conversion mechanism of the solar, heating and chemical energy was illustrated and furthermore, the calculated surface reaction rate and the variation tendency of the outlet-gas were consistent with the experimental results. Through the integration of solar energy, a high methane to solar fuel conversion efficiency could be achieved. The proposed process has the potential to produce solar fuels at high efficiency with reduced carbon footprint. © 2024, The Authors. All rights reserved.

关键词： Methane

Thermal-Mechanical Influence Aspects and Evaluation of Helical Cruciform Single Rod in Fluoride-Salt-Cooled High-Temperature Advanced Reactor

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Chen, Yiwen Zhang, Dalin Jiang, Dianqiang Li, Wei Wu, Xiaoli Tian, Wenxi Qiu, Suizheng Su, Guanghui Lu, Qi State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong University Xi’an710049 China Science Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China China

Helical cruciform fuels are novel in nuclear reactors, potential to increase reactor’s power density. However, the geometry is complicated so influence of it on the fuel performance is not identified yet. In this paper, impact of power density, cross-section parameters, and twist pitch on thermal and mechanical characteristics of fuel used in Fluoride-Salt-cooled high-Temperature Advanced Reactor is discussed based on fluid-thermal-mechanical coupling. For thermal features, twist pitch is key while others have few effects. Increase in twist pitch leads to temperature uniformity and rise owing to weaker mixing effects. Fuel center temperature at middle plane of 300mm-pitch rod is 829.58℃, 54.66℃ higher than that of 100mm-pitch rod. Difference of maximum and minimum temperature at 45° cross section of 500mm-pitch rod is 153.62℃, while the figure is only 74.00℃ of 300mm-pitch rod. Besides, axial temperature of cladding outer surface increases wavelike due to complex geometry. For mechanical features, not geometry sizes but temperature affects stress distribution. Maximum Von-Mises stress appears at the elbow, where maximum temperature exists, 116.8MPa under normal conditions, lower than tensile strength of the material. After identifying the influence of these factors, five dimensionless parameters are proposed to evaluate and rate fuel performance based on Technique for Order Preference by Similarity to an Ideal Solution. As a result, an optimization comes up, scoring 0.310, twice more than the original design, owing to the thermal uniformity and mechanical safety. This study provides a reference for identifying and evaluating the performance of helical structure. © 2024, The Authors. All rights reserved.

关键词： Geometry

Development in the application of laser-induced breakdown spectroscopy in recent years:A review

学校读者我要写书评

暂无评论

Frontiers of physics 2021年第2期16卷 45-69页

作者： Lian-Bo Guo Deng Zhang Lan-Xiang Sun Shun-Chun Yao Lei Zhang Zhen-Zhen Wang Qian-Qian Wang Hong-Bin Ding Yuan Lu Zong-Yu Hou Zhe Wang Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesSheyang 110016China School of Electric Power South China University of TechnologyGuangzhou 510640China State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi UniversityTaiyuan 030006China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China Key Laboratory of Photonic Information Technology School of Optics and PhotonicsBeijing Institute of TechnologyBeijing 100081China School of Physics Dalian University of TechnologyNo.2 Linggong RoadGanjingzi DistrictDalian 116024China Optics and Optoelectronics Laboratory Ocean University of ChinaQingdao 266100China State Key Lab of Power Systems Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

Laser-induced breakdown spectroscopy(LIBS)has been widely studied due to its unique advantages such as remote sensing,real-time multi-elemental detection and none-to-little *** the efforts of researchers around the world,LIBS has been developed by leaps and ***,in recent years,more and more Chinese LIBS researchers have put tremendous energy in promoting LIBS *** is worth mentioning that the application of LIBS in a specific field has its special application background and technical difficulties,therefore it may develop in different stages.A review summarizing the current development status of LIBS in various fields would be helpful for the development of LIBS technology as well as its applications especially for Chinese LIBS community since most of the researchers in this field work in *** the present work,we summarized the research status and latest progress of main research groups in coal,metallurgy,and water,*** on the current research status,the challenges and opportunities of LIBS were evaluated,and suggestions were made to further promote LIBS applications.

关键词： laser-induced breakdown spectroscopy application

Dynamics of two-dimensional water flow in angstrom-scale mono and hybrid channels

学校读者我要写书评

暂无评论

Physical Review Fluids 2024年第12期9卷 124201-124201页

作者： Chengzhen Sun Qiyuan Wang Mehdi Neek-Amal Runfeng Zhou Bofeng Bai State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an Shaanxi 710049 China Department of Physics Shahid Rajaee Teacher Training University 16875-163 Lavizan Tehran Iran Departement Fysica Universiteit Antwerpen Groenenborgerlaan 171 B-2020 Antwerpen Belgium

We investigate the dynamics of two-dimensional (2D) water flow within angstrom-scale channels (ASCs), a domain scarcely explored in nanofluidics. Our study focuses on the transformation of monolayer water through hybrid channels made of graphene and MoS2, as well as channels where both walls are made of either graphene or MoS2, with sizes ranging from 6 to 8 Å. We find that the transport of monolayer water through ASCs is significantly hindered under low-pressure conditions at nanoscale timescales. To comprehensively explore the flow dynamics, we introduce a refined extension of the Hagen-Poiseuille equation that accounts for frictional slippage dynamics. Our results indicate that hybrid channels exhibit lower flux compared to monochannels. These findings provide valuable insights into the 2D flow mechanisms of monolayer water molecules, highlighting their distinctive interactions with channel walls and unique structural properties.

关键词： flow confinement Nanofluidics Molecular dynamics Navier-Stokes equation

Investigation on the Effect of Hydrothermal Reaction with Cuso4 on Rheological Property of Heavy Oil

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhou, Yantao Zhao, Qiuyang Wang, Xuetao Miao, Yan Song, Zhiwei Jin, Hui Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Xinjin Weihua Institute of Clean Energy Research Foshan528216 China

The rheological property is one of important physical properties evaluating heavy oil and asphalt. This work investigated the rheological changes during hydrothermal reaction with CuSO4. The results showed that the addition of CuSO4 at a high reaction temperature had an effect similar to asphalt modifiers, increasing the viscosity and elasticity. Further analysis suggested that the Cu atoms from CuSO4 entered heavy oil molecules, enhancing the interaction attraction between oil molecules. While, at a low reaction temperature, the CuSO4 acted as a catalyst, reducing both viscosity and elasticity. Based on these findings, this work proposed a novel and potential asphalt modification method, which changed the association effect between oil molecules by the chemical reaction to adjust the rheological properties permanently. This method would not fail due to the separation of modifiers and can adjust performance by changing reaction conditions. © 2023, The Authors. All rights reserved.

关键词： Transition metals

Rotor Dynamic Analysis of Supercritical Carbon Dioxide Bryton Cycle Coaxial Integrated Unit

学校读者我要写书评

暂无评论

Rotor Dynamic Analysis of Supercritical Carbon Dioxide Bryto...

Prognostics and System Health Management Conference (PHM-Qingdao)

作者： Xiaokang Xu Yi Yang Jiangfeng Wang Juwei Lou Liangqi Chen State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an China Laboratory of Science and Technology on Integrated Logistics Support College of Intelligence Science and Technology National University of Defense Technology Changsha China

The rotor system plays a very important role in supercritical carbon dioxide Brayton cycle system, and its dynamic problem will directly affect the motion stability and safety of the whole unit. In this paper, the rotor dynamic model of supercritical CO 2 coaxial unit is established by finite element method, and the critical speed, modal shape and unbalance response of the rotor are studied. The first seven critical speed of the rotor and the first seven natural frequency of the rotor at the working speed are calculated. The bending modal of the rotor and the position where the rotor amplitude is the largest are analyzed, which can provide reference for the optimization design of the rotor stability. The influences of mass unbalances at the operational speed of rotor are analyzed. The research can provide some suggestions for the optimal design and actual operation of the supercritical CO 2 coaxial integrated unit.

关键词：

Performance Prediction and Geometry Optimization of Ejector in Pemfc System Using Coupled Cfd-Bpnn and Genetic Algorithm

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Pang, Zihui Han, Jiquan Feng, Jianmei Diao, Anna Yao, Yanchen Peng, Xueyuan School of Energy and Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Shanghai Marine Diesel Engine Research Institute Shanghai Shanghai201108 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China

The ejector is a promising hydrogen recirculation device in proton exchange membrane fuel cell (PEMFC) systems. However, the limited entrainment performance of the ejector at wide operating conditions hinders its development and widespread application in PEMFC systems. To address this challenge and design a high-performance ejector adapted to the wide power range of PEMFC systems, a backpropagation artificial neural network (BPNN) model with computational fluid dynamics (CFD) simulation data is developed. The sensitivity analysis of geometric parameters based on the CFD model reveals that the nozzle throat diameter (Dt) and the mixing chamber diameter (Dm) exert the most pronounced impact on the entrainment performance, with average influence rates of 24% and 57%, respectively. Furthermore, two advanced multi-objective genetic algorithms (LWGA and NSGA-II methods) are applied to improve ejector performance. The LWGA method proves effective in elevating the overall ejector performance, achieving a remarkable enhancement in entrainment performance of up to 7.9%. On the other hand, the NSGA-II method is favorable for expanding the operational power range of the ejector by 30%, as well as a 4.5% increase in overall ejector performance. This work provides a robust framework for designing and optimizing high-performance ejectors in high power PEMFC systems. © 2024, The Authors. All rights reserved.

关键词： Sensitivity analysis

Experimental Study on the flow Characteristics of a Plate with a Mechanically Choked Orifice

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2021年第1期17卷 97-107页

作者： Ming Liu Xingkai Zhang Dong Wang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Petroleum Engineering Technology Research Institute of Shengli Oilfield Company SINOPECDongying257000China Shandong Key Laboratory of Heavy Oil Production Technology Shengli Oilfield CompanySINOPECDongying257000China Petroleum Engineering College Yangtze UniversityWuhan430100China

The mechanically choked orifice plate (MCOP) is a new type of device for flow control by which choking conditionsfor incompressible fluids can be obtained with relatively small pressure losses. Given the lack of relevant results anddata in the literature, in the present study, we concentrate on the experimental determination of the flow coefficientfor the annular orifice, the pressure distribution in the MCOP, and the characteristics of the choked flow itself. Asconfirmed by the experimental results, the Reynolds number, the orifice plate thickness, the plug taper, and theeccentricity have an obvious influence on the aforementioned flow coefficient. The pressure drop in the MCOPis mainly generated near the orifice plate, and the pressure upstream of the orifice plate is slightly reduced in theflow direction, while the pressure downstream of the orifice plate displays a recovery trend. The choked flow rateof the MCOP can be adjusted by replacing the spring with a maximum flow control deviation of 4.91%.

关键词： Mechanical choked orifice plate flow control flow coefficient flow characteristics