检索结果-内蒙古大学图书馆

Beam dynamics induced by the quantum metric of exceptional rings

学校读者我要写书评

暂无评论

arXiv

arXiv 2024年

作者： Zhang, Zhaoyang Septembre, Ismaël Liu, Zhenzhi Kokhanchik, Pavel Liang, Shun Liu, Fu Li, Changbiao Wang, Hongxing Liu, Maochang Zhang, Yanpeng Xiao, Min Malpuech, Guillaume Solnyshkov, Dmitry Key Laboratory for Physical Electronics and Devices The Ministry of Education Shaanxi Key Lab of Information Photonic Technique School of Electronic Science and Engineering Faculty of Electronics and Information Xi’an Jiaotong University Xi’an710049 China Institut Pascal PHOTON-N2 Université Clermont Auvergne CNRS Clermont INP Clermont-FerrandF-63000 France Naturwissenschaftlich-Technische Fakultät Universität Siegen Walter-Flex-Straße 3 Siegen57068 Germany International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Department of Physics University of Arkansas FayettevilleAR72701 United States Paris75231 France

Topological physics has broadened its scope from the study of topological insulating phases to include nodal phases containing band structure singularities. The geometry of the corresponding quantum states is described by the quantum metric which provides a theoretical framework for explaining phenomena that conventional approaches fail to address. The field has become even broader by encompassing non-Hermitian singularities: in addition to Dirac, Weyl nodes, or nodal lines, it is now common to encounter exceptional points, exceptional or Weyl rings, and even Weyl spheres. They give access to fascinating effects that cannot be reached within the Hermitian picture. However, the quantum geometry of non-Hermitian singularities is not a straightforward extension of the Hermitian one, remaining far less understood. Here, we study experimentally and theoretically the dynamics of wave packets at exceptional rings stemming from Dirac points in a photonic honeycomb lattice. First, we demonstrate a transition between conical diffraction and non-Hermitian broadening in real space. Next, we predict and demonstrate a new non-Hermitian effect in the reciprocal space, induced by the non-orthogonality of the eigenstates. We call it transverse non-Hermitian drift, and its description requires biorthogonal quantum metric. The non-Hermitian drift can be used for applications in beam steering. Copyright © 2024, The Authors. All rights reserved.

关键词： Topology

Construction of a Transient Multi-Physics Model of Solid Oxide Fuel Cell Fed by Biomass Syngas Considering the Carbon Deposition and Temperature Effect

学校读者我要写书评

暂无评论

SSRN 2022年

作者： Zhu, Pengfei Yao, Jing Wu, Zhen Huang, Si-Min Abu Mansor, Mohd Radzi Yang, Fusheng Zhang, Zaoxiao School of Chemical Engineering and Technology Xi’an Jiaotong University Xi’an710049 China Guangdong Provincial Key Laboratory of Distributed Energy Systems Guangdong Provincial Engineering Research Center of Distributed Energy Systems Dongguan University of Technology Dongguan523808 China Department of Mechanical and Manufacturing Engineering University Kebangsaan Malaysia Selangor43600 Malaysia State Key Laboratory of Multiphase Flow for Power Engineering Xi’an Jiaotong University Xi’an710049 China

Carbon deposition is a thorny issue for the SOFC fueled by low carbon hydrocarbons such as biomass syngas. Moreover, long-term large temperature gradients would reduce SOFC durability. Regarding these two issues, a two dimensional transient multi-physical model considering carbon deposition and temperature effect is developed for SOFC in this work. Typically due to the carbon deposition, the SOFC anode porosity decreases from 0.5 to 0.26, and the reaction activity decreases from 1.0 to about 0.45 after running 140 day. Accordingly, the current density decreases by 1.6 % at t =42 d and 6% at t =140 d, which indicates the damage of SOFC durability compared to the durability target (1%/1000h) of commercial SOFC. The maximum temperature difference of the cell is predicted to be about 106 o C. It was found that the carbon deposition and large temperature gradient are closely related to the operating parameters. With the increase of operating voltage from 0.4 V to 0.8 V, the porosity and reaction activity respectively increase by 50% and 55%, and the maximum temperature difference is reduced from 150 o C to 16 o C after running 140 day. The increase of the inlet temperature could improve the overall temperature and decrease the porosity. Besides, the reduction in the ratio of CH 4 to H 2 O helps to suppress carbon deposition, thus to improving the performance. © 2022, The Authors. All rights reserved.

关键词： Solid oxide fuel cells (SOFC)

Fluoride-Salt-Cooled High-Temperature Reactor: An Integrated Nuclear-Based Energy Production and Conversion System

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhang, Dalin Li, Xinyu Jiang, Dianqiang Zhou, Xingguang Lv, Xindi Yun, Shichang Wu, Wenqiang He, Xuanang Li, Haoyang Min, Xin Chen, Kailong Tian, Wenxi Qiu, Suizheng Su, G.H. Zhao, Quanbin Fu, Yao Tang, Chuntao Zhuo, Wenbin Li, Jinggang Zuo, Jiaxu 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 Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai201800 China Shanghai Nuclear Engineering Research & Design Institute CO. LTD. Shanghai200233 China CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology Nuclear Power Institute of China Chengdu610213 China China Nuclear Power Technology Research Institute Guangdong Shenzhen518000 China Nuclear and Radiation Safety Center Ministry of Ecology and Environment People's Republic of China Beijing100082 China

Based on the analysis of energy structure and the development trends of advanced nuclear energy technology, combining the complementary advantages of nuclear energy and other energy sources in China, the Fluoride-salt-cooled High-temperature Reactor(FuSTAR) system has been proposed. FuSTAR system is designed to address production capacity issues in areas with energy shortages or resource concentration and can be combined with high-temperature process heat to achieve high-value-added processes such as hydrogen production. In this paper, the Tri-structural isotropic fuel combined with helical cruciform elements has been studied in detail on the neutron physics and thermal-hydraulic properties, and the flow and heat transfer experiment is carried out for the first time. The multilayer nonlinear programming method has been applied to the design of thermal transport systems. Then the optimal parameters and configuration of the thermoelectric conversion system are obtained by the superstructure optimization method. The inherent safety of FuSTAR is demonstrated through deterministic safety analysis. In addition, the iodine-sulfur cycle technology and the characteristics of tritium production are also analyzed. This study highlights the significant potential of integrating nuclear energy with other energy sources in an optimized energy-production system. © 2023, The Authors. All rights reserved.

关键词： Nonlinear programming

Thermodynamic, life cycle, and techno-economic assessment of an autothermal supercritical water gasification system for direct processing raw pig manure: Hydrogen generation and ammonia recovery

学校读者我要写书评

暂无评论

Energy 2025年 330卷

作者： Mingming Du Fan Liu Haoran Yuan Yu-nan Chen Jing Gu Guangzhou Institute of Energy Conversion Chinese Academy of Sciences (CAS) Guangzhou 510640 PR China State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF) Xi'an Jiaotong University Xi'an Shaanxi 710049 PR China Guangdong Provincial Key Laboratory of Renewable Energy Guangzhou 510640 PR China

Supercritical water gasification (SCWG) exhibits an excellent potential for the conversion from pig manure (PM) to H 2 . However, the low solid content characteristic of raw PM and ammonia discharge significantly constrain the thermodynamic efficiency of SCWG. To address these limitations, a novel SCWG system was designed for simultaneous autothermal H 2 production and ammonia recovery from raw PM. Thermodynamic analysis, life cycle, and techno-economic were carried out to assess system performance. Results indicated that the novel system exhibited exceptional adaptability to variations in concentration and mass flow of raw PM, with autothermal H 2 production achieved even at low concentration of 10 %. Raw PM was converted into high-concentration slurries through pulping operations, thereby reducing exergy losses of gasification, heat exchange, and cooling units. Further, the system implemented an efficient ammonia recovery utilizing steam generated during the pulping stage. Under a typical scenario, energy efficiency, exergy efficiency, GWPs, and EP of the novel system reached 50.34 %, 45.99 %, 0.005 kgCO 2 -eq/kgH 2 , and 0.07 kgNO 3 - -eq/kg H 2 , respectively. The levelized hydrogen cost of the new system was 15.81 CNY/kg. This study provides a valuable solution for autothermal SCWG of low-solid-content and high-nitrogen-content feedstocks to produce H 2 and recover ammonia.

关键词： Ammonia recovery Autothermal hydrogen generation Raw pig manure Supercritical water gasification Thermodynamic analysis

Cavitation characteristics of rotary vane pump in aeroengine lubricating oil system and their effects on pump performance

学校读者我要写书评

暂无评论

Hangkong Dongli Xuebao/Journal of Aerospace Power 2025年第7期40卷

作者： Wang, Ge Wang, Yijin He, Denghui Yang, Lina Cao, Ming Bai, Bofeng State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China Xi’an University of Technology Xi’an710048 China Department of Power Engineering Institute of Water Resources and Hydro-electric Engineering Xi’an University of Technology Xi’an710048 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Commercial Aircraft Engine Company Limited Aero Engine Corporation of China Shanghai200241 China Shanghai Center of Research for Commercial Aircraft Engine Engineering Techniques Shanghai200241 China

To meet the demand for high-performance oil pumps in the lubricating oil system of high thrust and high-speed aeroengines, numerical simulation was conducted on a new high-speed rotary vane oil pump. The Mixture multiphase flow model, Singhal full cavitation model, and renormalization group（RNG） k-Ε turbulence model were employed for numerical calculation, and the reliability of the numerical simulation method was verified through experiments. Then, cavitation characteristics of the rotary vane pump and its impact on pump performance under different inlet pressure and oil temperature conditions were analyzed. The results showed that the cavitation gas was mainly distributed in the volume chamber on the oil suction side, as well as on the suction surface of the rotary vane and near the inner wall of the rotor. With the decrease of inlet pressure and the increase of oil temperature, the cavitation phenomenon inside the rotary vane pump intensified, and the cavitation gas increased, which in turn led to a decrease in the average oil discharge flow rate at the pump outlet and a decrease in volumetric efficiency. When the inlet pressure dropped to 40 kPa and the temperature rose to 373.15 K, the average oil discharge flow rate and volumetric efficiency at the pump outlet both significantly decreased. The pressure pulsation at the monitoring point exhibited low-frequency and high-amplitude pulsation characteristics. The cavitation of the rotary vane pump affected not only its oil discharge and volumetric efficiency, but also the stable and reliable operation of the pump. © 2025 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.

关键词： Vane pumps

Mxene-Derived Ni/Tio2-X/Ti3c2 Catalyst for Enhanced Photothermal Co2 Methanation: Unraveling the Roles of Photoexcited Carriers

学校读者我要写书评

暂无评论

SSRN 2025年

作者： Sun, Fan Xin, Yu Xing, Xueli Lou, Jiahui Wang, Qiliang Hong, Hui International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China School of Aeronautics and Astronautics University of Chinese Academy of Sciences Beijing100049 China Huaneng Clean Energy Research Institute Beijing102209 China Shandong Institute of Advanced Technology Jinan250100 China Department of Architecture and Built Environment University of Nottingham NottinghamNG7 2RD United Kingdom Institute of Engineering Thermophysics China

Photothermal catalysis has emerged as a promising approach for CO2 conversion, which combines photo and thermal energy to drive catalytic reactions efficiently. While light can lower activation barriers and enhance reaction rates, the interplay between light and heat within the catalytic framework remains largely unexplored. In this study, we investigate the critical role of photoexcited carriers in enhancing catalytic performance under solar irradiation, unraveling their contribution to the CO2-to-CH4 conversion process. A multilayer accordion-like Ni/TiO2-x/Ti3C2 catalyst, which exhibits excellent photothermal and photoelectric response characteristics was fabricated for efficient photothermal CO2 methanation. Experimental results demonstrated that introduction of light during thermal catalysis markedly enhanced the CO2 conversion rate, with a 55% increase achieved at 275 ºC. Furthermore, the required temperature for maximum CO2 conversion rate was reduced by 50 ºC compared to the thermal-driven process. Meanwhile, the effects of concentrated ratio and incident wavelength on CO2 conversion were also examined, revealing a synergistic effect between photogenerated carriers and thermal energy. Further characterizations, including steady-state and transient photoluminescence spectroscopy, in-situ XPS, in-situ EPR, in-situ DRITFs, were employed to elucidate the enhancement mechanisms of photogenerated carriers in the catalytic reaction. At the same time, an outdoor experimental prototype was developed to verify the feasibility of photogenerated carrier-thermal synergistically driven CO2 methanation. The findings provide valuable insights into the role of photo-generated carriers in photothermal CO2 methanation, offering new perspectives for the design of efficient photothermal catalysts and advancing solar catalytic CO2 conversion technologies. © 2025, The Authors. All rights reserved.

关键词： Methanation

Bowl-Shaped Carbon Loaded Co9s8 Nanoparticles Connected by Carbon Nanotubes with Excellent Rate Performance for Sodium-Ion Batteries

学校读者我要写书评

暂无评论

SSRN 2022年

作者： Yang, Guorui Zhou, Ziyi Liu, Xiaofeng Zhang, Yue Wang, Silan Yan, Wei Ding, Shujiang School of Chemistry Engineering Research Center of Energy Storage Materials and Devices Ministry of Education "Four Joint Subjects One Union" School Enterprise Joint Research Center for Power Battery Recycling & Circulation Utilization Technology Xi’an Jiaotong University Xi’an710049 China Xi'an Key Laboratory of Solid Waste Recycling and Resource Recovery State Key Laboratory of Multiphase Flow in Power Engineering Department of Environmental Science and Engineering Xi'an Jiaotong University Xi'An710049 China

Sodium-ion batteries (SIBs) are expected to replace lithium-ion batteries in the energy storage sector owing to their low cost and abundant resources. However, developing suitable anode materials to meet the high energy density requirements of SIBs remains an ongoing challenge. Herein, we design a hollow nitrogen-doped bowl-like carbon decorated with Co9S8 nanoparticles linked by carbon nanotubes (HNBC@Co9S8@CNTs) as an anode material for SIBs. The HNBC@Co9S8@CNTs electrode exhibits impressive rate performance (280.9 mAh g-1 at 5 A g-1) and cycling stability (426.5 mAh g-1 after 500 cycles at high current density of 1 A g-1) due to the advantages of highly conductive three-dimensional (3D) interconnected structures. In addition, its pseudo-capacitance and sodium storage diffusion kinetics are analyzed in depth using Cyclic Voltammetry (CV) and galvanostatic intermittent titration technique (GITT). The results elucidate that the partially surface-induced capacitive sodium storage, highly conductive 3D interconnected structures, and fast reaction kinetics synergistically contribute to the high-rate performance. This work may provide new insights for the fabrication of various metal sulﬁde or sulﬁde composites with high sodium storage capacity. © 2022, The Authors. All rights reserved.

关键词： Sodium-ion batteries

Effects of A‐Site Replacement (Sm, Y, and Pr) on Catalytic Performances of Mullite Catalysts for No Oxidation

学校读者我要写书评

暂无评论

SSRN 2022年

作者： Chen, Lei Zhang, Chen Wu, Tiantian Huang, Boqiang Zhang, Jinping Guan, Guowei Zhang, Zaoxiao Hou, Xiaoke Hu, Chao Lu, Qiang School of Chemical Engineering and Technology Xi'an Jiaotong University Xi'An710049 China School of Chemistry Xi'an Jiaotong University Xi'An710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'An China National Engineering Research Center of New Energy Power Generation North China Electric Power University Beijing China

Mullite is one of the most promising NO-SCO catalyst alternatives to the commercial Pt/Al 2 O 3 , and deciphering its intrinsic properties that affecting the catalytic performance is a great challenge but critical to the development of mullite catalysts. Herein, a series of Mn-based mullite nanofibers with different A‐site cations are synthesized by electrospinning method and used for catalytic NO oxidation. Activity tests show that SmMn 2 O 5 exhibits a better NO conversion rate (77.8%) than these of PrMn 2 O 5 (63.3%) and YMn 2 O 5 (57.5%) under typical experimental conditions ( GHSV=120 000 h -1 , T =325 °C ). To investigate the factors influencing the catalytic activity, various techniques including XRD, N 2 adsorption, SEM, TEM, EDX, XPS, H 2 -TPR and O 2 -TPR are employed, and the results show that abundant surface adsorbed oxygen species and good reducibility contribute greatly to the catalytic performance of SmMn 2 O 5 . DFT calculations revealed that A-site cation played the decisive role in the Fermi level relative to the Mn 3d-band centre, thus affecting the adsorption and dissociation of O 2 molecule. The present synthetic strategy offers a new viable route for the large-scale preparation of metal oxide catalysts with remarkable NO oxidation performance for practical application. © 2022, The Authors. All rights reserved.

关键词： Positive ions

Sustainable hydrogen production from coal tar residue via supercritical water gasification

学校读者我要写书评

暂无评论

Journal of Cleaner Production 2025年 519卷

作者： Jingui Bai Yu Wang Shi Liu Libo Lu Wen Cao Ting Chen Yunan Chen Liejin Guo State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University No.28 Xianning West Road Xi'an 710049 China Ningxia Baoting New Materials Technology Co. Ltd. Yinchuan 751400 Ningxia China

Hazardous wastes such as coal tar residue (CTR) pose a serious hazard to the environment and human health. In the context of ‘carbon peak and carbon neutrality’, the conversion of wasted resources into energy to replace fossil fuels is in line with the requirements of future social development. Supercritical water (SCW) offers a promising approach for converting hazardous waste CTR into energy. This article combines supercritical water gasification (SCWG) technology with the efficient utilization of CTR for the first time, providing a scientific solution for reducing environmental pollution and preparing hydrogen. In this article, we systematically investigated the effects of temperature (540–700 °C), residence time (5–60 min), material concentration (3 wt%-11 wt%), and six different catalysts on CTR SCWG. Experimental results indicate that higher temperature, longer reaction time, and lower CTR concentration are beneficial for gasification. When the temperature, retention time, material concentration, and catalyst are set at 700 °C, 60 min, 3 wt%, and K 2 CO 3 respectively, most of the carbon in the CTR is converted into small molecular gases. The carbon gasification efficiency (CE) reaches 94.44 %, while the H 2 yield attains a value of 67.56 mol kg −1 . Finally, based on the analysis results of gas, liquid and solid products, the SCWG mechanism of CTR is summarized.

关键词：