检索结果-内蒙古大学图书馆

Protected Hematite Nanorod Arrays with Molecular Complex Co-Catalyst for Efficient and Stable Photoelectrochemical Water Oxidation

引用

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY 2019年第15期000卷 2078-2085页

作者： Chen, Xiangyan Fu, Yanming Kong, Tingting Shang, Yi Niu, Fujun Diao, Zhidan Shen, Shaohua Xi An Jiao Tong Univ Int Res Ctr Renewable Energy State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Xian Shiyou Univ Coll Chem & Chem Engn Xian 710054 Shaanxi Peoples R China

Herein, a hybrid structure of hematite (alpha-Fe2O3) nanorod arrays is designed, with surface catalyzed by Co molecular complex (Co(dca)(2), dca: dicyanamide) and then protected by TiO2 thin overlayer, for efficient and stable photoelectrochemical (PEC) water oxidation. The obtained alpha-Fe2O3/Co(dca)(2)/TiO2 hybrid nanorod arrays show much improved and stabilized PEC performance as compared to the pristine, and even the Co(dca)(2) or TiO2 modified alpha-Fe2O3, with a photocurrent density of 0.35 mA cm(-2) obtained at 1.23 V vs. reversible hydrogen electrode (RHE), and an incident photon-to-current conversion efficiency (IPCE) reaching 16 % at 400 nm at 1.6 V vs. RHE. It has been demonstrated that the adsorbed Co(dca)(2) molecular complex could effectively promote the interface charge transfer process and accelerate the water oxidation reaction kinetics, meanwhile the atomic layer deposited TiO2 overlayer could passivate the surface defects of alpha-Fe2O3 and suppress the surface charge carrier recombination. Moreover, the TiO2 overlayer could effectively protect Co(dca)(2) from detaching from the alpha-Fe2O3 surface and thus stabilize the PEC activity for water oxidation reaction. The present study provides some available thoughts and methods for rational design of highly efficient photoelectrodes for water splitting from the perspective of the surface and interface engineered charge carrier transfer and water oxidation processes.

关键词： alpha-Fe2O3 Molecular complex TiO2 Photoelectrochemical water oxidation

来源：评论

学校读者我要写书评

暂无评论

Thermal Simulation for a Mechanical Spindle With External Cooler Across Grease Coated Interface

Research Square

引用

Research Square 2021年

作者： Zhao, Liang Lei, Mohan Ren, Hongdi Wang, Jinshi Wang, Shuai Li, Ben Q. Yang, Jun Mei, Xuesong Xi'an Jiaotong University China State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'An710049 China Shaanxi Key Laboratory of Intelligent Robots Xi'an Jiaotong University Xi'An710049 China School of Mechanical and Precision Instrument Engineering Xi'an University of Technology 710048 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Department of Mechanical Engineering College of Engineering and Computer Science University of Michigan MI48128 United States

Spindles in precision boring machine often work in low speed and heavy load without internal cooling, and the thermal error is nonnegligible. So an external cooling system was designed, and the effectiveness of the designed scheme needs to be preliminarily verified by simulation before building the cooling system. Thermal simulations of the spindle with an external cooler require calculating the thermal resistance of the thermal grease-coated interface between the cooler and spindle. Models describing the contact thermal resistance and total thermal resistance for metal contact filled with silicone grease based on solid-liquid interface force equivalence were described in this paper, and experiments were also conducted to verify the accuracy of these models. The contact thermal resistances between the cast iron/copper and silicone grease on flat or arc surfaces were calculated, and the bulk thermal resistance of the silicone grease layer was calculated. The total heat transferred between the cooler and the silicone grease-coated interface of the spindle were calculated. Heat transfer and heat generation in the spindle were calculated, and a finite element model was established to verify the effectiveness of the designed external cooling scheme. Finally, results from experiments for the spindle in different conditions show that the external cooling system decreases the time to reach thermal equilibrium by more than 60%. The RMSE of the simulated thermal elongation is less than 5.7044 μm when the rotating speed of 3000 rpm, and is less than 3.9714 μm when the rotating speed is 1500 rpm. © 2021, CC BY.

关键词： Cooling

来源：评论

学校读者我要写书评

暂无评论

On the relevance of understanding and controlling the locations of dopants in hematite photoanodes for low-cost water splitting

引用

APPLIED PHYSICS LETTERS 2021年第20期119卷 200501-200501页

作者： Souza, Joao B., Jr. Souza, Flavio L. Vayssieres, Lionel Varghese, Oomman K. Brazilian Ctr Res Energy & Mat CNPEM Brazilian Nanotechnol Natl Lab LNNANO BR-13083970 Campinas Brazil Fed Univ ABC UFABC Ctr Ciencias Nat & Humanas CCNH BR-09210580 Santo Andre SP Brazil Xi An Jiao Tong Univ Int Res Ctr Renewable Energy IRCRE Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Univ Houston Dept Phys Nanomat & Devices Lab Houston TX 77204 USA

Successful large-scale implementation of solar fuel technologies relies on cost, performance, and reliability of materials, devices, and infrastructures. Earth-abundant, low-cost, easily recyclable, and environmentally benign light absorbers are desired for renewable fuel generation technologies, such as solar photoelectrochemical (PEC) water splitting. Hematite is considered an ideal material for PEC oxygen evolution reaction, which is a critical component in the overall water splitting process for hydrogen fuel generation. However, intrinsic and operational limitations have prevented hematite-based PEC devices from reaching their highest theoretical solar-to-hydrogen efficiency of 15%-17%. Literature clearly shows that no single approach can eliminate these limitations. An overall fundamental understanding of the effect of dopant addition as well as their physical locations and functions within the photoelectrode, in both as-synthesized form and under operating conditions, is of critical importance to unleash the tremendous potentials of hematite-based PEC systems. In this short perspective, the concept of effective doping (i.e., increase of charge carrier density) up to the limit of dopant segregation at the grain boundaries to lower the charge recombination is discussed. Based on relevant theoretical and experimental data from the literature on the effects of surface-to-bulk doping as well as dopant segregation at the grain boundaries on hematite photoelectrode performance, we discuss here the views on the necessity of understanding these processes and their individual and synergistic effects to unravel a simple yet powerful approach to design and develop highly efficient hematite photoanodes for clean hydrogen generation using water and sunlight.

关键词： Grain boundaries

来源：评论

学校读者我要写书评

暂无评论

Numerical study on saturated pool boiling heat transfer in presence of a uniform electric field using lattice Boltzmann method

引用

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2019年 135卷 885-896页

作者： Feng, Yuan Li, Huixiong Guo, Kaikai Lei, Xianliang Zhao, Jianfu Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Chinese Acad Sci Inst Mech CAS Key Lab Micrograv Beijing 100190 Peoples R China Univ Chinese Acad Sci Sch Engn Sci Beijing 100049 Peoples R China

For the industrial equipment with boiling, critical heat flux (CHF) is an important parameter that determines its upper limit of heat load for safe operation. Therefore, increasing CHF is of great importance in engineering field. Previous studies proved that it's an effective way to enhance boiling heat transfer and CHF by electrohydrodynamics (EHD). However, it is difficult to investigate the influence mechanism of the electric field on the bubble dynamics and boiling heat transfer because of the limit of experimental technical methods. Thus, in this paper, a two-dimensional lattice Boltzmann model was established by coupling the pseudopotential model with phase-change model and electric field model to meet the lack of studies on simulating the pool boiling in presence of an electric field. After validating the rationality of the two-dimensional lattice Boltzmann model established at present study, the heat transfer during nucleate boiling and film boiling under a uniform electric field were studied in detail. In addition, the influence of electric field intensity on boiling curves and CHF was investigated quantitatively. In the partial nucleate boiling regime, a uniform electric field had limited influence on bubble dynamics and boiling heat transfer. In the fully developed nucleate boiling regime, increasing electric field intensity could enhance boiling heat transfer obviously. In the film boiling regime, increasing electric field intensity could slightly enhance averaged heat flux at first. After the electric field intensity reached a certain value, averaged heat flux increased rapidly. Increasing electric field intensity could expand the nucleate boiling regime, and enhance CHF and the wall temperature at CHF point. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Lattice Boltzmann method Electrohydrodynamics Critical heat flux Saturated pool boiling Boiling curves

来源：评论

学校读者我要写书评

暂无评论

Study of mechanical choked Venturi nozzles used for liquid flow controlling

引用

flow MEASUREMENT AND INSTRUMENTATION 2019年 65卷 158-165页

作者： Zhang, Xingkai Wang, Dong Liao, Ruiquan Zhao, Hui Shi, Baocheng Yangtze Univ Petr Engn Coll Wuhan 430100 Hubei Peoples R China Yangtze Univ Branch Key Lab CNPC Oil & Gas Prod Jingzhou 434023 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

Motivated by the principles of the cavitating Venturi nozzle (CVN) used for controlling fluid flow and addressing limitations of CVN, this paper proposes a mechanical choked Venturi nozzle (MCVN) which achieves choking flow via a mechanical action. The MCVN is constructed by inserting a floating springed blockage into a Venturi nozzle to imitate the bubble dynamics of CVN. First, an initial MCVN design was derived theoretically. Then, using numerical simulation and an iterative procedure, this original design was corrected to build an optimized design. Finally, the optimized design was investigated and tested both numerically and experimentally. The experimental results show that the MCVN can maintain constant flow with a flow control error of 3.8% and a maximum back pressure ratio of 0.97. Since MCVN can achieve constant flow without fluid vaporization, the pressure ratio range for applying a choking flow device is expanded and some limitations of CVN are overcome. The principles and experimental results obtained in this research can be used as a framework for the design of improved constant flow control devices for liquid flow.

关键词： Choking flow Cavitating Venturi nozzle Mechanically choked Liquid flow flow control

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to “Enhanced oxygen reduction reaction activity of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ cathode via Pr-doping for intermediate-temperature solid oxide fuel cells” [J. Alloys Compd. 1022 (2025), 179947]

引用

Journal of Alloys and Compounds 2025年 1024卷

作者： Benlin Xiang Weihua Jia Yuqi Wang Fei Li Weibin Xu Xinyi Li Jianbing Huang Quanyi Tang Xin Ding Le Wu Lan Zheng School of Chemical Engineering Northwest University Xi’an Shaanxi 710127 China Xi'an Key Lab of Green Hydrogen Energy Production Storage & Application Integration Technology Xi’an Shaanxi 710127 China Shaanxi Key Laboratory for Carbon Neutral Technology Xi’an Shaanxi 710069 China School of Carbon Neutrality College Northwest University Xi’an Shaanxi 710127 China State Key Laboratory of Multiphase Flow in Power engineering Xi’an Jiaotong University Xi'an Shaanxi 710049 China

来源：评论

学校读者我要写书评

暂无评论

Polystyrene nanofluids for enhanced oil recovery

引用

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND engineering ASPECTS 2022年 649卷

作者： Li, Xinru Zhang, Xiaohan Zhang, Yanming Su, Yubin Hu, Yangming Huang, Hai Liu, Yang Liu, Maochang Xian Shiyou Univ Sch Petr Engn Shaanxi Key Lab Adv Stimulat Technol Oil & Gas Res Xi'an 710065 Shaanxi Peoples R China Xi An Jiao Tong Univ Int Res Ctr Renewable Energy Xi'an 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xi'an 710049 Shaanxi Peoples R China PetroChina Oil & Gas technol Res Inst Changqing Oilfield Branch Co Xi'an 710021 Shaanxi Peoples R China Univ Alberta Dept Civil & Environm Engn Edmonton AB T6G 1H9 Canada

We report the synthesis of nanosized polystyrene (PSt) microspheres with good uniformity, strong absorptivity, good shear resistance and controllable size. The PSt nanofluid, entitled with a high surface adsorption of nanoparticles, can effectively reduce interfacial tension without using surfactants and alter the wettability towards a more water-wet condition. Subsequently, their fluidic properties for chemical enhanced oil recovery of PSt nanofluidic microspheres were also investigated based upon core flooding experiments, sand-pack and NMR tests. It is found that remaining oil displacement can be realized by regulating the nanofluid behavior, including wettability and interfacial tension. Moreover, deep fluid diversion could be achieved through profile control by plugging pores. All these advantages made the PSt nanofluid to be favorable for oilfield practice.

关键词： Nanofluid Polystyrene microsphere Wettability Interfacial tension Oil recovery

来源：评论

学校读者我要写书评

暂无评论

Numerical study of co-firing lignite and agricultural biomass in utility boiler under variable operation conditions

引用

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2021年 181卷 121728-121728页

作者： Milicevic, Aleksandar Belosevic, Srdjan Crnomarkovic, Nenad Tomanovic, Ivan Stojanovic, Andrijana Tucakovic, Dragan Deng, Lei Che, Defu Univ Belgrade Natl Inst Republ Serbia VINCA Inst Nucl Sci Dept Thermal Engn & Energy Mike Petrovica Alasa 12-1411351 VincaPOB 522 Belgrade 11001 Serbia Univ Belgrade Fac Mech Engn Kraljice Marije 16 Belgrade 11120 35 Serbia Xi An Jiao Tong Univ Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China

The co-combustion of biomass and coal in a utility boiler could provide cleaner power production and ensure sustainable utilization of the solid fuels. This paper aims to numerically investigate complex pro-cesses in the tangentially-fired 900 MWth boiler furnace during direct co-firing of lignite and biomass with 10% thermal share of agricultural residues (wheat straw, corn straw and soybean straw) under vari-able boiler loads (100%, 85% and 70%). Simulations are conducted by means of in-house developed com-puter code, supported by the specially designed user-friendly graphical interface. Co-firing of agricultural residues provides lower pollutant emissions, somewhat higher furnace exit gas temperature and increase in unburnt carbon in bottom/fly ash, compared to the lignite combustion without biomass. Soybean is found to be the most suitable for co-firing regarding its ash melting point, however due to its abundance and availability the wheat straw is selected for this study. Co-combustion at partial boiler loads results in reduction of NOx and SOx up to 34% and 9.5%, respectively. Burners arrangement and furnace aerody-namics affect the abatement of pollutants. This study may help the global effort s in fighting the climate change, efficiently and cost-effectively, thus offering considerable economic and social benefits. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Numerical analysis co-firing fuel flexibility variable load boiler furnace in-house software

来源：评论

学校读者我要写书评

暂无评论

Insights into Charge Transfer at an Atomically Precise Nanocluster/Semiconductor Interface

引用

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 2020年第20期59卷 7748-7754页

作者： Wang, Yu Liu, Xiao-He Wang, Qiankun Quick, Martin Kovalenko, Sergey A. Chen, Qing-Yun Koch, Norbert Pinna, Nicola Humboldt Univ Inst Chem Brook Taylor Str 2 D-12489 Berlin Germany Humboldt Univ IRIS Adlershof Brook Taylor Str 2 D-12489 Berlin Germany Humboldt Univ Inst Phys Brook Taylor Str 6 D-12489 Berlin Germany Humboldt Univ IRIS Adlershof Brook Taylor Str 6 D-12489 Berlin Germany Xi An Jiao Tong Univ Sch Energy & Power Engn IRCRE Xian 710049 Peoples R China Xi An Jiao Tong Univ Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China

The deposition of an atomically precise nanocluster, for example, Ag-44(SR)(30), onto a large-band-gap semiconductor such as TiO2 allows a clear interface to be obtained to study charge transfer at the interface. Changing the light source from visible light to simulated sunlight led to a three orders of magnitude enhancement in the photocatalytic H-2 generation, with the H-2 production rate reaching 7.4 mmol h(-1) g(catalyst)(-1). This is five times higher than that of TiO2 modified with Ag nanoparticles and even comparable to that of TiO2 modified with Pt nanoparticles under similar conditions. Energy band alignment and transient absorption spectroscopy reveal that the role of the metal clusters is different from that of both organometallic complexes and plasmonic nanoparticles: A type II heterojunction charge-transfer route is achieved under UV/Vis irradiation, with the cluster serving as a small-band-gap semiconductor. This results in the clusters acting as co-catalysts rather than merely photosensitizers.

关键词： charge transfer co-catalysts photosensitizers silver nanoclusters

来源：评论

学校读者我要写书评

暂无评论

Trace doping of early transition metal enabled efficient and durable oxygen reduction catalysis on Pt-based ultrathin nanowires

引用

APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY 2022年第0期303卷 120918-120918页

作者： Gao, Lei Sun, Tulai Tan, Xin Liu, Maochang Xue, Fei Wang, Bin Zhang, Jiawei Lu, Yang-Fan Ma, Chao Tian, He Yang, Shengchun Smith, Sean C. Huang, Hongwen Hunan Univ Coll Mat Sci & Engn Hunan Joint Int Lab Adv Mat & Technol Clean Energ Changsha 410082 Hunan Peoples R China Zhejiang Univ Technol State Key Lab Breeding Base Green Chem Synth Tech Ctr Electron Microscopy Hangzhou 310014 Zhejiang Peoples R China Zhejiang Univ Technol Coll Chem Engn Hangzhou 310014 Zhejiang Peoples R China Australian Natl Univ Res Sch Phys Dept Appl Math Integrated Mat Design Lab Canberra ACT 2601 Australia Xi An Jiao Tong Univ MOE Key Lab Nonequilibrium Synth & Modulat Conden State Key Lab Multiphase Flow Power Engn Int Res Ctr Renewable EnergySch PhysInt Res Ctr Xian 710049 Shanxi Peoples R China Zhejiang Univ Sch Mat Sci & Engn State Key Lab Silicon Mat Hangzhou 310027 Zhejiang Peoples R China Univ Sci & Technol China Hefei Natl Lab Phys Sci Microscale Hefei 230026 Anhui Peoples R China

Discovering an active and durable catalyst for oxygen reduction reaction is crucial to the commercialization of fuel cells, but remains grand challenging. Here we report, for the first time, the trace doping of early transition metal (ETM) Re into ultrathin PtNiGa nanowires (Re-PtNiGa NWs) to construct a novel catalyst integrating the superior activity, long-time durability, and high utilization efficiency of Pt atoms. Impressively, the Re-PtNiGa tetrametallic NWs present a 19.6-fold enhancement in mass activity (3.49 A mg(Pt)(-1)) compared to commercial Pt/C catalyst and only a 10.6% loss in mass activity after 20,000 cycles of durability test. Moreover, the real fuel cell assembled by Re-PtNiGa NWs on the cathode strongly supports its great potential in fuel cells. The density functional theory calculations reveal that introduction of ETM Re into PtNiGa NWs could weaken binding strength of oxygenated species and elevate dissolution potential, well rationalizing the great enhancements in activity and durability.

关键词： Ultrathin Re-PtNiGa nanowires Doping of early transition metal Multicomponent alloy Electrocatalyst Oxygen reduction reaction

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：