检索结果-内蒙古大学图书馆

SSRN 2023年

作者： Wu, Yingtao Mai, Zhaoming Rao, Boxuan Liu, Jie Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi'An710049 China Department of Power Mechanical Engineering Beijing Jiaotong University Beijing100044 China

Species sampling during fuel autoignition can provide valuable insights in studying the chemical kinetic mechanism. Various species sampling techniques have been developed for speciation quantification in different reactors. However, unavoidable dilution in the physical sampling brings uncertainty to the measurements, particularly in the negative temperature coefficient (NTC) region where the effect of dilution remains unclear. To address this issue and improve measurement accuracy, numerical species samplings during the autoignition of n-butane mixture were studied in a rapid compression machine reactor. Results show that greater fuel consumption and intermediate generation were observed in regions with lower temperatures instead of the hot core zone. Therefore, the dilution effect on the sampling results is reversed inside the NTC region. Furthermore, results from two typical sampling methods were compared with the target core profiles to determine their uncertainties. Lastly, the feasibility of applying dilution ratio calibration on the sampling results in the NTC region was tested, which indicates the necessity of considering the NTC effect, particularly for intermediates with low concentrations. Alternatively, increasing the sampling duration of the fast-sampling method effectively reduces the uncertainty of species concentration and enhances the robustness of mechanism validation regardless of the NTC behavior. © 2023, The Authors. All rights reserved.

关键词： Temperature

来源：评论

学校读者我要写书评

暂无评论

Experimental and Numerical Study of Hydraulic Characteristics and Pressurization Deterioration Mechanism of a Three-Stage Mixed-flow multiphase Pump Under Gas Liquid Condition

SSRN

引用

SSRN 2023年

作者： Dai, Xiaoyu Xu, Qiang Yang, Chenyu Su, Xiaobin Chang, Liang Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Shanghai Institute of Satellite Engineering Shanghai201109 China

The mixed-flow multiphase pump may experience pressurization deterioration due to the high Gas Volume Fraction, resulting in pressurization failure and posing a threat to the pressurization unit's safety. In this paper, a three-stage mixed-flow multiphase pump with closed impeller structure is designed and developed. The hydraulic characteristics and pressurization deterioration mechanism of the multiphase pump were investigated at various rotational speeds and inlet conditions using the experiment and simulation. As the liquid flow rate rises, the multiphase pump experiences a 'three-stage' downward trend in pressurization. The first booster stage has a greater capacity for pressurizing the liquid phase. The gas-liquid pressurization exhibits a wave-shaped downward trend due to significant deterioration in stage-wise pressurization when the liquid flow rate is low. Once the Inlet Gas Volume Fraction reaches the initial critical Gas Volume Fraction, the gas aggregates on the impeller’s suction surface is removed at the impeller outlet, creating an annular air mass. When this mass of air meets the fluid behind it, it creates a chaotic vortex that absorbs the fluids' kinetic energy. As a result, the first booster stage experiences a significant reduction in its pressurization ability, causing an abrupt decrease in the pressurization curve. © 2023, The Authors. All rights reserved.

关键词： Computational fluid dynamics

来源：评论

学校读者我要写书评

暂无评论

Room-temperature photodeposition of conformal transition metal based cocatalysts on BiVO4 for enhanced photoelectrochemical water splitting

引用

Nano Research 2020年第1期13卷 231-237页

作者： Lu Wang Tao Zhang Jinzhan Su Liejin Guo International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringSchool of Energy&Power EngineeringXi’an Jiaotong UniversityXi’an710049China

Photoelectrochemical(PEC)water splitting using semiconductors offers a promising way to convert renewable solar energy to clean hydrogen ***,due to the sluggish reaction kinetics of water oxidation,significant charge recombination occurred at the photoanode/electrolyte interface and cause decrease of its PEC *** reduce the surface recombination,we deposit different transition metal complexes on BiVO4 nanocone arrays by a versatile light driven in-situ two electrode photodeposition approach without applied *** cobalt phosphate“Co-Pi”,nickel borate“Ni-Bi”and manganese phosphate“Mn-Pi”complexes were deposited on BiVO4 nanocone arrays to form core-shell structure photoanode,all of which lead to enhanced photoelectrochemical *** photocurrent of the Co-Pi/BiVO4 photoanode under front-side illumination for 5 min is increased by 4 folds comparing to that of bare BiVO4 photoanode at 0.6 V ***,reaching a hole transfer efficiency as high as 94.5%at 1.23 V *** proposed photodeposition strategy is simple and efficient,and can be extended to deposite cocatalyst on other semiconductors with a valence band edge located at a potential more positive than the oxidation potential of transition metal ion in the cocatalyst.

关键词： bismuth vanadate photoelectrochemcial water splitting conformal photodeposition cocatalyst

来源：评论

学校读者我要写书评

暂无评论

Heat transfer behaviors of some supercritical fluids: A review

引用

Chinese Journal of Aeronautics 2022年第1期35卷 290-306页

作者： Gongnan XIE Xiaoxiao XU Xianliang LEI Zhouhang LI Yong LI Bengt SUNDEN School of Marine Science and Technology Northwestern Poly technical UniversityXi'an 710072China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Chongqing UniversityChongqing 400044China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China School of Mechanical Engineering Northwestern Polyteclwical UniversityXi'an 710072China Department of Energy Sciences Lund UniversitySE-22100 LundSweden

Supercritical fluids(e.g.,hydrocarbon fuels,water,carbon dioxide,and organic working medium,etc)have been recognized as working media to improve thermal efficiencies in power cycles and energy conversion,and have been used or selected as the working fluids in engineering fields such as aerospace,nuclear power,solar energy,refrigeration,geothermal energy,chemical technology,and so *** better understand the interesting characteristic or abnormal behaviors of supercritical fluids,most valuable research works(including experimental results and numerical studies)from domestic and abroad have been *** such,this paper presents a comprehensive review on heat transfer behaviors of some supercritical fluids in engineering *** review focuses on recently available articles published mainly from 2016 up to the present *** common problems(i.e.,heat transfer enhancement and heat transfer deterioration particularly for the supercritical hydrocarbon fuels)in the supercritical field are summarized and some perspectives on future prospects are also included.

关键词： Heat transfer behavior Supercritical fluids Thermo-physical property Turbulence model Working condition

来源：评论

学校读者我要写书评

暂无评论

Sequential Growth of Cs_(3)Bi_(2)I_(9)/BiVO_(4)Direct Z-Scheme Heterojunction for Visible-Light-Driven Photocatalytic CO_(2)Reduction

引用

Transactions of Tianjin University 2023年第6期29卷 462-472页

作者： Long Jiang Hanrui Du Le Li Xiangjiu Guan Yihao Zhang Liwei Li Xiaoxu Liu Lei Li Yingcheng Tian Li Zhang Shuai Wang Jie Chen Shaohua Shen State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi’an 710077China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China CNPC National Engineering Research Center for Oil and Gas Drilling Equipment Co. Ltd.Baoji 721002China China Coal Energy Research Institute Co. Ltd.Xi’an 710049China

The high exciton binding energy and lack of a positive oxidation band potential restrict the photocatalytic CO_(2)reduction efficiency of lead-free Bi-based halide perovskites Cs_(3)Bi_(2)X_(9)(X=Br,I).In this study,a sequential growth method is presented to prepare a visible-light-driven(λ>420 nm)Z-scheme heterojunction photocatalyst composed of BiVO_(4)nanocrystals decorated on a Cs_(3)Bi_(2)I_(9)nanosheet for photocatalytic CO_(2)reduction coupled with water *** Cs_(3)Bi_(2)I_(9)/BiVO_(4)Z-scheme heterojunction photocatalyst is stable in the gas-solid photocatalytic CO_(2)reduction system,demonstrating a high visible-light-driven photocatalytic CO_(2)-to-CO production rate of 17.5μmol/(g·h),which is approximately three times that of pristine Cs_(3)Bi_(2)I_(9).The high efficiency of the Cs_(3)Bi_(2)I_(9)/BiVO_(4)heterojunction was attributed to the improved charge separation in Cs_(3)Bi_(2)I_(9).Moreover,the Z-scheme charge-transfer pathway preserves the negative reduction potential of Cs_(3)Bi_(2)I_(9)and the positive oxidation potential of BiVO_()*** study off ers solid evidence of constructing Z-scheme heterojunctions to improve the photocatalytic performance of lead-free halide perovskites and would inspire more ideas for developing leadfree halide perovskite photocatalysts.

关键词： Lead-free halide perovskite Z-scheme heterojunction CO_(2)reduction Visible-light photocatalysis Charge transfer

来源：评论

学校读者我要写书评

暂无评论

Review, Numerical Validation, and Experiment Verification for Definite Solution Analogy Theory (Dsat) in Thermal-Hydraulic Scaling

SSRN

引用

SSRN 2024年

作者： Li, Xinyu Zhang, Dalin Jiang, Dianqiang Zhou, Xingguang Lv, Xindi Tian, Wenxi Qiu, Suizheng Su, Guanghui 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 China

The new generation of reactor technology: Fluoride-Salt-cooled high-Temperature Advanced Reactor (FuSTAR), mainly applied to the steady supply of stable electricity and high-temperature process heat for remote, underground, and arid areas. So far, the design of the heat transport system and Passive Residual Heat Removal System (PRHRS) of FuSTAR has been finished, but the scaling and experiment verification still needs to be carried out. In this study, the Definite Solution Analogy Theory (DSAT) was used for scaling analysis, and the scaling experiment platform of PRHRS was built. DSAT was verified through numerical simulation and experiment results, which can support the design and optimization of the PRHRS. The numerical test results show that the similar distribution of physical fields in dimensionless space on the prototype and experiment is realized under the DSAT framework. The steady-state experiment results show that the prototype of PRHRS can take away more than 1% of the decay heat of the total thermal power and has a margin of about 15% under a stable natural cycle. The maximum deviation between the measured temperature and the calculated value with DSAT is more than 4°C. The transient experiment results show that the maximum deviation of dimensionless solutions is less than 4%, which proves the high accuracy of DSAT and the PRHRS based on this framework can effectively remove the decay heat in the reactor. This work can be used to extend the scaling method of thermal-hydraulic in high dimensional space and transient conditions. © 2024, The Authors. All rights reserved.

关键词： Fluorine compounds

来源：评论

学校读者我要写书评

暂无评论

Influence of light-dark cycles on hydrogen production from sugarcane bagasse by Rhodobacter sphaeroides

引用

International Journal of Hydrogen Energy 2025年 145卷 28-35页

作者： Cao, Wen Wei, Xuan Lu, Jiyan Li, Mengyao Feng, Jiali State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Shaanxi Xi'an710049 China College of Biology and Oceanography Weifang University Shandong Weifang261061 China Weifang Municipal Key Laboratory of Agricultural Planting Quantization and Application Shandong Weifang261061 China

Photo-fermentative hydrogen production from lignocellulosic biomass offers a clean, efficient, and eco-friendly alternative for energy generation. Large-scale photo-fermentative hydrogen production, ideally conducted under outdoor conditions is influenced by the daily light-dark cycle. This study examines the effect of a 12-h light-dark cycle (12L/12D) on hydrogen production by Rhodobacter sphaeroides HY01 using sugarcane bagasse (SCB), comparing it with continuous light (CL) conditions. The results show that bacterial growth was not significantly affected by the light-dark cycle. The optical density (OD660) of the culture reached 3.25 under 12L/12D and 3.49 under CL. However, total hydrogen yield decreased substantially under the light-dark cycle, from 6020.11 ± 54.71 mL/L in CL to 4242.73 ± 182.03 mL/L in the 12L/12D condition. Additionally, the rate of hydrogen production was higher under CL (119.78 ± 4.82 mL/(L·h)) compared to 12L/12D (60.97 ± 7.27 mL/(L·h)), while the lag phase was shorter under CL, at 17.25 ± 1.04 h, versus 20.37 ± 3.98 h under 12L/12D. Gas chromatography-mass spectrometry (GC-MS) analysis identified lactic acid, butyric acid, and ethanol as the primary soluble metabolites, with ethanol yield under 12L/12D being approximately half of that under CL. Notably, light conversion efficiency (LCE) for hydrogen production was significantly enhanced under the light-dark cycle, showing a 1.36-fold increase compared to CL conditions. These findings not only contribute to the understanding of the influence of light cycles on biohydrogen production but also support the development of more efficient and cost-effective biohydrogen systems for sustainable energy production. © 2025 Hydrogen Energy Publications LLC

关键词： Gas chromatography

来源：评论

学校读者我要写书评

暂无评论

Anchoring Single Nickel Atoms on Carbon-vacant Carbon Nitride Nanosheets for Efficient Photocatalytic Hydrogen Evolution

引用

Chemical Research in Chinese Universities 2022年第5期38卷 1243-1250页

作者： LIN Zhi ZHANG Zhengqi WANG Yiqing PENG Zhiming WANG Xinxin WANG Ruizhe HUANG Yu-Cheng MENG Fanqi LI Mingtao DONG Chung-Li ZHANG Qinghua GU Lin SHEN Shaohua International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049P.R.China Department of Physics Tamkang UniversityNew Taipei City 25137TaiwanP.R.China Institute of Physics Chinese Academy of SciencesBeijing 100190P.R.China

Polymeric carbon nitride(PCN)has emerged as a promising candidate for photocatalytic hydrogen evolution,but its dependence on scarce and high-cost noble metal co-catalysts severely limits its extensive *** will be of great promise to develop non-noble metal single-atom co-catalysts with low-cost and high atom utilization to improve the photocatalytic performance over ***,single Ni atoms are successfully anchored onto carbon-vacant PCN nanosheets(CCN-SANi)via a two-step ammonia thermal treatment and photo-deposition *** calculations and experimental results demonstrate that the optical absorption property and the charge transfer ability of CCN-SANi have been significantly improved with the introduction of single Ni atoms to form Ni-N3 *** comparison to carbon-vacant PCN(CCN)loaded with Ni clusters,the obtained CCN-SANi exhibits 11.4 times increased photocatalytic performance,with the highest hydrogen evolution rate reaching 511μmol/(g·h),which is even 1.7 times higher than that of CCN loaded with Pt *** research proposes an inspiring and reliable strategy to design novel single-atom semiconducting polymers with electronic structures manipulated for efficient photocatalysis.

关键词： Photocatalytic hydgogen evolution Single metal atom Polymeric carbon nitride

来源：评论

学校读者我要写书评

暂无评论

Supercritical Co2 -Promoted Degradation of Polystyrene to Aromatic Oils with Nio@C Catalyst

SSRN

引用

SSRN 2024年

作者： Liu, Yanbing Shi, Jinwen Zhuang, Zitong Kang, Xing Mao, Liuhao Li, Yi Jin, Hui Zhao, Qiuyang Guo, Liejin International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University 28 West Xianning Road Shaanxi Xi’an710049 China

Exploring new system for chemical recycling of plastic is an effective way to convert plastic waste into energy. Herein, the use of supercritical CO2 (Sc-CO2) to promote the catalytic degradation of polystyrene (PS) with high yield of aromatic oils was proposed. Sc-CO2 provided a homogeneous environment for the reaction, which not only facilitated the swelling of PS, but also inhibited the formation of coke, beneficial for the degradation of PS to aromatic oils. Importantly, CO2 was be consumed as an oxidant to generate new product and reduce greenhouse gas emission. The doped carbon material in NiO, which was stable in Sc-CO2 and had a simple preparation process, enriched the porous structure and increased the acidic sites, thus improving the catalytic activity. Under the co-action of Sc-CO2 and NiO@C, the yield of aromatic oils produced from PS was up to 89.3 ± 0.6 wt% at 300oC with a reaction time of 2 h and a catalyst loading amount of 10 wt%. Moreover, the NiO@C catalyst were used for three cycles without obvious change in the catalytic performance. The efficient catalytic degradation of PS to aromatic oils by Sc-CO2 promoted NiO@C catalysis provides a potential route for simultaneously recycling plastic and sequestering carbon. © 2024, The Authors. All rights reserved.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Thermodynamic optimization of closed air Brayton cycle and air-ORC combined cycle

Thermodynamic optimization of closed air Brayton cycle and a...

引用

International Conference on power engineering 2021, ICOPE 2021

作者： Qian, Yiran Zhang, Zhuohua Yi, Jingwei Chen, Weixiong Liu, Ming Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China Nuclear Power Institute of China Chengdu610213 China

In order to improve the flexibility and adaptability of small mobile nuclear power systems, air is considered as an optional working fluid of nuclear Brayton cycle system. It can avoid the shortage of working fluid under extreme conditions, and ensure the system operation with tight working fluid supply. In this study, simple regenerative cycle (SRC), intercooling regenerative cycle (IRC) and corresponding air-ORC combined cycle (SRCC and IRCC) are proposed and modeled. Thermodynamic analysis of key parameters is conducted. Genetic algorithm (GA) is applied for multi-parameter optimization to achieve the maximum cycle efficiency. With the increase of pressure ratio (PR), the efficiency of SRC increases firstly and then decreases. Pressure ratio corresponding to the maximum cycle efficiency increases gradually with turbine inlet temperature. The efficiency of IRC is slightly lower than that of SRC in low pressure ratio region, but IRC maintains a higher efficiency in high pressure ratio region. For SRCC, isobutane has the best performance among three selected organic working fluids. The multi-parameter optimization result indicates that the IRCC has lower cycle efficiency comparing with SRCC, and SRCC shows the optimal performance among the four configurations. © 2021 The Japan Society of Mechanical Engineers.

关键词： Efficiency

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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：