检索结果-内蒙古大学图书馆

Physico-chemical properties and gasification reactivity of co-pyrolysis char from different rank of coal blended with lignocellulosic biomass: Effects of the cellulose

引用

BIORESOURCE TECHNOLOGY 2017年 235卷 256-264页

作者： Wu, Zhiqiang Wang, Shuzhong Luo, Zhengyuan Chen, Lin Meng, Haiyu Zhao, Jun Xi An Jiao Tong Univ Sch Chem Engn & Technol Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Key Lab Thermofluid Sci & Engn Sch Energy & Power Engn Minist Educ Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China

In this paper, the influence of cellulose on the physicochemical properties and the gasification reactivity of co-pyrolysis char was investigated. A specific surface area analyzer and an X-ray diffraction system were used to characterize the pore structure and the micro-crystalline structure of char. Fractal theory and deconvolution method were applied to quantitatively investigate the influence of cellulose on the structure of co-pyrolysis char. The results indicate that the improvements in the pore structure due to the presence of cellulose are more pronounced in the case of anthracite char with respect to bituminous char. Cellulose promotes the ordering of micro-scale structure and the uniformity of both anthracite and bituminous char, while the negative synergetic effect was observed during gasification of co-pyrolysis char. The exponential relationships between fractal dimension and specific surface area were determined, along with the relations between the gasification reactivity index and the microcrystalline structure parameter. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Co-pyrolysis Coal Cellulose Chemical and physical properties Gasification reactivity

来源：评论

学校读者我要写书评

暂无评论

Strain effect on oxygen evolution reaction of the SrTiO3 (001) surface

引用

APPLIED PHYSICS LETTERS 2021年第10期119卷 1-6页

作者： Wen, Linyuan Li, Mingtao Shi, Jinwen Liu, Yingzhe Yu, Tao Liu, Maochang Zhou, Zhaohui Xi An Jiao Tong Univ Int Res Ctr Renewable Energy State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Xian Modern Chem Res Inst State Key Lab Fluorine & Nitrogen Chem Xian 710065 Peoples R China Changan Univ Sch Water & Environm Dept Chem Engn & Technol Xian 710064 Peoples R China

Strontium titanate (SrTiO3) is one of the most promising photocatalysts for overall water splitting (OWS). Strains can be commonly introduced in SrTiO3 during the synthetic processes, for example, in pulsed laser deposition. However, the effect of the strains on the catalytic performance of OWS is still unclear to date. Herein, first-principles calculations were performed to evaluate the impact of biaxial strains applied in SrTiO3 (001) surface on the oxygen evolution reaction (OER), the bottleneck of OWS. It was found that the applied strains, especially the compressive strains, significantly affect the free energy changes for H2O dissociation and *OOH deprotonation of OER on SrTiO3 (001). More interestingly, the tensile strains reduce the surface energy and lower the OER overpotential through reducing the free energy change for the rate-determining step, i.e., the second step of OER (*OH deprotonation), while the compressive strains increase the surface energy and the OER overpotential. Consequently, it is probable to introduce the tensile strains in the synthetic process to enhance the OER performance on SrTiO3 (001) surface.

关键词： Catalysts and Catalysis Transition metal oxides First-principle calculations Oxygen evolution reaction Water-splitting Density functional theory Perovskites

来源：评论

学校读者我要写书评

暂无评论

A ternary nanostructured α-Fe2O3/Au/TiO2 photoanode with reconstructed interfaces for efficient photoelectrocatalytic water splitting

引用

APPLIED CATALYSIS B-ENVIRONMENTAL 2020年 260卷 118206-000页

作者： Fu Yanming Dong Chung-Li Zhou Wu Lu Ying-Rui Huang Yu-Cheng Liu Ya Guo Penghui Zhao Liang Chou Wu-Ching Shen Shaohua Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Int Res Ctr Renewable Energy Xian 710049 Shaanxi Peoples R China Tamkang Univ Dept Phys Tamsui 25137 Taiwan Natl Chiao Tung Univ Dept Electrophys Hsinchu 30010 Taiwan

In this study, a ternary nanostructured alpha-Fe2O3/Au/TiO2 film with integrating a crystalline alpha-Fe2O3 core, metallic Au nanoparticles (NPs), and an amorphous TiO2 overlayer is fabricated and examined as a photoanode for photoelectrocatalytic water splitting. Under simulated solar illumination, the as-prepared photoanode exhibits a four-fold increase (1.05 mA cm(-2)) in photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) relative to bare alpha-Fe2O3. Based on systematic investigations, it is proposed that Au NPs extract photoholes from the bulk of alpha-Fe2O3 core and then shuttle them to the outer TiO2 overlayer, and meanwhile, TiO2 overlayer efficiently captures and stores the photoholes and facilitates the hole injection into electrolyte. Thus, the remarkably improved photoelectrocatalytic water splitting performance of alpha-Fe2O3/Au/TiO2 photoanode is attributed to the significantly suppressed bulk and surface charge recombination due to the relayed pumping of the photogenerated charge carriers through the photoanode/electrolyte interfaces reconstructed by Au NPs and TiO2 overlayer.

关键词： Hematite Photoelectrocatalytic water splitting Au nanoparticles TiO2 overlayer Reconstructed interfaces

来源：评论

学校读者我要写书评

暂无评论

Catalytic activity prediction of different metal surfaces for N₂O catalytic decomposition by density functional theory

引用

COMPUTATIONAL AND THEORETICAL CHEMISTRY 2015年 1057卷 1-6页

作者： Chen, Hao Yue, Jiaqi Li, Yingying Yi, Chunhai Yang, Bolun Qi, Suitao Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Sch Chem Engn & Technol Dept Chem Engn Xian 710049 Shaanxi Peoples R China

The catalytic activity trends of four different metal surfaces (Rh, Pd, Pt and Ni) for N2O direct catalytic decomposition were analyzed and predicted using density functional theory (DFT). Some adsorption features on different metal surfaces were investigated, such as the structure, electron and energy of two important N2O adsorption sites: the top site and the flat-bidentate site. The DFT results show that the adsorption energy of N2O on the top site over Rh, Pd and Pt metal surfaces was negative, which indicates that N2O can be easily adsorbed on these metal surfaces. The difficulty of the N-O bond breakage in the flat-adsorbed N2O was analyzed by combining the molecular structure, density of state and charge density to predict the catalytic activity of different metal surfaces. The catalytic activity trend of different metal surfaces for N2O decomposition is determined as Rh > Pd > Pt > Ni, which is consistent with the corresponding experimental results. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Direct catalytic decomposition N2O N-O bond breakage Catalytic activity Density functional theory (DFT)

来源：评论

学校读者我要写书评

暂无评论

NUMERICAL SIMULATION OF BLOOD flow THROUGH NORMAL AND STENOTIC CAROTID ARTERY

引用

JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY 2024年第2期24卷 2440003-2440003页

作者： Li, Guojie Chen, Bin Wang, Xinkai Nie, Peng Yulin Univ Sch Energy Engn Yulin 719000 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Huaihe Hosp Henan Univ Med Imaging Dept Kaifeng 475000 Peoples R China

The carotid artery sinus is often the site of vascular diseases such as atherosclerosis, which may induce cerebral stroke. Individual differences in the carotid artery can lead to different possibilities for atherosclerosis, and the different hemodynamics of the carotid artery with stenosis can help to reveal the occurrence of atherosclerosis. In this work, the hemodynamics in the patient-specific carotid bifurcation are studied by using the modified Herschel-Bulkley model. Calculations show that the helical flow is presented in the healthy carotid sinus and disappears in the stenosed carotid sinus. The disappearance of helical flow in the carotid artery enhances the risk of atherosclerosis. The atherosclerotic lesion is more prone to occur in the distal portion of the carotid sinus than in the proximal portion where the oscillatory shear index (OSI) is also high. The presence of stenosis makes the atherosclerotic lesion develop toward the proximal portion. The disappearance of helical flow in the carotid artery is an important risk signal for the occurrence of atherosclerosis.

关键词： Carotid artery helical flow stenosis modified Herschel-Bulkley model

来源：评论

学校读者我要写书评

暂无评论

Experimental Investigation of Two-Phase flow Instabilities in Low-Mass-Flux Water Wall Tubes of Supercritical Circular Fluidized Bed Boilers

Experimental Investigation of Two-Phase Flow Instabilities i...

引用

6th International Symposium on multiphase flow, Heat Mass Transfer and Energy Conversion

作者： Huang, Fan Luo, Yushan Wang, Haijun Chen, Tingkuan Wu, Yangyang Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Xian Petr Univ Key Lab Photoelect Gas & Oil Logging & Detecting Minist Educ Xian Peoples R China

For the purpose of disclosing the hydrodynamic flow characteristics, under the low mass velocity conditions of the 600-MW supercritical circular fluidized beds boilers, experimental studies on instability of two-phase flow in parallel vertical internally ribbed tubes were conducted. Two kinds of oscillations, pressure-drop oscillation and density-wave oscillation, have been observed. In the range of test parameters the effects of pressure, mass flux, inlet subcooling, compressible volume, exit throttle, and asymmetric heat flux to the two-phase instability were explored and analyzed. Indications from experiment data are: To increase system pressure, mass flux and inlet subcooling will intensify the stability of water wall tubes. To increase exit throttle will intensify the instability of water wall tubes. The bounding pressure and bounding mass flux of density-wave oscillations and the bounding pressure of pressure-drop oscillation have been obtained. Based on the results of testing and using a homogeneous model, the threshold relational expressions of instability were obtained. The results may be used for the design and safe operation of parallel vertical rifled water wall tubes of supercritical circular fluidized beds boilers.

关键词： Stability

来源：评论

学校读者我要写书评

暂无评论

Experimental Study on Electrocatalytic Reduction of CO2 to Methanol over Cu2O and Cu2O/ZnO films

Experimental Study on Electrocatalytic Reduction of CO2 to M...

引用

International Conference on power engineering 2021, ICOPE 2021

作者： Zhang, Wenfei Zhou, Qulan Qi, Ji Li, Na State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China China Mobile System Integration Co. Ltd Beijing100052 China

The Cu2O film electrodes were prepared by solution immersion method, the ZnO/Cu2O film electrodes were prepared by electrodeposition method. Then the pure Cu2O film electrodes and ZnO/Cu2O film electrodes were used to reduce CO2 to CH3OH. The crystal structure, morphology, particle size and specific surface area of pure Cu2O films prepared under different immersion time and ZnO/Cu2O films prepared under different deposition time and Zn2+ concentration were analyzed by XRD, SEM, and BET. The electrolytic activity of the pure Cu2O film electrodes and ZnO/Cu2O film electrodes were studied. Under the same reaction conditions, the Cu2O film electrode with 2 h preparation time has the best electrolysis effect in the three groups of pure Cu2O electrode. The increase of reaction temperature can significantly promote the reduction of CO2 to CH3OH on Cu2O film electrodes. the ZnO/Cu2O film electrode with the Zn2+ concentration of 0.05 M and the deposition time of 30 min had the highest total CH3OH yields. This study highlights that the ZnO have a very good promotion of electrolytic CO2 reduction on Cu2O film. © 2021 The Japan Society of Mechanical Engineers.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Evolution of hydrogen bubbles on a microelectrode driven by constant currents and its impact on potential response

引用

CHEMICAL engineering JOURNAL 2024年 500卷

作者： Lu, Xinlong Yadav, Devendra Zhou, Liwu Li, Xiaoping Ma, Lijing Jing, Dengwei Xian Jiaotong Univ XJTU Int Res Ctr Renewable Energy Xian 710049 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Shanxi Key Lab Catalysis & Energy Coupling Xian 710049 Shaanxi Peoples R China

To understand the relationship between electrolytic hydrogen bubble evolution and electric potential fluctuations, a synchronized measurement system, comprising a high-speed camera and an electrochemical workstation, was employed to analyze single hydrogen bubble evolution on a microelectrode and investigate the voltage-time characteristics of a typical hydrogen evolution reaction. The results show periodic potential fluctuations caused by the periodic evolution of single hydrogen bubbles. The overpotential fluctuation during single bubble evolution exhibits two stages: an initial increase (Stage I) followed by a decrease (Stage II). The duration of Stage I decreases with increasing applied current. Subsequently, a balance of known forces was developed to clarify the critical roles of the Marangoni effect and electric force in bubble detachment dynamics, enabling the prediction of bubble detachment size. Furthermore, it was observed that, during single bubble evolution, the overpotential shifts from activation dominance to ohmic dominance. The magnitude of ohmic overpotential correlates with the bubble diameter, whereas activation overpotential correlates with the bubble's contact diameter. This study contributes to the understanding of activation and ohmic overpotentials linked to bubble evolution in water electrolysis devices, thereby facilitating the development of more efficient multiphase electrochemical reactors.

关键词： Electrolysis Hydrogen bubble evolution Voltage-current correspondence Overpotential fluctuation Microelectrode

来源：评论

学校读者我要写书评

暂无评论

Combined effect of Cu⁰ and oxygen vacancies in Cu-based zeolites enables highly efficient photo-Fenton-like performance for water purification

引用

ENVIRONMENTAL SCIENCE-NANO 2024年第6期11卷 2481-2493页

作者： Zhang, Wei Wang, Lan Hou, Chen Zhu, Zhiqiang Lichtfouse, Eric Trapalis, Christos Wang, Chuanyi Shaanxi Univ Sci & Technol Sch Environm Sci & Engn Xian 710021 Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710000 Peoples R China NCSR Demokritos Inst Nanosci & Nanotechnol Aghia Paraskevi 15341 Greece

The Cu-based heterogeneous photo-Fenton-like process has emerged as a promising technology in wastewater treatment, but efficient light harvesting and sufficient utilization of photogenerated electrons are still core issues. Herein, a dual strategy was proposed to achieve the high-efficiency removal of refractory organic pollutants using a Cu-doped zeolite with Cu(0 )and oxygen vacancies (Cu-0@CuZ) in the photo-Fenton-like reaction. This is the first time that such a strategy employing Cu-based zeolites has been used. Cu-0@CuZ can completely degrade 20 mg L-1 phenol within 15 min under visible-light irradiation, and the rate constant was 40, 55, and 65 times higher than Cu2O, CuO, and Cu-0, respectively. Cu-0@CuZ also presented excellent degradation performance for other typical refractory organic pollutants, surpassing most of the reported Cu-based catalysts to date. This superior performance highly depends on oxygen vacancies (Vo) and plasmonic Cu nanoparticles. The introduction of Vo and the creation of the surface plasmon resonance effect greatly enhanced the visible-light harvesting ability of the catalyst. Impressively, Vo and Cu-0 nanoparticles served as dual-channels for efficient electron transfer by enriching and then transferring photogenerated electrons to Cu(ii), greatly expediting the reduction of Cu(ii) to Cu(i). The synergistic effects of the dual-channel electron transfer and light-harvesting ability achieved sustained Cu(ii)/Cu(i) cycling, thereby promoting H2O2 activation to produce more active species for organic pollutant degradation. This work provides an ingenious strategy to rationally establish a high-efficiency photo-Fenton-like catalyst for water remediation.

关键词： Organic pollutants

来源：评论

学校读者我要写书评

暂无评论

Experimental and kinetic study on laminar burning velocities of ammonia/ethylene/air premixed flames under high temperature and elevated pressure

引用

COMBUSTION AND FLAME 2023年第1期251卷

作者： Liu, Bowen Hu, Erjiang Yin, Geyuan Huang, Zuohua Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian Peoples R China

The laminar burning velocities (LBVs) of ammonia (NH3) blended with ethylene (C2H4) were measured at different blending ratios (alpha = 0-1), initial temperatures (Tu = 300-440 K), and initial pressures (Pu = 1-5 atm). The flame morphology showed that the NH3/C2H4/air flames suffer from cellular instability under elevated pressures (Pu = 5 atm). The Lewis number ( Le) was used to evaluate the thermal diffusion in-stability. Le was insensitive to the initial pressure and positively correlated with the blending ratio. The hydrodynamic instabilities were investigated under various initial conditions, which were exacerbated by elevated initial pressures and large blending ratios. The LBVs and hydrodynamic instabilities of NH3 were enhanced by adding C2H4. The existing kinetic models can only accurately predict measured data within a narrow range. Based on Konnov Mech (2021), a new detailed kinetic model with 119 species and 1,365 reactions was developed, which could satisfactorily predict the LBVs of NH3/C2H4/air flames under current conditions. The analysis of reaction flux, sensitivity, and radical concentration in the pure and blended fuels provided deep kinetic insights. The consumption pathways of NH3 and C2H4 were di-versified after blending. NH2, an important precursor of ammonia oxidation, adds a consumption channel with HO2, whereas HCCO, an important intermediate of ethylene oxidation, adds new channels with NO. H + O 2 = OH + O , a chain branching reaction, significantly contributes to the LBVs of NH3/C2H4/air flames. The peak concentrations of H, O, and OH radicals increased as the C2H4 percentages increased. The relationship between the H radical concentration and blending ratio was virtually the same as that for the LBVs.(c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

关键词： Ammonia Ethylene Laminar burning velocity Flame instability Chemical kinetic model Kinetic analysis

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：