检索结果-内蒙古大学图书馆

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

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

作者： Wen Cao Xuan Wei Jiyan Lu Mengyao Li Jiali Feng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 Shaanxi PR China College of Biology and Oceanography Weifang University Weifang 261061 Shandong PR China Weifang Municipal Key Laboratory of Agricultural Planting Quantization and Application Weifang 261061 Shandong PR 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 (OD 660 ) 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.

关键词：

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

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

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

Uncertainty Analysis of FLiNaK Thermophysical Properties on Convective Heat Transfer Characteristics in Circular Tube

SSRN

引用

SSRN 2024年

作者： Li, Haoyang Ding, Ming Guo, Zehua Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China 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

Molten salts have attracted a spate of quantity of interest in energy and chemistry fields due to their large volumetric capacity, and thermodynamic stability at elevated temperatures. However, on account of immature technology and measurement methods, the physical properties of molten salts, such as dynamic viscosity, thermal conductivity, specific heat capacity and density, have large uncertainties, which will be transported with CFD simulation equations and experimental processes. While present investigations normally focus on thermal-hydraulic characteristics, disregarding the impact of uncertainty on reactor safety. Thus, this paper firstly performs a numerical simulation to investigate the thermal-hydraulic performance of FLiNaK (LiF-NaF-KF, 46.5–11.5–42 mol%) in a horizontal tube using a computational fluid dynamic (CFD) tool, STAR-CCM+, and validates the applicability of classic correlations for molten salt. Based on this, an uncertainty analysis methodology, polynomial chaos expansion (PCE) is carried out to analyze the uncertainty that contributes to the heat transfer characteristic. Three primary physical properties of molten salt are considered as the input parameter, tensor product quadrature nodes are employed in this work to calculate the representative sample points to alleviate the computational expense. The contributions of each parameter to heat transfer are also analyzed by the sobol composition method. Finally, deviations in the experimental post-processing (compared with classic correlations) caused by discrepancies in the selected properties from the actual properties due to uncertainty are also taken into account. The result shows the thermal-hydraulic performance can be nicely modeled and simulated results are in good agreement with widely used correlations. Meanwhile, the consequences of uncertainty analysis suggest that the polynomial chaos expansion methodology is robust and neoteric for molten salt analysis. © 2024, The Authors. All righ

关键词： Uncertainty analysis

来源：评论

学校读者我要写书评

暂无评论

Digital twin modeling and fault diagnosis on the feedwater pump system of thermal power plant

Digital twin modeling and fault diagnosis on the feedwater p...

引用

Digital Twins and Parallel Intelligence (DTPI), IEEE International Conference on

作者： Yugang Liu Chi Luo Chen Chen Zhu Wang Ming Liu Clean Combustion and Flue Gas Purification Key Laboratory of Sichuan Province Dongfang Boiler Co. Ltd Chengdu China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

ISBN: (数字)9798350349252

ISBN: (纸本)9798350349269

The high penetration of renewable energy introduces increased volatility into the power system, presenting more challenging peak shaving and frequency modulation missions for thermal power plants that serve as schedulable power sources within the system. Frequent load cycling place higher demands on the operation stability of core power plant equipment and introduce additional safety risks. As the core system of the power cycle, the operational reliability and energy efficiency of the feedwater pump system (FPS) are crucial. Therefore, this paper focuses on the core equipment and parameters of the FPS, developing a digital twin model based on mechanism modeling method and neural network data-driven modeling method. By comparing the mean absolute error, root mean square error, and coefficient of determination of simulation parameters of different modeling methods, digital twin parameters with higher simulation accuracy were obtained. Utilizing these predicted parameters, an FPS fault diagnosis model (FFDM) for the FPS was developed. By calculating comprehensive deviation degree and the contribution of each parameter, fault early warning and source tracing were achieved, providing guidance for the closed-loop control.

关键词： Fault diagnosis Data-driven modeling Neural networks Predictive models power system stability Energy efficiency Digital twins Safety power system reliability power generation

来源：评论

学校读者我要写书评

暂无评论

Understanding the Reversal Dilution Effect of the Species Sampling in the Negative Temperature Coefficient Region

SSRN

引用

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

Study on the Three-Dimensional flow Control of Two-Phase flow Around a Cylinder by an Attached Cylinder

SSRN

引用

SSRN 2023年

作者： Xia, Yizhan Hu, Yu Huang, Shengxian Wang, Ying Shanghai key laboratory of multiphase flow and heat transfer of power engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai China

Enhancing the separation of flow, shedding of vortices, and sediment deposition around blunt bodies, particularly in cylindrical flows within the realm of ocean engineering, emerges as a pivotal safety factor. This study delves into the control of two-phase flow encircling a cylinder using an affixed cylinder under three-dimensional real ocean conditions. Employing the SST turbulence model, a two-dimensional incompressible RANS numerical simulation is performed. Initially, the influence of varying gap ratios between the auxiliary small cylinder and the main cylinder is scrutinized. Subsequently, the impact of attached small cylinders on the flow field surrounding the main cylinder is examined under different particle characteristics. Lastly, employing the UDF function, four small cylinders exhibiting distinct vibration modes are defined, and the numerical simulation investigates the effects of Grain flow on particle flow and distribution in the wake region of the main cylinder. © 2023, The Authors. All rights reserved.

关键词： Cylinders (shapes)

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

Electron-Deficient Zn-N_(6) Configuration Enabling Polymeric Carbon Nitride for Visible-Light Photocatalytic Overall Water Splitting

引用

Nano-Micro Letters 2022年第12期14卷 602-616页

作者： Daming Zhao Yiqing Wang Chung-Li Dong Fanqi Meng Yu-Cheng Huang Qinghua Zhang Lin Gu Lan Liu Shaohua Shen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022People’s Republic of China Department of Physics Tamkang UniversityNew Taipei City 25137TaiwanPeople’s Republic of China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190People’s Republic of China

Despite of suitable band structures for harvesting solar light and driving water redox reactions,polymeric carbon nitride(PCN)has suffered from poor charge transfer ability and sluggish surface reaction kinetics,which limit its photocatalytic activity for water ***,atomically dispersed Zn-coordinated three-dimensional(3D)sponge-like PCN(Zn-PCN)is synthesized through a novel intermediate coordination *** characterizations and theoretical calculations well evidence that Zn single atoms are coordinated and stabilized on PCN in the form of Zn-N_(6) configura-tion featured with an electron-deficient *** an electronic configuration has been demonstrated contributive to promoted electron excitation,accelerated charge separation and transfer as well as reduced water redox *** benefited from the abundant surface active sites derived from the 3D porous structure,Zn-PCN realizes visible-light photocatalysis for overall water splitting with H_(2) and O_(2) simultaneously evolved at a stoichiometric ratio of 2:*** work brings new insights into the design of novel single-atom photocatalysts by deepening the understanding of electronic configurations and reactive sites favorable to excellent photocatalysis for water splitting and related solar energy conversion reactions.

关键词： Zn single atoms Polymeric carbon nitride Overall water splitting Photocatalysis

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：