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Editorial

International Journal of Hydrogen Energy 2013年第29期38卷 12878-12878页

作者： Liejin Guo International Center for Renewable Energy Center & State Key Laboratory of Multiphase Flow in Power Engineering China

For many centuries, each generation gave to their offspring the same World that they received from their parents. The water in the rivers, seas, and oceans was clear; the forests were free to grow; and nature was empty of garbage. But everything has changed in just the last 250 years: year by year, while standards-of living increased, the Earth became a worse place for living, with less natural resources and more pollution.

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Effects of velocity ratio on turbulent mixing layer at high Reynolds number

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Journal of Physics: Conference Series 2009年第1期147卷

作者： Fude Guo Bin Chen Liejin Guo Ximin Zhang State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

In this paper the effect of velocity ratio on plane mixing layer was experimentally investigated by Particle Image Velocimetry (PIV). The velocity ratio between low and high speed side are 0.25 and 0.50, respectively. The Reynolds number based on the velocity difference of two streams and hydraulic diameter of the channel is 66000. The results indicate that the maximum mean Reynolds stress on the same cross section is decreasing with the velocity ratio increasing. The maximum dimensionless mean vorticity is decreasing according to an exponential law along the stream-wise direction and the decreasing speed of dimensionless mean maximum vorticity is increasing with the velocity ratio increasing. The dimensionless vorticity caused by plate wake is decreasing sharply in a very short distance along the down stream wise direction and the decreasing speed is faster when the velocity ratio is larger.

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Drop deformation and breakup with diffuse interface method

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AIP Conference Proceedings 2010年第1期1207卷

作者： S. L. Chen C. Z. Lin L. J. Guo Y. S. Wang State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710049 China

Two‐dimensional numerical simulation of the deformation and breakup of an isolated liquid drop suspended in immiscible viscous fluid under shear flow was performed with the diffuse interface method. The governing equations of the model were described by Navier—Stokes—Cahn—Hilliard equations. The surface tension was treated as a modified stress. In the paper, the critical Capillary number was plotted as a function of viscosity ratios with the method of approximation. Besides, From the numerical observations, the breakup of the droplets occurred by three mechanisms, namely, necking, end pinching, and capillary instability. Quantitative results for the deformation and breakup of drop are presented.

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PIV measurement of turbulent mixing layer flow with polymer additives

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Journal of Physics: Conference Series 2009年第1期147卷

作者： T Ning F Guo B Chen X Zhang State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an 710049 China

Turbulent mixing layer flow with polymer additives was experimentally investigated by PIV in present paper. The velocity ratio between high and low speed is 4:1 and the Reynolds number for pure water case based on the velocity differences of two steams and hydraulic diameter of the channel ranges from 14667~73333. flow field and turbulent quantities of turbulent mixing layer with 200ppm polymer additives were measured and compared with pure water mixing layer flow. It is shown that the dynamic development of mixing layer is greatly influenced by polymer addictives. The smaller vortices are eliminated and the coherent structure is much clearer. Similar with pure water case, Reynolds stress and vorticity still concentrate in a coniform area of central part of mixing layer and the width will increase with the Reynolds number increasing. However, compared with pure water case, the coniform width of polymer additives case is larger, which means the polymer additives will lead to the diffusion of coherent structure. The peak value of vorticity in different cross section will decrease with the development of mixing layer. Compared with pure water case, the vorticity is larger at the beginning of the mixing layer but decreases faster in the case with polymer additives.

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

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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)

Driving with Clean Footprint: Biodiesel Application and Sustainable Development of the Transportation Sector in China

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SSRN 2024年

作者： Chen, Chuangbin Deng, Chenchen Zhang, Bo Yang, Song Centre for Southeast Asia Studies Shantou University Guangdong Shantou City515063 China Jinhe Center for Economic Research Xi’an Jiaotong University Xianning West Road Shaanxi Xi’an710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Shaanxi 710049 China

The advancement of global endeavors to mitigate climate change significantly hinges upon developments within China's transportation sector. This study presents a pioneering examination of the pivotal role of biodiesel as a renewable energy source, accentuating its substantial contributions to China's ambitious objectives of attaining carbon neutrality and reaching the peak of carbon dioxide emissions. Employing the Long-range Energy Alternative Planning System, we formulate five distinct scenarios encompassing the prevailing trend, the promotion of B5 (5% biodiesel blend) and B10 (10% biodiesel blend), China's existing policy framework, policies embraced by the European Union, as well as alternative biofuels. Our analysis reveals that all scenarios exhibit varying degrees of CO2 emissions reduction by the year 2040. The third scenario, driven by China's informal environmental participation, tax incentives, and supportive policies, yields noteworthy outcomes, albeit less substantial in comparison to the EU policy scenario. The B5-B10 scenario presents a more significant reduction in CO2 emissions, although it proves to be less effective in addressing other pollutant emissions in contrast to the alternative biofuel scenario. Furthermore, the adoption of B5-B10 fuels also carries significant economic advantages, with projected emissions reductions amounting to 1.17 trillion yuan (approximately 0.17 trillion dollars) by 2030. Overall, our findings underscore the global implications of China’s low-carbon transportation strategy. The mutually advantageous interactions between formal environmental policies, informal public engagement, and lessons derived from the European Union's policies collectively shape the sustainable development of China's transportation sector. © 2024, The Authors. All rights reserved.

关键词： Sustainable development

Investigations of Sodium Droplet Spreading and Evaporation on Surfaces with Different Wettability Based on Lattice Boltzmann Simulations

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SSRN 2024年

作者： Tang, Songsheng Guo, Kailun Tian, Zhixing Wang, Mingjun Wang, Chenglong He, Xiaoqiang Su, Guanghui Qiu, Suizheng Tian, Wenxi School of Nuclear Science and Technology State Key Lab. of Multiphase Flow in Power Engineering Shaanxi Key Lab. of Advanced Nuclear Energy and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China Key Lab. of Nuclear Reactor System Design Technology China Nuclear Power Research and Design Institute Chengdu610213 China

The spreading and evaporation of sodium droplets is one of the fundamental phenomena in high-temperature heat pipes. The LBM sodium two-phase flow and phase transition model, which can simulate a huge liquid-vapor density ratio, is first established and validated. Then, the spreading and evaporation processes of sodium droplets on solid walls with different wettability are numerically simulated and analyzed. The main conclusions obtained are as follows: (1) The dimensionless spreading diameter and time of the droplet spreading process conforms to Tanner's power law, and the power exponent has exponential relationship with the equilibrium wetting angle;(2) The maximum dimensionless spreading diameter is negatively and linearly correlated with the equilibrium wetting angle;(3) Evaporation of sodium droplets under constant heat flow conditions shows a mixed pattern. The droplets will be detached from the droplet wall at the late stage of evaporation, and the larger the equilibrium wetting angle the sooner the droplets detach. © 2024, The Authors. All rights reserved.

关键词： Evaporation

Integrated analysis of lncRNAs expression profiling in systemic lupus erythematosus

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Rheumatology & Autoimmunity 2024年第2期4卷 119-121页

作者： Fen Zhang Guifang Zhao Yujie Bu Xing Cen Rong Zhao Fengwu Chen Shengxiao Zhang Junwei Chen Department of Rheumatology The Second Hospital of Shanxi Medical UniversityTaiyuanShanxiChina State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'anShaanxiChina

To the Editor,Systemic lupus erythematosus(SLE)is a chronic autoimmune disease with serious harm to human health and various clinical manifestations,which is characterized by over-activity of lymphocytes,production of autoantibodies,and effects on multiple organs.1 So far,the pathogenesis of SLE remains unclear;it is believed that genetic,environmental,infectious,and other factors participate in the pathogenesis of *** the gradual in-depth study of transcriptomics,genetic factors may be the root cause of SLE,2 and epigenetics plays an important role in genetic factors of SLE.3 Epigenetics means heritable changes in gene expression without shifting the DNA *** principal mechanisms of epigenetic regulation include histone modification,DNA methylation,and regulation of noncoding *** the past,studies of transcriptomics mainly focused on protein-coding ***,protein-coding genes that encode exons account for 1.5%of the genome,and genes without protein-coding capability account for more than 80%of the human genome.4 Therefore,studies of transcriptomics began to pay attention to long noncoding RNAs(lncRNAs),which play key roles in transcription control,posttranscriptional processing,protein metabolism,immune cell differentiation,and immune responses.5 However,knowledge of related lncRNAs in SLE remains limited.

关键词： lupus erythematosus organs

Spatial Heterogeneity of Point Defect Properties in Refractory Multi-Principal Element Alloy with Short-Range Order: A First-Principles Study

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SSRN 2022年

作者： Shi, Tan Lyu, Sixin Su, Zhengxiong Wang, Yunpeng Qiu, Xi Sun, Dan Xin, Yong Li, Wenjie Cao, Jiang Peng, Qing Li, Yuanming Lu, Chenyang School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China School of Electronic and Optical Engineering Nanjing University of Science and Technology Nanjing210094 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing100190 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China

The short-range order is inherently present in the multi-principal element alloys and has a profound impact on the defect behaviour. The effect of short-range order on vacancy and interstitial formation and migration was studied in body-centered cubic multi-principal element alloy NbZrTi by first-principles calculations. Two short-range order structures created by density functional theory and Monte Carlo method at 500 K and 800 K were compared with the random solid solution structure. Both vacancy and interstitial formation energies increase with the degree of short-range order. Point defect formation energies tend to be higher in region enriched in Nb and lower in region enriched in Zr and Ti. Both vacancies and interstitials prefer to migrate towards Zr,Ti-rich regions and away from Nb-rich regions, suggesting that Zr,Ti-rich region can act as recombination center for point defect annihilation. Compared to the random solid solution, the short-range order increases the spatial heterogeneity of point defect energy landscape. Tuning the degree of short-range order can be a viable strategy to optimize the point defect behaviour to achieve enhanced radiation resistance in multi-principal element alloys. © 2022, The Authors. All rights reserved.

关键词： Monte Carlo methods