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Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN Kun WU xuejun fan Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling systems.In particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability phenomena.This study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain methods.As the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD phenomena.This also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing monotonically.Additionally,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable channel.After FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation excursion.The novel instability mode of oscillation excursion involves a spontaneous transition of operating states.It oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced redistribution.However,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

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Prognostics of radiation power degradation lifetime for ultraviolet light-emitting diodes using stochastic data-driven models

能源与人工智能(英文)

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能源与人工智能(英文) 2021年第2期4卷 91-100页

作者： Jiajie fan Zhou Jing Yixing Cao Mesfin Seid Ibrahim Min Li xuejun fan Guoqi Zhang Institute of Future Lighting Academy for Engineering&TechnologyFudan UniversityShanghai 200433China Shanghai Research Center for Silicon Carbide Power Devices Engineering&Technology Fudan UniversityShanghai 200433China College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022China EEMCS Faculty Delft University of TechnologyDelft 2628the Netherlands Changzhou Institute of Technology Research for Solid State Lighting Changzhou 213161China Department of Industrial and System Engineering The Hong Kong Polytechnic UniversityHung HomHong Kong Department of Mechanical Engineering Lamar UniversityBeaumontTX 77710USA

With their advantages of high efficiency,long lifetime,compact size and being free of mercury,ultraviolet light-emitting diodes(UV LEDs)are widely applied in disinfection and purification,photolithography,curing and biomedical devices.However,it is challenging to assess the reliability of UV LEDs based on the traditional life test or even the accelerated life test.In this paper,radiation power degradation modeling is proposed to estimate the lifetime of UV LEDs under both constant stress and step stress degradation tests.Stochastic data-driven predic-tions with both Gamma process and Wiener process methods are implemented,and the degradation mechanisms occurring under different aging conditions are also analyzed.The results show that,compared to least squares regression in the IESNA TM-21 industry standard recommended by the Illuminating Engineering Society of North America(IESNA),the proposed stochastic data-driven methods can predict the lifetime with high accuracy and narrow confidence intervals,which confirms that they provide more reliable information than the IESNA TM-21 standard with greater robustness.

关键词： Ultraviolet light-emitting diodes(UV LEDs) Degradation modeling Gamma process Wiener process IESNA TM-21

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HER3 intracellular domains play a crucial role in HER3/HER2 dimerization and activation of downstream signaling pathways

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Protein & Cell 2012年第10期3卷 781-789页

作者： Byung-Kwon Choi Xiumei Cai Bin Yuan Zhao Huang xuejun fan Hui Deng Ningyan Zhang Zhiqiang An Texas Therapeutics Institute Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science Center at HoustonHoustonTX 77030USA Department of Biochemistry and Molecular Biology Shanghai Medical CollegeFudan UniversityShanghai 200032China The Methodist Hospital Research Institute HoustonTX 77030USA

Dimerization among the EGFR family of tyrosine kinase receptors leads to allosteric activation of the kinase domains of the partners.Unlike other members in the family,the kinase domain of HER3 lacks key amino acid residues for catalytic activity.As a result,HER3 is suggested to serve as an allosteric activator of other EGFR family members which include EGFR,HER2 and HER4.To study the role of intracellular domains in HER3 dimerization and activation of downstream signaling pathways,we constructed HER3/HER2 chimeric receptors by replacing the HER3 kinase domain(HER3-2-3)or both the kinase domain and the C-terminal tail(HER3-2-2)with the HER2 counterparts and expressed the chimeric receptors in Chinese hamster ovary(CHO)cells.While over expression of the intact human HER3 transformed CHO cells with oncogenic properties such as AKT/ERK activation and increased proliferation and migration,CHO cells expressing the HER3-2-3 chimeric receptor showed significantly reduced HER3/HER2 dimerization and decreased phosphorylation of both AKT and ERK1/2 in the presence of neuregulin-1(NRG-1).In contrast,CHO cells expressing the HER3-2-2 chimeric receptor resulted in a total loss of downstream AKT activation in response to NRG-1,but maintained partial activation of ERK1/2.The results demonstrate that the intracellular domains play a crucial role in HER3’s function as an allosteric activator and its role in downstream signaling.

关键词： HER3 HER2 cell proliferation cell migration PI3K/AKT MAPK/ERK1/2

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Research on the Damage of Porosityand Permeabilitydue to Perforation on Sandstone in the Compaction Zone

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Computers, Materials & Continua 2016年第1期51卷 21-42页

作者： Shifeng Xue Xiuxing Zhu Lin Zhang Shenghu Zhu Guigen Ye xuejun fan Departmentof Engineering Mechanics China University of PetroleumQingdao 266580China Well Logging Company ShengliOil Engineering Co.Ltd.Dongying 257000China Schlumberger Drilling Dynamic Solution Beijing 100022China Department of Mechanical Engineering Lamar UniversityBeaumontTX 77710USA

A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore.During the process of perforating due to explosion,the surrounding sandstone will be damaged to a certain extent,which will increase the well bore skin and lead to the decrease of production consequently.In this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction zone.Based on this developed model,the important data related to the damage of sandstone,such as matrix effective stress,plastic deformation,volumetric strain,and so on,can be numerically simulated.Especially the behaviors of plasticity kinematic hardening at high strain rate due to impact loads,which are the important characteristics in the sandstone,is taken into account in this developed model.Both numerical and testing results show that the damage due to perforation in the sandstone can be accurately predicted by the developed model together with the porosity and permeability evolving model of perforation in a compaction zone.As a practical application,a methodology for the analysis of damage of porosity and permeability around a perforation tunnel is supposed based on the developed model and the core flow efficiency test of interparticle pore spaced sandstone target in China Shengli Oilfield and the computed tomography test.

关键词： zone. sandstone reservoir

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基于迭代隐式线性化的网状配电网潮流计算及其最优潮流模型

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中国电机工程学报 2024年第6期44卷 2197-2207,I0009页

作者：赵飞樊雪君李亚楼张健吴俊玲张文杰中国电力科学研究院有限公司北京市海淀区100192 中国电子信息产业集团有限公司第六研究所北京市昌平区102209 香港理工大学电机工程学系中国香港特别行政区九龙城区999077

随着分布式能源和储能容量的增加以及电动汽车的普及,配电网的功率流动由单向转变为双向,且网络拓扑由径向转变为复杂的网状结构。为了高效应对网状配电网的潮流(power flow,PF)分析和最优潮流(optimal power flow,OPF)问题,以及进一步... 详细信息

随着分布式能源和储能容量的增加以及电动汽车的普及,配电网的功率流动由单向转变为双向,且网络拓扑由径向转变为复杂的网状结构。为了高效应对网状配电网的潮流(power flow,PF)分析和最优潮流(optimal power flow,OPF)问题,以及进一步提升现有线性化模型的近似精度、完善对网络损耗等元素的线性近似,该文构建迭代隐式线性化潮流(iterative implicit linearization power flow,IIL-PF)模型及其最优潮流模型(IIL-OPF)。该模型将非线性潮流流形M(Manifold)视为节点电压和节点注入功率之间的隐式代数关系,之后利用切平面对M进行局部近似,并迭代更新线性化点以提高线性模型的近似精度。此外,所提模型充分考虑了支路始/末端潮流、支路潮流平方、支路损耗等因素,并对其进行明确的线性化推导。最后,基于修改的IEEE 33系统,分别在径向和网状运行方式下,验证所提模型可快速收敛,并具有较高的近似精度。其中IIL-PF计算结果、IIL-OPF的目标函数和发电机出力等优化结果与MATPOWER的非线性模型相比,误差均在1%以内,因此所提模型可以满足工程规划或日前运行模拟等应用要求。

关键词：配电网网状拓扑潮流计算最优潮流隐式线性化

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Effects of Vapor Pressure and Super-Hydrophobic Nanocomposite Coating on Microelectronics Reliability

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Engineering 2015年第3期1卷 384-390页

作者： xuejun fan Liangbiao Chen C.P.Wong Hsing-Wei Chu G.Q.Zhang Department of Mechanical Engineering Lamar University State Key Laboratory of Solid State Lighting School of Materials Science and Engineering Georgia Tech Delft University of Technology Institute of Semiconductors Chinese Academy of Sciences

Modeling vapor pressure is crucial for studying the moisture reliability of microelectronics, as high vapor pressure can cause device failures in environments with high temperature and humidity. To minimize the impact of vapor pressure, a super-hydrophobic(SH) coating can be applied on the exterior surface of devices in order to prevent moisture penetration. The underlying mechanism of SH coating for enhancing device reliability, however, is still not fully understood. In this paper, we present several existing theories for predicting vapor pressure within microelectronic materials. In addition, we discuss the mechanism and effectiveness of SH coating in preventing water vapor from entering a device, based on experimental results. Two theoretical models, a micro-mechanics-based whole-field vapor pressure model and a convection-diffusion model, are described for predicting vapor pressure. Both methods have been successfully used to explain experimental results on uncoated samples. However, when a device was coated with an SH nanocomposite, weight gain was still observed, likely due to vapor penetration through the SH surface. This phenomenon may cast doubt on the effectiveness of SH coatings in microelectronic devices. Based on current theories and the available experimental results, we conclude that it is necessary to develop a new theory to understand how water vapor penetrates through SH coatings and impacts the materials underneath. Such a theory could greatly improve microelectronics reliability.

关键词：纳米复合涂层微电子技术蒸汽压力超疏水性可靠性对流扩散模型设备故障微电子材料

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海上平台三甘醇脱水装置故障分析及工艺优化

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石油与天然气化工 2024年第1期53卷 14-19页

作者：范学君李巍李华山于同川华东阳孟嘉岩海洋石油工程股份有限公司

目的解决某海上平台三甘醇脱水装置无法达到脱水要求的问题。方法基于现场实际生产数据,采用HYSYS软件进行该工艺系统的模拟分析,找出该系统运行问题的原因。结果脱水塔入口天然气中水含量过高是影响脱水系统效果的主要因素,改造方案应... 详细信息

目的解决某海上平台三甘醇脱水装置无法达到脱水要求的问题。方法基于现场实际生产数据,采用HYSYS软件进行该工艺系统的模拟分析,找出该系统运行问题的原因。结果脱水塔入口天然气中水含量过高是影响脱水系统效果的主要因素,改造方案应考虑入口过滤分离器和重沸器改造两方面。结合平台实际情况,最终确定改造方案为更换入口过滤分离器滤芯与重沸器电加热器。改造后,在表压5.2 MPa下的干气水露点从6℃降至-23℃,达到预期效果,且为后续扩容预留了操作空间。结论该海上平台三甘醇脱水装置处理量无法达到设计值的原因可能是入口过滤分离器性能不达标导致脱水塔入口天然气中水含量过高,建议在进行三甘醇脱水装置工艺设计时,严控入口过滤分离器处理指标,并根据入口过滤分离器处理指标配套三甘醇脱水装置。

关键词：三甘醇脱水海上平台水露点干气过滤分离器 HYSYS

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超临界碳氢燃料流动不稳定的频域分析与数值模拟

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推进技术 2024年第1期45卷 165-173页

作者：靳一超吴坤陆阳范学军北京应用物理与计算数学研究所北京100094 中国科学院力学研究所高温气体动力学国家重点实验室北京100190 中国科学院大学工程科学学院北京100049

再生冷却通道中的流动失稳是高超声速飞行器发动机热防护技术中的核心问题之一。为研究超临界碳氢燃料在冷却通道中的流动不稳定特性,基于有限体积法及流体物性近似,发展了高效的一维瞬态模拟方法;同时,基于小扰动假设,进一步提出了用... 详细信息

再生冷却通道中的流动失稳是高超声速飞行器发动机热防护技术中的核心问题之一。为研究超临界碳氢燃料在冷却通道中的流动不稳定特性,基于有限体积法及流体物性近似,发展了高效的一维瞬态模拟方法;同时,基于小扰动假设,进一步提出了用于预测稳定行为的频域分析方法。通过相关实验,验证了模型的可靠性。基于时域和频域方法的综合分析,沿内特征曲线讨论了主要失稳类型,重点分析了受密度波及Ledinegg不稳定共同影响的复合不稳定性。随后,进一步分析了工作压力和入口温度对稳定特性的耦合影响,并基于N_(tpc)-N_(spc)空间划分了稳定区域。研究发现,复合不稳定、Ledinegg不稳定以及密度波不稳定,随入口温度升高而相继消失。Ledinegg不稳定及密度波不稳定的稳定边界在N_(tpc)-N_(spc)空间具有高度相似性,而复合不稳定性的区域在较高的压力下略有缩小。

关键词：再生冷却热防护碳氢燃料超临界流体流动不稳定瞬态模拟频域分析

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Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction:Efficient photodegradation of organic pollutant and toxicity evaluation

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Journal of Materials Science & Technology 2024年第3期170卷 200-211页

作者： Yanyan Zhao Xu fan Hongxing Zheng Enzhou Liu Jun fan xuejun Wang College of Biology Pharmacy and Food Engineering Shangluo UniversityShangluo 726000China QinLing-Bashan Mountains Bioresources Comprehensive Development C.I.C. Shaanxi University of TechnologyHanzhong 723001China School of Chemical Engineering Northwest UniversityXi’an 710069China

Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants degradation.This Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and growth.Mechanism study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,respectively.The improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation capability.Additionally,a S-scheme charge transfer mechanism including multiple charge transfer channels was proposed.This work could provide an effective strategy for organic pollutants degradation in wastewater.

关键词： Photocatalysis S-scheme heterojunction AgInS_(2) Bi_(2)WO_(6) Toxicity experiments

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Novel Approach for Quantitative Measurement of Matrix Metalloprotease-1 (MMP1) in Human Breast Cancer Cells Using Mass Spectrometry

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Journal of Analytical Sciences, Methods and Instrumentation 2013年第1期3卷 54-61页

作者： Ming Fa Kathleen Hoch xuejun fan William P. Dubinsky Zhiqiang An Ningyan Zhang Proteomics Center Brown Foundation Institute of Molecular Medicine The University of Texas Health Science Center at Houston Houston USA Proteomics Center Brown Foundation Institute of Molecular Medicine The University of Texas Health Science Center at Houston Houston USA. Texas Therapeutics Institute Houston USA

Identification and quantification of low abundance growth factors and regulators in complex biological samples still present a challenging task in analytical biochemistry. Immunoassays are often used for such purpose but immunoassays face limitation of both availability and qualities of antibody reagents that are necessary for development of immune assays. With genomics data base available, mass spectrometry (MS) can analyze protein tryptic peptides directly for quantitative determination of proteins. In this study, we report a method for detection of matrix metalloproteinase 1 (MMP1), an important extracellular matrix modulator, in human breast cancer cells by quadrupole time-of-flight (Q-TOF) MS. Absolute quantification of MMP1 was conducted using the selected reaction monitoring (SRM) on a triple quadrupole (Triple-Quad) MS via transitions selected from MMP1 tryptic peptides using non isotope labeled MMP1 protein as a titration standard. In comparison with immune based assay, this MS method showed picogram level sensitivity for quantitative determination of MMP1 intotal cell lysates. Our results demonstrated the feasibility of absolute quantification of low abundance proteins using label-free protein standard by mass spectrometry. Therefore, this method provides not only advantages of high sensitivity but also cost saving in comparison with the commonly used mass spectrometry that currently employs isotype labeled proteins for quantitative analysis.

关键词： Matrix Metalloprotease-1 (MMP1) SKBR3 Breast Cancer Cells Mass Spectrometry Selected Reaction Monitoring Absolute Quantification

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