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Behavior of Nb influence on structure and properties of 30Cr13 cast martensitic stainless steel

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Journal of Iron and Steel Research International 2019年第5期26卷 462-471页

作者： Yang-fan jin Tuo Zhang Qi-yu Zang Yi-tao Yang School of Materials Science and Engineering Shanghai University Shanghai 200444 China

The microstructure, mechanical properties and corrosion resistance of 30Cr13 martensitic stainless steel (MSS) with different Nb contents were investigated by using the optical microscope, scanning electron microscope, X-ray diffractometer, HRC hardness measurement apparatus and tensile testing machine. Nb was found to retard the formation of austenite and promote the precipitation of carbides by calculating. The results showed that the addition of 0.2 wt.% Nb elements could improve the strength and corrosion resistance of 30Cr13 martensitic stainless steels while the reduction in toughness was less because of the inhibited effect on Cr-rich carbides precipitation by Nb addition. Specially, M23C6-type carbides almost disappeared in 0.6Nb-MSS. Moreover, the main existent form of Nb element was NbC and the strong carbide-forming ability of Nb element increased the quantity of carbides with the morphology changing from sphericaltype to chain-type. 0.2Nb-MSS shows excellent strength, adequate toughness and sufficient corrosion resistance for the application.

关键词： Niobium addition Martensitic stainless steel Microstructure Mechanical property Corrosion resistance

A MODIFIED LEVENBERG-MARQUARDT ALGORITHM FOR SINGULAR SYSTEM OF NONLINEAR EQUATIONS

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Journal of Computational Mathematics 2003年第5期21卷 625-636页

作者： jin-yan fan (Department of Mathematics, Shanghai Jiaotong University, Shanghai 200240, China) Department of Mathematics Shanghai Jiaotong University 上海 200240

Based on the work of paper [1], we propose a modified Levenberg-Marquardt algoithm for solving singular system of nonlinear equations F(x) = 0, where F(x) : Rn - Rn is continuously differentiable and F'(x) is Lipschitz continuous. The algorithm is equivalent to a trust region algorithm in some sense, and the global convergence result is given. The sequence generated by the algorithm converges to the solution quadratically, if ||F(x)||2 provides a local error bound for the system of nonlinear equations. Numerical results show that the algorithm performs well.

关键词： Singular nonlinear equations Levenberg-Marquardt method Trust region al- gorithm Quadratic convergence.

Relationship between dynamic characteristics of air film of aerostatic spindle and mid-frequency of surface topography

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Advances in Manufacturing 2022年第3期10卷 428-442页

作者： Dong-Ju Chen Shu-Pei Li Xuan Zhang jin-Wei fan Mechanical Industry Key Laboratory of Heavy Machine Tool Digital Design and Testing Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124People's Republic of China

The dynamic characteristics of the gas film of an aerostatic spindle primary affect workpiece waviness in ultra-precision *** improve the machining accuracy of the machine tool and provide a firm theoretical basis for the design of an aerostatic spindle,a simulation model combining transient computational fluid dynamics(CFD)analysis and transient dynamic analysis is established in this study to investigate the dynamic characteristics of the spindle under unstable operating *** on a large eddy simulation,a three-dimensional flow model of an air film in an aerostatic spindle is *** simulation results show that the gas flow in the throttle chamber is turbulent,and that complex vortices are *** dynamic grid modeling technology,a CFD numerical model for the unsteady calculation of the spindle is established,and the dynamic characteristics of the gas film are obtained.A transient dynamic simulation model of an aerostatic spindle is established,and the effect of the nonlinear dynamic characteristics of the gas film on the spindle displacement response is ***,a surface morphology prediction model is *** show that film fluctuation significantly affects the dynamic characteristics of the spindle and subsequently affects the generation of surface ripples on the workpiece.

关键词： Dynamic characteristics Aerostatic spindle Surface formation Ultra-precision flying cutting

Cathodic electrolyte engineering toward durable Zn–Mn aqueous batteries

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National Science Review 2023年第12期10卷 42-44页

作者： Wanhai Zhou Hong jin fan Dongyuan Zhao Dongliang Chao Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials Fudan University School of Physical and Mathematical Sciences Nanyang Technological University

Zn–Mn aqueous batteries (ZMABs)present potential for grid-scale energy storage with the benefits of low cost,high safety and eco-friendliness [1].Since 1866 (Leclanchéwet cell), we have witnessed the prosperity of Z... 详细信息

关键词： CHEMISTRY

Solidification of loess using microbial induced carbonate precipitation

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Journal of Mountain Science 2021年第1期18卷 265-274页

作者： LIU Xiao-jun fan jin-yue YU jing GAO Xin Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering College of Civil EngineeringXi'an University of Architecture and TechnologyXi'an 710055China College of Civil Engineering Xi'an University of Architecture and TechnologyXi'an 710055China

Microbial-induced carbonate precipitation(MICP)is a relatively innovative and environmentally-friendly soil reinforcement technology,primarily used on sand,but its application in loess has rarely been *** paper explores the viability of the MICP technique for improving the engineering properties of typical *** pasteurii was used to trigger carbonate *** such as reaction temperature,p H of the media,and the inoculation ratio were adopted to determine the optimum *** concentrations of Sporosarcina pasteurii and cementation reagent were selected for combination to treat the loess samples with a selfdesigned vacuum test *** unconfined compressive strength and calcium carbonate content of the treated samples were tested and Scanning Electron Microscopy(SEM)was carried out to evaluate the improving *** results showed that the optimum conditions are reaction temperature of 30℃,p H of the media of 9,a higher inoculation ratio can produce higher enzyme activity and monomer enzyme *** engineering properties of the MICP-treated loess are significantly *** obtained unconfined compressive strength increases nearly 4 times when the OD600 is 1.5 and cementation reagent concentration is 1 mol/*** test results of calcium carbonate content are consistent with unconfined compressive ***,the microstructure of loess samples was quantitatively analyzed by Pore(Particle)and cracks analysis system(PCAS).It was showed that MICP has a great influence on the surface porosity,followed by the pore fractal dimension and the probability entropy,but has little influence on the pore average form factor.

关键词： Loess solidification MICP Unconfined compressivestrength Calciumcarbonate Microstructure

Identification and functional analyses of a novel FOXL2 pathogenic variant causing blepharophimosis, ptosis, and epicanthus inversus syndrome

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International Journal of Ophthalmology(English edition) 2023年第5期16卷 680-686页

作者： Yu-Cheng Yan Lu Zhou jin-Cai fan Plastic Surgery Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100041China

AIM: To discover the molecular pathogenic basis of the blepharophimosis, ptosis, and epicanthus inversus syndrome(BPES), and to predict the clinical subtype according to in vitro experiments, which is significant to the ***: A 3-year-old sporadic female patient with typical clinical manifestations of BPES was enrolled. The coding region of forkhead box L2(FOXL2) gene was sequenced, and the functional assays were performed in vitro by Western blotting, subcellular localization experiment, luciferase reporter assay, and quantitative realtime polymerase chain ***: A novel FOXL2 point pathogenic variant(c.274G>T) was detected, resulting in a truncated protein(p.E92*). Functional studies demonstrated that the FOXL2 pathogenic variant induced the subcellular mislocalization and the abnormal transcriptional activity on promoters of the steroidogenic acute regulatory protein(StAR or STARD1) gene and the odd-skipped related 2 transcription factor(OSR2) ***: A novel pathogenic variant is identified to expand the spectrum of the known FOXL2 mutations. The in vitro experiments provide reference data and more insights to the molecular pathogenesis of BPES. The predicted high risk of ovarian insufficiency makes it significant for the patient enrolled to have further follow-up and therapy concerning female endocrinology.

关键词： novel mutation pathogenic variant blepharophimosis-ptosis-epicanthus inversus syndrome FOXL2

木犀草素对反复尿路感染大鼠模型尿路上皮屏障的影响

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中华医院感染学杂志 2024年第11期34卷 1658-1662页

作者：樊进军吕中一于宪芹许娟刘国业济南市第二妇幼保健院检验科山东济南271100 济南市人民医院检验科山东济南271100 济南市第二妇幼保健院妇产科山东济南271100

目的探究木犀草素对反复尿路感染大鼠模型尿路上皮屏障的影响.方法选取SPF级SD雌性大鼠45只,其中空白组、模型组、低剂量组、高剂量组各10只;空白组、模型组只进行生理盐水灌胃,不做其他任何处理,低剂量组在模型组的基础上给予木犀草素1... 详细信息

目的探究木犀草素对反复尿路感染大鼠模型尿路上皮屏障的影响.方法选取SPF级SD雌性大鼠45只,其中空白组、模型组、低剂量组、高剂量组各10只;空白组、模型组只进行生理盐水灌胃,不做其他任何处理,低剂量组在模型组的基础上给予木犀草素10 mg/kg灌胃,高剂量组给予40 mg/kg灌胃;检测尿量、尿白细胞水平、炎症因子、分泌型免疫球蛋白A(SIgA)、尿乙酰氨基葡萄糖苷酶(NAG)水平、尿路上皮屏障功能情况及Toll样受体4/核转录因子-κB(TLR4/NF-κB)信号通路相对表达量.结果与空白组比较,模型组、低剂量组、高剂量组尿量情况、E黏钙蛋白(E-cadherin)、闭合小带蛋白-1(ZO-1)水平降低,尿白细胞、白细胞介素-6(IL-6)、IL-8、SIg A、NAG水平、TLR4、NF-κB相对表达量均升高(P<0.05);与模型组相比,低剂量组、高剂量组,尿量、E-cad-herin、ZO-1水平升高,尿白细胞、IL-6、IL-8、SIgA、NAG、TLR4、NF-κB相对表达量均降低(P<0.05);与低剂量组比较,高剂量组尿量、E-cadherin、ZO-1水平升高,尿白细胞、IL-6、IL-8、SIgA、NAG、TLR4、NF-κB相对表达量均降低(P<0.05).结论木犀草素能对反复尿路感染大鼠尿路上皮屏障情况进行改善,减轻炎症情况,提高排尿功能,调节免疫功能,通过调节TLR4/NF-κB信号通路能反映出对反复尿路感染的干预效果.

关键词：反复尿路感染木犀草素尿路上皮屏障 Toll样受体4/核因子-κB 分泌型免疫球蛋白A 尿乙酰氨基葡萄糖苷酶炎症因子

Determination of methylene blue by resonance light scattering method using silica nanoparticles as probe

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Chinese Chemical Letters 2017年第5期28卷 1104-1110页

作者： jin fan Zhi-Hai Xie Xiao-Xiao Teng Yu Zhang Key Laboratory of Synthetic&Natural Functional Molecular Chemistry of The Ministry of Education College of Chemistry&Material ScienceNorthwest UniversityXi'an 710127China

A simple and novel method was developed to determine methylene blue（MB） by resonance light scattering（RLS） using silica nanoparticles（SiO2NPs） as the *** was found that MB could enhance the RLS intensity of ***,the increase in RLS intensity was linear with the concentration of MB over the range of 0.01-3.0 μg mL^-*** limit of detection（LOD） was as low as 4.36 ng mL^-1（3σ） and the relative standard deviation（RSD） was 2.4%（n=6）.Under the optimum experimental conditions,this proposed method was successfully applied for the determination of MB in aquaculture samples with recoveries between 96.3% and 107%.Possible mechanisms for the RLS enhancement of SiO2NPs in the presence of MB were also discussed.

关键词： Methylene blue Silica nanoparticles Aggregation Resonance light scattering Determination

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

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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 *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** 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 *** 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 *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,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 *** 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 *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,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