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Particuology 2019年第2期17卷 46-55页

作者： Shuyuan Liu Tat leung Chan Huijie Liu Department of mechanical Engineering The Hong Kong Polytechnic University Kowloon Hong Kong China

The bimodal Taylor expa nsion method of moments (B-TEmOm) model scheme was developed to simulate the formation and evolution of vehicle exhaust particles. Two independent types of log-normal particle size distributions were selected in the B-TEmOm model scheme, comprising large and small particles to represent background (i.e., the surrounding environment) and vehicle exhaust particles, respectively. Concentration distributions of exhaust and background particles derived using this model scheme were verified against results from a moving secti onal method and the bimodal quadrature method of moments, showing excellent agreement. The effects of vehicle tailpipe ex 让 cond 让 ions (e.g., exhaust particle concentrations and velocity), sulfurcontent, and relative humidity on the evoluti on of particles were investigated numerically. Both two-dimensional and three-dimensional numerical simulations showed that tailpipe exit velocity and relative humid让y did not greatly affect the steady-state concentrations or the diameters of particles in urban atmospheres. Although an increase in sulfur content had little effect on the particle concentration, it led to background particles with larger geometric average diameter entering the environment. This coupled CFD-B-TEmOm numerical model provides a simple but accurate and efficient method for studying bimodal aerosol dynamics.

关键词： Vehicle exhaust particles Bimodal Taylor expansi on method of moments Homogeneous nucleation Coagulation Tailpipe exit velocity Sulfur content and ambient relative humidity

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光纤光栅腐蚀传感器

光子学报 2006年第1期35卷 96-99页

作者：江毅严云 Christopher K.y.leung 北京理工大学信息学院光电子研究所北京100081 西南科技大学材料科学与工程学院绵阳621010 香港科技大学土木工程系

提出了一种测量钢筋腐蚀的新型传感器·这种传感器将光纤光栅拉伸后固定在圆形钢筋的表面,在钢筋被腐蚀后,光纤光栅所受到的拉伸应变将被释放,光纤光栅的反射光波长发生变化,通过测量光纤光栅的波长就可以测得钢筋腐蚀程度·这种传感器... 详细信息

提出了一种测量钢筋腐蚀的新型传感器·这种传感器将光纤光栅拉伸后固定在圆形钢筋的表面,在钢筋被腐蚀后,光纤光栅所受到的拉伸应变将被释放,光纤光栅的反射光波长发生变化,通过测量光纤光栅的波长就可以测得钢筋腐蚀程度·这种传感器测量准确度优于±0.1μm,测量范围约12μm,可用于混凝土结构中钢筋腐蚀的早期监测·

关键词：光纤光栅光纤传感器腐蚀

Regrowth and neuronal protection are key for mammalian hibernation:roles for metabolic suppression

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Neural Regeneration Research 2020年第11期15卷 2027-2028页

作者： Samantha m.Logan kenneth B.Storey Institute of Biochemistry Departments of Biology and ChemistryCarleton UniversityOttawaONCanada

Thought experiment:you're starving,huddled in the fetal position in a hole in the ground,with no sense of the world around you,except that you are really,really *** fact,your internal temperature can go as low as–2.9... 详细信息

关键词： really fetal suppression

Gaussian Beam Summation for Diffraction in Inhomogeneous media Based on the Grid Based Particle method

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Communications in Computational Physics 2010年第9期8卷 758-796页

作者： Shingyu leung Hongkai Zhao Department of mathematics Hong Kong University of Science and TechnologyClear Water BayHong Kong Department of mathematics University of California at IrvineIrvineCA 92697-3875USA

We develop an efficient numerical method to compute single slit or double slit diffraction patterns from high frequency wave in inhomogeneous *** approximate the high frequency asymptotic solution to the Helmholtz equation using the Eulerian Gaussian beam summation proposed in[20,21].The emitted rays from a slit are embedded in the phase space using an open *** evolution of this open curve is accurately computed using the recently developed Grid Based Particle method[24]which results in a very efficient computational *** the grid based particle method we proposed in[23,24],we represent the open curve or the open surface by meshless Lagrangian particles sampled according to an underlying fixed Eulerian *** end-points of the open curve are tracked explicitly and consistently with interior *** construct the overall wavefield,each of these sampling particles also carry necessary quantities that are obtained by solving advection-reaction *** experiments show that the resulting method can model diffraction patterns in inhomogeneous media accurately,even in the occurrence of caustics.

关键词： Dynamic interface Gaussian beams diffraction high frequency asymptotic solution

Comparison of reflux esophagitis and its complications between African Americans and non-Hispanic whites

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World Journal of Gastroenterology 2009年第23期15卷 2878-2881页

作者： kenneth J Vega Sian Chisholm m mazen Jamal Divisions of Gastroenterology and General Internal medicine University of Florida Health Sciences Center Jacksonville Florida 32207 United States Gastroenterology Section Veterans Affairs Medical Center 5901 E. 7th St. Long Beach CA 90822 United States

AIm: To determine the effect of ethnicity on the severity of reflux esophagitis (RE) and its complications. mETHODS: A retrospective search of the endoscopy database at the University of Florida Health Science Center/Jacksonville for all cases of reflux esophagitis and its complications from January 1 to march 31, 2001 was performed. Inclusion criteria were endoscopic evidence of esophagitis using the LA classif ication, reflux related complications and self-reported ethnicity. The data obtained included esophagitis grade, presence of a hiatal hernia, esophageal ulcer, stricture and Barrett's esophagus, and endoscopy indication. RESULTS: The search identified 259 patients with RE or its complications, of which 171 were non-Hispanic whites and 88 were African Americans. The mean ages and male/female ratios were similar in the two groups. RE grade, esophageal ulcer, stricture and hiatal hernia frequency were likewise similar in the groups. Barrett's esophagus was present more often in non-Hispanic whites than in African Americans (15.8% vs 4.5%; P more frequent indication for endoscopy in non-Hispanic whites with erosive esophagitis than in African Americans (28.1% vs 7.9%; P y of reflux-related esophageal ulcer, stricture andhiatal hernia are similar in non-Hispanic whites and African Americans. Heartburn was more frequently and nausea/vomiting less frequently reported as the primary endoscopic indication in non-Hispanic whites compared with African Americans with erosive esophagitis or its complications. African Americans have a decreased prevalence of Barrett's esophagus compared with non-Hispanic whites.

关键词： Reflux esophagitis African American Hiatal hernia Barrett's esophagus

Immunomodulatory Effects of Esculetin(6,7-Dihydroxycoumarin)on murine Lymphocytes and Peritoneal macrophages

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Cellular & molecular Immunology 2005年第3期2卷 181-188页

作者： Kwok-nam leung Dr.Kwok-nam leung Pui-yinleung Lai-pingKong Po-kileung Department of Biochemistry The Chinese University of Hong KongShatinHong KongChina Corresponding Department of Biochemistry The Chinese University of Hong KongShatinHong KongChina.

Coumarins belong to a diverse group of naturally occurring non-nutrient phytochemicals known as benzo-α- pyrones. In this study, esculetin, a 6,7-dihydroxy derivative of coumarin with pleiotropic biological activities, was found to have no significant cytotoxic effect on normal murine macrophages, but it could increase the in vivo migration of the thioglycollate-elicited macrophages in a dose-dependent manner. moreover, esculetin significantly increased the endocytic activity, and augmented the nitric oxide production and iNOS gene expression in LPS-treated macrophages. In addition, in vivo administration of esculetin into mice was shown to increase the mitogenesis of splenic lymphocytes towards Con A and LPS stimulations, and induced the LAK activity of splenic lymphocytes. Collectively, our results indicate that esculetin could exert immunomodulatory effects on murine macrophages and lymphocytes, both in vitro and in vivo, and this might be one of the possible mechanisms by which coumarins can exert their chemopreventive and anti-tumor activities in vivo. Cellular ＆ molecular Immunology. 2005;2（3）： 181-188.

关键词： immunomodulatory esculetin coumarin murine macrophage LAK cell

APPL2 Negatively Regulates Olfactory Functions by Switching Fate Commitments of Neural Stem Cells in Adult Olfactory Bulb via Interaction with Notch1 Signaling

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Neuroscience Bulletin 2020年第9期36卷 997-1008页

作者： Chong Gao Tingting yan Xingmiao Chen kenneth K.y.Cheng Aimin Xu Jiangang Shen School of Chinese medicine Li Ka Shing Faculty of MedicineThe University of Hong KongPok Fu LamHong Kong SARChina State Key Laboratory of Pharmaceutical Biotechnology The University of Hong KongPok Fu LamHong Kong SARChina Department of medicine Li Ka Shing Faculty of MedicineThe University of Hong KongPok Fu LamHong Kong SARChina Department of Health Technology and Informatics The Hong Kong Polytechnic UniversityHung HomHong Kong SARChina

Adult olfactory neurogenesis plays critical roles in maintaining olfactory ***-generated neurons in the subventricular zone migrate to the olfactory bulb(OB) and determine olfactory discrimination,but the mechanisms underlying the regulation of olfactory neurogenesis remain *** previous study indicated the potential of APPL2(adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 2) as a modulating factor for neurogenesis in the adult olfactory *** the present study,we report how APPL2 affects neurogenesis in the OB and thereby mediates olfactory discrimination by using both in vitro neural stem cells(NSCs) and an in vivo animal model-APPL2 transgenic(Tg) *** the in vitro study,we found that APPL2 overexpression resulted in NSCs switching from neuronal differentiation to gliogenesis while APPL2 knockdown promoted *** the in vivo study,APPL2 Tg mice had a higher population of glial cells and dampened neuronal production in the olfactory system,including the corpus callosum,OB,and rostral migratory *** APPL2 Tg mice displayed impaired performance in olfactory discrimination tests compared with wild-type ***,we found that an interaction of APPL2 with Notch1 contributed to the roles of APPL2 in modulating the neurogenic lineage-switching and olfactory *** conclusion,APPL2 controls olfactory discrimination by switching the fate choice of NSCs via interaction with Notch1 signaling.

关键词： APPL2 Neurogenesis Olfactory bulb Notch1 signaling

A Fast Semi-Implicit Level Set method for Curvature Dependent Flows with an Application to Limit Cycles Extraction in Dynamical Systems

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Communications in Computational Physics 2015年第6期18卷 203-229页

作者： Guoqiao you Shingyu leung The School of Science Nanjing Audit UniversityNanjingJiangsu ProvinceChina Department of mathematics The Hong Kong University of Science and TechnologyClear Water BayHong Kong

We propose a new semi-implicit level set approach to a class of curvature dependent *** method generalizes a recent algorithm proposed for the motion by mean curvature where the interface is updated by solving the Rudin-Osher-Fatemi(ROF)model for image *** proposal is general enough so that one can easily extend and apply the method to other curvature dependent *** the derivation is based on a semi-implicit time discretization,this suggests that the numerical scheme is stable even using a time-step significantly larger than that of the corresponding explicit *** an interesting application of the numerical approach,we propose a new variational approach for extracting limit cycles in dynamical *** resulting algorithm can automatically detect multiple limit cycles staying inside the initial guess with no condition imposed on the number nor the location of the limit ***,we also propose in this work an Eulerian approach based on the level set method to test if the limit cycles are stable or unstable.

关键词： Numerical methods for PDEs level set method dynamical systems flow visualization

High-spin structure in ^(187)Pt

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Science China(Physics,mechanics & Astronomy) 2008年第8期51卷 1053-1071页

作者： OSHImA m TOH y KOIZUmI m OSA A HATSUKAWA y SUGAWARA m Japan Atomic Energy Agency TokaiIbaraki 319-1195Japan Chiba Institute of Technology NarashinoChiba 275-0023Japan

High-spin states in 187Pt were studied via the 173yb(18O,4n) reaction. Rotational bands based on the νi13/2,ν7/2-[503],νi213/2νj,ν3/2-[512] and ν1/2-[521] configurations were observed,and interpreted within the framework of the cranked shell model. The TRS calculations show that the νi13/2 band has an appreciable negative γ deformation,and the negative-parity bands tend to have a near prolate shape with small positive γ values. Experimental values of B(m1) /B(E2) ratios have been extracted and compared with theoretical values from the semi-classical D-nau and Frauendof approach,strongly suggesting a low frequency πh9/2 alignment in the ν7/2-[503] band.

关键词： rotational band configuration shape coexistence

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.mUHAmmAD m.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(mHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in mATHEmATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

关键词： Nanofluidics