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FORCE REDUCTION OF FLOW AROUND A SINUSOIDAL WAVY CYlinDER

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Journal of Hydrodynamics 2009年第3期21卷 308-315页

作者： zou lin lin Yu-feng School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 430070 China Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong China

A large eddy simulation of cross-flow around a sinusoidal wavy cylinder at Re = 3000 was performed and the load cell measurement was introduced for the validation test. The mean flow field and the near wake flow structures were presented and compared with those for a circular cylinder at the same Reynolds number. The mean drag coefficient for the wavy cylinder is smaller than that for a corresponding circular cylinder due to the formation of a longer wake vortex generated by the wavy cylinder. The fluctuating lift coefficient of the wavy cylinder is also greatly reduced. This kind of wavy surface leads to the formation of 3-D free shear layers which are more stable than purely 2-D free shear layers. Such free shear layers only roll up into mature vortices at further downstream position and significantly modify the near wake structures and the pressure distributions around the wavy cylinder. Moreover, the simulations in laminar flow condition were also performed to investigate the effect of Reynolds number on force reduction control.

关键词： wavy cylinder force reduction Large Eddy Simulation (LES) Reynolds number effect

Attractors with controllable basin sizes from cooperation of contracting and expanding dynamics in pulse-coupled oscillators

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Chinese Physics B 2019年第1期28卷 267-274页

作者： Hai-lin zou Zi-Chen Deng School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China

Unstable attractors are a novel type of attractor with local unstable dynamics, but with positive measures of ***, we introduce local contracting dynamics by slightly modifying the function which mediates the interactions among the oscillators. Thus, the property of unstable attractors can be controlled through the cooperation of expanding and contracting dynamics. We demonstrate that one certain type of unstable attractor is successfully controlled through this simple modification. Specifically, the staying time for unstable attractors can be prolonged, and we can even turn the unstable attractors into stable attractors with predictable basin sizes. As an application, we demonstrate how to realize the switching dynamics that is only sensitive to the finite size perturbations.

关键词： unstable attractors switching dynamics pulse-coupled oscillators

LARGE-EDDY SIMULATION OF FLOW AROUND CYlinDER ARRAYS AT A SUBCRITICAL REYNOLDS NUMBER

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Journal of Hydrodynamics 2008年第4期20卷 403-413页

作者： zou lin lin Yu-feng LAM Kit School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 430070 China Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong China

The complex three-dimensional turbulent flows around a cylinder array with four cylinders in an in-line square configuration at a subcritical Reynolds number of 1.5 × 10^4 with the spacing ratio at L/D = 1.5 and 3.5 were investigated using the Large Eddy Simulation （LES）. The full field vorticity and velocity distributions as well as turbulent quantities were calculated in detail and the near wake structures were presented. The results show that the bi-stable flow nature was observed at L/D = 1.5 and distinct vortex shedding of the upstream cylinders occurred at L/D = 3.5 at Re = 1.5 × 10^4. The techniques of Laser Doppler Anemometry （LDA） and Digital Particle Image Velocimetry （DPIV） are also employed to validate the present LES method. The results show that the numerical predictions are in excellent agreement with the experimental measurements. Therefore, the full field instantaneous and mean quantities of the flow field, velocity field and vorticity field can be extracted from the LES results for further study of the complex flow characteristics.

关键词： four-cylinders array turbulent flow Large Eddy Simulation (LES) Laser Doppler Anemometry (LDA) Digital Particle Image Velocimetry (DPIV)

FLOW PATTERNS AND FORCE CHARACTERISTICS OF LAMINAR FLOW PAST FOUR CYlinDERS IN DIAMOND ARRANGEMENT

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Journal of Hydrodynamics 2011年第1期23卷 55-64页

作者： zou lin lin Yu-feng LU Hong School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 430070 China Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong China

A three-dimensional numerical investigation of cross-flow past four circular cylinders in a diamond arrangement at Reynolds number of 200 is carried *** the spacing ratios（L /D）ranging from 1.2 to 5.0,the flow patterns can be classified into three basic *** critical spacing ratio for the transition from narrow gap flow pattern to vortex impingement flow pattern around the cylinders is found to beL /D=3.0,while a single bluff-body flow pattern is observed atL /D=*** relationship between the three-dimensional flow patterns and force characteristics around the four cylinders shows that the variation of forces and Strouhal numbers againstL /D are generally governed by these three kinds of flow *** is concluded that the spacing ratio has important effects on the development of the free shear layers about the cylinders and hence has significant effects on the force and pressure characteristics of the four cylinders with different spacing ratios.

关键词： four cylinders spacing ratio flow pattern force characteristics

Effects of intracoronary injection of nicorandil and tirofiban on myocardial perfusion and short-term prognosis in elderly patients with acute ST-segment elevation myocardial infarction after emergency PCI

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World Journal of Emergency Medicine 2020年第3期11卷 157-163页

作者： Guo-xiong Chen Hong-na Wang Jin-lin zou Xiao-xu Yuan Department of Cardiology Zhoushan Hospital of Zhejiang ProvinceZhoushan 316000China

BACKGROUND:This study investigated the effects of the intracoronary injection of nicorandil and tirofiban on myocardial perfusion and short-term prognosis in elderly patients with acute ST-segment elevation myocardial infarction(STEMI)after emergency percutaneous coronary intervention(PCI).METHODS:Seventy-eight STEMI patients with age>65 years who underwent emergency PCI were consecutively *** patients received conventional PCI and were randomly divided into a control group and a treatment group(n=39 per group).The control group received an intracoronary injection of tirofiban followed by a maintenance infusion for 36 hours after *** treatment group received intracoronary injection of tirofiban and nicorandil,and then intravenous infusion of tirofiban and nicorandil 36 hours after *** following parameters were measured:TIMI grade,corrected TIMI frame count(c TFC),TIMI myocardial perfusion grade(TMPG),STsegment resolution(STR)rate 2 hours post-operatively,resolution of ST-segment elevation(STR)at 2 hours postoperatively,peak level of serum CK-MB,left ventricular end diastolic diameter(LVEDD)and left ventricular ejection fraction(LVEF)at 7–10 days postoperatively,and major adverse cardiac events(MACEs)in-hospital and within 30 days ***:Compared with the control group,more patients in the treatment group had TIMI 3 and TMPG 3,and STR after PCI was significantly *** treatment group also had significantly lower c TFC,lower infarction relative artery(IRA),lower peak CK-MB,and no reflow ratio after *** treatment group had significantly higher LVEDD and LVEF but lower incidence of MACEs than the control ***:The intracoronary injection of nicorandil combined with tirofiban can effectively improve myocardial reperfusion in elderly STEMI patients after emergency PCI and improve shortterm prognoses.

关键词： Acute ST-elevation myocardial infarction Elderly Emergency coronary intervention Nicorandil Tirofiban Myocardial reperfusion

Quantifying the carbon source of pedogenic calcite veins in weathered limestone: implications for the terrestrial carbon cycle

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Acta Geochimica 2019年第4期38卷 481-496页

作者： lin zou lin Dong Meng Ning Kangjun Huang Yongbo Peng Shujian Qin Honglin Yuan Bing Shen Key Laboratory of Orogenic Belts and Crustal Evolution MOE and School of Earth and Space SciencePeking UniversityBeijingPeople's Republic of China Shaanxi Key Laboratory of Early Life and Environments Department of GeologyNorthwest UniversityXi'anPeople's Republic of China Department of Geology and Geophysics Louisiana State UniversityBaton RougeLA 70803USA

The continent is the second largest carbon sink on Earth’s *** the diversification of vascular land plants in the late Paleozoic,terrestrial organic carbon burial is represented by massive coal formation,while the development of soil profiles would account for both organic and inorganic carbon *** compared with soil organic carbon,inorganic carbon burial,collectively known as the soil carbonate,would have a greater impact on the long-term carbon *** carbonate would have multiple carbon sources,including dissolution of host calcareous rocks,dissolved inorganic carbon from freshwater,and oxidation of organic matter,but the host calcareous rock dissolution would not cause atmospheric ***,to evaluate the potential effect of soil carbonate formation on the atmospheric p CO2level,different carbon sources of soil carbonate should be quantitatively *** this study,we analyzed the carbon and magnesium isotopes of pedogenic calcite veins developed in a heavily weathered outcrop,consisting of limestone of the early Paleogene Guanzhuang Group in North *** on the C and Mg isotope data,we developed a numerical model to quantify the carbon source of calcite *** modeling results indicate that4–37 wt%of carbon in these calcite veins was derived from atmospheric *** low contribution from atmospheric CO2might be attributed to the host limestone that might have diluted the atmospheric ***,taking this value into consideration,it is estimated that soil carbonate formation would lower 1 ppm atmospheric CO2within 2000 years,i.e.,soil carbonate alone would sequester all atmospheric CO2within 1 million ***,our study suggests the C–Mg isotope system might be a better tool in quantifying the carbon source of soil carbonate.

关键词： Mg isotope Calcite veins Pedogenic carbonate Silicate weathering Carbonate weathering

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： lin zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao Xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

Improved C_(3-4) transfer for treatment of root avulsion of the brachial plexus upper trunk Animal experiments and clinical application

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Neural Regeneration Research 2012年第20期7卷 1545-1555页

作者： lin zou Xuecheng Cao Jing Li Lifeng Liu Pingshan Wang Jinfang Cai Department of Orthopedics and Traumatic Surgery General Hospital of Jinan Military Command of Chinese PLA Jinan 250031 ShandongProvince China Department of Neurology General Hospital of Jinan Military Command of Chinese PLA Jinan 250031 Shandong Province China

Experimental rats with root avulsion of the brachial plexus upper trunk were treated with the improved C34 transfer for neurotization of 05-6. Results showed that Terzis grooming test scores were significantly increased at 6 months after treatment, the latency of C5-6 motor evoked potential was gradually shortened, and the amplitude was gradually increased. The rate of C3 instead of C5 and the C4 ＋ phrenic nerve instead of C6 myelinated nerve fibers crossing through the anastomotic stoma was approximately 80%. Myelinated nerve fibers were arranged loosely but the thickness of the myelin sheath was similar to that of the healthy side. In clinical applications, 39 patients with root avulsion of the brachial plexus upper trunk were followed for 6 months to 4.5 years after treatment using the improved C3 instead of C5 nerve root transfer and C4 nerve root and phrenic nerve instead of C6 nerve root transfer. Results showed that the strength of the brachial biceps and deltoid muscles recovered to level IIHV, scapular muscle to level Ill-W, latissimus dorsi and pectoralis major muscles to above level Ⅲ, and the brachial triceps muscle to level 0 Ill. Results showed that the improved 03-4 transfer for root avulsion of the brachial plexus upper trunk in animal models is similar to clinical findings and that C3-4 and the phrenic nerve transfer for neurotization of C5-6 can innervate the avulsed brachial plexus upper trunk and promote the recovery of nerve function in the upper extremity.

关键词： brachial plexus cervical plexus upper trunk root avulsion nerve transfer phrenic nerve translational medicine peripheral nerve injury neural regeneration

Clustering-triggered Emission of Cellulose and Its Derivatives

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Chinese Journal of Polymer Science 2019年第4期37卷 409-415,I0007页

作者： lin-lin Du Bing-Li Jiang Xiao-Hong Chen Yun-Zhong Wang lin-Min zou Yuan-Li Liu Yong-Yang Gong Chun Wei Wang-Zhang Yuan Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials Ministry of EducationCollege of Materials Science and EngineeringGuilin University of Technology College of Pharmacy Guilin Medical University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University

In recent years, nonconventional luminogens free of aromatic groups have attracted extensive attention due to their academic importance and promising wide applications. Whilst previous studies generally focused on fluorescence from aliphatic amine or carbonylcontaining systems, less attention has been paid to room temperature phosphorescence(RTP) and the systems with predominant oxygen functionalities. In this work, photophysical properties of the polyhydroxy polymers, including microcrystalline cellulose(MCC), 2-hydroxyethyl cellulose(HEC), hydroxypropyl cellulose(HPC), and cellulose acetate(CA), were studied and compared. While MCC,HEC, and HPC solids showed bright emission alongside distinct RTP, CA demonstrated relatively low intensity of solid emission without noticeable RTP. Their emissions were explained in terms of the clustering-triggered emission(CTE) mechanism and conformation rigidification. Additionally, on account of its intrinsic emission, concentrated HEC aqueous solution could be used as the probe for the detection of 2,4,6-trinitrophenol(TNP).

关键词： Cellulose Nonconventional luminogens Room temperature phosphorescent Clustering-triggered emission