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Drag reduction and hairpin packets of the turbulent boundary layer over the superhydrophobic-riblets surface

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Journal of Hydrodynamics 2021年第3期33卷 621-635页

作者： xin-wei wang Zi-ye Fan Zhan-qi Tang Nan Jiang School of Mechanical Engineering Tianjin UniversityTianjin300354China Tianjin Key Laboratory of Modern Engineering Mechanics Tianjin300354China

This paper presents experimental measurements by the time-resolved particle image velocimetry(TR-PIV)for the turbulent boundary layer(TBL)over the smooth surface,the superhydrophobic(SH)surface,and the superhydrophobic-riblets(SR)surface in an open-surface recirculating water *** Reynolds number based on the wall friction velocity and the thickness of the TBL over the smooth surface is *** SH surface and the SR surface are manufactured by the laser texturing method on the smooth surface and the riblets surface,*** employing the(modified)Clauser method,a superior efficacy of the drag reduction of about 22.1%is obtained on the SR surface,while the drag reduction rate for the SH surface is about 18.7%.Comparing with the SH surface,the declining 2-order statistics in the near-wall region also indicates a significant drag reduction over the SR *** large-scale structure components extracted by the proper orthogonal decomposition are found to generate a majority of the Reynolds shear stress in the region y^(+)>*** strength of the large-scale features over the rough surfaces(SH and SR surfaces)at disparate wall-normal positions is visualized by the Quadrant splitting method and the conditional *** appearance of the large-scale structures such as the hairpin packets characterized by the two-point correlation shows an excellent consistency with the statistics *** hairpin packets over the SH surface seem always smaller and weaker than those over the smooth *** the SR surface,the hairpin packets in the region 0.1≤y/δ<0.3 are the smallest and weakest among those over the three surfaces,while the scale and the strength of the hairpin packets exceed those over the smooth surface in the region 0.3

关键词： Turbulent boundary layer superhydrophobic riblets drag reduction hairpin packets

Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline

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Petroleum Science 2024年第4期21卷 2723-2733页

作者： Ao-Yang Zhang Meng Cai Na wei Hai-Tao Li Chao Zhang Jun Pei xin-wei wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina Research Institute of Production Engineering Daqing Oilfield Co.Ltd.Daqing163453HeilongjiangChina

During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of *** continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure ***,a cascade of risks is prone to *** address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is *** framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution *** analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are *** research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas ***,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal ***,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy ***,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas ***,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially tr

关键词： Natural gas hydrates Gathering pipeline Temperature variation Hydrate formation rate Sensitivity analysis

Polyisoprene Bearing Dual Functionalized Mini-blocky Chain-ends Prepared from Neodymium-mediated Coordinative Chain Transfer Polymerizations

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Chinese Journal of Polymer Science 2023年第5期41卷 720-727,I0008页

作者： wei-xin wang Wen-Peng Zhao Jing Dong Hua-Qiang Zhang Feng wang Heng Liu Xue-Quan Zhang Key Laboratory of Rubber-Plastics Ministry of EducationShandong Provincial Key Laboratory of Rubber-PlasticsQingdao University of Science&TechnologyQingdao 266042China Petrochemical Research Institute PetroChinaBeijing 102206China School of Chemical Engineering Changchun University of TechnologyChangchun 130012China

Through neodymium-mediated coordinative chain transfer copolymerizaiton(CCTcoP),polyisoprenes bearing dual hydroxylated mini-blocky chain-ends were prepared via a three-step *** studies revealed that,the polymerization demonstrated typical features of CCTcoP across the whole polymerization process,i.e.,quasi-living polymerization characteristic,tunable molecular weights,narrow molecular weight distributions,and atom *** to previously reported CCTP homopolymerization systems,the presence of oxygen-containing IpOAl polar comonomer slowed down chain transfer rates obviously,rendering slightly higher molecular weights of the resultant PIps and smaller Np(number of polymer chains per Nd atom)***,to mimic the structure of natural rubber,the hydroxyl end groups can be facilely modified into phosphonate,amide,and UPy,whose structures were further confirmed by NMR *** these functionalities could greatly improve the hydrophilic properties of the polymers,as revealed from the significantly reduced static water contact angles.

关键词： Functional polyisoprene Neodymium Coordinative chain transfer polymerization Synthetic rubber

mi R-29a promotes hepatitis B virus replication and expression by targeting SMARCE1 in hepatoma carcinoma

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World Journal of Gastroenterology 2017年第25期23卷 4569-4578页

作者： Hong-Jie Wu Ya Zhuo Yan-Cai Zhou xin-wei wang Yan-Ping wang Chang-Yun Si xin-Hong wang Department of Infectious Disease The First Affiliated Hospital of Xinxiang Medical University

AIM To investigate the functional role and underlying molecular mechanism of mi R-29 a in hepatitis B virus(HBV) expression and *** The levels of mi R-29 a and SMARCE1 in HBV-infected Hep G2.2.15 cells were measured by quantitative real-time PCR and western blot analysis. HBV DNA replication was measured by quantitative PCR and Southern blot analysis. The relative levels of hepatitis B surface antigen and hepatitis B e antigen were detected by enzyme-linked immunosorbent assay. The Cell Counting Kit-8(CCK-8) was used to detect the viability of Hep G2.2.15 cells. The relationship between mi R-29 a and SMARCE1 were identified by target prediction and luciferase reporter *** mi R-29 a promoted HBV replication and expression, w h i le S MA R C E 1 r e p r e s s e d H B V r e p lic a t io n a n d expression. Cell viability detection indicated that mi R-29 a transfection had no adverse effect on the host cells. Moreover, SMARCE1 was identified and validated to be a functional target of mi R-29 a. Furthermore, restored expression of SMARCE1 could relieve the increased HBV replication and expression caused by mi R-29 a *** mi R-29 a promotes HBV replication and expression through regulating SMARCE1. As a potential regulator of HBV replication and expression, mi R-29 a could be a promising therapeutic target for patients with HBV infection.

关键词： miR-29a SMARCE1 Hepatitis B surface antigen Hepatitis B virus replication Hepatitis B e antigen

Study on the mechanism of hydrodesulfurization of tetrahydrothiophene catalyzed by nickel phosphide

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Petroleum Science 2022年第3期19卷 1390-1400页

作者： Chuan-Tao Zhu Li-Qiang Zhang Mei-Ling Zhou xin-wei wang Zheng-Da Yang Ri-Yi Lin De-wei Yang College of New Energy China University of PetroleumQingdao266580China

Hydrodesulfurization(HDS)reaction can significantly reduce the viscosity and sulfur content of heavy oil,while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still *** HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide(Ni_(2)P)is carried out at 200-300°*** results indicate that the H_(2)S production under the catalysis of Ni_(2)P increases obviously within 200-250°*** main gas products of HDS reaction are butane,butene and H_(2)***,the mechanism of tetrahydrothiophene catalyzed by Ni_(2)P is analyzed based on Density Functional Theory(DFT).It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V-Ni-Hcp1 site of Ni_(2)P(001).The C-S bond is elongated and the C-C bond is shortened after ***(HYD)is the most possible reaction route of tetrahydrothiophene on Ni_(2)P(001)*** are two routes with the lowest activation energy,which are C_(4)H_(8)S→C_(4)H_(8)SH^(*)→C_(4)H_(9)SH^(*)→C_(4)H_(10)+H_(2)S and C_(4)H_(8)S→C_(4)H9S^(*)→C_(4)H_(9)^(*)+SH^(*)→C_(4)H_(10)+H_(2)*** and H_(2)S are produced in the reaction,corresponding to the experimental *** study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni_(2)P.

关键词： Tetrahydrothiophene Nickel phosphide Hydrodesulfurization Hydrogen sulfide DFT

Dissolution kinetics and reaction mechanism of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag

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Journal of Iron and Steel Research International 2024年第4期31卷 861-869页

作者： Yao-xin Du Yan-wu Dong Zhou-hua Jiang Ganna Stovpchenko Yu-shuo Li Jun Huang xin-wei wang Yu-xiao Liu School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Ecological Metallurgy of Multimetallic Mineral Northeastern UniversityShenyang 110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina E.O.Paton Electric Welding Institute of the National Academy of Science of Ukraine Kiev 03115Ukraine

The dissolution behavior of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag,a basic slag system of electroslag remelting process,was investigated by rotating cylinder method using corundum rods to simulate Al_(2)O_(3) inclusions in *** experimental results show that the dissolution rate of Al_(2)O_(3);rods in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in rotating speed and temperature,and the rate-controlling step is the mass transfer in the *** dissolution rate of Al_(2)O,in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in the ratio of CaO to Al_(2)O_(3),which is due to the increase in dissolution driving force and the decrease in slag *** apparent activation energy of the mass transfer of AlOs in slag C is calculated to be 222.86 kJ mol^(-1).During the dissolution of Al_(2)0,inclusions in the slag,it reacts with F in liquid slag at first,then reacts with CaO to form the intermediate compounds of xCaO-yAl_(2)O_(3) system,and finally dissolves in molten *** dissolution rate of Al_(2)O_(3) inclusions in CaF_(2)-CaO-Al_(2)O_(3) slag for electroslag remelting is positively correlated with the ratio of the dissolution driving force and slag viscosity,and the correlation coeficient is 2.487×10^(-11).

关键词： Inclusion Electroslag remelting Mass transfer:Dissolution rate-Dissolution driving force

Preparation and properties of nanosize MnZn ferrite from δ-FeOOH

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Rare Metals 2006年第z1期25卷 466-470页

作者： HAO Shunli wang xin wei Yu wang Yongming Liu Chunjing School of Material and Engineering Hebei University of Technology Tianjin 300130 China 　 College of Chemistry Hebei Normal University Shijiazhuang 050016 China 　　

Ferrous ion was transformed into feroxyhyte (δ-FeOOH) by oxidation. Then, manganese sulfate and zinc sulfate in some ratio were added to the feroxyhyte solution. The co-precipitation was boiling reflux conditions sometime under constant stirring. The nanosize MnZn ferrite powder was formed. The mechanism of preparation of the nanosize MnZn ferrite was discussed, and the formation of feroxyhyte which was playing a key role during the process was mentioned. The properties of powder was tested by means of X-ray diffraction, transmission electron microscopy and vibrating sample magnetometer. The results show that the samples of spherical particles about 20 nm, which have characteristics of ferrimagnetism, has larger saturation magnetization, but the remanent magnetization and coercivity are comparatively smaller. The spinel MnZn ferrite nanosize powder was successfully prepared from δ-FeOOH at low temperature, with low-carbon steel and peroxide as main material.

关键词： nanosize MnZn ferrite feroxyhyte preparation characterization

Notch pathway inhibitor DAPT enhances Atoh1 activity to generate new hair cells in situ in rat cochleae

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Neural Regeneration Research 2017年第12期12卷 2092-2099页

作者： Wen-wei Luo Zhao Han Dong-dong Ren xin-wei wang Fang-lu Chi Juan-mei Yang Department of Otolaryngology Eye & ENT Hospital of Fudan University Research Institute of Otolaryngology Fudan University

Atoh1 overexpression in cochlear epithelium induces new hair cell formation. Use of adenovirus-mediated Atoh1 overexpression has mainly focused on the rat lesser epithelial ridge and induces ectopic hair cell regeneration. The sensory region of rat cochlea is difficult to transfect, thus new hair cells are rarely produced in situ in rat cochlear explants. After culturing rat cochleae in medium containing 10% fetal bovine serum, adenovirus successfully infected the sensory region as the width of the supporting cell area was significantly increased. Adenovirus encoding Atoh1 infected the sensory region and induced hair cell formation in situ. Combined application of the Notch inhibitor DAPT and Atoh1 increased the Atoh1 expression level and decreased hes1 and hes5 levels, further promoting hair cell generation. Our results demonstrate that DAPT enhances Atoh1 activity to promote hair cell regeneration in rat cochlear sensory epithelium in vitro.

关键词： nerve regeneration Atoh 1 DAPT. transdifferentiation gamma secretase inhibitor cochlea sensory epithelium fetal bovine serum hair cell supporting cell hair cell regeneration neural regeneration

Optimal control based coordinated taxiing path planning and tracking for multiple carrier aircraft on flight deck

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Defence Technology（防务技术） 2022年第2期18卷 238-248页

作者： xin-wei wang Hai-jun Peng Jie Liu Xian-zhou Dong Xu-dong Zhao Chen Lu Department of Engineering Mechanics State Key Laboratory of Structural Analysis for Industrial EquipmentDalian University of TechnologyDalianLiaoning116024China Faculty of Electronic Information and Electrical Engineering Dalian University of TechnologyDalianLiaoning116024China War Research Institute Academy of Military SciencesBeijing100850China School of Reliability and Systems Engineering Beihang UniversityXueyuan RoadHaidian DistrictBeijing100191China

Coordinated taxiing planning for multiple aircraft on flight deck is of vital importance which can dramatically improve the dispatching *** this paper,first,the coordinated taxiing path planning problem is transformed into a centralized optimal control problem where collision-free conditions and mechanical limits are *** the formulated optimal control problem is of large state space and highly nonlinear,an efficient hierarchical initialization technique based on the Dubins-curve method is ***,a model predictive controller is designed to track the obtained reference trajectory in the presence of initial state error and external *** experiments demonstrate that the proposed“offline planningþonline tracking”framework can achieve efficient and robust coordinated taxiing planning and tracking even in the presence of initial state error and continuous external disturbances.

关键词： Carrier aircraft Coordinated path planning Centralized optimal control Trajectory tracking Model predictive control