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Torsional Response Analysis of Flexible Pipe Based on Theory and Finite Element Method

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China Ocean Engineering 2023年第2期37卷 190-203页

作者： LEI Qing-long zhu xiao-hua School of Mechanical Engineering Southwest Petroleum UniversityChengdu 610500China Oil and Gas Equipment Technology Sharing and Service Platform of Sichuan Province Chengdu 610500China

As key components connecting offshore floating production platforms and subsea imports, offshore flexible pipes play significant roles in oil, natural gas, and water injection. It is found that torsional failure is one of the failure modes of flexible pipes during transportation and laying. In this paper, a theoretical model(TM) of a flexible pipe section mechanics is established, in which the carcass layer and the pressure armor layer are equivalent to the orthogonal anisotropic layers due to its complex cross-section structure. The calculation results of the TM are consistent with those of a finite element model(FEM), which can accurately describe the torsional response of the flexible ***, the TM and FEM are used to discuss the influence of boundary conditions on the torsional *** structure of the flexible pipe is stable when twisted counterclockwise. However, limiting the top axial displacement can improve the axial and radial instability of the tensile armor layer when twisted clockwise. Finally, it is recommended that the flexible pipe can be kept under top fixation during service or installation to avoid torsional failure.

关键词： flexible pipe torsional response analytical model finite element model

Selenium-enriched Bifidobacterium longum protected alcohol and high fat diet induced hepatic injury in mice

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Chinese Journal of Natural Medicines 2020年第3期18卷 169-177页

作者： YI Hong-Wei zhu xiao-xiao HUANG xiao-Li LAI Yu-zhu TANG Yue Department of Pharmacology School of MedicineSoutheast UniversityNanjing 210009China

The objective of this study was to verify the protective effect of Bifidobacterium longum(BL) and the synergistical effect of Selenium and BL on alcohol plus high fat diet(HFD) induced hepatic injury in mice. We also want to explore the mechanism of Selenium-enriched Bifidobacterium longum(Se BL). C57 BL/6 mice were treated with alcohol plus HFD with or without different dosage of BL or Se BL for 4 weeks. Serum levels of ALT, AST, TC, TG, LDL-C, HDL-C, FFAs, TNF-α, IL-6 and IL-1β, hepatic MDA level, SOD activity, the m RNA levels of AMPK, PPAR-α and SREBP1 were invested. Se BL inhibited lipid accumulation in hepatocytes;reduced serum AST and ALT levels;improved dyslipidemia;decreased serum FFAs, TC, TG and LDL-C levels. Se BL also inhibited alcohol plus HFD-induced hepatocyte oxidative stress through decrease in hepatic MDA levels and increase in SOD activity. Se BL also regulated lipid metabolism related genes such as AMPK, PPAR-α and SREBP1. Although BL had similar effect as Se BL, Se BL is more effective than BL. Se BL protected mice from alcohol plus HFD-induced hepatic injury in mice because of its inhibitory effect on hepatocellular oxidative stress, lipogenesis and inflammation. Selenium enhanced the protective effect of BL.

关键词： Selenium-enriched Bifidobacterium longum Alcoholic liver disease Non-alcoholic fatty liver disease Oxidative stress Inflammation

Macular Perfusion Changes and Ganglion Cell Complex Loss in Patients with Silicone Oil-related Visual Loss

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Biomedical and Environmental Sciences 2020年第3期33卷 151-157页

作者： MA Ya zhu xiao Qing PENG xiao Yan Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Ophthalmology and Visual Science Key LabBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China Beijing Tongren Eye Center Beijing Ophthalmology and Visual Science Key LabBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China

Objective The aim of this study was to investigate macular perfusion changes and ganglion cell complex(GCC)loss in patients with unexplained visual loss following vitrectomy and silicone oil(SO)tamponade,and to evaluate the correlation between retinal blood flow and GCC loss using optical coherence tomography angiography(OCTA)and optical coherence tomography(OCT).Methods This retrospective study included seven eyes(seven patients)with unexpected visual loss after vitrectomy and SO *** was used to evaluate the alterations in retinal vessel density(VD)in the superficial capillary plexus(SCP),deep capillary plexus(DCP),and radial peripapillary capillary plexus(RPCP).OCT was used to measure the thickness of GCC and retinal nerve fiber layer(RNFL).Medical records of patients were *** Quantitative analysis of OCTA images revealed a significant reduction in SCP VD in the affected eyes compared with the controls(all sections P<0.05).No difference was found in GCC thickness,but FLV(focal loss volume)and GLV(global loss volume)were significantly higher in the affected eyes(both P<0.001).SCP VD was inversely correlated with FLV and *** Silicone oil-related severe visual loss was associated with superficial retinal microvasculature damage and ganglion cell apoptosis.

关键词： Silicone oil Visual loss Optical coherence tomography angiography Ganglion cell complex

Influence of baryons on the spatial distribution of matter:higher order correlation functions

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Research in Astronomy and Astrophysics 2012年第12期12卷 1603-1612页

作者： xiao-Jun zhu Jun Pan Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China National Astronomical Observatories Chinese Academy of Sciences B eijing 100012 China

Physical processes involving baryons could leave a non-negligible imprint on the distribution of cosmic matter.A series of simulated data sets at high resolution with identical initial conditions are employed for count-in-cell analysis,including one N-body pure dark matter run,one with only adiabatic gas and one with dissipative *** and higher order cumulants Sn of dark matter and gas are *** is found that physical processes with baryons mainly affect distributions of dark matter at scales less than 1 h-1 *** comparison with the pure dark matter run,adiabatic processes alone strengthen the variance of dark matter by～10%at a scale of 0.1 h-1 Mpc,while the Sn parameters of dark matter only mildly deviate by a few *** dissipative gas run does not differ much from the adiabatic run in terms of variance for dark matter,but renders significantly different Sn parameters describing the dark matter,bringing about a more than 10%enhancement to S3 at 0.1 h-1 Mpc and z=0 and being even larger at a higher *** patterns of gas in two hydrodynamical simulations are quite *** of gas at z=0 decreases by～30%in the adiabatic simulation but by～60%in the nonadiabatic simulation at 0.1 h-1 *** attenuation is weaker at larger scales but is still obvious at～10 h-1 *** parameters of gas are biased upward at scales 〈～4 h-1 Mpc,and dissipative processes show an～84%promotion at z=0 to S3 at 0.1 h-1 Mpc in contrast with the～7%change in the adiabatic *** segregation in clustering between gas and dark matter could have dramatic implications on modeling distributions of galaxies and relevant cosmological applications demanding fine details of matter distribution in a strongly nonlinear regime.

关键词： cosmology:dark matter-large-scale structure of universe-methods: statistical

The impact of regiochemistry of conjugated molecules on the performance of organic electronic devices

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Chinese Chemical Letters 2016年第8期27卷 1357-1366,1470页

作者： Cheng Zhang xiao-Zhang zhu Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

Organic photovoltaics and field-effect transistors have attracted considerable attention due to the easy fabrication,low cost,light weight,and *** conjugated building blocks are widely utilized for the design of new organic π-functional materials in order to achieve high-performance electronic devices,which has become a hot research topic in recent *** this review,we summarized some typical organic π-functional materials with regioregular conjugated backbones with unsymmetrical electron-deficiency moieties and focused on the influence of regiochemistry on the final device performance.

关键词： Organic π-functional materials Regiochemistry Unsymmetrical electron-deficiency moiety Organic photovoltaics Organic field-effect transistors

Minimum Time Extrema Estimation for Large-Scale Radio-Frequency Identification Systems

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Journal of Computer Science & Technology 2020年第5期35卷 1099-1114页

作者： xiao-Jun zhu Li-Jie Xu xiao-Bing Wu Bing Chen College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Jiangsu Key Laboratory of Dig Data Security and Intelligent Processing Nanjing University of Posts and TelecommunicationsNanjing 210049China Wireless Research Centre University of CanterburyChristchurch 8041New Zealand

We consider the extrema estimation problem in large-scale radio-frequency identification(RFID)systems,where there are thousands of tags and each tag contains a finite *** objective is to design an extrema estimation protocol with the minimum execution *** the standard binary search protocol wastes much time due to inter-frame overhead,we propose a parameterized protocol and treat the number of slots in a frame as an unknown *** formulate the problem and show how to find the best parameter to minimize the worst-case execution ***,we propose two rules to further reduce the execution *** first is to find and remove redundant *** second is to concatenate a frame from minimum value estimation with a frame from maximum value estimation to reduce the total number of *** show that,in a typical scenario,the proposed protocol reduces execution time by 79%compared with the standard binary search protocol.

关键词： radio-frequency identification(RFID)system maximum value estimation minimum value estimation time efficient protocol

Polarization Mechanism in Filled Tungsten Bronze Ba4Eu2Ti4Nb6O30 with Pinched P-E Hysteresis Loops

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Chinese Physics Letters 2021年第4期38卷 129-134页

作者： Lang zhu xiao-Li zhu xiao-Qiang Liu Xiang-Ming Chen School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China

Pinched P-E hysteresis loops have been observed in filled tungsten bronze Ba_(4)Eu_(2)Ti_(4)Nb_(6)O_(30),indicating the presence of novel polarization *** investigate the evolution of polar order in filled tungsten bronze Ba_(4)Eu_(2)Ti_(4)Nb_(6)O_(30),together with its dielectric properties over a wide temperature range,from 50 K to 773 *** temperature dependences of the dielectric properties exhibit two low-temperature dielectric relaxations,at around 300 K(P1),and 100 K(P2),and a high temperature peak at 588 K with no frequency dispersion,indicating the ferroelectric transition temperature T_(c).Pinched P-E loops are observed in the temperature range between the low temperature relaxation at P1,and the ferroelectric *** cooling,the pinched P-E hysteresis loops open gradually,with increasing remnant polarization(P_(r)).Two pairs of reversal electric fields indicate two types of polar reversal mechanisms,with an activated energy of 1.41 eV(E_(1)),and 0.94 eV(E_(2)),*** corresponds to the field-induced transition from a nonpolar to a polar state,which dominates at a high temperature close to T_(c),while the other relates to the reversal of ferroelectric domains which stabilize gradually on *** temperatures below 300 K,the polarization exhibits an evident decrease,probably related to the disruption of the polar order due to the dielectric relaxation at P1.

关键词： ferroelectric relaxation polarization

Kinetics of carbonated decomposition of hydrogarnet with different silica saturation coefficients

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International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 472-482页

作者： xiao-feng zhu Ting-an Zhang Guo-zhi Lü State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China School of Material Science and Engineering Lanzhou University of TechnologyLanzhou 730050China Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education Northeastern UniversityShenyang 110819China Special Metallurgy and Process Engineering Institute School of MetallurgyNortheastern UniversityShenyang 110819China

Carbonated decomposition of hydrogarnet is one of the vital reactions of the calcification–carbonation method,which is designed to dispose of low-grade bauxite and Bayer red mud and is a novel eco-friendly *** this study,the effect of the silica saturation coefficient(x)on the carbonation of hydrogarnet was investigated from the kinetic *** results indicated that the carbonation of hydrogarnets with different x values(x=0.27,0.36,0.70,and 0.73)underwent two stages with significantly different rates,and the kinetic mechanisms of the two stages can be described by the kinetic functions R3 and *** apparent activation energies at Stages 1 and 2 were 41.96–81.64 and 14.80–34.84 kJ/mol,***,the corresponding limiting steps of the two stages were interfacial chemical reaction and diffusion.

关键词： Bayer red mud hydrogarnet calcification carbonation kinetics silica saturation coefficient

Effect of baffles on bubble behavior in a bubbling fluidized bed for chemical looping processes

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Particuology 2020年第6期18卷 154-167页

作者： xiao zhu Xuan Feng Yuanyuan Zou Laihong Shen Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast UniversityNanjing 210096China

A bubbling fluidized bed is generally used as the fuel reactor in chemical looping ***,in sufficient gas-solid contact remains a steadfast *** such,we propose the use of in ternal baffles to split bubbles at a high gas velocity and to restrict the movement of large-scale solids in the fluidized *** investigated the effect of baffle arrangement on the bubble size and energy,pressure gradient,particle distribution,and particle velocity in a fluidized bed using a computational particle fluid dynamics simulation based on our experimental *** discuss the main influenci ng factors,which in elude presence of caps,number of baffles,and the baffle opening *** baffle structure with caps efficiently broke the large bubbles without creating jet *** baffles were deemed suitable in the bed owing to the small bubble size and uniform gas-solid distribution in each *** selected a baffle opening ratio of 20.5%,which improved the flow pattern without causing a significant increase in the pressure gradient and particle velocity through the *** also discussed the potential for sea ling up this baffled fluidized bed for industrial applications.

关键词： Baffle Bubble behavior Fluidized bed Chemical looping CPFD simulations