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Pressure transient characteristics of non-uniform conductivity fractured wells in viscoelasticity polymer flooding based on oil-water two-phase flow

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Petroleum Science 2024年第1期21卷 343-351页

作者： Yang wang Jia Zhang shi-Long Yang Ze-xuan Xu shi-Qing Cheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Polymer flooding in fractured wells has been extensively applied in oilfields to enhance oil recovery.In contrast to water,polymer solution exhibits non-Newtonian and nonlinear behavior such as effects of shear thinning and shear thickening,polymer convection,diffusion,adsorption retention,inaccessible pore volume and reduced effective permeability.Meanwhile,the flux density and fracture conductivity along the hydraulic fracture are generally non-uniform due to the effects of pressure distribution,formation damage,and proppant breakage.In this paper,we present an oil-water two-phase flow model that captures these complex non-Newtonian and nonlinear behavior,and non-uniform fracture characteristics in fractured polymer flooding.The hydraulic fracture is firstly divided into two parts:high-conductivity fracture near the wellbore and low-conductivity fracture in the far-wellbore section.A hybrid grid system,including perpendicular bisection(PEBI)and Cartesian grid,is applied to discrete the partial differential flow equations,and the local grid refinement method is applied in the near-wellbore region to accurately calculate the pressure distribution and shear rate of polymer solution.The combination of polymer behavior characterizations and numerical flow simulations are applied,resulting in the calculation for the distribution of water saturation,polymer concentration and reservoir pressure.Compared with the polymer flooding well with uniform fracture conductivity,this non-uniform fracture conductivity model exhibits the larger pressure difference,and the shorter bilinear flow period due to the decrease of fracture flow ability in the far-wellbore section.The field case of the fall-off test demonstrates that the proposed method characterizes fracture characteristics more accurately,and yields fracture half-lengths that better match engineering reality,enabling a quantitative segmented characterization of the near-wellbore section with high fracture conductivity and the far-wellbore section with low fracture conduct

关键词： Polymer flooding Non-Newtonian fluid Non-uniform fracture conductivity Two-phase flow Pressure transient analysis

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Adhesive Contact of Elastic Solids with Self-Affine Fractal Rough Surfaces

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Acta Mechanica Solida Sinica 2024年第2期37卷 265-270页

作者： xuan-Ming Liang shi-Wen Chen Si-He wang Zhen-Yuan Gong Jun Feng Gang-Feng wang Department of Engineering Mechanics SVL and MMMLXi’an Jiaotong UniversityXi’an710049China OPPO Mobile Telecommunications Corporation Ltd. Dongguan523860China

The elastic adhesive contact of self-affine fractal rough surfaces against a rigid flat is simulated using the finite element method. An array of nonlinear springs, of which the force-separation law obeys the Lennard–Jones potential, is introduced to account for the interfacial adhesion. For fractal rough surfaces, the interfacial interaction is generally attractive for large mean gaps, but turns repulsive as the gap continuously shrinks. The interfacial interactions at the turning point corresponding to the spontaneous contact are shown for various surfaces. For relatively smooth surfaces, the probability density distributions of repulsion and attraction are nearly symmetric. However, for rougher surfaces, the simulation results suggest a uniform distribution for attraction but a monotonously decreasing distribution with a long tail for repulsion. The pull-off force rises with increasing ratio of the work of adhesion to the equilibrium distance, whereas decreases for solids with a higher elastic modulus and a larger surface roughness. The current study will be helpful for understanding the adhesion of various types of rough solids.

关键词： Fractal rough surfaces Adhesion Contact mechanics Lennard-Jones potential

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Construction of Cu-Zn Co-doped layered materials for sodium-ion batteries with high cycle stability

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Chinese Chemical Letters 2024年第5期35卷 441-446页

作者： Xiping Dong xuan wang Zhixiu Lu Qinhao shi Zhengyi Yang xuan Yu Wuliang Feng Xingli Zou Yang Liu Yufeng Zhao Institute for Sustainable Energy&College of Sciences Shanghai UniversityShanghai 200444China Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province Yancheng Institute of TechnologyYancheng 224051China State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Due to its high operational voltage and energy density,P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) has become a leading cathode material for sodium-ion batteries(SIBs),which is an ideal option for large-scale energy storage.However,the practical application of P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) is limited by the capacity constraints and unwanted phase transitions,presenting significant challenges to the widespread application of SIBs.To address these challenges and optimize the electrochemical properties of the P2 phase cathode material,this study proposes a Cu and Zn co-doped strategy to improve the electrochemical performance.The incorporation of Cu/Zn can stabilize the P2-phase structure against P2-O2 phase transitions,thus enhancing its electrochemical properties.The as-obtained P2-type Na0.67[Ni_(0.3)Mn_(0.58)Cu_(0.09)Zn_(0.03)]O_(2) cathode material shows an impressive cycling stability,maintaining 80%capacity retention after 1000 cycles at 2 C.The cyclic voltammetry(CV)tests show that the Cu^(2+)/Cu^(3+)redox reaction is also involved in charge compensation during the charge/discharge process.

关键词： Sodium-ion batteries Cathode material Cycle performance Cu/Zn co-doped P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)

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Dynamic manipulation of multimodal emission in Er3+-activated non-core-shell structure for optical thermometry and information security

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Rare Metals 2024年第4期43卷 1702-1712页

作者： xuan Liu Zi-Xia Lin Yin-Biao shi Xiao-Yan wang Ming-Ye Ding Xiao-Fei Yang College of Science Nanjing Forestry University Testing Center Yangzhou University

Regulating luminescent dynamics of lanthanide-based luminescent materials via external stimuli is of great significance in the fields of optical thermometry and high-level anti-counterfeiting.However,it is still a huge challenge to realize multimodal emissions with tunable color outputs from a single activator in simple structures via smart dynamic control of photon transition processes.Herein,we present a mechanistic strategy to achieve multimodal luminescence of Er3+activators with color-switchable outputs in a non-core-shell host.Under the control of excitation dynamics(λex=980,808,1532,377 nm),the population among the intermediate en ergy levels of Er3+and the interaction between Er3+and Yb3+could be precisely modulated through energy transfer and migration processes,leading to the generation of colortunable multimodal luminescence upon diverse excitation modes（non-steady-state,single-/dual-wavelength steady,thermal activation）.Inspired by its special luminescent performance,the as-obtained material exhibits great potential in noncontact thermometry,multimodal anticounterfeiting,and high-capacity information encryption by performing a series of proof-of-concept experiments.Our findings might provide a conceptual model to modulate the luminescent dynamics in a simple-structured system for the generation of color-adjustable multimodal emissions,which is convenient for the development of advanced luminescent materials toward versatile cuttingedge applications.

关键词： Lanthanide ions Multimodal emission Upconversion Downshifting Anti-counterfeiting Luminescent thermometry

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Knockdown of RCN1 contributes to the apoptosis of colorectal cancer via regulating IP3R1

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BIOCELL 2024年第5期48卷 835-845页

作者： xuan shi YUFEN wang CHENYU LI wangSHU FU XINYUE ZHANG AIXIA GONG Department of Gastroenterology The First Affiliated Hospital of Dalian Medical UniversityDalianChina Department of Gastroenterology The First Affiliated Hospital of Jinzhou Medical UniversityJinzhouChina The First Clinical College Dalian Medical UniversityDalianChina

Background:The incidence of colorectal cancer(CRC)has been increasing in recent years.Thus,the discovery of factors that can assist in alleviating CRC is urgently warranted.Methods:To identify a potential factor involved in the development of CRC,we screened the upregulated genes in tumor tissues through four datasets from an online database.The expression of reticulocalbin 1(RCN1),a Ca2+-binding protein,was upregulated in the four datasets.Based on loss-offunction experiments,the effect of RCN1 on cell viability was assessed by Cell Counting Kit-8(CCK-8)assay.The regulatory effect of RCN1 on apoptosis was evaluated through Annexin V-fluorescein 5-isothiocyanate(FITC)/propidium iodide(PI)staining assay and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL)assay in RKO and SW480 cells.Activation of endoplasmic reticulum(ER)stress signaling pathways was confirmed by estimating the phosphorylation and expression of PRKR-like ER kinase(PERK),inositol-requiring kinase-1(IRE1),transcription factor 6(ACT6),and CCAAT/enhancer-binding protein-homologous protein(CHOP).The intracellular Ca2+homeostasis regulated by RCN1 was determined through the detection of Ca2+concentration and mitochondrial membrane potential(MMP)measurement.Moreover,whether inositol 1,4,5-trisphosphate receptor type 1(IP3R1)was involved in the regulation of RCN1 in CRC was verified through the depletion of IP3R1 in RKO cells.Results:Knockdown of RCN1 reduced cell viability and facilitated apoptosis in RKO and SW480 cells.Phosphorylation of PERK and IRE1,activation of ATF6,and upregulation of CHOP were induced by the absence of RCN1,suggesting that the unfolded protein response(UPR)was activated in CRC cells.The concentration of Ca2+in mitochondria was increased after RCN1 depletion,followed by reduction in the MMP and release of cytochrome c from mitochondria to the cytoplasm in RKO and SW480 cells.Moreover,it was demonstrated that IP3R1 mediates the effect of RCN1 on apoptosis induced by ER stress in CRC cells.The downregulat

关键词： Reticulocalbin 1 Unfolded protein response IP3R1 Colorectal cancer

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Total-factor energy efficiency of ten major global energy-consuming countries

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Journal of Environmental Sciences 2024年第3期137卷 41-52页

作者： xuan wang Yonglong Lu Chunci Chen Xiaojie Yi Haotian Cui State Key Laboratory of Urban and Regional Ecology Research Centre for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China State Key Laboratory of Marine Environmental Science and Key Laboratory of the Ministry of Education for Coastal Wetland Ecosystems College of the Environment and EcologyXiamen UniversityFujian 361102China University of Chinese Academy of Sciences Beijing 100049China

Improving energy efficiency is regarded as a key path to tackling global warming and achieving the Sustainable Development Goals(SDGs).In 2020,the energy consumption of the world's ten major energy-consuming countries accounted for 66.8%of the global total.This paper applied data envelopment analysis(DEA)to calculate these ten major energyconsuming countries'total-factor energy efficiency(TFEE)at national and sectoral levels from 2001-2020,and explored the infuencing factors of total-factor energy efficiency with the Tobit regression model.The results showed significant difference in the ten countries'energy efficiency.The United States and Germany topped the list for total-factor energy efficiency,while China and India were at the bottom.Meanwhile,the energy efficiency of the industrial subsector has increased significantly over the past two decades,while that of the other subsectors has been relatively fat.The industrial structure upgrading,per capita GDP,energy consumption structure,and foreign direct investment had significant impacts on energy efficiency with national heterogeneity.Energy consumption structure and GDP per capita were determinative factors of energy efficiency.

关键词： Total-factor energy efficiency SBM-UN model Major energy-consuming country Carbon emission reduction

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Demonstration of a small‐scale power generator using supercritical CO_(2)

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Carbon Energy 2024年第4期6卷 269-290页

作者： Ligeng Li Hua Tian Xin Lin Xianyu Zeng Yurong wang Weilin Zhuge Lingfeng shi xuan wang Xingyu Liang Gequn Shu State Key Laboratory of Engines Tianjin UniversityTianjinChina Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefeiChina State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijingChina

The supercritical CO_(2)(sCO_(2))power cycle could improve efficiencies for a wide range of thermal power plants.The sCO_(2)turbine generator plays an important role in the sCO_(2)power cycle by directly converting thermal energy into mechanical work and electric power.The operation of the generator encounters challenges,including high temperature,high pressure,high rotational speed,and other engineering problems,such as leakage.Experimental studies of sCO_(2)turbines are insufficient because of the significant difficulties in turbine manufacturing and system construction.Unlike most experimental investigations that primarily focus on 100 kW‐or MW‐scale power generation systems,we consider,for the first time,a small‐scale power generator using sCO_(2).A partial admission axial turbine was designed and manufactured with a rated rotational speed of 40,000 rpm,and a CO_(2)transcritical power cycle test loop was constructed to validate the performance of our manufactured generator.A resistant gas was proposed in the constructed turbine expander to solve the leakage issue.Both dynamic and steady performances were investigated.The results indicated that a peak electric power of 11.55 kW was achieved at 29,369 rpm.The maximum total efficiency of the turbo‐generator was 58.98%,which was affected by both the turbine rotational speed and pressure ratio,according to the proposed performance map.

关键词： generator performance map power generation supercritical CO_(2) turbine

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Engineering high-performance dielectric chiral shells with enhanced chiral fields for sensitive chiral biosensor

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Rare Metals 2024年第3期43卷 1197-1206页

作者： Yi-Fan wang Shan-Shan Huang Zhen-Dong Dai shi-Lin Xian xuan-Nan Wu Fu-Hua Gao Yi-Dong Hou College of Physics Sichuan UniversityChengdu610065China Graduate School of Sichuan University Sichuan UniversityChengdu610065China

Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical resonance.Here,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere monolayer.The form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,respectively.The strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell geometry.The chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically investigated.The DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.

关键词： Dielectric chiral shells(DCS) Si deposition Magnetic resonance Highly sensitive sensor Chiral field

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Impact of frailty on outcomes of elderly patients undergoing percutaneous coronary intervention: A systematic review and metaanalysis

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World Journal of Clinical Cases 2024年第1期12卷 107-118页

作者： shi-shi wang wang-Hao Liu Department of Emergency Medicine Huzhou Third Municipal HospitalThe Affiliated Hospital of Huzhou UniversityHuzhou 313000Zhejiang ProvinceChina Department of Geriatrics Huzhou Third Municipal Hospitalthe Affiliated Hospital of Huzhou UniversityHuzhou 313000Zhejiang ProvinceChina

BACKGROUND Frailty is a common condition in elderly patients who receive percutaneous coronary intervention(PCI).However,how frailty affects clinical outcomes in this group is unclear.AIM To assess the link between frailty and the outcomes,such as in-hospital complic-ations,post-procedural complications,and mortality,in elderly patients post-PCI.METHODS The PubMed/MEDLINE,EMBASE,Cochrane Library,and Web of Science databases were screened for publications up to August 2023.The primary outcomes assessed were in-hospital and all-cause mortality,major adverse cardiovascular events(MACEs),and major bleeding.The Newcastle-Ottawa Scale was used for quality assessment.RESULTS Twenty-one studies with 739693 elderly patients undergoing PCI were included.Frailty was consistently associated with adverse outcomes.Frail patients had significantly higher risks of in-hospital mortality[risk ratio:3.45,95%confidence interval(95%CI):1.90-6.25],all-cause mortality[hazard ratio(HR):2.08,95%CI:1.78-2.43],MACEs(HR:2.92,95%CI:1.85-4.60),and major bleeding(HR:4.60,95%CI:2.89-7.32)compared to non-frail patients.CONCLUSION Frailty is a pivotal determinant in the prediction of risk of mortality,development of MACEs,and major bleeding in elderly individuals undergoing percutaneous coronary intervention.

关键词： Frailty Elderly Percutaneous coronary intervention Systematic review Meta-analysis

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Comparative analysis between single-train passing and double-train intersection in a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 429-442页

作者： Jianming DU Qian FANG xuan ZHANG Hualao wang Bridge and Tunnel Research Center Research Institute of Highway Ministry of TransportBejing 100088China Tunnel and Underground Engineering Research Center of Ministry of Education Beijing Jiaotong UniversityBeijing 00044China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service performance.The aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single train.We used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track tunnel.First,the numerical method was verified by comparing the results of numerical simulation and on-site monitoring.Then,the characteristics of aerodynamic pressure were studied.Finally,the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was investigated.The results show that the aerodynamic pressure variation can be divided into stage I:irregular pressure fluctuations before the train tail leaves the tunnel exit,and stage II:periodic pressure declines after the train tail leaves the tunnel exit.In addition,the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel scenarios.The pressure amplitude in the two-train case is higher than that for a single train.The maximum positive peak pressure difference(P_(STP))and maximum negative peak pressure difference(P_(STN))increase as train speed rises to the power from 2.256 to 2.930 in stage I.The P_(STP) and P_(STN) first increase and then decrease with the increase of tunnel length in stage I.The P_(STP) and P_(STN) increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed Tunnel length Blockage ratio

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