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A new interacting capillary bundle model on the multiphase flow in micropores of tight rocks

Petroleum Science 2024年第2期21卷 1099-1112页

作者： wen-quan Deng Tian-Bo Liang wen-zhong Wang Hao Liu Jun-Lin Wu Fu-Jian Zhou National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettability alteration by surfactants. Although the interacting capillary bundle(ICB) model shows potential in characterizing imbibition rates in different pores during wettability alteration, the existing ICB models neglect the influence of wettability and viscosity ratio on the imbibition behavior, making it difficult to accurately describe the oil-water imbibition behavior within the porous media. In this work,a new ICB mathematical model is established by introducing pressure balance without assuming the position of the leading front to comprehensively describe the imbibition behavior in a porous medium under different conditions, including gas-liquid spontaneous imbibition and oil-water *** the pore size distribution of a tight rock is known, this new model can predict the changes of water saturation during the displacement process in the tight rock, and also determine the imbibition rate in pores of different sizes. The water saturation profiles obtained from the new model are validated against the waterflooding simulation results from the CMG, while the imbibition rates calculated by the model are validated against the experimental observations of gas-liquid spontaneous imbibition. The good match above indicates the newly proposed model can show the water saturation profile at a macroscopic scale while capture the underlying physics of the multiphase flow in a porous medium at a microscopic scale. Simulation results obtained from this model indicate that both wettability and viscosity ratio can affect the sequence of fluid imbibition into pores of different sizes during the multiphase flow, where less-viscous wetting fluid is preferentially imbibed into larger pores while more-viscous wetting fluid tends to be imbibed into smaller pores. Fur

关键词： Imbibition Multiphase flow Tight rock Interacting capillary bundle model Wettability

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Superoscillation:from physics to optical applications

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Light(Science & Applications) 2019年第1期8卷 688-710页

作者： Gang Chen zhong-quan wen Cheng-Wei Qiu College of Optoelectronic Engineering Chongqing University174 Shazheng StreetChongqing 400044China Department of Electrical and Computer Engineering National University of Singapore4 Engineering Drive 3Singapore 117583Singapore

The resolution of conventional optical elements and systems has long been perceived to satisfy the classic Rayleigh *** efforts have been made to develop different types of superresolution techniques to achieve optical resolution down to several nanometres,such as by using evanescent waves,fluorescence labelling,and *** imaging techniques,which are noncontact,far field and label free,are highly desirable but challenging to *** concept of superoscillation offers an alternative route to optical superresolution and enables the engineering of focal spots and point-spread functions of arbitrarily small size without theoretical *** paper reviews recent developments in optical superoscillation technologies,design approaches,methods of characterizing superoscillatory optical fields,and applications in noncontact,far-field and label-free superresolution *** work may promote the wider adoption and application of optical superresolution across different wave types and application domains.

关键词： optical oscillation resolution

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Thermal-force control ability under variation of electromagnetic stick structure parameters in RPECT

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Journal of Iron and Steel Research International 2024年第1期31卷 224-236页

作者： Ting-song Yang wen-quan Sun Feng-shan Du An-rui He quan Yang National Engineering Research Center of Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Institute of Engineering and Technology University of Science and Technology BeijingBeijing100083China College of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina

Thermal-force driving of roll profile electromagnetic control technology(RPECT),which can be used to adjust the roll profile,can be affected by the sequential temperature rise between the electromagnetic stick(ES)and electromagnetic control *** to the limited space of ES and induction coil,the cross-sectional area of induction coil can be inevitably affected by changing the size of the ES induction zone,which can further change the energy input under the same electromagnetic parameters,the temperature rising effect and the bulging *** investigate this phenomenon,the effects of the radius of the induction zone on the thermal-force contribution ratio,the heating ability of ES and the temperature distribution were analyzed through an electromagnetic-thermal-structural finite element *** ensure that the results are applicable to RPECT,the thermal energy conversion ability and thermal-force roll crown control ability under different lengths of the induction zone were *** was found that whether the current density regulation mode or the current frequency regulation mode is adopted,the cases with 20 or 25 mm radius of the induction zone have the great thermal energy conversion ability and the good thermal-force roll crown control *** reasonable adjustment of the length of the induction zone can reduce the radius required for the maximum energy efficiency *** with the results of the simulation analysis,the optimization of ES based on the control ability maximization requirement is achieved,which provides the base for the design and configuration of ES in RPECT.

关键词： Roll profile electromagnetic control technology Electromagnetic stick Electromagnetic control roll Induction area Thermal-force driving

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Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

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Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： Yue Lu Yu-quan Zhang zhong-wei He Yuan Zheng College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China College of Energy and Electrical Engineering Hohai UniversityNanjing210098China Huadong Engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the instability of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

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The association and underlying mechanism of the digit ratio(2D:4D)in hypospadias

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Asian Journal of Andrology 2024年第4期26卷 356-365页

作者： Yu Ding Zu-quan Chen wen-Feng Pan Hao-Jie Chen Min Wu Yi-Qing Lyu Hua Xie Yi-Chen Huang zhong-zhong Chen Fang Chen Department of Urology Shanghai Children’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200062China Urogenital Development Research Center Shanghai Children’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200062China Clinical Research Center for Hypospadias Pediatric CollegeShanghai Jiao Tong University School of MedicineShanghai 200062China.

The second-to-fourth digit(2D:4D)ratio is thought to be associated with prenatal androgen ***,the relationship between the 2D:4D ratio and hypospadias is poorly understood,and its molecular mechanism is not *** this study,by analyzing the hand digit length of 142 boys with hypospadias(23 distal,68 middle,and 51 proximal)and 196 controls enrolled in Shanghai Children’s Hospital(Shanghai,China)from December 2020 to December 2021,we found that the 2D:4D ratio was significantly increased in boys with hypospadias(P<0.001)and it was positively correlated with the severity of the *** was further verified by the comparison of control mice and prenatal low testosterone mice model obtained by knocking out the risk gene(dynein axonemal heavy chain 8[DNAH8])associated with ***,the discrepancy was mainly caused by a shift in *** characterization of a mouse model validated that low testosterone levels during pregnancy can impair the growth and development of *** mechanistic explorations revealed that during the androgen-sensitive window,the downregulation of the androgen receptor(AR)caused by low testosterone levels,as well as the suppressed expression of chondrocyte proliferation-related genes such as Wnt family member 5a(Wnt5a),Wnt5b,Smad family member 2(Smad2),and Smad3;mitochondrial function-related genes in cartilage such as AMP-activated protein kinase(AMPK)and nuclear respiratory factor 1(Nrf-1);and vascular development-related genes such as myosin light chain(MLC),notch receptor 3(Notch3),and sphingosine kinase 1(Sphk1),are responsible for the limitation of 4D growth,which results in a higher 2D:4D ratio in boys with hypospadias via decreased endochondral *** study indicates that the ratio of 2D:4D is a risk marker of hypospadias and provides a potential molecular mechanism.

关键词： androgen receptor digit ratio(2D:4D) endochondral ossification hypospadias testosterone level

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High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

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World Journal of Stem Cells 2024年第2期16卷 176-190页

作者： Yu-Su Wang wen-Hui Chu Jing-Jie Zhai wen-Ying Wang zhong-Mei He quan-Min Zhao Chun-Yi Li Institute of Antler Science and Product Technology Changchun Sci-Tech UniversityChangchun 130000Jilin ProvinceChina College of Chinese Medicinal Materials Jilin Agricultural UniversityChangchun 130118Jilin ProvinceChina School of Life Science Taizhou UniversityTaizhou 318000Zhejiang ProvinceChina Department of Oral Implantology Hospital of StomatologyJilin UniversityChangchun 130000Jilin ProvinceChina

BACKGROUND Cartilage defects are some of the most common causes of *** lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral *** studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral *** To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral *** We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM *** sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the *** weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee *** The defects were successfully repaired by applying the *** highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem *** Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

关键词： Osteochondral defect repair Mesenchymal stem cells Extracellular matrix Decellularization Antler stem cells Reserve mesenchymal cells Xenogeneic

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Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research International 2024年第7期31卷 1811-1823页

作者： zhong-lin Wang Zhi-hua Gong quan Li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

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Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo Xu zhong-li Liu Xiang Chen Yan-xiang Li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake *** this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical *** graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of *** peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction *** morphology of thermal cracks and 3D profiles of the worn surfaces were also *** is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue *** of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal *** the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

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Carbon efficiency modeling and optimization of solar-powered cellular networks

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Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi ZHAO Xiaohu GE wen YAN Tao HAN Yi zhong School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

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Rheological Behaviors of Polymers with Nanoparticles Tethered at Each End

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Chinese Journal of Polymer Science 2024年第3期42卷 400-406,I0009页

作者： Song-Qi Zhang wen-Qing Wang Jia-Ping Lin Li-quan Wang Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The polymer with nanoparticles tethered at each end is a unique model for unraveling the effect of chain ends on the polymer dynamics. We investigated the rheological behavior of this kind of polymer by using nonequilibrium molecular dynamics simulation. The effect of polymer lengths and nanoparticle radii on the complex moduli and viscosity was examined. The dependence of complex moduli on the frequency becomes less pronounced as the polymer is short or the nanoparticle is large. The shear thinning behavior was revealed for these systems, and the scaling exponent of complex viscosity with respect to the frequency was found to change from-1/2 to-3/4 as the polymer shortens or the nanoparticle enlarges. The rheological behavior was further explained by analyzing the mean square distance of nanoparticles. The simulation results were compared with the existing experimental finding, showing an agreement. The work provides information for understanding the chain end effect on polymer rheology.

关键词： Polymer rheology Modulus Viscosity Molecular dynamics

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