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Evaluation of frictional pressure drop correlations for air-water and air-oil two-phase flow in pipeline-riser system

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Petroleum Science 2024年第2期21卷 1305-1319页

作者： Nai-liang li Bin Chen School of Low-carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou221116JiangsuChina State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049ShaanxiChina

Accurate prediction of the frictional pressure drop is important for the design and operation of subsea oil and gas transporting system considering the length of the pipeline. The applicability of the correlations to pipeline-riser flow needs evaluation since the flow condition in pipeline-riser is quite different from the original data where they were derived from. In the present study, a comprehensive evaluation of 24prevailing correlation in predicting frictional pressure drop is carried out based on experimentally measured data of air-water and air-oil two-phase flows in pipeline-riser. Experiments are performed in a system having different configuration of pipeline-riser with the inclination of the downcomer varied from-2°to-5°to investigated the effect of the elbow on the frictional pressure drop in the riser. The inlet gas velocity ranges from 0.03 to 6.2 m/s, and liquid velocity varies from 0.02 to 1.3 m/s. A total of885 experimental data points including 782 on air-water flows and 103 on air-oil flows are obtained and used to access the prediction ability of the correlations. Comparison of the predicted results with the measured data indicate that a majority of the investigated correlations under-predict the pressure drop on severe slugging. The result of this study highlights the requirement of new method considering the effect of pipe layout on the frictional pressure drop.

关键词： Frictional pressure drop Pipeline-riser Gas-liquid two-phase flow Severe slugging Correlation

Five-view three-dimensional reconstructionfor ultrafast dynamic imaging of pulsedradiation sources

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Matter and Radiation at Extremes 2024年第2期9卷 63-73页

作者： Jianpeng Gao liang Sheng Xinyi Wang Yanhong Zhang liang li Baojun Duan Mei Zhang Yang li Dongwei Hei Department of Engineering Physics Tsinghua UniversityBeijing 100084China National Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear TechnologyXi’an 710024China

Multiaxial neutron/x-ray imaging and three-dimensional (3D) reconstruction techniques play a crucial role in gaining valuable insights intothe generation and evolution mechanisms of pulsed radiation sources. Owing to the short emission time (∼200 ns) and drastic changes of thepulsed radiation source, it is necessary to acquire projection data within a few nanoseconds in order to achieve clear computed tomography3D imaging. As a consequence, projection data that can be used for computed tomography image reconstruction at a certain moment are oftenavailable for only a few angles. Traditional algorithms employed in the process of reconstructing 3D images with extremely incomplete datamay introduce significant distortions and artifacts into the final image. In this paper, we propose an iterative image reconstruction methodusing cylindrical harmonic decomposition and a self-supervised denoising network algorithm based on the deep image prior method. Weaugment the prior information with a 2D total variation prior and a 3D deep image prior. Single-wire Z-pinch imaging experiments have beencarried out at Qin-1 facility in five views and four frames, with a time resolution of 3 ns for each frame and a time interval of 40 ns betweenadjacent frames. Both numerical simulations and experiments verify that our proposed algorithm can achieve high-quality reconstructionresults and obtain the 3D intensity distribution and evolution of extreme ultraviolet and soft x-ray emission from plasma.

关键词： frames image sources

Hybrid vibration isolation optimization of a flexible manipulator based on neural network agent model

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Chinese Journal of Aeronautics 2024年第5期37卷 482-505页

作者： Yongxin ZHANG liang li Dingguo ZHANG Wei-Hsin liAO Xian GUO School of Science Nanjing University of Science and TechnologyNanjing 210094China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flexible ***,machine learning technology is widely used in the engineering field because of its efficient multi-objective *** dynamic simulation of a rotational segmental flexible manipulator system is presented,in which enhanced active constrained layer damping is carried out,and the neural network model of Genetic Algorithm-Back Propagation(GA-BP)algorithm is *** suppression and structural optimization of the SACLD manipulator model are studied based on vibration mode and damping *** modal responses of the SACLD manipulator model at rest and rotation are *** addition,the four model indices are optimized using the GA-BP neural network:axial incision size,axial incision position,circumferential incision size,and circumferential incision ***,the best model for vibration suppression is obtained.

关键词： Machine learning Vibration suppression Flexible manipulator Segmented active constrained layer damping Structural optimization

Realization of flexible in-memory computing in a van der Waals ferroelectric heterostructure tri-gate transistor

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Nano Research 2024年第3期17卷 1886-1892页

作者： Xinzhu Gao Quan Chen Qinggang Qin liang li Meizhuang liu Derek Hao Junjie li Jingbo li Zhongchang Wang Zuxin Chen School of Semiconductor Science and Technology South China Normal UniversityFoshan 528225China Guangdong Provincial Key Laboratory of Chip and Integration Technology Guangzhou 510631China Institute of Solid State Physics Hefei Institutes of Physical Science Chinese Academy of SciencesHefei 230601China School of Science STEM CollegeRMIT UniversityMelbourne 3000Australia CAS Key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Technical Institute of Physics&ChemistryChinese Academy of SciencesUrumqi 830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China College of Optical Science and Engineering Zhejiang UniversityHangzhou 310027China International Iberian Nanotechnology Laboratory(INL) Av.Mestre Jose Veiga s/nBraga 4715-330Portugal

Combining logical function and memory characteristics of transistors is an ideal strategy for enhancing computational efficiency of transistor ***,we rationally design a tri-gate two-dimensional(2D)ferroelectric van der Waals heterostructures device based on copper indium thiophosphate(CuInP_(2)S_(6))and few layers tungsten disulfide(WS_(2)),and demonstrate its multi-functional applications in multi-valued state of data,non-volatile storage,and logic *** co-regulating the input signals across the tri-gate,we show that the device can switch functions flexibly at a low supply voltage of 6 V,giving rise to an ultra-high current switching ratio of 107 and a low subthreshold swing of 53.9 mV/*** findings offer perspectives in designing smart 2D devices with excellent functions based on ferroelectric van der Waals heterostructures.

关键词： two-dimensional(2D)ferroelectric heterostructure tri-gate polymorphic regulation in-memory computing

A Novel Analysis Approach of Uniform Persistence for an Epidemic Model with Quarantine and Standard Incidence Rate

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 695-707页

作者： Song-bai GUO Yu-ling XUE Xi-liang li Zuo-huan ZHENG School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematics and Information Science Shandong Technology and Business UniversityYantai 264005China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Inspired by the transmission characteristics of the coronavirus disease 2019(COVID-19),an epidemic model with quarantine and standard incidence rate is first developed,then a novel analysis approach is proposed for finding the ultimate lower bound of the number of infected individuals,which means that the epidemic is uniformly persistent if the control reproduction number R_(c)>*** approach can be applied to the related biomat hem at ical models,and some existing works can be improved by using *** addition,the infection-free equilibrium V^(0)of the model is locally asymptotically stable(LAS)if R_(c)linearly stable if R_(c)=1;while V^(0)is unstable if R_(c)>1.

关键词： uniform persistence epidemic model control reproduction number quarantine standard incidence rate

A Novel Fracturing Fluid with High-Temperature Resistance for Ultra-Deep Reservoirs

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Fluid Dynamics & Materials Processing 2024年第5期20卷 975-987页

作者： lian liu liang li Kebo Jiao Junwei Fang Yun Luo Northwest Oilfield Branch China Petroleum&Chemical CorporationUrumqi830011China Sinopec Key Laboratory for Enhanced Recovery in Fractured and Cavernous Reservoir Urumqi830011China

Ultra-deep reservoirs play an important role at present in fossil energy *** to the related high temperature,high pressure,and high formation fracture pressure,however,methods for oil well stimulation do not produce satisfactory results when conventional fracturing fluids with a low pumping rate are *** response to the above problem,a fracturing fluid with a density of 1.2~1.4 g/cm^(3)was developed by using Potassium formatted,hydroxypropyl guanidine gum and zirconium crosslinking *** fracturing fluid was tested and its ability to maintain a viscosity of 100 mPa.s over more than 60 min was verified under a shear rate of 1701/s and at a temperature of 175℃.This fluid has good sand-carrying performances,a low viscosity after breaking the rubber,and the residue content is less than 200 mg/*** with ordinary reconstruction fluid,it can increase the density by 30%~40%and reduce the wellhead pressure of 8000 m level reconstruction ***,the new fracturing fluid can significantly mitigate safety risks.

关键词： Ultra-deep reservoir high-temperature resistance weighted fracturing fluid guanidine gum potassium formatted

Large eddy simulation of flow over a three-dimensional hill with different slope angles

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Frontiers of Earth Science 2024年第1期18卷 98-111页

作者： liang li Deqian ZHENG Guixiang CHEN Pingzhi FANG Wenyong MA Shengming TANG School of Civil Engineering Henan University of TechnologyZhengzhou 450001China Henan International Joint Laboratory of Modern Green Ecological Storage System Zhengzhou 450001China Henan Key Laboratory of Grain Storage Facility and Safety Zhengzhou 450001China Shanghai Typhoon Institute of China Meteorological Administration Shanghai 200030China Wind Engineering Research Center Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Slope variation will significantly affect the characteristics of the wind field around a *** paper conducts a large-eddy simulation(LES)on an ideal 3D hill to study the impact of slope on wind field *** slopes ranging from 10°to 45°at 5°intervals are considered,which covers most conventional hill *** inflow turbulence for the LES is generated by adopting a modified generation method that combines the equilibrium boundary conditions with the Fluent inherent vortex method to improve the simulation *** time-averaged flow field and the instantaneous vortex structure under the eight slopes are comparatively *** accuracy of the present method is verified by comparison with experimental *** slope can affect both the mean and fluctuating wind flow fields around the 3D hill,especially on the hilltop and the leeward side,where a critical slope of 25°can be *** fluctuating wind speeds at the tops of steep hills(with slope angles beyond 25°)decrease with increasing slope,while the opposite phenomenon occurs on gentle *** increasing slope,the energy of the high-speed descending airflow is enhanced and pushes the separated flow closer to the hill surface,resulting in increased wind speed near the wall boundary on the leeward side and inhibiting the development of *** vortex shedding trajectory in the wake region becomes wider and longer,suppressing the growth of the mean wind near the wall boundary and enhancing the turbulence intensity.

关键词： large eddy simulation inflow turbulence topographic wind field critical slope flow mechanism

Systematic bibliometric analysis of research hotspots and trends on the application of premium IOLs in the past 2 decades

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International Journal of Ophthalmology(English edition) 2024年第4期17卷 736-747页

作者： liang-Pin li li-Yun Yuan De-Shen Mao Xia Hua Xiao-Yong Yuan Clinical College of Ophthalmology Tianjin Medical UniversityTianjin 300020China Tianjin Key Laboratory of Ophthalmology and Visual Science Tianjin Eye InstituteTianjin Eye HospitalTianjin 300020China School of Medicine Nankai UniversityTianjin 300071China Anhui Medical University Hefei 230032Anhui ProvinceChina Tianjin Aier Eye Hospital Tianjin UniversityTianjin 300190China

AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 ***:The literature search was performed on the Web of Science and included PIOLs studies published between January 2000 and December *** retrieved literature was collated and analyzed by R-tool’s Bibliometrix package,CitNetExplorer,CiteSpace and other ***:A total of 1801 articles about PIOLs were obtained,most of which were published in Spain and the United *** organization that published the most articles was the University of Valencia in ***ó JL,and Montés-Micó R,from Spain were the most influential authors in this *** Journal of Cataract and Refractive Surgery and Journal of Refractive Surgery were the core journals for this field;the top 10 cited articles mainly focus on postoperative satisfaction with multifocal intraocular lens(IOLs)and postoperative results of toric *** the keyword analysis,we found that trifocal IOLs,astigmatism and extended depth of focus(EDoF)IOLs are the most discussed topics at present,and the importance of astigmatism and the clinical application of the new generation of PIOLs are the emerging research ***:Bibliometric analysis can effectively help to identify multilevel concerns in PIOLs research and the prevailing research trends in the realm of PIOLs encompass the adoption of EDoF IOLs,trifocal IOLs,and their respective Toric models.

关键词： premium intraocular lens bibliometric H-index cataract surgery global trends

Nonstoichiometric In-S group yielding efficient carrier transfer pathway in In_(2)S_(3) photoanode for solar water oxidation

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SusMat 2024年第1期4卷 154-165页

作者： Runyu Chen linxing Meng Changda Wang Weiwei Xu Yulong Huang li Song liang li School of Physical Science and Technology Jiangsu Key Laboratory of Thin FilmsCenter for Energy Conversion Materials&PhysicsSoochow UniversitySuzhouJiangsuP.R.China Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow UniversitySuzhouJiangsuP.R.China National Synchrotron Radiation Laboratory CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefeiAnhuiP.R.China School of Electronic and Information Engineering Changshu Institute of TechnologyChangshuJiangsuP.R.China

The construction of high-efficiency photoanodes is essential for developing outstanding photoelectrochemical(PEC)water splitting ***,insufficient carrier transport capabilities and sluggish surface water oxidation kinetics limit its *** a solvothermal annealing strategy,we prepared a nonstoichiometric In-S(NS)group on the surface of an In_(2)S_(3) photoanode in situ and unexpectedly formed a type II transfer path of carrier,thereby reducing the interfacial recombination and promoting the bulk *** calculations and comprehensive characterizations demonstrated NS group as an excellent oxygen evolution cocatalyst(OEC)that effectively facilitated carrier transport,lowered the surface overpotential,increased the surface active site,and accelerated the surface oxygen evolution reaction kinetics by precisely altering the rate-determining steps of*to*OH and*O to**** synergistic effects remarkably enhanced the PEC performance,with a high photocurrent density of 5.02 mA cm^(−2)at 1.23 V versus reversible hydrogen electrode and a negative shift in the onset potential by 310 *** work provides a new strategy for the in situ preparation of high-efficiency OECs and provides ideas for constructing excellent carrier transfer and transport channels.

关键词： In_(2)S_(3) photoanode water splitting