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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

Controllable chemical redox reactions to couple microbial degradation for organic contaminated sites remediation:A review

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Journal of Environmental Sciences 2024年第5期139卷 428-445页

作者： bin chen Jiang Xu Lizhong Zhu College of Environmental and Resource Sciences Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Zhejiang UniversityHangzhou 310058China Zhejiang Agriculture&Forest University Lin'an 311300China

Global environmental concern over organic contaminated sites has been progressively conspicuous during the process of urbanization and industrial *** traditional physical or chemical remediation technologies may significantly destroy the soil structure and function,coupling moderate chemical degradation with microbial remediation becomes a potential way for the green,economic,and efficient remediation of contaminated ***,this work systematically elucidates why and how to couple chemical technology with microbial remediation,mainly focused on the controllable redox reactions of organic *** rational design of materials structure,selective generation of reactive oxygen species,and estimation of degradation pathway are described for chemical ***,current progress on efficient and selective reductions of organic contaminants(i.e.,dechlorination,defluorination,-NO_(2) reduction)is *** with the microbial remediation of contaminated sites,several consideration factors of how to couple chemical and microbial remediation are proposed based on both fundamental and practical points of *** review will advance the understanding and development of chemical-microbial coupled remediation for organic contaminated sites.

关键词： Soil remediation Groundwater remediation Rational design Reactive species Environmental nanotechnology

Tuning mechanical behaviors of highly entangled hydrogels with the random distribution of mobile entanglements

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 277-294页

作者： Jinlong LIU Di LU bin chen Department of Engineering Mechanics Zhejiang UniversityHangzhou 310027China Beijing System Design Institute of Electro-Mechanic Engineering Beijing 100854China Intelligent Robotic Research Center Zhejiang LaboratoryHangzhou 310027China Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Hangzhou 311100China

Highly entangled hydrogels exhibit excellent mechanical properties,including high toughness,high stretchability,and low *** considering the evolution of randomly distributed entanglements within the polymer network upon mechanical stretches,we develop a constitutive theory to describe the large stretch behaviors of these *** the theory,we utilize a representative volume element(RVE)in the shape of a cube,within which there exists an averaged chain segment along each edge and a mobile entanglement at each *** employing an explicit method,we decouple the elasticity of the hydrogels from the sliding motion of their entanglements,and derive the stress-stretch relations for these *** present theoretical analysis is in agreement with experiment,and highlights the significant influence of the entanglement distribution within the hydrogels on their *** also implement the present developed constitutive theory into a commercial finite element software,and the subsequent simulations demonstrate that the exact distribution of entanglements strongly affects the mechanical behaviors of the structures of these ***,the present theory provides valuable insights into the deformation mechanism of highly entangled hydrogels,and can aid in the design of these hydrogels with enhanced performance.

关键词： highly entangled hydrogel constitutive theory entanglement gamma distribution

The growth ofβphase in Mg-Gd-Y-Ni alloy by experimental and first-principles study

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Journal of Magnesium and Alloys 2024年第2期12卷 506-515页

作者： Yiqiang Hao Lei Zhou Zhiqing chen Zhixian Zhao bin chen School of Materials Science and Engineering Shanghai Jiao Tong University800 Dongchuan RoadShanghai200240China

The paper reports on the atomic investigation aboutβphase in Mg_(96)Gd_(2)Y_(1)Ni_(1) alloy by using the first-principles study and the high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM)corrected by atomic *** using HAADF-STEM,the rectangularβphases were observed in the underage and peak aging stages in Mg_(96)Gd_(2)Y_(1)Ni_(1) ***βphase could be precipitated from the previously precipitatedβphase,and theβphase grew in steps when it was precipitated.A special transition structure of three atomic layer thicknesses was first observed at the edge of theβphase and the structure of this interface is probably as theβ/Mg_(1) interface for the analysis of thermodynamic characterization and electronic ***β'phase and theβ_(H) structure were precipitated only at the edge of the length directions of theβ***β'phase continues to grow into aβphase directly without the formation ofβ_(1) phase,resulting in an increase in the length of theβphase,which is discovered for the first time.

关键词： HAADF-STEM First-principles study Mg-Gd-Y-Ni alloy βphase Growth Interface

Microlensing bias on the detection of strong lensing gravitational wave

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 156-165页

作者： Xikai Shan Xuechun chen bin Hu Guoliang Li Institute for Frontier in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Astronomy Beijing Normal UniversityBeijing 100875China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

Identifying strong lensing gravitational wave(SLGW)events is of utmost importance in astrophysics as we approach the historic first detection of SLGW amidst the growing number of gravitational wave(GW)***,one crucial method for identifying SLGW signals involves assessing the overlap of parameters between two ***,the distribution of discrete matter,such as stars and sub-halos,within the strong lensing galaxy can imprint a wave optical(WO)effect on the SLGW *** frequency dependent imprints introduce biases in parameter estimation and impact SLGW *** this study,we assess the influence of the stellar microlensing field embedded in a strong lensing *** findings demonstrate that the WO effect reduces the detection efficiency of SLGW by 5%-50%for various false alarm probabilities per pair(FAPper pair).Specifically,at an FAPper pairof 10^(-5),the detection efficiency decreases from~10%to~5%.Consequently,the presence of the microlensing field can result in missing half of the strong lensing ***,the microlensing WO effect introduces a noticeable bias in intrinsic parameters,particularly for chirp mass and mass ***,it has tiny influence on extrinsic *** all parameters,~30%of events exhibit a 1σparameter bias,~12%exhibit a 2σparameter bias,and~5%exhibit a 3σparameter bias.

关键词： gravitational wave gravitational strong lensing gravitational micro lensing wave optical effect

Enhanced piezoelectric performance of Cr/Ta non-equivalent co-doped Bi_(4)Ti_(3)O_(12)-based high-temperature piezoceramics

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Journal of Advanced Ceramics 2024年第3期13卷 263-271页

作者： Xuanyu chen Ziqi Ma bin Li Yejing Dai School of Materials Sun Yat-sen UniversityShenzhen 518107China

In this study,(Cr_(1/3)/Ta_(2/3))non-equivalent co-doped Bi_(4)Ti_(3)O_(12)(BIT)ceramics were prepared to solve the problem that high piezoelectric performance,high Curie temperature,and high-temperature resistivity could not be achieved simultaneously in BIT-based ceramics.A series of Bi_(4)Ti_(3-x)(Cr_(1/3)Ta_(2/3))_(x)O_(12)(x=0-0.04)ceramics were synthesized by the solid-state reaction *** phase structure,microstructure,piezoelectric performance,and conductive mechanism of the samples were systematically *** B-site non-equivalent co-doping strategy combining high-valence Ta^(5+)and low-valence Cr^(3+)significantly enhances electrical properties due to a decrease in oxygen vacancy ***_(4)Ti_(2.97)(Cr_(1/3)Ta_(2/3))_(0.03)O_(12)ceramics exhibit a high piezoelectric coefficient(d_(33)=26 pC·N^(-1))and a high Curie temperature(TC=687℃).Moreover,the significantly increased resistivity(ρ=2.8×10^(6)Ω·cm at 500℃)and good piezoelectric stability up to 600℃are also obtained for this *** the results demonstrate that Cr/Ta co-doped BIT-based ceramics have great potential to be applied in high-temperature piezoelectric applications.

关键词： high temperature piezoelectricity co-doped Bi_(4)Ti_(3)O_(12)(BIT)

Spectral Selectivity of CdTe Cells with Substrate Configuration for Photovoltaic/Thermal Applications

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Journal of Thermal Science 2024年第4期33卷 1542-1553页

作者： chen Ken HU Kongfu ZHAO bin chen Tao HAO Yong PEI Gang Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei230027China Key Laboratory of Solar Thermal Conversion of Anhui Province Hefei230027China Hefei National Laboratory for Physical Sciences at Microscale Department of Materials Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Existing photovoltaic cells with high infrared emissivity generate huge radiative heat loss in photovoltaic/thermal applications and degrade the photothermal *** purpose of this work is to evaluate the full spectral absorptivity of CdTe cells to find a spectrally selective photovoltaic cell for photovoltaic/thermal *** this end,the solar absorptivity and mid-infrared thermal emissivity of CdTe cells were tested by ellipsometry,UV-Vis-NIR spectrophotometer,and Fourier transform infrared *** experimental results show that the AM 1.5 solar spectrum weighted absorptivity of the substrate configuration CdTe cell reaches 0.91,and the mid-infrared emissivity is only 0.29,while the superstrate configuration cell emissivity is as high as *** research shows that substrate configuration with a transparent conductive layer on top can be flexibly grown on metal foils and has spectral selectivity with high solar absorptivity and low mid-infrared emissivity should be considered in the future for photovoltaic/thermal applications.

关键词： photovoltaic/thermal spectral selectivity substrate configuration CdTe cell ITO

High-efficiency Multiplexed Buck-type PFC Converter

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1053-1063页

作者： Lunquan Li Qianhong chen Jichao Huang bin Liu School of Automation Nanjing University of Aeronautics and AstronauticsNanjing 211106China Gaoyi Zhineng Electric Ltd. Shenzhen 518101China School of Information Engineering Nanchang Hang Kong UniversityNanchang 330063China IEEE CSEE

This paper proposes a high-efficiency PFC rectifier based on multiplexing the *** with a traditional six-switch PFC rectifier,the proposed rectifier extends the switches’active angle by making use of three bridge *** a result,lower conduction resistance can be realized for ***,system efficiency can be *** with a traditional six-switch PFC rectifier with doubled switches,the proposed rectifier can achieve almost the same efficiency improvement while no additional switches are *** continuous inductor current is chopped and resulting current pulses cannot be injected into the grid directly,input filter design and resonance damping are discussed for the proposed *** controller design of the rectifier is *** inductor current reference is shaped considering the input voltage envelope and forward ***,the effectiveness of the proposed rectifier is verified through simulations and experiments.

关键词： Buck-type rectifier commutation state controller design efficiency multiplex

An adaptive large neighborhood search for the multi-point dynamic aggregation problem

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Control Theory and Technology 2024年第3期22卷 360-378页

作者： Shengyu Lu bin Xin Jie chen Miao Guo School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Lab of Autonomous Intelligent Unmanned Systems Beijing 100081China Department of Control Science and Engineering Tongji UniversityShanghai 201804China

The multi-point dynamic aggregation(MPDA)problem is a challenging real-world *** the MPDA problem,the demands of tasks keep changing with their inherent incremental rates,while a heterogeneous robot fleet is required to travel between these tasks to change the time-varying state of each *** robots are allowed to collaborate on the same task or work separately until all tasks are *** is challenging to generate an effective task execution plan due to the tight coupling between robots abilities and tasks'incremental rates,and the complexity of robot *** effectiveness consideration,we use the variable length encoding to avoid redundancy in the solution *** creatively use the adaptive large neighborhood search(ALNS)framework to solve the MPDA *** the proposed algorithm,high-quality initial solutions are generated through multiple problem-specific solution construction *** heuristics are also used to fix the broken solution in the novel integrated decoding-construction repair process of the ALNS *** results of statistical analysis by the Wilcoxon rank-sum test demonstrate that the proposed ALNS can obtain better task execution plans than some state-of-the-art algorithms in most MPDA instances.

关键词： Adaptive large neighborhood search(ALNS) Multi-point dynamic aggregation(MPDA) Heuristic solution construction Multi-robot collaboration