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Micro segment analysis of supercritical methane thermal-hydraulic performance and pseudo-boiling in a PCHE straight channel

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Petroleum Science 2024年第2期21卷 1275-1289页

作者： Qian Li zi-jie Lin liu Yang Yue Wang Yue Li Wei-Hua Cai Laboratory of Thermo-Fluid Science and Nuclear Engineering Northeast Electric Power UniversityJilin132000JilinChina School of Energy and Power Engineering Northeast Electric Power UniversityJilin132000JilinChina

The printed circuit heat exchanger(PCHE) is receiving wide attention as a new kind of compact heat exchanger and is considered as a promising vaporizer in the LNG process. In this paper, a PCHE straight channel in the length of 500 mm is established, with a semicircular cross section in a diameter of 1.2 *** simulation is employed to investigate the flow and heat transfer performance of supercritical methane in the channel. The pseudo-boiling theory is adopted and the liquid-like, two-phase-like, and vapor-like regimes are divided for supercritical methane to analyze the heat transfer and flow *** results are presented in micro segment to show the local convective heat transfer coefficient and pressure drop. It shows that the convective heat transfer coefficient in segments along the channel has a significant peak feature near the pseudo-critical point and a heat transfer deterioration when the average fluid temperature in the segment is higher than the pseudo-critical point. The reason is explained with the generation of vapor-like film near the channel wall that the peak feature related to a nucleateboiling-like state and heat transfer deterioration related to a film-boiling-like state. The effects of parameters, including mass flow rate, pressure, and wall heat flux on flow and heat transfer were *** calculating of the averaged heat transfer coefficient of the whole channel, the traditional method shows significant deviation and the micro segment weighted average method is adopted. The pressure drop can mainly be affected by the mass flux and pressure and little affected by the wall heat flux. The peak of the convective heat transfer coefficient can only form at high mass flux, low wall heat flux, and near critical pressure, in which condition the nucleate-boiling-like state is easier to appear. Moreover,heat transfer deterioration will always appear, since the supercritical flow will finally develop into a filmboiling-like state. So hea

关键词： Printed circuit heat exchanger Vaporization Supercritical methane Pseudo-boiling Micro segment analysis

Precisely Control Relationship between Sulfur Vacancy and H Absorption for Boosting Hydrogen Evolution Reaction

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Nano-Micro Letters 2024年第4期16卷 14-24页

作者： Jing Jin Xinyao Wang Yang Hu zhuang zhang Hongbo liu jie Yin Pinxian Xi College of Chemistry and Chemical Engineering Frontiers Science Center for Rare IsotopesState Key Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000People’s Republic of China

Ef fective and robust catalyst is the core of water splitting to produce ***, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performance for hydrogen evolution reaction(HER). With the VS concentration change from 2.4% to 8.5%, the H* adsorption strength on S sites changed and NiS_(2)-VS 5.9% shows the most optimized H* adsorption for HER with an ultralow onset potential(68 m V) and has long-term stability for 100 h in 1 M KOH media. In situ attenuated-total-reflection Fourier transform infrared spectroscopy(ATR-FTIRS) measurements are usually used to monitor the adsorption of intermediates. The S-H* peak of the Ni S_(2)-VS 5.9% appears at a very low voltage, which is favorable for the HER in alkaline media. Density functional theory calculations also demonstrate the Ni S_(2)-VS 5.9% has the optimal |ΔG^(H*)| of 0.17 e V. This work offers a simple and promising pathway to enhance catalytic activity via precise vacancies strategy.

关键词： Hydrogen evolution reaction S vacancies Nanosheet H Adsorption

Dynamic thermo-mechanical responses of road-soft ground system under vehicle load and daily temperature variation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1722-1731页

作者： Chuxuan Tang jie liu zheng Lu Yang zhao Jing zhang Yinuo Feng State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China Xinjiang Transportation Planning Survey and Design Institute Co. Ltd.Urumqi830006China Hubei Key Laboratory of Geo-Environmental Engineering Wuhan430071China

A complete road-soft ground model is established in this paper to study the dynamic responses caused by vehicle loads and/or daily temperature variation.A dynamic thermo-elastic model is applied to capturing the behavior of the rigid pavement,the base course,and the subgrade,while the soft ground is characterized using a dynamic thermo-poroelastic *** to the road-soft ground system are derived in the Laplace-Hankel transform *** time domain solutions are obtained using an integration *** temperature,thermal stress,pore water pressure,and displacement responses caused by the vehicle load and the daily temperature variation are *** show that obvious temperature change mainly exists within 0.3 m of the road when subjected to the daily temperature variation,whereas the stress responses can still be found in deeper places because of the thermal swelling/shrinkage deformation within the upper road ***,it is important to consider the coupling effects of the vehicle load and the daily temperature variation when calculating the dynamic responses inside the road-soft ground system.

关键词： Dynamic response Vehicle load Daily temperature variation Thermo-poroelastic medium Coupling effects

Flame Structure of Methane and Kerosene Combustion with a Compact Concave Flame-Holder using the LES-pdf Method

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Journal of Thermal Science 2024年第1期33卷 222-234页

作者： WANG Fang WANG Yunfan WEI Guanyi liu Denghuan JIN jie JONES P.William School of Energy and Power Engineering Beihang UniversityBeijingBeijing 100191China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Compact flame-holders for afterburners are an increasing requirement for modern aero ***,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex turbulence,combustion,and spray coupling in modern *** this work,the LES-pdf and stochastic fields-Lagrangian particle spray methods are used to investigate methane and aviation kerosene combustion structures formed by new-type concave *** flow pattern,combustion mode,and flame structure of gaseous and liquid fuel around a concave flame-holder are analyzed,discussed,and compared with experimental *** reveal that the flame stability of a concave flame-holder is better than that of the non-concave ***,when using liquid fuel,the concave flame-holder forms a stable and compact *** results suggest concave flame-holders are a promising design for compact afterburners.

关键词： concave structure flame-holder LES-pdf spray combustion flame structure AECSC

Anti-abrasion collagen fiber-based membrane functionalized by UiO-66-NH_(2)with ultra-high efficiency and stability for oil-in-water emulsions separation

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Chinese Journal of Chemical Engineering 2024年第2期66卷 285-297页

作者： Xiaoxia Ye Rixin Huang zhihong zheng Juan liu jie Chen Yuancai Lv College of Environmental and Safety Engineering Fuzhou UniversityFuzhou 350108China College of Chemical Engineering Fuzhou UniversityFuzhou 350108China

Membrane separation strategies offer promising platform for the emulsion ***,the low mechanical strength of membrane separation layers and the trade-off between separation flux and efficiency present significant *** this study,we report a CFM@UiO-66-NH_(2)membrane with high separation flux,efficiency and stability,through utilizing a robust anti-abrasion collagen fiber membrane(CFM)as the multifunctional support and UiO-66-NH_(2)by an in-situ growth as the separation *** high mechanical strength of the CFM compensated for the weakness of the separation layer,while the charge-breaking effect of UiO-66-NH_(2),along with the size sieving of its constituent separating layers and the capillary effect of the collagen fibers,contributed to the potential for efficient ***,the CFM@UiO-66-NH_(2)membrane exhibited superhydrophilic properties,making it suitable for separating oil-in-water microemulsions and nanoemulsions stabilized by anionic *** membrane demonstrated remarkable separation efficiencies of up to 99.960%and a separation flux of370.05 L·m^(-2)·h^(-1).Moreover,it exhibits stability,durability,and abrasion resistance,maintaining excellent separation performance even when exposed to strong acids and alkalis without any damage to its structure and *** six cycles of reuse,it achieved a separation flux of 417.97 L·m^(-2)·h^(-1)and a separation efficiency of 99.747%.Furthermore,after undergoing 500 cycles of strong abrasion,the separation flux remained at 124.39 L·m^(-2)·h^(-1),with a separation efficiency of 99.992%.These properties make it suitable for the long-term use in harsh operating *** attribute these properties to the electrostatic effect resulting from the amino group on UiO-66-NH_(2)and its in-situ growth on the CFM,which forms a size-screening separation *** work highlights the potential of the CFM@UiO-66-NH_(2)membrane as an environmentally friendly size-screening

关键词： Collagen fibers Metal-organic frameworks Oil-in-water emulsion separation Size sieving

Temporal assembly patterns of microbial communities in three parallel bioreactors treating low-concentration coking wastewater with differing carbon source concentrations

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Journal of Environmental Sciences 2024年第3期137卷 455-468页

作者： Weijia Li Yu Xia Na Li jie Chang Jing liu Pei Wang Xuwen He School of Chemical and Environmental Engineering China University of Mining and Technology-BeijingBeijing 100083China

Carbon source is an important factor of biological treatment systems, the effects of which on their temporal community assembly patterns are not sufficiently understood *** this study, the temporal dynamics and driving mechanisms of the communities in three parallel bioreactors for low-concentration coking wastewater(CWW) treatment with differing carbon source concentrations(S0 with no glucose addition, S1 with 200 mg/L glucose addition and S2 with 400 mg/L glucose addition) were comprehensively studied. Highthroughput sequencing and bioinformatics analyses including network analysis and Infer Community Assembly Mechanisms by Phylogenetic bin-based null model(iCAMP) were used. The communities of three systems showed turnover rates of 0.0029~0.0034 every 15days. Network analysis results showed that the S0 network showed higher positive correlation proportion(71.43%) and clustering coefficient(0.33), suggesting that carbon source shortage in S0 promoted interactions and cooperation of microbes. The neutral community model analysis showed that the immigration rate increased from 0.5247 in S0 to 0.6478in S2. The iCAMP analysis results showed that drift(45.89%) and homogeneous selection(31.68%) dominated in driving the assembly of all the investigated microbial *** contribution of homogeneous selection increased with the increase of carbon source concentrations, from 27.92% in S0 to 36.08% in S2. The OTUs participating in aerobic respiration and tricarboxylic acid(TCA) cycle were abundant among the bins mainly affected by deterministic processes, while those related to the metabolism of refractory organic pollutants in CWW such as alkanes, benzenes and phenols were abundant in the bins dominated by stochastic processes.

关键词： Coking wastewater treatment Temporal dynamics Network analysis Deterministic processes Stochastic processes

An Integral Method for Solving Dynamic Equations with Fluid–Solid Coupling

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Acta Mechanica Solida Sinica 2024年第1期37卷 99-108页

作者： Xin zhang jie liu Pu Xue Shuowen Yan Yahao Xu M.S.zahran School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Civil Engineering Military Technical CollegeCairo 11435Egypt

In this work,a new methodology is presented to mainly solve the fluid–solid interaction(FSI)*** methodology combines the advantages of the Newmark precise integral method(NPIM)and the dual neural network(DNN)*** NPIM is employed to modify the exponential matrix and loading vector based on the DNN integral *** involves incorporating the basic assumption of the Newmark-βmethod into the dynamic equation and eliminating the acceleration term from the dynamic equilibrium *** a result,the equation is reduced to a first-order linear equation ***,the PIM is applied to integrate the system step by step within the *** DNN method is adopted to solve the inhomogeneous term through fitting the integrand and the original function with a pair of neural networks,and the integral term is solved using the Newton–Leibniz *** examples demonstrate that the proposed methodology significantly improves computing efficiency and provides sufficient precision compared to the DNN *** is particularly evident when analyzing large-scale structures under blast loading conditions.

关键词： Newmark precise integral method(NPIM) Dual neural networks(DNN) Fluid-solid interaction(FSI) Dynamic time-history analysis Blast loading

Advances in selective conversion of carbohydrates into 5-hydroxymethylfurfural

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Green Energy & Environment 2024年第9期9卷 1384-1406页

作者： jie Liang Jianchun Jiang Tingting Cai Chao liu Jun Ye Xianhai zeng Kui Wang Institute of Chemical Industry of Forest Products Chinese Academy of Forestry National Engineering Lab.for Biomass Chemical Utilization Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry University College of Energy State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University

Converting carbohydrates into 5-hydroxymethylfurfural(5-HMF) is an attractive and promising route for value-added utilization of agricultural and forestry biomass resource. As an important platform compound, 5-HMF possesses high active furan structure with hydroxymethyl and aldehyde group for production of various bio-chemicals and materials, meanwhile, which suffer from low stability and poor yield during the industrial biorefinery process. Hence, selective production of 5-HMF with high-yield and low-cost has attracted extensive attention from scientific and industrial researchers. This review sorted and described the latest advanced research on solvent and catalyst system, as well as energy field effect for production of 5-HMF with different feedstock in detail, emphatically discussing the solvent effect and its synergistic effect with other aspects. Besides, the future prospects and challenges for production of 5-HMF from carbohydrates were also presented, which provide a profound insight into industrial 5-HMF process with economic and environmental feature.

关键词： 5-Hydroxymethylfurfural Biorefinery Solvent Selectivity Carbohydrate

A reweighted damped singular spectrum analysis method for robust seismic noise suppression

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Petroleum Science 2024年第3期21卷 1671-1682页

作者： Wei-Lin Huang Yan-Xin zhou Yang zhou Wei-jie liu Ji-Dong Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China SINOPEC Petroleum Exploration and Production Research Institute Beijing102206China SINOPEC Geophysical Research Institute Nanjing211103jiangsuChina

(Multichannel)Singular spectrum analysis is considered as one of the most effective methods for seismic incoherent noise *** utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction ***,in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically larger than other *** presence of this kind of noise,called erratic noise,makes singular spectrum analysis(SSA)reconstruction unstable and has undesirable effects on the final *** robustify the low-rank reconstruction of seismic data by a reweighted damped SSA(RD-SSA)*** incorporates the damped SSA,an improved version of SSA,into a reweighted *** damping operator is used to weaken the artificial disturbance introduced by the low-rank projection of both erratic and random *** central idea of the RD-SSA method is to iteratively approximate the observed data with the quadratic norm for the first iteration and the Tukeys bisquare norm for the rest *** RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic *** feasibility of RD-SSA is validated via both synthetic and field data examples.

关键词： Singular spectrum analysis Damping operator Seismic erratic noise Seismic signal processing Robust low-rank reconstruction