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Eco-friendly calcium alginate microspheres enable enhanced profile control and oil displacement

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Petroleum science 2024年第3期21卷 1928-1943页

作者： xiao-Han Zhang Chang-Jing Zhou Yuan-Xiang xiao Bo Hui Yong-Gang Xie Yu-Bin Su Xin-Ru Li Jie Huang Mao-Chang Liu International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an710049ShaanxiPR.China Shaanxi Key Laboratory of Advanced Stimulation technology for Oil&Gas Reservoirs School of Petroleum EngineeringXi'an Shiyou UniversityXi'an 710065ShaanxiPR.China Oil&Gas technology Research Institute Changqing Oilfield Branch CompanyPetroChinaXi'an710021ShaanxiPR China Suzhou Academy of Xi'an Jiaotong university Suzhou215123JiangsuPR China

Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental ***,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for *** dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio *** comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil *** introduction of SDS will have a negative impact on rheological properties,which is not favored for *** results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 3..3.%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.

关键词： Calcium alginate microspheres Wettability Interfacial tension Rheology Viscoelasticity Enhanced oil recovery(EOR)

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 499-512页

作者： Yue-Hui Dang Sheng-Lin Liu xiao-Lei Ai xiao-Wei Feng Bo Feng Zhuo Tian Ying-Fei Lin Huan-Tao Chen Kai-Hong Zheng school of Materials science and Engineering Chang’an UniversityShaanxi 710064China Guangdong Key Laboratory of Metal Toughening technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510650China

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite *** rule of mixtures(ROM)for elongation was also *** results show that when there is no or thin diffusion layer with thickness of about 3.m,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental *** contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM *** plasticity of Mg-based bimetal plates increases with increasing sleeve *** study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

关键词： Mg-based composites Co-extrusion Microstructure Mechanical behavior Plastic deformation

The Choice of Mesh Size and Integration Points Number for the Electrostatically Controlled Membrane Antenna Structural-Electromagnetic Coupling Model

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Chinese Journal of Electronics 2024年第2期33卷 443-448页

作者： Yongzhen GU Qinggang ZHANG xiao YU Guixu LI Qingdao university of science and technology

It is of great significance for the improvement of the computational efficiency of the electrostatically controlled membrane antenna(ECMA) structural-electromagnetic coupling model through the choice of appropriate mesh size and integration points number. In this paper, the physical optics formulation is used to analyze the radiation pattern of the ECMA surface, and the finite element method is applied to the electrostatic-structural coupling analysis. An expression for the relation between the mesh size, the focal length of the parabolic antenna, and the wavelength is developed based on the discretization error analysis of the triangular mesh approximating the parabolic surface. Moreover, the integration points number in each triangular mesh is determined by the numerical evaluation of the physical optics integral. Numerical results show that the proposed method improves the computing efficiency by about 87% compared with the referenced method.

关键词： Couplings Surface waves Error analysis Computational modeling Physical optics Numerical models Finite element analysis

Impacts of Water-Sediment Regulation Scheme on Chromophoric Dissolved Organic Matter in the Lower Yellow River

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Journal of Ocean university of China 2024年第2期23卷 455-466页

作者： LIU xiao JIANG Xueyan LIU Qian SUI Juanjuan ZOU Li Key Laboratory of Marine Chemistry Theory and technology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China school of Earth sciences University of BristolBristolBS81RJUK North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai SeaMinistry of Natural ResourcesQingdao 266033China Key Laboratory of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Environmental science and Engineering Ocean University of ChinaQingdao 266100China

As a river with more than 3.00 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water ***-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water *** dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human ***,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during *** addition,a parallel factor fluorescence analysis(PARAFAC)method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3.and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3.increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM *** the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS *** resuspension inhibits microbial activities and reduces the production of autochthonous ***,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment.

关键词： chromophoric dissolved organic matter(CDOM) water-sediment regulation scheme(WSRS) Yellow River optical properties

Statistical study of magnetic holes in the upstream region of Mercury’s bow shock

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Earth and Planetary Physics 2024年第2期8卷 326-337页

作者： GuoQiang Wang SuDong xiao MingYu Wu YuanQiang Chen TieLong Zhang Institute of Space science and applied technology Harbin Institute of TechnologyShenzhen 518055China Shenzhen Key Laboratory of Numerical Prediction for Space Storm Harbin Institute of TechnologyShenzhen 518055China Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Chinese Academy of sciences Center for Excellence in Comparative Planetology Hefei 230026China Space Research Institute Austrian Academy of SciencesGrazAustria

Magnetic holes are magnetic depression structures that exist widely in many plasma *** magnetic holes with durations of>1 s in the solar wind at Mercury’s orbit have drawn much attention,but the properties of the magnetic holes with shorter durations are still ***,we investigate the magnetic holes with durations of 0.1-100 s in the upstream region of Mercury’s bow shock based on observations by the MESSENGER(MErcury Surface,Space ENvironment,GEochemistry,and Ranging)*** can be divided into two groups according to the distribution of their duration:small-duration magnetic holes(SDMHs,0.6 s).The duration of each group approximately obeys a log-normal distribution with a median of~0.25 s and 3.s,*** 1.7%(3..6%)of the SDMHs(LDMHs)reduce the magnetic field strength by more than 50%.For both groups,some structures have a linear or quasi-linear polarization,whereas others have an elliptical *** magnetic hole events in both groups tend to have a higher rate of occurrence when the interplanetary magnetic field strength is *** occurrence rates are also affected by Mercury’s foreshock,which can increase(decrease)the occurrence rate of the SDMHs(LDMHs).This finding suggests that Mercury’s foreshock might be one source of the SDMHs and that the foreshock can destroy some *** observations suggest that a new group of magnetic holes with durations of<0.6 s exist in the upstream region of Mercury’s bow shock.

关键词： magnetic hole solar wind Mercury foreshock

Measurement of the high energyγ-rays from heavy ion reactions usingČerenkov detector

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Nuclear science and Techniques 2024年第2期35卷 123-130页

作者： Da-Wei Si Yan Zhou Sheng xiao Zhi Qin Dong Guo Yu-Hao Qin Yi-Jie Wang Bo-Yuan Zhang Bai-Ting Tian Zhi-Gang xiao Department of Physics Tsinghua UniversityBeijing 100084China

The energetic bremsstrahlung photons up to 100 MeV produced in heavy ion collisions can be used as a sensitive probe for short-range correlation in atomic nuclei. The energy of the γ-rays can be measured by collecting the Čerenkov light in the medium induced by the fast electrons generated in the Compton scattering or electromagnetic shower of the incident γray. Two types of detectors based on pure water and lead glass as sensitive materials were designed for this purpose. The γresponse and optical photon propagation in the detectors were simulated based on electromagnetic and optical processes in Geant4. The inherent energy resolutions of 0.022(4) + 0.51(2)∕E^(1/2)_(γ) for water and 0.0026(3. + 0.446(3.∕E^(1/2)_(γ) for lead glass were obtained. The geometry sizes of the lead glass and water were optimized to 3. cm × 3. cm × 3. cm and 60 cm × 60 cm ×120 cm, respectively, to detect high-energy γ-rays at 160 MeV. The Hough transform method was applied to reconstruct the direction of the incident γ-rays, providing the ability to experimentally distinguish the high-energy γ-rays produced in the reactions on the target from random background cosmic-ray muons.

关键词： Bremsstrahlungγ-rays Čerenkov Geant4 Energy resolution Direction reconstruction Hough transform

IMPROVING EIGENVECTORS IN ARNOLDI'S METHOD

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Journal of Computational Mathematics 2000年第3期18卷 265-276页

作者： Zhong-xiao Jia (Department of applied Mathematics, Dalian university of {3., Dalian 116024, China) Ludwig Elsner (Fakultat fur Mathematik, university Bielefeld, Postfach 10013., 3.501 Bielefeld,Germany) 大连理工大学辽宁大连 116024 Universitt Bielefeld 德国 Bielefeld 33501

The Ritz vectors obtained by Arnoldi's method may not be good approxima- tions and even may not converge even if the corresponding Ritz values do. In order to improve the quality of Ritz vectors and enhance the efficiency of Arnoldi type algorithms, we propose a strategy that uses Ritz values obtained from an m-dimensional Krylov subspace but chooses modified approximate eigenvectors in an (m + 1)-dimensional Krylov subspace. Residual norm of each new approximate eigenpair is minimal over the span of the Ritz vector and the (m+1)th basis vector, which is available when the m-step Arnoldi process is run. The resulting modi- fied m-step Arnoldi method is better than the standard m-step one in theory and cheaper than the standard (m + 1)-step one. Based on this strategy, we present a modified m-step restarted Arnoldi algorithm. Numerical examples show that the modified m-step restarted algorithm and its version with Chebyshev acceleration are often considerably more efficient than the standard (m+ 1)-step restarted ones.

关键词： Large unsymmetric The m-step Arnoldi process The m-step Arnoldi method Eigenvalue Ritz value Eigenvector Ritz vector Modified

A Comparative Study on the Post-Buckling Behavior of Reinforced Thermoplastic Pipes(RTPs)Under External Pressure Considering Progressive Failure

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China Ocean Engineering 2024年第2期38卷 233-246页

作者： DING Xin-dong WANG Shu-qing LIU Wen-cheng YE xiao-han College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China Department of Marine technology Norwegian University of Science and Technology(NTNU)Trondheim NO-7491Norway

The collapse pressure is a key parameter when RTPs are applied in harsh deep-water *** investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are *** the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary *** for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with *** has been observed that the cross-section of the middle part collapses when it reaches the maximum *** collapse pressure obtained from the numerical simulations agrees well with that in the ***,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also *** has a relatively greater difference because of the ignorance of the progressive failure of *** the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.

关键词： reinforced thermoplastic pipes post-buckling behavior progressive failure of composites debonding initial ovality

Fast spreading of surface ozone in both temporal and spatial scale in Pearl River Delta

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Journal of Environmental sciences 2024年第3期137卷 540-552页

作者： Tianhui Cao Haichao Wang Lei Li xiao Lu Yiming Liu Shaojia Fan school of Atmospheric sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China

Surface ozone(O_(3.)is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),***,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during *** results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O_(3.)showed an overall upward trend by 1.11 ppbv/*** the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/*** hot spots of ozone were spreading to southwestern areas from the central areas since *** ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3.at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as≥3.days)was ***,the ozone concentration of continuous type was much higher than that of scattered exceedance type(3.days).In addition,although the occurrence of continuous type starts to decline since2017,the total number of exceedance days during the continuous type is *** results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O_(3.pollution in these cities.

关键词： Surface ozone pollution Ozone trend Spatial and temporal variability Pearl River Delta Pollution mitigation