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Fracture sealing performance of granular lost circulation materials at elevated temperature:A theoretical and coupled CFD-DEM simulation study

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Petroleum Science 2024年第1期21卷 567-581页

作者： Chong Lin qi-Cong Xu Lie-Xiang Han Gao Li hai he Hong-Ling Zhou Ji-Ping She CCDC Drilling&Production Technology Research Institute Guanghan618300SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina College of Materials Science and Engineering Chongqing UniversityChongqing400044China State Key Lab of Oil and Gas Reservoir Geology and Exploitation(Chengdu University of Technology) Chengdu610059SichuanChina College of Energy Chengdu University of TechnologyChengdu610059SichuanChina

Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)*** circulation material(LCM)is a regular preventive and remedial measure for lost ***,conventional LCMs seem ineffective in high-temperature *** may be due to the changes in the mechanical properties of LCMs and their sealing performance under high-temperature *** understand how high temperature affects the fracture sealing performance of LCMs,we developed a coupled computational fluid dynamics-discrete element method(CFD-DEM)model to simulate the behavior of granular LCMs in *** summarized the literature on the effects of high temperature on the mechanical properties of LCMs and the rheological properties of drilling *** conducted sensitivity analyses to investigate how changing LCM slurry properties affected the fracture sealing efficiency at increasing *** results show that high temperature reduces the size,strength,and friction coefficient of LCMs as well as the drilling fluid ***,softer,and less frictional LCM particles have lower bridging probability and slower bridging *** particles tend to form dual-particle bridges rather than single-particle *** result in a deeper,tighter,but unstable sealing *** drilling fluid viscosity leads to faster and shallower sealing zones.

关键词： Geothermal well drilling HTHP formationLost circulation material CFD-DEM Fracture sealing

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High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： Wei-Zhi Luo Mu he Liang Xia qi-Chang he State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et Simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

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Spatial construction of ultrasmall Pt-decorated 3D spinel oxidemodified N-doped graphene nanoarchitectures as high-efficiency methanol oxidation electrocatalysts

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Rare Metals 2024年第1期43卷 186-197页

作者： qi Zhang Min-Min Yan Wen-Fa Du Chen-Yu Yin Jian Zhang Lu Yang Yun-qing Kang hai-Yan he Hua-Jie Huang College of Mechanics and Materials Hohai UniversityNanjing 210098China New Energy Technology Engineering Lab of Jiangsu Province College of ScienceNanjing University of Posts&Telecommunications(NUPT)Nanjing 210023China International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials ScienceTsukuba 305-0044IbarakiJapan

Direct methanol fuel cell technology recently becomes the focus of both academic and engineering circles,which stimulates the exploitation and utilization of advanced electrode catalysts with high activity and long ***,we demonstrate a robust bottom-up approach to the spatial construction of three-dimensional(3D) spinel manganese-cobalt oxide-modified N-doped graphene nanoarchitectures decorated with ultrasmall Pt nanoparticles(Pt/MnCo_(2)O_(4)-NG) via a controllable selfassembly *** incorporation of MnCo_(2)O_(4)nanocrystals provides abundant hydroxyl sources to promote the oxidative removal of CO-like byproducts on Pt sites,while the existence of 3D porous N-doped graphene networks facilitates the transportation of both ions and electrons in the hybrid system,thus giving rise to remarkable synergetic coupling effects during the methanol oxidation ***,the optimized Pt/MnCo_(2)O_(4)-NG nano architecture expres ses exceptional electrocatalytic properties with a large electrochemically active surface area of 99.5 m^(2)·g^(-1),a high mass activity of1508.3 mA·mg^(-1),strong toxicity resistance and reliable long-term durability,which have obvious competitive advantages over those of conventional Pt/carbon black,Pt/carbon nano tube,Pt/graphene,and Pt/N-doped graphene catalysts with the same Pt usage.

关键词： Platinum MnCo_(2)O_(4) 3D graphene Electrocatalysts Methanol oxidation

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Sustained release of vascular endothelial growth factor A and basic fibroblast growth factor from nanofiber membranes reduces oxygen/glucose deprivation-induced injury to neurovascular units

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Neural Regeneration Research 2024年第4期19卷 887-894页

作者： Yifang Wu Jun Sun qi Lin Dapeng Wang Jian hai Department of Neurosurgery Tongji HospitalSchool of MedicineTongji University Department of Pharmacy Institute of Medical SciencesShanghai Jiao Tong University School of Medicine

Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective ***,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently *** this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning *** found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 *** 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose ***,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved ***,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.

关键词： brain ischemia brain microvascular endothelial cell nanofiber membrane neurovascular unit

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Identifying the best common factor model via exploratory eactor analysis

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 24-33页

作者： he Bao-hua TANG Rui TAGN qi-yi School of Big Data Fuzhou University of International Studies and TradeFuzhou 350202China School of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China Department of Computer Science University of BathUK Institute of Insect Science Zhejiang UniversityHangzhou 310058China.

Currently,there is no solid criterion for judging the quality of the estimators in factor *** paper presents a new evaluation method for exploratory factor analysis that pinpoints an appropriate number of factors along with the best method for factor *** proposed technique consists of two steps:testing the normality of the residuals from the fitted model via the Shapiro-Wilk test and using an empirical quantified index to judge the quality of the factor *** are presented to demonstrate how the method is implemented and to verify its effectiveness.

关键词： factor analysis Shapiro-Wilk normality residuals

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Effect of BaO and MgO on structure and properties of aluminate slag with various CaO/Al_(2)0_(3)ratios

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Journal of Iron and Steel Research(International) 2024年第1期31卷 204-214页

作者： Yu-qi Kong Ting Wu Wen-zhi Xia Wen Yang hai-chuan Wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various CaO/Al_(2)0_(3)(C/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at C/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at C/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at C/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at C/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at C/A of *** crystal types of all experimental slags were mainly Ca_(12)Al_(14)O_(33)and CaF_(2)at C/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of Ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property

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Role of polarization evolution in the hysteresis effect of Pb-based antiferroelecrtics

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Chinese Chemical Letters 2024年第4期35卷 516-519页

作者： Botao Gao he qi Hui Liu Jun Chen Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 201899China hainan University Haikou 570228China

The electric field-induced irreversible domain wall motion results in a ferroelectric(FE) hysteresis. In antiferroelectrics(AFEs), the irreversible phase transition is the main reason for the hysteresis effects, which plays an important role in energy storage performance. Compared to the well-demonstrated FE hysteresis,the structural mechanism of the hysteresis in AFE is not well understood. In this work, the underlying correlation between structure and the hysteresis effect is unveiled in Pb(Zr,Sn,Ti)O_(3) AFE system by using in-situ electrical biasing synchrotron X-ray diffraction. It is found that the AFE with a canting dipole configuration, which shows a continuous polarization rotation under the electric field, tends to have a small hysteresis effect. It presents a negligible phase transition, a small axis ratio, and electric field-induced lattice changing, small domain switching. All these features together lead to a slim hysteresis loop and a high energy storage efficiency. These results offer a deep insight into the structure-hysteresis relationship of AFEs and are helpful for the design of energy storage material.

关键词： Antiferroelectric Hysteresis effect Structure refinement Perovskite In situ synchrotron radiation

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Waste to treasure:Reutilization of fluid catalytic cracking coke block as photothermal conversion material for water evaporation

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Particuology 2024年第5期88卷 62-70页

作者： Zhuwei Gao Chengxin Li Jingjing he Zhuo Wang Xinyu qi Lan he Shihao Wang Zhongxin Liu School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China TJ-YZ School of Network Science Haikou University of EconomicsHaikou 570203China School of Food Science and Engineering Hainan UniversityHaikou 570228China Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education Hainan UniversityHaikou 570228China hainan Provincial Key Laboratory of Fine Chemicals Hainan UniversityHaikou 570228China

This study aims to analyze the coking process and propose an effective method for the reutilization of fluid catalytic cracking(FCC)coke ***,we analyzed the basic characteristics and chemical composition of FCC coke *** results showed that the main components were carbon,oxygen,and aluminum,accounting for 60.8%,26.6%,and 11.5%,*** the conventional catalytic cracking reaction temperature from 500℃ to 600℃,the formation of the first aromatic hydrocarbon was particularly important for the formation of *** condensation of oil-gas-entrained catalyst particles and their heavy components was the physical cause of coking,while the dehydrogenation condensation reaction of oil-gas heavy components was the chemical *** addition,the membrane prepared by powdered coke had excellent photothermal conversion ability,which could be heated to more than 110℃ within 360 s under two fixed light *** evaporation rate of photothermal water was 5.89 kg m^(2) h^(−1),which has great industrial application *** works provide a novel and effective method of separation membrane for the reutilization of FCC coke blocks.

关键词： Coking process Reutilization of FCC coke Carbonaceous deposition Membrane Photothermal conversion

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Salinity effect-induced ENSO amplitude modulation in association with the interdecadal Pacific Oscillation

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JOURNAL OF OCEANOLOGY AND LIMNOLOGY 2024年第4期42卷 1-18页

作者： Zhi, hai Wang, Xiaokun Zhang, Rong-Hua Lin, Pengfei qi, Jifeng Nanjing Univ Informat Sci & Technol Coll Atmospher Sci Nanjing 210044 Peoples R China Nanjing Univ Informat Sci & Technol Sch Marine Sci Nanjing 210044 Peoples R China Laoshan Lab Qingdao 266237 Peoples R China Chinese Acad Sci Inst Oceanol Key Lab Ocean Circulat & Waves Qingdao 266071 Peoples R China Chinese Acad Sci Ctr Ocean Mega Sci Qingdao 266071 Peoples R China Chinese Acad Sci Inst Atmospher Phys IAP State Key Lab Numer Modeling Atmospher Sci & Geoph Beijing 100029 Peoples R China

A 110-year ensemble simulation of an ocean general circulation model (OGCM) was analyzed to identify the modulation of salinity interdecadal variability on El Nino-Southern Oscillation (ENSO) amplitude in the tropical Pacific during 1901-2010. The simulating results show that sea surface salinity (SSS) variation in the region exhibits notable and coherent interdecadal variability signal, which is closely associated with the Interdecadal Pacific Oscillation (IPO). As salinity increases or reduces, the SSS modulations on ENSO amplitude during its warm/cold events vary asymmetrically with positive/negative IPO phases. Physically, salinity interdecadal variability can enhance or reduce ENSO-related conditions in upper-ocean stratification, contributing noticeably to ENSO variability. Salinity anomalies associated with the mixed layer depth and barrier layer thickness can modulate ENSO amplitude during positive and negative IPO phases, resulting in the asymmetry of sea surface temperature (SST) anomaly in the tropical Pacific. During positive IPO phases, SSS interdecadal variability contributes positively to El Nino amplitude but negatively to La Nina amplitude by enhancing or reducing SSS interannual variability, and vice versa during negative IPO phases. Quantitatively, the results indicate that the modulation of the ENSO amplitude by the SSS interdecadal variability is -15%-28% during negative IPO phases and -30%-20% during positive IPO phases, respectively. Evidently, the SSS interdecadal variability associated with IPO and its modulation on ENSO amplitude in the tropical Pacific are among factors essentially contributing ENSO diversity.

关键词： El Nino-Southern Oscillation (ENSO) amplitude Interdecadal Pacific Oscillation (IPO) ocean salinity variability tropical Pacific upper-ocean stratification FRESH-WATER FLUX EL-NINO TROPICAL PACIFIC DECADAL OSCILLATION BARRIER LAYER ATMOSPheRIC TELECONNECTIONS ASYMMETRIC MODULATION SOUTheRN-OSCILLATION FREQUENCY ASYMMETRY NORTH PACIFIC

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Frontiers and future perspectives of neuroimmunology

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Fundamental Research 2024年第2期4卷 206-217页

作者： hai qi Shumin Duan Yanying Xu Hongliang Zhang School of Medicine Tsinghua UniversityBeijing 100084China Faculty of Medicine and Pharmaceutical Sciences Zhejiang UniversityHangzhou 310014China Department of Life Sciences National Natural Science Foundation of ChinaBeijing 100085China

Neuroimmunology is an interdisciplinary branch of biomedical science that emerges from the intersection of studies on the nervous system and the immune *** complex interplay between the two systems has long been *** efforts directed at the underlying functional interface and associated pathophysiology,however,have garnered attention only in recent *** this narrative review,we highlight significant advances in research on neuroimmune interplay and modulation.A particular focus is on early-and middle-career neuroimmunologists in China and their achievements in frontier areas of"neuroimmune interface","neuro-endocrine-immune network and modulation","neuroimmune interactions in diseases","meningeal lymphatic and glymphatic systems in health and disease",and"tools and methodologies in neuroimmunology research".Key scientific questions and future directions for potential breakthroughs in neuroimmunology research are proposed.

关键词： Neuroimmunology Neuroimmune interplay Neuro-endocrine-immune network Basic research Key scientific questions

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