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Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng Sheng-Jie Wei guang-Qing Zhang Da-Wei Zhou Chuang-Chao Xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 10 Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1) this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01%.(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 100 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

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Numerical investigation on compressible flow around a cylinder in proximity to the heated wall

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Journal of Hydrodynamics 2024年第3期36卷 519-533页

作者： Yu-lu Liu Jun-wang Qu Yi-zhou Tao Yong-guang Lyu Xiang Qiu Shanghai Institute of Technology School of ScienceShanghai201418China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China

In this study,direct numerical simulations were conducted to investigate the compressible flow around a circular cylinder near a heated wall at a Reynolds number(Re)of 500 and a Mach number(Ma)of *** heating ratio T^(*)ranging from 1.0 to 1.6 represents the different situations of a heated wall,whereas the gap ratio ranges from 0.3 to *** study analyzed the impact of heating effect and wall proximity on flow characteristics and aerodynamic *** results indicated that the stability of the flow was enhanced as the gap ratio decreased or the heating ratio *** the calculation of enstrophy,it was found that the strength of shedding vortices weakens with a decrease in gap ratio or an increase in heating ***,the mean drag coefficient decreases as the heating ratio increases or the gap ratio *** contrast,the mean lift coefficient initially decreases and then increases as the gap ratio ***,the drag reduction mechanism was analyzed by examining the pressure distribution on the surface of the cylinder.

关键词： Compressible flow wall proximity heating effect stability enstrophy

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Genomic insights into adaptation to bipedal saltation and desert-like habitats of jerboas

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Science China(Life Sciences) 2024年第9期67卷 2003-2015页

作者： Simin Chai Yujie Chong Daiqing Yin Qiang Qiu Shixia Xu guang Yang Southern Marine Science and Engineering guangdong Laboratory(guangzhou) Guangzhou 511458China Jiangsu Key Laboratory for Biodiversity and Biotechnology School of Life SciencesNanjing Normal UniversityNanjing 210023China School of Ecology and Environment Northwestern Polytechnical UniversityXi’an 710072China

Jerboas is a lineage of small rodents displaying atypical mouse-like morphology with elongated strong hindlimbs and short *** have evolved obligate bipedal saltation and acute senses,and been well-adapted to vast desert-like *** a newly sequenced chromosome-scale genome of the Mongolian five-toed jerboa(Orientallactaga sibirica),our comparative genomic analyses and in vitro functional assays showed that the genetic innovations in both protein-coding and non-coding regions played an important role in jerboa morphological and physiological ***-specific amino acid substitutions,and segment insertions/deletions(indels)in conserved non-coding elements(CNEs)were found in components of proteoglycan biosynthesis pathway(XYLT1 and CHSY1),which plays an important role in limb ***,we found specific evolutionary changes functionally associated with energy or water metabolism(e.g.,specific amino acid substitutions in ND5 and indels in CNEs physically near ROR2)and senses(e.g.,expansion of vomeronasal receptors and the FAM136A gene family)in *** dual-luciferase reporter assay verified that some of the CNEs with jerboa-specific segment indels exerted a significantly different influence on luciferase activity,suggesting changes in their regulatory function in *** results revealed the potential molecular mechanisms underlying jerboa adaptation since the divergence from the Eocene-Oligocene transition,and provided more resources and new insights to enhance our understanding of the molecular basis underlying the phenotypic diversity and the environmental adaptation of mammals.

关键词： jerboa adaptive evolution comparative genomics conserved non-coding elements bipedal saltation

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The effects of various factors on spontaneous imbibition in tight oil reservoirs

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Petroleum Science 2024年第1期21卷 315-326页

作者： Cheng Liu Tian-Ru Wang Qing You Yue-Chun Du guang Zhao Cai-Li Dai School of Energy Resources China University of GeosciencesBeijing100083PR China School of Petroleum Engineering China University of PetroleumQingdao266580ShandongPR China

Slickwater fracturing fluids have gained widespread application in the development of tight oil reservoirs. After the fracturing process, the active components present in slickwater can directly induce spontaneous imbibition within the reservoir. Several variables influence the eventual recovery rate within this procedure, including slickwater composition, formation temperature, degree of reservoir fracture development, and the reservoir characteristics. Nonetheless, the underlying mechanisms governing these influences remain relatively understudied. In this investigation, using the Chang-7 block of the Changqing Oilfield as the study site, we employ EM-30 slickwater fracturing fluid to explore the effects of the drag-reducing agent concentration, imbibition temperature, core permeability, and core fracture development on spontaneous imbibition. An elevated drag-reducing agent concentration is observed to diminish the degree of medium and small pore utilization. Furthermore, higher temperatures and an augmented permeability enhance the fluid flow properties, thereby contributing to an increased utilization rate across all pore sizes. Reduced fracture development results in a lower fluid utilization across diverse pore types. This study deepens our understanding of the pivotal factors affecting spontaneous imbibition in tight reservoirs following fracturing. The findings act as theoretical, technical, and scientific foundations for optimizing fracturing strategies in tight oil reservoir transformations.

关键词： Tight oil reservoir Spontaneous imbibition Nuclear magnetic resonance Slickwater fracturing fluid Fluid utilization degree

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Efficient and stable PtFe alloy catalyst for electrocatalytic methanol oxidation with high resistance to CO

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Journal of Energy Chemistry 2024年第3期90卷 327-336,I0008页

作者： Qian Yang Sifan Zhang Fengshun Wu Lihua Zhu guang Li Mingzhi Chen An Pei Yingliang Feng Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry College of Chemistry and Chemical EngineeringFaculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000JiangxiChina College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005FujianChina

Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in terms of surface CO toxicity in long-term ***,the PtFe alloy nanoparticles(NPs) with small particle size(~4.12 nm) supported on carbon black catalysts with different Pt/Fe atomic ratios(Pt_(1)Fe_(2)/C,Pt_(3)Fe_(4)/C,Pt_(1)Fe_(1)/C,and Pt_(2)Fe_(1)/C) are successfully prepared for enhanced anti-CO poisoning during methanol oxidation reaction(MOR).The optimal atomic ratio of Pt/Fe for the MOR is 1:2,and the mass activity of Pt_(1)Fe_(2)/C(5.40 A mg_(Pt)^(-1)) is 13.5 times higher than that of conventional commercial Pt/C(Pt/C-JM)(0.40 A mg_(Pt)^(-1)).The introduction of Fe into the Pt lattice forms the PtFe alloy phase,and the electron density of Pt is reduced after forming the PtFe ***-situ Fourier transform infrared results indicate that the addition of oxyphilic metal Fe has reduced the adsorption of reactant molecules on Pt during the *** doping of Fe atoms helps to desorb toxic intermediates and regenerate Pt active sites,promoting the cleavage of C-O bonds with good selectivity of CO_(2)(58.1%).Moreover,the Pt_(1)Fe_(2)/C catalyst exhibits higher CO tolerance,methanol electrooxidation activity,and long-term stability than other Pt_(x)Fe_(y)/C catalysts.

关键词： Alloy catalyst PtFe Methanol oxidation In-situ FTIR CO resistance

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Design and construction of charged-particle telescope array for study of exotic nuclear clustering structure

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Nuclear Science and Techniques 2024年第8期35卷 114-123页

作者： Zheng‑Li Liao Xi‑guang Cao Yu‑Xuan Yang Chang‑Bo Fu Xian‑Gai Deng Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Zhengzhou University Zhengzhou 450001China Key Laboratory of Nuclear Physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan University Shanghai 200438China

The exploration of exotic shapes and properties of atomic nuclei,e.g.,αcluster and toroidal shape,is a fascinating field in nuclear *** study the decay of these nuclei,a novel detector aimed at detecting multipleα-particle events was designed and *** detector comprises two layers of double-sided silicon strip detectors(DSSD)and a cesium iodide scintillator array coupled with silicon photomultipliers array as light sensors,which has the advantages of their small size,fast response,and large dynamic *** coupled with cesium iodide crystal arrays are used to distinguish multipleα*** detector array has a compact and integrated design that can be adapted to different experimental *** detector array was simulated using Geant4,and the excitation energy spectra of someα-clustering nuclei were reconstructed to demonstrate the *** simulation results show that the detector array has excellent angular and energy resolutions,enabling effective reconstruction of the nuclear excited state by multipleαparticle *** detector offers a new and powerful tool for nuclear physics experiments and has the potential to discover interesting physical phenomena related to exotic nuclear structures and their decay mechanisms.

关键词： Cluster decay Toroidal structure Telescope array SiPM Energy resolution

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Swelling of Spherical Polyelectrolyte Gels

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Chinese Journal of Polymer Science 2024年第9期42卷 1386-1392,I0009页

作者： Ming-Yu Duan Jia-Dong Chen Yi-Ming Liu Zhao-Feng Peng guang Chen Department of Advanced Manufacturing and Robotics College of EngineeringPeking UniversityBeijing 100871China

Polyelectrolyte(PE)gels,distinguished by their unique stimuli-responsive swelling behavior,serve as the basis of broad applications,such as artificial muscles and drug *** this work,we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt *** minimizing the free energy of PE gels,we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt *** compare our predictions for the swelling ratio with experimental measurements,which show excellent *** addition,we employ a finite element method to assess the applicability range of our theoretical model and *** anticipate that our model will also provide valuable insights into drug adsorption and release,deformation of red blood cells,4D printing and soft robotics,where the underlying mechanism of swelling remains enigmatic.

关键词： Gels Polyelectrolytes Swelling Stimuli-responsive Electrostatic interaction Cell model

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DNA methylation of SMPD3-based diagnostic biomarkers of NASH and mild fibrosis

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Genes & Diseases 2024年第1期11卷 99-102页

作者： Na Wu Mofan Feng Siran Yue Xinyu Shi Nan Tang Yalan Xiong Jianying Wang Lei Zhang Hualing Song Yi Shi guang He guang Ji Baocheng Liu Shanghai Innovation Center of Traditional Chinese Medicine Health Service School of Public HealthShanghai University of Traditional Chinese MedicineShanghai 201203China Institute of Digestive Diseases Longhua HospitalShanghai University of Traditional Chinese MedicineShanghai 200032China Bio-X Institutes Key Laboratory for the Genetics of Developmental and Neuropsychiatric DisordersShanghai Jiao Tong UniversityShanghai 200030China Institute for Advancing Translational Medicine in Bone and Joint Diseases School of Chinese MedicineHong Kong Baptist UniversityHong Kong SAR 999077China

Non-alcoholic fatty liver disease(NAFLD)is a liver condition that is widely prevalent across the world.A considerable number of people with NAFLD have the potential to progress to a more severe form of the condition known as nonalcoholic steatohepatitis(NASH),accompanied by bridging *** advancement is more likely if the patient has metabolic risk factors such as obesity or type 2 diabetes that deteriorate over ***,even slight inflammation or fibrosis in NAFLD can significantly increase the likelihood of progression compared to steatosis *** underscores the importance of revising the present methods of monitoring NAFLD patients to ensure early detection and effective management of the disease.

关键词： NAFLD inflammation NASH

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Distribution of licensed acupuncturists and educational institutions in the United States at the start of 2023,during the late stage of the COVID-19 pandemic

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Journal of Integrative Medicine 2024年第4期22卷 379-384页

作者： Arthur Yin Fan De-guang He Anu Sangraula Sarah Faggert Alemi Amy Matecki American Traditional Chinese Medicine Association ViennaVA 22182USA McLean Center for Complementary and Alternative Medicine ViennaVA 22182USA New England School of Acupuncture Massachusetts College of Pharmacy and Health SciencesBostonMA 02115USA Lombardi Comprehensive Cancer Center Cancer Prevention and Control ProgramGeorgetown UniversityWashington DC 20057USA Eastern Roots Wellness PLCMcLeanVA 22101USA Sutter Health Alta Bates Summit Medical CenterOaklandCA 94609USA

This study was conducted to identify the number and density of active licensed acupuncturists(LAcs),as well as the number of accredited schools in acupuncture and Oriental medicine(AOM),as of January 1,2023,in the United States(U.S.).The number of active LAcs as of January 1,2023 was 34,524,potentially33,364 after removing license duplication in multiple states,among which the largest three states were California(with 7317 LAcs[21.19%of the total]),New York(5024[14.55%])and Florida(2644[7.66%]).The total number of LAcs decreased by 8.87%from 2018,and fell short of our projected number of LAcs in 2023 by 9037,or 20.75%.The overall LAc density in the *** as the number of LAcs per 100,000 populationDwas 10.36,less than in *** were 56 active,accredited AOM schools which offered a total of 147 programs(121 at the level necessary for licensing[entry-level],12 for an advanced practicing degree[advanced-level],and 14 for certifications).Broken down further,offerings included 50 master's degrees in acupuncture,40 master's degrees in Oriental medicine,31 entry-level doctorate degrees(10 in acupuncture and 21 in acupuncture plus Chinese herbal medicine),and 12advanced-level doctorate degrees in *** certification programs included one in East-Asian Medical Bodywork and 13 in *** these schools in 2023,institutions in the West and East Coast states comprised 67.86%(decreased from 77.42%in 2018)of the national ***,Florida and Illinois represented 39.29%.There were 48 jurisdictions with acupuncture practice laws in *** data suggests that the acupuncture profession in the *** been significantly impacted during the coronavirus disease 2019 pandemic.

关键词： Acupuncturist Acupuncture educational institution Distribution Density Oriental medicine United States

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Development and validation of a nomogram to predict allograft survival after pediatric liver transplantation

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World Journal of Pediatrics 2024年第3期20卷 239-249页

作者： guang-Xiang Gu Shu-Ting Pan Yi-Chen Fan Chen Chen Qiang Xia Department of Liver Surgery Renji HospitalShanghai Jiaotong University School of MedicineNo.160 Pujian RoadPudong New DistrictShanghai 200128China Department of Liver Transplantation Sun Yet-Sen Memorial HospitalSun Yat-Sen UniversityNo.107 Yanjiang West RoadGuangzhou 510080China Clinical Center for Investigation Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina Department of Anesthesiology Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina

Background Liver transplantation is the main treatment for cholestatic liver disease and some metabolic liver diseases in ***,no accurate prediction model to determine the survival probability of grafts prior to surgery *** study aimed to develop an effective prognostic model for allograft survival after pediatric liver *** This retrospective cohort study included 2032 patients who underwent pediatric liver transplantation between January 1,2006,and January 1,2020.A nomogram was developed using Cox regression and validated based on bootstrap *** and discriminatory accuracies were determined using the concordance index and visualized using calibration curves;net benefits were calculated for model *** online Shiny application was developed for easy access to the *** Multivariable analysis demonstrated that preoperative diagnosis,recipient age,body weight,graft type,preoperative total bilirubin,interleukin-1β,portal venous blood flow direction,spleen thickness,and the presence of heart disease and cholangitis were independent factors for survival,all of which were selected in the *** of the nomogram indicated that the 1-,3-,and 5-year predicted survival rates agreed with the actual survival *** concordance indices for graft survival at 1,3,and 5 years were 0.776,0.757,and 0.753,respectively,which were significantly higher than those of the Pediatric End-Stage Liver Disease and Child-Pugh scoring *** allograft dysfunction risk of a recipient could be easily predicted using the following URL:https://***/ASPELT/l Conclusion The allograft survival after pediatric liver transplantation(ASPELT)score model can effectively predict the graft survival rate after liver transplantation in children,providing a simple and convenient evaluation method for clinicians and patients.

关键词： Allograft survival Nomogram Pediatric liver transplantation

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