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Fracture geometry and breakdown pressure of radial borehole fracturing in multiple layers

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Petroleum Science 2024年第1期21卷 430-444页

作者： yu-Ning Yong Zhao-Quan Guo Shou-Ceng tian Lu-Yao Ma tian-yu Wang Mao Sheng National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Beijing Petroleum Machinery Company Limited CNPC Engineering Technology R&D Company LimitedBeijing102206China Smart Energy Co. LtdChina Xiongan GroupXiong’an New Area071000HebeiChina

Radial borehole fracturing that combines radial boreholes with hydraulic fracturing is anticipated to improve the output of tight oil and gas *** paper aims to investigate fracture propagation and pressure characteristics of radial borehole fracturing in multiple layers.A series of laboratory experiments with artificial rock samples(395 mm×395 mm×395 mm)was conducted using a true triaxial fracturing *** crucial factors corresponding to the vertical distance of adjacent radial borehole layers(vertical distance),the azimuth and diameter of the radial borehole are *** results show that radial borehole fracturing in multiple layers generates diverse fracture *** types of fractures are identified based on the connectivity between hydraulic fractures and radial *** vertical distance significantly influences fracture propagation perpendicular to the radial borehole *** increase in the vertical distance impedes fracture connection across multiple radial borehole layers and reduces the fracture propagation distance along the radial borehole *** azimuth also influences fracture propagation along the radial borehole *** the azimuth reduces the guiding ability of radial boreholes,which makes the fracture quickly curve to the maximum horizontal stress *** breakdown pressure correlates with diverse fracture geometries *** the fractures connect multi-layer radial boreholes,increasing the vertical distance decreases the breakdown *** the azimuth and increasing the diameter also decrease the breakdown *** extrusion force exists between the adjacent fractures generated in radial boreholes in multiple rows,which plays a crucial role in enhancing the guiding ability of radial boreholes and results in higher breakdown *** research provides valuable theoretical insights for the field application of radial borehole fracturing technology in tight oil and g

关键词： Multi-layer radial boreholes Hydraulic fracturing Fracture propagation Pressure characteristic

Anesthesia,Anesthetics,and Postoperative Cognitive Dysfunction in Elderly Patients

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Current Medical Science 2024年第2期44卷 291-297页

作者： Hong-yu ZHU Jian-li YAN Min ZHANG tian-yun XU chen chen Zhi-lin WU Department of Anesthesiology Linhe District People's HospitalBayannur 015000China Department of Neurosurgery Xinzhou District People's HospitalWuhan 430408China Department of Anesthesiology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China

Postoperative cognitive dysfunction(POCD)remains a major issue that worsens the prognosis of elderly surgery *** article reviews the current research on the effect of different anesthesia methods and commonly utilized anesthetics on the incidence of POCD in elderly patients,aiming to provide an understanding of the underlying mechanisms contributing to this condition and facilitate the development of more reasonable anesthesia protocols,ultimately reducing the incidence of POCD in elderly surgery patients.

关键词： anesthesia anesthetics postoperative cognitive dysfunction elderly patients

Photo-induced grease/oil switched lubricant for friction regulation

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Friction 2024年第8期12卷 1696-1706页

作者： Zheng ZHANG Shuangxi TANG Liran MA yu tian State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

Controllable friction regulation has drawn much interest in both scientific and industrial *** there have been many researches on friction regulation by many physical fields and chemical ***-sensitive materials are promising because it is relatively easy to change their properties compared with ***,a new kind of photo-induced grease/oil switched lubricant is designed and shows great reversibility under ultraviolet(UV)and visible(Vis)*** viscosity can change more than 50 times under different irradiation,and the coefficients of friction(COFs)obviously increase under Vis irradiation and decrease under UV irradiation,which performs better than those of the common *** to the experimental results,the phenomena are contributed to the break and reconstruction of the three-dimensional network inside the *** a switchable grease/oil state under different irradiation,this work provides a new principle for designing a smart lubricant with controllable friction regulation.

关键词： photo-induced spiropyran switched lubricant friction regulation

Photoinduced superlubricity on TiO_(2) surfaces

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Friction 2024年第3期12卷 428-438页

作者： Ke HAN Liran MA yu tian Jianbin LUO State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Received:16 September 2022/Revised:28 October 2022/Accepted:27 December 2022The author(s)2022.

Superlubricity control is of great interest in both industry and scientific research,and several methods have been proposed to achieve this *** this work,ultraviolet(UV)light was introduced into titanium dioxide(TiO_(2))and silicon nitride(Si_(3)N_(4))tribosystems to accomplish photoinduced *** friction coefficients(COFs)between Si_(3)N_(4) balls and TiO_(2) plates in the mixtures of sulfuric acid(H^(2)SO_(4))solution and glycerol solution were obviously reduced,and the system entered the superlubricity region(COF<0.01)after UV illumination at a speed of 56 mm/***,the COF was much larger without UV treatment than that with UV *** formation of silica(SiO_(2))layers on the surfaces of Si_(3)N_(4) balls and the elastohydrodynamic effects were determined to be fundamental to the low friction in this experiment,and the enhancement of the combination between the TiO_(2) surface and the hydroxy group of glycerol by UV illumination was the key to the photoinduced superlubricity in this *** findings showed one method for achieving superlubricity by introducing a light field that could be further applied to special working conditions.

关键词： light control friction superlubricity glycerol titanium dioxide(TiO_(2))

A PREDICTION SCHEME FOR THE PRECIPITATION OF SPR BASED ON THE DATA MINING ALGORITHM AND CIRCULATION ANALYSIS

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Journal of Tropical Meteorology 2019年第4期25卷 519-527页

作者： LI Chao SHI Da・wei chen yu-tian ZHANG Hong-hua GENG Huan-tong WANG Peng Jiangsu Meteorological Observatory Nanjing 210008 China Meteorological Bureau of Lianyungang City Lianyungang 222000 China College of Geography Nanjing University of Information Science and TechnologyNanjing 210044 China College of Continuing Education Nanjing University of Infbnnation Science and TechnologyNanjing 210044 China

Based on the 74 circulation indexes provided by National Climate Center of China(NCC) and the 24 indexes compiled by National Oceanic and Atmospheric Administration(NOAA) of the US, the study used the C4.5 algorithm in data mining to establish a decision tree prediction model to predict whether the spring persistent rains(SPR) of 55 years(from 1961 to 2015) is more than the normal, and obtained 5 rules to determine whether the SPR is more than the normal. The accuracy rate of the test set, namely "whether the SPR is more than the normal", is 98.18%. After the evaluation of the model by conducting ten 10-fold cross validations to take the average value, the test accuracy rate gained is 84%. There are differences between the three types of years with a SPR more than the normal when it comes to intensity and distribution. In spring, they have respective anomalous 850 hPa monthly mean wind fields and water-vapor flux distribution, and 700 hPa forms the zone where the vertical speed is anomalously negative. As indicated by the results, the SPR prediction model based on the C4.5 algorithm has a high prediction accuracy rate, the model is reasonably and effectively constructed, and the decision rules take comprehensive factors into consideration. The anomalous rainfall and circulation distribution characteristics obtained based on the decision classification results provide new ideas and methods for the prediction of SPR.

关键词： spring persistent rains data mining C4.5 algorithm prediction model model analysis

Late Quaternary fluvial terrace formation in the Luan River drainage basin,north China and its possible linkages with climate change and tectonic activation

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China Geology 2023年第3期6卷 395-408页

作者： yu-chen tian Xu-jiao Zhang Zhi-qiang Yin Hai Shao Ming-xu Gu Yingying-Ding Chao Peng Xiang-ge Zhang School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China China institute of Geo-Environment Monitoring China Geological SurveyMinistry of Natural ResourcesBeijing 100081China Hebei geological environment monitoring Institute Shijiazhuang 050021China

The Luan River is the most important water system in north-eastern Hebei Province,China and is located in the transitional zone of the Eastern Yan Mountains,North China Plain and Songliao *** well-developed river terraces of its tributary,the Yixun River,provide excellent information for studying neotectonics and climate *** are seven terraces in the lower reaches of the Yixun River,numbered *** optically stimulated luminescence dating results of 23 samples show that terraces T7-T2 formed at 111.36±5.83 ka,78.20±4.45 ka,65.29±4.15 ka,56.44±3.07 ka,40.08±2.66 ka,and 13.14±0.76 ka,respectively.A comparison with the oxygen isotope curves of deep-sea sediments reveals that the sediment formation of each terrace corresponded to cold periods of marine isotope stages MIS 4 and MIS 2 and the relatively cold periods of MIS 5e,MIS 3,and MIS *** the Late Pleistocene,the incision rate of the Yixun River has ranged from 0.371-1.740 mm/*** the formation of T7-T6,T5-T4,T4-T3,and T3-T2,the incision rate was ***,in the two stages during which T6-T5 and T2-T1 formed(13.14±0.76 ka to 0.58±0.08 ka and 10.79±0.64 ka to 0.16±0.01 ka),these rates reached 1.554 mm/a and 1.592-1.740 mm/a,*** approximately 30 ka,the activity of the Langying Fault increased,leading to footwall *** river gathered in the north of Langying to form the ancient Erdaowan Lake,which resulted in the drying of the river in the lower reaches of the Yixun River during the last glacial maximum without forming river *** the Early Holocene,headward erosion in the lower reaches of the Yixun River was enhanced,which resulted in the disappearance of the lake,and incised meandering formed due to increased *** on the analyses of river incision and the formation of ancient lakes and incised meandering,it was inferred that there have been three periods of strong tectonism in the river basin since the Late Pleistocene.

关键词： River terrace Paleoclimate change Tectonic activation Optically stimulated luminescence dating Marine isotope stage Last glacial maximum Neotectonics Geomorphology Geological survey engineering North China Plain

Differences in the effects and action modes of gut commensals against dextran sulfate sodium-induced intestinal inflammation

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Food Science and Human Wellness 2024年第3期13卷 1201-1211页

作者： Dingwu Qu Zhennan Gu Saisai Feng Leilei yu Fengwei tian Hao Zhang Wei chen Qixiao Zhai State Key Laboratory of Food Science and Technology Jiangnan UniversityWuxi 214122China School of Food Science and Technology Jiangnan UniversityWuxi 214122China National Engineering Research Center for Functional Food Jiangnan UniversityWuxi 214122China Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch Wuxi 214122China

Inflammatory bowel disease(IBD)is a complex relapsing inflammatory disease in the gut and is driven by complicated host-gut microbiome *** commensals have shown different functions in IBD prevention and *** gain a mechanistic understanding of how different commensals affect intestinal inflammation,we compared the protective effects of 6 probiotics(belonging to the genera Akkermansia,Bifidobacterium,Clostridium,and Enterococcus)on dextran sulfate sodium(DSS)-induced colitis in mice with or without gut ***-inflammatory properties(ratio of interleukin(IL)-10 and IL-12)of these strains were also evaluated in an in vitro mesenteric lymph nodes(MLN)co-culture *** showed that 4 probiotics(belonging to the species Bifidobacterium breve,Bifidobacterium bifidum,and Enterococcus faecalis)can alleviate colitis in normal *** probiotic strains differed in regulating the intestinal microbiota,cytokines(IL-10,IL-1βand interferon(IFN)-γ),and tight junction function(Zonulin-1 and Occludin).By constrast,Akkermansia muciniphila AH39 and Clostridium butyricum FHuNHHMY49T1 were not ***,*** JSNJJNM2 with high anti-inflammatory potential in the MLN model could relieve colitis symptoms in antibiotic cocktail(Abx)-treated ***,*** FJSWX25M1induced low levels of cytokines in vitro and showed no beneficial ***,we provided insight into the clinical application of probiotics in IBD treatment.

关键词： Gut commensals Dextran sulfate sodium(DSS)colitis Intestinal barrier Immunoregulation

Evolution of suspension bridge structural systems,design theories,and shape-finding methods:A literature survey

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 225-244页

作者： Wenming Zhang Genmin tian yupeng chen Key Laboratory of Concrete and Pre-stressed Concrete Structures of Ministry of Education Southeast UniversityNanjing 210096China State Key Laboratory of Safety Durability and Healthy Operation of Long Span BridgesSoutheast UniversityNanjing 210096China

Modern suspension bridges exhibit a trend of lighter structures,more diversified structural forms,and longer spans,the latter already exceeding two *** performance under dead and live loads depends on their structural and main cable systems,while cablesupported bridges especially rely on the design analysis and construction control of the main *** literary survey systematically analyzes the research progress and state-ofthe-art status quo in the structural systems and design theories of suspension bridges,focusing on the structural systems,main cable shape analyses,live load effect analyses,and emerging lucrative research *** than 100 reliable references have been surveyed.(1)Multi-span or multi-main cable schemes appeal to increasing attention,which may become a better choice in terms of structural systems in scenarios with extremely long spans and heavy *** cable layouts,such as spatial main cables and hybrid cable-stayed suspension systems have also become feasible approaches for enhancing structural stiffness.(2)The shape-finding analysis during the construction phase is more complex and has more essential factors than that of the completed bridge *** theories combining analytical methods and finite element methods are more suitable for the shape-finding analysis of complex cable systems than any single theory of the two,especially for novel cable systems.(3)The live load effect analysis methods based on traditional deflection theory or modified/improved deflection theories still have wide applications,but the refined theory of treating hangers as discrete members is also constantly developing,which is expected to provide new ideas for more complex structural analysis under the different types of live loads and their distribution forms.

关键词： Suspension bridges Structural system Cable analysis Shape-finding analysis Construction control and calculation Live load effect

Side-Chain Engineering of Non-Fullerene Acceptors with Trialkylsilyloxy Groups for Enhanced Photovoltaic Performancet

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Chinese Journal of Chemistry 2024年第18期42卷 2153-2160页

作者： Qingyuan Wang Qi chen Shixin Meng Li tian Haiqiao Wang yu chen Zitong Liu Lingwei Xue Zhi-Guo Zhang State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijingUniversityof Chemical TechnologyBeijing 100029China School of Materials Science and Engineering Henan University of TechnologyZhengzhouHenan 450001China Beijing Engineering Research Center for the Synthesis and Applications of Waterborne Polymers Beijing University of Chemical TechnologyBeijing100029China The Institute of High Energy Physics Chinese Academy of SciencesBejing 100049China state Key Laboratory of Applied Organic Chemistry(SKLAoc) College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhouGansu730000China Yaoshan Laboratory Pingdingshan UniversityPingdingshanHenan 467000China

Side-chain engineering has emerged as a highly effective strategy for tailoring the aggregation behavior and charge transport properties of non-fullerene small molecule acceptors(SMAs).In this study,we designed and synthesized two SMAs,namely BTPSi-Bu and BTPSi-Pr,respectively incorporating tributylsilyloxy and trisopropylsilyloxy groups in their outer ***,BTPSi-Bu exhibited better planarity,crystallization,and favorable phase separation when paired with PM6 donor polymer compared to its counterpart,*** resulting organic solar cells,utilizing the PM6:BTPSi-Bu blend,demonstrated a remarkable power conversion efficiency of 17.41%and a high open-circuit voltage of 0.859 *** findings underscore the significance of integrating trialkylsilyloxy side chains into SMAs as a rational design approach for enhancing the performance of photovoltaic systems.

关键词： Organic solar cells Non-fullerene acceptors Oligomers Side-chain engineering Energy conversion Synthesis design Donor-acceptor systems