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Effect of height-diameter ratio on the mechanical characteristics of shale w.th different bedding orientations

Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2482-2502页

作者： y.de guo Xibing Li Linqi Huang School of Resources and Safety.Engineering Central South UniversityChangsha410083China

Geological exploration cores obtained from shale gas w.lls several kilometers deep often show.different height-diameter ratios(H/D)because of complex geological conditions(core disking or developed fractures),w.ich makes further standard specimen preparation for mechanical evaluation of reservoirs *** multi-cluster hy.raulic fracturing,shale reservoirs betw.en planes of hy.raulic fractures w.th different lengths could be simplified to have different H/D *** the effect of H/D on the mechanical characteristics of shale specimens w.th different bedding orientations w.ll support mechanical evaluation tests of reservoirs based on disked geological cores and help to optimize multicluster fracturing *** this study.w. performed uniaxial compression tests and acoustic emission(AE)monitoring on cy.indrical Longmaxi shale specimens under five bedding orientations and four H/D *** experimental results show.d that both the H/D-dependent mechanical properties and AE parameters demonstrated significant *** H/D did not change the uniaxial compressive strength(UCS)evolution versus bedding orientation,demonstrating a V-shaped relationship,but enhanced the curve *** stress level of crack damage for the specimens significantly.increased w.th increasing H/D,excluding the specimens w.th a bedding orientation of 0°.w.th increasing H/D,the cumulative AE counts of the specimens w.th each bedding orientation tended to exhibit a stepped jump against the loading *** proportion of low.average-frequency.AE signals(below.100 kHz)in specimens w.th bedding orientations of 45°and 60°increased to over 70%by.increasing H/D,but it only.increased to 40%in specimens w.th bedding orientations of 0°,30°,and 90°.Finally.an empirical model that can reveal the effect of H/D on anisotropic UCS of shale reservoir w.s proposed,the anisotropic proportion of tensile and shear failure cracks in specimens under four H/D ratios w.s classified based o

关键词： Geological cores Multi-cluster hy.raulic fracturing Height-diameter ratio Longmaxi shale Uniaxial compression test

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Impacts of pancreatic exocrine insufficiency.on gut microbiota

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Journal of Zhejiang University.Science B(Biomedicine & Biotechnology. 2024年第4期25卷 271-279页

作者： y.lin guo Feng CAO Fei LI Department of General Surgery Xuanwu Hospital of Capital Medical UniversityBeijing 100053China Acute Pancreatitis Clinical Center of Capital Medical University Beijing 100053China

Pancreatic exocrine insufficiency.PEI)can be induced by.various kinds of diseases,including chronic pancreatitis,acute pancreatitis,and *** main pathogenetic mechanism of PEI involves the decline of try.sin sy.thesis,disorder of pancreatic fluid flow.and imbalance of secretion *** studies have show. that PEI could induce gut bacterial overgrow.h and dy.biosis,w.th the abundance of Lactobacillus and Bifidobacterium increasing the most,w.ich could be partially.reversed by.pancreatic enzy.e replacement *** studies have also confirmed the association betw.en PEI and the dy.biosis of gut *** exocrine secretions and changes in duodenal p H as w.ll as bile salt malabsorption brought about by.PEI may.affect and shape the abundance and composition of gut *** turn,the gut microbiota may.impact the pancreatic exocrine acinus through potential bidirectional *** forw.rd,more and higher-quality.studies are needed that focus on the mechanism underly.ng the impact of PEI on the gut microbiota.

关键词： Pancreatic exocrine insufficiency Gut microbiota Gut microbiome Pancreatic enzy.e replacement therapy

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A thermody.amics-based three-scale constitutive model for partially.saturated granular materials

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1813-1831页

作者： Jianqiu Tian Enlong Liu y.ancheng guo State Key.Laboratory.of Hy.raulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500China College of Civil Engineering Zhengzhou UniversityZhengzhou450001China

A three-scale constitutive model for unsaturated granular materials based on thermody.amic theory.is *** three-scale y.eld locus,derived from the explicit y.eld criterion for solid matrix,is developed from a series of discrete interparticle contact *** three-scale y.eld locus is sensitive to porosity.changes;therefore,it is reinterpreted as a corresponding constitutive model w.thout phenomenological ***,a w.ter retention curve is proposed based on special pore morphology.and experimental *** features of the partially.saturated granular materials are w.ll captured by.the *** w.tting and isotropic compression,volumetric compaction occurs,and the degree of saturation ***,the higher the matric suction,the greater the strength,and the smaller the volumetric *** w.th the phenomenological Barcelona basic model,the proposed three-scale constitutive model has few.r parameters;virtually.all parameters have clear phy.ical meanings.

关键词： Unsaturated granular material Unsaturated porous material Geomaterials Multi-scale constitutive model w.ter retention curve Plasticity

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For Mega-Constellations: Edge Computing and Safety.Management Based on Blockchain Technology

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China Communications 2024年第2期21卷 59-73页

作者： Zhen Zhang Bing guo Chengjie Li College of Computer Science Sichuan UniversityChengdu 610064China The Key.Laboratory.for Computer Sy.tems of State Ethnic Affairs Commission School of Computer Science and TechnologySouthwest Minzu UniversityChengdu 610225China National Key.Laboratory.of Science and Technology.on Communications University of Electronic Science and Technology of ChinaChengdu 611731China

In mega-constellation Communication Sy.tems, efficient routing algorithms and data transmission technologies are employ.d to ensure fast and reliable data transfer. How.ver, the limited computational resources of satellites necessitate the use of edge computing to enhance secure *** edge computing reduces the burden on cloud computing, it introduces security.and reliability.challenges in open satellite communication channels. To address these challenges, w. propose a blockchain architecture specifically.designed for edge computing in mega-constellation communication sy.tems. This architecture narrow. dow. the consensus scope of the blockchain to meet the requirements of edge computing w.ile ensuring comprehensive log storage across the netw.rk. Additionally. w. introduce a reputation management mechanism for nodes w.thin the blockchain, evaluating their trustw.rthiness, w.rkload, and efficiency. Nodes w.th higher reputation scores are selected to participate in tasks and are appropriately.incentivized. Simulation results demonstrate that our approach achieves a task result reliability.of 95% w.ile improving computational speed.

关键词： blockchain consensus mechanism edge computing mega-constellation reputation management

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Confluence of asy.metric cataly.is and electrosy.thesis in sustainable chemical transformations

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Science China Chemistry 2024年第3期67卷 755-758页

作者： Qinglin Zhang Kang Liang Chang guo Hefei National Research Center for Phy.ical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

Electrosy.thesis has gained w.despread recognition for its extraordinary.ability.to precisely.control the redox *** outstanding capability.enables the direct conversion of non-functionalized substrates into reactive intermediates by.utilizing easily.accessible starting materials, eliminating the need for preliminary.functionalization procedures and allow.ng for unconventional bond activations.

关键词： Confluence of asy.metric cataly.is and electrosy.thesis in sustainable chemical transformations

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A Local Tb Theorem for Square Functions and Parabolic Lay.r Potentials

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1941-1966页

作者： Zhi Dan w.NG guo Ming ZHANG School of Phy.ical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816P.R.China Frontiers Science Center for Nonlinear Expectations Ministry of EductionResearch Center for Mathematics and Interdisciplinary SciencesShandong UniversityQingdao266237P.R.China

In this paper,w. give a locally.parabolic version of Tb theorem for a class of vector-valued operators w.th off-diagonal decay.in L^(2) and certain quasi-orthogonality.on a subspace of L^(2),in w.ich the testing functions themselves are also *** an application,w. establish the boundedness of lay.r potentials related to parabolic operators in divergence form,defined in the upper half-space Rn+2+:={(x,t,λ)∈R^(n+1)×(0,∞)},w.th uniformly.complex elliptic,L^(∞),t,λ-independent coefficients,and satisfy.ng the De Giorgi/Nash estimates.

关键词： Local Tb theorems Calderon-Littlew.od-Paley.family Parabolic lay.r potentials Carleson measure estimates

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Oilfield analogy.and productivity.prediction based on machine learning: Field cases in PL oilfield, China

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Petroleum Science 2024年第4期21卷 2554-2570页

作者： w.n-Peng Bai Shi-Qing Cheng Xin-y.ng guo y.ng w.ng Qiao guo Chao-Dong Tan State Key.Laboratory.of Petroleum Resources and Engineering China University of Petroleum (Beijing)

In the early.time of oilfield development, insufficient production data and unclear understanding of oil production presented a challenge to reservoir engineers in devising effective development plans. To address this challenge, this study.proposes a method using data mining technology.to search for similar oil fields and predict w.ll productivity. A query.sy.tem of 135 analogy.parameters is established based on geological and reservoir engineering research, and the w.ight values of these parameters are calculated using a data algorithm to establish an analogy.sy.tem. The fuzzy.matter-element algorithm is then used to calculate the similarity.betw.en oil fields, w.th fields having similarity.greater than 70% identified as similar oil fields. Using similar oil fields as sample data, 8 important factors affecting w.ll productivity.are identified using the Pearson coefficient and mean decrease impurity.MDI） method. To establish productivity.prediction models, linear regression（LR）, random forest regression（RF）, support vector regression（SVR）, backpropagation（BP）, extreme gradient boosting（XGBoost）, and light gradient boosting machine（Light GBM） algorithms are used. Their performance is evaluated using the coefficient of determination（R2）, explained variance score（EV）, mean squared error（MSE）, and mean absolute error（MAE） metrics. The Light GBM model is selected to predict the productivity.of 30 w.lls in the PL field w.th an average error of only.6.31%, w.ich significantly.improves the accuracy.of the productivity.prediction and meets the application requirements in the field. Finally. a softw.re platform integrating data query.oil field analogy. productivity.prediction, and know.edge base is established to identify.patterns in massive reservoir development data and provide valuable technical references for new.reservoir development.

关键词： Data mining technique Analogy.parameters Oilfield analogy Productivity.prediction Softw.re platform

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Recent Advances in Enantioselective Reactions of Terminal Unactivated Alkenes

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Chinese Journal of Chemistry 2024年第7期42卷 760-776页

作者： Qihang guo Xuzhong Shen Zhan Lu Centerof Chemistry.orFrontier Technologies Departmentof ChemistryZhejiang UniversityHangzhouZhejiang 310058China ZJU-Hangzhou Global Scientific and Technological Innovation Center HangzhouZhejiang 311215China College of Chemistry Zhengzhou UniversityZhengzhouHenan 450001China

α-Olefins as aliphatic terminal alkenes could be obtained easily.from numerous contemporary.sy.thetic reactions as w.ll as petro-chemical industry.and also found in natural *** to the alkenes attaching the directing groups or activating group,the cataly.ic asy.metric reaction of unactivated terminal alkenes presents great challenges due to the w.ak electron effect and small steric hindrance *** review.mainly.summarizes the latest progress of the asy.metric reaction of unactivated terminal olefins since 2016.

关键词： Asy.metric cataly.is Terminal unactivated alkenes Hy.rofunctionalization Difunctionalization Metal-cataly.ed

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Harnessing bacteria for tumor therapy.Current advances and challenges

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Chinese Chemical Letters 2024年第2期35卷 97-106页

作者： Lina guo Jinsong Ding w.nhu Zhou Xiangy. School of Pharmaceutical Sciences Central South UniversityChangsha 410013China Changsha Medical University Academician WorkstationChangsha 410219China Key.Laboratory.of Biological Nanotechnology.of National Health Commission Changsha 410008China

After a century.of standstill,bacteria-based tumor therapy.has resurged recently.benefiting from the revolution of tumor immunotherapy.w.ich provides unique solutions to tackle the obstacles of traditional tumor *** and facultative anaerobes w.th active tropism can selectively.colonize at tumor sites and suppress tumor grow.h via different mechanisms,serving as attractive tools for tumor treatment either as a monotherapy.or combining w.th other therapies for sy.ergistic anti-tumor *** this critical review.w. introduce the recent advances of bacteria-based tumor therapy.from the follow.ng ***,the general properties of bacteria are review.d emphasizing on their structural components related to tumor immunotherapy.and the main bacteria that have been used in tumor therapy.are ***,the benefits of bacteria for tumor therapy.are illustrated,such as tumor targetability.deep penetration,and facile genetic engineering for attenuation,enhanced efficacy.as w.ll as ***,anti-tumor mechanisms of bacteria are summarized,w.ich refer to intrinsic tumoricidal activities,immune activation,bacteria metabolism,and their capability.to regulate gut microbiota ***,bacteria could act as carriers to deliver various ty.es of therapeutics to achieve combination therapy.w.th improved *** addition,several challenges for anti-tumor applications of bacteria are discussed regarding the delivery.efficacy.and safety.issues,and potential solutions are also ***,the possible improvements and perspectives are discussed in the end,w.ich provide a guideline for the design of advanced bacteria-based tumor therapeutics in the future.

关键词： Bacteria Tumor targeting Immunotherapy Combination therapy Genetic engineering Surface decoration

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Sy.thesis of Organofluorine Compounds w.th Acy.silanes

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Chinese Journal of Chemistry 2024年第8期42卷 887-902页

作者： y.uy.an guo Gang Zhou Xiao Shen The Institute for Advanced Studies Engineering Research Center of Organosilicon Compounds&MaterialsMinistry of EducationWuhan University299 Bayi RoadWuhanHubei430072 China

Comprehensive Summary.Organofluorine compounds are central in sy.thetic chemistry.medicinal chemistry.and material *** this review.w. summarize the investigations on the sy.thesis of organofluorine compounds w.th *** the non-fluorinated acy.silanes,the in situ generation of difluoroenoxy.ilanes from the reactions of the acy.silanes w.th trifluoromethy.ation reagents is the major pathw.y.leading to the facile preparation of variousα,α-*** the fluoroalky.acy.silanes,apart from the in situ generation of difluoroenoxy.ilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acy.silanes and the selective control of reactivities of the biradicals pave the w.y.for the sy.thesis of a variety.of organofluorine *** general,most of these reactions gave racemic products,and the asy.metric sy.thesis of organofluorine compounds w.th acy.silanes is still rare,w.ich w.uld be a future.

关键词： Acy.silanes Organofluorine compounds Brook rearrangement Radical rearrangement β-Fluoride elimination Asy.metric cataly.is Photocataly.is Defluoroalky.ation

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