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Correlation between longitudinal crack occurrence and mold heat transfer in continuous casting based on process data mining

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Journal of Iron and Steel Research International 2024年第5期31卷 1139-1152页

作者： Zhi-qiang Peng Zi-bing Hou Kai Yi Kun-hui guo Dong-wei guo Guang-hua Wen College of Materials Science and Engineering Chongqing UniversityChongqing400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing400044China

The correlation between the longitudinal crack occurrence and integrated heat transfer of the mold with data mining methods was ***,three kinds of support vector machine models based on principal component analysis with different input features were established to explore the effect of integrated heat transfer on the accuracy of the prediction model for the longitudinal *** results show that the accuracy was improved while features including mean and standard deviation of integrated heat transfer were ***,the difference in integrated heat transfer between defect and normal samples under the same process parameters was quantitatively *** with normal samples,the temperature difference of cooling water for defect samples decreased by 0.65%,and the temperature difference fluctuation increased by 31.1%.Finally,the literature data were used to provide support for the quantitative correlation according to defect formation mechanism.A new criterion for the prediction of longitudinal crack and a discovering method for correlation between product quality and process parameters in the manufacturing industry have been provided.

关键词： Continuous casting slab Longitudinal surface crack Heat transfer Data mining Quantitative correlation

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 Systems 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 Systems, efficient routing algorithms and data transmission technologies are employed to ensure fast and reliable data transfer. However, 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, we propose a blockchain architecture specifically designed for edge computing in mega-constellation communication systems. This architecture narrows down the consensus scope of the blockchain to meet the requirements of edge computing while ensuring comprehensive log storage across the network. Additionally, we introduce a reputation management mechanism for nodes within the blockchain, evaluating their trustworthiness, workload, and efficiency. Nodes with 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% while improving computational speed.

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

Effect of height-diameter ratio on the mechanical characteristics of shale with different bedding orientations

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

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

Geological exploration cores obtained from shale gas wells several kilometers deep often show different height-diameter ratios(H/D)because of complex geological conditions(core disking or developed fractures),which makes further standard specimen preparation for mechanical evaluation of reservoirs *** multi-cluster hydraulic fracturing,shale reservoirs between planes of hydraulic fractures with different lengths could be simplified to have different H/D *** the effect of H/D on the mechanical characteristics of shale specimens with different bedding orientations will support mechanical evaluation tests of reservoirs based on disked geological cores and help to optimize multicluster fracturing *** this study,we performed uniaxial compression tests and acoustic emission(AE)monitoring on cylindrical Longmaxi shale specimens under five bedding orientations and four H/D *** experimental results showed 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 with increasing H/D,excluding the specimens with a bedding orientation of 0°.With increasing H/D,the cumulative AE counts of the specimens with each bedding orientation tended to exhibit a stepped jump against the loading *** proportion of low-average-frequency AE signals(below 100 kHz)in specimens with bedding orientations of 45°and 60°increased to over 70%by increasing H/D,but it only increased to 40%in specimens with 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 was proposed,the anisotropic proportion of tensile and shear failure cracks in specimens under four H/D ratios was classified based o

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

A thermodynamics-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 Yuancheng guo State Key Laboratory of Hydraulics 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 thermodynamic theory is *** three-scale yield locus,derived from the explicit yield criterion for solid matrix,is developed from a series of discrete interparticle contact *** three-scale yield locus is sensitive to porosity changes;therefore,it is reinterpreted as a corresponding constitutive model without phenomenological ***,a water retention curve is proposed based on special pore morphology and experimental *** features of the partially saturated granular materials are well captured by the *** wetting 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 *** with the phenomenological Barcelona basic model,the proposed three-scale constitutive model has fewer parameters;virtually all parameters have clear physical meanings.

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

A Local Tb Theorem for Square Functions and Parabolic Layer Potentials

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

作者： Zhi Dan WANG guo Ming ZHANG School of Physical 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,we give a locally parabolic version of Tb theorem for a class of vector-valued operators with off-diagonal decay in L^(2) and certain quasi-orthogonality on a subspace of L^(2),in which the testing functions themselves are also *** an application,we establish the boundedness of layer potentials related to parabolic operators in divergence form,defined in the upper half-space Rn+2+:={(x,t,λ)∈R^(n+1)×(0,∞)},with uniformly complex elliptic,L^(∞),t,λ-independent coefficients,and satisfying the De Giorgi/Nash estimates.

关键词： Local Tb theorems Calderon-Littlewood-Paley family Parabolic layer potentials Carleson measure estimates

Confluence of asymmetric catalysis and electrosynthesis 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 Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

Electrosynthesis has gained widespread 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 allowing for unconventional bond activations.

关键词： Confluence of asymmetric catalysis and electrosynthesis in sustainable chemical transformations

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 Wenhu Zhou Xiangya 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,which provides unique solutions to tackle the obstacles of traditional tumor *** and facultative anaerobes with active tropism can selectively colonize at tumor sites and suppress tumor growth via different mechanisms,serving as attractive tools for tumor treatment either as a monotherapy or combining with other therapies for synergistic anti-tumor *** this critical review,we introduce the recent advances of bacteria-based tumor therapy from the following ***,the general properties of bacteria are reviewed 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 well as ***,anti-tumor mechanisms of bacteria are summarized,which refer to intrinsic tumoricidal activities,immune activation,bacteria metabolism,and their capability to regulate gut microbiota ***,bacteria could act as carriers to deliver various types of therapeutics to achieve combination therapy with 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,which 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

Synthesis of Organofluorine Compounds with Acylsilanes

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

作者： Youyuan 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 synthetic chemistry,medicinal chemistry and material *** this review,we summarize the investigations on the synthesis of organofluorine compounds with *** the non-fluorinated acylsilanes,the in situ generation of difluoroenoxysilanes from the reactions of the acylsilanes with trifluoromethylation reagents is the major pathway,leading to the facile preparation of variousα,α-*** the fluoroalkylacylsilanes,apart from the in situ generation of difluoroenoxysilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acylsilanes and the selective control of reactivities of the biradicals pave the way for the synthesis of a variety of organofluorine *** general,most of these reactions gave racemic products,and the asymmetric synthesis of organofluorine compounds with acylsilanes is still rare,which would be a future.

关键词： Acylsilanes Organofluorine compounds Brook rearrangement Radical rearrangement β-Fluoride elimination Asymmetric catalysis Photocatalysis Defluoroalkylation

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 ChemistryforFrontier 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 synthetic reactions as well as petro-chemical industry,and also found in natural *** to the alkenes attaching the directing groups or activating group,the catalytic asymmetric reaction of unactivated terminal alkenes presents great challenges due to the weak electron effect and small steric hindrance *** review mainly summarizes the latest progress of the asymmetric reaction of unactivated terminal olefins since 2016.

关键词： Asymmetric catalysis Terminal unactivated alkenes Hydrofunctionalization Difunctionalization Metal-catalyzed