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On hypersurfaces of h2×h2

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Science China mathematics 2024年第2期67卷 339-366页

作者： Dong Gao hui ma Zeke Yao School of Science Beijing University of Civil Engineering and Architecture Department of mathematical Sciences Tsinghua University

In this paper, we study hypersurfaces of h2× h2. We first classify the hypersurfaces with constant principal curvatures and constant product angle functions. Then we classify homogeneous hypersurfaces and isoparametric hypersurfaces, respectively. Finally, we classify the hypersurfaces with at most two distinct constant principal curvatures, as well as those with three distinct constant principal curvatures under some additional conditions.

关键词： constant principal curvature homogeneous hypersurface isoparametric hypersurface 53C42 53B25 53C40

An improved pulse coupled neural networks model for semantic IoT

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Digital Communications and Networks 2024年第3期10卷 557-567页

作者： Rong ma Zhen Zhang Yide ma Xiping hu Edith C.h.Ngai Victor C.M.Leung School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China School of Medical Technology Beijing Institute of TechnologyBeijing100081China Department of Electrical and Electronic Engineer The University of Hong KongHong Kong 999077China College of Computer Science and Software Engineering Shenzhen UniversityShenzhen 518060China Department of Electrical and Computer Engineering the University of British ColumbiaVancouverBC V6T 1Z4Canada

In recent years,the Internet of Things(IoT)has gradually developed applications such as collecting sensory data and building intelligent services,which has led to an explosion in mobile data ***,with the rapid development of artificial intelligence,semantic communication has attracted great attention as a new communication ***,for IoT devices,however,processing image information efficiently in real time is an essential task for the rapid transmission of semantic *** the increase of model parameters in deep learning methods,the model inference time in sensor devices continues to *** contrast,the Pulse Coupled Neural Network(PCNN)has fewer parameters,making it more suitable for processing real-time scene tasks such as image segmentation,which lays the foundation for real-time,effective,and accurate image ***,the parameters of PCNN are determined by trial and error,which limits its *** overcome this limitation,an Improved Pulse Coupled Neural Networks(IPCNN)model is proposed in this *** IPCNN constructs the connection between the static properties of the input image and the dynamic properties of the neurons,and all its parameters are set adaptively,which avoids the inconvenience of manual setting in traditional methods and improves the adaptability of parameters to different types of *** segmentation results demonstrate the validity and efficiency of the proposed self-adaptive parameter setting method of IPCNN on the gray images and natural images from the matlab and Berkeley Segmentation *** IPCNN method achieves a better segmentation result without training,providing a new solution for the real-time transmission of image semantic information.

关键词： Internet of things(IoT) Semantic information Real-time application Improved pulse coupled neural network Image segmentation

Testing Bell inequality through h→ττ at CEPC

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Chinese Physics C 2024年第10期48卷 59-71页

作者： Kai ma Tong Li Faculty of Science Xi'an University of Architecture and TechnologyXi'an 710055China School of Physics Nankai UniversityTianjin 300071China

The decay of higgs boson into two spin-1/2 particles provides an ideal system to reveal quantum entanglement and *** e^(+)e^(-) colliders can improve the measurement accuracy of the spin correlation of tau lepton pairs from higgs boson *** show the testability of Bell inequality through h→ττ at Circular Electron Positron Collider(CEPC).Two realistic methods of testing Bell inequality are investigated,i.e.,Törnqvist's method and Clauser-home-Shimony-holt(ChSh)*** the simulation,we consider the detector effects of CEPC including uncertainties for tracks and jets from Z boson in the production of e^(+)e^(-)→*** reconstruction approaches are described to measure quantum entanglement between τ^(+) and τ^(-).Finally,we show the sensitivity of CEPC to Bell inequality violation for the two methods.

关键词： Bell inequality higgs boson CEPC

Uncovering the hierarchical clusters in the heat-affected zone of an electron beam weldedα/βtitanium alloy joint

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Journal of materials Science & Technology 2024年第7期174卷 120-132页

作者： C.Xu X.h.Shao h.J.Yang M.Lv h.Q.Liu X.L.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Suzhou laboratory Suzhou 215028China Department of Mechanical Engineering Kyushu UniversityFukuoka 819-0395Japan Bay Area Center for Electron Microscopy Songshan Lake Materials LaboratoryDongguan 523808China

Using high-resolution transmission Kikuchi diffraction(TKD)and transmission electron microscopy(TEM),we examined the hierarchical clusters that form in situ in the heat-affected zone(hAZ),which are com-monly referred to as“ghost”structures,of bimodal titanium alloy Ti-5Al-2Sn-2Zr-4Mo-4Cr(wt%,TC17).The ghost structures are enriched with Al elements but poor in Mo and Cr compared to the surroundingβ*** results show that the ghost structure in middle-hAZ mainly consists ofα_(L)laths with a high-angle grain boundary,which exhibits the classic Burgers orientation relationship(BOR)with the host matrix,while it encircles theα_(P)grains in *** the ghost structure is evidenced to form via in-complete martensitic *** results further confirm that the ghost structure is composed ofαL and tinyβ_(L)laths with BOR,with the former being enriched with Al and poor with Cr and Mo,while the latter is the ***,twoα_(L)variant clusters with a check-mark morphology are fre-quently observed viewed along[0001]_(αL)//[110]_(βL)directions,which are dominated by the crystallographic and geometrical relationships betweenαandβ*** on the microstructural characterization,it is hypothesized that the ghost structure is transformed from the initialα_(P)phase,due to the coupling ef-fect of high thermal stress(which induces the formation of a large number of dislocations)and element diffusion caused by sudden temperature increase and plunge cooling in the hAZ during the welding pro-cess.

关键词： TC17 titanium alloy Electron beam welding(EBW) The ghost structure Transmission Kikuchi diffraction(TKD) Transmission electron microscopy(TEM)

Transition-metal-catalyzed remote meta-C-h alkylation and alkynylation of aryl sulfonic acids enabled by an indolyl template

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Chinese Chemical Letters 2024年第8期35卷 254-259页

作者： Pengfei Zhang Qingxue ma Zhiwei Jiang Xiaohua Xu Zhong Jin College of Chemistry State Key Laboratory of Elemento-organic ChemistryNankai UniversityTianjin 300071China Key Laboratory of Xinjiang Native Medicinal and Edible Plant Resource Chemistry College of Chemistry and Environmental SciencesKashi UniversityKashgar 844007China

Transition-metal-catalyzed remote sp^(2)C-h functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-h functionalization of aryl sulfonates and electron-deficient nature of phenyl ***,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-h alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta ***,remote meta-selective C-h alkynylation of aryl sulfonic acids was also accomplished with a rhodium *** meta-C-h functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.

关键词： C-h functionalization Aryl sulfonic acid Site-selectivity Transition-metal catalysis Alkylation Alkynylation

Photoluminescence and ratiometric thermo-response of Eu^(2+)and Eu^(3+)in BaAl_(2)B_(2)O_(7):Eu^(2+),Eu^(3+)phosphor materials

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Journal of rare Earths 2024年第7期42卷 1240-1249,I0002页

作者： Ziyao Wang haitao Fu Xiufeng Zhan Bo Tong Guofeng ma h.T.(Bert)hintzen Institute of Innovative Science and Technology Shenyang UniversityShenyang110044China College of Mechanical Engineering Shenyang UniversityShenyang110044China Faculty of Applied Sciences Delft University of Technology2629 JBDelftthe Netherlands

A novel Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state *** valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and *** phosphor shows high sensitivity(Sa=0.0173 K^(-1),S_(r)=0.461%/K)and superior signal discriminability(Δν∼10380 cm^(−1)).The thermo-sensitive performance is subject to the dual effects of different thermo-responses by Eu^(2+)versus Eu^(3+)combined with energy transfer from Eu^(2+)to Eu^(3+),so that the sensitivity of the phosphor in the temperature range presents a non-monotonic *** development of the BaAl_(2)B_(2)O_(7):Eu^(2+),Eu^(3+)phosphor is not only expected to be relevant for application in the field of temperature sensing,but also of reference significance for improving the sensitivity by means of energy transfer between co-activator ions over a wider temperature range of Eu^(2+)-Eu^(3+)co-activated ratiometric thermo-sensitive phosphors.

关键词： Photoluminescence ratiometric thermo-response Phosphor Eu^(2+)/Eu^(3+) rare earths

Synthesis of straight-chain C_(49)h_(100) alkane using a modular splicing strategy

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Journal of Energy Chemistry 2024年第5期92卷 414-421页

作者： Bing ma Jingqing Tian Xueling Lang Shutao Lei Bolong Li Chen Zhao Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China School of materials Science and Engineering Nankai UniversityTianjin 300350China

Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point *** conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as *** herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond *** synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.

关键词： Straight-chain alkane Aldol condensation F-Cacylation hydrodeoxygenation

Investigation into the roles of interfacial h_(2)O structure in catalytic oxidation of hChO and CO over CuMnO_(2) catalysts

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Journal of Environmental Sciences 2024年第3期137卷 310-320页

作者： Chunyan ma Jushuang Pan Cheng Chen Yuanyuan Dong Feng Yao Fengbang Wang maoyong Song Key Laboratory of Environmental Nanotechnology and health Effects Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China No.52 Institute of China North Industries Group Yantai Branch Co.Ltd. Yantai 264000China

The rapid deactivation of cost-effective MnO_(2)-based catalysts in humid air limits their application in practice,and the identification of the role of water in an oxidation process is significant for developing water-resistant MnO_(2)-based ***,CuMnO_(2)showed a20.3%hChO conversion in 10 hr at room temperature in humid air with relative humidity of 40%,but deactivated in 3 hr in dry *** excellent activity and stability of hChO oxidation in humid air were attributed to the positive effect of h_(2)O on hChO oxidation to the h_(2)O-hOCh_(2)Oh supermolecule assemblies via hydrogen bonds formed on CuMnO_(2).h_(2)O-hOCh_(2)Oh supermolecule assemblies tend to be oxidized to carbonate,which is further oxidized to CO_(2).Furthermore,CuMnO_(2)exhibited a much poorer activity of CO oxidation in humid air,but the CO conversion was still 100%in 10 hr in dry air.h_(2)O showed a competitive adsorption effect to CO on CuMnO_(2).CuMnO_(2)could be applied in hChO elimination in humid air and CO elimination in dry air.

关键词： h_(2)O-hOCh_(2)Oh supermolecule hChO oxidation humid air CuMnO_(2) CO oxidation

hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu ma Yuan LIU Ke hAN Yu TIAN Liran ma State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly h-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)