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Science China Mathematics 2024年第11期67卷 2433-2452页

作者： feng Shao Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

Let X be an irreducible Hermitian symmetric space of compact type(IHSS for short).In this paper,we give the irreducible decomposition of *** a by-product,we give a cohomological characterization of the rank of ***,we introduce pseudoeffective thresholds to measure the bigness of tangent bundles of smooth complex projective varieties precisely and calculate them for irreducible Hermitian symmetric spaces of compact type.

关键词： tangent bundle pseudoeffective threshold irreducible Hermitian symmetric space of compact type (IHSS) multiplicity free action

Oxygen vacancy boosting Fenton reaction in bone scaffold towards fighting bacterial infection

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International Journal of Extreme Manufacturing 2024年第1期6卷 296-311页

作者： Cijun Shuai Xiaoxin Shi feng yang Haifeng Tian Pei feng State Key Laboratory of Precision Manufacturing for Extreme Service Performance College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083People’s Republic of China Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013People’s Republic of China College of Mechanical Engineering Xinjiang UniversityUrumqi 830017People’s Republic of China

Bacterial infection is a major issue after artificial bone transplantation due to the absence of antibacterial function of bone scaffold,which seriously causes the transplant failure and even amputation in severe *** this study,oxygen vacancy(OV)defects Fe-doped Ti O2(OV-FeTiO2)nanoparticles were synthesized by nano TiO2and Fe3O4via high-energy ball milling,which was then incorporated into polycaprolactone/polyglycolic acid(PCLgA)biodegradable polymer matrix to construct composite bone scaffold with good antibacterial activities by selective laser *** results indicated that OV defects were introduced into the core/shell-structured OV-FeTiO2nanoparticles through multiple welding and breaking during the high-energy ball milling,which facilitated the adsorption of hydrogen peroxide(H2O2)in the bacterial infection microenvironment at the bone transplant *** accumulated H2O2could amplify the Fenton reaction efficiency to induce more hydroxyl radicals(·OH),thereby resulting in more bacterial deaths through·OH-mediated oxidative *** antibacterial strategy had more effective broad-spectrum antibacterial properties against gram-negative Escherichia coli(***)and gram-positive Staphylococcus aureus(***).In addition,the PCLgA/OV-FeTiO2scaffold possessed mechanical properties that match those of human cancellous bone and good biocompatibility including cell attachment,proliferation and osteogenic differentiation.

关键词： bacterial infection bone scaffold selective laser sintering Fenton reaction antibacterial properties

The noise spectral characteristics and noise reduction schemes of screw air-source heat pump:A case study

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Building Simulation 2024年第1期17卷 53-70页

作者： Dongsheng Liu yaohan feng Jikang Jia Pengfei Si ya feng China Southwest Architecture Design and Research Institute Co.Ltd. Chengdu 610041China CSCEC green Construction Engineering Research Center Chengdu 610041China

The screw air-source heat pump can cause incessant high noise levels during operation,which might hinder adoption of this energy-efficient heat ***,acoustic measurements and comparison testing were performed in this *** measurements revealed that the compressor is the main noise source of the heat pump,and it shows a multipeak frequency distribution and a wide frequency spectrum under different work conditions,with multiple peaks at 63,250,and 1000 ***,a compressor sound insulation cover with broadband absorption was proposed,and it was experimentally proven that the insulation cover can reduce the maximum sound pressure level of one unit from 89.8 dBA to 79.1 ***,we proposed several noise reduction strategies and compared their noise reduction effects using computer *** results showed that the noise problem can be effectively improved through the rational design of the sound barrier and the layout and opening options of heat *** distance between the sound barrier and heat pump and the sound attenuation due to diffraction ALa exhibit a U-shaped *** buildings of different heights,the optimal heights of noise barrier are *** 5.5-meter is the optimal height of the sound barrier for single-story *** conclusions can be applied to other building projects for heat pump noise reduction.

关键词： acoustic simulation broadband noise noise reduction air-source heat pump sound barrier

Fast nuclear-spin gates and electrons−nuclei entanglement of neutral atoms in weak magnetic fields

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Frontiers of physics 2024年第2期19卷 179-203页

作者： Xiao-feng Shi School of Physics Xidian UniversityXi’an 710071China

We present a novel class of Rydberg-mediated nuclear-spin entanglement in divalent atoms with global laser ***,we show a fast nuclear-spin controlled phase gate of an arbitrary phase realizable either with two laser pulses when assisted by Stark shifts,or with three ***,we propose to create an electrons−nuclei-entangled state,which is named a super bell state(SBS)for it mimics a large Bell state incorporating three small Bell ***,we show a protocol to create a three-atom electrons-nuclei entangled state which contains the three-body W and greenberger−Horne−Zeilinger(gHZ)states *** protocols possess high intrinsic fidelities,do not require single-site Rydberg addressing,and can be executed with large Rydberg Rabi frequencies in a weak,gauss-scale magnetic *** latter two protocols can enable measurement-based preparation of Bell,hyperentangled,and gHZ states,and,specifically,SBS can enable quantum dense coding where one can share three classical bits of information by sending one particle.

关键词： nuclear-spin qubit electrons−nuclei entanglement super Bell state greenberger−Horne−Zeilinger state Rydberg-mediated entanglement quantum dense coding

Recent Advances in Deciphering the Mechanisms and Biological Functions of DNA Demethylation

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Chinese Journal of Chemistry 2024年第6期42卷 645-651页

作者： yang feng Sheng-Jun Chen Bi-feng yuan Key Laboratory of Aquatic Product Processing Ministry of Agriculture and Rural AffairsNational R&D Center for Aquatic Product ProcessingSouth China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesGuangzhouGuangdong510300 China School of Public Health Research Center of Public HealthRenmin Hospital of Wuhan UniversityWuhan UniversityWuhanHubei430071 China

5-Methylcytosine (5mC) is a dynamic and reversible epigenetic modification in genomic DNA of higher *** has been well-established that the demethylation of 5mC occurs through the ten-eleven translocation (TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase (TDg)-initiated base excision repair (BER).Recent findings also have identified an alternative pathway of DNA *** this pathway,TET enzymes directly oxidize 5mC to form 5-formylcytosine (5fC) or 5-carboxylcytosine (5caC).These modified bases can undergo direct deformylation or decarboxylation,***,DNA demethylation can also occur through the deamination of 5mC and 5hmC,resulting in the production of thymine and 5-hydroxymethyluracil (5hmU),*** DNA demethylation pathways possess critical functional implications and roles in biological *** Recent Advances article will focus on the studies of mechanisms and biological functions of DNA demethylation,shedding light on the reversible nature of the epigenetic modification of 5mC.

关键词： Epigenetics DNA DNA methylation 5-Methylcytosine Demethylation Mechanisms Biological functions C—C bond cleavage Mass spectrometry

Unstructured Road Extraction in UAV Images based on Lightweight Model

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 372-384页

作者： Di Zhang Qichao An Xiaoxue feng Ronghua Liu Jun Han feng Pan School of Automation Beijing Institute of TechnologyBeijing 100081China Tianjin Institute of Maritime Navigation Instruments Tianjin 300130China The 716th Research Institute of China Shipbuilding group Co. LtdJiangsu 222061China

There is no unified planning standard for unstructured roads,and the morphological structures of these roads are complex and *** is important to maintain a balance between accuracy and speed for unstructured road extraction *** road extraction algorithms based on deep learning have problems such as high model complexity,high computational cost,and the inability to adapt to current edge computing ***,it is best to use lightweight network *** the need for lightweight models and the characteristics of unstructured roads with different pattern shapes,such as blocks and strips,a TMB(Triple Multi-Block)feature extraction module is proposed,and the overall structure of the TMBNet network is *** TMB module was compared with SS-nbt,Non-bottleneck-1D,and other modules via *** feasibility and effectiveness of the TMB module design were proven through experiments and *** comparison experiment,using multiple convolution kernel categories,proved that the TMB module can improve the segmentation accuracy of the *** comparison with different semantic segmentation networks demonstrates that the TMBNet network has advantages in terms of unstructured road extraction.

关键词： Unstructured road Lightweight model Triple Multi-Block(TMB) Semantic segmentation net

Frequency Domain Fatigue Evaluation on SCR girth-Weld Based on Structural Stress

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China Ocean Engineering 2024年第2期38卷 255-270页

作者： ZHANg Long ZHAO Tian-feng College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing 102249China

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating *** harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue *** structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue ***,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural ***,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into *** research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

关键词： SCR girth weld random vibration self(cross)power spectrum structural stress method biaxial fatigue damage

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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Journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang S.y.yang Z.H.Dai y.J.Liu J.H.Liao g.y.Zhong Z.J.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

Ag-doped CNT/HAP nanohybrids in a PLLA bone scaffold show significant antibacterial activity

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Bio-Design and Manufacturing 2024年第2期7卷 105-120页

作者： Cijun Shuai Xiaoxin Shi Kai Wang yulong gu feng yang Pei feng State Key Laboratory of Precision Manufacturing for Extreme Service Performance College of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China College of Mechanical Engineering Xinjiang UniversityUrumqi 830017China

Bacterial infection is a major problem following bone implant ***,poly-l-lactic acid/carbon nanotube/hydroxyapatite(PLLA/CNT/HAP)bone scaffolds possess enhanced mechanical properties and show good ***,wesynthesizedsilver(Ag)-dopedCNT/HAP(CNT/Ag-HAP)nanohybrids via the partial replacing of calcium ions(Ca2+)in the HAP lattice with silver ions(Ag+)using an ion doping technique under hydrothermal ***ﬁcally,the doping process was induced using the special lattice structure of HAP and the abundant surface oxygenic functional groups of CNT,and involved the partial replacement of Ca2+in the HAP lattice by doped Ag+as well as the in situ synthesis of Ag-HAP nanoparticles on CNT in a hydrothermal *** result-ing CNT/Ag-HAP nanohybrids were then introduced into a PLLA matrix via laser-based powder bed fusion(PBF-LB)to fabricate PLLA/CNT/Ag-HAP scaffolds that showed sustained antibacterial *** then found that Ag+,which pos-sesses broad-spectrum antibacterial activity,endowed PLLA/CNT/Ag-HAP scaffolds with this activity,with an antibacterial effectiveness of 92.65%.This antibacterial effect is due to the powerful effect of Ag+against bacterial structure and genetic material,as well as the physical destruction of bacterial structures due to the sharp edge structure of *** addition,the scaffold possessed enhanced mechanical properties,showing tensile and compressive strengths of 8.49 MPa and 19.72 MPa,***,the scaffold also exhibited good bioactivity and cytocompatibility,including the ability to form apatite layers and to promote the adhesion and proliferation of human osteoblast-like cells(Mg63 cells).

关键词： Ag-doped Carbon nanotube/hydroxyapatite(CNT/HAP) Antibacterial properties Bone scaffold

In-situ construction of grass-like hybrid architecture responsible for extraordinary corrosion performance: Experimental and theoretical approach

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Nano Materials Science 2024年第1期6卷 44-59页

作者： T.Suhartono F.Hazmatulhaq y.Sheng A.Chaouiki M.P.Kamil y.g.Ko Materials Electrochemistry group School of Materials Science and EngineeringYeungnam UniversityGyeongsan38541Republic of Korea Research Center for Advanced Materials National Research and Innovation Agency(BRIN)South TangerangBanten15314Indonesia

Despite the engineering potential by the co-existence of inorganic and organic substances to protect vulnerable metallic materials from corrosive environments,both their interaction and in-situ formation mechanism to induce the nature-inspired composite remained less *** present work used three distinctive mercaptobenzazole(MB)compounds working as corrosion inhibitors,such as 2-mercaptobenzoxazole(MBO),2-mercaptobenzothiazole(MBT),and 2-mercaptobenzimidazole(MBI)in a bid to understand how the geometrical structure arising from O,S,and N atoms affected the interaction toward inorganic *** compounds that were used here to control the corrosion kinetics would be interacted readily with the pre-existing MgO layer fabricated by plasma *** phenomenon triggered the nucleation of the root network since MB compounds were seen to be adsorbed actively on the defective surface through the active sites in MB ***,the molecule with twin donor atoms adjacent to the mercapto-sites affected the facile growth of the grass-like structures with‘uniform’distribution via molecular self-assembly,which showed better corrosion performance than those with having dissimilar donor atoms with the inhibition efficiency(η)of 97%*** formation mechanism underlying nucleation and growth behavior of MB molecule was discussed concerning the theoretical calculation of density functional theory.

关键词： Nature-inspired composite Organic-inorganic interaction Corrosion inhibitor Density functional theory Electrochemistry