检索结果-南通市图书馆

Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

引用

Chinese Journal of Mechanical Engineering 2024年第2期37卷 163-183页

作者： Chenbing Ni Junjie zhu Youqiang wang Dejian Liu Xuezhao wang Lida zhu School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266525China School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions,such as reducing friction,improving wear and increasing *** prediction of micro/nano surface textures is of great significance for the design,fabrication and application of functional textured *** this paper,based on the kinematic analysis of cutter teeth,the discretization of ultrasonic machining process,transformation method of coordinate systems and the cubic spline data interpolation,an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling(UVAM).Based on the theoretical model,the effect of key process parameters(vibration directions,vibration dimensions,cutting parameters and vibration parameters)on tool trajectories and microtextured surface morphology in UVAM is ***,the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling(UEVAM)was *** to conventional numerical models,the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM,which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro *** prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM,2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface *** study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

关键词： Theoretical modeling Microtextured surface Ultrasonic vibration-assisted milling Cubic spline interpolation Surface roughness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mott insulator-density ordered superfluid transition and‘shamrock transition’in a frustrated triangle lattice

引用

Communications in Theoretical Physics 2024年第3期76卷 157-164页

作者： Ce wang Yu Chen School of Physics Science and Engineering Tongji UniversityShanghai200092China Institute for Advanced Study Tsinghua UniversityBeijing100084China Graduate School of China Academy of Engineering Physics Beijing100193China

Density order is usually a consequence of the competition between long-range and short-range *** we report a density ordered superfluid emergent from a homogeneous Mott insulator due to the competition between frustrations and local *** transition is found in a Bose–Hubbard model on a frustrated triangle lattice with an extra pairing ***,we find a quantum phase transition between two different density ordered superfluids,which is beyond the Landau–Ginzburg(LG)paradigm.A U(1)symmetry is emergent at the critical point,while the symmetry in each density ordered superfluid is z_(2)×z_(3).We call the transition a‘shamrock transition’,due to its degenerate ground state in the parameter space being a shamrock-like curve rather than a circle in an LG-type *** low energy theories are established for the two transitions mentioned above and we find their resemblance and differences with clock models.

关键词： frustrated magnets superfluid mott insulator density wave ordered phase clock model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Single-particle spectroscopies of p-wave and d-wave interacting Bose gases in normal phase

引用

Communications in Theoretical Physics 2024年第5期76卷 140-147页

作者： zeqing wang Ran Qi Department of Physics Renmin University of ChinaBeijing 100872China

Motivated by experiments with interacting quantum gases across high partial wave resonance,we investigate the thermodynamic properties and single-particle spectra of Bose gases in normal phase for different interaction strengths for both p-and d-wave *** equation of state,contact density,momentum distributions and self-energies of single-particle Green’s functions are obtained in the spirit of ladder diagram *** radio-frequency(RF)spectrum,as an important experimental approach for detecting Feshbach molecules or the interaction effect,is calculated at different temperatures.A reversed temperature dependence on the Bose–Einstein condensation side and Bardeen–Cooper–Schrieffer side is identified for both p-and d-wave *** estimate for the signal of RF spectra under typical experimental conditions is also provided.

关键词： quantum gases ultracold atom high partial wave RF spectra

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pilot-Free End-to-End Underwater Acoustic Communication System Based on Autoencoder

引用

Journal of Communications and Information Networks 2024年第3期9卷 233-243页

作者： Yizhe wang Deqing wang Liqun Fu School of Informatics and Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of Ministry of EducationXiamen UniversityXiamen 361005China

The long delay spreads and significant Doppler effects of underwater acoustic(UWA)channels make the design of the UWA communication system more *** this paper,we propose a learning-based end-to-end framework for UWA communications,leveraging a double feature extraction network(DFEN)for data *** DFEN consists of an attentionbased module and a mixer-based module for channel feature extraction and data feature extraction,*** the diverse nature of UWA channels,we propose a stack-network with a two-step training strategy to enhance *** avoiding the use of pilot information,the proposed network can learn data mapping that is robust to UWA *** results show that our proposed algorithm outperforms the baselines by at least 2 dB under bit error rate(BER)10^(−2)on the simulation channel,and surpasses the compared neural network by at least 5 dB under BER 5×10^(−2)on the experiment channels.

关键词： underwater acoustic communications autoencoder time-varying channel

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Accelerating the Screening of Modified MA_(2)z_(4)Catalysts for Hydrogen Evolution Reaction by Deep Learning-Based Local Geometric Analysis

引用

Energy & Environmental Materials 2024年第6期7卷 290-302页

作者： Jingnan zheng Shibin wang Shengwei Deng zihao Yao Junhua Hu Jianguo wang Institute of Industrial Catalysis State Key Laboratory Breeding Base of Green-Chemical Synthesis TechnologyCollege of Chemical EngineeringZhejiang University of TechnologyHangzhou 310032China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China School of Materials Science and Engineering State Center for International Cooperation on Designer Low-Carbon&Environmental Materials(CDLCEM)Zhengzhou UniversityZhengzhou 450001China

Machine learning(ML)integrated with density functional theory(DFT)calculations have recently been used to accelerate the design and discovery of single-atom catalysts(SACs)by establishing deep structure–activity *** traditional ML models are always difficult to identify the structural differences among the single-atom systems with different modification methods,leading to the limitation of the potential application *** to the structural properties of several typical two-dimensional MA_(2)z_(4)-based single-atom systems(bare MA_(2)z_(4)and metal single-atom doped/supported MA_(2)z_(4)),an improved crystal graph convolutional neural network(CGCNN)classification model was employed,instead of the traditional machine learning regression model,to address the challenge of incompatibility in the studied *** CGCNN model was optimized using crystal graph representation in which the geometric configuration was divided into active layer,surface layer,and bulk layer(ASB-GCNN).Through ML and DFT calculations,five potential single-atom hydrogen evolution reaction(HER)catalysts were screened from chemical space of 600 MA_(2)z_(4)-based materials,especially V_(1)/HfSn_(2)N_(4)(S)with high stability and activity(Δ_(GH*)is 0.06 eV).Further projected density of states(pDOS)analysis in combination with the wave function analysis of the SAC-H bond revealed that the SAC-dz^(2)orbital coincided with the H-s orbital around the energy level of−2.50 eV,and orbital analysis confirmed the formation ofσ*** study provides an efficient multistep screening design framework of metal single-atom catalyst for HER systems with similar two-dimensional supports but different geometric configurations.

关键词： graph convolutional neural network hydrogen evolution reaction modified MA_(2)z_(4)substrate single atom catalyst

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Micromechanical interlocking-inspired dendritic porous silicabased multimodal resin composites for the tooth restoration

引用

Nano Research 2024年第10期17卷 9065-9077页

作者： Hongyan Chen Junjun wang Shi Yin Ruili wang Xinquan Jiang Meifang zhu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Material Science and EngineeringDonghua UniversityShanghai 201620China Shanghai Engineering Research Center of Advanced Dental Technology and Materials Shanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyNational Clinical Research Center for Oral DiseasesShanghai Ninth People’s HospitalCollege of StomatologyShanghai Jiao Tong University School of MedicineShanghai 200011China

Porous silica particles have shown great potential application as reinforcing fillers in the field of dentistry due to their ability to construct the micromechanical interlocking effect at filler-matrix ***,how to accurately regulate the pore structure,especially the pore size,to increase the degree of the micromechanical interlocking and the performance of materials remains a ***,we have proposed a facile self-assembly process to synthesize dendritic porous silica with tunable pore sizes(DPS-x)by adjusting the chain-length of the alcohols in the *** mechanism of nucleation-growth is further put *** results indicate that the pore size of DPS-x indeed affects the mechanical property of composites,where the DPSpen particles with intermediate pore size are chosen as the optimal reinforcing *** bimodal and multimodal filler formulations are further established to address the loading limitation of unimodal DPS-pen(46 wt.%).In virtue of the closepacked structure of identical spheres,the particle sizes of secondary silica embedded into the maximally loaded bimodal D3S7 composite(DPS-pen:Si430=30:70,w/w)are theoretically calculated without *** all formulations,the developed multimodal D3S7+Si178+Si90 filler exhibits superior mechanical properties,the lowest shrinkage,and high polymerization conversion for dental composites,along with satisfied waster sorption and solubility,and good biocompatibility in vitro and in vivo,which are comparable to commercial composite z350 XT(3M,USA).These DPS-x particles and their multimodal fillers can also be applied to other polymer-based biomaterials.

关键词： porous silica pore size multimodal filler dental composite physicochemical properties biosafety

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Polyoxometalates coupled covalent organic frameworks as highly active photothermal nanoreactor for CO_(2)cycloaddition

引用

Nano Research 2024年第7期17卷 5975-5984页

作者： Tian wang Yunqing zhu Wei wang Junfeng Niu zhiyi Lu Peilei He School of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021China Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of zhejiang Province Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China College of Environmental Science and Engineering North China Electric Power UniversityBeijing 102206China University of Chinese Academy of Sciences Beijing 100049China

Covalent organic frameworks(COFs)-based nanoreactors have attracted broad interest in many fields due to their voidconfinement ***,the inherent drawback of conventional nanoreactors is the lack of internal active sites,which limits their widespread ***,we report the construction of hierarchical COF(EB-TFP)nanoreactor with pre-synthesized polyoxometalates(POM,[PV_(2)W_(10)O_(40)]^(5–)(PV_(2)W_(10)))clusters encapsulated inside of COF(POM@COF).PV_(2)W_(10)@EB-TFP anchors nucleophilic-group(Br–ions)and PV_(2)W_(10)anion cluster within the COF framework via electrostatic interactions,which not only simplifies the reaction system but also enhances catalytic *** reaction performance of the PV_(2)W_(10)@EB-TFP nanoreactor can be tuned to achieve excellent catalytic activity in CO_(2)cycloaddition reaction(CCR)for~97.63%conversion and~100%selectivity under visible light irradiation.A mechanistic study based on density functional theory(DFT)calculations and insitu characterization was also carried *** summary,we have reported a method for achieving the uniform dispersion of POM single clusters into COF nanoreactor,demonstrating the potential of POM@COF nanoreactor for synergistic photothermal catalytic CO_(2)cycloaddition.

关键词： photothermal nanoreactor CO_(2)cycloaddition polyoxometalate photothermal-synergistic catalysis covalent organic frameworks

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Visible light cross-linking and bioactive peptides loaded integrated hydrogel with sequential release to accelerate wound healing complicated by bacterial infection

引用

Nano Research 2024年第3期17卷 1737-1747页

作者： Guiyan wang Ning Yuan Jun zhang Man Qin Suwei Dong Yuguang wang Department of Pediatric Dentistry Peking University School and Hospital of StomatologyBeijing 100081China State Key Laboratory of Natural and Biomimetic Drugs Chemical Biology Centerand School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Department of Prosthodontics Peking University School and Hospital of StomatologyBeijing 100081China

The effective management of bacterial infections that are resistant to multiple drugs remains a substantial clinical *** eradication of drug-resistant bacteria and subsequent promotion of angiogenesis are imperative for the regeneration of the infected ***,a novel and facile peptide containing injectable hydrogel with sustained antibacterial and angiogenic capabilities is *** antibacterial peptide that consists of 11 residues(CM11,WKLFKKILKVL)is loaded onto acrylate-modified gelatin through charge interactions.A vascular endothelial growth factor mimetic peptide KLT(KLTWQELYQLKYKGI)with a GCG(Gly-Cys-Gly)modification at the N-terminal is covalently coupled through a visible light-induced thiol-ene *** this reaction,the acrylate gelatin undergoes cross-linkage within *** on the physical/chemical double crosslinking strategy,the bioactive peptides achieve sustained and sequential *** results show that the hydrogel significantly inhibits methicillin-resistant Staphylococcus aureus(MRSA)growth through the rapid release of CM11 peptides at early stage;it forms obvious growth inhibition zones against pathogenic bacterial ***,cell counting kit-8 assay and scratch test confirm that the CM11/KLT-functionalized hydrogels promote cell proliferation and migration through the later release of KLT *** a mouse skin wound infected with self-luminous MRSA,the CM11/KLT-functionalized hydrogels enhance wound healing,with rapidly bacterial infection reduction,lower expression of inflammatory factors,and neovascularization *** results suggest that the rationally designed,sustained and sequential release CM11/KLT-functionalized hydrogels have huge potential in promoting the healing of multi-drug resistant bacterial infected wounds.

关键词： antimicrobial peptide vascular endothelial growth factor(VEGF)mimetic peptide sequential release visible-light crosslinking hydrogel wound therapy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Graphene Nanoribbons Enhancing the Electronic Conductivity and Ionic Diffusion of Graphene Electrodes for High-Performance Microsupercapacitors

引用

Energy & Environmental Materials 2024年第4期7卷 285-294页

作者： Yan zhang Huandi zhang Xiaoxiao wang Xiaowei Shi zehua zhao Yaling wang Jiamei Liu Cheng Tang Guolong wang Lei Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Center for Materials Chemistry Frontier Institute of Science and TechnologyXi'an Jiaotong University Instrument Analysis Center of Xi'an Jiaotong University Xi'an Jiaotong University

The electrochemical performance of microsupercapacitors with graphene electrodes is reduced by the issue of graphene sheets aggregation,which limits electrolyte ions penetration into *** the space between graphene sheets in electrodes facilitates the electrolyte ions penetration,but sacrifices its electronic conductivity which also influences the charge storage ability.

关键词： areal energy density graphene graphene nanoribbons microsupercapacitors structure engineering

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

SO_(2)-Insertion induced enantioselective oxysulfonylation to access β-chiral sulfones with quaternary carbon stereocenters

引用

Science China Chemistry 2024年第3期67卷 908-913页

作者： Jun zhang Xuefeng wang Peiqi wang Jiayuan Fang Shaoyu Li Jie Wu School of Pharmaceutical and Chemical Engineering&Institute for Advanced Studies Taizhou UniversityShanghai 200438China Department of Chemistry Fudan UniversityShanghai 200438China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

β-Chiral sulfones are structural motifs widely found in natural products and bioactive molecules, while also serving as important intermediates for the synthesis of valuable chiral scaffolds. In contrast to the rapid growth of sulfur dioxide insertion chemistry over the last decade, enantioselective catalytic variants for accessing β-chiral sulfones, especially those bearing a quaternary carbon stereocenter, remain rare. Herein, we report an enantioselective copper/bisoxazoline catalyzed oxysulfonylation of alkenes to yield isoxazolinyl-containing β-chiral sulfones bearing quaternary carbon stereocenters with moderate to excellent yields and up to 96:4 er. The advantage and irreplaceability of this sulfur dioxide insertion catalytic system have been demonstrated by achieving transformations clearly unavailable with the previously reported sulfonyl chloride system. Additionally,the recoverability of the new-developed bisoxazoline ligand L9 and its reusability without any erosion of the catalytic activity and enantioselectivity further demonstrate the usefulness of the protocol.

关键词： β-chiral sulfones sulfur dioxide insertion oxysulfonylation copper catalysis enantioselectivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：