检索结果-南通市图书馆

The effect of Laves phases and nano-precipitates on the electrochemical corrosion resistance of Mg-Al-Ca alloys under alkaline conditions

引用

Journal of Magnesium and Alloys 2024年第6期12卷 2447-2461页

作者： Markus Felten Veronika Chaineux Siyuan Zhang Ali Tehranchi Tilmann Hickel Christina Scheu Joshua Spille Marta Lipińska-Chwałek Joachim Mayer Benjamin Berkels Marcus Hans Imke Greving Silja Flenner Sandra Sefa Daniela Zander Chair of Corrosion and Corrosion Protection RWTH Aachen UniversityAachen 52072 Germany Max-Planck-Institut für Eisenforschung GmbH Düsseldorf 40237 Germany Central Facility for Electron Microscopy RWTH Aachen UniversityAachen 52074 Germany Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Forschungszentrum Jülich GmbHJülich 52428Germany Mathematical Image and Signal Processing Aachen Institute for Advanced Study in Computational Engineering ScienceRWTH Aachen UniversityAachen 52062 Germany Materials Chemistry RWTH Aachen UniversityAachen 52074 Germany institute of Materials Physics Helmholtz-Zentrum HereonGeesthacht 21502 Germany

The electrochemical corrosion mechanisms of Mg alloys were extensively studied in previous investigations of different chemical com-positions,modified surface states and various electrolyte ***,recent research focused on the active state of Mg dissolution,leading to unresolved effects of secondary phases adjacent to a stableα-solid solution passive *** present study investigates the fundamental electrochemical corrosion mechanisms of three different Laves phases with varying phase morphologies and phase fractions in the passive state of Mg-Al-Ca *** microstructure was characterized by(transmission-)electron microscopy and synchrotron-based transmission X-ray *** electrochemical corrosion resistance was determined with a standard three-electrode setup and advanced in-situ flow cell measurements.A new electrochemical activity sequence(C15>C36>α-Mg>C14)was obtained,as a result of a stable passive layer formation on theα-solid ***,nm-scale Mg-rich precipitates were identified within the Laves phases,which tend to inhibit the corrosion kinetics.

关键词： Laves phase STEM Magnesium Corrosion Passive layer

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

FedDAA:a robust federated learning framework to protect privacy and defend against adversarial attack

引用

Frontiers of Computer science 2024年第2期18卷 107-122页

作者： Shiwei LU Ruihu LI Wenbin LIU Fundamentals Department Air Force Engineering UniversityXi’an 710051China institute of advanced computational science and Technology Guangzhou UniversityGuangzhou 510006China

Federated learning(FL)has emerged to break data-silo and protect clients’privacy in the field of artificial ***,deep leakage from gradient(DLG)attack can fully reconstruct clients’data from the submitted gradient,which threatens the fundamental privacy of *** cryptology and differential privacy prevent privacy leakage from gradient,they bring negative effect on communication overhead or model ***,the original distribution of local gradient has been changed in these schemes,which makes it difficult to defend against adversarial *** this paper,we propose a novel federated learning framework with model decomposition,aggregation and assembling(FedDAA),along with a training algorithm,to train federated model,where local gradient is decomposed into multiple blocks and sent to different proxy servers to complete *** bring better privacy protection performance to FedDAA,an indicator is designed based on image structural similarity to measure privacy leakage under DLG attack and an optimization method is given to protect privacy with the least proxy *** addition,we give defense schemes against adversarial attack in FedDAA and design an algorithm to verify the correctness of aggregated *** results demonstrate that FedDAA can reduce the structural similarity between the reconstructed image and the original image to 0.014 and remain model convergence accuracy as 0.952,thus having the best privacy protection performance and model training *** importantly,defense schemes against adversarial attack are compatible with privacy protection in FedDAA and the defense effects are not weaker than those in the traditional ***,verification algorithm of aggregation results brings about negligible overhead to FedDAA.

关键词： federated learning privacy protection adversarial attacks aggregated rule correctness verification

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

A Symmetric-Actuating Linear Piezoceramic Ultrasonic Motor Capable of Producing a Scissoring Effect

引用

Research 2024年第1期2023卷 571-581页

作者： Zhanmiao Li Xingyu Yi Rongqi Zhu Zhonghui Yu Xiaoting Yuan MohammadJavad PourhosseiniAsl Shuxiang Dong School of Materials science and engineering Peking UniversityBeijing 100871China College of Mechatronics and Control engineering and Institute for Advanced StudyShenzhen UniversityShenzhen 518051China

Conventionally,to produce a linear motion,one motor’s stator is employed to drive one runner moving forward or *** far,there is almost no report of one electromechanical motor or piezoelectric ultrasonic motor that can directly generate two symmetrical linear motions,while this function is desired for precise scissoring and grasping in the minimally invasive surgery ***,we report a brandnew symmetric-actuating linear piezoceramic ultrasonic motor capable of generating symmetrical linear motions of two outputs directly without additional mechanical transmission *** key component of the motor is an(2×3)arrayed piezoceramic bar stator operating in the coupled resonant mode of the first longitudinal(L_(1))and third bending(B_(3))modes,leading to symmetric elliptical vibration trajectories at its two ends.A pair of microsurgical scissors is used as the end-effector,demonstrating a very promising future for high-precision microsurgical operations.

关键词： field symmetric backward

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

Phase-field simulations of the effect of temperature and interface for zirconiumδ-hydrides

引用

Chinese Physics B 2024年第4期33卷 701-710页

作者：陈子航盛杰刘瑜施小明黄厚兵许可王越超武帅孙博刘海风宋海峰 School of Materials science and engineering Beijing Institute of TechnologyBeijing 100081China advanced Research institute of Multidisciplinary science Beijing Institute of TechnologyBeijing 100081China Laboratory of computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Department of Physics University of Science and Technology BeijingBeijing 100083China

Hydride precipitation in zirconium cladding materials can damage their integrity and *** temperature and material defects have a significant effect on the dynamic growth of *** this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium *** results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride *** ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree *** escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection ***,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial ***,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack *** research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.

关键词： zirconium hydride phase-field method temperature effect mismatch degree

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

Modulating the alloying mode in the doping-induced synthesis of Au-Pd nanowires

引用

Nano Research 2024年第4期17卷 3334-3343页

作者： Hui Jin Xiaoliang Wei Lecheng Zhao Jialong Yu Qiao Pan Shumin Li Qian Wang Zhaotong Yuan Dan Yang Donghui Zhao Hongyu Chen Yawen Wang institute of advanced Synthesis School of Chemistry and Molecular EngineeringJiangsu National Synergistic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 211816China School of science Westlake UniversityHangzhou 310064China institute of Natural sciences Westlake Institute for Advanced StudyHangzhou 310064China

Heterogeneous doping is one effective strategy for synthesizing metal alloy ***,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and ***-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping *** effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were ***,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical *** kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy *** addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.

关键词： gold nanowires Au-Pd alloy oleylamine post-synthetic modification

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

Topological magnetoelectric response in ferromagnetic axion insulators

引用

National science Review 2024年第2期11卷 8-14页

作者： Yuhao Wan Jiayu Li Qihang Liu Department of Physics and Shenzhen institute for Quantum science and engineering(SIQSE) Southern University of Science and Technology Shenzhen Key Laboratory of advanced Quantum Functional Materials and Devices Southern University of Science and Technology Guangdong Provincial Key Laboratory for computational science and Material Design Southern University of Science and Technology

The topological magnetoelectric effect （TME） is a hallmark response of the topological field theory,which provides a paradigm shift in the study of emergent topological ***,its direct observation is yet to be realized due to the demanding magnetic configuration required to gap all surface ***,we theoretically propose that axion insulators with a simple ferromagnetic configuration,such as the MnBi2Te4/（Bi2Te3）nfamily,provide an ideal playground to realize the *** the designed triangular prism geometry,all the surface states are magnetically *** a vertical electric field,the surface Hall currents give rise to a nearly half-quantized orbital moment,accompanied by a gapless chiral hinge mode circulating in ***,the orbital magnetization from the two topological origins can be easily distinguished by reversing the electric *** work paves the way for direct observation of the TME in realistic axion-insulator materials.

关键词： topological magnetoelectric effect axion insulator magnetic topological materials

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

Unveiling the size effect of nitrogen-doped carbon-supported copper-based catalysts on nitrate-to-ammonia electroreduction

引用

Nano Research 2024年第4期17卷 2438-2443页

作者： Ran Li Taotao Gao Wenxi Qiu Minghao Xie Zhaoyu Jin Panpan Li College of Materials science and engineering Sichuan UniversityChengdu 610065China institute for advanced study Chengdu UniversityChengdu 610106China Materials science and engineering Program and Walker Department of Mechanical engineering The University of Texas at AustinAustinTexas 78712USA institute of Fundamental and Frontier sciences University of Electronic Science and Technology of ChinaChengdu 610054China

The electrocatalytic nitrate reduction reaction(NitRR)represents a promising approach toward achieving economically and environmentally sustainable ***,it remains a challenge to regulate the size effect of electrocatalysts to optimize the catalytic activity and ammonia ***,the Cu-based catalysts were tailored at the atomic level to exhibit a size gradient ranging from single-atom catalysts(SACs,0.15–0.35 nm)to single-cluster catalysts(SCCs,1.0–2.8 nm)and nanoparticles(NPs,20–30 nm),with the aim of studying the size effect for the NO_(3)^(-)-to-NH_(3) reduction ***,the Cu SCCs exhibit enhanced metal–substrate and metal–metal interactions by taking advantageous features of Cu SACs and Cu ***,Cu SCCs achieve exceptional electrocatalytic performance for the NitRR with a maximum Faradaic efficiency of ca.96%NH_(3)and the largest yield rate of ca.1.99 mg·h^(-1)·cm^(-2) at-0.5 V *** hydrogen electrode(RHE).The theoretical calculation further reveals the size effect and coordination environment on the high catalytic activity and selectivity for the *** work provides a promising various size-controlled design strategy for aerogel-based catalysts effectively applied in various electrocatalytic reactions.

关键词： nitrate electroreduction ammonia electrosynthesis size effect single-cluster 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

Combination of methylthio-chemistry with living crystallization-driven self-assembly toward uniformπ-conjugated nanostructures with antibacterial activity,surface tailorability,tunable morphology and dimension

引用

science China Chemistry 2024年第7期67卷 2341-2352页

作者： Chuyu Duan Binbin Xu Ruru Li Xiaoyu Huang Shaoliang Lin Chun Feng Shanghai Key Laboratory of advanced Polymeric Materials School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Materials science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Key Laboratory of Fluorine and Nitrogen Chemistry and advanced Materials Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Living crystallization-driven self-assembly(CDSA)provides robust access to uniformπ-conjugated nanostructures(CNSs)from block copolymers(BCPs)containing a crystallineπ-conjugated segment with controlled dimension,morphology and composition,which show appealing applications in biomedicine,photocatalysis and *** further expand the application spectrum of these CNSs,the development of facile strategies toward diverse CNSs with varying structures/functionalities is highly ***,BCPs consisting of oligo(p-phenylene ethynylene)-b-poly(polypropyl-3-methanethiol acrylate)(OPE_(9)-bPMTPA35and OPE_(9)-b-PMTPA_(58);the subscript represents the number of repeat unit of each block)consisting of a crystallineπ-conjugated core-forming OPE_(9)segment and a corona-forming PMTPA block are *** efficient“click-type”alkylation of methylthio groups,OPE_(9)-b-PMTPA with varying contents of sulfonium unit is *** ribbon-like micelles with different widths and lengths can then be generated in a controlled manner via the self-seeding approach of living ***,negatively charged polymeric and Ag nanoparticles can be immobilized on sulfonium/methylthio-containing shells by taking advantage of electrostatic attraction and coordination interaction,***,the ribbon-like micelles with positively charged shells exhibit antibacterial activity against *** the ease of modification of PMTPA-based shell and attractive opto-electronic/photocatalytic properties ofπ-conjugated units,the combination of methylthio-chemistry and living CDSA opens a new avenue to generate multi-functional CNSs for widespread applications from biomedicine to photocatalysis.

关键词： crystallization-driven self-assembly block copolymer π-conjugated nanostructure methylthio-chemistry

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

Boring holes in Au nanoplates by active surface etching

引用

Nano Research 2024年第9期17卷 8610-8617页

作者： Haiyang Hu Yuntao Wang Qian Wang Xudong Peng An Su Hong Wang Hongyu Chen institute of advanced Synthesis(IAS)and School of Chemistry and Molecular engineering Jiangsu National Synergetic Innovation Centre for Advanced MaterialsNanjing Tech UniversityNanjing 211816China Department of Environmental science and engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry School of Science and Key Laboratory for Quantum Materials of Zhejiang ProvinceResearch Center for Industries of the FutureWestlake UniversityHangzhou 310030China institute of Natural sciences Westlake Institute for Advanced StudyHangzhou 310024China

In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make *** critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the ***,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly *** choice of ligand MBIA is also of importance,as it carries negative charge and repels each *** inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less *** etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are *** believe that the ability of boring holes is an important tool for future synthetic designs.

关键词： Au nanoplates active surface etching boring etching mode cetyltrimethylammonium bromide(CTAB)passivation holes

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

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：