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Mixed-valence copper coordination polymers based on CuSCN or CuN_(3) as bridging motifs

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Science china Chemistry 2005年第Z1期48卷 41-44页

作者： FAN Guang,GAO Shengli,CHEN Sanping,ZENG Minghua & xiE Gang Department of Chemistry,northwest university,xi’an 710069,china Department of Chemistry,Guangxi Normal university,Guilin 541000,china Department of Chemistry Northwest University Xi’an China Department of Chemistry Guangxi Normal University Guilin China

Two novel mixed valence copper coordination polymers, [Cu(2-pac)2(CuN3)(H2O)]n (1) and [Cu(2-pac)2(CuSCN)2]n (2), have been prepared through hydrothermal synthesis and analyzed for structure determination, which exhibit two- and three-dimensional structures respectively. In complex (1), zigzag chains of [CuN3]n running parallel to the c direction are interconnected by Cu(2pac)2 to form a two-dimensional layer structure. In complex (2), the arrangement of μ-1,1,3 bridging thiocyanate ligand leads to the formation of ten-membered Cu-SCN- Cu-S-Cu-NCS rings, and each Cu atom is further linked by Cu(2-pac)2 to afford a three-dimensional configuration.

关键词： hydrothermal synthesis, crystal structure, 2-pyrazinecarboxylic acid, coordination polymer.

An Accelerated Proximal Gradient Algorithm for Hankel Tensor Completion

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Journal of the Operations Research Society of china 2024年第2期12卷 461-477页

作者： Chuan-Long Wang xiong-Wei Guo xi-Hong Yan Key Laboratory of Engineering and Computational Science Shanxi Provincial Department of EducationJinzhong 030619ShanxiChina Department of Mathematics Taiyuan Normal UniversityJinzhong 030619ShanxiChina

In this paper,an accelerated proximal gradient algorithm is proposed for Hankel tensor completion *** our method,the iterative completion tensors generated by the new algorithm keep Hankel structure based on projection on the Hankel tensor ***,due to the special properties of Hankel structure,using the fast singular value thresholding operator of the mode-s unfolding of a Hankel tensor can decrease the computational ***,the convergence of the new algorithm is discussed under some reasonable ***,the numerical experiments show the effectiveness of the proposed algorithm.

关键词： Hankel tensor Tensor completion Accelerated proximal gradient algorithm

Heterostructure of 2D MoSe_(2) nanosheets vertically grown on bowllike carbon for high-performance sodium storage

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Nano Research 2024年第5期17卷 4023-4030页

作者： Nianxiang Shi Guangzeng Liu Baojuan xi Xuguang An Changhui Sun Shenglin xiong School of Chemistry and Chemistry Engineering Qilu Normal UniversityJinan 250200China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer ***,its practical application is hampered by the sluggish kinetics of Na^(+)insertion and structure collapse caused by Na^(+)insertion/***,the heterostructures of MoSe_(2) nanosheets vertically growing on bowl-like carbon(MoSe_(2)@C)are designed and prepared by a template method coupled with selenization treatment to boost storage sodium *** hollow and collapse could provide enough storage space for Na^(+)and alleviate the volume expansion during the charge/discharge ***_(2) nanosheets vertically grown on carbon could expose more active sites for adsorbing Na^(+)to enhance the utilization rate of electrode ***,building heterostructures by combining different phase components could facilitate Na^(+)diffusion and advance reaction *** from these merits,the bowl-like MoSe_(2)@C shows outstanding reversible capacity(356.8 mAh·g^(-1) after 1500 cycles at 1 A·g^(-1))and remarkable rate performance(249.9 mAh·g^(-1)10 A·g^(-1)).

关键词： MoSe_(2)nanosheets bowl-like carbon heterostructure sodium ion batteries

Effect of Mn Addition and Heat Treatment on the Corrosion Behaviour of Mg-Ag-Mn Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 665-677页

作者： You Lv Yupeng Zhang xi Liu Zehua Dong xiaorong Zhou xinxin Zhang Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China Hubei Engineering Research Centre for Biomaterials and Medical Protective Materials Huazhong University of Science and TechnologyWuhan430074China Corrosion and Protection Centre Department of MaterialsThe University of ManchesterManchesterM139PLUK

The high corrosion sensitivity and the potential bio-toxicity of Mg-Ag alloys limit their wide applications for the production of implanted devices. In the present work, Mn is added into the Mg-Ag alloy to optimize its corrosion behaviour. The corrosion behaviour of Mg-Ag-Mn alloys is investigated with the underlying microstructural factors examined. The Mg-Ag alloy with 2 wt% Mn exhibits the highest corrosion resistance after post-casting heat treatment at 440 ℃. The addition of Mn results in α-Mn phase with the incorporation of Fe, which suppresses the cathodic activity of impurity Fe. Further, heat treatment of the cast alloys homogenizes the distribution of Ag and promotes the precipitation of α-Mn phase. The former removes Ag segregations as potential cathodes;the latter promotes a more uniform distribution of cathodes and, therefore, prevents localized corrosion.

关键词： Mg-Ag alloy Mn addition Post-casting heat treatment Cathodic activity Corrosion mechanism

Transition metal complexes bearing 2,6-bis(imino)pyridyl:Synthesis, structure, ethylene polymerization/oligomerization studies

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Science china Chemistry 2005年第Z1期48卷 45-49页

作者： SU Biyun,ZHAO Jianshe & SUN Wenhua Department of Chemistry,northwest university,xi’an 710069,china State Key Laboratory of Engineering Plastics and Center for Molecular Science,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080,china Department of Chemistry Northwest University Xi’an China State Key Laboratory of Engineering Plastics and Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing China

A series of new complexes {2,6-bis[1-((2-methyl-4-methoxyphenyl)imino)ethyl]pyri-dine}MCI2 [M=Fe(Ⅱ) (2), Co(Ⅱ) (3), Ni(Ⅱ) (4), Cu(Ⅱ) (5), Zn(Ⅱ) (6)] have been synthesized. At 25℃, using 500 equiv of methylaluminoxane (MAO), the activities of Fe(Ⅱ), Co(Ⅱ) catalysts can reach 4.02×106 g/mol-Fehatm for ethylene polymerization and 3.98×105 g/mol-Cohatm for ethylene oligomerization. The effects of polymerization conditions such as reaction temperature, Al/M molar ratio and time on the activity of catalyst have been explored.

关键词： Bis(imino)pyridine transition metal complex, ethylene polymerization/oligomerization, catalytic activity.

Variational Neural Inference Enhanced Text Semantic Communication System

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china Communications 2024年第7期21卷 50-64页

作者： Zhang xi Zhang Yiqian Li Congduan Ma xiao School of Electronics and Communication Engineering Sun Yat-Sen UniversityShenzhen 518107China Guizhou university State Key Laboratory of Public Big Data Guiyang 550025China Shenzhen Key Laboratory of Navigation and Communication Integration Shenzhen 518107China School of Computer Science and Engineering Sun Yat-Sen UniversityGuangzhou 510006China

Recently,deep learning-based semantic communication has garnered widespread attention,with numerous systems designed for transmitting diverse data sources,including text,image,and speech,*** efforts have been directed toward improving system performance,many studies have concentrated on enhancing the structure of the encoder and ***,this often overlooks the resulting increase in model complexity,imposing additional storage and computational burdens on smart ***,existing work tends to prioritize explicit semantics,neglecting the potential of implicit *** paper aims to easily and effectively enhance the receiver's decoding capability without modifying the encoder and decoder *** propose a novel semantic communication system with variational neural inference for text ***,we introduce a simple but effective variational neural inferer at the receiver to infer the latent semantic information within the received *** information is then utilized to assist in the decoding *** simulation results show a significant enhancement in system performance and improved robustness.

关键词： deep learning semantic communication variational neural inference

Direct CP violation in hadronic B decays

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Science china(physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2 & Lü Caidian3 1. Department of physics, Lishui university, Lishui 323000,china 2. Department of physics, Shanghai Jiaotong university, Shanghai 200030, china 3. Institute of High Energy physics, Beijing 100049,china Department of physics Lishui University Lishui China Department of physics Shanghai Jiaotong University Shanghai China Institute of High Energy physics Beijing China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

Solar energetic particles intensity variations associated with a tilted-dipole 3D corotating interaction region

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Earth and Planetary physics 2024年第5期8卷 797-810页

作者： YuJi Zhu Fang Shen xi Luo Yang Wang BoFeng Tang State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences Shandong Institute of Advanced Technology (SDIAT) College of Earth and Planetary Sciences University of Chinese Academy of Sciences School of Science Harbin Institute of Technology

The effect of a tilted-dipole three-dimensional corotating interaction region(CIR) on the transport and acceleration of solar energetic particles(SEPs) is *** this work,we discussed how the particle intensity longitudinal and radial dependence might be influenced by the background ***,we investigate how the spectral index distribution is modulated by the CIR structure We use the focused transport equation(FTE) to describe the propagation and acceleration of SEPs in a tilt-dipole 3D CIR,generated by the high-resolution 3D magnetohydrodynamic(MHD) *** forward stochastic differential method is used to solve the *** protons with theE～(-4.4)spectrum from 0.5 to 15 MeV are injected uniformly at the heliographic equator of 0.15 *** quantities are extracted along each interplanetary magnetic field(IMF) line to show the *** the tilted-dipole CIR background,if injected from the solar equator at the inner boundary,particles in the slow flow are transported to higher latitudes due to the extension of the IMF lines to higher *** longitudinal patterns of the particles are dominated by the density of IMF *** focusing effect modulates the longitudinal variation of the particle intensity and gives rise to new longitudinal intensity *** adiabatic effect largely increases the intensity fluctuation along the *** structure of the solar wind can also lead to the difference of the index α in the empirical functionI＿(max)=kR～(-α),describing the radial variation of peak intensity according to our *** the influence of the CIR structure,the index α varies from 1.9 to 3.4 at 0.3-1.0 *** variation of the solar wind speed should be considered when estimating the radial dependence of the SEP peak *** spectra indices rise near the CIR boundaries and drop near the stream interface(SI).The adiabatic effect makes the spatial variability of the spectral index *** spectral index could be sim

关键词： solar energetic particle (SEP) corotating interaction regions (CIR) magnetohydrodynamic (MHD)

A state-of-the-art review of the development of self-healing concrete for resilient infrastructure

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 151-169页

作者： Dong LU xi JIANG Yao ZHANG Shaowei ZHANG Guoyang LU Zhen LENG Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China Laboratory of Fire Safety School of Safety Engineering and Emergency ManagementShijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Architecture and Civil Engineering City University of Hong KongHong Kong 999077China

The brittleness of cement composites makes cracks almost inevitable,producing a serious limitation on the lifespan,resilience,and safety of concrete *** address this brittleness,self-healing concrete has been developed for regaining its mechanical and durability properties after becoming cracked,thereby promising sustainable development of concrete *** paper provides a comprehensive review of the latest developments in self-healing *** begins by summarizing the methods used to evaluate the self-healing efficiency of ***,it compares strategies for achieving healing *** then discusses the typical approaches for developing self-healing ***,critical insights are proposed to guide future studies on the development of novel self-healing *** review will be useful for researchers and practitioners interested in the field of self-healing concrete and its potential to improve the durability,resilience,and safety of concrete infrastructure.

关键词： resilient infrastructure sustainable concrete self-healing cracks