检索结果-南通市图书馆

Which algebraic groups are Picard varieties?

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2015年第3期58卷 461-478页

作者： BRION michel Institut Fourier Universit'e de Grenoble

We show that every connected commutative algebraic group over an algebraically closed field of characteristic 0 is the Picard variety of some projective variety having only finitely many non-normal *** contrast,no Witt group of dimension at least 3 over a perfect field of prime characteristic is isogenous to a Picard variety obtained by this construction.

关键词：代数群品种皮卡代数闭域正常点射影

New results on the hadronic vacuum polarization contribution to the muon g-2

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2010年第6期34卷 718-727页

作者： michel Davier Laboratoire de l'Acclrateur Linaire IN2P3/CNRSUniversit Paris-Sud 11

Results on the lowest-order hadronic vacuum polarization contribution to the muon magnetic anomaly are presented. They are based on the latest published experimental data used as input to the dispersion integral. Thus recent results on τ→υτππ^0 decays from Belle and on e^＋e^- annihilation to π^＋π^- from BABAR and KLOE are included. The new data, together with improved isospin-breaking corrections for τ decays, result into a much better consistency among the different results. A discrepancy between the Standard Model prediction and the direct g- 2 measurement is found at the level of 3σ.

关键词： muon magnetic moment vacuum polarization electron-positron annihilation tau decays g-2

MXene-based symmetric supercapacitors with high voltage and high energy density

在线全文

学校读者我要写书评

暂无评论

Materials Reports(Energy) 2022年第1期2卷 105-111页

作者： Wei Zheng Joseph Halim Per O.Å.Persson Johanna Rosen michel W.Barsoum Department of Physics Chemistry and Biology(IFM)Linkoping University58183LinkopingSweden Department of Materials Science and Engineering Drexel University19104PhiladelphiaPAUSA

MXene-based aqueous symmetric supercapacitors(SSCs)are attractive due to their good rate performances and green ***,it remains a challenge to reach voltages much over 1.2 V,which significantly diminishes their energy ***,we report on Mo_(1.33)CTz MXene-based SSCs possessing high voltages in a 19.5 M LiCl *** from the vacancy-rich structure and high stable potential window of Mo_(1.33)CTz,the obtained SSCs deliver a maximum energy density of>38.2 mWh cm^(-3) at a power density of 196.6 mW cm^(-3) under an operating voltage of 1.4 V,along with excellent rate performance and impressive cycling *** highly concentrated LiCl electrolyte is also applicable to Ti_(3)C_(2)Tz,the most widely studied MXene,achieving a maximum energy density of>41.3 mWh cm^(-3) at a power density of 165.2 mW cm^(-3) with an operating voltage of 1.8 *** drop in energy density with increasing power in the Ti_(3)C_(2)Tz cells was steeper than for the Mo-based *** work provides a roadmap to develop superior SSCs with high voltages and high energy densities.

关键词： MXene Symmetric supercapacitor High voltage High energy density Highly concentrated electrolyte

Predicting 2D silicon allotropes on SnS2

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

Nano Research 2017年第5期10卷 1697-1709页

作者： Emilio Scalise michel Houssa Max-Planck-lnstitut fur Eisenforschung GmbH Max-Planck-StraBe 1 40237 Dusseldorf Germany Semiconductor Physics Laboratory Department of Physics and Astronomy University of Leuven Celestijnenlaan 200 D B-3001 Leuven Belgium

A first principles study on the stability and structural and electronic properties of two-dimensional silicon allotropes on a semiconducfing layered metal-chalcogenide compound, namely SnS2, is performed. The interactions between the two- dimensional silicon layer, commonly known as silicene, and the layered SnS2 template are investigated by analyzing different configurations of silicene. The calculated thermodynamic phase diagram suggests that the most stable configuration of silicene on SnS2 belongs to a family of structures with Si atoms placed on three different planes; so-called dumbbell silicene. This particular dumbbell silicene structure preserves its atomic configuration on SnS2 even at a temperature of 500 K or as a ＂flake＂ layer （i.e., a silicene cluster terminated by H atoms）, thanks to the weak interactions between the silicene and the SnS2 layers. Remarkably, an electric field can be used to tune the band gap of the silicene layer on SnS2, eventually changing its electronic behavior from semiconducting to （semi）metallic. The stability of silicene on SnS2 is very promising for the integration of silicene onto semiconducting or insulating substrates. The tunable electronic behavior of the silicene/SnS2 van der Walls heterostructure is very important not only for its use in future nanoelectronic devices, but also as a successful approach to engineering the bang-gap of layered SnS2 paving the way for the use of this layered compound in energy harvesting applications.

关键词： silicene tin sulfide van der Waals (vdW)heterostructure dumbbell chalcogenide

Multifunctional MXene/C Aerogels for Enhanced Microwave Absorption and Thermal Insulation

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

纳微快报:英文版 2023年第11期15卷 74-89页

作者： Fushuo Wu Peiying Hu Feiyue Hu Zhihua Tian Jingwen Tang Peigen Zhang Long Pan michel WBarsoum Longzhu Cai ZhengMing Sun School of Materials Science and Engineering Southeast UniversityNanjing 211189People’s Republic of China Department of Materials Science&Engineering Drexel UniversityPhiladelphiaPA 19104USA The State Key Laboratory of Millimeter Waves School of Information Science and EngineeringSoutheast UniversityNanjing 210096People’s Republic of China

Two-dimensional transition metal carbides and nitrides(MXene)have emerged as promising candidates for microwave absorption(MA)***,they also have some drawbacks,such as poor impedance matching,high self-stacking tendency,and high *** tackle these challenges,MXene nanosheets were incorporated into polyacrylonitrile(PAN)nanofibers and subsequently assembled into a three-dimensional(3D)network structure through PAN carbonization,yielding MXene/C *** 3D network effectively extends the path of microcurrent transmission,leading to enhanced conductive loss of electromagnetic(EM)***,the aerogel’s rich pore structure significantly improves the impedance matching while effectively reducing the density of the MXenebased *** parameter analysis shows that the MXene/C aerogels exhibit a minimum reflection loss(RL_(min))value of−53.02 dB(f=4.44 GHz,t=3.8 mm),and an effective absorption bandwidth(EAB)of 5.3 GHz(t=2.4 mm,7.44–12.72 GHz).Radar cross-sectional(RCS)simulations were employed to assess the radar stealth effect of the aerogels,revealing that the maximum RCS reduction value of the perfect electric conductor covered by the MXene/C aerogel reaches 12.02 dB m^(2).In addition to the MA performance,the MXene/C aerogel also demonstrates good thermal insulation performance,and a 5-mm-thick aerogel can generate a temperature gradient of over 30℃ at 82℃.This study provides a feasible design approach for creating lightweight,efficient,and multifunctional MXene-based MA materials.

关键词： MXene Microwave absorption Aerogel Radar cross-sectional(RCS)simulation Thermal insulation

Novel single-ion conducting polymer electrolytes with high toughness and high resistance against lithium dendrites

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第6期16卷 8457-8468页

作者： David Fraile-Insagurbe Nicola Boaretto Itziar Aldalur Iñigo Raposo Francisco Javier Bonilla michel Armand María Martínez-Ibañez Centre for Cooperative Research on Alternative Energies CIC energiGUNEBasque Research and Technology Alliance(BRTA)Alava Technology ParkAlbert Einstein 48Vitoria-Gasteiz 01510Spain University of the Basque Country(UPV/EHU) Barrio Sarrienas/nLeioa 48940Spain

Solid-state polymer electrolytes are considered as an alternative to classic liquid electrolytes,particularly for application in highenergy lithium metal *** respect to common dual-ion conductors,single-ion conducting polymer electrolytes(SICPEs)are less affected by lithium dendrites growth and thus are particularly interesting for application in lithium metal *** this work,novel SIC-PEs are developed,based on an ionomer having poly(ethylene-alt-maleimide)backbone and lithium phenylsulfonyl(trifluoromethanesulfonyl)imide pendant moieties,further blended with poly(ethylene oxide)(PEO)and poly(ethylene glycol)dimethyl ether(PEGDME).These SIC-PEs exhibit ionic conductivity around~7×10^(−6)S·cm^(−1) at 70℃,lithium transference number close to unity,and excellent mechanical properties,with fracture toughness over 30 J·cm^(−3).Additionally,the electrolytes show very high resistance against lithium dendrites growth,by cycling for more than 1200 h in Li°symmetric cells at a current density of 0.1 mA·cm^(−2).LiFePO4||Li°cells with these SIC-PEs were cycled at 70℃ and C/10,showing initial capacity of almost 160 mAh·g^(−1)and residual capacity of 45%after 100 *** work shows that single-ion conducting polymer electrolytes based on poly(ethylene-alt-maleimide)backbone are promising materials for application as electrolytes or catholytes in lithium metal polymer batteries.

关键词： single-ion conductors solid-state Li metal batteries polymer electrolytes lithium dendrites transference number mechanical properties

Mechanochemistry and hydrogen storage properties of 2Li_(3)N+Mg mixture

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

Rare Metals 2022年第12期41卷 4223-4229页

作者： Zhi-Nian Li Hao-Chen Qiu Shu-Mao Wang Li-Jun Jiang Jun Du Jun-Xian Zhang michel Latroche Fermin Cuevas Department of Energy Materials and Technology General Research Institute for Nonferrous MetalsBeijing 100088China UMR7182 CMTR/ICMPE/CNRS-UPEC94320 Thiais CedexFrance

The Li-Mg-N-H hydrogen storage system is a promising hydrogen storage material due to its moderate operation temperature,good reversibility,and relatively high *** this work,the Li-Mg-N-H composite was directly synthesized by reactive ball milling(RBM) of Li3N and Mg powder mixture with a molar ratio of 2:1 under hydrogen pressure of 9 *** than 8.8 wt%hydrogen was absorbed during the RBM *** phases and structural evolution during the in situ hydrogenation process were analyzed by means of in situ solidgas absorption and ex situ X-ray diffraction(XRD) *** is determined that the hydrogenation can be divided into two steps,leading to mainly the formation of a lithium magnesium imide phase and a poorly crystallized amide phase,*** H-cycling properties of the as-milled composite were determined by temperature-programmed dehydrogenation(TPD) method in a closed *** onset dehydrogenation temperature was detected at 125℃,and it can reversibly desorb 3.1 wt% hydrogen under a hydrogen back pressure of 0.2 *** structural evolution during dehydrogenation was further investigated by in situ XRD *** is found that Mg(NH_(2))_(2)phase disappears at about 200 ℃,and Li_(2)Mg_(2)N_(3)H_(3),LiNH_(2),and Li_(2)MgN_(2)H_(2)phases coexist at even 300 ℃,revealing that the dehydrogenation process is step-wised and only partial hydrogen can be desorbed.

关键词： Mechanochemistry Hydrogen storage properties Li-Mg-N-H

Analytical investigation of bidirectional ductile diaphragms in multi-span bridges

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2018年第2期17卷 235-250页

作者： Xiaone Wei michel Bruneau Michael Baker International ChicagoIL 60606USA Department of Civil Structuraland Environmental EngineeringUniversity at BuffaloBuffaloNY 14260USA

In the AASHTO Guide Specifications for Seismic Bridge Design Provisions,ductile diaphragms are identified as Permissible Earthquake-Resisting Elements（EREs）,designed to help resist seismic loads applied in the transverse direction of *** adding longitudinal ductile diaphragms,a bidirectional ductile diaphragm system is created that can address seismic excitations acting along both the bridge’s longitudinal and transverse *** paper investigates bidirectional ductile diaphragms with Buckling Restrained Braces（BRBs）in straight multi-span bridge with simply supported floating *** flexibility of the substructures in the transverse and longitudinal direction of the bridge is *** procedures for the bidirectional ductile diaphragms are first *** analytical model of the example bridge with bidirectional ductile diaphragms,designed based on the proposed methodology,is then built in *** and nonlinear time history analyses are performed on the bridge model,and corresponding results are *** effect of changing the longitudinal stiffness of the bidirectional ductile diaphragms in the end spans connecting to the abutment is also investigated,in order to better understand the impact on the bridge’s dynamic performance.

关键词： bidirectional ductile diaphragm seismic resistance multi-span bridge with floating spans

Conditions for Set Agreement with an Application to Synchronous Systems

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2009年第3期24卷 418-433页

作者： Francois Bonnet michel Raynal IRISA University of Rennes35042 Rennes CedexFrance

The k-set agreement problem is a generalization of the consensus problem： considering a system made up of n processes where each process proposes a value, each non-faulty process has to decide a value such that a decided value is a proposed value, and no more than k different values are decided. While this problem cannot be solved in an asynchronous system prone to t process crashes when t≥ k, it can always be solved in a synchronous system; [t/k]＋1 is then a lower bound on the number of rounds （consecutive communication steps） for the non-faulty processes to decide. The condition-based approach has been introduced in the consensus context. Its aim was to both circumvent the consensus impossibility in asynchronous systems, and allow for more efficient consensus algorithms in synchronous systems. This paper addresses the condition-based approach in the context of the k-set agreement problem. It has two main contributions. The first is the definition of a framework that allows defining conditions suited to the l-set agreement problem and the second is a generic synchronous k-set agreement algorithm based on conditions.

关键词： agreement problem condition efficiency lower bound synchronous system