检索结果-南通市图书馆

Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 1949-1952页

作者： YANG JinMin 1,2 1 Department of Physics,Henan Normal University,Xinxiang 453007,china 2.institute of Theoretical Physics,chinese academy of sciences,beijing 100190,china 1. Department of Physics Henan Normal University Xinxiang 453007 China2. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw *** work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the ***,supersymmetry can be probed via these decays at GigaZ.

关键词： Z-decay GigaZ supersymmetry

Biodegradable amphiphilic block copolymers containing functionalized PEO blocks:Controlled synthesis and biomedical potentials

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2010年第3期53卷 519-527页

作者： ZHANG Yu1,2,SUN PeiJian1,2 & GAN ZhiHua1 1CAS Key Laboratory of Engineering Plastics,institute of Chemistry,chinese academy of sciences,beijing 100190,china 2Graduate University of chinese academy of sciences,beijing 100039,china 1. CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China

A series of controllable amphiphilic block copolymers composed of poly(ethylene oxide)(PEO) as the hydrophilic block and poly(ε-caprolactone)(PCL) as the hydrophobic block with the amino terminal group at the end of the PEO chain(PCL-b-PEO-NH2) were *** on the further reaction of reactive amino groups,diblock copolymers with functional carboxyl groups(PCL-b-PEO-COOH) and functional compounds RGD(PCL-b-PEO-RGD) as well as the triblock copolymers with thermosensitive PNIPAAm blocks(PCL-b-PEO-b-PNIPAAM) were *** well-controlled structures of these copolymers with functional groups and blocks were characterized by gel permeation chromatography(GPC) and 1H NMR *** copolymers with functionalized hydrophilic blocks were fabricated into microspheres for the examination of biofunctions via cell culture experiments and in vitro drug *** results indicated the significance of introducing functional groups(e.g.,NH2,COOH and RGD) into the end of the hydrophilic block of amphiphilic block copolymers for biomedical potentials in tissue engineering and controlled drug release.

关键词： amphiphilic block copolymers biodegradable polymers functional terminal group cell growth drug release

Dynamic tree-based authenticated group key exchange protocol

在线全文

学校读者我要写书评

暂无评论

Science china(Information sciences) 2010年第8期53卷 1591-1602页

作者： LI Hui 1,2 , WU ChuanKun 1 & TENG JiKai 1,2 1 State Key Laboratory of Information Security, institute of Software, chinese academy of sciences, beijing 100190, china 2 Graduate University of chinese academy of sciences, beijing 100049, china 1. State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Authenticated group key exchange protocols allow a group of users over a public network to establish a shared secret key for the subsequent cryptographic goals. In this paper, we extend BD-II scheme into a dynamic setting, and propose a tree-based authenticated key exchange protocol which is more suitable for dynamic groups in such as ad hoc networks. Our protocol is proven secure in random-oracle model. Additionally, we analyze the costs of our protocols in both communication and computation terms, and compare its performance with three well-known protocols.

关键词： tree-based group key exchange dynamic provable security

Electrochemical properties and interfacial reactions of LiNi0.5Mn1.5O4-δ nanorods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2012年第3期22卷 207-212页

作者： Liping Wang, Hong Li, Xuejie Huang institute of Physics, chinese academy of sciences, beijing 100190, china institute of Physics Chinese Academy of Sciences Beijing 100190 China

LiNi0.5Mn1.5O4-δ which possesses a high voltage of 4.7 V vs. Lit/Li and stable structure has been considered as a promising cathode material for high energy Li-ion batteries. In this study, well-crystallized LiNi0.5Mn1.5O4-δ nanorods with diameter of ～50 nm and length of ～500 nm were synthesized by a hydrothermal-solid state process followed by a lithiation reaction. It delivers ～120 mA h-g 1 discharge capacity under 30 mA g-1 at 3.5-4.9 V, and 90 mA h g-1 at 150 mA g-1. An unstable solid electrolyte interphase (SEI) film with thickness 2-10 nm was observed by transmission electron microscopy. The thick and unstable SEI layers are responsible for its low rate performance and low coulombic efficiency during cycling.

关键词： Lithium ion battery High voltage spinel Nanorods Surface reaction

Maximal effective baseline for polarimetric interferometric SAR forest height estimation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information sciences) 2012年第4期55卷 867-876页

作者： ZHOU YongSheng 1,2,3,HONG Wen 1,2,WANG YanPing 1,2 & WU YiRong 1,2 1 National Key Laboratory of Science &Technology on Microwave Imaging,beijing 100190,china 2.institute of Electronics,chinese academy of sciences,beijing 100190,china 3 academy of Opto-Electronics,chinese academy of sciences,beijing 100094,china 1. National Key Laboratory of Science & Technology on Microwave Imaging Beijing 100190 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Academy of Opto-Electronics Chinese Academy of Sciences Beijing 100094 China

The concepts of critical baseline and maximal effective baseline have been defined for interferometric SAR (InSAR) DEM application based on the spatial decorrelation (which is a function of baseline).This paper puts forward these two concepts to polarimetric interferometric SAR (Pol-InSAR) forest height estimation *** application makes use of volume decorrelation,which is also a function of *** both the spatial decorrelation and volume decorrelation are considered to determine Pol-InSAR critical and maximal effective *** various decorrelation effects are *** the calculation formula of Pol-InSAR maximal effective baseline are presented and compared to that of *** validation,RVoG-based and PolSARpro-based simulation data and DLR ESAR data are *** concept of Pol-InSAR maximal effective baseline is of practical significance in selection of Pol-InSAR image pairs as well as in the design of further Pol-InSAR systems.

关键词： Pol-InSAR maximal baseline forest height estimation

The correspondence between the concepts in description logics for contexts and formal concept analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information sciences) 2012年第5期55卷 1106-1122页

作者： MA Yue 1,2,SUI YueFei 1 & CAO CunGen 1 1 Key Laboratory of Intelligent Information Processing,institute of Computing Technology,chinese academy of sciences,beijing 100190,china 2 Graduate University of chinese academy of sciences,beijing,china 1. Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Formal concept analysis (FCA) and description logic (DL) are meant to be formalizations of concepts.A formal concept in the former consists of its intent and extent,where the intent is the set of all the attributes shared by each object in the extent of the concept,and the extent is the set of all the objects sharing each property in the intent of the concept.A concept in the latter formalization is simply a concept name,the interpretation of which is a subset of a *** consider the correspondence between concepts in both formalizations,a multi-valued formal context must be represented both as a knowledge base and as a model of the DL for contexts,where concepts are decomposed into tuple concepts C,interpreted as a set of tuples and value concepts V,interpreted as a set of attribute-value *** show that there is a difference between the interpretation of concepts R.V /R.C and the Galois connection between the extent/intent of formal concepts in *** to the Galois connection,there should be concepts of the form + R.V and + R.C inter-preted in FCA,and hence the logical language L for DL is extended to be L + together with + as a constructor so that + R.V and + R.C are well-defined ***,according to the interpretation in DL there should be pseudo concepts in FCA so that the interpretation of concepts R.V /R.C is the extent/intent of pseudo *** correspondence between formal concepts and concepts in L +,and between pseudo concepts and concepts in L are presented in this paper.

关键词： description logic formal concept analysis concept attribute/role

^(40)Ar/^(39)Ar dating of shear deformation of the Xianshuihe fault zone in west Sichuan and its tectonic significance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth sciences 2004年第9期47卷 794-803页

作者： ZHANG Yueqiao1, CHEN Wen2, 3 & YANG Nong1 1. institute of Geomechanics, chinese academy of Geological sciences, beijing 100081, china 2. institute of Geology, chinese academy of Geological sciences, beijing 100037, china 3. institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, china institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Based on field geological survey, structural measurements and classical Ar/Ar dating of mica, biotite and K-feldspar, we obtain cooling ages for Miocene left-lateral shear along the Xianshuihe fault zone. The results document two thermal events during the sinistral shear. The early event (12-10 Ma) corresponds to rapid cooling of the Zheduoshan granitic massif from above 700℃ to below 350℃. The late event (5-3.5 Ma) corresponds to cooling of granites intruded along the eastern side of the fault zone. These dating results provide important thermochronological constraint on the timing of late Cenozoic eastward extrusion of the Chuan-Dian Block in the SE Tibetan margin.

关键词： Xianshuihe fault zone, Zheduoshan granitic massif, sinistral shear deformation, 40Ar/39Ar dating, late Cenozoic.

Monaural voiced speech segregation based on elaborate harmonic grouping strategies

在线全文

学校读者我要写书评

暂无评论

Science china(Information sciences) 2011年第12期54卷 2491-2500页

作者： LIU WenJu 1 , ZHANG XueLiang 1 , JIANG Wei 1 , LI Peng 2 & XU Bo 2 1 National Laboratory of Pattern Recognition, institute of Automation, chinese academy of sciences, beijing 100190, china 2 Digital Media Content Technology Research Center, institute of Automation, chinese academy of sciences, beijing 100190, china 1. National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100190 China2. Digital Media Content Technology Research Center Institute of Automation Chinese Academy of Sciences Beijing 100190 China

In this paper, an enhanced algorithm based on several elaborate harmonic grouping strategies for monaural voiced speech segregation is proposed. Main achievements of the proposed algorithm lie in three aspects. Firstly, the algorithm classifies the time-frequency (T-F) units into resolved and unresolved ones by carrier-to-envelope energy ratio, which leads to more accurate classification results than by cross-channel correlation. Secondly, resolved T-F units are grouped together according to minimum amplitude principle, which has been verified to exist in human perception, as well as the harmonic principle. Finally, "enhanced" envelope autocorrelation function is employed to detect amplitude modulation rates, which helps a lot in reducing half-frequency error in grouping of unresolved units. Systematic evaluation and comparison show that performance of separation is greatly improved by the proposed algorithm. Specifically, signal-to-noise ratio (SNR) is improved by 0.96 dB compared with that of previous method. Besides, our algorithm is also effective in improving the PESQ score and subjective perception score.

关键词： computational auditory scene analysis voiced speech separation harmonistic principle minimum amplitude principle elaborate harmonic grouping strategies

ELTA-WAVE IN A SIMPLE 1-D 2 x 2 HYPERBOLIC PROBLEM

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 1996年第4期14卷 311-318页

作者： S.L. Yang(institute of Applied Mathematics, chinese academy of sciences, beijing, china) institute of Applied Mathematics Chinese Academy of Sciences Beijing China

A simple one-dimensional 2 x 2 hyperbolic system is considered in the *** model contains a linear hyperbolic equation, as well as a hyperbolic equation ofwhich the coefficients are about the solution of the linear one. The exact solution ispresented and discussed, then numerical experiments are given by TVD (or MmB)type schemes for Riemann problems. From the results, we know that the solutionsdo have δ-waves for some suitable initial data.

关键词： Zhang Figure DELTA-WAVE IN A SIMPLE 1-D 2 HYPERBOLIC PROBLEM