检索结果-南通市图书馆

Generation of Pair Coherent States in Two Dimensional Trapped Ion

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第3期18卷 367-369页

作者： WANG Kai-Ge S Maniscalco A Napoli A Messina Department of Physics Beijing Normal UniversityBeijing 100875 infm and Dipartimento di Scienze Fisiche ed Astronomiche dell’Universitädi Palermo Palermo 90123Italy

We consider a two-dimensional(2D)trapped ion model in which two laser beams drive the corresponding vibrational motions and are carrier resonant with the two-level of the *** to the coherent superposition of two sub-Rabi oscillations involved in the bimodal vibrations,the Rabi frequency degeneration and offset may occur in this *** provides a possibility to generate the pair coherent state in the 2D trapped ion.

关键词： coherent degeneration modal

Ionic Interactions in Molecular and Liquid States ofPolyvalent Metal Halides

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

Journal of Materials Science & Technology 1999年第4期15卷 303-306页

作者： M.P.Tosi(Instituto Nazionale di Fisica della Materia and Classe di Scienze, Scuola Normate Superiore,I-56126 Pisa, Italy)E-mail: tosim@bib.sns.it Scuola Normale Super Pisa INFM I-56126 Pisa Italy Scuola Normale Super Pisa Classe Sci I-56126 Pisa Italy

Progress in the development of phenomenological models for the microscoplc interactions in the halides of polyvalent metals is reviewed, with main attention to neutral and ionized molecular states and to the melts of these materials. The following physical problems are discussed: (1)bond bending in the molecules of the alkaline-earth halides, (2) binding of molecular dimers and halogen transfer reactions relevant to the melts of trivalent metal halides, (3) stability of molecular ions in liquid mixtures of polyvalent metal halides and alkali halides, and (4) stabilityof molecular ions and reduced-valence states in molten cryolite under addition of sodium metal.

关键词： Cl NaF Ionic Interactions in Molecular and Liquid States ofPolyvalent Metal Halides Rev

Effects of V and Cr Addition on the Structural and Sensing Properties of Titania

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2006年第A03期35卷 113-115页

作者： E.Comini I.Alessandri G.Faglia E.Bontempi L.E.Depero G.Sberveglieri Sensor Laboratory INFMUniversita'di Brescia25133 BRESCIAItaly Laboratorio di Chimica perle Tecnoiogie Universita'di Brescia25133 BRESCIAItaly

We have comparatively studied the addition of Cr and V in *** and V content were changed by means of insets placed in the Ti ***,compositional and electrical analyses of different series of thin films,made by XRF, XRD,are *** characterization not only showed that Cr doped layers were very sensitive to ethanol within a useful range for applications,but also allowed to verify that the electrical behaviour is dependent on the structure of film. Finally,the Cr and V concentrations that gives the best results in terms of sensing performances has been determined and a correlation between structural and electrical measurement has been evidenced.

关键词： titania V Cr ethanol sensors thin films

Probing Local Lattice Fluctautions in Cuprates and Manganites by High k-Resolution EXAFS

在线全文

学校读者我要写书评

暂无评论

中国科学技术大学学报 2001年第3期31卷 289-298页

作者： N.L. Saini (Unitá infm and Dipartimento di Fisica, Università di Roma “La Sapienza” P.le Aldo Moro 2, 00185 Roma, Italy) Unita infm and Dipartimento di Fisica Universita di Roma“La Sapienza”P 意大利 20 0 1 85

X ray absorption fine structure has been exploited as a tool to study local lattice distortions in the perovskite cuperates and manganites, showing novel phenomena as high temperature superconductivity and colossal magneto resistance. Temperature dependent Cu K \%edge\% and Mn K \%edge\% EXAFS have been used to investigate the local lattice distortions associated with the doped charge at metallic densities in these materials. Temperature dependent correlated Debye Waller factors of the Cu O in the cuprates shows an upturn at the stripe formation temperature T \%so\% . Capabilities of the EXAFS technique have been further demonstrated for the case of the manganites, revealing key information on their metal insulator transition. The EXAFS has been shown to be capable of providing quantitative local distortions that are closely associated with the characteristic properties of these complex materials.

关键词：铜系化合物锰系化合物局域晶格形变 EXAFS

Dynamic and Configurational Approach to the Glass Transition by Nanoscale Cooperativity

在线全文

学校读者我要写书评

暂无评论

Open Journal of Biophysics 2012年第3期2卷 88-100页

作者： G. Romeo Physics Department and infm Messina University Messina Italy

Here we examine the findings obtained for disaccharide/water mixtures near glass transition that involves cooperative relaxation features on kinetic by viscosity and on thermodynamic behaviour by neutron scattering. Then to address cooperative phenomena that mitigate the Debye-Waller behaviour we invoke Adam-Gibbs’ idea of a cooperative rearranging region. Neutron results suggest that the excess mean square displacement behaves as free volume and is closely connected to an elementary step of the structural relaxation. Then viscosity data evidence a breakdown of the Einstein-Debye relation, decoupling attributed to the intermolecular cooperativity.

关键词： Glass-Forming Neutron Scattering Einstein-Debye’s Breakdown Cooperative Rearranging Region

高组分稀磁半导体Cd_(1 -x)Mn_xTe/CdTe超晶格的光调制反射谱研究

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

红外与毫米波学报 2002年第5期21卷 332-336页

作者：陈辰嘉王学忠梁晓甘李海涛凌震王迅 V Bellani M Geddo A Stella S Tavazzi A Borghesi A Sassella 北京大学物理系北京100871 复旦大学应用表面物理实验室上海200433 infm-Dipartimento di Fisica"A.Volta"dell’Universitiy di pavia infm-Dipartimento di Scienza dei Materiali University di Milano Bicocca milanoitaly20125

报道用分子束外延 (MEB)技术生长的x =0 4 ,0 8的高组分稀磁半导体Cd1-xMnxTe/CdTe超晶格的光调制反射谱在室温和液氮下的实验结果 .观测到 11H ,2 2H ,33H和 11L等激子跃迁结构 ,计及子能级的量子限定效应和晶格失配导致的应力效应 ... 详细信息

报道用分子束外延 (MEB)技术生长的x =0 4 ,0 8的高组分稀磁半导体Cd1-xMnxTe/CdTe超晶格的光调制反射谱在室温和液氮下的实验结果 .观测到 11H ,2 2H ,33H和 11L等激子跃迁结构 ,计及子能级的量子限定效应和晶格失配导致的应力效应 ,对子能级结构进行了计算 ,除x =0 8样品的 33H能量计算值与实验值有较大偏差外 ,实验结果与理论符合得很好 .还与光致发光谱实验结果进行了比较 .

关键词：光调制反射激子跃迁应力效应超晶格

在线全文

学校读者我要写书评

暂无评论

Mn/Sb多层膜的磁性和磁光特性(英文)

红外与毫米波学报 2004年第4期23卷 241-245页

作者：陈辰嘉王学忠蔡明吴克丁晓民孙允希 Filippo Maglia A.Stella 北京大学物理系北京100871 Department of Physical Chemistry University of Pavia infm-Dipartimento of Fisica"A.Volta"dell’Universita

用超高真空蒸发技术在GaAs(10 0 )和玻璃衬底上生长不同厚度Mn/Sb多层膜 ,并经短时间热退火 (～ 1,2 0min) .磁化强度测量显示具有很强的室温铁磁特性 .当多层膜厚度从 70 0 增至 16 0 0 时 ,饱和强度增加了近一倍 ,极向和纵向克尔角... 详细信息

用超高真空蒸发技术在GaAs(10 0 )和玻璃衬底上生长不同厚度Mn/Sb多层膜 ,并经短时间热退火 (～ 1,2 0min) .磁化强度测量显示具有很强的室温铁磁特性 .当多层膜厚度从 70 0 增至 16 0 0 时 ,饱和强度增加了近一倍 ,极向和纵向克尔角也增加了 ,但不到一倍 .这表明磁化强度和克尔角两者均依赖于多层摸的厚度 ,但不是简单的正比于厚度的关系 .增加Mn/Sb多层膜的厚度能增强饱和磁化强度和极向和纵向克尔饱和角 .X射线衍射谱图结果表明高质量单晶结构的Mn/Sb多层膜能用超高真空蒸发技术生长 ,对较厚的多层薄膜 ,热退火的时间可很短(约 1min) .

关键词：锰/锑多层膜铁磁性磁光克尔效应 X射线衍射退火处理

How toxic are gold nanoparticles？ The state-of-the-art

在线全文

学校读者我要写书评

暂无评论

Nano Research 2015年第6期8卷 1771-1799页

作者： Ilaria Fratoddi Iole Venditti Cesare cametti Maria Vittoria Russo Dipartimento di Chimica Universita' di Roma 'La Sapienza' Piazzale A. Moro 5 1-00185 Rome Italy Dipartimento di Fisica and infm CNR-SOFT Universita' di Roma 'La Sapienza' Piazzale A. Moro 51-00185 Rome Italy

With the growing interest in the applications of gold nanoparticles in biotechnology and their physiological effects, possible toxicity of gold nanoparticles is becoming an increasingly important issue. A large number of studies carried out over the past few years under a variety of experimental conditions and following different protocols have produced conflicting results, leading to divergent views about the actual safety of gold nanoparticles in human applications. This work is intended to provide an overview of the most recent experimental results and thereby summarize current state-of-the-art. Rather than presenting a comprehensive review of the available literature in this field, which would be impractically broad, we have selected representative examples of both in vivo and in vitro studies, which clearly demonstrate the need for urgent and rigorous standardization of experimental protocols. Despite their significant potential, the safety of gold nanoparticles is highly controversial at this time, and important concerns have been raised that need to be properly addressed. Factors such as shape, size, surface charge, coating, and surface functionalization are expected to influence the interactions of particles with biological systems to a different extent, resulting in different outcomes and influencing the potential of gold nanoparticles for biomedical applications. Moreover, despite continuous attempts to establish a correlation between structure of the particles and their interactions with biological systems, we are still far from elucidating the toxicological profile of gold nanoparticles in an indisputable manner. This review is intended to contribute towards this goal, offering a number of suggestions on how to achieve the systematization of data on the most relevant physico-chemical parameters, which govern and control the toxicity of ~old nanot^articles at cellular and whole-organism levels.

关键词： gold nanoparticles nanospheres nanorods nanocages nanostars toxicity

高组分稀磁半导体Cd_(1-x)Mn_xTe/CdTe超晶格的荧光谱研究

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

光谱学与光谱分析 2006年第3期26卷 396-398页

作者：陈辰嘉王学忠 Bellani V Stella A 北京大学物理学院 Dipartimento di Fisica "A.Volta" and infm Università degli Studi Pavia 27100 Pavia Italy

报道用分子束外延(MBE)技术生长的x=0.4,0.8的高组分稀磁半导体Cd1-xMnxTe/CdTe超晶格低温和室温荧光谱研究结果。基态激子跃迁能级荧光谱实验结果显示高组分超晶格中具有高量子效率和高质量光发射。对激子能级随温度的变化进行了详细研... 详细信息

报道用分子束外延(MBE)技术生长的x=0.4,0.8的高组分稀磁半导体Cd1-xMnxTe/CdTe超晶格低温和室温荧光谱研究结果。基态激子跃迁能级荧光谱实验结果显示高组分超晶格中具有高量子效率和高质量光发射。对激子能级随温度的变化进行了详细研究,给出激子跃迁能量的温度系数。激子能级线型的展宽随温度变化关系可用激子-纵向光学声子耦合模型解释。与光调制反射谱实验结果进行了比较。

关键词：荧光谱超晶格稀磁半导体光学声子激子跃迁