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1.
Mn掺杂对多铁性BiFeO_3薄膜铁电性能以及漏电流的影响   总被引:3,自引:0,他引:3  
本文利用脉冲激光沉积技术在(LaAlO3)0.3(Sr2AlTaO6)0.7(001)衬底上生长了BiFe1-xMnxO3(x=0~5%)外延薄膜,研究了Mn掺杂对BiFeO3(BFO)薄膜结构、铁电特性和漏电流的影响.XRD和SEM结果表明薄膜具有良好的结晶质量.漏电流测量显示Mn掺杂有效地减小了BFO薄膜的漏电流密度,因而在室温下5%Mn掺杂的BFO薄膜能够获得饱和的电滞回线.XPS分析证明,Mn掺杂改善BFO薄膜性能的可能原因在于其极大地减少了BFO薄膜中的Fe2+离子.  相似文献
2.
Based on the logical labelling method, we prepare an effective pure state in a subsystem of a three spin system via liquid nuclear magnetic resonance technique. Then with this subspace effective pure state we implement the Deutsch-Jozsa algorithm. The tomography for the subspace effective pure state and the corresponding spectrum of the output for the Deutsch-Jozsa algorithm agree with theoretical predictions, which shows that we have successfully implemented the Deutsch-Jozsa algorithm in a subsystem of a nuclear spin system and demonstrated a subspace quantum computation.  相似文献
3.
单分子物理与化学的新进展   总被引:1,自引:0,他引:1  
本文对新兴边缘学科-单分子物理与化学的一些研究进展进行简要综述。在对单分子科学中几类基本实验技术如扫描隧道显微术和光镊技术等作了简要介绍之后,重点评述了单分子实验技术和研究方法在物理、化学、生物和分子电子学等学科领域的应用和影响。基于扫描隧道显微术和电子结构计算,列举了最近几个关于单分子高分辨表征、单分子器件和单分子量子调控等方面的研究实例。最后对单分子物理与化学的发展前景进行了展望。  相似文献
4.
刘安雯  胡水明  丁昀  朱清时 《中国物理》2005,14(10):1946-1953
Stretching vibrational band intensities of XH3 (X=N, Sb) molecules are investigated employing three-dimensional dipole moment surfaces combined with the local mode Hamiltonian model.The dipole moment surfaces of NH3 and SbH3 are calculated with the density functional theory and at the correlated MP2 level,respectively. The calculated band intensities are in good agreement with the available experimental data. The contribution to the band intensities from the different terms in the polynomial expansion of the dipole moments of four group V hydrides (NH3, PH3,AsH3 and SbH3) are discussed. It is concluded that the breakdown of the bond dipole approximation must be considered. The intensity “borrowing” effect due to the wave function mixing among the stretching vibrational states is found to be less significant for the molecules that reach the local mode limit.  相似文献
5.
对用流化床生物质气化器合成富氢气体,建立了基于非预混燃烧的模型对气化器中的生物质在空气-水蒸汽环境中的气化反应过程的模型,并采用流体力学软件 FLUENT 6.0对过程进行了模拟.通过模拟结果与实验结果的对比分析发现,水蒸汽与生物质的比、空氧比和生物质颗粒的粒径大小是决定产气中氢气含量的重要参数.同时,对气化器中氢气的分布进行了研究.  相似文献
6.
吴兴举  陈向军  单旭  陈丽清  徐克尊 《中国物理》2004,13(11):1857-1861
The triple differential cross section for the low-energy electron impact ionization of inner-valence 3s orbital of argon has been calculated using the modified distorted wave Born approximation in coplanar symmetric energy-sharing geometry. Satisfactory agreement between theory and experiraent is achieved when the polarization and post-collisional interaction (PCI) are included in the calculations. It is shown that the polarization and PCI effects play a very important role in the case of argon at low incident energies.  相似文献
7.
We report free-space distribution of entangled photon pairs over a noisy ground atmosphere of 13 km. It is shown that the desired entanglement can still survive after both entangled photons have passed through the noisy ground atmosphere with a distance beyond the effective thickness of the aerosphere. This is confirmed by observing a spacelike separated violation of Bell inequality of 2.45+/-0.09. On this basis, we exploit the distributed entangled photon source to demonstrate the Bennett-Brassard 1984 quantum cryptography scheme. The distribution distance of entangled photon pairs achieved in the experiment is for the first time well beyond the effective thickness of the aerosphere, hence presenting a significant step towards satellite-based global quantum communication.  相似文献
8.
In-plane ferromagnetism in charge-ordering Na0.55CoO2   总被引:1,自引:0,他引:1  
The magnetic and transport properties are systematically studied on the single crystal Na(0.55)CoO2 with the resistivity divergence below 50 K. A weak ferromagnetic ordering is observed in susceptibility below 20 K with the magnetic field parallel to the Co-O plane, while no such ferromagnetic ordering is observed with the field perpendicular to the Co-O plane. It gives evidence for the existence of in-plane ferromagnetism below 20 K. The observed magnetoresistance of 30% at the field of 6 T at low temperatures indicates an unexpectedly strong spin-charge coupling in the triangle lattice NaxCoO2 system.  相似文献
9.
高灵敏的连续激光光腔衰荡光谱仪及其应用   总被引:1,自引:0,他引:1  
基于连续可调谐的钛宝石激光光源,建立了光腔衰荡光谱(CRDS)装置,实验表明,其不但具有10-4cm-1的光谱分辨率,测靖灵敏度也好于10-10·cm-1.通过对C2H2气体在12 696.4 cm-1附近的吸收光谱测量,验证了该装置的定量测量能力,并通过对混有痕量C2H2气体的氮气样品的光谱测量,表明该装置对C2H2气体的检测限为0.2 ppmv.  相似文献
10.
Eu3+掺杂MMoO4 (M=Ca,Sr)荧光粉的表征及发光性质   总被引:1,自引:0,他引:1  
本文采用简易的Pechini方法制备了Eu3+掺杂MMoO4 (M=Ca, Sr)红色荧光粉。产物的结构、形貌和性质分别通过X射线衍射(XRD)、扫描电子显微镜(SEM)、光致发光发射谱(PL)和激发谱(PLE)进行表征分析。XRD表明反应得到了纯相目标掺杂产物, SEM照片显示两种体系掺杂产物形貌均匀性不同, Eu3+掺杂CaMoO4尺寸小、比表面积大。光致发光光谱结果显示强的614 nm波长的发射, 其源于Eu3+离子的5D0→7F2跃迁。在掺杂浓度范围内我们观察到从基质到Eu3+离子的能量转移及浓度猝灭效应。实验得到掺杂浓度为7.5 mol%的CaMoO4:Eu3+ 表现出良好的发光性质, 它将在荧光粉转换型白光LED中有着潜在的应用。  相似文献
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