搜索结果: 1-15 共查到“物理学 Sr”相关记录27条 . 查询时间(0.193 秒)
精密测量院首次揭示了负能态对Sr光钟多极极化率的影响（图）
光钟体系 非线性 原子光晶
2023/11/22
2023年11月17日，精密测量院史庭云、唐丽艳、吴芳菲以及倪维斗等研究人员在光钟体系多极极化率的理论研究方面取得了重要进展。研究团队成功突破了传统理论方法的限制，首次揭示了以往理论计算中缺失的负能态的重要性。这一发现阐明了Sr光钟多极极化率之差理论与实验强烈不相容的根本原因，从而消除了限制Sr光钟精度进一步提高的主要障碍。相关研究成果以Letter形式发表在国际学术期刊《Physical Rev...
北京师范大学化学学院吴立明与陈玲课题组报道首例非公度调制结构红外非线性光学材料Re2SnS5(Re=Ba, Sr)：兼具强二阶倍频响应和高激光损伤阈值（图）
北京师范大学化学学院 吴立明 陈玲 非公度 调制结构 红外非线性光学材料 Re2SnS5 强二阶倍频响应 高激光 损伤阈值
2020/4/17
红外非线性光学材料（NLO）在长距离激光通讯、红外对抗及光电设备等领域具有非常重要的应用价值。现有的红外非线性光学商用材料AgGaS2(AGS), AgGaSe2和ZnGeP2虽然具有非常大的非线性系数，但其存在的缺点如：带隙较小，激光损伤阈值低，不能实现相位匹配等限制了这些材料的应用。因此，同时提升红外非线性光学材料的激光损伤阈值和非线性光学性质是该领域的一个难点和热点，具有重要的科学意义和应用...
A combined high-pressure experimental and theoretical study of the electronic band-structure of scheelite-type AWO4 (A = Ca, Sr, Ba, Pb) compounds
high-pressure experimental theoretical study the electronic band-structure scheelite-type AWO4
2011/8/17
Abstract: The optical-absorption edge of single crystals of CaWO4, SrWO4, BaWO4, and PbWO4 has been measured under high pressure up to ~20 GPa at room temperature. From the measurements we have obtain...
Plasmons and Interband Transitions of Ca$_{11}$Sr$_3$Cu$_{24}$O$_{41}$ investigated by Electron Energy-Loss Spectroscopy
Plasmons and Interb Transitions
2010/11/24
Electron energy-loss spectroscopy studies have been performed in order to get a deeper insight
into the electronic structure and elementary excitations of the two - leg ladder system
Ca11Sr3Cu24O41....
Evidence for strong orbital fluctuations below the Jahn-Teller transition in Sr$_3$Cr$_2$O$_8$
Evidence for strong orbital fluctuations Jahn-Teller transition
2010/11/23
We report on the magnetic and phononic excitation spectrum of Sr3Cr2O8 determined by THz and
infrared (IR) spectroscopy, specific heat, and electron spin resonance measurements. We identify the singl...
Spin-Density Wave near the Vortex Cores of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$
Spin-Density Wave Vortex Cores
2010/11/18
Competition with magnetism is at the heart of high temperature superconductivity, most intensely felt near a vortex core. To investigate vortex magnetism we have developed a spatially resolved probe u...
General DFT++ method implemented with projector augmented waves: Electronic structure of SrVO$_3$ and the Mott Transition in Ca$_{2-x}$Sr$_{x}$RuO$_4$
General DFT++ method implemented projector augmented waves Mott Transition
2010/11/24
The realistic description of correlated electron systems has taken an important step forward a few years ago as the combination of density functional methods and the dynamical mean-field theory was co...
Static magnetic order of Sr$_{4}$A$_{2}$O$_{6}$Fe$_{2}$As$_{2}$ (A = Sc and V) revealed by local probes
Static magnetic order local probes
2010/11/19
Static magnetic order of quasi two-dimensional FeAs compounds Sr4A2O6−xFe2As2, with A = Sc
and V, has been detected by 57Fe M¨ossbauer and muon spin relaxation (μSR) spectroscopies. The non-sup...
Structure, Transport and Magnetic properties in La$_{2x}$Sr$_{2-2x}$Co$_{2x}$Ru$_{2-2x}$O$_{6}$
Structure Transport Magnetic properties
2010/11/22
The perovskite solid solutions of the type La2xSr2−2xCo2xRu2−2xO6 with 0.25 x 0.75 have been investigated for their structural, magnetic and transport properties.All the compounds cryst...
采用波长1 064 nm的调Q脉冲Nd∶YAG激光器和多通道小型光纤光栅光谱仪，建立了一套激光诱导击穿光谱分析装置。记录了系列土壤标准样品的激光诱导等离子体发射光谱，详细研究了重金属原子Cr和Sr的特征辐射谱线信号强度、标准偏差与数据采样方式以及采样平均次数的关系，首次采用300个激光脉冲轰击样品表面同一点，并取其中最大光谱信号后的200次激光轰击等离子体发射光谱的平均值进行分析的取样平均方式，发...
采用固相法制备了绿色LiM(M=Ca, Sr, Ba)BO3∶Tb3+发光材料。测量结果显示材料均可被紫外(350～410 nm)光激发，发射绿光。研究了Tb3+浓度对材料发射光谱的影响，结果显示，随Tb3+浓度的增大，发射光谱峰位未发生变化，但其强度呈现出先增大后减小的趋势，即：存在浓度猝灭效应。加入电荷补偿剂Li+，Na+和K+提高了LiM(M=Ca, Sr, Ba)BO3∶Tb3+材料的发射...
采用高温固相反应法合成了掺杂Eu3+及Tb3+的17MO-7.88Y2O3-75B2O3样品，研究了它们的光谱特性，结果表明，MO-Y2O3-B2O3基质在真空紫外(VUV)区有很强的吸收，MgO-Y2O3-B2O3:Eu在147 nm真空紫外光激发下产生对应于Eu3+的5D0→7FJ(J=1, 2, 3, 4)跃迁的590和613 nm强发射峰;MgO-Y2O3-B2O3:Eu中Sr的引入使材料...
SR-FEL宽带腔镜与双带腔镜光学膜系实验研究与研制
储存环自由电子激光 腔镜光学膜系 电子束蒸发沉积 离子束溅射沉积
2009/7/30
利用“电子束蒸发沉积薄膜生长技术+离子束溅射沉积薄膜生长技术”、“HfO2/SiO2+Al2O3/SiO2+M-SiO2”复合光学膜系设计技术、400°C4h高温处理技术, 研制的SR-FEL宽带腔镜光学膜系在355nm中心波长的绝对光学反射率测量值为R(355nm)=99.45%, 反射光谱带宽测量值为Δλ(R≥99.00%)=75nm; 研制的355nm/248nm双带腔镜光学膜系, 在355...
采用高温固相反应合成磁铅矿型(Sr, Ba)Al12O19∶RE3+(RE=Ce, Tb)发光材料，X射线衍射结果证明生成单一磁铅矿型结构。Ce3+产生302 nm的发射峰和340 nm左右的不太明显的肩，分别对应于5d→2F5/2和5d→2F7/2跃迁；激发光谱显示两个宽带峰，158 nm峰对应于基质吸收，260 nm峰是由4f-5d跃迁引起的。Tb3+的发射光谱显示特征的5D3→7Fj(j=2...
N+(N=Li, Na, K)对发光材料M3(M=Ca, Sr, Ba)Y2(BO3)4∶Eu3+光谱的影响
M3(M=Ca,Sr,Ba)Y2(BO3)4∶Eu3+ 发射光谱 激发光谱 Li+ Na+ K+
2009/5/11
采用高温固相反应方法在空气中制备了M3(M=Ca, Sr, Ba)Y2(BO3)4∶Eu3+红色发光材料，测量结果显示，材料的主发射峰均位于613 nm处，监测613 nm发射峰时，所得材料的激发光谱相同。研究了Li+,Na+和K+对M3(M=Ca, Sr, Ba)Y2(BO3)4∶Eu3+材料激发与发射光谱的影响，结果显示，加入Li+,Na+和K+后，M3(M=Ca, Sr, Ba)Y2(BO3...