搜索结果: 31-45 共查到“知识库 磁学”相关记录137条 . 查询时间(2.899 秒)
First-principles study on the magnetic properties in Mg dooped BiFeO3 with and without oxygen vacancies
Vacancies Magnesium Magnetic moments Antiferromagnetism Band gap
2016/12/2
The magnetic properties of Mg-doped BiFeO3 (BFO) with and without oxygen vacancies are studied through first-principles calculations. The Mg-doping prefers to occupy the ferromagnetic planes and produ...
通过引入同极型径向主动磁悬浮轴承（AMB）和轴向永磁轴承（PMB）建立了低损耗磁悬浮电主轴试验装置，给出了主要设计过程和结构参数，分析了磁悬浮电主轴的动态性能，并通过系统的高速旋转试验进行了验证.研究结果表明：该试验装置结构简单，功耗较小，能够平稳越过前2阶临界转速并在40000r/min稳定运行，最大振幅为7μm.
本文在考察分析原有的低纬度化极阻尼因子的基础上,提出了对原有阻尼因子的改造方法,即提出变频双向阻尼因子,改造后的阻尼因子不仅考虑了对振幅的压制,并兼顾了对相位谱的改造,同时还增加了频率控制因子.通过模型数据和实际资料检验,表明在低纬度地区,特别是在极低纬度地区,变频双向阻尼方法的化极结果能更有效地突出地质信息.
本文报道青藏高原羌北地区中-晚侏罗世雁石坪群古地磁新结果.对采自青海省格尔木市唐古拉山乡雁石坪剖面(33.6°N, 92.1°E)11个灰岩采点(118块)和10个碎屑岩采点(99块)定向样品系统古地磁学研究表明,大部分样品的退磁曲线具有双分量特征.低温分量方向在地理坐标系下较为集中,应该为地层褶皱之后的黏滞剩磁.高温特征剩磁分量方向可分为两类:(1)索瓦组(J3s)和布曲组(J2b)灰岩,以磁铁...
中国伊犁黄土磁化率一般在S0最高, 但在其他古土壤层低, 磁化率增减机制存在争议. 对尼勒克县的一个剖面进行系统的磁学研究后发现, 黄土层含有风成多畴磁铁矿, S0含有较多成壤成因的超细粒亚铁磁性矿物, 其他古土壤层含有较多过湿条件下形成的非亚铁磁性矿物. 非亚铁磁性矿物高含量、高矫顽力、亚铁磁性矿物低含量与较细的磁颗粒粒径对应于较高的成壤强度, 揭示存在相互竞争的磁化率成壤增强过程和成壤削弱过程...
Multi-step magnetization of the Ising model on a Shastry–Sutherland lattice:a Monte Carlo simulation
Multi-step magnetization Ising model Shastry–Sutherland lattice Monte Carlo simulation
2016/12/2
The magnetization behaviors and spin configurations of the classical Ising model on a Shastry-Sutherland lattice are investigated using Monte Carlo simulations, in order to understand the fascinating ...
承德钒钛磁铁矿钒和钛物相的联测分析方法
钒钛磁铁矿 钒 钛 物相测定
2014/5/30
依据承德地区大庙式钒钛磁铁矿床特征,通过人工重砂分离及单矿物化学分析并结合电子探针、岩矿鉴定结果查明了承德钒钛磁铁矿石中的含钒矿物主要是钛磁铁矿和磁铁矿,次要矿物是钛铁矿和硅酸盐;含钛矿物主要是钛铁矿、钛磁铁矿,次要矿物是金红石、榍石。根据承德钒钛磁铁矿石钒和铁呈正比的关系,选取代表性试样进行了钒钛物相分析项目的确定及溶剂选择的实验,最终确定了钒和钛物相分析测定流程。钒物相分析测定项目为磁铁矿和钛...
Multiferroic phase competitions in perovskite manganite thin films
Multiferroic phase competitions perovskite manganite thin films
2016/12/2
Based on the Mochizuki- Furukawa model, the cycloid al spin structures of orthorh ombic RMnO3 manganite thin films on various magnetic substrates are simulated using Monte Carlo method. It is revealed...
分子基磁体Cr[N(CN)2]2电子结构和半金属性的第一性原理研究
第一性原理 磁性 半金属性
2012/1/5
基于第一性原理方法结合广义梯度近似，研究了分子基磁体Cr[N(CN)2]2的电子结构和半金属性. 对总能量，自旋极化的能带结构，态密度以及自旋磁矩的计算表明该分子磁体为半金属铁磁体．每个分子的总磁矩为2.00μB，其中Cr2+对分子磁矩的贡献较大，而配位体上的碳原子和氮原子的贡献相对较小．讨论了当晶格常数发生小幅变化时材料半金属性的变化.
Isospin Character of the Pygmy Dipole Resonance in 124Sn
Isospin Character Pygmy Dipole Resonance
2011/1/10
The pygmy dipole resonance has been studied in the proton-magic nucleus 124Sn with the ( , ′) coincidence method at E = 136 MeV.
Magnetoelectric properties of multiferroic FeVO4
Magnetoelectric properties multiferroic FeVO4
2010/11/24
We report the magnetic, dielectric and ferroelectric properties of polycrystalline iron
vanadate(FeVO4), which has been recently found to exhibit multiferroicity in low temperature
with noncollinear...
Interplay of antiferromagnetism, ferromagnetism and superconductivity in EuFe_2(As_1-xP_x)_2 single crystals
Interplay of antiferromagnetism ferromagnetism superconductivity
2010/11/24
We report a systematic study on the influence of antiferromagnetic and ferromagnetic phases of
Eu2+ moments on the superconducting phase upon doping the As site by isovalent P, which acts as
chemica...
Orbital occupation and magnetic moments of tetrahedrally coordinated iron in CaBaFe4O7
Orbital occupation magnetic moments tetrahedrally coordinated iron
2010/11/25
CaBaFe4O7 is a mixed-valent transition metal oxide having both Fe2+ and Fe3+ ions in tetrahedral coordination. Here we characterize its magnetic properties by magnetization measurements and investigat...
We consider a scattering formulation of radiative momentum transfer to a Magneto-Chiral system
that is subjected to a constant background magnetic field. The system takes the form of a collection mag...
Strong coupling treatment of the polaronic system consisting of an impurity in a condensate
Other Bose-Einstein condensation phenomena
2010/11/18
The strong coupling treatment of the Fr¨ohlich-type polaronic system, based on a canonical
transformation and a standard Landau-Pekar type variational wave function, is applied to the
polaronic syst...