全文获取类型
收费全文 | 69篇 |
免费 | 12篇 |
国内免费 | 3篇 |
专业分类
化学 | 18篇 |
晶体学 | 1篇 |
数学 | 4篇 |
物理学 | 61篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有84条查询结果,搜索用时 15 毫秒
41.
We propose a general scheme for the computational design of new materials using density functional theory. We then apply the scheme to two classes of materials; ferromagnetic ferroelectrics and half-metallic antiferromagnets. Our first “designer” ferromagnetic ferroelectric has subsequently been synthesized and the predicted properties verified. Our computations on half-metallic antiferromagnets have stimulated experimental study but the phenomenon remains unconfirmed. 相似文献
42.
使用微波辅助聚合方法制备了单分散单畴Ni纳米球,由MFM发现,尺度分布在100~180 nm的Ni球的一个相关特征是条型磁畴结构。用XRD、TEM、XPS以及EDAX测量了由Ni球进一步制备的NicoreNiOshell高度球型纳米结构。用VSM 和SQUID进一步讨论了其铁磁/反铁磁界面耦合效应,估算了交换耦合场与粒子尺寸的关系。 相似文献
43.
R. G. Tarkhanian 《International Journal of Infrared and Millimeter Waves》1994,15(4):739-750
Dispersion relations of coupled magnon-plasmon surface electromagnetic waves propagating along the interface between antiferrodielectric and uniaxial semiconductor are considered. Total transmission of infrared wave trough such layered structure induced by resonant excitation of the surface wave is investigated. 相似文献
44.
Frank J. Berry Fiona C. Coomer Örn Helgason Peter R. Slater Michael F. Thomas 《Journal of solid state chemistry》2011,184(6):1361-1366
Fluorination of the parent oxide, BaFeO3−δ, with polyvinylidine fluoride gives rise to a cubic compound with a=4.0603(4) Å at 298 K. 57Fe Mössbauer spectra confirmed that all the iron is present as Fe3+. Neutron diffraction data showed complete occupancy of the anion sites, indicating a composition BaFeO2F, with a large displacement of the iron off-site. The magnetic ordering temperature was determined as TN=645±5 K. Neutron diffraction data at 4.2 K established G-type antiferromagnetism with a magnetic moment per Fe3+ ion of 3.95 μB. However, magnetisation measurements indicated the presence of a weak ferromagnetic moment that is assigned to the canting of the antiferromagnetic structure. 57Fe Mössbauer spectra in the temperature range 10-300 K were fitted with a model of fluoride ion distribution that retains charge neutrality of the perovskite unit cell. 相似文献
45.
46.
47.
《Physics letters. A》2014,378(26-27):1773-1779
Geometrically frustrated clusters of Ising spins of different shapes on a triangular lattice are studied by exact enumeration. The focus is laid on the ground-state energy and residual entropy behaviors as functions of the cluster shape and size, as well as the spin value. Depending on the cluster shape, the residual entropy density in approach to the thermodynamic limit can either vanish or remain finite and the dependence can be decreasing, increasing or non-monotonic. Nevertheless, the relative entropies normalized by the respective thermodynamic limit values turn out to be little sensitive to the spin value. Attention is drawn to magnetocaloric properties of systems of selected cluster shapes. 相似文献
48.
A. Ali BiswasY.M. Jana 《Journal of magnetism and magnetic materials》2011,323(24):3202-3209
The temperature dependence of the experimental results of dc (macroscopic) magnetic susceptibility and nuclear hyperfine properties of frustrated magnetic Gd-based pyrochlore compounds, Gd2Ti2O7, Gd2Sn2O7, Gd2Hf2O7 and Gd2Zr2O7, are analyzed within the frame work of appropriate crystal-field theory and a mean field approximation by introducing effective anisotropic molecular field tensors, and formulating an exact relation between single-ion susceptibility tensors and site susceptibility tensors. Components of the calculated susceptibility along and perpendicular to the local 〈1 1 1〉 axis of the tetrahedral sublattice of pyrochlore structure show that these pyrochlores are easy-planar anisotropic magnetic systems. The crystal-field parameters and anisotropic exchange coupling have been determined and their systematic variations over the Gd-based pyrochlores studied here are discussed. 相似文献
49.
Dr. Saul H. Lapidus Prof. Peter W. Stephens Dr. Christopher M. Kareis Peter E. VanNatta Prof. Joel S. Miller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(7):1752-1757
The reaction of MnII(O2CMe)2 and NaCN or LiCN in water forms a light green insoluble material. Structural solution and Rietveld refinement of high-resolution synchrotron powder diffraction data for this unprecedented, complicated compound of previously unknown composition revealed a new alkali-free ordered structural motif with [MnII4(μ3-OH)4]4+ cubes and octahedral [MnII(CN)6]4− ions interconnected in 3D by MnII-N≡C-MnII linkages. The composition is {[MnII(OH2)3][MnII(OH2)]3}(μ3-OH)4][MnII(μ-CN)2(CN)4] ⋅ H2O=[MnII4(μ3-OH)4(OH2)6][MnII(μ-CN)2(CN)4] ⋅ H2O, which is further simplified to [Mn4(OH)4][Mn(CN)6](OH2)7 ( 1 ). 1 has four high-spin (S=5/2) MnII sites that are antiferromagnetically coupled within the cube and are antiferromagnetically coupled to six low-spin (S=1/2) octahedral [MnII(CN)6]4− ions. Above 40 K the magnetic susceptibility, χ(T), can be fitted to the Curie–Weiss expression, χ ∝(T−θ)−1, with θ=−13.4 K, indicative of significant antiferromagnetic coupling and 1 orders as an antiferromagnet at Tc=7.8 K. 相似文献
50.
Magnetic and magnetocaloric effect in a stuffed honeycomb polycrystalline antiferromagnet GdInO3 下载免费PDF全文
Yao-Dong Wu 《中国物理 B》2022,31(6):67501-067501
The magnetic and magnetocaloric properties were studied in a stuffed honeycomb polycrystalline antiferromagnet GdInO3. The onset temperature of antiferromagnetic ordering was observed at ~ 2.1 K. Negligible thermal and magnetic hystereses suggest a reversible magnetocaloric effect (MCE) in the GdInO3 compound. In the magnetic field changes of 0 kOe-50 kOe and 0 kOe-70 kOe, the maximum magnetic entropy change values are 9.65 J/kg· K and 18.37 J/kg· K, respectively, near the liquid helium temperature, with the corresponding relative cooling power values of 115.01 J/kg and 211.31 J/kg. The MCE investigation of the polycrystalline GdInO3 serves to illuminate more exotic properties in this frustrated stuffed honeycomb magnetic system. 相似文献