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Nontrivial Topological States in BaSn5 Superconductor Probed by de Haas–van Alphen Quantum Oscillations 下载免费PDF全文
We report the nontrivial topological states in an intrinsic type-Ⅱ superconductor BaSn5(Tc~4.4 K) probed by measuring the magnetization, specific heat, de Haas–van Alphen(d Hv A) effect, and by performing first-principles calculations. The first-principles calculations reveal a topological nodal ring structure centered at the H point in the kz = π plane of the Brillouin zone, which could be gapped by spin-orbit coupling(SOC), yielding relatively small gaps below ... 相似文献
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A new transition metal diphosphide α-MoP2 synthesized by a high-temperature and high-pressure technique 下载免费PDF全文
Xiaolei Liu 《中国物理 B》2023,32(1):18102-018102
Monoclinic $\alpha $-MoP$_{2}$, with the OsGe$_{2}$-type structure (space group $C2/m$, $Z = 4$) and lattice parameters $a = 8.7248(11) $ Å, $b = 3.2322(4) $ Å, $c = 7.4724(9) $ Å, and $\beta =119.263^\circ $, was synthesized under a pressure of 4 GPa at a temperature between 1100 ${^\circ}$C and 1200 ${^\circ}$C. The structure of $\alpha $-MoP$_{2}$ and its relationship to other transition metal diphosphides are discussed. Surprisingly, the ambient pressure phase orthorhombic $\beta $-MoP$_{2}$ (space group Cmc2$_{1}$) is denser in structure than $\alpha $-MoP$_{2}$. Room-temperature high-pressure x-ray diffraction studies exclude the possibility of phase transition from $\beta $-MoP$_{2}$ to $\alpha $-MoP$_{2}$, suggesting that $\alpha $-MoP$_{2}$ is a stable phase at ambient conditions; this is also supported by the total energy and phonon calculations. 相似文献
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运用标准差、变异系数、基尼系数、沃尔夫森指数对山东省17个地市的旅游经济发展空间差异与极化进行测度.研究发现:(1)旅游经济发展相对差异不断缩小,绝对差异不断扩大.(2)旅游经济发展呈现出鲁西到鲁东轴向发展差异,三大梯度格局已经形成.(3)旅游经济发达地市主要集中于鲁东,也包括鲁中的部分地市及鲁西南的济宁.(4)旅游经济发展空间极化趋势不断下降,逐步呈现空间均衡发展态势. 相似文献
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