Subjects: Geosciences >> Geography submitted time 2021-04-13 Cooperative journals: 《干旱区地理》
Abstract： 通过采集兰州市和延安市主城区的土壤灰尘样品，测量了其粒径组成，界定了土壤和灰尘 不同粒径的空间分布，分析了环境影响。结果表明：兰州市和延安市城市土壤灰尘粒径组成有明 显的分布特征，主要集中在小于 100 μm 的部分，整体粒径分布情况为：粉黏粒（极细砂（50~100 μm）>细砂（100~250 μm）>中砂（250~500 μm）>粗砂（500~1000 μm）。其中兰州市小于 100 μm灰尘颗粒物粒径所占比例（69.17%）大于延安市（53.49%），极易在外动力条件下再次扬起成为扬尘污染的潜在污染源。从 2 个城市土壤和灰尘
Subjects: Physics >> Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties Subjects: Physics >> Interdisciplinary Physics and Related Areas of Science and Technology submitted time 2021-02-02
Abstract：The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems. Novel particles, emerged as excitations around exotic band degeneracy points, continue to be reported in real materials and artificially engineered systems, but so far, we do not have a complete picture on all possible types of particles that can be achieved. Here, via systematic symmetry analysis and modeling, we accomplish a complete list of all possible particles in time reversal-invariant systems. This includes both spinful particles such as electron quasiparticles in solids, and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks. We establish detailed correspondence between the particle, the symmetry condition, the effective model, and the topological character. This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems.
Peer Review Status:
Awaiting Review
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