地形と環境風が局地的な雷雨の予測可能性に及ぼす影響

京都大学新制・課程博士博士(理学)甲第24124号理博第4852号新制||理||1694(附属図書館)京都大学大学院理学研究科地球惑星科学専攻(主査)教授 竹見 哲也, 教授 榎本 剛, 准教授 重 尚一学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDFA

Variational Monte Carlo simulations using tensor-product projected states

We propose an efficient numerical method, which combines the advantages of recently developed tensor-network based methods and standard trial wave functions, to study the ground state properties of quantum many-body systems. In this approach, we apply a projector in the form of a tensor-product operator to an input wave function, such as a Jastrow-type or Hartree-Fock wave function, and optimize the tensor elements via variational Monte Carlo. The entanglement already contained in the input wave function can considerably reduce the bond dimensions compared to the regular tensor-product state representation. In particular, this allows us to also represent states that do not obey the area law of entanglement entropy. In addition, for fermionic systems, the fermion sign structure can be encoded in the input wave function. We show that the optimized states provide good approximations of the ground-state energy and correlation functions in the cases of two-dimensional bosonic and fermonic systems.Comment: 7 pages, 5 figures, published versio

X-Ray Diffraction Used in Observation and Characterization on Guest Molecules in Metal-Organic Frameworks

Knowledge about the interactions between gas molecules and adsorption sites is essential to customize Metal Organic Frameworks (MOFs) as adsorbents. The dynamic interactions occurring during adsorption/desorption working cycles with several states are especially complicated. Even so, the gas dynamics based upon experimental observations and the distribution of guest molecules under various conditions in MOFs have not been extensively studied yet. In this work, a direct time-resolved diffraction structure envelope (TRDSE) method using sequential measurements by in situ synchrotron powder X-ray diffraction has been developed to monitor several gas dynamics processes taking place in MOFs: infusion, desorption, and gas redistribution on temperature change. The electron density maps indicate that gas molecules prefer to redistribute over heterogeneous types of sites rather than to exclusively occupy the primary binding sites. We found that the gas molecules are entropically driven from open metal sites to larger neighboring spaces during the gas infusion period, matching the localized-to-mobile mechanism. In addition, the partitioning ratio of molecules adsorbed at each site varies with different temperatures, as opposed to an invariant distribution mode. Equally important, the gas adsorption in MOFs is intensely influenced by the gas-gas interactions, which might induce more molecules to be accommodated in an orderly compact arrangement. This sequential TRDSE method is generally applicable to most crystalline adsorbents, yielding information on distribution ratios of adsorbates at each type of site

Hookworm infestation, an old but not vanished disease

AbstractHookworms, together with other helminthes infestations, were serious health problems in Taiwan before. With improvements in public health and medicine, the prevalence of parasite infestations drops significantly and current attention has been shifted to foreign laborers coming from the Southeast Asia. Herein we reported a case of hookworm infestation who presented as subacute diarrhea. Initially, only peripheral eosinophilia was revealed. Anti-helminth treatment, but not the immunosuppressant for eosinophilic gastroenteritis, was given when the hookworm ova were finally harvested after repeated stool examinations. Please remember the old diseases when you meet a patient with gastrointestinal complaints and peripheral eosinophilia, especially when there are intermittent skin atopic manifestations. Repeated parasite ova checks with concentration method are necessary in acute stage, especially when the worm burden is not heavy

Fisher information analysis on quantum-enhanced parameter estimation in electromagnetically-induced-transparency spectrum with single photons

Electromagnetically-induced-transparency (EIT) spectroscopy has been used as a sensitive sensor in quantum metrology applications. The sensitivity of a sensor strongly depends on the measurement precision of EIT spectrum. In this work, we present a theoretical study of the spectral lineshape measurement on a three-level $\Lambda$-type EIT media based on Fisher information (FI) analysis. Using two kinds of probing source: the single-photon Fock state and the coherent state, we calculate the FI in an EIT medium and quantify the quantum advantage and limitations of the single-photon probe. The analysis of FI structure also provides a clear picture to classify the spectral lineshape into two different regimes, the EIT and Aulter-Townes splitting (ATS). This work provides a systematic analysis of the single-photon EIT spectrum, which provides essential knowledge of quantum sensing based on EIT and deepens our understanding of spectral characteristics of $\Lambda$-type media.Comment: 15 pages, 15 figure

Towards A Holographic Model of D-Wave Superconductors

The holographic model for S-wave high T_c superconductors developed by Hartnoll, Herzog and Horowitz is generalized to describe D-wave superconductors. The 3+1 dimensional gravitational theory consists a symmetric, traceless second-rank tensor field and a U(1) gauge field in the background of the AdS black hole. Below T_c the tensor field which carries the U(1) charge undergoes the Higgs mechanism and breaks the U(1) symmetry of the boundary theory spontaneously. The phase transition characterized by the D-wave condensate is second order with the mean field critical exponent beta = 1/2. As expected, the AC conductivity is isotropic below T_c and the system becomes superconducting in the DC limit but has no hard gap.Comment: 14 pages, 2 figures, Some typos corrected, Matched with the published versio