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1.
J Phys Condens Matter ; 29(11): 11LT01, 2017 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-28170353

RESUMEN

We report synthesis, crystal structure and physical properties of a novel quinary compound RbGd2Fe4As4O2. The new iron oxyarsenide is isostructural to the fluo-arsenide KCa2Fe4As4F2, both of which contain separate double Fe2As2 layers that are self hole-doped in the stoichiometric composition. Bulk superconductivity at [Formula: see text] K is demonstrated by the measurements of electrical resistivity, dc magnetic susceptibility and heat capacity. An exceptionally high value of the initial slope of the upper critical field ([Formula: see text]d[Formula: see text]/d[Formula: see text] [Formula: see text] T K-1) is measured for the polycrystalline sample.

2.
J Am Chem Soc ; 138(25): 7856-9, 2016 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-27321364

RESUMEN

We report the synthesis, crystal structure, and physical properties of a quinary iron arsenide fluoride, KCa2Fe4As4F2. The new compound crystallizes in a body-centered tetragonal lattice (space group I4/mmm, a = 3.8684(2) Å, c = 31.007(1) Å, Z = 2) that contains double Fe2As2 conducting layers separated by insulating Ca2F2 layers. Our measurements of electrical resistivity, direct-current magnetic susceptibility, and heat capacity demonstrate bulk superconductivity at 33 K in KCa2Fe4As4F2.

3.
J Am Chem Soc ; 136(43): 15386-93, 2014 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-25314008

RESUMEN

We have synthesized a novel europium bismuth sulfofluoride, Eu3Bi2S4F4, by solid-state reactions in sealed evacuated quartz ampules. The compound crystallizes in a tetragonal lattice (space group I4/mmm, a = 4.0771(1) Å, c = 32.4330(6) Å, and Z = 2), in which CaF2-type Eu3F4 layers and NaCl-like BiS2 bilayers stack alternately along the crystallographic c axis. There are two crystallographically distinct Eu sites, Eu(1) and Eu(2) at the Wyckoff positions 4e and 2a, respectively. Our bond valence sum calculation, based on the refined structural data, indicates that Eu(1) is essentially divalent, while Eu(2) has an average valence of ∼ +2.64(5). This anomalous Eu valence state is further confirmed and supported, respectively, by Mössbauer and magnetization measurements. The Eu(3+) components donate electrons into the conduction bands that are mainly composed of Bi 6px and 6py states. Consequently, the material itself shows metallic conduction and superconducts at 1.5 K without extrinsic chemical doping.

4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 26(3): 187-9, 2005 Mar.
Artículo en Chino | MEDLINE | ID: mdl-15941505

RESUMEN

OBJECTIVE: To explore the effect of SF-36 scale being applied in different countries under different culture and to describe the quality of life of pulmonary tuberculosis patients in China and Thailand. METHODS: SF-36 scale was applied to pulmonary tuberculosis patients in both countries using face to face interview. RESULTS: Many coefficients among domains were greater than 0.5 when quality of life of tuberculosis patient in both countries was measured. Cronbach's coefficient of all domains were greater than 0.7 for tuberculosis patients in China while cronbach's Coefficient of most domains were equal or greater than 0.7 for tuberculosis patients in Thailand except for vitality and social domains. The score of social domain for patients in Thailand was greater than that of China. CONCLUSION: Structure validity was not good for tuberculosis patients in both countries since there were some items overlapped in different domains. However, the reliability was good for measuring quality of life of tuberculosis patients both in China and in Thailand.


Asunto(s)
Calidad de Vida , Encuestas y Cuestionarios , Tuberculosis Pulmonar/psicología , China/epidemiología , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Tailandia/epidemiología , Tuberculosis Pulmonar/fisiopatología
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