量子シミュレーションによる水素化アモルファスシリコンの理論的研究

京都大学新制・課程博士博士(工学)甲第24323号工博第5072号新制||工||1972(附属図書館)京都大学大学院工学研究科機械理工学専攻(主査)教授 黒瀬 良一, 教授 嶋田 隆広, 准教授 松本 充弘, 教授 江利口 浩二学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDFA

Accepting but not engaging with it: Digital participation in local government‐run social credit systems in China

Over the past decade, China's central and municipal governments have consistently supported the development of social credit systems (SCSs). While research has highlighted the Chinese public's high approval and backing of SCSs, their engagement with these digital projects has not been fully explored. Based on 44 semi‐structured interviews, our research examines Chinese citizens' digital participation in government‐run SCSs at the local level. Our findings suggest that, despite perceiving SCSs as accepting and positive, most interviewees do not actively engage with local government‐run SCSs. Multiple factors can explain the gap between the high acceptance and low participation rates, including a lack of awareness regarding local SCSs, a perception that registering and maintaining a decent credit score requires major effort, various concerns involving data privacy and safety, algorithm accuracy and fairness, potential risks, unappealing benefits offered by SCSs, and the voluntary aspect of participating in local SCSs. Our research adds to the existing literature on digital governance in authoritarian contexts by explaining why Chinese citizens do not necessarily engage with state‐promoted digital projects

Electronic transport properties of a-Si:H

To investigate the electron transport properties of hydrogenated amorphous silicon (a-Si:H), a series of quantum simulations and electron transport analyses were performed. The target system is a nano-scale junction of a-Si:H with various hydrogen concentrations sandwiched between two metal electrodes. The density functional based tight binding simulation was conducted to obtain the electronic structure, and the non-equilibrium Green’s function method was adopted to evaluate the electron transmission coefficient and the electric current under a bias field. It is confirmed that the hydrogen atoms passivate a part of defects in amorphous silicon, but the remaining defects realize the energy states in the bandgap; the p orbitals of silicon atoms mainly contribute to the electron transmission. The transport behavior is greatly affected by the hydrogen concentration. The interface between a-Si:H and the metal electrodes also influences the transport behavior through changing the spatial charge density inside the a-Si:H

Effects of Hydrogen Concentration and Cooling Speed on Fabrication of Hydrogenated Amorphous Silicon: Quantum Simulation

In order to investigate various properties of hydrogenated amorphous silicon (a-Si:H) for improvement of low conversion efficiency and stability of solar cells, a series of quantum simulations based on the density functional theory combined with the tight binding model were performed for a-Si:H with various hydrogen concentrations and cooling rates. The radial distribution function (RDF) for Si-Si pairs indicates that samples with higher H concentration (20% and 25%) give a structure in better agreement with experiments, but the RDF of Si-H pairs suggests that samples with lower H concentration (14%) may give more appropriate structure. The coordination number (Nc) analysis indicates that more defects (dangling bonds and floating bonds) exist in 20% and 25% H concentration samples. Overall, a-Si:H with 14% H concentration gives most preferable structure. The cooling rate has also much effect on the structure. Sample with the slowest cooling rate is slightly more structured based on Si-Si pair RDF and Nc. The electron transport of a-Si and a-Si:H were evaluated and the superiority of a-Si:H was confirmed

A study on the genus Phaecasiophora Grote (Lepidoptera: Tortricidae: Olethreutinae) from the mainland of China, with descriptions of five new species

Fourteen species of Phaecasiophora Grote from the Chinese Mainland are treated, including five new species (P. supparallelica sp. n., P. levis sp. n., P. curvicosta sp. n., P. lushina sp. n., and P. similithaiensis sp. n.) and three new species records for China. Phaecasiophora leechi is transferred from subgenus Megasyca to subgenus Phaecasiophora, and a new synonym of it, viz. P. obligata Kawabe, is proposed. Photographs of the adults, genitalia of the new species, and the species with new synonyms are provided. A key to the species from the Chinese Mainland based on genitalia is given

Effect of stabilizer on flutter stability of truss girder suspension bridges

An aerodynamic optimization measure of the flutter stability of long-span suspension bridges with truss girder is presented in this paper. At first, the improvement of several kinds of central stabilizers and horizontal stabilizers on flutter stability is examined through series of section model and full aeroelastic model wind tunnel tests. Subsequently, the flutter derivatives of the truss girder with and without stabilizer are identified based on two degrees of freedom coupling free vibration method. Furthermore, based on the identified flutter derivatives, the critical flutter velocities of the truss girder section with and without stabilizer are analyzed through two dimensional flutter analysis method and the critical flutter velocities of the full bridge with and without stabilizer are analyzed through three dimensional method. Afterwards, the influence of each flutter derivative on the flutter stability of the truss girder is investigated. The results indicate that central upper stabilizer can effectively increase the critical flutter velocity of the truss girder. In contrast, the central lower stabilizer and horizontal stabilizer have less influence. Setting up central upper stabilizer leads to an obvious decrease in the value of the flutter derivatives A2* and H2*, while the flutter derivatives H1*, H4*, A1* and A3* are little influenced. The two dimensional and three dimensional flutter analysis results agree well with the sectional model and full model wind tunnel test results respectively

Assessing the utility of multiplexed liquid chromatography-mass spectrometry for gluten detection in Australian breakfast food products

Coeliac disease (CD) is an autoimmune disorder triggered by the ingestion of gluten that is associated with gastrointestinal issues, including diarrhea, abdominal pain, and malabsorption. Gluten is a general name for a class of cereal storage proteins of wheat, barley, and rye that are notably resistant to gastrointestinal digestion. After ingestion, immunogenic peptides are subsequently recognized by T cells in the gastrointestinal tract. The only treatment for CD is a life-long gluten-free diet. As such, it is critical to detect gluten in diverse food types, including those where one would not expect to find gluten. The utility of liquid chromatography-mass spectrometry (LC-MS) using cereal-specific peptide markers to detect gluten in heavily processed food types was assessed. A range of breakfast products, including breakfast cereals, breakfast bars, milk-based breakfast drinks, powdered drinks, and a savory spread, were tested. No gluten was detected by LC-MS in the food products labeled gluten-free, yet enzyme-linked immunosorbent assay (ELISA) measurement revealed inconsistencies in barley-containing products. In products containing wheat, rye, barley, and oats as labeled ingredients, gluten proteins were readily detected using discovery proteomics. Panels comprising ten cereal-specific peptide markers were analyzed by targeted proteomics, providing evidence that LC-MS could detect and differentiate gluten in complex matrices, including baked goods and milk-based products

Characteristics of intense winds in mountain area based on field measurement: Focusing on thunderstorm winds

Abstract With the development of mountain areas, more wind-sensitive infrastructures are constructed. In the design of these infrastructures, the wind loading cannot be accurately obtained from the code based on the flat area. Hence, it is of great importance to study the mountain wind characteristics. In this study, the wind field measurement was initiated in a mountain area of western China. After the examination of the measured data, two typical wind events including the thunderstorm wind and thermally developed wind are highlighted. To extract and separate these wind events, an automatic classification method is proposed. The thunderstorm wind is analyzed in order to capture the rapid variation of its maximum wind speed, mean temperature and mean humidity through the boxplot method while the analysis of thermally developed winds relies on the correlation between the mean wind speed and mean temperature. Since the thunderstorm wind is relatively more important for wind engineering, its wind characteristic is focused hereafter and analyzed in detail based on the ultrasonic anemometer data. The characteristics of the thermally developed wind and other wind will be the matter of further studies and investigations. Results show that the characteristics of the thunderstorm wind measured in the mountainous area have no significant difference in comparison with those in the flat area. Due to the limited data, the above results deserve further investigations when more measurements become available

Involvement of NF-κB/IL-6 Pathway in the Processing of Colorectal Carcinogenesis in Colitis Mice

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