グラファイト型窒化炭素を用いた高活性可視光応答型ナノハイブリット光触媒の開発に関する研究

九州工業大学博士学位論文（要旨）学位記番号：工博甲第437号 学位授与年月日：平成29年3月24

Bis[1-hydroxy­ethyl­idenediphosphon­ato(1−)](1,10-phenanthroline)nickel(II) mono­hydrate

In the mononuclear title compound, [Ni(C2H6O7P2)2(C12H8N2)]·H2O, the NiII atom (site symmetry 2) is bonded to two phosphate-based O,O′-bidentate chelate ligands and one N,N′-bidentate 1,10-phenanthroline ligand, resulting in a slightly distorted cis-NiN2O4 octa­hedral geometry. In the crystal structure, pairs of complexes are linked by double hydrogen bonds, forming a one-dimensional chain-like structure. Aromatic π–π stacking inter­actions [centroid–centroid separation = 3.768 (2) Å] and further hydrogen bonds generate a two-dimensional structure. The water O atom also lies on a crystallographic twofold axis

The Performance of U.S. Equity Mutual Funds during the Recent Recession

The world economy is suffering under the financial crisis. The mutual fund market, one of the most popular investments, is worth to observe during the recent recession in order to provide some valuable information for investors to reconsider their investment strategies. In this paper, 180 actively managed U.S. equity mutual funds from 2004 to 2010 are selected as the sample data. It empirically examines the persistence performance of mutual funds within the period 2004 to 2007(bull) and 2007 to 2010(recession), plus tests the size effect in different periods by comparing Jensen’s Alpha, Treynor’s ratio and Sharpe’s ratio. The findings suggest performances of mutual funds are, on average, worse than S&P 500 in any sample periods; while mutual funds have a greater performance in bull rather than in recession. In addition, performances in different size funds are not much difference in any particular periods; whereas, the same size funds perform better in bull rather than in recession

Synthesis high specific surface area nanotube g-C3N4 with two-step condensation treatment of melamine to enhance photocatalysis properties

High specific surface area nanotube g-C3N4 was fabricated by a simple two-step condensation method. Photocatalytic activity was evaluated by decomposition of Rhodamine B (Rh B) under visible light. Nanotube g-C3N4 showed 12 times higher photocatalytic activity than bulk g-C3N4. The improvement of photocatalytic activity was mainly due to the higher surface area, the unique morphology and the number of defects

Porous cerium dioxide hollow spheres and their photocatalytic performance

Uniform-sized and monodiperse cerium dioxide porous hollow spheres (CeO2-PH) based on the Ostwald ripening process were fabricated by a simple solvothermal method in the absence of any templates. The structure and morphology of CeO2-PH and CeO2-NP (cerium dioxide nanoparticles) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) surface area analysis. The average diameter of face-centered cubic (fcc) phase CeO2-PH was ca. 160 nm with a high specific surface area, and it is composed of small crystal grain particles (ca. 10 nm). Furthermore, CeO2-PH has high activity for the evaluation of acetaldehyde decomposition. Optical, defect, and chemical state properties were characterized by Raman spectra, ultraviolet-visible absorption spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The presence of Ce3+ ions narrowed the band gap of CeO2-PH, resulting in the high light harvesting. The large amount of oxygen vacancy defects provided many activity sites on CeO2-PH in the photocatalytic process. The formation scheme and photocatalyic mechanism will be discussed in this paper

Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir

AbstractWater content and distribution have important impacts on gas production in water-bearing tight gas reservoirs. However, due to the structural and chemical heterogeneity of tight reservoirs, the water phase exists in various states, which has complicated the analyses of the effects of water characteristics on tight gas production performance. In this work, the water phase is distinguished from immobile to mobile states and the term of constrained water saturation is proposed. It is established that water can flow when the driving pressure difference is larger than the critical driving pressure difference. A new theoretical model of threshold pressure gradient is derived to incorporate the influences of constrained water saturation and permeability. On this basis, a new prediction model considering the varied threshold pressure gradient is obtained, and the result indicates that when threshold pressure gradient is constant, the real gas production capacity of the reservoir will be weakened. Meanwhile, a dynamic supply boundary model is presented, which indicates that the permeability has a strong influence on the dynamic supply boundary, whereas the impact of initial water saturation is negligible. These findings provide insights into the understanding of the effects of water state and saturation on the threshold pressure gradient and gas production rate in tight gas reservoirs. Furthermore, this study provides useful guidance on the prediction of field-scale gas production.Cited as: Zhu, W., Liu, Y., Shi, Y., Zou, G., Zhang, Q., Kong, D. Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir. Advances in Geo-Energy Research, 2022, 6(4): 286-295. https://doi.org/10.46690/ager.2022.04.0

Generation of an external guide sequence library for a reverse genetic screen in Caenorhabditis elegans

<p>Abstract</p> <p>Background</p> <p>A method for inhibiting the expression of particular genes using external guide sequences (EGSs) has been developed in bacteria, mammalian cells and maize cells.</p> <p>Results</p> <p>To examine whether EGS technology can be used to down-regulate gene expression in <it>Caenorhabditis elegans </it>(<it>C. elegans</it>), we generated EGS-Ngfp-lacZ and EGS-Mtgfp that are targeted against <it>Ngfp-lacZ </it>and <it>Mtgfp </it>mRNA, respectively. These EGSs were introduced, both separately and together, into the <it>C. elegans </it>strain PD4251, which contains <it>Ngfp-lacZ </it>and <it>Mtgfp</it>. Consequently, the expression levels of <it>Ngfp-lacZ </it>and <it>Mtgfp </it>were affected by EGS-Ngfp-lacZ and EGS-Mtgfp, respectively. We further generated an EGS library that contains a randomized antisense domain of tRNA-derived EGS ("3/4 EGS"). Examination of the composition of the EGS library showed that there was no obvious bias in the cloning of certain EGSs. A subset of EGSs was randomly chosen for screening in the <it>C. elegans </it>strain N2. About 6% of these EGSs induced abnormal phenotypes such as P0 slow postembryonic growth, P0 larval arrest, P0 larval lethality and P0 sterility. Of these, EGS-35 and EGS-83 caused the greatest phenotype changes, and their target mRNAs were identified as ZK858.7 mRNA and <it>Lin-13 </it>mRNA, respectively.</p> <p>Conclusion</p> <p>EGS technology can be used to down-regulate gene expression in <it>C. elegans</it>. The EGS library is a research tool for reverse genetic screening in <it>C. elegans</it>. These observations are potentially of great importance to further our understanding and use of <it>C. elegans </it>genomics.</p

Noise Calculation Method for Deep Groove Ball Bearing With Considering Raceway Surface Waviness and Roller Size Error

Rolling bearing is a kind of important part of mechanical equipment, and the noise of the rolling bearing is also one of the important criteria for evaluating the quality of a rolling bearing. In the past, researches on rolling bearings are mainly on bearing vibration when people study the noise of bearings. Few studies have established rolling bearing's noise model. In this paper, a mathematical model for calculating the inner ring's axis center orbit and ball center's trajectory of bearing is established based on the mechanics theory with considering raceway waviness and ball size error. Combined with the acoustics theory, a noise calculation model for deep grove ball bearing is established by taking the bearing inner ring and rolling balls as cylindrical sound source and spherical sound source respectively by using the single source compound method. The influences of waviness wave number, waviness amplitude, bearing speed, bearing load, and ball size errors on bearing noise at a fixed measuring point are studied by numerical calculation. Results show that with the increase of the waviness wave number, the bearing SPL (Sound Pressure Level) will change with irregular way. With the increase of waviness amplitude, bearing speed, bearing load and ball size error band, the bearing SPL will increase

Synthesis and photocatalytic performance of yttrium-doped CeO 2 with a porous broom-like hierarchical structure

In this study, yttrium-doped CeO2 with a broom-like porous hierarchical structure was successfully prepared by a simple template-free hydrothermal method with cerium nitrate hexahydrate and yttrium nitrate hexahydrate as original materials. Through systematic experiments, the different effects of doping concentrations on characteristics of the ceria were examined in detail and the optimal doping ratio was determined simultaneously. The morphology and element distribution of the as-prepared samples were characterized by field emission scanning electron microscopy and high-resolution transmission electron microscopy. Structure information with Rietveld refined data were obtained by using an X-ray diffractometer. Extinctive oxygen vacancy and doping oxygen vacancy were analyzed from Raman spectra. Analyses of elements and chemical valence analysis were carried out by X-ray photoelectron spectroscopy, and changes in reactive oxygen species were determined by calculation. Based on structural information, element valence states, results of hydrogen temperature-programmed reduction and oxygen temperature-programmed decomposition analysis and the results of photocatalytic decomposition of acetaldehyde, we can draw the conclusion that a certain amount of Y-doped CeO2 with a broom-like porous hierarchical structure has high catalytic activity, attributed to more oxygen vacancies and surface active oxygen species generated after yttrium doping