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141.
142.
Mesoporous SiO2–TiO2 was synthesized by the sol–gel method using Si(OC2H5)4, Ti(OC2H5)4, and stearyltrimethylammonium chloride. By using acetylacetone as the capping agent of Ti(OC2H5)4, homogeneous SiO2–TiO2 composite was obtained. Spherical mesoporous SiO2–TiO2 was also synthesized by the sol–gel method using W/O emulsion under microwave irradiation. The specific surface area of these
mesoporous SiO2–TiO2 materials decreased when the Ti/Si molar ratio was higher than 0.1, which indicated that Ti was homogeneously distributed
in mesoporous SiO2 matrix at Ti/Si ≦ 0.1. The photocatalytic activity of mesoporous SiO2–TiO2 materials was investigated by the degradation of methylene-blue in water under UV light irradiation. Mesoporous SiO2–TiO2 was effective for the adsorption–decomposition of methylene-blue. 相似文献
143.
Muncipinto G Kaya T Wilson JA Kumagai N Clemons PA Schreiber SL 《Organic letters》2010,12(22):5230-5233
A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis. 相似文献
144.
Lawrence Asamoah Adutwum Naoya Kishikawa Kaname Ohyama Shiro Harada Kenichiro Nakashima Naotaka Kuroda 《Analytical and bioanalytical chemistry》2010,398(2):823-829
A sensitive and selective high performance liquid chromatography-peroxyoxalate chemiluminescence (PO-CL) method has been developed
for the simultaneous determination of chlorpheniramine (CPA) and monodesmethyl chlorpheniramine (MDCPA) in human serum. The
method combines fluorescent labeling with 4-(4,5-diphenyl-1H-imidazole-2-yl)phenyl boronic acid using Suzuki coupling reaction with PO-CL detection. CPA and MDCPA were extracted from
human serum by liquid–liquid extraction with n-hexane. Excess labeling reagent, which interfered with trace level determination of analytes, was removed by solid-phase
extraction using a C18 cartridge. Separation of derivatives of both analytes was achieved isocratically on a silica column
with a mixture of acetonitrile and 60 mM imidazole-HNO3 buffer (pH 7.2; 85:15, v/v) containing 0.015% triethylamine. The proposed method exhibited a good linearity with a correlation coefficient of 0.999
for CPA and MDCPA within the concentration range of 0.5–100 ng/mL. The limits of detection (S/N = 3) were 0.14 and 0.16 ng/mL
for CPA and MDCPA, respectively. Using the proposed method, CPA could be selectively determined in human serum after oral
administration. 相似文献
145.
Kuse N Nomura Y Ozawa A Kuwata-Gonokami M Watanabe S Kobayashi Y 《Optics letters》2010,35(23):3868-3870
Compensation of the intracavity dispersion in the mode-locked oscillator is known to be one of the most important factors for ultrashort pulse generation. However, recent investigations of a Yb-doped fiber mode-locked oscillator revealed that precise third-order dispersion (TOD) compensation is not always necessary for ultrashort pulse generation, owing to the strong nonlinearity that compensates residual TOD without reducing its spectral bandwidth. The origin of the nonlinear TOD compensation has remained unclear. To investigate the process in detail, we studied the pulse evolution inside a 30 fs Yb-doped fiber mode-locked oscillator both experimentally and numerically, and we found that the nonlinear phase shift with a temporally asymmetric pulse shape introduces an appropriate amount of TOD that exactly cancels the residual cavity dispersion. 相似文献
146.
Eunyoung Bae Naoya Murakami Teruhisa Ohno 《Journal of molecular catalysis. A, Chemical》2009,300(1-2):72-79
Size-, shape-, and phase structure-controlled synthesis of TiO2 nanocrystallites has long been one of the main themes in TiO2 research. Many synthetic techniques have been utilized in the preparation of TiO2 nanocrystals, among which hydrothermal treatment has been drawing much attention because it directly produces well-crystallized nanocrystallities of a wide range of compositions of crystal phases within a short reaction time. In this study, we carried out hydrothermal growth of rutile TiO2 rods by using aqueous titanium trichloride (TiCl3) solutions containing NaCl. Uniform ultrafine rutile TiO2 particles were obtained, and developed crystal faces were observed by TEM, SEM, XRD, and specific surface area measurements. The obtained rutile fine particles showed high levels of activity for degradation of 2-propanol and acetaldehyde under UV irradiation compared to the activity levels of anatase fine particles (ST-01) developed for environmental clean-up. The surface chemistry of the rutile TiO2 particles was also investigated. From photodeposition of Pt and PbO2, we suggest that the (1 1 0) face provides reductive sites and that the (1 1 1) face provides oxidative sites. These results indicate that the crystal faces facilitate the separation of electrons and holes, resulting in improvement of photocatalytic activity. 相似文献
147.
An efficient algorithm is proposed for finding all solutions of systems of n nonlinear equations. This algorithm is based on interval analysis and a new strategy called LP narrowing. In the LP narrowing strategy, boxes (n-dimensional rectangles in the solution domain) containing no solution are excluded, and boxes containing solutions are narrowed so that no solution is lost by using linear programming techniques. Since the LP narrowing is very powerful, all solutions can be found very efficiently. By numerical examples, it is shown that the proposed algorithm could find all solutions of systems of 5000-50,000 nonlinear equations in practical computation time. 相似文献
148.
Katsumi Murata Naoya Nagata Isao Nakanishi Kazuo Kitaura 《Journal of computational chemistry》2010,31(15):2714-2722
We previously reported that solvent dipole ordering (SDO) at the ligand binding site of a protein indicates an outline of the preferred shape and binding pose of the ligands. We suggested that SDO‐mimetic pseudo‐molecules that mimic the 3D shape of the SDO region could be used as molecular queries with a shape similarity matching method in virtual screening. In this work, a virtual screening method based on SDO, named SDOVS, was proposed. This method was applied to virtual screening of ligands for four typical drug target proteins and the performance compared with that of FRED (well‐known rigid docking method); the efficiency of SDOVS was demonstrated to be better than FRED. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 相似文献
149.
150.
Muguruma H Kase Y Murata N Matsumura K 《The journal of physical chemistry. B》2006,110(51):26033-26039
Adsorption of glucose oxidase (GOD) onto plasma-polymerized thin films (PPF) with nanoscale thickness was characterized by atomic force microscopy (AFM), quartz crystal microbalance (QCM), and electrochemical measurements. The PPF surface is very flat (less than 1-nm roughness), and its properties (charge and wettability) can be easily changed while retaining the backbone structure. We focused on three types of surfaces: (1) the pristine surface of hexamethyldisiloxane (HMDS) PPF (hydrophobic and neutral surface), (2) an HMDS PPF surface with nitrogen-plasma treatment (hydrophilic and positive-charged surface), and (3) an HMDS PPF surface treated with oxygen plasma (hydrophilic and negative-charged surface). The AFM image showed that the GOD molecules were densely adsorbed onto surface 2 and that individual GOD molecules could be observed. The longer axis of GOD ellipsoid molecules were aligned parallel to the surface, called the "lying position", because of electrostatic association. On surface 1, clusters of GOD molecules did not completely cover the original PPF surface (surface coverage was ca. 60%). The 10-nm-size step height between the GOD clusters and the PPF surface suggests that the longer axes of individual GOD molecules were aligned perpendicular to the surface, called the "standing position". On surface 3, only a few of the GOD molecules were adsorbed because of electrostatic repulsion. These results indicate that the plasma polymerization process can facilitate enhancement or reduction of protein adsorption. The AFM images show a corresponding tendency with the QCM profiles. The QCM data indicate that the adsorption behavior obeys the Langmuir isotherm equation. The amperometric biosensor characteristics of the GOD-adsorbed PPF on a platinum electrode showed an increment in the current because of enzymatic reaction with glucose addition, indicating that enzyme activity was mostly retained in spite of irreversible adsorption. 相似文献