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81.
Naoto Sugimoto Seiji Fukushima Yasuhiro Suzuki Yoshihisa Sakai Hiromasa Tanobe Takeshi Kurosaki Kazuto Noguchi Kimio Oguchi Hiromu Toba 《光学学报》2003,23(Z1)
A new generation of network interface card for fiber-to-the-desktop has been fabricated. The fabricated card is PC-card size and suitable for notebook PCs. It could become the key element in the coming optical Ethernet age. 相似文献
82.
Tsuyoshi Kiyotsukuri Naoto Tsutsumi Ying-Hsien Chen 《Journal of polymer science. Part A, Polymer chemistry》1990,28(5):1197-1208
Novel regular network polyester films were prepared from benzenetricarboxylic acids of trimesic (Y) and trimellitic (Z) acids, and glycols of ethylene (2G), tetramethylene (4G), and hexamethylene (6G) glycols. Prepolymers prepared by melt polycondensation for a short period within 1 h were cast from a DMF solution and successively post-polymerized at various temperatures and times to form a network. The resultant films were transparent, flexible, and insoluble in any solvents. Distortion temperature measured by a penetration mode of thermomechanical analysis (TMA) increased with increasing post polymerization time and temperature, and leveled out at 222, 168, 125 and 75°C, for the 2GY, 2GZ, 4GY, and 6GY films, respectively. Temperatures close to 400°C at which the probe had completely penetrated corresponded to the thermal decomposition temperature of these films. Two broad but strong peaks in the x-ray diffraction curves appears for the 2GY, 4GY, and 6GY, suggesting the formation of some ordered supramolecular structure owing to the regular network formed by symmetrical trimesic acid moiety, and the intensity of diffraction peaks became higher with increasing length of the methylene chain of the glycol monomer. Densities of the 2GY and 2GZ films decreased with increasing post-polymerization time and temperature. Tensile strength and Young's modulus increased and elongation decreased with increasing network formation. These tensile properties was affected by the chemical structure of the network films. 相似文献
83.
Communicated by P.-L. Lions 相似文献
84.
Mamoru Tobisu Toshifumi Morioka Akimichi Ohtsuki Naoto Chatani 《Chemical science》2015,6(6):3410-3414
The reductive cleavage of the C–O bonds of aryl ethers has great potential in organic synthesis. Although several catalysts that can promote the reductive cleavage of aryl ethers have been reported, all such systems require the use of an external reductant, e.g., hydrosilane or hydrogen. Here, we report the development of a new nickel-based catalytic system that can cleave the C–O bonds of ethers in the absence of an external reductant. The hydrogen atom required in this new reductive cleavage reaction is provided by the alkoxy group of the substrate, which serves as an internal reductant. The absence of an external reductant enables the unique chemoselectivity, i.e., the selective reduction of an alkoxy group over alkenes and ketones. 相似文献
85.
Runyan Ni Naoto Mitsuda Takeru Kashiwagi Kazunobu Igawa Katsuhiko Tomooka 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(4):1206-1210
A variety of medium‐sized cycloalkynes were efficiently synthesized by the double Nicholas reaction of cobalt complex and bis(hetero)substituted acyclic compound. The alkyne moiety within the ring has a unique bent structure and high reactivity toward cycloaddition reactions. Furthermore, preparation of multifunctionalized alkynes was achieved by embedding the cycloalkyne within a peptide chain. 相似文献
86.
Fukumoto Y Hagihara M Kinashi F Chatani N 《Journal of the American Chemical Society》2011,133(26):10014-10017
The reaction of terminal alkynes with hydrosilanes and tert-alkyl isocyanides in the presence of Rh(4)(CO)(12) gives (Z)-β-silyl-α,β-unsaturated imines in good yields. On the other hand, the use of aryl isocyanides in place of tert-alkyl isocyanides leads to the formation of E isomers. 相似文献
87.
A simple and sensitive high-performance liquid chromatography (HPLC) method was developed to quantitate imatinib in human plasma. Imatinib and the internal standard dasatinib were separated using a mobile phase of 0.5% KH(2)PO(4) (pH3.5)-acetonitrile-methanol (55:25:20, v/v/v) on a CAPCELL PAK C18 MG II column (250 mm × 4.6 mm) at a flow rate of 0.5 mL/min and measurement at UV 265 nm. Analysis required 100 μL of plasma and involved a solid phase extraction with an Oasis HLB cartridge, which gave recoveries of imatinib from 73% to 76%. The lower limit of quantification for imatinib was 10 ng/mL. The linear range of this assay was between 10 and 5000 ng/mL (regression line r(2) > 0.9992). Inter- and intra-day coefficients of variation were less than 11.9% and accuracies were within 8.3% over the linear range. The plasma concentrations of imatinib obtained by our present method were almost the same as those assayed by an LC-MS-MS method at the Toray Research Center, Inc. This method can be applied effectively to measure imatinib concentrations in clinical samples. 相似文献
88.
Nanostructured noble metals exhibit an intense optical near field due to surface plasmon resonance, therefore promising widespread
applications and being of interest to a broad spectrum of scientists, ranging from physicists, chemists, and materials scientists
to biologists. A wealth of research is available discussing the synthesis, characterization, and application of noble metal
nanoparticles in optical sensing. However, with respect to the sensitivity of the frequency and width of these surface plasmon
resonance modes to the particle’s shape, size, and environment, in nearly every case, success strongly depends on the availability
of highly stable, adhesive, and sensitive nanoparticles. This undoubtedly presents a challenging task to nanofabrication.
The past decade has witnessed fascinating advances in this field, in particular, the construction of oxide-based hybrid plasmonic
interfaces to overcome the problem addressed above by (1) coating the metallic nanostructures with thin overlayers to form
sandwiched structures or (2) embedding metallic nanostructures in a dielectric matrix to obtain metal/dielectric matrix nanocomposite
films. In this critical review, we focus on recent work related to this field, beginning with a presentation of hybrid films
with enhanced structural and optical stability, readily and selectively designed using chemical and physical techniques. We
then illustrate their interesting optical properties and demonstrate exciting evidence for the postulated application in surface
plasmon sensing fields. Finally, we survey the work remaining to be done for that potential to be realized. 相似文献
89.
Saeki A Yamamoto N Yoshida Y Kozawa T 《The journal of physical chemistry. A》2011,115(36):10166-10173
Dynamics of radical cations and electrons in an admixture of a linear saturated hydrocarbon (n-dodecane) and halocarbon (carbon tetrachloride, CCl(4)) were investigated by picosecond electron beam pulse radiolysis. The decay of thermalized electrons (e(th)(-)) observed in infrared transient photoabsorption were simply accelerated by the addition of CCl(4), giving a high rate constant of 2.3 × 10(11) mol(-1) dm(3) s(-1). The decrease of the initial yield of e(th)(-) was quantified by C(37) (50 mmol), which is linked to the reaction of epithermal electrons (e(-)) with CCl(4). In contrast, the n-dodecane radical cation (RH(2)(?+)) monitored in the near-infrared indicated a convex-type dependence of the decay rate on CCl(4) concentration, although the initial yield of RH(2)(?+) remained almost constant up to a much higher CCl(4) concentration. The decay of RH(2)(?+) was analyzed by Monte Carlo simulations of geminate ion recombination with e(th)(-), chlorine anion (Cl(-)) formed via dissociative electron attachment, and CCl(4) radical anion. The results showed a good agreement with the experiments by considering two assumptions: (1) CCl(4) radical anion formed via e(th)(-) attachment and (2) narrowing of the initial distribution of Cl(-). The decrease in the initial yield of RH(2)(?+) at high CCl(4) concentration was well explained by immediate decomposition of CCl(4)(?+) to CCl(3)(+) and hole transfer from CCl(4)(?+) to adjacent RH(2) without diffusive motion of the reactants. Time-dependent density functional theory supported the spectroscopic assignment of intermediate species in the n-dodecane/CCl(4) system. The present results would be of help in understanding the electron capture reaction in multicomponent systems such as a chemically amplified resist in lithography. 相似文献
90.
Preparation of carbon quantum dots with tunable photoluminescence by rapid laser passivation in ordinary organic solvents 总被引:2,自引:0,他引:2
Li X Wang H Shimizu Y Pyatenko A Kawaguchi K Koshizaki N 《Chemical communications (Cambridge, England)》2011,47(3):932-934
A simple approach to prepare carbon quantum dots is presented in this communication by laser rapid passivation of nano carbon particles in ordinary organic solvent. The as-prepared carbon dots exhibited visible, tunable and stable photoluminescence (PL). XPS analysis showed that the increased oxygen concentration might be concerned with the origin of PL. 相似文献