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81.
82.
83.
Syusaku Koie Gentaro Tanaka Hiroki Fukumoto Take-aki Koizumi Takakazu Yamamoto 《Reactive and Functional Polymers》2013,73(9):1180-1187
π-Conjugated polymers based on 1-aminopyrrole and 4-amino-1,2,4-triazole were prepared. Pd-catalyzed organometallic polycondensation gave poly(arylene-ethynylene) (PAE)-type π-conjugated polymers consisting of BOC-protected 4-amino-1,2,4-triazole (Taz(BOC)) units (BOC = t-butoxycarbonyl). The number average molecular weights (Mn) were determined to be 5200–19,200 using GPC. An alternating copolymer of Taz(BOC) and bithiophene (Th–Th) units, P(Taz(BOC)-Th-Th)n-Pd, with an Mn of 10,800 was also prepared by Pd-catalyzed organometallic polycondensation. (Taz(BOC)-Th-Th)n-Pd showed a UV–Vis absorption peak at λmax = 425 nm, which is reasonable for a π-conjugated five-membered ring polymer with a coplanar structure. The deprotection of the BOC group of the polymers proceeded at 200 °C; this BOC-deprotection was investigated using a model compound. The optical and electrochemical properties of the π-conjugated polymers are reported. 相似文献
84.
Hiroki Iwamoto Alexey Stankovskiy Luca Fiorito Gert Van den Eynde 《Journal of Nuclear Science and Technology》2018,55(5):539-547
The applicability of Monte Carlo techniques, namely the Monte Carlo sensitivity method and the random-sampling method, for uncertainty quantification of the effective delayed neutron fraction βeff is investigated using the continuous-energy Monte Carlo transport code, MCNP, from the perspective of statistical convergence issues. This study focuses on the nuclear data as one of the major sources of βeff uncertainty. For validation of the calculated βeff, a critical configuration of the VENUS-F zero-power reactor was used. It is demonstrated that Chiba's modified k-ratio method is superior to Bretscher's prompt k-ratio method in terms of reducing the statistical uncertainty in calculating not only βeff but also its sensitivities and the uncertainty due to nuclear data. From this result and a comparison of uncertainties obtained by the Monte Carlo sensitivity method and the random-sampling method, it is shown that the Monte Carlo sensitivity method using Chiba's modified k-ratio method is the most practical for uncertainty quantification of βeff. Finally, total βeff uncertainty due to nuclear data for the VENUS-F critical configuration is determined to be approximately 2.7% with JENDL-4.0u, which is dominated by the delayed neutron yield of 235U. 相似文献
85.
86.
Single-wall carbon nanotubes were grown by thermal chemical vapor deposition using either boron- or nitrogen-containing feedstocks or both. Carrier doping was evidenced by hardenings of the G band in Raman spectra, and the estimated carrier concentration reached ∼0.4%. In the G′ and D band spectra, a doping-induced component was observed at the high- or low-energy side of the original one. However, the appearance of the new component did not always coincide with the carrier doping. The doped SWCNTs often show radial breathing mode peaks in the off-resonance region, indicating a defect-induced modification of absorption spectrum. 相似文献
87.
88.
Koichi DoiSatoshi Hino Hiroki MiyaokaTakayuki Ichikawa Yoshitsugu Kojima 《Journal of power sources》2011,196(1):504-507
A lithium silicon alloy was synthesized by mechanical alloying method. Hydrogen storage properties of this Li-Si-H system were studied. During hydrogenation of the lithium silicon alloy, lithium atom was extracted from the alloy and lithium hydride was generated. Equilibrium hydrogen pressures for desorption and absorption reactions were measured in a temperature range from 400 to 500 °C to investigate the thermodynamic characteristics of the system, which can reversibly store 5.4 mass% hydrogen with smaller reaction enthalpy than simple metal Li. Li absorbing alloys, which have been widely studied as a negative electrode material for Li ion rechargeable batteries, can be used as hydrogen storage materials with high hydrogen capacity. 相似文献
89.
In this investigation, a systematic procedure that can be used for modeling joint constraints for the absolute nodal coordinate
formulation is developed. To this end, the non-generalized intermediate coordinates are introduced to derive a mapping between
the generalized gradient coordinates and the non-generalized rotation parameters. With this mapping, a wide variety of joint
constraints can be defined for the absolute nodal coordinate formulation in terms of the non-generalized reference coordinates
and, therefore, existing well-developed constraint libraries formulated for the rigid body reference coordinates can be directly
employed without significant modifications in existing codes. Furthermore, in order to define a rigid surface at the joint
definition point, a set of orthonormality conditions is imposed on the gradient coordinates. This leads to not only accurate
modeling of interface to mechanical joint, but also a simpler definition of the joint coordinate system obtained by the orthonormal
gradient vectors. For this reason, a simpler form of constraint Jacobian and quadratic velocity vectors can be obtained as
compared to those of the existing approach which requires the use of highly nonlinear joint coordinate system. A systematic
procedure for eliminating the non-generalized coordinates and the dependent Lagrange multipliers associated with the coordinate
mapping equations from the equations of motion is presented. As a result, a standard augmented form of the equations of motion
can be obtained in terms of the generalized coordinates only. Several numerical examples are presented in order to demonstrate
the use of the joint constraint formulation developed in this investigation. 相似文献
90.
Sasaki K. Ishibashi K. Shimohigashi K. Yamanaka T. Moriwake N. Honjo S. Ikeda S. Koike A. Meguro S. Minato O. 《Solid-State Circuits, IEEE Journal of》1990,25(5):1075-1081
A 4-Mb CMOS SRAM having 0.2-μA standby current at a supply voltage of 3 V has been developed. Current-mirror/PMOS cross-coupled cascade sense-amplifier circuits have achieved the fast address access time of 23 ns. A new noise-immune data-latch circuit has attained power-reduction characteristics at a low operating cycle time without access delay. A 0.5-μm CMOS, four-level poly, two-level metal technology with a polysilicon PMOS load memory cell, yielded a small cell area of 17 μm2 and the very small standby current. A quadruple-array, word-decoder architecture allowed a small chip area of 122 mm2 相似文献