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Kimiyoshi Naito Yutaka Kagawa Seishi Utsuno Tamaki Naganuma Kanshi Kurihara 《Composites Science and Technology》2009,69(11-12):2027-2029
Electromagnetic wave transmittances of plain woven fabric glass fiber reinforced epoxy matrix composite (PW-GFRP) and eight-harness-stain fabric glass fiber reinforced polyimide matrix composite (8H-GFRP) with 1.0 mm thickness were measured in a terahertz (THz) frequency range. The transmittance values for both composites are nearly zero at a frequency of 1.0 THz. The real parts of the complex dielectric constant, ε′(ω) are 4.45 and 3.87 for PW-GFRP and 8H-GFRP, respectively, in the frequency range from 0.2 to 1.0 THz, and they are almost frequency independent. Conversely, the imaginary parts of the dielectric constant, ε′′(ω) for both composites linearly increases with increase of the frequency from 0.13 to 0.37 for PW-GFRP, and from 0.12 to 0.33 for 8H-GFRP. 相似文献
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The mechanical properties of Fe-13 wt% Cr-2 wt% Mo-2.5 wt% Ti alloy were examined by tensile tests with respect to its fracture mechanism. In order to improve the properties, 1 wt% Nb was added and its effects were examined. In the temperature range, room temperature to 500° C, the fracture characteristics of the alloys are mainly governed by the characteristics of the x-phase precipitation. Fracture elongation is a function of (C/r)1/2 where C is the radius of the x-phase and r is its mean spacing. 1 wt% Nb addition is an effective method for improving the ductility without a decrease in the strength of the alloy. 相似文献
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Nakamoto H. Yamazaki D. Yamamoto T. Kurata H. Yamada S. Mukaida K. Ninomiya T. Ohkawa T. Masui S. Gotoh K. 《Solid-State Circuits, IEEE Journal of》2007,42(1):101-110
A passive UHF RF identification (RFID) tag IC with embedded 2-KB ferroelectric RAM (FeRAM) for rewritable applications enables a 2.9 times faster read-and-write transaction time over EEPROM-based tag ICs. The resulting FeRAM-based tag has a nominally identical communication range for both read and write operations, which is indispensable for data write applications. The evaluated tag communication range with a folded dipole antenna is from 0 m to 4.3 m, at the 953-MHz carrier frequency with 4-W transmitting Effective Isotropic Radiated Power (EIRP) from a reader/writer. The developed tag IC features two circuit blocks to maximize the communication range in 0.35-mum CMOS/FeRAM technology. First is a CMOS-only full-wave rectifier, which can improve the measured efficiency by up to 36.6% by reducing the input parasitic capacitances and optimization of multiplier structure. This efficiency is more than twice that of previously-published results. Second is a low-voltage current-mode ASK demodulator to accommodate a low-breakdown voltage of FeRAM, which converts the ASK power modulation into a linearly modulated current over an incoming power range of 27 dB, corresponding to the entire communication range. The developed demodulator can thus resolve the primary design tradeoff issue between device protection and detection sensitivity in the conventional voltage-mode demodulator 相似文献
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The importance of concrete permeability is discussed relative to its effect on durability. Experimental studies were made of the effect of water/cement ratio and curing temperature on the porosity, pore size distribution and permeability of cement pastes. Although total porosities of samples cured at 60°C are smaller than in those cured at 27°C, the pore volume larger than 750Å radius is greater in the 60°C samples and is related to higher permeabilities also in the latter. 相似文献
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R. Masui 《International Journal of Thermophysics》2002,23(4):921-935
The development of a magnetic suspension densimeter that has been built for measurement of the density of compressed liquid at pressures up to 30 MPa in the temperature range 20 to 150°C is described. The densimeter was first built by the author and his coworkers at NIST. We describe here further improvements made on a second system built at NMIJ based on the same principle. The densimeter uses a small coil suspended from an electronic balance. Within the coil is placed a sample cell in which the pressurized sample and a buoy, which is a permanent magnet, are enclosed. For measurement of density, balance readings are recorded (1) with the buoy at rest and (2) with the buoy in magnetic suspension. The measurement procedure is basically a hydrostatic weighing, which is simpler than those of conventional magnetic densimetry. As an example, measurements of toluene density performed as part of an inter-laboratory comparison are presented. The data agreed with reliable literature values to within a few hundredths of a per cent. 相似文献
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Purification and characterization of a protease from Pseudomonas aeruginosa grown in cutting oil 总被引:2,自引:0,他引:2
The Pseudomonas aeruginosa san-ai strain was isolated from water-soluble cutting oil used for cooling and lubrication during industrial metal-working processes. This strain, which is grown in a high alkaline (pH 10) mixture of surfactants and mineral oil, produces an extracellular proteolytic enzyme. We have purified and characterized this 18 kDa protease. The P. aeruginosa san-ai protease functions optimally at pH 9.0 and 60 degrees C. Additionally, it is a Zn-containing metalloenzyme, and its monomeric structure contains at least one disulfide bond. Because the enzyme is stable in the presence of organic solvents, it is suitable for peptide synthesis. Furthermore, the P. aeruginosa san-ai protease could be used in an intelligent drug delivery system (DDS) designed for applications in the metal industry for prevention of putrefaction of cutting oil. 相似文献