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排序方式: 共有238条查询结果,搜索用时 15 毫秒
21.
Toshiki Yamada Hidenori Shinohara Toshiya Kamikado Yoshishige Okuno Hitoshi Suzuki Shinro Mashiko Shiyoshi Yokoyama 《Thin solid films》2008,516(9):2522-2526
The spray-jet molecular beam apparatus enabled us to produce a molecular beam of non-volatile molecules under high vacuum from a sprayed mist of sample solutions. The apparatus has been used in spectroscopic studies and as a means of molecular beam deposition. We analyzed the molecular beam, consisting of non-volatile, solvent, and carrier-gas molecules, by using femtosecond- and nanosecond- laser mass spectroscopy. The information thus obtained provided insight into the molecular beam produced by the spray-jet technique. 相似文献
22.
Thanks to rapid progress in microelectronics technology, a new, nomadic lifestyle has become widespread these days. People, regardless of location, enjoy greater connectivity through communication networks and intelligent electronic terminals. This nomadic lifestyle will become even more common as technology frees people from the constraints of time and location. The cool chip, characterized by high performance and low power consumption, will play a key role in inaugurating the Nomadic Age. Rather than describe its technical details, we take a broader, more historic view of the cool chip's impact. More than a necessary innovation, cool chips' increased portability and reduced power consumption will play a key role in building a better future society 相似文献
23.
High spectral efficiency combined with power efficiency, is a requirement for high speed digital broadcast satellite systems. The effect of the recovered carrier phase noise and the nonlinearity on the performance of 16-QAM (quadrature amplitude modulation) and staggered 16-QAM is investigated and compared. It is found that for the phase noise, 16-QAM is more degraded for a roll-off factor of less than 0.4. For roll-off factor of more than 0.8, staggered 16-QAM has superior performance. For the nonlinearity staggered 16-QAM is more sensitive for a roll-off factor of less than 0.4. It is concluded that coincident 16-QAM is suitable for spectrally efficient digital broadcast systems 相似文献
24.
Toshiki Oguchi Atsushi Watanabe Takayoshi Nakamizo 《International journal of control》2013,86(8):582-590
This paper considers the input-output linearization problem for retarded non-linear systems, which have time-delays in the state. By using an extension of the Lie derivative for functional differential equations, we derive a coordinates transformation and a static state feedback to obtain linear input-output behaviour for a class of retarded non-linear systems. The obtained coordinates transformation is allowed to contain not only the current value of the state variables but also the past values of ones. In addition, we show that the coordinates transformation is invertible in a neighbourhood of the origin and examine the stability condition of the closed loop system with the static state feedback. The effectiveness of the proposed technique is demonstrated through numerical simulations. 相似文献
25.
Toshiki Tsubota Kaori TakenakaNaoya Murakami Teruhisa Ohno 《Journal of power sources》2011,196(23):10455-10460
In order to investigate the performance of an electrochemical capacitor consisting of a nitrogen- and sulfur-containing carbon material, the carbon material derived from thiourea and urea was synthesized by a polymerization process of the urea resin. No solid appeared after the polymerization process. When the dried sample after the polymerization process was heated in flowing N2 gas, we obtained carbon material. However, there was no product when only thiourea was heated under the same conditions. The percentages of nitrogen and sulfur in all the samples synthesized from thiourea were roughly 5-20 wt.% and 3-8 wt.% even after washing with hot water, respectively. No specific peak derived from the redox reaction appeared in the CV graphs for the samples. The capacitance value of T-urea800W, which was synthesized by the heat treatment at 800 °C and then wash with hot water, was 138.8 F g−1 at the current density of 50 mA g−1 in a 1 M H2SO4 water solution whereas that value of a commercial activated carbon was 107.1 F g−1 under the same conditions. It was presumed from the XPS measurements that the status of the nitrogen and sulfur in the materials are a pyridine-like nitrogen at the edge part of the graphitic structure, a quaternary nitrogen in the graphitic-layered structure, and S0, S4+, and S2−, respectively. 相似文献
26.
C. X. Wang N. Maeda M. Hiroki T. Tawara T. Makimoto T. Kobayahsi T. Enoki 《Journal of Electronic Materials》2005,34(4):361-364
AlGaN/GaN-based metal-insulator-semiconductor heterostructure field-effect transistors (MIS-HFETs) with Al2O3/Si3N4 bilayer as insulator have been investigated in detail, and compared with the conventional HFET and Si3N4-based MIS-HFET devices. Al2O3/Si3N4 bilayer-based MIS-HFETs exhibited much lower gate current leakage than conventional HFET and Si3N4-based MIS devices under reverse gate bias, and leakage as low as 1×10−11 A/mm at −15 V has been achieved in Al2O3/Si3N4-based MIS devices. By using ultrathin Al2O3/Si3N4 bilayer, very high maximum transconductance of more than 180 mS/mm with ultra-low gate leakage has been obtained in the MIS-HFET
device with gate length of 1.5 μm, a reduction less than 5% in maximum transconductance compared with the conventional HFET
device. This value was much smaller than the more than 30% reduction in the Si3N4-based MIS device, due to the employment of ultra-thin bilayer with large dielectric constant and the large conduction band
offset between Al2O3 and nitrides. This work demonstrates that Al2O3/Si3N4 bilayer insulator is a superior candidate for nitrides-based MIS-HFET devices. 相似文献
27.
High-density polyethylene films 50 μm thick were exposed to the downstream plasma flow of RF glow discharges in argon, hydrogen, or oxygen. It was found that many transvinylene and unreacted radicals remain after the argon or hydrogen plasma treatment, and that carbonyl groups are formed in the oxygen plasma treatment. The conduction current was smaller in the hydrogen-plasma treated samples and the samples exposed to oxygen or ozone after hydrogen-plasma treatment than in the untreated samples. Thermal pulse current measurements indicate that the treated surface layer traps electrons or holes and reduces the field strength at the electrode surface, thus suppressing further injection of electrons or holes. 相似文献
28.
Measurement method of Stokes parameters using a quarter-wave plate with phase difference errors 总被引:1,自引:0,他引:1
Kihara T 《Applied optics》2011,50(17):2582-2587
The Stokes parameters (S0, S1, S2, and S3) of monochromatic light can be measured using the adjustable azimuth settings of a quarter-wave plate and a polarizer. When measuring the Stokes parameters of light of an arbitrary wavelength, the measurement of S3 is affected by the phase difference error Δq(λi), due to the mismatch with respect to wavelength with the quarter-wave plate. In this method, Δq(λi), due to such a mismatch of incident light of arbitrary wavelength, can be overcome by a judicious choice of azimuth settings of the quarter-wave plate and the use of a polarizer; however, the use of a precision quarter-wave plate is necessary. The present paper proposes a measurement method of Stokes parameters of incident light of arbitrary wavelength using a quarter-wave plate with phase difference errors. 相似文献
29.
A transverse scanning laser Doppler velocimeter (LDV) that does not require any moving mechanism in its sensor probe is proposed, and the scanning function is demonstrated theoretically and experimentally. In the proposed scanning LDV, the measurement position is transversely scanned on the basis of a wavelength change induced by a tunable laser and a combination of a grating and a Dove prism. To demonstrate the scanning function in the transverse direction, an experiment was carried out using a setup of the sensor probe consisting of bulk optical components. The experimental results indicate that a transverse scanning function was successfully obtained. The scanning range in the vertical direction is estimated to be 11.3 mm over wavelengths of 1520 to 1570 nm. 相似文献
30.