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排序方式: 共有2095条查询结果,搜索用时 15 毫秒
91.
Wakejima A. Matsunaga K. Okamoto Y. Ando Y. Nakayama T. Miyamoto H. 《Electronics letters》2005,41(25):1371-1372
A single-ended amplifier using small packaged GaN-FETs exhibits a record 2.14 GHz W-CDMA output power. The amplifier, composed of paralleled 48 mm gate periphery FET die, delivers a peak saturated output power of 371 W with a linear gain of 11.2 dB at a drain voltage of 45 V under 2.14 GHz 3GPP W-CDMA signal input. The output power density (output power/package size) of 1.1 W/mm/sup 2/ is twice as high as that of the existing over 300 W GaAs-FET amplifiers. A low 5 MHz offset ACLR of -36 dBc with a drain efficiency of 24% is also obtained at 8 dB power back off from the saturated output power. 相似文献
92.
Toshiki Ueno Takeru Nakaki Taisei Mukogawa Shuonan Dong Hiroki Kurita Keisuke Otsuka Kanjuro Makihara Fumio Narita 《Advanced Engineering Materials》2023,25(19):2300185
In this study, the Fe–Co alloy is combined with cobalt ferrite (CoFe2O4) and nickel (Ni) to form Fe–Co/CoFe2O4 and Fe–Co/Ni clad sheets and their energy-harvesting performance is evaluated. The Fe–Co/CoFe2O4 clad sheet exhibits an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m s−1. The energy-harvesting performance of both these clad sheets cannot be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe2O4 are higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW). 相似文献
93.
Y. Miyamoto Y. Kubo N. Ono M. Hashimoto T. Takahashi I. Ito F. Arezzo P. Gimondo 《Thin solid films》1995,270(1-2):253-259
A new coil-coating pilot plant, capable of utilizing ion plating, sputtering and plasma-assisted chemical vapor deposition (PACVD) processes, independently or in series, was developed and optimum conditions for TiN, TiC, AlxOy, SiOx and Cr coating were established. This paper is mostly concerned with the results of characterization (conducted in parallel by the authors′ two institutions) of TiN films deposited by ion plating or sputtering onto type-304 stainless steel strips. In particular, the dependence of the basic properties such as chemical composition, structure, adhesion, and color on the coating process are discussed with respect to anti-corrosion, anti-wear, and decorative applications. TiN coatings with a very attractive gold coloration were obtained; they performed well in wear testing, but did not show satisfactory corrosion resistance. However, it was found that the latter can be improved significantly by depositing a SiOx, top layer by PACVD above the TiN coating. Thus the in-line dry coating processes are capable of producing highly functional steel surfaces with decorative color and high corrosion resistance. 相似文献
94.
液闪效率示踪法校正效果的评价 总被引:1,自引:0,他引:1
本文评价了Aloka商品液闪仪效率示踪法dpm校正的效果。轻,中度猝灭校正效果理想,具有简便、实用和适用性广泛的特点。严重化学和颜色猝灭样品的校正结果分别随猝灭增加而向增大和减小的方向偏离,形成喇叭状曲线,文中对这一现象给出初步解释。 相似文献
95.
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
96.
A light modulator using piezoelectric films based on optical interference of the Mach-Zehnder type has been proposed and demonstrated. The modulator is constructed with two optical waveguides joined to each other at both ends to divide the incident light and to recombine them, and each waveguide is fabricated on a polyvinylidene fluoride (PVDF) film to serve as a voltage-driven phase-shifter. 相似文献
97.
快速烧结制备纳米Y-TZP材料 总被引:28,自引:1,他引:28
研究了快速热压烧结和放电等离子快速烧结(SPS)制备纳米Y-TZP材料.利用快速热压烧结和 SPS快速烧结,可在烧结温度为 1200℃、保温9~10min条件下,制得相对密度超过99%的 Y-TZP材料.研究发现:虽然快速热压烧结和 SPS烧结都可使Y-TZP在相同温度下的密度高于普通热压烧结,但两种快速烧结所得Y-TZP的晶粒都大于无压烧结所得;另外,快速热压烧结所得样品的结构不够均匀,而SPS烧结的样品的均匀性较好.文章对产生这些现象的原因进行了理论探讨. 相似文献
98.
Hyun Goo Ji Pablo Solís‐Fernndez Daisuke Yoshimura Mina Maruyama Takahiko Endo Yasumitsu Miyata Susumu Okada Hiroki Ago 《Advanced materials (Deerfield Beach, Fla.)》2019,31(42)
Monolayers of transition metal dichalcogenides (TMDCs) have attracted a great interest for post‐silicon electronics and photonics due to their high carrier mobility, tunable bandgap, and atom‐thick 2D structure. With the analogy to conventional silicon electronics, establishing a method to convert TMDC to p‐ and n‐type semiconductors is essential for various device applications, such as complementary metal‐oxide‐semiconductor (CMOS) circuits and photovoltaics. Here, a successful control of the electrical polarity of monolayer WSe2 is demonstrated by chemical doping. Two different molecules, 4‐nitrobenzenediazonium tetrafluoroborate and diethylenetriamine, are utilized to convert ambipolar WSe2 field‐effect transistors (FETs) to p‐ and n‐type, respectively. Moreover, the chemically doped WSe2 show increased effective carrier mobilities of 82 and 25 cm2 V?1s?1 for holes and electrons, respectively, which are much higher than those of the pristine WSe2. The doping effects are studied by photoluminescence, Raman, X‐ray photoelectron spectroscopy, and density functional theory. Chemically tuned WSe2 FETs are integrated into CMOS inverters, exhibiting extremely low power consumption ( ≈ 0.17 nW). Furthermore, a p‐n junction within single WSe2 grain is realized via spatially controlled chemical doping. The chemical doping method for controlling the transport properties of WSe2 will contribute to the development of TMDC‐based advanced electronics. 相似文献
99.
A 200 km nonrepeatered transmission experiment and a 400 km transmission experiment using three in-line amplifiers are carried out at 20 Gbit/s by using a simple but highly sensitive optical preamplifier receiver based on a 0.98 μm LD-pumped EDFA. High sensitivity of -31.6 dBm (270 photon/bit) at 20 Gbit/s is obtained 相似文献
100.
Sanjay Kumar Ankur Jain Hiroki Miyaoka Takayuki Ichikawa Yoshitsugu Kojima 《International Journal of Hydrogen Energy》2017,42(27):17178-17183
Bis(cyclopentadienyl) nickel II is one of the best precursors of nickel catalyst which remarkably improved the hydrogen absorption-desorption of Mg–MgH2 system. The X-ray photoelectron spectroscopy (XPS) and Furrier Transformed Infrared Spectroscopy (FTIR) analyses revealed that bis (cyclopentadienyl) nickel II decomposed into metallic nickel during ball milling with MgH2. The nickel thus formed has homogeneously doped over the Mg - MgH2 surface. The Ni-doped Mg-MgH2 have shown the excellent catalytic effect on hydrogen absorption-desorption. The catalyzed MgH2 could desorb hydrogen below 225 °C (Tonset) under Ar flow, and absorb hydrogen at 50 °C under 1.5 MPa H2 pressure. The hydrogen absorption-desorption temperatures are remarkably decreased as compared to the uncatalyzed Mg-MgH2 system under the identical experimental conditions. 相似文献