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81.
We investigated the diffusion process of H2O2 generated during O2 reduction at a Pt microdisk electrode used as a generator for scanning electrochemical microscopy (SECM). First, the amount of O2 consumption and generated H2O2 at the Pt generator electrode are estimated using a detector electrode installed in the SECM. Based on the results, a large amount of O2 consumption and generated H2O2 are detected at the center of each generator electrode. According to the measurement, the O2 starvation and H2O2 detection currents can be defined. Subsequently, the O2 starvation and H2O2 detection currents are measured by varying the generator size. As a result, these currents decrease with a decrease in the generator electrode size, however, the H2O2 diffusion process is changed for the generator diameter of less than 50 μm. Finally, the O2 starvation and H2O2 detection measurements were conducted using a Nafion-coated Pt microdisk electrode. The amount of O2 consumption is not suppressed, while the amount of generated H2O2 decreases with the Nafion layer prepared on the Pt electrode. This result indicates that the thickness of the H2O2 diffusion layer in the H2SO4 solution is dramatically diminished by coating the Nafion layer on the Pt generator. 相似文献
82.
Shoichi MATSUDA Naomichi SAJI Minoru YAGA Masaaki ISHIKAWA Kenyu OYAKAWA 《热科学学报(英文版)》2010,19(3):228-233
This paper will present the characteristics of flow behavior and thermal field of both free and
impingement jet issued from a circular orifice nozzle at Re=8900.The flow behavior of a single round
jet and impingement jet was observed by smoke flow visualization recorded by a high speed camera
using 5000 frame per second.Heat transfer coefficient on the impingement surface was measured by
means of infrared camera (TVS-8500,Avio) with a two-dimensional array of Indeum-Antimony (In Sb)
sensors varying in the separation distance between the nozzle and the target plate.The heat transfer
coefficient changes in time and spatial.Therefore,the root mean square distribution of the heat
transfer was obtained from the data.As a result,it was confirmed that the longitudinal vortex was
observed outside of the ring vortex,and then the longitudinal vortex was penetrated in the jet
flow.Moreover,the high value of root mean square of the heat transfer coefficient has spread radially
in stripy manner,which is caused as the results of the longitudinal vortexes flowing in the radial
direction on the impingement plate. 相似文献
impingement jet issued from a circular orifice nozzle at Re=8900.The flow behavior of a single round
jet and impingement jet was observed by smoke flow visualization recorded by a high speed camera
using 5000 frame per second.Heat transfer coefficient on the impingement surface was measured by
means of infrared camera (TVS-8500,Avio) with a two-dimensional array of Indeum-Antimony (In Sb)
sensors varying in the separation distance between the nozzle and the target plate.The heat transfer
coefficient changes in time and spatial.Therefore,the root mean square distribution of the heat
transfer was obtained from the data.As a result,it was confirmed that the longitudinal vortex was
observed outside of the ring vortex,and then the longitudinal vortex was penetrated in the jet
flow.Moreover,the high value of root mean square of the heat transfer coefficient has spread radially
in stripy manner,which is caused as the results of the longitudinal vortexes flowing in the radial
direction on the impingement plate. 相似文献
83.
Yoshitsugu Kojima Takashi Ohta Mitsumasa Matsushita Minoru Takahara Toshio Kurauchi 《Polymer Engineering and Science》1992,32(10):686-689
Flat packages (FPs) were formed from epoxy molding compounds with various physical properties using a transfer molding machine. The compounds were prepared by changing kinds and amounts of additives and addition methods. The thermal shock test was carried out by the following procedures. The plastic package was soaked alternately in liquid nitrogen (?196°) and in liquid solder (200°) in the cycle of 140s. The median life to crack initiation was defined to be the cycles when half of the specimens exhibited crack initiation. According to linear fracture mechanics, the following expression was obtained relating the median life N, thermal stress σt, and strength σb; N = C/σ·(σb/σt)m. We found the linear relation between logarithm of Nσ and logarithm of σb/σt for various packages, and estimated the values of C and m as 5 × 104 MPa2 and 5.5, respectively. The value of m was the same as that obtained for a dual-in-line package. 相似文献
85.
Minoru Mochihara Kazuyuki Hokamoto Masahiro Fujita 《Metals and Materials International》1998,4(4):911-914
A shearing process of a metal plate by an impulsive pressure generated by underwater explosion was numerically simulated, and the analytical result was compared with some experimental results. The features of the deformation and the shearing process were discussed by considering the fracture condition. 相似文献
86.
Prof. Minoru Yoshimoto Satoshi Kobirata Wataru Sakamoto Hidenobu Aizawa Shigeru Kurosawa 《仪器科学与技术》2013,41(5):495-505
Abstract The present work reports the new characteristics of the immersion‐angle dependence of the resonant‐frequency shift (ΔF) of the one‐face sealed quartz crystal microbalance (QCM) in three types of Newtonian liquids, i.e., sucrose, glucose, and glycerol solutions. Below some 1.80×10?2 g cm?2 · s?1/2, the ΔF values are dependent on the immersion angles in all solutions. However, we have found that the transition phenomenon of ΔF occurs between 1.78×10?2 and 4.80×10?2 g · cm?2 · s?1/2 in the sucrose solution, between 1.75×10?2 and 4.34×10?2 g · cm?2 · s?1/2 in the glucose solution and between 1.83×10?2 and 3.03×10?2 g · cm?2 · s?1/2 in the glycerol solution, respectively. Moreover, above the concentrations of the end points of the transition phenomenon, the ΔF values of the sucrose solution are equal to those of 90° at all immersion angles. On the other hand, those of the glucose and the glycerol solutions are the same as those of 30°. This difference may be caused by inherent characteristics of adsorption to the surface of the QCM electrode. 相似文献
87.
Mizuno Makoto Imai Satoshi Tsukada Minoru Hida Eiki Naka Ken-Ichi 《IEEE transactions on bio-medical engineering》1985,(1):56-60
A microcomputer system was developed to measure visual spatiotemporal receptive fields. The system performs three functions: 1) generation of a binary spatiotemporal white-noise stimulus, 2) acquisition of spike discharges from retinal ganglion cells, and 3) extraction of the linear part of the spatiotemporal receptive flelds by cross correlating the input against the output. We have applied this system to the measurement of the spatiotemporal receptive fields of cat and catfish retinal ganglion cells. 相似文献
88.
Liwei Lin Hideo Watanabe Masayoshi Fuji Minoru Takahashi 《Advanced Powder Technology》2009,20(2):185-189
Zinc oxide with a diversity of well-defined morphologies was synthesized via a simple aqueous solution route by decomposing ZnxOy(OH)z precursor at suitable reaction conditions. Flower-like ZnO composed of rods was obtained by treating ZnxOy(OH)z precursor in the reaction solution at 90 °C for 6 h. The precipitate of layer-like ZnxOy(OH)z precursor was decomposed by drying at 90 °C for 24 h in air, resulting in the formation of ZnO microtubes. 相似文献
89.
The formation of thin AlN films and some of their electrical properties have been investigated. The films were prepared by exposing the surface of evaporated aluminium films to a glow discharge in pure nitrogen gas. It has been confirmed by transmission electron diffraction that the structure of the film is of the wurtzite type, as is that of the bulk material. It was observed that the thickness of the AlN films depends on the voltage of the glow discharge, the distance from the discharge electrode to the films and the treatment time. The electrical properties were measured in the form of a sandwich diode, i.e. Al-AlN-Au. The voltage-controlled negative resistance, which was first discovered in Al-Al2O3-metal diodes, has also been observed in this nitride film diode and shows very good reproducibility and stability. 相似文献
90.