以不同PAN系炭纤维布制备燃料电池气体扩散层之研究

采用石墨化PAN系炭纤维布制备了高分子电解质燃料电池气体扩散层。通过电学实验、X-ray绕射与元素分析考察了所制气体扩散层的性能。结果表明：随热处理温度的升高，气体扩散层的电阻率降低，L2增加，d（x）2减小。高温处理后的炭纤维布作为高分子电解质燃料电池气体扩散层显示了较高的电池效能。     

Polarity control of GaN epilayers grown on ZnO templates

We report the successful growth of Ga-polar GaN epilayers on O-polar ZnO templates pre-deposited on c-sapphire. Prior to GaN growth, NH₃ is exposed onto the ZnO template. The polarity of the GaN layers is confirmed by etching of the surface and by conversion beam electron diffraction (CBED), while the O-polar ZnO is confirmed by CBED. It is suggested that the NH₃ pre-exposure helps form a Zn₃N₂ layer, which possesses inversion symmetry and inverts the crystal from anion polar to cation polar.     

Dynamic RSVP protocol

RSVP is a resource reservation setup protocol that can be used by a host to request specific QoS for multicast multimedia flows on the Internet. Multiprotocol label switching (MPLS) architecture also needs RSVP. The fact that the resolutions of the display system used in different receiver nodes might have different, multi-resolution characteristics is supported in the MPEG-4 standard, and the EZW compression algorithm can cease decoding at any point in the bitstream. However, RSVP does not provide a more flexible mechanism. In this article we propose an extension of RSVP to provide the needed mechanism, coined dynamic RSVP (DRSVP), to dynamically adjust reserved resources on nodes without much effort. It provides different video resolutions to different receiver nodes with different needed reserved resources. Therefore, it does not waste precious Internet resources to transmit unnecessary multimedia packets.     

Reinjection experiment at the matsukawa vapor-dominated geothermal field: Increase in steam production and secondary heat recovery from the reservoir

A reinjection experiment has been conducted in an attempt to sustain reservoir pressure and steam production and to extract remaining heat energy in the superheated reservoir in the Matsukawa vapor-dominated geothermal field. This experiment was undertaken because the increase in superheat of produced steam and the decline of steam production are the current major issues for stable operation of the power plant. Almost all the reinjected fluid into well MR 1 was recovered from well M5, and the steam production of well M5 has increased by approximately 67%.     

Transient behavior of subthreshold characteristics of fullydepleted SOI MOSFETs

It has been found that the subthreshold currents of fully depleted silicon-on-insulator (SOI) MOSFETs show a transient behavior under certain front-gate and back-gate voltage conditions. The cause of this anomaly is explained, and applications for the phenomenon are pointed out. Particularly, a simple way to measure the silicon film thickness is suggested     

Laboratory aid and ultrasonography in the diagnosis of appendicitis in children

The purpose of this study was to evaluate the relationship between the number of yolk sacs and amnionicity in monochorionic twin pregnancies scanned early in the first trimester. We retrospectively reviewed images of all monochorionic twins scanned between 6 and 9.5 weeks' gestation and with pathologic or sonographic confirmation of chorionicity-amnionicity. Each film was reviewed for the number of yolk sacs present, as well as for the gestational age at which the amniotic membrane was first visualized. Twenty monochorionic-diamniotic pregnancies and two monochorionic-monoamniotic pregnancies met the criteria for inclusion in the study. In diamniotic pregnancies scanned at less than 8 weeks' gestation, only the yolk sacs were identified; none of the dividing amniotic membranes were detected. Two yolk sacs were identified in all but one case. In this case, although one yolk sac was seen at 6 weeks, follow-up scanning at 8 weeks revealed two yolk sacs. In each of the monochorionic-monoamniotic twin pregnancies, one yolk sac was seen at 9 weeks and a single amnion encircled both embryos. We conclude that the sonographic identification of two yolk scas in monochorionic twins enables us to make the diagnosis of diamniotic twins early in the first trimester, before the amniotic membrane can be imaged. The presence of one yolk sac should prompt a follow-up ultrasonogram to assign amnionicity definitively.     

Suppression of boron penetration in p+ polysilicon gateP-MOSFETs using low-temperature gate-oxide N2O anneal

It has been reported that high-temperature (~1100°C) N₂ O-annealed oxide can block boron penetration from poly-Si gates to the silicon substrate. However, this high-temperature step may be inappropriate for the low thermal budgets required of deep-submicron ULSI MOSFETs. Low-temperature (900~950°C) N₂O-annealed gate oxide is also a good barrier to boron penetration. For the first time, the change in channel doping profile due to compensation of arsenic and boron ionized impurities was resolved using MOS C-V measurement techniques. It was found that the higher the nitrogen concentration incorporated at Si/SiO₂ interface, the more effective is the suppression of boron penetration. The experimental results also suggest that, for 60~110 Å gate oxides, a certain amount of nitrogen (~2.2%) incorporated near the Si/SiO₂ interface is essential to effectively prevent boron diffusing into the underlying silicon substrate     

Short-circuit power driven gate sizing technique for reducing powerdissipation

One major challenge in low-power technology is how to reduce overall power dissipation of a given subsystem without impacting its performance. In this paper we present a technique that can be applied to the nonspeed-critical nets in a circuit in order to reduce overall power dissipation. This technique involves a study of short-circuit power dissipation as a function of input signal slews and output load conditions, to aid in making a judicious choice of drive strengths for various gates in a circuit. The resulting low-power solution does not degrade the original performance and yields a circuit which occupies less silicon area. The technique described here can be incorporated into any power optimization or synthesis tool. Lastly, we present the savings in power and area for a 32-b carry lookahead adder which was designed using the technique described here