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181.
Tomohiro Yamaguchi Teruyoshi Yoshimura Tomohiko Yamakami Seiichi Taruta Kunio Kitajima 《Microporous and mesoporous materials》2008,111(1-3):285-291
New porous solids from alumina-pillared fluorine micas (APMs), which were obtained from synthetic Na-tetrasilicic fluorine mica [NaMg2.5Si4O10F2], were prepared by sulfuric acid-treatment under mild conditions at 25 °C. The products were investigated by XRD, ICP, SEM, TEM and N2 adsorption–desorption isotherm at 77 K. XRD measurements indicated that the interlayer pillared structure having a large basal spacing collapsed during the early stages of the acid-treatment. ICP analyses indicated that Al3+ and Mg2+ ions were leached out from the pillared micas during the acid-treatment. The pore properties of the leached products were found to differ from those of the mother pillared micas: the acid leaching of the pillared micas leads to the formation of mesopores around 3.2 nm in diameter. The correlation between the change in pore properties and cation elution behavior suggests that the mesopore formation results from the leaching of Mg2+ ions from the octahedral sheet of the pillared micas. The leached products thus obtained retained the flaky morphology of the mother pillared micas. These results show that the mild acid-treatment using APMs provides a novel route for obtaining unique mesopore solids having the large particle sizes of the mother micas. 相似文献
182.
An optical polarisation control scheme utilising optical heterodyne detection for coherent transmission is proposed and demonstrated at a wavelength of 1.5 ?m. It converts an arbitrary polarisation state to a linear state at a received optical power level of less than ?70 dBm. 相似文献
183.
Yamaguchi H. Wada M. Yamamoto H. 《Selected Areas in Communications, IEEE Journal on》1986,4(8):1202-1209
Seeing-while-talking has been a dream of mankind for over a 100 years since the invention of telephone. In the past, various trials were performed in spite of the difficulty in installing the network for the actual service. However, with the progress of ISDN and the advancement of digital signal processing technology, the environment has been changing rapidly. In this paper, an integrated visual communication system is described for the enhanced communication service at 64 kbits/s, the fundamental bit rate of ISDN. The roles of state-of-theart compression of the audio and video signals are discussed and an integrated transmission method based on the priority of the information content is proposed. 相似文献
184.
185.
Effects of indeloxazine hydrochloride, an inhibitor of serotonin (5-HT) and norepinephrine (NE) reuptake with a facilitatory effect on 5-HT release, on acetylcholine (ACh) output in frontal cortex of conscious rats were characterized using an in vivo microdialysis technique. Systemic administration of indeloxazine (3 and 10 mg/kg, i.p.) increased ACh and 5-HT output in a dose-dependent manner. Depletion of endogenous monoamines by reserpine and of 5-HT by p-chlorophenylalanine, but not that of catecholamines by alpha-methyl-p-tyrosine, significantly attenuated the facilitatory effect of indeloxazine on ACh release. When applied locally by reverse dialysis, indeloxazine (10 and 30 microM) and the selective 5-HT reuptake inhibitor citalopram (10 microM), but not the NE reuptake inhibitor maprotiline (30 microM), increased cortical ACh output. Indeloxazine (10 mg/kg)-induced increase in ACh release was significantly inhibited by local application of the 5-HT4 receptor antagonists RS23597 (50 microM) and GR113803 (1 microM), while the 5-HT1A antagonist WAY-100135 (100 microM), 5-HT1A/1B/beta-adrenoceptor antagonist (-)propranolol (150 microM), 5-HT2A/2C antagonist ritanserin (10 microM) and 5-HT3 antagonist ondansetron (10 microM) failed to significantly modify this effect. Neither depletion of monoamines nor treatment with serotonergic antagonists significantly changed the basal ACh level, indicating that endogenous monoamines do not tonically activate ACh release. These results suggest that indeloxazine-induced facilitation of ACh release in rat frontal cortex is mediated by endogenous 5-HT and involves at least in part cortical 5-HT4 receptors. 相似文献
186.
Miyake J. Maeda T. Nishimichi Y. Katsura J. Taniguchi T. Yamaguchi S. Edamatsu H. Watari S. Takagi Y. Tsuji K. Kuninobu S. Cox S. Duschatko D. MacGregor D. 《Solid-State Circuits, IEEE Journal of》1990,25(5):1199-1206
A 1-million transistor 64-b microprocessor has been fabricated using 0.8-μm double-metal CMOS technology. A 40-MIPS (million instructions per second) and 20-MFLOPS (million floating-point operations per second) peak performance at 40 MHz is realized by a self-clocked register file and two translation lookaside buffers (TLBs) with word-line transition detection circuits. The processor contains an integer unit based on the SPARC (scalable processor architecture) RISC (reduced instruction set computer) architecture, a floating-point unit (FPU) which executes IEEE-754 single- and double-precision floating-point operations a 6-KB three-way set-associative physical instruction cache, a 2-KB two-way set-associative physical data cache, a memory management unit that has two TLBs, and a bus control unit with an ECC (error-correcting code) circuit 相似文献
187.
Takai Y. Fujita M. Nagata K. Isa S. Nakazawa S. Hirobe A. Ohkubo H. Sakao M. Horiba S. Fukase T. Takaishi Y. Matsuo M. Komuro M. Uchida T. Sakoh T. Saino K. Uchiyama S. Takada Y. Sekine J. Nakanishi N. Oikawa T. Igeta M. Tanabe H. Miyamoto H. Hashimoto T. Yamaguchi H. Koyama K. Kobayashi Y. Okuda T. 《Solid-State Circuits, IEEE Journal of》2000,35(2):149-162
This paper describes three circuit technologies indispensable for high-bandwidth multibank DRAM's. (1) A clock generator based on a bidirectional delay (BDD) eliminates the output skew. The BDD measures the cycle time as the quantity charged or discharged of an analog quantity, and replicates it in the next cycle. This achieves a 0.18-mm 2, two-cycle-lock clock generator operating from 25 to 167 MHz with a 30-ps resolution. (2) A quad-coupled receiver eliminates the internal skew caused by the difference between a rise input and a fall input by 40%. (3) An interbank shared redundancy scheme (ISR) with a variable unit redundancy (VUR) efficiently increases yield in multibank DRAM's. The ISR allows redundancy match circuits to be shared with two or more banks. The VUR allows the number of units replaced to be variable. These circuit technologies achieved a 250-Mb/s/pin, 8-bank, 1-Gb double-data-rate synchronous DRAM 相似文献
188.
The formation of lead niobates in the PbO-rich region is studied using powders prepared by the simultaneous hydrolysis of lead and niobium alkoxides. Cubic 3PbO·2Nb2P O5 solid solutions crystallize at low temperatures from amorphous materials having concentrations of 58 to 75 mol% PbO. The lattice parameter a increases linearly from 1.0544 to 1.0708 nm with increasing PbO. At higher temperatures the solid solutions made with 66.67 and 71.43 mol% PbO transform into 2PbO·Nb2 O5 (monoclinic) and 5PbO·2Nb2 Os (monoclinic), respectively. Monoclinic 5PbO·2Nb2 O5 transforms into a new modification at = 3850° to = 3900°C. It has a rhombohedral unit cell with a = 0.7461 nm and c = 4.8092 nm ( a = 1.6599 nm, a = 25.97°). In the presence of excess lead, monoclinic 5PbO·2Nb2 O5 transforms into tetragonal 3PbO·Nb2 O5 . 相似文献
189.
190.
Saitoh Y. Yamaguchi K. Imai H. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1990,36(3):645-647
The authors give a tabulation of the numbers of codewords in new binary codes with the asymmetric/unidirectional error-correcting capabilities of 3, 4, 5, 6 for lengths 14, 15, . . . , 23. The new codes have greater sizes than the known codes for 14⩽n ⩽23 and 3⩽t ⩽6 相似文献