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21.
Hamasaki T. Shinohara Y. Terasawa H. Ochiai K. Hiraoka M. Kanayama H. 《Solid-State Circuits, IEEE Journal of》1996,31(12):1888-1894
The area ratio of analog to digital for mixed-mode chip has been inversely proportional to the process design rule for a given dynamic range objective, in contradiction to the LSI trend. This paper presents a design approach to realize a high degree of size reduction with process design rules for analog circuitry and a signal processing architecture for digital circuitry. A five-level current-mode ΣΔ digital-to-analog converter (DAC) system reveals full scale total harmonic: distortion plus noise (THD+N) of -90 dB and dynamic-range of 100 dB at 3 V (low power of 22 mW). Analog-area down-scaling can be accomplished by this architecture to be 1.09 mm2, using 0.6-μm double-poly double-metal (DPDM) CMOS. For the digital filter, a pipeline instruction sequence with multiplierless architecture also gives small area of 1.98 mm2 相似文献
22.
Satoshi Nishimura Zhi-Gang Zhang Ken-Ichiro Sugiyama Izumi Kinoshita 《Nuclear Engineering and Design》2007,237(23):2201-2209
In order to clarify the fragmentation mechanism of a metallic alloy (U–Pu–Zr) fuel on liquid phase formed by metallurgical reactions (liquefaction temperature = 650 °C), which is important in evaluating the sequence of core disruptive accidents for metallic fuel fast reactors, a series of experiments was carried out using molten aluminum (melting point = 660 °C) and sodium mainly under the condition that the boiling of sodium does not occur. When the instantaneous contact interface temperature (Ti) between molten aluminum drop and sodium is lower than the boiling point of sodium (Tc,bp), the molten aluminum drop can be fragmented and the mass median diameter (Dm) of aluminum fragments becomes small with increasing Ti. When Ti is roughly equivalent to or higher than Tc,bp, the fragmentation of aluminum drop is promoted by thermal interaction caused by the boiling of sodium on the surface of the drop. Furthermore, even under the condition that the boiling of sodium does not occur and the solid crust is formed on the surface of the drop, it is confirmed from an analytical evaluation that the thermal fragmentation of molten aluminum drop with solid crust has a potential to be caused by the transient pressurization within the melt confined by the crust. These results indicate the possibility that the metallic alloy fuel on liquid phase formed by the metallurgical reactions can be fragmented without occurring the boiling of sodium on the surface of the melt. 相似文献
23.
The integral experiment on beryllium with D-T neutrons for verification of tritium breeding 总被引:1,自引:0,他引:1
Yury Verzilov Satoshi Sato Kentaro Ochiai Masayuki Wada Axel Klix Takeo Nishitani 《Fusion Engineering and Design》2007,82(1):1-9
A clean benchmark experiment on beryllium was performed with D-T neutrons at the FNS facility of the Japan Atomic Energy Agency. The main objective was to verify the integral data related to the tritium production on lithium isotopes. Tritium production rates, as well as activation reaction rates were measured inside the beryllium assembly that was shaped as a pseudo-cylindrical slab with an area-equivalent diameter of 628 mm and a thickness of 355 mm. Experimental results were analyzed with a three-dimensional Monte Carlo transport code MCNP-4C and FENDL/MC-2.0, JENDL-3.2/3.3 neutron transport libraries. Evaluation of reaction rates was based on the cross section data taken from the JENDL Dosimetry File and ENDF B-VI data libraries. Analysis shows that all calculation combinations (transport and activation cross section libraries) used for evaluation of reaction rates give data that is agreeable with measured values within 10%. 相似文献
24.
Linear stress analysis without body force can be easily carried out by means of the boundary element method. Some cases of linear stress analysis with body force can also be solved without the domain integral. However domain integrals are generally necessary to solve the linear stress problems with complicated body forces. This paper shows that the linear stress problems with complicated body forces can be solved approximately without the domain integral. In order to solve these problems, the domain is divided into small areas using contour lines of body force. In these areas, the distributions of body force are assumed approximately to satisfy the Laplace equation. 相似文献
25.
Yuji Fukaishi Yoshihiro Ohta Kohji Higuchi Eiji Takegami Satoshi Tomioka Kosin Chamnongthai 《Artificial Life and Robotics》2012,17(1):1-6
A robust DC?CDC converter which can covers extensive load change and also input voltage changes with one controller is needed. Then the demand to suppress output voltage change becomes still severer. We propose an approximate 2-degree-of-freedom (2DOF) digital controller which realized start-up response and dynamic load response independently. The controller makes a control bandwidth wider, and at the same time makes variations of the output voltage small at sudden changes of a load and an input voltage. In this paper, a new approximate 2DOF digital control system with additional zeros is proposed. Using the additional zeros, the second-order differential transfer characteristics between equivalent disturbances and a output voltage are realized. Therefore, the new controller makes variations of the output voltage smaller and the sudden changes of the load and the input voltage. This controller is actually implement on a DSP and is connected to the DC?CDC converter. Experimental results demonstrate that this type of digital controller can satisfy given severe specifications with low frequency sampling. 相似文献
26.
Natsuhiko Kuratomi Shinichi Takano Mitsuharu Fukasawa Shinya Maekawa Makoto Kadokura Hiroko Shindo Ei Takahashi Sumio Hirose Yoshimitsu Fukasawa Satoshi Kawakami Hiroshi Hayakawa Hitomi Takada Natsuko Nakakuki Ryoh Kato Tatsuya Yamaguchi Yasuhiro Nakayama Hiromichi Kawaida Hiroshi Kono Taisuke Inoue Tetsuo Kondo Daisuke Ichikawa Nobuyuki Enomoto 《International journal of molecular sciences》2021,22(6)
New biomarkers are needed to further stratify the risk of malignancy in intraductal papillary mucinous neoplasm (IPMN). Although microRNAs (miRNAs) are expected to be stable biomarkers, they can vary owing to a lack of definite internal controls. To identify universal biomarkers for invasive IPMN, we performed miRNA sequencing using tumor-normal paired samples. A total of 19 resected tissues and 13 pancreatic juice samples from 32 IPMN patients were analyzed for miRNA expression by next-generation sequencing with a two-step normalization of miRNA sequence data. The miRNAs involved in IPMN associated with invasive carcinoma were identified from this tissue analysis and further verified with the pancreatic juice samples. From the tumor-normal paired tissue analysis of the expression levels of 2792 miRNAs, 20 upregulated and 17 downregulated miRNAs were identified. In IPMN associated with invasive carcinoma (INV), miR-10a-5p and miR-221-3p were upregulated and miR-148a-3p was downregulated when compared with noninvasive IPMN. When these findings were further validated with pancreatic juice samples, miR-10a-5p was found to be elevated in INV (p = 0.002). Therefore, three differentially expressed miRNAs were identified in tissues with INV, and the expression of miR-10a-5p was also elevated in pancreatic juice samples with INV. MiR-10a-5p is a promising additional biomarker for invasive IPMN. 相似文献
27.
The feeding and gustatory responses to ecdysone and 20-hydroxyecdysone were investigated in the silkworm,Bombyx mori. 20-Hydroxyecdysone reduced feeding response strongly in fourth- and fifth-instar larvae, whereas ecdysone had no effect on feeding response. 20-Hydroxyecdysone stimulated the R receptor, the receptor to feeding deterrents, to a great degree. By contrast, ecdysone was much less effective for stimulating the R receptor. These results indicate that ecdysone and 20-hydroxyecdysone have different effects on feeding response due to different interactions with mouthpart chemoreceptors. 相似文献
28.
Minoru Ueno Satoshi Yamamoto Kenjiro Meguro 《Journal of the American Oil Chemists' Society》1974,51(8):373-376
Several salts of α,ω-sulfates, MO3SO(CH2)n OSO3M(n=12, 14, 16, 18, and M=Li, Na, and K) were prepared from the corresponding α,ω-alkane diols. The Krafft points of these
α,ω-sulfates with common counterion as estimated by electroconductivity measurements increased with the increase of the hydrocarbon
chain length, and the effect of the counterions on the Krafft points of the α,ω-sulfates with the same hydrocarbon chain length
was in the order : Li<Na<K. Solutions of the α,ω-sulfates, except disodium dodecanediol disulfate, showed two break points
corresponding to the first and second critical micelle concentration in each plot of the electroconductivity as a function
of the concentration. The existence of the second break point suggested that another aggregation of rearrangement of the existing
aggregates occurs in α,ω-sulfate solutions in addition to the usual micelle formation. The first and second break points of
α,ω-sulfates with sodium counterion decreased logarithmically with increasing total number of methylene groups. The relationships
were given as follows: log(first break point)=−0.138Nc−0.095; log(second break point)=−0.104Nc−0.251. The effect of the counterions
upon the break points of α,ω-sulfates with the same hydrocarbon chain length was in accordance with their positions in the
lyotropic series. 相似文献
29.
The dynamic moduli, E′ and E″, and tan δ for nylon–CR and PET–CR composites with unidirectional short fibers were studied as a function of temperature by using a Rheovibron. The temperature dependence of tan δ showed two dispersion peaks for nylon–CR composite. The peak at ?28°C corresponded to the main dispersion of CR and the peak at 100°C to the α-dispersion of nylon 6. For a PET-CR composite, in addition to the individual dispersion of CR and PET, a small and broad peak was observed at about 90°C. The angular dependence of E′ indicated that the short fibers assumed good orientation. The storage modulus for the composites was given by the parallel model as E′ = Vf′Ef + VmE′m., where E′c, E′f and E′m were the storage modulus for the composite, fiber, and matrix and Vf and Vm were the volume fraction of fiber and matrix, respectively. In the transverse direction of fiber, the peak values of tan δ at ?28°C were given by the following equation; tan δc = tan δm ? δVf, where tan δc and tan δm are the loss tangent for the composite and matrix, respectively, and α is coefficient depending on fiber type. The results indicated that a region with strong interaction was formed between fibers and CR matrix. 相似文献
30.
This study investigated the relationships between thumb muscle activity and thumb operating tasks on a smartphone touch screen with one-hand posture. Six muscles in the right thumb and forearm were targeted in this study, namely adductor pollicis, flexor pollicis brevis, abductor pollicis brevis (APB), abductor pollicis longus, first dorsal interosseous (FDI) and extensor digitorum. The performance measures showed that the thumb developed fatigue rapidly when tapping on smaller buttons (diameter: 9 mm compared with 3 mm), and moved more slowly in flexion–extension than in adduction–abduction orientation. Meanwhile, the electromyography and perceived exertion values of FDI significantly increased in small button and flexion–extension tasks, while those of APB were greater in the adduction–abduction task. This study reveals that muscle effort among thumb muscles on a touch screen smartphone varies according to the task, and suggests that the use of small touch buttons should be minimised for better thumb performance. 相似文献