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排序方式: 共有1186条查询结果,搜索用时 31 毫秒
991.
S Terazawa A Kimura T Inoue T Murai T Kurosawa A Takao 《Canadian Metallurgical Quarterly》1998,40(6):638-640
We investigated the in vivo effects of thalidomide on the production of tumor necrosis factor-alpha (TNF-alpha). An in vivo systemic release of TNF-alpha occurred after the injection of lipopolysaccharide (LPS) in male ddY mice, and the TNF-alpha serum levels reached 652.2 +/- 75.7 pg/ml 90 min after the injection of LPS (0.3 mg/kg, i. p.). When thalidomide (1, 3, or 6 mg/kg) was administered intraperitoneally 3 h before the injection of LPS (0.3 mg/kg, i. p.), thalidomide markedly enhanced LPS-induced TNF-alpha release in a dose-dependent manner. The TNF-alpha serum levels at 90 min were 640 +/- 58.6, 1985 +/- 132.6, and 2795 +/- 203.5 pg/ml, respectively, compared to 628.6 +/- 64.4 pg/ml in mice treated with LPS-alone. Pretreatment with a single injection of thalidomide (1, 3, or 6 mg/kg, i. p.) dose-dependently increased the subsequent mortality caused by a challenge with LPS (15 mg/kg, i. p.), a dose that caused death in 10% of the control mice. We conclude that thalidomide enhances in vivo TNF-alpha secretion and the lethality of LPS in mice. 相似文献
992.
Masayuki Sanada Yoji Takeda Sadao Ishikawa Takao Hirasa 《Electrical Engineering in Japan》1993,113(4):135-144
A linear pulse motor (LPM) has many advantages for a high-accuracy positioning actuator because it has linear motion without any mechanical link. The flat-type LPM generally is used in many industrial applications. However, it has a disadvantage in that the mover support mechanism becomes complex and heavy because the attraction force between the stator and the mover is very large. As the attraction force is balanced in the cylindrical structure, the cylindrical LPM is allowed to have a simple and lightweight support mechanism. The inset magnet-type cylindrical LPM, which has a permanent magnet between the A-phase and B-phase stator, has such merits as a magnet of simple shape and a reduction of the motor diameter. Its weak point is that thrust unbalance occurs because the magnetic flux pass of the outer poles is longer than that of the inner poles. The thrust unbalance decreases the pull-in thrust force and increases the positioning error. This paper proposes two practical methods to improve the thrust unbalance: 1) the exciting current adjustment; and 2) the method with compensation permanent magnet. These effects are examined with theoretical and experimental results. 相似文献
993.
A new multiscale modeling approach for the prediction of mechanical properties of polymer-based nanomaterials 总被引:1,自引:0,他引:1
A detailed knowledge about the physics and chemistry of multiphase materials on different length and time scales is essential to tailor their macroscopic physical and mechanical properties. A better understanding of these issues is also highly relevant to optimize their processing and, thus, their elucidation can be decisive for their final industrial application. In this paper, we develop a new multiscale modeling method, which combines the self-consistent field theory approach with the kinetic Monte Carlo method, to simulate the structural–dynamical evolution taking place in thermoplastic elastomers, where hard glassy and soft rubbery phases alternate. Since the early seventies, it is well established that the properties of the core nanophases in these multiphase materials considerably affect their overall mechanical properties. However, recent experimental studies have clearly demonstrated that, besides the efficient handling of the core nanophases, the appropriate treatment of their interfacial region is another major challenge one has to face on the way of target-oriented development of these materials. In this work, we set a particular focus on the complex structural–dynamical processes occurring at the interphases, and study their influence on the local structural and mechanical properties. To reach our objectives, we apply the new methodology on a thermoplastic elastomer composed of ABA triblock copolymers, subjected to a sizeable external perturbation, and determine its time-averaged internal stress and composition profile. We deduce from this investigation that, to obtain the correct local mechanical properties of these multiphase materials, their structure and dynamics need to be taken into account on an equal footing. Finally, our investigation also provides an explanation and confirms the importance of the chain-pullout mechanism in the viscoelastic and stress relaxation behavior of these materials. 相似文献
994.
Hydrogen production by the partial oxidation and steam reforming of tar from hot coke oven gas 总被引:1,自引:0,他引:1
Masaki Onozaki Koji Watanabe Takao Hashimoto Hitoshi Saegusa Yukuo Katayama 《Fuel》2006,85(2):143-149
Hot coke oven gas (COG) with a temperature of about 1050 K was produced from a test unit for coke production, the capacity of which was 80 kg of coal. The COG was introduced into an experimental unit with a tar converter where oxygen and steam were injected. Over 98% of the total carbon in the hot COG was partially oxidized, reformed with steam and converted to hydrogen and CO. About 1 Nm3/h of hydrogen was continuously produced for 5 h in this experiment. The experimental results suggest that three to five times the amount of hydrogen and CO that were present in the original COG could be recovered by this technology, utilizing the heat of the hot COG for the reaction. The feasibility study showed that hydrogen can be produced by this technology at a lower cost and higher efficiency than by the separation of cold COG. 相似文献
995.
Takaaki Mizuki Hiroki Shizuya Takao Nishizeki 《International Journal of Information Security》2002,1(2):131-142
Using a random deal of cards to players and a computationally unlimited eavesdropper, all players wish to share a one-bit
secret key which is information-theoretically secure from the eavesdropper. This can be done by a protocol to make several
pairs of players share one-bit secret keys so that all these pairs form a tree over players. In this paper we obtain a necessary
and sufficient condition on the number of cards for the existence of such a protocol.
Published online: 29 January 2002 相似文献
996.
Makoto Saito Makoto Sakamoto Youichirou Nakama Takao Ito Katsushi Inoue Hiroshi Furutani Susumu Katayama 《Artificial Life and Robotics》2006,10(2):166-170
Recently, due to the advances in many application areas such as computer animation, motion image processing, and so forth,
it has become increasingly apparent that the study of four-dimensional pattern processing is of crucial importance. Thus,
we think that research into four-dimensional automata as a computational model of four-dimensional pattern processing is also
meaningful. This article introduces four-dimensional multicounter automata, and investigates some of their properties. We
show the differences between the accepting powers of seven-way and eight-way four-dimensional multicounter automata, and between
the accepting powers of deterministic and nondeterministic seven-way four-dimensional multicounter automata.
This work was presented in part at the 10th International Symposium on Artificial Life and Robotics, Oita, Japan, February
4–6, 2005 相似文献
997.
In Asian and Pacific regions, economic growth in the last decade has propelled the use of air-conditioners for space cooling along with the use of reversible heat pumps for year round space conditioning. This has led to the rapid increase of electricity demand for air conditioning in summer. To cope with the increasing power demand and the requirement for efficient energy use for space conditioning, governments and energy supply utilities have encouraged effective use and leveling of power load using a heat pump with thermal storage systems and gas cooling systems, by enacting financial and promotional supports. Status and trends of heat pumps in Asian and Pacific regions, related to the use of heat pumps for space heating and cooling were surveyed from the view points of climate, energy consumption, technologies, markets and promotion measures. 相似文献
998.
V. Jayashankar S. Anand T. Geetha S. Santhakumar V. Jagadeesh Kumar M. Ravindran T. Setoguchi M. Takao K. Toyota S. Nagata 《Renewable Energy》2009,34(3):692-698
Experimental results from near shore bottom standing OWC based wave energy plants in Japan and India have now been available for about a decade. Historically the weakest link in the conversion efficiency of OWC based wave energy plants built so far has been the bidirectional turbine. This is possibly because a single turbine has been required to deliver power when the plant is exposed to random incident wave excitation varying by a factor of 10. A new topology that uses twin unidirectional turbines (which features a high efficiency spanning a broad range) is proposed. Using the Indian Wave Energy plant as a case study, it is shown that the power output from such a module considerably exceeds existing optimal configurations including those based on a fixed guide vane impulse turbine, linked guide vane impulse turbine or a Well's turbine. A wave to wire efficiency of the order of 50% over the incident range is shown to be feasible in a credible manner by showing the output at all stages of the conversion process. A frequency domain technique is used to compute the OWC efficiency and a time domain approach used for the power module with the turbine pressure being the pivotal variable. 相似文献
999.
Yoshihiro Takao Hiroshi KudoJunichi Mitani Yoshiyuki KotaniSatoshi Yamaguchi Keizaburo YoshieKazuo Sukegawa Nobuhisa NaoriSatoru Asai Michiari KawanoTakashi Nagano Ikuhiro YamamuraMasaya Uematsu Naoki NagashimaShingo Kadomura 《Microelectronics Reliability》2002,42(1):15-25
This paper describes a 0.11 μm CMOS technology with high-reliable copper (Cu) and very low k (VLK) (k<2.7) interconnects for high-performance and low-power applications of a 0.13 μm generation. Aggressive design rules, 0.11 μm gate transistor and 2.2 μm2 six-transistor SRAM cell are realized by using KrF 248 nm lithography, optical proximity effect correction, and gate-shrink techniques. Eight-level interconnects are fabricated with seven level of Cu/VLK interconnect and one level of Al/SiO2 interconnect. Drain current of 0.67 and 0.28 mA/μm are realized for nMOSFET and pMOSFET with 0.11 μm gate, respectively. Propagation delay of two input NAND with the Cu/VLK interconnect is estimated. The delay is improved by more than 70%, compared to 0.18 μm CMOS technology with Cu/FSG interconnects. Functional 288 kbit SRAM circuit is demonstrated with 2.2 μm2 cell and Cu/VLK interconnect. 相似文献
1000.
Yusaku Kato Tsuyoshi Sekitani Makoto Takamiya Masao Doi Kinji Asaka Takayasu Sakurai Takao Someya 《Electron Devices, IEEE Transactions on》2007,54(2):202-209
A large-area, flexible, and lightweight sheet-type Braille display has been successfully fabricated on a plastic film by integrating high-quality organic transistors and soft actuators. An array of rectangular plastic actuators is mechanically processed from a perfluorinated polymer electrolyte membrane. A small semisphere, which projects upward from the rubberlike surface of the display, is attached to the tip of each rectangular actuator. The effective display size is 4times4 cm2. Each Braille letter consists of 3times2 dots and 24 letters; in other words, 6 letters times 4 lines can be displayed. Pentacene field-effect transistors with top-contact geometry have a channel length of 20 mum and a mobility of 1 cm2/Vmiddots. The Braille dots on one line are driven for 0.9 s. The total thickness and weight of the entire device are 1 mm and 5.3 g, respectively. The present scheme will enable people with visual impairments to carry the Braille sheet display in their pockets and read Braille e-books at any time. Since all the device components are manufactured on plastic films, these sheet-type Braille displays are mechanically flexible, lightweight, shock resistant, and potentially inexpensive to manufacture; therefore, they are suitable for mobile electronics 相似文献