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排序方式: 共有1676条查询结果,搜索用时 15 毫秒
141.
Tsuyoshi Nishiwaki Atsushi Yokoyama Zen-ichiro Maekawa Hiroyuki Hamada 《Composite Structures》1995,32(1-4):635-640
Localized impact problems for composite structures have recently become important. In this study, some elastic wave velocities in 7-ply GFRP laminate with [02/903/02] ply orientation after low speed impact was investigated by using both experimental methods and finite element methods. For the finite element simulation, the quasi-three-dimensional model was used. Comparing the results, the validity for the application of this model to the dynamic problem was estimated. Moreover the quasi-three-dimensional model is applied to the GFRP plates with interlaminar delamination. The relationship between the elastic wave velocities and delaminated states is discussed. 相似文献
142.
H Tsukamoto Y Hamada D Wu RJ Boado WM Pardridge 《Canadian Metallurgical Quarterly》1998,58(1-2):170-177
Visually identified and electrophysiologically characterized sympathetic preganglionic neurons (SPNs) were recorded using the whole-cell voltage clamp technique in slices of neonatal rat spinal cord. Monosynaptic excitatory postsynaptic currents (EPSCs) were evoked by electrical stimulation of the nucleus intercalatus in the presence of strychnine (5 microM) and bicuculline (10 microM). These EPSCs were abolished by the antagonist of AMPA-type glutamate receptors, 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX; 10 microM). Bath applied noradrenaline (NA; 0.5-50 microM) dose-dependently and reversibly decreased by up to around 60% the amplitude of the EPSC, without affecting the holding current. The EPSC depression by NA was not accompanied by a change in EPSC reversal potential (around +5 mV), nor were inward currents generated by pressure application of glutamate affected by NA application. A comparable degree of EPSC depression was also seen with the alpha2-adrenoceptor agonist clonidine (5 microM), and the alpha2A-agonist oxymetazoline (5 microM), while the alpha1-agonist phenylephrine (100 microM) caused only a 22% depression. The EPSC depression caused by NA (10 microM) was completely antagonized by either the alpha-antagonist phentolamine (10 microM) or the alpha2-antagonist idazoxan (2 microM). Conversely, the beta-adrenoceptor antagonist popranolol (5 microM), and the alpha1-, alpha2B- and alpha2C-antagonist prazosin (2 microM) were without effect. These results indicate that activation of presynaptic alpha2A-adrenoceptors on inputs to SPNs decreases glutamate release. 相似文献
143.
Tetsukuni Oikawa Masaaki Kondo Yoshinobu Mizuno Yuichi Watanabe Hiroshi Fukuoka Ken Muramatsu 《Reliability Engineering & System Safety》1998,62(3):251-271
An integrated code system SECOM-2, developed at the Japan Atomic Energy Research Institute (JAERI), has the following functions for systems reliability analysis in seismic probabilistic safety assessments (PSAs): (1) calculation of component failure probability, (2) extraction of minimal cut sets (MCSs) from a given fault tree (FT), (3) calculation of frequencies of accident sequences and core damage, (4) importance analysis with several measures with consideration of unique parameters of seismic PSAs, (5) sensitivity analysis, and (6) uncertainty analysis. This paper summarizes the special features of SECOM-2 to perform the analyses mentioned above. At JAERI, using an integrated FT which represents seismically induced core damage due to all initiating events as a system model to calculate core damage frequency of a nuclear power plant, SECOM-2 can calculate conditional point estimate probabilities of system failures, losses of safety functions, and core damage as a function of earthquake motions. The point estimate is computed by a method which gives an exact numerical solution using the Boolean arithmetic model method. As for consideration of correlation of component failure, which has been an important issue in seismic PSAs, a new technique based on direct FT quantification by a Monte Carlo simulation is being added to SECOM-2. Adding this technique, the core damage frequency can be calculated not only with the upper bound approximation based on MCSs but also with a near exact solution taking into account the correlation among all components. This paper also presents the preliminary results of a seismic PSA of a generic BWR plant in Japan performed at JAERI to demonstrate the functions of the SECOM-2 code. 相似文献
144.
Hydrothermal flames in supercritical water oxidation: investigation in a pilot scale continuous reactor 总被引:1,自引:0,他引:1
Roberto M. Serikawa Takashi UsuiTatuya Nishimura Hirokazu SatoShusaku Hamada Hideo Sekino 《Fuel》2002,81(9):1147-1159
Hydrothermal flames at 25 MPa supercritical water environment were investigated using a 4800 ml reaction tower, in which the sapphire windows were fitted for optical access. Down flowing hydrothermal flames were observed for oxidation of 2-propanol when the reactor was fed with inlet organic concentration higher than 2 vol% and air ratio higher than 1.8. Flame temperature, as high as 1100 °C, was measured by means of a thermocouple and the temperature was found to be strongly influenced by air ratio. Effective and stable oxidation of organics with TOC removal rate of 99.9% was achieved. Dioxins were also decomposed with a ratio higher than 99.9%, within 1 min reaction time in this reactor configuration. 相似文献
145.
A Huwiler el-S Akool A Aschrafi FM Hamada J Pfeilschifter W Eberhardt 《Canadian Metallurgical Quarterly》2003,278(51):51758-51769
Renal mesangial cells express high levels of matrix metalloproteinase 9 (MMP-9) in response to inflammatory cytokines such as interleukin (IL)-1 beta. We demonstrate here that the stable ATP analog adenosine 5'-O-(thiotriphosphate) (ATP gamma S) potently amplifies the cytokine-induced gelatinolytic content of mesangial cells mainly by an increase in the MMP-9 steady-state mRNA level. A Luciferase reporter gene containing 1.3 kb of the MMP-9 5'-promoter region showed weak responses to ATP gamma S but conferred a strong ATP-dependent increase in Luciferase activity when under the additional control of the 3'-untranslated region of MMP-9. By in vitro degradation assay and actinomycin D experiments we found that ATP gamma S potently delayed the decay of MMP-9 mRNA. Gel-shift and supershift assays demonstrated that three AU-rich elements (AREs) present in the 3'-untranslated region of MMP-9 are constitutively bound by complexes containing the mRNA stabilizing factor HuR. The RNA binding of these complexes was markedly increased by ATP gamma S. Mutation of each ARE element strongly impaired the RNA binding of the HuR containing complexes. Reporter gene assays revealed that mutation of one ARE did not affect the stimulatory effects by ATP gamma S, but mutation of all three ARE motifs caused a loss of ATP-dependent increase in luciferase activity without affecting IL-1 beta-inducibility. By confocal microscopy we demonstrate that ATP gamma S increased the nucleo cytoplasmic shuttling of HuR and caused an increase in the cytosolic HuR level as shown by cell fractionation experiments. Together, our results indicate that the amplification of MMP-9 expression by extracellular ATP is triggered through mechanisms that likely involve a HuR-dependent rise in MMP-9 mRNA stability. 相似文献
146.
Based on the present state of the art of the separation technology, recycling of fission-product rare elements (FRE) in the FBR spent fuel is discussed. The rad.-waste fractionation is in accordance with the present society's trend toward zero-emission, and the mean of salt-free method utilizing electrochemistry agrees with the principles of the newly established green chemistry. A catalytic electrolytic extraction method is proposed to separate the target, radioactive but potentially strategic elements, Pd, Ru, Rh, Re (Tc), Te and Se dissolved in the HLLW. It avoids secondary waste arising. This method is particularly feasible for the separation of Pd where cyclic reaction of metal cations such as Pd(II) or Fe(II), acting as promoters or mediators and already contained in HLLW, accelerates the electrochemical deposition of Ru, Rh and Re. Elemental separation not only offers alternative material resources to meet expanding demands for catalysts in Fuel Cell/Soft Energy system but is also the first step for transmutation or other selective strategies for waste management of long-lived fission products (LLFP). 相似文献
147.
148.
Chemtob Claude M.; Novaco Raymond W.; Hamada Roger S.; Gross Douglas M. 《Canadian Metallurgical Quarterly》1997,65(1):184
With a randomized group design, a 12-session anger treatment was evaluated with severely angry Vietnam War veterans suffering combat-related posttraumatic stress disorder (PTSD). Eight participants in anger treatment and 7 in a routine clinical care control condition completed multiple measures of anger control, anger reaction, and anger disposition, as well as measures of anxiety, depression, and PTSD at pre- and posttreatment. Controlling for pretreatment scores, significant effects were found on anger reaction and anger control measures but not on anger disposition or physiological measures. Eighteen-month follow-up (for both completers and dropouts) supported the posttreatment anger control findings. The challenges of treatment research with this refractory population are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
149.
Design methodology for a braided cylinder 总被引:1,自引:0,他引:1
Asami Nakai Akihiro Fujita Atsushi Yokoyama Hiroyuki Hamada 《Composite Structures》1995,32(1-4):501-509
In this study, the design methodology for a braided cylinder was presented. The concept of an analytical model which involved both micro model and macro model was proposed. The analytical method was applied to estimate the rigidity and elastic limit of a braided cylinder subjected to bending and torsional load independently and as combined load. Using the analysis method, the design of a braided cylinder would be carried out in consideration of the factors that decide the mechanical properties of braided cylinder. This method has the possibility to be useful for structural design of braided composites and can be included as a unit in CAE systems for braided composites. 相似文献
150.
Tadao Tanabe Yuichi Kozawa Ken Suto Jun-ichi Nishizawa Ytaka Oyama 《Journal of Infrared, Millimeter and Terahertz Waves》2005,26(6):881-892
Stimulated Raman gain (SRG) spectroscopy using infrared pump pulses with narrow linewidth and a low-noise cw probe infrared laser was proposed. High-resolution Raman spectra of solutions were obtained. The SRG spectra of crystal GaP, benzene, and toluene were measured to confirm the spectral resolution and sensitivity over the terahertz (THz) region. We discuss the polarization dependence of the spectral measurement of carbon tetrachloride. Our system can detect organic molecules in aqueous solutions. 相似文献