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881.
882.
We derived for the first time the relationships among shear stress and normal stress differences for ellipsoidal interfaces
under large step shear strains considering interface velocity term and Laplace pressure term in the expression of the stress
tensor for mixtures of two Newtonian fluids. In the derivation, orientation angle of the interface is assumed to be given
by the affine deformation assumption and is independent of time based on experimental results for blends with 0.048 ≤ K ≤ 0.54 where K is the ratio of droplet viscosity to matrix viscosity. For ellipsoidal droplets, the shear stress is only proportional to
the first normal stress difference. On the other hand, for spheroidal droplets, proportionality among the shear stress, the
first and the second normal stress differences was derived, and the ratio of the second normal stress difference to the first
normal stress difference was given as a function of step strain. The shear stress and the first normal stress difference obtained
experimentally satisfy the derived relationship, indicating applicability of the stress expression for polymer blends. 相似文献
883.
I. Okuda J. Ma E. Takahashi I. Matsushima Y. Matsumoto S. Kato Y. Owadano 《Applied physics. B, Lasers and optics》2001,72(5):623-626
The initial test results of the high-repetition-rate (rep-rate) electron-beam (e-beam) pumped KrF laser amplifier under development
in our laboratory are reported. This amplifier is aimed at producing a laser energy of 20 J per pulse at a rep rate of 1 Hz.
Thus far, 700 consecutive e-beampulses (250 kV, 270 J/pulse) were generated at a rep rate of 1 Hz. The laser gas was repetitively
pumped by the e-beams injected through the water-cooled diaphragm foils.
Received: 5 February 2001 / Published online: 21 March 2001 相似文献
884.
F. Kokai K. Takahashi D. Kasuya M. Yudasaka S. Iijima 《Applied Physics A: Materials Science & Processing》2001,73(4):401-407
Single-wall carbon nanotubes (SWNTs) were synthesized by the irradiation of 20-ms CO2 laser pulses onto a graphite–Co/Ni target at room temperature. We investigated the effect of laser power density (10–150 kW/cm2) and ambient Ar gas pressure (150–760 Torr) on the abundance of SWNTs with lengths of up to about 200 nm in soot-like carbonaceous
deposits. For a constant power density (30 kW/cm2), depending on the Ar gas pressure, SWNTs with diameters of 1.2–1.4 nm were synthesized. Expansion behavior and temperature-fall
rates of clusters and/or particles in laser plumes were also analyzed by high-speed video imaging and temporally and spatially
resolved emission spectroscopy. The temperature-fall rates were estimated to be 171–427 K/ms. The SWNT growth on the time
scale of a few milliseconds appeared to be related to some features of condensing clusters and/or particles, including resident
densities, collision frequencies and temperatures.
Received: 16 July 2001 / Accepted: 23 July 2001 / Published online: 30 August 2001 相似文献
885.
N. Yasuda K. Uchikawa K. Amemiya N. Watanabe H. Takahashi M. Nakazawa M. Yamamoto K. Ogura 《Radiation measurements》2001,34(1-6):45-49
As a frame work of the study for the latent track size measurement using atomic force microscope, we have measured the minute etch pits and the extremely small amount of bulk etch of CR-39 at the beginning of chemical etching, and obtained its growth curves in nanometer dimensions. The pieces of CR-39 were exposed to 6 MeV/nC and Fe ions with normal incidence angle and were etched in 70°C 7 N NaOH solution for 0.5,1,2,3,5 min. The diameters of latent track were estimated to be 17 nm for Fe ions and 8 nm for C ions, respectively. These values are comparable to the experimental data on the average ‘track core diameters’ that have been obtained by various experimental techniques. 相似文献
886.
Shinji Sugihara Shin‐Ichiro Matsuzono Hideki Sakai Masahiko Abe Sadahito Aoshima 《Journal of polymer science. Part A, Polymer chemistry》2001,39(18):3190-3197
Amphiphilic diblock copolymers were prepared by the living cationic polymerization of vinyl ethers in the presence of added bases, and their selective solvent‐induced physical gelation behavior was investigated. The block copolymerization of 2‐phenoxyethyl vinyl ether (PhOVE) and 2‐methoxyethyl vinyl ether (MOVE) was carried out in the presence of ethyl acetate with Et1.5AlCl1.5 in toluene at 0 °C. Despite the rate difference, diblock copolymers with a very narrow molecular weight distribution were obtained, quantitatively. By adding the selective solvent, water, to the acetone solution of the diblock copolymer, PhOVE200‐b‐MOVE400, physical gelation occurred suddenly and the system ceased to flow, maintaining transparency. Viscoelastic measurements and transmission electron microscopic observations were performed to examine the characteristic gelation behavior and structure of the obtained gels. Various gelation conditions and physical gelation by other amphiphilic block copolymers were also designed on the basis of the solubility of each block segment. Further, new forms of physical gelation, accompanied by the solubilization of immiscible organic compounds, were achieved using similar diblock copolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3190–3197, 2001 相似文献
887.
Masae Takahashi Mitsuo Kira Kenkichi Sakamoto Thomas Müller Yitzhak Apeloig 《Journal of computational chemistry》2001,22(13):1536-1541
Vertical electronic transition energies of diaminosilylenes and their dimers (disilenes and nitrogen‐bridged) were investigated by ab initio and density functional calculations. A good linear correlation was found between the observed UV transition energies of various silylenes and disilenes and those of model compounds calculated using the CIS and TD–DFT methods. On the basis of these computations the experimental UV absorption maximum observed for the dimer of (i‐Pr2N)2Si: (λmax 439 nm at 77 K), could be assigned to an Si? Si bonded dimer with an unusually long Si? Si distance of 2.472 Å, and the isomeric amino‐bridged cyclic dimer could be discarded. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1536–1541, 2001 相似文献
888.
Let H be a real Hilbert space and let T: H→2H be a maximal monotone operator. In this paper, we first introduce two algorithms of approximating solutions of maximal monotone operators. One of them is to generate a strongly convergent sequence with limit vT−10. The other is to discuss the weak convergence of the proximal point algorithm. Next, using these results, we consider the problem of finding a minimizer of a convex function. Our methods are motivated by Halpern's iteration and Mann's iteration. 相似文献
889.
Taku Katayama Kiyotaka Onitsuka Shigetoshi Takahashi 《Journal of organometallic chemistry》2000,610(1-2):31-37
Treatment of ruthenium complexes [CpRu(AN)3][PF6] (1a) (AN=acetonitrile) with iron complexes CpFe(CO)2X (2a–2c) (X=Cl, Br, I) and CpFe(CO)L′X (6a–6g) (L′=PMe3, PMe2Ph, PMePh2, PPh3, P(OPh)3; X=Cl, Br, I) in refluxing CH2Cl2 for 3 h results in a triple ligand transfer reaction from iron to ruthenium to give stable ruthenium complexes CpRu(CO)2X (3a–3c) (X=Cl, Br, I) and CpRu(CO)L′X (7a–7g) (L′=PMe3, PMe2Ph, PMePh2, PPh3, P(OPh)3; X=Br, I), respectively. Similar reaction of [CpRu(L)(AN)2][PF6] (1b: L=CO, 1c: P(OMe)3) causes double ligand transfer to yield complexes 3a–3c and 7a–7h. Halide on iron, CO on iron or ruthenium, and two acetonitrile ligands on ruthenium are essential for the present ligand transfer reaction. The dinuclear ruthenium complex 11a [CpRu(CO)(μ-I)]2 was isolated from the reaction of 1a with 6a at 0°C. Complex 11a slowly decomposes in CH2Cl2 at room temperature to give 3a, and transforms into 7a by the reaction with PMe3. 相似文献
890.
On a synchronization queue with two finite buffers 总被引:1,自引:0,他引:1
In this paper, we consider a synchronization queue (or synchronization node) consisting of two buffers with finite capacities.
One stream of tokens arriving at the system forms a Poisson process and the other forms a PH-renewal process. The tokens are
held in the buffers until one is available from each flow, and then a group-token is instantaneously released as a synchronized
departure. We show that the output stream of a synchronization queue is a Markov renewal process, and that the time between
consecutive departures has a phase type distribution. Thus, we obtain the throughput of this synchronization queue and the
loss probabilities of each type of tokens. Moreover, we consider an extended synchronization model with two Poisson streams
where a departing group-token consists of several tokens in each buffer.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献