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21.
Robert G.?PaytonEmail author Kazumi?Watanabe 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,55(4):658-677
The two-dimensional wave front shape caused by a point impulse excitation in a
cylindrically anisotropic elastic solid is considered. The elastic parameters of the solid are
constrained such that
E
=
G
This constraint allows the parametric equations of
the wave front to be expressed exactly in terms of elementary transcendental functions. The precise
location of double and cusp points on the front is treated in detail. Time histories of several
wave front patterns are presented and an interesting feature of the front is generalized to the
unconstrained solid. 相似文献
22.
Nilvadipine (NIL) solid dispersion using crospovidone (Cross-linked-N-vinyl-2-pyrolidone, cl-PVP) and methylcellulose (MC) as carriers was applied to tablet formulation. Several grades of cl-PVP and MC were used, and their influence on tablet properties such as hardness, disintegration, dissolution and chemical stability were investigated. The agitation granulation method was used for preparation of solid dispersion granules, and the granules were compressed using a rotary tableting machine, and finally the obtained tablets were coated with film. As the particle size of cl-PVP decreased, hardness and apparent solubility were increased, while dissolution rate was lowered. When a higher viscosity grade of MC was used, hardness and dissolution rate were increased, and apparent solubility did not change. All batches of tablets were chemically stable at 40 degrees C, 75% relative humidity (R.H.) for six months. Finally, tablets with enhanced dissolution properties were obtained by using Polyplasdone XL-10 and Metolose SM-25 as the grades of cl-PVP and MC, respectively. These formulation tablets showed higher solubility and dissolution rate during storage as well as initial indicating good physical stability. 相似文献
23.
Kimura M Wada K Iwashima Y Ohta K Hanabusa K Shirai H Kobayashi N 《Chemical communications (Cambridge, England)》2003,(19):2504-2505
Sol-gel polymerization of tetraethoxysilane in the presence of amphiphilic phthalocyanine polymer 2 produced organic-inorganic composites with the rod-like phthalocaynine polymers incorporated within ordered hexagonal channels. 相似文献
24.
4,4'-Dihydroxytriphenylmethanes were synthesized using Br?nsted acid or Lewis acid in yields of 24-86% as target compounds for developing antiviral agents. Most of the 4,4'-dihydroxytriphenylmethanes showed significant activity against herpes simplex virus type 1 (anti-HSV-1 activity) in a plaque reduction assay. Higher cytotoxicity was observed generally in halogenated 4,4'-dihydroxytriphenylmethanes (2a-d) than in non-halogenated derivatives. The non-halogenated derivative, 4,4',4"-trihydroxy-3"-methoxytriphenylmethane (3), showed remarkable antiviral activity with an EC(50) value of 1.8 microg/ml. 相似文献
25.
Kazumi Okuro 《Tetrahedron letters》2010,51(38):4959-4961
Ionic diamine rhodium complexes catalyze the hydroaminomethylation of 2-allylanilines. The reaction involves initial hydroformylation followed by reductive amination, which provides direct access to 1,2,3,4-tetrahydroquinolines and 2,3,4,5-1H-1-benzazepines. 相似文献
26.
We find an exact classical solution in Euclidean gravity coupled to a scalar field with a particular form of potential commonly used in tachyon cosmology. This solution represents a tunneling between two vacua. 相似文献
27.
Polytetrafluoroethylene (PTFE) films were successfully coated with tin oxide in aqueous solutions. Tin oxide was crystallized in the solution and formed nanocrystal coatings on the polymer films. The coatings consisted of SnO2 and SnO crystals. They were assemblies of tin oxide nanosheet of about 10 to 50 nm in size and about 5 nm in thickness. The nanocrystal films can be exfoliated from the PTFE substrates. Tin oxide nanocrystal films had a rough liquid surface and a dense substrate‐side surface. Transparency of PTFE films coated with tin oxide was same as that of bare PTFE films in the range from 400 to 800 nm. The PTFE films coated with tin oxide nanocrystals can be pasted on desired substrates. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
28.
Masaharu Okazaki Taizo Ono Kenji Komaguchi Nobuaki Ohta Haruhiko Fukaya Kazumi Toriyama 《Applied magnetic resonance》2009,36(1):89-95
Room temperature fluorine electron nuclear double resonance (ENDOR) has been successfully observed for several superstable
fluorocarbon radicals ·C(C2F4R)(i-C3F7)2 in solution. Three radicals were employed in which CF3, F, and O-c-C6F10SO3C2F5 were introduced as R, and all the hyperfine couplings (hfcs) obtained by ENDOR were assigned with the help of ESR simulation
and ab initio MO calculation. In case of ·C(i-C3F7)3 large 13C and considerable β-fluorine couplings suggest the nonplaner arrangement for the central and three carbons at the β-position, in spite of the
fact that all the methyl fluorine show the same hfc. Therefore, a rapid puckering motion along the C3 axis together with the methyl rotation should average the hfc’s of the 18 fluorine nuclei to give the same value. When one
of the CF3 groups is substituted with an F nucleus, the five CF3 groups give two hfc values, suggesting some dynamics still exists for the molecular frame. When a large group, O-c-C6F10SO3C2F5, is substituted for CF3, all the five CF3 groups become nonequivalent and the ENDOR signal becomes intensive and sharp even at 290 K, indicating that the molecular
frame becomes rigid. The relation between the ENDOR spectra of these systems and the intramolecular dynamics is discussed. 相似文献
29.
A new approach to reduce the reverse current of Ge pin photodiodes on Si is presented, in which an i-Si layer is inserted between Ge and top Si layers to reduce the electric field in the Ge layer. Without post- growth annealing, the reverse current density is reduced to -10 mA/cm^2 at -1 V, i.e., over one order of magnitude lower than that of the reference photodiode without i-Si layer. However, the responsivity of the photodiodes is not severely compromised. This lowered-reverse-current is explained by band-pinning at the i-Si/i-Ge interface. Barrier lowering mechanism induced by E-field is also discussed. The presented "non-thermal" approach to reduce reverse current should accelerate electronics-photonics convergence by using Oe on the Si complementary metal oxide semiconductor (CMOS) platform. 相似文献
30.
Kazumi Watanabe Robert G. Payton 《Journal of the mechanics and physics of solids》2002,50(11):2425-2439
Green's function for SH-waves in a cylindrically monoclinic material is considered for impulsive and time-harmonic sources. Closed form expressions for the Green's function are derived for a few limited values of anisotropic parameters. A very interesting time development of the wave front shape is illustrated and the wave front singularity is discussed for the transient SH-wave. Contours of the displacement amplitude for the time-harmonic wave are also shown. 相似文献