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31.
Crack extension behavior and fracture toughness of ductile cast iron were examined by three-point bend tests, where various
detection methods of crack initiation under static and dynamic loading conditions were adopted. Loading on the specimens was
interrupted at various displacement points, and the final fracture surfaces of the specimen were observed via scanning electron
microscopy (SEM). Crack-tip opening displacement (CTOD) obtained under the dynamic loading condition was smaller than that
under the static loading condition in ferritic ductile cast iron, and CTOD additionally decreased with increasing pearlite
content in the matrix. The relationship between J (ΔC) obtained by the compliance changing rate method and J(R) established
by the intersection of the crack extension resistance curve and the theoretical blunting line varied with pearlite content.
The average value of .J(ΔC) and J(R), that is J (mid), was proposed to define the fracture toughness of ductile cast iron;
J (mid) was considered to be a reasonable measure for the fracture toughness of ductile cast iron, irrespective of loading
condition and the pearlite content in the matrix. 相似文献
32.
J Tanuma H Shisa H Hiai S Higashi Y Yamada T Kamoto Y Hirayama H Matsuuchi M Kitano 《Canadian Metallurgical Quarterly》1998,58(8):1660-1664
The incidence of tongue carcinomas (TCs) induced by oral administration of 4-nitroquinoline 1-oxide in rats is strain dependent. The inbred Dark-Agouti (DA) strain showed a much higher susceptibility to large mass-forming infiltrative TCs than did the Wistar-Furth (WF) strain. Our previous study (M. Kitano et al, Jpn. J. Cancer Res., 87: 1097-1101, 1996) on crosses between these two strains postulated a dominant susceptibility gene in DA and a dominant resistance gene in WF rats. The present study mapped these loci by analyzing the backcrosses to each parent with simple sequence repeat polymorphisms. Five quantitative parameters were analyzed: (a) the number of TCs > 5 mm in diameter; (b) the total number of TCs per rat; (c) the diameter of the largest TCs (DTCmax values); (d) the number of non-TC cancers per rat; and (e) and the number of cancers of any site per rat. All of these parameters were closely correlated (P < 0.0001). DA rats had a semidominant gene (Stc1) favoring the development of 4-nitroquinoline 1-oxide-induced cancers on chromosome 19, closely linked to D19Mit9. Peak linkage was observed 4 cM distal from D19Mit9, with a logarithm of the odds (lod) score of 5.72 for the number of large TCs and 6.08 for the DTCmax. On the other hand, WF rats had a semidominant gene (Rtc1) mapped between D1Mit1 and D1Mit3, approximately 20 cM from D1Mit1, with a peak lod score of 3.30 for both the number of large TCs and the DTCmax. The main effect of Rtc1 seemed to be to reduce the size of the TCs. The action of these genes was dose dependent and cooperative. The final incidence of TC in DA, WF, F1, and backcross rats seemed to be explained by combinations of genotype at these two loci. Possible candidate genes for Stc1 and Rtc1 are discussed. 相似文献
33.
Yasushi Nagato Seiji Higashitani Kotaro Yamada Katsuhiko Nagai 《Journal of Low Temperature Physics》1996,103(1-2):1-22
We present a Green's function theory of the rough surface effects on the anisotropic BCS states using the formulation developed in the randomly rippled wall model. It is shown that the randomly rippled wall formulation is general enough to treat rough surface effects from the specular limit to the diffusive limit. We propose a statistical wall configuration such that gives the diffusive limit in the normal state. Within the weak coupling theory, we give a formal solution of the quasi-classical Green's function in a slab geometry and in a semi-infinite geometry with arbitrarily rough surfaces. The formal solution already satisfies the boundary condition. In the diffusive limit, the present theory correctly recovers the linearized gap equation obtained by Kjäldman et al. for the p-wave state in a slab geometry. 相似文献
34.
Stable optical pulse trains with repetition rates as high as 20-30 GHz have been successfully generated at 1.55 mu m from an InGaAs/InAlAs multiquantum well electroabsorption modulator for the first time.<> 相似文献
35.
K Yamada K Senzaki Y Komori T Nikai H Sugihara T Nabeshima 《Canadian Metallurgical Quarterly》1997,762(1-2):72-78
The role of glial cells in nitric oxide production in the cerebellum of conscious rats was investigated with a glial selective metabolic inhibitor, fluorocitrate. The levels of nitric oxide metabolites (nitrite plus nitrate) in the dialysate following in vivo microdialysis progressively increased to more than 2-fold the basal levels during a 2-h infusion of fluorocitrate (1 mM), and the increase persisted for more than 2 h after the treatment. Pretreatment with N(G)-nitro-L-arginine methyl ester attenuated the fluorocitrate-induced increase in nitric oxide metabolite levels. None of the glutamate receptor antagonists, including D(-)-2-amino-5-phosphonopentanoic acid, 6,7-dinitroquinoxaline-2,3-dione, and (+/-)-alpha-methyl-4-carboxyphenylglycine, inhibited the fluorocitrate-induced increase. The L-arginine-induced increase was significantly reduced by fluorocitrate treatment, while N-methyl-D-aspartate, (+)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, and trans-(+/-)-1-amino-(1S,3R)-cyclopentane-dicarboxylic acid increased nitric oxide metabolites levels in the fluorocitrate-treated rats, as much as in control animals. These results suggest that glial cells play an important role in modulating nitric oxide production in the cerebellum by regulating L-arginine availability. 相似文献
36.
Using spin-on glass (SOG) as an adhesive, an Si wafer with thermal oxide was successfully bonded to one with an RF-sputtered Si3N4 film. This ensures that SOG films are effective in bonding Si wafers to less reactive surfaces than Si or SiO2 such as silicon nitride. It was also found that the previously reported bonding procedure can be simplified by suppressing the spin-induced radial striations of the SOG films. 相似文献
37.
A GalnAsP edge-detecting photodiode was coupled with an SiO2-TiO2 single-mode waveguide in a simple hybrid integration scheme. The newly developed edge-detecting photodiode with a window region was used to improve photodiode durability. 相似文献
38.
Hiroyuki Nakahira Masakatsu Maruyama Hideshi Ueda Haruyasu Yamada 《The Journal of VLSI Signal Processing》1993,5(2-3):133-140
This paper describes an image processing system using Image Signal Multiprocessors (ISMPs) adapted to gray-level image preprocessing for image analysis and image enhancement. It is composed of four ISMPs, five 1H-delay-lines, two 512×512×8-bit frame memories, a video timing controller (VTC), two 256-word ×8-bit ×8-table Look Up Tables (LUTs) and 80 nsec/sampling A/D and D/A converters. This multiprocessor system performs convolution operations such as spatial filters, contrast enhancement, and binarization for gray-level images, thinning, thickening, pattern matching etc. for binary images, and image quality improvement for moving images such as T.V. images. Otherwise, it performs feature extraction operations such as area calculations, fillet coordination, and moment calculations for objective image data. Moreover, this system is capable of applying color image processing by using a multiboard system. 相似文献
39.
Takada K. Kitagawa T. Hattori K. Yamada M. Horiguchi M. Hickernell R.K. 《Electronics letters》1992,28(20):1889-1891
The group delay and dispersion, including the erbium ion contributions, of the highly erbium-doped silica planar waveguide amplifier and multicomponent glass fibre amplifiers are directly measured at different pump powers using a low coherence reflectometer and dispersive Fourier spectroscopy. This method derives the refractive index spectra of these amplifiers directly from the produced reflectograms without any physical or mathematical assumptions. The dispersion of the planar waveguide amplifier at 500 mW pumping changes between +300 and -200 ps/km/nm with a 0.4 wt.% erbium concentration.<> 相似文献
40.
Various aspects of our communication are well known to have changed over time (1-3). This article describes a cross-sectional study that examined the acoustic characteristics of two groups of Australian women aged 18-25 years from recordings made in 1945 and 1993 and investigated the possible changes in the voice across generations. Archival recordings from 1945 which had been used in a longitudinal study (4) were compared to recordings made in 1993. The results of this study show that women in 1993 have significantly deeper voices than women of the same age recorded in 1945. The possible factors influencing this change are discussed. 相似文献