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51.
CW operation at - 10°C for InGaP/InGaAlP double heterostructure (DH) laser diodes has been achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapour deposition using methyl metalorganics as the source of group III elements. Under room-temperature pulsed operation, the lasing wavelength was 663 nm and the lowest threshold current density was 7.8 kA/cm2. The CW characteristic temperature T0 was 63 K at around -30°C. 相似文献
52.
Marked low-loss coupling between a laser diode and a single-mode fibre has been realised, utilising a planoconvex, high-numerical-aperture graded-index rod lens with greatly improved small wavefront aberration. 相似文献
53.
T. Ishikawa J. T. Okada P.-F. Paradis Y. Watanabe 《International Journal of Thermophysics》2010,31(2):388-398
Thermophysical properties of liquid gadolinium were measured using non-contact diagnostic techniques with an electrostatic
levitator. Over the 1585 K to 1920 K temperature range, the density can be expressed as ρ(T) = 7.41 × 103 − 0.46 (T − T
m) (kg · m−3) where T
m = 1585 K, yielding a volume expansion coefficient of 6.2 × 10−5 K−1. In addition, the surface tension data can be fitted as γ(T) = 8.22 × 102 − 0.097(T − T
m)(10−3 N · m−1) over the 1613 K to 1803 K span and the viscosity as η(T) = 1.7exp[1.4 × 104/(RT)](10−3 Pa · s) over the same temperature range. 相似文献
54.
Takehiro Matsunaga Yoshio Nakayama Mitsuaki Iida Senzo Oinuma Noboru Ishikawa Katsumi Tanaka 《Propellants, Explosives, Pyrotechnics》1992,17(2):63-69
Molecular properties of benzene nitro derivatives were investigated by using semi-empirical MO calculations. As the results, the molecular structures and the rotational barrier of the nitro group calculated by AM1 showed a good agreement with the experimental values. The heats of formation in gaseous and condensed phases were obtained by considering isodesmic reactions. By this procedure, the heat of formation of hexanitrobenzene in solid phase was calculated to be +22.7 kcal/mol. The detonation parameters were also calculated by using four equations of state. The predicted detonation velocities showed a good agreement with the experimental values. 相似文献
55.
The elastic and yield properties of drawn poly(methyl methacrylate) (PMMA) filled with ultrafine SiO2 are described as functions of filler content and size. The drawn PMMA composites were made by uniaxially drawing to x4.0 at 100°C and at a rate of 20 mm/min. Four compliance values, i.e., S33, S11, S13, and S44 were determined. These values decreased with filler content and decreasing filler size. The relative compliance values Sde/Sdo(Sde is the compliance of drawn PMMA composites and Sdo is that of drawn unfilled PMMA) are almost equivalently changed with changes in filler content. The elastic properties of drawn PMMA composites are thus reinforced isotopically. This is characteristic of PMMA which has a large side group. The yield behavior of drawn PMMA composites have similar filler size and content dependence to those of elastic properties except that the transverse yield stresses become more brittle with filler content. The anisotropy in yield stress is relatively larger than that of elastic properties. This is probably because the anti-reiforcing effect, such as fibrillation becomes prominent with increasing filler content in the perpendicular direction. 相似文献
56.
Yuki Sugiura Melvin L. Munar Kunio Ishikawa 《Journal of materials science. Materials in medicine》2018,29(10):151
Although octacalcium phosphate (OCP) powder and a collagen/gelatin composite demonstrate good potential as bone substitutes, an OCP block has not been fabricated to date. In this study, the feasibility of fabricating an OCP block was evaluated through a dissolution-precipitation reaction using a calcium sulfate hemihydrate (CSH) block as a precursor. When the block was immersed in a phosphate salt solution, its composition changed to that of OCP, while its structure was maintained. The diametral tensile strength (DTS) of the OCP block was 1.0?±?0.2?MPa. The macroporosity and microporosity of the OCP block were 33.4?±?4.5% and, 69.0?±?1.6%, respectively. New bone attached well to the OCP block, and this block was partially replaced by bone 2 weeks after implantation. Four weeks after implantation, the surface of the OCP block was nearly covered with new bone and ~30% of the block was replaced by new bone, while no replacement by bone was observed in the case of a hydroxyapatite (HAp) block used as a control. It is concluded that OCP blocks are potentially suitable for their use as artificial bone substitutes. 相似文献
57.
F. Ono S. Komatsu Y. Chimi N. Ishikawa A. Iwase T. Kambara 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2005,230(1-4):279-283
High-energy ion irradiation was performed using a ring-cyclotron installed at the Institute of Physical and Chemical Research (RIKEN). The incident ions were Ta with the energy of 3.71 GeV, and the fluence was fixed to 5 × 1012 ions/cm2. As a target, three sheets of square plates of Fe–30.2 at.% Ni invar alloys were put one upon another. The shift of the Curie temperature TC of the first sample was 14 K, while that of the second one was 22 K. Comparing these two, the shift was as large as 46 K in the last sample in which ions stopped in the middle. It was concluded that there are at least two different mechanisms that contribute to the shift of TC. 相似文献
58.
Depletion-mode GaInAsP/InP junction field-effect transistors have been fabricated on Fe-doped semi-insulating InP substrates using liquid-phase epitaxial growth techniques. The authors achieved transconductance of 24 mS (160 mS/mm), drain-source saturation current at an on gate bias of 486 mA/mm and current cutoff frequency of 18.8 GHz using a GaInAsP channel layer owing to the gate length reduction 相似文献
59.
Cutaneous lesions caused by M. ulcerans were shown to bear only a superficial resemblance to those produced by certain spider species. M. ulcerans was not found in either the venoms or the midguts of several Australian spiders, and deliberate contamination by inoculation of the fangs and digestive system of the wolf spider, Lycosa godeffroyi, did not result in permanent colonization. M. ulcerans was successfully introduced into the skin of mice through a small trauma site similar to that caused by a spider bite. However, because M. ulcerans was shown to survive on exposed surfaces for only a short period, a successful inoculation is likely only if the skin is contaminated with this organism after, or at the same time as, the skin suffers damage. The claim by other workers that M. ulcerans produces cutaneous ulcers by release of an exotoxin could not be confirmed. The authors conclude that M. ulcerans is not involved in most cases of necrotic arachnidism and hence there is no justification for prescribing anti-mycobacterial antibiotics to resolve alleged spider bite lesions unless the presence of M. ulcerans has been demonstrated by appropriate laboratory tests. 相似文献
60.
T Dumrese S Stevanovi? FH Seeger N Yamada Y Ishikawa K Tokunaga M Takiguchi H Rammensee 《Canadian Metallurgical Quarterly》1998,48(5):350-353
BACKGROUND: Fiberoptic flexible sigmoidoscopy (FFS) is routinely requested preoperatively as part of evaluation of pelvic masses to exclude colonic involvement by the tumor or concurrent colonic neoplasm. The aim of our study was to evaluate the utility of preoperative FFS in patients with suspected gynecologic malignancy. METHODS: FFS, performed using a 60 cm sigmoidoscope, evaluated (1) presence of bowel involvement by the tumor, (2) extrinsic compression by the tumor, and (3) presence of colonic neoplasms. FFS findings were correlated with surgical findings. RESULTS: A total of 107 women underwent preoperative FFS and subsequent surgery. Eleven patients (11%) had lower gastrointestinal symptoms. At surgery, 63% of pelvic tumors were malignant and 37% were benign. The most common abnormality at FFS was colonic polyps in 23 patients (21%). Colonic adenomas were found in 11 patients (10%). Extrinsic compression by the tumor without mucosal abnormalities was seen in 15 patients (14%). The most common intraoperative finding was tumor adhering to the bowel in 18 patients requiring dissection, but only 1 patient required bowel resection. Eight of these 18 patients had preoperative lower gastrointestinal symptoms. All 15 patients with extrinsic compression at FFS had tumor adhering to the bowel. CONCLUSIONS: Pelvic masses cause extrinsic compression at FFS in 14% of patients. This is suggestive of tumor adherent to the bowel at surgery. However, bowel resection is rarely required because of tumor involvement. Most patients with bowel adherence by tumor have lower gastrointestinal symptoms. Colonic adenomas are found in one tenth of patients, mostly in patients older than 50 years of age. Preoperative FFS does not change the surgical management of pelvic tumors. Screening FFS is indicated in all patients with pelvic tumors over age 50, as in persons with average risk, but is otherwise unnecessary in evaluation of pelvic masses. 相似文献