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101.
Kyoto University has developed a laboratory computer network that demonstrates an easy yet versatile way of accessing several kinds of computers from a single, small-scale computer. Known as "Labolink,"1,2the network is designed to support laboratory research and education. Unlike the RIG System, another university network reported on recently,3Labolink required no modification of the existing operating system. 相似文献
102.
103.
Kitamura M Ohtsuki C Iwasaki H Ogata S Tanihara M Miyazaki T 《Journal of materials science. Materials in medicine》2004,15(10):1153-1158
Tricalcium phosphate (TCP) ceramic is known in orthopedics to be a bioresorbable bone substitute. A porous TCP ceramic body also has high potential as a drug delivery system in bony defects. Porous alpha-TCP ceramic can be easily fabricated using conventional sintering of beta-TCP, since alpha-TCP is the thermodynamically stable phase at temperatures above 1 100 degrees C. However, the solubility of alpha-TCP is much higher than that of beta-TCP. Therefore, the dissolution of porous alpha-TCP progresses at a higher rate than bone repair. In the present study, we attempted to reduce the dissolution rate of porous alpha-TCP by employing an organic polymer coating. We fabricated porous alpha-TCP ceramic with a continuous 10-50 microm diameter pore structure by sintering a body made from a beta-TCP and potato starch slurry. The porous body obtained was coated with hydroxypropylcellulose (HPC), and then subjected to heat treatment. The chemical durability and mechanical properties of the body were examined before and after coating with the HPC. The dissolution of porous alpha-TCP in buffered solutions was reduced by coating with HPC and drying at 60 degrees C. The compressive strength of the porous alpha-TCP was also improved by coating with HPC. The results of in vivo experiments showed that some parts of the porous alpha-TCP ceramic coated with HPC remained in the canal of the tibia of a rabbit four weeks after implantation, whereas no residual was observed in a non-coated alpha-TCP ceramic. Coating with HPC was found to be effective for controlling bioresorption and improving the workability of porous alpha-TCP ceramic. The prepared porous alpha-TCP ceramic is expected to be useful as a novel material for bone fillers by incorporating it with drugs or osteoinductive factors. 相似文献
104.
Lin Li Syuma Yasuzuka Yufeng Weng Keiichi Yokogawa Tsutomu Fujimoto Toyonari Sugimoto Hideki Fujiwara Toshiki Hayashi Takashi Hiraoka Keizo Murata 《Journal of Low Temperature Physics》2006,142(3-4):473-476
Hall resistance and magnetic torque measurements have been carried out in the field-induced spin-density-wave (FISDW) phase
of deuterated (TMTSF)2ClO4 for various cooling rates through the anion ordering temperature. We have found that the Hall resistance in the intermediate
cooled state shows a phase transition from the non-quantized Hall phase to the quantized Hall phase (n=1) with hysteresis.
We have also found that the magnetic torque in the non-quantized Hall phase rapidly decreases with increasing cooling rate.
These results suggest that there is a new phase transition from the non-quantized Hall phase to the quantized Hall phase in
(TMTSF)2ClO4. 相似文献
105.
Highly hydrophilic interpenetrating polymer network (IPN) membranes were prepared from a mixture system of poly(4-vinylpyridine) (P4VP) and poly(vinyl alcohol) (PVA) by quaternizing crosslinking of P4VP with 1,4-dibromobutane (DBB) and simultaneous crosslinking of PVA with hexamethylene diisocyanate (HMDI). The membrane performance in pervaporation (PV) for the azeotropic mixture of ethanol with a less polar organic liquid (chloroform, benzene, carbon tetrachloride, and cyclohexane) was investigated. The strength of these IPN membranes was higher than that of the cellulose acetate membrane and depended on the membrane composition. All the membranes were ethanol permselective for the azeotropic feeds and equimolar mixture feeds as well. Only the swelling degree Q of the membrane, among several physicochemical factors, showed a relationship with the separation performance for the four feeds; a lower value of Q generally corresponded to a higher separation factor and smaller permeability. The membrane composition, which exhibited an optimum membrane performance, was examined in detail for some membranes. Both the separation factor for sorption and that for diffusion far exceeded unity, but the latter was greater in most cases than was the former and dominated the overall separation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2729–2738, 2001 相似文献
106.
The cyclic-oxidation behavior of Fe–20Cr–4Al alloys with 3, 35, 53, 104, and 171 ppm sulfur was studied in oxygen at 1273, 1373, 1473, 1573, and 1673 K by mass-change measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron-probe microanalysis (EPMA). The cyclic oxidation consisted of an 18.0 ksec exposure that was repeated up to five times. Amounts of spalled oxides of the alloys with 35 and 53 ppm sulfur increased after one and two oxidation cycles, and then decreased after three or more oxidation cycles at 1473 and 1573 K. On the other hand, spalling of oxide scales on the alloys with 3 and 171 ppm sulfur was scarcely recognized after all cycles used in this study. SEM observations of both sides of the spalled oxides indicated that spallation was related to the morphology of the surface oxides and to the morphology and volume of cavities at the oxide–alloy interface. 相似文献
107.
108.
The problem of finding a largest stable matching where preference lists may include ties and unacceptable partners (MAX SMTI) is known to be NP-hard. It cannot be approximated within 33/29 (>1.1379) unless P=NP, and the current best approximation algorithm achieves the ratio of 1.5. MAX SMTI remains NP-hard even when preference lists of one side do not contain ties, and it cannot be approximated within 21/19 (>1.1052) unless P=NP. However, even under this restriction, the best known approximation ratio is still 1.5. In this paper, we improve it to 25/17 (<1.4706). 相似文献
109.
Toshiki Hagiwara Manabu Yamazaki Tomohiro Suzuki Takashi Sawaguchi Shoichiro Yano 《Polymer》2011,52(24):5426-5430
A novel poly[2]catenane having rigid triazole rings between [2]catenane moieties was synthesized by the 1,3-dipolar cycloaddition of diazido[2]catenane with 4,4′-diethynylbiphenyl. The reaction proceeded effectively under mild conditions and gave a polymer in high yield. The number average molecular weight (Mn) of the polymers was 1.5 × 104-2.5 × 104. A cyclic dimer consisting of two [2]catenane moieties and two biphenylene units was formed along with the polymer. The cyclodimerization was suppressed by performing the reaction at a low temperature without lowering the yield or molecular weight of the polymer. The novel poly[2]catenane had higher solubility in some solvents than the corresponding non-catenated polymer having a similar primary structure. 相似文献
110.
Masayuki Uchida Tomokatsu Hayakawa Toshiki Suhara Jean-Rene Duclère Philippe Thomas 《International Journal of Applied Glass Science》2015,6(1):83-93
In this study, by a conventional melt quenching method, we synthesized novel up-conversion phosphors of 60TeO2–30TlO0.5–(9−x)ZnO–xTm2O3–1Yb2O3 (x = 0.1–0.5) glasses, whose system was recently developed in our collaborative group, and their blue up-conversion photoluminescence (UCPL) of Tm3+ ions via three-step energy transfer from near-infrared (NIR) sensitizer of Yb3+ ions was observed. In particular, the substantial rate of the energy transfer <γd5> in the third step from Yb3+ to Tm3+ under excitation at 975 nm, which determined the final blue UCPL intensity, was estimated as a function of the rare-earth concentration. With an aid of analytical methods of PL lifetime and Judd–Ofelt theory, it was revealed that the highest energy transfer rate <γd5> was achieved to be 2.07 × 10−17 cm3/s for x = 0.2, and further increasing Tm2O3 content x in the fixed Yb2O3 resulted in the decrease in the energy transfer rate <γd5>. One of the plausible causes was concentration quenching of Yb3+ ions. The other was back-transfer from Tm3+ to Yb3+ ions. The influence of the condition of glass synthesis and the melting time on <γd5> was also discussed. 相似文献