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941.
Hisayoshi Mitamura Seiichiro Matsumoto Takashi Miyazaki Timothy J. White Kiyoshi Nukaga Yoshihiro Togashi Tamio Sagawa Shingo Tashiro Desmond M. Levins Akira Kikuchi 《Journal of the American Ceramic Society》1990,73(11):3433-3441
The polyphase titanate ceramic containing sodium-rich simulated high-level nuclear waste was doped with 0.69 wt% of 244 Cm to accelerate long-term self-irradiation due to α decays. α autoradiography showed that α emissions were almost uniformaly distributed throughout the curium-doped samples on a >20-μm scale although micropore surfaces and titanium oxide agglomerates were free of α-emitting nuclides. The phase assemblage of the curium-doped titanate ceramic included freudenbergite and loveringite in addition to the more abundant oxide phases: hollandite, perovskite, and zirconolite. Accumulation of α decays was accompanied by a gradual decrease in density. The increment of density was – 1% after an equivalent age of 5000 yr. Leach tests showed a slight trend toward higher total release of curium with equivalent age. The release of soluble nonradioactive elements (e.g., Na, Cs, Sr, and Ca) in the oldest specimens (equivalent age, 2000 yr) varied from specimen to specimen but, on average, were higher than specimens that had suffered a lower radiation dose. 相似文献
942.
The flexural vibration analysis of rectangular Mindlin plates using the collocation method is described. The results obtained by the present method are compared with published results for plates with uniform thickness and two opposite edges simply supported. The comparison shows that the method yields very good results with a relatively small number of collocation points, and that estimates for the higher modes can be obtained without any difficulties. Furthermore, the method is applied to plates with linearly varying thickness, and new findings are presented for the frequencies of plates. 相似文献
943.
944.
Positions of both the first- and second-order satellite reflections in the newly found charge-density-wave phase of 1T-TaS2 are measured by x-ray diffraction. The discommensuration network with a lower symmetry and its stacking sequence are determined. This phase appears on cooling from the nearly-commensurate phase as well as on heating from the commensurate phase, on contrast with results of previous measurements. 相似文献
945.
The effects of a mixed solvent consisting of water and organic solvents such as acetone and methanol on the photografting (λ > 300 nm) of N‐isopropylacrylamide (NIPAAm) on linear low‐density polyethylene film (thickness = 30 μm) was investigated at 30°C and 60°C. Xanthone, which had been coated on the film, was used as a photoinitiator. The photografting initiated even in the system at 30°C by using a longer irradiation time. It was found that the maximum percentage of grafting was attained at a certain concentration of organic solvent in the mixed solvent, which shifted to a lower concentration of organic solvent in the system at 60°C compared with the system at 30°C. It was found that the grafted chains of the sample prepared in the system with the higher polymerization temperature and the use of mixed solvent penetrated into the center of the film compared with the sample prepared in the system with the lower polymerization temperature and use of a water solvent. Moreover, the NIPAAm‐grafted films exhibited temperature responsiveness, swelling and shrinking in water at 0°C and 50°C, respectively. The extent of this characteristic was found to be closely related to the location of the grafted chains in film substrate, which was measured by an attenuated total reflection infrared spectroscope and a scanning electron microscope. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 458–463, 2003 相似文献
946.
Munetoshi Numada Takashi Nomura Kazuhide Kamiya Hatsuzo Tashiro Hiroyasu Koshimizu 《Precision Engineering》2006,30(4):431-442
In this study, we propose a low-pass filter whose transmission characteristics are determined to be more than 99.99% identical to the designed transmission characteristics at wavelengths greater than the cut-off wavelength. This low-pass filter is realized using a frequency-domain method which uses down-sampling, a frequency filter, and a cubic B-spline. When the frequency characteristics of a Gaussian filter (GF) were used as the designed transmission characteristics, this low-pass filter perfectly replaced the GF. In addition, no end effects and directional characteristics developed, and high-speed computation was possible. Furthermore, we can easily realize a low-pass filter having transmission characteristics that rise sharply at a right angle like a step edge. 相似文献
947.
Takayuki Sawaki Masakatsu Sasada Munetake Sasaki Katsuhiro Tsukimura Masami Hyodo Takashi Okabe Toshihiro Uchida Masahiko Yag 《Geothermics》1997,26(3):281-303
Synthetic fluid inclusion logging is a new tool to measure temperatures and sample fluids in high-temperature geothermal wells. Fluid in the microcracks of a crystal can be trapped in inclusions through healing. Fluid inclusions in quartz, for example, can be synthesized easily in geothermal boreholes and can be used as long as the host crystal is stable (e.g. α-quartz is stable up to 573°C). This technique can be applied to high-temperature geothermal wells where conventional temperature measurement methods are not feasible. Cracked crystals of quartz, soaked in silica-saturated solutions in gold or platinum capsules mounted on containers, are placed in a geothermal borehole. Geothermal fluid enters the microcracks in the crystals at the selected sampling depths, and inclusions containing ambient fluid are formed through crack healing. Trapping temperatures of fluid inclusions in quartz are determined by microthermometry using a heating stage with pressure corrections. Other cracked crystals mounted in containers with rupture disks are used for fluid sampling. The first borehole experiment was conducted at WD-1, a deep research hole drilled in the Kakkonda geothermal field, northeast Japan, from September to October 1994 (24 days). Results from the experiment confirmed that temperatures measured from fluid inclusions are consistent with borehole temperatures measured by conventional logging tools. 相似文献
948.
Crack growth behavior in a viscoelastic epoxy strip above and below the glass temperature Tg is extensively discussed by focusing on
(1) the threshold condition of crack growth;
(2) subsequent crack growth behavior; and
(3) the characteristics of fracture surface.
To realize good reproducibility of crack growth behavior that depends strongly on time and temperature, a new technique for
introducing an initial crack simulating the mathematical model, i.e., a single plane crack with sharp tip, has been developed.
Taking experimental evidence into account, an approach to the MID criterion, based on the displacement field around the crack tip for crack growth under monotonically increasing loading,
is proposed. Two types of equations predicting crack growth rate are evaluated through the comparison with experimental results.
As a measure of the critical condition of crack growth, an extended J-integral derived for linearly viscoelastic material,
is discussed. The fracture surface is carefully investigated for morphological features of the submicroscopic structural change
related with heterogeneous local deformation around the crack tip. Only stable crack growth of a single main crack is observed
above Tg, while below Tg not only both of stable and unstable crack growth, but sometimes branching to multi-cracks is observed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
949.
A high performance liquid chromatographic (HPLC) method is described for separation and quantitation of 1-alkyl-3-acyl- and
1-alkyl-2-acyl-sn-glycerol, products of the detritylation reaction of 1-alkyl-2-acyl-3-trityl-sn-glycerol. The alkyl glycerides were separated on a 25 cm×4.6 mm ID column packed with ∼5–6 μm silica and eluted isocratically
with isooctane/isopropanol (98∶2, v/v) as mobile phase. The good separation and linear refractive index (RI) detector responses
using cholesterol as an internal standard indicated the applicability of the method not only for the quantitative determination
of the alkylglycerols but also for their semipreparative isolation. This HPLC method shows excellent reproducibility and accuracy
and is applicable to other types of glycerides such as mono- and diacylglycerols.
Presented in part at the AOCS annual meeting, Honolulu, Hawaii, May 1986. 相似文献
950.
Analogy by abstraction: Case retrieval and adaptation for inventive design expert systems 总被引:4,自引:0,他引:4
Takashi IshikawaTakao Terano 《Expert systems with applications》1996,10(3-4):351-356