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101.
Nobuhiko Onda Kunio Furusawa Noriko Yamaguchi Masatoshi Tokiwa Yasumasa Hirai 《应用聚合物科学杂志》1980,25(10):2363-2372
In a study of polyacrylamide in solutions we have required the rapid characterization on chromatographies. The application to the aqueous solution of the GPC using controlled-porosity glass has been examined from both the viewpoint of the effect of salt addition and the GPC mechanism. An adequate addition to neutral salt, 0.005M KCI to the eluent, gave rise to the elution behaviors being in accord with the hydrodynamic volume concept of the GPC separation. 相似文献
102.
Energy absorption in blends of polycarbonate with ABS and SAN 总被引:21,自引:0,他引:21
Polycarbonate and its blends with ABS and SAN were tested to study the energy absorbing properties and the deformation mechanism. In tension and impact tests, these blends were found to possess a high energy absorbing capability, high yield strength and large rupture elongation. ABS and SAN particles in the blends deform in a ductile manner to an elongation of more than 100% under a tensile stress. In an elongation test of ABS under a hydraulic pressure of 90×105 N m–2, the transformation from crazing to a cold-drawing mechanism was found to occur. The large elongation of ABS and SAN in the blends is attributed to the cold drawing which occurs under the influence of the pressure acting on the dispersed ABS and SAN, caused by the difference between the elastic moduli of the dispersoid and the matrix. 相似文献
103.
Takemitsu Kunio Tatsuya Yamazaki Eiji Ohta Makoto Sakata 《Solid-state electronics》1983,26(2):155-160
The transient capacitance technique has been used to study the chromium-related levels in the silicon band gap. Chromium was diffused at temperature of 1100 and 1150°C for 0.5 and 3 hr. Five different levels at Ec?0.11 eV, Ec?0.21 eV, Ec?0.28 eV, Ec?0.36 eV and Ec?0.45 eV were obtained from the Arrheniu plots of the electron thermal-emission rates. The number of levels in the upper half of the band gap decreased from five to two with an increase of Cr-diffusion period. Two levels were located at Ec?0.20 eV (donor) and Ec?0.43 eV (acceptor). A donor level was also observed at Ev + 0.25 eV. The donor level was not affected by the diffusion condition. The majority carrier capture cross sections of the three dominant levels have been measured by the transient capacitance technique modified by the pulse transformer. The values were σn = 4.1 × 10?15 cm2 for the upper donor at Ec?0.20 eV, σn = 2.0 × 10?16 cm2 for the acceptor at Ec ?0.43 eV and σp = 9.1 × 10?18 cm2 for the lower donor at Ev + 0.25 eV, and were independent of temperature. The three dominant levels are due to distinct chromium centers. 相似文献
104.
New Submicron (0.5-1.0 mu m diam) bubble garnets have been developed. In order to reduce saturation induction4piMs as low as possible, suitable choice of amounts of nonmagnetic ions substituting for ferric ions in both tetrahedral and octahedral sites were studied in (YSm)3 (FeAl)5 O12 , (YSmLu)3 - (FeGaSc)5 O12 , (YSmLu)3 (FeAlSc)5 O12 and (LaLuSm)3 - (FeGa)5 O12 garnet systems. For example, in (YSmLu)3 - (FeAlSc)5 O12 a film with the following properties was grown; strip widthw = 0.7mu m, film thicknessh= 0.7mu m, quality factorq=2.8 , Curie temperatureTc= 140deg C and4piMs=770 G. The temperature properties of those films could be improved drastically by doping with a small amount of Gd ion. Wall mobilities μw of those films are in the region from 200 to 500cm/s/Oe. Preceding these material studies, several film characterization methods have been investigated. Film thickness was measured by Fluorescent X-ray method, strip width by using a highly sensitivity TV camera, and bubble collapse field by FMR resonance technique respectively. 相似文献
105.
Two simple chromenes with anti-JH activity have been isolated and identified from the bedding plant Ageratum houstoianum. By contact and fumigation these compounds induce precocious metamorphosis and sterilization in several hemipteran species of insects. Certain holometabolous species are sterilized, forced into diapause, or both. Each of these biological actions is equivalent to removal of the corpora allata, which produce the JH's, and is reversible by treatment with exogenous JH. Thus, the action of these compounds is to stop the production or depress the titer of the JH's. To our knowledge, this is the first discovery of anti-JH, and we hope it will guide the way to the emergence of a fourth generation of safe and insect-specific pesticides. 相似文献
106.
The expressions for Walsh functions in terms of shifted Rademacher functions are applicable to the design of a directive and selective array antenna for Walsh waves which is capable of eliminating the interference caused by impulsive noises. They also are applicable to voice processing because of their shift-invariant property. The shifted Rademacher functions were previously introduced by shiftiAg horizontally the periodic Rademacher functions. It was shown that the Walsh functions could be expressed as a linear combination of a finite number of the shifted Rademacher functions. This paper develops the actual expansions of the Walsh functions in terms of the shifted Rademacher functions. The coefficients in this series take only the values of either + 1 or -1. The shifted Rademacher coefficients appearing in the expansion of a given function in tenns of shifted Rademacher functions have the advantage that the coefficients of a shifted function are available by shifting cyclically the original coefficients. 相似文献
107.
108.
109.
Hirata K Tsujimoto Y Namba T Ohta T Hirayanagi N Miyasaka H Zenk MH Miyamoto K 《Journal of Bioscience and Bioengineering》2001,92(1):24-29
Synthesis of phytochelatins (PCs), heavy-metal-sequestering peptides, in the marine green alga, Dunaliella tertiolecta, was evaluated under various conditions of exposure to heavy metals. To investigate the effect of heavy metals on both PC synthesis and their upstream biosynthetic reactions, an ion-pair-HPLC system was developed in this study, by which PCs and their biosynthetic intermediates, cysteine (Cys), gamma-glutamylcysteine (gammaEC) and glutathione (GSH), could be determined simultaneously with high sensitivity. When the cells were exposed to Zn2+, the level of PCs was maximal at 200 microM and significantly higher than that obtained after exposure to 400 microM Cd2+, which is the strongest inducer of PC synthesis in higher plants in vivo and in vitro as well as in microalgae. The predominant PC subtype was PC4, followed by PC3 and PC5, whereas PC2, which is generally abundant in higher plants, has the lowest level among PC2 to PC5. These results suggest that the characteristics of PC synthase in D. tertiolecta including the requirement of heavy metals for its catalysis and substrate specificity towards GSH and PC(n) are considerably different from those in higher plants and other algae. While PC synthesis proceeded in the heavy-metal-treated cells, the level of GSH did not appreciably change. To maintain the same size of the GSH pool, GSH must be newly synthesized to balance the amount consumed for PC synthesis. 相似文献
110.
Among passerines, Bengali finches are known to sing extremely complex courtship songs with three hierarchical structures:
namely, the element, the chunk, and the syntax. In this work, we theoretically studied the mechanism of the song of Bengali
finches in aides to provide a dynamic view of the development of birdsong learning. We first constructed a model of the Elman
network with chaotic neurons that successfully learned the supervisor signal defined by a simple finite-state syntax. Second,
we focused on the process of individual-specific increases in the complexity of song syntax. We propose a new learning algorithm
to produce the intrinsic diversification of song syntax without a supervisor on the basis of the itinerant dynamics of chaotic
neural networks and the Hebbian learning rule. The emergence of novel syntax modifying the acquired syntax is demonstrated.
This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January
23–25, 2006 相似文献