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排序方式: 共有474条查询结果,搜索用时 15 毫秒
101.
A variety of synthetic methods have been developed for azulene derivatives due to their potential applications in pharmaceuticals and organic materials. Particularly, 2H-cyclohepta[b]furan-2-one and its derivatives have been frequently used as promising precursors for the synthesis of azulenes. In this review, we describe the development of the synthesis of azulenes by the reaction of 2H-cyclohepta[b]furan-2-ones with olefins, active methylenes, enamines, and silyl enol ethers as well as their reactivity and properties. 相似文献
102.
Measured breakdown characteristics of capacitively coupled RF discharges are compared with numerical simulations performed under different boundary conditions at the electrode. When a pair of glass‐covered aluminum disks are used in the breakdown measurement of N2 and Ar gases at RF frequency of 13.56 MHz, the peculiar bend in the left branch of the minimum of V‐shaped breakdown curves is not observed, suggesting the absence of secondary electron emission. For the treated boundary condition of the electron density n, the simulation with the zero gradient gives satisfactory agreement with the experimental V‐shaped curves, while the simulation with n = 0 is shown to be effective in the region of small electric fields. The development of RF breakdown is explained based on the simulation for spatiotemporal profiles of n. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 8–14, 2000 相似文献
103.
A new model for generalized fuzzy inference neural networks (GFINN) is proposed in this paper. The networks consist of three layers: an input-output layer, an if layer, and a then layer. In each layer, there are the operational nodes. A GFINN can perform three representative fuzzy inference methods by changing the connectivity and the operational nodes. There are three learning processes in a GFINN: a self-organizing process, a rule-integration process, and a LMS learning process. In the rule-integration process, a GFINN employs two feature maps in order to integrate appropriate rules effectively. Computer simulations were carried out to show the superiority of a GFINN over back-propagation networks. © 1998 Scripta Technica, Electr Eng Jpn, 125(3): 40–49, 1998 相似文献
104.
Four new diimide-dicarboxylic acids (I–IV) were prepared by condensation of s- or a-BPDA with para- or meta-aminobenzoic acid. A series of aromatic poly(amide-imide)s containing these diimide-dicarboxylic units was prepared by three methods: (1) acid chloride method, (2) triphenylphosphite method, and (3) one-pot method. A typical polymer of the series is readily soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP), dimethylsulfoxide (DMSO), and pyridine (py) and could be cast into tough and flexible films. These were characterized by inherent viscosity, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) measurements. The glass transition temperatures of these polymers were in the range of 220–290°C, and the 5% weight loss temperatures were 450–500°C. Films prepared by casting from polymer solutions exhibited good tensile properties. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 865–873, 1997 相似文献
105.
北海道では旧来,米粒外観品質を東北以南に遜色ない程度まで向上させるため,乳白,腹白などの未熟粒が少なく整粒歩合や玄米と精米の白度が高くなるように,主に達観により選抜を行ってきた。その結果,1903年以降に育成された新旧品種では,整粒は育成年次が新しいほど概して多く,未熟粒,被害粒および着色粒は減少した。とくに,1961年育成の「ユーカラ」は,整粒歩合が同時代や以前の品種に比べ顕著に高く,系譜からみてその良質性はその後に育成された良質良食味米品種に受け継がれた。1984年以降に育成された主要品種は東北以南の銘柄米品種に比べ,整粒歩合がやや低く未熟粒歩合はやや高かった。玄米と精米の白度は,1971年より前の育成品種では腹白粒等の混入が多く,それが白度を上げるため育成年次と一定の関係が無かった。それ以降,両白度は新しい品種ほど高くなり,精米蛋白質含有率が低いほど高い傾向があった。現在の主要品種は東北以南の銘柄米品種に比べ,玄米白度はやや劣るが,精米白度,玄米透明度および精米透明度には明確な差異が無かった。さらに,整粒のみの玄米白度では,差異はなかった。以上から,現在の北海道主要品種の米粒外観品質は,東北以南銘柄米品種に比べ未熟粒がやや多く整粒がやや少ないことを除き,明確な違いはなくなった。 相似文献
106.
107.
Toru Okabe Masafumi Kikuchi Chikahiro Ohkubo Marie Koike Osamu Okuno Yutaka Oda 《JOM Journal of the Minerals, Metals and Materials Society》2004,56(2):46-48
To optimize the properties of titanium for use in dentistry, alloying is necessary. This study reports on the characterization
of some titanium alloys for grindability, wear, and corrosion resistance. Improvements in grindability and wear seemed to
occur with the presence of the eutectoid in the alloy.
For more information, contact Toru Okabe, Baylor College of Dentistry, Dept. of Biomaterials Science, 3302 Gaston Ave., Dallas,
TX 75246; (214) 828-8190; fax (214) 828-8458; e-mail tokabe@tambcd.edu. 相似文献
108.
The functions and structure of the network management subsystem of the GAMMA-NET, a local computer network at the University of Tsukuba, are presented. The network management subsystem is an integrated subsystem that offers a convenient man-machine interface for the network users during the execution of required jobs, and levels the workload throughout the system, as well as managing the network operations. 相似文献
109.
110.
Osamu Kimura Masafumi Matsumoto Mitsuo Sakakura 《Journal of the American Ceramic Society》1995,78(10):2857-2860
The high-frequency magnetic properties of strontium-partially-substituted Z-type magnetoplumbite with the composition 2CoO·3Ba1-x .Srx O.yFe2 O3 were studied using a hot-pressing technique. The best properties were obtained for a sample hot-pressed in oxygen, having x and y values of 0.5 and 10.8, respectively. The resonant frequency of that sample, corresponding to a μ" maximum reaching 2.5 GHz, was significantly larger than the value of 1.4 GHz previously reported for unsubstituted Z with the composition 2CoO·3BaO·12Fe2 O3 . This result implies that a new ferrite material, applicable in the gigahertz region, has been obtained. 相似文献