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排序方式: 共有817条查询结果,搜索用时 21 毫秒
41.
The reduction of 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasila-2-yne 1 with an equivalent amount of alkali metal (Li, Na, K, KC8) in THF produced the corresponding disilyne anion radicals 2a–c. Their EPR spectra are independent of the metals used in THF, indicating that the disilyne anion radical species exists as solvent-separated ion pairs in polar solvents. The one-electron reduction also occurred with potassium in toluene to produce the potassium salt of the anion radical 3, which was isolated as extremely air- and moisture-sensitive dark brown crystals. The molecular structure of 3 was established by X-ray crystallography, which showed that the potassium ion is solvated by one toluene molecule. The EPR spectrum of 3 in toluene showed the interaction of the anionic silicon atom with the K+ ion. 相似文献
42.
Shingo Hirose Akihiro Yoshida Masaaki Yamaura Nobuo Kano Hiro Munekata 《Journal of Materials Science: Materials in Electronics》2000,11(1):7-10
We demonstrate a method for successfully controlling carbon incorporation in AlAs layers grown by atomic layer epitaxy (ALE) using various GaAs substrates with different orientations. The number of alkyl radicals attached to an Al atom at the surface, which is a main factor in carbon incorporation, can be intentionally controlled by changing substrate orientation. We found that the carbon incorporation in ALE-AlAs using the (3 1 1)B surface is 2 x 1017,cm-3, which is the lowest value ever reported for ALE-AlAs that satisfies one-monolayer self-limiting growth conditions. 相似文献
43.
Hitoshi Tanaka Morimasa Tanimoto Akira Matsuda Takeo Uno Masaaki Kurihara Shoji Shiga 《Journal of Electronic Materials》1999,28(11):1216-1223
Pb-free solderable surface finishing is essential to implement Pb-free solder assembly in order to meet with the growing demand
of environmental consciousness to eliminate Pb from electronic products. Two types of widely applicable Pb-free surface finishing
technologies are developed. One is the multilayer-system including Pd with Ni undercoat. Heat-resistance of Pd enables whole-surface-plating
on to leadframe before IC-assembling process. The other is the double-layer-system with low-melting-point-materials, for example,
thicker Sn underlayer and thinner Sn-Bi alloy overlayer, dilutes Sn-Bi alloy’s defects of harmful reactivity along with substrate
metal and mechanical brittleness with keeping its advantages of solder-wettability and no whisker. 相似文献
44.
45.
Wei Zhang Kenji Ochi Michiya Fujiki Masanobu Naito Masaaki Ishikawa Kei‐ichi Kaneto Wataru Takashima Akinori Saeki Shu Seki 《Advanced functional materials》2010,20(22):3941-3947
In this paper a simple, casting solution technique for the preparation of two‐dimensional (2D) arrays of very‐high molecular weight (MW) 1D‐Pc supramolecular inorganic polymers is described. The soluble fluoroaluminium tetra‐tert‐butylphthalocyanine (ttbPcAlF) is synthesized and characterized, which can be self‐assembled to form 2D arrays of very‐high‐MW 1D‐Pc supramolecular inorganic polymers. High‐resolution transmission electron microscopy (HRTEM) demonstrates that the 1D‐ttbPcAlF, having a cofacial ring spacing of ~0.36 nm and an interchain distance of ~1.7 nm, self‐assembles into 2D‐nanosheets (~140 nm in length, ~20 nm in width, and equivalent to MW of 3.2 × 105 g mol?1). The film cast from a 1,2‐dichloroethane (DCE) solution shows a minimum hole‐mobility of ~0.3 cm2 V?1 s?1 at room temperature by flash‐photolysis time‐resolved microwave conductivity (TRMC) measurements and a fairly high dark dc‐conductivity of ~1 × 10?3 S cm?1. 相似文献
46.
47.
Tetsukuni Oikawa Masaaki Kondo Yoshinobu Mizuno Yuichi Watanabe Hiroshi Fukuoka Ken Muramatsu 《Reliability Engineering & System Safety》1998,62(3):251-271
An integrated code system SECOM-2, developed at the Japan Atomic Energy Research Institute (JAERI), has the following functions for systems reliability analysis in seismic probabilistic safety assessments (PSAs): (1) calculation of component failure probability, (2) extraction of minimal cut sets (MCSs) from a given fault tree (FT), (3) calculation of frequencies of accident sequences and core damage, (4) importance analysis with several measures with consideration of unique parameters of seismic PSAs, (5) sensitivity analysis, and (6) uncertainty analysis. This paper summarizes the special features of SECOM-2 to perform the analyses mentioned above. At JAERI, using an integrated FT which represents seismically induced core damage due to all initiating events as a system model to calculate core damage frequency of a nuclear power plant, SECOM-2 can calculate conditional point estimate probabilities of system failures, losses of safety functions, and core damage as a function of earthquake motions. The point estimate is computed by a method which gives an exact numerical solution using the Boolean arithmetic model method. As for consideration of correlation of component failure, which has been an important issue in seismic PSAs, a new technique based on direct FT quantification by a Monte Carlo simulation is being added to SECOM-2. Adding this technique, the core damage frequency can be calculated not only with the upper bound approximation based on MCSs but also with a near exact solution taking into account the correlation among all components. This paper also presents the preliminary results of a seismic PSA of a generic BWR plant in Japan performed at JAERI to demonstrate the functions of the SECOM-2 code. 相似文献
48.
An ultrasonic wave was applied during brazing of alumina to Cu. First alumina was metallized by applying ultrasonicwave in braze bath. Then the metallized alumina was brazed with Cu using the same filler alloy. The filler used wereZn-Al alloys and Zn-Sn A 相似文献
49.
Identification and field evaluation ofAnomala octiescostata (Coleoptera: Scarabaeidae) sex pheromone
Walter Soares Leal Makoto Hasegawa Masaaki Sawada Mikio Ono Yasuo Ueda 《Journal of chemical ecology》1994,20(7):1643-1655
Using GC-EAD, the sex pheromone of the scarab beetleAnomala octiescostata was identified to be a 8:2 binary mixture of (R,Z)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one and (R,Z)-5-(–)-(dec-1-enyl)oxacyclopentan-2-one. These semiochemicals have been also reported as sex pheromone constituents of otherAnomala species, either geographically or seasonally isolated fromA. octiescostata. Synthetic sex pheromone was highly attractive in the field; 0.1 mg captured significantly more males than two virgin females. Buried traps were significantly more attractive than those positioned at 30, 90, and 150 cm above the ground. In a dose-response test (0.1–100 mg), no saturation due to overdose of pheromone was observed, but in most cases, two dosages differing by 10-fold were not significantly different. Response of males to traps baited with different ratios of the two components was tested in two experiments with randomized blocks and Latin-square designs. Deviation from the natural ratio (8:2) of sex pheromone did not significantly diminish the response of males. Peak flight activity of beetle was recorded at 9:00–10:00 AM JST on sunny days in the end of April 1993.Presented in part at the 10th Annual ISCE Meeting, July 31–August 4, 1993, Clearwater Beach, Florida. 相似文献
50.
Masaaki Yokoyama Tomohiro Zaita 《International journal for numerical methods in engineering》1992,35(6):1277-1288
In order to obtain accurate results and to reduce computation time, we have proposed in this paper a new strategic method, where quadratic elements are used at the corner points and linear elements at the points off the corner points. A computer program using this method has been developed and applied to several problems of various shapes. The usefulness of this method was illustrated by the application results. 相似文献