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71.
Summary We define a notion of contact totally umbilical submanifolds of Sasakian space forms corresponds to those of totally umbilical
submanifolds of complex space forms. We study a contact totally umbilical submanifold M of a Sasakian space form
(c ≠ −3) and prove that M is an invariant submanifold or an anti-invariant submanifold. Furthermore we study a submanifold
M with parallel second fundamental form of a Sasakian space form
(c ≠ 1) and prove that M is invariant or anti-invariant.
Entrata in Redazione il 7 settembre 1976. 相似文献
72.
Ikuo Atsuya Hirotsugu Minami Qiangbin Zhang 《Fresenius' Journal of Analytical Chemistry》1993,346(12):1054-1057
Summary A pre-ashing method by a conventional electrothermal furnace was used as a concentration technique for powdered biological samples in the solid sampling technique with GF-ZAAS. A relationship equation between the concentration factors and the concentrations of main inorganic components in biological samples has been established, and it has become possible to calculate the concentration factors, if the total concentration of K, Na, Mg and Ca, or total concentration of K and Mg, or the concentration of K only are known. The proposed method has been successfully applied to the direct determination of Co, Ni, Mn and Pb at the g/kg levels in biological samples.Presented at the 5th International Colloquium on Solid Sampling, with Atomic Spectroscopy, May 18–20, 1992; Geel, Belgium. Papers edited by R.F.M. Herber, Amsterdam 相似文献
73.
Yoshio Hamashima Sadao Yamamoto Tadatoshi Kubota Katsuya Tokura Koji Ishikura Kyogi Minami Fumihiko Matsubara Masaaki Yamaguchi Ikuo Kikkawa Wataru Nagata 《Tetrahedron letters》1979,20(51):4947-4950
Synthesis of optically active 3′-nor-type 1-oxacephems from 6-APA was described. -Nitrobenzyl 7β-amino-3-chloro-7α-methoxy-1-oxa-3-cephem-4-carboxylate was also prepared. 相似文献
74.
75.
76.
We introduce a new condition for {Yτn} to have the same asymptotic distribution that {Yn} has, where {Yn} is a sequence of random elements of a metric space (S, d) and {τn} is a sequence of random indices. The condition on {Yn} is that maxiDnd(Yi, Yan)→p0 as n → ∞, where Dn = {i: |ki−kan| ≤ δankan} and {δn} is a nonincreasing sequence of positive numbers. The condition on {τn} is that P(|(kτn/kan)−1| > δan) → 0 as n → ∞. Under these conditions, we will show that d(Yτn, Yan) → P0 and apply this result to the CLT for a general class of sequences of dependent random variables. 相似文献
77.
Nakanishi I Nishizawa C Ohkubo K Takeshita K Suzuki KT Ozawa T Hecht SM Tanno M Sueyoshi S Miyata N Okuda H Fukuzumi S Ikota N Fukuhara K 《Organic & biomolecular chemistry》2005,3(18):3263-3265
Photoreduction of pyridine N-oxide, which has a key structure of antitumor agents for hypoxic solid tumors, by 1-benzyl-1,4-dihydronicotinamide in deaerated aprotic media resulted in generation of hydroxyl radical, leading to the oxidation of salicylic acid to 2,3- and 2,5-dihydroxybenzoic acids, and catechol. 相似文献
78.
An enolate-imine condensation using the lithium dianion of 3-hydroxy-butanoate and N-acylaldimines gave the key intermediate for the preparation of (+)-thienamycin with improved stereoselection in the presence of lithium chloride. 相似文献
79.
Ikuo Narisawa Masaru Ishikawa Hiroyuki Ogawa 《Journal of Polymer Science.Polymer Physics》1977,15(6):1055-1066
The micromechanism of the fatigue process in highly oriented nylon 6 fibers is discussed on the basis of changes in mechanical and structural properties during fatiguing. Experimental results show that the fatigue process can be divided into two stages. The characteristic features in the initial period are increases in breaking strength, long period, and molecular orientation, and a reduction in dye penetration. In the second period, after about 500 cycles, breaking strength and orientation decrease slightly, and the long period, permanent strain, and dye penetration increase with duration of fatiguing. It is demonstrated that the structural changes mainly occur in the amorphous regions of the fiber structure. The structural and mechanical changes in the initial period lead to the conclusion that the initial cyclic strain causes strain hardening caused by extended tie chains which do not rupture. A combination of load bearing by tie chains and sliding motion of the fibrillar elements can explain the progressive degradation of the fiber during the second stage of fatiguing. 相似文献
80.
Mitsuru Yoshioka Ikuo Kikkawa Teruji Tsuji Yasuhiro Nishitani Sachio Mori Kyo Okada Masayuki Murakami Fumihiko Matsubara Masaaki Yamaguchi Wataru Nagata 《Tetrahedron letters》1979,20(44):4287-4290
A intermediate was obtained by novel reductive cleavage of , prepared from in steps including a new ester to ketone conversion. Regioselective bromination of followed by substitution and known conversions gave 1-oxacephems . 相似文献