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191.
Minakata S Morino Y Ide T Oderaotoshi Y Komatsu M 《Chemical communications (Cambridge, England)》2007,(31):3279-3281
A new and simple method for the synthesis of oxazolines from readily accessible olefins and amides using tert-butyl hypoiodite is described; aromatic/aliphatic olefins and amides can be used in the reaction to give a variety of oxazolines. 相似文献
192.
Yoshinobu Nakai Keiji Yamamoto Katsuhide Terada Hidetoshi Horibe 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(3-4):523-531
Summary The effect of tri-O-methyl--cyclodextrin(methyl--CD) on the partition coefficients of drugs, such as p-nitrophenol, salicylic acid, benzoic acid, and aspirin, was studied at 25°C. The partition coefficients of these drugs were increased linearly with methyl--CD concentration. The increase of partition coefficients was interpreted by the 11 complex formation between methyl--CD and the drug in CHCl3 phase.The interaction between p-nitrophenol and methyl--CD in solution was studied by UV and PMR spectroscopies. It was concluded that p-nitrophenol is included in the cavity of methyl--CD in both aqueous solution and CHCl3 solution.Inclusion compounds of these drugs with methyl--CD in the solid state were studied by X-ray diffractometry, IR spectroscopy, and DSC measurements. 11 crystalline inclusion compounds were obtained from hot water. It is also suggested that amorphous inclusion compound was obtained by the grinding of drug with methyl--CD.The dissolution rate and the bioavailability of ketoprofen were significantly increased in the presence of methyl--CD. The bioavailability of ketoprofen after oral administration with methyl--CD to rats was 3.7 times that of ketoprofen alone. 相似文献
193.
Kiyomi Kakiuchi Takuo Nakao Mitsunori Takeda Yoshito Tobe Yoshinobu Odaira 《Tetrahedron letters》1984,25(5):557-560
The novel synthesis of descarboxyquadrone (3) and its model compound (4) by using the acid-catalyzed rearrangement of [4.3.2]propellanones is described. 相似文献
194.
Yasuo Sakai Shingo Toyotani Yoshito Tobe Yoshinobu Odaira 《Tetrahedron letters》1979,20(40):3855-3856
Oxidative decarboxylation of [n.2.2]propellane carboxylic acids (-) with lead tetraacetate gave the bicyclic acetates (, ) having a bridgehead double bond and/or the tricyclic acetates (, ) in good yields. Vapor phase thermolysis of or afforded the bridgehead olefin or quantatively. 相似文献
195.
Itaru Sakurai Jinji Suzuki Yoshinobu Kotani Hiroyoshi Naito Akira Yoshida 《Proceedings of the Combustion Institute》2013,34(2):2727-2734
In the present study, extinguishment of propane/air co-flowing diffusion flame by fine water droplets was investigated experimentally. Water droplets are generated by piezoelectric atomizers with the maximum droplets flow rate of 1500 ml/h. When the fuel injection velocity Uf is low, an attached laminar diffusion flame with a premixed flame at the base is stabilized. At some distance from the burner rim, a transition from laminar to turbulent diffusion flame occurs, and a turbulent diffusion flame is formed in the downstream region. When the fuel injector rim is thin (δ = 0.5 mm), the flame stability deteriorates with increase of the co-flowing air stream velocity Ua and the water droplets flow rate Qm. The stability mechanism can be explained by the balance of the gas velocity and the burning velocity of premixed flame formed at the base. However, when the injector rim is thick (δ = 5 mm), a recirculation zone is produced downstream of the injector rim. The dependence of the quenching distance Hq on Uf and Qm is relatively weak, and the stability diagram shows curious features. It was shown that Ua is crucially important since it determines flow residence time; if Ua < 0.4 m/s, water droplets can evaporate when they go by the recirculation zone, and the water vapor can diffuse into the recirculation zone. However, if Ua > 0.4 m/s, the water droplets should pass by the recirculation zone without sufficiently evaporated and are not so effective to extinguish the flame. The supply velocity of droplet-laden air should be low enough so that water droplets can evaporate and water vapor can diffuse into the premixed region at the base to obtain sufficient effectiveness of water droplets for fire suppression. 相似文献
196.
Yoshinobu Habara 《Physics letters. [Part B]》2012,707(1):198-202
We propose a mechanism for the generation of temperature fluctuations of cosmic microwave background. We consider a large number of fields, such as Kaluza-Klein modes and string excitations. Each field contributes to the gravitational potential by a small amount, but an observable level of temperature fluctuations is achieved by summing up the contribution of typically of order 1014 fields. Tensor fluctuations are hardly affected by these fields. Our mechanism is based on purely quantum effects of the fields which are classically at rest, and is different from the one in slow-roll inflation. Using the observed data, we find constraints on the parameters of this model, such as the size of the extra dimensions and the string scale. Our model predicts a particular pattern of non-gaussianity with a small magnitude. 相似文献
197.
Kajikawa T Okumura S Iwashita T Kosumi D Hashimoto H Katsumura S 《Organic letters》2012,14(3):808-811
Fucoxanthin exhibits high energy transfer efficiencies to Chlorophyll a (Chl a) in photosynthesis in the sea. In order to reveal how each characteristic functional group, such as the length of the polyene chain, allene, and conjugated carbonyl groups, of this marine natural product are responsible for its remarkably efficient ability, the total synthesis of fucoxanthin by controlling the stereochemistry was achieved. The method established for fucoxanthin synthesis was successfully applied to the synthesis of the C42 longer chain analogue. 相似文献
198.
Product study and kinetic data of the solvolysis of the bridgehead chlorides () and ( indicate the neighboring group participation of the strained bridgehead double bonds. 相似文献
199.
Akiko Takeda Mahesan Niranjan Jun-ya Gotoh Yoshinobu Kawahara 《Computational Management Science》2013,10(1):21-49
Index tracking is a passive investment strategy in which a fund (e.g., an ETF: exchange traded fund) manager purchases a set of assets to mimic a market index. The tracking error, i.e., the difference between the performances of the index and the portfolio, may be minimized by buying all the assets contained in the index. However, this strategy results in a considerable transaction cost and, accordingly, decreases the return of the constructed portfolio. On the other hand, a portfolio with a small cardinality may result in poor out-of-sample performance. Of interest is, thus, constructing a portfolio with good out-of-sample performance, while keeping the number of assets invested in small (i.e., sparse). In this paper, we develop a tracking portfolio model that addresses the above conflicting requirements by using a combination of L0- and L2-norms. The L2-norm regularizes the overdetermined system to impose smoothness (and hence has better out-of-sample performance), and it shrinks the solution to an equally-weighted dense portfolio. On the other hand, the L0-norm imposes a cardinality constraint that achieves sparsity (and hence a lower transaction cost). We propose a heuristic method for estimating portfolio weights, which combines a greedy search with an analytical formula embedded in it. We demonstrate that the resulting sparse portfolio has good tracking and generalization performance on historic data of weekly and monthly returns on the Nikkei 225 index and its constituent companies. 相似文献
200.
Yoshinobu Kamishima 《Geometriae Dedicata》2001,84(1-3):115-124
The purpose of this note is to show that the complex two-dimensional locally conformal Kähler solvmanifold obtained by L. de Andres, Fernandez, Mencia and Cordero is holomorphically homothetic to the Inoue surface equipped with the locally conformal Kähler structure constructed by Tricerri. In order to prove it, we collect several facts related to the existence of locally conformal Kähler structure on compact complex surfaces. 相似文献