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961.
A successive quadratic programming method for a class of constrained nonsmooth optimization problems
Masao Fukushima 《Mathematical Programming》1990,49(1-3):231-251
In this paper we present an algorithm for solving nonlinear programming problems where the objective function contains a possibly nonsmooth convex term. The algorithm successively solves direction finding subproblems which are quadratic programming problems constructed by exploiting the special feature of the objective function. An exact penalty function is used to determine a step-size, once a search direction thus obtained is judged to yield a sufficient reduction in the penalty function value. The penalty parameter is adjusted to a suitable value automatically. Under appropriate assumptions, the algorithm is shown to produce an approximate optimal solution to the problem with any desirable accuracy in a finite number of iterations. 相似文献
962.
(Z)-1-Bromo-1-alkenes were stereoselectively prepared in high yields in a short reaction time by microwave irradiation of the corresponding anti-2,3-dibromoalkanoic acids in a Et3N/DMF system. A one-pot synthesis of terminal alkynes and enynes from 2,3-dibromoalkanoic acids were also developed by microwave-induced reaction. 相似文献
963.
Gao JJ Nakamura N Min BS Hirakawa A Zuo F Hattori M 《Chemical & pharmaceutical bulletin》2004,52(6):688-695
For quantitative determination of 19 triterpene constituents, including six ganoderma alcohols (1-6) and 13 ganoderma acids (7-19), in the products of Ganoderma lucidum, an analytical system was developed using high-performance liquid chromatography with an ODS column. The mobile phase was a linear gradient of 1% AcOH/H(2)O-CH(3)CN and 2% AcOH/H(2)O-CH(3)CN, and the elution profile was monitored at 243 and 250 nm for ganoderma alcohols and acids, respectively. The relative standard deviations of this method were less than 2.35% and 2.18% (n=5) for intraday and interday assays, and the recoveries were 90.9-100.8% and 93.4-103.9% for constituents of alcohol and acid groups, respectively. This system was applied to a quantitative determination of the constituents in 10 different products of G. lucidum: six usual umbrella forms of the fruiting bodies, three antlered forms of the fruiting bodies and spores, and eight specimens from the same G. lucidum strain, which was parasitized on logs from different plants or different fungus beds. The analytical results indicated that the quantity and composition of these triterpenes differed appreciably among various specimens, but the relative ratio of the alcohols and acids was not significantly different when the same strain of G. lucidum was used. 相似文献
964.
The pH response of an a-ISFET with xanthine oxidase immobilized on a ca. 20-μm thick poly(vinyl butyral) membrane over the gate insulator, is used to detect the uric acid produced by enzyme-catalyzed oxidation of hypoxanthine. The pH sensitivity between pH 5.0 and 10.0 is ca 48 mV/pH at 32°C in 10 mM phosphate buffer. The change in the output gate voltage 1 min after sample injection, is linearly related to the logarithm of the hypoxanthine concentration in the range 0.02–0.1 mM. The optimum buffer pH is 7.5. The system can be used for 2 weeks with 30% loss of enzymatic activity. 相似文献
965.
Cation-exchange displacement chromatography of VO2+ was carried out for studying vanadium isotope effects in carboxylate ligand-exchange systems. The heavier isotope 51V was enriched in the carboxylate complex solution. The isotope separation coefficients epsilon(= alpha-1) for 50V/51V were 2.2 x 10(-4) and 2.4 x 10(-4) for citrate and lactate systems at 298 K, respectively. These values are much larger than those obtained in a previous study on the malate system. The existence of binuclear complexes of VO2+ may create the conditions for larger isotope fractionation. From the viewpoint of the process development of isotope separation, the heights equivalent to a theoretical plate of these processes were analyzed and found to be very small in each system due to the homogeneous, small and highly porous resin used. Citrate may be better than the other tested systems for the vanadium isotope separation. 相似文献
966.
Densities and sound velocities in dilute aqueous solutions ofN-acetyl-DL-serinamide andN-acetyl-L-threoninamide were measured at 5, 15, 25, 35, and 45°C. Partial molar volumes and partial molar adiabatic compressibilities
of these amino acid derivatives at infinite dilution were determined. The partial molar quantities for the parent amino acids,
serine and threonine, were also determined and compared with the acetyl amide derivatives. The contribution of the side chain
of theN-acetyl amino acid amide or amino acid to the partial molar quantities were estimated from the difference between the partial
molar quantities for the solute studied and those for the corresponding species,N-acetyl-glycinamide or glycine, without the side chain. 相似文献
967.
Michihiko Noguchi Kenjiro Onimura Yuji Isomura Shoji Kajigaeshi 《Journal of heterocyclic chemistry》1991,28(4):885-890
The treatment of (5,5-dimethyl-3-oxo-1-cyclohexenyl)iminotriphenylphosphorane ( 2 ) with phenyl isocyanate ( 3a ) gave N-(5,5-dimethyl-3-oxo-1-cyclohexenyl)-N'-phenylcarbodiimide ( 4a ) in situ. The reaction of 4a with enamines proceeded smoothly to afford the pyridine ring formation with the elimination of amine. This means that 4a is regarded as a new class of 2-aza-1,3-butadiene. The scopes and limitation of this reaction are also discussed. 相似文献
968.
4-dimethylamino-2-glycosylaminoquinazoline derivatives were synthesized by cyclodesulfurization of N-aryl-N'-glycosyl thioureas with dimethylcyanamide in the presence of silver triflate in good yields. 相似文献
969.
Yamamura K Kawabata S Kimura T Eda K Hashimoto M 《The Journal of organic chemistry》2005,70(22):8902-8906
[reaction: see text] Benzalacetone analogues of naphth[1,2-a]azulene (8), naphth[2,1-a]azulene (13), and naphth[2,3-a]azulene (18) were synthesized from 2-(5-methyl-2-furyl)-1-tropylionaphthalene (7), 1-(5-methyl-2-furyl)-2-tropylionaphthalene (12), and 2-(5-methy-2-furyl)-3-tropylionaphthalene (17), respectively. The synthetic method is based on furan ring-opening reaction by the intramolecular electrophilic attack of a tropylium ion. Single-crystal X-ray work on the naphth[1,2-a]azulene derivative (8) revealed that its tetracyclic system exhibited deformation from planarity similar to that of benzo[c]phenanthrene (tetrahelicene). A centrosymmetric associated dimer structure, just like the molecules of carboxylic acids but via C=O...H-C hydrogen bonds, was found in the crystal. Reduction of bond-length alternation in the seven-membered ring was also found. 相似文献
970.
Pyrochlore-type oxide, SnII1.64(Ta1.88SnIV0.12)O6.58 was oxidized for exploring novel metastable phases. Two novel SnIV0.82(Ta0.94SnIV0.06)O4.11 phases with a fluorite-related structure, which was obtained as a pure phase, and with a rutile-related structure appearing as an impurity for the fluorite-related phase were successfully obtained similar to the previous Sn-Nb-O system. The ordered arrangement of respective cations of Sn and (0.94Ta+0.06Sn) in the precursor SnII1.64(Ta1.88SnIV0.12)O6.58 was left in the both oxidized SnIV0.82(Ta0.94SnIV0.06)O4.11 phases. In contrast to the previous Sn-Nb-O system, the cation-ordered α-PbO2-related SnIV0.82(Ta0.94SnIV0.06)O4.11 could not be obtained in the present conditions. Such a difference between the Sn-Ta-O and Sn-Nb-O systems was interpreted by larger energy barrier of the transformation from the fluorite-related phase to α-PbO2-related phase in Sn-Ta-O system than in Sn-Nb-O system. 相似文献