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991.
992.
993.
Liang-Yuh Ouyang Neng-Che Yeh Kun-Shan Wu 《The Journal of the Operational Research Society》1996,47(6):829-832
In a recent paper, Ben-Daya and Raouf presented a continuous review inventory model in which they considered both lead time and the order quantity as decision variables where the shortages are neglected. We assume here that the shortages are allowed and we extend the Ben-Daya and Raouf model by adding the stockout cost. Furthermore, the effects of parameters are also included. 相似文献
994.
欧阳功博 《首都师范大学学报(自然科学版)》1988,(4)
本文定义了Z上正交对称阵的合同相似,并给出了Z上n阶正交对称阵在合同相似这一等价关系下的标准形式、完备不变量和分类数目。 相似文献
995.
Biocatalytic synthesis of (R)-(-)-mandelic acid from racemic mandelonitrile by a newly isolated nitrilase-producer Alcaligenes sp. ECU0401 总被引:1,自引:0,他引:1
Yu Cai He Jian He Xu Yi Xu Li Ming Ouyang Jiang Pan Laboratory of Biocatalysis Biopwcessing State Key Laboratory of Bioreactor Engineering East China University of Science Technology Shanghai China 《中国化学快报》2007,18(6):677-680
By using acetonitrile as the sole nitrogen source, a microbial strain with high nitrilase activity, named as Alcaligenes sp. ECU0401, was newly isolated from soil, which could enantioselectively transform racemic mandelonitrile into (R)-(-)-mandelic acid, with an enantiomeric excess of >99.9%. 相似文献
996.
Conan F Le Gall B Kerbaol JM Le Stang S Sala-Pala J Le Mest Y Bacsa J Ouyang X Dunbar KR Campana CF 《Inorganic chemistry》2004,43(12):3673-3681
Under strictly anhydrous conditions, no reaction occurs between Mo(2)(O(2)CCMe(3))(4) and tetracyanoethylene, TCNE, at room temperature, but after addition of 1 equiv of water, a reaction proceeds to form [Mo(2)(O(2)CCMe(3))(3)((NC)(2)CC(CN)CONH)], 1. The compound contains a quadruple-bonded Mo(2) unit and the 2,3,3-tricyanoacrylamidate anion as a ligand (TC3A), a very unusual hydrolyzed form of TCNE. Two different solid-state structures were obtained after crystallization of 1. Crystals obtained from CH(2)Cl(2) consist of a two-dimensional network, and crystals grown from a C(6)H(6) solution form a 1-D chain motif. In both cases, the TC3A ligand acts as a polydentate ligand involving a bidentate OCN bridging unit and two CN groups. The electrochemical and spectroscopic (IR, UV/vis/near-IR, NMR, EPR) properties of 1 support the formulation in solution as a discrete 1:1 complex of the TC3A donor ligand and a Mo(2) unit with no charge transfer. The coordinated TC3A ligand exhibits redox properties similar to those of free TCNE. 相似文献
997.
X. M. Li C. F. Ding B. Q. Tian Q. Liu S. S. Zhang H. Xu P. K. Ouyang 《Chemical Papers》2006,60(3):220-223
The crystal structure of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane has been determined by single crystal X-ray diffraction method. The crystal belongs to triclinic system, space group P-1 with unit cell constants a = 11.2877(9) Å, b = 11.9539(9) Å, c = 12.2365(9) Å, α = 97.2580(10)°, β = 116.2850(10)°, γ = 106.3710(10)°, V = 1358.48(18) Å 3, Z = 2, D c = 1.234 g/cm3, μ = 0.079 mm?1, F(000) = 536, R and w(R) are 0.0718 and 0.2055, respectively, for 5239 unique reflections with 3745 observed reflections (I > 2σ(I)). 相似文献
998.
Chai Z Mao X Hu Z Zhang Z Chen C Feng W Hu S Ouyang H 《Analytical and bioanalytical chemistry》2002,372(3):407-411
Recent achievements in speciation studies of trace elements in the biological and environmental sciences by nuclear analytical techniques, mainly molecular activation analysis, position-sensitive spectrometry with a variety of exciting sources, and synchronous radiation-based analytical techniques (although radioisotope or enriched stable isotope-based speciation techniques are also used), particularly in our laboratory, are outlined. In this paper the merits and drawbacks of the nuclear analytical techniques are discussed, as are reagent blanks, contamination, and artifacts. 相似文献
999.
High-speed counter-current chromatography was applied as a method to develop fingerprinting of Salvia miltiorrhiza Bunge, a popular traditional Chinese medicine, in our previous study. Important active constituents that were directly related to the therapy effect should be identified. Each effluent fraction and standard samples (cryptotanshinone, tanshinoneI and tanshinoneIIA) were analyzed by ultraviolet spectroscopy and liquid chromatography-mass spectroscopy. It was concluded from the UV-Vis spectrograms, retention times in LC analysis and mass spectrograms, that fractions 7, 8 and 11 were respectively cryptotanshinone (Mr 296), tanshinone I (Mr 276) and tanshinone IIA (Mr 294). 相似文献
1000.
Xing-Mei Ouyang Taka-aki Okamura Wei-Yin Sun Wen-Xia Tang 《Journal of solid state chemistry》2004,177(1):350-360
A macrocyclic ligand L with two diethylenetriamine units linked by two rigid biphenylene spacers was used as building block for construction of metal-organic frameworks. A silver(I) complex with macrocyclic and open-chain mix-type ligands [Ag2(L)(L′)](ClO4)2 (1) [L′=1,6-bis(4-imidazol-1′-ylmethylphenyl)-2,5-diazahexane] was obtained by reaction of L and L′ together with AgClO4·H2O. It is interesting that the open-chain tetradentate ligand L′ only served as a bidentate ligand to bridge the Ag2L units into an infinite one-dimensional (1D) cationic chain. Neutral 1D chain coordination polymer [Cu2(L)(μ-SO4)2]·3H2O·3MeOH (2) is formed by sulfate bridges between the neighboring Cu2L units. When L reacted with nickel(II) sulfate instead of copper(II) sulfate, a monomacrocycle molecular complex [Ni2(L)(H2O)4(SO4)2] (3) was obtained in which the sulfate anion acts as monodentate ligands rather than as bridges. When Cd(II) salts were used for the reactions with L, another two neutral 1D coordination polymers, [Cd2(L)(μ-Cl)2Cl2]·2H2O (4) and [Cd2(L)(μ-Br)2Br2] (5), with the same structure were isolated. All the synthesized complexes exhibit three-dimensional framework structures linked by various hydrogen bonds. The photoluminescent properties of the synthesized complexes were studied in the solid state at room temperature, and the Ag(I) and Cd(II) complexes were found to show strong blue luminescence. 相似文献