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61.
Shmuel Cohen Georgia Wollmann Lina Ben-Dor Yizhak Marcus 《Journal of Crystal Growth》2004,270(3-4):589-592
Single crystals of the congruently melting equimolar mixture of magnesium nitrate hexahydrate and nickel nitrate hexahydrate have been grown. The compound crystallizes in a structure foreign to both components, namely in the monoclinic cobalt nitrate hexahydrate structure. The cations are located at random on the cation sub-lattice of the latter crystalline structure. 相似文献
62.
George Ioannou Gregory Prastacos Georgia Skintzi 《Annals of Operations Research》2004,126(1-4):195-213
In this paper we address the problem of inventory positioning, i.e., the determination of the supply chain node where inventory should be held, to minimize holding costs given a pre-specified order fill rate. A single-echelon inventory system with multiple products models the problem. The value of inventory is assumed to be an increasing function of the amount of processing performed at upstream nodes, while achieved fill-rates are dependent on the distance or time between the inventory storage and customer locations. We propose a novel analytical approach to solve the problem for the case of normally distributed demand that is based on iterative calculations of inventory holding costs at the various potential inventory locations. 相似文献
63.
64.
A general method to construct a variety of nitrogen heterocycles is introduced. 2-Bromobenzoic acids or acid chlorides are used as the common building blocks to couple with appropriate nitrogen-containing compounds. Sequential aryl radical cyclizations including conjugate additions, spirocyclizations, homolytic and ipso aromatic substitutions, and 1,5-hydrogen atom transfers are employed to prepare tri- and tetracyclic isoindolinones, benzolactams, isoquinolinones, azabenzoisocoumarins, and bridged-azabicyclic compounds. 相似文献
65.
Teacher education programs are cognizant of the need to prepare preservice teachers (PTs) to work effectively with children from diverse cultural backgrounds. Well-constructedfield experiences can help PTs develop awareness and gain understanding of important cultural considerations related to effective teaching and learning ( Sleeter, 2001 ). This paper describes a unique field assignment created for an Elementary Math Methods course in which 61 PTs were trained to conduct a semi-structured interview with a student whose cultural background was different than their own. PTs transcribed their own interviews and completed a guided reflection on their experiences. Reflections were submitted and analyzed for emerging themes. Analyses suggest that the structured interview component of this field assignment provided PTs with increased insight into mathematics instruction and the learning needs of diverse students. We also discuss the value and limitations of this instructional innovation and propose avenues by which to continue to help PTs grow toward becoming culturally relevant pedagogists ( Irvine, 2003 ). 相似文献
66.
Reviewing the literature solubility isotherms in the ternary systems K2SO4–MSO4–H2O (M = Co, Ni, Cu, Zn) revealed a lack at ambient temperatures. The solid–liquid phase equilibria have been determined in the systems K2SO4–MSO4–H2O (M = Co, Ni, Cu) at T = 313 K. With increasing bivalent metal sulfate concentration, the solubility of potassium sulfate rises until the two-salt point is reached. Reciprocally, the solubility of the bivalent metal sulfate hydrates (CoSO4·7H2O, α-NiSO4·6H2O, CuSO4·5H2O) increases with rising potassium sulfate concentration. In all three systems the double salts of Tutton's type K2SO4·MSO4·6H2O (M = Co, Ni, Cu) are formed. 相似文献
67.
We provide sharp lower and upper bounds on the ratio of decentralized to centralized profits when multiproduct firms offering differentiated products engage in price competition. The bounds depend on the demand sensitivity matrix but are independent of marginal costs. 相似文献
68.
Kousoulos C Tsatsou G Apostolou C Dotsikas Y Loukas YL 《Analytical and bioanalytical chemistry》2006,384(1):199-207
A semi-automated liquid chromatography–tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous quantification
of the antifungal drug itraconazole (ITZ) and its coactive metabolite hydroxyitraconazole (OH-ITZ) in human plasma. The plasma
samples underwent liquid–liquid extraction (LLE) in 2.2 mL 96 deepwell plates. ITZ, OH-ITZ and the internal standard (IS)
R51012 were extracted from plasma, using a mixture of acetonitrile (ACN) and methyl t-butyl ether (MTBE) as the organic solvent. This specific mixture, due to its composition, had a significant impact on the
performance of the assay. All liquid transfer steps, including preparation of calibration standards and quality control samples
as well as the addition of the IS, were performed automatically using robotic liquid handling workstations for parallel sample
processing. After vortexing, centrifugation and freezing, the supernatant organic solvent was evaporated. The analytes and
IS were dissolved in a small volume of a reconstitution solution, an aliquot of which was analyzed by combined reversed phase
LC/MS/MS, with positive ion electrospray ionization and a TurboIonSpray interface, using multiple reactions monitoring (MRM).
The method was shown to be sensitive and specific to both ITZ and OH-ITZ, it revealed excellent linearity for the range of
concentrations 2–500 ng mL−1 for ITZ and 4–1000 ng mL−1 for OH-ITZ, it was very accurate and it gave very good inter- and intra-day precisions. The proposed high-throughput method
was employed in a bioequivalence study after per os administration of two 100 mg tablets of ITZ, and it allowed this study
to be completed in under four days. 相似文献
69.
In this paper, we consider a variety of models for dealing with demand uncertainty for a joint dynamic pricing and inventory
control problem in a make-to-stock manufacturing system. We consider a multi-product capacitated, dynamic setting, where demand
depends linearly on the price. Our goal is to address demand uncertainty using various robust and stochastic optimization
approaches. For each of these approaches, we first introduce closed-loop formulations (adjustable robust and dynamic programming),
where decisions for a given time period are made at the beginning of the time period, and uncertainty unfolds as time evolves.
We then describe models in an open-loop setting, where decisions for the entire time horizon must be made at time zero. We
conclude that the affine adjustable robust approach performs well (when compared to the other approaches such as dynamic programming,
stochastic programming and robust open loop approaches) in terms of realized profits and protection against constraint violation
while at the same time it is computationally tractable. Furthermore, we compare the complexity of these models and discuss
some insights on a numerical example. 相似文献
70.
Georgia Pagona Takayuki Aono Hisanori Shinohara Nikos Tagmatarchis 《Tetrahedron letters》2010,51(45):5896-5912
La@C82 is recognized by an isophthaloyl-bridged porphyrin dimer forming a stable 1:1 supramolecular complex with an association constant Kassoc = (67.3 ± 3.2) × 103 M−1. 相似文献