排序方式: 共有205条查询结果,搜索用时 171 毫秒
101.
Farshid Samadi Abolfazl Mirzazadeh Mir Mohsen Pedram 《Applied Mathematical Modelling》2013,37(10-11):6683-6694
In the real world markets, demand is influenced by different parameters. Recently, many researchers have been interested in integrated production and marketing planning strategies in inventory models where demand depends on different parameters such as price and/or marketing expenditure. The quality of services that are offered to customers of a product is one of the most important parameters that affects demand in the real markets and has not been considered in development of inventory models. On the other hand, the cost parameters in real inventory systems and other parameters such as price, marketing and service elasticity to demand are imprecise and uncertain in nature. So, the notion of fuzziness can be applied to cope with this uncertainty. In this paper, a new fuzzy profit maximization inventory model with shortages is proposed. The demand is considered as a power function of price, marketing expenditure and service expenditure. Furthermore, unit cost is determined as a power function of order quantity. Since the proposed model is in a fuzzy environment, a fuzzy decision should be made to meet the decision criteria, and the results should be fuzzy. Therefore, the proposed model is formulated and solved using geometric programming and fuzzy optimization techniques to derive an approximation of the results’ membership functions. The model is illustrated with a numerical example and finally a case study is provided for evaluation and validation of the results of model. 相似文献
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103.
A hydrophilic transparent triacetyl cellulose membrane was adopted as a pH optode by immobilizing highly selective and sensitive Nile blue indicator on the membrane. Contrary to the common procedure for determinations using optodes, in which a steady state response is measured, a new approach is introduced in which the dynamic response of the optode is used as the analytical signal. While in common procedures, pH optodes exhibit limited linear dynamic range (often 2–4 pH units only), it is shown that in a time-based flow method, an optode with only one acid-base indicator can be used for measurement in the pH range of 0–10. The procedure is simple, inexpensive and rapid. 相似文献
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105.
A simple and efficient procedure for the synthesis of symmetrical bis-Schiff bases has been described that employs a condensation reaction of symmetrical primary bis-amine of 5,5′-methylenebis(2-aminothiazole) with a series of aromatic aldehyde derivatives under solvent-free conditions at elevated temperature. The advantages of these reactions are simplicity of the reaction procedure, short reaction times, simple workup, catalyst-free conditions, and pure products in good to excellent yields. Details of the reaction conditions are discussed. 相似文献
106.
A one-pot, three-component, Mannich condensation of electron-rich aromatic compounds such as 5-methyl-2-hydroxyphenyl sulfide, 2-aminopyrimidine, and various aromatic aldehydes were used to prepare a series of new unsymmetrical multidentate aminophenol ligands. These compounds were synthesized in solvent-free conditions as a fast, simple, convenient, and uncatalyzed method. Details of the reaction conditions are discussed. 相似文献
107.
Ghandi M Bozcheloei AH Nazari SH Sadeghzadeh M 《The Journal of organic chemistry》2011,76(24):9975-9982
We have developed a solvent-dependent method for the synthesis of novel benzo-δ-sultone scaffolds. A variety of benzylbenzo[e][1,2]oxathiin-4(3H)-one-2,2-dioxides were obtained in high yields in DMF using a one-pot, DBU-catalyzed condensation of 2-hydroxybenzaldehydes with a number of (E)-2-phenylethenesulfonyl chlorides. On the other hand, the initially prepared 2-formylphenyl-(E)-2-phenylethenesulfonate derivatives underwent DBU-catalyzed reactions to a series of 3-[methoxy(phenyl)methyl]benzo[e][1,2]oxathiine-2,2-dioxides in moderate to good yields in MeOH. These reactions presumably proceed via DBU-catalyzed O-sulfonylation/intramolecular Baylis-Hillman/1,3-H shift or dehydration tandem sequences, respectively. 相似文献
108.
We propose a new fast scalable method for achieving a two-qubit entangling gate between arbitrary distant qubits in a network by exploiting dispersionless propagation in uniform chains. This is achieved dynamically by switching on a strong interaction between the qubits and a bus formed by a nonengineered chain of interacting qubits. The quality of the gate scales very efficiently with qubit separations. Surprisingly, a sudden switching of the couplings is not necessary. Moreover, our gate mechanism works for multiple gate operations without resetting the bus. We propose a possible experimental realization in cold atoms trapped in optical lattices and near field Fresnel trapping potentials. 相似文献
109.
Abolfazl Mohebbi Arjomand Mehrabani-Zeinabad Mohammadhossein Navid-Famili 《Polymer Science Series A》2011,53(11):1076-1085
In this study, dynamic behaviour of nucleation was investigated during foaming process of polystyrene in presence of nano aluminium oxide. Nano aluminium oxide played a role of a bubble nucleating agent within polystyrene matrix. Foaming process was visually observed in conjunction with supercritical N2. Furthermore, the effect of nano Al2O3 compositions on the growth rate was studied. Also, final density per unit area and the average size in the latest growth steps were assessed. The obtained data were compared with foaming process for unfilled polystyrene under the same conditions. The results demonstrated that the final sizes of bubbles as well as the average cell density of the foam were reduced by using of nucleating agent. The growth rate of bubbles was also decreased by increasing the nano Al2O3 particles content. In addition, influence of temperature on foam density of nanocomposite specimens was greater than unfilled polystyrene foam. In presence of nano particle, the cell density was uniformly distributed in nanocomposites specimens. The article is published in the original. 相似文献
110.
Noruzian Fatemeh Olyaei Abolfazl Hajinasiri Rahimeh 《Research on Chemical Intermediates》2019,45(9):4383-4394
Research on Chemical Intermediates - A catalyst-free, simple and green protocol has been accomplished for the synthesis of novel 1H-furo[2,3-c]pyrazole-4-amines in a one-pot four-component domino... 相似文献