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61.
In this article, a multiobjective problem with a feasible set defined by inequality, equality and set constraints is considered, where the objective and constraint functions are locally Lipschitz. Several constraint qualifications are given and the relations between them are analyzed. We establish Kuhn-Tucker and strong Kuhn-Tucker necessary optimality conditions for (weak) quasi e?ciency in terms of the Clarke subdifferential. By using two new classes of generalized convex functions, su?cient conditions for local (weak) quasi e?cient are also provided. Furthermore, we study the Mond-Weir type dual problem and establish weak, strong and converse duality results. 相似文献
62.
Ghassan?ShobakiEmail author Jafar?Jamal 《Computational Optimization and Applications》2015,60(2):343-376
This article presents an exact algorithm for the precedence-constrained traveling salesman problem, which is also known as the sequential ordering problem. This NP-hard problem has applications in various domains, including operational research and compilers. In this article, the problem is presented and solved in the context of minimizing switching energy in compilers. Most previous work on minimizing switching energy in the compiler domain has been limited to simple heuristics that are not guaranteed to give an optimal solution. In this work, we present an exact algorithm for solving the switching energy minimization problem using a branch-and-bound approach. The proposed algorithm is simple and intuitive, yet powerful. It is the first exact algorithm for the switching energy problem that is shown to solve real instances of the problem within a few seconds per instance. Compared to previous work in the operational research domain, the proposed algorithm is believed to be the most powerful exact algorithm that does not require a linear programming formulation. The proposed algorithm is experimentally evaluated using instances taken from a production compiler. The results show that with a time limit of 10 ms per node, the proposed algorithm optimally solves 99.8 % of the instances. It optimally solves instances with up to 598 nodes within a few seconds. The resulting switching cost is 16 % less than that produced without energy awareness and 5 % less than that produced by a commonly used heuristic. 相似文献
63.
Synthesis of Novel α‐(Acyloxy)‐α‐(quinolin‐4‐yl)acetamides by a Three‐Component Reaction between an Isocyanide,Quinoline‐4‐carbaldehyde,and Arenecarboxylic Acids
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Jafar Taran Ali Ramazani Sang Woo Joo Katarzyna Ślepokura Tadeusz Lis 《Helvetica chimica acta》2014,97(8):1088-1096
Novel α‐(acyloxy)‐α‐(quinolin‐4‐yl)acetamides were synthesized by the Passerini three‐component reaction between an isocyanide, quinoline‐4‐carbaldehyde, and arenecarboxylic acids in H2O. The reactions were carried out in one pot at room temperature with quantitative yields. 相似文献
64.
Mohammad Behbahani Hamid Sadeghi Abandansari Mani Salarian Meysam Babapour Akbar Bagheri Mohammad Reza Nabid 《Mikrochimica acta》2014,181(1-2):129-137
We have designed and synthesized a thermosensitive tri-block copolymer for selective trace extraction of Pb(II) ions from biological and food samples. The polymer was characterized by Fourier transform IR and NMR spectroscopy, and by gel permeation chromatography. The critical aggregation concentration and lower critical solution temperature were determined via fluorescence and UV spectrophotometry, respectively. The effects of solution pH value, amount of copolymer, of the temperature on extraction and on phase separation, and of the matrix on the extraction of Pb(II) were optimized. Pb(II) ions were then quantified by FAAS. The use of this copolymer resulted in excellent figures of merit including a calibration plot extending from 0.5 to 160 μg L?1 (with an R2 of >0.99), a limit of detection (LOD) as low as 90 pg L?1, an extraction efficiency of >98 %, and relative standard deviations of <4 % for eight separate extraction experiments. Figure
In this paper, for the first time an intelligent system using a thermosensitive tri-block copolymer for selective trace removal of Pb(II) in biological and food samples was designed and its determination was carried out by flame atomic absorption spectrometry. 相似文献
65.
Jafar Ezzati Nazhad DolatabadiOmid Mashinchian Baharak AyoubiAli Akbar Jamali Ahmad MobedDusan Losic Yadollah Omidi Miguel de la Guardia 《Trends in analytical chemistry : TRAC》2011,30(3):459-472
In the past two decades, nanoscale advanced materials have been explored for biosensing molecules, so new horizons have opened up for identifying and quantifying biomolecules, and possible early diagnosis of diseases.DNA nanobiosensors show promise. This article provides an overview on their optical and electrochemical aspects. We discuss recent progress in this field, describing basic concepts of molecular beacons and quantum dots as optical nano-imaging systems. Also, carbon nanotubes provide a platform for development and advancement of electrochemical DNA nanobiosensors, which are increasingly being implemented as robust tools for detection in biomedical sciences. 相似文献
66.
Precise measurements of density and sound velocity at different temperatures ranging from 283.15 to 308.15 K for solutions of PEGDME250, PEGDME500 and PEGDME2000 in water and of PEGDME500 in aqueous solutions of 0.500 mol kg−1 ammonium di-hydrogen phosphate ((NH4)H2PO4) and di-ammonium hydrogen phosphate ((NH4)2HPO4), binodal curves at temperature ranges 293.15-318.15 K for the aqueous PEGDME500 + (NH4)2HPO4, PEGDME500 + (NH4)3PO4, PEGDME2000 + (NH4)H2PO4, PEGDME2000 + (NH4)2HPO4, PEGDME2000 + (NH4)3PO4 and PPG400 + (NH4)2HPO4 two-phase systems, and liquid-liquid equilibrium data at temperature ranges 298.15-318.15 K for the aqueous PEGDME500 + (NH4)2HPO4 and PEGDME2000 + (NH4)2HPO4 two-phase systems have been taken. From the experimental density and sound velocity data, the apparent specific volume, excess specific volume, isentropic compressibility and isentropic compressibility deviation values have been determined and the effect of temperature, charge on the anion of electrolytes and molar mass of PEGDME on the volumetric and compressibility properties of the investigated polymer solutions as well as on the salting-out effect of PEGDMEs produced by ammonium phosphate salts has been studied. 相似文献
67.
Morra S Valetti F Sadeghi SJ King PW Meyer T Gilardi G 《Chemical communications (Cambridge, England)》2011,47(38):10566-10568
[FeFe]-hydrogenases are efficient natural catalysts that can be exploited for hydrogen production. Immobilization of the recombinant [FeFe]-hydrogenase CaHydA was achieved for the first time on an anatase TiO(2) electrode. The enzyme is able to interact and exchange electrons with the electrode and to catalyze hydrogen production with an efficiency of 70%. 相似文献
68.
Kumar KS Kumar PM Kumar KA Sreenivasulu M Jafar AA Rambabu D Krishna GR Reddy CM Kapavarapu R Shivakumar K Priya KK Parsa KV Pal M 《Chemical communications (Cambridge, England)》2011,47(17):5010-5012
Concurrent construction of five and six membered fused N-heretocyclic ring was achieved via a conceptually new three-component reaction affording 6,6a-dihydroisoindolo[2,1-a]quinazoline-5,11-diones as novel inhibitors of TNF-αin vitro. This represents one of the few examples of direct TNF-α inhibition by small molecules. 相似文献
69.
Mohammad Ghadermazi Marilyn M. Olmstead Jafar Attar Gharamaleki Shahideh Rostami 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(4):o134-o138
Two related proton‐transfer compounds, namely piperazine‐1,4‐diium 4‐oxo‐4H‐pyran‐2,6‐dicarboxylate monohydrate, C4H12N22+·C7H2O62−·H2O or (pipzH2)(cdo)·H2O, (I), and piperazine‐1,4‐diium bis(6‐carboxy‐4‐oxo‐4H‐pyran‐2‐carboxylate), C4H12N22+·2C7H3O6− or (pipzH2)(cdoH)2, (II), were obtained by the reaction of 4‐oxo‐4H‐pyran‐2,6‐dicarboxylic acid (chelidonic acid, cdoH2) and piperazine (pipz). In (I), both carboxyl H atoms of chelidonic acid have been transferred to piperazine to form the piperazine‐1,4‐diium ion. The structure is a monohydrate. All potential N—H donors are involved in N—H...O hydrogen bonds. The water molecule spans two anions via the 4‐oxo group of the pyranose ring and a carboxylate O atom. The hydrogen‐bonding motif is essentially two‐dimensional. The structure is a pseudomerohedral twin. In the asymmetric unit of (II), the anion consists of monodeprotonated chelidonic acid, while the piperazine‐1,4‐diium cation is located on an inversion centre. The single carboxyl H atom is disordered in two respects. Firstly, the disordered H atom is shared equally by both carboxylic acid groups. Secondly, the H atom is statistically disordered between two positions on either side of a centre of symmetry and is engaged in a very short hydrogen‐bonding interaction; the relevant O...O distances are 2.4549 (11) and 2.4395 (11) Å, and the O—H...O angles are 177 (6) and 177 (5)°, respectively. Further hydrogen bonding of the type N—H...O places the (pipzH2)2+ cations in pockets formed by the chains of (cdoH)− anions. In contrast with (I), the (pipzH2)2+ cations form hydrogen‐bonding arrays that are perpendicular to the anions, yielding a three‐dimensional hydrogen‐bonding motif. The structures of both (I) and (II) also feature π–π stacking interactions between aromatic rings. 相似文献
70.