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91.
Cyclization of hydralazine 1 with acid chlorides or ethyl cyanoacetate gave the appropriate s-triazolo derivatives, while with ketoesters or 1,2-dicyclohexanedione it afforded the as-triazino derivatives. Reaction of 1 with ketosteroids yielded hydrazones. Preliminary cardiovascular testing revealed possible hypotensive activity of some of these derivatives. 相似文献
92.
Ata Allah Taleizadeh Seyed Taghi Akhavan Niaki Farnaz Barzinpour 《Applied mathematics and computation》2011,217(22):9234-9253
In this paper, a multi-buyer multi-vendor supply chain problem is considered in which there are several products, each buyer has limited capacity to purchase products, and each vendor has warehouse limitation to store products. In this chain, the demand of each product is stochastic and follows a uniform distribution. The lead-time of receiving products from a vendor to a buyer is assumed to vary linearly with respect to the order quantity of the buyer and the production rate of the vendor. For each product, a fraction of the shortage is backordered and the rest are lost. The ordered product quantities are placed in multiple of pre-defined packets and there are service rate constraints for the buyers. The goal is to determine the reorder points, the safety stocks, and the numbers of shipments and packets in each shipment of the products such that the total cost of the supply chain is minimized. We show that the model of this problem is of an integer nonlinear programming type and in order to solve it a harmony search algorithm is employed. To validate the solution and to compare the performance of the proposed algorithm, a genetic algorithm is utilized as well. A numerical illustration and sensitivity analysis are given at the end to show the applicability of the proposed methodology in real-world supply chain problems. 相似文献
93.
Muhammad Amir Arain Feroza Hamid Wattoo Muhammad Hamid Sarwar Wattoo Allah Bux Ghanghro Syed Ahmad Tirmizi Javed Iqbal Shahnila Amir Arain 《Arabian Journal of Chemistry》2009,2(1):25-29
River water samples before and after mixing with industrial effluents were collected at an interval of 4 weeks for one year and analyzed for simultaneous determination of Fe3+, Cr3+, Mn2+, Cu2+, Ni2+and Co2+ after preconcentration using pentamethylene dithiocarbamate (PMDTC) as derivatizing reagent and subsequent solvent extraction by high performance liquid chromatography (HPLC). The average levels (n = 12) of metal ions were found in the range of 14.2–542 μg/L. The results were then compared with a standard flame atomic absorption spectrophotometric method revealed no significant differences. 相似文献
94.
In this work, a linear stability analysis is used to investigate a capillary surface waves between two horizontal finite fluid layers. The system is acted upon by a vertical periodic electric field. The problem examines few representatives of porous media. It is also includes finite conductivity, mass and heat transfer. It is assumed that the basic flow is two-dimensional streaming flow. A general dispersion relation governing the linear stability is derived. In contrast with our previous work [23], the present problem shows that the stability criterion depends on the mass and heat transfer parameter. The present study recovers some special cases upon appropriate data choices. The presence of finite conductivity’s together with the dielectric permeability’s make the uniform electric field plays a dual role in the stability criterion. This shows some analogy with the nonlinear stability theory. In addition, the mass and heat transfer parameter as well as the Darcy’s coefficients play a stabilizing role in the stability picture. In case of the Rayleigh–Taylor instability, by means of the Whittaker technique, the parametric excitation of the electrohydrodynamic surface waves is obtained. The transition curve equations are calculated up to the fourth order for a small dimensionless parameter. The analytical results are numerically confirmed. 相似文献
95.
Yong Sup Kim M. A. Rakha A. K. Rathie 《Computational Mathematics and Mathematical Physics》2010,50(3):387-402
The aim of this research paper is to obtain single series expression of
$
e^{ - x/2} _1 F_1 (\alpha ;2\alpha + i;x)
$
e^{ - x/2} _1 F_1 (\alpha ;2\alpha + i;x)
相似文献
96.
Synthetic approaches towards new condensed thienopyridine ring systems including furo[2,3-b]thieno[3,2-e]pyridines, bisthieno[2,3-b:3′,2′-e]pyridines, 5H-chromeno[2,3-b]thieno[3,2-e]pyridines, 5H-benzo(f)chromeno[2,3-b]thieno[3,2-e]pyridines have been achieved by application of intramolecular 4+2 cycloaddition reactions of suitably designed thieno[2,3-e][1,2,4]triazines tethered with alkene or alkyne terminals. 相似文献
97.
Sanaa O. Abd Allah Hamed A. Ead Nazmi A. Kassab Mohey M. Zayed 《Journal of heterocyclic chemistry》1983,20(1):189-191
The new fused imidazo[5,1-c]-1,2,4-triazoles 4 were obtained by cyclization of the corresponding 2-imidazolidinone 4-phenylhydrazones 2 which were obtained by the action of phenylhydrazine on the arylmethylene derivatives of 4-thioxo-2-imidazolidinone 1 . The benzylimino derivatives 6 were obtained by the reaction of benzylamine with 1 . Alkylation of 1 with phenacyl bromide and/or ethyl bromoacetate afforded the S-alkyl derivatives 7. 相似文献
98.
Tawfik H. Rakha Ahmed A. El-Asmy Mohsen M. Mostafa Abd El-Ghany El-Kourshy 《Transition Metal Chemistry》1987,12(2):125-127
Summary Benzenesulphonylhydrazine (HB) reacts with bivalent metal ions either in the keto-or enol forms. The complexes have been characterized by spectral (u.v., i.r., n.m.r.,), magnetic and thermal (d.t.a., d.t.g, t.g., d.s.c.) measurements. I.r. spectra suggest that HB is monodentate coordinatingvia NH or NH2, depending on the medium of the reaction. The participation of the O=S=O group in bondingvia bridge-formation in a polymeric chain is also considered. The substitution of ethanol in the CoII complex, [(CoB2EtOH)n], by H2O, pyridine or acetonitrile was also investigated. 相似文献
99.
Sanaa O. Abd Allah Hamdy A. Hammouda Fatma A. Ali 《Journal of heterocyclic chemistry》1985,22(2):497-500
5-Salicylidenethiazolidine-2,4-dithione ( 1 ) reacts with acrylonitrile, N-phenylmaleimide and dimethyl acet-ylenedicarboxylate to afford the fused thiopyrano[2,3-d]thiazolidinethione derivatives 2, 4 and 6 , respectively. The salicylidene derivative 1 reacts with ethyl acrylate and malononitrile to afford the fused [1]benzopyrano[3′,4′:4,5]thiopyrano[2,3-d]thiazoles 3 and 9 , respectively. 4-Phenylhydrazono-2-thiazolidinethione ( 11 ) reacts with ethyl bromoacetate and/or phenacyl bromide to yield the fused thiazolo[3,4-c]triazines 13 and 14. 相似文献
100.
Wen Cong-Ying Chen Jingjing Li Mengmeng Xue Yutong Aslam Sobia Subhan Fazle Zhao Rusong Yu Jianfeng Zeng Jingbin Chen Xi 《Mikrochimica acta》2017,184(10):3929-3936
Microchimica Acta - Gold nanoparticles (AuNPs) were in-situ deposited onto the ordered mesoporous carbon (OMC) to function as a novel SPME coating. The specific area, pore volumes and average pore... 相似文献
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