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51.
S Sayin 《The Journal of the Operational Research Society》2000,51(3):371-375
In this paper, I present a mixed integer programming (MIP) formulation for the 1-maximin problem with rectilinear distance. The problem mainly appears in facility location while trying to locate an undesirable facility. The rectilinear distance is quite commonly used in the location literature. Our numerical experiments show that one can solve reasonably large location problems using a standard MIP solver. We also provide a linear programming formulation that helps find an upper bound on the objective function value of the 1-maximin problem with any norm when extreme points of the feasible region are known. We discuss various extension alternatives for the MIP formulation. 相似文献
52.
On Chalcogenolates. 118. Crystal and Molecular Structure of Oxovanadium(V) Ethylxanthate VO[S2C? OC2H5]3 crystallizes with Z = 8 in the monoclinic space group P21/n with cell dimensions a = 15.065(7) Å, b = 18.540(48) Å, c = 12.824(7) Å, = 99.31(7)°. The crystal and molecular structure has been determined from single crystal X-ray data at 20°C and refined to a conventional R of 0.045. 相似文献
53.
Mahmure Ü. Özgür Güzin Alpdoğan Bürge Aşçi 《Monatshefte für Chemie / Chemical Monthly》2002,133(2):219-223
Summary. A simple and rapid derivative spectrophotometric assay procedure is described for the analysis of caffeine (1), acetaminophen (2), and propyphenazone (3) in tablet formulations. The concentration range of application is 5.0–25.0 μg·cm−3 for 2 and 3 and 1.0–5.0 μg·cm−3 for 1. The method involves the extraction of the drugs from tablets with 0.1 N H2SO4, filtration, appropriate dilution, and measurement of the fourth derivative absorbance values at zero crossing wavelengths
of 230.0, 263.2, and 256.6 nm for 1, 2, and 3. As a reference method, a reversed phase HPLC procedure was developed. Commercially available tablets were analyzed; statistical
comparison of the results with those obtained from the reference method showed good agreement. The derivative spectrophotometric
method has the advantage of being simple, rapid, inexpensive, and easy to perform.
Received April 18, 2001. Accepted (revised) June 5, 2001 相似文献
54.
The mostly crystalline polymorph β-FeMoO4 was prepared by solvothermal synthesis from organic precursors, followed by high temperature supercritical drying in an autoclave. Crystallization of the synthesized particles occurred during subsequent heat treatment at 350 °C, confirmed by X-ray diffraction pattern analysis. The presence of Fe3+ ions in the powder, both well-crystallized and amorphous after heat treatment at 500 °C, was confirmed by room temperature Mössbauer spectrum. Thick-film gas sensors were prepared by conventional hand coating of a paste, the Fe2(MoO4)3 powder mixed with an α-terpineol-based solvent, over the Au electrodes. The response of the prepared sensors to H2S gas in the low concentration range 1–10 ppm in air was investigated. Moderately fast response and recovery times were observed. The iron molybdate, produced at low temperature, may be successfully used in the preparation of a H2S gas sensor. 相似文献
55.
56.
Recently, researchers and practitioners have been increasingly interested in the problem (P) of maximizing a linear function over the efficient set of a multiple objective linear program. Problem (P) is generally a difficult global optimization problem which requires numerically intensive procedures for its solution. In this paper, simple linear programming procedures are described for detecting and solving four special cases of problem (P). When solving instances of problem (P), these procedures can be used as screening devices to detect and solve these four special cases. 相似文献
57.
M. Englert J. Kowalski F. Mayer R. Neumann S. Noehte R. Schwarzwald H. Suhr K. Winkler G. zu Putlitz Ch. J. Bordé S. Avrillier A. van Lerberghe Ch. Salomon Ch. Breant D. Bassi G. Scoles J. Helmcke D. Zevgolis B. Ü. Yen W. Gawlik F. Träger M. Vollmer E. Gustafson R. L. Byer J. H. M. Neijzen A. Donszelmann G. Leuchs J. Rerf H. Walther M. Inguscio A. Moretti F. Strumia J. L. Picqué J. L. Le Gouët F. Wuilleumier J. M. Bizau P. Dhez P. Koch D. Ederer O. Poulsen U. Nielsen N. I. Winstrup P. S. Ramanujam J. V. James X. Tang C. C. Wang 《Applied physics. B, Lasers and optics》1982,28(2-3):81-91
58.
59.
Serkan Sayin Gülderen Uysal Akkuş Radek Cibulka Ivan Stibor Mustafa Yilmaz 《Helvetica chimica acta》2011,94(3):481-486
The synthesis of two new flavin substituted calix[4]arene derivatives, 9 and 10 , is described. The first flavin substituted calix[4]arene derivative 9 was synthesized by the reaction of 3‐methylalloxazine ( 5 ) with 25,27‐bis(3‐bromopropoxy)‐26,28‐dihydroxy‐5,11,17,23‐tetra(tert‐butyl)calix[4]arene ( 4 ) in high yield (92%). The other derivative 10 was prepared from 3‐methylalloxazine‐1‐acetic acid ( 7 ) and 25,27‐bis(3‐cyanopropoxy)calix[4]arene ( 3 ). All new compounds were characterized by a combination of FT‐IR and 1H‐NMR spectroscopy, and elemental‐analysis techniques. 相似文献
60.
The compounds, C21H27N4O3(L1) and C21H27N7(L2), is a tripodal Schiff base that was obtained from the reaction of tris(2-aminoethyl)amine (tren) and furan-2-carbaldehyde and pyrole- 2- carbaldehyde. The tripodal Schiff bases and their oxovanadium complexes have been characterized on the basis of the results of the elemental analysis, magnetic susceptibility measurements and spectroscopic studies FT-IR, 1H-NMR, UV–Vis, ESR, magnetic moment and thermal analysis (TGA). Job's method of continuous variation shows 3:2 metal to ligand ratio. 相似文献