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51.
We consider a convex and nondifferentiable optimization problem for deterministic flow shop systems in which the arrival times of the jobs are known and jobs are processed in the order they arrive. The decision variables are the service times that are to be set only once before processing the first job, and cannot be altered between processes. The cost objective is the sum of regular costs on job completion times and service costs inversely proportional to the controllable service times. A finite set of subproblems, which can be solved by trust-region methods, are defined and their solutions are related to the optimal solution of the optimization problem under consideration. Exploiting these relationships, we introduce a two-phase search method which converges in a finite number of iterations. A numerical study is held to demonstrate the solution performance of the search method compared to a subgradient method proposed in earlier work. 相似文献
52.
We show that the numbers of vertices of a given degree k ≥ 1 in several kinds of series‐parallel labeled graphs of size n satisfy a central limit theorem with mean and variance proportional to n, and quadratic exponential tail estimates. We further prove a corresponding theorem for the number of nodes of degree two in labeled planar graphs. The proof method is based on generating functions and singularity analysis. In particular, we need systems of equations for multivariate generating functions and transfer results for singular representations of analytic functions. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010 相似文献
53.
Hong KH Siddiqui A Moses J Gopinath J Hybl J Ilday FO Fan TY Kärtner FX 《Optics letters》2008,33(21):2473-2475
We generate linearly polarized, 287 W average-power, 5.5 ps pulses using a cryogenically cooled Yb:YAG amplifier at a repetition rate of 78 MHz. An optical-to-optical efficiency of 41% is obtained at 700 W pump power. A 6 W, 0.4 nm bandwidth picosecond seed source at 1029 nm wavelength is constructed using a chirped-pulse fiber amplification chain based on chirped volume Bragg gratings. The combination of a fiber amplifier system and a cryogenically cooled Yb:YAG amplifier results in good spatial beam quality at large average power. Low nonlinear phase accumulation as small as 5.1 x 10(-3) rad in the bulk Yb:YAG amplifier supports power scalability to a > 10 kW level without being affected by self-phase modulation. This amplification system is well suited for pumping high-power high-repetition-rate optical parametric chirped-pulse amplifiers. 相似文献
54.
Omer Lustgarten Raanan Carmieli Leila Motiei David Margulies 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(1):190-194
A method for implementing a secret sharing scheme at the molecular level is presented. By creating molecular code generators that are self‐assembled from several molecular components, we established a means for distributing distinct code‐activating elements among several participants. In this way, an authorization code can only be generated when all the participants are present, which ensures that highly secured systems cannot be operated by unauthorized individuals or disloyal users. Additional layers of protection result from the ability to program the security code by replacing one or several molecular components and by subjecting the system to distinct chemical inputs. 相似文献
55.
Afzal Hafiz Muhammad Shehzad Farrukh Zubair Mukarram Bakather Omer Yahya Al-Harthi Mamdouh A. 《Journal of Thermal Analysis and Calorimetry》2020,139(1):353-365
Journal of Thermal Analysis and Calorimetry - This article discusses the effect of microwave irradiation on the thermal properties of poly(vinyl alcohol)/graphene nanocomposites, prepared using a... 相似文献
56.
Ummuhan Solmaz Gun Binzet Omer Celik Gulten Kavak Balci Aylin Dogen 《Journal of Coordination Chemistry》2018,71(2):200-218
N,N-Di-R-N′-(4-chlorobenzoyl)thiourea (Di-R: diethyl, di-n-propyl, di-n-butyl and diphenyl) ligands (HL1–4) and their Pt(II) complexes (cis-[Pt(L1–4-S,O)2]) have been synthesized and structurally characterized by elemental analyses, FT-IR and NMR spectroscopy. HL2 ligand and cis-[Pt(L4-S,O)2] metal complex have been also characterized by a single-crystal X-ray diffraction study. HL2, C14H19ClN2OS, crystallizes in the monoclinic space group P21/n (no. 14), with Z = 4, and unit cell parameters, a = 11.1405(16) Å, b = 9.7015(12) Å, c = 14.790(2) Å, β = 106.547(7)°. The cis-[Pt(L4-S,O)2], C40H28Cl2N4O2PtS2: triclinic, space group P-1 (no. 2), a = 8.9919(3) Å, b = 14.7159(6) Å, c = 15.7954(6) Å, α = 113.9317(18)°, β = 97.4490(18)°, and γ = 105.0492(16)°. Single crystal analysis of complex, cis-[Pt(L1–4-S,O)2], revealed that a square planar coordination geometry is formed around the platinum atom by two sulfur and two oxygen atoms of the related ligands, which are in a cis configuration. In addition, the thiourea derivative ligands and their complexes were evaluated for both their in-vitro antibacterial and antifungal activity. The results have been reported, explained, and compared with fluconazole and ampicillin, used as reference drugs. 相似文献
57.
We studied the synthesis and characterization of polymeric coordination complexes of Co(II) and Ni(II) ions with pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole. The e lemental analysis, infrared spectroscopy, powder X-ray diffraction, magnetic susceptibility, thermal analysis and X-ray single crystal techniques were used in the characterization. The X-ray single crystal analysis suggests that the pyrazine-2,3-dicarboxylato ligand acts as a bridging ligand through the oxygen atoms of the carboxylate groups and the nitrogen atoms on the pyrazine ring. The 1-vinylimidazole ligand behaves as a monodentate ligand via the ring nitrogen atom. Further, the H2 adsorption studies were carried out at 75 K for various increasing pressures and the highest H2 adsorption performances for Co(II) and Ni(II) complexes were estimated as 2.66 and 2.99 wt% at 87 bar. The theoretical calculations using the crystal data were also performed to determine the voids in the structure of Co(II) complex. 相似文献
58.
Omer Schewket 《Fresenius' Journal of Analytical Chemistry》1914,53(6):388-389
Ohne Zusammenfassung 相似文献
59.
From leaves of Rhus alata, one new benzofuranic acid named [(2E)-3-(4-hydroxy-5,7-dimethyl- benzo[3,4-b] furan-6-yloxy)-prop-2-enoic acid has been isolated together with eight known compounds: dimethyl ester of terephthalic acid, beta-amyrin, friedelin, lupeol, beta-sitosterol, oleanolic acid, taraxerone and ethyl gallate. Structural elucidations were done on the basis of chemical and physical data (IR, UV, 1H-NMR, 13C-NMR and MS spectra). 相似文献
60.
Sarac OS Gürsoy-Yüzügüllü O Cetin-Atalay R Atalay V 《Computational Biology and Chemistry》2008,32(2):122-130
Automated classification of proteins is indispensable for further in vivo investigation of excessive number of unknown sequences generated by large scale molecular biology techniques. This study describes a discriminative system based on feature space mapping, called subsequence profile map (SPMap) for functional classification of protein sequences. SPMap takes into account the information coming from the subsequences of a protein. A group of protein sequences that belong to the same level of classification is decomposed into fixed-length subsequences and they are clustered to obtain a representative feature space mapping. Mapping is defined as the distribution of the subsequences of a protein sequence over these clusters. The resulting feature space representation is used to train discriminative classifiers for functional families. The aim of this approach is to incorporate information coming from important subregions that are conserved over a family of proteins while avoiding the difficult task of explicit motif identification. The performance of the method was assessed through tests on various protein classification tasks. Our results showed that SPMap is capable of high accuracy classification in most of these tasks. Furthermore SPMap is fast and scalable enough to handle large datasets. 相似文献