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81.
This paper presents a simple yet efficient heuristic for rectilinear Steiner routing. The basic heuristic introduces a new edge into the existing tree for another, costlier edge such that the resulting graph remains a tree. The simplicity of the heuristic led to an O(n2) implementation using basic data structures. Asymptotic time requirement of the heuristic can be further improved to O(n log n) using sophisticated data structures. Due to the generality of the heuristic different cost criteria can be applied to produce routes with different properties. The heuristic has been successfully applied to the problem of minimum-length Steiner routing and minimizing critical-sink Elmore delay. 相似文献
82.
Bishnu Das Sakira Tabbasum Borah Dr. Sagar Ganguli Dr. Parna Gupta 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(65):14987-14995
In this study we have analysed the comparative photophysical and electrochemical properties of two isomeric heterotrinuclear PtII–IrIII–PtII complexes 3 and 6 and the four corresponding intermediate isomeric homonuclear cyclometalated iridium(III) complexes 1 , 2 , 4 and 5 . The isomerisation originates from positional differences in the formyl, di-2-picolylamine and Pt–di-2-picolylamine moieties appended to cyclometalated or ancillary ligands. The interaction of 5′-GMP with the trinuclear complexes 3 and 6 shows that platinum centres appended to the cyclometalated ligand in 3 facilitate the binding of two 5′-GMP units per PtII centre in preference to a single 5′-GMP unit per PtII centre as observed in 6 . The 1:2 and 1:1 PtII–5′-GMP binding patterns probably arise from the convenient arrangements of the Pt–di-2-picolylamine units in different planes in complex 3 , which is absent in complex 6 . 相似文献
83.
A catalyst-free protocol has been developed for amidation of alkyl aromatics and aldehydes using TsNBr(2)via a nitrene transfer process in the presence of a base in excellent yield within a short time. The reaction was found to be selective for secondary and tertiary benzylic C-H bonds and C-H bonds of aldehydic groups. 相似文献
84.
Cramer-Rao lower bounds (CRLBs) on the estimation of the pointing parameters of a laser system using the return signal are obtained. A maximum likelihood estimator is found to obtain an estimation performance close to the CRLB in most scenarios considered. 相似文献
85.
For several decades various chemical industries are involved in environment pollution by using hazardous chemicals or excessive use of solvents or catalysts to get maximum amount of desired product. In this case acidic ionic liquids may act as safer substitute of volatile organic solvents/or traditional Brønsted or Lewis acid catalysts with their unique dual task-specific solvent-catalyst properties. Recent surge in the literature review clearly describes the importance, properties and applications of acidic ionic liquids as solvent and efficient reusable catalyst in organic reactions. This review presents an account of some recent reports indicating the synthesis and uses of –SO3H functionalized ionic liquids(SFILs) as catalyst in organic synthesis. 相似文献
86.
U. Ibotomba Singh R. K. Bhubon Singh M. J. Borah J. P. Jasinski J. A. Golen 《Journal of Structural Chemistry》2013,54(1):116-122
A new monoclinic Cu(II) salt complex (C6H6N2) 2 + [Cu(2,6-dipico)2]2?·6H2O, (2,6-dipico=pyridine-2,6-dicarboxylic acid) is synthesized and characterised by CHN analyses, IR, UV-Vis, magnetic susceptibility measurements, and single crystal X-ray crystallography. The structure contains two pyridine-2,6-dicarboxylate species as tridentate ligands with protonated aniline acting as a counter cation and six uncoordinated water molecules. The complex crystallizes in the monoclinic space group C2/c with unit cell parameters a = 20.9393(4) Å, b = 7.94330(10) Å, c = 19.9093(4) Å, V(Å3) = 2932.32(9), Z = 4. Crystal packing is stabilized by N-H…O, O-H…O intermolecular hydrogen bonds and weak π…π interactions. The water molecules are trapped by a cooperative association of coordination interactions forming water clusters as well as by a hydrogen bond to the Cu (II) complex. 相似文献
87.
Dipu Borah Claudia D. Simao Ramsankar Senthamaraikannan Sozaraj Rasappa Achille Francone Olivier Lorret Mathieu Salaun Barbara Kosmala Nikolaos Kehagias Marc Zelsmann Clivia M. Sotomayor-Torres Michael A. Morris 《European Polymer Journal》2013
We report here the fabrication of periodic sub-25 nm diameter size cylinder structures using block copolymer (BCP) directed self-assembly on nanoimprinted topographically patterned substrates. Tailored polyhedral oligomeric silsesquioxanes (POSSs) films were spin coated onto silicon substrates and were patterned by nanoimprint lithography to produce topographies commensurable with the BCP domain spacing. The chemistry of the POSS was tuned to control the alignment and orientation of the BCP films. The substrates were used to direct the microphase separation (following toluene solvent annealing) of a hexagonal structure forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) having a domain spacing of 42.6 nm and PDMS cylinder widths of 23.7 nm. On more hydrophilic POSS substrates the cylinders were obtained parallel to the substrate plane and aligned with the topography. In contrast, in more hydrophobic POSS patterns, the cylinders align perpendicular to the substrate plane. The use of these methods for the nanofabrication of vias, nanofluidic devices or interconnect structures of sub-25 nm feature size is discussed. 相似文献
88.
Some novel spiro substituted pyrido[2,3-c]coumarin derivatives were synthesized from 4-hydroxycoumarin by exploring ‘tertiary amino effect’ reaction strategy. 相似文献
89.
Balin Kumar BhuyanArun Jyoti Borah Kula Kamal SenapatiProdeep Phukan 《Tetrahedron letters》2011,52(21):2649-2651
Titanium exchanged ZSM-5 catalyst has been prepared by treating an aqueous solution of titanium (IV) chloride with ZSM-5. The supported catalyst has been explored as effective and reusable catalyst for allylation reaction of aldehydes with allyltributylstannane. The new catalytic system promotes efficiently the allylation reaction in toluene condition to produce homoallylic alcohols in high yield. 相似文献
90.
Gogoi SK Borah SM Dey KK Paul A Chattopadhyay A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(20):12263-12269
We introduce a new lithographic method for the generation of 2D patterns of composite nanoparticles (NPs) of Ag and Au by taking recourse to combine top-down and bottom-up approaches. Micrometer-scale and submicrometer-scale patterned Ag foils of commercially available compact disks (CDs) and digital versatile disks (DVDs), respectively, were used as templates. The galvanic replacement reaction of Ag by HAuCl(4) in the presence of the dye coatings on the foils led to the formation of patterned NP composites of Ag and Au, in addition to the formation of AgCl. The resultant structures appeared in the form of cross patterns of particles with micrometer and submicrometer dimensions. The AgCl crystals thus formed could be removed by using either a saturated NaCl solution or aqueous ammonia. In addition, AgCl could be converted to Ag by electrochemical reduction, thus generating Ag-coated Au NPs. Interestingly, the digital writing on CDs led to the formation of tertiary imprints on the patterns, based on the original writing patterns. This provided an additional handle in generating hierarchical patterns using light in combination with a chemical reaction diffusion process and the nearly parallel line patterns originally present in commercial CDs. The reactions could be carried out in aqueous solution, and the method does not require any additional curing. Also, the density of patterned particles is scalable on the basis of the choice of the original line patterns as present in CDs and DVDs. 相似文献