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31.
Kenneth Darby-Dowman Holly S. Lewis 《The Journal of the Operational Research Society》1988,39(11):1035-1040
Lagrangian relaxation has been widely used in solving a number of hard combinatorial optimization problems. The success of the approach depends on the structure of the problem and on the values assigned to the Lagrange multipliers. A recent paper on the single-source capacitated facility-location problem proposed the use of Lagrangian relaxation in which the capacity constraints were relaxed. In this paper, a class of such problems is defined for which the proposed relaxation is guaranteed to result in an infeasible solution, irrespective of the values assigned to the Lagrange multipliers. In these cases, the bounds on the optimal solution, obtained from the relaxation, are generally poor. It is concluded that, when using Lagrangian relaxation, it may be worthwhile carrying out a preliminary analysis to determine the potential viability of the approach before extensive development takes place. 相似文献
32.
The temperature dependent anomalous peak in the amide I band of crystalline acetanilide is thought to be due to self-trapped states. On the contrary, according to the present model, the anomalous peak comes from the fraction of ACN molecules strongly hydrogen-bonded to a neighboring ACN molecule, and its intensity decreases because, on average, this fraction decreases as temperature increases. This model provides, for the first time, an integrated and theoretically consistent view of the temperature dependence of the full amide I band and a qualitative explanation of some of the features of nonlinear pump–probe experiments. 相似文献
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34.
Holly Warren Reece D. Gately Patrick O'Brien Robert Gorkin III Marc in het Panhuis 《Journal of Polymer Science.Polymer Physics》2014,52(13):864-871
The electrical impedance behavior of gellan gum (GG), GG–carbon nanotube, and GG–carbon nanofiber hydrogel composites is reported. It is demonstrated that the impedance behavior of these gels can be modeled using a Warburg element in series with a resistor. Sonolysis (required to disperse the carbon fillers) does not affect GG hydrogel electrical conductivity (1.2 ± 0.1 mS/cm), but has a detrimental effect on the gel's mechanical characteristics. It was found that the electrical conductivity (evaluated using impedance analysis) increases with increasing volume fraction of the carbon fillers and decreasing water content. For example, carbon nanotube containing hydrogels exhibited a six‐ to sevenfold increase in electrical conductivity (to 7 ± 2 mS/cm) at water content of 82%. It is demonstrated that at water content of 95 ± 2% the electrical behavior of multiwalled nanotube containing hydrogels transitions (percolates) from transport dominated by ions (owing to GG) to transport dominated by electrons (owing to the carbon nanotube network). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 864–871 相似文献
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Lszl Ktai KalyanK. Banerji Istvn Saj Jnos Kristf B. Sreedhar Sndor Holly Gbor Keresztury Antal Rockenbauer 《Helvetica chimica acta》2002,85(8):2316-2327
Tetraamminecopper(2+) bis(permanganate) ([Cu(NH3)4](MnO4)2; 1 ) was prepared, and its properties were studied in both aqueous solution and the solid phase. The presence of H‐bond interactions between the ammonia ligand of the complex cation and an O‐atom of the permanganate ion was detected by IR and Raman methods. The solid‐phase thermal deammoniation of 1 led to an unusual intramolecular redox reaction between the Mn O⋅⋅⋅H N linkage with formation of NH4NO3 and CuMn2O4‐type mixed oxides instead of stepwise deammoniation, even below 100°. The thermal deammoniation of 1 in aqueous solution led, instead of to hydrated copper(2+) bis(permanganate), to the formation of NH4MnO4 ( 2 ). Since the temperature of the thermal deammoniation of 1 is lower than the decomposition temperature of the permanganate ion, the regulated solid‐phase decomposition of 1 allowed preparation of CuMn2O4‐type oxides with mixing of copper and manganese at the atomic level. 相似文献
37.
Paroxysmal vocal cord movement/motion (PVCM), paroxysmal vocal cord dysfunction (PVCD), episodic paroxysmal laryngospasm (EPL), and irritable larynx syndrome (ILS) are terms used to describe laryngeal dysfunction masquerading as asthma, upper airway obstruction, or functional and organic voice disorders. The differential diagnosis of PVCM, PVCD, EPL, and ILS is critical to successful medical and behavioral management of the patient. During the past 10 years, 27 subjects, ages 15–79 years, were identified to have paroxysms of inspiratory stridor, acute respiratory distress, associated aphonia and dysphonia, resulting in misdiagnosis and unnecessary emergency treatments, including endotracheal intubation, cardiopulmonary resuscitation, massive pharmacotherapy, or tracheostomy. A multifactorial management program is proposed utilizing principles of motor learning, neurolinguistic programming model, respiratory and phonatory synchronization, relaxation techniques, concurrent monitoring of behavioral adjustments, and formal psychological counseling. 相似文献
38.
Wobma HM Blades ML Grekova E McGuire DL Chen K Chan WC Cramb DT 《Physical chemistry chemical physics : PCCP》2012,14(10):3290-3294
Direct three-colour fluorescence cross-correlation spectroscopy can reveal interactions between three fluorescently labelled biomolecules, giving insight toward the complex events that constitute signal transduction pathways. Here we provide the optical and theoretical basis for this technology and demonstrate its ability to detect specific biological associations between nanoparticle-labelled DNA molecules. 相似文献
39.
Holly D. Bendorf Kyle E. Ruhl Andrew J. Shurer Jennie B. Shaffer Tess O. Duffin Theresa L. LaBarte Michelle L. Maddock Oscar W. Wheeler 《Tetrahedron letters》2012,53(10):1275-1277
Medium-ring heterocycles are prepared via an amine-directed, rhodium(I)-catalyzed intramolecular hydroacylation. The presence of an allyl substituent on the amine accelerates the reaction and increases product yields. 相似文献
40.
Nguyen HN Cee VJ Deak HL Du B Faber KP Gunaydin H Hodous BL Hollis SL Krolikowski PH Olivieri PR Patel VF Romero K Schenkel LB Geuns-Meyer SD 《The Journal of organic chemistry》2012,77(8):3887-3906
Herein we describe a general three-step synthesis of 4-substituted chlorophthalazines in good overall yields. In the key step, N,N-dimethylaminophthalimide (8a) directs the selective monoaddition of alkyl, aryl, and heteroaryl organometallic reagents to afford 3-substituted 3-hydroxyisoindolinones 9b, 9i-9am. Many of these hydroxyisoindolinones are converted to chlorophthalazines 1b-1v via reaction with hydrazine, followed by chlorination with POCl(3). We have also discovered two novel transformations of 3-vinyl- and 3-alkynyl-3-hydroxyisoindolinones. Addition of vinyl organometallic reagents to N,N-dimethylaminophthalimide (8a) provided dihydrobenzoazepinediones 15a-15c via the proposed ring expansion of 3-vinyl-3-hydroxyisoindolinone intermediates. 3-Alkynyl-3-hydroxyisoindolinones react with hydrazine and substituted hydrazines to afford 2-pyrazolyl benzoic acids 16a-16d and 2-pyrazolyl benzohydrazides 17a-17g rather than the expected alkynyl phthalazinones. 相似文献