Search results for "Optical"
showing 10 items of 7671 documents
<title>Using infrared thermography as a tool to analyze curling and cockling of paper</title>
1992
Paper surface topology analysis with infrared thermography is described. Heat is applied perpendicular to the target. Temperature distribution of the sheet correlates well with the surface height distribution when the sheet is placed on the isothermic plate. Mathematical tools for data analysis and the mechanisms behind the curl and cockles are briefly discussed. Curl in paper and paperboard is defined as deviation from the flat form.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Observation of Kuznetsov-Ma soliton dynamics in optical fibre
2012
International audience; The nonlinear Schro¨dinger equation (NLSE) is a central model of nonlinear science, applying to hydrodynamics, plasma physics, molecular biology and optics. The NLSE admits only few elementary analytic solutions, but one in particular describing a localized soliton on a finite background is of intense current interest in the context of understanding the physics of extreme waves. However, although the first solution of this type was the Kuznetzov-Ma (KM) soliton derived in 1977, there have in fact been no quantitative experiments confirming its validity. We report here novel experiments in optical fibre that confirm the KM soliton theory, completing an important serie…
Response properties with explicitly correlated coupled-cluster methods using a Slater-type correlation factor and cusp conditions
2009
The recently proposed extension of the explicitly correlated coupled-cluster ansatz using cusp conditions [A. Kohn, J. Chem. Phys. 130, 104104 (2009)] is tested for suitability in the calculation of response properties. For this purpose, static and dynamic electrical properties up to ESHG hyperpolarizabilities as well as optical rotations have been computed within the CCSD(F12) model. It is shown that effectively converged correlation contributions can reliably be obtained using augmented quadruple zeta basis sets already. The ansatz is optionally equipped with an extension capable of reducing the one-electron basis set error. A further simplification of the method specific Lagrangian aimed…
Cyanide-bridged Fe(III)–Co(II) bis double zigzag chains with a slow relaxation of the magnetisation
2003
Reaction of [FeIII(bipy)(CN)4]¯ with fully solvated MII cations [M = Co (1) and Mn (2)] produces the isostructural bis double zigzag chains [[FeIII(bipy)(CN)4]2MII(H2O)]·MeCN·1/2H2O; 1 exhibits intrachain ferromagnetic and interchain antiferromagnetic couplings, slow magnetic relaxation and hysteresis effects. Luminita Marilena, Toma, Luminita.Toma@uv.es ; Lescouezec, Alain Francois Rodri, Alain.Lescouezec@uv.es ; Lloret Pastor, Francisco, Francisco.Lloret@uv.es ; Julve Olcina, Miguel, Miguel.Julve@uv.es
Photoinduced HS state in the first spin-crossover chain containing a cyanocarbanion as bridging ligand
2009
A new polymeric approach, based on cyanocarbanion ligands, for the design of spin crossover (SCO) compounds led us to the compound [Fe(abpt)2(tcpd)] (1) (tcpd^2 = (C[C(CN)2|3)^2 , abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) which has been characterised as the first SCO molecular chain involving a cyanocarbanion as bridging ligand. Gomez Garcia, Carlos Jose, Carlos.Gomez@uv.es
Polarity profiles in reverse micelles of Triton X-100, as studied by spin probe and absorption probe techniques
1997
The microenvironment characteristics — polarity, viscosity and order degree - in Triton X-100 reverse micelles (RM) in cyclohexane and benzene — n-hexane 30 : 70 (v/v), were investigated with the aid of a homologous series of cationic spin probes, CAT n, of 5- and 16-doxyl stearic acids and of a new absorption probe, 4-nitropyridine-N-oxide (NP). The spectral parameters were related to local hydration values by means of a series of poly(oxyethylene) (PEO)/water calibration mixtures. All results regarding the polarities in RM and calibration mixtures have been expressed in terms of Kosower's Z values, by determining the linear dependence of the transition energies of NP, ENP, on Z, for a ser…
Fluorescent Sensing of Maleate versus Fumarate by a Neutral Cyclohexane Based Thiourea Receptor.
2006
A new cyclohexyl based fluorescent anion receptor, is able to recognize maleate versus fumarate both as their TMA salts. Costero Nieto, Ana Maria, Ana.Costero@uv.es ; Colera Llavata, Manuel, Manuel.Colera@uv.es ; Gaviña Costero, Pablo, Pablo.Gavina@uv.es ; Gil Grau, Salvador, Salvador.Gil@uv.es
Asymmetric synthesis of cyclopentanes bearing four contiguous stereocenters via an NHC-catalyzed Michael/Michael/esterification domino reaction.
2016
An NHC-catalyzed Michael/Michael/esterification domino reaction via homoenolate/enolate intermediates for the asymmetric synthesis of tetrasubstituted cyclopentanes is described.
Enantiocontrol in the intermolecular cyclopropanation reaction catalyzed by dirhodium(II) complexes with ortho-metalated aryl phosphine ligands
2001
(P) and (M) dirhodium(II) complexes with ortho-metalated aryl phosphines are assessed as chiral catalysts in the enantioselective cyclopropanation of styrenes by ethyl diazoacetate; enantioselectivities up to 91% and up to 87%, respectively, for cis- and trans-2-arylcyclopropanecarboxylates are observed. Barberis, Mario, Mario.Barberis@uv.es ; Lahuerta Peña, Pascual, Pascual.lahuerta@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es ; Sanau Torrecilla, Mercedes, Mercedes.Sanau@uv.es
Enantio- and diastereocontrol in intermolecular cyclopropanation reaction of styrene catalyzed by dirhodium(II) complexes with bulky ortho-metalated …
2004
Enantiomerically pure dirhodium(II) complexes with ortho-metalated p-substituted aryl phosphines have been shown to be enantio- and diastereoselective in the cyclopropanation of styrene by ethyl diazoacetate. Enantioselectivities up to 91% and diastereoselectivities up to 90% are observed for ethyl cis-2-phenylcyclopropanecarboxylate. Estevan Estevan, Francisco, Francisco.Estevan@uv.es ; Lahuerta Peña, Pascual, Pascual.lahuerta@uv.es ; Lloret Fillol, Julio, Julio.Lloret@uv.es ; Sanau Torrecilla, Mercedes, Mercedes.Sanau@uv.es ; Ubeda Picot, M Angeles, Angeles.Ubeda@uv.es ; Vila Gomez, Jaume Llorenc, Jaume.Vila@uv.es