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排序方式: 共有87条查询结果,搜索用时 15 毫秒
1.
MARIA BOCHENSKA VICTOR CH. KRAVTSOV VALERII E. ZAVODNIK 《Journal of inclusion phenomena and macrocyclic chemistry》1997,28(2):125-140
The structure of the lithium complex with1,3,5-tris[oxymethylene(N,N-dicyclohexyl)carboxyamido]cyclohexanehas been determined by the X-ray method.The compound is triclinic, space group P¯1,a = 15.623(3), b = 19.279(4),c = 19.295(4)Å = 102.32(3), = 92.45(3), = 105.67(3)0, V = 5436(2)Å3, Z = 4. Itscomposition is represented by the formulaC48H82N3O6LiI 0.5H2O. The lithium cationis encapsulated in a polar pseudo-cavity of six oxygen atoms of the ligandmolecule and displays a distorted trigonal prism coordination. The conformationof the ligand in the solid state complex has been compared with the conformationof the complex in solution determined by 1H-NMR measurements.Supplementary data relevant to this publication have been deposited with the British Library, No. SUP 82224 (21 pages). 相似文献
2.
Surya Prakash Singh CH Pavan Kumar G. D. Sharma J. A. Mikroyannidis Manjeet Singh Rajnish Kurchania 《Journal of Polymer Science.Polymer Physics》2012,50(23):1612-1618
Power conversion efficiency (PCE) of phenylenevinylene‐based copolymer with BF2 azopyrrole complex (PB)/modified PC70BM, that is, CN‐PC70BM bulk heterojunction solar cells improves from 2.16 to 4.90% using a processing additive and drying condition. The results demonstrate that a processing additive and drying condition provides an effective means to control both the surface roughness and finer interpenetrating networks to enhance the exciton dissociation into free charge carriers, charge transportation, and collection. Taking into the account of simple device fabrication process without thermal annealing, the PCE of the polymer solar cell can further improved by chloronapthalene (CN) additive under the fast drying condition. The average carrier lifetimes extracted from the impedance spectra and found to correlate with measured PCEs. At short circuit conditions and illumination, the average charge carrier lifetime was found vary from 16.8 to 32 μs with power conversion efficiencies ranging from 3.0 to 4.9%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
3.
Kenneth J. Shackleton 《Geometriae Dedicata》2012,160(1):243-259
We address the lack of local-finiteness in Harvey??s curve complex by computational means, computing bounds on certain intersection numbers among curves lying on a natural family of geodesics. We give a finite time algorithm for constructing all of these geodesics between any two curves, and treat stable lengths. 相似文献
4.
The fission γ-ray multiplicity measurement in the 239Pu resonances has been carried out, using the Saclay 60 MeV electron linac as a neutron source. Large fluctuations are observed from resonance to resonance, in correlation with the number Gn of prompt neutrons, the total energy of these γ-rays and the fission width Γf. The results are interpreted in terms of a competition between the fission and the radiative capture during the de-excitation of the compound nucleus. They are the first experimental evidence of the (n, γf) reaction. Some parameters like the width are deduced. 相似文献
5.
A M Falick C H Shackleton B N Green H E Witkowska 《Rapid communications in mass spectrometry : RCM》1990,4(10):396-400
A combination of mass spectrometric techniques (electrospray mass spectrometry, liquid secondary-ion mass spectrometry (LSIMS), tandem mass spectrometry) has been used for variant hemoglobin detection and characterization. Electrospray mass spectrometry allowed analysis of mixtures of intact globins giving the molecular weights (accuracy 1-2 Da), and information about relative amounts of globins present, simultaneously. Abnormal hemoglobins detected in this way and by other means (screening, clinical symptoms) were fractionated by C-4 reverse phase high-performance liquid chromatography (HPLC), and the separated globin chains (or the mixture of whole precipitated globin) were digested with trypsin. The tryptic peptides were separated by C-18 reverse phase HPLC and analysed by LSIMS to narrow down the mutation site to a single peptide. In some instances, the molecular weight of a variant peptide was sufficient to determine the mutation uniquely. When molecular weight information alone was insufficient to identify the mutation and its site, the peptide was sequenced by tandem mass spectrometry on a 4-sector instrument. In cases where more than one possible mutation site was present in the peptide and the mutation resulted in a change of only 1 Da in the peptide mass, the resolution and mass measurement accuracy of the 4-sector machine were essential in determining the correct sequence. The practical application of the methodologies presented is illustrated by the identification and analysis of Hb G-San Jose, Hb Willamette and D-Iran. 相似文献
6.
J. Dorenbosch F. Udo J. V. Allaby U. Amaldi G. Barbiellini M. Baubillier F. Bergsma A. Capone W. Flegel F. Grancagnolo M. Jonker L. Lanceri M. Metcalf C. Nieuwenhuis J. Panman R. Plunkett C. Santoni K. Winter I. Abt F. W. Büsser H. Daumann P. D. Gall T. Hebbeker F. Niebergall P. Stähelin P. Gorbunov E. Grigoriev V. Kaftanov V. Khovansky A. Rosanov A. Baroncelli L. Barone B. Borgia C. Bosio M. Diemoz U. Dore F. Ferroni E. Longo L. Luminari P. Monacelli S. Morganti F. de Notaristefani L. Tortora V. Valente CHARM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,41(4):567-589
A determination of sin2 θ w based on measurements of elastic scattering of muon-neutrinos and muon-anti-neutrinos on atomic electrons is described. These purely leptonic processes were studied using the CHARM calorimeter exposed to neutrino and antineutrino wide-band beams at the CERN super proton synchrotron. A total of 83±16 neutrino-electron and 112±21 antineutrino-electron events have been detected. From the measurement of the ratio of muon-neutrino and muon-antineutrino cross-sections a value of sin2 θ w =0.211±0.037 was obtained. 相似文献
7.
8.
It is well known that apparently similar discretization schemes of Maxwell's equations in Fourier series may provide very different convergence performances because of truncation. We argue that this work performed in grating theory can be applied to other electromagnetic theories relying on expansions over series different from Fourier series. This generalization is supported by an intuitive argument and by a simple numerical example with Hermite–Gauss functions. 相似文献
9.
The optimal concentration of a blue dye solution with 'tracer' properties, enabling a pollutant to be marked was determined by the use of numerical, theoretical and experimental approaches. Experimental investigations were performed on a transparent Hele–Shaw cell and the concentration distribution was analyzed using an optical technique based on dye light absorption properties. The injected optimal concentration was established thanks to a theoretical and experimental study carried out on the output signal dynamics. Using the same experimental conditions, numerical simulations were performed. The very good agreement between the data (experimental and numerical) clarified that: (i) the choice of the blue dye optimal concentration was valid and (ii) the concentration-dependent density should not be neglected in flow and transport equations even if it concerns a so-called 'tracer'. Following this remark, a theoretical aspect was developed in order to determine the analogous conditions between a Hele–Shaw cell and a porous medium for the variable density transport phenomenon. The structure of the concentration-dependent dispersion tensor used in the numerical code was obtained by homogenizing the Stokes flow of a bi-component mixture. The numerical results show that, as long as the tracer density does not exceed a certain value, it is not necessary to take into account a density contrast in terms of the dispersion tensor. The classical form of the Taylor dispersion tensor can be used successfully. 相似文献
10.
We give a stability and error analysis of linearly implicitone-step methods for time discretization of non-linear parabolicequations. We derive precise error bounds for Rosenbrock andW-methods, and we explain the error reduction by Richardsonextrapolation of the linearly implicit Euler method which occursin spite of the breakdown of asymptotic expansions. The parabolicequations are studied in a Hilbert space framework that includessemilinear and quasilinear parabolic equations, and also stiffreaction-diffusion equations with reactions at different timescales. 相似文献