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1.
The dielectric responses (i.e. the refractive indices and the second order nonlinear susceptibilities) of all orthorhombic rare earth molybdates have been studied on the basis of the relationship between dielectric responses and the average atomic number of constituent atoms of crystals. Both the linear and second order nonlinear optical responses at 1.064 μm decrease with increasing atomic number from La to Lu. 相似文献
2.
Becky Lavi Abraham Marmur 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):409-414
An equation for the kinetics of partial drop spreading is proposed. This equation was empirically derived from experimental data for the spreading kinetics of partially wetting liquids in terms of the wet area versus time. The equation has the form of an exponential power law (EPL), and transforms into the well-known power law for complete wetting, when the equilibrium contact angle approaches zero. The EPL fits very well available experimental data. To lend additional support to the validity of this generalized equation, it will be demonstrated that when it is transformed to present the dynamic contact angle (DCA), it fits very well DCA experimental data for other wetting processes, such as capillary flow and tape coating. 相似文献
3.
Peter G. Casazza Gitta Kutyniok Mark C. Lammers 《Journal of Fourier Analysis and Applications》2004,10(4):383-408
Duality principles in Gabor theory such as the Ron–Shen duality principle and the
Wexler–Raz biorthogonality relations play a fundamental role for analyzing Gabor systems. In this
article we present a general approach to derive duality principles in abstract frame theory. For
each sequence in a separable Hilbert space we define a corresponding sequence dependent only
on two orthonormal bases. Then we characterize exactly properties of the first sequence in terms
of the associated one, which yields duality relations for the abstract frame setting. In the last part
we apply our results to Gabor systems. 相似文献
4.
H.C.G. Verhaar H. Donker G.J. Dirksen M.J.J. Lammers G. Blasse C.C. Torardi L.H. Brixner 《Journal of solid state chemistry》1985,60(1):20-28
The luminescence of undoped and rare-earth-doped LaNb3O9 is reported. The two modifications (α and β) show striking differences. Whereas undoped β-LaNb3O9 does not luminesce at all (down to 4.2 K), α-LaNb3O9 emits efficiently with a quenching temperature of 250 K. Energy transfer from niobate to rare-earth dopants is observed for the α, but not for the β modification. The rare-earth dopant emission consists of sharp lines for the α modification, but is considerably broadened for the β modification. The luminescence properties are discussed in terms of the crystal structure. In addition results for α-NbPO5 will be given. 相似文献
5.
6.
7.
Bart J. Crielaard Cristianne J. F. Rijcken Lingdong Quan Steffen vanderWal Isil Altintas Martin vanderPot John A. W. Kruijtzer Rob M. J. Liskamp Raymond M. Schiffelers Cornelus F. vanNostrum Wim E. Hennink Dong Wang Twan Lammers Gert Storm 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(29):7366-7370
8.
9.
Castro-Puyana M Lammers I Buijs J Gooijer C Ariese F 《Analytical and bioanalytical chemistry》2011,400(9):2913-2919
Quenched phosphorescence was used, for the first time, as detection mode in the chiral separation of methotrexate (MTX) enantiomers
by electrokinetic chromatography. The detection is based on dynamic quenching of the strong emission of the phosphorophore
1-bromo-4-naphthalene sulfonic acid (BrNS) by MTX under deoxygenated conditions. The use of a background electrolyte with
3 mg/mL 2-hydroxypropyl-β-cyclodextrin and 20% MeOH in 25 mM phosphate buffer (pH 7.0) and an applied voltage of 30 kV allowed
the separation of l-MTX and its enantiomeric impurity d-MTX with sufficient resolution. In the presence of 1 mM BrNS, a detection limit of 3.2 × 10−7 M was achieved, about an order of magnitude better than published techniques based on UV absorption. The potential of the
method was demonstrated with a degradation study and an enantiomeric purity assessment of l-MTX. Furthermore, l-MTX was determined in a cell culture extract as a proof-of-principle experiment to show the applicability of the method to
biological samples. 相似文献
10.
G. J. de Jong N. Lammers F. J. Spruit U. A. Th. Brinkman R. W. Frei 《Chromatographia》1984,18(3):129-133
Summary A peroxyoxalate chemiluminescence detection system for liquid chromatography is described. The excitation of fluorophores is generated by the reaction of bis-(2,4,6-trichlorophenyl)oxalate or bis(2,4-dinitrophenyl)oxalate and hydrogen peroxide, which are added to the column effluent. The influence of the solvents and the concentrations of the reagents have been investigated. The influence of the flow cell volume on sensitivity and on band broadening have also been studied and a chemical band narrowing effect has been observed. Different types of apparatus have been compared for detection of the emitted light. The system has been used for the detection of the dansyl derivative of a drug with a secondary amine functional group in serum samples. The detection limits are in the 1–10pg range. 相似文献