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101.
We propose a novel fiber Fabry-Perot interferometer (FPI) that incorporates a length of microfiber as its cavity and two fiber Bragg gratings (FBGs) as reflectors. The microfiber FPI is simply fabricated by flame-heated taper-drawing the central spot of an FBG into a section of microfiber. Ambient refractive index (RI) influences the effective index of microfiber, and thus the free spectrum range of the microfiber FPI, resulting in RI sensing. A dual-wavelength fiber laser based on the microfiber FPI is constructed, enabling radio frequency interrogation with high resolution. RI sensitivity of 911 MHz/RIU is experimentally demonstrated for microfiber FPI with equivalent diameter of 1.455 μm. Simulation results indicate that the sensitivity can be further enhanced by reducing the diameter of the microfiber. 相似文献
102.
Zal U’yun Wan Mahmood Nik Azlin Nik Ariffin Abdul Kadir Ishak Norfaizal Mohamed Mei Wo Yii Kamaruzaman Ishak Zainab Pa’wan 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(3):901-906
A method is described for the determination of 90Sr in environmental samples using combination of developed in-house method, Eichrom Sr resin and Beta Counter. Strontium was
efficiently, rapidly and simply separated from Ca and other interfering matrix components by Eichrom Sr resin. All the results
in general showed good accuracy, high precision, reliable and in good agreement between these two measured and certified value
of SRM (i.e. IAEA-375, IAEA-326, IAEA-152 and IAEA-414). As a whole, the procedure described in this work notably improves
conventional methods in particular concerning the time needed, sample volume, safer and others. Thus, the introduced method
was successfully performed and will be applied to actual sample for the determination of 90Sr in different environmental materials such as soil, sediments, milk, biological sample, water etc. 相似文献
103.
Wiesława Wołodkiewicz Tadeusz Głowiak 《Monatshefte für Chemie / Chemical Monthly》2000,131(7):711-719
Summary. The reaction products of Co(II)-2,3- and -2,5-dichlorobenzoate with imidazole (1, 2; CoL
2⋯2imdċ2H2O, L=C7H3Cl2O, imd=imidazole) were characterized by their spectroscopic and thermochemical properties. The compounds crystallize in the monoclonic
system with space group = P21/c, a=13.848(3), b=12.841(3) ?, c= 7.064(2) ?, β=98.12 °, V=1243.5(4) ?3, Z=2 for 1 and space group =P21/n, a=13.293(3), b= 6.964(2), c=13.800(3) ?, β=108.92(3) °, V=1208.6(4) ?3, Z=2 for 2. The complexes lose their crystal water in one step at 333 K and subsequently decompose to CoO with intermediate formation
of Co3O4.
Received August 9, 1999. Accepted (revised) February 11, 2000 相似文献
104.
105.
106.
We study the problem of multivariate integration and the construction of good lattice rules in weighted Korobov spaces with
general weights. These spaces are not necessarily tensor products of spaces of univariate functions. Sufficient conditions
for tractability and strong tractability of multivariate integration in such weighted function spaces are found. These conditions
are also necessary if the weights are such that the reproducing kernel of the weighted Korobov space is pointwise non-negative.
The existence of a lattice rule which achieves the nearly optimal convergence order is proven. A component-by-component (CBC)
algorithm that constructs good lattice rules is presented. The resulting lattice rules achieve tractability or strong tractability
error bounds and achieve nearly optimal convergence order for suitably decaying weights. We also study special weights such
as finite-order and order-dependent weights. For these special weights, the cost of the CBC algorithm is polynomial. Numerical
computations show that the lattice rules constructed by the CBC algorithm give much smaller worst-case errors than the mean
worst-case errors over all quasi-Monte Carlo rules or over all lattice rules, and generally smaller worst-case errors than
the best Korobov lattice rules in dimensions up to hundreds. Numerical results are provided to illustrate the efficiency of
CBC lattice rules and Korobov lattice rules (with suitably chosen weights), in particular for high-dimensional finance problems. 相似文献
107.
Dr.-Ing. E. Baron Prof.Dr. Hab.-Ing. Cz. Woźniak 《Archive of Applied Mechanics (Ingenieur Archiv)》1995,66(1-2):126-133
Summary The subject of the contribution is an investigation of elastic composite plates with a microperiodic structure along the plate's midsurface. The computational models of the plates are largely based on the homogenization procedures leading to equations with constant coefficients. However, the homogenization theories neglect the microstructure length-scale effect on the plate's dynamic behaviour. The objective of this research is to formulate and investigate a refined theory of the composite plates under consideration, which would describe the microdynamic plate behaviour caused by the microstructure. The possible applications of the proposed theory are shown by an example.This research was partly supported by KBN, Warsaw, under grant 3 3310 92 03. 相似文献
108.
Dominiak PM Filarowski A Hansen PE Woźniak K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(16):4758-4766
We have analyzed deuterium isotope effects on (13)C chemical shifts in a series of o-hydroxy Schiff bases by applying factor analysis. Two orthogonal factors were obtained that explain about 80 and 10 % of the variance of the data. The numerical values of these factors can be related to 1H NMR chemical shifts of the proton involved in the intramolecular bonds delta(XH) (X = O or N). Such a relation allows one to identify clusters of compounds with different tautomeric forms of hydrogen bonding. Application of a similar approach to solution 13C NMR chemical shifts produces three important factors, which have a different structure to factors describing isotope effects. This illustrates well the different nature of chemical shifts and isotope effects. The three factors explain about 54, 15, and 13 % of variance. They can be rationalized and are strongly related to the electronic properties and location of substituents. 相似文献
109.
Some consequences of non-orthogonality of the basic functions of LCAO approximation, on the relations used for calculations of hyperfine splittings in ESR spectra of conjugated radicals, are discussed. Special attention has been paid on the problem of transferability of the hyperfine coupling constants. The discussion is illustrated by some calculations of the hyperfine splittings for radical-ions of naphthalene, and tetracene.
Sponsored by Institute of Low Temperature and Structure Research, Polish Academy of Sciences (contract No. PAN-3.1.03). 相似文献
Zusammenfassung Einige Folgerungen aus der Nichtorthogonalität der Basis in der LCAO-Näherung für die Beziehungen, die für die Berechnung der Hyperfeinaufspaltung im ESR-Spektrum konjugierter Radikale benutzt werden, werden untersucht. Insbesondere wird die Frage der Übertragbarkeit der Hyperfein-kopplungskonstanten behandelt. Die Diskussion wird durch einige Berechnungen der Hyperfeinaufspaltung für die Radikalionen des Naphtalins und des Tetracens ergänzt.
Sponsored by Institute of Low Temperature and Structure Research, Polish Academy of Sciences (contract No. PAN-3.1.03). 相似文献
110.
Comparative determinations of various phenothiazine derivatives in blood and urine samples were carried out using HPLC in reversed-phase mode and non-aqueous capillary electrophoresis (NACE). The examined samples of biological fluids originated from six forensic cases concerning poisonings with drugs, including the following commonly used phenothiazines: chlorpromazine, levomepromazine, promazine, and perazine. The quantification limits for both methods were similar and ranged from 0.02 to 0.35 µg mL?1. The correlation coefficient (r2) between the results obtained by two methods was 0.9869. 相似文献