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61.
H. Schultes K. Neumann V. Ionescu W. Scholl R. O. E. Davis 《Analytical and bioanalytical chemistry》1936,106(4-6):187-189
62.
Radu Ioan Bo? Sorin-Mihai Grad 《Journal of Mathematical Analysis and Applications》2008,337(2):1315-1325
We give some necessary and sufficient conditions which completely characterize the strong and total Lagrange duality, respectively, for convex optimization problems in separated locally convex spaces. We also prove similar statements for the problems obtained by perturbing the objective functions of the primal problems by arbitrary linear functionals. In the particular case when we deal with convex optimization problems having infinitely many convex inequalities as constraints the conditions we work with turn into the so-called Farkas-Minkowski and locally Farkas-Minkowski conditions for systems of convex inequalities, recently used in the literature. Moreover, we show that our new results extend some existing ones in the literature. 相似文献
63.
64.
Motivated by a classical result concerning the ε-subdifferential of the sum of two proper, convex and lower semicontinuous functions, we give in this paper a similar result for the enlargement of the sum of two maximal monotone operators defined on a Banach space. This is done by establishing a necessary and sufficient condition for a bivariate inf-convolution formula. 相似文献
65.
Aurelian Luca Maria Sahagia Andrei Antohe Mihail-Răzvan Ioan Leonardo Şerbina Constantin Ivan 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(2):1075-1079
In order to validate its original method for the radon gas activity standardization and to assure the international metrological traceability and equivalence, the Radionuclide Metrology Laboratory of IFIN-HH participated recently in the international comparison CCRI(II)-K2.Rn-222, organized by the International Committee for Weights and Measures—CIPM-CCRI(II)-Radionuclide Measurements. The radon gas sample received, the measurement equipment and the experimental procedures are described. Because the comparison is underway, the results are presented only as relative values to the liquid scintillator vial measurement result. The uncertainty budget of the measurements performed is provided. 相似文献
66.
Guoliang Li Ioan Silaghi-Dumitrescu R. Bruce King Henry F. Schaefer III 《Journal of organometallic chemistry》2010,695(6):804-808
Density functional theory studies on a series of Cp2Co2E2 derivatives (E = S and PX; X = H, Cl, OH, OMe, NH2, NMe2) predict global minimum butterfly structures with one Co-Co bond for the “body” of the butterfly and four Co-E bonds at the edges of the “wings” of the butterfly. Tetrahedrane structures with both Co-Co and E-E bonds are higher in energy for Cp2Co2S2 and Cp2Co2(PH)2 and are not found in the other systems. This differs from the corresponding Fe2(CO)6S2 and Fe2(CO)6(PX)2 derivatives where tetrahedrane structures are predicted to be the lowest energy structures for all cases except X = NR2 and OH and such a tetrahedrane structure is found experimentally for Fe2(CO)6S2. The butterfly structures for the Cp2Co2E2 derivatives are of two types. For Cp2Co2(PX)2 (X = H, OH, OMe, NH2, NMe2) the lowest energy structures are unsymmetrical butterflies Cp2Co2(P)(PX2) with two X groups on one phosphorus atom and a lone pair on the other (naked) phosphorus atom. Related low-energy unsymmetrical butterfly Fe2(CO)6(P)(PX2) structures, not observed in previous theoretical studies, are now found for the corresponding Fe2(CO)6(PX)2 derivatives. Symmetrical butterfly singlet diradical structures with one X group on each phosphorus atom in relative cis or trans positions are also found for the Cp2Co2(PX)2 derivatives and are the global minima for Cp2Co2(PCl)2 as well as Cp2Co2S2. In all cases the cis structures are of lower energy than the corresponding trans structures. Rhombus structures having neither Co-Co nor E-E bonds are also found for all of the Cp2Co2(PX)2 derivatives but always at higher energies than the butterfly structures, ranging from 17 to 29 kcal/mol above the global minima. 相似文献
67.
Véronique Vacchina Sébastien Oguey Catherine Ionescu David Bravo Ryszard Lobinski 《Analytical and bioanalytical chemistry》2010,398(1):435-449
A method was developed for the determination of metal complexes with glycine (glycinates, [M(Gly)x(H2O)y(SO4)z]n, where M denotes Zn, Cu, Mn and Fe) in premix samples used for the preparation of animal feeds enriched in essential trace
elements. The method was based on the extraction of the glycinates with 10 mM ammonium acetate (pH 7.4) followed by their
determination using capillary electrophoresis with ICP MS detection. The stability of the glycinates in solution was verified
by electrospray TOF-MS. Each supplement was shown to be a mixture of complexes, with polymerization degrees ranging from n = 1 to n = 4 (depending on the metal), that were fully or partially dehydrated. The metal glycine complex moiety was found to be preserved
during capillary electrophoresis. The detection limits, calculated as three times the standard deviation of the blank plus
the blank, were between 0.05 and 0.2 μg mL−1 (as the metal), and the calibration curves were linear, allowing the analysis of premix samples. Repeatability for glycinate
standards was below 12%, and analytical precision was typically within 15%. 相似文献
68.
Marian Vîrgolici Corneliu Ponta Mihaela Manea Daniel Neguţ Mihalis Cutrubinis Ioan Moise Rareş Şuvăilă Eugen Teodor Costel Sârbu Andrei Medvedovici 《Journal of chromatography. A》2010,1217(12):1977-1987
Research on the chemical composition of fossil resins has evolved during the last decades as a multidisciplinary field and is strongly oriented toward the correlation with their geological and botanical origin. Various extraction procedures and chromatographic techniques have been used together for identifying the volatile compounds contained in the fossil resin matrix. Hyphenation between thermal desorption (TD), gas chromatography (GC) and mass spectrometry detection (MS) has been chosen to investigate the volatile compounds fraction from ambers with a focus on Romanite (Romanian amber) and Baltic amber species. A data analysis procedure was developed for the main purpose of fingerprinting ambers based on the MS identity of the peaks generated by the volatile fraction, together with their relative percentual area within the chromatogram. Chromatographic data analysis was based entirely on Automated Mass Spectral Deconvolution & Identification System (AMDIS) software to produce deconvoluted mass spectra which were used to build-up a mixed mass spectra and relative retention scale library. Multivariate data analysis was further applied on AMDIS results with successful discrimination between Romanite and Baltic ambers. A special trial was conducted to generate pyrolysis “like” macromolecular structure breakdown to volatile compounds by gamma irradiation with a high absorbed dose of 500 kGy. Contrary to our expectations the volatile fraction fingerprints were not modified after irradiation experiments. A complementary non-destructive new approach by ESR spectroscopy was also proposed for discriminating between Romanite and Baltic ambers. 相似文献
69.
Xiangbo Meng Mihnea Ionescu Mohammad Norouzi Banis Yu Zhong Hao Liu Yong Zhang Shuhui Sun Ruying Li Xueliang Sun 《Journal of nanoparticle research》2011,13(3):1207-1218
This study attempted to synthesize one-dimensional (1D) coaxial nanotubes of Fe2O3 based on carbon nanotubes (CNT@Fe2O3) via atomic layer deposition (ALD) using ferrocene and oxygen as precursors. Results disclosed that undoped CNTs were suitable
for the ALD of Fe2O3 (ALD-Fe2O3) only if they were chemically functionalized, due to their inert surface nature. It was further demonstrated that the effects
of both covalent and non-covalent methodologies were limited in functionalizing undoped CNTs, leading to random and non-uniform
deposition of Fe2O3. In sharp contrast, it was found that, as an alternative, nitrogen-doped CNTs (N-CNTs) contributed uniform and tunable ALD-Fe2O3, due to their active surface nature induced by incorporated N atoms. Consequently, various 1D heterostructural coaxial nanotubes
were obtained with well-controlled growth of Fe2O3 on N-CNTs. For a better understanding, the underlying mechanisms were explored based on different N-doping configurations.
In addition, high-resolution transmission electron microscopy and X-ray diffraction jointly demonstrated that as-deposited
Fe2O3 is single-phase crystalline α-Fe2O3 (hematite). The as-synthesized heterostructural coaxial nanotubes of CNT@Fe2O3 may find great potential applications in photocatalysis, gas-sensing, and magnetic fields. 相似文献
70.
Roslinda Nazar Mihaela Jaradat Norihan M. Arifin Ioan Pop 《Central European Journal of Physics》2011,9(5):1195-1202
In this paper, the stagnation-point flow and heat transfer towards a shrinking sheet in a nanofluid is considered. The nonlinear
system of coupled partial differential equations was transformed and reduced to a nonlinear system of coupled ordinary differential
equations, which was solved numerically using the shooting method. Numerical results were obtained for the skin friction coefficient,
the local Nusselt number as well as the velocity and temperature profiles for some values of the governing parameters, namely
the nanoparticle volume fraction φ, the shrinking parameter λand the Prandtl number Pr. Three different types of nanoparticles are considered, namely Cu, Al2O3 and TiO2. It was found that nanoparticles of low thermal conductivity, TiO2, have better enhancement on heat transfer compared to nanoparticles Al2O3 and Cu. For a particular nanoparticle, increasing the volume fraction φ results in an increase of the skin friction coefficient and the heat transfer rate at the surface. It is also found that
solutions do not exist for larger shrinking rates and dual solutions exist when λ < −1.0. 相似文献