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121.
Shvartsburg AA Bryskiewicz T Purves RW Tang K Guevremont R Smith RD 《The journal of physical chemistry. B》2006,110(43):21966-21980
Approaches to separation and characterization of ions based on their mobilities in gases date back to the 1960s. Conventional ion mobility spectrometry (IMS) measures the absolute mobility, and field asymmetric waveform IMS (FAIMS) exploits the difference between mobilities at high and low electric fields. However, in all previous IMS and FAIMS experiments ions experienced an essentially free rotation; thus the separation was based on the orientationally averaged cross-sections Omega(avg) between ions and buffer gas molecules. Virtually all large ions are permanent electric dipoles that will be oriented by a sufficiently strong electric field. Under typical FAIMS conditions this will occur for dipole moments >400 D, found for many macroions including most proteins above approximately 30 kDa. Mobilities of aligned dipoles depend on directional cross-sections Omega(dir) (rather than Omega(avg)), which should have a major effect on FAIMS separation parameters. Here we report the FAIMS behavior of electrospray-ionization-generated ions for 10 proteins up to approximately 70 kDa. Those above 29 kDa exhibit a strong increase of mobility at high field, which is consistent with predicted ion dipole alignment. This effect expands the useful FAIMS separation power by an order of magnitude, allowing separation of up to approximately 10(2) distinct protein conformers and potentially revealing information about Omega(dir) and ion dipole moment that is of utility for structural characterization. Possible approaches to extending dipole alignment to smaller ions are discussed. 相似文献
122.
Lisiecki R Solarz P Dominiak-Dzik G Ryba-Romanowski W Łukasiewicz T 《Optics letters》2010,35(23):3940-3942
Optical spectra and luminescence decay curves were measured for thulium-doped YVO(4), GdVO(4), and LuVO(4) single crystals as a function of temperature in the 300-670 K temperature region. In spite of structural similarity, the three systems studied display significantly different transition intensities and nonradiative relaxation rates. It was found, in particular, that the peak value of the pump band absorption intensity diminishes by about 30% for Tm:YVO(4) and Tm:GdVO(4), and the effective emission cross section for the laser transition of Tm(3+) diminishes by a factor of 2 roughly when temperature increases from 300 to 500 K. An unusually small quantum efficiency of the upper laser level in Tm:LuVO(4) has been derived from the analysis of luminescence decay curves. 相似文献
123.
T. Antczak 《Journal of Optimization Theory and Applications》2018,176(1):205-224
In the paper, the classical exact absolute value function method is used for solving a nondifferentiable constrained interval-valued optimization problem with both inequality and equality constraints. The property of exactness of the penalization for the exact absolute value penalty function method is analyzed under assumption that the functions constituting the considered nondifferentiable constrained optimization problem with the interval-valued objective function are convex. The conditions guaranteeing the equivalence of the sets of LU-optimal solutions for the original constrained interval-valued extremum problem and for its associated penalized optimization problem with the interval-valued exact absolute value penalty function are given. 相似文献
124.
We consider the critical behavior at the threshold of black-hole formation for the five-dimensional vacuum Einstein equations satisfying the cohomogeneity-two triaxial Bianchi type-IX ansatz. Exploiting a discrete symmetry present in this model we predict the existence of a codimension-two attractor. This prediction is confirmed numerically and the codimension-two attractor is identified as a discretely self-similar solution with two unstable modes. 相似文献
125.
Miroslaw Zimnoch Dorota Jelen Michal Galkowski Tadeusz Kuc Jaroslaw Necki Lukasz Chmura 《Isotopes in environmental and health studies》2013,49(3):421-433
Regular measurements of atmospheric CO 2 mixing ratios and their carbon isotope composition (13C/12C and 14C/12C ratios) performed between 2005 and 2009 at two sites of contrasting characteristics (Krakow and the remote mountain site Kasprowy Wierch) located in southern Poland were used to derive fossil fuel-related and biogenic contributions to the total CO 2 load measured at both sites. Carbon dioxide present in the atmosphere, not coming from fossil fuel and biogenic sources, was considered ‘background’ CO 2. In Krakow, the average contribution of fossil fuel CO 2 was approximately 3.4%. The biogenic component was of the same magnitude. Both components revealed a distinct seasonality, with the fossil fuel component reaching maximum values during winter months and the biogenic component shifted in phase by approximately 6 months. The partitioning of the local CO 2 budget for the Kasprowy Wierch site revealed large differences in the derived components: the fossil fuel component was approximately five times lower than that derived for Krakow, whereas the biogenic component was negative in summer, pointing to the importance of photosynthetic sink associated with extensive forests in the neighbourhood of the station. While the presented study has demonstrated the strength of combined measurements of CO 2 mixing ratios and their carbon isotope signature as efficient tools for elucidating the partitioning of local atmospheric CO 2 loads, it also showed the important role of the land cover and the presence of the soil in the footprint of the measurement location, which control the net biogenic surface CO 2 fluxes. 相似文献
126.
Tadeusz Jankowski 《Applicable analysis》2013,92(1-2):103-114
The method of quasilinearization is a well-known technique for obtaining approximate solutions of nonlinear differential equations. We use this technique to initial value problems of functional differential equations showing that corresponding linear iterations converge to the unique solution of our problem and this convergence is superlinear 相似文献
127.
Tadeusz Sozański 《The Journal of mathematical sociology》2013,37(2-3):105-125
A minimal social situation is a game‐like situation in which there are two actors, each of them has two possible actions, and both evaluate the outcomes of their joint actions in terms of two categories (say, ‘success’ and ‘failure'). By fixing actors and actions and varying ‘payoffs’ the set of 256 ‘configurations’ is obtained. This set decomposes into 43 ‘structural forms’, or equivalence classes with respect to the relation of isomorphism defined on it. This main theorem and other results concerning related configurations (minimal decision situations) are derived in this paper by means of certain tools of group theory. Some extensions to larger structures are proved in the Appendix. In the introductory section after a brief explanation of the meaning given to the terms ‘structure’ and ‘isomorphism’ in mathematics (Bourbaki) it is shown how these terms can be used to formalize the concept of ‘social form’. 相似文献
128.
T. Antczak 《Journal of Optimization Theory and Applications》2013,159(2):437-453
In the paper, we consider the exact minimax penalty function method used for solving a general nondifferentiable extremum problem with both inequality and equality constraints. We analyze the relationship between an optimal solution in the given constrained extremum problem and a minimizer in its associated penalized optimization problem with the exact minimax penalty function under the assumption of convexity of the functions constituting the considered optimization problem (with the exception of those equality constraint functions for which the associated Lagrange multipliers are negative—these functions should be assumed to be concave). The lower bound of the penalty parameter is given such that, for every value of the penalty parameter above the threshold, the equivalence holds between the set of optimal solutions in the given extremum problem and the set of minimizers in its associated penalized optimization problem with the exact minimax penalty function. 相似文献
129.
Tadeusz Kulczycki 《Potential Analysis》2013,39(1):69-98
We study gradient estimates of q-harmonic functions u of the fractional Schrödinger operator Δ α/2?+?q, α?∈?(0, 1] in bounded domains D???? d . For nonnegative u we show that if q is Hölder continuous of order η?>?1???α then $\nabla u(x)$ exists for any x?∈?D and $|\nabla u(x)| \le c u(x)/ ({\rm dist}(x,\partial D) \wedge 1)$ . The exponent 1???α is critical i.e. when q is only 1???α Hölder continuous $\nabla u(x)$ may not exist. The above gradient estimates are well known for α?∈?(1, 2] under the assumption that q belongs to the Kato class $\mathcal{J}^{\alpha - 1}$ . The case α?∈?(0, 1] is different. To obtain results for α?∈?(0, 1] we use probabilistic methods. As a corollary, we obtain for α?∈?(0, 1) that a weak solution of Δ α/2 u?+?q u?=?0 is in fact a strong solution. 相似文献
130.
Anatol Jaworek Tadeusz Czech Arkadiusz T. Sobczyk Andrzej Krupa 《Journal of Electrostatics》2013,71(2):165-175
This paper presents comparative experimental studies of the morphology and elemental composition of fly ash particles from coal- and biomass-fired boilers, deposited in each stage of 3-stage electrostatic precipitators (ESPs). It was shown that fly ash morphology, its physical properties, and the percentage of elements in the fly ash taken from each stage of ESP depend on the kind of fuel. The biomass fly ash contains many irregular large particles, which are pieces of unburned wood. Bulk density of biomass fly ash is on average lower than that of coal fly ash, and drastically decreases in the second and third stages of ESP. The resistivity, measured at electric field of 4 kV/cm, of fly ash from biomass-fired boilers is much lower than that from coal, and can be below 102 Ω m, whereas from coal, except the first stage, varies in the range from 107 to 1010 Ω m. The low resistivity of coal fly ash in the first stage of ESP results from high carbon content, and of biomass is probably an effect of additional high percentage of potassium, calcium and sodium sulfates. The percentage of Si, Al, Na, Fe, and Ti in fly ash from coal-fired boilers is much higher than from biomass, and in the opposite, the percentage of Mg, K, Ca, Mn, Mo, S, Cl, and P in biomass ash exceeds that in coal fly ash. Potential detrimental effects of biomass combustion products (salts, acids, tar) leaving the boiler on the construction elements of the electrostatic precipitator, including electrodes and HV insulators have been discussed in this paper. It was concluded that the long-term effects of biomass co-firing on the electrostatic precipitator performance, including the collection efficiency, have not been sufficiently studied in the literature and these issues require further detailed investigations. 相似文献