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991.
介绍了目前分离分析生物体系化合物的一般步骤和注意事项.综述了联用技术在生物体系化合物分析中的应用进展情况.展望了联用技术在生物体系化合物分析中的发展方向和应用前景. 相似文献
992.
The standard molar Gibbs free energy of formation of ZnRh2O4(s) has been determined using an oxide solid-state electrochemical cell wherein calcia-stabilized zirconia (CSZ) was used
as an electrolyte. The oxide cell can be represented by: . The electromotive force was measured in the temperature range from 943.9 to 1,114.2 K. The standard molar Gibbs energy of
formation of ZnRh2O4(s) from elements in their standard state using the oxide electrochemical cell has been calculated and can be represented
by: . Standard molar heat capacity C
o
p,m(T) of ZnRh2O4(s) was measured using a heat flux-type differential scanning calorimeter in two different temperature ranges, from 127 to
299 and 307 to 845 K. The heat capacity in the higher temperature range was fitted into a polynomial expression and can be
represented by: . The heat capacity of ZnRh2O4(s), was used along with the data obtained from the oxide electrochemical cell to calculate the standard enthalpy and entropy
of formation of the compound at 298.15 K. 相似文献
993.
Molecular diagnostics of infectious diseases, in particular, nucleic-acid-based methods, are the fastest growing field in
clinical laboratory diagnostics. These applications are stepwise replacing or complementing culture-based, biochemical, and
immunological assays in microbiology laboratories. The first-generation nucleic acid assays were monoparametric such as conventional
tests, determining only a single parameter. Improvements and new approaches in technology now open the possibility for the
development of multiparameter assays using microarrays, multiplex nucleic acid amplification techniques, or mass spectrometry,
while the introduction of closed-tube systems has resulted in rapid microbial diagnostics with a subsequently reduced contamination
risk. Whereas the first assays were focused on the detection and identification of microbial pathogens, these new technologies
paved the way for the parallel determination of multiple antibiotic resistance determinants or to perform microbial epidemiology
and surveillance on a genetic level. 相似文献
994.
Y. Xu W. Lser F. Tang C. G. F. Blum L. Liu B. Büchner 《Crystal Research and Technology》2011,46(2):135-139
Nd2PdSi3 single crystals were grown by a vertical floating zone method with radiation heating at a zone traveling rate of 3 mm/h. The compound exhibits congruent melting behavior at a liquidus temperature of about 1790 °C. The actual crystal composition (35.3 ± 0.5) at.% Nd, (16.2 ± 0.5) at.% Pd, and (48.5 ± 0.5) at.% Si is slightly depleted in Pd and Si with respect to the nominal stoichiometry. Therefore, the gradual accumulation of these elements in the traveling zone led to a decrease of the operating temperature during the growth process. Single crystalline samples exhibit a large anisotropy due to the crystal electric field effect and order ferromagnetically below the Curie temperature TC = 15.1 K. The [001] orientation was identified as the magnetic easy axis at low temperatures. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
995.
In this paper, we consider a system of general variational inclusions in q-uniformly smooth Banach spaces. Using proximal-point mapping technique, we prove the existence and uniqueness of solution and suggest a Mann type perturbed iterative algorithm for the system of general variational inclusions. We also discuss the convergence criteria and stability of Mann type perturbed iterative algorithm. The techniques and results presented here improve the corresponding techniques and results for the variational inequalities and inclusions in the literature. 相似文献
996.
G. I. Shishkin 《Computational Mathematics and Mathematical Physics》2009,49(8):1348-1368
The Dirichlet problem for a singularly perturbed parabolic reaction-diffusion equation with a piecewise continuous initial condition in a rectangular domain is considered. The higher order derivative in the equation is multiplied by a parameter ?2, where ? ∈ (0, 1]. When ? is small, a boundary and an interior layer (with the characteristic width ?) appear, respectively, in a neighborhood of the lateral part of the boundary and in a neighborhood of the characteristic of the reduced equation passing through the discontinuity point of the initial function; for fixed ?, these layers have limited smoothness. Using the method of additive splitting of singularities (induced by the discontinuities of the initial function and its low-order derivatives) and the condensing grid method (piecewise uniform grids that condense in a neighborhood of the boundary layers), a finite difference scheme is constructed that converges ?-uniformly at a rate of O(N ?2ln2 N + n 0 ?1 ), where N + 1 and N 0 + 1 are the numbers of the mesh points in x and t, respectively. Based on the Richardson technique, a scheme that converges ?-uniformly at a rate of O(N ?3 + N 0 ?2 ) is constructed. It is proved that the Richardson technique cannot construct a scheme that converges in ?-uniformly in x with an order greater than three. 相似文献
998.
Size-controlled, low-dispersed calcium carbonate microparticles were synthesized in the presence of the amphiphilic block copolymer polystyrene-b-poly(acrylic acid) (PS-b-PAA) by modulating the concentration of block copolymer in the reactive system. This type of hybrid microparticles have acid-resistant properties. By investigating the aggregation behaviors of PS-b-PAA micelles by transmission electron microscopy (TEM), the mechanism of hybrid calcium carbonate formation illustrated that the block copolymer served not only as "pseudonuclei" for the growth of calcium carbonate nanocrystals, but also forms the supramicelle congeries, a spherical framework, as templates for calcium carbonate nanocrystal growth into hybrid CaCO(3) particles. Moreover, this pilot study shows that the hybrid microparticle is a novel candidate as a template for fabricating multilayer polyelectrolyte capsules, in which the block copolymer is retained within the capsule interior after core removal under soft conditions. This not only facilitates the encapsulation of special materials, but also provides "micelles-enhanced" polyelectrolyte capsules. 相似文献
999.
1000.
We study the nonlinear propagation of dust-ion acoustic (DIA) shock waves in an un-magnetized dusty plasma which consists of electrons, both positive and negative ions and negatively charged immobile dust grains. Starting from a set of hydrodynamic equations with the ion thermal pressures and ion kinematic viscosities included, and using a standard reductive perturbation method, the Kadomtsev-Petviashivili-Burgers (K-P-Burgers) equation is derived, which governs the evolution of DIA shocks. A stationary solution of the K-P-Burgers equation is obtained and its properties are analysed with different plasma number densities, ion temperatures and masses. It is shown that a transition from shocks with negative potential to positive one occurs depending on the negative ion concentration in the plasma and the obliqueness of propagation of DIA waves. 相似文献