表面润湿法合成β沸石体系中晶种作用的研究

系统研究了表面润湿法合成β沸石的体系中,干晶种、润湿态晶种、异晶晶种(Y沸石、ZSM 5沸石)以及碱处理β沸石晶种在此晶化体系中的作用.采用β沸石产品及异晶作晶种时,可使产品的相对结晶度稍有提高,但对沸石微晶核的结构导向作用不明显.经浓碱液处理20min后的β沸石产品(碱处理晶种)作晶种引入晶化体系后,可以显著提高产品的相对结晶度,降低模板剂的用量,缩短晶化诱导期,成为表面润湿法合成β沸石体系的有效晶种形式.     

Magneto-optical visualization of three spatial components of inhomogeneous stray fields

The article deals with the physical principles of magneto-optical visualization (MO) of three spatial components of inhomogeneous stray fields with the help of FeCo metal indicator films in the longitudinal Kerr effect geometry. The inhomogeneous field is created by permanent magnets. Both p- and s-polarization light is used for obtaining MO images with their subsequent summing, subtracting and digitizing. As a result, the MO images and corresponding intensity coordinate dependences reflecting the distributions of the horizontal and vertical magnetization components in pure form have been obtained. Modeling of both the magnetization distribution in the indicator film and the corresponding MO images shows that corresponding to polar sensitivity the intensity is proportional to the normal field component, which permits normal field component mapping. Corresponding to longitudinal sensitivity, the intensity of the MO images reflects the angular distribution of the planar field component. MO images have singular points in which the planar component is zero and their movement under an externally homogeneous planar field permits obtaining of additional information on the two planar components of the field under study. The intensity distribution character in the vicinity of sources and sinks (singular points) remains the same under different orientations of the light incidence plane. The change of incident plane orientation by π/2 alters the distribution pattern in the vicinity of the saddle points.     

Admissible consensus and consensualization of high-order linear time-invariant singular swarm systems

Admissible consensus analysis and consensualizing controller design problems for high-order linear time-invariant singular swarm systems are investigated. Firstly, by projecting the state of a singular swarm system onto a consensus subspace and a complement consensus subspace, a necessary and sufficient condition for admissible consensus is presented in terms of linear matrix inequalities (LMIs). An approach to decrease the calculation complexity is proposed, by which only three LMIs independent of the number of agents need to be checked. Then, by using the changing variable method, sufficient conditions for admissible consensualization are shown. An explicit expression of the consensus function is given, and it is shown that the modes of the consensus function can be arbitrarily placed if each agent is R$R$-controllable and impulse controllable and the interaction topology has a spanning tree. Finally, theoretical results are applied to deal with cooperative control problems of multi-agent supporting systems.     

Wavenumber space and physical space responses of a periodically ribbed plate to a point drive: A discrete approach

An efficient technique to estimate the vibration of and sound radiation from a stiffened fluid-loaded plate excited by a mechanical point force is presented. The process is based on the formulation in the wavenumber domain of the transversal displacement of the plate and of the acoustic pressure in the fluid domain. Analytical expressions can be easily obtained for these fields in the case of an infinite plate with stiffeners uniformly spaced. The approach consists then on using the discrete Fourier Transform to deduce the associated fields in the physical space. This transform necessitates truncation of the wavenumber domain and sampling of these wavenumber fields with adequate criterions to avoid loss of information and aliasing. These criterions are discussed in this paper concerning displacement point results on the plate and pressure point results in a part of the fluid domain “close to” the plate. This technique requires relatively small computing time and provides an efficient tool to analyse the vibro-acoustic behaviour of the stiffened plate, both, in the physical and the wavenumber spaces. A comparison between a case discussed in the literature and some examples are presented to illustrate the validity and interests of this approach.     

AC susceptibility of magnetic markers in suspension for liquid phase immunoassay

AC susceptibility of magnetic markers in solution was studied for biosensor applications. First, frequency dependence of the susceptibility was measured, and size distribution of the markers was estimated by analyzing the experimental result with the so-called singular value decomposition (SVD) method. The size distribution estimated with the magnetic measurement agreed with that obtained from conventional optical measurement. Next, susceptibility measurement was applied to the liquid-phase immunoassay without bound/free (B/F) separation. We performed the detection of biotin-coated polymer beads in suspension using avidin-coated magnetic markers. Changes of the susceptibility and the size distribution caused by the binding reaction were shown.     

Photoinduced optical activity of C<Subscript>70</Subscript> fullerene in organic solvents

We have experimentally studied for the first time the effect of photoinduced rotation of the plane of polarization for pulsed laser radiation in solutions of C₇₀ fullerene in organic solvents and their mixtures. We have shown that the effect is observed for elliptical polarization of the laser radiation and is absent for linear polarization. We present the results of a study of the nonlinear optical characteristics of the C₇₀ solutions. We discuss the physical mechanisms by which nonlinear gyrotropy is induced in solutions. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 93–99, January–February, 2009.     

Effects of pressure and temperature on the solubility of monosodium L-glutamate monohydrate in water

Abstract

The solubility of monosodium L-glutamate monohydrate (MSG.H₂O) in water was measured at pressures in the range of 0.10-300MPa and 298.15K. The density of MSG solution at high concentrations and heat of solution at saturated concentration were also measured at atmospheric pressure. The solubility, m_s, increased with increasing pressure and the pressure coefficient, Θ_p, [?(? In m_s,? p)_T] at 0.10 MPa was (2.0 ± 0.1) × 10-¹⁰Pa-1. It agrees well with (2.1 ±0.2)× 10-¹⁰ Pa-¹ thermodynamically estimated using the partial molar volume, the activity coefficient of the solute in solution, and the molar volume of the crystal. The excellent agreement at 0.10MPa gives us confidence in the solubility data at higher pressures. The heat of solution data and other pertinent values were used to calculate the temperature coefficient of solubility, Θ_T [? (? In m_s/?(1/T))_p], by a thermodynamic equality. The resulting Θ_T compares well with the data directly measured by Ogawa.     

Analytical expressions for partial wave two-body Coulomb transition matrices at ground-state energy

Leaning upon the Fock method of the stereographic projection of the three-dimensional momentum space onto the four-dimensional unit sphere the possibility of the analytical solving of the Lippmann–Schwinger integral equation for the partial wave two-body Coulomb transition matrix at the ground bound state energy has been studied. In this case new expressions for the partial p$p$-, d$d$- and f$f$-wave two-body Coulomb transition matrices have been obtained in the simple analytical form. The developed approach can also be extended to determine analytically the partial wave Coulomb transition matrices at the energies of excited bound states.     

Effect of hemp surface modification on the morphological and tensile properties of linear medium density polyethylene (LMDPE) composites

This work investigates different hemp surface modifications (mercerization, maleated polyethylene (MAPE) addition in solution or in melt blending) to improve the properties of linear medium density polyethylene (LMDPE). From the composites produced, a complete morphological and tensile characterization was performed for a fixed hemp content (30% wt.). The morphological analysis showed that both the direct (melt blending) and solution modifications were able to significantly improve the composites interface quality and therefore the tensile properties (151% increase in modulus and 36% increase in strength over the neat matrix) within the range of conditions tested.     

Recent Results on Recurrent Solutions and Limit Distributions of SDEs

The limit distribution for homogeneous Markov processes is studied extensively and well understood, but it is not the case for inhomogeneous Markov processes. In this paper, we review some recent results on inhomogeneous Markov processes generated by non-autonomous stochastic (partial) differential equations (SDE in short). Under some suitable conditions, we show that the distribution of recurrent solutions of SDEs constitutes the limit distribution of the corresponding inhomogeneous Markov processes.