光波导二氧化氮气敏传感元件的研究

本文用离子交换法制备K+交换玻璃光波导元件,并在其表面固定纳米级敏感层酞菁铜(CuPc)薄膜,利用光波导气体检测系统对NO2气体进行测试.结果表明,该传感元件常温下对NO2等气体有快速、可逆的响应,并具有重现性好,灵敏度高等特点.     

Photoluminescent layered Y(III) and Tb(III) silicates doped with Ce(III)

The synthesis and structural characterization of new layered rare-earth silicates K(3)[M(1-a)Ce(a)Si(3)O(8)(OH)(2)], M = Y(3+), Tb(3+), a < 1 (AV-22 materials), have been reported. These materials combine the properties of layered silicates, such as intercalation chemistry, and photoluminescence and may find applications in new types of sensor devices. For mixed Tb/Ce-AV-22, evidence has been found for the energy transfer from the large Ce(3+) 4f( 1) --> 5d(1) broad band to the sharp Tb(3+) 4f (8) lines. This energy transfer allows the fine-tuning of the color emission in the blue-green region of the chromaticity diagram. Upon Ce(3+) excitation (342 nm), the radiance of Tb/Ce-AV-22 is approximately 2 times higher than that measured under direct Tb(3+) excitation, which reinforces the existence of effective room-temperature Ce(3+)-to-Tb(3+) energy transfer.     

RP-HPLC of some metal phthalocyanines

The retention parameters of phthalocyanine, tetra-4-t-butylphthalocyanine and the latter's complexes with zinc, copper, rhodium and lutetium, as well as the copper complex of tetra-4-t-butyltetrabenzotriazaporphyrin were determined with Bondapak C₁₈ sorbent. It is shown that retention depends on azasubstitution, introduction of aliphatic substituents in the macrocycle, the number of macrocycles in molecules and the nature of the central metal ion in conditions of reversed-phase system. The ligand and complex peaks are symmetrical and they can be used for qualitative and quantitative estimation of the phthalocyanines contents in raw products of the synthesis and in the purified material.     

“One‐pot” synthesis of aromatic poly(1,3,4‐oxadiazole)s in novel solvents—ionic liquids

The new convenient method for the synthesis of high molecular weight aromatic poly(1,3,4‐oxadiazole)s (PODs) has been proposed. These polymers were prepared by “one‐pot” procedure from dicarboxylic acid and hydrazine's salt (sulfate, phosphate) or dicarboxylic acid dihydrazides. The mixture of ionic liquid and triphenyl phosphite was used both as a solvent and condensing agent. The polycyclization occurred at a sufficiently low temperature of 210 °C for 2–5 h and resulted in obtaining film‐forming PODs having inherent viscosities up to 0.9 dL/g and good thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 380–394, 2006     

Post‐Synthesis Stabilization of Germanosilicate Zeolites ITH,IWW, and UTL by Substitution of Ge for Al

Germanosilicate zeolites often suffer from low hydrothermal stability due to the high content of Ge. Herein, we investigated the post‐synthesis introduction of Al accompanied by stabilization of selected germanosilicates by degermanation/alumination treatments. The influence of chemical composition and topology of parent germanosilicate zeolites ( ITH , IWW , and UTL ) on the post‐synthesis incorporation of Al was studied. Alumination of ITH (Si/Ge=2–13) and IWW (Si/Ge=3–7) zeolites resulted in the partial substitution of Ge for Al (up to 80 %), which was enhanced with a decrease of Ge content in the parent zeolite. In contrast, in extra‐large pore zeolite UTL (Si/Ge=4–6) the hydrolysis of the interlayer Ge?O bonds dominated over substitution. The stabilization of zeolite UTL was achieved using a novel two‐step degermanation/alumination procedure by the partial post‐synthesis substitution of Ge for Si followed by alumination. This new method of stabilization and incorporation of strong acid sites may extend the utilization of germanosilicate zeolites, which has been until now been limited.     

Radical polymerization of radical-labeled monomers: The triarylmethyl-based radical monomer as an example

Recent development of spin-labeled nitroxide-mediated polymerization (NMP) involving successful polymer preparation with high livingness and narrow dispersity in the presence of persistent trityl-based stable radicals attached to the initiators (90% recovery of a trityl radical signal after the polymerization) led us to the preparation of stable organic radical polymers based on trityl radical-substituted monomers using NMP as the method of polymerization despite the claims in the literature about its expected failure. Here, we present successful radical polymerization and NMP of a trityl radical-based tri- and mono-monomer yielding more than 90% recovery of the trityl radical signal. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2656–2664     

A criterion of unconditional basis property for the families of vector exponentials

A criterion of unconditional basis property for the families of vector-functions \( {E}_k(t):={c}_k{e}^{i{\uplambda}_k t},{c}_k\in {\mathbb{C}}^n,{\uplambda}_k\in \Lambda \) in the Cartesian product of n spaces L ₂(0, a) without the restrictive condition inf _k Im λ _k > ?∞ is proved.     

Quadrupole Mass Filter: Design and Performance for Operation in Stability Zone 3

The predicted performance of a quadrupole mass filter (QMF) operating in Mathieu stability zone 3 is described in detail using computer simulations. The investigation considers the factors that limit the ultimate maximum resolution (R_max) and percentage transmission (%Tx), which can be obtained for a given QMF for a particular scan line of operation. The performance curve (i.e., the resolution (R) versus number (N) of radio frequency (rf) cycles experienced by the ions in the mass filter) has been modeled for the upper and lower tip of stability zone 3. The saturation behavior of the performance curve observed in practice for zone 3 is explained. Furthermore, new design equations are presented by examining the intersection of the scan line with stability zone 3. Resolution versus transmission characteristics of stability zones 1 and 3 are compared and the dependence of performance for zones 1 and 3 is related to particular instrument operating parameters.

On the full and block-decoupling of nonlinear functions

We review a method that decouples multivariate functions into linear combinations of a set of univariate (or simpler multivariate) functions of transformed variables. In this way the given nonlinear multiple-input-multiple-output function is decoupled into a structure having simpler parallel internal branches that are linked by linear transformations to the original inputs and outputs. The procedure collects first-order information by evaluating the Jacobian matrix of the given function in a set of points. These matrices are stacked into a three-way tensor, whose decomposition reveals the decoupled representation. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Generalized Darcy–Oseen resolvent problem

In this paper, we study the well‐posedness of a coupled Darcy–Oseen resolvent problem, describing the fluid flow between free‐fluid domains and porous media separated by a semipermeable membrane. The influence of osmotic effects, induced by the presence of a semipermeable membrane, on the flow velocity is reflected in the transmission conditions on the surface between the free‐fluid domain and the porous medium. To prove the existence of a weak solution of the generalized Darcy–Oseen resolvent system, we consider two auxiliary problems: a mixed Navier–Dirichlet problem for the generalized Oseen resolvent system and Robin problem for an elliptic equation related to the general Darcy equations. © 2016 The Authors Mathematical Methods in the Applied Sciences Published by John Wiley & Sons Ltd.