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81.
Summary Lattice parameter values were determined for the ternary B 2-phase in the Al-Co-Ga system, and it was found that a continuous solid solution exists between -AlCo and -CoGa. Phase boundaries of the ternary phase at 1 100 K were derived from the variation of the lattice parameter with composition.
Über die ternäre B 2-Phase im System Al-Co-Ga
Zusammenfassung Im Bereich der ternären B 2-Phase im System Al-Co-Ga wurden die Werte des Gitterparameters bestimmt; es stellte sich heraus, daß eine durchgehende feste Lösung zwischen -AlCo und -CoGa besteht. Die Phasengrenzen der ternären Phase bei 1 100 K wurden aus der Änderung des Gitterparameters mit der Zusammensetzung abgeleitet.相似文献
82.
H. Binder B. Kohlstrunk U. Brenn W. Schwieger G. Klose 《Colloid and polymer science》1998,276(12):1098-1109
Microcrystals of the metal silicate hydrate ilerite orient macroscopically on the surface of a ATR-crystals and thus, are
accessible for infrared linear dichroism measurements. We present first results which indicate that the alkyl chain packing
and the orientation of the polar group of dodecyltrimethylammoniumbromide (DTAB) intercalated between silicate layers can
be determined in terms of infrared order parameters. The properties of DTAB can be modulated by the relative humidity of the
surrounding atmosphere and by temperature. Upon heating DTAB undergoes a phase transition from a paraffin-like solid to a
fluid phase. The former is characterized by the orthorhombic perpendicular packing of the frozen alkyl chains with tilted
long axes. The interactions between the ionic groups of the surfactant and that of the host matrix stabilize the lamellar
arrangement of DTAB in the crystalline and in the fluid phases.
Received: 14 January 1998 Accepted: 27 July 1998 相似文献
83.
We present a unified approach for linear and nonlinear sensitivity analysis for models of reaction kinetics that are stated in terms of systems of ordinary differential equations (ODEs). The approach is based on the reformulation of the ODE problem as a density transport problem described by a Fokker-Planck equation. The resulting multidimensional partial differential equation is herein solved by extending the TRAIL algorithm originally introduced by Horenko and Weiser in the context of molecular dynamics (J. Comp. Chem. 2003, 24, 1921) and discussed it in comparison with Monte Carlo techniques. The extended TRAIL approach is fully adaptive and easily allows to study the influence of nonlinear dynamical effects. We illustrate the scheme in application to an enzyme-substrate model problem for sensitivity analysis w.r.t. to initial concentrations and parameter values. 相似文献
84.
《Surface and interface analysis : SIA》2003,35(12):991-997
In x‐ray photoelectron spectroscopy (XPS) the Auger parameter is often used to study the electronic properties of elements, particularly in insulator materials, because this parameter is assumed to be independent of charging effects. In this paper we report on subtle differences in sample structure and experimental conditions for which the sample potential may not remain constant during the measurements for some spectrometers or experimental arrangements; for such conditions the Auger parameter is not independent of charging. We compare a series of measurements with insulating plate substrates of Al2O3 on which different amounts of SnO2 and Au were deposited. X‐ray photoelectron spectra were collected for different conditions of the sample that was placed either grounded or left floating on a metallic sample holder during measurement. It is found that the Auger parameter is independent of the experimental conditions for Au but substantial differences were found for deposited SnO2. Surprisingly, measurement artifacts due to charging appeared in the Auger parameter for Sn when the sample holder was grounded but not when it was left floating. In the grounded samples differences up to 0.6 eV in the Auger parameter for Sn were found with respect to the actual value of this parameter measured with substrates where charging effects were not significant. Because no differences in peak broadening have been observed under different measurement conditions, it has been assumed that the shift was not caused by a conventional differential charging phenomenon. Considering the different response of the substrate and the deposited layer on stabilizing the charge when the sample is grounded, we have worked out a possible explanation to account for the observed artifacts. Instrumental specifications should be optimized very carefully, especially if (as here) relatively high charging shifts point to a non‐optimum self‐biasing of the surface potential at the insulating samples. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
85.
热重分析(TG)和微商热重法(DTG)广泛应用于各个研究领域,用非等温热重法测定固体化合物的热分解动力学参数已有报导.许多作者提出各种不同的数据处理方法.本文用的ρ-CH_3C_6H_4SR 型硫醚对钯的萃取具有选择性好、分配比高、气味较小、易溶于脂肪烃类溶剂、易于合成、是很有发展前途的一类萃取剂.我们合成五种ρ-CH_3C_6H_4SR(R:n-C_4H_9,n-C_6H_(13),n-C_8H_(17),n-C_(10)H_(21),n-C_(12)H_(25))型硫醚与钯(Ⅱ)的配合物,用TG-DTG 法研究它们的热分解过程,用微商法(Freeman-Carroll 方程)及积分法(Coats-Redfern 方程)获得了这些配合物的热分解动力学参数. 相似文献
86.
密胺树脂/硼酸锌双层包覆微胶囊化红磷的制备及其在阻燃聚烯烃中的应用 总被引:3,自引:0,他引:3
描述了采用密胺树脂和硼酸锌连续双层包覆微胶囊化红磷(MRP)的最新制备方法。采用红外光谱、电子能谱和透射电镜等分析手段对其进行了表征,并证实红磷已被完全包覆。实验数据表明:经包覆的MRP的热稳定性获得了明显改善,吸水率和磷化氢的发生量均大大减少。MRP作为阻燃助剂应用于聚烯烃阻燃材料表现出了良好的阻燃效果。实时红外和热失重测量以及扫描电镜观察表明:其阻燃机制是红磷受热时与树脂反应促进了含磷膨胀炭层的形成,从而提高了材料的热稳定性,碳层起到了隔氧、隔热作用,而且主要在凝聚相中发挥其阻燃作用。 相似文献
87.
88.
An electrochemical quartz crystal microbalance (EQCM) is employed for monitoring the growth of poly(neutral red) films on
platinum in the electrolytic solution containing 5.0 mmol dm−3 neutral red, 0.3 mol dm−3 H2SO4, and 0.5 mol dm−3 Na2SO4. The in situ measurement of the frequency changes of the EQCM reveals that both the adsorption/desorption of neutral red
and the formation of poly(neutral red) film can be observed together with anion sorption/desorption during the redox transformation
of the polymer, and that the polymerization rate of neutral red increases slowly before the 11th cycle and then increases
quickly with increasing number of potential cycles.
Published in Russian in Elektrokhimiya, 2007, Vol. 43, No. 3, pp. 284–289.
The text was submitted by the authors in English. 相似文献
89.
90.
Melamine cyanurate-microencapsulated red phosphorus flame retardant unreinforced and glass fiber reinforced polyamide 66 总被引:1,自引:0,他引:1
A novel microencapsulated red phosphorus (RP) was prepared through the molecular self-assembly of melamine cyanurate (MCA). Compared with the conventional encapsulated RP, MCA-encapsulated RP (MERP) shows simpler and more environment-friendly preparation process higher thermal stability and lower moisture absorption. With MERP filled in unreinforced polyamide 66 (PA66) and glass fiber (GF) reinforced PA66, flame retardant materials with satisfactory flame retardancy and mechanical performance can be obtained. The influence of the MCA/RP ratio on the flame retardancy as well as the condensed phase of MERP flame retardant PA66 was investigated to reveal the nitrogen-phosphorus (N-P) synergistic flame retarding effects between MCA and RP. 相似文献