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1.
Suńol J. J. Saurina J. Carrillo F. Colom X. 《Journal of Thermal Analysis and Calorimetry》2003,72(2):753-758
Comparison of Lyocell, modal and viscose fibers was performed by means of differential scanning calorimetry, thermogravimetry
and scanning electron microscopy. Thermal analysis was performed in air atmosphere. Samples were mercerized (21.3 g 100 mL-1)
or submitted to solar radiation (seven months). Solar degraded samples presents a higher thermal stability and are initially
less degraded. Furthermore, Lyocell fiber is the most stable under thermal degradation conditions. Heating produces a reduction
of the fiber diameter (about 50%).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
We study the derivation of a Langevin equation from a microscopic basis in order to elucidate the nature of the random force. We arrive at the conclusion that the consistent interpretation of the microscopic Langevin equation in terms of a stochastic differential equation (SDE) is according to I
o rules. In addition, the random force is in general not Gaussian, and it is hence not completely characterized by its second moments. 相似文献
3.
4.
Fast neutrons of 14 MeV produced in the IMICAM CISE 150-kV generator by the (d, t) reaction in a tritium-titanium target, were used in the indirect determination of Al(2)O(3). The samples were irradiated for 30 sec and the total (16)N activity was determined, by counting for ten 2-sec periods and graphically integrating. The standards were a known sintered aluminium powder and nylon pieces of identical shape. The method is competitive with the chemical one, because of its quickness, sensitivity and precision. 相似文献
5.
Coll R. Saurina J. Escoda L. Suñol J. J. 《Journal of Thermal Analysis and Calorimetry》2018,131(2):1277-1286
Journal of Thermal Analysis and Calorimetry - This paper reports the effects of welan gum on the hydration and hardening behaviors of Portland cement (PC) by using X-ray diffractometry, mercury... 相似文献
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8.
Veronika Šolínová Petr Tůma Maria Butnariu Václav Kašička Dušan Koval 《Electrophoresis》2022,43(20):1953-1962
We present a method for finely adjustable electroosmotic flow (EOF) velocity in cathodic direction for the optimization of separations in capillary electrophoresis. To this end, we use surface modification of the separation fused silica capillary by the covalently attached copolymer of acrylamide (AM) and 2-acrylamido-2-methyl-1-propanesulfonate (AMPS), that is, poly(AM-co-AMPS) or PAMAMPS. Coatings were formed by the in-capillary polymerization of a mixture of the neutral AM and anionic AMPS monomers premixed in various ratios in order to control the charge density of the copolymer. EOF mobility varies in the 0 to ∼40 × 10−9 m2 V−1 s−1 interval for PAMAMPS coatings ranging from 0 to 60 mol.% of charged AMPS monomer. For EOF in PAMAMPS-treated capillaries, we observed (i) a negligible dependence on pH in the 2–10 interval, (ii) a minor variance among background electrolytes (BGEs) in function of their components and (iii) its standard decrease with increasing ionic strength of the BGE. Interest in variable cathodic EOF was demonstrated by the amelioration of separation of two kinds of isomeric anionic analytes, that is, monosaccharides phosphates and helquat enantiomers, in counter-EOF mode. 相似文献
9.
P. Español J. A. de la Torre M. Ferrario G. Ciccotti 《The European physical journal. Special topics》2011,200(1):107-129
The method of constraints in molecular dynamics is useful because it avoids the resolution of high frequency motions with
very small time steps. However, the price to pay is that both the dynamics and the statistics of a constrained system differ
from those of the unconstrained one. Instead of using constraints, we propose to dispose of high frequency motions by a coarse-graining
procedure in which fast variables are eliminated. These fast variables are thus modeled as friction and thermal fluctuations.
We illustrate the methodology with a simple model case, a diatomic molecule in a monoatomic solvent, in which the bond between
the atoms of a diatomic molecule is stiff. Although the example is very simple and does not display the interesting effects
of “wrong” statistics of the constrained system (i.e. the well-known issue connected to the Fixman potential), it is well
suited to give the proof of concept of the whole procedure. 相似文献
10.
R. Coll L. Escoda J. Saurina J. L. Sánchez-Llamazares B. Hernando J. J. Suñol 《Journal of Thermal Analysis and Calorimetry》2010,99(3):905-909
Three magnetic shape memory alloys: Mn50Ni50−x
Sn
x
(x = 5, 7.5, and 10) were produced as bulk polycrystalline ingots by arc melting. The structural austenite–martensite transformation
was checked by calorimetry. The transformation temperatures decrease as increasing the Sn content. The same trend is found
in the entropy and enthalpy changes related to the transformation. The control of the valence electron by atom e/a determines the transformation temperatures range in this kind of alloys and it is possible to develop alloys that can be
candidates in applications as sensors and actuators. Furthermore, X-ray diffraction was performed to check the crystalline
structure at room temperature. 相似文献