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511.
This paper reports the investigation of the thermal
stability of a series of new complexes with azo and azomethinic chromophores
of the type [Er(HL)2(H2O)2](HO);
((B) H2L: o,o’-dihydroxy-azobenzene (A);
(D) H2L: N-(2-hydroxy-1-naphthalidene)aminophenol
(C); (F)
H2L: N-(2-hydroxy-1-naphthalidene)anthranilic acid
(E)). The complexes thermal behaviour steps
were investigated and comparatively presented with those of corresponding
ligand. The thermal transformations are complex processes according to TG
and DTG curves including phenol elimination, oxidative condensation and thermolysis
processes. The final product of complexes decomposition is Er2O3. 相似文献
512.
We show that the acceptance probability for swaps in the parallel tempering Monte Carlo method for classical canonical systems is given by a universal function that depends on the average statistical fluctuations of the potential and on the ratio of the temperatures. The law, called the incomplete beta function law, is valid in the limit that the two temperatures involved in swaps are close to one another. An empirical version of the law, which involves the heat capacity of the system, is developed and tested on a Lennard-Jones cluster. We argue that the best initial guess for the distribution of intermediate temperatures for parallel tempering is a geometric progression and we also propose a technique for the computation of optimal temperature schedules. Finally, we demonstrate that the swap efficiency of the parallel tempering method for condensed-phase systems decreases naturally to zero at least as fast as the inverse square root of the dimensionality of the physical system. 相似文献
513.
Mihaela Badea Laura Micheli Maria Cristina Messia Tiziana Candigliota Emanuele Marconi Toby Mottram Maria Velasco-Garcia Danila Moscone Giuseppe Palleschi 《Analytica chimica acta》2004,520(1-2):141-148
A flow-injection immunoassay (FI-IA) method with amperometric detection for aflatoxin M1 (AFM1) determination in milk has been developed. The first step consists in an incubation of the sample containing AFM1 (Ag) with fixed amounts of anti-AFM1 antibody (Ab) and of the tracer (Ag*, AFM1 covalently coupled to HRP) until equilibrium is reached. In this mixture a competition occurs between Ag and Ag* for the Ab. The mixture is then injected into a flow system where the separation of the free tracer (Ag*) and the antibody-bound tracer (AbAg*) is performed in a column with immobilized Protein G. The antigen–antibody complexes are retained in the column due to the high affinity of the Protein G for the antibody. The activity of the eluted enzyme label is then amperometrically detected.
The immunoassay was optimised relative to conditions for antibody–antigen incubation (pH, incubation time, ionic strength, temperature) and enzymatic label detection. This method showed a dynamic concentration range between 20 and 500 ppt AFM1, a low detection limit (11 ppt), good reproducibility (RSD < 8%) and a high throughput (six samples per hour in triplicate). Different milk samples were analysed and the results were in good agreement with those obtained by HPLC using the AOAC 2000.08 method. 相似文献
514.
Maria Cazacu Carmen Racles Anton Airinei Mihaela Alexandru Angelica Vlad 《Journal of polymer science. Part A, Polymer chemistry》2009,47(21):5845-5852
A ferrocenyl‐siloxane polyamide, poly{1,1′‐ferrocene‐diamide‐[1,3‐bis(propylene)tetramethyldisiloxane]}, FAS, prepared by polycondensation in solution (methylene chloride) of 1,1′‐di(chlorocarbonyl)ferrocene with 1,3‐bis(aminopropyl)tetramethyldisiloxane has been dissolved in various concentrations in the range 0–1.5 g/dL in dimethylformamide. The solutions were investigated by tensiometry, viscometry, and UV–vis spectrophotometry at different temperatures. The results suggested the association occurrence, depending on the two parameters (concentration and temperature). The aggregates formation and their sizes were emphasized by dynamic light scattering and scanning electron microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5845–5852, 2009 相似文献
515.
516.
Andreea Micle Natalia Miklova Richard A. Varga Aurelia Pascariu Nicoleta Pleu Mihaela Petric Gheorghe Ilia 《Tetrahedron letters》2009,50(40):5622-5624
The iminophosphorane CH2CH2[P{NP(O)(OPh)2}Ph2]2 is synthesized in high yields (80–97%) via a very convenient procedure using diphenylphosphoryl azide (DPPA) and 1,2-bis(diphenylphosphino)ethane. 相似文献
517.
Various primary 2-aminothiols have been prepared by a general and efficient method, in three steps, starting from commercially available 2-aminoalcohols and methyldithioacetate as a convenient source of sulfur. 相似文献
518.
Lucia Odochian Anca Mihaela Mocanu C. Moldoveanu Gabriela Carja C. Oniscu 《Journal of Thermal Analysis and Calorimetry》2008,94(2):329-334
The paper deals with the characterization of three hydrazinic complexes with Ni, Cu and Cr respectively, by means of non-isothermal
thermal methods, TG, DTG and DTA, under nitrogen atmosphere in order to investigate the structure-thermostability-thermal
degradation mechanism correlation. The thermal analysis made evident the degradation mechanisms characteristic of every sample
in accordance with the chemical structure. The quantitative analysis by TG-DTG afforded the estimation of the metal amount
in the complex on the basis of the resulting metallic oxide nature as well as of some aspects of the thermal degradation mechanism
supported by mass spectral measurements. The melting points given by DTA and confirmed by the Boetius method and the initial
temperatures of thermal degradation from TG-DTG-DTA afforded to ascertain the temperature range proper for using and storing
the complexes under study which show potential practical applications as drugs. 相似文献
519.
520.
In this paper the authors purpose the conception and modelling of a possible application in a circular flexible manufacturing cell. This flexible cell is composed from five manufacturing points for realizing the final technological itinerary of a type of radiator. This flexible manufacturing cell is served by an industrial articulated robot, which possess in his cinematic chain three degrees of freedom, type RRT. In virtue of real values of the functional parameters which are input data in the analysis of the flexible manufacturing cell, had been dignify the cost of the flexible manufacturing cell, determining the value of the included industrial robot in the system and the value of the entire flexible cell where the robot realize the manipulating process of the radiators. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献