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排序方式: 共有187条查询结果,搜索用时 15 毫秒
1.
2.
Ezequiel V. Albano 《Journal of statistical physics》1995,78(3-4):1147-1155
The spreading of a globally distributed damage, created in the stationary regime, is studied in a single-component irreversible reaction process, i.e., the BK model [Browne and Kleban,Phys. Rev. A
40, 1615 (1989)]. The BK model describes one variant of the A+AA2 reaction process on a lattice in contact with a reservoir of A species. The BK model has a single parameter, namely the rate of arrival of A species to the lattice (Y). The model, exhibits an irreversible phase transition between a stationary reactive state with production of A2 species and a poisoned state with the lattice fully covered by A species. The transition takes place at critical points (Y
C
) which solely depend on the Euclidean dimensiond. It is found that the system is immune ford=1 andd=2, in the sense that even 100% of initial damage is healed within a finite healing period (T
H
). Within the reactive regime,T
H
diverges when approachingY
C
according toT
H
(Y
C
–Y)–, with 1.62 and 1.08 ford=1 andd=2, respectively. Ford=3 a frozen-chaotic transition is found close toY
s
0.4125, i.e., well inside the reactive regime 0YY
C
0.4985. Just atY
S
the damageD(t) heals according toD(t) t
–, with 0.71. For the frozen-chaotic transition atd=3 the order parameter critical exponent 0.997 is determined. 相似文献
3.
Thomas Andre´s Wolcan Ezequiel Fe´liz Mario R. Capparelli Alberto L. 《Transition Metal Chemistry》1997,22(6):541-544
The kinetics of the complexation of NiII by pteroylglutamic acid have been studied in the 545 ∘C range, the ionic strength
(0.6 M) being regulated with KNO3, in the 5.5–7.0pH range, using the stopped-flow method. Under the experimental conditions
two processes were observed. The faster process was detected in the millisecond range and is associated with the reaction
between NiII and the ligand. The slower is observed within a few seconds. Complementary equilibrium studies were made at 25
∘C. The results are consistent with the formation of a 1:1 complex between the reactants, and a mechanism is proposed to account
for the observed behaviour. Equilibrium constants for the NiII plus pteroylglutamic acid system, as well as activation parameters,
are reported.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Vidal E Palomeque ME Lista AG Fernández Band BS 《Analytical and bioanalytical chemistry》2003,376(1):38-41
A novel flow injection analysis (FIA) method with Rayleigh light scattering (RLS) detection was developed for the determination of total protein concentrations. This method is based on the weak intensity of RLS of bromothymol blue (BB) (3',3"-dibromothymolsulfonephthalein) which can be enhanced by the addition of protein in weakly acidic solution. A common spectrofluorimeter was used as a detector. It was proved that the application of this method to quantify the total proteins in real samples by using bovine serum albumin was possible. The RLS signal was detected at lambda(ex)= lambda(em)=572 nm. The linear range was 7.0-70.0 microg mL(-1), the detection limit was 3.75 microg mL(-1), the reproducibility was 5.5% (n=7), and the sample throughput was 26 h(-1). 相似文献
5.
Ezequiel?P.?M.?LeivaEmail author C.?G.?Sánchez 《Journal of Solid State Electrochemistry》2003,7(9):588-592
In the present work, an important point concerning the NEMCA effect is addressed. We analyse the reasons why the changes in the work function of the gas exposed catalyst-electrode surface are one to one related to the changes in the catalyst working electrode potential E with respect to a reference electrode. It is concluded that this is due to the unique properties of the catalyst/solid electrolyte interface: the structure of the double layer in this region is very different from that in liquid electrolytes, being the potential difference at this interface mainly determined by the specific adsorption of the mobile species in the solid electrolyte.
相似文献
Ezequiel P. M. LeivaEmail: |
6.
Ramo Marceli Fernandes Gelson Manzoni de Oliveira Ernesto Schulz Lang Ezequiel M. Vzquez‐Lpez 《无机化学与普通化学杂志》2004,630(15):2687-2691
The reaction of tellurium(IV) tetrahalides with hydrochloric and hydrobromic acid leads to the formation of (H3O)2[TeX6], which reacts subsequently with (2‐Br‐C5NH5)+X‐ to afford (2‐Br‐C5NH5)2[TeCl6] ( 1 ) and (2‐Br‐C5NH5)2[TeBr6] ( 2 ). The structure of the complex salts were analysed by X‐ray diffractometry affording the centrosymmetric space groups P21/n (monoclinic, 1 ) and P1¯ (triclinic, 2 ). Interionic hydrogen bondings hold their lattices in bidimensional supramolecular arrays not yet described in the literature. The lone electron pair of the AX6E‐system of the hexahalotellurates [TeX6]2‐ (X = Cl, Br) seems to be fully delocalized since only small octahedral deviations were observed for the anionic species. The structures of the title compounds were refined with the Te atoms occupying sites with full point symmetry, approximately m3¯m. In both cases the Te atoms enclose centers of inversion and the octahedrally dynamic structures are enforced and stabilized along the supramolecular lattices by the crystal field of the 2‐Br‐pyridinium cations. 相似文献
7.
Jacqueline Grewe Adelheid Hagenbach Brigitte Stromburg Roger Alberto Ezequiel Vazquez‐Lopez Ulrich Abram 《无机化学与普通化学杂志》2003,629(2):303-311
Novel rhenium(I) tricarbonyl complexes have been prepared by reactions of (Et4N)2[Re(CO)3Br3] with acetylpyridine benzoylhydrazone, Hapbhyd, di(2‐pyridyl)ketone benzoylhydrazone, Hpy2bhyd, bis(2‐pyridine)ketone, py2CO, and pyridinealdehyde terephtalaldehydebishydrazone, pytehyd. The ligands remain protonated when no supporting base is added and the following complexes have been isolated: [Re(CO)3Br(Hapbhyd)], [Re(CO)3Br(Hpy2bhyd‐py, hyd)], [Re(CO)3Br(Hpy2bhyd‐py1, py2)], [Re(CO)3Br(py2CO‐N, N)] and [Re(CO)3Br(pytehyd)]. Addition of triethyl amine results in deprotonation of Hapbhyd and the formation of [Re(CO)3(OH2)(apbhyd)], whereas Hpy2bhyd is hydrolysed and a rhenium complex with the monoanionic bis(2‐pyridyl)hydroxymethanolato ligand, {py2C(OH)O}‐, is formed. The same compound, [Re(CO)3{py2C(OH)O}], is obtained when triethyl amine and water are added to a mixture of (Et4N)2[Re(CO)3Br3] and py2CO. The air‐stable products have been studied by spectroscopic methods and X‐ray crystallography. 相似文献
8.
Carballo R Casas JS García-Martínez E Pereiras-Gabián G Sánchez A Sordo J Vázquez-López EM 《Inorganic chemistry》2003,42(20):6395-6403
The reactions of methylacetoacetate and ethyl 2-methylacetoacetate thiosemicarbazones (H(2)L(A) and H(2)L(B), respectively) with [ReX(CO)(5)] and [ReX(CO)(3)(CH(3)CN)(2)] (X = Cl, Br) were explored under various experimental conditions. Besides the adducts fac-[ReX(CO)(3)(H(2)L)], in which the rhenium is coordinated to three carbonyl groups, the X anion, and the N,S-bidentate thiosemicarbazone ligand, the following complexes were also isolated: fac-[ReBr(CO)(3)(Hpyz(B))], the tetrameric complexes fac-[Re(pyz(A))(CO)(3)](4) and fac-[Re(pyz(B))(CO)(3)](4), and fac-[Re(pyz(B))(CO)(3)(H(2)O)] (where Hpyz(A) and Hpyz(B) are pyrazolones derived by cyclization of H(2)L(A) and H(2)L(B), respectively). The cyclization reactions were monitored by (1)H NMR spectroscopy and the complexes isolated were identified by elemental analysis, mass spectrometry, IR and (1)H NMR spectroscopy, and in some cases by X-ray diffractometry. The isolation and the full structural identification of the rather unusual fac-[ReBr(CO)(3)(Hpyz(B))], which contains the enol form of the pyrazolone ligand, affords new insight into the cyclization of thiosemicarbazones derived from beta-keto esters. 相似文献
9.
Nonlinear Dynamics - In this paper, type V intermittency is studied using the M function methodology developed in the last years. This methodology is applied on two different maps to evaluate the... 相似文献
10.
Wei Duo Orlandi Ezequiel Barriet Mathilde Simon Sébastien Sjöblom Johan 《Journal of Thermal Analysis and Calorimetry》2015,121(1):463-468
Journal of Thermal Analysis and Calorimetry - This paper describes the self-association of tetrameric acids (TA) and their interactions with asphaltenes using isothermal titration calorimetry. In... 相似文献