Materials Literature
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Introduction In the previous chapter we discussed the econometric problems that might occur when we run a regression with different orders of integrated variables. To avoid this problem, the first thing we have to do is to identify the correct order of the integration of each variable. In the context of ARIMA modeling…
Water-insoluble poly(ethylene oxide - b -ε-caprolactone) (PEO - b -PCL) diblock copolymer ( M w = 1.71 × 10 4 g/mol and W PEO = 20%) was successfully micronized into small polymeric core−shell nanoparticles (micelles) stable in water via a microphase inversion method. Such formed PEO - b -PCL nanoparticles are biodegr…
We have performed ab-initio calculations of exchange couplings in the layered vanadates CaV2O5, MgV2O5, CaV3O7 and CaV4O9. The uniform susceptibility of the Heisenberg model with these exchange couplings is then calculated by quantum Monte Carlo method; it agrees well with the experimental measurements. Based on our r…
The role of the intrinsic surface state ($n=0$) in the decay of the first image state ($n=1$) at the (111) surface of copper is investigated. Inelastic linewidths are evaluated from the knowledge of the imaginary part of the electron self-energy, which we compute, within the GW approximation of many-body theory, by go…
Theoretical aspects of polymers in mixed solvents are considered using the Edwards Hamiltonian formalism. Thermodynamic and structural properties are investigated and some predictions are made when the mixed solvent approaches criticality. Both the single and the many chain problems are examined. When the pure mixed s…
The process of controlled laser sintering for powdered SHS compositions with the bases Ni-Ti and Ni-Al was realized. The optimal parameters of laser effect, under which the reaction of SHS proceeds in controlled regime, were determined. The phase composition of the sintered structure was revealed by the x-ray phase an…
The structures and energies of the binary dititanium dicarbide, Ti 2 C 2, in the lowest singlet, triplet, and quintet states have been investigated by density functional theory using the hybrid B3LYP functionals. Geometries and frequencies for a number of isomeric structures are presented at the B3LYP level. A rhombic…
Chain length of substituted n -alkyl groups is proposed to be a convenient design element for the generation of noncentrosymmetric crystal lattices of interest in optical second harmonic generation (SHG). Powder studies on 7,7-Bis( n -alkylamino)-8,8-dicyanoquinodimethanes indicate that moderate solid-state optical SH…
The structural and electronic consequences of reduction and oxidation of a peroxo-bridged Mn(2)(IV/IV) dimer, Mn(2)(&mgr;-O)(2)(&mgr;-O(2))(NH(3))(6)(2+), are examined using approximate density functional theory. In both cases, the initial electron-transfer step is localized on the metal centers, but subsequent struct…
An extension of the replica Ornstein−Zernike (ROZ) equations for partly quenched polydisperse systems is presented. Explicit calculations have been performed for a hard sphere fluid confined by a polydisperse hard sphere disordered matrix. A numerical solution of the ROZ equations makes use of the orthonormal polynomi…
Small angle neutron scattering (SANS) was used for the characterization of the microstructure of carbons derived from organic-loaded inorganic template materials that are used as anodes in lithium ion cells. Pillared clays (PILC), layered silicates whose sheets have been permanently propped open by sets of thermally s…
The dependence on wavelength of repetitive-pulse (10 Hz, 8-10 ns) laser-induced damage on beta barium metaborate (BBO) has been investigated. The thresholds of dielectric breakdown in bulk crystal have been found to be 0.3 GW/cm(2) at 266 nm, 0.9 GW/cm(2) at 355 nm, 2.3 GW/cm(2) at 532 nm, and 4.5 GW/cm(2) at 1064 nm.…
Various functional alkanethiols were found to be able to reduce polyaniline backbones from the emeraldine state 1 to the leucoemeraldine state 2, simultaneously derivatizing the backbones to form functionalized polyanilines. X-ray photoelectron spectroscopy (XPS) studies proved that these thiols formed sulfide bond li…
Magnesium−alumina mixed oxide catalysts at Mg:Al atomic ratios of 3:1, 2:1.8, and 1:2.8 were synthesized by using the sol−gel technique. Dehydroxylation and phase transformations were studied with thermogravimetry. Crystalline structures were measured with X-ray powder diffraction. Position and concentration of anioni…
Pump−probe spectroscopy and steady state emission measurements have been used to demonstrate electron transfer from the excited state populated by excitation in the Soret band (denoted S 2 ) of a zinc porphyrin to a covalently linked ruthenium(II) tris -bipyridine complex (ZnTTP-L-Ru(bpy) 3 ). The lifetime of 1.6 ps m…
The equilibrium geometries, binding energies, electronic structure, and magnetic properties of small stoichiometric MnO clusters are presented for the first time. The results are based on first-principles self-consistent calculations performed within the framework of density functional theory and the generalized gradi…
The molecular weight distribution and its moments for the hyperbranched polymer formed by the polycondensation of an AB 2 type monomer with a multifunctional core moiety were derived rigorously by means of the kinetic method. The variations of several molecular parameters of the growing polymer during the reaction wer…
The isothermal crystallization of three different types of poly[ε-caprolactone- co -ethylene glycol] (PCL−PEG) incompatible block copolymers [A−B, (A) 2 −B, and A−B−A] was investigated using DSC. The PEG weight fraction in the copolymers was slightly varied from 18 to 22 wt %. It was established that the kinetic param…
Solutions containing divalent metal [M(II) = Mg2+, Zn2+, Co2+, Ni2+, Mn2+] chlorides and CrCl3 6H2O were titrated with NaOH to yield, for M(II) = Zn, Co, and Ni, hydrotalcite-like layered double hydroxides (LDHs), [[M(II)]1-z[Cr(III)]z(OH)2][Cl]z yH2O, in a single step, without intermediate formation of chromium hydro…
The combination of two metals in an oxide matrix can produce materials with novel physical and chemical properties. The reactivity of a series of cobalt and nickel molybdates (α-AMoO 4, β-AMoO 4, and AMoO 4 · n H 2 O; A = Co or Ni) toward H 2 and H 2 S was examined using temperature programmed reduction (TPR), synchro…