Materials Literature
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Magnetic, linear thermal expansion (LTE), anisotropic ($λ_t$) and volume ($ω$) magnetostriction properties of Pr$_{0.5}$Sr$_{0.5}$MnO$_3$ were investigated. The LTE decreases smoothly from 300 K without a clear anomaly either around the Curie (T$_C$ = 270 K) or the Neel temperature (T$_N$ = 100 K) and it exhibits hyst…
Photocatalysts involving titanium oxides were prepared by an ion-exchange and impregnation method in which zeolites with different Si/Al ratios were used as supports. Those photocatalysts with low Si/Al ratios exhibited high and unique photocatalytic reactivity for the direct decomposition of NO into N 2, O 2, and N 2…
A first-principles derived approach is combined with the inverse Monte Carlo technique to determine the atomic orderings leading to prefixed properties in Pb(Sc(0.5)Nb(0.5))O(3) perovskite alloy. We find that some arrangements between Sc and Nb atoms result in drastic changes with respect to the disordered material, i…
Wurtzite (Ga,Mn)N films showing ferromagnetic behaviour at room temperature were successfully grown on sapphire(0001) substrates by molecular beam epitaxy using ammonia as nitrogen source. Magnetization measurements were carried out by a superconducting quantum interference device at the temperatures between 1.8K and…
On the basis of a topological discussion as well as an {\it ab initio} calculation, we show that it is possible to construct a fullerene-like Si cage by doping of a transition metal atom. The cage is a simple 3-polytope which maximizes the number of its inner diagonals close to the metal atom. Our topological argument…
We present a modified method of preparation of the new superconductor MgB$_2$. The polycrystalline samples were characterized using x-ray and magnetic measurements. The surface barriers control the isothermal magnetization loops in powder samples. In bulk as prepared samples we always observed symmetric magnetization…
no abstract available.
The perfect quenching of spin tunneling that has previously been discussed in terms of interfering instantons, and has recently been observed in the magnetic molecule ${\mathrm{Fe}}_{8},$ is treated using a discrete phase integral (or Wentzel-Kramers-Brillouin) method. The simplest model Hamiltonian for the phenomenon…
The perfect quenching of spin tunneling first predicted for a model with biaxial symmetry, and recently observed in the magnetic molecule ${\mathrm{Fe}}_{8},$ is further studied using the discrete phase integral or WKB (Wentzel-Kramers-Brillouin) method. The analysis of the previous paper is extended to the case where…
Temperature dependence of electrical conductivity \ensuremath{\sigma} is investigated for a set of icosahedral $(i\ensuremath{-}){\mathrm{Al}}_{70.5}{\mathrm{Pd}}_{21}{\mathrm{Re}}_{8.5}$ samples. We focus on ribbon samples with resistance ratios $R=\ensuremath{\rho}(4 \mathrm{K})/\ensuremath{\rho}(300 \mathrm{K})$ be…
The phase structure and biodegradability were investigated for amorphous blends of chemosynthetic fully amorphous atactic poly(R,S-3-hydroxybutyrate) (a-PHB) with atactic poly(methyl methacrylate) (PMMA) and atactic poly(R,S-lactide) (a-PLA). The differential scanning calorimetry thermal analysis indicated that a-PHB/…
Helices IV and V in the lactose permease of Escherichia coli contain the major determinants for substrate binding [Glu126 (helix IV), Arg144 (helix V), and Cys148 (helix V)]. Structural and dynamic features of this region were studied by using site-directed sulfhydryl modification of 48 single-Cys replacement mutants…
The effects of copper deposition on the $\mathrm{ZnO}(0001\ifmmode\bar\else\textasciimacron\fi{})$ O-terminated surface at 300 K have been studied by surface x-ray diffraction (SXRD). Terraces about 550 \AA{} wide, presenting a $(1\ifmmode\times\else\texttimes\fi{}1)$ bulk-derived order, were obtained on the clean sur…
We study the potential energy surface (PES) sampled by a liquid modeled via the widely studied extended simple point charge (SPC/E) model for water. We characterize the curvature of the PES by calculating the instantaneous normal mode (INM) spectrum for a wide range of densities and temperatures. We discuss the inform…
Abstract Maleic anhydride (MAH) was photografted onto low‐density polyethylene (LDPE) films with a grafting efficiency of about 70% in the absence of a photoinitiator. The self‐initiating performance was attributed to a mechanism of abstracting hydrogen atoms from LDPE chains by excited MAH dimers. The supporting expe…
1,4,8,11,15,18,22,25-octabutoxyphthalocyanines ((OBu)8Pcs) having eight 2-thienyl (1) and [2,2'-bithiophene]-5-yl (2) groups at beta positions and their zinc(II) and cobalt(II) derivatives were prepared from 2-thienyl- (3) or [2,2'-bithiophene]-5-yl (4)-substituted phthalonitriles in moderate to good yields. The elect…
Cavities or packing defects in proteins may generally be related with the dynamics and function of a protein. In the c-Myb R2 subdomain, its single cavity has been shown to be crucial for its DNA recognition. Cavities are also considered important in determining the pressure stability of a protein. In the present work…
In order to facilitate the large-scale preparation of active class II polyhydroxyalkanoate (PHA) synthase, we constructed a vector pT7-7 derivative that contains a modified phaC1 gene encoding a PHA synthase from Pseudomonas aeruginosa possessing six N-terminally fused histidine residues. Overexpression of this phaC1…
The orbital free ab initio molecular dynamics method is applied to study the static and dynamic structure of liquid Al near the triple point. The method uses a new kinetic energy functional, along with a local pseudopotential constructed within the same kinetic energy functional. The results obtained for the dynamic s…
Resonant behavior of the Raman process is predicted when the laser frequency is close to the orbital excitation energy of ${\mathrm{LaMnO}}_{3}$ at 2 eV. The incident photon creates a vibrationally excited self-trapped ``orbiton'' state from the orbitally ordered Jahn-Teller (JT) ground state. Trapping occurs by local…