Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The electrical transport in quasiperiodic systems at zero temperature is studied by means of the Kubo-Greenwood formula within a tight-binding model. Their dc conductivity is compared with that obtained from the Landauer formula. Special attention is paid to the transparent states, whose transmittance is unity. The ac…
Monoclinic and hexagonal forms of celsians (BaAl 2 Si 2 O 8 ) were synthesized by hydrolysis–polycondensation of Si/Al alkoxide mixtures. Dilatometry, Raman scattering, IR absorption, and X‐ray diffraction techniques were used to identify various hexacelsian phases and their conversion into the monoclinic phase as a f…
Phase‐pure perovskite Pb(Zn x Mg 1– x ) 1/3 Nb 2/3 O 3 solid solution (PZ x M 1– x N) is obtained for x ≦ 0.7 by heating a milled stoichiometric mixture of PbO, Mg(OH) 2 , Nb 2 O 5 , and 2ZnCO 3 ·3Zn(OH) 2 ·H 2 O at 1100°C for 1 h. Percent perovskite ( f P ) with respect to total crystalline phase decreases with incre…
Among other soft chemistry processes, sol-gel chemistry offers a versatile access to chemically designed new hybrid organic-inorganic materials. Two approaches to synthesize hybrids are presented: the hydrolysis of organo functional metal alkoxides or the assembly of nanobuilding blocks.
A generalized theory that includes short-range elasticity, long-range elasticity, and flow effects is used to simulate and characterize the shear flow of liquid crystalline materials as a function of the Deborah (De) and Ericksen (Er) numbers in the presence of fixed planar director boundary conditions; the results ar…
Complex particles have been formed by the electrostatic association of protonated polystyrene- b -poly(2-vinylpyridine) (PS- b -PVPH + ) micelles with sodium poly(styrenesulfonate) (PSS - Na + ), all at pH 1. Light scattering demonstrates that there is a large mass excess of PSS - associated with each PS- b -PVPH + mi…
Abstract Owing to their large and chemically active surface, hydroxy-intercalated and pillared clays can be potent sorbents for organic compounds. The sorption behavior of Al and Zr-hydroxy-intercalated bentonite (HAl-, HZr-MX80), Al and Zr-pillared bentonite (Al-MX80, Zr-MX80), and a commercial Al-pillared bentonite…
The compound $({\mathrm{CH}}_{3}{)}_{2}{\mathrm{CHNH}}_{3}{\mathrm{CuCl}}_{3},$ which consists of ferromagnetic-dominant ferromagnetic and antiferromagnetic alternating Heisenberg chains with $S=1/2,$ is regarded as a Haldane system with $S=1$ at low temperatures because a pair of ferromagnetically coupled spins behav…
It is shown that the fraction f(u) of imaginary-frequency instantaneous normal modes (INM) may be defined and calculated in a random energy model (REM) of liquids. The configurational entropy S(c) and the averaged hopping rate among the states, R, are also obtained and related to f(u) with the results R approximately…
Abstract Two analogous inorganic-organic hybrids with a phyllosilicate-like structure SILMg1 and SILMg2, containing 3-aminopropyl- and N-propylethylenediaminetrimethoxysilane were synthesized through a sol-gel process. These hybrids adsorbed divalent cations of cobalt, nickel, copper, and zinc from aqueous solution to…
The dispersing behavior of MgO‐doped mullite suspension suitable for the production of reticulate ceramics by sponge impregnation was studied. Three deflocculants were tested and the optimum dispersing conditions for the mullite suspension were found. Electrokinetic studies of magnesia in water evidence that it underg…
We have described a method that maximizes the phase separation of graphitic particles (GP) and multiwalled carbon nanotubes (MWNT) in solutions of various organic polymeric hosts. This involves the formation of sediment and a solute. These components were characterized for MWNT and GP content using electron paramagnet…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTCharacterization of Binary Solvent MixturesJ. Catalán, C. Díaz, and F. García-BlancoView Author Information Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain, and Departamento de Físico-Química, Facultad de Farmacia, Uni…
An alternative, pyroelectric effect based technique was developed for the direct measurement of the surface polarization in homogeneously and homeotropically oriented nematic cells as well as for the measurement of the flexoelectric polarization in hybrid aligned nematic cells. The pyroelectric response was measured w…
Closed analytical expressions for scattering intensity and other global structure factors are derived for a new solvable model of polydisperse sticky hard spheres. The starting point is the exact solution of the “mean spherical approximation” for hard core plus Yukawa potentials, in the limit of infinite amplitude and…
INTRODUCTION: Eye drops made from Euphrasia rostkoviana Hayne have been used in anthroposophical medicine for more than 70 years for the structuring of the fluid organism in the eye, especially in inflammatory and catarrhal conjunctivitis. The aim of this prospective cohort trial was to describe the efficacy and toler…
Electrical and optical properties of MoO3–TeO2 amorphous films prepared by vacuum deposition method were investigated. X-ray diffraction patterns show an amorphous structure. The dc conductivity of the films was measured in the temperature range 323–523 K and follows a non-adiabatic small polaron hopping conduction me…
We provide a systematic study on the nonlinear optical properties of silicon nanocrystals within a fused silica matrix. Nonlinear measurements at various wavelengths exhibited the role of three bands in the visible spectrum. Measurements at various laser pulse durations showed several time constants, which exhibited t…
In this work, we study the spin dynamics of ${\mathrm{Mn}}_{12}$-acetate molecules in the regime of thermally assisted tunneling. In particular, we describe the system in the presence of a strong transverse magnetic field. Similar to recent experiments, the relaxation time/rate is found to display a series of resonanc…
The saturated vapor pressures of tetraphenylporphyrin H 2 TPP , its four-coordinated metallo-complexes MTPP ( M ≡ Ni , Cu , Zn , Pd , Ag , Cd ) and some phenyl-substituted derivatives H 2 T ( R ) PP ( R ≡ 2-, 3-, 4- CH 3 ; 2-, 4- F ; 2-, 3-, 4- Cl ; 3-, 4- Br ; 3,5- C ( CH 3 ) 3 ) have been measured using the inert ga…