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。
A series of phosphorus(V), germanium(IV), and tin(IV) porphyrin-based, "axial-bonding"-type hybrid trimers have been readily constructed by employing a new "building-block" approach. The approach is modular in nature, and it involves simple "inorganic" reactions such as axial bond formation of main group element conta…
Two series of redox-active, iron−sulfur core dendrimers of the general structure (nBu 4 N) 2 [Fe 4 S 4 (S-Dend) 4 ] (Dend = dendrons of generations 1 through 4) were prepared. Heterogeneous electron-transfer rate constants indicated that the rigid series of dendrimers were more effective at attenuating the rate of ele…
Transport behavior of monovalent and divalent solutes across mesoporous Anopore γ-alumina membranes was investigated as a function of pore diameter, pH, ionic strength, and nature of the salt or complexing species in solution. Radiotracers 137 Cs, 85 Sr, 22 Na, and 45 Ca were present in the feed solutions at very low…
Reduction in the amount of ammonia in fuel gas from biomass gasification was studied. Experiments were carried out in a fixed-bed reactor at 200−1000 °C, 21 atm. A kinetic model for ammonia decomposition was developed. The partial pressure of hydrogen in the fuel gas was a key factor to model ammonia decomposition. Ac…
The phenanthroline adduct of the tris(2-thenoyltrifluoroaceto- O, O ‘)europium(III) complex, Eu(TTA) 3 phen, was doped into organically modified silicate (ORMOSIL) matrixes via the sol−gel process, and the luminescence properties of the resultant ORMOSIL composite phosphors (ORMOSIL:Eu(TTA) 3 phen) were characterized.…
The charge-ordering states with lattice distortions of a halogen-bridged binuclear-metal mixed-valence complex (called MMX chain), Pt 2 ( dta ) 4 I ( dta = CH 3 CS 2 - ), have been investigated by transport, magnetic, and optical measurements. This complex is a binuclear unit-assembled conductor containing metal−metal…
Using Monte Carlo simulations, we investigate the possibility of an orientational melting transition within a "rope" of (10,10) carbon nanotubes. When twisting nanotubes bundle up during the synthesis, orientational dislocations or twistons arise from the competition between the anisotropic inter-tube interactions, wh…
We discuss the effects of an applied magnetic field on the low energy excitations in the low temperature phase of Yb4As3. We show also why the magnetic interaction of the Yb{3+} ions is nearly of an isotropic Heisenberg spin-1/2 type. A small anisotropy due to an intrachain dipolar interaction leads to the opening of…
Uniform inorganic and hybrid inorganic−organic hollow microspheres have been produced by coating colloidal core templates with alternating layers of oppositely charged nanoparticles and polymer, and thereafter removing the core either by heating or chemical treatment. The multilayers were constructed by consecutively…
The order−disorder transition temperature ( T ODT ) of symmetric styrene−isoprene diblock copolymers (AB) and its hetero-four-arm star analog (A 2 B 2 ) was measured using dynamic mechanical spectroscopy and small-angle X-ray scattering (SAXS). Care was taken to ensure that the arm molecular weights of both AB and A 2…
An analysis of the ligand field stabilization energy which makes allowance for the nephelauxetic effect is shown to give satisfactory results when applied to the hydration enthalpies of the hexaaqua 3+ complexes of the first transition series. The contribution from the nephelauxetic effect is substantial, and the base…
Intense visible upconversion luminescence is observed in a Re(4+)-doped low-phonon host material, Cs(2)ZrCl(6), with excitation in the near-infrared. The upconversion excitation wavelength, temperature, power, and time dependence is studied using variable-temperature absorption and luminescence spectroscopies, and mod…
Despite the great experimental effort carried out over the past years by means of different techniques, the segmental dynamics in the model blend system poly(vinylethylene)/polyisoprene (PVE/PI) is still a topic of strong debate. One of the most controversial questions is the possibility of a bimodal distribution of s…
Many biological processes, such as transmembrane signaling and pathogen-host interactions, are initiated by a protein recognizing a specific pattern of binding sites on part of a membrane or cell surface. By recognition, we imply that the polymer quickly finds and then adsorbs strongly on the pattern-matched region an…
Foreword. Preface. List of Contributors. VOLUME 1. Synthetic Methods. 1 Synthetic Methods for Semiconducting Polymers (Alberto Bolognesi and Maria Cecilia Pasini). 1.1 Introduction and Overview. 1.2 Synthetic Pathways for PA. 1.3 Conjugated Polymers by Step-Growth Polymerizations. 1.4 Block Copolymers. 1.5 Towards Aut…
An extremely easy method for accurately calculating the adiabatic connection of density functional theory is presented, and its accuracy tested on both Hooke's atom and the He atom. The method is easy because calculations are needed only for different values of parameters in the external potential, which can be achiev…
We present a near-field optical technique for second harmonic imaging using bare tapered optical fiber tip illuminated with femtosecond laser pulses. Enhancement of electric field at the tip of the fiber results in enhanced second harmonic generation (SHG) from the sample region near the tip. This SH emission is colle…
Freezing of simple liquid metals and the relative stabilities of competing crystalline solids are investigated using thermodynamic perturbation theory, the interactions between ions being modeled by effective pair potentials derived from pseudopotential theory. The ionic free energy of the solid phase is calculated, t…
Unstable homoepitaxy on rough substrates is treated within a linear continuum theory. The time dependence of the surface width W(t) is governed by three length scales: The characteristic scale $l_0$ of the substrate roughness, the terrace size $l_D$ and the Ehrlich-Schwoebel length $l_{ES}$. If $l_{ES} \ll l_D$ (weak…
We investigate the formation of ripples on the surface of windblown sand based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71, 197 (1993)], which contains the processes of saltation and grain relaxation. We carry out a nonlinear analysis to determine the propagation speed of the restabilized…