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 field of synthesis and physical characterization of oligomeric porphyrin arrays has been the subject of intense research in recent years. Some of these systems present unique physical and optical properties which reflect the extent of electronic interaction between the monomers in the array, and determines their p…
Bile acid derivatives functionalized at the 3-position with an aromatic group formed gels in organic solvents in the presence of trinitrofluorenone.
The bonding of alkyl monolayers to Si(111) surfaces has been studied with high-resolution core level photoelectron spectroscopy (PES). Two very different wet-chemical methods have been used to prepare the alkyl monolayers: (i) Olefin insertion into the H–Si bond of the H–Si(111) surface, and (ii) replacement of Cl on…
Abstract Introduction of isopropyl substituents to 2 and 2′ positions of benzothiophene rings of bis(1-benzothiophen-3-yl)hexa-fluorocyclopentene increased the population of anti-parallel conformation, and enhanced the quantum yield of the cyclization reaction.
Detailed spectroscopic measurements have been used to elucidate the nature of Ti(IV)-centred active sites that were anchored to a mesoporous silica surface (MCM41) by two distinct routes from titanocene precursors. The catalyst prepared in dry argon (Ti-MCM41 [Ar]) is more active than that prepared in air (in the pres…
The surface of CexZr1-xO2 compounds has been studied by Fourier transform infrared (FTIR) spectroscopy using adsorbed probe species. Methoxy species, from methanol dissociative adsorption, compensate the coordinative unsaturation of surface cations. From the ν(OC) vibration of methoxy species it was shown that mixed c…
The freezing of the dynamic process in a 9/65/35 lanthanum lead zirconate-titanate (PLZT) ceramics has been investigated by measurements of the frequency-dependent complex dielectric constant and the quasistatic field-cooled (FC) and zero-field-cooled (ZFC) dielectric susceptibilities. It was found that the aging proc…
The literature on melt growth of single crystalline fibers is reviewed. The paper introduces in the characteristic features and wide field of advanced applications of micro single crystals in elongated form having a small diameter in the region mykrometer-millimeter. A brief historical survey is given. After that typi…
Several biaxial proportional and nonproportional loading experiments are reported for thin-wall tubes of a pseudoelastic Ni-Ti shape memory alloy (SMA). In addition to the mechanical behavior, temperature was measured during the experiments. It is shown that the phase transformation exhibits asymmetrical behavior in t…
To estimate numerically multidimensional director configurations in a liquid crystal cell, it is important to use the Q tensor representation of the strain free energy because it solves the problem of the difference between the directors, n and - n , in the Frank-Oseen free energy representation. In this paper, we dis…
The constrained dye 3 was prepared and shown to have a sharper, red-shifted, and more intense fluorescence emission than the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY®) dye 2 in which the aryl groups can rotate freely.
We report the latest release (version 1.4) of the CATH protein domains database (http://www.biochem.ucl.ac.uk/bsm/cath). This is a hierarchical classification of 13 359 protein domain structures into evolutionary families and structural groupings. We currently identify 827 homologous families in which the proteins hav…
Much progress had been made during the last two decades in acoustic and optical methods for measuring charge distributions in dielectrics. A review on this topic is given, which mainly covers the past research activities associated with that at our laboratory. For acoustic methods, we will discuss andoompare the pulse…
We extend Karma and Rappel's improved asymptotic analysis of the phase field model to different diffusivities in solid and liquid. We consider both second-order "classical" asymptotics, in which the interface thickness is taken much smaller than the capillary length, and the new "isothermal" asymptotics, in which the…
A simple preparative method for mesoporous carbons with high pore volumes using surfactant stabilized silica particles as templates is reported.
Nanocrystalline aluminate spinels with cobalt, nickel or copper as bivalent cations have been prepared in different particle sizes using single-source heterometal alkoxides of the type [M{Al(OR) 4 } 2 ] (M II =Co, Ni, Cu; R=Pr i , Bu t ) in a microemulsion assisted sol-gel process. The compatibility of the metal stoic…
A new smectic type mesophase without in-plane order is presented which is formed by nitro substituted banana-shaped compounds. The structure of this phase is not yet known in detail. The growth of germs and also the textures point to a helicoidal structure. The helical structure is obviously the result of the chiralit…
Density functional calculations have been performed to study the structure and energetics of mainly neutral Aln with n up to 153. Clusters up to n=15 have been investigated systematically, in part by simulated annealing techniques. No pronounced islands of stability are found in this range although Al7 and Al13 are of…
The dicyanamide anion has been observed to adopt two bridging co-ordination modes (µ and µ3) in α-Mn(dca)2, [Mn(dca)2(H2O)2]·H2O, [Mn(dca)2(C2H5OH)2]·(CH3)2CO, [Fe(dca)2(CH3OH)2] and [Mn(dca)2(L)2] [L = py, CH3OH or DMF; dca = dycanamide N(CN)2–], and generates weak ligand fields thus stabilising high spin configurati…
The migration of cells over substrata is a fundamental and critical function that requires the co-ordination of several cellular processes which operate in a cycle. At the level of the light microscope, the cycle can be divided into five steps: (1) extension of the leading edge; (2) adhesion to matrix contacts; (3) co…