First donor–acceptor interaction promoted gelation of organic fluids
Bile acid derivatives functionalized at the 3-position with an aromatic group formed gels in organic solvents in the presence of trinitrofluorenone.
Materials Literature
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Alkyl-terminated Si(111) surfaces: A high-resolution, core level photoelectron spectroscopy study
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…
Substitution Effect on the Coloration Quantum Yield of a Photochromic Bisbenzothienylethene
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.
Structure–functionality relationships of grafted Ti-MCM41 silicas. Spectroscopic and catalytic studies
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…
Surface investigation on CexZr1-xO2 compounds
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…
Slow dynamics and ergodicity breaking in a lanthanum-modified lead zirconate titanate relaxor system
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…
Fiber Crystal Growth From the Melt
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…
Mechanical Behavior of an Ni-Ti Shape Memory Alloy Under Axial-Torsional Proportional and Nonproportional Loading
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…
Multidimensional Director Modeling Using the Q Tensor Representation in a Liquid Crystal Cell and Its Application to the π Cell with Patterned Electrodes
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…
Synthesis and spectroscopic properties of a new 4-bora-3a,4a-diaza-s-indacene (BODIPY®) dye
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.
The CATH Database provides insights into protein structure/function relationships
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…
Acoustic and optical methods for measuring electric charge distributions in dielectrics
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…
Second-Order Phase Field Asymptotics for Unequal Conductivities
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…
Simple silica-particle template synthesis of mesoporous carbons
A simple preparative method for mesoporous carbons with high pore volumes using surfactant stabilized silica particles as templates is reported.
Microemulsion mediated sol-gel synthesis of nano-scaled MAl2O4 (M=Co, Ni, Cu) spinels from single-source heterobimetallic alkoxide precursors
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…
Preliminary communication Helical superstructures in a novel smectic mesophase formed by achiral banana-shaped molecules
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…
Clusters of aluminium, a density functional study
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…
Syntheses, structures and magnetism of 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], where L = pyridine, CH3OH or DMF and dca− = dicyanamide, N(CN)2− †
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…
Cell migration as a five-step cycle.
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…
Non-fouling properties of polysaccharide-coated surfaces
Hyaluronic acid and alginic acid, examples of hydrophilic polysaccharides whose biological and technological properties are deeply related to strong interaction with water, have been coupled to substrate surfaces. These coatings can prevent mammalian cells adhesion and greatly reduce bacterial cells adhesion in vitro…