bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen in Semiconductors: Crystal growth and device processing
Authors: Pearton Stephen , Stavola Michael , Corbett James W. 
Published: May 2005

AbstractThe effects of unintentional hydrogen incorporation into both Si and III‐V materials during processing is likely to become more important as device dimensions are scaled down and even tighter control is required on the doping densities within the active and contact regions. Since hydrogen is a constituent of virtually every chemical reagent or gas that is used in semiconductor processing it is almost impossible to avoid near‐surface dopant passivation occurring during some of the processing steps. However, relatively low‐temperature heat treatments are effective in reactivating these dopants.
Direct writing of pure rhodium lines by laser induced chemical vapor deposition
Authors: Messelhäuser Johannes , Flint Edward B. , Suhr Harald 
Published: May 2005

The deposition of thin rhodium lines of use in the electronics industry, for example as chip interconnections, is demonstrated using laser‐induced CVD and the rhodium precursor Rh(CO)2hfa (see figure). The deposited line exhibit a conductivity close to that of the bulk metal, and the precursor has a high vapor pressure leading to an attractively low deposition temperature. magnified image
Morphology of pentadecanoic acid monolayers at the air/water interface studied by BAM
Authors: Honig Dirk , Overbeck Gernot A. , Mobius Dietmar 
Published: May 2005

Brewster angle microscopy (BAM) provides the opportunity to visualize birefringence and long‐range orientational order in floating monolayers with the advantage over fluorescence microscopy that no probe molecules are required. The Figure shows the hexagonal domains formed during the compression of pentadecanoic acid monolayers. The method and its potential are discussed. magnified image
Conducting polymers as membranes with variable permeabilities for neutral compounds: Polypyrrole and polyaniline in aqueous electrolytes
Authors: Schmidt Volkmar M. , Tegtmeyer Dietrich , Heitbaum Joachim 
Published: May 2005

A combination of mass spectrometry and cyclic voltammetry has proved a powerful tool for the simultaneous study of the structure changes and membrane properties of conducting polymers. The oxidized state of polypyrrole and the emeraldine structure of polyaniline, the two materials used in the study, are shown in the Figure. magnified image
Diamond from fullerenes
Authors: Regueiro Manuelnúñez 
Published: May 2005

Buckminsterfullerene has been enjoying intense attention from physicists and chemists alike in an attempt to modify and examine it in every possible way. Realistic applications for this form of carbon are, however, few and far between. Recently a group based in Grenoble have shown that it is possible to convert C60 (see Figure) into diamoned. The process and its consequences are discussed. magnified image
Tetraphenylporphyrins as coupling reagents and corrosion inhibitors
Authors: Meyer‐Roscher Bernd , Siemens Thomas , Brockmann Hans 
Published: May 2005

The irreversible protection of iron surfaces with metalloporphyrins through electrolysis is reported. Tetraphenyl porphyrins (see figure) are also shown to exhibit a corrosion‐inhibiting effect when iron samples coated with the various porphyrin derivatives are treated with 5% sulfuric acid. magnified image
Disordered stripe domain phases in two dimensions: “Labyrinths” and “stripe liquids” in magnetic and organic thin films
Authors: Seul Michael 
Published: May 2005

Amphilic “Langmuir” monolayers, thin layers of type‐I superconductors ferromagnetic colloids (ferrofluids), and ferroelectrics are just some of the materials in which domains patterns, such as the labyrinthine stripe domain in a ferrimagnetic garnet film (see figure), and their evolution in response to changing experimental parameters are discussed. magnified image
Atomistic modeling of materials properties by Monte Carlo Simulation
Authors: Binder Kurt 
Published: May 2005

AbstractIn order to optimize materials properties, in many cases a deeper understanding of the relationship between the chemical‐atomistic structure and the physical properties of the solid and fluid phases of the material is necessary. Monte Carlo simulation is a tool that allows the reliable calculation of thermodynamic properties of strongly interacting many‐body condensed matter systems. Given a model of effective interatomic or intermolecular interactions (drawn either from quantum‐chemical‐type interactions or from analysis of suitable experimental data), macroscopic bulk properties of a material can be simulated, as well as interfacial phenomena and certain kinds of slow dynamic processes (of relaxational or diffusive type). After a brief review of the foundations of this approach in statistical mechanics, the wide potential of this method is illustrated with examples taken from magnetism, metallurgy and amorphous polymeric materials. Strengths and limitations of this atomistic approach towards modeling materials properties are discussed and directions of future research are spelled out.
Spin–spin coupling between the two unpaired electrons in bis(tetrathiafulvalenyl)ketone dications
Authors: Sugimoto Toyonari , Yamaga Seiji , Nakai Makoto , Nakatsuji Hiroshi , Yamauchi Jun , Fujita Hideo , Fukutome Hideo , Ikawa Atsushi , Mizouchi Hideo , Kai Yasushi , Kanehisa Nobuko 
Published: May 2005

In the search for stable organic ferromagnets, well‐characterized one‐ and two‐dimensional high‐spin organic oligomers and polymers are of great interest. Here, the synthesis of the title compounds (see Figure) is reported and the nature of the dication ground state is discussed based on theoretical and experimental studies. magnified image
Conductive polymer/high‐temperature superconductor composite structures
Authors: Haupt Steven G. , Riley David R. , McDevitt John T. 
Published: May 2005

High‐Tc superconductors and conducting polymers can be used to form composite structures that exhibit interesting properties (the Figure shows polypyrrole grown on YBa2Cu3O7‐δ). The polymers can be used to control the electrical properties of the thin film superconductor structure. magnified image
Fabrication of organic nanocrystals for electronics and photonics
Authors: Nalwa Hari Singh , Kakuta Atsushi , Mukoh Akio , Kasai Hitoshi , Okada Shuji , Oikawa Hidetoshi , Nakanishi Hachiro , Matsuda Hiro 
Published: May 2005

AbstractWe have presented a simple technique for the fabrication of nanocrystals of organic molecules and polymers and have shown that it is possible, using the liquid‐phase technique, to fabricate organic nanocrystals ranging in size from 10 nm to 1 μm by manipulating the preparative conditions. In particular, nanocrystals of poly(4‐BCMU) ranging from 20 nm to 350 nm were prepared by controlling the preparation conditions. The main advantages of the liquid‐phase technique are the practicality and suitability of the technique for a wide range of materials. The fabrication of organic nanocrystals, though at a very early stage, seems a promising approach for producing low‐dimensional organic materials and, like inorganic nanocrystals, another important objective for future study would be to incorporate organic nanocrystals into a variety of inorganic and organic media. It is hoped that extensive work will be done on organic nanocrystals to evaluate their potential for electronics and photonics.
Magnetic properties of polyoxovanadates: Magnetic confirmation of the valence state of the vanadium centers in Na6[H6 V12O30F2] · 22H2O
Authors: Müller Achim , Rohlfing Ralf , Barra Anne‐Laure , Gatteschi Dante 
Published: May 2005

Oxovanadium clusters are intersting both as moels of bulk magnets and in their own right. Results are presented suggesting that in Na6[H6V12O30F2]·22H2O (see Figure) it is meaningful to decide which particular vanadium centers should be considered at 5⊕ and which as 4⊕. It is shown that in principle ist is possible to tune and design the topology, and thus the magnetic properties, of polyoxovanadates(IV/V) by means of the template effect. magnified image
Mechanical properties of Ultrahigh Boron Steels
Authors: Jiménez José A. , González‐Doncel Gaspar , Ruano Oscar A. 
Published: May 2005

A fine and stable grain size in steelresults in greatly improved mechanical properties. In analogy to the addition of larger quantities of carbon to form ultra‐high carbon steels, the formation of borides in steel through rapid solidification and powder metallurgical techniques leads to the required grain size (see Figure) The materials processing, microstructure control, and properties of the materials are reviewed.magnified image
Synthesis of regioregular poly(methyl pyridinium vinylene): An isoelectronic analogue to poly(phenylene vinylene)
Authors: Marsella Michael J. , Fu Dian‐Kui , Swager Timothy M. 
Published: May 2005

Poly(phenylene vinylene), PPV, and its derivatives have generated much interest due to their high conductivity and electroluminescent properties which allow for LED applications. Highly electron‐deficient PPV analogues are desirable as they would allow the use of environmentally stable metals as the electrodes in the LEDs. The title compound (see Figure) is just such as material. magnified image
Extraction of aqueous gold sols with styrene/2‐vinylpyridine block copolymers in toluene
Authors: Roescher G. Arno , Möller Martin 
Published: May 2005

Polymers containing small noble‐metal particles are of interest for catalysis and in the generation of optically tunable composites. The currently used process results in materials which are often difficult to process. A method is presented here for the direct transfer of small gold particles from an aqueous sol into a non‐aqueous polymer solution (e.g. a block copolymer, see Figure) facilitating the formation of films. magnified image
Mesomorphous polyelectrolyte‐surfactant complexes
Authors: Antonietti Markus , Burger Christian , Effing Jochem 
Published: May 2005

Polyelectrolyte–surfactant complexation allows the design and synthesis of a variety of highly ordered materials (sch as that modeled in the Figure). The variation of the polyelectrolyte and surfactant properties enables the tuning of the mechanical, electrical, and optical properties of the materials. The highly ordered media produced could be combined with a number of functional componentn (e.g., NLO dyes, conducting subunits, or gas selective groups) magnified image.
Optically Polarized 129Xe in NMR Spectroscopy*
Authors: Pietraiß Tanja , Gaede Holly C. 
Published: May 2005

Abstract129 Xe has found widespread applications in NMR spectroscopy, but its use is often restricted by its low sensitivity and long relaxation times. Optical pumping of rubidium followed by spin exchange with xenon provides a well understood technique to enhance the 129 XePolarization by several orders of magnitude. The exploitation of this highly spin‐polarized xenon as a surface probe in NMR studies of various meterials is discussed. Applications of this technique make use not only of 129Xe NMR detection, but also of the‐high spin polarization as a magnetization reservoir for selective cross‐polarization experiments to surface nuclei. A diverse variety of materials has been studied, ranging from mesoscopic structures such as semiconductor nanocrystals and porous silicon to high surface area polymers.
Spontaneous magnetization in a 2:3 complex formed by 3,4′,5‐tris(N‐oxy‐tert‐butylamino)biphenyl and manganese(II)bis(hexafluoroacetylacetonate)
Authors: Iwamura Hiizu , Inoue Katsuya 
Published: May 2005

The basic problem in the design of molecular magnets is how to assemble unpaired electrons and align their spins on the macroscopic scale. One line of investigation involves heterospin systems consisting of transition metal ions and organic free radicals as ligands. Results are reported for such a system (see figure) in which the heterospin system forms a 2‐D network, which increases Tc compared to a 1‐D network. magnified image
Mapping the elemental distribution in sol‐gel derived ceramics
Authors: Houk Carol S. , Page Catherine J. 
Published: May 2005

Elemental dispersive x‐ray (EDX) composition distribution mapping using a scanning electron microscope (SEM) provides information about samples that is complementary to that obtained from X‐ray diffraction. Examples are given (e.g., Ba and Cu maps of YBa2Cu3O7 − δ, see figure) to demonstrate the usefulness of this technique in evaluating the homogeneity of sol‐gel products and in elucidating elemental zoning (see also cover picture). magnified image
The electronic structure of solid α‐sexithiophene
Authors: Taliani Carlo , Blinov Lev M. 
Published: May 2005

The properties of α‐sexithiophene (α‐T6), e.g., the pronounced one‐dimensionality of the molecule (see Figure), the layered crystal packing, and the low exciton binding energy, make it a very interesting material for electronic and optoelectronic applications. Investigations into the origin of its optical gap and conclusions drawn from them are reported. magnified image
The exciton binding energy in luminescent conjugated polymers
Authors: Brédas Jean‐Luc , Cornil Jérôme , Heeger Alan J. 
Published: May 2005

Luminescence in organic conjugated polymers is considered in this article, which tries to clarify some of the issues related to the nature of the emitting species. A comparison of recent experimental and theoretical data on the exciton binding energy in luminescent poly(arylenevinylene)s, polyarylenes, and their derivatives (e.g., see Figure) leads to he conclusion that they sustain rather weakly bound polaronexitons. magnified image
Crystal growth and characterization of the organic salt 4‐N, N‐dimethylamino‐4′‐N‐methyl‐stilbazolium tosylate (dast)
Authors: Pan Feng , Wong Man Shing , Bosshard Christian , Günter Peter 
Published: May 2005

The growth of bulk crystals of organic salts with large chromophoric has received little attention, despite the importance of crystal quality for both applications and research. Here, the growth of the title compound (DAST), see Figure, is reported and the main results of the linear, nonlinear, and electro‐optical characterization are presented DAST is shown to be of interest for nonlinear optical applications. magnified image
Donor‐Linked Fullerenes: Photoinduced electron transfer and its potential application
Authors: Imahori Hiroshi , Sakata Yoshiteru 
Published: May 2005

AbstractRedox‐active fullerenes can be covalently bound to a variety of donors, their photophysical properties have been investigated. Their photochemical processes. Including electron transfer and energy transfer, are varied, depending on the donor, linkage between the donor and C60, and solvent. Regardless of the solvent and linkage, the charge‐separated state is produced efficiently in zinc porphyrin‐C60 systems, showing that C6o is a good electron acceptor. The most intriguing characteristic of C60 in electron transfer is that C60 accelerates photoinduced charge separation and retards charge recombination in the dark. The long‐lived charge‐transfer state: of the C60–porphyrin dyad was successfully converted to photocurrent using a self‐assembled monolayer technique. These findings will provide a new strategy for the design and synthesis of artificial photosynthetic systems and photoactive materials using C60 as a building block.
Synthesis of cellular inorganic films from self‐organized Media
Authors: Walsh Dominic , Mann Stephen 
Published: May 2005

Cellular and honeycomb structures of inorganic materials are of interest for applications requiring, e.g., catalyst supports or heat‐resistant membranes. The synthesis fo cellular films from solvent‐extracted metal‐ion‐containing microemulsions (the Figure shows a resulting hollow spherical shell of calcium carbonate) is extended here to FeIII, MnIII/IV, and CoIII oxides. The preparation is detailed and the mechanism of formation discussed. magnified image
Highly ordered polymer–inorganic nanocomposites via monomer self assembly: In situ condensation approach
Authors: Gray David H. , Hu Sanlin , Juuang Elizabeth , Gin Douglas L. 
Published: May 2005

A highly ordered organic inorganic nanocomposite can be synthesized by photopolymerizing an inverse hexagonal lyotropic liquid crystal phase consisting of an amphiphilic monomer and organic crosslinker as the organic matrix and a sol‐gel silica precursor solution as the hydrophilic component (see Figure). In situ silica condensation gives the ordered nanocomposite. A simple example is discussed.magnified image
Spatially functionalized polymer surfaces produced via cell‐mediated lithography
Authors: Alexander Cameron , Vulfson Evgeny N. 
Published: May 2005

Cell‐mediated lithography—which generates polymer particles with anisotropic patches of addressable functionality of exactly the same size and shape as the template microorganism—is described. The Figure shows the first step in the process. Similarities with lithography using self‐assembled monolayers of alkane‐thiolates on gold substrates are pointed out and some of the many practical applications indicated.magnified image
An enhanced chemiluminescent enzyme immunoassay for serum carcinoembryonic antigen based on a modification of a commercial kit
Authors: Haggart R. , Thorpe G. H. G. , Moseley S. B. , Kricka L. J. , Whitehead T. P. 
Published: May 2005

AbstractA conventional colorimetric peroxidase end‐point (ortho‐phenylenediamine substrate), used in an enzyme immunoassay for carcinoembryonic antigen, employing plastic beads as solid support, has been replaced by a much faster (30 seconds versus 30 minutes) enhanced chemiluminescent assay for the peroxidase label. Para‐iodophenol was used to enhance the light emission from the peroxidase catalysed chemiluminescent reaction between luminol and hydrogen peroxide. Values for precision and carcinoembryonic antigen concentration obtained with the chemiluminescent and colorimetric versions of the immunoassay on 62 serum specimens were in good agreement.
Luminol dependent chemiluminescence and thiol group oxidation provoked by neutrophils is attributable to different oxidizing species
Authors: Jenner David E. , Holt Mary E. , Campbell Anthony K. 
Published: May 2005

AbstractLuminol‐dependent chemiluminescence and thiol group oxidation of glutathione and human serum albumin were measured in order to demonstrate whether the inhibition of polymorphonuclear leukocyte chemiluminescence by albumin was attributable to thiol group oxidation. We have shown that:

thiol groups on glutathione and albumin are oxidized by PMNL stimulated by soluble and phagocytic stimuli;
thiol group oxidation in albumin and glutathione did not correlate with the inhibitory effects of these substances on luminol‐dependent chemiluminescence with respect to time course, magnitude, effects of known scavengers or extracellular activity. It was therefore concluded that thiol group oxidation was not the cause of albumin inhibition of luminol‐dependent chemiluminescence;
a metastable oxidant was identified after PMNL activation which was capable of oxidizing thiol groups but unable to elicit chemiluminescence form luminol.
Dyakia bioluminescence—1. Bioluminescence and fluorescence spectra of the land snail, D. striata
Authors: Isobe Minoru , Uyakul Duangchan , Goto Toshio , Counsilman James J. 
Published: May 2005

AbstractThe luminescent land snail Dyakia striata displayed a bioluminescence spectrum with a maximum wavelength of 515 nm. A green fluorescent substance extracted from the photogenic organ of an adult snail had a similar wavelength maximum but its fluorescence spectrum differed from that of flavin chromophore substances involved in light emission in some other luminescent organisms.
Effect of surfactants on the intensity of chemiluminescence emission from acridinium ester labelled proteins
Authors: Bagazgoitia F. Javier , Garcia J. Luis , Diéquez Carlos , Weeks Ian , Woodhead J. Stuart 
Published: May 2005

AbstractIn order to establish optimum conditions for the chemiluminescent (CL) reaction of two acridinium ester labelled proteins (human albumin and rabbit anti‐human albumin IgG), we investigated the effects of the following factors known to influence the CL emission: pH, presence of proteins, relative concentrations of components of CL reaction and presence of surfactants. Under optimal conditions of pH and hydrogen peroxide concentration, hexadecyl trimethyl ammonium chloride (CTAC) increased the intensity of the CL reaction of the acridinium ester labelled albumin by 42‐fold. Triton X‐100, Tween‐20, 23 lauryl ether (Brij 35) and sodium dodecyl sulphate (SDS) exerted a much smaller effect. In the case of the acridinium ester labelled antibody, the greatest increase was obtained with Triton X‐100 (15‐fold) followed by CTAC, Brij 35 and Tween 20 (SDS decreased the emission intensity).
Long‐term preservation of active luminous bacteria by lyophilization
Authors: Janda Ivan , Opekarová Miroslava 
Published: May 2005

AbstractA simple method for long‐term preservation of luminous bacteria is described. Cells of Vibrio fischeri, Photobacterium leiognathi and four strains of P. phosphoreum were suspended in a protective medium of low ionic strength (1% NaCI) supplemented with 15% lactose and 2% soluble starch, and lyophilized. The freeze‐dried preparations were sealed under vacuum and stored at 4°C. Luminous bacteria were resuscitated affer six months by adding 2% NaCl up to the original volume. The rehydrated cells exhibited 16‐28% of initial bioluminescence so that they could be used for a microbial test of toxicity (the Microtox test). This method is also useful for maintaining luminous bacteria in strain collections.
Use of a microtitre plate chemiluminescence reader to study surface phagocytosis by human monocytes
Authors: Cree Ian A. , Blair Andrea L. , Beck J. Swanson 
Published: May 2005

AbstractHuman mononuclear cells were separated from freshly obtained peripheral venous blood by density centrifugation and the number of monocytes present estimated by volume spectroscopy. The mononuclear cells were then placed directly into the wells of a microtitre plate and incubated for one hour at 37°C to promote adherence of the monocytes to the plastic wells. Non‐adherent cells were then removed by washing, thus avoiding the need to treat the monocytes with EDTA or other reagents during cell preparation. The time course and dynamics of the chemiluminescence response of adherent monocytes towards opsonized zymosan was similar to those seen using non‐adherent cells.The ability of adherent monocyte preparations to produce chemiluminescence following incubation for varying periods with T‐lymphocyte conditioned medium was investigated. The use of a microtitre plate chemiluminescence reader allows several plates to be assayed over the 24‐hour period and since small numbers of cells are required, many cultures can be analysed in one experiment. This technique (Patent applied for) promises to be a powerful tool for dissecting the cellular events which occur during macrophage activation and examining the effect of various lymphokines on the ability of monocytes to produce a chemiluminescence response.
Effect of a new fluorinated quinolone (ofloxacin) on the chemiluminescence of phagocytosing human neutrophils
Authors: Aquilini Donatella , Bartoloni Alessandro , Paradisi Franco 
Published: May 2005

AbstractWe measured the chemiluminescence (CL) of human neutrophils (PMNLs) exposed to different concentrations of ofloxacin (2, 4, and 6 μg/ml) readily achievable in therapy. CL reaction during zymosan phagocytosis by PMNLs obtained from human healthy volunteers was registered in a computer‐linked LKB 1251 luminometer. Ofloxacin did not induce significant variations on the respiratory burst of PMNLs.