bluuebunny/crossref_metadata_2025 huggingface dataset:
A new method used to control the structure of high rate microcrystalline silicon thin films
Authors: Zhang X. D. , Zhang H. , Yue Q. , Wei C. C. , Sun J. , Hou G. F. , Xiong S. Z. , Geng X. H. , Zhao Y.
Published: January 2010

We report a systematic study of plasma heating effect on microcrystalline silicon (μc‐Si:H) deposition. Normally, substrate surface temperature increases with time during a high rate deposition of μc‐Si:H thin film, especially under a high power and high pressure condition. We deposited μc‐Si:H films using a very high frequency discharge under the high pressure and high power condition at a fixed heater temperature or a profiled heater temperature. Raman spectra with different wavelength excitations showed that a proper heater temperature profiling during μc‐Si:H deposition is an effective method to modify the structure of μc‐Si:H films, which can control the structure evolution to form a uniform crystallinity along the growth direction and reduce the amorphous incubation layer thickness (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
B‐doped a‐Si:H contact improvement on silicon heterojunction solar cells and interdigitated back contact structure
Authors: Desrues T. , Ribeyron P.‐J. , Vandeneynde A. , Ozanne A.‐S. , Souche F. , Muñoz D. , Denis C. , Diouf D. , Kleider J.‐P.
Published: January 2010

This study reports on the p‐type a‐Si:H emitter layer of silicon heterojunction (Si‐HJ) solar cells and its contacting scheme. The influence of the ratio between p‐type a‐Si:H emitter width and its contact width is checked on Interdigitated Back Contact (IBC) Si‐HJ both experimentally and by 2D modelling. A low emitter contact fraction value is found to be detrimental to the IBC Si‐HJ cells efficiency due to distributed series resistance effects. This not only limits the cell fill factor (FF) but also its short circuit current density (Jsc). By increasing the emitter contact fraction an efficiency of 12.7% is obtained on 25 cm2 IBC Si‐HJ solar cells. New B‐doped a‐Si:H emitter layers and contacts are also developed on inverted Si‐HJ cells. Depending on the a‐Si:H conductivity, we observe a great impact of the contact material on Si‐HJ cells performance (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Aluminum doped silicon‐carbon alloys prepared by hot wire chemical vapor deposition
Authors: Chen T. , Schmalen A. , Wolff J. , Yang D. , Carius R. , Finger F.
Published: January 2010

Aluminum doped stoichiometric microcrystalline silicon carbide (µc‐SiC:H) thin films deposited by Hot Wire Chemical Vapor Deposition (HWCVD) technique have been studied. Without Al‐doping, highly crystalline µc‐SiC:H thin films prepared from monomethysilane (MMS) and hydrogen are mainly cubic polytype and are unintentionally doped into n‐type. Trimethyaluminum (TMAl) is used as a source of Aluminum. By increasing the TMAl/MMS ratio (rdoping), the dark conductivity of µc‐SiC:H thin film firstly decreases and then increases. This variation indicates the compensation from n‐type to p‐type, which is confirmed by the thermo‐power measurements. It is observed in the infrared spectra that the crystallinity of µc‐SiC:H thin film deceases with increasing rdoping. In order to improve the crystallinity of this conductive p‐type µc‐SiC:H thin film, the effect of deposition pressure (pdepo) has been investigated. With increasing pdepo, the crystallinity is improved and the structure of SiC alloys changes according to the Raman spectra. A maximum dark conductivity of 1.3×10–1 S/cm has been achieved at rdoping = 0.0620 and pdepo = 100 Pa. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new luminescent defect state in low temperature grown amorphous SiNxOy thin films
Authors: Dong Hengping , Chen Kunji , Wang Danqing , Li Wei , Ma Zhongyuan , Xu Jun , Huang Xinfan
Published: January 2010

We reported the observation of photoluminescence (PL) from low‐temperature grown amorphous silicon oxynitride (a‐SiNxOy) films with its peak location tunable in a wide range from 450 to 600 nm by controlling the Si/N ratios. The origin of luminescence from a‐SiNxOy film has been thoroughly investigated. From the results of the optical absorbance spectrum, an oxygen‐induced new luminescent defect state, which was characterized to be responsible for the light emission, was determined to locate at about 0.65 eV from the absorption edge. The measurements of Fourier transform infrared (FTIR) spectra and X‐ray photoelectron spectrum (XPS) has verified the existence of O‐Si‐N bonding configuration, which serves as this new luminescent defect state in this kind of material (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectral selectivity constraints in fluo‐ rescence detection of biomolecules using amorphous silicon based detectors
Authors: Conde J. P. , Jóskowiak A. , Lipovšek B. , Pimentel A. , Pereira A. T. , Santos M. , Krč J. , Topic M. , Prazeres D. M. F. , Chu V.
Published: January 2010

A microdevice based on a thin‐film hydrogenated amorphous silicon (a ‐Si:H) p‐i‐n photodiode is used to quantify the density of DNA oligonucleotides labelled with a fluorophore and the density of E. coli cells expressing GFP (green fluorescent protein) by fluorescence. An absorption filter is integrated in the device which filters the excitation light and transmits the emitted light to the photodetector. This filter is an amorphous silicon carbon (a‐SiC:H) alloy in which the bandgap can be selected according to the excitation and emission wavelengths of the fluorophores used by varying the carbon content of the film. Control of the thickness of the a‐SiC:H film allows the modulation of the transmission ratio between the excitation wavelength and the emission wavelength. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Imaging ferroelectric domains in multiferroics using a low‐energy electron microscope in the mirror operation mode
Authors: Cherifi Salia , Hertel Riccardo , Fusil Stéphane , Béa Hélène , Bouzehouane Karim , Allibe Julie , Bibes Manuel , Barthélémy Agnès
Published: January 2010

We report on low‐energy electron microscopy imaging of ferroelectric domains with submicron resolution. Periodic strips of ‘up’ and ‘down’‐polarized ferroelectric domains in bismuth ferrite – a room temperature multiferroic – serve as a model system to compare low‐energy electron microscopy with the established piezoresponse force microscopy. The results confirm the possibility of full‐field imaging of ferroelectric domains with short acquisition times by exploiting the sensitivity of ultraslow electrons to small variations of the electric potential near surfaces in the “mirror” operation mode.

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(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation on (Sr,Co)Bi2Nb2O9 thin films: A lead‐free room temperature multiferroics
Authors: Kumar Ashok , Collazo Bryan , Sánchez Dilsom , Katiyar R. S.
Published: January 2010

Novel room temperature single phase multiferroic 10% Co doped SrBi2Nb2O9 (SCBN) thin films were fabricated on Pt/Ti/SiO2/Si(100) substrate by pulse laser deposition. The surface morphology indicates homogeneous grains with average grain size and surface roughness of ∼40–130 nm and 6 nm, respectively. High dielectric constant, low dielectric loss <2–5%, negligible frequency independent conductivity, moderate polarization, frequency dependent coercive field, and weak saturation magnetization were observed. The change in the shape of magnetic hysteresis and values of coercive field along in‐plane and out‐of‐plane M–H hysteresis indicates a magnetic anisotropy. The presence of magnetic moments and electric dipole in the same plane suggest mutual cooperation between electric and magnetic ordering on the mesoscopic and microscopic scale. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient spectrally dynamic blue‐to‐green emission of bipyridine‐based bridged silsesquioxanes for solid‐state lighting
Authors: Nobre Sónia S. , Cattoën Xavier , Ferreira Rute A. S. , Man Michel Wong Chi , Carlos Luis D.
Published: January 2010

We report a metal‐free bpy‐bridged silsesquioxane displaying an efficient and tuneable blue‐to‐green emission (maximum quantum yield and luminance values of 0.22 ± 0.02 cd m–2 and 63 ± 3 cd m–2, respectively) when excited by commercial InGaN light emitting diodes (LEDs) (385–405 nm). This is the highest quantum yield value reported so far for metal‐free phosphors easily excited by commercial InGaN long‐UV/blue LEDs bringing organic/inorganic hybrids on the way to applications as metal‐free phosphors for smart LED‐based lighting and LED‐addressed displays. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Milliwatt power AlGaN‐based deep ultraviolet light emitting diodes by plasma‐assisted molecular beam epitaxy
Authors: Liao Yitao , Thomidis Christos , Kao Chen‐kai , Moldawer Adam , Zhang Wei , Chang Yi‐chung , Nikiforov A. Yu. , Bellotti Enrico , Moustakas Theodore D.
Published: January 2010

We report the development of AlGaN‐based deep ultraviolet LEDs by plasma‐assisted molecular beam epitaxy. The devices were evaluated under bare‐die configuration, placed outside an integrated sphere, and were found to have optical power of 1.3 mW and 1.2 mW at 300 nm and 277 nm, under pulsed driving current of 200 mA and 500 mA, respectively. The external quantum efficiency (EQE) of the 300 nm LED is 0.16% at drive current of 90 mA. These data suggest that AlGaN alloys grown by MBE under excess Ga are capable of producing deep UV‐LEDs with high IQE. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conductance through a redox system in the Coulomb blockade regime: Many‐particle effects and influence of electronic correlations
Authors: Tornow Sabine , Zwicknagl Gertrud
Published: January 2010

We investigate the transport characteristics of a redox system weakly coupled to leads in the Coulomb blockade regime. The redox system comprises a donor and acceptor separated by an insulating bridge in a solution. It is modeled by a two‐site extended Hubbard model which includes on‐site and inter‐site Coulomb interactions and the coupling to a bosonic bath. The current–voltage characteristics is calculated at high temperatures using a rate equation approach. For high voltages exceeding the Coulomb repulsion at the donor site the calculated transport characteristics exhibit pronounced deviations from the behavior expected from single‐electron transport. Depending on the relative sizes of the effective on‐site and inter‐site Coulomb interactions on one side and the reorganization energy on the other side we find either negative differential resistance or current enhancement.

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Schematic view of the redox system with donor (D) and acceptor (A) coupled to the leads L and R. The electronic degrees of freedom of the DA system are coupled to the environment comprising internal vibrations and the solvent dynamics. The current is calculated as a function of the bias voltage Vb and gate voltage Vg.

(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of unstratified and centre‐stratified randomization in multi‐centre clinical trials
Authors: Anisimov Vladimir V.
Published: January 2010

This paper deals with the analysis of randomization effects in multi‐centre clinical trials. The two randomization schemes most often used in clinical trials are considered: unstratified and centre‐stratified block‐permuted randomization. The prediction of the number of patients randomized to different treatment arms in different regions during the recruitment period accounting for the stochastic nature of the recruitment and effects of multiple centres is investigated.

A new analytic approach using a Poisson‐gamma patient recruitment model (patients arrive at different centres according to Poisson processes with rates sampled from a gamma distributed population) and its further extensions is proposed. Closed‐form expressions for corresponding distributions of the predicted number of the patients randomized in different regions are derived. In the case of two treatments, the properties of the total imbalance in the number of patients on treatment arms caused by using centre‐stratified randomization are investigated and for a large number of centres a normal approximation of imbalance is proved. The impact of imbalance on the power of the study is considered. It is shown that the loss of statistical power is practically negligible and can be compensated by a minor increase in sample size. The influence of patient dropout is also investigated. The impact of randomization on predicted drug supply overage is discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Hydropyrolysis over a platinum catalyst as a preparative technique for the compound‐specific carbon isotope ratio measurement of C27 steroids
Authors: Meredith Will , Gomes Rachel L. , Cooper Mick , Snape Colin E. , Sephton Mark A.
Published: January 2010

Compound‐specific stable carbon isotope analysis by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) is an important method for the determination of the 13C/12C ratios of biomolecules such as steroids, for a wide range of applications. However, steroids in their natural form exhibit poor chromatographic resolution, while derivatisation adds carbon thereby corrupting the stable isotopic composition. Hydropyrolysis with a sulphided molybdenum catalyst has been shown to defunctionalise the steroids, while leaving their carbon skeleton intact, allowing for the accurate measurement of carbon isotope ratios. The presence of double bonds in unsaturated steroids such as cholesterol resulted in significant rearrangement of the products, but replacing the original catalyst system with one of platinum results in higher conversions and far greater selectivity. The improved chromatographic performance of the products should allow GC/C/IRMS to be applied to more structurally complex steroid hormones and their metabolites. Copyright © 2010 John Wiley & Sons, Ltd.
Measurement at the field scale of soil δ13C and δ15N under improved grassland
Authors: Dixon E. R. , Blackwell M. S. A. , Dhanoa M. S. , Berryman Z. , Martinez N. de la Fuente , Junquera D. , Martinez A. , Murray P. J. , Kemp H. F. , Meier‐Augenstein W. , Duffy A. , Bol R.
Published: January 2010

Variations in natural abundance of carbon (C) and nitrogen (N) stable isotopes are widely used as tools for many aspects of scientific research. By examining variations in the ratios of heavy to light stable isotopes, information can be obtained as to what physical, chemical and biological processes may be occurring. The spatial heterogeneity of soil δ15N‐ and δ13C‐values across a range of scales and under different land use have been described by a number of researchers and the natural abundances of the C and N stable isotopes in soils have been found to be correlated with many factors including hydrology, topography, land use, vegetation cover and climate. In this study the Latin square sampling +1 (LSS+1) sampling method was compared with a simple grid sampling approach for δ13C and δ15N measurement at the field scale. A set of 144 samples was collected and analysed for δ15N and δ13C from a 12 × 12 grid (in a 1 ha improved grassland field in south‐west England). The dimension of each cell of the grid was approximately 11 × 6 m. The 12 × 12 grid was divided into four 6 × 6 grids and the LSS+1 sampling technique was applied to these and the main 12 × 12 grid for a comparison of sample means and variation. The LSS+1 means from the 12 × 12 grid and the four 6 × 6 grids compared well with the overall grid mean because of the low variation within the field. The LSS+1 strategy (13 samples) generated representative samples from the 12 × 12 grid, and hence would be an acceptable method for sampling similar plots for the measurement of mean isotopic composition. Copyright © 2010 John Wiley & Sons, Ltd.
Movement of newly assimilated 13C carbon in the grass Lolium perenne and its incorporation into rhizosphere microbial DNA
Authors: Clayton S. J. , Clegg C. D. , Bristow A. W. , Gregory P. J. , Headon D. M. , Murray P. J.
Published: January 2010

One of the key processes that drives rhizosphere microbial activity is the exudation of soluble organic carbon (C) by plant roots. We describe an experiment designed to determine the impact of defoliation on the partitioning and movement of C in grass (Lolium perenne L.), soil and grass‐sterile sand microcosms, using a 13CO2 pulse‐labelling method. The pulse‐derived 13C in the shoots declined over time, but that of the roots remained stable throughout the experiment. There were peaks in the atom% 13C of rhizosphere CO2 in the first few hours after labelling probably due to root respiration, and again at around 100 h. The second peak was only seen in the soil microcosms and not in those with sterilised sand as the growth medium, indicating possible microbial activity. Incorporation of the 13C label into the microbial biomass increased at 100 h when incorporation into replicating cells, as indicated by the amounts of the label in the microbial DNA, started to increase. These results indicate that the rhizosphere environment is conducive to bacterial growth and replication. The results also show that defoliation had no impact on the pattern of movement of 13C from plant roots into the microbial population in the rhizosphere. Copyright © 2010 John Wiley & Sons, Ltd.
Quantification of alkylresorcinols in human plasma by liquid chromatography/tandem mass spectrometry
Authors: Ross Alastair B. , Redeuil Karine , Vigo Mario , Rezzi Serge , Nagy Kornél
Published: January 2010

Alkylresorcinols (AR) are of interest as biomarkers of wholegrain wheat and rye intake in epidemiological studies and are currently mainly measured by gas chromatography/mass spectrometry (GC/MS) after labour‐intensive sample preparation including liquid‐liquid extraction, solid‐phase extraction (SPE) and chemical derivatization. This manuscript describes and validates an alternative approach based on normal‐phase liquid chromatography/tandem mass spectrometry for the quantification of alkylresorcinols in human plasma. The method requires neither SPE nor chemical derivatization and has a shortened run time compared to GC/MS. Normal‐ and reversed‐phase columns and various mobile phases were evaluated with and without previous SPE of the samples. Normal‐phase chromatography allowed separation of AR from the interfering triacylglycerols, diacylglycerols and sterols and enabled detection of AR even without SPE of the samples. The described method has instrumental lower limits of detection in the 25–75 pg range, and lower limits of quantification in the 75–250 pg range. Pooled human plasma and 2H4‐nonadecylresorcinol (internal standard) was applied to calibrate the method in the 20–12 000 nM range. The overall method showed intra‐batch precision of 8.6% and an averaged accuracy of 100.2%. Applications for diverse human plasma samples are presented and are compared with the results determined by GC/MS. Based on the presented data; this method requiring less sample preparation is suggested for further evaluation as an alternative to GC/MS for analysis of biomarkers of wholegrain wheat and rye intake in epidemiological studies. Copyright © 2010 John Wiley & Sons, Ltd.
The implementation of an integrated computer‐assisted system for minimally invasive cardiac surgery
Authors: Cai Junfeng , Luo Zhe , Gu Lixu , Xu Rong , Zhao Qiang
Published: January 2010

Background

Preoperative planning and surgical navigation are two crucial aspects of a computer‐assisted system for the success of minimally invasive cardiac surgery.

Methods

In the first part, port placement planning was mainly discussed. We proposed an algorithm based on four criteria to achieve optimized placement. In the second part, an optical tracker was used to locate the thoracoscope and surgical instruments accurately and to show the relative positions between the thoracoscope, surgical instruments and the patient's anatomical structures. An image‐matching technique was employed to help the surgeon locate the target, using real‐time thoracoscopic video images during the procedure.

Results

In order to verify our proposed algorithms, several clinical planning cases were performed to compare our port placement algorithm to the traditional method. Both phantom test and animal study experiments were also done to demonstrate the validity of the target tracking of the system. Both the phantom test and the animal study revealed that the fiducial registration error (FRE) was 1.08 ± 0.16 mm and system error was 5.05 ± 0.67 mm, respectively.

Conclusion

A novel computer‐assisted system for minimally invasive cardiac surgery has been developed. This method has shown its capability to achieve the preoperative planning and real‐time surgery navigation. Copyright © 2010 John Wiley & Sons, Ltd.
Network delay inference from additive metrics
Authors: Bhamidi Shankar , Rajagopal Ram , Roch Sébastien
Published: January 2010

We use computational phylogenetic techniques to solve a central problem in inferential network monitoring. More precisely, we design a novel algorithm for multicast‐based delay inference, that is, the problem of reconstructing delay characteristics of a network from end‐to‐end delay measurements on network paths. Our inference algorithm is based on additive metric techniques used in phylogenetics. It runs in polynomial time and requires a sample of size only poly(logn). We also show how to recover the topology of the routing tree. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2010
Konstruktiver Glasbau – auf Distanz
Authors: Knaack Ulrich , Techen Holger
Published: January 2010

Was ist passiert in den letzten Jahren des Konstruktiven Glasbaus? Wir haben uns mit Details beschäftigt sowie Berechnungsverfahren entwickelt, von denen allerdings selbst die Entwickler sagen, dass sie für eine Praxisanwendung zu komplex sind. Wir haben eine nicht unerhebliche Zahl von innovativen Projekten verwirklicht, die in ihrer Summe eine Evolutionskette der Entwicklung darstellen und weiteres Potential erwarteten lassen. Die Frage ist nur, wo dieses Potential liegt – ob tatsächlich in noch mehr verfeinerten Details oder grundsätzlich anderen Herangehensweisen an die Konstruktion und das Material Glas. Dieser Frage versucht der hier vorliegende Artikel zu folgen und möchte Richtungen aufzeigen, die jenseits der bereits eingeschlagenen Wege liegen und Potentiale bieten, um die nächsten Evolutionsschritte zu erreichen.
Selbsttragende Glasdächer mit lastabtragender Verglasung
Authors: Weller Bernhard , Reich Stefan , Ebert Jan
Published: January 2010

Das Institut für Baukonstruktion, Technische Universität Dresden, ist maßgeblich an der Entwicklung von selbsttragenden, transparenten Glasdachkonstruktionen beteiligt. Der vorliegende Beitrag beschreibt das Grundprinzip einer solchen materialeffizienten Struktur. Ausgehend von zweilagigen Stahlraumfachwerken werden geeignete Geometrien identifiziert, die es erlauben, alle Stäbe der Druckebene durch in ihrer Ebene lastabtragende Verglasung zu ersetzen. Die Kraftweiterleitung der Glasscheiben geschieht durch in den Ecken angeordnete Knotenpunkte. Neben statischen Berechnungen wurden an kleineren Prüfkörpern als auch an Versuchsfeldern von bis zu 15 m Länge umfangreiche Versuche durchgeführt, die Schwerpunkt des Beitrages sind. Sie umfassen die Lasteinleitung, das Stabilitätsverhalten der Scheiben, die Tragfähigkeit des Gesamtsystems als auch die Betretbarkeit und Resttragfähigkeit.
Glasdach für den Hurlingham Gentlemen's in London
Authors: Laufs Wilfried , Luessi Walter
Published: January 2010

Der Aufsatz behandelt ein elegantes Stahl‐Glasdach für den Gentlemen's Club Hurlingham in London, basierend auf einem Vorbild des zerstörten historischen Originals, bestehend aus einer langgezogenen Halbtonne, welche in eine Halbkuppel mündet und mit einer neuartigen, facettierten Verglasung eingedeckt ist. Beschrieben werden der integrierte Entwurfsprozess und seine ingenieurmäßige Ausarbeitung samt seiner Besonderheiten in der Detaillierung sowie der Herstellungs‐ und Montageprozess des transparenten Daches. Gezeigt wird, wie alle bautechnisch relevanten Aspekte des Glasdachs in den statischen Entwurf bereits von Beginn der Planung an integriert wurden.
Hybridbauteile im Konstruktiven Glasbau
Authors: Weller Bernhard , Härth Kristina , Werner Frank , Hildebrand Jörg
Published: January 2010

Träger und Stützen werden zunehmend in Glas ausgeführt. Die Sprödigkeit des Werkstoffes Glas erschwert dabei einen optimalen Einsatz. Innovative Klebtechnik ermöglicht die stoffschlüssige Verbindung von Glas mit duktilen Werkstoffen zu Hybridelementen. Transparente Kunststoffzwischenschichten in Kombination mit Klebstoffschichten können die Übertragung von Schubkräften in optimierten Querschnitten übernehmen und sorgen für ausreichende Resttragfähigkeiten. Diese Art von zusammengesetzten Querschnitten erhöht die Sicherheit und die Leistungsfähigkeit von konstruktiven Glasbauteilen. Im Rahmen eines DFG‐Forschungsprojektes werden innovativ geklebte Hybridbauteile experimentell und numerisch untersucht. Werkstoffuntersuchungen an Kunststoffen und Klebstoffen sowie Festigkeitsuntersuchungen der Glaskanten in verschiedenen Qualitäten bilden die Grundlage komplexer Betrachtungen. Größere Hybridbauteile werden anschließend Tragfähigkeitsprüfungen und Klimabelastungen unterzogen. Entsprechende Ausführungsbeispiele verdeutlichen die Erweiterung des Einsatzes von tragendem Glas.
Geklebte Stahl‐Glas‐Verbundtragwerke
Authors: Bucak Ömer , Geiß Paul Ludwig , Kötter Mark Pascal , Bues Martin , Illguth Marcus
Published: January 2010

Der aktuelle Trend in der Architektur wird durch äußerst filigrane, schlanke und leichte Konstruktionen bestimmt. Gerade durch den Einsatz des Baustoffes Glas in Kombination mit metallischen Verbindungselementen, kann dies optimal verwirklicht werden. In einem Forschungsprojekt der Hochschule München und der TU Kaiserslautern wird mit der Klebtechnik ein neues Fügeverfahren für Stahl‐Glas‐Verbundtragwerke eingesetzt. Hierbei wurden geeignete Klebstoffsysteme ausgewählt, Kleinbauteilversuche durchgeführt, praktikable Fertigungsverfahren erarbeitet, umfangreiche theoretische Betrachtungen angestellt sowie zum Projektabschluss mehrere Stahl‐Glas‐Hybridtragwerk‐Demonstratoren mit Spannweiten bis zu 11 m gefertigt.
Innovative Glaskonstruktionen in Amerika
Authors: Schober Hans , Dunham Michael , Justiz Stefan
Published: January 2010

In New York entsteht derzeit am 11 Times Square ein 40‐stöckiges Bürohochhaus mit einer neuartigen Stahl‐Glas‐Konstruktion für die über vier Stockwerke reichende verglaste Eingangslobby.

Die hybride Fassadenkonstruktion besteht aus 16,5 m langen, stehenden Schwertern aus tragendem Glas mit Edelstahlgurten und die Queraussteifung erfolgt über die Glasscheiben der Fassade. Als weithin sichtbares Eingangselement wurde ein beleuchtetes gläsernes Prisma entworfen, das ebenfalls über vier Stockwerke reicht und die äußere Plaza mit der inneren Lobby verbindet.

Darüber hinaus werden folgende Projekte unseres Büros kurz vorgestellt:

– die Luminous Glass Shell der Bank of America, Charlotte

– die Glastreppe für das Four Seasons Center of Performing Arts in Toronto

– die Seilnetzfassaden für das 7 World Trade Center, den Freedomtower und das Time Warner Center in Manhattan.
Friedrich August Siemens – Glastechniker in Dresden
Authors: Weller Bernhard
Published: January 2010

Die wesentliche Periode seines Schaffens wurde für Friedrich Siemens die Tätigkeit in seiner Dresdner Glasfabrik. Im Oktober 1867 gelang ihm, angeregt durch die Erfolge seiner glastechnischen Versuche, erstmalig den intermittierenden Betrieb der Glasherstellung auf den kontinuierlichen umzustellen. Friedrich Siemens revolutionierte mit der kontinuierlich arbeitenden Glasschmelzwanne die gesamte Glasindustrie und bereitete den Weg zur modernen automatisierten Glasproduktion.
ITO‐coatings by reactive low‐voltage ion plating: film properties and plasma analysis
Authors: Huber Daniel , Pulker H.K
Published: January 2010

Transparent conductive oxides (TCO) are widely used materials for multifarious applications. According to today's state of knowledge, indium‐tin‐oxide (ITO) still offers the best electrical properties among numerous TCOs. However, ITO films produced by ion plating have only rarely been reported to be investigated. For most coating processes, ITO films need to be deposited under high temperature conditions (some 100 °C substrate heating) or require post‐deposition heat treatment in order to obtain high film quality. In this study, reactive low‐voltage ion plating (RLVIP) was used, which allows ‐ due to plasma assistance during the coating process ‐ deposition of ITO films at temperatures below 100 °C. Essential film properties, i.e. resistivity and optical transmission, were optimised by variation of arc current, gas pressure and deposition rate. These quantities ‐ particularly arc current and gas pressure ‐ have huge influence on the characteristics of the supporting plasma. This was shown by analysing the plasma with a mass‐spectrometric plasma monitoring system and with a Langmuir probe. In comparison with formerly studied coating materials (Ta2O5,Nb2O5,HfO2), different plasma compositions regarding the presence of metal oxide ions were determined, which could be attributed to elemental and molecular energy properties (ionisation and binding energies).
Important Roles of Weak Interactions: Syntheses and Supramolecular Structures of Four CoII/NiII‐Thiocyanato Compounds
Authors: Lu Jing , Liu Hou‐Ting , Zhang Xian‐Xi , Wang Da‐Qi , Niu Mei‐Ju
Published: January 2010

Four thiocyanato complexes with CoII and NiII, [Co(NCS)2(htm)2(H2O)2][Co(NCS)2(H2O)4]·H2O (1), [Ni(NCS)2(htm)(CH3OH)2(H2O)] (2), [Ni(NCS)4(Hhtm)2] (3), and [Co(NCS)2(apm)2(H2O)2]·2H2O (4) (htm = hexamethylenetetramine, apm = 2‐aminopyrimidine), were synthesized and characterized by single‐crystal X‐ray diffraction analyses. For compounds 1–4, NCS– acts as terminal ligand and coordinates to the metal ion through the nitrogen atom. The uncoordinated sulfur atom is involved in hydrogen bonds, which link these discrete units to form 3D supramolecular structures. For compounds 2 and 3, these networks are further stabilized by van der Waals S···S interactions. According to the analytical data of compounds 1–4 and some reported discrete thiocyanato compounds, it can be concluded that the presence of S···S interaction or not may be determined by the metal and NCS– ratio, as well as by the size of the ligand.
A Trinuclear Iron(III) Complex Containing the Semi‐Cubane [Fe3(μ3‐O)]7+ Core: Structural, Spectroscopic, Magnetic and Electrochemical Study
Authors: Lalia‐Kantouri Maria , Papadopoulos Christos D. , Hatzidimitriou Antonios G. , Bakas Thomas , Pachini Sofia
Published: January 2010

A trinuclear iron(III) oxo‐centered complex [Fe3(μ3‐O)(3‐OCH3‐salnec)3]OH·5H2O was synthesized and characterized as cluster containing the semi‐cubane [Fe3(μ3‐O)]7+ core. The central oxygen atom is bridging the three iron(III) ions, which form an equilateral triangle with an average edge of –3.00 Å as it was deduced from X‐ray diffraction studies. The new tetradentate ligand 3‐OCH3‐salnecH2 = 1‐[1‐hydroxy‐2‐(9′‐methyl‐1,10′‐phenanthrolin‐2‐yl)ethyl]‐3‐methoxyphenol‐2, was generated “in situ” during the synthesis process as a product of the addition reaction between the starting ligands 2,9‐dimethyl‐phenanthroline(neoc) and 3‐methoxy‐salicylaldehyde(3‐OCH3‐saloH2), in the presence of sodium methoxide and Fe3+. Variable‐temperature magnetic measurements indicate antiferromagnetic exchange interactions between the iron(III) ions in the cluster. Additionally, spectroscopic (IR, UV/Vis, Mössbauer, EPR) and electrochemical studies (CV) are presented and discussed.
Partial Anion Exchange in Ag23Te12X: The Solid Solutions Ag23Te12Cl1–xBrx, Ag23Te12Br1–yIy and Ag23Te12Cl1–zIz
Authors: Osters Oliver , Nilges Tom
Published: January 2010

X‐ray powder diffraction, EDX and DSC measurements were performed in order to determine the structural and thermal properties of the solid solutions of Ag23Te12Cl1–xBrx, Ag23Te12Br1–yIy and Ag23Te12Cl1–zIz. A complete solid solution exists between the two ternary end members Ag23Te12Cl and Ag23Te12Br, whereas the substitution of bromine by iodine can only be observed up to y = 0.3 in Ag23Te12Br1–yIy under thermodynamically controlled synthesis conditions. Even chlorine can be partially substituted by small amounts of iodine up to a certain extend. Temperature dependent single crystal structure determinations of crystals with the nominal composition Ag23Te12Cl0.95I0.05 substantiated the significant influence of the iodine intake on the lattice parameters of the pseudo‐tetragonal orthorhombic system, especially at low temperatures. A systematic deviation from the 1:1 ratio of the a and b lattice parameter (pseudo‐tetragonal ratio) was observed upon cooling, which could not be detected in the case of the ternary compounds. X‐ray powder diffraction experiments gave a first hint on the non‐stoichiometry of this set of materials and all compounds show peritectic decomposition to binary phases at temperatures slightly above 680 K.
Synthesis, Crystal Structure, and Thermal, Magnetic and Spectroscopic Properties of New Thiocyanato Transition Metal Coordination Polymers Based on Pyrimidine as Ligand
Authors: Wriedt Mario , Näther Christian
Published: January 2010

Reaction of manganese and iron thiocyanate with pyrimidine in solution at room temperature leads to the formation of the isotypic new ligand‐rich 1:2 (1:2 = ratio between metal and ligand) compounds [Mn(NCS)2(pyrimidine)2]n (1) and [Fe(NCS)2(pyrimidine)2]n (2). Their crystal structures were determined by single crystal X‐ray analysis. The metal cations are coordinated by four pyrimidine ligands, which connect them into layers, and two terminal N‐bonded thiocyanato anions in a distorted octahedral arrangement. Investigations on their thermal behavior show that the complexes decompose quantitatively into the ligand‐deficient 1:1 compounds [Mn(NCS)2(pyrimidine)]n (3) and [Fe(NCS)2(pyrimidine)]n (4). It must be noted that they can only be prepared by thermal decomposition of their ligand‐rich 1:2 precursor compounds, whereas a synthesis in solution is not possible. In comparison with the structure of their 1:2 precursors, the thiocyanato anions become μ‐1,3 bridging, which was proved by X‐ray powder diffraction and spectroscopic investigations. Magnetic measurements of the ligand‐rich and ‐deficient compounds reveal similar behavior with an antiferromagnetic ordering at lower temperatures, which in the case of the ligand‐rich compounds must be mediated by the aromatic π‐system of the pyrimidine ligands.
Structural Transformation of Three‐Dimensional Bimetallic Phosphites Containing Corner‐Sharing 4‐Ring Chains
Authors: Lin Zhien , Nayek Hari Pada , Dehnen Stefanie
Published: January 2010

Two open‐framework bimetallic phosphites, [C6H18N2][Co0.3Zn2.7 (HPO3)4] (1) and [C2H8N]2[Co0.3Zn2.7(HPO3)4] (2) were synthesized and characterized. The inorganic frameworks of the two compounds are constructed from strictly alternating MO4 (M = Zn, Co)tetrahedra and HPO3 pseudo pyramids, forming three‐dimensional networks with 8‐ring and 12‐ring channels for 1 and 16‐ring channels for 2. The anionic frameworks of the two compounds can be easily transformed to a neutral framework structure with 16‐ring channels at room temperature.
One‐ and Two‐Dimensional PbII Complexes Constructed from N‐Donor Chelating Ligands with Extended π‐System and Organic Dicarboxylates
Authors: Wang Xiu‐Li , Chen Yong‐Qiang , Zhang Jin‐Xia , Liu Guo‐Cheng , Lin Hong‐Yan , Tian Ai‐Xiang
Published: January 2010

Two new coordination polymers [Pb(TIP)(1,3‐bdc)]n (1) and [Pb(Dpq)(fum)]n (2) (TIP = 2‐(2‐thienyl)imidazo[4,5‐f]1,10‐phenanthroline, Dpq = dipyrido[3,2‐d:2′,3′‐f]quinoxaline, 1,3‐H2bdc = benzene‐1,3‐dicarboxylic acid, fum = fumaric acid) were synthesized by hydrothermal reactions and were characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 is a one‐dimensional (1D) chain, which is bridged by 1,3‐bdc ligands. This is further extended into a three‐dimensional (3D) supramolecular structure by hydrogen bonding interactions. Compound 2 exhibits a two‐dimensional (2D) network structure, which is further stacked by π–π interactions to form a 3D supramolecular framework. The most important feature of these two complexes is that the N‐donor ligands with an extended π‐system play a crucial role in the formation and stabilization of the final supramolecular frameworks. Moreover, the fluorescence property of complex 1 was also investigated in the solid state at room temperature.
One‐Dimensional and Two‐Dimensional Coordination Polymers of Copper(II) Nitrobenzoate with Bridging 3‐Pyridylmethanol Ligand
Authors: Kavalírová Jana , Vasková Zuzana , Maroszová Jaroslava , Moncol Jan , Koman Marian , Lis Tadeusz , Mazur Milan , Valigura Dušan
Published: January 2010

Complexes of composition [Cu(X‐NO2bz)2(μ‐3PM)2]n[X‐NO2bz = 2‐nitrobenzoate (1), 3‐nitrobenzoate (2) or 4‐nitrobenzoate (3) and 3PM = 3‐pyridylmethanol] were prepared and studied by elemental analysis, UV/Vis, IR and EPR spectroscopy. The molecular structures of two new complexes 1 and 3 were solved. The copper atoms of both complexes exhibit an elongated octahedral coordination environment with the equatorial positions occupied by two monodentate nitrobenzoato anions and two 3‐pyridylmethanol nitrogen atoms in trans positions. The both axial positions are occupied by oxygen atoms of bridging 3‐pyridylmetanol ligands The polymeric structure of complex [Cu(2‐NO2bz)2(μ‐3PM)2]n (1) contains two‐dimensional layers. The complex 3 exhibits a polymeric chain‐like structure [Cu(4‐NO2bz)2(μ‐3PM)2]n with copper atoms double‐bridged by two 3‐pyridylmethanol molecules similarly as it was found for complex 2.
Reactions between Boron and Magnesium Halides and the Bicyclic Guanidine hppH (1,3,4,6,7,8‐Hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine): Guanidinates with New Structural Motifs
Authors: Ciobanu Oxana , Fuchs Alexander , Reinmuth Matthias , Lebkücher Anna , Kaifer Elisabeth , Wadepohl Hubert , Himmel Hans‐Jörg
Published: January 2010

Herein we report on the synthesis and chemical properties of some binuclear and oligonuclear compounds of boron‐ and magnesium‐containing bridging guanidinate ligands. These species were prepared by reaction of the bicyclic guanidine hppH (hppH = 1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐a]pyrimidine) and BCl3, the diborane(4) B2Cl2(NMe2)2 or the Grignard compound MeMgBr. The experimental results are complemented by quantum chemical (DFT) calculations.
Synthesis, Structure and Luminescence of Cd3Cu2 and Cd2Ni4 Heteronuclear Complexes with Macrocyclic Oxamide and 5‐Sulfosalicylicate
Authors: Sun Ya‐Qiu , Fan Lan‐Lan , Gao Dong‐Zhao , Zhang Guo‐Ying
Published: January 2010

Two novel heteronuclear complexes [Cd3(SSAL)2(CuL)2(H2O)4]n (1) and [Cd2(HSSAL)2(NiL)4]·4H2O (2) were synthesized and structurally determined, where SSAL is the fully deprotonated 5‐sulfosalicylic ion (CuL and NiL, H2L = 2,3‐dioxo‐5,6,14,15‐dibenzo‐1,4,8,12‐tetraazacyclopentadeca‐7,13‐diene). Compound 1 displays a 1D ladder‐like chain and all these chains are further interlinked through hydrogen bonds resulting in a 2D architecture. The structure of 2 consists of 5‐sulfosalicylates and an oxamido‐bridge and is arranged in butterfly‐like hexanuclear molecules. The luminescent properties of compounds 1 and 2 are also discussed.
Synthesis of an Unprecedented CuI Polymer with Alternate Cu(μ‐S)2Cu and Cu(μ‐Cl)2Cu Cores Bridged by Pyridine‐2‐carbaldehyde Thiosemicarbazone
Authors: Lobana Tarlok S , Khanna Sonia , Castineiras Alfonso , Hundal Geeta
Published: January 2010

Pyridine‐2‐carbaldehyde thiosemicarbazone {(C5H5N)(H)C2=N–NH–C1(=S)NH2; Hpytsc} formes an unprecedented 1D copper(I) coordination polymer, {Cu4Cl4(μ3‐S,N4‐Hpytsc)2 (PPh3)4}n (1) in which pyridyl nitrogen binds to Cu(μ‐Cl)2Cu core and sulfur bridges two CuCl units, to form alternate Cu(μ‐S)2Cu and Cu(μ‐Cl)2Cu cores in the polymer. The Cu···Cu contact in Cu(μ‐Cl)2Cu core [3.0877(6) Å] is shorter than in Cu(μ‐S)2Cu core [3.1826(6) Å].
Polytypism of Layered Alkaline Hydroxides: Crystal Structure of TlOH
Authors: Siidra Oleg I. , Britvin Sergey N. , Krivovichev Sergey V. , Depmeier Wulf
Published: January 2010

The crystal structure of TlOH was solved by direct methods: monoclinic, space group C121, a = 5.949(2), b = 6.220(2), c = 21.232(6) Å, β = 91.590(5)°, V = 785.3(4) Å3, R1 = 0.075 for 439 unique reflections with |Fo| ≥ 4σF. There are four symmetrically independent Tl+ cations and four oxygen atoms of OH– groups in the structure. Each of the OH– groups forms three short Tl+–O bonds thus forming OHTl3 triangles, which, in turn, share common edges to form [OH2Tl4]2+ dimeric groups. These hydroxocentered units are interconnected with each other through common corners into layers. The layers are positioned so that hydrogen bonds are formed between two OH anionic planes. The structure of TlOH is significantly more complicated than those of the AOH (A = Na, K, Rb, Cs) hydroxides. The appearance of such complexity is induced by the presence of the stereochemically active lone electron pair on the Tl+ cations. Structural distortions occur in order to minimize destabilizing interactions. The stacking sequence in layered AOH hydroxides may involve one (KOH, RbOH), two (NaOH, CsOH) and four (TlOH) layers per unit cell. This feature may be considered as a special case of chemically induced polytypism.
Three Dicyanidometallate(I)‐based Complexes Incorporating Hydrogen‐bonding, π–π Packing and d10–d10 Interactions with Auxiliary 2,2′‐Bipyridyl‐like Ligands
Authors: Guo Yang , Ma Yue , Zhou Na , Liu Zhan‐Quan , Wang Qing‐Lun , Yan Shi‐Ping , Liao Dai‐Zheng
Published: January 2010

To investigate the influence of the non‐covalent interactions, such as hydrogen‐bonding, π–π packing and d10–d10 interactions in the supramolecular motifs, three cyanido‐bridged heterobimetallic discrete complexes {Mn(bipy)2(H2O)[Ag(CN)2]}[Ag(CN)2] (1), {Mn(phen)2(H2O)[Au(CN)2]}2[Au(CN)2]2·4H2O (2), and {Cd(bipy)2(H2O)[Au(CN)2]}[Au(CN)2] (3) (bipy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline), which are based on dicyanidometallate(I) groups with 1:2 stoichiometry of metal ions and 2,2′‐bipyridyl‐like co‐ligands were synthesized and structurally characterized. In compound 1, hydrogen bonding and π–π interactions governed the supramolecular contacts. In compound 2, the incorporation of aurophilic, hydrogen bonding and π–π interactions result in a 3D supramolecular network. In compound 3, hydrogen bonding and π–π stacking interactions result in a 2D supramolecular layer. In the three complexes, hydrogen‐bonding, π–π packing and/or d10–d10 interactions can play important roles in increasing the dimensionality of supramolecular assemblies.
Synthese und Eigenschaften von Ph3Sn‐substituierten Telluraten – Die Kristallstrukturen von trans‐[(Ph3SnO)4Te(OH)2] und trans‐[(Ph3SnO)2Te(OMe)4]
Authors: Herntrich Tobias , Merzweiler Kurt
Published: January 2010

The reaction of Te(OH)6 with Ph3SnOH in ethanol leads to the formation of trans‐[(Ph3SnO)4Te(OH)2] (1). Compound 1 crystallizes triclinic in the space group P\bar{1} with a = 996.6(2) pm, b = 1365.4(3) pm, c = 1368.2(3) pm and α = 71.15(2)°, β = 71.48(2)°, γ = 74.81(3)° (at 220 K). The molecular structure of 1 consists of a tellurium atom, which is coordinated nearly octahedrally by four Ph3SnO units and two hydroxyl groups that are trans to each other. The Te–O bond lengths are in the range of 190.5(2) and 193.7(2) pm. Treatment of 1 with methanol under reflux yields trans‐[(Ph3SnO)2Te(OMe)4] (2). Compound 2 crystallizes triclinic in the space group P\bar{1} with a = 1012.8(1) pm, b = 1422.4(2) pm, c = 1618.1(2) pm, and α = 100.44(1)°, β = 107.92(1)°, γ = 110.66(1)° (at 220 K). 2 forms centrosymmetric molecules in which the tellurium atom is surrounded nearly octahedrally by four methoxy groups and two trans arranged Ph3SnO units. The Te–O bond lengths of 187.9(3)–194.5(3) pm are similar to those observed in 1.
Synthesis, Structure, and Properties of Mesoporous B/C/N Microspheres
Authors: Raidongia Kalyan , Hembram K. P. S. S. , Waghmare Umesh V. , Eswaramoorthy M. , Rao C. N. R.
Published: January 2010

Reaction of low surface area carbon with a mixture of urea and boric acid at 930 °C yields a composition close to BC4N with a graphitic structure. BC4N was characterized by electron energy loss spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, and X‐ray diffraction. BC4N is a porous ceramic with a surface area of 428 m2·g–1, and shows a CO2 uptake of 40 wt‐%. The layered structure of BC4N involves a random distribution of boron, carbon, and nitrogen atoms and shows high thermal stability up to 1000 °C. A comparative analysis of the structure and properties of BC4N and graphene using first‐principles pseudopotential based density functional theoretical calculations is presented. The calculations predict it to be an insulator. The bulk modulus of BC4N exhibits an interesting dependence on the ordering of boron and nitrogen on the graphene lattice.
2D Metallosupramolecular Arrays of Zinc‐5,10,15,20‐tetra(4‐pyridyl)porphyrin via Self‐complementary Coordination and Peripheral Linkage
Authors: Seidel Rüdiger W. , Oppel Iris M.
Published: January 2010

A structural study on two isotypic infinite 2D metallosupramolecular arrays of Zinc‐5,10,15,20‐tetra(4‐pyridyl)porphyrin (ZnTPyP) has been undertaken. [ZnX2(μ3‐ZnTPyP)·3TCE]n (X = Cl, Br; TCE = 1,1,2,2‐tetrachloroethane) form extended 2D grid structures driven by self‐complementary axial coordination of the metalloporphyrin entities. They both crystallize in the monoclinic system, P21/c, Z = 4, a = 19.1176(15), b = 12.931(1), c = 21.8124(18) Å, β = 103.306(8)°, V = 5247.6(7) Å3 for X = Cl and a = 19.1644(7), b = 12.9984(5), c = 21.9013(9) Å, β = 103.141(4)°, V = 5312.9(4) Å3 for X = Br.
Synthesis and Characterization of New Chlorocarbonylrhenium(I) Complexes with P‐Donor Chelate Ligands
Authors: Bolaño Sandra , Bravo Jorge , Castro Jesús , García‐Fontán Soledad , Marín M. Carmen
Published: January 2010

Chlorocarbonylrhenium(I) complexes fac,cis‐[ReCl(CO)3L1–3][L1 = Ph2PO(CH2)2OPPh2 (1); L2 = Ph2PO(CH2)3OPPh2 (2); L3 = iPr2PO(CH2)2OPiPr2 (3)] were synthesized by reaction of [ReCl(CO)5] with the appropriate diphosphinite ligands L1–3. Reaction of mer,cis‐[ReH(CO)3L2] with HCl affords an isomer of compound 2, the complex mer,cis‐[ReCl(CO)3L2] (4). The new complexes were characterized by IR, 1H, 13C{1H} and 31P{1H} NMR spectroscopy and in the case of complexes 2 and 4 by single‐crystal X‐ray structure determination.
Solvothermal Synthesis, Crystal Structure, and Properties of a New Organic‐Templated Holmium Sulfate with 1D Single Ladder Chains
Authors: Zhou Wanli , Ding Xiaorun , Zhang Zhibin , Zheng Lei , Xu Yan , Zhu Dunru
Published: January 2010

A new organic amine templated 1D holmium sulfate (C2H8N)[Ho(SO4)2·H2O] (1) has been synthesized and solvothermally and structurally characterized by single‐crystal X‐ray diffraction, IR spectroscopy, thermogravimetric and X‐ray diffraction analyses as well as scanning electron microscopy (SEM). The structure of framework 1 is constructed from HoO8 polyhedra and SO4 tetrahedra. S(1) and S(2) connects Ho(1) and its crystallographic partners by using three S–O–Ho linkages to generate double chains, whereas the adjacent double chain are connected by μ3‐O (O5) atoms to form a novel single ladder chains.