bluuebunny/crossref_metadata_2025_split huggingface dataset:
TRAFICOS – an Échelle Zeeman spectrograph
Authors: Hildebrandt G. , Scholz G. , Rendtel J. , Woche M. , Lehmann H. 
Published: July 2007

AbstractWe describe the TRAnsportable Flbre COupled échelle Spectrograph (TRAFICOS) equipped with a Zeeman analyzer and manufactured mainly for the observation of stellar magnetic fields. The spectrograph, designed at the Astrophysikalisches Institut Potsdam and constructed at the Thüringer Landessternwarte Tautenburg, is laid out in a quasi‐Littrow configuration. The part attached to the Nasmyth focus of the 2 m telescope contains the telescope adapter for the fibre input and output of the star and calibration light, the cases for the flatfield and the wavelength calibration, and the Zeeman analyzer. The optical scheme and the reduction software are mentioned in some details and the first results of the determination of the magnetic field and radial velocity of several stars are given showing the performance of the device in comparison with existing data.
Inhomogeneous potentials producing homogeneous orbits
Authors: Bozis G. , Anisiu M.‐C. , Blaga C. 
Published: July 2007

AbstractWe prove that, in general, a given two‐dimensional inhomogeneous potential V(x,y) does not allow for the creation of homogeneous families of orbits. Yet, depending on the case at hand, if the given potential satisfies certain conditions, this potential is compatible either with one (or two) monoparametric homogeneous families of orbits or at most with five such familes. The orbits are then found on the grounds of the given potential.
Interacting Galaxies — the X‐ray View
Authors: Hasinger G. , Fischer J.‐U. , Schwope A. D. , Boller T. , Trümper J. , Voges W. 
Published: July 2007

AbstractWe have selected a complete, flux‐limited sample of bright point‐like sources with absorbed X‐ray spectra from the ROSAT All‐Sky survey, the ROSAT Hard Survey (RHS). The sample is drawn from the high‐galactic latitude sky, |bII| > ±30°, and avoids the general direction of the Magellanic Clouds and the Virgo Cluster. It comprises a total of 182 objects of which 118 were previosly catalogued objects and 64 were new AGN candidates. Through optical follow‐up studies at La Silla, Calar Alto and the 6m Zelentchuk telescope we could identify 56 of the new objects, thus achieving a spectrscopic completeness of 96% of the sample. The selection strategy turned out to be extremely useful. Out of the new identifications, 84% are indeed active galaxies or emission line galaxies. While 14 objects are new BL Lac candidates 33 of the new AGN are Seyfert galaxies with a redshift distribution in the range 0.021–0.63, peaking at around 0.06, i.e. relatively local. Surprisingly, about 40% of the X‐ray selected Seyfert galaxies seem to reside in interacting systems. With smaller selection uncertainties this fraction exceeds the number of paired galaxies in optically selected samples and therefore gives strong support to the idea that AGN activity is triggered by interaction.
X‐ray Surveys Workshop
Authors: Hasinger G. , White N. E. 
Published: July 2007

AbstractTo mark the occasions of the 35th anniversary of the birth of X‐ray astronomy on June 18, 1962, and the 7th anniversary of the first light of ROSAT on June 16, 1990, the Astrophysikalisches Institut Potsdam (AIP) and the NASA Goddard Space Flight Center X‐ray Astrophysics Branch cosponsored a workshop entitled “X‐ray Surveys”.
Sky surveys with ASCA — Deep Sky Survey
Authors: Ogasaka Y. , Kii T. , Ueda Y. , Takahashi T. , Inoue H. , Ishisaki Y. , Ohta K. , Yamada T: , Makishima K. , Miyaji T. , Hasinger G. 
Published: July 2007

AbstractASCA Deep Sky Survey (DSS) is aimed to investigate the constituents of the CXB in 2–10 keV band, by faint source survey observations reaching to the source confusion limit of ASCA X‐Ray Telescopes. So far, 0.29 deg2 sky regions were systematically studied and about 40% of the CXB intensity was resolved into discrete sources. In this paper, we present the latest results on the number‐flux relation (LongN‐LogS) and spectrum properties of faint X‐ray sources.
Astro‐E Mission and the X‐ray survey
Authors: Takahashi T. , Inoue H. , Ogawara Y. 
Published: July 2007

AbstractThe fifth Japaniese X‐ray astronomy satellite, Astro‐E, following Hakucho, Tenma, Ginga, and ASCA is scheduled for launch in the year 2000 by the Institute of Space and Astronautical Science (ISAS) with an M‐V rocket. The satellite will be put into an approximately circular orbit with an altitude of ∽550 km and an inclination of ∽31°. There will be three experiments on board Astro‐E: an X‐ray micro‐calorimeter array, four X‐ray CCDs and a hard X‐ray detector. All three experiments combined, Astro‐E will become a spectrometer facility covering a wide energy band from 0.5 keV to 600 keV.
Identification of new low‐mass members of the Alpha Persei open cluster by ROSAT. I
Authors: Prosser C. F. , Randich S. 
Published: July 2007

AbstractFollowing the work of Randich et al. (1996) involving a ROSAT raster scan survey of the α Persei open cluster, we present here the results of a photometric/spectroscopic program examining the possible optical counterparts to a group of 73 X‐ray sources in the raster survey which were not matched to catalogued stars. Of the 73 sources investigated, ∽ 40 have an optical counterpart with photometry acceptable for cluster membership and ∽ 20 of these also have radial velocities consistent with membership. We discuss the X‐ray properties of these potential new members and why they may not have been identified in earlier membership surveys of this cluster.
Recent developments in the site‐specific immobilization of proteins onto solid supports
Authors: Camarero Julio A. 
Published: July 2007

AbstractImmobilization of proteins onto surfaces is of great importance in numerous applications, including protein analysis, drug screening, and medical diagnostics, among others. The success of all these technologies relies on the immobilization technique employed to attach a protein to the corresponding surface. Non‐specific physical adsorption or chemical cross‐linking with appropriate surfaces results in the immobilization of the protein in random orientations. Site‐specific covalent attachment, on the other hand, leads to molecules being arranged in a definite, orderly fashion and allows the use of spacers and linkers to help minimize steric hindrances between the protein and the surface. The present work reviews the latest chemical and biochemical developments for the site‐specific covalent attachment of proteins onto solid supports. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 450–458, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Presentation of functional organophosphorus hydrolase fusions on the surface of Escherichia coli by the AIDA‐I autotransporter pathway
Authors: Li Chaokun , Zhu Yaran , Benz Inga , Schmidt M. Alexander , Chen Wilfred , Mulchandani Ashok , Qiao Chuanling 
Published: July 2007

AbstractWe report, the surface presentation of organophosphorus hydrolase (OPH) and green fluorescent protein (GFP) fusions by employing the adhesin‐involved‐in‐diffuse‐adherence (AIDA‐I) translocator domain as a transporter and anchoring motif. The surface location of the OPH–GFP fusion protein was confirmed by immunofluorescence microscopy, and protease accessibility, followed by Western blotting analysis. The investigation of growth kinetics and stability of resting cultures showed that the presence of the AIDA‐I translocator domain in the outer membrane neither inhibits cell growth nor affects cell viability. Furthermore, the surface‐exposed OPH–GFP was shown to have enzymatic activity and a functional fluorescence moiety. These results suggest that AIDA‐I autotransporter is a useful tool to present heterologous macromolecule passenger proteins on the bacterial surface. Our strategy of linking GFP to OPH and the possibility to employ various bacterial species as host has enormous potential for enhancing field use. Biotechnol. Bioeng. 2008;99: 485–490. © 2007 Wiley Periodicals, Inc.
Target‐driven liquid animation with interfacial discontinuities
Authors: Shin Seung‐Ho , Kim Chang‐Hun 
Published: July 2007

AbstractWe propose a novel method of controlling a multi‐phase fluid so that it flows into a target shape in a natural way. To preserve the sharp detail of the target shape, we represent it as an implicit function and construct the level‐set of that function. Previous approaches add the target‐driven control force as an external term, which then becomes attenuated during the velocity projection step, making the convergence process unstable and causing sharp detail to be lost from the target shape. But we calculate the force on the fluid from the pressure discontinuity at the interface between phases, and integrate the control force into the projection step so as to preserve its effect. The control force is calculated using an enhanced version of the ghost fluid method (GFM), which guarantees that the fluid flows from the source shape and converges into the target shape, while achieving a more natural animation than other approaches. Our control force is merged during the projection step avoiding the need for a post‐optimization process to eliminate divergence at the liquid interface. This makes our method easy to implement using existing fluid engines and it incurs little computational overhead. Experimental results show the accuracy and robustness of this technique. Copyright © 2007 John Wiley & Sons, Ltd.
Metal–Metal Electronic Coupling in syn and anti Stereoisomers of Mixed‐Valent (FeCp)2‐, (RhL2)2‐, and (FeCp)(RhL2)‐as‐Indacenediide Ions
Authors: Santi Saverio , Orian Laura , Durante Christian , Bencze Eva Zsuzsanna , Bisello Annalisa , Donoli Alessandro , Ceccon Alberto , Benetollo Franco , Crociani Laura 
Published: July 2007

AbstractThe extent of metal–metal electronic coupling was quantified for a series of syn and anti stereoisomers of (FeCp)2‐, (RhL2)2‐ and (FeCp)(RhL2)‐ (L2=1,5‐cyclooctadiene (cod), L=CO) as‐indacenediide mixed‐valent ions by spectroelectrochemical and DFT studies. The effect of the syn/anti orientation of the metal units with respect to the planar aromatic ligand indicates that electron transfer occurs through the bridge rather than through space. The nature of the metal was found to be crucial: while homobimetallic diiron species are localised valence‐trapped ions (Class II), the dirhodium analogues are almost delocalised mixed‐valent ions (borderline and Class III). Finally, despite their redox asymmetry, even in the heterobimetallic iron–rhodium as‐indacenediide complexes, strong metal–metal coupling is present. In fact, oxidation of the iron centre is accompanied by electron transfer from rhodium to iron and formation of a reactive 17‐electron rhodium site. syn and anti Fe–Rh as‐indacenediide complexes are rare examples of heterobimetallic systems which can be classified as borderline Class II/Class III species.
N‐Heterocyclic Carbene and Phosphine Ruthenium Indenylidene Precatalysts: A Comparative Study in Olefin Metathesis
Authors: Clavier Hervé , Nolan Steven P. 
Published: July 2007

AbstractKinetic studies on ring‐closing metathesis of unhindered and hindered substrates using phosphine and N‐heterocyclic carbene (NHC)‐containing ruthenium‐indenylidene complexes (first and second generation precatalysts, respectively) have been carried out. These studies reveal an appealing difference, between the phosphine and NHC‐containing catalysts, associated with a distinctive rate‐determining step in the reaction mechanism. These catalysts have been compared with the benzylidene generation catalysts and their respective representative substrates. Finally, the reaction scope of the two most interesting precatalysts, complexes that contain tricyclohexylphosphine and 1,3‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene (SIMes), has been investigated for the ring‐closing and enyne metathesis for a large range of olefins. Owing to their high thermal stability, the SIMes‐based indenylidene complexes were more efficient than their benzylidene analogues in the ring‐closing metathesis of tetrasubstituted dienes. Importantly, none of the indenylidene precatalysts were found to be the most efficient for all of the substrates, indeed, a complementary complex‐to‐substrate activity relationship was observed.
Bis‐alkynyl Diruthenium Compounds with Built‐in Electronic Asymmetry: Toward an Organometallic Aviram–Ratner Diode
Authors: Ying Jie‐Wen , Cordova Antoinette , Ren Tony Y. , Xu Guo‐Lin , Ren Tong 
Published: July 2007

AbstractConditions to prepare trans‐[Ru2(dmba)4(CCAr)2] from [Ru2(dmba)4(NO3)2] (DMBA=N,N′‐dimethylbenzamidinate) and HCCAr were optimized; Et2NH was found to be the most effective among a number of weak bases in facilitating the product formation. Furthermore, a series of unsymmetric trans‐[(ArCC)Ru2(dmba)4(CCAr′)] compounds were prepared under optimized conditions, in which one or both of Ar and Ar′ are donor (NMe2)‐/acceptor (NO2)‐substituted phenyls. While the X‐ray crystallographic studies revealed a minimal structural effect upon donor/acceptor substitution, voltammetric measurements indicated a significant influence of substituents on the energy level of frontier orbitals. In particular, placing a donor and an acceptor on the opposite ends of trans‐[(ArCC)Ru2(dmba)4(CCAr′)] moiety results in an energetic alignment of frontier orbitals that favors a directional electron flow, a necessary condition for unimolecular rectification.
Confocal Microscopy Imaging of Electrochemiluminescence at Double Band Microelectrode Assemblies: Numerical Solution of the Inverse Optical Problem
Authors: Amatore Christian , Oleinick Alexander , Klymenko Oleksiy V. , Thouin Laurent , Servant Laurent , Svir Irina 
Published: July 2007

AbstractA realistic theoretical model describing the outcome of confocal microscopic imaging of electrochemiluminescence (ECL) light emission is derived for a two parallel band microelectrodes assembly operated under steady state. The model takes into account the experimental distortions ensuing from a) the specific finite shape of the sampling volume in confocal microscopy, b) the light arising directly from out‐of‐focus area but transmitted through the microscope diaphragm or c) transmitted after reflection from the polished platinum band electrodes. The model is based on a detailed optical, physico‐mathematical and numerical analysis of the problem at hand, and on simulations of the concentration distribution of the species giving rise to the ECL generation. Its outcome allows the reconstruction of the real spatial distribution of ECL light emission based on the confocal microscopy measurements upon correcting for the effect of experimental distortions using numerical fitting procedure.
Optimization of control parameters of cadmium zinc telluride Bridgman single crystal growth
Authors: Juncheng Liu , Dejie Song , Hongying Zhang , Shenqiu Zhai 
Published: July 2007

AbstractThe temperature gradient within a furnace chamber and the crucible pull rate are the key control parameters for cadmium zinc telluride Bridgman single crystal growth. Their effects on the heat and mass transfer in front of the solid‐liquid interface and the solute segregation in the grown crystal were investigated with numerical modeling. With an increase of the temperature gradient, the convection intensity in the melt in front of the solid‐liquid interface increases almost proportionally to the temperature gradient. The interface concavity decreases rapidly at faster crucible pull rates, while it increases at slow pull rates. Moreover, the solute concentration gradient in the melt in front of the solid‐liquid interface decreases significantly, as does the radial solute segregation in the grown crystal. In general, a decrease of the pull rate leads to a strong decrease of the concavity of the solid‐liquid interface and of the radial solute segregation in the grown crystal, while the axial solute segregation in the grown crystal increases slightly. A combination of a low crucible pull rate with a medium temperature gradient within the furnace chamber will make the radial solute segregation of the grown crystal vanish. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature field design, process analysis and control of SAPMAC method for the growth of large size sapphire crystals
Authors: Xu C. H. , Zhang M. F. , Meng S. H. , Han J. C. , Wang G. G. , Zuo H. B. 
Published: July 2007

AbstractIn this paper, the relationship between quality of sapphire crystal and growing parameters of SAPMAC (Sapphire growth technique with micro‐pulling and shoulder‐expanding at cooled center) method was discussed. Optimized temperature distribution and technique control were proposed by theoretical analysis, numerical simulation computation and experimental validation to obtain large size sapphire crystals. For a‐axis crystallized direction, with 1.0‐5.0mm/h growth velocity and 10‐30K/h temperature decreasing speed, large sapphire single crystal (∅︁240mm×210mm, 27.5kg) having high optical quality was successfully grown. The absorption spectrum of standard samples was measured as well. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and thermal, phase transition and FTIR spectral characterization of tetraethylammonium tetrachlorocuprate (II) crystals
Authors: Amirthaganesan G. , Kandhaswamy M. A. 
Published: July 2007

AbstractSingle crystals of tetraethylammonium tetrachlorocuprate (II), [N(C2H5)4]2CuCl4, were grown by slow evaporation method at room temperature. The crystals were characterized through powder XRD, thermogravimetric (TG‐DTA), low temperature differential scanning calorimetric (DSC) studies and FTIR spectroscopy. While the powder XRD pattern of the compound shows sharp Bragg peaks confirming the crystallinity of the compound, the TG‐DTA studies confirm formation of the compound in the stoichiometric ratio. The thermal anomalies observed in DSC curve at ‐120°C in the heating cycle and around ‐30°C in the cooling cycle indicate a first order phase transition. The phase transition was predicted to be associated with the ordering of CuCl42‐ and successive long range orientation of [N(C2H5)4]+ ions which are disordered at high temperatures. The cationic [N(C2H5)4]+ plays a role in phase transitions at low temperatures. The sharp exothermic peak observed in high temperature DSC indicates a structural phase transition when [N(C2H5)4]CuCl3 is formed on heating the compound. The FTIR spectra of the compound characterize the various chemical bonding and water molecules adsorbed in the compound. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gesamtstrahlung des stationären und impulsüberlagerten Argon‐Hochtemperaturbogens
Authors: Neumann Werner 
Published: July 2007

AbstractDie Gesamtstrahlungsleistung eines Argon‐Hochtemperaturbogens wird als Funktion der Bogenleistung im absoluten Maße bestimmt. Ferner wird die Gesamtstrahlungsenergie gemessen, die zusätzlich abgestrahlt wird, wenn dem stationären Bogenstrom ein Impulsstrom, der aus einer Kondensatorbatterie gespeist wird, überlagert wird. Diese Strahlungsenergie wird als Funktion der im Bogen umgesetzten gepulsten elektrischen Energie, die mit einem ballistischen Wattsekundenmesser gemessen wurde, in ein Diagramm eingetragen. Ergänzend wird die Bogencharakteristik nach. großen Stromstärken fortgesetzt, und ferner wird der radiale Temperaturverlauf im stationären Bogen im Abstand von 3 mm vor der Kathode bei einer Bogenstromstärke von 180 A angegeben.
Über den elektrischen Durchschlag von Argon unter hohem Druck
Authors: List Gunther 
Published: July 2007

AbstractBei Durchschlagsfeldstärken über 105 V/cm werden in komprimierten Gasen Abweichungen vom Paschen‐Gesetz beobachtet.Es wurden die Durchschlagsspannungen von Argon bei Drücken bis zu 300 at und bei Verwendung verschiedener Elektrodenmetalle gemessen. Die Streuung der Durchschlagspannung wird durch eine Konstante c charakterisiert, die vom Elektrodenmaterial, den Eigenschaften der Kathodenoberfläche und dem Quotienten aus Durchschlagsfeldstärke und Gasdruck abhängt.Der Durchschlag bei hohem Druck wird als ein Feldemissionsdurchschlag erklärt, wobei die erforderliche Feldstärke durch Anlagerung positiver Gasionen an die oxydierte Kathodenoberfläche erzeugt wird. Mit der Aufladung der Kathodenoberfläche steht ein Ladungsausgleich infolge der Leitfähigkeit der Oxydschicht in Konkurrenz. Beide Prozesse zusammen erklären die Größe der Streukonstanten c. Aus dem Gleichgewicht beider Prozesse wird eine Bedingung für die statische Durchschlagspannung abgeleitet.
Theorie der Schichtungswellen in Niederdruck‐Gasentladungen
Authors: Wojaczek Karl 
Published: July 2007

AbstractDie in der positiven Säule der Niederdruck‐Gasentladung im Übergangsregime durch lokale, impulsförmige Störungen erzeugbaren Schichtungswellen werden als Wellenpakete laufender Schichten nicht verschwindenden Instabilitätsinkrements aufgefaßt. Sind das Dispersions‐ und das Amplifikationsverhalten stationärer laufender Schichten bekannt, so lassen sich so‐wohl die Kenndaten der Einhüllenden als auch die Kenndaten der Einzelschichten innerhalb der Schichtungswelle bezüglich ihrer Orts‐ und Zeitabhängigkeit vollständig berechnen.Die in der Peakárekschen Theorie der Schichtungswelle bei Berücksichtigung von Stufenprozessen auftretenden Zeitparameter können in der Regel so bestimmt werden, daß die Ausbreitungsgeschwindigkeit und die Halbwertsbreite der Schichtungswelle mit den von der Dispersionstheorie geforderten Werten übereinstimmen. Jedoch ergeben die von beiden Theorien gefundenen Ausdrücke für die Asymmetrie der Schichtungswelle unterschiedliche Werte.
Der Zusammenhang zwischen stationär angeregten laufenden Schichten und den Schichtungswellen in Niederdruckentladungen
Authors: Novák Miloš , Wojaczek Karl 
Published: July 2007

AbstractIn einer Neon‐Niederdruckentladung im Puppschen Übergangsbereich wurden sowohl stationäre laufende Schichten als auch unter den gleichen Entladungsbedingungen Schichtungswellen angeregt. Die direkt gemessenen Kenndaten der Schichtungswellen stimmen gut mit den Werten überein, die sich mit Hilfe der Dispersionstheorie aus dem Frequenzgang von Schichtweite und Amplifikation stationärer laufender Schichten errechnen lassen. Demnach kann die der Dispersionstheorie zugrunde liegende Auffassung der Schichtungswelle als eines Wellenpaketes laufender Schichten auch als experimentell gut begründet angesehen werden.
Bestimmung des absoluten Strahlungsanteils von Hochdruckbögen in schweren Edelgasen
Authors: Neumann W. 
Published: July 2007

AbstractDie Gesamtstrahlung von in zylindrischen Lampen brennenden wandstabilisierten Hochdruckbögen in den schweren Edelgasen Argon, Krypton und Xenon wurde gemessen und auf die in der Bogensäule umgesetzte elektrische Leistung bezogen. Die asymptotischen Werte der Strahlungsausbeute, die für große Bogenleistungen gelten, wurden zu 0,88 (Xenon), 0,72 (Krypton) und 0,52 (Argon) bestimmt. Diese Werte werden mit bisher aus der Literatur bekannten Werten verglichen.
Über magnetohydrodynamische Generatoren vom Hall‐Typ
Authors: Rothhardt Ludwig 
Published: July 2007

AbstractFür heiße, schwach ionisierte Gase, die durch magnetische Felder strömen, gilt nicht mehr das Ohmsche Gesetz in seiner elementaren Form. Die Behandlung magnetohydrodynamischer Generatoren, die Effekte höherer als erster Ordnung in Strom und Feld ausnützen, muß daher von einem verallgemeinerten Ohmschen Gesetz in tensorieller Form ausgehen. Dabei ist auch zu beachten, daß ein durch den Hall‐Effekt getriebener Strom im Gas dessen Dynamik beeinflussen kann.Drei Generatortypen, in denen der Hall‐Effekt die Arbeitsweise wesentlich bestimmt, werden besprochen. Die sich daraus ergebenden Aufgabenstellungen für in nächster Zeit durchzuführende Experimente werden skizziert.