bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surprisingly Long‐Range Surface‐Enhanced Raman Scattering (SERS) on Au–Ni Multisegmented Nanowires
Authors: Wei Wei , Li Shuzhou , Millstone Jill E. , Banholzer Matthew J. , Chen Xiaodong , Xu Xiaoyang , Schatz George C. , Mirkin Chad A. 
Published: May 2009

AbstractErstaunlich weitreichend ist die oberflächenverstärkte Raman‐Streuung an einem Nickelnanodraht, der sich in 120 nm Entfernung von zwei Goldnanoscheiben befindet. Die Anregung der Oberflächenplasmonenresonanz (SPR) im Nanoscheibenpaar erhöht das elektromagnetische Feld nahe dem Nickelsegment (SEM, links), was zu einer erhöhten Raman‐Intensität führt (rechts).magnified image
Palladiumkatalysierte Carbonylierungen von Arylhalogeniden und ähnlichen Substraten
Authors: Brennführer Anne , Neumann Helfried , Beller Matthias 
Published: May 2009

AbstractUm eine CO‐Gruppe reicher: (Hetero‐)Arene sind aus der industriellen Herstellung von Agrochemikalien, Farbstoffen, Pharmaka etc. nicht wegzudenken. Während der vergangenen Jahrzehnte wurden übergangsmetallkatalysierte Kupplungen von Arylhalogeniden mit Nucleophilen aller Art entwickelt. Dieser Aufsatz fasst aktuelle Fortschritte auf dem Gebiet der palladiumkatalysierten Carbonylierungen von Arylhalogeniden und ähnlichen Verbindungen zusammen (siehe Schema).magnified imagePalladiumkatalysierte Carbonylierungen von Arylhalogeniden in Gegenwart verschiedener Nucleophile haben sich seit ihrer Einführung durch Heck und Mitarbeiter im Jahr 1974 schnell weiterentwickelt, sodass heute eine Vielzahl von Palladiumkatalysatoren für unterschiedliche Carbonylierungsreaktionen verfügbar ist. Auf diesem Weg erhältliche Carbonsäurederivate, Aldehyde und Ketone sind wichtige Zwischenstufen bei der industriellen Herstellung von Farbstoffen, Pharmaka, Agrochemikalien und anderen Produkten. In diesem Aufsatz werden aktuelle Ergebnisse aus der akademischen Forschung und erste industrielle Prozesse zusammengefasst.
Fluorescence Detection of Single‐Nucleotide Polymorphisms with a Single, Self‐Complementary, Triple‐Stem DNA Probe
Authors: Xiao Yi , Plakos Kory J. I. , Lou Xinhui , White Ryan J. , Qian Jiangrong , Plaxco Kevin W. , Soh H. Tom 
Published: May 2009

AbstractEine Abweichung genügt: Bei einer einstufigen, nur eine Komponente nutzenden, fluoreszenzbasierten Methode zum Nachweis von Einzelnucleotidpolymorphismen bei Raumtemperatur besteht der Sensor aus einem einzigen, selbstkomplementären DNA‐Strang, der eine Dreifachstammstruktur bildet. Die große Konformationsänderung beim Binden an perfekt komplementäre (PM‐)Ziele führt zu einer deutlichen Zunahme der Fluoreszenz (siehe Bild; F=Fluorophor, Q=Quencher).magnified image
A p‐Type NiO‐Based Dye‐Sensitized Solar Cell with an Open‐Circuit Voltage of 0.35 V
Authors: Gibson Elizabeth A. , Smeigh Amanda L. , Le Pleux Loïc , Fortage Jérôme , Boschloo Gerrit , Blart Errol , Pellegrin Yann , Odobel Fabrice , Hagfeldt Anders , Hammarström Leif 
Published: May 2009

AbstractStarkes Tandem: Eine molekulare Diade und ein cobalthaltiger Elektrolyt sorgen für eine Verdreifachung der Leerlaufspannung (VOC) in einer p‐NiO‐Zelle (VOC= 0.35 V) und eine viermal effizientere Energieumwandlung. Eine farbstoffsensibilisierte TiO2/NiO‐Tandemsolarzelle mit diesem verbesserten System brachte es auf VOC=0.91 V (siehe Bild; LB=Leitungsband, VB=Valenzband).magnified image
Das ungeradzahlig elektronenkonfigurierte Komplexion [Ruk(NOm)(Qn)(terpy)]2+ mit zwei idealtypischen “nicht‐unschuldigen” Liganden
Authors: Das Atanu Kumar , Sarkar Biprajit , Duboc Carole , Strobel Sabine , Fiedler Jan , Záliš Stanislav , Lahiri Goutam Kumar , Kaim Wolfgang 
Published: May 2009

AbstractSechs Kombinationen von Oxidationszuständen stehen der paramagnetischen Titelverbindung zur Auswahl. Kristallographische, computergestützte (DFT) und spektroskopische Studien (EPR bei konventionellen und hohen Frequenzen, IR) sprechen für die Iminosemichinon‐Form mit k=2+, m=1+ und n=1−.magnified image
Funktionalisierte Template für den konvergenten Aufbau von Polyethern: Synthese der HIJK‐Ringe von Gymnocin A
Authors: Van Dyke Aaron R. , Jamison Timothy F. 
Published: May 2009

AbstractLeiterverlängerung: Der Erfolg einer Epoxidöffnungsstrategie zur Synthese leiterförmiger Polyether hängt davon ab, ob die entstehenden Produkte weiter umgesetzt werden können. Mithilfe zweier funktionalisierter Template wurde ein Fragment von Gymnocin A synthetisiert, das vier differenzierte Stellen für die darauffolgende Fragmentkupplung enthält (siehe Schema; Bn=Benzyl).magnified image
Enantioselective Addition of Boronates to Acyl Imines Catalyzed by Chiral Biphenols
Authors: Bishop Joshua A. , Lou Sha , Schaus Scott E. 
Published: May 2009

AbstractSchnell gefunden: Ein Screening chiraler Biphenolkatalysatoren ermöglichte die rasche Identifizierung enantioselektiver nucleophiler Reaktionen von Boronaten mit Acyliminen (siehe Schema). Damit konnte ein einzigartiger Katalysator für die Reaktion von Aryl‐, Vinyl‐ und Alkinylboronaten gefunden werden. Mechanistische Studien ergaben, dass ein Ligandenaustausch zwischen Boronat und Katalysator für die Aktivierung notwendig ist.magnified image
Molekulare Stäbe mit Oligospiroketal‐Rückgrat als Anker in Biomembranen
Authors: Müller Peter , Nikolaus Jörg , Schiller Sabine , Herrmann Andreas , Möllnitz Kristian , Czapla Sylvia , Wessig Pablo 
Published: May 2009

AbstractAnker im Nanomaß‐Stab: Ein hydrophober molekularer Stab mit terminalen fluoreszierenden Gruppen wurde synthetisiert und ließ sich effizient in Modellmembranen und biologische Membranen einbauen (siehe Bild; grau C, blau N, rot O). Derartige Stäbe können als stabile membranassoziierte Anker für die Funktionalisierung von Membranoberflächen eingesetzt werden.magnified image
Oxygen Electroreduction Catalyzed by Gold Nanoclusters: Strong Core Size Effects
Authors: Chen Wei , Chen Shaowei 
Published: May 2009

AbstractGrößer heißt nicht besser: Gold‐Nanocluster zeigten eine erhöhte elektrokatalytische Aktivität in der Sauerstoffreduktion, wenn der Partikelkern von Au140 auf Au11 verkleinert wurde (siehe Auftragung des Onset‐Potentials Eonset und der Spitzenstromdichte JK). Der zunehmende Anteil an Oberflächenatomen und die Verschiebung des d‐Elektronenbands zum Fermi‐Niveau erleichtern die Sauerstoffadsorption.magnified image
Fast Attrition‐Enhanced Deracemization of Naproxen by a Gradual In Situ Feed
Authors: Noorduin Wim L. , Kaptein Bernard , Meekes Hugo , van Enckevort Willem J. P. , Kellogg Richard M. , Vlieg Elias 
Published: May 2009

AbstractMahlen heilt: Mithilfe des nichtsteroidalen Entzündungshemmers Naproxen ist es möglich, die Geschwindigkeit der kürzlich entdeckten Deracemisierung durch abrasives Vermahlen enorm zu erhöhen. Das Verfahren nutzt ein kontinuierliches Einspeisen des racemischen Zielmaterials durch In‐situ‐Umwandlung.magnified image
Palladium‐Catalyzed Carbonylation Reactions of Aryl Halides and Related Compounds
Authors: Brennführer Anne , Neumann Helfried , Beller Matthias 
Published: May 2009

AbstractA CO group richer: (Hetero)arenes are vital intermediates in the manufacture of agrochemicals, dyes, pharmaceuticals, and other industrial products. In the past decades transition‐metal‐catalyzed coupling reactions of aryl halides with all types of nucleophiles have been developed. This Review summarizes recent work in the area of palladium‐catalyzed carbonylation reactions of aryl halides and related compounds (see scheme).magnified imagePalladium‐catalyzed carbonylation reactions of aromatic halides in the presence of various nucleophiles have undergone rapid development since the pioneering work of Heck and co‐workers in 1974, such that nowadays a plethora of palladium catalysts are available for different carbonylative transformations. The carboxylic acid derivatives, aldehydes, and ketones prepared in this way are important intermediates in the manufacture of dyes, pharmaceuticals, agrochemicals, and other industrial products. In this Review, the recent academic developments in this area and the first industrial processes are summarized.
Fluorescence Detection of Single‐Nucleotide Polymorphisms with a Single, Self‐Complementary, Triple‐Stem DNA Probe
Authors: Xiao Yi , Plakos Kory J. I. , Lou Xinhui , White Ryan J. , Qian Jiangrong , Plaxco Kevin W. , Soh H. Tom 
Published: May 2009

AbstractSingled out for its singularity: In a single‐step, single‐component, fluorescence‐based method for the detection of single‐nucleotide polymorphisms at room temperature, the sensor is comprised of a single, self‐complementary DNA strand that forms a triple‐stem structure. The large conformational change that occurs upon binding to perfectly matched (PM) targets results in a significant increase in fluorescence (see picture; F=fluorophore, Q=quencher).magnified image
Enantioselective Addition of Boronates to Acyl Imines Catalyzed by Chiral Biphenols
Authors: Bishop Joshua A. , Lou Sha , Schaus Scott E. 
Published: May 2009

AbstractOn the big screen: A chiral biphenol catalyst screening protocol was developed for the rapid identification of enantioselective nucleophilic boronate reactions with acyl imines (see scheme). The approach successfully identified a unique catalyst for the reaction of aryl, vinyl, and alkynyl boronates. Mechanistic studies demonstrate boronate ligand exchange with the catalyst is necessary for activation towards nucleophilic addition.magnified image
Oxygen Electroreduction Catalyzed by Gold Nanoclusters: Strong Core Size Effects
Authors: Chen Wei , Chen Shaowei 
Published: May 2009

AbstractBigger isn't better: Gold nanoclusters exhibit enhanced electrocatalytic activity in oxygen reduction when the core size decreased from Au140 to Au11, as reflected by the onset potential Eonset and peak current density JK (see picture). The increasing fraction of surface atoms with low coordination numbers and the shift of the d‐band center to the Fermi level facilitate oxygen adsorption.magnified image
Fast Attrition‐Enhanced Deracemization of Naproxen by a Gradual In Situ Feed
Authors: Noorduin Wim L. , Kaptein Bernard , Meekes Hugo , van Enckevort Willem J. P. , Kellogg Richard M. , Vlieg Elias 
Published: May 2009

AbstractGrind and cure: Using the nonsteroidal anti‐inflammatory drug naproxen, a novel concept is demonstrated to dramatically enhance the rate of the recently discovered process of deracemization using abrasive grinding. The process relies on a gradual feed of the racemic target material by an in situ conversion.magnified image
Synthesis and application of water‐soluble hyperbranched poly(ester)s from maleic anhydride and glycerol
Authors: Zhao Xiaofei , Liu Lixin , Dai Hongxia , Ma Chunxi , Tan Xiaohong , Yu Rihua 
Published: May 2009

AbstractA water‐soluble hyperbranched polyester with a considerable number of hydroxyl terminal groups was synthesized by reacting maleic anhydride and glycerol in the absence of a solvent. The synthesized intermediate product was converted to the hyperbranched polyester by condensation polymerization, and the water by‐product produced during the esterification reaction may be removed by vacuum distillation. In the synthesis process, the crosslinking reaction occurs readily if maleic anhydride is in excess. The result shows that the product synthesized by this one‐step method is insoluble in water at room temperature, whereas the product of a quasi one‐step method, in which pentaerythritol was added as a core molecule, has good water solubility when pentaerythritol and the raw material have a molar ratio of 1 : 100 or 1 : 150. The resulting hyperbranched polyester was purified by column chromatography and characterized by infrared spectrometry. The synthetic hyperbranched polyester was used at 0.5% as a crosslinking agent for acrylic ester to inform acrylic ester latex film; the water absorption of the film was decreased significantly, the viscosity was increased, and some mechanical properties were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and rheological behavior of a novel N‐sulfonate ampholyte chitosan
Authors: Yin Qiang , Li Yan , Yin Qin‐Jian , Miao Xia , Jiang Bo 
Published: May 2009

AbstractModified chitosan derivatives with different degrees of substitution varying from 0.17 to 0.96 were synthesized by the heterogeneous reaction of chitosan with 3‐chloro‐2‐hydroxy propanesulfate in a neutral aqueous solution. The modified chitosans with a degree of substitution higher than 0.36 were soluble in water, whatsoever the pH. The structures of the polymers were characterized by Fourier transform infrared and 1H‐nuclear magnetic resonance spectroscopies. The potentiometric titration revealed that the modified chitosan had an isoelectric point at around pH = 5.7, and its rheological behaviors in aqueous solution were studied under different conditions. The results showed that the modified chitosan had typical polyampholyte characteristics, which exhibited polyelectrolyte effect at pH = 1.7 or 13 and antipolyelectrolyte effect at pH = 8. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Tensile performance and crack propagation of coated woven fabrics under multiaxial loads
Authors: Chen Shouhui , Ding Xin , Fangueiro Raul , Yi Honglei , Yang XuDong 
Published: May 2009

AbstractThe tensile performance of coated woven fabrics under multiaxial loads is examined in the present study. Two groups of experiments were conducted to investigate the influences of the configuration of the fabric specimen and the loading speed on the multiaxial tensile properties of the fabrics. The configuration of the specimen for the multiaxial tensile tests is identified as gear‐shape with large arm widths. A loading speed of lower than 20 mm/min is suggested to obtain the tensile properties of the coated woven fabrics under multiaxial loads. The tensile performances of coated woven fabrics under uni‐, bi‐, and multiaxial loads were compared. We found that the tensile performances under bi‐ and multiaxial loads are much better than those under uniaxial loads. Therefore, for the application of the coated woven fabrics in lightweight structures, biaxial or multiaxial loading conditions will be necessary. Experiments on the specimens with an initial crack in the center under multiaxial loads show that, by comparison with other loading directions, the tensile properties in warp direction of the coated woven fabrics play an important role in the failure performance and crack propagation under multiaxial loads. To eliminate the dependence on the mechanical properties in warp direction, the balance of the two principle directions of coated woven fabrics should be improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Novel aluminum phosphate/cyanate ester composites: Thermodegradation behaviors and kinetic analyses
Authors: Sun Zhouqiang , Gu Aijuan , Liang Guozheng , Dai Shankai , Yuan Li 
Published: May 2009

AbstractThermodegradation behaviors of novel aluminum phosphate/cyanate ester (AlPO4(KH550)/CE) composites were studied in detail. Results show that thermodegradation behaviors and kinetic parameters of AlPO4(KH550)/CE composites are greatly dependent on the AlPO4(KH550) loading. The addition of AlPO4(KH550) into CE resin changes the thermodegradation mechanism (mainly at the temperature lower than 450°C) and degradation process from two steps to three steps. Comparing with CE resin, AlPO4(KH550)/CE composites have lower initial degradation temperature and greatly higher char yield. Besides, for each thermodegradation step, the more the AlPO4 content, the smaller the activation energy value is. All reasons leading to these outcomes are investigated intensively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of high temperature and pressure ammonia solution treatment on interfacial behavior of carbon fiber/epoxy resin composites
Authors: Meng L. H. , Chen Z. W. , Song X. L. , Liang Y. X. , Huang Y. D. , Jiang Z. X. 
Published: May 2009

AbstractThe method of high temperature and pressure ammonia solution treatment to improve the interfacial performances of carbon fiber/epoxy composites is discussed in this study. Besides, the influence of high temperature and pressure ammonia solution treatment on carbon fiber and its reinforced epoxy composite interface performance were studied. The untreated and treated carbon fibers were characterized by monofilament tensile test, X‐ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). The interfacial adhesion of the untreated and treated carbon fibers reinforced epoxy resin composites were also evaluated by interface shear strength (IFSS) test, interlaminar shear strength (ILSS) test, and fracture morphology analysis. It was found that the interfacial adhesion of composites increased greatly after high temperature and pressure ammonia solution treatment. The improvement of interfacial adhesion was attributed to the increase of polar functional groups and surface roughness of carbon fibers surface after treatment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Chemically modified sugarcane bagasse as an improving agent for the properties of styrene–butadiene rubber
Authors: Abdelwahab N. A. , Helaly F. M. 
Published: May 2009

AbstractThe agrowaste of sugarcane bagasse was used as a filler to improve the properties of rubber. Sugarcane bagasse waste was ground and sieved to a particle size less than 75 nm and then purified and chemically modified by an acetylation method and stearic acid adsorption. The modified bagasse was incorporated into styrene–butadiene rubber formulations with different concentrations (20, 30, 50, and 70 phr) in comparison with carbon black and hisil, commercial fillers used in industry. The physicomechanical properties of the rubber vulcanizates were determined before and after thermal aging at 90°C. The retained values of the tensile strength, elongation at break, and equilibrium swelling increased as the concentration of the modified bagasse increased in styrene–butadiene rubber vulcanizates until 50 phr; after this concentration, the retained values of each property decreased. Rubber vulcanizates containing modified bagasse with a concentration of 50 phr may be better for retained values of the physicomechanical properties and equilibrium swelling in comparison with those containing carbon black, hisil, and untreated bagasse. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Aminofunctionalization effect on the microtribological behavior of carbon nanotube/bismaleimide nanocomposites
Authors: Liu Lina , Fang Zhengping , Gu Aijuan , Guo Zhenghong 
Published: May 2009

AbstractOriginal multiwalled carbon nanotubes (O‐MWCNTs) and aminofunctionalized ethylenediamine‐treated multiwalled carbon nanotubes (MWCNTs‐EDA) were mixed with bismaleimide (BMI) resin to prepare O‐MWCNT/BMI and MWCNT‐EDA/BMI composites, respectively. Raman spectroscopy, thermogravimetric analysis, and infrared spectroscopy were used to investigate the influence of aminofunctionalization on the multiwalled carbon nanotube (MWCNT) framework. Dynamic mechanical analysis, scanning electron microscopy images of the fractured surface, and field emission scanning electron microscopy of the worn surface were used to determine the possible friction and wear mechanisms of the system. The MWCNT‐EDA/BMI composite exhibited a higher friction coefficient value and a lower wear loss rate value than the O‐MWCNT/BMI composite, which was attributed to the larger number of defects caused by the aminofunctionalization of the MWCNTs, the stronger interfacial adhesion formed between the MWCNTs‐EDA and the BMI resin, and the better dispersive state of the MWCNTs‐EDA in the BMI matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The characteristics of carbon nanotube‐reinforced poly(phenylene sulfide) nanocomposites
Authors: Yu Suzhu , Wong Wai Mun , Hu Xiao , Juay Yang Kay 
Published: May 2009

AbstractMultiwall carbon nanotube reinforced poly (phenylene sulfide) (PPS) nanocomposites were successfully fabricated through melt compounding. Structural, electrical, thermal, rheological, and mechanical properties of the nanocomposites were systematically studied as a function of carbon nanotube (CNT) fraction. Electrical conductivity of the polymer was dramatically enhanced at low loading level of the nanotubes; the electrical percolation threshold lay between 1 and 2 wt % of the CNTs. Rheological properties of the PPS nanocomposites also showed a sudden change with the CNT fraction; the percolation threshold was in the range of 0–0.5 wt % of CNTs. The difference in electrical and rheological percolation threshold was mainly due to the different requirements needed in the carbon nanotube network in different stages. The crystallization and melting behavior of CNT‐filled PPS nanocomposites were studied with differential scanning calorimetry; no new crystalline form of PPS was observed in the nanocomposites, but the crystallization rate was reduced. The thermal and mechanical properties of the nanocomposites were also investigated, and both of them showed significant increase with CNT fraction. For 5 wt % of CNT‐filled PPS composite, the onset of degradation temperature increased by about 13.5°C, the modulus increased by about 33%, and tensile strength increased by about 172%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Study on the optical properties of sulfur‐containing poly(methyl methacrylate)‐inorganic hybrid
Authors: Liu Shujuan , Tian Liying , Zheng Zhen , Wang Xinling 
Published: May 2009

AbstractHigh refractive index homogeneous hybrid materials were successfully prepared. The polymer matrix was the copolymer of methyl methacrylate, sulfur‐containing monomer 2,2′‐mercaptoethylsulfide dimethacrylate (MESDMA), and nanotitania was prepared by in situ solgel process of titanium n‐butoxide. The transmission electron microscope (TEM) study suggested that the hybrid was homogeneous without inorganic agglomerate, and the inorganic particles were 4–7 nm. The refractive index was ∼ 1.75 when the inorganic content of the hybrid film reached to 70 wt %, and the transmittance maintained up to 85%. The sulfur‐containing monomer was used to improve the refractive index, also, it was a crosslinking reagent, which improved the film‐forming ability of the hybrid. After copolymerized with MESDMA, the film‐forming ability of the hybrid was better than the one without MESDMA. Even if the inorganic content exceeded 75 wt %, the films kept integrity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synergistic effect of halide ions and polyethylene glycol on the corrosion inhibition of aluminium in alkaline medium
Authors: Umoren S.A. , Ebenso E.E. , Ogbobe O. 
Published: May 2009

AbstractThe corrosion inhibition of aluminium in alkaline medium was studied at 30 and 40°C in the presence of polyethylene glycol (PEG) using gravimetric (weight loss) and thermometric techniques. The effect of halides (KCl, KBr, and KI) on the inhibitory action of PEG was also studied. It was found that PEG acted as inhibitor for aluminium corrosion in the alkaline medium. Inhibition efficiency increased with increasing inhibitor concentration. An increase in temperature led to increase in both the corrosion rate and inhibition efficiency in the absence and presence of inhibitor and halides. Phenomenon of chemical adsorption mechanism is proposed from the values of Ea, Qads, and ΔG obtained. The adsorption of PEG on the surface of aluminium was found to obey Flory–Huggins and Temkin adsorption isotherms. The synergism parameter, S1 evaluated was found to be greater than unity indicating that the enhanced inhibition efficiency caused by the addition of halides is synergistic in nature. The inhibition efficiency, surface coverage and synergism parameter increased in the order; I−> Br−> Cl− showing that a joint adsorption of PEG and halide ions on aluminium plays a significant role in the adsorption process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009