bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fullerenes: Aspects, prospects, limits and speculations
Authors: Hennrich Frank H. , Eisler Hans‐Jürgen , Gilb Stefan , Gerhardt Philip , Wellmann Ralf , Schulz Robert , Kappes Manfred M. 
Published: July 2012

AbstractIn ten years fullerenes have gone from structural speculation to single crystals as ever more efficient preparation and separation procedures have been developed. Today fullerene solids comprise an extensive family of all‐carbon materials assembled from a large number of different ∼ 1 nm sized subunits. We discuss a number of issues related to the unique electronic and geometric structure of these molecular subunits.
Nanocrystalline metals and oxides II: Reverse microemulsions
Authors: Härtl W. , Beck Ch. , Roth M. , Meyer F. , Hempelmann R. 
Published: July 2012

AbstractIn this contribution the synthesis of nanocrystalline metal oxides and the formation of NH4MnF3 by microemulsion techniques is investigated in detail. The size and size distribution of the primary reverse micelles are determined by dynamic light scattering. Further it was possible to characterize intermediate species in the reaction process. The size of the final nanocrystal material was evaluated from the line broadening of X‐ray reflections. The size distribution is very narrow and for the metaloxides a strong correlation exists between the size of the final product and the reverse micelles.
QMS‐controlled production of nanocrystalline metals by inert gas condensation in a flow system
Authors: Daub O. , Langel W. , Reiner C. , Kienle L. 
Published: July 2012

AbstractNanocrystals of about 40 nm in size are produced by evaporation of zinc in a flow system. The metal atom concentration is monitored in relation to the argon carrier by a quadrupole mass spectrometer. The aggregation kinetics are observed on a time scale of 10‐100 ms by varying the distance between evaporation source and mass spectrometer inlet. Several grams of the resulting metal powder were retained in a filter and studied by powder diffraction, neutron small angle scattering and scanning electron microscopy.
Anomalous elastic behaviour of Pb0.76Ca0.24TiO3 (PTC) at the transition from the amorphous to the nanocrystalline state compared to Pb0.88La0.08(Zr0.65Ti0.35)O3 (PLZT)
Authors: Holtwick R. , Ziebert C. , Marx M. , Schmitt H. , Krüger J. K. , Birringer R. , Jiménez B. 
Published: July 2012

AbstractThin amorphous films of PTC and PLZT of 1‐3 μm thickness were produced by rf‐sputtering at ambient temperature. Different grain sizes between the subnanometer and the micrometer region could be prepared by a subsequent annealing process. The increasing size of the crystallites was characterised by profile analysis of x‐ray powder diffraction spectra. It is expected that the small grain size of compact nanocrystalline materials will have drastic influences on their elastic properties. High resolution Brillouin spectroscopy was used to probe the hypersonic properties of the two materials at ambient temperature. For the PLZT samples the elastic modulus c11 shows the expected increase at the transition from the amorphous to the nanocrystalline state. On the contrary the PTC samples exhibit a surprising elastic instability in the same region.
Electrochemical and photoelectrochemical insertion and transport of hydrogen in pyrite
Authors: Bungs M. , Tributsch H. 
Published: July 2012

AbstractThe (photo) electrochemical insertion of hydrogen into a pyrite electrode was studied in an electrochemical two compartment cell. Investigation of the oxidative hydrogen release through the palladium covered back side permitted the determination of relevant kinetic and energetic properties. Hydrogen was found to diffuse with a diffusion coefficient of D = 10−5 cm2/s after sufficient traps (1018 per cm3) were saturated. Upon illumination the hydrogen permeation rate P(P = ratio of penetrating hydrogen atoms to electrochemically reduced protons) can be increased from P = 0.45 up to P = 0.80. The mechanism responsible for the photoinduced insertion and transport of hydrogen is analyzed. The relevance of photo induced proton insertion mechanisms for information storage and energy conversion is discussed.
The kinetics and mechanism of pyrite thermal decomposition
Authors: Hong Y. , Fegley B. 
Published: July 2012

AbstractPyrite (FeS2) decomposition in He, N2, CO2‐CO‐SO2, O2‐CO2 and H2S‐H2 gas mixtures was studied from 400–590°C using optical microscopy, X‐ray diffraction, electron microprobe analyses, and gas chromatography. The rate constants were determined from the weight loss and the thickness change of pyrite in reacted samples. The temperature dependent composition of the product, pyrrhotite (Fe1‐xS), was measured by electron microprobe analysis and X‐ray diffraction. Pyrite decomposition to pyrrhotite and sulfur vapor (dominantly S2) was observed in all gases and follows linear kinetics. The apparent activation energy of pyrite thermal decomposition is 297 + 34 kJ mol−1 in inert gases (e.g. He, N2), and 275 + 20 kJ mol−1 in purified CO2 and in low concentration CO‐SO2 gas mixtures with CO2. The rate constants are the same regardless of gas composition at a given temperature. In oxidizing (O2‐CO2) or reducing (H2S‐H2) gas mixtures, the rate constants are larger than that in inert gases because additional reactions between pyrite and oxidizing/reducing gases accelerate the overall process while reducing the apparent activation energies. A mechanism of pyrite decomposition, which explains our experimental results, as well as the discordant activation energy data in the literature, is proposed.
Magnetic properties of new thio‐ and oxo‐verdazyls
Authors: Ballüder K. , Kelemen M. , Pérez F. , Pilawa B. , Wachter Ch. , Dormann E. 
Published: July 2012

AbstractCrystalline samples of the free radicals 1,3,5‐triphenyl‐6‐thio‐verdazyl (TPTV), 1,5‐diphenyl‐3‐thienyl‐6‐thio‐verdazyl (DPTTV), 1,3,5‐triphenyl‐6‐oxo‐verdazyl (TPOV) and 1,5‐diphenyl‐3‐thienyl‐6‐oxo‐verdazyl (DPTOV) were magnetically characterized by SQUID magnetometry, specific heat and electron spin resonance. The strength of antiferromagnetic exchange interaction is increased by almost an order of magnitude in thio‐verdazyls compared to the familiar verdazyl 1,3,5‐triphenyl‐verdazyl. Magnetic order at above 5 K and hysteresis loops with very low field metamagnetic transitions are observed in both oxo‐verdazyls.
Solvent effects on the proton‐transfer reactions of 7‐hydroxycoumarin and its 4‐methyl derivative with tertiary amines in the ground and excited singlet states [1]
Authors: Mizoguchi Hiroki , Kubo Kanji , Sakurai Tadamitsu , Inoue Hiroyasu 
Published: July 2012

AbstractUV absorption, fluorescence, and 13C NMR analyses of the proton‐transfer reactions between the title compounds (HC) and tertiary amines showed that the hydrogen‐bonded hydroxycoumarin tautomer anion III (which is stable in the ground state at room temperature) is exclusively produced in the polar aprotic solvent, acetonitrile, containing 1,8‐diazabicyclo[5.4.0]undec‐7‐ene. In addition, HC in the ground state was found to give the hydrogen‐bonded complex I and HC anion II in the presence of the less basic amines, pyridine and triethylamine, respectively, but not to produce the HC tautomer anion III. Both the less polar aprotic solvents (1,4‐dioxane and benzene) and a methyl substituent (that is introduced into the coumarin ring) had a tendency to decrease the thermodynamic stability of a given proton‐transferred ion pair. On the other hand, it was confirmed that the protic polar solvent, methanol (which is able to form a hydrogen‐bonded complex with HC) greatly accelerates the production of the ground‐state tautomer ion pair through the strong hydrogen‐bonding solvation of this ion pair. Close examination of the fluorescence and its lifetime of the HC anion and the HC tautomer anion (the formation of which is markedly enhanced in the excited singlet state) strongly suggested that the former anion serves as a precursor of the latter.
An FT‐IR study on the structure of water solubilized by cetyltrimethylammonium bromide reverse aggregates in chloroform/n‐Dodecane
Authors: Novaki Luzia P. , El Seoud Omar A. , Lopes Júlio C. D. 
Published: July 2012

AbstractThe structure of water (4% D2O in H2O, v/v) solubilized by the reverse aggregates of cetyltrimethylammonium bromide in a chloroform/n‐dodecane mixture (6:4, v/v) was probed by FT‐IR. The vOD band of solubilized HOD was recorded as a function of the [water]/[surfactant]molar ratio, W/S, from 2.1 to 40.2. Curve fitting of this band showed the presence of a main peak at 2518+7 cm−1 and two small ones at 2365+42 cm−1 and 2662+20 cm−1. At any W/S the main peak corresponds to 90+2% of the total peak area, and it obeys Beer's law. As a function of increasing W/S, the frequency of the main peak decreases, whereas its full width at half‐height increases, values of both properties at W/S of 40.2 are close to the corresponding ones of HOD in bulk aqueous phase. These results show that the reverse aggregate‐solubilized water, although different from bulk water, does not seem to coexist in “layers” of different degrees of structure, as suggested, e.g., by the multi‐state water solubilization model.
Surface order effects on the dynamics in thin free standing films of smectic liquid crystals
Authors: Becker A. , Stegemeyer H. 
Published: July 2012

AbstractThe Goldstone mode has been measured in a homeotropically oriented ferroelectric liquid crystal in SSFLC cells and in free standing films by means of optical reflectivity. In cells the Goldstone mode was found only in the smectic C* phase as expected. In the free standing films, however, the Goldstone mode was still detectable several degrees above the bulk phase transition temperature to the smectic A phase. This effect is due to a molecular tilt in the boundary layers of the smectic A film caused by surface ordering.
Application of Polyaniline and Polyaniline/Multiwalled Carbon Nanotubes‐Coated Fibers for Analysis of Ecstasy
Authors: Khajeamiri A. R. , Kobarfard F. , Bayandori Moghaddam A. 
Published: July 2012

AbstractA fiber coated by polyaniline (PANI) was obtained through electrochemical deposition and applied for solid‐phase microextraction (SPME). The same method was applied for the preparation of an SPME fiber coated by a PANI/multiwalled carbon nanotubes (PANI/MWCNTs) composite. The prepared fibers were employed for extraction of methylenedioxymethamphetamine (MDMA) hydrochloride from aqueous and chloroform samples. The resulting substances were analyzed by gas chromatography‐mass spectrometry. The developed method proved to be simple with high reproducibility. The amount of extracted MDMA hydrochloride from aqueous solution and MDMA from chloroform solution by the PANI/MWCNTs fiber was about 3.5‐fold and 2‐fold that of the one without CNTs. It could be suggested that the composite material with CNTs has both an augmented surface area and an elevated adsorptive capacity which lead to the increased extractive capacity for MDMA.
Selected‐Control Synthesis of Monodisperse Fe3O4@C Core–Shell Spheres, Chains, and Rings as High‐Performance Anode Materials for Lithium‐Ion Batteries
Authors: Li Lu , Wang Tingting , Zhang Lingyu , Su Zhongmin , Wang Chungang , Wang Rongshun 
Published: July 2012

AbstractA method is reported for the first time for the selected‐control, large‐scale synthesis of monodispersed Fe3O4@C core–shell spheres, chains, and rings with tunable magnetic properties based on structural evolution from eccentric Fe2O3@poly(acrylic acid) core–shell nanoparticles. The Fe3O4@C core–shell spheres, chains, and rings were investigated as anode materials for lithium‐ion batteries. Furthermore, a possible formation mechanism of Fe3O4@C core–shell chains and rings has also been proposed.
ChemInform Abstract: Substitutional Mechanism of Ni into the Wide‐Band‐Gap Semiconductor InTaO4 and Its Implications for Water Splitting Activity in the Wolframite Structure Type.
Authors: Malingowski Andrew C. , Stephens Peter W. , Huq Ashfia , Huang Qingzhen , Khalid Syed , Khalifah Peter G. 
Published: July 2012

AbstractSubstitution of Ni for In in InTaO4 is reinvestigated by synchrotron X‐ray and neutron powder diffraction, diffuse reflectance spectroscopy, XANES, and magnetic susceptibility measurements, providing insights into its previously reported photoactivity.
ChemInform Abstract: High‐Density Chemical Intercalation of Zero‐Valent Copper into Bi2Se3 Nanoribbons.
Authors: Koski Kristie J. , Cha Judy J. , Reed Bryan W. , Wessells Colin D. , Kong Desheng , Cui Yi 
Published: July 2012

AbstractUp to 60 at.% copper can be intercalated into layered Bi2Se3 nanoribbons without disrupting the host lattice.
ChemInform Abstract: Novel Synthesis and Structural Analysis of Ferrihydrite.
Authors: Smith Stacey J. , Page Katharine , Kim Hyunjeong , Campbell Branton J. , Boerio‐Goates Juliana , Woodfield Brian F. 
Published: July 2012

AbstractChemically pure ferrihydrite crystallites with sizes of 2—6 nm are prepared by a solvent‐deficient method by grinding 1:3 molar mixtures of solid Fe(NO3)3·9H2O and NH4HCO3 followed by drying the resulting slurry in air between 80 and 100 °C.
ChemInform Abstract: Modular Synthesis of Optically Active Lactones by Ru‐Catalyzed Asymmetric Allylic Carboxylation and Ring‐Closing Metathesis Reaction.
Authors: Takii Koichiro , Kanbayashi Naoya , Onitsuka Kiyotaka 
Published: July 2012

AbstractA new synthetic route to optically active unsaturated γ‐ and δ‐lactones (IV) and (VII) is demonstrated via asymmetric allylic carboxylation with planar‐chiral Ru‐catalyst and subsequent ring‐closure metathesis reaction.
ChemInform Abstract: Reaction of 2‐Alkoxy‐4,5‐diphenyl‐1,3‐oxazin‐6‐one with Different Alcohols and Elucidation of the Products.
Authors: Assadieskandar Amir , Amini Mohsen , Haukka Matti , Shafiee Abbas 
Published: July 2012

AbstractIn contrast to a previous report, reaction of title compounds (I) and (IV) with methanol (II) under reflux results in formation of carbamate esters (III), (V), and (VI) involving cleavage of the oxazinone ring.
ChemInform Abstract: Heck—Matsuda Reaction for Allylic Nitro Compounds: A Short Asymmetric Synthesis of an FTY720 Derivative.
Authors: Nakano Toshiki , Miyahara Mizuki , Itoh Toshiyuki , Kamimura Akio 
Published: July 2012

AbstractBy application of the optimal dibenzylideneacetone palladium catalyst Pd2(dba)3, (Ia), or (Ib), aryldiazonium salts bearing electron‐donating or electron‐deficient substituents are coupled with allylic nitro compound (II) at room temperature to give cinnamyl nitro compounds in good yields, with some exceptions.
ChemInform Abstract: Enantioselective Oxidation of Racemic Secondary Alcohols Catalyzed by Chiral Mn(III)‐Salen Complexes with N‐Bromosuccinimide as a Powerful Oxidant.
Authors: Xu Daqian , Wang Shoufeng , Shen Zhiqiang , Xia Chungu , Sun Wei 
Published: July 2012

AbstractThe methodology works efficiently for numerous secondary alcohols including benzylic alcohols with ortho substituted aromatic rings.
ChemInform Abstract: Selective Reduction of Carboxylic Acids to Aldehydes by a Ruthenium‐Catalyzed Reaction with 1,2‐Bis(dimethylsilyl)benzene.
Authors: Miyamoto Konoka , Motoyama Yukihiro , Nagashima Hideo 
Published: July 2012

AbstractThe bifunctional hydrosilane as well as the Ru catalyst are stable towards air and moisture.
ChemInform Abstract: Efficient Chiral Monophosphorus Ligands for Asymmetric Suzuki—Miyaura Coupling Reactions.
Authors: Tang Wenjun , et al. et al. 
Published: July 2012

AbstractThe phosphorus compounds (POM) and (PNP) efficiently promote the asymmetric coupling of aromatic boronic acids with aryl bromides bearing bulky amide or phosphorous groups.
ChemInform Abstract: Hf(IV)‐Catalyzed Enantioselective Epoxidation of N‐Alkenyl Sulfonamides and N‐Tosyl Imines.
Authors: Olivares‐Romero Jose Luis , Li Zhi , Yamamoto Hisashi 
Published: July 2012

AbstractThe sulfonyl group is established as an effective directing group for epoxidation reactions.
ChemInform Abstract: An Efficient Synthesis of Azetidines with (2‐Bromoethyl)sulfonium Triflate.
Authors: Fritz Sven P. , Moya Juan F. , Unthank Matthew G. , McGarrigle Eoghan M. , Aggarwal Varinder K. 
Published: July 2012

AbstractThe synthesis of N‐substituted azetidines is extended to the preparation of an oxetane (X) under similar conditions.
ChemInform Abstract: Copper‐Catalyzed Regioselective C—H Aerobic Oxidative Cycloetherification of o‐Arylphenols Bearing an Additional Directing Group.
Authors: Zhao Jiaji , Wang Yong , Zhu Qiang 
Published: July 2012

AbstractThe reaction permits the synthesis of 2,6‐disubstituted dibenzofurans by regioselective activation of the sterically more hindered C—H bond.
ChemInform Abstract: Synthesis of New Thieno[2,3‐d]pyrimidines, Thieno[3,2‐e]pyridines, and Thieno[2,3‐d][1,3]oxazines.
Authors: Kanawade Shrikant B. , Patil Shivaraj P. , Nikam Prashant S. , Gangurde Sachin A. , Jachak Madhukar N. , Toche Raghunath B. 
Published: July 2012

AbstractA new category of title heterocycles is obtained in satisfactory to very good yields from thiophene derivatives (I) and (II) with simple work‐up and clean products.
ChemInform Abstract: CuSO4—Glucose for in situ Generation of Controlled Cu(I)—Cu(II) Bicatalysts: Multicomponent Reaction of Heterocyclic Azine and Aldehyde with Alkyne, and Cycloisomerization Toward Synthesis of N‐Fused Imidazoles.
Authors: Guchhait Sankar K. , Chandgude Ajay L. , Priyadarshani Garima 
Published: July 2012

AbstractThe simple, efficient, and widely applicable method affords a broad spectrum of N‐heterocyclic systems which are of therapeutic interest.
ChemInform Abstract: The Regioselective Switch for Amino‐NHC Mediated C—H Activation of Benzimidazole via Ni—Al Synergistic Catalysis.
Authors: Shih Wei‐Chun , Chen Wen‐Ching , Lai Ying‐Chieh , Yu Ming‐Shiuan , Ho Jhao‐Jhe , Yap Glenn P. A. , Ong Tiow‐Gan 
Published: July 2012

AbstractEither branched or linear products can be formed following the conditions A)‐C).
ChemInform Abstract: Synthesis of 3‐(3,5‐Dinitropyrazol‐4‐yl)‐4‐nitrofurazan and Its Salts.
Authors: Sheremetev Aleksei B. , Yudin Igor L. , Palysaeva Nadezhda V. , Suponitsky Kyrill Yu. 
Published: July 2012

AbstractReaction of furazan‐modified vinamidinium salt (III) with hydrazine furnishes the pyrazolyl‐furazan skeleton (IV).
ChemInform Abstract: Highly Efficient Asymmetric Mannich Reaction of Dialkyl α‐Diazomethylphosphonates with N‐Carbamoyl Imines Catalyzed by Chiral Broensted Acids.
Authors: Zhang Hui , Wen Xiaojing , Gan Lihua , Peng Yungui 
Published: July 2012

AbstractThe reaction tolerates a wide range of aromatic imines where the ortho‐substituted substrates show decreased reactivity.
ChemInform Abstract: Glycerol as a Recyclable Solvent for Copper‐Catalyzed Cross‐Coupling Reactions of Diaryl Diselenides with Aryl Boronic Acids.
Authors: Ricordi Vanessa G. , Freitas Camilo S. , Perin Gelson , Lenardao Eder J. , Jacob Raquel G. , Savegnago Lucielli , Alves Diego 
Published: July 2012

AbstractThe cross‐coupling reaction of diaryl diselenides (I) and diphenyl ditelluride (IVb) with boronic acids (II) leads to desired diaryl dichalcogenides (III) and (Vb), resp., in good to high yields, whilst low yield of diarylsulfide (Va) is observed in the analogous reaction of diphenyl disulfide (IVa).
ChemInform Abstract: A Water Soluble CuI—NHC for CuAAC Ligation of Unprotected Peptides under Open Air Conditions.
Authors: Gaulier Christelle , Hospital Audrey , Legeret Bertrand , Delmas Agnes F. , Aucagne Vincent , Cisnetti Federico , Gautier Arnaud 
Published: July 2012

AbstractThe reaction does not require the presence of reducing agents or protective additives.
ChemInform Abstract: Catalytic α‐Allylation of Unprotected Amino Acid Esters.
Authors: Fang Ping , Chaulagain Mani Raj , Aron Zachary D. 
Published: July 2012

Abstractα‐Quaternary α‐allylated amino acid esters are obtained by catalytic allylation reaction of racemic amino acid salts.
ChemInform Abstract: Endohedral Metallofullerenes — Filled Fullerene Derivatives Towards Multifunctional Reaction Center Mimics
Authors: Rudolf Marc , Wolfrum Silke , Guldi Dirk M. , Feng Lai , Tsuchiya Takahiro , Akasaka Takeshi , Echegoyen Luis 
Published: July 2012

AbstractReview: 128 refs.
ChemInform Abstract: 2‐Substituted‐pyridazin‐3(2H)‐ones as Green Electrophilic Agents in Synthesis
Authors: Sung Gi Hyeon , Kim Bo Ram , Lee Sang‐Gyeong , Kim Jeum‐Jong , Yoon Yong‐Jin 
Published: July 2012

AbstractReview: 63 refs.
ChemInform Abstract: Potential Energy Surfaces for Reactions of X Metal Atoms (X: Cu, Zn, Cd, Ga, Al, Au, or Hg) with YH4 Molecules (Y: C, Si, or Ge) and Transition Probabilities at Avoided Crossings in Some Cases
Authors: Novaro Octavio , del Alba Pacheco‐Blas Maria , Pacheco‐Sanchez Juan Horacio 
Published: July 2012

AbstractReview: ab initio studies based on quantum mechanics; 104 refs.
Lightweight PIM—a new multicast routing protocol
Authors: Bartczak Tomasz , Zwierzykowski Piotr 
Published: July 2012

SUMMARYMulticast holds out great promise to significantly reduce network load between the sender and a group of receivers by delivering a single data stream to many recipients. Protocol‐Independent Multicast (PIM) Sparse Mode and its variant PIM Source‐Specific Multicast (PIM SSM) are the most widely used IP multicast protocols. Protocols offer low latency data delivery capabilities with relatively high reliability and are characterized by large signaling overhead. This article presents a new multicast protocol, called Lightweight PIM (LPIM), tackling the main problem hindering widespread usage of IP multicast protocols, which is a large volume of signaling traffic. Given the existing usability of the PIM family protocols, a decision was made to base the new LPIM protocol on PIM SSM. The improvements used in LPIM lead to a considerable reduction of state data and signaling messages required by LPIM as compared with PIM SSM. Similar to its predecessor, LPIM is capable of handling large groups, although with significantly lower overhead. Copyright © 2012 John Wiley & Sons, Ltd.
An efficient method of P2P traffic identification based on wavelet packet decomposition and kernel principal component analysis
Authors: Du Min , Chen Xingshu , Tan Jun 
Published: July 2012

SUMMARYPeer‐to‐peer (P2P) traffic identification is currently an important challenge to network management and measurement. Many approaches based on statistics have been proposed to identify P2P traffic. However, flow features extracted by traditional methods are rough and one‐sided, which might lead to inaccuracy identification of network traffic. Besides, P2P traffic has too many statistical features, which is a challenge to the time complexity and space complexity of the classifier. This work focuses on the study of flow features. First, micro features of flow signals are extracted based on wavelet packet decomposition, and we combine them with the traditional features into combination features. The experimental results show that combination features have better performance than traditional features for P2P traffic identification, and 16 kinds of wavelet functions were tested to find the best one. Second, a feature reduction algorithm based on improved kernel principal component analysis is provided. The results show that the feature reduction algorithm proposed in this paper plays good performance to P2P traffic identification, because it could greatly reduced the number of features while having no affection on identification accuracy. Copyright © 2012 John Wiley & Sons, Ltd.