bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is the HO4− Anion a Key Species in the Aqueous‐Phase Decomposition of Ozone?
Authors: Anglada Josep M. , Torrent‐Sucarrat Miquel , Ruiz‐Lopez Manuel F. , Martins‐Costa Marilia 
Published: September 2012

AbstractThe role of the HO4− anion in atmospheric chemistry and biology is a matter of debate, because it can be formed from, or be in equilibrium with, key species such as O3 + HO− or HO2 + O2−. The determination of the stability of HO4− in water therefore has the greatest relevance for better understanding the mechanism associated with oxidative cascades in aqueous solution. However, experiments are difficult to perform because of the short‐lived character of this species, and in this work we have employed DFT, CCSD(T) complete basis set (CBS), MRCI/aug‐cc‐pVTZ, and combined quantum mechanics/molecular mechanics (QM/MM) calculations to investigate this topic. We show that the HO4− anion has a planar structure in the gas phase, with a very large HOOOO bond length (1.823 Å). In contrast, HO4− adopts a nonplanar configuration in aqueous solution, with huge geometrical changes (up to 0.232 Å for the HOOOO bond length) with a very small energy cost. The formation of the HO4− anion is predicted to be endergonic by 5.53±1.44 and 2.14±0.37 kcal mol−1 with respect to the O3 + HO− and HO2 + O2− channels, respectively. Moreover, the combination of theoretical calculations with experimental free energies of solvation has allowed us to obtain accurate free energies for the main reactions involved in the aqueous decomposition of ozone. Thus, the oxygen transfer reaction (O3 + OH− → HO2 + O2−) is endergonic by 3.39±1.80 kcal mol−1, the electron transfer process (O3 + O2− → O3− + O2) is exergonic by 31.53±1.05 kcal mol−1, supporting the chain‐carrier role of the superoxide ion, and the reaction O3 + HO2− → OH + O2− + O2 is exergonic by 12.78±1.15 kcal mol−1, which is consistent with the fact that the addition of small amounts of HO2− (through H2O2) accelerates ozone decomposition in water. The combination of our results with previously reported thermokinetic data provides some insights into the potentially important role of the HO4− anion as a key reaction intermediate.
Central‐Atom Size Effects on the Methyl Torsions of Group XIV Tetratolyls
Authors: Ng Maggie C. C. , Harper Jason B. , Stampfl Anton P. J. , Kearley Gordon J. , Rols Stéphane , Stride John A. 
Published: September 2012

AbstractThe Group XIV tetratolyl series X(C6H4‐CH3)4 (X=C, Si, Ge, Sn, Pb) were studied by using inelastic neutron scattering to measure the low‐energy phonon spectra to directly access the methyl‐group torsional modes. The effect of increased molecular radius as a function of the size of the central atom was shown to have direct influence on the methyl dynamics, reinforced with the findings of molecular dynamics and contact surface calculations, based upon the solid‐state structures. The torsional modes in the lightest analogue were found to be predominantly intramolecular: the Si and Ge analogues have a high degree of intermolecular methyl–methyl group interactions, whilst the heaviest analogues (Sn and Pb) showed pronounced intermolecular methyl interactions with the whole phonon bath of the lattice modes.
Synthesis and Characterization of Multiferrocenyl‐Substituted Group 4 Metallocene Complexes
Authors: Kaleta Katharina , Strehler Frank , Hildebrandt Alexander , Beweries Torsten , Arndt Perdita , Rüffer Tobias , Spannenberg Anke , Lang Heinrich , Rosenthal Uwe 
Published: September 2012

AbstractThe reaction of different metallocene fragments [Cp2M] (Cp=η5‐cyclopentadienyl, M=Ti, Zr) with diferrocenylacetylene and 1,4‐diferrocenylbuta‐1,3‐diyne is described. The titanocene complexes form the highly strained three‐ and five‐membered ring systems [Cp2Ti(η2‐FcC2Fc)] (1) and [Cp2Ti(η4‐FcC4Fc)] (2) (Fc=[Fe(η5‐C5H4)(η5‐C5H5)]) by addition of the appropriate alkyne or diyne to Cp2Ti. Zirconocene precursors react with diferrocenyl‐ and ferrocenylphenylacetylene under CC bond coupling to yield the metallacyclopentadienes [Cp2Zr(C4Fc4)] (3) and [Cp2Zr(C4Fc2Ph2)] (5), respectively. The exchange of the zirconocene unit in 3 by hydrogen atoms opens the route to the super‐crowded ferrocenyl‐substituted compound tetraferrocenylbutadiene (4). On the other hand, the reaction of 1,4‐diferrocenylbuta‐1,3‐diyne with zirconocene complexes afforded a cleavage of the central CC bond, and thus, dinuclear [{Cp2Zr(μ‐η1:η2‐CCFc)}2] (6) that consists of two zirconocene acetylide groups was formed. Most of the complexes were characterized by single‐crystal X‐ray crystallography, showing attractive multinuclear molecules. The redox properties of 3, 5, and 6 were studied by cyclic voltammetry. Upon oxidation to 3n+, 5n+, and 6n+ (n=1–3), decomposition occured with in situ formation of new species. The follow‐up products from 3 and 5 possess two or four reversible redox events pointing to butadiene‐based molecules. However, the dinuclear complex 6 afforded ethynylferrocene under the measurement conditions.
Aza‐BODIPY Derivatives: Enhanced Quantum Yields of Triplet Excited States and the Generation of Singlet Oxygen and their Role as Facile Sustainable Photooxygenation Catalysts
Authors: Adarsh Nagappanpillai , Shanmugasundaram Madhesh , Avirah Rekha R. , Ramaiah Danaboyina 
Published: September 2012

AbstractA new series of aza‐BODIPY derivatives (4 a–4 c, 5 a,c, and 6 b,c) were synthesized and their excited‐state properties, such as their triplet excited state and the yield of singlet‐oxygen generation, were tuned by substituting with heavy atoms, such as bromine and iodine. The effect of substitution has been studied in detail by varying the position of halogenation. The core‐substituted dyes showed high yields of the triplet excited state and high efficiencies of singlet‐oxygen generation when compared to the peripheral‐substituted systems. The dye 6 c, which was substituted with six iodine atoms on the core and peripheral phenyl ring, showed the highest quantum yields of the triplet excited state (ΦT=0.86) and of the efficiency of singlet‐oxygen generation (ΦΔ=0.80). Interestingly, these dyes were highly efficient as photooxygenation catalysts under artificial light, as well as under normal sunlight conditions. The uniqueness of these aza‐BODIPY systems is that they are stable under irradiation conditions, possess strong red‐light absorption (620–680 nm), exhibit high yields of singlet‐oxygen generation, and act as efficient and sustainable catalysts for photooxygenation reactions.
Revealing the Absolute Configuration of the CO and CN− Ligands at the Active Site of a [NiFe] Hydrogenase
Authors: Rippers Yvonne , Horch Marius , Hildebrandt Peter , Zebger Ingo , Mroginski Maria Andrea 
Published: September 2012

AbstractCombined molecular dynamics (MD) and quantum mechanical/molecular mechanical (QM/MM) calculations were performed on the crystal structure of the reduced membrane‐bound [NiFe] hydrogenase (MBH) from Ralstonia eutropha to determine the absolute configuration of the CO and the two CN− ligands bound to the active‐site iron of the enzyme. For three models that include the CO ligand at different positions, often indistinguishable on the basis of the crystallographic data, we optimized the structures and calculated the ligand stretching frequencies. Comparison with the experimental IR data reveals that the CO ligand is in trans position to the substrate‐binding site of the bimetallic [NiFe] cluster.
Scientific Communication in Clinical Psychology: Examining Patterns of Citations and References
Authors: Kiselica Andrew M. , Ruscio John 
Published: September 2012

Previous studies of scientific communication used citation mapping, establishing psychology as a ‘hub science’ from which many other fields draw information. Within psychology, the clinical and counselling discipline is a major ‘knowledge broker’. This study analyzed scientific communication among three major subdisciplines of clinical psychology—the cognitive–behavioural, psychodynamic and humanistic schools of thought—by examining patterns of references within and citations to 305 target articles published in leading journals of these subdisciplines. The results suggest that clinical researchers of each theoretical orientation engage in more insular scientific communication than an integrationist would find desirable and that cognitive–behavioural articles are more closely connected to mainstream psychology and related fields. Copyright © 2012 John Wiley & Sons, Ltd.Key Practitioners Message

Eclectic practitioners draw on several different theoretical orientations to inform their practice; as such, they should be interested in understanding the patterns of scientific communication within and across theoretical orientations.
Practitioners work in a variety of different mental health settings, with a variety of other professionals in psychology‐related fields, and should be interested in how much influence their particular theoretical orientation has on the work of colleagues.
Many practitioners rely on new, evidence‐based research to inform their work. The results of this study provide these individuals with an objective measure of the influence of empirical work in different areas of clinical psychology.
Room Temperature Solid‐State Synthesis of a Conductive Polymer for Applications in Stable I2‐Free Dye‐Sensitized Solar Cells
Authors: Kim Byeonggwan , Koh Jong Kwan , Kim Jeonghun , Chi Won Seok , Kim Jong Hak , Kim Eunkyoung 
Published: September 2012

AbstractA solid‐state polymerizable monomer, 2,5‐dibromo‐3,4‐propylenedioxythiophene (DBProDOT), was synthesized at 25 °C to produce a conducting polymer, poly(3,4‐propylenedioxythiophene) (PProDOT). Crystallographic studies revealed a short interplane distance between DBProDOT molecules, which was responsible for polymerization at low temperature with a lower activation energy and higher exothermic reaction than 2,5‐dibromo‐3,4‐ethylenedioxythiophene (DBEDOT) or its derivatives. Upon solid‐state polymerization (SSP) of DBProDOT at 25 °C, PProDOT was obtained in a self‐doped state with tribromide ions and an electrical conductivity of 0.05 S cm−1, which is considerably higher than that of chemically‐polymerized PProDOT (2×10−6 S cm−1). Solid‐state 13C NMR spectroscopy and DFT calculations revealed polarons in PProDOT and a strong perturbation of carbon nuclei in thiophenes as a result of paramagnetic broadening. DBProDOT molecules deeply penetrated and polymerized to fill nanocrystalline TiO2 pores with PProDOT, which functioned as a hole‐transporting material (HTM) for I2‐free solid‐state dye‐sensitized solar cells (ssDSSCs). With the introduction of an organized mesoporous TiO2 (OM‐TiO2) layer, the energy conversion efficiency reached 3.5 % at 100 mW cm−2, which was quite stable up to at least 1500 h. The cell performance and stability was attributed to the high stability of PProDOT, with the high conductivity and improved interfacial contact of the electrode/HTM resulting in reduced interfacial resistance and enhanced electron lifetime.
The Effect of Switchable Water Additives on Clay Settling
Authors: Chen Chien‐Shun , Lau Ying Yin , Mercer Sean M. , Robert Tobias , Horton J. Hugh , Jessop Philip G. 
Published: September 2012

AbstractThe recycling of process water from strip mining extractions is a very relevant task both industrially and environmentally. The sedimentation of fine tailings during such processes, however, can often require long periods of time and/or the addition of flocculants which make later water recycling difficult. We propose the use of switchable water additives as reversible flocculants for clay/water suspensions. Switchable water additives are compounds such as diamines that make it possible to reversibly control the ionic strength of an aqueous solution. Addition of CO2 to such an aqueous solution causes the ionic strength to rise dramatically, and the change is reversed upon removal of the CO2. These additives, while in the presence of CO2, promote the aggregation of clay tailings, reduce settling times, and greatly increase the clarity of the liberated water. The removal of CO2 from the liberated water regenerates a low ionic strength solution that does not promote clay aggregation and settling until CO2 is added again. Such reversible behavior would be useful in applications such as oil sands separations in which the recycled water must not promote aggregation. When added to kaolinite and montmorillonite clay suspensions, switchable water provided process waters of lower turbidity than those additives from inorganic salts or by CO2‐treatment alone. When recollected, the switchable water supernatant was shown to be recyclable over three cycles for enhanced settling of kaolinite.
Towards Alternatives to Anodic Water Oxidation: Basket‐Handle Thiolate FeIII Porphyrins for Electrocatalytic Hydrocarbon Oxidation
Authors: Li Peiyi , Alenezi Khalaf , Ibrahim Saad K. , Wright Joseph A. , Hughes David L. , Pickett Christopher J. 
Published: September 2012

AbstractSelective electrocatalytic oxidation of hydrocarbons to alcohols, epoxides or other (higher value) oxygenates should in principal present a useful complementary anodic half‐cell reaction to cathodic generation of fuels from water or CO2 viz. an alternative to oxygen evolution. A series of new basket‐handle thiolate FeIII porphyrins have been synthesised and shown to mediate anodic oxidation of hydrocarbons, specifically adamantane hydroxylation and cyclooctene epoxidation. We compare yields obtained by electrochemical and chemical oxidation of the thiolate porphyrins and benchmark their behaviour against that of FeIII tetraphenyl porphyrin chloride and its tetrapentafluorophenyl analogue.
Privacy‐preserving registration protocol for mobile network
Authors: Liu He , Liang Mangui 
Published: September 2012

SUMMARYIn this paper, we propose a novel privacy‐preserving registration protocol that combines the verifier local revocation group signature with mobile IP. The protocol could achieve strong security guarantee, such as user anonymity via a robust temporary identity, local user revocation with untraceability support, and secure key establishment against home server and eavesdroppers. Various kinds of adversary attacks can be prevented by the proposed protocol, especially that deposit‐case attack does not work here. Meanwhile, a concurrent mechanism and a dynamical revocation method are designed to minimize the handover authentication delay and the home registration signals. The theoretical analysis and simulation results show that the proposed scheme could provide high security level besides lightweight computational cost and efficient communication performance. For instance, compared with Yang's scheme, the proposed protocol could decrease the falling speed of handover authentication delay up to about 40% with privacy being preserved. Copyright © 2012 John Wiley & Sons, Ltd.
Cryptanalysis of a dynamic ID‐based remote user authentication with key agreement scheme
Authors: Tang Hong‐bin , Liu Xin‐song 
Published: September 2012

SUMMARYA dynamic user authentication scheme allows a user and a remote server to authenticate each other without leaking the user's identity. In 2011, Wen and Li proposed an improved dynamic ID‐based remote user authentication with key agreement scheme for mobile and home networks. They claimed that their scheme was more secure than the scheme of Wang et al. However, we demonstrate that their scheme is vulnerable to the privileged insider, off‐line password guessing, impersonation, and server spoofing attacks. At the same time, it does not provide any user anonymity and forward secrecy property. Thus, it is not feasible for real‐life implementation.Copyright © 2012 John Wiley & Sons, Ltd.
MMSE‐based transceiver design for distributed MIMO amplify‐and‐forward cooperative networks in correlated channels
Authors: Hu Chia‐Chang , Liang Wei‐Yu , Li Guan‐Yi 
Published: September 2012

SUMMARYIn this paper, the source‐precoder, multiple‐relay amplifying matrices, and destination‐equalizer joint optimization is investigated in distributed MIMO amplify‐and‐forward multiple‐relay networks with direct source–destination transmission in correlated fading channels. With the use of taking both the direct link and spatial correlation between antenna elements into account, the cooperative transceiver joint design is developed based on the minimum mean‐squared error criterion under individual power constraints at the source and multiple‐relay nodes. Simulation results demonstrate that the cooperative transceiver joint design architecture for an amplify‐and‐forward MIMO multiple‐relay system outperforms substantially the noncooperative transceiver design techniques on the BER performance under the spatial‐correlation channels.Copyright © 2012 John Wiley & Sons, Ltd.
High resolution accurate mass screening of prohibited substances in equine plasma using liquid chromatography – Orbitrap mass spectrometry
Authors: Ho Emmie N. M. , Kwok W. H. , Wong April S. Y. , Wan Terence S. M. 
Published: September 2012

A recent trend in the use of high resolution accurate mass screening (HRAMS) for doping control testing in both human and animal sports has emerged due to significant improvement in high resolution mass spectrometry in terms of sensitivity, mass accuracy, mass resolution, and mass stability. A number of HRAMS methods have been reported for the detection of multi‐drug residues in human or equine urine. As blood has become a common matrix for doping control analysis, especially in equine sports, a sensitive, fast and wide coverage screening method for detecting a large number of drugs in equine blood samples would be desirable. This paper presents the development of a liquid chromatography‐high resolution mass spectrometry (LC‐HRMS) screening method for equine plasma samples to cover over 320 prohibited substances in a single analytical run.Plasma samples were diluted and processed by solid‐phase extraction. The extracts were then analyzed with LC‐HRMS in full‐scan positive electrospray ionization mode. A mass resolution of 60 000 was employed. Benzyldimethylphenylammonium was used as an internal lock mass. Drug targets were identified by retention time and accurate mass, with a mass tolerance window of ±3 ppm. Over 320 drug targets could be detected in a 13‐min run. Validation data including sensitivity, specificity, extraction recovery and precision are presented. As the method employs full‐scan mass spectrometry, an unlimited number of drug targets can theoretically be incorporated. Moreover, the HRAMS data acquired can be re‐processed retrospectively to search for drugs which have not been targeted at the time of analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Isoreticular Lanthanide Metal‐Organic Frameworks: Syntheses, Structures and Photoluminescence of a Family of 3D Phenylcarboxylates
Authors: Min Zeyar , Singh‐Wilmot Marvadeen A. , Cahill Christopher L. , Andrews Michael , Taylor Richard 
Published: September 2012

AbstractFive isoreticular lanthanide (Ln) metal‐organic frameworks (MOFs) – Er(bdc)(HCOO) (1a), Dy(bdc)(HCOO) (1b), Tb(bpdc)(HCOO) (2a), Gd(bpdc)(HCOO) (2b) and Tb(bpydc)(HCOO) (3) (bdc = 1,4‐benzenedicarboxylate, bpdc = 4,4′‐biphenyldicarboxylate and bpydc = 2,2′‐bipyridine‐5,5′‐dicarboxylate) – were synthesized under solvothermal conditions. The complexes were characterized by powder X‐ray diffraction, elemental analyses, infrared spectroscopy and single‐crystal X‐ray crystallography. Each LnIII ion is eight‐coordinated and forms a binuclear pseudo‐paddlewheel secondary building unit (SBU), [Ln2(CO2)2(CO2)2]. The SBUs are interconnected into 2D Ln–carboxylate nets, which act as tertiary building units (TBUs) that are linked by the rigid organic linkers to form 3D pillared frameworks. Preliminary luminescence studies reveal that energy transfer from Tb3+ to Eu3+ trace impurities is active in crystals of 2a and 3 and contributes to interesting temperature‐dependent photoluminescence. At 298 K, under UV excitation, 2a is lilac and 3 glows bright red, whereas at 77 K both 2a and 3 emit green light. Together with the previously published Tb(bdc)(HCOO), Eu(bdc)(HCOO), Gd(bdc)(HCOO) and Ln(bpedc)(HCOO) (bpedc = biphenylethene‐4,4′‐dicarboxylate), these complexes form the first examples of isoreticular LnMOFs.
Zein–Fibrous Clays Biohybrid Materials
Authors: Alcântara Ana C. S. , Darder Margarita , Aranda Pilar , Ruiz‐Hitzky Eduardo 
Published: September 2012

AbstractThe present work introduces a new type of biohybrid materials that is based on the combination of fibrous clays (sepiolite or palygorskite) with zein, a highly hydrophobic protein extracted from corn. C, H, N, and S chemical analyses, FTIR spectroscopy, 13C solid‐state NMR spectroscopy, field‐emission scanning electron microscopy (FESEM), thermal analysis, as well as dynamic vapor sorption were employed in the characterization of the resulting biohybrids to discern the type of interaction between the protein and the clay fibers and to evaluate the reduced hydrophilic character of the novel biohybrids in comparison to the pristine clays. With the aim of profiting from such a property, zein–fibrous clay biohybrids were tested as additives in the preparation of nanocomposites. For this purpose, alginate was chosen as a model polymer matrix, as it forms suitable self‐supporting films and is a biocompatible and biodegradable material; but one of its main drawbacks for applications is its high hydrophilic character. In a similar way to conventional organoclays that are based on alkylammonium compounds, the zein–clay biohybrids reported here were effective in improving several features of the biopolymer matrix, mainly those related to mechanical and barrier properties. In addition, the nontoxic character of zein‐based bioorganoclays is an advantageous feature that would allow the application of these new eco‐friendly materials in the food‐packaging sector.
The effects of adding water and polyglycerol polyricinoleate on the texture, appearance, and sensory qualities of compound milk chocolate
Authors: Raoufi Nassim , Tehrani Mostafa Mazaheri , Farhoosh Reza , Golmohammadzadeh Shiva 
Published: September 2012

AbstractWater and polyglycerol polyricinoleate (PGPR) contents were varied to investigate the effects of these parameters on the textural properties, surface color, and sensory qualities of compound chocolates. The content levels of water and PGPR were manipulated between 3–10 and 0.3–3.3%, respectively (content expressed as % by weight of finished product). Simultaneous variations in water and PGPR levels, especially in high ratios, resulted in a drastic reduction in the hardness values (p<0.001), darker color (p<0.01), and an unusual taste (p<0.05) but the effect of water addition was more pronounced than PGPR. It was observed that compound chocolates with 3% water content were not dissimilar from the control with respect to all properties. In the samples of the same water content, the effect of PGPR addition was nearly insignificant. For these confectionaries, the best proportion of ingredients for producing water‐containing compound chocolate was considered the one which has the least negative effects on bloom surface area and the texture.Practical applications: Manufacturing water‐containing imitation chocolates represent a general approach for adding all water‐base materials to chocolate such as cream, yogurt, milk, etc. or water‐soluble substances like trace elements and vitamins. Conventional chocolates become soft at above 28°C, and lose shape retention at above 32°C. Water addition provides a heat‐resistance compound chocolate with shape retention at a temperature above 40°C, being not sticky to the direct touch. However, there has been very limited information about water addition's effects on the chocolate structure. In order to be able to predict the structural variations, it is important to study how water affects the physical properties of the chocolates.