bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction of Carbon Dioxide in γ Ray Irradiated Carbon Dioxide : Water System Containing Cu2+ and SO32−
Authors: Wu Xing-Zheng , Hatashita Masanori , Enokido Yuji , Kakihana Hidetake 
Published: December 2003

Abstract
Enhancing effect of various metal powders, metal oxides, metal ions, and inorganic anions on reduction of CO2 in γ ray irradiated CO2-water systems were investigated. Experimental results showed that Cu2+ and SO32− have large enhancing effect. Furthermore, their synergical enhancing effect was found. The enhancing factor was about 100-fold.
New Aspects of Knoevenagel Condensation and Michael Addition Reactions on Alkaline Carbonates
Authors: Aramendía María A , Borau Victoriano , Jiménez César , Marinas José M , Romero Francisco J 
Published: December 2003

Abstract
The Knoevenagel condensation of malononitrile with benzaldehyde on K2CO3, Rb2CO3 and Cs2CO3 gave the condensation product benzylidenemalononitrile but the reaction proceeded to the hydrogenated product benzylmalononitrile. Also, the Michael addition of malononitrile to certain double bonds occurs in the presence of K2CO3.
Lipase-Catalyzed Reaction of Molecularly Pure Linear and Cyclic Poly(3-hydroxybutanoate)s: Evidence of Cyclic Polymer Formation
Authors: Osanai Yasushi , Toshima Kazunobu , Matsumura Shuichi 
Published: December 2003

Abstract
Molecularly pure linear and cyclic poly(3-hydroxybutanoate) [P(3HB)] polymer species were subjected to hydrolysis, transesterification and intramolecular esterification by lipase to produce two series of linear and cyclic polymer structures having higher and lower molecular weights. It was found that a cyclic polymer was produced by the lipase-catalyzed reaction of the polymer chain.
Superior Decomposition of NO over Plasma-Assisted Catalytic System Induced by Microwave
Authors: Roh Hyun-Seog , Park Yong-Ki , Park Sang-Eon 
Published: December 2003

Abstract
More than 99% of NO was directly decomposed into N2 and O2 without formation of N2O at space velocity of 45360 h−1 and apparent temperature of 280 °C over plasma-assisted Co3O4/Cu-ZSM-5 catalyst.
A New Method for the Synthesis of Unsymmetrical Bis-Aldols by the Samarium(II) Iodide-Mediated Aldol Reaction of Aldehydes with Aryl or Alkyl Oxiranyl Ketones
Authors: Mukaiyama Teruaki , Arai Hidehiro , Shiina Isamu 
Published: December 2003

Abstract
Unsymmetrical alkyl or aryl 2-hydroxy-1-(1-hydroxyalkyl)alkyl ketones (bis-aldols) were synthesized by the samarium(II) iodide-mediated aldol reaction of aldehydes with alkyl or aryl oxiranyl ketones. Bis-aldols were formed via the aldol reaction of aldehydes with samarium enolates generated by epoxy-fragmentation of oxiranyl ketones using two moles of samarium(II) iodide.
Bicyclic and Tricyclic Ladder Compounds Consisting of Two Oligosiloxane Chains Bridged by Si–Si Rungs
Authors: Kyushin Soichiro , Takahashi Masaki , Matsumoto Hideyuki 
Published: December 2003

Abstract
The bicyclic and tricyclic ladder compounds consisting of two oligosiloxane chains bridged by Si–Si rungs were synthesized by the condensation of 1,2-dihydroxy-1,1,2,2-tetraisopropyldisilane and 1,1,2,2-tetrachloro-1,2-diisopropyldisilane with aniline. The structures of these compounds were confirmed by X-ray crystallography.
Synthesis of Spiro[indoline-3,2′-pyrrolidine] Derivatives from β-3-Indolyl Ketone Oximes
Authors: Tanaka Kenichi , Mori Yutaka , Narasaka Koichi 
Published: December 2003

Abstract
Spiro[indoline-3,2′-pyrrolidine] derivatives were prepared from β-3-indolyl ketone oximes by treatment with methanesulfonyl chloride and triethylamine via the bond formation between 3-position of the indole ring and oxime nitrogen. These diazaspirocycles were readily transformed to the corresponding spiro oxindole derivatives.
Energy Structure and Photocatalytic Activity of Niobates and Tantalates Containing Sn(II) with a 5s2 Electron Configuration
Authors: Hosogi Yasuhiro , Tanabe Kentaro , Kato Hideki , Kobayashi Hisayoshi , Kudo Akihiko 
Published: December 2003

Abstract
SnNb2O6 (BG = 2.3 eV) containing Sn2+ with a 5s2 electron configuration showed the photocatalytic activity for H2 evolution from an aqueous methanol solution under visible light irradiation (λ &gt; 420 nm) in the presence of a Pt cocatalyst. The energy structure calculation by the plane wave based density functional method revealed that the conduction and valence bands consisted of Nb4d and Sn5s orbitals, respectively. The valence band level consisting of the Sn5s orbitals was more negative than that consisting of O2p orbitals resulting in SnNb2O6 being responsive to visible light.
A New Amorphous Lithium-ion Conductor in the System Li2S–P2S3
Authors: Machida Nobuya , Yamamoto Hidekazu , Shigematsu Toshihiko 
Published: December 2003

Abstract
Amorphous solid electrolytes in the system Li2S–P2S3 were obtained in a narrow composition range at around 66.7 mol % Li2S content by a high-energy ball-milling process. The 66.7Li2S·33.3P2S3 (mol %) sample showed the highest ion conductivity of 1.1 × 10−4 S·cm−1 at room temperature among the obtained samples. Cyclic voltammetry revealed that the sample had a wide electrochemical window of about 5 V.
First Observation of the Vibrational Circular Dichroism Spectra of Synthetic Chiral Porphyrazines
Authors: Kobayashi Nagao , Fukuda Takamitsu 
Published: December 2003

Abstract
Vibrational circular dichroism (VCD) spectra of (R)-(−)- and (S)-(+)-camphor-substituted tetrapyrazinoporphyrazines, which show a mirror-image relationship with respect to the line of intensity = 0, were recorded as the first VCD spectra of synthetic porphyrins.
A Novel Catalyst Iron(II) Tetra(1,4-dithin)porphyrazine for Oxygenating Degradation of Organic Pollutants in Aqueous Solutions
Authors: Deng Kejian , Huang Fei , Wang Duoyuan , Peng Zhenghe , Zhou Yunhong 
Published: December 2003

Abstract
An efficient catalyst of the title complex (abbreviated as FePz(dtn)4) is a porphyrin-like complex, which is able to activate molecular oxygen for oxidative degradation of organic compounds in an extensive pH region without light excitation. The experiments indicated that the FePz(dtn)4/O2 system showed an excellent oxygenation capability, in which the Rhodamine B(RhB) was degraded nearly 52% in alkaline aqueous solution in the seven hours and the p-nitrobenzoic acid(NBA) could be also oxygenated nearly 85% detected by UV–vis, HPLC in the similar conditions. The degradation components of RhB and NBA were analyzed by GC–MS and IR. The mineralization rate of RhB and NBA were 12 and 11.1% after reaction for 24 h respectively.
Comparison of Mercury Removal Efficiency from a Simulated Exhaust Gas by Several Types of TiO2 under Various Light Sources
Authors: Lee Yong Gyu , Park Jin-Won , Kim Jung-Hyun , Min Byoung Ryul , Jurng Jongsoo , Kim Jinsoo , Lee Tai Gyu 
Published: December 2003

Abstract
A removal efficiency of vapor-phase elemental mercury by TiO2 irradiated using various light sources was investigated. The effective surface area of TiO2 for Hg adsorption and UV radiation was increased by packing the adsorption bed with mixture of TiO2 and glass beads. A rotating-type reactor was specially designed to maximize the photocatalyst’s exposure to the light source. For three types of commercially available TiO2, more than 99% of initial Hg was removed under all the light sources tested except for the blue light still achieving a Hg removal efficiency close to 85%.
Silylium Ion to Silylium Ion Rearrangement Caused by 1,3-Methyl Migration
Authors: Nakamoto Masaaki , Fukawa Tomohide , Sekiguchi Akira 
Published: December 2003

Abstract
One-electron oxidation of a stable tris[di-tert-butyl(methyl)silyl]silyl radical by the triphenylmethylium ion produces the corresponding silylium ion 2. However, this underwent a rapid intramolecular methyl group migration to form a more stable silylium ion 4 via a Wagner–Meerwein type rearrangement. The facile 1,3-methyl migration over the three peripheral silicon atoms in 4 was observed in NMR time scale.
Pyrene-Fused Porphyrins: Annulation Reactions of meso-Pyrenylporphyrins
Authors: Yamane Osamu , Sugiura Ken-ichi , Miyasaka Hitoshi , Nakamura Kazuya , Fujimoto Tatsuhiko , Nakamura Kazuki , Kaneda Takahiro , Sakata Yoshiteru , Yamashita Masahiro 
Published: December 2003

Abstract
We prepared novel pyrene-fused porphyrins via the oxidative intramolecular ring closure reactions of meso-pyrenylporphyrin. The excitation energies and the oxidation potentials of the isolated dark-colored pyrene-fused porphyrins were significantly low compared with those of the corresponding precursors.
Fabrication of Polymer Crystals/Ag Nanocomposite by Intercalation
Authors: Matsumoto Akikazu , Odani Toru 
Published: December 2003

Abstract
The intercalation of alkali metals into the polymer crystals of benzylammonium muconate is achieved by immersion in the corresponding alkaline aqueous solution at room temperature, followed by an ion-exchange reaction to the silver salt and subsequent photoreduction of the polymer, leading to the fabrication of a new type of nanocomposite consisting of organic polymer crystals and Ag nanoparticles.
Poly[2,7-(9-oxo-9-phosphafluorenylene)-alt-co-(1,4-arylene)]s: Phosphorus-containing π-Conjugated Polymers
Authors: Makioka Yoshikazu , Hayashi Teruyuki , Tanaka Masato 
Published: December 2003

Abstract
Poly[2,7-(9-oxo-9-phosphafluorenylene)-alt-co-(1,4-arylene)]s, readily prepared from 2,7-dibromo-9-oxo-9-phosphafluorenes and arylene bisboronates, behaved as extended π-conjugated polymers in the UV–vis absorption spectroscopy and displayed green-blue fluorescence with high quantum yields. Cyclic voltammetry revealed the polymers exhibited electrochromic behaviors and afforded a bandgap of ca. 2.8 eV, consistent with the value from the absorption edge.
New Conducting Polymers Based on Poly(3,4-ethylenedioxypyrrole): Synthesis, Characterization, and Properties
Authors: Kim In Tae , Lee Jung Youl , Lee Sang Woo 
Published: December 2003

Abstract
Solution-processible conducting polymers 1 and 2, based on 3,4-ethylenedioxypyrrole, were synthesized. A comparison of the polymers’ optical and electrical properties showed that the introduction of a vinyl group in polymer 1 produced a decrease of bandgap. This occurrence was attributed to the enhancement of the planarity of polymer 1.
Rational Synthetic Strategy. From Layered Structure to MnO2 Nanotubes
Authors: Wang Xun , Li Yadong 
Published: December 2003

Abstract
In this manuscript, a rational synthetic strategy from layer structure to nanotubes has been developed in the synthesis of δ-MnO2 single crystal nanotubes by employing layered α-NaMnO2 as precursors through a controlled hydrothermal intercalation process.
Synthesis and Properties of Amorphous Hole Transport Materials of Triphenylamine Based Trihydrazones
Authors: Jiang Ke Jian , Sun Ya Li , Shao Ke Feng , Yang Lian Ming 
Published: December 2003

Abstract
A novel class of amorphous state triphenylamine-based trihydrazones were synthesized by condensation reaction of tris(p-formylphenyl)amine with N-methyl-N-phenyl hydrazine, N,N-diphenylhydrazine, N-1-naphthyl-N-phenyl-hydrazine, and N-2-naphthyl-N-phenyl-hydrazine, respectively, and characterized using different scanning calorimetry (DSC) and cyclic voltammetry (CV).
Dynamic Covalent Chemistry in Rotaxane Synthesis. Slipping Approach to [2]Rotaxane Utilizing Reversible Cleavage–Rebondage of Trityl Thioether Linkage
Authors: Furusho Yoshio , Oku Tomoya , Rajkumar G Abraham , Takata Toshikazu 
Published: December 2003

Abstract
A [2]rotaxane was synthesized in a high yield from a dumbbell-shaped sec-ammonium salt having trityl thioether and 3,5-di-t-butylphenyl groups at the both ends and dibenzo-24-crown-8-ether, through the slipping, utilizing the reversible cleavage–rebondage of the trityl thioether linkage.
Novel Synthesis of Tin Dioxide Nanoribbons via a Mild Solution Approach
Authors: Ye Changhui , Fang Xiaosheng , Wang Yinhai , Xie Ting , Zhao Aiwu , Zhang Lide 
Published: December 2003

Abstract
Single crystalline tin dioxide nanoribbons have been synthesized in bulk quantity by a mild solution approach using cetyltrimethylammonium bromide surfactant as a soft template. The as-synthesized SnO2 nanoribbons have a length up to tens of micrometers, width of several hundred nanometers, and thickness of several tens of nanometers.
Formation of Nanocrystalline TiC by a Low-temperature Route
Authors: Shi Liang , Gu Yunle , Chen Luyang , Yang Zeheng , Ma Jianhua , Qian Yitai 
Published: December 2003

Abstract
Nanocrystalline cubic titanium carbide (TiC) powders were successfully synthesized at 450 °C in an autoclave by using Ti, Na, and CCl4 as the reactants. The X-ray powder diffraction pattern indicates the formation of TiC. Transmission electron microscopy images show that typical TiC crystallites are composed of nanoparticles with the average grain size of about 30 nm.
Lithium Carbonate Flux Effects on the Luminescence Properties of Europium-doped Lanthanum Oxycarbonate Phosphor
Authors: Tamura Shinji , Koyabu Kazuhiko , Masui Toshiyuki , Imanaka Nobuhito 
Published: December 2003

Abstract
Lithium carbonate flux was introduced in the preparation of La2O2CO3: Eu3+ oxycarbonate phosphor particles to improve the photoluminescence intensities. The flux treatment brought increasing in the crystallinity of oxycarbonate phosphor accompanying the phase transition from the two-phase mixture of tetragonal and monoclinic forms to single hexagonal phase of rare earth oxycarbonate, resulting in the increase of the emission intensity.
Adsorption of Aromatic Thiols on Gold Nanoparticle Surfaces Investigated by UV–vis Absorption Spectroscopy and Surface Enhanced Raman Scattering
Authors: Joo Sang-Woo 
Published: December 2003

Abstract
A UV–vis absorption spectroscopy and surface-enhanced Raman scattering (SERS) study shows that benzyl mercaptan was found to be adsorbed faster than thiophenol on gold nanoparticle surfaces at a low bulk concentration of ≈10−7 M, whereas they appeared to exhibit almost identical spectral behaviors at high concentration of ≈10−5 M.
A numerical study of the genesis of concentric eyewalls in hurricanes
Authors: Nong Shangyao , Emanuel Kerry 
Published: December 2003

AbstractWe use two axisymmetric numerical models to explore the dynamics of concentric eyewalls in hurricanes. The first is a simple two‐layer model using balanced dynamics and parametrized convection, while the second is a cloud‐resolving non‐hydrostatic model. In the case of the balanced model, infinitesimal disturbances amplify into secondary eyewalls provided the lower troposphere is sufficiently moist; otherwise, finite‐amplitude perturbations are necessary to initiate amplifying structures. But experiments with the full‐physics model show that finite‐amplitude disturbances are always necessary to initiate secondary eyewalls, regardless of the initial humidity of the lower troposphere. Experiments with both models, in which the surface wind is held constant in the surface flux formulations, fail to develop secondary eyewalls, demonstrating that in these models the disturbances, once initiated, grow through the wind‐induced surface heat exchange (WISHE) mechanism. Based on this work, we hypothesize that real secondary eyewalls result from a finite‐amplitude WISHE instability, triggered by external forcing, such as interaction of the tropical cyclone with baroclinic eddies, topography, or local perturbations in sea surface temperature. Copyright © 2003 Royal Meteorological Society
Adjustment to heating, potential vorticity and cyclogenesis
Authors: Delden Aarnout Van 
Published: December 2003

AbstractSolutions of an isentropic coordinate model of the atmosphere, permitting acoustic waves and inertial gravity waves, demonstrate that a vertically symmetric heat source in the troposphere usually induces a vertically asymmetric dipole anomaly in the potential vorticity (PV), with an intense, tall and thin positive (cyclonic) anomaly below a less intense, flat and broad negative (anticyclonic) anomaly. The emergence of this asymmetry is associated with the vertical gradient of the PV, which is an important factor in the local PV budget, even when this gradient is zero initially. The degree of vertical asymmetry of the response to heating depends on the ‘thickness’ (in K) of the heated layer relative to the total heat added. The adjusted balanced state shows little sensitivity to the heating intensity (i.e. the time‐scale within which the heat is added), in spite of the existence of large‐amplitude waves when the heating is applied very abruptly relative to the adiabatic adjustment time‐scale. The surrounding (non‐heated) region shows little permanent change due to the process of adjustment as far as PV substance and mass is concerned, and only functions as a transmitter of acoustic waves and inertial gravity waves. The balanced state is sensitive to variations in the horizontal scale of the heat source. The response to heating within a PV stratified region (for example, in the region of the tropopause) is quite subtle. For example, it is shown that a heat source in the tropopause region induces a predominantly anticyclonic wind anomaly. Copyright © 2003 Royal Meteorological Society
Modelling of error covariances by 4D‐Var data assimilation
Authors: Lorenc Andrew C. 
Published: December 2003

AbstractThe extended Kalman filter is presented as a good approximation to the optimal assimilation of observations into a numerical weather prediction (NWP) model, as long as the evolution of errors stays close to linear. The error probability distributions are approximated by Gaussians, characterized by their mean and covariance. The full nonlinear forecast model is used to propagate the mean, and a linear model (not necessarily tangent to the full model) the covariances. Since it is impossible to determine the covariances in detail, physically based assumptions about their behaviour must be made; for instance, three‐dimensional balance relationships are used. The linear model can be thought of as extending the covariance relationships to the time dimension. Incremental four‐dimensional variational (4D‐Var) is derived as a practical implementation of the extended Kalman filter, optimally using these modelled covariances for a finite time window. It is easy to include a simplified model of forecast errors in the representation. This Kalman filter based paradigm differs from more traditional derivations of 4D‐Var in attempting to estimate the mean, rather than the mode, of the posterior probability density function. The latter is difficult for a NWP system representing scales which exhibit chaotic behaviour over the period of interest.The covariance modelling assumptions often result in a null space of error modes with little variance. It is argued that this is as important as the variance and correlation structures usually examined, since the implied constraints allow optimal use of observations giving gradient and tendency information.Difficulties arise in the approach when the NWP system is capable of resolving significant structures (such as convective cells) not always determined by the observations. © Crown copyright, 2003. Royal Meteorological Society
The potential of the ensemble Kalman filter for NWP—a comparison with 4D‐Var
Authors: Lorenc Andrew C. 
Published: December 2003

AbstractThe ensemble Kalman filter (EnKF) is reviewed for its expected assimilation characteristics and ease of implementation, and compared to the currently more popular four‐dimensional variational assimilation (4D‐Var). The EnKF is attractive when building a new medium‐range ensemble numerical weather prediction (NWP) system. However it is less suitable for NWP systems with uncertainty in a wide range of scales; it may not use high‐resolution satellite data as effectively as 4D‐Var. For limited‐area mesoscale NWP systems a hybrid method is attractive. © Crown copyright, 2003. Royal Meteorological Society
The omega equation and potential vorticity
Authors: Hoskins Brian , Pedder Mike , Jones David Wyn 
Published: December 2003

AbstractTwo fundamental perspectives on the dynamics of midlatitude weather systems are provided by potential vorticity (PV) and the omega equation. The aim of this paper is to investigate the link between the two perspectives, which has so far received very little attention in the meteorological literature. It also aims to give a quantitative basis for discussion of quasi‐geostrophic vertical motion in terms of components associated with system movement, maintaining a constant thermal structure, and with the development of that structure. The former links with the isentropic relative‐flow analysis technique. Viewed in a moving frame of reference, the measured development of a system depends on the velocity of that frame of reference. The requirement that the development should be a minimum provides a quantitative method for determining the optimum system velocity. The component of vertical velocity associated with development is shown to satisfy an omega equation with forcing determined from the relative advection of interior PV and boundary temperature. The analysis carries through in the presence of diabatic heating provided the omega equation forcing is based on the interior PV and boundary thermal tendencies, including the heating effect. The analysis is shown to be possible also at the level of the semi‐geostrophic approximation.The analysis technique is applied to a number of idealized problems that can be considered to be building blocks for midlatitude synoptic‐scale dynamics. They focus on the influences of interior PV, boundary temperature, an interior boundary, baroclinic instability associated with two boundaries, and also diabatic heating. In each case, insights yielded by the new perspective are sought into the dynamical behaviour, especially that related to vertical motion. Copyright © 2003 Royal Meteorological Society
The global distribution of ice‐supersaturated regions as seen by the Microwave Limb Sounder
Authors: Spichtinger Peter , Gierens Klaus , Read William 
Published: December 2003

AbstractCloud‐screened microwave limb‐sounder data of relative humidity with respect to ice have been used to produce maps of the global distribution of ice‐supersaturated regions (ISSRs) at pressure levels 147 and 215 hPa. Geographical regions where ISSRs occur most frequently (in a relative sense) are the tropics at both pressure levels, the midlatitude storm belts at 215 hPa (in the respective hemispheric summer and autumn seasons) and Antarctica in southern winter and spring (at both pressure levels). Additionally, temperatures and absolute humidities were compared in supersaturated and subsaturated air masses. Consistent with earlier results based on data from the Measurement of Ozone by Airbus in‐service Aircraft, it is found that ISSRs are generally colder and moister than their subsaturated counterparts. Temperature and humidity contrasts between supersaturated and subsaturated air masses vary considerably, both geographically and between the troposphere and the lowermost stratosphere. Copyright © 2003 Royal Meteorological Society