bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accurate extrapolation to zero cell size by Padé approximation
Authors: Ingelström Pär , Lindholm Love , Rylander Thomas 
Published: April 2003

AbstractIt is shown that extrapolation to zero cell size can be made accurately by means of Padé approximation. The extrapolation procedure is tested on waveguide cavity filters analysed by the finite difference‐time domain (FDTD) scheme. Extrapolation by the traditional Taylor series can yield unphysical results in the vicinity of resonances where it is outperformed by extrapolation based on the Padé approximation. Direct computation with the FDTD scheme (without extrapolation) requires extreme and infeasible resolutions to achieve a reasonable accuracy close to resonances. Copyright © 2003 John Wiley & Sons, Ltd.
On the Laplace operator and on the vector potential problems in the half‐space: an approach using weighted spaces
Authors: Boulmezaoud Tahar Zamène 
Published: April 2003

AbstractThe purpose of the present paper is twofold. The first object is to study the Laplace equation with inhomogeneous Dirichlet and Neumann boundary conditions in the half‐space of ℝN. The behaviour of solutions at infinity is described by means of a family of weighted Sobolev spaces. A class of existence, uniqueness and regularity results are obtained. The second purpose is to investigate some properties of grad, div and curl operators in order to treat curl–div systems of the formcurl w = u, div w = 0and problems related to vector potentials and Helmholtz decomposition.Copyright © 2003 John Wiley & Sons, Ltd.
Global behaviour of 1‐D viscous compressible barotropic flows with free boundary and self‐gravitation
Authors: Zlotnik Alexander 
Published: April 2003

AbstractWe consider an initial–boundary value problem for a system of quasilinear equations for one‐dimensional flows of a viscous compressible barotropic fluid with large data. An outer pressure (possibly zero) is prescribed on one of the boundaries; also a self‐gravitation is taken into account. The case of the stationary pressure with possible degeneration is studied. For a general non‐monotone state function, either global estimates for the solution and its stabilization are proved or the growth of the fluid volume is bounded from below as t → ∞. For the power state function, in addition, stabilization rate estimates (of the power type) are given. The study is accomplished in the Lagrangian mass co‐ordinates. Copyright © 2003 John Wiley & Sons, Ltd.
Anionic living polymerization of tert‐Aminostyrenes and application of the polymers
Authors: Se Kazunori 
Published: April 2003

AbstractAnionic living polymerization of tertiary aminostyrenes (tAS) that serve as chemical links between two polymers are studied and the applications of the polymers to reversible recording materials are summarized in this paper. For preparing well‐defined polymers that have desired molecular weights and narrow molecular weight distributions by anionic living mechanism, three conditions are satisfied and the corresponding five experimental proofs are discussed using tAS as an example. The three poly(tertiary aminostyrene)s (PtAS) were prepared. The degree of quaternization of PtAS with n‐butyl bromide could be controlled from 0 to 100%. The amino groups of PtAS were quaternized by p, p′‐bis(chloromethyl)azobenzene (CAB) to prepare the cross‐linked film and the network concentration was characterized by an equilibrium‐swelling test. Photochemical isomerization of CAB incorporated in PtAS was investigated in order to prepare the reversible recording materials. Copyright © 2003 John Wiley & Sons, Ltd.
The biodegradation of poly(3‐hydroxy‐butyrate‐co‐3‐hydroxyvalerate) (PHB/V) and PHB/V‐degrading microorganisms in soil
Authors: Song Cunjiang , Wang Shufang , Ono Shin , Zhang Banghua , Shimasaki Choichiro , Inoue Masami 
Published: April 2003

AbstractTo assess the polyhydroxyalkanoate (PHA)‐biodegrading capacity of soil, numbers of aerobic poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHB/V)‐degrading microorganisms (degraders) were estimated by the film‐MPN method. The numbers of PHB/V degraders were estimated to be 4.3 × 105 per gram of dry garden soil, 5.06 × 105 per gram of dry paddy‐field soil, and 3.87 × 105 per gram of dry river‐bank soil. The degradations of PHB/V in suspensions of the three kinds of soil were investigated. It was found that the PHB/V‐biodegrading capacity of the soil increased as the number of PHB/V degraders in the soil increased. The relationship between weight loss of PHB/V and proliferation rate of PHB/V degraders in garden soil suspension was investigated. The effect of glucose on the biodegradation of PHB/V in garden soil was also studied. The weight loss after one week in garden soil suspension supplemented with 20 mM of glucose (GSS‐20G) was 2.60%, which was lower than that in garden soil suspension (GSS) (7.14%). After five weeks, the weight loss had increased to 24.97% in GSS‐20G but only to 18.26% in GSS. The results showed that glucose played important roles in inhibition and acceleration of different biodegrading phases and finally accelerated the PHB/V biodegradation in soil suspension. Copyright © 2003 John Wiley & Sons, Ltd.
Preparation of IPN‐type stimuli‐Responsive heavy‐Metal‐Ion adsorbent gel
Authors: Yamashita Keiji , Nishimura Takashi , Nango Mamoru 
Published: April 2003

AbstractWe apply the interpenetration network (IPN) gel of poly(N‐isopropylacrylamide) (PNIPAm) and poly(sodium acrylate) (PNaAAc) to the stimuli‐responsive heavy‐metal‐ion adsorbent system. In the IPN gel system, PNIPAm and PNaAAc units are expected to behave independently. Therefore, the IPN gel of PNIPAm exhibits a thermosensitive volume–phase transition behavior in spite of the presence of polyelectrolytes like PNaAAc that are well known to prevent PNIPAm from shrinking when above their lower critical solution temperature (LCST). NIPAm‐co‐NaAAc copolymer gel (copoly gel) absorbed water and adsorbed Cu(II) ions sufficiently but did not exhibit the volume–phase transition behavior at all in the Cu(II) ion adsorption‐condition. On the other hand, the IPN gel consisting of PNIPAm and PNaAAc exhibited the volume–phase transition behavior in the adsorbtion‐condition. That is, the IPN gel adsorbed Cu(II) ion sufficiently below its LCST but not above the LCST. We could thermally control the adsorption abilities for heavy‐metal ions by using the IPN gel system. The swelling IPN gel, which adsorbed Cu(II) ions, suddenly shrank when the temperature rose above the LCST. The IPN gel released water but did not release heavy‐metal ions when shrinking. We are planning to construct an easy‐recovery system for heavy‐metal ions from wastewater by using this stimuli‐responsive IPN gel. That is, we quickly adsorb the heavy metal ions from wastewater by using our swelling IPN gel below the LCST, and then squeeze the swelling IPN gel, which has bound the heavy metal ions, by raising the temperature above the LCST in order to facilitate ion handling. Finally, we can remove the heavy metal ions by means of acidic‐treatment of the IPN gel and recycle the IPN gel‐adsorbent. Copyright © 2003 John Wiley & Sons, Ltd.
Ionic conducting polymer encapsulated graphite as the anode material for lithium ion batteries
Authors: Pan Qinmin , Wang Lingzhi , Fang Shibi 
Published: April 2003

AbstractA novel surface modification approach involving the application of radiation technology to the development of graphite anode of lithium ion batteries. Ionic conductive poly(stylene sulfonic acid) lithium salt (PSSALi) was microencapsulated on the surface of graphite particles by means of radiation‐initiated polymerization. Results showed that the cointercalation of solvated Li+ in a propylene carbonate (PC) based electrolyte was depressed successfully and the initial coulombic efficiency was enhanced after encapsulation. The high stability of the surface structure of encapsulated graphite during the initial intercalation process was observed by in situ Raman spectroscopy. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of comb graft copolymersI–Ring‐opening metathesis polymerization of norbornyl‐polymethacrylate by a supported ruthenium carbene complex generated in situ
Authors: Li Hong , Zhang Wenfang , Wang Yuqin , Binglin He 
Published: April 2003

AbstractThe Diels–Alder reaction of cyclopentadiene (CPD) and allyl chloride (AC) was carried out by using BF3·Et2O or its supported counterpart on tailor‐made polystyrene supports as catalysts. The activity of the latter is double that of the former, and the yield of the product 5‐chloromethyl‐2‐norbornene (NBCH2Cl) reached up to 67.4%. Then, via living anionic polymerization, a cycloolefinyl macromonomer, 5‐PMMA‐2‐norbornene (NB‐PMMA), was synthesized using NBCH2Li as the initiator which in turn was prepared by a lithiation reaction of NBCH2Cl in THF. Comb‐shaped graft copolymer PNB‐g‐PMMA was finally synthesized via ring‐opening metathesis polymerization (ROMP) of the synthesized macromonomer NB‐PMMA under the catalysis of a polymer‐supported ruthenium carbene complex generated in situ. The polymer‐supported carbene species shows much better initiation behavior than its unsupported counterpart. In both cases, that is in the Diels–Alder reaction and ROMP, the effect mechanism of the tailored supports of the catalysts is discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Influence of core–Shell structured particles on the impact resistance of poly(vinyl chloride)
Authors: Guo Tian‐Ying , Tang Guang‐Liang , Hao Guang‐Jie , Wang Shu‐Fang , Song Moud‐Dao , Zhang Bang‐Hua 
Published: April 2003

AbstractThe core–shell structured particles which comprise rubbery and glassy layers were prepared by emulsifier‐free emulsion polymerization of poly(n‐butyl acrylate/methyl methacrylate)/poly(methyl methacrylate/n‐butyl acrylate) [P(BA/MMA)/P(MMA/BA)]. The core–shell structured particle toughened PVC blends were investigated in detail. Impact strength, elongation at break and the related mechanical properties were measured for further evaluation of the toughening efficiency. Copyright © 2003 John Wiley & Sons, Ltd.
Morphology and levonorgestrel release behavior of polycaprolactone/ poly(ethylene oxide)/Polylactide tri‐component copolymeric microspheres
Authors: Li Guangming , Cai Qing , Bei Jianzhong , Wang Shenguo 
Published: April 2003

AbstractA novel polycaprolactone/poly(ethylene oxide)/polylactide (PCEL) tri‐component copolymer was synthesized and used for the investigation of lipid‐soluble drug levonorgestrel (LNG), in vitro release from drug‐loaded microspheres. The hydrophilicity of the PCEL strongly depended on the content of the poly(ethylene oxide) (PEO) segment. LNG‐loaded biodegradable polylactide (PLA) and PCEL microspheres have been successfully prepared by using an oil‐in‐water emulsion and solvent‐evaporation method. The effect of various factors such as chemical composition and molecular weight on the morphology of the microspheres produced has been investigated. The influence of chemical composition and hydrophilicity on the drug‐loading efficiency has also been investigated. The release behaviors of LNG in vitro from the PLA and PCEL microspheres were determined. The drug‐loading efficiency and LNG‐release behavior closely depended on the chemical composition and morphology of the polymeric microspheres. With the addition of a PEO segment in the copolymer chains, the structure of the microspheres became porous which would lower the drug‐loading efficiency and speed up the drug‐release rate. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis, characterization and properties of azobenzene side‐chain polythiophene
Authors: Gan Leong Huat , Xia Xulin , Chan Chee Yun , Hu Xiao , Zhao Xiongyan 
Published: April 2003

AbstractThiophene monomers with an azobenzene moiety of different spacer length at the 3‐position of the thiophene ring were synthesized. The monomers were polymerized and copolymerized with 3‐hexyl thiophene to investigate the influence of an azobenzene side‐chain on the properties of polythiophene, which has been widely used as a conducting polymer and has also been found many other applications. The polymers were characterized with UV‐vis, FT‐IR spectrophotometry, gel permeation chromatographic (GPC) analysis, DSC, TGA, elemental analysis and X‐ray diffractometry. The polymers showed novel thermochromic and photoresponsive properties in polymer solutions and solid films. It was found that an azobenzene side‐chain could bring about substantial thermochromic and photochromic changes to the polythiophene backbone as compared with non‐azobenzene side‐chain polythiophenes. These property changes could be triggered or controlled by light or heat on the basis of azobenzene trans–cis or cis–trans isomerization. Copyright © 2003 John Wiley & Sons, Ltd.
Hydrogenation of carboxylic acids catalyzed by magnesia‐supported poly‐γ‐aminopropylsiloxane–Ru complex
Authors: Mao Bao‐Wei , Cai Zhong‐Zhan , Huang Mei‐Yu , Jiang Ying‐Yan 
Published: April 2003

AbstractMagnesia‐supported poly‐γ‐aminopropylsiloxane–ruthenium complex catalysts (MgO‐NH2‐Ru) have been prepared by a very simple method and have been found to be capable of catalyzing the hydrogenation of some simple carboxylic acids, such as acetic acid, propionic acid, lactic acid and isobutyric acid to give ethanol, propanol, 1,2‐propanediol and isobutyl alcohol in 100% yields respectively in the presence of water at 240 °C and under 5.0 × 106 Pa H2 for 18 h. The catalyst was very stable and could be used repeatedly without any noticeable changes in its catalytic activity. Copyright © 2003 John Wiley & Sons, Ltd.
Intra‐ and intermolecular charge‐transfer phenomena in a triphenylamine‐containing anthrylenevinylene‐based copolymer and its model compound
Authors: Zheng Min , Bai Fenglian , Zhu Daoben 
Published: April 2003

AbstractOptical properties of a triphenylamine‐containing anthrylenevinylene‐based copolymer and its model compound were evaluated using absorption and steady‐state fluorescence spectroscopy. The polymer and model compound show a strong solvatochromic shift as a function of solvent polarity, indicating the emission of an additional charge‐transfer species. More direct and convincing evidences of the charge transfer, such as temperature and concentration‐dependent emission, are presented. Low temperature (77 K) fluorescence also confirmed the existence of charge transfer. Additionally, a twisted intramolecular charge transfer state was observed in the model compound when excited by higher energy, which could not be observed in the polymer whatever the excitation was. The results indicate that there are more charge transfer states including intramolecular, intermolecular and interchain charge transfer states in polymers than in the model compound. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis, characterization and Cis–Trans photoisomerization of a series of hyperbranched conjugated polymers
Authors: He Qingguo , Yang Junlin , Lin Hongzhen , Zhang Lin , Song Yan , Bai Fenglian 
Published: April 2003

AbstractA series of hyperbranched polyphenylene vinylenes (HPVs) with different alkoxy substituted end groups were synthesized and characterized. The photoluminescence properties were investigated, and the cis–trans isomerization was found by prolonging the exposure time to UV light for the HPVs. The viscosity and end‐group effects on the photoisomerization were studied. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis and photophysical properties of alternating copolymers containing triphenylamine moieties
Authors: Huang Hongmin , He Qingguo , Song Yan , Lin Hongzhen , Yang Junlin , Bai Fenglian 
Published: April 2003

AbstractTwo alternating copolymers containing triphenylamine and biphenyl or fluorene, poly[triphenylamine‐alt‐biphenylene vinylene] (TPA‐PBPV) and poly[triphenylamine‐alt‐2,7‐fluorenenylene vinylene] (TPA‐FLV) were synthesized by means of the Wittig reaction. Both the polymers show good solubility in common organic solvents and excellent film‐forming ability. Thermogravimetric analysis investigation demonstrates that the polymers have high thermal stability, the degradation temperature of TPA‐FLV is as high as 499.0 °C. Differential scanning calorimetry results indicate that the glass transition temperature of poly TPA‐FLV is higher than 200 °C, much higher than that of PBPV‐TPA, which might be a merit for the long‐life operation of light‐emitting devices. The photophysical properties of the polymers were investigated in both CH2Cl2 solution and spin‐coated film, photoluminescence efficiencies are also determined, PFV‐TPA has a higher efficiency, which may make it a more promising candidate for light‐emitting materials. Copyright © 2003 John Wiley & Sons, Ltd.
Tubular poly(ortho‐toluidine) synthesized by a template‐free method
Authors: Wan Meixiang , Li Junchao 
Published: April 2003

AbstractMicrotubules of poly(ortho‐toluidine) (POT), with 0.8–6.0 µm diameter and 10−4–10−2 S/cm room‐temperature conductivity, were synthesized by a template‐free method in the presence of β‐naphthalene sulfonic acid (β‐NSA) as a dopant. It was found that the completeness, size, room‐temperature conductivity and crystallinity of the resulting POT‐NSA microtubules depended upon the concentration of the NSA dopant. UV‐vis. spectra, XPS and X‐ray diffraction were used to characterize the molecular structure, showing that the polymer chain of POT‐NSA microtubules is identical to that of the doped POT synthesized by a common method, but that its crystallinity is higher than that of common POT. It was proposed that the monomer salt formed with NSA played a template‐like role in forming POT‐NSA microtubules. Copyright © 2003 John Wiley & Sons, Ltd.
Self‐assembled hyperbranched poly(para‐Phenylene vinylene) monolayers: fabrication and characterization
Authors: Wang Wenlong , He Qingguo , Zhai Jin , Yang Junlin , Bai Fenglian 
Published: April 2003

AbstractCovalently‐bound self‐assembled monolayer of a kind of functional hyperbranched polymer, pyridine‐capped hyperbranched poly(para‐phenylene vinylene) (Py‐HPV), was prepared on hydrophilic quartz or single‐crystal silicon substrates using siloxane self‐assembly techniques. The assembling procedure was characterized by contact angle measurement, X‐ray photoelectron spectroscopy (XPS), UV‐vis spectra and fluorescence spectroscopy. Atomic force microscopy (AFM) was also used to investigate the surface morphology and microstructure of the resulting Py‐HPV self‐assembled monolayer. Copyright © 2003 John Wiley & Sons, Ltd.
Peroxidation of benzaldehyde catalyzed by cobalt(II)‐chelated copolymer
Authors: Wang Cheng‐Chien , Chen Hui‐Chun , Bin Hsueh‐Huai , Chen Chuh‐Yung 
Published: April 2003

AbstractA cobalt(II)‐chelated copolymer was prepared through copolymerization of styrene, acrylonitrile (AN), and divinyl benzene with glycidyl methacrylate (GMA)‐iminodiacetic acid (IDA) chelating monomers. Based on the experimental results of FTIR and EA, iminodiacetic acid was grafted on to the side chain of copolymer support. IDA contained in these copolymers was 22.67 wt%. BET was employed to measure the 0.7136 m2/g surface area, which provided the reaction sites for the reactants and active groups of the polymeric support. Additionally, the peroxidation of benzaldhyde with cobalt(II)‐chelated copolymer was investigated. After 3 h, the perbenzoic acid yield increased to 82%. As well, the high yield and perbenzoic acid selectivity were 68.9% and 69%, respectively. More cobalt(II)‐chelated copolymer used to catalyse peroxidation of benzaldehyde, the reaction rate was higher but the selectivity was decreased slightly in high conversion. Lower reaction temperature could moderate the characteristics of peroxidation for high conversion combined with low selectivity of perbenzoic acid. The perbenzoic acid content would decrease slightly owing to the presence of highly hydrophilic cobalt(II)‐chelated copolymer, prepared when the oxidation reaction reached high conversion. Furthermore, the perbenzoic acid product was stable and not decomposed by this cobalt(II)‐chelated copolymer. A moderate amount of water had a co‐activing effect on the cobalt(II)‐chelated copolymer. Copyright © 2003 John Wiley & Sons, Ltd.
Hydrogenation of nitrobenzene, cyclohexanone and octene catalyzed by silica‐supported starch‐L‐Glutamic acid–Fe complex
Authors: Liu Hong‐Wen , Huang Kai , Mi Ji‐Dong , Jia Yi , Huang Mei‐Yu , Jiang Ying‐Yan 
Published: April 2003

AbstractA new polymer‐base metal complex, silica‐supported starch‐L‐glutamic acid–Fe complex (SiO2‐ST‐Glu‐Fe) has been prepared by a simple method. Starch was reacted with L‐glutamic acid in the presence of silica to give a ligand SiO2‐ST‐Glu, then this was reacted with FeCl3·6H2O to form the Fe complex (SiO2‐ST‐Glu‐Fe). The complex has been found to be able to catalyze the hydrogenation of nitrobenzene to give aniline in 100% yield, cyclohexanone to give cyclohexanol in 93% yield and octene to give octane in 84% yield at 45 °C and under atmospheric pressure. Experimental data show that the catalyst was very stable and could be reused without any noticeable change in its catalytic activity. Copyright © 2003 John Wiley & Sons, Ltd.
Friedel‐Crafts acylation of benzene derivatives catalyzed by silica and alumina‐supported polytrifluoromethanesulfosiloxane
Authors: Zhou Da‐Qing , Zhang Yan‐Hong , Huang Mei‐Yu , Jiang Ying‐Yan 
Published: April 2003

AbstractInorganic polymer, silica and alumina‐supported polytrifluoromethanesulfosiloxane solid superacids (abbreviated as SiO2‐Si‐SCF3 and Al2O3‐Si‐SCF3), have been prepared. The acid strength of superacids is higher than that of 100% H2SO4. It was found that SiO2‐Si‐SCF3 and Al2O3‐Si‐SCF3 could catalyze Friedel–Crafts acylation of benzene and benzene derivatives with aroyl chlorides under relatively mild conditions. The yield could amount to 97.6% and 92.1% respectively. The yield and the isomer distribution of corresponding ketones were influenced by reaction temperature and reaction time. The catalysts have considerably high stability and can be reused repeatedly without any large changes in their catalytic activity. The reactions are very clean, with HCl as the only by‐product escaping during the reaction. Copyright © 2003 John Wiley & Sons, Ltd.
Design, synthesis and characterization of semi‐conducting interpenetrating polymer network (IPN) of pyridine and poly(antimony acrylate)
Authors: Kamal Meet , Srivastava A K 
Published: April 2003

AbstractA new series of semi‐conducting interpenetrating polymer networks (IPNs) based on pyridine and poly(antimony acrylate) were synthesized. Structural evidence for IPNs come from the infrared spectra indicating characteristic frequencies of (>C = O) of poly(antimony acrylate) at 1680 cm−1. Properties such as percentage swelling, average molecular weight between crosslinks (Mc) and Young's modulus are direct functions of the concentration of linear polymer and initiator (benzoyl peroxide), whereas inverse relationships with concentration of monomer (pyridine) and crosslinker (divinyl benzene) are observed. The presence of antimony in the IPNs is determined by SEM and elementac analysis. The DSC curve shows two glass transition temperatures (Tg), at 110 and 150 °C. The IPNs formed with a low content of pyridine exhibited processability, mechanical properties and conductivity.© 2003 Society of Chemical Industry