bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of large porous poly(HEMA‐co‐EDMA) microspheres with narrow size distribution by modified membrane emulsification method
Authors: Qu Huanhuan , Gong Fangling , Ma Guanghui , Su Zhiguo 
Published: April 2007

AbstractPorous poly(2‐hydroxyethyl methacrylate‐co‐ethylene dimethacrylate) [p(HEMA‐co‐EDMA)] microspheres have important applications in chromatography. In this study, p(HEMA‐co‐EDMA) microspheres with controllable size were successfully prepared by modified membrane emulsification technique. The CV value of the obtained microspheres was as low as 14.4%. An oil phase mainly composed of toluene was permeated through a membrane with uniform pores into an aqueous phase to form fairly uniform seed emulsion. The secondary emulsion composed of HEMA and EDMA was prepared by a homogenizer. Then, the two emulsions were mixed together. HEMA and EDMA diffused into the aqueous phase, and then were absorbed by the seed droplets. The swollen droplets were further polymerized to prepare monodisperse porous microspheres. It was found that HEMA/EDMA ratio and toluene/monomer ratio showed a significant influence on swelling degree, diameter, and morphology of the obtained microspheres. The swelling degree of the microspheres increased with the increase of toluene/monomer ratio, whereas the average diameter increased with decrease of the ratio. Microspheres with controllable size (28–73 μm) and porosity were obtained, by varying HEMA/EDMA ratios and toluene/monomer ratios. It can be expected that the p(HEMA‐co‐EDMA) microspheres with controllable size and porosity will provide many advantages in their applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Mechanism of curing process for polycarbosilane fiber with cyclohexene vapor
Authors: Mao X. H. , Song Y. C. , Li W. , Yang D. X. 
Published: April 2007

AbstractThe reaction process of polycarbosilane (PCS) fiber cured by cyclohexene vapor has been studied and compared with that of PCS fiber cured by air. The influence of curing temperature on SiH bond reaction degree and gel content, the structure and composition of PCS were investigated by FTIR, EA, TGA, NMR, and GC‐MS. The results showed that, SiH bond in the molecular structure of PCS reacted during cyclohexene curing process and the reaction degree increased when the curing temperature increases. Simultaneously, gel content of PCS fiber rapidly increased till PCS fiber became infusible. SiH radical and SiCH2 radicals formed SiCH2Si crosslinking of PCS molecules through the agency of cyclohexene. Some cyclohexyls linked to principal chain of PCS, which was proven by 13C‐CPMAS‐NMR, and broke off, and cyclohexane and some monosilane are generated as byproducts when temperature increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Foams based on low density polyethylene/hectorite nanocomposites: Thermal stability and thermo‐mechanical properties
Authors: Velasco J. I. , Antunes M. , Ayyad O. , Saiz‐Arroyo C. , Rodríguez‐Pérez M. A. , Hidalgo F. , de Saja J. A. 
Published: April 2007

AbstractNovel polymer nanocomposite foams made by a two step compression molding method are analyzed in this article. Nanocomposites of low density polyethylene and an organo‐modified hectorite were first melt compounded and then foamed using a compression molding method. To study the influence of the presence and the amount of hectorite in both mechanical and thermal properties, samples with 3% and 7% content of hectorite were prepared. Polyethylene crystalline characteristics and thermal stability of the samples were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Mechanical properties of foams and solid nanocomposites were analyzed by using dynamical mechanical analysis (DMA). Thermal expansion of the samples was analyzed by thermomechanical analysis. The results indicate that the exfoliation of hectorite platelets was achieved after the foaming process, but not during the melt mixing step. Foams with hectorite nanoparticles exhibit improved thermal stability and mechanical properties when compared with neat polymeric foams. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Development, optimization, and characterization of electrospun poly(lactic acid) nanofibers containing multi‐walled carbon nanotubes
Authors: McCullen Seth D. , Stano Kelly L. , Stevens Derrick R. , Roberts Wesley A. , Monteiro‐Riviere Nancy A. , Clarke Laura I. , Gorga Russell E. 
Published: April 2007

AbstractElectrospinning of poly (L‐D‐lactic acid) (PLA) was investigated with the addition of multi‐walled carbon nanotubes (MWNT) for development of a scaffold for tissue engineering. Through this experiment, it was determined that the optimal concentration of PLA with weight average molecular weight (Mw) 250,000 g/mol is ∼20 wt % as indicated by scanning electron microscopy. This concentration produces fibers with no beading or film formation. The preferred solvent system is a combination of chloroform and dimethyl formamide to alleviate the volatile action of chloroform. The optimum processing parameters for PLA are an electric field of 1 kV/cm which was determined by a surface response plot to minimize fiber diameter based on the applied voltage, working distance, and addition of MWNT. Fourier Transform infrared spectroscopy has indicated the removal of the solvent system. With the addition of MWNT, the fiber diameter was drastically reduced by 70% to form fibers with a mean diameter of 700 nm. This is believed to be due to an increased surface charge density for the MWNT/polymer solution. Transmission electron microscopy validated the alignment of the MWNT within the fibers. MWNT loading exhibited an increase in the conductance of the scaffold and the tensile modulus at an optimal loading level of 0.25 wt %. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Supramolecular inclusion complexes of biodegradable cholesteryl‐(ϵ‐caprolactone)n functionalized polymer with α‐cyclodextrin
Authors: Guo Jinbao , Sun Jie , Zhu Siquan , Cao Hui , Zhao Dongyu , Wang Liping , Yang Huai 
Published: April 2007

AbstractThe biodegradable cholesteryl‐(ϵ‐caprolactone)10 (Chol‐(CL)10) functionalized polymer was synthesized and then investigated for inclusion complexation with α‐cyclodextrin (α‐CD). The supramolecular inclusion complexes (ICs) were in detail characterized by fourier transform infrared (FTIR), 1H‐nuclear magnetic resonance, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X‐ray diffraction (WAXD), and 13C‐NMR, respectively. All analyses indicated that oligo(ϵ‐caprolactone)10 chains of the Chol‐(CL)10 were included into the hydrophobic α‐CD cavities and their original crystalline properties were completely suppressed. Moreover, the ICs of biodegradable Chol‐(CL)10 functionalized polymer with α‐CD had a channel‐type crystalline structure similar to that formed between the poly(ϵ‐caprolactone) and α‐CD. Further more, The TGA analysis revealed that the ICs had better thermal stability than their free components due to the inclusion complexation, suggesting that the complexation stabilized the polymer included in the CD chan‐nels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Characterization of metallized biaxially oriented polypropylene film
Authors: Vassiliadi E. , Tarantili P. A. 
Published: April 2007

AbstractThe effect of corona unit energy applied for retreatment of metallized biaxially oriented polypropylene film surfaces before the lamination process was studied using optical, scanning electron, and atomic force microscopies. Increased surface roughness and polarity due to oxygen groups were detected, and these changes became more evident with the increase of corona treatment intensity. The number and size of spots on the surface, possibly deriving from processing aids incorporated as additives into the polymer, increase with corona treatment. The response of specimens in accelerated aging was also studied for evaluation of the outdoor stability of these composite structures. Specimens were exposed to the combined action of UV‐radiation, humidity, and heat, and the stability of yellow, orange‐yellow, orange, green, and bordeaux colors was determined as a function of the exposure time. Minor color changes were recorded for exposure up to 100 h, which became more significant for longer exposure intervals depending on the type of color. Finally, a 40% decrease in tensile strength was observed after 216 h of ageing, accompanied with a decrease of 15% of modulus and an increase of 160% in the elongation at break, possibly because of the plasticizing effect taking place during the ageing process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of steady shear on the microstructural evolution of melt‐intercalated polymer/clay nanocomposites
Authors: Wu Defeng , Zhou Chixing , Zhang Ming 
Published: April 2007

AbstractA sheet sample composed of poly(butylene terephthalate) and clay prepared by solid‐state compression was melt‐annealed in a rheometer under steady shear flow to investigate the whole hybridization process. The results of the offline morphology and thermogravimetric analysis as well as Fourier transform infrared characterization show that shear flow can reduce the dynamic process of hybridization, facilitating the formation of an intercalated nanoscale structure. With an increase in the shear intensity, the detachment level of clay increases more remarkably than the swollen degree. However, an increase in the shear intensity does not induce an exfoliated structure but can decrease the average thickness of the clay tactoids, leading to a remarkable enhancement in the thermal stability due to the increase in the effective filling volume of the clay. Furthermore, those intercalated nanocomposites annealed at a high shear rate still present a distinct hierarchical structure, which suggests that steady shear is not as good as dynamic or complex shear for promoting hybridization effectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Information and higher things in life: Addressing the pleasurable and the profound in information science
Authors: Kari Jarkko , Hartel Jenna 
Published: April 2007

AbstractThe article discusses lower and higher contexts for information phenomena, and argues that there is clearly a need for a more concerted research effort in the latter sphere. The discipline of information science has traditionally favored lower contexts—like everyday life and problem solving—that are neutral or even negative by nature. In contrast, the neglected higher things in life are pleasurable or profound phenomena, experiences, or activities that transcend the daily grind. A literature sample of the scarce information research related to higher things indicates that beyond the spotlight of mainstream research, information processes often seem different and there may be significant dimensions of information phenomena that have been overlooked. Therefore, the article outlines a contextual research area in information studies to address higher things from the perspective of information. It is concluded that optimal functioning requires bringing the lower and higher sides to balance in information science. This would offer a rare chance to promote holism and interdisciplinarity in the field, and to make the discipline more relevant to the human being.
Using lessons from health care to protect the privacy of library users: Guidelines for the de‐identification of library data based on HIPAA
Authors: Nicholson Scott , Smith Catherine Arnott 
Published: April 2007

AbstractAlthough libraries have employed policies to protect the data about use of their services, these policies are rarely specific or standardized. Since 1996, the U.S. health care system has been grappling with the Health Insurance Portability and Accountability Act (HIPAA; Health Insurance Portability and Accountability Act, 1996), which is designed to provide those handling personal health information with standardized, definitive instructions as to the protection of data. In this work, the authors briefly discuss the present situation of privacy policies about library use data, outline the HIPAA guidelines to understand parallels between the two, and finally propose methods to create a de‐identified library data warehouse based on HIPAA for the protection of user privacy.
Unexpected Thermally Stable, Cholesteric Liquid‐Crystalline Helical Polyisocyanides with Memory of Macromolecular Helicity
Authors: Hase Yoko , Mitsutsuji Yuuki , Ishikawa Masayoshi , Maeda Katsuhiro , Okoshi Kento , Yashima Eiji 
Published: April 2007

AbstractThe achiral sodium salt of poly(4‐carboxyphenyl isocyanide) (poly‐1–Na) folds into a one‐handed helix induced by optically active amines in water. The induced helicity remains when the optically active amines are completely removed, and further modification of the side groups to amide residues is possible without loss of memory of macromolecular helicity. Although the helical poly‐1–Na loses its chiral memory at high temperature, helical polyisocyanides modified with achiral primary amines, which no longer have any chiral components, keep their memory perfectly even at 100 °C in N,N‐dimethylformamide in some cases and exhibit cholesteric liquid‐crystalline phases, thus providing a robust scaffold with heat resistance to which a variety of functional groups can be introduced.
Modelling financial time series with threshold nonlinearity in returns and trading volume
Authors: So Mike K. P. , Chen Cathy W. S. , Chiang Thomas C. , Lin Doris S. Y. 
Published: April 2007

AbstractThis paper investigates the effect of past returns and trading volumes on the temporal behaviour of international market returns. We propose a class of nonlinear threshold time‐series models with generalized autoregressive conditional heteroscedastic disturbances. Using Bayesian approach, an implementation of Markov chain Monte Carlo procedure is used to obtain estimates of unknown parameters. The proposed family of models incorporates changes in log of volumes in the sense of
regime changes and asymmetric effects on the volatility functions. The results show that when differences of log volumes are involved in the system of log return and volatility models, an optimum selection can be achieved. In all the five markets considered, both mean and variance equations involve volumes in the best models selected. Our best models produce higher posterior‐odds ratios than that in Gerlach et al.'s (Phys. A Statist. Mech. Appl. 2006; 360:422–444) models, indicating that our return–volume partition of regimes can offer extra gain in explaining return‐volatility term structure. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and Characterization of Monodisperse Oligo(fluorene‐co‐bithiophene)s
Authors: Zhang Xiaojie , Qu Yao , Bu Laju , Tian Hongkun , Zhang Jingping , Wang Lixiang , Geng Yanhou , Wang Fosong 
Published: April 2007

AbstractA series of monodisperse oligo(9,9‐di‐n‐octylfluorene‐co‐bithiophene)s (OFbTs) with molecular lengths of up to 19.5 nm and molecular weights up to 7025 g mol−1 has been synthesized by a divergent/convergent approach involving Stille coupling reactions. Stille coupling is quite efficient in preparing this class of oligomers, and even the molecule with nine fluorene units and eight bithiophene units (F9Th16) can be synthesized in a yield as high as 70 %. Because of easy functionalization of the thiophene ring at its α position, no additional protecting group allowing activation for further reaction is necessary. However, the synthetic routes must be optimized to eliminate contamination of the targeting compounds with the homocoupling product of the organotin reagents. Synthesis of the longest oligomer F13Th24 in a relative large quantity is limited by its low yield due to the pronounced ligand‐exchange side reactions of the starting materials and reaction intermediates. All oligomers longer than F4Th6 are nematic mesomorphs and exhibit enhanced glass transition temperature and clearing point with increasing molecular length, as revealed by differential scanning calorimetry and polarizing optical microscopy. Absorption and photoluminescence (PL) measurements reveal that OFbTs are well‐conjugated systems with an effective conjugation length longer than the length of F13Th24.
Desymmetrisation of a Centrosymmetric Molecule by Carbon–Carbon Bond Formation: Asymmetric Aldol Reactions of a Centrosymmetric Dialdehyde
Authors: Dodd Karen , Morton Daniel , Worden Stephen , Narquizian Robert , Nelson Adam 
Published: April 2007

AbstractThe desymmetrisation of centrosymmetric molecules by enantioselective carbon–carbon bond formation has been reported for the first time. A bimetallic zinc catalyst developed by Trost was exploited in the desymmetrisation of a centrosymmetric dialdehyde. The approach was successful with a range of ketone nucleophiles and was uniformly highly diastereoselective (>98:<2). The yield and the enantioselectivity of the reaction varied as a function of the ketone used, and the desymmetrised products were obtained in up to 74 % yield and 97 % ee (ee=enantiomeric excess). The desymmetrisation of centrosymmetric molecules by enantioselective carbon–carbon bond formation is an efficient and convergent synthetic approach which is likely to find wide application in synthesis, particularly in the total synthesis of natural products with embedded centrosymmetric fragments.
Crystal Structure of the Ln2PbSe4 (Ln: Er and Yb) Compounds.
Authors: Gulay L. D. , Daszkiewicz M. , Stepien‐Damm J. , Pietraszko A. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Ln(Au≈0.75Sb≈ 0.25)2 (Ln: La, Ce, Pr) with UHg2 Structure Type, New Members of the AlB2 Family.
Authors: Salamakha L. P. , Sologub O. L. , Goncalves A. P. , Mudryi S. I. , Almeida M. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Structures of the Ln4In4.72Se13 (Ln: La and Ce) Compounds.
Authors: Gulay L. D. , Huch M. R. , Olekseyuk I. D. , Pietraszko A. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structure and Dielectric Characterization of a New A‐Site Deficient La5/3MgTaO6 Perovskite.
Authors: Khalyavin D. D. , Senos A. M. R. , Mantas P. Q. , Argyriou D. N. , Tarroso Gomes I. , Vieira L. G. , Ribeiro J. L. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Tb2Ni2Mg3: A New Structure Type Derived from the Ru3Al2B2 Type.
Authors: Solokha Pavlo , De Negri Serena , Saccone Adriana , Pavlyuk Volodymyr , Marciniak Bernard , Tedenac Jean‐Claude 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Syntheses, Crystal and Electronic Structure, and Some Optical and Transport Properties of LnCuOTe (Ln: La, Ce, Nd).
Authors: Liu Min Ling , Wu Li Bin , Huang Fu Qiang , Chen Li Dong , Ibers James A. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Properties of the Double Perovskites La2NiVO6, La2CoVO6, and La2CoTiO6.
Authors: Holman K. L. , Huang Q. , Klimczuk T. , Trzebiatowski K. , Bos J. W. G. , Morosan E. , Lynn J. W. , Cava R. J. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Phase Relations of the Ag—Ga—N System.
Authors: Zhang Y. , Liang J. K. , Li J.‐B. , Liu Q. L. , Xiao Y. G. , Zhang Q. , Sun B. J. , Rao G. H. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Solid‐Phase Equilibria in the Gd—Co—Al Ternary System at 1173 K
Authors: Zhou Bo , Gu Zhengfei , Li Junqin , Cheng Gang , Cheng Jun , Xu Chengfu , Ma Lei 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Thermodynamic Modeling of the Ba—Ni—Ti System.
Authors: Shang Shunli , Liu Zhi‐Jie , Liu Zi‐Kui 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Syntheses and Crystal Structures of the Thallium(I) Iodobismuthates(III) Tl7Bi3I16 and Tl3BiI6.
Authors: Aussieker Thomas , Keller Hans‐Lothar , Oldag Thorsten , Prots Yurii , Ruck Michael , Wosylus Aron 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrothermal Synthesis of Lindgrenite with a Hollow and Prickly Sphere‐Like Architecture.
Authors: Xu Jiasheng , Xue Dongfeng 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
First Chiral Phosphoroamidite‐Phosphite Ligands for Highly Enantioselective and Versatile Pd‐Catalyzed Asymmetric Allylic Substitution Reactions.
Authors: Raluy Eva , Claver Carmen , Pamies Oscar , Dieguez Montserrat 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Multicomponent Reactions to Form Heterocycles by Microwave‐Assisted Continuous Flow Organic Synthesis.
Authors: Bremner W. Stacy , Organ Michael G. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct α‐Thiocyanation of Carbonyl and β‐Dicarbonyl Compounds Using Potassium Peroxydisulfate—Copper(II).
Authors: Kumar Atul , Ahamd P. , Maurya R. A. 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct N‐Cyclopropylation of Cyclic Amides and Azoles Employing a Cyclopropylbismuth Reagent.
Authors: Gagnon Alexandre , St‐Onge Miguel , Little Kelly , Duplessis Martin , Barabe Francis 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Regioselective Methylenation and in situ Methanolation of Ketones Prone to C—C Double Bond Isomerization.
Authors: Bjornstad Vidar , Undheim Kjell 
Published: April 2007

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.