bluuebunny/crossref_metadata_2025_split huggingface dataset:
An effective NF‐FF transformation with a hybrid cylindrical and bipolar scanning
Authors: D'Agostino F. , Ferrara F. , Gennarelli C. , Gennarelli G. , Guerriero R. 
Published: January 2009

AbstractAn efficient and innovative near‐field‐far‐field transformation technique with a hybrid cylindrical and bipolar scanning is proposed in this article. It allows one to considerably reduce the truncation error, which unavoidably affects the cylindrical near‐field‐far‐field transformation. To this end, nonredundant measurements are acquired by employing a cylindrical facility integrated with a rotating arm, which allows to collect the bipolar data on the upper and lower surfaces of the cylinder. Then, by applying the equivalence theorem, the knowledge of the electric field tangential components on the top and bottom of the cylinder is properly exploited to recover the nonredundant cylindrical near‐field data external to the measurement zone. At last, the near‐field data needed to perform the classical near‐field‐far‐field transformation with cylindrical scanning are efficiently computed via an optimal sampling interpolation algorithm. The effectiveness of the approach in reducing the truncation error is assessed by numerical tests. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 772–779, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24165
Compact dualband filter with wide upper stopband
Authors: Singh Pramod K. , Basu Sarbani , Wang Yeong‐Her 
Published: January 2009

AbstractA compact dualband filter with wide upper stopband using folded stepped impedance resonators (SIRs) and open stub is presented in this letter. The anti‐parallel coupled SIRs are used for the realization of the dual passband and open stubs for the widening of the upper stopband. The SIRs are folded for the compact filter size. Two different folding structures are investigated for the size compactness and the frequency response of the filter. The wide stopband is useful for suppressing harmonics and noise in the RF circuit. Dualband filters at frequencies of 2.45/5.25 GHz and 2.45/5.75 GHz are realized. The wide and deep upper stopband as well as deep mid‐stopband are achieved. The size of the filters are less than 190 mm2 on a RO 4003C (εr = 3.38, h = 0.81 mm) substrate. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 804–808, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24174
A 60‐GHz millimeter‐wave CMOS Marchand balun using 0.18‐μm CMOS technology
Authors: Liu C.‐H. , Hsu C.‐Y. , Chuang H.‐R. , Chen C.‐Y. 
Published: January 2009

AbstractA novel 60‐GHz wideband Marchand balun fabricated with a standard 0.18 μm six‐metal‐layer CMOS process for millimeter‐wave applications is presented. A technique for achieving good balance with the fourth metal layer microstrip conductor is used in the designed Marchand balun. The fabricated CMOS balun uses multilayer coupling with the top two layers. An output matching network is added to improve the output return loss. The measured amplitude imbalance was about ±1.5 dB from 25 to 65 GHz, over the 89% operating frequency band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 766–770, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24176
Extended stop‐band band pass filter using new spurious suppression technique
Authors: Ma Kaixue , Yeo Kiat Seng 
Published: January 2009

AbstractA spurious suppression method by using the “T” feeders is proposed and investigated. A novel band pass filter using “T” feeders is implemented. The measured results of the filter demonstrate good spurious suppression. The experimental results of the filter operating at the center frequency f0 = 1.87 GHz are the fractional bandwidth of 9%, the insertion loss of 1.7 dB, the return loss better than 25 dB. The spurious frequency with rejection larger than 25 dB is up to 5f0. Below 1 GHz, the stop‐band rejection is larger than 51.5 dB, and the largest stop‐band rejection is 54 dB in the upper stop‐band. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 706–709, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24179
A folded substrate integrated waveguide cavity filter using novel negative coupling
Authors: Wang Rui , Zhou Xi‐Lang , Wu Lin‐Sheng 
Published: January 2009

AbstractThis article presents a cross‐coupled folded substrate integrated waveguide (FSIW) cavity bandpass filter. A novel type of negative coupling between FSIW cavities has been investigated and demonstrated. A prototype of four‐pole FSIW cavity bandpass filter has been designed, fabricated with multilayer standard printed circuit board process. The filter has good selectivity which is demonstrated by the measured results, indicating 7.5% bandwidth and more than 14‐dB return loss, with good agreement obtained when compared with the simulated ones. In addition, the rejection band of this filter is quite wide, implying good harmonic rejection. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 866–871, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24181
Optically envelope detected QAM and QPSK RF modulated signals in hybrid wireless‐fiber systems
Authors: Tafur Monroy Idelfonso , Prince Kamau , Seoane Jorge , Yu Xianbin 
Published: January 2009

AbstractWe experimentally demonstrate optical envelope detection of 40 Mbaud 16‐QAM and QPSK RF modulated signals. The proposed system employs an electro‐absorption modulator performing the function of an optical halfwave rectifier. In this experiment, the QAM and QPSK signals are frequency down converted from a 1.6 GHz carrier frequency to an IF at 500 MHz, requiring no high frequency local oscillator and mixer at the remote base station. This result proves the feasibility of optical envelope detection for complex modulation formats of RF signals for hybrid wireless‐fiber transmission links. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 864–866, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24182
Thin absorbers using space‐filling curve artificial magnetic conductors
Authors: McVay John , Hoorfar Ahmad , Engheta Nader 
Published: January 2009

AbstractFollowing our previous work, here an artificial magnetic conducting (AMC) surface, comprised of Hilbert and/or Peano space‐filling curve inclusions is utilized as a thin electromagnetic absorber. Numerical results are presented to show the effects of the incident angle, conducting strip widths and substrate thicknesses on the absorbing properties of such surfaces. The performance of a fabricated thin absorber in reducing the RCS of a conducting plate is demonstrated through measurement. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 785–790, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24186
Structure elucidation and NMR assignments for three anthraquinone derivatives from the marine fungus Fusarium sp. (No. ZH‐210)
Authors: Chen Yiguang , Cai Xiaoling , Pan Jiahui , Gao Junping , Li Jing , Yuan Jie , Fu Liwu , She Zhigang , Lin Yongcheng 
Published: January 2009

AbstractThe structure elucidations and complete 1H and 13C NMR assignments are reported for three new anthraquinone derivatives: Fusaquinon A (1), B (2), and C (3) isolated from the fermentation medium of the marine fungus Fusarium sp. (No. ZH‐210). HREIMS, Fourier transform infrared absorption spectrometry (FT‐IR), NMR experiments including gCOSY, gHMQC, gHMBC, and NOESY were used for the determination of the structures and NMR spectral assignments. Preliminary pharmacological test showed that they exhibited low cytotoxic activity towards KB, KBv200, and MCF‐7 cell lines. Copyright © 2009 John Wiley & Sons, Ltd.
Consistency of iterative operator‐splitting methods: Theory and applications
Authors: Geiser Jürgen 
Published: January 2009

AbstractIn this article, we describe a different operator‐splitting method for decoupling complex equations with multidimensional and multiphysical processes for applications for porous media and phase‐transitions. We introduce different operator‐splitting methods with respect to their usability and applicability in computer codes. The error‐analysis for the iterative operator‐splitting methods is discussed. Numerical examples are presented. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010
Role of polyethylene‐graft‐glycidyl methacrylate compatibilizer on the biodegradation of poly(ε‐caprolactone)/cellulose acetate blends
Authors: Rosa D. S. , Bardi M. A. G. , Guedes C. G. F. , Angelis D. A. 
Published: January 2009

AbstractBiodegradable polymers provide an attractive solution to reduce environmental pollution caused by the accumulation of plastic waste in landfills. In this study, the effect of polyethylene‐graft‐glycidyl methacrylate (PE‐g‐GMA) on the biodegradation of blends of poly(ε‐caprolactone) (PCL) and cellulose acetate (CA) (80/20, 60/40, 40/60, and 20/80 PCL/CA, w/w) was assessed by mass retention, tensile strength, and morphological properties. The principal fungal strains present in the soil after biodegradation were also identified. PCL and the blends containing 60% and 80% PCL showed greater mass loss and superficial change in simulated soil. PE‐g‐GMA increased the tensile strength retention during 3 months of aging in simulated soil. Scanning electron microscopy (SEM) indicated that pure PCL was more porous, which enhanced the hydrolysis and biodegradation of PCL. PE‐g‐GMA decreased the mass loss of the polymers, possibly by enhancing the interaction between PCL and CA, with the formation of hydrogen bonds between the carbonyl groups of PCL and the hydroxyl groups of CA. This effect was marked in blends with >40% PCL. Microbiological analysis revealed the presence of several species of fungi in the soil. Copyright © 2009 John Wiley & Sons, Ltd.
N‐Isopropylacrylamide/monoalkyl itaconate copolymers and N‐isopropylacrylamide/itaconic acid/dimethyl itaconate terpolymers
Authors: Erbil Candan , Yıldız Yalçın , Uyanık Nurseli 
Published: January 2009

AbstractTemperature‐ and pH‐sensitive copolymers and terpolymers of N‐isopropylacrylamide (NIPAAm) with itaconic acid (IA), monomethyl itaconate (MMeI), monobutyl itaconate (MBuI), monooctyl itaconate (MOcI), monocetyl itaconate (MCeI), and dimethyl itaconate (DMI) were prepared by free radical solution polymerization method. The dependence of coil‐to‐globule transition on pH and composition, molecular structures, and reactivities of monoalkyl itaconates, molecular weight distributions, and glass transition temperatures of copolymers and terpolymers were investigated using FT‐IR and UV–visible spectroscopic techniques, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and acid–base titration methods. The temperature‐/pH‐dependent coil‐to‐globule transition measurements showed that, upon increasing the content and length of alkyl chains, the lower critical solution temperatures (LCSTs) were shifted to higher temperatures. This meant that with increase in the length of hydrophobic alkyl chain in the monoitaconates intramolecular intreactions between the carboxyl groups were suppressed and LCSTs increased. The aqueous solution behaviors of NIPAAm/IA/DMI terpolymers also revealed that, even if the terpolymer hydrophobicity is increased by adding DMI units, the presence of IA units overcame the decrease in hydrophilicity of the terpolymers. The presence of DMI units in the terpolymers balanced the hydrophilic character of IA. DSC results supported the ones obtained from the pH‐dependent coil‐to‐globule transition measurements. An increase in both the chain length of alkyl groups attached to the monoitaconates and the contents of the mono‐ and dialkyl itaconates in the copolymers and terpolymers decreased the Tgs. In the case of NIPAAm/IA and NIPAAm/MMeI copolymers, the presence of the carboxyl groups forming hydrogen bonds increased the Tg, while the monoalkyl and dialkyl itaconates such as MBuI, MOcI, MCeI and DMI lead to a decrease in Tg of copolymers and terpolymers because of the suppression of intramolecular interactions (resulting from the COOH and COO− groups) through the longer alkyl spacers. The dependence of the thermosensitivity of these NIPAAm copolymers and terpolymers on different conditions of pH, and the nature and content of comonomers suggests that they can be useful in biotechnology and drug delivery applications which involve small changes in pH and temperature. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and applications of novel cross‐linked fluoroalkyl end‐capped oligomeric nanocomposites possessing aromatic siloxane segments as core units
Authors: Goto Yuki , Mugisawa Masaki , Sawada Hideo 
Published: January 2009

AbstractFluoroalkyl end‐capped N,N‐dimethylacrylamide oligomer and N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide oligomer were reacted with phenylene‐ and biphenylene‐bridged ethoxysilanes under alkaline conditions to yield cross‐linked fluoroalkyl end‐capped oligomeric composites possessing aromatic siloxane segments as core units. These isolated fluorinated composite powders were found to be nanometer size‐controlled fine particles with a good dispersibility and stability in water and organic solvents. Nitrogen adsorption–desorption isotherms confirmed the presence of micropores in these nanocomposites; the micropore size estimated by the HK method was 0.7–0.8 nm. Interestingly, fluorinated nanocomposites possessing a higher micropore volume ratio were found to exhibit a selective encapsulation ability of fullerene into their composite cores. These fluorinated nanocomposites were also applied to the surface modification of poly(methyl methacrylate) film, resulting in a good oleophobicity imparted by fluorine on the surface. In addition, fluorescence emission was visibly observed only from the modified PMMA film surface treated with fluorinated nanocomposites possessing biphenylene units when irradiated by light. Copyright © 2009 John Wiley & Sons, Ltd.
A novel calixarene‐containing hyperbranched aliphatic polyester incorporated with pendant europium complexes
Authors: Feng Jichang , Liu Kuan , Li Yang , Yang Mujie 
Published: January 2009

AbstractA novel calixarene‐containing hyperbranched aliphatic polyester incorporated with pendant europium complexes (H20‐Cal‐Eu) was synthesized and characterized by FTIR, UV, and element analysis. The polymer H20‐Cal‐Eu shows a glass‐transition temperature (Tg) of 127°C, and a deposition temperature in the range of 280–600°C, as revealed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The investigation on its photoluminescence (PL) properties revealed that the polymer emitted a remarkably strong red luminescence. Furthermore, its half spectral bandwidth of the polymer film is only about 10 nm as determined from luminescence spectra, suggesting that the light is nearly monochromatic. It is proposed that the hyperbranched polymer (HBP) containing rare earth element exhibits great potential as a red light emitting material. Copyright © 2009 John Wiley & Sons, Ltd.
Composite polymer electrolytes prepared by in situ copolymerization of poly(methyl methacrylate‐acrylonitrile) on the surface of poly(methyl methacrylate)‐coated nano‐TiO2
Authors: Zhang P. , Zhang H. P. , Li Z. H. , Wu Y. P. , van Ree T. 
Published: January 2009

AbstractComposite polymer electrolytes (CPE) for lithium ion batteries are reported. Initially, nano‐TiO2 was modified by coating with a layer of poly(methyl methacrylate) (PMMA) by emulsion polymerization. CPE with this modified nano‐TiO2 were then prepared by the in situ copolymerization of poly(methyl methacrylate‐acrylonitrile) (P(MMA‐AN)). Morphology, thermal, electrochemical, and spectroscopic measurements were used to characterize the electrolytes. The PMMA‐coated nano‐TiO2 was well dispersed in the polymer matrix due to the PMMA coating layer making the nanoparticles hydrophobic to effectively avoid the aggregation of the nanoparticles. The homogeneous CPEs of this PMMA‐coated nano‐TiO2 have better thermal tolerance, higher ionic conductivity, and wider electrochemical stability, thus providing a practical route to improved polymer electrolytes. Copyright © 2009 John Wiley & Sons, Ltd.
Scratch behavior of epoxy nanocomposites containing α‐zirconium phosphate and core‐shell rubber particles
Authors: Moghbelli Ehsan , Sun Luyi , Jiang Han , Boo Woong J. , Sue Hung‐Jue 
Published: January 2009

AbstractThe effects of nanoscale core‐shell rubber (CSR) particles and α‐zirconium phosphate (ZrP) nanoplatelet fillers on the scratch behavior of epoxy have been examined using a newly established ASTM scratch testing method. The critical load for onset of microcrack formation is utilized to determine scratch resistance of the epoxy nanocomposites. Optical microscopy and scanning electron microscopy were performed to determine failure and fracture patterns caused by the scratch. The findings of this study suggest that the introduction of nanoparticles or nanoplatelets does not necessarily enhance the scratch resistance of epoxy. This implies that increases in ductility and fracture toughness alone, i.e., the epoxy/CSR case, and enhancements in modulus and tensile strength alone, i.e., the epoxy/ZrP case, will not necessarily improve scratch resistance of epoxy matrix. A combination of material property attributes is needed to prepare scratch resistant polymers. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Regulation of the interfacial activation within the Candida rugosa lipase family
Authors: Pernas María A. , Pastrana Lorenzo , Fuciños Pablo , Rúa M. Luisa 
Published: January 2009

AbstractThe fungus Candida rugosa produces several lipase isoenzymes and the 3D structure of three was solved (Lip1, Lip2 and Lip3). In an aqueous solution, the hydrophobic catalytic cavity of these lipases is buried under a flap that blocks the entrance of the substrate. In the hydrolysis of triacetin, the limiting step of the catalytic process was the activation of the enzyme and only the existence of the highly hydrophobic interface provided by hexane was able to shift the equilibrium towards the open conformation. In the case of Lip1, the hexane interface was crucial and once the open conformation was stabilised, Lip1 was as efficient as Lip3 for the hydrolysis of triacetin. Lip2 isoenzyme behaves more similarly to mLip3 reinforcing the higher structural and functional similarity between these isoenzymes. Inhibition experiments carried out under non‐kinetic conditions allowed to correlate the higher flexibility of the closed flap and the higher hydrophobicity of the catalytic pocket of mLip3 with the greater facility of this isoenzyme to become activated by interfaces of different chemical nature. Both factors might allow a more intense penetration of mLip3 into the interfaces. In these systems, we observed a unique behaviour of Lip2, enzyme that although in a monomeric state and provide with an analogous flap structure to that of Lip1 or Lip3 underwent a very fast activation even in the absence of supramicellar concentrations of surfactants. We determined that the inhibitor itself forms micelles and hypothesised that they might provide an adequate interface for Lip2 activation. Copyright © 2009 John Wiley & Sons, Ltd.
Drilling and installation of boreholes for permafrost thermal monitoring on Livingston Island in the maritime Antarctic
Authors: Ramos Miguel , Hasler Andreas , Vieira Gonzalo , Hauck Christian , Gruber Stephan 
Published: January 2009

AbstractThree new boreholes up to 25 m deep were drilled on Mount Reina Sofía (275 m a.s.l.), Livingston Island, where previous near‐surface temperature measurements (mean annual ground temperatures of −2.1 to −2.6°C) have indicated the presence of permafrost. A thermistor chain and logging system were installed in the deepest borehole, while the others were equipped with individual miniature temperature loggers (iButtons). Initial data from the 25 m borehole indicates a permafrost body several decametres thick. Future data from these boreholes are expected to provide insight into ground temperature evolution in maritime Antarctica. Copyright © 2009 John Wiley & Sons, Ltd.
Using an F2 screen to monitor frequency of resistance alleles to Bt cotton in field populations of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)
Authors: Xu Zhiping , Liu Fengyi , Chen Jin , Huang Fangneng , Andow David A , Wang Yanhua , Zhu Yu Cheng , Shen Jinliang 
Published: January 2009

AbstractBACKGROUND: In an effort to control the most devastating cotton pest, Helicoverpa armigera (Hübner), in Qiuxian County (Hebei, China), Bt cotton has been planted almost exclusively since 1998 in this area. Owing to the high insecticidal selection pressures in this region, monitoring of Bt resistance in H. armigera is necessary so that proactive actions can be implemented before field control measures fail. From 2003 to 2005, an F2 screen was conducted in order to monitor Bt resistance in H. armigera populations collected from this area.RESULTS: The F2 screen showed that 15 out of 278 isofemale lines carried resistance alleles to Bt cotton. The resistance allele frequency in field populations of H. armigera ranged from 0.0119 to 0.0297, with an overall frequency of 0.0146 and a 95% confidence interval of 0.0084–0.0225 for the 3 year period. This value is greater than the value reported from 1999 (P < 0.05).CONCLUSION: A fluctuating but overall increase in resistance allele frequency was detected in the field populations of H. armigera in Qiuxian County from 1999 to 2005. To prevent further increases in Bt resistance frequency in this pest, it is necessary to introduce Bt cotton expressing multiple Bt toxins and integrate this technology with other tactics for management of this key pest. Copyright © 2009 Society of Chemical Industry
Direct observation of host–guest triplet–triplet annihilation in phosphorescent solid mixed films
Authors: Reineke Sebastian , Schwartz Gregor , Walzer Karsten , Leo Karl 
Published: January 2009

AbstractTriplet–triplet annihilation (TTA) between excited states of host and guest species in organic mixed films, comprising a phosphorescent heavy‐metal complex, is usually only accessed indirectly, as one is only able to monitor the radiative guest phosphorescence. We compare two different host materials, 4,4′,4″‐tris(N ‐carbazolyl)‐triphenylamine (TCTA) and 4,4′‐N,N ′‐dicarbazole‐biphenyl (CBP) in combination with the green emitter fac ‐tris(2‐phenylpyridine) iridium which differ in their triplet state energy. At excitation levels in the saturation range of guest emission, we observe increasing non‐linearities in photoluminescence transients with increasing excitation power for the CBP host material, which can directly be attributed to TTA of host and guest excited states. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)