bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient electron heating in short-pulsed magnetron discharges
Authors: Seo Sang-Hun , In Jung-Hwan , Chang Hong-Young
Published: October 2005

The effect of the duty cycle of the cathode pulse on the electron energy distribution function and the plasma parameters was investigated by means of the time-resolved probe measurements in the pulsed and unbalanced magnetron discharges. The discharges were driven by the cathode pulse with the repetition frequency of 20kHz in three regulation modes of constant voltage, constant current, and constant power. As the duty cycle was reduced, the electron temperature averaged during the pulse-on period rapidly increased irrespective of the regulation mode. The comparison of the measured electron energy distribution functions shows that the increase of the electron temperature is caused by the decrease of the population of trapped low-energy electrons and the increase of the population of drifting high-energy electrons. It will be shown that these results can be explained from efficient electron heating by the high-voltage cathode sheath more deeply penetrating into the bulk with the reduction of the duty cycle during the pulse-on period.
Modeling saturated and unsaturated ferroelectric hysteresis loops: An analytical approach
Authors: Tsang C. H. , Wong C. K. , Shin F. G.
Published: October 2005

In ferroelectric materials, hysteresis behavior is very difficult to model due to its nonlinear and history-dependent characteristics. Among approaches that are able to describe unsaturated loops, many of them are either very complicated (numerical procedures must be employed) or the resulting loops contain some undesirable or defective features. In this work, a simple hysteresis model based on a special construction of the Preisach function is proposed. Explicit expressions for the polarization-field (P-E) responses under increasing and decreasing applied fields have been derived. The saturated and unsaturated P-E loops can be conveniently calculated by piecing together such responses. The technique is widely applicable to the modeling of ferroelectric hysteresis behavior of ceramics and polymers. As examples we study the applied field dependence of dielectric permittivity of a ferroelectric film and the remanent polarization of ferroelectric composites after ac poling. We find that the model predictions agree well with the experimental results.
Characterization of the physical and electrical properties of Indium tin oxide on polyethylene napthalate
Authors: Han H. , Adams Daniel , Mayer J. W. , Alford T. L.
Published: October 2005

Indium tin oxide (ITO) thin films, on polyethylene napthalate (PEN) of both good electrical and optical properties were obtained by radio-frequency sputtering. The optoelectronic properties of the ITO films on PEN substrate were evaluated in terms of the oxygen content and the surface morphology. Rutherford backscattering spectrometry analysis was used to determine the oxygen content in the film. Hall-effect measurements were used to evaluate the dependence of electrical properties on oxygen content. The results showed that the resistivity of the ITO film increases with increasing oxygen content. For an oxygen content of 1.6×1018–2.48×1018atoms∕cm2, the resistivity varied from 0.38×10−2to1.86×10−2Ωcm. Typical resistivities were about ∼10−3Ωcm. UV-Vis spectroscopy and atomic force microscopy measurements were used to determine the optical transmittance and surface roughness of ITO films, respectively. Optical transmittances of ∼85% were obtained for the ITO thin films. Our results revealed that substrate roughness were translated onto the deposited ITO thin layers. The ITO surface roughness influences both the optical and electrical properties of the thin films. For a 125μm PEN substrate the roughness is 8.4nm, whereas it is 3.2nm for 200μm substrate thicknesses. The optical band gap is about 3.15eV for all ITO film and is influenced by the polymer substrate. A model is proposed that the optical transmittance in the visible region is governed by the carrier concentration in the ITO thin films.
Large pyroelectric response in relaxor-based ferroelectric (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 single crystals
Authors: Tang Yanxue , Wan Xinming , Zhao Xiangyong , Pan Xiaoming , Lin Di , Luo Haosu , Sun Jinglan , Meng Xiangjian , Zhu Junhao
Published: October 2005

The pyroelectric properties of (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 (PMN–xPT) single crystals have been investigated over a broad composition range of 0.13⩽x⩽0.40. The best pyroelectric performances are achieved in ⟨111⟩-oriented PMN–0.26PT single crystal. At room temperature, the figures of merit for voltage responsivity and detectivity reach up to 0.11m2∕C and 15.3×10−5Pa−1∕2, respectively. These properties are superior to those of conventional pyroelectric ceramics that have been widely used in device applications. PMN–0.26PT single crystal also possesses a relative high Curie temperature (∼120°C) and a low thermal diffusivity (∼4.4×10−7m2∕s). Furthermore, the pyroelectric properties of PMN–xPT (x⩾0.26) single crystals are weak dependent on temperature and nearly independent of frequency in the experimental temperature range of 20–55°C and frequency range of 50–10000Hz. The superior pyroelectric performances of the single crystal make it a promising candidate for high-performance uncooled infrared detectors and thermal imagers.
Internal solitons in laboratory experiments: Comparison with theoretical models
Authors: Ostrovsky L. A. , Stepanyants Y. A.
Published: October 2005

Nonlinear internal solitary waves observed in laboratory experiments are discussed from the standpoint of their relation to different soliton theories, from the classical integrable models such as the Korteweg–de Vries, Gardner, Benjamin–Ono, and Joseph–Kubota–Ko–Dobbs equations and their modifications, through the nonintegrable models describing higher-order nonlinear effects, viscosity, rotation, and cylindrical spreading, to the strongly nonlinear models. First, these theoretical models are briefly described and, then, laboratory data and their comparison with the theory are presented.
Energy balance in laser ablation of metal targets
Authors: Sobral H. , Villagrán-Muniz M. , Bredice F.
Published: October 2005

Laser-generated plasma was induced on metallic targets glued to a piezoelectric microphone and placed between the plates of a planar charged capacitor. The plasma generates a temporal redistribution of electric charge on the plates that can easily be measured by a resistor connected to the ground plate; this signal is proportional to the total number of ions removed by breakdown. Both the absorbed and scattered energies were simultaneously monitored by the photoacoustic signal and an energy meter. From these signals it was possible to determine the energy involved in each of the processes. Just above the ablation threshold most of the delivered energy is absorbed and the acoustic signal prevails compared to other contributions. Above this region, the electric signal, which is proportional to the energy involved in the ablation process, becomes dominant.
Oxygen adsorption at anionic free and supported Au clusters
Authors: Molina L. M. , Hammer B.
Published: October 2005

The structure, stability, and O2 adsorption properties of anionic Aun (n=1–11) clusters either free or supported at defected MgO(100) surfaces are investigated using density-functional theory. O2 adsorption is strong whenever unpaired electrons are present, except for at some small, supported, planar, high-band-gap clusters. These clusters have the unpaired electrons pinned by the Madelung potential of the support. Larger clusters (starting at Au7–Au8) become three dimensional and metallic. This ensures that while one cluster orbital is pinned to the defect, another orbital at comparable energy can undergo depletion, thus binding O2 with charge transfer.
Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density
Authors: Wei Z. F. , Xu S. J. , Duan R. F. , Li Q. , Wang Jian , Zeng Y. P. , Liu H. C.
Published: October 2005

Variable-temperature photoluminescence (PL) spectra of Si-doped self-assembled InGaAs quantum dots (QDs) with and without GaAs cap layers were measured. Narrow and strong emission peak at 1075nm and broad and weak peak at 1310nm were observed for the buried and surface QDs at low temperature, respectively. As large as 210meV redshift of the PL peak of the surface QDs with respect to that of the buried QDs is mainly due to the change of the strain around QDs before and after growth of the GaAs cap layer. Using the developed localized-state luminescence model, we quantitatively calculate the temperature dependence of PL peaks and integrated intensities of the two samples. The results reveal that there exists a large difference in microscopic mechanisms of PL thermal quenching between two samples.
Vibrational spectroscopy and microwave dielectric properties of Ca5−xBaxNb2TiO12 and Ca5−xBaxTa2TiO12 ceramics
Authors: Dias Anderson , Bijumon Pazhoor Varghese , Sebastian Mailadil Thomas , Moreira Roberto Luiz
Published: October 2005

Complex ceramics Ca5−xBaxNb2TiO12 and Ca5−xBaxTa2TiO12 were prepared by conventional solid-state ceramic route. The crystalline structures were determined by x-ray diffraction, which showed that solid solutions were formed for x=4 (CaBa4Nb2TiO12 and CaBa4Ta2TiO12) and crystalline multiphases appeared for 1⩽x⩽3. The dielectric properties of the sintered ceramics were measured in the microwave frequency range. The dielectric constant and temperature variation of resonant frequency increased and the quality factor decreased with increasing x value. Raman analyses showed different spectra depending upon the composition, with variations in both intensity and frequency, as well as in the number of bands strictly related to the phases present. For both Nb- and Ta-based systems, the results indicated an increase in the short-range ordering with barium substitution, which explained the reduction in the unloaded quality factor (Qu). The results of far-infrared spectroscopy agree well with the Raman data, with few variations when Nb replaces Ta, and an increase in the complexity of the vibrational modes for Ca∕Ba mixed ceramics.
Space-charge waves in silicon carbide
Authors: Petrov M. P. , Bryksin V. V. , Lebedev A. A. , Lemmer M. , Imlau M.
Published: October 2005

Space-charge waves (trap recharging waves) and the effect of spatial rectification of space-charge waves have been investigated in single crystals of 4H-SiC polytype. The relevant experimental dependencies have been found to be in quite good quantitative agreement with the theory of space-charge waves. The following parameters of the samples studied were determined: μτ=(7.4±0.8)×10−7cm2∕V, τM=(5.3±0.6)×10−4s, and Neff=(5±1)×1013cm−3.
Deformation of a surfactant-covered drop in a linear flow
Authors: Vlahovska Petia M. , Loewenberg Michael , Blawzdziewicz Jerzy
Published: October 2005

We study the effect of adsorbed surfactant on drop deformation in linear flows by means of analytical solutions for small perturbations of the drop shape and surfactant distribution, and by numerical simulations for large distortions. We consider a drop with the same viscosity as the suspending fluid. Under these conditions, the problem simplifies because the disturbance flow field results solely from the interfacial stresses that oppose the distortion of shape and surfactant distribution induced by the incident flow. A general form of perturbation analysis valid for any flow is presented. The analysis can be carried out to arbitrary order given its recursive structure; a third-order perturbation solution is explicitly presented. The expansions are compared to results from boundary integral simulations for drops in axisymmetric extensional and simple shear flows. Our results indicate that under weak-flow conditions, deformation is enhanced by the presence of surfactant, but the leading-order perturbation of the drop shape is independent of the (nonzero) surfactant elasticity. In strong flows, drop deformation depends nonmonotonically on surfactant elasticity. The non-Newtonian rheology in a dilute emulsion that results from drop deformation and surfactant redistribution is predicted. Shear thinning is most pronounced for low values of the surfactant elasticity. In the weak-flow limit with finite surfactant elasticity, the emulsion behaves as a suspension of rigid spheres. In strong flows, the stresses can approach the behavior for surfactant-free drops.
Nonlinear I-V characteristics of nanotransistors in the Landauer-Büttiker formalism
Authors: Nemnes G. A. , Wulf U. , Racec P. N.
Published: October 2005

We present the nonlinear I-V characteristics of a nanoscale metal-oxide-semiconductor field-effect transistor in the Landauer-Büttiker formalism. In our three-dimensional ballistic model the gate, source, and drain contacts are treated on an equal footing. As in the drift-diffusion regime for ballistic transport a saturation of the drain current results. We demonstrate the quantum mechanism for the ballistic drain current saturation. As a specific signature of ballistic transport we find a specific threshold characteristic with a close-to-linear dependence of the drain current on the drain voltage. This threshold characteristic separates the ON-state regime from a quasi-OFF-state regime in which the device works as a tunneling transistor. Long- and short-channel effects are analyzed in both regimes and compared qualitatively with existing experimental data by Intel [B. Doyle et al., Intel Technol. J. 6, 42 (2002)].
Long-range ordered nanoaperture array with uniform diameter and interpore spacing
Authors: Lin Ming-Nung , Lin Minn-Tsong , Y. Liu C. , Lai M. Y. , Liu N. W. , Peng C. Y. , Wang H. H. , Wang Y. L.
Published: October 2005

In application of focused-ion-beam lithography and grazing Ar+ milling on the U-shape barrier layer of anodic alumina nanochannels, we fabricated a hexagonally symmetry aperture array with nominal diameter of 12±2nm and interspacing of 100±2nm. Besides long-range spatial ordering, the focused-ion-beam guided-grown process has also significantly improved uniformity of both the interpore spacing and the aperture size. This aperture array membrane can be applied to the fabrication of nanostructures, such as a lithographic contact mask for ordered quantum-dot array.
High-performance photorefractive polymer operating at 1550 nm with near-video-rate response time
Authors: Tay Savaş , Thomas Jayan , Eralp Muhsin , Li Guoqiang , Norwood Robert A. , Schülzgen Axel , Yamamoto Michiharu , Barlow Stephen , Walker Gregory A. , Marder Seth R. , Peyghambarian N.
Published: October 2005

The development of a high-performance photorefractive polymer composite operating at 1550 nm is reported. We show 40% internal diffraction efficiency with response time of 35 ms and a net gain of 20cm−1 in four-wave mixing and two-beam coupling experiments, respectively. This is more than an order of magnitude improvement in the diffraction efficiency and net two beam coupling gain and two orders of magnitude in the response time than the previously reported photorefractive polymer operating at this technologically important wavelength. The improvement in photorefractive characteristics is accomplished by an enhanced orientation of the nonlinear optical chromophore in the present composite.
Experimental demonstration of Fano-type resonance in photoluminescence of ZnS:Mn∕SiO2 one-dimensional photonic crystals
Authors: Baba Takeshi , Makino Hisao , Mori Takahiro , Hanada Takashi , Yao Takafumi , Lee Hyun-Yong
Published: October 2005

We investigated the photoluminescence (PL) properties of ZnS:Mn∕SiO2 one-dimensional photonic-crystal structures. PL spectra were measured from two opposite directions perpendicular to the sample. The cavity mode emission measured from the sample surface showed asymmetric spectral shape; measurements from the back side of the sample showed a symmetric spectral shape. The experimental spectra were analyzed by a simple model calculation based on the transfer matrix method. From the model calculation, it was found that the asymmetric shape observed in cavity mode emission is caused by Fano-type resonance which is the coupling effect between discrete emission from the ZnS:Mn cavity layer and continuous background emission from all ZnS:Mn layers except the cavity layer.
Effect of stray field on local spin modes in exchange-biased magnetic tunnel junction elements
Authors: Rietjens J. H. H. , Józsa C. , de Jonge W. J. M. , Koopmans B. , Boeve H.
Published: October 2005

We report on the detection of localized spin modes in a multilayered spintronic device by means of time-resolved scanning Kerr microscopy. Measurements on this 13×9μm2 exchange-biased magnetic tunnel junction element at different applied bias fields indicate a strong effect of the stray field from the pinned CoFe layer on the magnetization dynamics in the free NiFe layer. This view is supported by micromagnetic simulations, which also show that the dynamics can be attributed to the specific shape of the internal magnetic field in the element.
Experimental characterization of the separation between wavelength-multiplexed quantum and classical communication channels
Authors: Nweke N. I. , Toliver P. , Runser R. J. , McNown S. R. , Khurgin J. B. , Chapuran T. E. , Goodman M. S. , Hughes R. J. , Peterson C. G. , McCabe K. , Nordholt J. E. , Tyagi K. , Hiskett P. , Dallmann N.
Published: October 2005

Quantum key distribution (QKD) is a new technique for secure key distribution based on the laws of physics rather than mathematical or algorithmic computational complexity used by current systems. Understanding the compatibility of QKD at 1310 nm with the existing commercial optical networks bearing classical wavelength-division-multiplexed (WDM) channels at 1550 nm is important to advance the deployment of QKD systems in such networks. The minimum wavelength separation for multiplexing QKD and WDM channels on a shared fiber is experimentally determined for impairment-free QKD+WDM transmission.
Direct contact buckling of electrochemically grown gold nanowires
Authors: Kim W. J. , Carr S. M. , Wybourne M. N.
Published: October 2005

We report the electrochemical growth and direct probing of near-vertical gold nanowires several micrometers long that are attached at one end to a substrate. Controllable contact is made to the wires using a straightforward tip-probe arrangement inside a scanning electron microscope. The contact allowed us to perform mechanical and electrical measurements. Through elastic nanowire buckling, we have observed dynamic low-frequency parametric pumping caused by small vibrations of the probe. A numerical simulation of the recorded motion is consistent with an estimated value of Young’s modulus of about 80GPa, which is close to that of bulk gold.
Structural and transport properties of epitaxial NaxCoO2 thin films
Authors: Venimadhav A. , Soukiassian A. , Tenne D. A. , Li Qi , Xi X. X. , Schlom D. G. , Arroyave R. , Liu Z. K. , Sun H. P. , Pan Xiaoqing , Lee Minhyea , Ong N. P.
Published: October 2005

We have studied structural and transport properties of epitaxial NaxCoO2 thin films on (0001) sapphire substrate prepared by topotaxially converting an epitaxial Co3O4 film to NaxCoO2 with annealing in Na vapor. The films are c-axis oriented and in-plane aligned with [101¯0]NaxCoO2 rotated by 30° from [101¯0] sapphire. Different Na vapor pressures during the annealing resulted in films with different Na concentrations, which showed distinct transport properties.
Mid-infrared intersublevel absorption of vertically electronically coupled InAs quantum dots
Authors: Kammerer C. , Sauvage S. , Fishman G. , Boucaud P. , Patriarche G. , Lemaître A.
Published: October 2005

We have studied mid-infrared intersublevel absorption of samples containing two layers of vertically self-aligned, self-assembled InAs quantum dots separated by a thin GaAs barrier. Samples with coupled quantum dots exhibiting different average size between the two layers are investigated. The electronically coupled quantum dot absorption is compared with the absorption of a reference sample containing uncoupled quantum dots. Electronically coupled quantum dots present a spectrally narrow absorption line (∼20meV full width at half maximum) mainly polarized along the growth axis in the range 110–150meV. This absorption is attributed to the bound-to-bound transition between bonding (symmetric-like) and antibonding (antisymmetric-like) s state combinations of the double quantum dot structure. This assignment is supported by the electronic structure of the coupled quantum dots as calculated by the three-dimensional resolution of the Schrödinger equation written in the 8-band k.p envelope function formalism.
Diffusion, activation, and recrystallization of boron implanted in preamorphized and crystalline germanium
Authors: Satta A. , Simoen E. , Clarysse T. , Janssens T. , Benedetti A. , De Jaeger B. , Meuris M. , Vandervorst W.
Published: October 2005

We have investigated diffusion and activation of boron implanted with 6 keV energy to a maximum concentration of 8.0×1020atoms∕cm3 in crystalline germanium (c-germanium) and preamorphized germanium, employing rapid thermal annealing in the range of 400–600 °C. As-implanted boron profiles in preamorphized germanium are shallower than the ones in c-germanium due to channeling suppression. While boron diffusion is not observed either in c-germanium or during the germanium regrowth from amorphous state, the boron activation level achieved from the two starting phases is significantly different. A boron activation level of 2.4×1020atoms∕cm3 has been found in regrown germanium, while a level of only 1.2×1019atoms∕cm3 is observed in c-germanium. Remarkably, there is no evidence of any residual extended defectivity at the original crystalline/amorphous interface, when preamorphization is performed.
Acoustic modes and elastic properties of polymeric nanostructures
Authors: Hartschuh R. D. , Kisliuk A. , Novikov V. , Sokolov A. P. , Heyliger P. R. , Flannery C. M. , Johnson W. L. , Soles C. L. , Wu W.-L.
Published: October 2005

Phonon spectra of polymeric linear nanostructures have been characterized using Brillouin light scattering. In addition to phonon modes similar to those present in uniform thin films, the phonon spectra of the nanolines reveal a new mode with a lower frequency that depends on the width of the nanolines. Classic wave theory and finite element analysis were combined to identify this new mode as a flexural vibration of the nanolines. Analysis of the phonon spectra gave estimates of elastic constants in the nanostructures and indicated that there is no significant deviation from bulk mechanical properties and no mechanical anisotropy in structures as small as 88nm.
Room-temperature ferromagnetic Co-doped ZnO nanoneedle array prepared by pulsed laser deposition
Authors: Chen J. J. , Yu M. H. , Zhou W. L. , Sun K. , Wang L. M.
Published: October 2005

A Co-doped ZnO nanoneedle array with room-temperature ferromagnetic properties was successfully fabricated by pulsed laser deposition (PLD) method. Detailed nanostructures were studied by transmission electron microscopy (TEM) and x-ray diffraction (XRD). High resolution TEM images and selected area electron diffraction (SAD) patterns showed nanoneedles grew along c-axis of ZnO with a preferential growth perpendicular to Si (100) substrate, which is also confirmed by XRD. Uneven surface and stacking faults along the nanoneedles were observed, which implies lattice distortion due to the Co doping. Electron energy loss spectroscopy (EELS) analysis of different positions along the growth direction of nanoneedles shows homogeneous distribution of the Co dopant. No segregated clusters of impurity phase were detected by TEM. Superconducting quantum interference device (SQUID) magnetometer measurements show room temperature ferromagnetic ordering, which is attributed to the Co substitution for Zn in the ZnO nanoneedle.
Shift in low-frequency vibrational spectra of transition-metal zirconium compounds
Authors: Han Jiaguang , Wan Fan , Zhu Zhiyuan , Liao Yi , Ji Te , Ge Min , Zhang Zengyan
Published: October 2005

The far-infrared terahertz(THz) spectra of ZrC, ZrN, ZrO2, and ZrF4 have been measured using terahertz time-domain spectroscopy. The characterization of the frequency-dependent power absorption, index of refraction and complex dielectric function in the frequency range 0.1–2.0THz are obtained. A standard Drude-Lorentz model gives a good fit on the transmission measurement results. We first observe the shift in the low-frequency vibrational spectra of different zirconium compounds. We analyze that the influence of the anion on the vibration modes causes the shift in low-frequency vibrational spectra of zirconic compounds.
Simultaneously B- and P-doped silicon nanoclusters: Formation energies and electronic properties
Authors: Ossicini S. , Degoli E. , Iori F. , Luppi E. , Magri R. , Cantele G. , Trani F. , Ninno D.
Published: October 2005

The effects of B and P codoping on the impurity formation energies and electronic properties of Si nanocrystals (Si-nc) are calculated by a first-principles method. We show that, if carriers in the Si-nc are perfectly compensated by simultaneous doping with n- and p-type impurities, the Si-nc undergo a minor structural distortion around the impurities and that the formation energies are always smaller than those for the corresponding single-doped cases. The band gap of the codoped Si-nc is strongly reduced with respect to the gap of the pure ones showing the possibility of an impurity based engineering of the photoluminescence properties of Si-nc.
Electronic excited-state mixing in NeCl2
Authors: Hernández-Lamoneda Ramón , Janda Kenneth C.
Published: October 2005

Ab initio calculations that explicitly include spin-orbit interactions are reported for the NeCl2 system of electronic states. A surprising curve crossing is observed for the C2v, T-shaped geometry. Away from the C2v geometry, the states mix, as expected. On the basis of these new results we propose a new mechanism for electronic energy transfer from highly vibrationally excited levels of the B electronic state of the chlorine molecule. It is proposed that as long as vibrational predissociation of NeCl2 proceeds by direct coupling of the initial state to the continuum states the Ne atom does not sample geometries that efficiently quench the Cl2 B electronic state. However, when the vibrational dynamics changes to the intramolecular vibrational relaxation regime the Ne atom becomes quite effective at coupling the Cl2 B Π0u+3 state with aΠ2g3 state.
White organic light-emitting diodes based on tandem structures
Authors: Guo Fawen , Ma Dongge
Published: October 2005

White organic light-emitting diodes made of two electroluminescent (EL) units connected by a charge generation layer were fabricated. Thus, with a tandem structure of indium tin oxide/N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB)/9,10-bis-(β-naphthyl)-anthrene (ADN)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/tris(8-hydroxyquinoline) aluminum (Alq3)∕BCP:Li∕V2O5∕NPB∕Alq3:4-(dicyanomethylene)-2-t-butyle-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)4H-pyran (DCJTB)∕Alq3∕LiF∕Al, a stable white light with Commission Internationale De L’Eclairage chromaticity coordinates from (0.35, 0.32) at 18V to (0.36, 0.36) at 50V was generated. It was clearly seen that the EL spectra consist of red band at 600nm due to DCJTB, green band at 505nm due to Alq3, and blue band at 435nm due to ADN, and the current efficiency and brightness equal basically to the sum of the two EL units. As a result, the tandem devices showed white light emission with a maximum brightness of 10200cd∕m2 at a bias of 40V and a maximum current efficiency of 10.7cd∕A at a current density of 3.5mA∕cm2.
Observation of ferroelectricity in a confined crystallite using electron-backscattered diffraction and piezoresponse force microscopy
Authors: Gupta P. , Jain H. , Williams D. B. , Kalinin Sergei V. , Shin J. , Jesse S. , Baddorf A. P.
Published: October 2005

La B Ge O 5 is a model transparent ferroelectric glass-ceramic (TFGC) material, developed as an inexpensive alternative to single-crystal nonlinear optical materials. The optical activity of the TFGC originates from the ferroelectric phase which remains under a hydrostatic pressure exerted by the surrounding glass matrix. A combination of two techniques, electron-backscattered diffraction (EBSD) and piezoresponse force microscopy (PFM), is employed to monitor the development of the ferroelectric phase. A method is proposed to theoretically construct PFM amplitude maps from EBSD orientation maps. The theoretical vertical piezoresponse map is compared with the experimental piezoresponse map from PFM. A good correlation between the theoretical and experimental maps is observed.
Exchange-correlation functional with broad accuracy for metallic and nonmetallic compounds, kinetics, and noncovalent interactions
Authors: Zhao Yan , Schultz Nathan E. , Truhlar D. G.
Published: October 2005

By incorporating kinetic-energy density in a balanced way in the exchange and correlational functionals and removing self-correlation effects, we have designed a density functional that is broadly applicable to organometallic, inorganometallic, and nonmetallic bonding, thermochemistry, thermochemical kinetics, and noncovalent interactions as well as satisfying the uniform electron gas limit. The average error is reduced by a factor of 1.3 compared with the best previously available functionals, but even more significantly, we find a functional that has a high accuracy for all four categories of interaction.
Composition and changes of yolk proteins from silkwormBombyx moriduring embryonic development stages
Authors: Xin-Pei Yan , Bo-Xiong Zhong , Meng-Kui Xu , Guo-Hua Yao , Qi-Long Chen , Xiao-Fen Tong
Published: October 2005

The yolk proteins of the silkworm,Bombyx mori, are important sources of nutrition and energy during embryo development. By analysing the yolk proteins from silkworm eggs, the composition and the metabolism of yolk proteins during embryo development stages can be studied at the proteome level. Yolk proteins were obtained from unfertilized eggs and eggs at different embryo development stages by dissection and then separated and analysed by two-dimensional electrophoresis and its corresponding image analysis system. It was discovered that over 200 proteins exist in mature silkworm eggs. Some specific spots of yolk proteins were found in different silkworm strains, while few differences in yolk proteins appeared during different development stages in the same silkworm strain. This result indicates that the silkworm embryo does not utilize yolk proteins selectively by absorbing one or some special proteins, but by absorbing the yolk protein grains one by one during development.
Separation andin vitroculture of goat fetal testicular cells and behaviour of male germ-line stem cells (mGSCs)
Authors: Wu-Zi Dong , Jin-Lian Hua , Shu-Zhen Zhuang , Wen-Zheng Shen , Zhong-Ying Dou
Published: October 2005

Seminiferous tubule tissues from goat fetal testis were treated using four methods. One of the treatments, with 0.1% collagenase for 15 min and then with an enzyme mixture (containing 0.25% trypsin, 10 μg/ml DNase I, 0.04% EDTA) for 5 min showed ideal cell dispersal after centrifugation and washing. Thein vitroculture of the cells separated with a different medium system showed that mulberry-shaped male germ-line stem cell (mGSC) clusters and a single layer of Sertoli cells appeared as the original generation in 120 h. The mGSC clusters developed in suspension and were distributed in different locations from the Sertoli cells in the plate. The cells in the marginal area of incompletely digested mGSCs clusters, and the single cells from them, were obviously homogenized after culture for 5 days in a fibre cell feeding layer from fetal mice (MEF feeding layer), whereas identically treated mGSCs clusters co-cultured with Sertoli cells in the same culture system did not displayed clear homogenization in marginal cells of the clusters. Also, the first generation of mGSC clusters co-cultured with Sertoli cells could form the same morphological properties with the original generation; cells in clusters were tight and mGSCs divided more slowly than those in the MEF feeding layer.
Cloning and expression ofSpodoptera lituranucleopolyhedrovirusgp41gene inEscherichia coliand preparation of antibody
Authors: Li-Jing Pan , Zhao-Fei Li , Chong Yin , Lei Lv , Yi Pang
Published: October 2005

GP41, a major glycoprotein, identified in the occlusion-derived virions (ODV) of baculoviruses, is required for the egress of nucleocapsids from the nucleus in the pathway of budded virion (BV) synthesis. Using the polymerase chain reaction (PCR), the open reading frame (ORF) ofSpodoptera lituranucleopolyhedrovirus (SpltMNPV)gp41gene was obtained from SpltMNPV genomic DNA. The PCR product was cloned into pMD18-T vector to get the recombinant plasmid (pT-gp41). Thegp41gene was recombinedin vitrowith prokaryotic expression vector pQE30 and transformed intoEscherichia coliM15 [pREP4]. The M15 [pREP4] strain, containinggp41recombinant plasmid, expressed a 37.9 kDa 6×His-tag fusion protein after induction with 1 mmol/l isopropylthio-β-d-galactoside (IPTG). The fusion protein was purified with a nickel-nitrilotriacetic acid (Ni–NTA) resin column and used as the immunogen to raise GP41-specific antibody. Western blotting analysis indicated that the antibody was suitable to be used for further analysis of GP41 protein.
Construction of antagonistic, insecticidal, and endophytic strains of Bacillus spp. by protoplast fusion
Authors: Nian-Long Yan , Si-Xin Qiu , Hong He , Xiong Guan , Fang-Ping Hu
Published: October 2005

A multifunctional-engineering strain was constructed by fusing the insecticidal bacterium (Bacillus thuringiensis) with vip3A gene and the endophytic bacterium (B. subtilis) protoplasts. Results of polymerase chain reaction (PCR) showed that the insecticidal vip3A gene of B. thuringiensis was present in the fusant. The fusant's antagonism to Fusarium oxysporum f. sp. cucumerinum, the adjusted mortality to Plutella xylostella and the endophytic characters were detected. The result showed that the antagonism of the fusant was against the F. oxysporum f. sp. cucumerinum; the adjusted mortality to P. xylostella reached 59% and it had insecticidal characteristics.
Bone morphogenetic protein receptor IB as a candidate gene for prolificacy in Small Tail Han and Hu ewes
Authors: Ya-Dong Yan , Ming-Xing Chu , Yong-Qing Zeng , Li Fang , Su-Cheng Ye , Li-Min Wang , Qing-Kun Guo , Dai-Qin Han , Zhao-Xin Zhang , Xi-Jun Wang , Zhao-Xin Zhang
Published: October 2005

The bone morphogenetic protein receptor IB (BMPR-IB) gene, which controls the fecundity of Booroola Merino ewes, was studied as a candidate gene for the prolificacy of Small Tail Han and Hu ewes. A single nucleotide polymorphism of the BMPR-IB gene was detected in both high (Small Tail Han and Hu) and low (Suffolk and Dorset) fecundity sheep breeds by polymerase chain reaction–single-strand conformation polymorphism (PCR-SSCP) analysis. The results indicated the presence of the same mutation (A746G) of the BMPR-IB gene in both Small Tail Han and Hu ewes and in Booroola Merino ewes, but not in both Suffolk and Dorset ewes. In Small Tail Han ewes, frequencies of BB, B+ and ++ genotypes were 0.524, 0.383 and 0.093, respectively. In Hu ewes, these frequencies were 0.882, 0.118 and 0.000. The BMPR-IB genotype distributions were significantly different (P<0.001) among high- and low-fecundity sheep breeds. Small Tail Han ewes with genotype BB had 0.92 (P<0.01) and 1.02 (P<0.01) lambs more than those with genotype ++ in the first and second parity, respectively. These results demonstrated that the BMPR-IB gene is a major gene affecting the prolificacy in both Small Tail Han and Hu ewes, and could be used as a molecular genetic marker to select the litter size in sheep.
Monotonically countably paracompact, collectionwise Hausdorff spaces and measurable cardinals
Authors: Good Chris , Knight Robin
Published: October 2005

We show that, if an MCP (monotonically countably paracompact) space fails to be collectionwise Hausdorff, then there is a measurable cardinal and that, if there are two measurable cardinals, then there is an MCP space that fails to be collectionwise Hausdorff.
Remarks on product 𝑉𝑀𝑂
Authors: Lacey Michael , Terwilleger Erin , Wick Brett
Published: October 2005

Well known results related to the compactness of Hankel operators of one complex variable are extended to little Hankel operators of two complex variables. Critical to these considerations is the result of Ferguson and Lacey (2002) characterizing the boundedness of the little Hankel operators in terms of the product BMO of S.-Y. Chang and R. Fefferman (1985), (1980).
Fixed point theorems in ordered 𝐿-spaces
Authors: Petruşel Adrian , Rus Ioan
Published: October 2005

The purpose of this paper is to present some fixed point results in ordered L-spaces. Our results generalize and extend a recent result of Ran and Reurings (2004). Some applications to matrix equations are also considered.
A dual graph construction for higher-rank graphs, and 𝐾-theory for finite 2-graphs
Authors: Allen Stephen , Pask David , Sims Aidan
Published: October 2005

Given a

k
k

-graph

Λ
\Lambda

and an element

p
p

of

N

k

\mathbb {N}^k

, we define the dual

k
k

-graph,

p
Λ

p\Lambda

. We show that when

Λ
\Lambda

is row-finite and has no sources, the

C
∗

C^*

-algebras

C
∗

(
Λ
)

C^*(\Lambda )

and

C
∗

(
p
Λ
)

C^*(p\Lambda )

coincide. We use this isomorphism to apply Robertson and Steger’s results to calculate the

K
K

-theory of

C
∗

(
Λ
)

C^*(\Lambda )

when

Λ
\Lambda

is finite and strongly connected and satisfies the aperiodicity condition.
Fixed point theorems under the interior condition
Authors: Jiménez-Melado Antonio , Morales Claudio
Published: October 2005

We show a fixed point theorem for condensing mappings under a new condition of the Leray-Schauder type. We call it the Interior Condition. We also discuss examples that demonstrate the independence of these two conditions.
A large deviation principle for random upper semicontinuous functions
Authors: Terán Pedro
Published: October 2005

We obtain necessary and sufficient conditions in the Large Deviation Principle for random upper semicontinuous functions on a separable Banach space. The main tool is the recent work of Arcones on the LDP for empirical processes.
Cube-approximating bounded wavelet sets in ℝⁿ
Authors: Yu Xiaojiang
Published: October 2005

We prove that for any real expansive

n
×
n

n\times n

matrix

A
A

, there exists a bounded

A
A

-dilation wavelet set in the frequency domain

R

n

\mathbb {R}^{n}

(the inverse Fourier transform of whose characteristic function is a band-limited single wavelet in the time domain

R

n

\mathbb {R}^{n}

). Moreover these wavelet sets can approximate a cube in

R

n

\mathbb {R}^{n}

arbitrarily. This result improves Dai, Larson and Speegle’s result about the existence of (basically unbounded) wavelet sets for real expansive matrices.
A finitely presented group with unbounded dead-end depth
Authors: Cleary Sean , Riley Tim
Published: October 2005

The dead-end depth of an element

g
g

of a group

G
G

, with respect to a generating set

A

\mathcal {A}

, is the distance from

g
g

to the complement of the radius

d

A

(
1
,
g
)

d_{\mathcal {A}}(1,g)

closed ball, in the word metric

d

A

d_{\mathcal {A}}

defined with respect to

A

\mathcal {A}

. We exhibit a finitely presented group

G
G

with a finite generating set with respect to which there is no upper bound on the dead-end depth of elements.
A refinement of the complex convexity theorem via symplectic techniques
Authors: Krötz Bernhard , Otto Michael
Published: October 2005

We apply techniques from symplectic geometry to extend and give a new proof of the complex convexity theorem of Gindikin-Krötz.
A problem of Baernstein on the equality of the 𝑝\mspace{1𝑚𝑢}-harmonic measure of a set and its closure
Authors: Björn Anders , Björn Jana , Shanmugalingam Nageswari
Published: October 2005

A. Baernstein II (Comparison of

p

p\mspace {1mu}

-harmonic measures of subsets of the unit circle, St. Petersburg Math. J. 9 (1998), 543–551, p. 548), posed the following question: If

G
G

is a union of

m
m

open arcs on the boundary of the unit disc

D

\mathbf {D}

, then is

ω

a
,
p

(
G
)
=

ω

a
,
p

(

G
¯

)

\omega _{a,p}(G)=\omega _{a,p}(\overline {G})

, where

ω

a
,
p

\omega _{a,p}

denotes the

p

p\mspace {1mu}

-harmonic measure? (Strictly speaking he stated this question for the case

m
=
2

m=2

.) For

p
=
2

p=2

the positive answer to this question is well known. Recall that for

p
≠
2

p \ne 2

the

p

p\mspace {1mu}

-harmonic measure, being a nonlinear analogue of the harmonic measure, is not a measure in the usual sense. The purpose of this note is to answer a more general version of Baernstein’s question in the affirmative when

1
>
p
>
2

1>p>2

. In the proof, using a deep trace result of Jonsson and Wallin, it is first shown that the characteristic function

χ
G

\chi _G

is the restriction to

∂

D

\partial \mathbf {D}

of a Sobolev function from

W

1
,
p

(

C

)

W^{1,p}(\mathbf {C})

. For

p
≥
2

p \ge 2

it is no longer true that

χ
G

\chi _G

belongs to the trace class. Nevertheless, we are able to show equality for the case

m
=
1

m=1

of one arc for all

1
>
p
>
∞

1>p>\infty

, using a very elementary argument. A similar argument is used to obtain a result for starshaped domains. Finally we show that in a certain sense the equality holds for almost all relatively open sets.
Smooth actions of 𝑅ⁿ
Authors: Schwartzman Sol
Published: October 2005

Given a smooth action of

R
n

R^n

on a

k
k

-dimensional differentiable manifold

M
k

M^k

, for each

0
≤
r
≤
k

0\le r\le k

we associate with “almost all" oriented orbits of dimension

r
r

an element of

H
r

(

M
k

,
R
)

H_r(M^k,R)

.
On the rigidity of magnetic systems with the same magnetic geodesics
Authors: Burns Keith , Matveev Vladimir
Published: October 2005

We study the analogue for magnetic flows of the classical question of when two different metrics on the same manifold share geodesics, which are the same up to reparametrization.
Linking in Hilbert space
Authors: Schechter Martin , Tintarev Kyril
Published: October 2005

We present the most general definition of the linking of sets in a Hilbert space and, drawing on the theory given in earlier papers by Schechter and Tintarev, give a necessary and sufficient geometric condition for linking when one set is compact.
Equivalence of topologies and Borel fields for countably-Hilbert spaces
Authors: Becnel Jeremy
Published: October 2005

We examine the main topologies—weak, strong, and inductive—placed on the dual of a countably-normed space and the

σ
\sigma

-fields generated by these topologies. In particular, we prove that for certain countably-Hilbert spaces the strong and inductive topologies coincide and the

σ
\sigma

-fields generated by the weak, strong, and inductive topologies are equivalent.
Chironomus tentans-Repressor Splicing Factor Represses SR Protein Function Locally on Pre-mRNA Exons and Is Displaced at Correct Splice Sites
Authors: Björk Petra , Wetterberg-Strandh Ingela , Baurén Göran , Wieslander Lars
Published: October 2005

Chironomus tentans-repressor splicing factor (Ct-RSF) represses the activation of splicing by SR proteins in vitro. Ct-RSF colocalizes with the Ser-Arg-rich (SR) protein hrp45 in interchromatin granule clusters and coimmunoprecipitates with hrp45 in nuclear extracts. Ct-RSF and hrp45 can also interact directly in vitro. Ct-RSF and hrp45 are recruited together to transcribing genes and associate with growing pre-mRNAs. Ct-RSF and hrp45 colocalize at a large number of gene loci. Injection of anti-Ct-RSF antibodies into nuclei of living cells blocks association of both Ct-RSF and hrp45 with the growing pre-mRNA, whereas binding of U2 small nuclear ribonucleoprotein particle (snRNP) to the pre-mRNA is unaffected. On the intron-rich Balbiani ring (BR) 3 pre-mRNA, hrp45 as well as U1 and U2 snRNPs bind extensively, whereas relatively little Ct-RSF is present. In contrast, the BR1 and BR2 pre-mRNAs, dominated by exon sequences, bind relatively much Ct-RSF compared with hrp45 and snRNPs. Our data suggest that Ct-RSF represses SR protein function at exons and that the assembly of spliceosomes at authentic splice sites displaces Ct-RSF locally.
From Function to Shape: A Novel Role of a Formin in Morphogenesis of the FungusAshbya gossypii
Authors: Schmitz Hans-Peter , Kaufmann Andreas , Köhli Michael , Laissue Pierre Philippe , Philippsen Peter
Published: October 2005

Morphogenesis of filamentous ascomycetes includes continuously elongating hyphae, frequently emerging lateral branches, and, under certain circumstances, symmetrically dividing hyphal tips. We identified the formin AgBni1p of the model fungus Ashbya gossypii as an essential factor in these processes. AgBni1p is an essential protein apparently lacking functional overlaps with the two additional A. gossypii formins that are nonessential. Agbni1 null mutants fail to develop hyphae and instead expand to potato-shaped giant cells, which lack actin cables and thus tip-directed transport of secretory vesicles. Consistent with the essential role in hyphal development, AgBni1p locates to tips, but not to septa. The presence of a diaphanous autoregulatory domain (DAD) indicates that the activation of AgBni1p depends on Rho-type GTPases. Deletion of this domain, which should render AgBni1p constitutively active, completely changes the branching pattern of young hyphae. New axes of polarity are no longer established subapically (lateral branching) but by symmetric divisions of hyphal tips (tip splitting). In wild-type hyphae, tip splitting is induced much later and only at much higher elongation speed. When GTP-locked Rho-type GTPases were tested, only the young hyphae with mutated AgCdc42p split at their tips, similar to the DAD deletion mutant. Two-hybrid experiments confirmed that AgBni1p interacts with GTP-bound AgCdc42p. These data suggest a pathway for transforming one axis into two new axes of polar growth, in which an increased activation of AgBni1p by a pulse of activated AgCdc42p stimulates additional actin cable formation and tip-directed vesicle transport, thus enlarging and ultimately splitting the polarity site.
CREB4, a Transmembrane bZip Transcription Factor and Potential New Substrate for Regulation and Cleavage by S1P
Authors: Stirling Julie , O'Hare Peter
Published: October 2005

Regulated intramembrane proteolysis of the factors SREBP and ATF6 represents a central control mechanism in sterol homeostasis and stress response within the endoplasmic reticulum. Here, we compare localization of ATF6-related bZip factors CREB4, CREB-H, Luman, and OASIS. These factors contain the defining features of a bZip domain, a predicted transmembrane domain and an adjacent cleavage site for the Golgi protease S1P, with conserved features which indicate that it represents a specific subclass of S1P sites. Each factor localizes to the endoplasmic reticulum (ER), but a population of CREB4 was also observed in the Golgi. Deletion of the transmembrane domain in CREB4 resulted in efficient nuclear accumulation. An N-terminal variant of CREB4 containing the BZIp domain potently activated expression from a target gene containing ATF6 binding sites and from the promoter for the ER chaperone GRP78/BIP. CREB4 was cleaved in a site-specific manner in response to brefeldin A disruption of the Golgi or by coexpression with S1P but only after deletion or substitution of its C-terminal lumenal domain. Thus, S1P cleavage of CREB4 may be suppressed by a determinant in the C-terminal region. Dithiothreitol induced more complete transport of CREB4 to the Golgi, but not cleavage. Together, the data identify at least one additional bZip factor whose localization responds to ER stress, and we propose a model based on these results that indicates additional levels of control of this novel class of transcription factors.