bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient and generic strategy for producing soluble human proteins and domains in E. coli by screening construct libraries
Authors: Cornvik Tobias , Dahlroth Sue‐Li , Magnusdottir Audur , Flodin Susanne , Engvall Benita , Lieu Victoria , Ekberg Monica , Nordlund Pär 
Published: August 2006

AbstractThe implementation of generic and efficient technologies for the production of recombinant eukaryotic proteins remains an outstanding challenge in structural genomics programs. We have recently developed a new method for rapid identification of soluble protein expression in E. coli, the colony filtration blot (CoFi blot). In this study, the CoFi blot was used to screen libraries where the N‐terminal translation start point was randomized. To investigate the efficiency of this strategy, we have attributed a large number of proteins to this process. In a set of 32 mammalian proteins, we were able to double the success rate (from 34 to 68%) of producing soluble and readily purifiable proteins in E. coli. Most of the selected constructs had their N‐termini close to predicted domain borders and the method therefore provides a mean for experimental “domain foot printing.” Surprisingly, for most of the targets, we also observed expressing constructs that were close to full‐length. In summary this strategy constitutes a generic and efficient method for producing mammalian proteins for structural and functional studies. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Measures for the assessment of fuzzy predictions of protein secondary structure
Authors: Lee Julian 
Published: August 2006

AbstractMany of the recent secondary structure prediction methods incorporate the idea of fuzzy set theory, where instead of assigning a definite secondary structure to a query residue, probability for the residue being in each of the conformational states is estimated. Moreover, continuous assignment of conformational states to the experimentally observed protein structures can be performed in order to reflect inherent flexibility. Although various measures have been developed for evaluating performances of secondary structure prediction methods, they depend only on the most probable secondary structures. They do not assess the accuracy of the probabilities produced by fuzzy prediction methods, and they cannot incorporate information contained in continuous assignments of conformational states to observed structures. Three important measures for evaluating performance of a secondary structure prediction algorithm, Q score, Segment OVerlap (SOV) measure, and the k‐state correlation coefficient (Corr), are deformed into fuzzy measures F score, Fuzzy OVerlap (FOV) measure, and the fuzzy correlation coefficient (Forr), so that the new measures not only assess probabilistic outputs of fuzzy prediction methods, but also incorporate information from continuous assignments of secondary structure. As an example of application, prediction results of four fuzzy secondary structure prediction methods, PSIPRED, PROFking, SABLE, and PREDICT, are assessed using the new fuzzy measures. Proteins 2006. © 2006 Wiley‐Liss, Inc.
On the dielectric properties of the spin crossover complex [Fe(bpp)2] [BF4]2
Authors: Guillon Thomas , Bonhommeau Sébastien , Costa José Sanchez , Zwick Antoine , Létard Jean‐François , Demont Philippe , Molnár Gábor , Bousseksou Azzedine 
Published: August 2006

AbstractThe thermal variation of the dielectric constant in the spin crossover complex [Fe(bpp)2] [BF4]2 displays a 16 K large hysteresis loop centered around 178 K corresponding to the spin transition temperatures. Unexpectedly, the dielectric constant has a higher value in the low‐spin state. DFT calculations were carried out to determine the microscopic electronic polarizabilities, but these latter could not be correlated with the macroscopic permittivity changes pointing the importance of the effect of the counter‐anions which must be necessarily taken into account in future DFT calculations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Polarized Raman scattering studies of nonpolar a ‐plane GaN films grown on r ‐plane sapphire substrates by MOCVD
Authors: Gao Haiyong , Yan Fawang , Li Jinmin , Wang Junxi , Yan Jianchang 
Published: August 2006

AbstractNonpolar (11$ \bar 2 $0) a ‐plane GaN thin films were grown on r ‐plane (1$ \bar 1 $02) sapphire substrates by low‐pressure metal organic chemical vapor deposition (MOCVD). The stress characteristics of the a ‐plane GaN films were investigated by means of polarized Raman scattering spectra in backscattering configurations. The experimental results show that there are strong anisotropic in‐plane stresses within the epitaxial a ‐plane GaN films by calculating the corresponding stress tensors. The temperature dependence of Raman scattering spectra was studied in the range from 100 K to 550 K. The measurements reveal that the Raman phonon frequencies decrease with increasing temperature. The temperature at which nonpolar a ‐plane GaN films are strain free is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Precipitation kinetics of LiNbO3 and LiNb3O8 crystalline phases in thermally annealed amorphous LiNbO3 thin films
Authors: Akazawa H. , Shimada M. 
Published: August 2006

AbstractThe pyrochlore (LiNb3O8) phase in lithium niobate crystal does not contribute to ferroelectric or electro‐optic properties. We investigated a way to suppress the precipitation of this phase that was formed by thermally annealing amorphous LiNbO3 films. The volume fraction of LiNb3O8 with respect to LiNbO3 becomes higher during longer annealing periods and at higher annealing temperatures because of the evaporation of Li2O units from the surface. Annealing in an O2 atmosphere promotes the formation of the pyrochlore phase more than in a vacuum. We propose rapid thermal annealing of oxygen‐rich LiNbO3 film in a vacuum to provide the best solution to obtaining transparent, single LiNbO3 phase film. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric properties, conduction mechanism, and possibility of nanodomain state with quantum dot formation in impurity‐doped gamma‐irradiated incommensurate TlInS2
Authors: Sardarly R. M. , Mamedov N. T. , Wakita K. , Shim Y. , Nadjafov A. I. , Samedov O. A. , Zeynalova E. A. 
Published: August 2006

AbstractTemperature‐dependent dielectric and conduction properties of the impurity‐doped and gamma‐irradiated samples of TlInS2 semiconductor‐ferroelectric with incommensurate phase are presented. As found, in both cases a stable relaxor state is emerging in the material with temperature provided that the central ion in InS4 tetrahedron is replaced by an impurity atom such as Mn or Cr, or radiation dose exceeds 400 Mrad. Same as NMR‐studies, the present work drives to a conclusion that In‐displacements are among the components of the order parameter of the incommensurate phase transition. The origin of the non‐activated conductivity observed in the relaxor state of TlInS2 is assumed to be resonance tunneling executed by charge carriers from electron levels in the band gap through potential barriers created by incommensurate superstructure. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties and electronic band structure of AgInSe2
Authors: Ozaki Shunji , Adachi Sadao 
Published: August 2006

AbstractOptical properties of a chalcopyrite semiconductor AgInSe2 have been studied by optical absorption, spectroscopic ellipsometry (SE), and thermoreflectance (TR) measurements. The measurements reveal distinct structures at energies of the critical points in the Brillouin zone. By performing the band‐structure calculation, these critical points have been successfully assigned to specific points in the Brillouin zone. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Systematic studies on electronic structures of CuInSe2 and the other chalcopyrite related compounds by first principles calculations
Authors: Maeda T. , Takeichi T. , Wada T. 
Published: August 2006

AbstractWe have systematically studied electronic structure of chalcopyrite‐type CuInSe2 and the other chalcopyrite compounds, ABX 2 (A = Cu, Ag; B = In, Ga, Al; X = Se, S). First‐principles calculations were performed within a density functional theory with the generalized gradient approximation (GGA), using a plane‐wave pseudopotential method. Valence band maximum (VBM) of CuBX 2 is an antibonding state of Cu 3d and Se 4p (S 3p), while conduction band minimum (CBM) is also an antibonding state derived from B n s and Se 4p (S 3p). Theoretical band gap increases at the order of In, Ga, Al and the values of sulfides, CuB S2 were larger than those of the corresponding selenides, CuB Se2. In present study, we found that the lowest unoccupied n s orbital of B atom in the conduction band shift up to higher energy. Therefore, the band gaps of CuB Se2 (CuB S2) increase at the order of In, Ga, Al with shifting of n s orbital for B atom. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic and dielectric properties of the ruthenium double perovskites La2MRuO6 (M = Mg, Co, Ni, and Zn)
Authors: Yoshii Kenji , Ikeda Naoshi , Mizumaki Masaichiro 
Published: August 2006

AbstractMagnetic and dielectric properties of the ruthenium double perovskites La2MRuO6 (M = Mg, Co, Ni, and Zn) were investigated. The magnetization measurements for M = Co and Ni showed the existence of magnetic order at 20–30 K. Though the oxides with M = Zn and Mg exhibit a deviation from the Curie–Weiss law, magnetic order was not clearly observed. The result of La2ZnRuO6 was different from that previously reported, in which a ferromagnetic transition was found at around 165 K. The AC dielectric measurements for M = Co and Ni showed large dielectric constants (typically larger than 1000) at around room temperature, suggesting both the formation of short‐ranged polar regions and the magnetic origin of large dielectric constant. In addition, two peaks were found for the temperature dependence of the tan δ component for La2NiRuO6. The behavior suggests the existence of two different polar regions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐assembled nanowhiskers grown by MBE on InP(001) surface
Authors: Bouravleuv Alexei , Minami Kazuyuki , Ishibashi Takayuki , Sato Katsuaki 
Published: August 2006

AbstractGe and MnP nanowhiskers were synthesized by molecular‐beam epitaxy technique on InP(001) surface concurrently. The growth of Ge nanowhiskers is found to be assisted by Mn‐based nanocluster‐mediated vapour‐liquid‐solid mechanism of growth, whereas the growth of MnP nanowhiskers seems to be caused by catalyst‐free mechanism. Magnetic property measurements revealed that samples with prevailing Ge nanowhiskers exhibit ferromagnetic behaviour up to room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time investigations of selenization reactions in the system Cu–In–Al–Se
Authors: Jost Stefan , Hergert Frank , Hock Rainer , Purwins Michael , Enderle Ralph 
Published: August 2006

AbstractIn this article we present results of a detailed study of selenization reactions in the quaternary system Cu–In–Al–Se and of the binary subsystem aluminum–selenium. The investigation of solid‐state reactions involved in the formation of the compound semiconductor Cu(In,Al)Se2 was performed using real‐time X‐ray diffraction (XRD) with a time resolution of 22.5 s while annealing an elemental layer stack of the metals covered with selenium. A temperature‐resolved phase analysis shows that the formation of the semiconductor takes place via metal‐selenides. Ex‐situ XRD measurements of the processed thin films show a phase segregation concerning the aluminum content of the formed chalcopyrite. Subsequent Rietveld‐refinement of real‐time measurements reveals a formation reaction of the quaternary semiconductor Cu(In,Al)Se2 from the γ‐In2Se3 related crystal structure of (Al,In)2Se3 and Cu2Se as educts. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Predicted reaction paths for the formation of multinary chalcopyrite compounds
Authors: Hergert Frank , Jost Stefan , Hock Rainer , Purwins Michael , Palm Jörg 
Published: August 2006

AbstractWe apply the concept of epitaxy, which has been proven to be essential for the formation of CuInSe2 and CuGaSe2 out of binary selenide compounds to multinary compounds. We show that the formation of quaternary chalcopyrites is possible starting either with binary or with mixed crystal chalcogenide compounds. The complete sets of chemical solid‐state reactions equations are given. The solid‐state reactions are expected to proceed faster, if only one sublattice needs to be rearranged. It shows out, that ternary and quaternary chalcopyrite compounds can be synthesised by fast reaction mechanisms directly from chalcogenide compounds. The fastest way to obtain chalcopyrites containing more than four elements is a stepwise process. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO based ternary transparent conductors
Authors: Polity Angelika , Meyer Bruno K. , Krämer Thorsten , Wang Changzhong , Haboeck Ute , Hoffmann Axel 
Published: August 2006

AbstractZnO1–x Sx films in the whole composition range were deposited by radio‐frequency reactive sputtering on different substrates. Raman measurements verified that the LO phonon of ZnO shifts towards lower frequencies as a function of the S content in the alloyed films. The composition dependence of the band gap energy in the ternary system was determined by optical transmission and the optical bowing parameter was found to be about 3 eV. We compare this behavior to ZnOSe films which can, however, only be synthesized in a narrow composition range close to the binary constituents ZnO and ZnSe. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Host lattice materials in the system Ca3N2–AlN–Si3N4 for white light emitting diode
Authors: Uheda K. , Hirosaki N. , Yamamoto H. 
Published: August 2006

AbstractNew host lattice materials whose red phosphors for white LEDs have been investigated in the ternary system Ca3N2–AlN–Si3N4, just as Ca2Si5N8 and CaSiN2:Eu were found in the binary system Ca3N2–Si3N4. A new red phosphor of CaAlSiN3:Eu which is effectively excited by blue‐GaN and near UV‐GaInN LED chips has been synthesized at 1600 °C for 2 h and subsequently at 1800 °C for 2 h under nitrogen pressure of 1 MPa. The host‐compound has an orthorhombic structure with the space group Cmc21 (No. 36), which is isotypic with LiSi2N3 and NaSi2N3. The red phosphor showed the emission peak around 650 nm which was assinged to 5d → 4f of Eu2+ ion, and its color coordinates were estimated to be 0.667 and 0.327. The optimum concentration of Eu2+ ion was 1.6 mol%. The phosphor also had a high chemical stability, high quantum output, and especially a good thermal property compared to the other phosphors, Ca2Si5N8:Eu2+ and CaSiN2:Eu2+. CaAlSiN3:Eu2+ maintained 83% of the initial efficiency above 150 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Blue‐shift of absorption edge in LaTiO2N by controlling the anion nonstoichiometry
Authors: Moriga Toshihiro , Aoki Daisuke , Nishida Yasuhiro , Kitaji Kazuya , Takahara Keiko , Murai Kei‐ichiro , Nakabayashi Ichiro 
Published: August 2006

AbstractThe perovskite‐type oxynitride LaTiO2N was prepared by heating an oxide precursor at 950 °C for 5 hours under NH3 atmosphere at a flow rate of 1 dm3/min. The precursor was prepared by the polymerized complex method. The oxynitride obtained was almost stoichiometric, LaTi(O0.68N0.32)2.9, with a reddish orange color. The oxynitride was successively annealed at 950 °C for 3 hours under a NH3 atmosphere at flow rates of 50 cm3/min, 30 cm3/min and 10 cm3/min, respectively. The color and composition varied from yellow LaTi(O0.89N0.11)2.8 through green‐yellow LaTi(O0.93N0.07)2.9 to light‐blue LaTi(O0.98N0.02)2.9 in accordance with the decreased flow rate. The absorption edges varied from 2.28 eV for the reddish orange, 2.56 eV for the yellow, 3.17 eV for the green‐yellow, to 3.44 eV for the light‐blue oxynitrides. Annealing under NH3 is therefore effective in color tuning, mainly resulting in a blue‐shift of the absorption edge. DV‐Xα calculations support the conclusion that the lower flow rate of NH3 led to a lower amount of nitrogen and higher oxygen levels in the oxynitrides. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallographic growth orientation of Cu(InGa)Se2 films in relation to substrate material nature
Authors: Yamada A. , Matsubara K. , Nakamura S. , Ishizuka S. , Sakurai K. , Tampo H. , Shibata H. , Nakanishi H. , Niki S. 
Published: August 2006

AbstractMo films deposited on glass substrates by rf sputtering, and Cu(InGa)Se2 (CIGS) films deposited on the Mo films by the three‐stage method and CuGaSe2 (CGS) films deposited directly on glass substrates by co‐evaporation of elemental source materials were observed by X‐ray diffraction (XRD) pole figure measurements. The texture analysis of the Mo films revealed a wide variety of solid‐spatial orientations, being dependent on the sputtering device configuration and deposition conditions. The in‐plane orientation of the CIGS or CGS films was affected by the Mo film texture, however, the predominant crystallographic lattice plane along the substrate surface was found to be close to (115) in any case. It must be noticed that the CIGS film is apt to grow in (115) orientation because of the lattice plane nature although this orientation cannot be detected by the XRD 2θ –θ scan due to its zero structural factor. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bismuth containing III–V quaternary alloy InGaAsBi grown by MBE
Authors: Feng G. , Oe K. , Yoshimoto M. 
Published: August 2006

AbstractInGaAsBi epilayers were created on InP substrates by molecular beam epitaxy for the first time. The high crystalline quality of the InGaAsBi epilayer with smooth interface was confirmed by high resolution X‐ray diffraction measurements. Up to 2.5% Bi was incorporated in the film based on Rutherford back scattering (RBS) results. The RBS channeling spectra give clear evidence that the Bi atoms were substitutionally located in the InGaAs zinc‐blende lattice sites. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Helicon‐wave‐excited plasma sputtering deposition of Ga‐doped ZnO transparent conducting films
Authors: Sugiyama Mutsumi , Murayama Akira , Imao Takashi , Saiki Keita , Nakanishi Hisayuki , Chichibu Shigefusa F. 
Published: August 2006

AbstractSputtering deposition of Ga‐doped ZnO (ZnO:Ga) thin films was carried out using the helicon‐wave‐excited plasma sputtering (HWPS) method. The films sputtered above 150 °C had a preferential {0001} orientation. According to the surface‐damage‐free nature, the films having featureless surface morphology exhibited an optical transmittance greater than 80% in the visible spectral wavelengths. However, because the deposition temperature was limited to 250 °C, the electron mobility was limited to as low as 2–3 cm2/V s due to the small grain size (∼25 nm). The results indicate that ZnO:Ga films deposited by HWPS can be used in the transparent conducting oxide layer, provided that higher electron mobility is achieved. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray spectroscopic investigation of forbidden direct transitions in CuGaO2 and CuInO2
Authors: Makhova L. , Wett D. , Lorenz M. , Konovalov I. 
Published: August 2006

AbstractWe studied experimentally the local partial density of electronic states (LPDOS) in the conduction band (CB) and in the valence band (VB) of CuGaO2 and CuInO2 by means of X‐ray absorption spectroscopy (XAS) and X‐ray emission spectroscopy (XES). The edges of both the CB and VB are found to be the copper s‐ and/or d‐states. Therefore, direct transitions between the band edges in these materials should be forbidden by symmetry selection rules. The crystal phases in the samples were identified as having delafossite structure, determined by X‐ray powder diffraction (XRD). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent progress towards the development of ferromagnetic nitride semiconductors for spintronic applications
Authors: Newman N. , Wu S. Y. , Liu H. X. , Medvedeva J. , Gu Lin , Singh R. K. , Yu Z. G. , Krainsky I. L. , Krishnamurthy S. , Smith D. J. , Freeman A. J. , van Schilfgaarde M. 
Published: August 2006

AbstractThis article describes progress towards producing prototype magnetoelectronic structures based on III–N semiconductor materials. We focus on the materials properties connected with the key physical phenomena underlying potential spintronic devices: producing, injecting, transporting, manipulating and detecting spin‐polarized electron populations. Our experiments have shown that the maximum magnetic moment is realized for a composition of Ga0.97Cr0.03N and a substrate growth temperature of ∼1050 K. Ion channeling experiments show that ∼90% of Cr sits substitutionally on the cation site. The highest measured magnetization was 1.8μB/Cr atom (∼60% of the expected moment from band theory for ideal material) with the Curie temperature over ∼900 K. This strongly suggests a link between the CrGa impurity band and ferromagnetism and suggests that a double‐exchange‐like mechanism is responsible for the ferromagnetic ordering. The transport properties of spin‐polarized charge carriers were modeled theoretically taking into account both the Elliott–Yafet and the D'yakonov–Perel' scattering mechanisms. We include the spin–orbit interaction in the unperturbed Hamiltonian and treat scattering by ionized impurities and phonons as a perturbation. Our numerical calculations predict two orders of magnitude longer electron spin relaxation times and an order of magnitude shorter hole spin relaxation times in GaN than in GaAs. First‐principles electronic structure calculations predict that efficient spin injection can be achieved using a ferromagnetic GaN:Cr electrode in conjunction with an AlN tunnel barrier. In this structure, the electrode is found to be half‐metallic up to the interface and is thus a candidate for high‐efficiency magnetoelectronic devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic phase modulated ellipsometry in application to some novel single and polycrystalline ternary compounds
Authors: Mamedov N. , Shim Y. , Toyota H. , Wakita K. , Yamamoto N. , Iida S. 
Published: August 2006

AbstractThe results of the application of the spectroscopic phase modulated ellipsometry (SPME) to a series of novel ternary compounds from anisotropic to polycrystalline are presented to show the high effectiveness of this optical technique with regard to the dielectric function of the new materials. Besides, SPME in specular reflection mode to study the polarization degree of the light reflected at specular angle is shown to be very informative in determination of the best conditions for optical measurements on rough surfaces such as, for example, surfaces of the polycrystalline ternary thiogallate compounds studied in this work. An incoherent approach relating the measured depolarization with the surface variance and optical constants of a material or thin film is proposed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)