F. M. Pontes、Sérgio Henrique Leal、E. R. Leite 等 7 位作者2004-06-23Journal of Applied Physics
We have carried out dielectric and Raman spectroscopy studies at the 298–623 K temperature range in polycrystalline Pb0.70Sr0.30TiO3 thin films grown by a soft chemical method. The diffuse phase-transition behavior of the thin films was observed by means of the dielectric constant versus temperature curves, which show…
Ferroelectric and Piezoelectric MaterialsPhotorefractive and Nonlinear OpticsAcoustic Wave Resonator Technologies
Runying Chen、Kathryn A. Jakes、Dennis W. Foreman2004-06-23Journal of Applied Polymer Science
Abstract The precision and accuracy of diffraction peak positions resolved from the powder X‐ray diffraction spectra of cotton fibers by means of the residuals peak‐fitting procedure of a commercial peak‐fitting software package (PeakFit®) was investigated to explore the potential of such programs in providing reliabl…
Advanced Cellulose Research StudiesDyeing and Modifying Textile FibersBamboo properties and applications
Igor A. Levitsky、Peter T. Kanelos、William B. Euler2004-06-23The Journal of Chemical Physics
An actuating system composed of nafion ionomeric polymer coated with single-walled carbon nanotubes electrodes was studied as an electromechanical actuator. The actuator gives a sizable mechanical response to low voltages (turn-on voltage of approximately 2.5 V) under open-air conditions, i.e., in the absence of a sur…
Advanced Sensor and Energy Harvesting MaterialsConducting polymers and applicationsDielectric materials and actuators
Hani M. Hilles、Francisco Ortega、Ramón G. Rubio 等 4 位作者2004-06-23Physical Review Letters
We have carried out an experimental study on the mechanical relaxation of Langmuir films of a glass-forming polymer, poly-(4-hydroxystyrene), a good example of a two-dimensional system made of condensed polymer coils (at poor-solvent conditions). This study allows us to explore the response functions of the film and t…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesTheoretical and Computational Physics
Ali Reza Mahdavian、Mahdi Abdollahi、Hamid Reza Bijanzadeh2004-06-23Journal of Applied Polymer Science
Abstract Solution and radical polymerization of acrylamide in the presence of potassium persulfate in D 2 O was investigated up to high conversion by high‐field 1 H‐NMR spectroscopy. The kinetics of reaction was studied according to the data obtained from the corresponding spectra at various times during the polymeriz…
Advanced Polymer Synthesis and CharacterizationThermal and Kinetic AnalysisPolymer Science and PVC
K. H. Chen、Z.Q. Jin、J. Li 等 9 位作者2004-06-23Journal of Applied Physics
Exchange-coupled R2Fe14B/α-Fe (R=Nd or Pr) nanocomposite bulk magnets with nearly full density have been successfully produced by shock compaction of melt-spun powders. X-ray diffraction and transmission electronic microscopy analyses of the shock-consolidated compacts showed no grain growth upon compaction, in fact,…
Magnetic properties of thin filmsRare-earth and actinide compoundsMagnetic Properties of Alloys
C. Masciovecchio、S. C. Santucci、Alessandro Gessini 等 6 位作者2004-06-23Physical Review Letters
Using the novel synchrotron radiation based inelastic ultraviolet scattering technique, the dynamic structure factor of normal and supercooled liquid water has been measured at a momentum transfer Q approximately equal to 0.1 nm(-1), in the temperature range 260-340 K. The structural (alpha) relaxation has been observ…
Material Dynamics and PropertiesThermodynamic properties of mixturesSpectroscopy and Quantum Chemical Studies
Udo Schwingenschlögl、Volker Eyert2004-06-23Annalen der Physik
Abstract To compare the metal‐insulator transitions (MITs) of VO 2 and V 2 O 3 we analyze the relations between the structural and electronic properties of the vanadium Magnéli phases. These materials set up the homologous series V n O 2 n ‐1 (3 ≤ n ≤ 9) and have crystal structures comprising typical dioxide‐like and…
Transition Metal Oxide NanomaterialsAdvanced Condensed Matter PhysicsCatalysis and Oxidation Reactions
B. Vodopivec、C. Filipič、A. Levstik 等 6 位作者2004-06-23Physical Review B
Linear and third-order nonlinear dielectric susceptibilities and the dielectric polarization were measured in $6.5∕65∕35$ lanthanum lead zirconate titanate (PLZT) hot-pressed ceramics. On cooling linear dielectric data show a transition from an ergodic to a nonergodic relaxor phase, while, on heating, a ferroelectric…
Ferroelectric and Piezoelectric MaterialsGlass properties and applicationsMultiferroics and related materials
George Psomas、N. Bréfuel、Françoise Dahan 等 4 位作者2004-06-23Inorganic Chemistry
Anaerobic reaction of ferrous thiocyanate with the deprotonated form of the pentadentate dinucleating Schiff base 1,3-bis[(2-pyridylmethyl)imino]propan-2-ol (LH) yields the novel trinuclear [Fe3L2(NCS)4(H2O)] species 1. LH results from the bis-condensation of 2-acetyl-pyridine with 1,3-diaminopropan-2-ol and includes…
Magnetism in coordination complexesMetalloenzymes and iron-sulfur proteinsMetal-Catalyzed Oxygenation Mechanisms
Jung‐Kun Lee、Jae Yun Yi、Kug Sun Hong2004-06-23Journal of Applied Physics
Changes in structure and phase transition behavior are investigated for two types of La-doped sodium bismuth titanate ceramics. When A-site vacancies are formed by La incorporation, the phase transition near 200 °C becomes pronounced. Hysteresis loop and ε(T) demonstrate that the structure above 200 °C is the incommen…
Ferroelectric and Piezoelectric MaterialsAcoustic Wave Resonator TechnologiesMicrowave Dielectric Ceramics Synthesis
M. Souza、Ado Jório、Cristiano Fantini 等 12 位作者2004-06-23Physical Review B
This work reports Raman spectroscopy measurements from single wall carbon nanotubes (SWNTs) addressing the nature of the $G$-band resonance Raman spectra. Experimental results on different samples are presented, i.e., aligned and misaligned SWNT samples, as well as isolated and bundled SWNTs. It is shown that the Rama…
Carbon Nanotubes in CompositesSilicon Nanostructures and PhotoluminescenceMechanical and Optical Resonators
Yi Chen、De X. Zeng2004-06-23The Journal of Organic Chemistry
A photochromic diarylethene with phenolic Schiff base 1a can be easily transformed to photochromic diarylethene with benzoxazole 3a in the conditions of base and phototrigger. Both of their photochromic properties are investigated. They show that the conversions of ring-open form to ring-closed form at photostationary…
Porphyrin and Phthalocyanine ChemistryPhotochromic and Fluorescence ChemistryPhotoreceptor and optogenetics research
Sergey I. Pokutnyi、Lucjan Jacak、J. Misiewicz 等 5 位作者2004-06-23Journal of Applied Physics
A theory of the Stark effect in semiconductor quantum dots has been developed for the case of dominating polarization interaction of an electron and a hole with the nanocrystal surface. A shift of electron and hole quantum well levels in a nanocrystal in the interband absorption range in a uniform external electric fi…
Semiconductor Quantum Structures and DevicesQuantum Dots Synthesis And PropertiesSilicon Nanostructures and Photoluminescence
Tatjana N. Parac‐Vogt、Kristof Kimpe、Sophie Laurent 等 7 位作者2004-06-23European Journal of Inorganic Chemistry
Abstract Four monoamide derivatives of Gd−DTPA with alkyl chains consisting of 12, 14, 16, or 18 carbon atoms were synthesized. The gadolinium( III ) complexes with chain lengths of 14, 16 or 18 carbon atoms were efficiently incorporated into mixed micelles whereas the complex with a chain length of 12 carbon atoms wa…
Advanced MRI Techniques and ApplicationsMagnetism in coordination complexesLanthanide and Transition Metal Complexes
C.K. Jayasankar、K. Ramanjaneya Setty、P. Babu 等 5 位作者2004-06-23Physical Review B
The effect of hydrostatic pressure on the emission spectra and fluorescence lifetimes of ${\mathrm{Eu}}^{3+}$:lithium borate glass has been measured up to $32.6\phantom{\rule{0.3em}{0ex}}\text{GPa}$ at room temperature (RT) and up to $25.2\phantom{\rule{0.3em}{0ex}}\text{GPa}$ at $15\phantom{\rule{0.3em}{0ex}}\mathrm{…
Luminescence Properties of Advanced MaterialsHigh-pressure geophysics and materialsGlass properties and applications
Lin-Hui Ye、Bang‐Gui Liu、Dingsheng Wang 等 4 位作者2004-06-23Physical Review B
Phonon-dispersion curves for a series of single-wall carbon nanotubes (SWCNT's) have been obtained by ab initio supercell approach. Force constants are calculated using norm-conserving pseudopotential plane-wave method in the framework of the density-functional theory and local-density approximation. Cumulant force-co…
Carbon Nanotubes in CompositesGraphene research and applicationsThermal properties of materials
P. Gorría、David Martínez‐Blanco、J.A. Blanco 等 8 位作者2004-06-23Physical Review B
Both $\mathrm{Cu}$ and $\mathrm{Fe}$ metals, with face-centered cubic (fcc) crystal structures, are nonmagnetic. However, the substitution of $\mathrm{Cu}$ atoms by Fe in the fcc-$\mathrm{Cu}$ lattice leads to the formation of a random solid solution and the appearance of ferromagnetic order, with a value of the magne…
Magnetic properties of thin filmsRare-earth and actinide compoundsMagnetic Properties of Alloys
Jan Helbing、Harald Bregy、Jens Bredenbeck 等 9 位作者2004-06-23Journal of the American Chemical Society
Thio amino acids can be integrated into the backbone of peptides without significantly perturbing their structure. In this contribution we use ultrafast infrared and visible spectroscopy as well as state-of-the-art ab initio computations to investigate the photoisomerization of the trans form of N-methylthioacetamide…
Photochromic and Fluorescence ChemistryPhotoreceptor and optogenetics researchbioluminescence and chemiluminescence research
Bilal El‐Zahab、Hongfei Jia、Ping Wang2004-06-23Biotechnology and Bioengineering
Multistep reactions catalyzed by a covalently immobilized enzyme-cofactor-enzyme system were achieved. Lactate dehydrogenase (LDH), glucose dehydrogenase (GDH), and cofactor NADH were incorporated into two porous silica glass supports. One of the glass supports had pores of 30 nm in diameter, while the other was of 10…
Electrochemical sensors and biosensorsMesoporous Materials and CatalysisCovalent Organic Framework Applications