bluuebunny/crossref_metadata_2025 huggingface dataset:
HEROIC HAYDN, THE OCCASIONAL WORK AND ‘MODERN’ POLITICAL MUSIC
Authors: MATHEW NICHOLAS
Published: May 2007

Several compositions by Haydn from the 1790s appear to reflect, both directly and indirectly, the newly martial and patriotic atmosphere generated by the war with France. While this has long been recognized by music historians – in particular with reference to ‘Gott erhalte Franz den Kaiser’ – Haydn scholars have yet to describe or explain this trend adequately. Only Beethoven scholars have considered this music in any depth, portraying Haydn as the Viennese progenitor of the so-called heroic style. The paradox of this teleological Beethovenian reading of Haydn’s music from the 1790s is that the type of compositions that music historians have traditionally denigrated with the label ‘occasional works’ are portrayed as the ancestors of some of the most vaunted symphonic masterworks in the canon: historically situated music somehow creates the very pieces that supposedly instantiated the historically resistant ‘work concept’ in the period around 1800. Yet this paradox points to a growing tension within Haydn’s public identity and music in the 1790s – a tension between the emerging ideal of aesthetic autonomy and the reality of political appropriation during the revolutionary and Napoleonic Wars. Indeed, this very tension allowed Haydn and his music to enter political life and political discourse as never before, articulating a relationship between music and contemporary events that cannot adequately be described by the notion of the ‘occasional work’. Haydn’s emergence as a cultural hero, on a par with contemporary war heroes, and the attribution to his music of a sublime power analogous to worldly, even political, powers meant that his music could be heard as possessing a voice in its own right – a voice that could thus speak independently, and persuasively, on behalf of institutions and ideologies, rather than merely echoing them.
‘NICHT DIESE TÖNE’: LESSONS IN SONG AND SINGING FROM BEETHOVEN’S NINTH SYMPHONY
Authors: GLAUERT AMANDA
Published: May 2007

Discussions of the recitative intervention from the solo baritone in the finale of Beethoven’s Ninth Symphony usually focus on how his words might offer a commentary on the discourse of the symphony as understood in instrumental terms. This article seeks to interpret the baritone’s words as a call to song – song in its literal as well as idealized sense, as identified through strophic treatment and folk-like character. Beethoven’s borrowing of material from his own setting of Bürger’s Gegenliebe for his ‘Ode to Joy’ tune is taken as a sign of the composer engaging with Bürger’s advocacy of simple diegetic song, an advocacy that sits provocatively alongside the abstract idealism of Schiller’s An die Freude. Concentrating on the song-like aspects within the finale of the Ninth Symphony in this way might seem to magnify the effect of the silences and disjunctures within the movement. However, Johann Gottfried Herder (the poet and theorist of the lyric) embraced silence as one of the conditions of folk-like song, as Beethoven seems to have understood from his own settings of Herder’s poetry. A comparison between the Ninth Symphony finale and some of Beethoven’s actual settings suggests a new understanding of how the composer uses silence within the symphony. It also points up the radical nature of his balance between abstract and literal renditions of song in this work, a balance that even outstrips the Helen-Gretchen contrast in Goethe’s Faust for its subtlety and pervasiveness.
‘ES LEBE DIE ORDNUNG UND BETRIEBSAMKEIT! WAS HILFT DAS BESTE HERZ OHNE JENE!’: A NEW LOOK AT FANTASIA ELEMENTS IN THE KEYBOARD SONATAS OF C. P. E. BACH
Authors: WOLLENBERG SUSAN
Published: May 2007

How do we use the information contained in treatises written by composers and performers? I examine here the light that might be thrown on C. P. E. Bach’s keyboard sonatas by the material contained in his celebrated Versuch über die wahre Artdas Clavier zu spielen.
Geostatistical analysis of soil gas data in a high seismic intermontane basin: Fucino Plain, central Italy
Authors: Ciotoli G. , Lombardi S. , Annunziatellis A.
Published: May 2007

Numerous soil gas measurements of four gaseous species with very different geochemical behaviors were performed in the Fucino Basin, an area characterized by known and inferred structural discontinuities. A comprehensive statistical and geostatistical treatment of these data followed in order to provide insight into the spatial influence of tectonic discontinuities and geology on deep‐seated gas migration toward the surface. The results yielded anomalies with different features, reflecting the different gas‐bearing properties of the eastern seismogenic faults related to the 1915 earthquake (Mb= 7.0) and the hidden structural features occurring in the western side of the plain. In particular, this approach demonstrates that soil gas concentration (i.e., Rn and CO2) can identify the simpler normal faults of the eastern sector of the plain. In contrast, the more pervasive fracturing and faulting, as well as the occurrence of coarser deposits, on the western side of the area, make the location of faults less clear. The results show that gases migrate preferentially through zones of brittle deformation by advective processes, as suggested by the relatively high rate of migration needed to obtain anomalies of short‐lived222Rn in the soil pores. Furthermore, a geostatistical study of soil gas data was conducted to quantify the spatial domain of correlation and the gas‐bearing properties of faults on the basis of shallow soil gas distribution (i.e., anisotropic behavior). The results provide a clear correlation between the shape and orientation of the anomalies and the different geometry of the faults recognized in the plain.
Investigations into the applicability of adaptive finite element methods to two‐dimensional infinite Prandtl number thermal and thermochemical convection
Authors: Davies D. R. , Davies J. H. , Hassan O. , Morgan K. , Nithiarasu P.
Published: May 2007

An adaptive finite element procedure is presented for improving the quality of solutions to convection‐dominated problems in geodynamics. The method adapts the mesh automatically around regions of high solution gradient, yielding enhanced resolution of the associated flow features. The approach requires the coupling of an automatic mesh generator, a finite element flow solver, and an error estimator. In this study, the procedure is implemented in conjunction with the well‐known geodynamical finite element code ConMan. An unstructured quadrilateral mesh generator is utilized, with mesh adaptation accomplished through regeneration. This regeneration employs information provided by an interpolation‐based local error estimator, obtained from the computed solution on an existing mesh. The technique is validated by solving thermal and thermochemical problems with well‐established benchmark solutions. In a purely thermal context, results illustrate that the method is highly successful, improving solution accuracy while increasing computational efficiency. For thermochemical simulations the same conclusions can be drawn. However, results also demonstrate that the grid‐based methods employed for simulating the compositional field are not competitive with the other methods (tracer particle and marker chain) currently employed in this field, even at the higher spatial resolutions allowed by the adaptive grid strategies.
Crustal structure and magmato‐tectonic processes in an active rift (Asal‐Ghoubbet, Afar, East Africa): 2. Insights from the 23‐year recording of seismicity since the last rifting event
Authors: Doubre C. , Manighetti I. , Dorbath L. , Dorbath C. , Bertil D. , Delmond J. C.
Published: May 2007

The Asal‐Ghoubbet (AG) Rift has sustained a major volcano‐tectonic rifting episode in 1978 and has been subsequently monitored with continuous geodetic and seismological surveys. It is therefore an ideal place to study the transient magmato‐tectonic processes that operate after a rifting episode. We examine the space‐time evolution of ∼2500 Md ≤ 2.8 earthquakes recorded in the rift from 1979 to 2001. We focus on the relationships between this seismic activity and both the three‐dimensional structure of the rift and its postrifting behavior depicted from geodesy. The results highlight the major role of the central magmatic system (Fieale‐Shark Bay) on the structure, seismic activity, and overall behavior of the rift. From 1978 to 1986, the rift opens at a fast rate, yet mainly aseismically; the opening is magmatically driven and accommodated. Since 1986, when the opening rate abruptly decreased, the seismicity is concentrated in the central part of the rift and reveals pulses of activity of the central volcanic system. These pulses result from that magmatic zone undergoing alternating stretching and inflating episodes. Thus, while the plate‐driven induced stresses have been rebuilding in the rift since 1987, the rift opening is still essentially accommodated in the axial magmatic zone. The AG Rift has thus sustained a postrifting unsteady opening over more than 23 years following its stretching episode. That transient opening has essentially occurred aseismically, and most tectonic faults remain relaxed and locked.
Seismological evidence for variable growth of crust along the Izu intraoceanic arc
Authors: Kodaira Shuichi , Sato Takeshi , Takahashi Narumi , Ito Aki , Tamura Yoshihiko , Tatsumi Yoshiyuki , Kaneda Yoshiyuki
Published: May 2007

The processes that create continental crust in an intraoceanic arc setting are a matter of debate. To address this issue, we conducted an active source wide‐angle seismic study to examine along‐arc structural variations of the Izu intraoceanic arc. The data used were acquired over a 550‐km‐long profile along the volcanic front from Sagami Bay to Tori‐shima. The obtained structural model showed the existence of felsic to intermediate composition middle crust with a P wave velocity (Vp) of 6.0–6.5 km s−1 in its upper part and 6.5–6.8 km s−1 in its lower part. The thickness of the middle crust varied markedly from 3 to 13 km. The underlying lower crust also consisted of two layers (Vp of 6.8–7.2 km s−1 in the upper part and Vp of 7.2–7.6 km s−1 in the lower part). The upper of these layers was interpreted to consist of plutonic gabbro, and the lower layer was interpreted to be mafic to ultramafic cumulates. Average crustal velocities calculated from our model showed remarkable lateral variation, which correlated well with arc volcanism. Low average crustal seismic velocities (∼6.7 km s−1), due to thick middle crust, were obtained beneath basaltic volcanoes (e.g., O‐shima, Miyake‐jima, Hachijo‐jima, Aoga‐shima), while higher average velocities (∼7.1 km s−1) were obtained beneath rhyolitic volcanoes (e.g., Nii‐jima, Kurose, South Hachijo caldera, Myoji knoll, and South Sumisu caldera). We concluded from these observations that continental crust grows predominantly beneath the basaltic volcanoes of the Izu arc and that rhyolitic volcanism may be indicative of a more juvenile stage of crustal evolution, or remelting of preexisting continental crust, or both.
Diagnostic analyses of the ageostrophic vector in the non‐uniformly saturated, frictionless, and moist adiabatic flow
Authors: Yang Shuai , Gao Shouting , Wang Donghai
Published: May 2007

Because of the discontinuity of the latent heat release in the thermodynamic equation in the transitional area between the unsaturated and saturated air, the condensation probability function (q/qs)k (q and qs are specific humidity and saturated specific humidity, respectively, k = 9) is introduced into the thermodynamic equation. Then, the ageostrophic diabatic ω equation, in which · um is the single forcing term, is derived in a non‐uniformly saturated moist atmosphere. um includes the effects of both latent heat and relative humidity, and it is generated only in nearly saturated regions by the effect of the condensation probability function. To diagnose um, a rainfall case associated with the Meiyu front in the midlower reaches of the Yangtze River in China is numerically simulated using the Weather Research and Forecasting model. The results show that the divergence of um diagnoses the occurrence and evolution of rainfall better than those of dry vector and m in the lower troposphere do, and that ∇ · um is a better precursor for the future 6‐hour precipitation.
Finite-size nanoscaling of the critical temperature of ferromagnets with variable range of spin interactions
Authors: Willis R. F. , Bramfeld T. S. , Podolak K. R.
Published: May 2007

We report an analysis of data on the thickness-dependent Curie temperatures TC of itinerant ferromagnetic thin films with variable range of spin interactions “tuned” by alloying transition metals. We observe that TC decreases with decreasing film thickness according to the finite-size effect power law for two-dimensional Ising thin films, down to a critical thickness R0, beyond which point TC reduces linearly with further decreasing thickness. The demarcation point scales with the range of spin interactions R0. The parameter R0 scales with the evolution of the magnetic moment on the Slater-Pauling curve. This analysis of ultrathin film data provides a measure of the effective range of spin interactions in ferromagnets and demonstrates that, when the dimension L reduces below the intrinsic interaction length R0, TC no longer follows the finite-size effect power law behavior.
Spin structure of exchange-biased NiFe∕FeMn∕NiFe trilayers
Authors: Alsmadi A. M. , te Velthuis S. G. E. , Felcher G. P. , Kim C. G.
Published: May 2007

The magnetic hysteresis curves of NiFe(t)∕FeMn(15nm)∕NiFe(5nm) exchange-biased trilayers, with t ranging from 3.8to18nm, show two clearly separated loops, which were interpreted as corresponding to the independent magnetic reversal of the two ferromagnetic (FM) NiFe layers. Polarized neutron reflectometry allowed the determination of the evolution of these two layer magnetizations at various fields along the hysteresis curve. For increasing t, the behavior of the magnetization evolved from one where both layer magnetizations were always collinear to the applied field to one where rotation of the magnetizations was observed at various fields. Measurements on the thickest field-annealed sample additionally showed that, during the reversal, the magnetizations of the two NiFe layers are close to being perpendicular to each other. This magnetic configuration is discussed in terms of the FM/antiferromagnetic (AFM) interactions and of a possible coupling between the two FM layers across the thick AFM FeMn spacer.
Facile large-scale synthesis of monodisperse Fe nanoparticles by modest-temperature decomposition of iron carbonyl
Authors: Yang Haitao , Ito Fumiyuki , Hasegawa Daiji , Ogawa Tomoyuki , Takahashi Migaku
Published: May 2007

A facile synthesis method for monodisperse Fe nanoparticles has been developed by the injection of iron carbonyl into kerosene at a modest temperature, typically 180°C. By controlling the reaction time, the molar ratio of surfactants to Fe(CO)5, and the Fe(CO)5 concentration in kerosene, 3–12nm monodisperse Fe nanoparticles were prepared. The size distribution is very narrow and any size-selective treatment is not required even when several grams of Fe nanoparticles are synthesized in one pot. Magnetic measurements reveal that the saturation magnetization (Ms) of the 9.3nm Fe nanoparticles is always over 150emu∕g at room temperature.
Magnetism in Zn1−xCoxO (0⩽x<0.1) and Co3−yZnyO4 (y=0, 0.25, and 1) thin films
Authors: Sudakar C. , Kharel P. , Lawes G. , Suryanarayanan R. , Naik R. , Naik V. M.
Published: May 2007

We have investigated the properties of homogeneous spinel Co3−yZnyO4 (y=0, 0.25, and 1) and wurtzite CoxZn1−xO (0<x<0.1) films. Air annealed Co3−yZnyO4 films were found to develop only a small magnetic moment (∼10−3μB∕Co). Conversely, these samples exhibited greatly enhanced magnetic moments after vacuum annealing. The vacuum annealed films reveal the presence of Zn doped CoO, but no detectable Co metal clusters. When field cooled to 10K, the hysteresis curves of the vacuum annealed samples are displaced along the magnetization axis, which we attribute to uncompensated surface spins.
Mixed-cation designs of magnetic perovskites for Faraday rotation at IR wavelengths
Authors: Dionne Gerald F. , Taussig Alexander R. , Bolduc Martin , Bi Lei , Ross Caroline A.
Published: May 2007

Magnetic garnets with Bi3+ are the standard media of discrete Faraday rotation isolators for IR-laser∕fiber-optical transmission at 1.55μm wavelength. For monolithic integration with semiconductors, perovskites of generic formula A[B]O3 offer promising alternatives that involve combinations of select transition-metal ions in octahedral B sites. In this paper, two concepts are described. In both cases, the 180° B–O–B bonding of the perovskite lattice could provide superexchange fields large enough to maintain spin ordering at room temperature. One model proposes a quasiferrite arrangement with antiferromagnetic alignment between Fe3+ and Ni2+ charge ordered in the double perovskite compound {A3+A′4+}[Fe3+Ni2+]O6. The other concept relies on ferromagnetism through delocalization superexchange with the composition A23+[Mn4+Ni2+]O6. Where appropriate to enhance Faraday rotation, Bi3+ can be used for A3+.
Microwave electromagnetic and absorption properties of Nd2Fe14B∕α-Fe nanocomposites in the 0.5–18 and 26.5–40GHz ranges
Authors: Lian Li-Xian , Deng L. J. , Han M. , Tang W. , Feng Shao-Dong
Published: May 2007

Nd 2 Fe 14 B ∕ α - Fe nanocomposites were prepared using a melt-spinning method, subsequent annealing treatment, and ball milling. The complex permittivity and permeability of the composites were measured in the 0.5–18 and 26.5–40GHz frequency ranges. The permeability spectra of the Nd2Fe14B∕α-Fe nanocomposites exhibit relaxation and resonance type characteristic in the 0.5–18 and 26.5–40GHz frequency ranges, respectively. The resonance frequency (fr) of Nd10Fe78Co5Zr1B6 nanocomposite is 30GHz due to the large anisotropy field (HA). However, the resonance frequency of the Nd2Fe14B∕α-Fe sample is lower than that of Nd2Fe14B, due to the decrease of HA induced by the exchange interaction between hard and soft magnetic phases. These samples also showed good microwave absorption performance (reflection loss: <−20dB) in 9, 17, and 35–38GHz with matching thicknesses of 2, 1.2, and 0.37mm, respectively. Therefore, Nd2Fe14B∕α-Fe nanocomposites are thought to be a potential candidate for thinner microwave absorbers not only in the centimeter wave but also in the millimeter wave band.
Muon spin resonance study on UCu1.5Sn2
Authors: El-Khatib S. , Llobet A. , Kalvius G. M. , Noakes D. R. , Stronach C. E. , Ansaldo E. J. , Torikachvili M. S. , Nakotte H.
Published: May 2007

We report muon spin relaxation measurements results on UCu1.5Sn2, which crystallizes in the CaBe2Ge2-type structure. Our analysis is consistent with collinear antiferromagnetic order that occurs below 108K, in agreement with previous reports. The Brillouin-like behavior of the temperature dependence of the magnetic response is consistent with localized 5f moments. The phase transition at TN is unusual. Critical slowing down for the paramagnetic U spin fluctuations is absent, a behavior usually observed in first-order transitions. In contrast, the temperature dependence of the local field generated by the U spins is a typical second-order feature.
Effects of microvoids on the linewidth dependence of electromigration failure of dual-damascene copper interconnects
Authors: Chang C. W. , Thompson C. V. , Gan C. L. , Pey K. L. , Choi W. K. , Lim Y. K.
Published: May 2007

The electromigration lifetime of dual-damascene Cu interconnects was found to significantly decrease with increasing linewidth, for linewidths ranging between 0.2 and 2.25μm. Voids were also found to preexist in these lines. When void nucleation is required for failure, the electromigration reliability is generally found to be at most weakly dependent on the linewidth. In contrast, the current study suggests that growth, drift, and accumulation of existing voids lead to the observed strong linewidth dependence.
Gauge theory for finite-dimensional dynamical systems
Authors: Gurfil Pini
Published: May 2007

Gauge theory is a well-established concept in quantum physics, electrodynamics, and cosmology. This concept has recently proliferated into new areas, such as mechanics and astrodynamics. In this paper, we discuss a few applications of gauge theory in finite-dimensional dynamical systems. We focus on the concept of rescriptive gauge symmetry, which is, in essence, rescaling of an independent variable. We show that a simple gauge transformation of multiple harmonic oscillators driven by chaotic processes can render an apparently “disordered” flow into a regular dynamical process, and that there exists a strong connection between gauge transformations and reduction theory of ordinary differential equations. Throughout the discussion, we demonstrate the main ideas by considering examples from diverse fields, including quantum mechanics, chemistry, rigid-body dynamics, and information theory.
Thermoacoustic nanotechnology: Derivation of a lower limit to the minimum reachable size
Authors: Benavides Efrén Moreno
Published: May 2007

A physical limit to the minimum reachable size of a thermoacoustic engine has been obtained. It aims for a better physical understanding of the influence of the gas behavior in the energy dissipation of such smallest devices, and it is based on physical considerations about pipes of large aspect ratios. The solution depends on the gas properties and on the main aspect ratio of the pipes configuring the engine. The expressions obtained may be used by designers to establish the expected frontier to the minimum size for a given working gas at a given thermodynamic condition inside a pipe of a given aspect ratio. Numerical values for several common gases used by actual engines are presented and the results are discussed.
Effective method to compute vibrationally resolved optical spectra of large molecules at finite temperature in the gas phase and in solution
Authors: Santoro Fabrizio , Lami Alessandro , Improta Roberto , Barone Vincenzo
Published: May 2007

The authors present a new method for the computation of vibrationally resolved optical spectra of large molecules, including the Duschinsky rotation of the normal modes and the effect of thermal excitation. The method automatically selects the relevant vibronic contributions to the spectrum, independently of their frequency, and it is able to provide fully converged spectra with moderate computational times, both in vacuo and in solution. By describing the electronic states in the frame of the density functional theory and its time-dependent extension, they computed the room temperature absorption spectra of coumarin C153 and trans-stilbene in cyclohexane and the phosphorescence spectrum of porphyrazine in gas phase, showing that the method is fast and efficient. The comparison with experiment for trans-stilbene and coumarin C153 is very satisfactory, confirming the progress made toward a reliable method for the computation and interpretation for the optical spectra of large molecules.
Basic moments of phonon density of states spectra and characteristic phonon temperatures of group IV, III–V, and II–VI materials
Authors: Pässler Roland
Published: May 2007

We have redigitized a large variety of phonon density of states (PDOS) spectra, that have been published by diferent researchers for group IV (diamond, 3C-SiC, Si, and Ge), III–V (BN, BP, BAs, BSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb), and II–VI materials (ZnO, ZnS, ZnSe, ZnTe, CdS, and CdTe), including calculations of their moments, ⟨εn⟩, of orders n=−1, 1, 2, and 4. Notwithstanding the obvious differences in concrete shapes of spectra presented for one and the same material by different authors, the respective magnitudes of estimated moments have been found in most cases to be nearly the same (to within uncertainties of some few percent). For most materials under study, the average phonon temperatures of the lower and upper sections of PDOS spectra, ΘL and ΘU, are found to be by factors of order 0.6 lower or 1.4 higher, respectively, than the average phonon temperature, ΘP, of the total PDOS spectra. The estimated high-temperature limits of Debye temperatures, ΘD(∞), are found to be significantly higher (by factors of order 1.4) than ΘP, implying an order-of-magnitude equality, ΘD(∞)≈ΘU (within differences not exceeding an order of ±10%, for all materials under study). The phonon temperatures, Θg, that are effective in controlling the observable temperature dependences of fundamental energy gaps, Eg(T), are found to be usually of the same order as the respective average phonon temperatures, Θg≈ΘP. The existing differences between these two qualitatively different types of characteristic phonon temperatures are seen to be limited, for diamond, 3C-SiC, Si, Ge, AlN, GaN, GaP, GaAs, GaSb, InP, InSb, ZnS, ZnSe, ZnTe, and CdTe, to an order of ±12%. We design an exemplary way for precalculating harmonic parts of isochoric heat capacities on the basis of the estimated quadruplets of PDOS spectra moments. This novel calculation scheme is exemplified for silicon and germanium.
Preparation and properties of highly (100)-oriented
Pb
(
Zr
0.2
Ti
0.8
)
O
3
thin film prepared by rf magnetron sputtering with a PbOx buffer layer
Authors: Wu Jiagang , Zhu Jiliang , Xiao Dingquan , Zhu Jianguo , Tan Junzhe , Zhang Qinglei
Published: May 2007

A method for fabrication of highly (100)-oriented Pb(Zr0.2Ti0.8)O3 (PZT) thin films by rf magnetron sputtering with a special buffer of PbOx (RFMS-SBP) was developed. With this method, highly (100)-oriented Pb(Zr0.2Ti0.8)O3 thin films were prepared on the PbOx∕Pt(111)∕Ti∕SiO2∕Si(100) substrates, and the preferential (100) orientation of the Pb(Zr0.2Ti0.8)O3 film is 92%. The (100) orientation of the PbOx buffer layer leads to the (100) orientation of the PZT thin films, and the thickness of the buffer layer plays a significant role on the phase purity and electrical properties of the films. Highly (100)-oriented Pb(Zr0.2Ti0.8)O3 thin films with proper thickness of PbOx buffer layer possess good electrical properties with larger remnant polarization Pr (69.7 μC∕cm2), lower coercive field Ec (92.4 kV/cm), and good pyroelectric coefficient at room temperature (2.6×10−8 C∕cm2 K). The butterfly-shaped ε-E characteristic curve gives the evidence of the improved in-plane ferroelectric property in the films.
Thermal analysis studies of doping effects on the conformational motions of polymer chains in solid solutions with lasing molecules
Authors: Kalogeras Ioannis M. , Pallikari Fotini , Vassilikou-Dova Aglaia , Neagu Eugen R.
Published: May 2007

The advancement of the solid-state dye laser performance largely depends on the systematic study of the dye-matrix interactions at the nanoscopic scale. The current work deals with blends of a comparatively inert dye host, poly(methyl methacrylate) (PMMA), with nonionic/apolar (substituted perylenes) and ionic/polar (rhodamine 6G, pyrromethene 567) dyes at ≈10−4 mol L−1 loading. Differential scanning calorimetry (DSC) and thermally stimulated currents (TSC) were used to explore the relative strength of inter- and intramolecular guest-host interactions by monitoring blending-induced modifications of the high-temperature signals: the segmental relaxation, the space-charge relaxation, and the liquid-liquid transition. Both techniques revealed the antiplasticizing role of the oligomeric organics on the relaxation dynamics of polymer segments, evidenced by clear glass-transition temperature upshifts. It becomes apparent that this effect is independent of the size, polarity, and ionicity of the dopant, signifying a common mechanism underway. It is suggested that, at least for the dyes under investigation, the chromophores simply fill the voids within the matrix, imposing strong steric hindrances on the rearrangement of the long-range structure. A comparison between the present results and earlier low-temperature dielectric data reveals that the large-scale relaxation dynamics show stronger perturbations due to blending, in comparison to the localized rotational motion of the pendant groups. DSC provided estimates for the unconverted monomer percentages in the solid blends. These were also determined more accurately by nuclear magnetic resonance (NMR), which additionally confirmed that the tacticity of the chains is not affected by the presence of the dye.
High-resolution stress assessments of interconnect/dielectric electronic patterns using optically active point defects of silica glass as a stress sensor
Authors: Leto Andrea , Porporati Alessandro Alan , Zhu Wenliang , Green Martin , Pezzotti Giuseppe
Published: May 2007

A piezospectroscopic (PS) cathodoluminescence (CL) study has been carried out on a Cu-Ta∕SiOx (carbon-doped) model chip prepared on a Si substrate. The PS approach was applied to CL spectra arising from optically active point defects in dielectric silica. The red CL emission arising from nonbridging oxygen hole centers (NBOHC) in the carbon-doped SiOx dielectric layer was calibrated and used as a stress sensor. This approach enabled us to locate the trace of the residual stress tensor, as locally developed during manufacturing process in the dielectric interlayers between Cu-Ta interconnects. A minimally invasive electron beam allowed probing local residual stress fields with an improved spatial resolution as compared to more conventional photostimulated PS techniques applied to the Si substrate. In addition, a two-dimensional deconvolution procedure was attempted to retrieve the “true” residual stress distribution piled up between adjacent Cu-Ta lines, according to a theoretical model for embedded structural elements. As probed on the nanometer scale by the NBOHC sensor, the interfaces were found under a substantially enhanced residual stress, characteristic for low-temperature Si∕SiOx growth in the presence of metallic interconnects. CL/PS spectroscopy represents an improved tool to quantitatively monitor the residual stresses developed at SiOx∕metal interfaces, thus opening the possibility to systematically engineer the interface itself in search for high-reliability Si-based devices.
Ionization of H2 Rydberg molecules at a metal surface
Authors: Lloyd G. R. , Procter S. R. , McCormack E. A. , Softley T. P.
Published: May 2007

The ionization of a beam of H2 Rydberg molecules in collision with a metal surface (evaporated Au or Al) is studied. The Rydberg states are excited in an ultraviolet–vacuum ultraviolet double-resonant process and are state selected with a core rotational quantum number N+=0 or 2 and principal quantum numbers n=17–22 (N+=2) or n=41–45 (N+=0). It is found that the N+=0 states behave in a very similar manner to previous studies with atomic xenon Rydberg states, the distance of ionization from the surface scaling with n2. The N+=2 states, however, undergo a process of surface-induced rotational autoionization in which the core rotational energy transfers to the Rydberg electron. In this case the ionization distance scales approximately with ν02, the effective principal quantum number with respect to the adiabatic threshold. This process illustrates the close similarity between field ionization in the gas phase and the surface ionization process which is induced by the field due to image charges in the metal surface. The surface ionization rate is enhanced at certain specific values of the field, which is applied in the time interval between excitation and surface interaction. It is proposed here that these fields correspond to level crossings between the N+=0 and N+=2 Stark manifolds. The population of individual states of the N+=2, n=18 Stark manifold in the presence of a field shows that the surface-induced rotational autoionization is more facile for the blueshifted states, whose wave function is oriented away from the surface, than for the redshifted states. The observed processes appear to show little dependence on the chemical nature of the metallic surface, but a significant change occurs when the surface roughness becomes comparable to the Rydberg orbit dimensions.
On the hysteresis in E to H and H to E transitions and the multistep ionization in inductively coupled plasma
Authors: Lee Min-Hyong , Lee Kyeong Hyo , Hyun Dong-Seok , Chung Chin-Wook
Published: May 2007

Plasma densities, E to H and H to E transition coil currents, and electron energy distribution functions (EEDFs) are measured at various argon pressures in an inductively coupled plasma. The measured plasma density versus coil current shows that the hysteresis during the E-H transition is clearly observed only when the pressure is sufficiently high. At low gas pressures the hysteresis is not obvious. The measured EEDFs show that when the hysteresis is obvious (high pressures), electrons whose energy is not sufficient for excitation or ionization of the ground state atom are strongly depleted in the H mode. This depletion may be caused by multistep ionization. However, for the case where the hysteresis is not obvious (low pressures), the depletion due to multistep ionization is also not present. These experimental results show that the multistep ionization is a dominant factor in the E-H transition hysteresis.
Characterization of hardened cylindrical C1018 steel rods (0.14%–0.2% C, 0.6%–0.9% Mn) using photothermal radiometry
Authors: Wang Chinhua , Mandelis Andreas
Published: May 2007

Frequency-domain photothermal radiometry has been used for the evaluation of the hardened case depth and the measurement of the thermophysical properties (thermal conductivity and diffusivity) of cylindrical C1018 heat-treated steel rods. The measurement results of several steel cylinders nominally hardened identically during a common heat-treating process were consistent with each other and also with mechanical indentation hardness test results. The application of the two-layer composite cylinder thermal-wave theory yielded an effective case depth within the discrete two-layer thermal-wave approximation. This technique provides a relatively simple noncontact and nondestructive method for evaluating the thermophysical parameters of layered cylindrical samples. The good fit of the experimental frequency scans to the two-layer thermal-wave model was shown to constitute a reasonable method for calibrating actual continuously decreasing hardness depth profiles by means of abrupt two-layer-equivalent profiles.
Dual-frequency resonant phonon scattering in BaxRyCo4Sb12 (R=La, Ce, and Sr)
Authors: Yang J. , Zhang W. , Bai S. Q. , Mei Z. , Chen L. D.
Published: May 2007

Low temperature transport properties of polycrystalline dual-element-filled skutterudites BaxRyCo4Sb12 (R=La, Ce, and Sr) are reported. Remarkably the combination of Ba and La or Ba and Ce is much more effective in reducing lattice thermal conductivity (κL) than Ba and Sr. The density-functional theory calculations and experimental data suggest that multiple-filled skutterudites using filler elements of different chemical natures, such as the rare earths, the alkaline earths, or the alkalines provide a broader range of resonant phonon scattering. The thermoelectric figure of merit of filled skutterudites can likely be improved by means of such multiple-element void filling.
Detection of single biomolecule fluorescence excited through energy transfer: Application to light-harvesting complexes
Authors: Wörmke S. , Mackowski S. , Brotosudarmo T. H. P. , Bräuchle Ch. , Garcia A. , Braun P. , Scheer H. , Hofmann E.
Published: May 2007

The authors show that energy transfer is a feasible mechanism for exciting fluorescence of single light-harvesting complexes with different characters of the fluorescing state. This approach is applied for excitons consisting of 18 strongly coupled bacteriochlorophylls in light-harvesting complex 2 as well as for peridinin-chlorophyll-protein monomers containing either two chlorophyll a molecules or a pair of chlorophyll a and chlorophyll b characterized with the emission energy difference of 400cm−1. Using this method the authors are able to observe fluorescence spectral dynamics on the scale comparable or larger than the emission linewidth of a single chromophore.
Arrays of crystalline C60 and pentacene nanocolumns
Authors: Zhang Jian , Salzmann Ingo , Rogaschewski Siegfried , Rabe Jürgen P. , Koch Norbert , Zhang Fujun , Xu Zheng
Published: May 2007

Crystalline nanocolumn arrays of two organic semiconductors, C60 and pentacene, were fabricated by glancing angle deposition and characterized by scanning electron microscopy and x-ray diffraction. The diameter of the nanocolumns is typically 100nm and essentially independent of column height (up to 360nm for pentacene). The surface diffusion length of the molecules is identified as a key parameter for the formation of the nanocolumns. Our results indicate that glancing angle deposition is a simple technique to fabricate organic crystalline nanocolumn arrays, and controlling the surface diffusion via chemical and/or morphological patterning may lead to innovative organic nanostructures.
Superconducting single photon detectors made by local oxidation with an atomic force microscope
Authors: Delacour C. , Claudon J. , Poizat J.-Ph. , Pannetier B. , Bouchiat V. , Espiau de Lamaestre R. , Villegier J.-C. , Tarkhov M. , Korneev A. , Voronov B. , Gol’tsman G.
Published: May 2007

The authors present a fabrication technique of superconducting single photon detectors made by local oxidation of niobium nitride ultrathin films. Narrow superconducting meander lines are obtained by direct writing of insulating niobium oxynitride lines through the films using voltage-biased tip of an atomic force microscope. Due to the 30nm resolution of the lithographic technique, the filling factor of the meander line can be made substantially higher than detector of similar geometry made by electron beam lithography, thus leading to increased quantum efficiency. Single photon detection regime of these devices is demonstrated at 4.2K.
Charge transfer in nanocrystalline-Au∕ZnO nanorods investigated by x-ray spectroscopy and scanning photoelectron microscopy
Authors: Chiou J. W. , Ray S. C. , Tsai H. M. , Pao C. W. , Chien F. Z. , Pong W. F. , Tsai M.-H. , Wu J. J. , Tseng C. H. , Chen C.-H. , Lee J. F. , Guo J.-H.
Published: May 2007

O K- and Zn and Au L3-edge x-ray absorption near-edge structure (XANES), x-ray emission spectroscopy (XES), and scanning photoelectron microscopy (SPEM) are performed to investigate the electronic structure of ZnO nanorods with nanocrystalline (nc)-Au particles grown on the surfaces. The XANES spectra of nc-Au∕ZnO nanorods reveal the decrease of the number of both O 2p and Zn 4s∕3d unoccupied states with the increase of the nc-Au particle size. The number of Au 6s∕5d unoccupied states increases when the size of nc-Au particle decreases, indicating that the deposition of nc-Au particles on the surface of ZnO nanorods promotes charge transfer from the ZnO nanorods to nc-Au particles. Excitation energy dependent XES and SPEM spectra show that the number of electrons in the valence band of O 2p-Zn 4sp hybridized states decreases as the nc-Au particle size increases, revealing that more electrons are excited from the valence band to the conduction band of ZnO nanorods and the storage of electrons in nc-Au particles.
Ultraviolet photoluminescence from ferromagnetic Fe-doped AlN nanorods
Authors: Ji X. H. , Lau S. P. , Yu S. F. , Yang H. Y. , Herng T. S. , Sedhain A. , Lin J. Y. , Jiang H. X. , Teng K. S. , Chen J. S.
Published: May 2007

Fe-doped AlN (AlN:Fe) nanorods on silicon substrates were fabricated using a catalysis-free vapor phase method. The AlN:Fe nanorods exhibited high crystalline quality and preferred c-axis orientation. The spontaneous saturated magnetization of the AlN:Fe nanorods was determined to be ∼0.64μB∕Fe at room temperature. Room temperature photoluminescence measurement of the AlN:Fe nanorods revealed two strong ultraviolet emissions at 3.69 and 6.02eV which could be attributed to Fe3+-related and band edge emissions, respectively. The Fe-doped AlN nanorods not only exhibited ferromagnetism but also significantly enhanced the band edge emission as compared to the undoped AlN nanorods.
14
-
pixel
, multiplexed array of gamma-ray microcalorimeters with 47eV energy resolution at 103keV
Authors: Doriese W. B. , Ullom J. N. , Beall J. A. , Duncan W. D. , Ferreira L. , Hilton G. C. , Horansky R. D. , Irwin K. D. , Mates J. A. B. , Reintsema C. D. , Vale L. R. , Xu Y. , Zink B. L. , Rabin M. W. , Hoover A. S. , Rudy C. R. , Vo D. T.
Published: May 2007

The authors present a prototype for a high-energy-resolution, high-count-rate, gamma-ray spectrometer intended for nuclear forensics and international nuclear safeguards. The prototype spectrometer is an array of 14 transition-edge-sensor microcalorimeters with an average energy resolution of 47eV (full width at half maximum) at 103keV. The resolution of the best pixel is 25eV. A cryogenic, time-division multiplexer reads out the array. Several important topics related to microcalorimeter arrays are discussed, including cross-talk, the uniformity of detector bias conditions, fabrication of the arrays, and the multiplexed readout. The measurements and calculations demonstrate that a kilopixel array of high-resolution microcalorimeters is feasible.
Influence of grain size on ultrafast carrier dynamics in thin nanocrystalline silicon films
Authors: Lioudakis Emmanouil , Othonos Andreas , Nassiopoulou A. G. , Lioutas Ch. B. , Frangis N.
Published: May 2007

The ultrafast carrier dynamics in thin nanocrystalline silicon films (10 and 20nm thick) on quartz over a broad spectral range using optical pumping at a moderate fluence of 2.5mJ∕cm2 were studied. The films were composed of randomly oriented silicon nanocrystals of various sizes and shapes. The authors probed a fast and a slow relaxation mechanism. The slow decay (∼300ps) was attributed to bulk nanocrystal states similar to those of bulk silicon, while the faster one (∼3ps) was attributed to surface states at grain boundaries, more dominant in the smaller nanocrystals due to their larger surface/volume ratio.
Validated estimation of growth and age in the New Zealand abalone Haliotis iris using stable oxygen isotopes
Authors: Naylor J. R. , Manighetti B. M. , Neil H. L. , Kim S. W.
Published: May 2007

The growth and reproductive patterns of abalone are central to an understanding of the dynamics of their populations, and provide essential input into many of the stock assessment models currently used as the basis of assessing the sustainability of the fisheries. At present, most of this knowledge is obtained by tag-recapture methods, which are time consuming, often expensive and potentially confounding. The aim of the present study was to determine whether variations in the ratios of oxygen and carbon isotopes in the shells of Haliotis iris can be used to determine age, growth and reproductive patterns. Isotopic analyses of H. iris shells indicated that oxygen isotope profiles within the shells reflected ambient water temperature at the time of shell precipitation, and that these profiles could be used to determine age and growth patterns. To match the variation in isotopic ratios with ambient temperature cycles, we also adopted the novel approach of fitting a growth function to the data sets. The method should allow the collection of abalone growth information over the finer scales more appropriate for the rational management of abalone fisheries. Variations in the ratios of carbon isotopes showed no consistent patterns and, unlike some mollusc species, did not appear to be useful predictors of reproductive status at length.
Contribution of hydrophobic and electrostatic interactions to the membrane integration of the Shaker K
+
channel voltage sensor domain
Authors: Zhang Liyan , Sato Yoko , Hessa Tara , von Heijne Gunnar , Lee Jong-Kook , Kodama Itsuo , Sakaguchi Masao , Uozumi Nobuyuki
Published: May 2007

Membrane-embedded voltage-sensor domains in voltage-dependent potassium channels (K
v
channels) contain an impressive number of charged residues. How can such highly charged protein domains be efficiently inserted into biological membranes? In the plant K
v
channel KAT1, the S2, S3, and S4 transmembrane helices insert cooperatively, because the S3, S4, and S3–S4 segments do not have any membrane insertion ability by themselves. Here we show that, in the
Drosophila
Shaker K
v
channel, which has a more hydrophobic S3 helix than KAT1, S3 can both insert into the membrane by itself and mediate the insertion of the S3–S4 segment in the absence of S2. An engineered KAT1 S3–S4 segment in which the hydrophobicity of S3 was increased or where S3 was replaced by Shaker S3 behaves as Shaker S3–S4. Electrostatic interactions among charged residues in S2, S3, and S4, including the salt bridges between E283 or E293 in S2 and R368 in S4, are required for fully efficient membrane insertion of the Shaker voltage-sensor domain. These results suggest that cooperative insertion of the voltage-sensor transmembrane helices is a property common to K
v
channels and that the degree of cooperativity depends on a balance between electrostatic and hydrophobic forces.
The directed cooperative assembly of proteorhodopsin into 2D and 3D polarized arrays
Authors: Liang Hongjun , Whited Gregg , Nguyen Chi , Stucky Galen D.
Published: May 2007

Proteorhodopsin is the membrane protein used by marine bacterioplankton as a light-driven proton pump. Here, we describe a rapid cooperative assembly process directed by universal electrostatic interactions that spontaneously organizes proteorhodopsin molecules into ordered arrays with well defined orientation and packing density. We demonstrate the charge density-matching mechanism that selectively controls the assembly process. The interactions among different components in the system are tuned by varying their charge densities to yield different organized transmembrane protein arrays: (
i
) a bacteriorhodopsin purple membrane-like structure where proteorhodopsin molecules are cooperatively arranged with charged lipids into a 2D hexagonal lattice; (
ii
) selected liquid-crystalline states in which crystalline lamellae made up of the coassembled proteorhodopsin and charged lipid molecules are coupled three-dimensionally with polarized proteorhodopsin orientation persisting through the macroscopic scale. Understanding this rapid electrostatically driven assembly process sheds light on organizing membrane proteins in general, which is a prerequisite for membrane protein structural and mechanistic studies as well as
in vitro
applications.