bluuebunny/crossref_metadata_2025 huggingface dataset:
Method and context perspectives on learning and knowledge creation in quality management
Authors: Choo Adrian S. , Linderman Kevin W. , Schroeder Roger G.
Published: October 2006

This research develops a framework of learning and knowledge‐based quality improvement by integrating the two perspectives of learning and knowledge creation. One perspective focuses on adhering to a prescribed methodology while the other emphasizes managing the context. By conceptualizing a comprehensive quality program as comprising basic contextual and methodological elements, we develop theoretically how a comprehensive quality program such as Six Sigma can produce dissimilar types of learning and knowledge, and how a quality advantage can become more sustainable.
Radiative effect of clouds on tropospheric chemistry in a global three‐dimensional chemical transport model
Authors: Liu Hongyu , Crawford James H. , Pierce Robert B. , Norris Peter , Platnick Steven E. , Chen Gao , Logan Jennifer A. , Yantosca Robert M. , Evans Mat J. , Kittaka Chieko , Feng Yan , Tie Xuexi
Published: October 2006

Clouds exert an important influence on tropospheric photochemistry through modification of solar radiation that determines photolysis frequencies (J‐values). We assess the radiative effect of clouds on photolysis frequencies and key oxidants in the troposphere with a global three‐dimensional (3‐D) chemical transport model (GEOS‐CHEM) driven by assimilated meteorological observations from the Goddard Earth Observing System data assimilation system (GEOS DAS) at the NASA Global Modeling and Assimilation Office (GMAO). We focus on the year of 2001 with the GEOS‐3 meteorological observations. Photolysis frequencies are calculated using the Fast‐J radiative transfer algorithm. The GEOS‐3 global cloud optical depth and cloud fraction are evaluated and generally consistent with the satellite retrieval products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the International Satellite Cloud Climatology Project (ISCCP). Results using the linear assumption, which assumes linear scaling of cloud optical depth with cloud fraction in a grid box, show global mean OH concentrations generally increase by less than 6% because of the radiative effect of clouds. The OH distribution shows much larger changes (with maximum decrease of ∼20% near the surface), reflecting the opposite effects of enhanced (weakened) photochemistry above (below) clouds. The global mean photolysis frequencies for J[O1D] and J[NO2] in the troposphere change by less than 5% because of clouds; global mean O3 concentrations in the troposphere increase by less than 5%. This study shows tropical upper tropospheric O3 to be less sensitive to the radiative effect of clouds than previously reported (∼5% versus ∼20–30%). These results emphasize that the dominant effect of clouds is to influence the vertical redistribution of the intensity of photochemical activity while global average effects remain modest, again contrasting with previous studies. Differing vertical distributions of clouds may explain part, but not the majority, of these discrepancies between models. Using an approximate random overlap or a maximum‐random overlap scheme to take account of the effect of cloud overlap in the vertical reduces the impact of clouds on photochemistry but does not significantly change our results with respect to the modest global average effect.
Escaping ion measurement with high time resolution on CHS
Authors: Shinohara K. , Isobe M. , Darrow D. S.
Published: October 2006

A scintillator-based lost ion probe can measure the temporal evolution of both the gyroradius and the pitch angle of energetic ions escaping a magnetically confined plasma. For the probe on the Compact Helical System, the time resolution of this detailed two-dimensional measurement is determined by a framing rate of the video camera that records the luminous images produced by the ions striking the scintillator plate. The framing rate of the old camera was 30Hz, thus the time resolution was about 33ms. Our interest is to understand the energetic ion transport in fast events such as a bursting energetic ion driven mode. The typical time scale of these events is less than 1ms, meaning that the old camera was too slow. By replacing it with an image-intensified high-speed video camera system, the temporal resolution was improved from 33to0.07ms. We have successfully installed the fast camera and captured some fast events caused by magnetohydrodynamics, which were unobservable using the original camera.
Sub-nanometric metallic Au clusters as efficient Er3+ sensitizers in silica
Authors: Trave Enrico , Mattei Giovanni , Mazzoldi Paolo , Pellegrini Giovanni , Scian Carlo , Maurizio Chiara , Battaglin Giancarlo
Published: October 2006

Silica films co-implanted with Er and Au ions show an enhancement of rare earth photoluminescence after gold introduction in the matrix. Er excitation originates in a broad spectral region, from the red to the near ultraviolet. We have investigated the influence of gold aggregation on the optical properties of co-doped samples by varying the temperature of post-Au implantation annealing in the 400–900°C range. Optical measurements and extended x-ray absorption analysis support the hypothesis of an energy transfer process mediated by sub-nanometric Au aggregates with metallic character that are optically activated mostly through electron interband transitions between d and sp-conduction levels.
On the mechanism of anion desorption from DNA induced by low energy electrons
Authors: Ptasińska Sylwia , Sanche Léon
Published: October 2006

Our knowledge of the mechanisms of radiation damage to DNA induced by secondary electrons is still very limited, mainly due to the large sizes of the system involved and the complexity of the interactions. To reduce the problem to its simplest form, we investigated specific electron interactions with one of the most simple model system of DNA, an oligonucleotide tetrameter compound of the four bases. We report anion desorption yields from a thin solid film of the oligonucleotide GCAT induced by the impact of 3–15eV electrons. All observed anions (H−, O−, OH−, CN−, and OCN−) are produced by dissociative electron attachment to the molecule, which results in desorption peaks between 6 and 12eV. Above 14eV nonresonant dipolar dissociation dominates the desorption yields. By comparing the shapes and relative intensities of the anion yield functions from GCAT physisorbed on a tantalum substrate with those obtained from isolated DNA basic subunits (i.e., bases, deoxyribose, and phosphate groups) from either the gas phase or condensed phase experiments, it is possible to obtain more details on the mechanisms involved in low energy electron damage to DNA, particularly on those producing single strand breaks.
Structural instability of metallic glasses under radio-frequency-ultrasonic perturbation and its correlation with glass-to-crystal transition of less-stable metallic glasses
Authors: Ichitsubo T. , Matsubara E. , Chen H. S. , Saida J. , Yamamoto T. , Nishiyama N.
Published: October 2006

It has been reported that the structural stability is significantly deteriorated under radio-frequency-ultrasonic perturbation at relatively low temperatures, e.g., near/below the glass transition temperature Tg, even for thermally stable metallic glasses. Here, we consider an underlying mechanism of the ultrasound-induced instability, i.e., crystallization, of a glass structure to grasp the nature of the glass-to-liquid transition of metallic glasses. Mechanical spectroscopy analysis indicates that the instability is caused by atomic motions resonant with the dynamic ultrasonic-strain field, i.e., atomic jumps associated with the β relaxation that is usually observed for low frequencies of the order of 1Hz at temperatures far below Tg. Such atomic motions at temperatures lower than the so-called kinetic freezing temperature Tg originate from relatively weakly bonded (and/or low-density) regions in a nanoscale inhomogeneous microstructure of glass, which can be straightforwardly inferred from a partially crystallized microstructure obtained by annealing of a Pd-based metallic glass just below Tg under ultrasonic perturbation. According to this nanoscale inhomogeneity concept, we can reasonably understand an intriguing characteristic feature of less-stable metallic glasses (fabricated only by rapid melt quenching) that the crystallization precedes the glass transition upon standard heating but the glass transition is observable at extremely high rates. Namely, in such less-stable metallic glasses, atomic motions are considerably active at some local regions even below the kinetic freezing temperature. Thus, the glass-to-crystal transition of less-stable metallic glasses is, in part, explained with the present nanoscale inhomogeneity concept.
Improvement on macroscopic compressibility approximation and beyond
Authors: Zhou Shiqi
Published: October 2006

A numerical procedure is proposed to extend the thermodynamic perturbation expansion (TPE) to a higher order. It is shown that the present second order term is superior to that due to a macroscopic compressibility approximation (MCA), a local compressibility approximation, and a superposition approximation by Barker and Henderson [Rev. Mod. Phys. 48, 587 (1976)]. Extensive model calculation and comparison with simulation data available in literature and supplied in the present report indicate that the present third order TPE is superior to a previous second order TPE based on the MCA, two previous perturbation theories, which are respectively based on an analytical mean spherical approximation for an Ornstein-Zernike equation, and an assumed explicit functional form for the Laplace transform of radial distribution function multiplied by radial distance, and a recent generalized van der Waals theory. The present critical temperature for a hard core attractive Yukawa fluid of varying range is in very good agreement with that due to a hierarchical reference theory. The present third order TPE is computationally far more modest than the self-consistent integral equation theory, and therefore is a viable alternative to use of the latter.
Combined rf and transport effects in magnetized capacitive discharges
Authors: Carter M. D. , Ryan P. M. , Hoffman D. , Lee W. S. , Buchberger D. , Godyak V.
Published: October 2006

Magnetic fields can be used to enhance the performance and operational envelope of rf capacitive discharges for semiconductor processing. Antennas in magnetized experimental fusion devices can experience similar rf processes that lead to surface erosion and degraded antenna performance. Two-dimensional modeling is needed to understand the combined effects of production and transport in these plasmas; however, magnetized plasma is a complicated medium because of tensor rf conductivity, anisotropic transport, and the fact that rf power alone sustains the plasma. In this paper, we give results from a model originally derived for studies of magnetized fusion and helicon discharges that has been adapted to capacitive discharges and compare the results with experimental data. The two-dimensional model combines the effects of the magnetic field on the plasma’s rf properties and the bulk transport of plasma, including a sheath layer with finite thickness at the boundaries. A collisionless sheath model uses the rf fields in the sheath region, along with the density at the interface between the bulk plasma and the sheath, to determine the sheath thickness and to estimate the rectified dc potential. The driven rf fields are resolved inside the sheath region by including resistive dissipation caused by ion acceleration. These results are iterated with a model for transport of the bulk plasma to produce a global model of the sheath voltages and bulk rf plasma heating. The results at various iterative steps help isolate magnetic field effects that are caused by modification of the plasma’s rf response from transport effects that are caused by the reduced electron mobility perpendicular to the magnetic field. The magnetic field can enhance confinement for some pressure regimes and magnetic configurations. More importantly, the magnetic field can restrict the motion of electrons that are heated by the rf, localizing the nonequilibrium distribution of electron energy and reducing the electron transport across magnetic field lines. Changes in the plasma rf response can also play a role in the behavior of the discharge by further localizing the rf power deposition in the plasma.
Water properties inside nanoscopic hydrophobic pocket studied by computer simulations
Authors: Setny Piotr , Geller Maciej
Published: October 2006

The structure and dynamics of water in the vicinity of the hemispherical hydrophobic pocket of 8Å radius were examined via molecular dynamics simulations in NVT ensemble. Density, hydrogen bonding properties, and residence times of water molecules were projected on two-dimensional planes providing a spatial description of water behavior. We found that the average water density is significantly depleted relative to bulk value. A detailed analysis of pocket occupancy revealed fluctuations between states of completely empty pocket and a pocket filled with a bulklike fluid, which seem to result from collective behavior of water molecules. Free energy differences accompanying these fluctuations are rather small, suggesting that the given pocket radius is close to the critical one for transition between gas and liquid phases in the considered system. We show that the situation is different in the case of a simple Lennard-Jones fluid. These results indicate that changing the surface curvature from flat to concave may lead to qualitative difference in water behavior in its vicinity. We think that our studies may also put some light on binding site desolvation process which is necessary to understand to make correct predictions of binding energies.
Local deformation of liquid crystal director induced by translational motion of carbon nanotubes under in-plane field
Authors: Baik In-Su , Jeon Sang Yeon , Jeong Seok Jin , Lee Seung Hee , An Kay Hyeok , Jeong Seok Ho , Lee Young Hee
Published: October 2006

The translational motion of carbon nanotubes (CNTs) dispersed in a nematic liquid crystal (NLC) has been observed in the fabricated CNT-doped homogeneously aligned NLC cells by applying in-plane electric field. The long axis of CNTs was aligned along the LC director in the initial state. However, the CNTs above a critical ac electric field, due to their net charge, overcame the LC director field to generate translational motion and as a consequence distorted the local LC directors to have light leakage. We observed the motional textures in the form of vertical stripes in the local area between electrodes, which were explained by a translational motion of CNTs above critical ac fields.
Tunable, narrow, and enhanced electroluminescent emission from porous-silicon-reflector-based organic microcavities
Authors: Qiu X. J. , Tan X. W. , Wang Z. , Liu G. Y. , Xiong Z. H.
Published: October 2006

Microcavity organic light-emitting diodes (MC-OLEDs) based on porous silicon distributed Bragg reflectors (PS-DBRs) have been realized, and improved structural, optical, and electrical properties have been observed. In the device, a multilayer OLED functions as the central active element, sandwiched between a top silver film and a bottom PS-DBR formed by electrochemical etching of a p++-Si substrate. Field-emission scanning-electron-microscopy cross-sectional images show that there exist nanoscale layered structures and flat interfaces inside the cavity. Widths of green and red electroluminescent (EL) peaks emitted from the MC-OLEDs are 8 and 12nm, respectively, greatly reduced in comparison with 85 and 70nm measured from noncavity structures. The narrowed EL emission from the MC-OLEDs is directional and in single mode, with off-resonant optical modes highly suppressed, which is mainly due to the good optical properties of PS-DBR with high reflectivity in a wide smooth stop band. Further increases in the green and red EL intensities by factors of about 6 and 4, respectively, are achievable. The improvement is physically attributable to the spatial redistribution of the photon density of states in the cavities. In addition, current-brightness-voltage properties and lifetime-related parameters of the devices are discussed. Such device structure and emission patterns of the MC-OLEDs should be useful in silicon compatible optical interconnects and light-emitting diode array printing.
Derivation of the generalized Young-Laplace equation of curved interfaces in nanoscaled solids
Authors: Chen Tungyang , Chiu Min-Sen , Weng Chung-Ning
Published: October 2006

In nanoscaled solids, the mathematical behavior of a curved interface between two different phases with interface stress effects can be described by the generalized Young-Laplace equations [T. Young, Philos. Trans. R. Soc. London 95, 65 (1805); P. S. Laplace, Traite de Mechanique Celeste (Gauthier-Villars, Paris, 1805), Vol. 4, Supplements au Livre X]. Here we present a geometric illustration to prove the equations. By considering a small element of the curved thin interface, we model the interface stresses as in-plane stresses acting along its edges, while on the top and bottom faces of the interface the tractions are contributed from its three-dimensional bulk neighborhood. With this schematic illustration, simple force balance considerations will give the Young-Laplace equations across the interface. Similar procedures can be applied to conduction phenomena. This will allow us to reconstruct one type of imperfect interfaces, referred to as highly conducting interfaces.
Analytic calculation of the diagonal Born-Oppenheimer correction within configuration-interaction and coupled-cluster theory
Authors: Gauss Jürgen , Tajti Attila , Kállay Mihály , Stanton John F. , Szalay Péter G.
Published: October 2006

Schemes for the analytic calculation of the diagonal Born-Oppenheimer correction (DBOC) are formulated and implemented for use with general single-reference configuration-interaction and coupled-cluster wave function models. Calculations are reported to demonstrate the convergence of the DBOC with respect to electron-correlation treatment and basis set as well as to investigate the size-consistency error in configuration-interaction calculations of the DBOC. The importance of electron-correlation contributions to the DBOC is illustrated in the computation of the corresponding corrections for the reaction energy and activation barrier of the F+H2→FH+H reaction as well as of the atomization energy for trans-butadiene.
Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers
Authors: Hanna M. C. , Nozik A. J.
Published: October 2006

We calculate the maximum power conversion efficiency for conversion of solar radiation to electrical power or to a flux of chemical free energy for the case of hydrogen production from water photoelectrolysis. We consider several types of ideal absorbers where absorption of one photon can produce more than one electron-hole pair that are based on semiconductor quantum dots with efficient multiple exciton generation (MEG) or molecules that undergo efficient singlet fission (SF). Using a detailed balance model with 1 sun AM1.5G illumination, we find that for single gap photovoltaic (PV) devices the maximum efficiency increases from 33.7% for cells with no carrier multiplication to 44.4% for cells with carrier multiplication. We also find that the maximum efficiency of an ideal two gap tandem PV device increases from 45.7% to 47.7% when carrier multiplication absorbers are used in the top and bottom cells. For an ideal water electrolysis two gap tandem device, the maximum conversion efficiency is 46.0% using a SF top cell and a MEG bottom cell versus 40.0% for top and bottom cell absorbers with no carrier multiplication. We also consider absorbers with less than ideal MEG quantum yields as are observed experimentally.
Unbiased sampling of lattice Hamilton path ensembles
Authors: Mansfield Marc L.
Published: October 2006

Hamilton paths, or Hamiltonian paths, are walks on a lattice which visit each site exactly once. They have been proposed as models of globular proteins and of compact polymers. A previously published algorithm [Mansfield, Macromolecules 27, 5924 (1994)] for sampling Hamilton paths on simple square and simple cubic lattices is tested for bias and for efficiency. Because the algorithm is a Metropolis Monte Carlo technique obviously satisfying detailed balance, we need only demonstrate ergodicity to ensure unbiased sampling. Two different tests for ergodicity (exact enumeration on small lattices, nonexhaustive enumeration on larger lattices) demonstrate ergodicity unequivocally for small lattices and provide strong support for ergodicity on larger lattices. Two other sampling algorithms [Ramakrishnan et al., J. Chem. Phys. 103, 7592 (1995); Lua et al., Polymer 45, 717 (2004)] are both known to produce biases on both 2×2×2 and 3×3×3 lattices, but it is shown here that the current algorithm gives unbiased sampling on these same lattices. Successive Hamilton paths are strongly correlated, so that many iterations are required between statistically independent samples. Rules for estimating the number of iterations needed to dissipate these correlations are given. However, the iteration time is so fast that the efficiency is still very good except on extremely large lattices. For example, even on lattices of total size 10×10×10 we are able to generate tens of thousands of uncorrelated Hamilton paths per hour of CPU time.
Piezoelectric transformer based ultrahigh sensitivity magnetic field sensor
Authors: Islam Rashed A. , Kim Hyeoungwoo , Priya Shashank , Stephanou Harry
Published: October 2006

Magnetoelectric particulate composites with varying ferrite content (3–20mol%) were synthesized in the system Pb(Zr0.52Ti0.48)O3 (PZT)–Ni0.8Zn0.2Fe2O4 (NZF) and it was found that 0.8PZT-0.2NZF composite material exhibited high response of the order of 450mV∕cmOe at the low frequency of 1kHz with 600Oe dc bias. This is one of the highest magnitudes reported for the sintered particulate composite materials. This material was used to fabricate a magnetic field sensor which utilizes the piezoelectric transformer structure with ring/dot electrode pattern. The size of the magnetic field sensor was ϕ20×1.5mm2. The sensor was characterized for the changes in the output voltage and resonance frequency shift under constant current condition. A dramatic change in the magnitude of the output voltage and frequency shift was observed on application of the magnetic field. The sensor design presented in this letter clearly shows the possibility of fabricating an extremely cost-effective magnetometer.
Photodissociation dynamics of vinyl fluoride (CH2CHF) at 157 and 193nm: Distributions of kinetic energy and branching ratios
Authors: Lee Shih-Huang , Chen Wei-Kan , Chaudhuri Chanchal , Huang Wen-Jian , Lee Yuan T.
Published: October 2006

Using photofragment translational spectroscopy and tunable vacuum-ultraviolet ionization, we measured the time-of-flight spectra of fragments upon photodissociation of vinyl fluoride (CH2CHF) at 157 and 193nm. Four primary dissociation pathways—elimination of atomic F, atomic H, molecular HF, and molecular H2—are identified at 157nm. Dissociation to C2H3+F is first observed in the present work. Decomposition of internally hot C2H3 and C2H2F occurs spontaneously. The barrier heights of CH2CH→CHCH+H and cis-CHCHF→CHCH+F are evaluated to be 40±2 and 44±2kcalmol−1, respectively. The photoionization yield spectra indicate that the C2H3 and C2H2F radicals have ionization energies of 8.4±0.1 and 8.8±0.1eV, respectively. Universal detection of photoproducts allowed us to determine the total branching ratios, distributions of kinetic energy, average kinetic energies, and fractions of translational energy release for all dissociation pathways of vinyl fluoride. In contrast, on optical excitation at 193nm the C2H2+HF channel dominates whereas the C2H3+F channel is inactive. This reaction C2H3F→C2H2+HF occurs on the ground surface of potential energy after excitation at both wavelengths of 193 and 157nm, indicating that internal conversion from the photoexcited state to the electronic ground state of vinyl fluoride is efficient. We computed the electronic energies of products and the ionization energies of fluorovinyl radicals.
Tokamak current driven by poloidally asymmetric fueling
Authors: Helander P. , Fülöp T. , Lisak M.
Published: October 2006

It is shown that poloidally asymmetric particle transport or fueling in a tokamak generally produces an electric current parallel to the magnetic field, in particular if the transport or fueling is up-down asymmetric. For instance, a current arises in the edge region if most particle transport across the last closed flux surface occurs in the midplane while most refueling comes from recycling near the X-point. This current is negative relative to the bulk plasma current (and thus stabilizing to peeling modes) if the ion drift is toward the X-point, and changes direction if the magnetic field is reversed. However, this current appears to be smaller than the pedestal bootstrap current under typical conditions.
Electrostatic interaction between dust particles in weakly ionized complex plasmas
Authors: Ratynskaia S. , de Angelis U. , Khrapak S. , Klumov B. , Morfill G. E.
Published: October 2006

The electrostatic potential around a dust particle in a complex plasma is calculated, taking into account ion-neutral collisions and collective effects, in a range of plasma parameters relevant for typical laboratory experiments. The existence of attractive wells and dependence of their shape on the main experimental control parameters, neutral gas pressure, and dust number density, is investigated.
Co–Au core-shell nanocrystals formed by sequential ion implantation into SiO2
Authors: Kluth P. , Hoy B. , Johannessen B. , Dunn S. G. , Foran G. J. , Ridgway M. C.
Published: October 2006

Co–Au core-shell nanocrystals (NCs) were formed by sequential ion implantation of Au and Co into thin SiO2. The NCs were investigated by means of transmission electron microscopy and extended x-ray absorption fine structure spectroscopy. The latter reveals a bond length expansion in the Co core compared to monatomic Co NCs. Concomitantly, a significant contraction of the bond length and a significant reduction of the effective Au–Au coordination number were observed in the Au shells. Increased Debye-Waller factors indicate significant strain in the NCs. These experimental results verify recent theoretical predictions.
Transition between wurtzite and zinc-blende GaN: An effect of deposition condition of molecular-beam epitaxy
Authors: Shi B. M. , Xie M. H. , Wu H. S. , Wang N. , Tong S. Y.
Published: October 2006

GaN exists in both wurtzite and zinc-blende phases and the growths of the two on its (0001) or (111) surfaces are achieved by choosing proper deposition conditions of molecular-beam epitaxy (MBE). At low substrate temperatures but high gallium fluxes, metastable zinc-blende GaN films are obtained, whereas at high temperatures and/or using high nitrogen fluxes, equilibrium wurtzite phase GaN epilayers resulted. This dependence of crystal structure on substrate temperature and source flux is not affected by deposition rate. Rather, the initial stage nucleation kinetics plays a primary role in determining the crystallographic structures of epitaxial GaN by MBE.
Organic diodes as monolithically integrated surface plasmon polariton detectors
Authors: Ditlbacher H. , Aussenegg F. R. , Krenn J. R. , Lamprecht B. , Jakopic G. , Leising G.
Published: October 2006

The authors show that organic p∕n heterojunction diodes enable the direct electric detection of surface plasmon polaritons (SPPs). The organic diodes are built from two organic semiconductor thin film layers with an area of 150×500μm2 deposited on an extended silver thin film. Besides serving as the bottom electrode of the diode this silver thin film is as well a waveguide feeding SPPs to the diode area. The authors visualize the direct SPP detection by a spatially resolved induced current map.
Effective suppression of Fermi level pinning in polycrystalline-silicon/high-k gate stack by using polycrystalline-silicon-germanium gate electrode
Authors: Yu Xiongfei , Zhu Chunxiang , Yu Mingbin
Published: October 2006

In this study, the crucial issue of unacceptably high threshold voltage (Vth) induced by Fermi level pinning in poly-Si/high-k complementary metal-oxide-semiconductor field-effect transistor (MOSFET) was effectively suppressed by inserting a poly-SiGe gate electrode. The Vth of −1.02V in poly-Si∕HfO2 p-channel MOSFET was tuned to −0.81V in poly-Si∕Al2O3∕HfO2 and further reduced to −0.49V in poly-Si/poly-SiGe∕Al2O3∕HfO2 gate stack. Meanwhile, the Vth of 0.3V was achieved in the n-channel MOSFET with the poly-SiGe gate. Moreover, transconductance and Vth stability in the MOSFETs with poly-SiGe gate were remarkably improved compared to poly-Si∕HfO2 and poly-Si∕Al2O3∕HfO2 devices. The low Vth and good Vth stability observed in the devices with poly-SiGe gate may be mainly attributed to the suppressed formation of oxygen vacancies in high-k gate dielectric, which is commonly believed to cause the Fermi level pinning effect in poly-Si/high-k device.
Highly efficient optical pumping of photonic crystal nanocavity lasers using cavity resonant excitation
Authors: Nomura Masahiro , Iwamoto Satoshi , Nishioka Masao , Ishida Satomi , Arakawa Yasuhiko
Published: October 2006

The authors demonstrate highly efficient optical pumping of photonic crystal (PhC) nanocavity lasers with InGaAs single quantum wells (QWs) using cavity resonant excitation at 10K. The laser threshold power is largely reduced when the central wavelength of the excitation pulse is resonant with a higher-order cavity mode. The localized excitation by the cavity resonant effect increases the effective absorption of the QW region in the nanocavity. The direct photocarrier generation in the QW also results in the highly efficient optical pumping. This cavity resonant excitation technique can lower the laser threshold of PhC nanocavity lasers and avoid detrimental device heating.
History of Australian Phycology: The significance of early French Exploration.
Authors: Ducker SC
Published: October 2006

The chronology of exploration in Australian waters
is presented together with the names of the ships. the commanders and the scientists of
the expeditions. Important literature dealing with the algae collected on these expeditions
is tabulated and examples of algae are given. It is hoped that this will lead to the establishment
of the provenance of type material. and show the importance of the French collections
for Australian phycology. Brvopsis vesrita J.Ag. has been referred into the synonomy
of B. rosae C.Ag.
Hygrochloa, a new genus of Aquatic grasses from the Northern Territory.
Authors: Lazarides M
Published: October 2006

A new genus of two species of grasses (Hygrochloa aquatica,
H. cravenii), with distinctive aquatic and unisexual features, is described and illustrated.
Diagnostic characters include staminate and pistillate, dimorphic spikelets in different
parts of the same inflorescence, papillose leaf blades, hollow culms with air canals in
the culm walls, and prolonged apices of the rhachides and axes. The genus, though most
closely allied to Paspalidium Stapf, is of remote affinity in the Tribe Paniceae.
A revision of the informal serises Foecundae Pryor and ohnson of the genus Eucalyptus L'herit. and notes on variation in the genus.
Authors: Brooker MIH
Published: October 2006

An account is given of the features which circumscribe the informal series Foecundue
(series Fruticosae Blakely) plus a summary of the five species Eucalyprus albrda Maiden
and Blakely, E. foecunda Schau., E. formanii C. A. Gardn., E. rigidula Maiden and E.
unclnara Turcz. In addition, E. discreta and E. fruticosa, two new species belonging to
the series are described. Divergence and variation in the genus Eucalyptus are discussed
particularly in relation to the series Foecundae.
A taxonomic revision of the Lichen genus Hypogymnia in Australasia.
Authors: Elix JA
Published: October 2006

The Australian, New Zealand and Papua New Guinean representatives
of Hypogymia are reviewed. Photographs, keys and descriptions are given for the 11
species and five varieties.
Two new species are described, H. enteromorphoides and H. kosciuskoensis, as well as
a new variety, H. subphysodes var. austerodioides and six new combinations are made,
namely H. lugubris var. sublugubris, H. lugubris var. compactior, H. pulchrilobata, H. pul-
verata, H. tubularis and H. turgidula.
Distribution of these taxa is discussed and maps have been provided. The species
included in this revision are H. billardieri, H. enteromorphoides, H. kosciuskoensis,
H. lugubris, H. mundata, H. pulchrilobata, H. pulverata, H. subphysodes, H. tubularis, H.
turgidula and H. vittata.
A revision of the genus Riccia (Hepaticae) in Australia.
Authors: Na-Thalang O
Published: October 2006

Spore features are the least variable characters and therefore the most
reliable for taxonomic purposes. A key for the identification of the 33 species is provided.
All species are described and illustrated with line drawings, chromosome numbers are
reported, typification and relationships are discussed, and collections are listed; scanning
electron micrographs of the spores are provided for 29 species. New taxa described
include one section (Viridisquamata), nine species (R. areolata, R. blackii, R. caroliniana,
R. collata, R. luticola, R. longiciliata, R. olgensis, R. rorida and R. spongiosula), and five
varieties (R. duplex var. megaspora, R. rnultifida var. divaricata, R. rnj?da var. jiliformis,
R. mult~jida var. torticolla and R. papulosa var. variabilis). Two binomials are considered
to be of uncertain status.
The genus Leptochloa Beauv. (Poaceae, Eragrostideae) in Australia and Papua New Guinea.
Authors: Lazarides M
Published: October 2006

A taxonomic revision based on
morphology is presented for 10 species constituting the genus Leptochloa in Australia (7
spp.) and Papua New Guinea (3 spp.). One species from Queensland, L. ligulata, is
described as new. For the first time, L. chinensis (L.) Nees is reported from Papua New
Guinea, and L. divaricatissima S. T. Blake from New South Wales. L. brownii C. E.
Hubb., described from northern Australia, is considered to be conspecific with L. neesii
(Thw.) Benth. from tropical Asia, and L. peacockii (Maid. & Betche) Domin described
from New South Wales conspecific with L. decipiens (R. Br.) Stapf ex Maid, from
Queensland.
A new series, Ovulares, of the genus Eucalyptus based on the subseries Ovularinae Pryor & Johnson.
Authors: Brooker MIH
Published: October 2006

The series Ovulares Brooker (series
Dundasianae Pryor & Johnson in part) is established. The new series is based on the
informal subseries Ovularinae Pryor & Johnson, that is four of the five species in the
series Dundasianae but excluding, on account of its bisected cotyledons, E. dundasii
Maiden on which the series' name was based by Pryor and Johnson. Two new species
in the series are described, namely E. myriadena Brooker and E. cydostoma Brooker. A
botanical description, distribution and notes on associated Eucalyptus species are given
for the six species of the new series.
Studies in the Cunoniaceae. III. Additional notes on Ceratopetalum and Acrophyllum.
Authors: Hoogland RD
Published: October 2006

Ceratopetalum macrophyllum sp. nov. from
north-eastern Queensland is described. For reasons of priority the name Acrophyllum has
to be accepted for the genus previously treated under the name Calycomis; Acrophyllum
australe comb. nov. is the correct name for the only species.
The genus Lepidium L. (Brassicaceae) in Australia.
Authors: Hewson HJ
Published: October 2006

A taxonomic revision of the genus Lepidium L. in Australia is presented; 116
names have been accounted for and a key is provided to the recognized 34 endemic or
native species and 8 naturalized introductions. Nine new species are described and illustrated:
L. biplicatum, L. catapycnon, L. genistoides, L. hypenantion, L. lyratogynum, L.
platypetalum, L. pseudo-hyssopifolium, L. scandens and L. xylodes. An attempt to analyse
the subgeneric classification is made and two new sections and one new subsection are
described: sect. Oleracea, sect. Papillosa and subsect. Diploploca.
Macroscopic and Microscopic features of Mycena interrupta and Mycena viscido-cruenta.
Authors: Grgurinovic CA , Holland AA
Published: October 2006

Detailed descriptions of
Mycena interrupta (Berk.) Sacc. and Mycena viscido-cruenta (del. and Cheel) del. are
provided, along with camera lucida drawings of habit, basidiospores, cystidia and pileal
cuticles. The uncertainty concerning the 'interrupted' nature of the gill attachment in M.
interrupta is clarified. The supposed similarity of M. viscido-cruenta to M. coccinea is shown
to be invalid.
A revision of the genus Notothixos (Viscaceae)
Authors: Barlow BA
Published: October 2006

Notothixos is a genus of eight species distributed from Ceylon, Lower Burma and the
Philippines southwards and eastwards through the Malesian region to Santa Cruz Islands
and south-eastern Australia. It is distinguished by a dense and conspicuous indumentum
of dendritic, stellately branched or peltate hairs or scales, and by lateral stems subtended
by two prophylls and two cataphylls. The basic inflorescence unit is a small cymose
cluster subtended by a pair of small bracts, and conflorescence evolution has involved
the aggregation of cymules, and development of indeterminate conflorescences from
determinate ones. The entire genus has not been revised previously; four names are
reduced to synonymy of others for the first time here. Notothixos curranii Merrill, N.
merguiensis Danser and N. spicatus Krause are conspecific with N. floccosus (Thw.)
Hook.f, and N. schlechteri Krause is conspecific with N. leiophyllus Schumann. New
chromosome numbers are reported for two species: N. incanus (n= 13) and N. subaureus
(n = 12). Evidence suggests that the genus originated in the Malesian region, and that
it has reached Papuasia and Australia as part of an intrusive element following Miocene
collision of the Australian and Sunda plates.
The marine algae of Lord Howe Island (NSW) the family Solieriaceae (Gigartinales, Rhodophyta)
Authors: Gabrielson PW , Kraft GT
Published: October 2006

The red algal family Solieriaceae is represented by the three genera Solieria, Meristotheca
and Eucheuma at Lord Howe Island (31�33'S.,159�05'E.). Each genus is represented by
two species, one of which is widespread geographically and the other newly described.
The new species (Solieria anastomosa, Eucheuma deformans, Meristotheca procumbens)
are characterized vegetatively and reproductively, as are the three previously described
species [Solieria robusta (Greville) Kylin, Eucheuma serra (J. Agardh) J. Agardh,
Meristotheca papulosa (Montagne) J. Agardh]. Mychodea halymenioides Zanardini, which
is based on a Lord Howe specimen, is placed in synonymy with Meristotheca papulosa.
Partly as a result of the Lord Howe study, the Solieriaceae is recircumscribed using a
suite of characters that is taxonomically more useful than that currently delimiting the
family.
Variation in Indumentum Morphology in the Melaleuca leucadendra Complex (Myrtaceae)
Authors: Barlow BA , Forrester J
Published: October 2006

A light and scanning
electron microscope study of variation in leaf hairs in the Melaleuca leucadendra complex
is described as a precursor to a taxonomic revision. The indumentum is homogeneous
with respect to cellular structure, the hairs being simple, unicellular and unbranched.
Hairs of different lengths are produced, with shorter hairs possibly produced later than
the longer ones. The shorter hairs tend to be bent or crisped. There is diversity in the
degree of crisping of short hairs which appears to be genetically based and this attribute
is of some value as a diagnostic character. Two apparent geographical subspecies of M.
nervosa are distinguished by differences in crisping of the shorter hairs. However
similarities with hair patterns in other species suggest polyphylesis, and raise questions
of natural relationships between entities within the M. leucadendra complex.
Myrophyllum (Haloragaceae) in Australasia. 2. The Australian Species.
Authors: Orchard AE
Published: October 2006

The 36 species of Myriophyllum found in Australia are
keyed, described and illustrated. Fifteen species (M. alpinum, M. austropygmaeum,
M. balladoniensis, M. costatum, M. crispatum, M. decussatum, M. echinatum, M. im-
plicatum, M. limnophilum, M. lophatum, M. muricatum, M. papillosum, M. petraeum,
M. simulans, M. striatum), one subspecies (M. callitrichoides ssp. striatum) and two
varieties (M. gracile var. lineare and var. laeve) are newly recognized, and one new com-
bination (M. pedunculatum ssp. longibracteolatum) is proposed. The grouping of the
Australian species into 'alliances' is discussed, and their relationships with some extra-
Australian species are explored.
Some marine diatoms from the Australian region, especially from Port Phillip Bay and Tropical Nort-eastern Australia.
Authors: Von Stosch HA
Published: October 2006

Ten taxa
of marine diatoms from SE. or NE. Australia are described or redescribed, and their
characters are supplemented by fine-structural and developmental data. One genus
(Pseudoguinardia von Stosch), one species (Pseudoguinardia recta von Stosch), and two
varieties (Odontella retiformis var. trigona von Stosch and Haslea gigantea var. tennis von
Stosch) are newly described. Six other taxa [Coscinodiscus alboranii Pavillard, C.
concinniformis Simonsen, Dactyliosolen blavyanus (Peragallo) Hasle, Rhizosolenia
phuketensis Sundstrom, Haslea gigantea (Hustedt) Simonsen, and H. wawrikae (Hustedt)
Simonsen] are new to the Australian flora. Gross and fine-structural characters are added
to the descriptions of the world-wide and common R. stolterfothii (Stolterfoth) Peragallo
and of the non-Australian Odontella retiformis var. retiformis von Stosch in order to bring
them on a level of detail sufficient for their comparison with R. phuketensis or the new
variety, respectively. The new species, although overlooked up to now, as well as C.
alboranii and probably R. phuketensis, seem to be distributed world-wide in warmer
neritic waters.
Three new species of Ranunculus (Ranunculaceae) form Tasmania.
Authors: Menadue Y , Crowden RK
Published: October 2006

Three newspecies of the genus Ranunculus
L. are reported from Tasmania. Two of the new species, R. collicolus and R. prasinus,
are stoloniferous and show affinities with R. acaulis Banks & Sol. ex DC., R. collinus
R. Br. ex DC. and R. glabrifolius Hook. The third, R. jugosus, has close affinity with the
endemic R. triplodontus Melville.
A new species of Chondropsis (Lichenised Ascomycotina) from Australia and New Zealand.
Authors: Elix JA , Child P
Published: October 2006

A new lichen species,
Chondropsis sorediata, is described from Australia and New Zealand.
Variation in Eucalyptus cypellocarpa L. Johnson in Victoria, and a new taxon form the Grampian Ranges and Anglesea
Authors: Watson RJ , Ladiges PY , Griffin AR
Published: October 2006

Patterns of variation in adult and seedling morphology, seedling growth and root/shoot ratios were assessed for populations of E. cypellocarpa, E. goniocalyx and equivocal populations from the Grampian Ranges and Anglesea. F1 hybrids of the two species were also produced to assist evaluation of a previous hypothesis of phantom hybrid origin. The Grampians populations were similar to E. cypellocarpa in adult morphology, but had distinctly different seedlings that were not the same as the F1 hybrids. The Anglesea population, although intermediate between E. cypellocarpa and E. goniocalyx in some adult characters, had the same seedling form, including root/shoot ratio, and the same bark type as the Grampians populations. The study provided no evidence to support the hypothesis of a phantom hybrid origin for the Grampians and Anglesea forms. A more parsimonious interpretation is evolution by the splitting of an ancestral taxon. The Grampians and Anglesea populations are described as E. alaticaulis sp. nov., with minor population variation being interpreted as a result of geographic disjunction.
Natural variation in
Drosophila melanogaster
diapause due to the insulin-regulated PI3-kinase
Authors: Williams Karen D. , Busto Macarena , Suster Maximiliano L. , So Anthony K.-C. , Ben-Shahar Yehuda , Leevers Sally J. , Sokolowski Marla B.
Published: October 2006

This study links natural variation in a
Drosophila melanogaster
overwintering strategy, diapause, to the insulin-regulated phosphatidylinositol 3-kinase (PI3-kinase) gene,
Dp110
. Variation in diapause, a reproductive arrest, was associated with
Dp110
by using
Dp110
deletions and genomic rescue fragments in transgenic flies. Deletions of
Dp110
increased the proportion of individuals in diapause, whereas expression of
Dp110
in the nervous system, but not including the visual system, decreased it. The roles of phosphatidylinositol 3-kinase for both diapause in
D. melanogaster
and dauer formation in
Caenorhabditis elegans
suggest a conserved role for this kinase in both reproductive and developmental arrests in response to environmental stresses.
Pressure-driven transport of confined DNA polymers in fluidic channels
Authors: Stein Derek , van der Heyden Frank H. J. , Koopmans Wiepke J. A. , Dekker Cees
Published: October 2006

The pressure-driven transport of individual DNA molecules in 175-nm to 3.8-μm high silica channels was studied by fluorescence microscopy. Two distinct transport regimes were observed. The pressure-driven mobility of DNA increased with molecular length in channels higher than a few times the molecular radius of gyration, whereas DNA mobility was practically independent of molecular length in thin channels. In addition, both the Taylor dispersion and the self-diffusion of DNA molecules decreased significantly in confined channels in accordance with scaling relationships. These transport properties, which reflect the statistical nature of DNA polymer coils, may be of interest in the development of “lab-on-a-chip” technologies.
Recruitment of CD63 toCryptococcus neoformansphagosomes requires acidification
Authors: Artavanis-Tsakonas Katerina , Love J. Christopher , Ploegh Hidde L. , Vyas Jatin M.
Published: October 2006

The subcellular localization of the cluster of differentiation 63 (CD63) tetraspanin and its interaction with the class II MHC antigen presentation pathway were examined in the context of phagocytosis by live cell imaging, by using monomeric red fluorescent protein-tagged mouse CD63 expressed in primary bone marrow-derived cell cultures. Upon phagocytosis ofCryptococcus neoformansand polystyrene beads, CD63 was recruited selectively toC. neoformans-containing phagosomes in a MyD88-independent acidification-dependent manner. Bead-containing phagosomes, within aC. neoformans-containing cell, acidified to a lesser extent and failed to recruit CD63 to a level detectable by microscopy. CD63 recruitment to yeast phagosomes occurred independently of class II MHC and LAMP-1. These observations indicate that the composition of distinct phagosomal compartments within the same cell is determined by phagosomal cargo and may affect the outcome of antigen processing and presentation.