bluuebunny/crossref_metadata_2025 huggingface dataset:
Having a brother or sister with Down syndrome: Perspectives from siblings
Authors: Skotko Brian G. , Levine Susan P. , Goldstein Richard
Published: September 2011

This study asks brothers and sisters about their feelings and perceptions toward their sibling with Down syndrome (DS). We analyzed valid and reliable surveys from 822 brothers and sisters whose families were on the mailing lists of six non‐profit DS organizations around the country. More than 96% of brothers/sisters that responded to the survey indicated that they had affection toward their sibling with DS; and 94% of older siblings expressed feelings of pride. Less than 10% felt embarrassed, and less than 5% expressed a desire to trade their sibling in for another brother or sister without DS. Among older siblings, 88% felt that they were better people because of their siblings with DS, and more than 90% plan to remain involved in their sibling's lives as they become adults. The vast majority of brothers and sisters describe their relationship with their sibling with DS as positive and enhancing. © 2011 Wiley‐Liss, Inc.
Self‐perceptions from people with Down syndrome
Authors: Skotko Brian G. , Levine Susan P. , Goldstein Richard
Published: September 2011

This study asks people with Down syndrome (DS), ages 12 and older, about their self‐perception so that their information could be shared with new and expectant parents of children with DS. We analyzed valid and reliable survey instruments from 284 people with DS on the mailing lists of 6 non‐profit DS organizations around the country. Among those surveyed, nearly 99% of people with DS indicated that they were happy with their lives, 97% liked who they are, and 96% liked how they look. Nearly 99% people with DS expressed love for their families, and 97% liked their brothers and sisters. While 86% of people with DS felt they could make friends easily, those with difficulties mostly had isolating living situations. A small percentage expressed sadness about their life. In our qualitative analysis, people with DS encouraged parents to love their babies with DS, mentioning that their own lives were good. They further encouraged healthcare professionals to value them, emphasizing that they share similar hopes and dreams as people without DS. Overall, the overwhelming majority of people with DS surveyed indicate they live happy and fulfilling lives. © 2011 Wiley‐Liss, Inc.
Characterization of phenazone transformation products on light‐activated TiO2 surface by high‐resolution mass spectrometry
Authors: Calza P. , Medana C. , Raso E. , Giancotti V. , Minero C.
Published: September 2011

The paper examines the transformation of phenazone (2,3‐dimethyl‐1‐phenyl‐3‐pyrazolin‐5‐one), a widely used analgesic and antipyretic drug, under simulated solar irradiation in pure water, using titanium dioxide, and in river water. High‐resolution mass spectrometry was employed to monitor the evolution of photoinduced processes. Initially, laboratory experiments were performed to simulate drug‐transformation pathways in aqueous solution, using TiO2 as photocatalyst. Thirteen main phenazone transformation products were detected, and full analysis of their MS and MSn spectra identified the diverse isobaric species. All these transformation products were themselves easily degraded, and no compounds were recognized to remain until 1h of irradiation. From these findings, a tentative degradation pathway is proposed to account for the photoinduced transformation of phenazone in natural waters. These simulation experiments were verified in the field, seeking phenazone in River Po water samples. Copyright © 2011 John Wiley & Sons, Ltd.
Photoemission ambient pressure ionization (PAPI) with an ultraviolet light emitting diode and detection of organic compounds
Authors: Short Luke C. , Ewing Robert G. , Barinaga Charles J.
Published: September 2011

The development of compact, rugged and low‐power ion sources is critical for the further advancement of handheld mass analyzers. Further, there is a need to replace the common 63Ni source used at atmospheric pressure with a non‐radioactive substitute. We present here a description of a light emitting diode (LED) photoemission ionization source for use in mass spectrometry for the detection of volatile organic compounds. This technique relies upon the generation of photoelectrons from a low‐work function metal via low‐energy ultraviolet (UV) light (280 or 240 nm) generated by a single LED in air at atmospheric pressure. These low‐energy photoelectrons result in either direct electron capture by the analyte or chemical ionization. Currently, only negative ions are demonstrated due to operation at atmospheric pressure. Ion generation occurs without use of high electric fields such as those found in corona discharge or electrospray ionization. This source is effective for measuring organic vapors from gases, liquids and surface residues via atmospheric pressure chemical ionization, initiated by photoemission off a conductive surface. Several classes of organic vapors are analyzed and found to be effectively detected, including compounds that ionize via electron attachment, dissociative electron capture, proton abstraction, adduct formation and replacement ionization. Copyright © 2011 John Wiley & Sons, Ltd.
Kardiorenales Anämiesyndrom – Was ist das?
Authors: Ritz Eberhard
Published: September 2011

Der Begriff ”kardiorenales Anämiesyndrom“ weist auf die häufig vergesellschaftete, sich gegenseitig verstärkende, Beziehung zwischen eingeschränkter Herzfunktion, eingeschränkter Nierenfunktion und Anämie hin. Diese Klassifizierung ist nützlich, da sie Hinweise auf Therapieoptionen gibt, obwohl diese noch gegenwärtig sich nur teilweise auf kontrollierte Evidenz stützen können.
Kardiorenales Anämiesyndrom – Die kardiologische Sichtweise
Authors: von Haehling Stephan
Published: September 2011

Die chronische Herzinsuffizienz ist eine Multisystemerkrankung, deren Komorbiditäten in letzter Zeit verstärkt Beachtung finden. Das kardiorenale Anämiesyndrom entsteht auf dem Boden der Dysfunktion von Herz oder Niere, die sich auf das jeweils andere Organsystem ausweitet und oft mit der Entwicklung einer Anämie vergesellschaftet ist. Ätiologisch stehen bei der Anämie bei einer chronischen Herzinsuffizienz der funktionelle und der absolute Eisenmangel ganz im Vordergrund, sodass klinisch eine intravenöse Eisensubstitution sinnvoll sein kann. Studien belegen allerdings, dass nicht nur anämische, sondern auch nichtanämische Patienten von einer derartigen Eisensubstitution symptomatisch profitieren können, wenn bereits ein absoluter oder funktioneller Eisenmangel vorliegt. Die Rolle von Erythropoetin und seinen Derivaten ist in diesem Zusammenhang derzeit weniger klar, und entsprechende Studienergebnisse werden mit Spannung erwartet.
Dilute nitride InGaAsN/GaAs V-groove quantum wires emitting at 1.3 μm wavelength at room temperature
Authors: Carron R. , Fekete D. , Gallo P. , Dwir B. , Rudra A. , Felici M. , Bartova B. , Cantoni M. , Kapon E.
Published: September 2011

Site-controlled InGaAsN quantum wires (QWRs) emitting at 1.3 μm at room temperature were grown on V-grooved GaAs substrates by modulated-flux metallorganic vapor phase epitaxy. The nonplanar substrate template is shown to enhance the nitrogen uptake, evidenced by a redshift in photoluminescence wavelength twice larger for the QWRs than for the adjacent quantum well regions. The mechanism of this increase in nitrogen incorporation efficiency, achieved without degradation in optical properties, is explained by the extended gradient of In content at the step-rich QWR interfaces.
Lagrangian coherent structures are associated with fluctuations in airborne microbial populations
Authors: Tallapragada P. , Ross S. D. , Schmale D. G.
Published: September 2011

Many microorganisms are advected in the lower atmosphere from one habitat to another with scales of motion being hundreds to thousands of kilometers. The concentration of these microbes in the lower atmosphere at a single geographic location can show rapid temporal changes. We used autonomous unmanned aerial vehicles equipped with microbe-sampling devices to collect fungi in the genus Fusarium 100 m above ground level at a single sampling location in Blacksburg, Virginia, USA. Some Fusarium species are important plant and animal pathogens, others saprophytes, and still others are producers of dangerous toxins. We correlated punctuated changes in the concentration of Fusarium to the movement of atmospheric transport barriers identified as finite-time Lyapunov exponent-based Lagrangian coherent structures (LCSs). An analysis of the finite-time Lyapunov exponent field for periods surrounding 73 individual flight collections of Fusarium showed a relationship between punctuated changes in concentrations of Fusarium and the passage times of LCSs, particularly repelling LCSs. This work has implications for understanding the atmospheric transport of invasive microbial species into previously unexposed regions and may contribute to information systems for pest management and disease control in the future.
Comment on Li pellet conditioning in tokamak fusion test reactor
Authors: Budny R. V.
Published: September 2011

Li pellet conditioning in TFTR results in a reduction of the edge electron density which allows increased neutral beam penetration, central heating, and fueling. Consequently, the temperature profiles became more peaked with higher central Ti, Te, toroidal rotation, and neutron emission rates.
Luminescence measurements of Xe+ + N2 and Xe2+ + N2 hyperthermal charge transfer collisions
Authors: Prince Benjamin D. , Chiu Yu-Hui
Published: September 2011

Luminescence spectra are recorded for collisions between Xe+/Xe2+ and molecular nitrogen at energies ranging from 4.5 to 316 eV in the center-of-mass frame. In the Xe+ + N2 collision system, evidence for luminescent charge-transfer products is only found through Xe I emission lines. The most intense features of the luminescence spectra are attributed to atomic N emissions observed above ∼20 eV. Intense ${\rm N}_{2}^{+}$N2+ A 2Πu − ${\rm X}\;^{2}\Sigma_{\rm g}^{+}$X2Σg+ and ${\rm B}\;^{2}\Sigma_{\rm u}^{+}$B2Σu+ − ${\rm X}\;^{2}\Sigma_{\rm g}^{+}$X2Σg+ radiance is observed from Xe2+ + N2 collisions. The B state formation cross section decreases with collision energy until 20 eV, after which it becomes independent of impact energy with an approximate value of 3 Å2. The cross section for ${\rm N}_{2}^{+}$N2+ A (v > 0) formation increases with energy until 20 eV, after which it remains nearly constant at ∼1 Å2. The ${\rm N}_{2}^{+}$N2+ product vibrational distributions extracted from the spectra are non-Franck-Condon for both electronic product states at low collision energies. The distributions resemble a Franck-Condon distribution at the highest energies investigated in this work.
Towards an accurate description of anharmonic infrared spectra in solution within the polarizable continuum model: Reaction field, cavity field and nonequilibrium effects
Authors: Cappelli Chiara , Lipparini Filippo , Bloino Julien , Barone Vincenzo
Published: September 2011

We present a newly developed and implemented methodology to perturbatively evaluate anharmonic vibrational frequencies and infrared (IR) intensities of solvated systems described by means of the polarizable continuum model (PCM). The essential aspects of the theoretical model and of the implementation are described and some numerical tests are shown, with special emphasis towards the evaluation of IR intensities, for which the quality of the present method is compared to other methodologies widely used in the literature. Proper account of an incomplete solvation regime in the treatment of the molecular vibration is also considered, as well as inclusion of the coupling between the solvent and the probing field (cavity field effects). In order to assess the quality of our approach, comparison with experimental findings is reported for selected cases.
High energy resolution bandpass photon detector for inverse photoemission spectroscopy
Authors: Maniraj M. , D’Souza S. W. , Nayak J. , Rai Abhishek , Singh Sanjay , Sekhar B. N. Raja , Barman S. R.
Published: September 2011

We report a bandpass ultraviolet photon detector for inverse photoemission spectroscopy with energy resolution of 82 ± 2 meV. The detector (Sr0.7Ca0.3F2/acetone) consists of Sr0.7Ca0.3F2 entrance window with energy transmission cutoff of 9.85 eV and acetone as detection gas with 9.7 eV photoionization threshold. The response function of the detector, measured using synchrotron radiation, has a nearly Gaussian shape. The n =  1 image potential state of Cu(100) and the Fermi edge of silver have been measured to demonstrate the improvement in resolution compared to the CaF2/acetone detector. To show the advantage of improved resolution of the Sr0.7Ca0.3F2/acetone detector, the metal to semiconductor transition in Sn has been studied. The pseudogap in the semiconducting phase of Sn could be identified, which is not possible with the CaF2/acetone detector because of its worse resolution.
Exchange bias effect in multiferroic CoCr2O4/Cr2O3 nanogranular system synthesized through a phase segregation route
Authors: Tian Zhaoming , Chen Jingting , Yuan Songliu , Tang Jianbang , Huo Shaoxin , Duan Hanning
Published: September 2011

A nanogranular system of multiferroic CoCr2O4 nanoparticles embedded in an antiferromagnetic Cr2O3 matrix has been synthesized through a high-temperature phase segregation route from a Co-doped Cr2O3 matrix. Magnetic studies show that exchange bias fields (HEB) accompanying vertical magnetization shifts (MShift) are observed at low temperatures after field cooled from 350 K. The corresponding exchange bias field can be as large as 1420 Oe, and the vertical magnetization shift reaches 0.116 emu/g at 10 K. The exchange bias field decreases with temperature increasing and disappears at T ≈ 70 K, while the coercive field (HC) initially increases with the temperature up to 40 K, and thereafter, it decreases to zero at 100 K. This exchange bias behavior is discussed in terms of the existence of exchange coupling between the ferrimagnetic CoCr2O4 core and spin glass-like phase at the interfaces.
The visible spectrum of zirconium dioxide, ZrO2
Authors: Le Anh , Steimle Timothy C. , Gupta Varun , Rice Corey A. , Maier John P. , Lin Sheng H. , Lin Chih-Kai
Published: September 2011

The electronic spectrum of a cold molecular beam of zirconium dioxide, ZrO2, has been investigated using laser induced fluorescence (LIF) in the region from 17 000 cm−1 to 18 800 cm−1 and by mass-resolved resonance enhanced multi-photon ionization (REMPI) spectroscopy from 17 000 cm−1–21 000 cm−1. The LIF and REMPI spectra are assigned to progressions in the $\tilde A{^1}B_2$ÃB21(ν1, ν2, ν3) ← $\tilde X{^1}A_1$X̃A11(0, 0, 0) transitions. Dispersed fluorescence from 13 bands was recorded and analyzed to produce harmonic vibrational parameters for the $\tilde X{^1}A_1$X̃A11 state of ω1 = 898(1) cm−1, ω2 = 287(2) cm−1, and ω3 = 808(3) cm−1. The observed transition frequencies of 45 bands in the LIF and REMPI spectra produce origin and harmonic vibrational parameters for the $\tilde A{^1}B_2$ÃB21 state of Te = 16 307(8) cm−1, ω1 = 819(3) cm−1, ω2 = 149(3) cm−1, and ω3 = 518(4) cm−1. The spectra were modeled using a normal coordinate analysis and Franck-Condon factor predictions. The structures, harmonic vibrational frequencies, and the potential energies as a function of bending angle for the $\tilde A{^1}B_2$ÃB21 and $\tilde X{^1}A_1$X̃A11 states are predicted using time-dependent density functional theory, complete active space self-consistent field, and related first-principle calculations. A comparison with isovalent TiO2 is made.
Optically functional surface composed of patterned graded-refractive-index coatings to enhance light-extraction of GaInN light-emitting diodes
Authors: Noemaun Ahmed N. , Mont Frank W. , Lin Guan-Bo , Cho Jaehee , Fred Schubert E. , Bum Kim Gi , Sone Cheolsoo , Kyu Kim Jong
Published: September 2011

Graded-refractive-index (GRIN) coatings, composed of multiple dielectric layers of TiO2 and SiO2 are sputter-deposited on the nitrogen-face of thin-film GaInN/GaN light emitting diodes (LEDs). The thickness and refractive index of each layer in the GRIN stack is designed to minimize light trapping inside the LED caused by total internal reflection at the semiconductor–air interface. Patterning the GRIN stack forms an optically functional surface, which converts trapped modes of light into desirable extracted modes that have preferential directions. Inductively coupled-plasma reactive-ion-etching is used to fabricate various patterns, including arrays of cylindrical pillars and diamond-shaped pillars on the GRIN coatings. In comparison to an uncoated planar reference device, the light-output power is enhanced by 131% and 104% for an array of GRIN diamond-shaped pillars and an array of GRIN cylindrical pillars, respectively. This enhancement in light-output power is comparable to N-face roughened LEDs, which show an enhancement of 124%. In addition, the peak emission intensity of the GRIN LEDs with an array of GRIN pillars is between 25° and 55° off-surface-normal.
Free energy balance in gyrokinetic turbulence
Authors: Bañón Navarro A. , Morel P. , Albrecht-Marc M. , Carati D. , Merz F. , Görler T. , Jenko F.
Published: September 2011

Free energy plays an important role in gyrokinetic theory, since it is known to be a nonlinear invariant. Its evolution equations are derived and analyzed for the case of ion temperature gradient driven turbulence, using the formalism adopted in the Gene code. In particular, the ion temperature gradient drive, the collisional dissipation as well as entropy/electrostatic energy transfer channels represented by linear curvature and parallel terms are analyzed in detail.
Theoretical study of substitution effects on molecular reorganization energy in organic semiconductors
Authors: Geng Hua , Niu Yingli , Peng Qian , Shuai Zhigang , Coropceanu Veaceslav , Brédas Jean-Luc
Published: September 2011

Chemical substitutions are powerful molecular design tools to enhance the performance of organic semiconductors, for instance, to improve solubility, intermolecular stacking, or film quality. However, at the microscopic level, substitutions in general tend to increase the molecular reorganization energy and thus decrease the intrinsic charge-carrier mobility. Through density functional theory calculations, we elucidate strategies that could be followed to reduce the reorganization energy upon chemical substitution. Specific examples are given here for hole-transport materials including indolo-carbazoles and several triarylamine derivatives. Through decomposition of the total reorganization energy into the internal coordinate space, we are able to identify the molecular segment that provides the most important contributions to the reorganization energy. It is found that when substitution reduces (enhances) the amplitude of the relevant frontier molecular orbital in that segment, the total reorganization energy decreases (increases). In particular, chlorination at appropriate positions can significantly reduce the reorganization energy. Several other substituents are shown to play a similar role, to a greater or lesser extent.
Influence of carrier density on the electronic cooling channels of bilayer graphene
Authors: Limmer T. , Houtepen A. J. , Niggebaum A. , Tautz R. , Da Como E.
Published: September 2011

We study the electronic cooling dynamics in a single flake of bilayer graphene by femtosecond transient absorption probing the photon-energy range 0.25–1.3 eV. From the transients, we extract the carrier cooling curves for different initial temperatures and densities of the photoexcited electrons and holes. Two regimes of carrier cooling, dominated by optical and acoustic phonons emission, are clearly identified. For increasing carrier density, the crossover between the two regimes occurs at larger carrier temperatures, since cooling via optical phonons experiences a bottleneck. Acoustic phonons, which are less sensitive to saturation, show an increasing contribution at high density.
On the bootstrap current in stellarators and tokamaks
Authors: Helander P. , Geiger J. , Maaßberg H.
Published: September 2011

The expression for the long-mean-free-path limit of the bootstrap current in stellarators is rederived in such a way that the expansion procedure is identical to that used in the corresponding calculation for a tokamak. In addition, the first correction due to finite collisionality is calculated and shown to vanish in quasi-isodynamic configurations without net current. This correction, which is proportional to the square root of the collisionality, is found to compare well with a numerical solution of the first-order drift kinetic equation in spherical tokamak geometry. Numerically, it appears that there is a similar correction in general stellarator geometry, which however depends on the strength of the radial electric field.
TRIPLE Q: A three channel quantum cascade laser absorption spectrometer for fast multiple species concentration measurements
Authors: Hübner M. , Welzel S. , Marinov D. , Guaitella O. , Glitsch S. , Rousseau A. , Röpcke J.
Published: September 2011

A compact and transportable three channel quantum cascade laser system (TRIPLE Q) based on mid-infrared absorption spectroscopy has been developed for time-resolved plasma diagnostics. The TRIPLE Q spectrometer encompasses three independently controlled quantum cascade lasers (QCLs), which can be used for chemical sensing, particularly for gas phase analysis of plasmas. All three QCLs are operated in the intra-pulse mode with typical pulse lengths of the order of 150 ns. Using a multiplexed detection, a time resolution shorter than 1 μs can be achieved. Hence, the spectrometer is well suited to study kinetic processes of multiple infrared active compounds in reactive plasmas. A special data processing and analysis technique has been established to account for time jitter effects of the infrared emission of the QCLs. The performance of the TRIPLE Q system has been validated in pulsed direct current plasmas containing N2O/air and NO2/air.
Prospect of charge enhancement by increasing top oxide thickness of silicon-on-insulator fin field effect transistors
Authors: Zunaid Baten Md. , Islam Raisul , Amin Emran Md. , Khosru Quazi D. M.
Published: September 2011

The variation of electrostatic and transport characteristics of silicon-on-insulator fin field effect transistors (FinFETs) having sub-10 nm fin dimensions is investigated with the variation of top oxide thickness. Capacitance voltage and ballistic transport characteristics of double gate (DG) and triple gate (TG) FinFETs are obtained by self-consistently solving the coupled Schrödinger’s and Poisson’s equations. Performance enhancement can be obtained in terms of both on-state current and inversion capacitance by increasing the top oxide thickness of highly scaled FinFETs. The work suggests limiting values of the device parameter to differentiate the DG and TG variants of FinFET.
Ferroelectricity in hafnium oxide thin films
Authors: Böscke T. S. , Müller J. , Bräuhaus D. , Schröder U. , Böttger U.
Published: September 2011

We report that crystalline phases with ferroelectric behavior can be formed in thin films of SiO2 doped hafnium oxide. Films with a thickness of 10 nm and with less than 4 mol. % of SiO2 crystallize in a monoclinic/tetragonal phase mixture. We observed that the formation of the monoclinic phase is inhibited if crystallization occurs under mechanical encapsulation and an orthorhombic phase is obtained. This phase shows a distinct piezoelectric response, while polarization measurements exhibit a remanent polarization above 10 μC/cm2 at a coercive field of 1 MV/cm, suggesting that this phase is ferroelectric. Ferroelectric hafnium oxide is ideally suited for ferroelectric field effect transistors and capacitors due to its excellent compatibility to silicon technology.
Unusual high-temperature ferromagnetism of PbPd0.81Co0.19O2 nanograin film
Authors: Su H. L. , Huang S. Y. , Chiang Y. F. , Huang J. C. A. , Kuo C. C. , Du Y. W. , Wu Y. C. , Zuo R. Z.
Published: September 2011

Single-phase PbPd0.81Co0.19O2 film with a body-centered orthorhombic structure was prepared using the sol-gel spin-coating technique and an oxidation treatment. Film resistivity has a power dependence on temperature. The insulator-metal transition temperature was 358 K, markedly higher than the reported values of similar material systems. Ferromagnetism and superparamagnetism coexisted in the film and the ferromagnetism persisted up to 380 K. As temperature increased, the notable increasing tendencies were found for the film’s saturation magnetization and for the magnetic field where saturation magnetization decreases abruptly. The special spin gapless band structure and the film’s nanograin microstructure are likely responsible for these interesting properties.
Crystal structure of FAS thioesterase domain with polyunsaturated fatty acyl adduct and inhibition by dihomo-γ-linolenic acid
Authors: Zhang Wei , Chakravarty Bornali , Zheng Fei , Gu Ziwei , Wu Hongmei , Mao Jianqiang , Wakil Salih J. , Quiocho Florante A.
Published: September 2011

Human fatty acid synthase (hFAS) is a homodimeric multidomain enzyme that catalyzes a series of reactions leading to the de novo biosynthesis of long-chain fatty acids, mainly palmitate. The carboxy-terminal thioesterase (TE) domain determines the length of the fatty acyl chain and its ultimate release by hydrolysis. Because of the upregulation of hFAS in a variety of cancers, it is a target for antiproliferative agent development. Dietary long-chain polyunsaturated fatty acids (PUFAs) have been known to confer beneficial effects on many diseases and health conditions, including cancers, inflammations, diabetes, and heart diseases, but the precise molecular mechanisms involved have not been elucidated. We report the

crystal structure of the hFAS TE domain covalently modified and inactivated by methyl γ-linolenylfluorophosphonate. Whereas the structure confirmed the phosphorylation by the phosphonate head group of the active site serine, it also unexpectedly revealed the binding of the 18-carbon polyunsaturated γ-linolenyl tail in a long groove-tunnel site, which itself is formed mainly by the emergence of an α helix (the “helix flap”). We then found inhibition of the TE domain activity by the PUFA dihomo-γ-linolenic acid; γ- and α-linolenic acids, two popular dietary PUFAs, were less effective. Dihomo-γ-linolenic acid also inhibited fatty acid biosynthesis in 3T3-L1 preadipocytes and selective human breast cancer cell lines, including SKBR3 and MDAMB231. In addition to revealing a novel mechanism for the molecular recognition of a polyunsaturated fatty acyl chain, our results offer a new framework for developing potent FAS inhibitors as therapeutics against cancers and other diseases.
Effects of crystal parameters on power and efficiency of Nd : YVO4 laser in-band pumped by 914 nm laser
Authors: Ding X , Shi C P , Yin S J , Li X , Li B , Sheng Q , Yu X Y , Wen W Q , Yao J Q
Published: September 2011

To overcome the main drawback of poor pump absorption of Nd : YVO4 lasers in-band pumped at 914 nm, three possible methods of higher temperature, longer crystal length and higher doping concentration were experimentally studied. A Nd : YVO4 laser operating at 914 nm was used as high beam quality, narrow line-width pump source to make the measurement of pump absorption accurate. Four different Nd : YVO4 crystals were used as gain mediums to investigate the effects of crystal parameters. We found that heating the crystal effects differently on output power and overall efficiency when crystal doping concentration changed. To improve the pump absorption and meanwhile achieve high efficiency, longer crystal with proper doping concentration and pump feedback should be adopted instead of highly doped crystal.
Theoretical Studies on Structures and Spectroscopic Properties of Highly Efficient Phosphorescent [Ru(terpy)(phen)X]+ Complexes
Authors: Jin Li , Zhang Jian-po , Zhang Hong-xing , Bai Fu-quan
Published: September 2011

The ground and the lowest-lying triplet excited state geometries, electronic structures, and spectroscopic properties of three mixed-ligand Ru(II) complexes [Ru(terpy)(phen)X]+ (terpy=2,2′,6′,2″-terpyridine, phen=1,10-phenanthroline, and X=—C≡CH (1), X=Cl (2), X=CN (3)) were investigated theoretically using the density functional theory method. The ground and excited state geometries have been fully optimized at the B3LYP/LanL2DZ and UB3LYP/LanL2DZ levels, respectively. The absorption and emission spectra of the complexes in CH3CN solutions were calculated by time-dependent density functional theory with the PCM solvent model. The calculated bond lengths of Ru—C, Ru—N, and Ru—Cl in the ground state agree well with the corresponding experimental results. The highest occupied molecular orbital were dominantly localized on the Ru atom and monodentate X ligand for 1 and 2, Ru atom and terpy ligand for 3, while the lowest unoccupied molecular orbital were π* (terpy) type orbital. Therefore, the lowest-energy absorptions of 1 and 2 at 688 and 631 nm are attributed to a dyz (Ru)+π/p(X)→π* (terpy) transition with MLCT/XLCT (metal-to-ligand charge transfer/X ligand to terpy ligand charge transfer) character, whereas that of 3 at 529 nm is related to a dyz(Ru)+π(terpy)→π*(terpy) transition with MLCT and ILCT transition character. The calculated phosphorescence of three complexes at 1011 nm (1), 913 nm (2), and 838 nm (3) have similar transition properties to that of the lowest-lying absorption. It is shown that the lowest lying absorptions and emissions transition character of these Ru(II) complexes can be tuned by changing the electron-withdrawing ability of the monodentate ligand.
Evaluation of Phonon-level Density of UO2 by Molecular Dynamics Simulation
Authors: Zhang Hui-fen , Li Gan , Tian Xiao-feng , Gao Tao
Published: September 2011

Molecular dynamics calculation of UO2 in a wide temperature range are presented and discussed. The calculated lattice parameters, mean square displacements, and dynamic property of phonon-level density of the velocity auto-correlation functions for UO2 are provided. The Morelon potential and the Basak potential are employed. It confirms that the calculated lattice parameters using the Basak potential are in nearly perfect agreement with the reported values. The models successfully predict mean square displacement and Bredig transition. Furthermore, the phonon-level density of uranium dioxide are discussed. The intensity of phonon-level density increases with temperature, and the properties of UO2 are characterized by large thermal vibrations rather than extensive disorder.
Calculation of Viscosity and Diffusion Coefficients for Two Binary Gaseous Mixtures Using the Semi-empirical Inversion Method
Authors: Rafiee Hamid Reza , Rastgar Mina , Heidari Neda
Published: September 2011

The accurate reduced potential energies for two binary gas mixtures including benzene-methanol and methane-tetrafluoromethane at low density have been obtained by direct inversion of the viscosity collision integral equations. The kinetic theory along with the extended principle of corresponding-states has been used to calculate the viscosity and diffusion coefficients over a wide range of temperature and composition. Good agreements between calculated and experimental data are obtained.
Coarse-grained Simulations of Chemical Oscillation in Lattice Brusselator System
Authors: Rao Ting , Zhang Zhen , Hou Zhong-huai , Xin Hou-wen
Published: September 2011

The oscillation behavior of a two-dimension lattice-gas Brusselator model was investigated. We have adopted a coarse-grained kinetic Monte Carlo (CG-KMC) procedure, where m×m microscopic lattice sites are grouped together to form a CG cell, upon which CG processes take place with well-defined CG rates. Such a CG approach almost fails if the CG rates are obtained by a simple local mean field (s-LMF) approximation, due to the ignorance of correlation among adjcent cells resulting from the trimolecular reaction in this nonlinear system. By proper incorporating such boundary effects, thus introduce the so-called b-LMF CG approach. Extensive numerical simulations demonstrate that the b-LMF method can reproduce the oscillation behavior of the system quite well, given that the diffusion constant is not too small. In addition, the deviation from the KMC results reaches a nearly zero minimum level at an intermediate cell size, which lies in between the effective diffusion length and the minimal size required to sustain a well-defined temporal oscillation.
Theoretical Study on First Hyperpolarizabilities of End-Capped Triply Branched Dendrimers
Authors: Wang Yan-hua , Liu Kai
Published: September 2011

A series of end-capped triply branched dendritic chromophores have been studied by means of density functional theory calculations. It is found that the second order nonlinear optical properties of the end-capped dendrimers are strongly dependent on the mutual orientations of the three chromophores, numbers of caps and the conjugation length of the chromophores. Large enhancement of the first hyperpolarizability can be obtained when dipole moments of three branches in the dendrimers are highly parallelized.
Bio-methanol from Bio-oil Reforming Syngas Using Dual-reactor
Authors: Ye Tong-qi , Yan Shi-zhi , Xu Yong , Qiu Song-bai , Liu Yong , Li Quan-xin
Published: September 2011

A dual-reactor, assembled with the on-line syngas conditioning and methanol synthesis, was successfully applied for high efficient conversion of rich CO2 bio-oil derived syngas to bio-methanol. In the forepart catalyst bed reactor, the catalytic conversion can effectively adjust the rich-CO2 crude bio-syngas into the CO-containing bio-syngas using the CuZnAlZr catalyst. After the on-line syngas conditioning at 450 °C, the CO2/CO ratio in the bio-syngas significantly decreased from 6.3 to 1.2. In the rearward catalyst bed reactor, the conversion of the conditioned bio-syngas to bio-methanol shows the maximum yield about 1.21 kg/(kgcatal·h) MeOH with a methanol selectivity of 97.9% at 260 °C and 5.05 MPa using conventional CuZnAl catalyst, which is close to the level typically obtained in the conventional methanol synthesis process using natural gas. The influences of temperature, pressure and space velocity on the bio-methanol synthesis were also investigated in detail.
The inefficiency of re-weighted sampling and the curse of system size in high-order path integration
Authors: Ceriotti Michele , Brain Guy A. R. , Riordan Oliver , Manolopoulos David E.
Published: September 2011

Computing averages over a target probability density by statistical re-weighting of a set of samples with a different distribution is a strategy which is commonly adopted in fields as diverse as atomistic simulation and finance. Here we present a very general analysis of the accuracy and efficiency of this approach, highlighting some of its weaknesses. We then give an example of how our results can be used, specifically to assess the feasibility of high-order path integral methods. We demonstrate that the most promising of these techniques—which is based on re-weighted sampling—is bound to fail as the size of the system is increased, because of the exponential growth of the statistical uncertainty in the re-weighted average.
Dissection of the Transcriptional Program Regulating Secondary Wall Biosynthesis during Wood Formation in Poplar
Authors: Zhong Ruiqin , McCarthy Ryan L. , Lee Chanhui , Ye Zheng-Hua
Published: September 2011

Wood biomass is mainly made of secondary cell walls; hence, elucidation of the molecular mechanisms underlying the transcriptional regulation of secondary wall biosynthesis during wood formation will be instrumental to design strategies for genetic improvement of wood biomass. Here, we provide direct evidence demonstrating that the poplar (Populus trichocarpa) wood-associated NAC domain transcription factors (PtrWNDs) are master switches activating a suite of downstream transcription factors, and together, they are involved in the coordinated regulation of secondary wall biosynthesis during wood formation. We show that transgenic poplar plants with dominant repression of PtrWNDs functions exhibit a drastic reduction in secondary wall thickening in woody cells, and those with PtrWND overexpression result in ectopic deposition of secondary walls. Analysis of PtrWND2B overexpressors revealed up-regulation of the expression of a number of wood-associated transcription factors, the promoters of which were also activated by PtrWND6B and the Eucalyptus EgWND1. Transactivation analysis and electrophoretic mobility shift assay demonstrated that PtrWNDs and EgWND1 activated gene expression through direct binding to the secondary wall NAC-binding elements, which are present in the promoters of several wood-associated transcription factors and a number of genes involved in secondary wall biosynthesis and modification. The WND-regulated transcription factors PtrNAC150, PtrNAC156, PtrNAC157, PtrMYB18, PtrMYB74, PtrMYB75, PtrMYB121, PtrMYB128, PtrZF1, and PtrGATA8 were able to activate the promoter activities of the biosynthetic genes for all three major wood components. Our study has uncovered that the WND master switches together with a battery of their downstream transcription factors form a transcriptional network controlling secondary wall biosynthesis during wood formation.
Structural and Functional Assays of AtTLP18.3 Identify Its Novel Acid Phosphatase Activity in Thylakoid Lumen
Authors: Wu Hsin-Yi , Liu Mao-Sen , Lin Tsan-Piao , Cheng Yi-Sheng
Published: September 2011

The membrane protein AtTLP18.3 of Arabidopsis (Arabidopsis thaliana) contains a domain of unknown function, DUF477; it forms a polysome with photosynthetic apparatuses in the thylakoid lumen. To explore the molecular function of AtTLP18.3, we resolved its crystal structures with residues 83 to 260, the DUF477 only, and performed a series of biochemical analyses to discover its function. The gene expression of AtTLP18.3 followed a circadian rhythm. X-ray crystallography revealed the folding of AtTLP18.3 as a three-layer sandwich with three α-helices in the upper layer, four β-sheets in the middle layer, and two α-helices in the lower layer, which resembles a Rossmann fold. Structural comparison suggested that AtTLP18.3 might be a phosphatase. The enzymatic activity of AtTLP18.3 was further confirmed by phosphatase assay with various substrates (e.g. p-nitrophenyl phosphate, 6,8-difluoro-4-methylumbelliferyl phosphate, O-phospho-l-serine, and several synthetic phosphopeptides). Furthermore, we obtained the structure of AtTLP18.3 in complex with O-phospho-l-serine to identify the binding site of AtTLP18.3. Our structural and biochemical studies revealed that AtTLP18.3 has the molecular function of a novel acid phosphatase in the thylakoid lumen. DUF477 is accordingly renamed the thylakoid acid phosphatase domain.
Targeted Identification of Short Interspersed Nuclear Element Families Shows Their Widespread Existence and Extreme Heterogeneity in Plant Genomes
Authors: Wenke Torsten , Döbel Thomas , Sörensen Thomas Rosleff , Junghans Holger , Weisshaar Bernd , Schmidt Thomas
Published: September 2011

Short interspersed nuclear elements (SINEs) are non-long terminal repeat retrotransposons that are highly abundant, heterogeneous, and mostly not annotated in eukaryotic genomes. We developed a tool designated SINE-Finder for the targeted discovery of tRNA-derived SINEs. We analyzed sequence data of 16 plant genomes, including 13 angiosperms and three gymnosperms and identified 17,829 full-length and truncated SINEs falling into 31 families showing the widespread occurrence of SINEs in higher plants. The investigation focused on potato (Solanum tuberosum), resulting in the detection of seven different SolS SINE families consisting of 1489 full-length and 870 5′ truncated copies. Consensus sequences of full-length members range in size from 106 to 244 bp depending on the SINE family. SolS SINEs populated related species and evolved separately, which led to some distinct subfamilies. Solanaceae SINEs are dispersed along chromosomes and distributed without clustering but with preferred integration into short A-rich motifs. They emerged more than 23 million years ago and were species specifically amplified during the radiation of potato, tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum). We show that tobacco TS retrotransposons are composite SINEs consisting of the 3′ end of a long interspersed nuclear element integrated downstream of a nonhomologous SINE family followed by successfully colonization of the genome. We propose an evolutionary scenario for the formation of TS as a spontaneous event, which could be typical for the emergence of SINE families.
New perspectives on the convergence of academic libraries and campus information technology departments
Authors: Joint Nicholas
Published: September 2011

Purpose

The purpose of this paper is to give some insight into current evidence about the value of converging library and information technology departments into single organisational units.

Design/methodology/approach

A narrative account of attempts to merge libraries, IT departments and other campus support services, with analysis supported by a selected, representative number of published case studies. A conclusion is offered that emphasises the practical benefits of convergence at the level of the working library professional and everyday library user.

Findings

The recent history of convergence has moved through three phases: an early period of optimistic and energetic commitment to the idea of merging IT and library services, gave way to an interim stage of reflection and reconsideration during which some degree of “deconvergence” took place. After this pause, a new dynamic was created, associated both with the trend towards “super‐convergence”, and also with new, more pragmatic ideas about how to bring workers from different professional traditions together.

Originality/value

The paper attempts to give some highly contemporary insights into the latest thinking and developments on the topic in question, and emphasises the importance of relating abstract management strategies to practical organisational outcomes.
Business model dynamics and innovation: (re)establishing the missing linkages
Authors: Cavalcante Sérgio , Kesting Peter , Ulhøi John
Published: September 2011

Purpose

This paper aims to discuss the need to dynamize the existing conceptualization of business model, and proposes a new typology to distinguish different types of business model change.

Design/methodology/approach

The paper integrates basic insights of innovation, business process and routine research into the concept of business model. The main focus of the paper is on strategic and terminological issues.

Findings

The paper offers a new, process‐based conceptualization of business model, which recognizes and integrates the role of individual agency. Based on this, it distinguishes and specifies four different types of business model change: business model creation, extension, revision, and termination. Each type of business model change is associated with specific challenges.

Practical implications

The proposed typology can serve as a basis for developing a management tool to evaluate the impact of specific changes to a firm's business model. Such a tool would be particularly useful in identifying path dependencies and resistance at the process level, and would therefore allow a firm's management to take focused action on this in advance.

Originality/value

The paper makes two main contributions: first, it offers a new, process‐based conceptualization of business models; second, it is the first paper to establish a direct link between business model change and the degree of innovation (such as “incremental” vs “radical”), and which distinguishes and specifies different types of business model change.
Sustainability managers or rogue mid‐managers?
Authors: Tang Kevin , Robinson David A. , Harvey Michael
Published: September 2011

Purpose

This paper aims to look into the motivations of managers to commit their time and energies to look at environmental, social, and ethical issues. In short, this research set out to answer the following research questions: What are the different types of change agents for sustainability, in terms of their existential needs? What are the motivations and frustrations faced by sustainability managers as change agents? and How are the motivations and frustrations of sustainability managers framed by the sources of meaning in their life and work?

Design/methodology/approach

As the research is still at an exploratory stage, a qualitative methodology was adopted. This methodology was also appropriate for the purpose of this research, which was focused on studying how meaning emerges and changes in situated organizational settings. The authors were engaged in 27 value‐laden semi‐structured interviews where they were looking to build a close relationship between the researcher and what was studied. The interview process was divided into three phases to ensure the planning and validity of the process.

Findings

It identifies four such categories of sustainability managers, those being Scientist, Messenger, Artist and Storyteller. The findings suggest the key role of expertise, empowerment, values, inspiration, strategic thinking and social contribution as key meaning for these managers. The empirical findings help build on understanding of the different psychological dimensions of corporate sustainability management, and provides a useful tool for developing effective organizational leadership, enhancing recruitment and retention of sustainability talent, and improving individual and team performance for key sustainability growth.

Originality/value

This research has helped to deal application of existential psychology theories to complement corporate sustainability. The findings more or less confirm the usability of major existential psychology theories to find sources of motivations of sustainability managers.
A leadership point of view: key principles
Authors: Wills Stefan
Published: September 2011

Purpose

This paper aims to understand what leadership is and how it occurs within organizations.

Design/methodology/approach

Highlights four key principles which serve as a guiding template or frame of reference to help enhance managers' confidence and credibility and encourage strong leadership inside an organization.

Findings

Followers choose our leaders – leaders do not choose their followers. This kind of relationship and connection between people goes beyond the transactional (i.e. managers and their direct reports) and into the realm of the transformational.

Practical implications

The phenomenon we call leadership/followership is an episodic series of events intending significant change. So, to be clear, leadership does not reside in a person or even several persons; it resides in a dynamic and ever‐changing relationship among people.

Originality/value

Creating leadership energy is an inside job, the stimulus for it comes from inside an individual. It can come from inside any individual of any type. This sits in opposition to the view that there is a universal list of character traits which determines who becomes a leader in any culture or any industry.