bluuebunny/crossref_metadata_2025 huggingface dataset:
Water mediated reactions: TiO2and ZnO nanoparticle catalyzed multi component domino reaction in the synthesis of tetrahydroacridinediones, acridindiones, xanthenones and xanthenes
Authors: Pugazhenthi Ilangovan , Ghouse Shaik Mohammed , Nawaz Khan Fazlur-Rahman , Jeong Euh Duck , Bae Jong Seong , Kim Jong-Pil , Chung Eun Hyuk , Kumar Yadavalli Suneel , Dasaradhan Changalraya
Published: January 2015

Tetrahydroacridine-1,8-(2H,5H,9H,10H)-diones4from 1,3-cyclohexanedione and/or dimedone 1,2-chloro-3-formylquinoline2and anilines3in water at 90 °C were obtained by domino reaction approach.
Interactions in globular proteins with polyampholyte: coacervation route for protein separation
Authors: Pathak Jyotsana , Rawat Kamla , Aswal V. K. , Bohidar H. B.
Published: January 2015

Representative model of protein–protein separation in a BSA–GB–β-Lg aqueous solution.
Optical trapping enhancement from high density silicon nanohole and nanowire arrays for efficient hybrid organic–inorganic solar cells
Authors: Thiyagu Subramani , Syu Hong-Jhang , Hsueh Chen-Chih , Liu Chien-Ting , Lin Tzu-Ching , Lin Ching-Fuh
Published: January 2015

The SiNH arrays exhibit excellent light-absorbing structures and higher optical trapping as compared to SiNW arrays, resulting in leading performance power conversion efficiency of 11.25% in the hybrid organic–inorganic solar cells.
How do organic gold compounds and organic halogen molecules interact? Comparison with hydrogen bonds
Authors: Gao Meng , Li Qingzhong , Li Hai-Bei , Li Wenzuo , Cheng Jianbo
Published: January 2015

Au⋯halogen interactions exist extensively in crystal materials and exhibit some similar and different properties with hydrogen bonds.
Preparation and dielectric properties of cyanoethyl cellulose/BaTiO3 flexible nanocomposite films
Authors: Jia Chao , Shao Ziqiang , Fan Haoyu , Wang Jianquan
Published: January 2015

Cyanoethyl cellulose-based high dielectric permittivity nanocomposite films were successfully prepared for the first time by introducing BaTiO3 into cyanoethyl cellulose.
p-type ZnTe:Ga nanowires: controlled doping and optoelectronic device application
Authors: Luo Lin-Bao , Zhang Shun-Hang , Lu Rui , Sun Wei , Fang Qun-Ling , Wu Chun-Yan , Hu Ji-Gang , Wang Li
Published: January 2015

p-type ZnTe:Ga nanowires with a tunable electrical conductivity can be used to fabricate a high-performance semiconductor/graphene Schottky diode photodetector.
A fibre forming smectic twist–bent liquid crystalline phase
Authors: Tamba M. G. , Salili S. M. , Zhang C. , Jákli A. , Mehl G. H. , Stannarius R. , Eremin A.
Published: January 2015

We demonstrate the nanostructure and filament formation of a novel liquid crystal phase of a dimeric mesogen below the twist–bend nematic phase.
Supramolecular functionalized polybenzoxazines from azobenzene carboxylic acid/azobenzene pyridine complexes: synthesis, surface properties, and specific interactions
Authors: Mohamed Mohamed Gamal , Hsiao Chi-Hui , Hsu Kuo-Chih , Lu Fang-Hsien , Shih His-Kang , Kuo Shiao-Wei
Published: January 2015

Supramolecular complex of azobenzene carboxylic acid/pyridine functionalized benzoxazine system featured significantly lower curing temperatures and maintain high water contact angles.
Remotely triggered micro-shock wave responsive drug delivery system for resolving diabetic wound infection and controlling blood sugar levels
Authors: Gnanadhas Divya Prakash , Elango Monalisha , Thomas Midhun Ben , Gopalan Jagadeesh , Chakravortty Dipshikha
Published: January 2015

A novel, micro-shock wave responsive spermidine and dextran sulfate microparticle was developed.
Graphene boosts thermoelectric performance of a Zintl phase compound
Authors: Bhardwaj A. , Shukla A. K. , Dhakate S. R. , Misra D. K.
Published: January 2015

The nanocomposite of Mg3Sb2-based Zintl phase compound, fabricated by utilizing, GNS, as a nanocomposite additive, enhances significantly the thermoelectric performance.
LED lighting as a simple, inexpensive, and sustainable alternative for Wolff rearrangements
Authors: Bernardim Barbara , Hardman-Baldwin Andrea M. , Burtoloso Antonio C. B.
Published: January 2015

The Wolff rearrangement suffers from many drawbacks with respect to its practical execution in the laboratory. Herein, commercial LED lamps are employed as a sustainable alternative for the classic protocols typically used for Wolff rearrangements.
Ternary polymer electrolytes incorporating pyrrolidinium-imide ionic liquids
Authors: de Vries Henrik , Jeong Sangsik , Passerini Stefano
Published: January 2015

Amorphous PEO-ionic liquid–LiX polymer electrolytes containing mixed imide anions exhibit high ionic conductivity and lithium plating–stripping capability at moderate temperatures.
Colorimetric sensors with different reactivity for the quantitative determination of cysteine, homocysteine and glutathione in a mixture
Authors: Niu Li-Ya , Jia Ming-Yan , Chen Peng-Zhong , Chen Yu-Zhe , Zhang Yuan , Wu Li-Zhu , Duan Chun-Feng , Tung Chen-Ho , Guan Ya-Feng , Feng Liang , Yang Qing-Zheng
Published: January 2015

We report a facile method for the quantitative detection of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) in a mixture.
On the existence of and mechanism for microwave-specific reaction rate enhancement
Authors: Dudley Gregory B. , Richert Ranko , Stiegman A. E.
Published: January 2015

Microwave-specific chemical rate enhancement originates from the selective heating and accumulation of energy by solvated dipolar molecules in solution.
Stripe to slab confinement for the linearization of macromolecules in nanochannels
Authors: Benková Zuzana , Námer Pavol , Cifra Peter
Published: January 2015

Chain extension along the channelvs.the confinement curves for the stripe-like channel (upper curve) and in the four slab-like channels of increasing thickness in the transition curves below.
Trifluoroacetylazobenzene for optical and electrochemical detection of amines
Authors: Lin Jhih-Fong , Kukkola Jarmo , Sipola Teemu , Raut Dilip , Samikannu Ajaikumar , Mikkola Jyri-Pekka , Mohl Melinda , Toth Geza , Su Wei-Fang , Laurila Tomi , Kordas Krisztian
Published: January 2015

Optical and electrochemical sensors based on 4-(dioctylamino)-4′-(trifluoroacetyl)azobenzene and its Nafion®–SWCNT composites show potential for practical applications in detecting various kinds of amines.
Influence of different chemical modifications on the icephobic properties of superhydrophobic surfaces in a condensate environment
Authors: Wang Yuanyi , Li Mingzhen , Lv Ting , Wang Qingjun , Chen Qingmin , Ding Jianfu
Published: January 2015

The icephobic properties (both in ice-adhesion reduction and water rebound) of different superhydrophobic surfaces varied wildly at sub-zero condensate environment.
Precise control of chemical vapor deposition graphene layer thickness using NixCu1−x alloys
Authors: Choi Hyonkwang , Lim Yeongjin , Park Minjeong , Lee Sehui , Kang Younsik , Kim Min Su , Kim Jeongyong , Jeon Minhyon
Published: January 2015

We investigated a simple but effective method to precisely control the desired number of graphene layers on the NixCu1−x alloy substrates by thermal chemical vapor deposition.
A water-soluble eumelanin polymer with typical polyelectrolyte behaviour by triethyleneglycol N-functionalization
Authors: Cicco Stefania R. , Ambrico Marianna , Ambrico Paolo F. , Talamo Maurizio Mastropasqua , Cardone Antonio , Ligonzo Teresa , Di Mundo Rosa , Giannini Cinzia , Sibillano Teresa , Farinola Gianluca M. , Manini Paola , Napolitano Alessandra , Criscuolo Valeria , d'Ischia Marco
Published: January 2015

Oxidative polymerization of 5,6-dihydroxyindole N-functionalized with TEG chains as a new route to water-soluble eumelanin-like materials..
Luminescent sensing profiles based on anion-responsive lanthanide(iii) quinolinecarboxylate materials: solid-state structures, photophysical properties, and anionic species recognition
Authors: Xu Wentao , Zhou Youfu , Huang Decai , Su Mingyi , Wang Kun , Xiang Ming , Hong Maochun
Published: January 2015

Eu2PQC6 has been developed to detect HSO4− and H2PO4− through different recognition mechanisms with low detection limits.
Transistor application of new picene-type molecules, 2,9-dialkylated phenanthro[1,2-b:8,7-b′]dithiophenes
Authors: Kubozono Yoshihiro , Hyodo Keita , Mori Hiroki , Hamao Shino , Goto Hidenori , Nishihara Yasushi
Published: January 2015

Field-effect transistors have been fabricated that use thin films of 2,9-dialkylated phenanthro[1,2-b:8,7-b′]dithiophenes (Cn-PDTs), with the transistor based on a thin film of C12-PDT showing aμas high as ∼2 cm2V−1s−1, which is promising for future practical electronics.
Enhanced thermoelectric property by the construction of a nanocomposite 3D interconnected architecture consisting of graphene nanolayers sandwiched by polypyrrole nanowires
Authors: Zhang Zhuang , Chen Guangming , Wang Hanfu , Zhai Wentao
Published: January 2015

A new strategy is developed to significantly enhance polymer thermoelectric property by the construction of 3D interconnected architecture consisting of rGO nanolayers sandwiched by PPy nanowires.
Hybrid nanomaterials YVO4:Eu/Fe3O4for optical imaging and hyperthermia in cancer cells
Authors: Singh Laishram Priyobarta , Jadhav Neena V. , Sharma Sachil , Pandey Badri N. , Srivastava Sri Krishna , Ningthoujam Raghumani Singh
Published: January 2015

YVO4:Eu/Fe3O4can be used for optical imaging and hyperthermia in cancer cells.
Transcriptomic alterations induced by Monuron in rat and human renal proximal tubule cells in vitro and comparison to rat renal-cortex in vivo
Authors: Bloch Katarzyna M. , Yaqoob Noreen , Sharma Sikander , Evans Andrew , Aschauer Lydia , Radford Robert , Jennings Paul , Ryan Michael P. , van Delft Joost H. M. , Lock Edward A.
Published: January 2015

Monuron (1,1-dimethyl-3-(4-chlorophenyl)urea) is a widely used herbicide in developing countries although concerns have been raised about its toxicity and carcinogenicity.
Regulation of the self-assembly morphology of azobenzene-bearing double hydrophobic block copolymers in aqueous solution by shifting the dynamic host–guest complexation
Authors: Tong Zai-Zai , Wang Rui-Yang , Huang Jie , Xu Jun-Ting , Fan Zhi-Qiang
Published: January 2015

The complexation equilibrium between azo and β-CD can be shifted by various methods, thus the micellar morphology of azo-bearing block copolymers is altered.
Methylsulfone as a leaving group for synthesis of hyperbranched poly(arylene pyrimidine ether)s by nucleophilic aromatic substitution
Authors: Guan Yue , Wang Chunbo , Wang Daming , Dang Guodong , Chen Chunhai , Zhou Hongwei , Zhao Xiaogang
Published: January 2015

Using a novel leaving group, methylsulfone activated by pyrimidine, 4,6-dichloro-2-(methylsulfonyl)pyrimidine was used to synthesize two new hyperbranched poly(arylene pyrimidine ether)s with diphenol via a nucleophilic substitution polymerization.
The MAP kinase-interacting kinases regulate cell migration, vimentin expression and eIF4E/CYFIP1 binding
Authors: Beggs James E. , Tian Shuye , Jones Greg G. , Xie Jianling , Iadevaia Valentina , Jenei Veronika , Thomas Gareth , Proud Christopher G.
Published: January 2015

This study shows, based on genetic data and a new pharmacological agent, that the MAP kinase-interacting kinases are required for efficient migration of cancer cells. These kinases may therefore play a role in processes associated with tumour metastasis.
Semi‐active laser/millimetre wave beam combiner design and test
Authors: Tian Yi , Yan Hui , Sun Gang , Lv Lijun , Wang Xin , Zhang Li , Li Zhuo
Published: January 2015

The semi‐active laser /millimetre wave (MMW) beam combiner design methods including the MMW transmission structure design method and laser diffuse surface design method were proposed. The transmission line theory was adopted to design the MMW transmission structure. The Lambert's law assumption was adopted when the diffuse reflection surface of the beam combiner was designed. In the aim of illustrating the design methods, a thin plate beam combiner design case was given to meet the performance requirements which were proposed according to the test requirements of the unit under test. In order to validate the MMW transmission structure design method, a prototype made of polytetrafluoroethylene was fabricated and it was tested in a Ka band compact range anechoic chamber. In order to evaluate the laser reflection performance, the laser reflection performance at a wavelength of 1.064 μm was also tested and analysed by an empirical bidirectional reflectance distribution function model.
Design of millimetre wave diplexers with relaxed fabrication tolerances
Authors: Aitken John Ross , Hong Jiasheng
Published: January 2015

A novel millimetre wave waveguide diplexer topology that can be fabricated using relaxed fabrication tolerances is presented. This is achieved by using a highpass filter/hybrid coupler topology in addition to a low order capacitive iris bandpass filter. By targeting the most sensitive centre resonators in the bandpass filter and increasing their length to full wavelength, the sensitivity to fabrication errors associated with changes to the resonator length can be reduced without the introduction of spurious responses close to the passband. The main benefit of this topology is that only one bandpass filter is required to realise the final diplexing response. This is advantageous when tolerance is considered as it is found that resonating structures associated with bandpass filters contribute to tolerance effects. In addition to this, the authors find that the choice of iris discontinuity used to realise the impedance inverters in the bandpass filter can help to relax fabrication tolerances. By subjecting the proposed circuit to a tolerance analysis, simulated results suggest that the circuit can be fabricated with relaxed fabrication tolerances. These discussions are verified with the fabrication of a Ka‐band waveguide diplexer, where the measured and simulated scattering parameters are in very good agreement.
Millimetre‐wave slotted array antenna based on double‐layer substrate integrated waveguide
Authors: Li Teng , Dou Wen Bin
Published: January 2015

In this study, a millimetre‐wave slotted array antenna based on double‐layer substrate integrated waveguide (SIW) is proposed. The radiating array and feeding network are arranged on different substrate layers with a normal printed circuit board process. The design procedure of radiating elements based on array parameters extraction is introduced. A broadband T‐junction and tilted coupling slots are used for power division in feeding network. A broadband right‐angle transition between SIW and standard rectangular waveguide WR28 is designed and integrated in the bottom metallic plate for measurement. An 8 × 8 array operating at 35 GHz is designed and fabricated. Measured gain is 19.94 dB with sidelobe suppression of −19.8 dB in the E‐plane and −17.7 dB in the H‐plane at the centre frequency. The measured bandwidth of 20 dB return loss is 1.32 GHz. The good agreements between simulations and experiments demonstrate that the proposed double‐layer SIW slotted array antenna is a good choice for un‐rectangular aperture array and large array applications.
High step‐up current‐fed ZVS dual half‐bridge DC–DC converter for high‐voltage applications
Authors: Meghdad Taheri , Jafar Milimonfared , Bijan Abbasi
Published: January 2015

In this study, a new high step‐up current‐fed zero voltage switching (ZVS) dual half‐bridge DC–DC converter is proposed. The presented topology is composed of two paralleled boost half‐bridge converters. In this converter, only two switches are efficiently utilised such that the adopted scheme has a simpler control circuit, lower losses and lower cost. It is very noteworthy that over the whole range of load and input voltage variations, the switches keep ZVS operation and the output diodes operate in zero current switching (ZCS) condition leading to high overall efficiency. Also, taking the advantage of voltage‐doubler circuits, transformers with lower turn‐ratio and diodes with lower reverse voltage can be used to build the desired high output voltage. Regarding the mentioned characteristics, the proposed converter can be well nominated for distributed generation systems. In‐depth analysis, design and performance comparison of this new converter are illustrated; then for verification purpose, experimental results with an output voltage of 400 V and output current of 2.5 A are presented.
Two‐step microfocal lens with enhanced optical coupling efficiency suitable for large‐scale fabrication
Authors: Miao Lingyun , Hsiang Thomas Y.
Published: January 2015

A two‐step microfocal lens design that can achieve high‐efficiency optical coupling is reported. Simulation results show that the lens enhances optical coupling efficiency by over one‐third compared with its prototype previously reported. It also slightly reduces the focal spot size. A simple top‐down fabrication process flow is discussed, which indicates that the proposed two‐step lens can be fabricated at low cost using conventional industrial equipment.
Theoretical reproduction of the Q-band absorption spectrum of free-base chlorin
Authors: Wójcik Justyna , Ratuszna Alicja , Peszke Jerzy , Wrzalik Roman
Published: January 2015

The computational results of the features observed in the room-temperature Q-band absorption spectrum of free-base chlorin (H2Ch) are presented. The vibrational structures of the first and second excited singlet states were calculated based on a harmonic approximation using density functional theory and its time dependent extension within the Franck-Condon and Herzberg-Teller approaches. The outcome allowed to identify the experimental bands and to assign them to the specific vibrational transitions. A very good agreement between the simulated and measured wavelengths and their relative intensities provided the opportunity to predict the origin of the S0 → S2 transition which could not be determined experimentally.
Systematic theoretical investigation of the zero-field splitting in Gd(III) complexes: Wave function and density functional approaches
Authors: Khan Shehryar , Kubica-Misztal Aleksandra , Kruk Danuta , Kowalewski Jozef , Odelius Michael
Published: January 2015

The zero-field splitting (ZFS) of the electronic ground state in paramagnetic ions is a sensitive probe of the variations in the electronic and molecular structure with an impact on fields ranging from fundamental physical chemistry to medical applications. A detailed analysis of the ZFS in a series of symmetric Gd(III) complexes is presented in order to establish the applicability and accuracy of computational methods using multiconfigurational complete-active-space self-consistent field wave functions and of density functional theory calculations. The various computational schemes are then applied to larger complexes Gd(III)DOTA(H2O)−, Gd(III)DTPA(H2O)2−, and Gd(III)(H2O)83+ in order to analyze how the theoretical results compare to experimentally derived parameters. In contrast to approximations based on density functional theory, the multiconfigurational methods produce results for the ZFS of Gd(III) complexes on the correct order of magnitude.
Self-consistent continuum solvation for optical absorption of complex molecular systems in solution
Authors: Timrov Iurii , Andreussi Oliviero , Biancardi Alessandro , Marzari Nicola , Baroni Stefano
Published: January 2015

We introduce a new method to compute the optical absorption spectra of complex molecular systems in solution, based on the Liouville approach to time-dependent density-functional perturbation theory and the revised self-consistent continuum solvation model. The former allows one to obtain the absorption spectrum over a whole wide frequency range, using a recently proposed Lanczos-based technique, or selected excitation energies, using the Casida equation, without having to ever compute any unoccupied molecular orbitals. The latter is conceptually similar to the polarizable continuum model and offers the further advantages of allowing an easy computation of atomic forces via the Hellmann-Feynman theorem and a ready implementation in periodic-boundary conditions. The new method has been implemented using pseudopotentials and plane-wave basis sets, benchmarked against polarizable continuum model calculations on 4-aminophthalimide, alizarin, and cyanin and made available through the Quantum ESPRESSO distribution of open-source codes.
Second virial coefficient of a generalized Lennard-Jones potential
Authors: González-Calderón Alfredo , Rocha-Ichante Adrián
Published: January 2015

We present an exact analytical solution for the second virial coefficient of a generalized Lennard-Jones type of pair potential model. The potential can be reduced to the Lennard-Jones, hard-sphere, and sticky hard-sphere models by tuning the potential parameters corresponding to the width and depth of the well. Thus, the second virial solution can also regain the aforementioned cases. Moreover, the obtained expression strongly resembles the one corresponding to the Kihara potential. In fact, the Fk functions are the same. Furthermore, for these functions, the complete expansions at low and high temperature are given. Additionally, we propose an alternative stickiness parameter based on the obtained second virial coefficient.
A new proof of a formula for the type A2 fusion rules
Authors: Barker Amy , Swinarski David , Vogelstein Lauren , Wu John
Published: January 2015

We give a new proof of a formula for the fusion rules for type A2 due to Bégin, Mathieu, and Walton. Our approach is to symbolically evaluate the Kac-Walton algorithm.
A semi-empirical model relating micro structure to acoustic properties of bimodal porous material
Authors: Mosanenzadeh Shahrzad Ghaffari , Doutres Olivier , Naguib Hani E. , Park Chul B. , Atalla Noureddine
Published: January 2015

Complex morphology of open cell porous media makes it difficult to link microstructural parameters and acoustic behavior of these materials. While morphology determines the overall sound absorption and noise damping effectiveness of a porous structure, little is known on the influence of microstructural configuration on the macroscopic properties. In the present research, a novel bimodal porous structure was designed and developed solely for modeling purposes. For the developed porous structure, it is possible to have direct control on morphological parameters and avoid complications raised by intricate pore geometries. A semi-empirical model is developed to relate microstructural parameters to macroscopic characteristics of porous material using precise characterization results based on the designed bimodal porous structures. This model specifically links macroscopic parameters including static airflow resistivity (σ), thermal characteristic length (Λ′), viscous characteristic length (Λ), and dynamic tortuosity (α∞) to microstructural factors such as cell wall thickness (2t) and reticulation rate (Rw). The developed model makes it possible to design the morphology of porous media to achieve optimum sound absorption performance based on the application in hand. This study makes the base for understanding the role of microstructural geometry and morphological factors on the overall macroscopic parameters of porous materials specifically for acoustic capabilities. The next step is to include other microstructural parameters as well to generalize the developed model. In the present paper, pore size was kept constant for eight categories of bimodal foams to study the effect of secondary porous structure on macroscopic properties and overall acoustic behavior of porous media.
Raman measurements of substrate temperature in a molecular beam epitaxy growth chamber
Authors: Hutchins T. , Nazari M. , Eridisoorya M. , Myers T. M. , Holtz M.
Published: January 2015

A method is described for directly measuring the temperature of a substrate in a molecular-beam epitaxy (MBE) growth system. The approach relies on the establishment of the temperature dependence of Raman-active phonons of the substrate material using independently known calibration points across the range of interest. An unknown temperature in this range is then determined based on the Raman peak position with the substrate in situ the MBE chamber. The apparatus relies on conventional optics and Raman components. Shifting and broadening of the Raman spectrum are described based on the effects of thermal expansion and anharmonic decay. The choice of reference temperature is discussed. The method is qualified by examining the substrate temperature dependence, relative to that of a standard thermocouple, during a commonly used ramp procedure. Both temperature difference and time lag are obtained.
R matrices of three-state Hamiltonians solvable by coordinate Bethe ansatz
Authors: Fonseca T. , Frappat L. , Ragoucy E.
Published: January 2015

We review some of the strategies that can be implemented to infer an R-matrix from the knowledge of its Hamiltonian. We apply them to the classification achieved in Crampé, Frappat, and Ragoucy, J. Phys. A 46, 405001 (2013), on three state U(1)-invariant Hamiltonians solvable by coordinate Bethe ansatz, focusing on models for which the S-matrix is not trivial. For the 19-vertex solutions, we recover the R-matrices of the well-known Zamolodchikov–Fateev and Izergin–Korepin models. We point out that the generalized Bariev Hamiltonian is related to both main and special branches studied by Martins in Nucl. Phys. B 874, 243 (2013), that we prove to generate the same Hamiltonian. The 19-vertex SpR model still resists to the analysis, although we are able to state some no-go theorems on its R-matrix. For 17-vertex Hamiltonians, we produce a new R-matrix.
The fluctuation energy balance in non-suspended fluid-mediated particle transport
Authors: Pähtz Thomas , Durán Orencio , Ho Tuan-Duc , Valance Alexandre , Kok Jasper F.
Published: January 2015

Here, we compare two extreme regimes of non-suspended fluid-mediated particle transport, transport in light and heavy fluids (“saltation” and “bedload,” respectively), regarding their particle fluctuation energy balance. From direct numerical simulations, we surprisingly find that the ratio between collisional and fluid drag dissipation of fluctuation energy is significantly larger in saltation than in bedload, even though the contribution of interparticle collisions to transport of momentum and energy is much smaller in saltation due to the low concentration of particles in the transport layer. We conclude that the much higher frequency of high-energy particle-bed impacts (“splash”) in saltation is the cause for this counter-intuitive behavior. Moreover, from a comparison of these simulations to particle tracking velocimetry measurements which we performed in a wind tunnel under steady transport of fine and coarse sand, we find that turbulent fluctuations of the flow produce particle fluctuation energy at an unexpectedly high rate in saltation even under conditions for which the effects of turbulence are usually believed to be small.
Characterizing the nonlinear interaction of S- and P-waves in a rock sample
Authors: Gallot Thomas , Malcolm Alison , Szabo Thomas L. , Brown Stephen , Burns Daniel , Fehler Michael
Published: January 2015

The nonlinear elastic response of rocks is known to be caused by the rocks' microstructure, particularly cracks and fluids. This paper presents a method for characterizing the nonlinearity of rocks in a laboratory scale experiment with a unique configuration. This configuration has been designed to open up the possibility of using the nonlinear characterization of rocks as an imaging tool in the field. In our experiment, we study the nonlinear interaction of two traveling waves: a low-amplitude 500 kHz P-wave probe and a high-amplitude 50 kHz S-wave pump in a room-dry 15 × 15 × 3 cm slab of Berea sandstone. Changes in the arrival time of the P-wave probe as it passes through the perturbation created by the traveling S-wave pump were recorded. Waveforms were time gated to simulate a semi-infinite medium. The shear wave phase relative to the P-wave probe signal was varied with resultant changes in the P-wave probe arrival time of up to 100 ns, corresponding to a change in elastic properties of 0.2%. In order to estimate the strain in our sample, we also measured the particle velocity at the sample surface to scale a finite difference linear elastic simulation to estimate the complex strain field in the sample, on the order of 10−6, induced by the S-wave pump. We derived a fourth order elastic model to relate the changes in elasticity to the pump strain components. We recover quadratic and cubic nonlinear parameters: β̃=−872 and δ̃=−1.1×1010, respectively, at room-temperature and when particle motions of the pump and probe waves are aligned. Temperature fluctuations are correlated to changes in the recovered values of β̃ and δ̃, and we find that the nonlinear parameter changes when the particle motions are orthogonal. No evidence of slow dynamics was seen in our measurements. The same experimental configuration, when applied to Lucite and aluminum, produced no measurable nonlinear effects. In summary, a method of selectively determining the local nonlinear characteristics of rock quantitatively has been demonstrated using traveling sound waves.
Transformation volume effect on the magnetic anisotropy of Ni-Mn-Ga thin films
Authors: L'vov V. A. , Golub V. , Salyuk O. , Barandiarán J. M. , Chernenko V. A.
Published: January 2015

Ni-Mn-Ga ferromagnetic shape memory films with similar thickness and chemical composition, deposited onto cold (with a subsequent annealing) and hot MgO(001) substrates exhibit different internal stress and structure giving rise to a different orientation of the magnetic easy axes. A quantitative theoretical analysis of the crystallographic and ferromagnetic resonance (FMR) data shows that the different anisotropies can be caused by the difference in sign between the transformation volume changes in these films, as influenced by the internal stresses. To explain FMR data, the magnetoelastic coupling term of fourth-order in the magnetic vector and linear in the strain tensor components, appearing in the Landau expansion for the free energy, is taken into account. The coefficient of the term, which couples the magnetic vector components with the volume change of the Ni-Mn-Ga alloy, was estimated to be equal to about 107 erg cm−3.
Oxygen plasma assisted high performance solution-processed Al2Ox gate insulator for combustion-processed InGaZnOx thin film transistors
Authors: Wang Han , Xu Wangying , Zhou Shuang , Xie Fangyan , Xiao Yubin , Ye Lei , Chen Jian , Xu Jianbin
Published: January 2015

The effects of oxygen-plasma treatment on solution-processed Al2Ox gate dielectrics for InGaZnOx (IGZO) thin film transistors (TFTs) are investigated in this paper. Thin films of amorphous Al2Ox are successfully fabricated by annealing temperature of 300 °C. Utilizing oxygen-plasma treated gate dielectrics, combustion-processed IGZO TFTs, which are annealed at a temperature of 300 °C, show a mobility of 7.3 cm2 V−1 s−1, a threshold voltage of −0.3 V, an on-off current ratio of 1 × 105, a subthreshold swing of 160 mV/decade, when operating with a voltage ranging from −2 V to +5 V. Our experimental results demonstrate that oxygen-plasma treatment can remarkably improve dielectric performance. This is presumably due to the passivation of interfacial and bulk traps, and the reduced concentration of oxygen vacancies.
Influence of grain size on transition temperature of thermochromic VO2
Authors: Miller Mark J. , Wang Junlan
Published: January 2015

Vanadium(IV) oxide (VO2) is a unique material that undergoes a reversible phase transformation around 68 °C. The material could potentially be used as an energy-efficient coating for windows since its reflectance in the infrared (IR) increases significantly more than in the visible region. Currently, VO2 is limited by a transition temperature (τc) that is too high, luminous transmittance that is too low or both. In this study, a transition temperature of 45 °C is achieved for a reactively sputtered, undoped film by restricting grain size to approximately 30 nm. It is concluded that a higher density of grain boundaries (smaller grain size) provides a greater number of nucleating defects which in turn reduces τc. Similarly, a higher density of grain boundaries may reduce the hysteresis width (difference between transition temperatures in heating and cooling). Also in this study, a new set of optical performance metrics is proposed in which the solar spectrum is divided into the ultraviolet (UV), visible and near infrared (NIR) regions. This approach is more closely aligned with the goals of limiting UV, allowing luminous and modulating NIR transmission. Using these metrics, the optical properties of the low-τc sample were: 2% UV transmittance, 47% luminous transmittance, and 23% NIR modulation (decrease from 43 to 33%). This study demonstrates that the grain size of VO2 should be viewed as an important parameter for controlling the transition temperature of the material.
Electron and hole transport in ambipolar, thin film pentacene transistors
Authors: Saudari Sangameshwar R. , Kagan Cherie R.
Published: January 2015

Solution-processed, ambipolar, thin-film pentacene field-effect transistors were employed to study both electron and hole transport simultaneously in a single, organic solid-state device. Electron and hole mobilities were extracted from the respective unipolar saturation regimes and show thermally activated behavior and gate voltage dependence. We fit the gate voltage dependent saturation mobility to a power law to extract the characteristic Meyer-Neldel (MN) energy, a measure of the width of the exponential distribution of localized states extending into the energy gap of the organic semiconductor. The MN energy is ∼78 and ∼28 meV for electrons and holes, respectively, which reflects a greater density of localized tail states for electrons than holes. This is consistent with the lower measured electron than hole mobility. For holes, the well-behaved linear regime allows for four-point probe measurement of the contact resistance independent mobility and separate characterization of the width of the localized density of states, yielding a consistent MN energy of 28 meV.
Phase transitions in classical biquadratic Heisenberg model for strained iron pnictides
Authors: Li W. C. , Feng J. J. , Qin M. H. , Xie Y. L. , Yan Z. B. , Jia X. T. , Liu J.-M.
Published: January 2015

Based on the notion of magnetically driven nematicity, we study the phase transitions in a frustrated classical Heisenberg model with biquadratic and anisotropic exchange interactions on square lattice by means of Monte Carlo simulations, in order to understand the uniaxial strain effect in BaFe2As2. The variation of both structural and antiferromagnetic transition temperatures with uniaxial stress reported in experiments can be qualitatively reproduced by including the exchange anisotropy, suggesting that the anisotropy may be responsible for the strain effect on the phase transitions.
Effect of interlayer interaction on domain structure of CoPt stacked films with perpendicular anisotropy
Authors: Kawamura H. , Hayakawa K. , Nomiya N. , Sugita R.
Published: January 2015

The effect of interlayer magnetostatic interaction on the domain structure of CoPt (3 nm)/Pt (δPt nm)/CoPt (10 nm) stacked films having perpendicular anisotropy is investigated. The domain structure of the demagnetized CoPt stacked films is observed using magnetic force microscope. The Co80Pt20 stacked films with Pt interlayer thickness δPt less than about 20 nm have the maze domain similar to that of the film with δPt of 0 nm. This is because the top and bottom layers are connected by the magnetostatic interaction and the magnetization distribution of both layers is integrated. The domain structure of the films with δPt around 25 nm is mixture of the maze and irregular domains. For the films with δPt over about 30 nm, because the interaction between the top and bottom layers decreases, the irregular domain which is observed in the 3 nm thick CoPt single layer film appears. In the region where the domain structure changes from the maze domain to the irregular one, domain size steeply increases with increase of δPt.
Observation of complete space-charge-limited transport in metal-oxide-graphene heterostructure
Authors: Chen Wei , Wang Fei , Qin Shiqiao , Fang Jingyue , Wang Chaocheng , Wang Guang , Wang Li , Zhang Xue-Ao
Published: January 2015

The metal-oxide-graphene heterostructures have abundant physical connotations. As one of the most important physical properties, the electric transport property of the gold-chromium oxide-graphene heterostructure has been studied. The experimental measurement shows that the conductive mechanism is dominated by the space-charge-limited transport, a kind of bulk transport of an insulator with charge traps. Combining the theoretical analysis, some key parameters such as the carrier mobility and trap energy also are obtained. The study of the characteristics of the metal-oxide-graphene heterostructures is helpful to investigate the graphene-based electronic and photoelectric devices.
Observation of laser-driven shock propagation by nanosecond time-resolved Raman spectroscopy
Authors: Yu Guoyang , Zheng Xianxu , Song Yunfei , Zeng Yangyang , Guo Wencan , Zhao Jun , Yang Yanqiang
Published: January 2015

An improved nanosecond time-resolved Raman spectroscopy is performed to observe laser-driven shock propagation in the anthracene/epoxy glue layer. The digital delay instead of optical delay line is introduced for sake of unlimited time range of detection, which enables the ability to observe both shock loading and shock unloading that always lasts several hundred nanoseconds. In this experiment, the peak pressure of shock wave, the pressure distribution, and the position of shock front in gauge layer were determined by fitting Raman spectra of anthracene using the Raman peak shift simulation. And, the velocity of shock wave was calculated by the time-dependent position of shock front.
Annealing effect on the magnetic induced austenite transformation in polycrystalline freestanding Ni-Co-Mn-In films produced by co-sputtering
Authors: Crouïgneau G. , Porcar L. , Courtois P. , Pairis S. , Mossang E. , Eyraud E. , Bourgault D.
Published: January 2015

Ni-Co-Mn-In freestanding films, with a magneto-structural transformation at room temperature were successfully produced by co-sputtering and post-annealing methods leading to film composition mastering. For a post-annealing temperature of 700 °C, the phase transformation occurs slightly above room temperature, with a twisted martensitic microstructure phase observed at 300 K by Field Emission Scanning Electron Microscopy. Magnetization measurements on a polycrystalline film showed a phase transformation from a weakly magnetic martensite to a magnetic austenite phase. Moreover, an inverse magnetocaloric effect with an entropy variation of 4 J/kg K under 5 T was also measured. A simple magneto-actuation experiment based on the magnetic induced austenite transformation was also successfully completed. The possibility to insert such films in microsystems is clearly demonstrated in this work.
Free-standing graphene membranes on glass nanopores for ionic current measurements
Authors: Walker Michael I. , Weatherup Robert S. , Bell Nicholas A. W. , Hofmann Stephan , Keyser Ulrich F.
Published: January 2015

A method is established to reliably suspend graphene monolayers across glass nanopores as a simple, low cost platform to study ionic transport through graphene membranes. We systematically show that the graphene seals glass nanopore openings with areas ranging from 180 nm2 to 20 μm2, allowing detailed measurements of ionic current and transport through graphene. In combination with in situ Raman spectroscopy, we characterise the defects formed in ozone treated graphene, confirming an increase in ionic current flow with defect density. This highlights the potential of our method for studying single molecule sensing and filtration.
Sample dependence of giant magnetocaloric effect in a cluster-glass system Ho5Pd2
Authors: Toyoizumi Saori , Kitazawa Hideaki , Kawamura Yukihiko , Mamiya Hiroaki , Terada Noriki , Tamura Ryo , Dönni Andreas , Morita Kengo , Tamaki Akira
Published: January 2015

In order to investigate the effect of vacancy on the magnetocaloric effect in Ho5Pd2, we have carried out X-ray diffraction, magnetization, and specific heat measurements in the rare-earth intermetallic compound Ho5+xPd2(−0.4 ≤ x ≤ 0.4). The maximum magnetic entropy change −ΔSmmax, the maximum adiabatic temperature change ΔTadmax, and the relative cooling power of Ho5+xPd2 take large values at x = 0−0.4 for the field change of 5 T. The paramagnetic Curie temperature θp increases with an increase of x. This fact suggests that the enhancement of ferromagnetic coupling among the correlated spins leads to the increase of magnetocaloric effect.
The Changing Character of Private Force
Authors: Percy Sarah
Published: January 2015

This chapter examines the evolution of the use of private force and what the mercenaries of the past reveal about their descendants today. It addresses four questions: First, who are the private fighters? Second, who hires private fighters? Third, why hire them? Fourth, what concerns about the use of private force have been raised over time?
A direct comparison of X-ray spectral models for tori in active galactic nuclei
Authors: Liu Yuan , Li Xiaobo
Published: January 2015

Several X-ray spectral models for tori in active galactic nuclei (AGNs) are available to constrain the properties of tori; however, the accuracy of these models has not been verified. We recently constructed a code for the torus using geant4, which can easily handle different geometries. Thus, we adopt the same assumptions as Murphy & Yaqoob (2009, MNRAS, 397, 1549) and Brightman & Nandra (2011, MNRAS, 413, 1206) and try to reproduce their spectra. As a result, we can reproduce well the reflection spectra and the strength of the Fe Kα line of Murphy & Yaqoob, for both NH = 1024 and 1025 cm−2. However, we cannot produce the strong reflection component of Brightman & Nandra in the low-energy band. The origin of this component is the reflection from the visible inner wall of the torus, and the reflection should be very weak in the edge-on directions under the geometry of Brightman & Nandra. Therefore, the behaviour of the reflection spectra in Brightman & Nandra is not consistent with their geometry. The strength of the Fe Kα line of Brightman & Nandra is also different from our results and the analytical result in the optically thin case. The limitation of the spectral model will bias the parameters from the X-ray spectral fitting.
A systematic survey of the Cys2His2 zinc finger DNA-binding landscape
Authors: Persikov Anton V. , Wetzel Joshua L. , Rowland Elizabeth F. , Oakes Benjamin L. , Xu Denise J. , Singh Mona , Noyes Marcus B.
Published: January 2015

Cys2His2 zinc fingers (C2H2-ZFs) comprise the largest class of metazoan DNA-binding domains. Despite this domain's well-defined DNA-recognition interface, and its successful use in the design of chimeric proteins capable of targeting genomic regions of interest, much remains unknown about its DNA-binding landscape. To help bridge this gap in fundamental knowledge and to provide a resource for design-oriented applications, we screened large synthetic protein libraries to select binding C2H2-ZF domains for each possible three base pair target. The resulting data consist of >160 000 unique domain–DNA interactions and comprise the most comprehensive investigation of C2H2-ZF DNA-binding interactions to date. An integrated analysis of these independent screens yielded DNA-binding profiles for tens of thousands of domains and led to the successful design and prediction of C2H2-ZF DNA-binding specificities. Computational analyses uncovered important aspects of C2H2-ZF domain–DNA interactions, including the roles of within-finger context and domain position on base recognition. We observed the existence of numerous distinct binding strategies for each possible three base pair target and an apparent balance between affinity and specificity of binding. In sum, our comprehensive data help elucidate the complex binding landscape of C2H2-ZF domains and provide a foundation for efforts to determine, predict and engineer their DNA-binding specificities.
Digit evolution in gymnophthalmid lizards
Authors: Roscito Juliana G. , Nunes Pedro M.S , Rodrigues Miguel T.
Published: January 2015

Background

The tetrapod limb is a highly diverse structure, and reduction of the limbs accounts for much of the phenotypes observed within species. Squamate reptiles represent one of the many lineages in which the limbs have been greatly modified from the pentadactyl generalized pattern; within the group, limb-reduced morphologies can vary from minor reductions in size of elements to complete limblessness, with several intermediate forms in between. Even though limb reduction is widespread, it is not clear what are the evolutionary and developmental mechanisms involved in the formation of reduced limb morphologies.

Methods

In this study, we present an overview of limb morphology within the microteiid lizard group Gymnophthalmidae, focusing on digit number.

Results

We show that there are two major groups of limb-reduced gymnophthalmids. The first group is formed by lizard-like - and frequently pentadactyl - species, in which minor reductions (such as the loss of 1-2 phalanges mainly in digits I and V) are the rule; these morphologies generally correspond to those seen in other squamates. The second group is formed by species showing more drastic losses, which can include the absence of an externally distinct limb in adults. We also show the expression patterns of Sonic Hedgehog (Shh) in the greatly reduced fore and hindlimb of a serpentiform gymnophthalmid.

Conclusions

Our discussion focus on identifying shared patterns of limb reduction among tetrapods, and explaining these patterns and the morphological variation within the gymnophthalmids based on the current knowledge of the molecular signaling pathways that coordinate limb development.
Serine 133 phosphorylation is not required for hippocampal CREB-mediated transcription and behavior
Authors: Briand Lisa A. , Lee Bridgin G. , Lelay John , Kaestner Klaus H. , Blendy Julie A.
Published: January 2015

The cAMP response element (CRE)-binding protein, CREB, is a transcription factor whose activity in the brain is critical for long-term memory formation. Phosphorylation of Ser133 in the kinase-inducible domain (KID), that in turn leads to the recruitment of the transcriptional coactivator CREB-binding protein (CBP), is thought to mediate the activation of CREB. However, the importance of phosphorylation for CREB binding to DNA and subsequent gene transcription in vivo is controversial. To definitively address the role of CREB phosphorylation in gene transcription and learning and memory, we derived mutant mice lacking the Ser133 phosphorylation site. These mice exhibit normal CREB-mediated gene transcription for a number of genes implicated in learning and memory processes. Furthermore these mice have no deficits in hippocampus- or striatum-dependent learning. Strikingly, our findings show that CREB phosphorylation at Ser133 is not necessary for CREB binding to CRE sites, CREB-mediated transcription, or CREB-mediated behavioral phenotypes associated with learning and memory.