bluuebunny/crossref_metadata_2025 huggingface dataset:
Mirror neuron therapy for hemispatial neglect patients
Authors: Wang Wei , Zhang Xin , Ji Xiangtong , Ye Qian , Chen Wenli , Ni Jun , Shen Guangyu , Zhang Bing , Yuan Ti-Fei , Shan Chunlei
Published: March 2015

Mirror neuron system(MNS) based therapy has been employed to treat stroke induced movement disorders. However, its potential effects on patients with hemispatial neglect were uninvestigated. The present study set out to test the therapeutic efficiency of video watching of series of hand actions/movements (protocol A) in two patients with left hemispatial neglect, due to the right hemisphere stroke. The video containing dynamic landscape of natural scene or cities but not human/animals was used as the protocol B. The “ABA” training procedure for 3 weeks therefore allows us to internally control the individual differences. Before and after each week of training, the Chinese behavioral inattention test- Hongkong version (CBIT-HK) was implemented to evaluate the hemispatial neglect severity. Functional magnetic resonance imaging (fMRI) experiment was implemented in two health subjects to reveal the difference of brain activation between protocol A and B. The results showed that protocol A rather than protocol B significantly improved the CBIT-HK scores at first and third weeks, respectively. Protocol A induced more bilateral activations including right inferior parietal lobe (supramarginal gyrus), which belongs to MNS and is also critical region resulting to hemineglect. Conclusion: MNS activation can provide a novel therapy for hemispatial neglect patients.
Understanding the influence of all nodes in a network
Authors: Lawyer Glenn
Published: March 2015

Centrality measures such as the degree, k-shell, or eigenvalue centrality can identify a network's most influential nodes, but are rarely usefully accurate in quantifying the spreading power of the vast majority of nodes which are not highly influential. The spreading power of all network nodes is better explained by considering, from a continuous-time epidemiological perspective, the distribution of the force of infection each node generates. The resulting metric, the expected force, accurately quantifies node spreading power under all primary epidemiological models across a wide range of archetypical human contact networks. When node power is low, influence is a function of neighbor degree. As power increases, a node's own degree becomes more important. The strength of this relationship is modulated by network structure, being more pronounced in narrow, dense networks typical of social networking and weakening in broader, looser association networks such as the Internet. The expected force can be computed independently for individual nodes, making it applicable for networks whose adjacency matrix is dynamic, not well specified, or overwhelmingly large.
Legacies of Past Exploitation and Climate affect Mammalian Sexes Differently on the Roof of the World - The Case of Wild Yaks
Authors: Berger Joel , Schaller George B. , Cheng Ellen , Kang Aili , Krebs Michael , Li Lishu , Hebblewhite Mark
Published: March 2015

In polar environments, a lack of empirical knowledge about biodiversity prompts reliance on species distribution models to predict future change, yet these ignore the role of biotic interactions including the role of long past human exploitation. To explore how mammals of extreme elevation respond to glacial recession and past harvest, we combined our fieldwork with remote sensing and used analyses of ~60 expeditions from 1850–1925 to represent baseline conditions for wildlife before heavy exploitation on the Tibetan Plateau. Focusing on endangered wild yaks (Bos mutus), we document female changes in habitat use across time whereupon they increasingly relied on steeper post-glacial terrain and currently have a 20x greater dependence on winter snow patches than males. Our twin findings—that the sexes of a cold-adapted species respond differently to modern climate forcing and long-past exploitation—indicate that effective conservation planning will require knowledge of the interplay between past and future if we will assure persistence of the region's biodiversity.
The study of surface states in a semi-infinite crystal
Authors: Wang Huiping , Gao Tingting , Tao Ruibao
Published: March 2015

An infinite three dimensional (3D) crystal can be constructed by an infinite number of parallel 2D (hkl) crystal planes (CPs) coupled to each other. Based on lattice model Hamiltonian with the hopping between the nearest neighbor (1NN) CPs and all possible neighbor hoppings within each CP, we analytically prove that a (hkl) cut crystal will not accommodate any surface states if the original infinite crystal has the reflection symmetry which results in the forward transfer matrix F to be equal to the backward one B, named as F-B dynamical symmetry. We also study the effect of the longer range couplings among the nNN (n > 1) CPs and surface relaxation on our conclusion and find that the small perturbation from both factors has no effect on our conclusion based on the perturbation theory. Thus our model may have the potential for studying surface states in some cut crystals with low-index surfaces. Our result may be helpful to visually predict which cutting direction in some non-topological crystals is unfavorable to generate surface states.
Transformation optics with Fabry-Pérot resonances
Authors: Sadeghi M. M. , Li Sucheng , Xu Lin , Hou Bo , Chen Huanyang
Published: March 2015

Transformation optics is a powerful tool to design various novel devices, such as invisibility cloak. Fantastic effects from this technique are usually accompanied with singular mappings, resulting in challenging implementations and narrow bands of working frequencies. Here in this article, Fabry-Pérot resonances in materials of extreme anisotropy are used to design various transformation optical devices that are not only easy to realize but also work well for a set of resonant frequencies (multiple frequencies). As an example, a prototype of a cylindrical concentrator is fabricated for microwaves.
Gluing together metallic and covalent layers to form Ru2C under ambient conditions
Authors: Sun Weiwei , Li Yunguo , Zhu Li , Ma Yanming , Marco Igor Di , Johansson Börje , Korzhavyi Pavel
Published: March 2015

We explore the structures of Ru2C at ambient conditions by using an unbiased swarm structure searching algorithm. The structures withR3mandR3̄msymmetries have been respectively found to have the lowest energies for one and two formula units.
Fine tunable aqueous solution synthesis of textured flexible SnS2 thin films and nanosheets
Authors: Nørby Peter , Johnsen Simon , Iversen Bo Brummerstedt
Published: March 2015

We present an environmentally benign aqueous synthesis method to obtain fine tunable layered SnS2 thin films as well as methods to obtain freestanding nanosheets or transfer to flexible substrates.
Multi-scale promoting effects of lead for palladium catalyzed aerobic oxidative coupling of methylacrolein with methanol
Authors: Han Junxing , Zhang Suojiang , Li Yuchao , Yan Ruiyi
Published: March 2015

The promoting effects of lead for palladium catalyzed aerobic oxidative coupling of methylacrolein with methanol were illustrated from a multi-scale viewpoint.
Deciphering the physical mechanism of the topography effect for oxygen isotope measurements using a Cameca IMS-1280 SIMS
Authors: Tang Guo-Qiang , Li Xian-Hua , Li Qiu-Li , Liu Yu , Ling Xiao-Xiao , Yin Qing-Zhu
Published: March 2015

Topography effects can be reduced by increasing transfer optics magnification in high precision SIMS isotope analysis.
Enhanced hydrogen production under a visible light source and dye degradation under natural sunlight using nanostructured doped zinc orthotitanates
Authors: Nikam Latesh , Panmand Rajendra , Kadam Sunil , Naik Sonali , Kale Bharat
Published: March 2015

Nanostructured zinc orthotitanates were successfully employed as solar light driven photocatalysts for waste degradation such as H2S which produces H2, a clean energy source, and dye degradation.
Facile synthesized highly active BiOI/Zn2GeO4 composites for the elimination of endocrine disrupter BPA under visible light irradiation
Authors: Yan Tao , Liu Hongye , Gao Picheng , Sun Meng , Wei Qin , Xu Wenguo , Wang Xiaodong , Du Bin
Published: March 2015

A high-performance BiOI/Zn2GeO4 visible light photocatalyst for the decomposition of organic pollutants was fabricated using a simple chemical bath approach.
In vitro antioxidant potential of Shemamruthaa (a herbal formulation) and its anticancer activity in the MCF-7 cell line
Authors: Elumalai Nandhakumar , Ayyakkannu Purushothaman , Palanivelu Shanthi , Panchanadham Sachdanandam
Published: March 2015

The current study investigates the free radical scavenging activities of methanolic and aqueous extracts of Shemamruthaa (Hibiscus rosa sinensis,Emblica officinalisand honey in definite ratio) and their anticancer activity in the breast cancer (MCF-7) cell lineex vivo.
Investigation of the activity and stability of Pd-based catalysts towards the oxygen reduction (ORR) and evolution reactions (OER) in iron–air batteries
Authors: Alegre C. , Stassi A. , Modica E. , Lo Vecchio C. , Aricò A. S. , Baglio V.
Published: March 2015

Palladium on carbon has proved to be a suitable bi-functional catalyst for application in the air electrode of a metal–air battery.
Physical and electrochemical characterization of reduced graphene oxide/silver nanocomposites synthesized by adopting a green approach
Authors: Roy Indranil , Rana Dipak , Sarkar Gunjan , Bhattacharyya Amartya , Saha Nayan Ranjan , Mondal Soumya , Pattanayak Sutanuka , Chattopadhyay Sanatan , Chattopadhyay Dipankar
Published: March 2015

Synthesis and characterization of reduced graphene oxide/silver (RGO/Ag) nanocomposites by adopting green approach.
Facile synthesis of copper nanoparticles in glycerol at room temperature: formation mechanism
Authors: Ong Huei Ruey , Rahman Khan Md. Maksudur , Ramli Ridzuan , Du Yonghua , Xi Shibo , Yunus Rosli Mohd
Published: March 2015

A copper sol is usually synthesized by the reduction of a copper precursor with a suitable reducing agent in the presence of a stabilizer.
Proteo-lipobeads for the oriented encapsulation of membrane proteins
Authors: Frank Pinar , Siebenhofer Bernhard , Hanzer Theresa , Geiss Andreas F. , Schadauer Florian , Reiner-Rozman Ciril , Durham Bill , Loew Leslie M. , Ludwig Bernd , Richter Oliver-M. H. , Nowak Christoph , Naumann Renate L. C.
Published: March 2015

Protons (blue) move from the inner layer to the outside of the proteo-lipobeads if cytochrome c oxidase (red) is excited by illumination of Ru complexes (green).
Yielding and flow of highly concentrated, few-layer graphene suspensions
Authors: Barwich Sebastian , Coleman Jonathan N. , Möbius Matthias E.
Published: March 2015

We propose a simple model to explain the measured yielding behaviour of concentrated suspensions of graphene platelets which allows us to model the viscoelastic response in terms of bond energy, packing fraction and platelet dimensions.
Enhancement of photovoltaic properties of CH3NH3PbBr3 heterojunction solar cells by modifying mesoporous TiO2 surfaces with carboxyl groups
Authors: Kim Hyun Bin , Im Iseul , Yoon Yeomin , Sung Sang Do , Kim Eunji , Kim Jeongho , Lee Wan In
Published: March 2015

In a novel heterojunction solar cell employing CH3NH3PbBr3 (MAPbBr3) as the light absorber, the introduction of a carboxylate monolayer on the mesoporous TiO2 surfaces significantly enhances JSC as well as VOC.
Postsynthetic ligand exchange for the synthesis of benzotriazole-containing zeolitic imidazolate framework
Authors: Jiang Jun-Qing , Yang Cheng-Xiong , Yan Xiu-Ping
Published: March 2015

A postsynthetic ligand exchange strategy is used for introducing benzotriazole to ZIF-7 without changing its framework, high stability and morphology.
Rh(iii)-catalyzed oxime ether-directed heteroarylation of arene through oxidative C–H/C–H cross-coupling
Authors: Qin Dekun , Wang Jing , Qin Xurong , Wang Chunxia , Gao Ge , You Jingsong
Published: March 2015

A rhodium(iii)-catalyzed dehydrogenative cross-coupling reaction has been developed for the synthesis of bi(hetero)aryl scaffolds by using oxime ethers as the directing group. This protocol features a relatively broad substrate scope and a good tolerance of functional groups.
Excellent electrochemical performance of NiV3O8/natural graphite anodes via novel in situ electrochemical reconstruction
Authors: Ni Shibing , Ma Jianjun , Zhang Jicheng , Yang Xuelin , Zhang Lulu
Published: March 2015

NiV3O8/natural graphite anodes show excellent electrochemical performance via a novel in situ electrochemical reconstruction.
Antibacterial properties and atomic resolution X-ray complex crystal structure of a ruthenocene conjugated β-lactam antibiotic
Authors: Lewandowski Eric M. , Skiba Joanna , Torelli Nicholas J. , Rajnisz Aleksandra , Solecka Jolanta , Kowalski Konrad , Chen Yu
Published: March 2015

Crystal structure of β-lactam product complex with CTX-M-14 E166A mutant sheds light on β-lactamase catalysis and ruthenocene binding by proteins.
A Lewis acid-free and phenolate-based magnesium electrolyte for rechargeable magnesium batteries
Authors: Pan Baofei , Zhang Junjie , Huang Jinhua , Vaughey John T. , Zhang Lu , Han Sang-Don , Burrell Anthony K. , Zhang Zhengcheng , Liao Chen
Published: March 2015

Development of a strong Lewis acid-free and phenolate-based electrolyte for rechargeable magnesium-ion batteries.
Uthrene, a radically new molecule?
Authors: Melle-Franco Manuel
Published: March 2015

Quantum chemical models show that uthrene possesses an open-shell ground state and could be synthetically feasible.
Aqueous self-assembly of a charged BODIPY amphiphile via nucleation–growth mechanism
Authors: Yang Le , Fan Gang , Ren Xiangkui , Zhao Lingyun , Wang Jingkang , Chen Zhijian
Published: March 2015

A new amphiphilic boron-dipyrromethene dye forms fluorescent vesicular aggregates in water through a highly cooperative self-assembly process.
The role of isomerization in the kinetics of self-assembly: p-terphenyl-m-dicarbonitrile on the Ag(111) surface
Authors: Abbasi-Pérez David , Manuel Recio J. , Kantorovich Lev
Published: March 2015

para-Terphenyl-meta-dicarbonitrile molecules diffuse by pivoting on the Ag(111) surface, and by means of the assisted isomerization mechanism self-assemble to form ribbons, linkers, clusters and brickwall islands.
Electrical conductivity and thermopower of (1 − x) BiFeO3– xBi0.5K0.5TiO3(x = 0.1, 0.2) ceramics near the ferroelectric to paraelectric phase transition
Authors: Wefring E. T. , Einarsrud M.-A. , Grande T.
Published: March 2015

The change from p-type to n-type conductivity in BiFeO3-based materials.
Enantioselective femtosecond laser photoionization spectrometry of limonene using photoelectron circular dichroism
Authors: Rafiee Fanood Mohammad M. , Janssen Maurice H. M. , Powis Ivan
Published: March 2015

Circularly polarized, femtosecond laser multiphoton ionization can clearly distinguish between the enantiomers of limonene from a 4% chiral asymmetry in the photoelectron angular distribution.
A two-photon fluorescent probe for detecting endogenous hypochlorite in living cells
Authors: Wang Xunming , Wang Xiaohui , Feng Yan , Zhu Manzhou , Yin Hang , Guo QingXiang , Meng Xiangming
Published: March 2015

A highly selective two-photon fluorescent probe (HQ) for endogenous hypochlorite (ClO−) was developed.
The effect of steric changes on the isoselectivity of dinuclear indium catalysts for lactide polymerization
Authors: Osten K. M. , Aluthge D. C. , Mehrkhodavandi P.
Published: March 2015

Functionalized diaminophenolates as ligands for dinuclear indium catalysts were investigated in the ring-opening polymerization of lactide. An increase in the steric bulk of the ligand phenolates decreases the selectivity of the catalysts due to catalyst dissociation during polymerization.
Ligand field variations: tuning the toroidal moment of Dy6 rings
Authors: Baniodeh Amer , Magnani Nicola , Bräse Stefan , Anson Christopher E. , Powell Annie K.
Published: March 2015

We show how the toroidal moment in Dy6 cyclic coordination clusters can be tuned and optimised.
In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications
Authors: Khamis K. , Sorensen J. P. R. , Bradley C. , Hannah D. M. , Lapworth D. J. , Stevens R.
Published: March 2015

This study combines laboratory experimentation and field trials to provide new insights into the standardization of in situ tryptophan-like fluorescence measurements for freshwater applications.
Polyphenols from artichoke heads (Cynara cardunculus (L.) subsp. scolymus Hayek): in vitro bio-accessibility, intestinal uptake and bioavailability
Authors: D'Antuono Isabella , Garbetta Antonella , Linsalata Vito , Minervini Fiorenza , Cardinali Angela
Published: March 2015

Bioavailability of artichoke head polyphenols after simulated physiological digestion process and intestinal absorption.
Droplet-based electro-coalescence for probing threshold disjoining pressure
Authors: Liu Zhou , Chan San To , Faizi Hammad Ali , Roberts Robert C. , Shum Ho Cheung
Published: March 2015

Droplet-based electro-coalescence represents a simple and robust probe of the elusive threshold disjoining pressure and hence the emulsion stability.
Simple 1,3-diamines and their application as ligands in ruthenium(ii) catalysts for asymmetric transfer hydrogenation of aryl ketones
Authors: Facchetti Giorgio , Gandolfi Raffaella , Fusè Marco , Zerla Daniele , Cesarotti Edoardo , Pellizzoni Michela , Rimoldi Isabella
Published: March 2015

A new efficient synthesis of 1,3-diamines was realized and their ruthenium(ii) complexes were studied in ATH in aqueous media.
Benzimidazoles and benzoxazoles via the nucleophilic addition of anilines to nitroalkanes
Authors: Aksenov Alexander V. , Smirnov Alexander N. , Aksenov Nicolai A. , Bijieva Asiyat S. , Aksenova Inna V. , Rubin Michael
Published: March 2015

PPA-induced umpolung triggers efficient nucleophilic addition of unactivated anilines to nitroalkanes to afford benzoxazoles and benzimidazoles.
On the properties of Au2P3z(z = −1, 0, +1): analysis of geometry, interaction, and electron density
Authors: Xu Kang-Ming , Jiang Shuai , Zhu Yu-Peng , Huang Teng , Liu Yi-Rong , Zhang Yang , Lv Yu-Zhou , Huang Wei
Published: March 2015

Au2P3has been discovered to exhibit remarkable semiconductor properties among metal phosphides. A theoretical study focusing on the electron and interatomic interactions of Au2P3is performed and provides new insights for the synthesis of new materials.
A simple method for the preparation of magnesium phosphate conversion coatings on a AZ31 magnesium alloy with improved corrosion resistance
Authors: Zhao Huan , Cai Shu , Ding Zetao , Zhang Ming , Li Yan , Xu Guohua
Published: March 2015

A simple method has been proposed for the preparation of magnesium phosphate conversion coating on a magnesium alloy (AZ31) to achieve protection against fast degradation in an implant environment.
Synthesis of conjugated microporous polymer nanotubes for polymer composites
Authors: Xiang Zhentao , Sun Hanxue , Zhu Zhaoqi , Liang Weidong , Yang Baoping , Li An
Published: March 2015

Tubular conjugated microporous polymers were synthesized and used as fillers for preparation of polymer composites with enhanced properties.
Catalyst-dependent morphological evolution by interfacial stress in crystalline–amorphous core–shell germanium nanowires
Authors: Palavalli Nithin Devarajulu , Yaghoubi Alireza , Lai Chih-Chung , Tin Chin-Che , Javey Ali , Chueh Yu-Lun
Published: March 2015

Computational models show stress-induced deformation in nanowire morphologies where the amorphous shell gives rise to straight, tapered and spiral geometries.
Facile synthesis of mesoporous SiO2 nanoparticles using the mobility differences of etchants
Authors: Lee Yi Seul , Jang Wooree , Koo Hye Young , Choi Won San
Published: March 2015

Mesoporous SiO2 nanoparticles (MSNPs): a novel approach for the synthesis of MSNPs that were prepared by treatment of styrene sulfonate monomer as an etchant on the SiO2 nanoparticles was demonstrated.
Gold nanoparticle decorated single walled carbon nanotube nanocomposite with synergistic peroxidase like activity for d-alanine detection
Authors: Haider Waqar , Hayat Akhtar , Raza Yousuf , Anwar Chaudhry Aqif , Rehman Ihtesham-Ur- , Marty Jean Louis
Published: March 2015

In this report, a gold nanoparticle decorated single walled carbon nanotube (SWCNTs) nanocomposite was shown to possess synergistic intrinsic peroxidase like activity and enhanced affinity towards H2O2 oxidation.
Antibacterial hybrid cellulose–graphene oxide nanocomposite immobilized with silver nanoparticles
Authors: Chook Soon Wei , Chia Chin Hua , Zakaria Sarani , Ayob Mohd Khan , Huang Nay Ming , Neoh Hui Min , Jamal Rahman
Published: March 2015

An antibacterial hybrid GO–AgNPs cellulose membrane was prepared. Incorporation of GO created a more porous structure of the regenerated cellulose membrane, improved the deposition of AgNPs and demonstrated an effective antibacterial activity with minimal release of Ag ions.
Amino-functionalized carbon nanofibres as an efficient metal free catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones from CO2and 2-aminobenzonitriles
Authors: Kumar Subodh , Verma Sanny , Shawat Efrat , Nessim Gilbert Daniel , Jain Suman L.
Published: March 2015

Carbon nanofibres functionalized with pyridyl moieties were used as an efficient metal free catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones from CO2and 2-aminobenzonitriles.
Retracted Article: Tuning the chemistry of graphene oxides by a sonochemical approach: application of adsorption properties
Authors: Sun Yubing , Yang Shubin , Ding Congcong , Jin Zhongxiu , Cheng Wencai
Published: March 2015

The change in the chemical properties of graphene oxides (GOs) can be tuned by the sonochemical approach.
Correction: Hollow Al2O3 spheres prepared by a simple and tunable hydrothermal method
Authors: Xue Guangxin , Huang Xin , Zhao Ning , Xiao Fukui , Wei Wei
Published: March 2015

Correction for ‘Hollow Al2O3 spheres prepared by a simple and tunable hydrothermal method’ by Guangxin Xue et al., RSC Adv., 2015, 5, 13385–13391.
Boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with silylborane and an alkoxy base: expanded scope and mechanistic studies
Authors: Yamamoto Eiji , Ukigai Satoshi , Ito Hajime
Published: March 2015

A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides using a silylborane/alkoxy-base reagent. Borylation of (Z)-alkenyl halides proceeded in a stereoretentive manner.
Multi-responsible chameleon molecule with chiral naphthyl and azobenzene moieties
Authors: Kim Dae-Yoon , Lee Sang-A , Park Minwook , Choi Yu-Jin , Kang Shin-Woong , Jeong Kwang-Un
Published: March 2015

A newly synthesized multi-responsible chameleon molecule with chiral naphthyl and azobenzene moieties was successfully applied as a reversible modulating device responding to temperature, electric field and light.
Titanium trisulphide (TiS3) nanoribbons for easy hydrogen photogeneration under visible light
Authors: Barawi M. , Flores E. , Ferrer I. J. , Ares J. R. , Sánchez C.
Published: March 2015

Flat band potential of TiS3 in a photoelectrochemical cell is determined and the photogenerated hydrogen is quantified by mass spectrometry.
A stable luminescent anionic porous metal–organic framework for moderate adsorption of CO2 and selective detection of nitro explosives
Authors: Zhou En-Long , Huang Peng , Qin Chao , Shao Kui-Zhan , Su Zhong-Min
Published: March 2015

A new stable pillared-layer metal–organic framework was constructed, which showed moderate adsorption of CO2 and selective sensing of TNP.
Microporous covalent triazine polymers: efficient Friedel–Crafts synthesis and adsorption/storage of CO2 and CH4
Authors: Puthiaraj Pillaiyar , Cho Sung-Min , Lee Yu-Ri , Ahn Wha-Seung
Published: March 2015

Microporous covalent triazine polymers were synthesized from inexpensive starting materials and their CO2 and CH4 gas uptakes were investigated.
Interfacial architectures based on a binary additive combination for high-performance Sn4P3 anodes in sodium-ion batteries
Authors: Jang Jun Yeong , Lee Yongwon , Kim Youngjin , Lee Jeongmin , Lee Sang-Min , Lee Kyu Tae , Choi Nam-Soon
Published: March 2015

Interfacial architectures based on the FEC + TMSP binary additive prevent the formation of Na15Sn4 with severe volume expansion and electrolyte decomposition.
Low frequency electric current noise in glioma cell populations
Authors: Rocha P. R. F. , Schlett P. , Schneider L. , Dröge M. , Mailänder V. , Gomes H. L. , Blom P. W. M. , de Leeuw D. M.
Published: March 2015

A low-noise measuring system was developed to accurately detect minute membrane capacitive current oscillations across populations of C6 glioma cells.
Adaptive backstepping control for permanent magnet linear synchronous motor servo drive
Authors: Ting Chen‐Sheng , Chang Yong‐Nong , Shi Bo‐Wei , Lieu Jyun‐Fan
Published: March 2015

This paper presents a position servo control approach for a permanent magnet linear synchronous motor. The non‐linear motor dynamics is expressed in the backstepping control scheme on which a recursive designing procedure is carried out. Based on the desired motion trajectory, the magnetic thrust force is first calculated and then treated as the control objective for the next subsystems. The command voltages to stabilise the whole system are established concerning the electric properties of the magnetic windings. To overcome the impacts of system uncertainties, an adaptive neural network is exploited to estimate the uncertainty and provide necessary compensation in the control effort. Based on the Lyapunov functional analysis, the adaptive laws for online tuning the parameters of the neural networks are derived so that the precision of position servo control can be improved. Compared with the conventional current regulated control scheme, this investigation introduces a voltage‐controlled pulse‐width modulation with a complete theoretic base, including the mechanical and electrical dynamics. The effectiveness of the proposed approach is verified by the experimental results and a comparison study with a recent work developed in the robust fuzzy PI control scheme.
Capsule‐like CdS‐modified TiO2 nanocomposites with enhanced photodegradation under visible light irradiation
Authors: Song Xiaojie , Yang Fan , Fang Qunling , Hu Hanmei , Sun Liuqian
Published: March 2015

Novel cadmium sulfide (CdS)/titanium dioxide (TiO2) nanocomposites with uniform ‘capsule‐like’ distribution of CdS nanocrystals on TiO2 nanoparticles (NPs) were successfully prepared by the hydrothermal method and the hot‐injection method. The CdS/TiO2 nanocomposites were characterised by X‐ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, high‐resolution transmission electron microscopy and scanning electron microscopy. The CdS/TiO2 nanocomposites (with Ti/Cd mass ratio of 1:1) exhibited excellent photocatalytic activity in the degradation of rhodamine B in water compared with pure TiO2 NPs and CdS NPs under visible light. The product might have potential applications in the cleanup of the environment because of its excellent photocatalytic activity.
Detection and modeling of leakage current in AlGaN-based deep ultraviolet light-emitting diodes
Authors: Moseley Michael W. , Allerman Andrew A. , Crawford Mary H. , Wierer Jonathan J. , Smith Michael L. , Armstrong Andrew M.
Published: March 2015

Current-voltage (IV) characteristics of two AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) with differing densities of open-core threading dislocations (nanopipes) are analyzed. A three-diode circuit is simulated to emulate the forward-bias IV characteristics of the DUV-LEDs, but is only able to accurately model the lower leakage current, lower nanopipe density DUV-LED. It was found that current leakage through the nanopipes in these structures is rectifying, despite nanopipes being previously established as inherently n-type. Using defect-sensitive etching, the nanopipes are revealed to terminate within the p-type GaN capping layer of the DUV-LEDs. The circuit model is modified to account for another p-n junction between the n-type nanopipes and the p-type GaN, and an excellent fit to the forward-bias IV characteristics of the leaky DUV-LED is achieved.
One-dimensional behavior and high thermoelectric power factor in thin indium arsenide nanowires
Authors: Mensch P. , Karg S. , Schmidt V. , Gotsmann B. , Schmid H. , Riel H.
Published: March 2015

Electrical conductivity and Seebeck coefficient of quasi-one-dimensional indium arsenide (InAs) nanowires with 20 nm diameter are investigated. The carrier concentration of the passivated nanowires was modulated by a gate electrode. A thermoelectric power factor of 1.7 × 10−3 W/m K2 was measured at room temperature. This value is at least as high as in bulk-InAs and exceeds by far typical values of thicker InAs nanowires with three-dimensional properties. The interpretation of the experimental results in terms of power-factor enhancement by one-dimensionality is supported by model calculations using the Boltzmann transport formalism.
Open-frame system for single-molecule microscopy
Authors: Arsenault Adriel , Leith Jason S. , Henkin Gil , McFaul Christopher M. J. , Tarling Matthew , Talbot Richard , Berard Daniel , Michaud Francois , Scott Shane , Leslie Sabrina R.
Published: March 2015

We present the design and construction of a versatile, open frame inverted microscope system for wide-field fluorescence and single molecule imaging. The microscope chassis and modular design allow for customization, expansion, and experimental flexibility. We present two components which are included with the microscope which extend its basic capabilities and together create a powerful microscopy system: A Convex Lens-induced Confinement device provides the system with single-molecule imaging capabilities, and a two-color imaging system provides the option of imaging multiple molecular species simultaneously. The flexibility of the open-framed chassis combined with accessible single-molecule, multi-species imaging technology supports a wide range of new measurements in the health, nanotechnology, and materials science research sectors.
Local pressure components and interfacial tensions of a liquid film in the vicinity of a solid surface with a nanometer-scale slit pore obtained by the perturbative method
Authors: Fujiwara K. , Shibahara M.
Published: March 2015

A classical molecular dynamics simulation was conducted for a liquid-solid interfacial system with a nanometer-scale slit pore in order to reveal local thermodynamic states: local pressure components and interfacial tensions of a liquid film in the vicinity of the slit. The simulation also examined the transition mechanism between the two states of the liquid film: (a) liquid film on the slit and (b) liquid film in the slit, based on the local thermodynamic quantities from a molecular point of view. An instantaneous expression of the local pressure components and interfacial tensions, which is based on a volume perturbation, was presented to investigate time-dependent phenomena in molecular dynamics simulations. The interactions between the particles were described by the 12-6 Lennard-Jones potential, and effects of the fluid-solid interaction intensity on the local pressure components and interfacial tensions of the fluid in the vicinity of the slit were examined in detail by the presented perturbative method. The results revealed that the local pressure components tangential to the solid surface in the vicinity of the 1st fluid layer from the solid surface are different in a two dimensional plane, and the difference became pronounced in the vicinity of the corner of the slit, for cases where the fluid-solid interaction intensities are relatively strong. The results for the local interfacial tensions of the fluid inside the slit suggested that the local interfacial tensions in the vicinity of the 2nd and 3rd layers of the solid atoms from the entrance of the slit act as a trigger for the transition between the two states under the influence of a varying fluid-solid interaction.
Shape-dependence of particle rotation in isotropic turbulence
Authors: Byron M. , Einarsson J. , Gustavsson K. , Voth G. , Mehlig B. , Variano E.
Published: March 2015

We consider the rotation of neutrally buoyant axisymmetric particles suspended in isotropic turbulence. Using laboratory experiments as well as numerical and analytical calculations, we explore how particle rotation depends upon particle shape. We find that shape strongly affects orientational trajectories, but that it has negligible effect on the variance of the particle angular velocity. Previous work has shown that shape significantly affects the variance of the tumbling rate of axisymmetric particles. It follows that shape affects the spinning rate in a way that is, on average, complementary to the shape-dependence of the tumbling rate. We confirm this relationship using direct numerical simulations, showing how tumbling rate and spinning rate variances show complementary trends for rod-shaped and disk-shaped particles. We also consider a random but non-turbulent flow. This allows us to explore which of the features observed for rotation in turbulent flow are due to the effects of particle alignment in vortex tubes.
Double-reconnected magnetic structures driven by Kelvin-Helmholtz vortices at the Earth's magnetosphere
Authors: Borgogno D. , Califano F. , Faganello M. , Pegoraro F.
Published: March 2015

In an almost collisionless magnetohydrodynamic plasma in a relatively strong magnetic field, stresses can be conveyed far from the region where they are exerted, e.g., through the propagation of Alfvèn waves. The forced dynamics of line-tied magnetic structures in solar and stellar coronae (see, e.g., A. F. Rappazzo and E. N. Parker, Astrophys. J. 773, L2 (2013) and references therein) is a paradigmatic case. Here, we investigate how this action at a distance develops from the equatorial region of the Kelvin-Helmholtz unstable flanks of the Earth's magnetosphere leading to the onset, at mid latitude in both hemispheres, of correlated double magnetic field line reconnection events that can allow the solar wind plasma to enter the Earth's magnetosphere.
A theory of heating of quiet solar corona
Authors: Wu C. S. , Yoon P. H. , Wang C. B.
Published: March 2015

A theory is proposed to discuss the creation of hot solar corona. We pay special attention to the transition region and the low corona, and consider that the sun is quiet. The proposed scenario suggests that the protons are heated by intrinsic Alfvénic turbulence, while the ambient electrons are heated by the hot protons via collisions. The theory contains two prime components: the generation of the Alfvénic fluctuations by the heavy minor ions in the transition region and second, the explanation of the temperature profile in the low solar atmosphere. The proposed heating process operates continuously in time and globally in space.
Impact-induced high-energy orbits of nonlinear energy harvesters
Authors: Zhou Shengxi , Cao Junyi , Inman Daniel J. , Liu Shengsheng , Wang Wei , Lin Jing
Published: March 2015

This letter presents an impact-induced method for nonlinear energy harvesters to obtain high-energy orbits over a wide frequency range under low excitation levels. Based on the impact principle and conservation of momentum, nonlinear electromechanical equations are derived to describe the system response due to initial impacts. Numerical and experimental results show that nonlinear bistable and tristable harvesters can sustain large-amplitude interwell oscillations over a wide range of frequencies, by achieving high-energy orbits in the beginning induced by an initial impact. The proposed impact-induced method could facilitate to efficient energy harvesting from low level ambient vibrations.
Neutral gas temperature maps of the pin-to-plate argon micro discharge into the ambient air
Authors: Xu S. F. , Zhong X. X. , Majeed Asif
Published: March 2015

This study is designed to explore the two dimensional temperature maps of the atmospheric argon discharge consisting of pin-to-plane electrodes supplied by a high voltage DC source. After checking the stability of the micro discharge, the two dimensional image plane focused by a quartz lens was scanned by the fiber probe driven by a 3D Mobile Platform. The rotational and vibrational temperatures are calculated using nitrogen emissions collected by the high resolution spectrometer and high sensitive intensified charge coupled device. The rotational temperature varies from 1558.15 K to 2621.14 K and vibrational temperature varies from 3010.38 K to 3774.69 K, indicating a great temperature gradient due to small discharge size. The temperature maps show a lateral expansion and a sharp truncation in the radial direction. A double layers discharge is identified, where an arc discharge coats the glow discharge.
Magnetic dipolar and quadrupolar transitions in two-electron atoms under exponential-cosine-screened Coulomb potential
Authors: Modesto-Costa Lucas , Canuto Sylvio , Mukherjee Prasanta K.
Published: March 2015

A detailed investigation of the magnetic dipolar and quadrupolar excitation energies and transition probabilities of helium isoelectronic He, Be2+, C4+, and O6+ have been performed under exponential cosine screened Coulomb potential generated in a plasma environment. The low-lying excited states 1s2:1Se → 1sns:3Se0, and 1snp:3Po2 (n = 2, 3, 4, and 5) are considered. The variational time-dependent coupled Hartree-Fock scheme has been used. The effect of the confinement produced by the potential on the structural properties is investigated for increasing coupling strength of the plasma. It is noted that there is a gradual destabilization of the energy of the system with the reduction of the ionization potential and the number of excited states. The effect of the screening enhancement on the excitation energies and transition probabilities has also been investigated and the results compared with those available for the free systems and under the simple screened Coulomb potential.
A continuous cold atomic beam interferometer
Authors: Xue Hongbo , Feng Yanying , Chen Shu , Wang Xiaojia , Yan Xueshu , Jiang Zhikun , Zhou Zhaoying
Published: March 2015

We demonstrate an atom interferometer that uses a laser-cooled continuous beam of 87Rb atoms having velocities of 10–20 m/s. With spatially separated Raman beams to coherently manipulate the atomic wave packets, Mach–Zehnder interference fringes are observed at an interference distance of 2L = 19 mm. The apparatus operates within a small enclosed area of 0.07 mm2 at a bandwidth of 190 Hz with a deduced sensitivity of 7.8×10−5 rad/s/Hz for rotations. Using a low-velocity continuous atomic source in an atom interferometer enables high sampling rates and bandwidths without sacrificing sensitivity and compactness, which are important for applications in real dynamic environments.
Electric-field dependence of photocarrier generation efficiency of organic photoconductors
Authors: Umeda Minoru
Published: March 2015

The electric-field dependence of photocarrier generation efficiency has been investigated in several different types of organic photoconductor for electrophotography to elucidate the controlling factors of light-to-electrical energy conversion. The rate-determining step in generating photocarriers has been considered to be the charge transfer between two neighboring molecules. Overall photocarrier generation efficiency has been determined using the charge transfer velocity at the rate-determining step as a function of electric-field-dependent activation energy, which is influenced by the symmetry factor α and the energy gap ΔE. The formula used successfully fits the experimental data for different types of organic photoconductor over a wide field strengths range. From the fitting results of high-sensitivity photoconductors, the zero-field activation energy is small and the reactant lifetime is long. In addition, ΔE is zero, which implies that the hole-electron interaction in the reactant is negligible at the rate-determining step. In contrast, for low-sensitivity photoconductors, the zero-field activation energy is large and the reactant lifetime is short; however, ΔE < 0 and α > 0.5, which suggest that the hole-electron interaction is not negligible. Consequently, the proposed formula well explains the electric-field dependence of photocarrier generation efficiency on the basis of its controlling factors.
Picosecond dynamics of photoexcited carriers in silicon nanocrystal/Si3N4 superlattices: Presence of K centers
Authors: Kořínek M. , Trojánek F. , Hiller D. , Gutsch S. , Zacharias M. , Malý P.
Published: March 2015

We report in detail on the picosecond dynamics of photoexcited charge carriers in size-controlled silicon nanocrystals in silicon nanocrystal/Si3N4 superlattices. The samples were prepared using plasma enhanced chemical vapor deposition and subsequent thermally induced phase separation. The pump and probe transmission technique was used to monitor directly the initial (picosecond) carrier dynamics. The transient transmission signal (decay time about 2 ps) was found to be independent of the nanocrystal size, pump pulse intensity and wavelength from the interval 400 to 700 nm. The signal is attributed to the dynamics of photoexcited carriers captured on the K0 centers in Si3N4.
Significant thermal conductivity reduction of silicon nanowire forests through discrete surface doping of germanium
Authors: Pan Ying , Hong Guo , Raja Shyamprasad N. , Zimmermann Severin , Tiwari Manish K. , Poulikakos Dimos
Published: March 2015

Silicon nanowires (SiNWs) are promising materials for the realization of highly-efficient and cost effective thermoelectric devices. Reduction of the thermal conductivity of such materials is a necessary and viable pathway to achieve sufficiently high thermoelectric efficiencies, which are inversely proportional to the thermal conductivity. In this article, vertically aligned forests of SiNW and germanium (Ge)-doped SiNW with diameters around 100 nm have been fabricated, and their thermal conductivity has been measured. The results show that discrete surface doping of Ge on SiNW arrays can lead to 23% reduction in thermal conductivity at room temperature compared to uncoated SiNWs. Such reduction can be further enhanced to 44% following a thermal annealing step. By analyzing the binding energy changes of Ge-3d and Si-2p using X-ray photoelectron spectroscopy, we demonstrate that surface doped Ge interacts strongly with Si, enhancing phonon scattering at the Si-Ge interface as has also been shown in non-equilibrium molecular dynamics studies of single nanowires. Overall, our results suggest a viable pathway to improve the energy conversion efficiency of nanowire-forest thermoelectric nanomaterials.
Extraordinary enhancement of Néel transition temperature in nanoparticles of multiferroic tetragonal compositions of (1 − x)BiFeO3-xPbTiO3 solid solutions
Authors: Upadhyay Chandan , Harijan Pappu Kumar , Senyshyn Anatoliy , Ranganathan R. , Pandey Dhananjai
Published: March 2015

The Néel temperature (TN) in conventional antiferromagnets (AFM) decreases with decreasing particle size. In contrast, we present here evidence for an exotic facet of multiferroicity, whereby one can raise the TN by more than 200 K by decreasing the particle size. We illustrate this by taking the example of a tetragonal composition with x = 0.5 in the solid solutions of (1 − x)BiFeO3-xPbTiO3 (BF-xPT). We attribute it to the increase in the strength of the superexchange interaction via a decrease in the ferroelectric distortion in nanocrystalline powder of BF-0.5PT. The BF-0.5PT nanoparticles also exhibit exchange bias effect due to AFM core-FM shell type magnetic nanostructure.
Patchy Janus particles with tunable roughness and composition via vapor-assisted deposition of macromolecules
Authors: Shepard Kimberly B. , Christie Dane A. , Sosa Chris L. , Arnold Craig B. , Priestley Rodney D.
Published: March 2015

Here, we present a technique for the fabrication of patchy Janus particles utilizing a vapor-assisted macromolecular deposition technique, termed Matrix Assisted Pulsed Laser Evaporation (MAPLE). Using this technique, both inorganic and organic precursor particles, immobilized on a surface, are functionalized on one hemisphere with nanodroplets of a desired polymer, thus forming particles with a patchy Janus morphology and textured surface topology. This fabrication method is flexible with respect to the chemical identity of the precursor particle and the selection of the deposited polymer. By tuning MAPLE deposition parameters, e.g., target composition or deposition time, the Janus anisotropy and roughness (i.e., patchiness) can be tuned, thus enabling greater control over the particles' behavior for applications as nanoparticle surfactants for stabilization of emulsions and foams.
Visible light carrier generation in co-doped epitaxial titanate films
Authors: Comes Ryan B. , Smolin Sergey Y. , Kaspar Tiffany C. , Gao Ran , Apgar Brent A. , Martin Lane W. , Bowden Mark E. , Baxter Jason B. , Chambers Scott A.
Published: March 2015

Perovskite titanates such as SrTiO3 (STO) exhibit a wide range of important functional properties, including ferroelectricity and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications; however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr, we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr3+ dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to 2.4–2.7 eV depending on doping levels. Transient reflectance spectroscopy measurements are in agreement with the observations from ellipsometry and confirm that optically generated carriers are present for longer than 2 ns. Finally, through photoelectrochemical methylene blue degradation measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.
A dielectric-filled magnetically insulated transmission line oscillator
Authors: Fan Yu-Wei , Wang Xiao-Yu , Zhong Hui-Huang , Zhang Jian-De
Published: March 2015

A dielectric-filled magnetically insulated transmission line oscillator (DFMILO) is presented in this paper, which introduces a low-loss dielectric to fill its resonant cavities and thus improves its technical performances. The fundamental mode frequency of the DFMILO is derived and its dispersion curve is analyzed. In simulation, high-power microwave is generated from the DFMILO with peak power of 3.1 GW, frequency of 1.467 GHz, and peak power conversion efficiency of 14.0% when the voltage is 455 kV and the current is 48.7 kA. However, the peak power conversion efficiency of the relevant unfilled MILO is only 8.5%. The comparative result shows that the filled dielectric helps to enhance the power conversion efficiency of the DFMILO. In addition, the filled dielectric contributes to decrease the MILO's dominant frequency, which means that if the dominant frequency is same, the volume of the DFMILO (especially the low-frequency DFMILO) is more compact than that of the relevant unfilled MILO.