bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical immune‐monitoring strategies for predicting infection risk in solid organ transplantation
Authors: Fernández‐Ruiz Mario , Kumar Deepali , Humar Atul
Published: February 2014

Infectious complications remain a leading cause of morbidity and mortality after solid organ transplantation (SOT), and largely depend on the net state of immunosuppression achieved with current regimens. Cytomegalovirus (CMV) is a major opportunistic viral pathogen in this setting. The application of strategies of immunological monitoring in SOT recipients would allow tailoring of immunosuppression and prophylaxis practices according to the individual's actual risk of infection. Immune monitoring may be pathogen‐specific or nonspecific. Nonspecific immune monitoring may rely on either the quantification of peripheral blood biomarkers that reflect the status of a given arm of the immune response (serum immunoglobulins and complement factors, lymphocyte sub‐populations, soluble form of CD30), or on the functional assessment of T‐cell responsiveness (release of intracellular adenosine triphosphate following a mitogenic stimulus). In addition, various methods are currently available for monitoring pathogen‐specific responses, such as CMV‐specific T‐cell‐mediated immune response, based on interferon‐γ release assays, intracellular cytokine staining or main histocompatibility complex‐tetramer technology. This review summarizes the clinical evidence to date supporting the use of these approaches to the post‐transplant immune status, as well as their potential limitations. Intervention studies based on validated strategies for immune monitoring still need to be performed.
A ‘hidden’ 18O-enriched reservoir in the sub-arc mantle
Authors: Liu Chuan-Zhou , Wu Fu-Yuan , Chung Sun-Lin , Li Qiu-Li , Sun Wei-Dong , Ji Wei-Qiang
Published: February 2014

Plate subduction continuously transports crustal materials with high-δ18O values down to the mantle wedge, where mantle peridotites are expected to achieve the high-δ18O features. Elevated δ18O values relative to the upper mantle value have been reported for magmas from some subduction zones. However, peridotites with δ18O values significantly higher than the well-defined upper mantle values have never been observed from modern subduction zones. Here we present in-situ oxygen isotope data of olivine crystals in Sailipu mantle xenoliths from South Tibet, which have been subjected to a long history of Tethyan subduction before the India-Asia collision. Our data identify for the first time a metasomatized mantle that, interpreted as the sub-arc lithospheric mantle, shows anomalously enriched oxygen isotopes (δ18O = +8.03 ± 0.28 ‰). Such a high-δ18O mantle commonly does not contribute significantly to typical island arc basalts. However, partial melting or contamination of such a high-δ18O mantle is feasible to account for the high-δ18O signatures in arc basalts.
New insight into the size-controlled synthesis of silver nanoparticles and its superiority in room temperature sintering
Authors: Tang Yao , He Wei , Wang Shouxu , Tao Zhihua , Cheng Lijuan
Published: February 2014

Silver nanoparticles with a controlled size present a high conductivity after room temperature sintering achieved by a chemical process.
Design, synthesis and photophysical studies of dipyrromethene-based materials: insights into their applications in organic photovoltaic devices
Authors: Bessette André , Hanan Garry S.
Published: February 2014

This review article presents the most recent developments in the use of materials based on dipyrromethene and some structurally related azadipyrromethenes for OPV applications.
Tetratopic pyrimidine–hydrazone ligands modified with terminal hydroxymethyl and acryloyl arms and their Pb(ii), Zn(ii), Cu(ii) and Ag(i) complexes
Authors: Hutchinson Daniel J. , Hanton Lyall R. , Moratti Stephen C.
Published: February 2014

Tetratopic pym–hyz strands with terminal hydroxymethyl (L1) and acryloyl groups (L2) were synthesised, characterised and reacted with Pb(ii), Zn(ii), Cu(ii) and Ag(i) ions resulting in new linear, horse-shoe shaped and double helical complexes.
Colorimetric detection of copper and efficient removal of heavy metal ions from water by diamine-functionalized SBA-15
Authors: Wang Zhuqing , Wang Min , Wu Genhua , Wu Dayu , Wu Aiguo
Published: February 2014

A novel diamine-functionalized mesoporous SBA-15 was developed for the colorimetric detection and removal of Cu2+ ions from water.
High-quality Prussian blue crystals as superior cathode materials for room-temperature sodium-ion batteries
Authors: You Ya , Wu Xing-Long , Yin Ya-Xia , Guo Yu-Guo
Published: February 2014

High-quality Prussian blue crystals with a small number of vacancies and a low water content show high specific capacity and remarkable cycle stability as cathode materials for Na-ion batteries.
Ecological and enzymatic responses to petroleum contamination
Authors: Wu Binbin , Lan Tian , Lu Diannan , Liu Zheng
Published: February 2014

The micro-ecology of soil contaminated with different PHCs was monitoredviaquantification of relevant genes and enzymatic activities.
Functionalized dicyandiamide–formaldehyde polymers as efficient heterogeneous catalysts for conversion of CO2 into organic carbonates
Authors: Meng Xiang-Lei , Nie Yi , Sun Jian , Cheng Wei-Guo , Wang Jin-Quan , He Hong-Yan , Zhang Suo-Jiang
Published: February 2014

The ABMDFP exhibited high activity on cycloaddition of CO2 and transesterification reaction of EC, which was also suitable for various substrates. A possible mechanism of ring-opening of epoxide and activation of CO2 was proposed.
A multiple-channel, multiple-assay platform for characterization of full-range shear stress effects on vascular endothelial cells
Authors: Booth R. , Noh S. , Kim H.
Published: February 2014

Vascular endothelial cells (VECs), which line blood vessels and are key to understanding pathologies and treatments of various diseases, experience highly variable wall shear stress (WSS)in vivo(1–60 dyn cm−2), imposing numerous effects on physiological and morphological functions.
Catalytic asymmetric allylation of carbonyl compounds and imines with allylic boronates
Authors: Huo Hua-Xing , Duvall Jeremy R. , Huang Meng-Yuan , Hong Ran
Published: February 2014

Enantioselective allylation is a highly used organic reaction to prepare chiral homoallylic alcohols and amines, which serve as important building blocks in the synthesis of a variety of natural products and pharmaceuticals.
Self-powered pendulum and micro-force active sensors based on a ZnS nanogenerator
Authors: Wu Jyh Ming , Kao Chi Chun
Published: February 2014

A pendulum and micro-force active sensors have been first made from zinc sulfur nanowires based nanogenerator. The ZnS nanogenerator can be self-powered to trace a simple harmonic motion of a pendulum that released from different angle. A various momentums from 0.077 N s to 0.177 N s were able to detect owing to the output voltage and current of the ZnS nanogenerator were proportional to the momentum.
Molecular-iodine-catalyzed aerobic oxidative synthesis of β-hydroxy sulfones from alkenes
Authors: Kariya Atsumasa , Yamaguchi Tomoaki , Nobuta Tomoya , Tada Norihiro , Miura Tsuyoshi , Itoh Akichika
Published: February 2014

The synthesis of β-hydroxy sulfones from alkenes and sodium sulfinates under aerobic oxidative conditions was achieved in the presence of a catalytic amount of molecular iodine.
The self-aggregation of fluorophore-triphenylamine nanostructures with tunable luminescent properties: the effect of acidity and rare earth ions
Authors: Chen Qi-yu , Kong Lin , Tian Yu-peng , Xu Xian-yun , Yang Long-Mei , Zhang Gao-bin , Jia Wen-bin , Yang Jia-xiang
Published: February 2014

The self-aggregation of a fluorophore triphenylamine nanostructure in different acidity aqueous solutions and/or under the guidance of rare earth ions is studied to optimize the optical properties.
Photochromic spiropyran-embedded PDMS for highly sensitive and tunable optochemical gas sensing
Authors: Nam Yoon-Seung , Yoo Imsung , Yarimaga Oktay , Park In Sung , Park Dong-Hoon , Song Simon , Kim Jong-Man , Lee Chan Woo
Published: February 2014

A highly sensitive, tunable, flexible and microfluidic compatible gas sensor was developed based on a photochromic spiropyran-embedded PDMS composite.
Pillar[5]- and pillar[6]arene-based supramolecular assemblies built by using their cavity-size-dependent host–guest interactions
Authors: Ogoshi T. , Yamagishi T.
Published: February 2014

We discuss various pillar[5]- and pillar[6]arene-based supramolecular assemblies built using their host–guest interactions.
Electrocatalysis of hydrogen peroxide reactions on perovskite oxides: experimentversuskinetic modeling
Authors: Poux T. , Bonnefont A. , Ryabova A. , Kéranguéven G. , Tsirlina G. A. , Savinova E. R.
Published: February 2014

A kinetic model sheds light on the mechanism of the hydrogen peroxide reactions on Mn- and Co-perovskite oxides.
Luminescent metal–organic frameworks for chemical sensing and explosive detection
Authors: Hu Zhichao , Deibert Benjamin J. , Li Jing
Published: February 2014

This review provides an update on the photoluminescence properties of LMOFs and their utility in chemical sensing and explosive detection.
Dinuclear NHC–palladium complexes containing phosphine spacers: synthesis, X-ray structures and their catalytic activities towards the Hiyama coupling reaction
Authors: Yang Jin , Li Pinhua , Zhang Yicheng , Wang Lei
Published: February 2014

Six dinuclear N-heterocyclic carbene–palladium complexes were synthesized from [Pd(μ-Cl)(Cl)(NHC)]2 and Ph2P(CH2)nPPh2, and their catalytic activities towards the Hiyama reaction were investigated.
The zircon ‘matrix effect’: evidence for an ablation rate control on the accuracy of U–Pb age determinations by LA-ICP-MS
Authors: Marillo-Sialer E. , Woodhead J. , Hergt J. , Greig A. , Guillong M. , Gleadow A. , Evans N. , Paton C.
Published: February 2014

This papers describes the source of systematic bias in U–Pb zircon dating by LA-ICP-MS.
CO2-activated, hierarchical trimodal porous graphene frameworks for ultrahigh and ultrafast capacitive behavior
Authors: Yun Sol , Kang Sung-Oong , Park Sungjin , Park Ho Seok
Published: February 2014

CO2-activated macroscopic graphene architectures with hierarchical trimodal pore systems that consist of macro-, meso- and micropores show ultrahigh capacitance and ultrafast capacitive performance under both chemical and electrochemical adsorption conditions.
Synthesis of well-defined functionalized poly(2-(diisopropylamino)ethyl methacrylate) using ATRP with sodium dithionite as a SARA agent
Authors: Góis Joana R. , Rocha Nuno , Popov Anatoliy V. , Guliashvili Tamaz , Matyjaszewski Krzysztof , Serra Arménio C. , Coelho Jorge F. J.
Published: February 2014

2-(Diisopropylamino)ethyl methacrylate was polymerized by Atom Transfer Radical Polymerization using sodium dithionite as a reducing agent and supplemental activator with a Cu(ii)Br2/Me6TREN catalytic system.
Establishing α-bromo-γ-butyrolactone as a platform for synthesis of functional aliphatic polyesters – bridging the gap between ROP and SET-LRP
Authors: Olsén Peter , Undin Jenny , Odelius Karin , Albertsson Ann-Christine
Published: February 2014

Utilizing α-bromo-γ-butyrolactone (αBrγBL) as a comonomer with ε-caprolactone (εCL) or l-lactide (LLA) produces copolymers with active and available grafting sites, e.g., for SET-LRP, where the choice of the grafting monomers is limited only by one's imagination.
Fe3+ facilitating the response of NiO towards H2S
Authors: Li Fang , Chen Yuejiao , Ma Jianmin
Published: February 2014

Fe2O3-loaded NiO nanoplates were prepared by immersing NiO nanoplates in aqueous Fe(NO3)3 solution and annealing the corresponding as-immersed NiO nanoplates.
Fast and facile fabrication of porous polymer particles via thiol–ene suspension photopolymerization
Authors: Tan Jiaojun , Li Chunmei , Zhou Jian , Yin Changjie , Zhang Baoliang , Gu Junwei , Zhang Qiuyu
Published: February 2014

The porous particles were fabricated via thiol–ene click chemistry within 5 minutes under mild conditions.
AuNP based selective colorimetric sensor for cysteine at a wide pH range: investigation of capping molecule structure on the colorimetric sensing and catalytic properties
Authors: Vinod Kumar V. , Philip Anthony Savarimuthu
Published: February 2014

Gold nanoparticles (AuNPs) stabilized with different surfactants, SDS, PEG, PVA, PVP, PSS and T-80, were synthesized and explored for cysteine colorimetric sensing and catalytic properties.
Size-controlled synthesis, characterization and electrocatalytic behaviors of polymer-protected nickel nanoparticles: a comparison with respect to two polymers
Authors: Roy Partha Sarathi , Bhattacharya Swapan Kumar
Published: February 2014

A facile reduction of nickel chloride in aqueous solution with sodium borohydride leads to fairly monodisperse, and electrochemically active nickel nanoparticles by the separate use of a capping polymer like polyvinyl pyrrolidone (PVP) and polyacrylic acid (PAA).
Oxidative coupling of primary amines to imines under base-free and additive-free conditions over AuNPs/SBA-NH2 nanocatalyst
Authors: Neeli Chinna Krishna Prasad , Ganji Saidulu , Ganjala Venkata Siva Prasad , Kamaraju Seetha Rama Rao , Burri David Raju
Published: February 2014

Oxidative coupling of benzylamines to N-benzylbenzylimines under base- and additive-free conditions is achieved over AuNPs/SBA-NH2. Facile preparation, high activity, ease of separation and good reusability are the credentials of AuNPs/SBA-NH2 catalyst.
Palladium nanoparticles supported in a polymeric membrane: an efficient phosphine-free “green” catalyst for Suzuki–Miyaura reactions in water
Authors: Faria Vinícius W. , Oliveira Deyvid G. M. , Kurz Márcia H. S. , Gonçalves Fábio F. , Scheeren Carla W. , Rosa Gilber R.
Published: February 2014

Palladium(0) nanoparticles supported on a polymeric membrane, CA/Pd(0), were found to be a highly efficient “dip catalyst” (heterogeneous catalyst) for Suzuki–Miyaura cross-coupling reactions.
First-principles study of the halide-passivation effects on the electronic structures of CdSe quantum dots
Authors: Wang Youwei , Zhang Yubo , Zhang Wenqing
Published: February 2014

Our DFT calculations demonstrate that halide passivants remove the dangling-bond-derived states of surface cationic atoms. The modulation of halide passivants to electronic structures of CdSe quantum dots depends on the coordination numbers of halide passivants. Cl passivants need three coordinated atoms to remove the effect of passivants on band edges.
Magnitude and consequences of OR ligand σ-donation on alkene metathesis activity in d0 silica supported (SiO)W(NAr)(CHtBu)(OR) catalysts
Authors: Mougel V. , Copéret C.
Published: February 2014

Well-defined silica supported W catalysts with the general formula [(SiO)W(NAr)(CHtBu)(OR)] (OR = OtBuF9, OtBuF6, OtBuF3, OtBu and OSi(OtBu)3), prepared by grafting bis-alkoxide complexes [W(NAr)(CHtBu)(OR)2] on silica dehydroxylated at 700 °C (SiO2(700)), display unexpectedly high activity in comparison with their Mo homologues.
A maize-like FePO4@MCNT nanowire composite for sodium-ion batteries via a microemulsion technique
Authors: Xu Shuojiong , Zhang Shiming , Zhang Junxi , Tan Tian , Liu Yao
Published: February 2014

A maize-like FePO4@MCNT composite was prepared through non-covalent surface treatment and used as a cathode for sodium-ion batteries.
Highly hydrogen permselective ZIF-8 membranes supported on polydopamine functionalized macroporous stainless-steel-nets
Authors: Huang Aisheng , Liu Qian , Wang Nanyi , Caro Jürgen
Published: February 2014

Inspired by the bio-adhesive ability of the marine mussel, highly hydrogen permselective ZIF-8 membranes with a “reinforced concrete” structure were prepared on polydopamine functionalized inexpensive macroporous stainless-steel-nets.
Effective synergistic effect of Al2O3 and SiC microparticles on the growth of carbon nanotubes and their application in high dielectric permittivity polymer composites
Authors: Dichiara Anthony B. , Yuan Jinkai , Yao Shenghong , Sylvestre Alain , Zimmer Laurent , Bai Jinbo
Published: February 2014

Polymer composites prepared using the simultaneous growth of aligned CNTs on different ceramic microparticles reveal enhanced dielectric properties, providing great potential for power energy storage applications.
Layer-by-layer self-assembly of a sandwich-like graphene wrapped SnOx@graphene composite as an anode material for lithium ion batteries
Authors: Tang Jingjing , Yang Juan , Zhou Limin , Xie Jing , Chen Guanghui , Zhou Xiangyang
Published: February 2014

Sandwich-like hybrid nanosheets consisting of graphene wrapped SnO/SnO2 nanocrystals anchored on graphene have been synthesized via a facile layer-by-layer self-assembly approach.
LixV2O5/LiV3O8 nanoflakes with significantly improved electrochemical performance for Li-ion batteries
Authors: Sun Dan , Jin Guanhua , Wang Haiyan , Huang Xiaobing , Ren Yu , Jiang Jiecao , He Hanna , Tang Yougen
Published: February 2014

A novel strategy involving the self-transformation of superficial LiV3O8 in a reducing atmosphere (H2/Ar) was reported to fabricate core–shell structured LixV2O5/LiV3O8 nanoflakes. The cycling stability and rate performance were significantly improved.
A Case for the Implementation of Cognitive-Communication Screenings in Acute Stroke
Authors: Hinckley Jacqueline J.
Published: February 2014

Purpose

The purpose of this article was to illustrate the importance of the implementation of cognitive-communication screenings in acute stroke and to discuss the need for further research on whether and how these screenings are implemented. Cognitive-communication screenings after stroke are the subject of existing practice guidelines and are supported by accumulated evidence.

Method

The author uses anautoethnographic narrative—a tool founded in phenomenology—to provide an in-depth description of the experiences of a family in which one member experienced right-hemispheric stroke. She uses systematic introspection to produce a narrative using literary techniques.

Results

The narrative illustrates the experiences of one family when one of their members has a right-hemisphere stroke, and cognitive-communication impairments are never formally identified by professionals involved in the patient's care.

Conclusions

The narrative is linked to the published literature and the importance of identifying and managing cognitive-communication impairments after stroke. A model of implementation science is presented as one way to consider the challenges clinicians face when attempting to implement evidence-based practices. The model and examples from other fields show avenues for further research.
An Enhanced Protocol for Constraint-Induced Aphasia Therapy II: A Case Series
Authors: Johnson Margaret L. , Taub Edward , Harper Leslie H. , Wade Jamie T. , Bowman Mary H. , Bishop-McKay Staci , Haddad Michelle M. , Mark Victor W. , Uswatte Gitendra
Published: February 2014

Purpose

The initial version of Constraint-Induced Aphasia Therapy (CIAT I) consisted of a single exercise. This study sought to evaluate the feasibility for future trials of an expanded and restructured protocol designed to increase the efficacy of CIAT I.

Method

The subjects were 4 native English speakers with chronic stroke who exhibited characteristics of moderate Broca's aphasia. Treatment was carried out for 3.5 hr/day for 15 consecutive weekdays. It consisted of 3 components: (a) intensive training by a behavioral method termed
shaping
using a number of expressive language exercises in addition to the single original language card game, (b) strong discouragement of attempts to use gesture or other nonverbal means of communication, and (c) a transfer package of behavioral techniques to promote transfer of treatment gains from the laboratory to real-life situations.

Results

Participation in speech in the life situation improved significantly after treatment. The effect sizes (i.e.,
d
′) in this domain were ≥ 2.2;
d
′ values ≥ 0.8 are considered large. Improvement in language ability on a laboratory test, the Western Aphasia Battery—Revised (Kertesz, 2006), did not achieve statistical significance, although the effect size was large—that is, 1.3 (13.1 points).

Conclusion

These pilot results suggest in preliminary fashion that CIAT II may produce significant improvements in everyday speech.

Supplemental Material

https://doi.org/10.23641/asha.6170207
Selective combining for hybrid cooperative networks
Authors: Huo Qiang , Liu Tianxi , Sun Shaohui , Song Lingyang , Jiao Bingli
Published: February 2014

In this study, we consider the selective combining in hybrid cooperative networks (SCHCNs scheme) with one source node, one destination node and N relay nodes. In the SCHCN scheme, each relay first adaptively chooses between amplify‐and‐forward protocol and decode‐and‐forward protocol on a per frame basis by examining the error‐detecting code result, and Nc(1 ≤ Nc ≤ N) relays will be selected to forward their received signals to the destination. We first develop a signal‐to‐noise ratio (SNR) threshold‐based frame error rate (FER) approximation model. Then, the theoretical FER expressions for the SCHCN scheme are derived by utilising the proposed SNR threshold‐based FER approximation model. The analytical FER expressions are validated through simulation results.
Performance evaluation of a fault‐tolerant decoupled dual‐channel switched reluctance motor drive under open‐circuits
Authors: Ding Wen , Liu Yunpeng , Hu Yanfang
Published: February 2014

This study presents a new configuration for dual‐channel switched reluctance motor (DCSRM) called as decoupled DCSRM (DDCSRM), which can be proposed as a suitable candidate for high‐reliability applications. In this new DDCSRM, the two channels could be considered as two synchronously independent 6/4 three‐phase SRMs with no mutual coupling when they are excited simultaneously. The machine topology and magnetic characteristics of flux distribution, static flux linkage and torque by using finite‐element analysis are presented. Then, the mathematic models of the DDCSRM drive under normal and open‐circuit fault operations are proposed. To achieve fault‐tolerant operation, a control strategy of open‐circuit faults for the DDCSRM drive is presented. The key of the fault‐tolerant control strategy is to maintain the rotor speed as the normal motoring operation. The dynamic performances of the DDCSRM drive under normal and open‐circuit fault conditions are analysed by using the control strategy. Finally, an experimental setup for a 12/8 DDCSRM drive system is built for verification. The experimental results at normal and various open‐circuit fault conditions are presented to verify the control strategy of the DDCSRM drive system and the analytical and simulation results.
The Elastic Scattering and Neutralization of Low Velocity Hydrogen Ions in Methane
Authors: Simons J. H. , Fryburg G. C.
Published: February 2014

The low velocity scattering of H+, H2+, and H3+ in methane was measured at voltȧges between about 1 and 150. Neutralization is found in all three cases, being much greater for H2+ and H+ than for H3+. The elastic scattering is also relatively high compared to hydrogen and helium. It was found that there was an effect of pressure at constant voltage on the experimental determination of effective cross section for elastic scattering. This has been explained on the basis of multiple scattering. Approximate potential laws for the interactions have been evaluated.
Microbial oil production by Rhodotorula glutinis CICC 31643 using sugar cane molasses
Authors: Wang Xinhui , Ren Hongyang
Published: February 2014

Lipid accumulation in Rhodotorula glutinis CICC 31643 using sugar cane molasses as carbon source was studied. In the bath cultivation, the optimal sugar concentration and initial medium pH was 20% (w/w) and 6.0, respectively. The low C/N ratio (25 and 20) was more suitable for cell growth, while high C/N ratio (100 and 50) was more suitable for oil production. The C/N ratio 100 was the most beneficial for oil production of R. glutinis CICC 31643 with a notable lipid accumulation of 44.5% (w/w). 7.93 g/l lipid production was obtained during the fed-bath cultivation, whereas 6.31 g/l lipid production was obtained during the bath cultivation. Fatty acids produced by R. glutinis CICC 31643 were composed of oleic (C18:1), palmitic (C16:0), and stearic acid (C18:0) and the palmitic and oleic acid dominated the total of the fatty acids. It is suggested that the lipid production could be suitable for the production of good quality biodiesel.
Fundamental Equation of State for Deuterium
Authors: Richardson I. A. , Leachman J. W. , Lemmon E. W.
Published: February 2014

World utilization of deuterium is anticipated to increase with the rise of fusion-energy machines such as ITER and NIF. We present a new fundamental equation of state for the thermodynamic properties of fluid deuterium. Differences between thermodynamic properties of orthodeuterium, normal deuterium, and paradeuterium are described. Separate ideal-gas functions were fitted for these separable forms together with a single real-fluid residual function. The equation of state is valid from the melting line to a maximum pressure of 2000 MPa and an upper temperature limit of 600 K, corresponding to available experimental measurements. The uncertainty in predicted density is 0.5% over the valid temperature range and pressures up to 300 MPa. The uncertainties of vapor pressures and saturated liquid densities are 2% and 3%, respectively, while speed-of-sound values are accurate to within 1% in the liquid phase.
Implementation of magnetic field assistance to current-induced perpendicular-magnetic-anisotropy racetrack memory
Authors: Zhang Y. , Zhao W. S. , Klein J.-O. , Chappert C. , Ravelosona D.
Published: February 2014

Due to the increase of resistance of nanowire as the technology continuously scales down, generating a current enough high for shifting domain wall (DW) becomes one of the most serious issues to hinder the progress of Racetrack memory (RM). It is recently reported that magnetic field can assist to trigger the DW motion below intrinsic current threshold, which can be a promising alternative to help RM address this current threshold issue. In this paper, we present an implementation of magnetic field assistance to perpendicular-magnetic-anisotropy Co/Ni RM. By using a spice-compatible model and CMOS 40 nm design kit, we perform mixed simulation to validate its functionality. Storage capacity and power analyses demonstrate that lowering the critical current density of DW shifting allows higher feasibility for ultra-denser RM and provides a relatively acceptable energy performance.
Focused-ion-beam induced damage in thin films of complex oxide BiFeO3
Authors: Siemons W. , Beekman C. , Fowlkes J. D. , Balke N. , Tischler J. Z. , Xu R. , Liu W. , Gonzales C. M. , Budai J. D. , Christen H. M.
Published: February 2014

An unexpected, strong deterioration of crystal quality is observed in epitaxial perovskite BiFeO3 films in which microscale features have been patterned by focused-ion-beam (FIB) milling. Specifically, synchrotron x-ray microdiffraction shows that the damaged region extends to tens of μm, but does not result in measureable changes to morphology or stoichiometry. Therefore, this change would go undetected with standard laboratory equipment, but can significantly influence local material properties and must be taken into account when using a FIB to manufacture nanostructures. The damage is significantly reduced when a thin metallic layer is present on top of the film during the milling process, clearly indicating that the reduced crystallinity is caused by ion beam induced charging.
Cross-nucleation between clathrate hydrate polymorphs: Assessing the role of stability, growth rate, and structure matching
Authors: Nguyen Andrew H. , Molinero Valeria
Published: February 2014

Cross-nucleation is a phenomenon where a new crystal nucleates and grows upon the surface of a different polymorph. Previous studies indicate that faster growth rate of the new crystal is a necessary but not sufficient condition for cross-nucleation. The thermodynamic stability of the different polymorphs can also affect cross-nucleation by modulating the rates of crystal growth. The interplay between thermodynamic stability of the polymorphs involved, the growth rate of the crystals, and the need for creation of an interfacial transition layer that seamlessly connects the two structures has not yet been fully elucidated. Predicting cross-nucleation is particularly challenging for clathrate hydrates, for which there are sometimes several polymorphs with similar stability and for which growth rates are not known. In this work, we use molecular dynamics simulations to investigate which factor (stability, growth rate, or formation of interfacial transition layer) controls cross-nucleation between the four known Frank-Kasper clathrate hydrate polymorphs: sI, sII, TS, and HS-I. We investigate the growth and cross-nucleation of these four hydrates filled with a set of guest molecules that produce different order of stabilities for the four crystal structures. We determine that the growth rate of sII clathrate is the fastest, followed by TS, HS-I, and sI. We find that cross-nucleation into or from sII clathrates is preceded by the formation of an interfacial transition layer at the seed crystal/liquid interface because sII does not share a crystal plane with sI, HS-I, or TS. Cross-nucleation between the latter three can occur seamlessly and is determined only by their growth rates. Our results indicate that nucleation of an interfacial transition layer between non-matching polymorphs can control cross-nucleation or lack thereof under conditions of small driving force. Under conditions of sufficient supercooling clathrate hydrate polymorphs cross-nucleate into the fastest growing phase even if that new phase is less stable and does not share a common crystal plane with the initial polymorph.
Generalised Eisenhart lift of the Toda chain
Authors: Cariglia Marco , Gibbons Gary
Published: February 2014

The Toda chain of nearest neighbour interacting particles on a line can be described both in terms of geodesic motion on a manifold with one extra dimension, the Eisenhart lift, or in terms of geodesic motion in a symmetric space with several extra dimensions. We examine the relationship between these two realisations and discover that the symmetric space is a generalised, multi-particle Eisenhart lift of the original problem that reduces to the standard Eisenhart lift. Such generalised Eisenhart lift acts as an inverse Kaluza-Klein reduction, promoting coupling constants to momenta in higher dimension. In particular, isometries of the generalised lift metric correspond to energy preserving transformations that mix coordinates and coupling constants. A by-product of the analysis is that the lift of the Toda Lax pair can be used to construct higher rank Killing tensors for both the standard and generalised lift metrics.
Adsorption of CO2, N2, and CH4 in Cs-exchanged chabazite: A combination of van der Waals density functional theory calculations and experiment study
Authors: Shang Jin , Li Gang , Singh Ranjeet , Xiao Penny , Danaci David , Liu Jefferson Z. , Webley Paul A.
Published: February 2014

The crucial role of dispersion force in correctly describing the adsorption of some typical small-size gas molecules (e.g., CO2, N2, and CH4) in ion-exchanged chabazites has been investigated at different levels of theory, including the standard density functional theory calculation using the Perdew, Burke, and Ernzerhof (PBE) exchange-correlation functional and van der Waals density functional theory (vdWDFT) calculations using different exchange-correlation models – vdW_DF2, optB86b, optB88, and optPBE. Our results show that the usage of different vdWDFT functionals does not significantly change the adsorption configuration or the profile of static charge rearrangement of the gas–chabazite complexes, in comparison with the results obtained using the PBE. The calculated values of adsorption enthalpy using different functionals are compared with our experimental results. We conclude that the incorporation of dispersion interaction is imperative to correctly predict the trend of adsorption enthalpy values, in terms of different gas molecules and Cs+ cation densities in the adsorbents, even though the absolute values of adsorption enthalpy are overestimated by approximate 10 kJ/mol compared with experiments.
High spatial range velocity measurements in a high Reynolds number turbulent boundary layer
Authors: de Silva C. M. , Gnanamanickam E. P. , Atkinson C. , Buchmann N. A. , Hutchins N. , Soria J. , Marusic I.
Published: February 2014

Here, we detail and analyse a multi-resolution particle image velocity measurement that resolves the wide range of scales prevalent in a zero pressure gradient turbulent boundary layer at high Reynolds numbers (up to Reτ ≈ 20 000). A unique configuration is utilised, where an array of eight high resolution cameras at two magnification levels are used simultaneously to obtain a large field of view, while still resolving the smaller scales prevalent in the flow. Additionally, a highly magnified field of view targeted at the near wall region is employed to capture the viscous sublayer and logarithmic region, with a spatial resolution of a few viscous length scales. Flow statistics from these measurements show good agreement with prior, well resolved hot-wire anemometry measurements. Analysis shows that the instantaneous wall shear stress can be reliably computed, which is historically known to be challenging in boundary layers. A statistical assessment of the wall shear stress shows good agreement with existing correlations, prior experimental and direct numerical simulation data, extending this view to much higher Reynolds numbers. Furthermore, conditional analysis using multiple magnification levels is detailed, to study near-wall events associated with high skin friction fluctuations and their associated overlaying structures in the log region. Results definitively show that the passage of very large-scale positive (or negative) velocity fluctuations are associated with increased (or reduced) small-scale variance in wall shear stress fluctuations.
Calibration of a 32 channel electron cyclotron emission radiometer on the HL-2A tokamak
Authors: Shi Z. B. , Jiang M. , Huang X. L. , Zhong W. L. , Chen W. , Che Y. L. , Liu Z. T. , Ding X. T. , Yang Q. W. , Duan X. R.
Published: February 2014

A novel 32-channel electron cyclotron emission radiometer has been designed and tested for the measurement of electron temperature profiles on the HL-2A tokamak. This system is based on the intermediate frequency filter detection technique, and has the features of wide working frequency range and high spatial resolution. Two relative calibration methods have been investigated: sweeping the toroidal magnetic field and hopping the output frequency of the local oscillator. Preliminary results show that both methods can ensure reasonable profiles.
Mobilization of a trapped non-wetting fluid from a three-dimensional porous medium
Authors: Datta Sujit S. , Ramakrishnan T. S. , Weitz David A.
Published: February 2014

We use confocal microscopy to directly visualize the formation and complex morphologies of trapped non-wetting fluid ganglia within a model 3D porous medium. The wetting fluid continues to flow around the ganglia after they form; this flow is characterized by a capillary number, Ca. We find that the ganglia configurations do not vary for small Ca; by contrast, as Ca is increased above a threshold value, the largest ganglia start to become mobilized and are ultimately removed from the medium. By combining our 3D visualization with measurements of the bulk transport, we show that this behavior can be quantitatively understood by balancing the viscous forces exerted on the ganglia with the pore-scale capillary forces that keep them trapped within the medium. Our work thus helps elucidate the fluid dynamics underlying the mobilization of a trapped non-wetting fluid from a 3D porous medium.
Finite element analyses of a linear-accelerator electron gun
Authors: Iqbal M. , Wasy A. , Islam G. U. , Zhou Z.
Published: February 2014

Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000 °C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.
Structural properties and large coercivity of bulk Mn3−xGa (0 ≤ x ≤ 1.15)
Authors: Wei J. Z. , Wu R. , Yang Y. B. , Chen X. G. , Xia Y. H. , Yang Y. C. , Wang C. S. , Yang J. B.
Published: February 2014

The tetragonal DO22 phase of the Mn3−xGa compounds, with x varying from 0 to 1.15, has been successfully synthesized by annealing the ingots with the cubic γ-phase. It is found that the lattice parameter a of the tetragonal cell remains almost constant, while the lattice parameter c increases significantly as x varies from 0 to 1.15. In the meantime, the magnetization of Mn3−xGa (at 7 T) increases dramatically with increasing x. A substitution model, which is different to the model with manganese vacancies, is proposed to explain these changes. According to this model, the increase of the lattice parameter c and the magnetization with x can be explained by an assumption that Mn atoms at 2b sites are preferentially substituted by larger and nonmagnetic Ga atoms. A coercivity which is higher than that of other bulk Mn3−xGa alloys ever reported is achieved. Coercivities as large as iHc = 21.4 kOe and 18.2 kOe are obtained for Mn3.0Ga at 5 K and 300 K, respectively.
Pseudo-“blindsight” under exposure to extremely low frequency electromagnetic fields
Authors: Nakagawa Hidenori , Masamune Ken , Kotani Makoto , Ueno Shoogo
Published: February 2014

To show distinct evidence of the pseudo-blindsight caused by electromagnetic stimulations in order to reveal a cure for lost visual functions, it is necessary to investigate the differences from the usual optic pathway in terms of the data processing route from the electromagnetically stimulated retina. For elucidating the scheme of phosphenes like blindsight, we designed a new stimulus coil system and measured the hemodynamic responses in the occipital regions during the stimulations, employing a functional brain-imaging technique. Results showed the possibility that the phosphene as a pseudo-blindsight induces activation of a parietal association area by an alternate route without the primary visual cortex and can be expected as therapy for lost visual functions.
Coherent frequency combs produced by self frequency modulation in quantum cascade lasers
Authors: Khurgin J. B. , Dikmelik Y. , Hugi A. , Faist J.
Published: February 2014

One salient characteristic of Quantum Cascade Laser (QCL) is its very short τ ∼ 1 ps gain recovery time that so far thwarted the attempts to achieve self-mode locking of the device into a train of single pulses. We show theoretically that four wave mixing, combined with the short gain recovery time causes QCL to operate in the self-frequency-modulated regime characterized by a constant power in time domain and stable coherent comb in the frequency domain. Coherent frequency comb may enable many potential applications of QCL's in sensing and measurement.
Effects of MnPt:C seed-layer on growing FePt:C granular films
Authors: Wen Wei-Chih , Wang Liang-Wei , Chang Kai-Chieh , Lai Chih-Huang
Published: February 2014

A particulate MnPt:C seed-layer is employed to induce the granular growth of FePt:C with a reduction of C inclusions and to suppress the formation of large islands at high substrate temperatures. We demonstrate the insertion of a MnPt:C seed-layer between MgO and FePt:C can effectively improve granular isolation and reduce granular size. FePt granules (around 7 nm) are formed with only 15% vol. C deposited at 350 °C and reveal an out-of-plane coercivity of 10 kOe. With the insertion of MnPt:C seed-layer, we may have more tuning parameters to manipulate microstructure of FePt:C granular films.
Enhanced piezoelectricity in YbGaN films near phase boundary
Authors: Yanagitani Takahiko , Suzuki Masashi
Published: February 2014

Weak piezoelectricity in GaN is a problem in bulk acoustic wave filters and heterostructure field-effect transistors. In this study, enhancement of piezoelectricity in c-axis direction by substituting Yb for Ga was experimentally demonstrated. Thickness extensional mode electromechanical coupling coefficient kt for the YbxGa1−xN films increases with the Yb concentration from x = 0 to 0.3. Yb0.30Ga0.70N film near the phase boundary exhibited a maximum kt of 3.1%, which is approximately 2.5 times larger than that for a pure GaN.
Correlation among the transient characteristics of doubly fed induction generators under grid fault
Authors: Ouyang Jinxin , Xiong Xiaofu , Qi Xiaoguang
Published: February 2014

Doubly fed induction generator (DFIG) under grid fault has increasingly gained attention among researchers for the better protection and control of power system. However, existing studies which focus on the single DFIG are incomplete, because other DFIGs can significantly affect the transient process of DFIG in the wind farm. Thus, this paper investigates the correlation among the transient characteristics of DFIGs when a three-phase fault occurs in power grids. A vector model of a DFIG is built with consideration for the excitation regulation. Transient processes of the DFIG when wind farm contains different numbers of DFIGs are mathematically deduced by dividing the fault process into two periods according to converter regulation. The analytic expressions indicate the relationship between the transient electrical variables of a DFIG and the number of DFIGs is proposed to acquire the varying pattern of the correlation. The correlation phenomenon is verified both through analysis and simulation, which provide positive implications for the operation of wind power integrated systems.
Impact of preparation condition of ZnO electron transport layer on performance of hybrid organic-inorganic light-emitting diodes
Authors: Huang Chun-Yuan , Yang Chih-Chiang , Yu Hsin-Chieh , Chen Ying-Chih
Published: February 2014

In this article, we have demonstrated the hybrid polymer light-emitting diodes (PLEDs) with a sol-gel derived or rf-sputtered ZnO electron transport layer (ETL). For the ZnO films prepared under different conditions, low annealing temperature (300 °C) leads to the film amorphous while the polycrystalline films is readily achieved by sputtering. Though the surface roughness can be improved by thermal annealing at 400 °C for sputtered films, the release of compressive stress after treatment has shrunk the optical band gap from 3.282 to 3.268 eV. As the ETL in PLEDs, the reduced band gap could increase potential barrier for electron injection and decrease the hole blocking capability. In our cases, luminance larger than 7000 cd/m2 can be obtained in device with pristine sputtered ZnO ETL. It is concluded that crystalline structure of ZnO films is important to facilitate the balance of carrier mobility to obtain high luminance and high efficiency devices.
Electronic structure and optical responses of nanocrystalline BiGaO3 films: A combination study of experiment and theory
Authors: Zhang J. Z. , Ding H. C. , Zhu J. J. , Li Y. W. , Hu Z. G. , Duan C. G. , Meng X. J. , Chu J. H.
Published: February 2014

High-quality nanocrystalline BiGaO3 (BGO) films have been prepared by a modified sol-gel method. X-ray diffraction analysis shows that the films are polycrystalline and exhibit an orthorhombic structure. The dispersion functions near infrared-ultraviolet region were extracted by fitting spectroscopic ellipsometry with the Tauc-Lorentz model. Moreover, first-principle calculations on dielectric functions and band gap were carried out, which are in good agreement with the experimental results. It was found that BGO belongs to an indirect band gap oxide with the fundamental gap of about 2.17 eV, which is suitable for ferroelectric based photovoltaic devices.
Ultrafast thermally induced magnetic switching in synthetic ferrimagnets
Authors: Evans Richard F. L. , Ostler Thomas A. , Chantrell Roy W. , Radu Ilie , Rasing Theo
Published: February 2014

Synthetic ferrimagnets are composite magnetic structures formed from two or more anti-ferromagnetically coupled magnetic sublattices with different magnetic moments. Here, we report on atomistic spin simulations of the laser-induced magnetization dynamics on such synthetic ferrimagnets and demonstrate that the application of ultrashort laser pulses leads to sub-picosecond magnetization dynamics and all-optical switching in a similar manner as in ferrimagnetic alloys. Moreover, we present the essential material properties for successful laser-induced switching, demonstrating the feasibility of using a synthetic ferrimagnet as a high density magnetic storage element without the need of a write field.
Luminescence properties of Si-capped β-FeSi2 nanodots epitaxially grown on Si(001) and (111) substrates
Authors: Amari Shogo , Nakamura Yoshiaki , Ichikawa Masakazu
Published: February 2014

We studied the luminescence properties of Si-capped β-FeSi2 nanodots (NDs) epitaxially grown on Si substrates by using photoluminescence (PL) and electroluminescence (EL) spectroscopies. Codepositing Fe and Si on ultrathin SiO2 films induced the self-assembly of epitaxial β-FeSi2 NDs. The PL spectra of the Si/β-FeSi2 NDs/Si structure depended on the crystal orientation of the Si substrate. These structures exhibited a broad PL peak near 0.8 eV on both Si(001) and (111) substrates. The PL intensity depended on the shape of the β-FeSi2 NDs. For the flat NDs, which exhibited higher PL intensity, we also recorded EL spectra. We explained the luminescence properties of these structures by the presence of nanostructured Si offering radiative electronic states in the Si cap layers, generated by nano-stressors for upper Si layer: the strain-relaxed β-FeSi2 NDs.
Pressure distribution based optimization of phase-coded acoustical vortices
Authors: Zheng Haixiang , Gao Lu , Ma Qingyu , Dai Yafei , Zhang Dong
Published: February 2014

Based on the acoustic radiation of point source, the physical mechanism of phase-coded acoustical vortices is investigated with formulae derivations of acoustic pressure and vibration velocity. Various factors that affect the optimization of acoustical vortices are analyzed. Numerical simulations of the axial, radial, and circular pressure distributions are performed with different source numbers, frequencies, and axial distances. The results prove that the acoustic pressure of acoustical vortices is linearly proportional to the source number, and lower fluctuations of circular pressure distributions can be produced for more sources. With the increase of source frequency, the acoustic pressure of acoustical vortices increases accordingly with decreased vortex radius. Meanwhile, increased vortex radius with reduced acoustic pressure is also achieved for longer axial distance. With the 6-source experimental system, circular and radial pressure distributions at various frequencies and axial distances have been measured, which have good agreements with the results of numerical simulations. The favorable results of acoustic pressure distributions provide theoretical basis for further studies of acoustical vortices.