bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum speed limits in open systems: Non-Markovian dynamics without rotating-wave approximation
Authors: Sun Zhe , Liu Jing , Ma Jian , Wang Xiaoguang
Published: February 2015

We derive an easily computable quantum speed limit (QSL) time bound for open systems whose initial states can be chosen as either pure or mixed states. Moreover, this QSL time is applicable to either Markovian or non-Markovian dynamics. By using of a hierarchy equation method, we numerically study the QSL time bound in a qubit system interacting with a single broadened cavity mode without rotating-wave, Born and Markovian approximation. By comparing with rotating-wave approximation (RWA) results, we show that the counter-rotating terms are helpful to increase evolution speed. The problem of non-Markovianity is also considered. We find that for non-RWA cases, increasing system-bath coupling can not always enhance the non-Markovianity, which is qualitatively different from the results with RWA. When considering the relation between QSL and non-Markovianity, we find that for small broadening widths of the cavity mode, non-Markovianity can increase the evolution speed in either RWA or non-RWA cases, while, for larger broadening widths, it is not true for non-RWA cases.
Fermi Level shifting, Charge Transfer and Induced Magnetic Coupling at La0.7Ca0.3MnO3/LaNiO3 Interface
Authors: Ning Xingkun , Wang Zhanjie , Zhang Zhidong
Published: February 2015

A large magnetic coupling has been observed at the La0.7Ca0.3MnO3/LaNiO3 (LCMO/LNO) interface. The x-ray photoelectron spectroscopy (XPS) study results show that Fermi level continuously shifted across the LCMO/LNO interface in the interface region. In addition, the charge transfer between Mn and Ni ions of the type Mn3+ − Ni3+ → Mn4+ − Ni2+ with the oxygen vacancies are observed in the interface region. The intrinsic interfacial charge transfer can give rise to itinerant electrons, which results in a “shoulder feature” observed at the low binding energy in the Mn 2p core level spectra. Meanwhile, the orbital reconstruction can be mapped according to the Fermi level position and the charge transfer mode. It can be considered that the ferromagnetic interaction between Ni2+ and Mn4+ gives rise to magnetic regions that pin the ferromagnetic LCMO and cause magnetic coupling at the LCMO/LNO interface.
Analysis of fast channel blockage: revealing substrate binding in the microsecond range
Authors: Bodrenko Igor , Bajaj Harsha , Ruggerone Paolo , Winterhalter Mathias , Ceccarelli Matteo
Published: February 2015

The effect of filtering can be taken into account within the Markov state description to obtain the “real” power density spectrum in noise analysis of ion currents.
9,9′-Anthryl-anthroxyl radicals: strategic stabilization of highly reactive phenoxyl radicals
Authors: Aotake Tatsuya , Suzuki Mitsuharu , Aratani Naoki , Yuasa Junpei , Kuzuhara Daiki , Hayashi Hironobu , Nakano Haruyuki , Kawai Tsuyoshi , Wu Jishan , Yamada Hiroko
Published: February 2015

Stable anthroxyl radical with a half-life over 10 days in solution.
Supercharged green fluorescent proteins as bimodal reporter genes for CEST MRI and optical imaging
Authors: Bar-Shir Amnon , Liang Yajie , Chan Kannie W. Y. , Gilad Assaf A. , Bulte Jeff W. M.
Published: February 2015

Superpositively charged GFP mutants demonstrate dramatically improved chemical exchange saturation transfer (CEST) MRI contrast compared to their wild type counterparts.
Self-assembled supramolecular cages containing ruthenium(ii) polypyridyl complexes
Authors: Yang Jiajia , Bhadbhade Mohan , Donald William A. , Iranmanesh Hasti , Moore Evan G. , Yan Hong , Beves Jonathon E.
Published: February 2015

Substitution-inert, redox- and photo-active ruthenium(ii) complexes based on 2,2′,6′,2′′-terpyridine ligands were self-assembled into discrete supramolecular cages via coordination to palladium(ii) centres and characterised by NMR, ESI-MS and X-ray crystallography.
Photosensitizer conjugated iron oxide nanoparticles for simultaneous in vitro magneto-fluorescent imaging guided photodynamic therapy
Authors: Nafiujjaman Md , Revuri Vishnu , Nurunnabi Md , Jae Cho Kwang , Lee Yong-kyu
Published: February 2015

A hybrid nanoparticle composed of a photodynamic agent pheophorbide A linked with Fe3O4 through heparin and APTES for MR imaging and phototherapy.
Localization and dynamics of amylose–lipophilic molecules inclusion complex formation in starch granules
Authors: Manca Marianna , Woortman Albert J. J. , Mura Andrea , Loos Katja , Loi Maria Antonietta
Published: February 2015

Inclusion complex formation between lipophilic dye molecules and amylose polymers in starch granules is investigated using laser spectroscopy and microscopy.
Features of chemical bonds based on the overlap polarizabilities: diatomic and solid-state systems with the frozen-density embedding approach
Authors: Moura Jr. Renaldo T. , Duarte Gian C. S. , da Silva Thiago E. , Malta Oscar L. , Longo Ricardo L.
Published: February 2015

The chemical bond overlap properties and their implications to covalency and several spectroscopies were obtained for NaY (Y = F, Cl, Br), MX (M = Ca, Mg and X = O, S, Se), Li, Na, and Mg diatomics and in the solid-state by a DFT embedding approach.
Non-doped solid-state white light-emitting electrochemical cells employing the microcavity effect
Authors: Lin Guan-Rung , Chen Hsiao-Fan , Shih Hsien-Chang , Hsu Jia-Hong , Chang Yi , Chiu Chih-Hung , Cheng Chia-Yu , Yeh Yun-Shiuan , Su Hai-Ching , Wong Ken-Tsung
Published: February 2015

White electroluminescence can be obtained in non-doped light-emitting electrochemical cells (LECs) by employing the microcavity effect.
Intermolecular hydroaminoalkylation of alkenes and dienes using a titanium mono(formamidinate) catalyst
Authors: Dörfler Jaika , Preuß Till , Brahms Christian , Scheuer Dennis , Doye Sven
Published: February 2015

A titanium mono(formamidinate) complex catalyzes the hydroaminoalkylation of unactivated, sterically demanding, disubstituted alkenes and styrenes with secondary amines.
Atomic scale enhancement of metal–support interactions between Pt and ZrC for highly stable electrocatalysts
Authors: Cheng Niancai , Norouzi Banis Mohammad , Liu Jian , Riese Adam , Mu Shichun , Li Ruying , Sham Tsun-Kong , Sun Xueliang
Published: February 2015

The metal–support interactions was enhanced by the atomic layer deposition through precisely controlling the metal–support interface at the atomic level.
Separation/recycling methods for homogeneous transition metal catalysts in continuous flow
Authors: Vural Gürsel Iris , Noël Timothy , Wang Qi , Hessel Volker
Published: February 2015

An overview on the separation/recycling methods for homogeneous transition metal catalysts in continuous flow on the lab- and industrial scale is provided.
Control of the interface between heterotypic cell populations reveals the mechanism of intercellular transfer of signaling proteins
Authors: Kshitiz Kshitiz , Afzal Junaid , Suhail Yasir , Ahn Eun Hyun , Goyal Ruchi , Hubbi Maimon E. , Hussaini Qasim , Ellison David D. , Goyal Jatinder , Nacev Benjamin , Kim Deok-Ho , Lee Justin Ho , Frankel Sam , Gray Kevin , Bankoti Rashmi , Chien Andy J. , Levchenko Andre
Published: February 2015

Direct intercellular transfer of cellular components is a recently described general mechanism of cell–cell communication.
The English (H6R) familial Alzheimer's disease mutation facilitates zinc-induced dimerization of the amyloid-β metal-binding domain
Authors: Kozin S. A. , Kulikova A. A. , Istrate A. N. , Tsvetkov P. O. , Zhokhov S. S. , Mezentsev Y. V. , Kechko O. I. , Ivanov A. S. , Polshakov V. I. , Makarov A. A.
Published: February 2015

The English familial mutation causes the exclusion of His6 from the zinc chelation pattern and triggers the assembly of Aβ1–16 dimers.
Tunable and enhanced simultaneous magnetism-luminescence bifunctionality assembled into a coaxial nanofiber
Authors: Bi Fei , Dong Xiangting , Wang Jinxian , Liu Guixia
Published: February 2015

CoFe2O4@YAG:7%Tb3+ coaxial nanofibers with tuned luminescence intensity, color and saturation magnetization have been successfully fabricated via electrospinning technology.
Design and solid phase synthesis of new DOTA conjugated (+)-biotin dimers planned to develop molecular weight-tuned avidin oligomers
Authors: Pratesi Alessandro , Ginanneschi Mauro , Melani Fabrizio , Chinol Marco , Carollo Angela , Paganelli Giovanni , Lumini Marco , Bartoli Mattia , Frediani Marco , Rosi Luca , Petrucci Giorgio , Messori Luigi , Papini Anna Maria
Published: February 2015

Oligomeric architectures of avidin generated by a new class of bis-biotins.
Paclitaxel-loaded cholesterol-conjugated polyoxyethylene sorbitol oleate polymeric micelles for glioblastoma therapy across the blood–brain barrier
Authors: Li Chang , Li Shasha , Tu Taojian , Qi Xingxing , Xiong Yerong , Du Shuang , Shen Yan , Tu Jiasheng , Sun Chunmeng
Published: February 2015

Design of a brain-targeted drug delivery system consisting of cholesterol-polyoxyethylene sorbitol oleate (CPSO) diblock copolymers for glioblastoma therapy.
Hierarchically structured porous organic polymer microspheres with built-in Fe3O4 supraparticles: construction of dual-level pores for Pt-catalyzed enantioselective hydrogenation
Authors: Xu Shuai , Weng Zhihuan , Tan Jing , Guo Jia , Wang Changchun
Published: February 2015

A magnetic responsive, dual-pore-distributed, and hyper-crosslinking polymer composite microsphere is synthesized and inlaid with platinum nanoparticles for enantioselective catalytic hydrogenation.
Synthesis of fluorinated monomer and formation of hydrophobic surface therefrom
Authors: Han Dongxiao , Zhu Liqun , Chen Yichi , Li Weiping , Wang Xianming , Ning Liang
Published: February 2015

A novel route was developed to prepare fluorine-containing copolymers with long side chains of perfluoroalkyl group.
Self-powered sensor for Hg2+detection based on hollow-channel paper analytical devices
Authors: Zhang Lina , Wang Yanhu , Ma Chao , Wang Panpan , Yan Mei
Published: February 2015

In this work, a novel and effective self-powered device was introduced in a microfluidic paper-based analytical device (μ-PAD) with hollow channels to transport fluids for mercury ion (Hg2+) detection.
Surfactant-assisted electroless deposition of silver nanoparticles on Ge crystal for ultra-sensitive detection by surface-enhanced infrared absorption spectroscopy
Authors: Rao Gadupudi Purna Chandra , Tharmaraj Vairaperumal , Yang Jyisy
Published: February 2015

Fabrication of highly sensitive substrates for SEIRA measurements via assistance of surfactant to electrolessly deposit silver nanoparticles on Ge crystal.
Efficient synthesis of highly soluble and functionalized fulleropyrrolidines
Authors: Parveen Abdulrazack , Sughanya Venkatesan , Nagarajan Samuthira
Published: February 2015

New functionalized fulleropyrrolidines with high emission and absorption.
Effect of apple, baobab, red-chicory, and pear extracts on cellular energy expenditure and morphology of a Caco-2 cells using transepithelial electrical resistance (TEER) and scanning electron microscopy (SEM)
Authors: Finotti Enrico , Gezzi Riccardo , Nobili Fabio , Garaguso Ivana , Friedman Mendel
Published: February 2015

The present study investigated the effects of four food extracts on the Caco-2 intestinal cell line using a new transepithelial electrical resistance method (TEER) concurrent with electron microscopy (SEM).
Reductant- and stabilizer-free synthesis of graphene–polyaniline aqueous colloids for potential waterborne conductive coating application
Authors: Zhang Xinxing , Zhou Zehang , Lu Canhui
Published: February 2015

The chemical reduction of graphene oxide (GO) typically involves highly toxic reducing agents which could contaminate and have a negative effect on the conductivity of the resulting materials.
High temperature stationary phase of polysiloxane containing N,N′-bis(diphenylsilyl) tetramethylcyclodisilazane for gas chromatography
Authors: Zhao Pengchao , Niu Yanyan , Yu Miao , Niu Na , Wang Huan , He Xinxin , Wu Bo
Published: February 2015

A polysiloxane copolymer (P(BPTMC)-alt-ODMS) containing N,N′-bis(diphenyl-silyl) tetramethylcyclodisilazane (BPTMC) was used as stationary phase in gas chromatography with high thermal stability.
Unique torsional cruciform π-architectures composed of donor and acceptor axes exhibiting mechanochromic and electrochromic properties
Authors: Sun Jingwei , Dai Yuyu , Ouyang Mi , Zhang Yujian , Zhan Lingling , Zhang Cheng
Published: February 2015

Cruciform D-A π-architecture is proposed as a platform for constructing bifunctional optoelectronic materials, in which the ICT from donor axis to acceptor axis can be finely tuned to regulate mechanochromic and electrochromic properties.
Effect of stereoisomerism of the alkyl chain on the gas sensing properties based on perylene dyes
Authors: Li Chunli , Zhai Haiyan , Liu Xiaotian , Zhang Weiguang , Huang Yongwei
Published: February 2015

It is shown that the sensing properties of perylenes can be modulated by stereoisomerism of alkyl chains in the bay regions.
Structures and charge transport properties of “selenosulflower” and its selenium analogue “selflower”: computer-aided design of high-performance ambipolar organic semiconductors
Authors: Yin Jun , Chaitanya Kadali , Ju Xue-Hai
Published: February 2015

The crystal structure of “selflower” C16Se8was predicted on the basis of the C16S4Se4crystal, and charge transport properties were investigated.
Prato and Bingel–Hirsch cycloaddition to heptagon-containing LaSc2N@Cs(hept)-C80: importance of pentalene units
Authors: Deng Qingming , Popov Alexey A.
Published: February 2015

In heptagon-containing LaSc2N@C80both thermodynamically controlled Prato addition and kinetically-controlled Bingel–Hirsch reaction are predicted to functionalize pentalene fragments.
High efficiency thermally activated delayed fluorescence based on 1,3,5-tris(4-(diphenylamino)phenyl)-2,4,6-tricyanobenzene
Authors: Taneda Masatsugu , Shizu Katsuyuki , Tanaka Hiroyuki , Adachi Chihaya
Published: February 2015

A trigonal donor–acceptor molecule of 1,3,5-tris(4-(diphenylamino)phenyl)-2,4,6-tricyanobenzene (3DPA3CN) was synthesized to exhibit efficient thermally activated delayed fluorescence.
Low-coordinate iridium NHC complexes derived from selective and reversible C–H bond activation of fluoroarenes
Authors: Hauser Simone A. , Prokes Ivan , Chaplin Adrian B.
Published: February 2015

A reactive iridium(i) fragment supported by conformationally rigid NHC ligands undergoes mild and reversible C–H bond activation of simple fluoroarenes.
Chirality in charge-transfer salts of BEDT-TTF of tris(oxalato)chromate(III)
Authors: Martin Lee , Akutsu Hiroki , Horton Peter N. , Hursthouse Michael B.
Published: February 2015

Crystallisation from chiral electrolyte (R)-(−)-carvone has produced three new chiral semiconducting salts of BEDT-TTF from racemic anion tris(oxalato)chromate(III).
Carboranes in the chemist's toolbox
Authors: Grimes Russell N.
Published: February 2015

A carborane-fullerene dyad for organic field-effect transistors illustrates one of the many diverse areas of technology in which the special properties of these polyhedral boron clusters are being exploited.
The Discovery Channel: microfluidics and microengineered systems in drug screening
Authors: Moraes Christopher
Published: February 2015

We highlight exciting findings and promising approaches in the recent literature in which researchers integrate advanced micro-engineering, design, and analytical strategies to improve the relevance and utility of high-throughput screening in the drug discovery pipeline.
C-terminal heat shock protein 90 modulators produce desirable oncogenic properties
Authors: Wang Y. , McAlpine S. R.
Published: February 2015

The cellular protection mechanism, the heat shock response, is only activated by classical heat shock 90 inhibitors (Hsp90) that “target” the N-terminus of the protein, but not by those that modulate the C-terminus.
Nanofibrous hydrogels self-assembled from naphthalene diimide (NDI)/amino acid conjugates
Authors: Hsu Ling-Huang , Hsu Shu-Min , Wu Fang-Yi , Liu Yu-Hao , Nelli Srinivasa Rao , Yeh Mei-Yu , Lin Hsin-Chieh
Published: February 2015

A new approach is proposed for the design of NDI-capped supramolecular hydrogels.
Aqueous Sonogashira coupling of aryl halides with 1-alkynes under mild conditions: use of surfactants in cross-coupling reactions
Authors: Roberts Gina M. , Lu Wenya , Woo L. Keith
Published: February 2015

Aqueous solutions of common and inexpensive surfactants (e.g.SDS and CTAB) are surveyed as an alternative to organic solvents in Sonogashira cross-coupling. Aryl-bromide substrates are best coupled under Cu-free conditions.
Au encapsulated into Al-MCM-41 mesoporous material: in situ synthesis and electronic structure
Authors: Fu Liangjie , Huo Chengli , He Xi , Yang Huaming
Published: February 2015

A facile one-step technique is proposed for the successful synthesis of highly ordered Au/Al-MCM-41. The charge state of Au3+ in the mesoporous framework was partially reduced due to the accompanying Al when clay was used as source.
Core–shell structured MgO@mesoporous silica spheres for enhanced adsorption of methylene blue and lead ions
Authors: Gui Chen-Xi , Li Qian-Jie , Lv Ling-Ling , Qu Jin , Wang Qian-Qian , Hao Shu-Meng , Yu Zhong-Zhen
Published: February 2015

Mesoporous silica coating not only serves as a stable shell to improve the mechanical stability of MgO core, but also enriches the adsorbates into the mesopores to get higher adsorption rate and capacity than MgO spheres.
A strategy for effective radioprotection by chitosan-based long-circulating nanocarriers
Authors: Zhou Yuan , Hua Song , Yu Jiahua , Dong Ping , Liu Fenju , Hua Daoben
Published: February 2015

Effective radioprotection is achieved by chitosan-based long-circulating nanocarriers with radioprotective agents. The stable encapsulation does not reduce its radioprotective capability and exhibits prolonged retention time, thereby showing more beneficial effects.
Magnetic nanomaterials with near-infrared pH-activatable fluorescence via iron-catalyzed AGET ATRP for tumor acidic microenvironment imaging
Authors: Liu Xiaodong , Chen Qian , Yang Guangbao , Zhang Lifen , Liu Zhuang , Cheng Zhenping , Zhu Xiulin
Published: February 2015

This work provides a fluorescent/magnetic iron oxide nanomaterials prototype to visualize the solid tumor in vivo by sensing the tumor acidic microenvironment, and a satisfactory tumor-to-normal tissue signal ratio (T/N ratio) and a prolonged time-window for 4T1 tumor visualization were observed in vivo.
Versatile nano-platforms for hybrid systems: expressing spin-transition behavior on nanoparticles
Authors: Paquirissamy A. , Ruyack A. R. , Mondal A. , Li Y. , Lescouëzec R. , Chanéac C. , Fleury B.
Published: February 2015

Hybrid spin-transition nanoparticles (HSTNs) have been prepared by the formation of octahedral Fe(ii) complexes at the surface of silica nanoparticles.
Blue emitting BCNO phosphors with high quantum yields
Authors: Zhang Xinghua , Lu Zunming , Liu Hui , Lin Jing , Xu Xuewen , Meng Fanbin , Zhao Jianling , Tang Chengchun
Published: February 2015

Blue emitting BCNO phosphors with very high quantum yields.
The Relationship Between EABR and Auditory Performance and Speech Intelligibility Outcomes in Pediatric Cochlear Implant Recipients
Authors: Wang Yu , Pan Tao , Deshpande Shruti Balvalli , Ma Furong
Published: February 2015

Purpose

The primary purpose of the present study was to investigate the relationship between postimplant electrically evoked auditory brainstem response (EABR) measures (wave V threshold, wave V latency, input–output functions) and auditory performance and speech intelligibility outcomes measured using parental rating scales, such as Categories of Auditory Performance (CAP; Archbold, Lutman, & Marshall, 1995) and the Speech Intelligibility Rating scale (SIR; Allen, Nikolopoulos, Dyar, & O'Donoghue, 2001), respectively. The secondary purpose was to evaluate the relationship between age at implantation and ratings on the CAP and SIR.

Method

Forty children with congenital sensorineural hearing loss participated. Preimplant parental ratings on the CAP and SIR were obtained, and all the children underwent cochlear implantation. Intracochlear EABRs were recorded postimplantation. Postimplant parental ratings on the CAP and SIR were obtained. The relationships between EABR parameters and auditory performance and speech intelligibility outcomes were studied. The effect of age at implantation on auditory performance and speech intelligibility outcomes was also investigated.

Results

A significant negative correlation was found between EABR wave V thresholds and SIR growth (
r
= −.415,
p
= .016). Children with better CAP growths tended to have lower wave V thresholds than those with poorer CAP growths. Age at implantation had an effect on the auditory performance as measured using the CAP.

Conclusions

The present study provides evidence for the relationship between wave V thresholds of the intracochlear EABR and auditory performance and speech intelligibility outcomes measured using parental rating scales in pediatric cochlear implant recipients. Data also indicate that early intervention has a positive impact on auditory performance outcomes.
Are Young Children With Cochlear Implants Sensitive to the Statistics of Words in the Ambient Spoken Language?
Authors: Guo Ling-Yu , McGregor Karla K. , Spencer Linda J.
Published: February 2015

Purpose

The purpose of this study was to determine whether children with cochlear implants (CIs) are sensitive to statistical characteristics of words in the ambient spoken language, whether that sensitivity changes in expected ways as their spoken lexicon grows, and whether that sensitivity varies with unilateral or bilateral implantation.

Method

We analyzed archival data collected from the parents of 36 children who received cochlear implantation (20 unilateral, 16 bilateral) before 24 months of age. The parents reported their children's word productions 12 months after implantation using the MacArthur Communicative Development Inventories: Words and Sentences (Fenson et al., 1993). We computed the number of words, out of 292 possible monosyllabic nouns, verbs, and adjectives, that each child was reported to say and calculated the average phonotactic probability, neighborhood density, and word frequency of the reported words.

Results

Spoken vocabulary size positively correlated with average phonotactic probability and negatively correlated with average neighborhood density, but only in children with bilateral CIs.

Conclusion

At 12 months postimplantation, children with bilateral CIs demonstrate sensitivity to statistical characteristics of words in the ambient spoken language akin to that reported for children with normal hearing during the early stages of lexical development. Children with unilateral CIs do not.
Affective Properties of Mothers' Speech to Infants With Hearing Impairment and Cochlear Implants
Authors: Kondaurova Maria V. , Bergeson Tonya R. , Xu Huiping , Kitamura Christine
Published: February 2015

Purpose

The affective properties of infant-directed speech influence the attention of infants with normal hearing to speech sounds. This study explored the affective quality of maternal speech to infants with hearing impairment (HI) during the 1st year after cochlear implantation as compared to speech to infants with normal hearing.

Method

Mothers of infants with HI and mothers of infants with normal hearing matched by age (NH-AM) or hearing experience (NH-EM) were recorded playing with their infants during 3 sessions over a 12-month period. Speech samples of 25 s were low-pass filtered, leaving intonation but not speech information intact. Sixty adults rated the stimuli along 5 scales: positive/negative affect and intention to express affection, to encourage attention, to comfort/soothe, and to direct behavior.

Results

Low-pass filtered speech to HI and NH-EM groups was rated as more positive, affective, and comforting compared with the such speech to the NH-AM group. Speech to infants with HI and with NH-AM was rated as more directive than speech to the NH-EM group. Mothers decreased affective qualities in speech to all infants but increased directive qualities in speech to infants with NH-EM over time.

Conclusions

Mothers fine-tune communicative intent in speech to their infant's developmental stage. They adjust affective qualities to infants' hearing experience rather than to chronological age but adjust directive qualities of speech to the chronological age of their infants.

Supplemental Material

https://doi.org/10.23641/asha.6170579
Single‐phase single‐stage multifunctional grid interfaced solar photo‐voltaic system under abnormal grid conditions
Authors: Jain Chinmay , Singh Bhim
Published: February 2015

This study deals with a single‐phase single‐stage multifunctional grid interfaced solar photo‐voltaic (SPV) system. The proposed SPV system is multifunctional as it has MPPT (maximum power point tracking) and it provides harmonics elimination, reactive power compensation and feeding SPV energy into the grid at unity power factor. The PV array is connected at the DC link of voltage source converter. The MPPT controller estimates reference PV voltage and a proportional integral controller is used to maintain the PV string voltage to the reference value. Feed‐forward terms are used for SPV array and load components for fast dynamic response. The performance of the system is analysed under abnormal grid (sudden sag and swell) conditions. Simulation studies are performed on MATLAB‐based platform. Simulation results are verified experimentally on a developed SPV system. Under steady‐state operating conditions, the total harmonic distortion of grid voltage and currents are found well under IEEE‐519 standard. A wide range of simulation and experimental results are presented to demonstrate all the features of the proposed SPV system.
Covariance differencing‐based matrix decomposition for coherent sources localisation in bi‐static multiple‐input–multiple‐output radar
Authors: Hong Sheng , Wan Xianrong , Cheng Feng , Ke Hengyu
Published: February 2015

In this study, a covariance differencing‐based matrix decomposition algorithm is proposed for locating coherent sources under spatially coloured noise in bi‐static multiple‐input–multiple‐output (MIMO) radar. The method contains three steps. First, the covariance differencing technique is employed to eliminate sensor noise, especially the spatially coloured noise. Second, a block Toeplitz or block Hankel matrix is constructed for decorrelation with the covariance differenced matrix. The forward‐only, backward‐only and combined forward‐backward block Toeplitz/Hankel matrix constructions are defined, respectively. Third, unitary estimation of signal parameters by rotational invariance techniques (ESPRIT) algorithm is applied to estimate directions‐of‐departure (DODs) and directions‐of‐arrival (DOAs) of sources. The proposed algorithm offers several advantages. First, it is more robust and provides better estimation performance than other methods. Then, the coloured noise problem is overcome in a simple and effective way. Further, the computational load is comparatively low. Simulation results demonstrate the validity of the proposed algorithm.
Sea clutter suppression and micromotion marine target detection via radon‐linear canonical ambiguity function
Authors: Chen Xiaolong , Wang Guoqing , Dong Yunlong , Guan Jian
Published: February 2015

The micro‐Doppler (m‐D) signature of a marine target is used for detection within sea clutter in this study. The marine target usually has translational and rotational motions, and the corresponding radar returns can be modelled as a quadratic frequency modulated signal over a period of time. To compensate the range walk and Doppler migration of the micromotion target simultaneously, a novel long‐time coherent integration detection algorithm, that is, Radon‐linear canonical ambiguity function (RLCAF), is proposed. It has been proved that the m‐D signal can be well matched and accumulated in the RLCAF domain using the long‐time instantaneous autocorrelation function and associated with the parameterisation of the linear canonical transform. Furthermore, to suppress sea clutter and improve signal‐to‐clutter ratio, the authors propose a RLCAF spectrum subtraction method using the different properties of RLCAF representations between the target and sea clutter. Finally, experiments with real radar dataset indicate that the proposed method can achieve better integration and detection performance of a marine target with micromotion in case of high sea state.
Long‐distance imaging with frequency modulation continuous wave and inverse synthetic aperture radar
Authors: Wen Chang , Zenghui Li , Kan Jin , Jian Yang , Chunmao Yeh
Published: February 2015

In a frequency modulation continuous wave and inverse synthetic aperture radar (FMCW–ISAR) system, imaging a target beyond the maximum unambiguous range causes the ambiguity in the range domain. This ambiguity phenomenon greatly reduces resolution and degrades image quality, and limits the application of long‐distance imaging of an FMCW–ISAR system. In this study, ambiguity correction method, based on mutual‐coherence processing, is proposed for long‐distance imaging in an FMCW–ISAR system. In the process, the singularity point of the beat signal caused by the ambiguity phenomenon is determined by the wavelet transform modulus maxima method. All‐pole models are used to fit the beat signal subbands of different Doppler frequencies, and then adjust the models until they optimally match. The simulation results validate the effectiveness of the proposed correction method. This study shows the promising prospect of long‐distance imaging using an FMCW–ISAR system.
Simultaneous analysis of the Ballik-Ramsay and Phillips systems of C2 and observation of forbidden transitions between singlet and triplet states
Authors: Chen Wang , Kawaguchi Kentarou , Bernath Peter F. , Tang Jian
Published: February 2015

6229 lines of the Ballik-Ramsay system (b3Σg−–a3Πu) and the Phillips system (A1Πu–X1Σg+) of C2 up to v = 8 and J = 76, which were taken from the literature or assigned in the present work, were analyzed simultaneously by least-squares fitting with 82 Dunham-like molecular parameters and spin-orbit interaction constants between the b3Σg− and X1Σg+ states with a standard deviation of 0.0037 cm−1 for the whole data set. As a result of the deperturbation analysis, the spin-orbit interaction constant AbX was determined as 6.333(7) cm−1 and the energy difference between the X1Σg+ and a3Πu states was determined as 720.008(2) cm−1 for the potential minima or 613.650(3) cm−1 for the v = 0 levels with Merer and Brown’s N2 Hamiltonian for 3Π states, which is about 3.3 cm−1 larger than the previously determined value. Due to this sizable change, a new energy-level crossing was found at J = 2 for v = 3 (F1) of b3Σg− state and v = 6 of X1Σg+ state, where the strong interaction causes a nearly complete mixing of the wave functions of the b3Σg− and X1Σg+ states and the forbidden transitions become observable. Using the predictions of our deperturbation analysis, we were able to identify 16 forbidden transitions between the singlet and triplet states at the predicted frequencies with the expected intensities, which verifies our value for the energy difference between the X1Σg+ and a3Πu states.
Gravity driven current during the coalescence of two sessile drops
Authors: Zhang Ying , Oberdick Samuel D. , Swanson Ellen R. , Anna Shelley L. , Garoff Stephen
Published: February 2015

Coalescence of liquid drops is critical in many phenomena such as emulsion stability, inkjet printing, and coating applications. For sessile drops on a solid surface, the coalescence process is more complicated than the coalescence of drops suspended in a fluid medium as a result of the coupling of the contact line motions to the fluid flow. In this paper, we use video microscopy to track the evolution of the interfaces and contact lines as well as the internal fluid motion within a merged sessile droplet. In this study, the fluids in the coalescing drops are miscible and have similar surface tensions and drop volumes but different viscosities and densities. Coalescence occurs in three stages. During the first stage, rapid healing of the bridge between the drops occurs just after they touch. In the second stage, slower rearrangement of the liquids occurs. We show that these intermediate rearrangements are driven by gravity even for density differences of the two fluids as small as 1%. For the systems examined, little to no mixing occurs during these first two stages. Finally, in the third stage, diffusion leads to mixing of the fluids. Dimensional analysis reveals the scaling of the intermediate flow behavior as a function of density difference and geometric dimensions of the merged drop; however, the scaling with viscosity is more complicated, motivating development of a lubrication analysis of the coalescence problem. Numerical calculations based on the lubrication analysis capture aspects of the experimental observations and reveal the governing forces and time scales of the coalescence process. The results reveal that internal fluid motions persist over much longer time scales than imaging of the external interface alone would reveal. Furthermore, nearly imperceptible motions of the external composite drop interface can lead to important deviations from the predominant gravity current scaling, where viscous resistance of the lighter fluid layer plays a significant role in the internal fluid motion.
Constant curvature surfaces of the supersymmetric ℂP
N−1 sigma model
Authors: Delisle L. , Hussin V. , Yurduşen İ. , Zakrzewski W. J.
Published: February 2015

Constant curvature surfaces are constructed from the finite action solutions of the supersymmetric ℂPN−1 sigma model. It is shown that there is a unique holomorphic solution which leads to constant curvature surfaces: the generalized Veronese curve. We give a general criterion to construct non-holomorphic solutions of the model. We extend our analysis to general supersymmetric Grassmannian models.
Thermoacoustic modeling and uncertainty analysis of two-dimensional conductive membranes
Authors: Bin Jonghoon , Oates William S. , Taira Kunihiko
Published: February 2015

A model for two-dimensional graphene-based thermoacoustic membranes is investigated analytically and numerically validated using Bayesian statistics in this study. The temperature and the pressure variables are first analytically determined in one-dimension by noticing that the magnitude of the pressure time derivative is small in the heat transfer equations and by taking advantage of the large disparity between the length scales. The one-dimensional findings are then extended to three-dimensions, where pressure fluctuation produced by the surface temperature variation is determined using an acoustic piston model. Through the one and three-dimensional model analysis, the dependence of acoustic pressure as a function of frequency is studied. The acoustic response with respect to the frequency shows different characteristics when assuming Dirichlet (temperature) or Neumann (heat flux) boundary conditions. The thermoacoustic model is validated with a graphene-on-paper loudspeaker using Bayesian statistical methods and a Delayed Rejection Adaptive Metropolis algorithm to identify model parameters and their uncertainty. The findings provide insights into the heat transport mechanisms associated with sound generation from thermally cycling thin conductive membranes at high frequencies.
Calculation of energy-barrier lowering by incoherent switching in spin-transfer torque magnetoresistive random-access memory
Authors: Munira Kamaram , Visscher P. B.
Published: February 2015

To make a useful spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device, it is necessary to be able to calculate switching rates, which determine the error rates of the device. In a single-macrospin model, one can use a Fokker-Planck equation to obtain a low-current thermally activated rate ∝exp(−Eeff/kBT). Here, the effective energy barrier Eeff scales with the single-macrospin energy barrier KV, where K is the effective anisotropy energy density and V the volume. A long-standing paradox in this field is that the actual energy barrier appears to be much smaller than this. It has been suggested that incoherent motions may lower the barrier, but this has proved difficult to quantify. In the present paper, we show that the coherent precession has a magnetostatic instability, which allows quantitative estimation of the energy barrier and may resolve the paradox.
Physical properties of V 1−xTixO2 (0 < x < 0.187) single crystals
Authors: Kong Tai , Masters Morgan W. , Bud’ko Sergey L. , Canfield Paul C.
Published: February 2015

Free standing, low strain, single crystals of pure and titanium doped VO2 were grown out of an excess of V 2O5 using high temperature solution growth techniques. At TMI ∼ 340 K, pure VO2 exhibits a clear first-order phase transition from a high-temperature paramagnetic tetragonal phase (R) to a low-temperature non-magnetic monoclinic phase (M1). With Ti doping, another monoclinic phase (M2) emerges between the R and M1 phases. The phase transition temperature between R and M2 increases with increasing Ti doping while the transition temperature between M2 and M1 decreases.
Effects of wall electrodes on Hall effect thruster plasma
Authors: Langendorf S. , Xu K. , Walker M.
Published: February 2015

This paper investigates the physical mechanisms that cause beneficial and detrimental performance effect observed to date in Hall effect thrusters with wall electrodes. It is determined that the wall electrode sheath can reduce ion losses to the wall if positioned near the anode (outside the dense region of the plasma) such that an ion-repelling sheath is able to form. The ability of the wall electrode to form an ion-repelling sheath is inversely proportional to the current drawn—if the wall electrode becomes the dominant sink for the thruster discharge current, increases in wall electrode bias result in increased local plasma potential rather than an ion-repelling sheath. A single-fluid electron flow model gives results that mimic the observed potential structures and the current-sharing fractions between the anode and wall electrodes, showing that potential gradients in the presheath and bulk plasma come at the expense of current draw to the wall electrodes. Secondary electron emission from the wall electrodes (or lack thereof) is inferred to have a larger effect if the electrodes are positioned near the exit plane than if positioned near the anode, due to the difference in energy deposition from the plasma.
Sensitivity of inertial confinement fusion hot spot properties to the deuterium-tritium fuel adiabat
Authors: Melvin J. , Lim H. , Rana V. , Cheng B. , Glimm J. , Sharp D. H. , Wilson D. C.
Published: February 2015

We determine the dependence of key Inertial Confinement Fusion (ICF) hot spot simulation properties on the deuterium-tritium fuel adiabat, here modified by addition of energy to the cold shell. Variation of this parameter reduces the simulation to experiment discrepancy in some, but not all, experimentally inferred quantities. Using simulations with radiation drives tuned to match experimental shots N120321 and N120405 from the National Ignition Campaign (NIC), we carry out sets of simulations with varying amounts of added entropy and examine the sensitivities of important experimental quantities. Neutron yields, burn widths, hot spot densities, and pressures follow a trend approaching their experimentally inferred quantities. Ion temperatures and areal densities are sensitive to the adiabat changes, but do not necessarily converge to their experimental quantities with the added entropy. This suggests that a modification to the simulation adiabat is one of, but not the only explanation of the observed simulation to experiment discrepancies. In addition, we use a theoretical model to predict 3D mix and observe a slight trend toward less mixing as the entropy is enhanced. Instantaneous quantities are assessed at the time of maximum neutron production, determined dynamically within each simulation. These trends contribute to ICF science, as an effort to understand the NIC simulation to experiment discrepancy, and in their relation to the high foot experiments, which features a higher adiabat in the experimental design and an improved neutron yield in the experimental results.
Magnetization reversal and coercivity of Fe3Se4 nanowire arrays
Authors: Li D. , Li S. J. , Zhou Y. T. , Bai Y. , Zhu Y. L. , Ren W. J. , Long G. , Zeng H. , Zhang Z. D.
Published: February 2015

The microstructure and magnetic properties of Fe3Se4 nanowire (NW) arrays in anodic aluminum oxide (AAO) porous membrane are studied. Cross-sectional SEM and plane-view TEM images show that the mean wire diameter (dw) and the center-to-center spacing (D) of Fe3Se4 nanowires are about 220 nm and 330 nm, respectively. The field-cooled magnetization dependent on the temperature indicates a Curie temperature around 334 K for the Fe3Se4 nanowires. The coercivities of Fe3Se4 nanowires at 10 K, obtained from the in-plane and out-of-plane hysteresis loops, are as high as 22.4 kOe and 23.3 kOe, which can be understood from the magnetocrystalline anisotropy and the magnetization reversal process.
Electrically tunable microwave properties in NiFeTa/[Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32(011) magnetoelectric heterostructures
Authors: Phuoc Nguyen N. , Ong C. K.
Published: February 2015

The studied magnetoelectric heterostructure consisting of a NiFeTa thin film grown onto a [Pb(Mg1/3Nb2/3)O3]0.68-[PbTiO3]0.32(011) (PMN-PT) substrate was prepared by using gradient-composition sputtering technique. A shorted micro-strip transmission-line perturbation method using a vector network analyzer was employed to study the electrical field modulation of microwave properties of the NiFeTa/PMN-PT heterostructure. It was found that the resonance frequency of the sample can be tuned from 1.72 GHz to 2.05 GHz when the applied electrical field is varied from −6 kV/cm to 6 kV/cm. Moreover, we experimentally observed a quasi-linear relationship between the resonance frequency and the electrical field in a wide range of electrical field from 0 kV/cm to 6 kV/cm in the heterostructure, which is suggested to be useful for applications. All the results are discussed taking into account the reverse magnetostrictive effect and the reverse piezoelectric effect.
Energetic ions in ITER plasmas
Authors: Pinches S. D. , Chapman I. T. , Lauber Ph. W. , Oliver H. J. C. , Sharapov S. E. , Shinohara K. , Tani K.
Published: February 2015

This paper discusses the behaviour and consequences of the expected populations of energetic ions in ITER plasmas. It begins with a careful analytic and numerical consideration of the stability of Alfvén Eigenmodes in the ITER 15 MA baseline scenario. The stability threshold is determined by balancing the energetic ion drive against the dominant damping mechanisms and it is found that only in the outer half of the plasma (r/a>0.5) can the fast ions overcome the thermal ion Landau damping. This is in spite of the reduced numbers of alpha-particles and beam ions in this region but means that any Alfvén Eigenmode-induced redistribution is not expected to influence the fusion burn process. The influence of energetic ions upon the main global MHD phenomena expected in ITER's primary operating scenarios, including sawteeth, neoclassical tearing modes and Resistive Wall Modes, is also reviewed. Fast ion losses due to the non-axisymmetric fields arising from the finite number of toroidal field coils, the inclusion of ferromagnetic inserts, the presence of test blanket modules containing ferromagnetic material, and the fields created by the Edge Localised Mode (ELM) control coils in ITER are discussed. The greatest losses and associated heat loads onto the plasma facing components arise due to the use of the ELM control coils and come from neutral beam ions that are ionised in the plasma edge.
Ultrathin graphene and graphene oxide layers as a diffusion barrier for advanced Cu metallization
Authors: Bong Jae Hoon , Yoon Seong Jun , Yoon Alexander , Hwang Wan Sik , Cho Byung Jin
Published: February 2015

We report on the diffusion barrier properties of chemical-vapor-deposition grown graphene, graphene oxide, and reduced graphene oxide (rGO) for copper metallization in integrated circuits. Single-layer graphene shows the best diffusion barrier performance among the three but it has poor integration compatibility, displaying weak adhesion and poor nucleation for Cu deposition on top of it. Within the allowable thermal budget in the back-end-of-line process, rGO in a range of 1 nm thickness shows excellent thermal stability with suitable integration compatibility at 400 °C for 30 min. The diffusion barrier property was verified through optical, physical, and chemical analyses. The use of an extremely thin rGO layer as a Cu barrier material is expected to provide an alternative route for further scaling of copper interconnect technology.
Determination of band diagram for a p-n junction between Mott insulator LaMnO3 and band insulator Nb:SrTiO3
Authors: Kitamura M. , Kobayashi M. , Sakai E. , Takahashi R. , Lippmaa M. , Horiba K. , Fujioka H. , Kumigashira H.
Published: February 2015

The authors report on the band diagram of epitaxial p-n junctions between the Mott insulator with “p-type carriers” LaMnO3 and the n-type semiconductor Nb-doped SrTiO3 (Nb:STO) using x-ray photoemission spectroscopy. By changing the donor concentration in Nb:STO from 0.1 at. % to 1.0 at. %, the value of the built-in potential for the Nb:STO side (Vbn) is reduced from 0.55 ± 0.05 eV to 0.25 ± 0.05 eV. The modulation of Vbn is well described in the framework of the conventional p-n junction model. These results suggest that the characteristics of perovskite oxide p-n junctions can be predicted and designed using the transport properties of the constituent oxides, irrespective of their strongly correlated electronic nature.
p- to n-type conductivity transition in 1.0 eV GaInNAs solar cells controlled by the V/III ratio
Authors: Langer Fabian , Perl Svenja , Höfling Sven , Kamp Martin
Published: February 2015

In this work, we report a p- to n-type conductivity transition of GaInNAs (1.0 eV bandgap) layers in p-i-n dilute nitride solar cells continuously controlled by the V/III ratio during growth. Near the transition region, we were able to produce GaInNAs layers with very low effective electrically active doping concentrations resulting in wide depleted areas. We obtained internal quantum efficiencies (IQEs) up to 85% at 0.2 eV above the bandgap. However, the high IQE comes along with an increased dark current density resulting in a decreased open circuit voltage of about 0.2 V. This indicates the formation of non-radiant defect centers related to the p-type to n-type transition. Rapid-thermal annealing of the solar cells on the one hand helps to anneal some of these defects but on the other hand increases the effective doping concentrations.
Stabilization of multiple resistance levels by current-sweep in SiOx-based resistive switching memory
Authors: Zhou Fei , Chang Yao-Feng , Fowler Burt , Byun Kwangsub , Lee Jack C.
Published: February 2015

Using current-sweep measurements, the set process in SiOx-based resistive random access memory (RRAM) has been found to consist of multiple resistance-reduction steps. Variation in set behaviors was observed and attributed to different defect distributions in the resistance switching region. Physical mechanism of electroforming process is discussed, which further explains the observed variation of defect distributions. A compliance current study confirms that the achievable memory states of SiOx RRAM are determined by its set behavior. This finding provides additional insight on achieving multi-bit memory storage with SiOx RRAM.