bluuebunny/crossref_metadata_2025 huggingface dataset:
Edge-mediated skyrmion chain and its collective dynamics in a confined geometry
Authors: Du Haifeng , Che Renchao , Kong Lingyao , Zhao Xuebing , Jin Chiming , Wang Chao , Yang Jiyong , Ning Wei , Li Runwei , Jin Changqing , Chen Xianhui , Zang Jiadong , Zhang Yuheng , Tian Mingliang
Published: October 2015

The emergence of a topologically nontrivial vortex-like magnetic structure, the magnetic skyrmion, has launched new concepts for memory devices. Extensive studies have theoretically demonstrated the ability to encode information bits by using a chain of skyrmions in one-dimensional nanostripes. Here, we report experimental observation of the skyrmion chain in FeGe nanostripes by using high-resolution Lorentz transmission electron microscopy. Under an applied magnetic field, we observe that the helical ground states with distorted edge spins evolve into individual skyrmions, which assemble in the form of a chain at low field and move collectively into the interior of the nanostripes at elevated fields. Such a skyrmion chain survives even when the width of the nanostripe is much larger than the size of single skyrmion. This discovery demonstrates a way of skyrmion formation through the edge effect, and might, in the long term, shed light on potential applications.
A novel siderophore system is essential for the growth of Pseudomonas aeruginosa in airway mucus
Authors: Gi Mia , Lee Kang-Mu , Kim Sang Cheol , Yoon Joo-Heon , Yoon Sang Sun , Choi Jae Young
Published: October 2015

Pseudomonas aeruginosa establishes airway infections in Cystic Fibrosis patients. Here, we investigate the molecular interactions between P. aeruginosa and airway mucus secretions (AMS) derived from the primary cultures of normal human tracheal epithelial (NHTE) cells. PAO1, a prototype strain of P. aeruginosa, was capable of proliferating during incubation with AMS, while all other tested bacterial species perished. A PAO1 mutant lacking PA4834 gene became susceptible to AMS treatment. The ΔPA4834 mutant was grown in AMS supplemented with 100 μM ferric iron, suggesting that the PA4834 gene product is involved in iron metabolism. Consistently, intracellular iron content was decreased in the mutant, but not in PAO1 after the AMS treatment. Importantly, a PAO1 mutant unable to produce both pyoverdine and pyochelin remained viable, suggesting that these two major siderophore molecules are dispensable for maintaining viability during incubation with AMS. The ΔPA4834 mutant was regrown in AMS amended with 100 μM nicotianamine, a phytosiderophore whose production is predicted to be mediated by the PA4836 gene. Infectivity of the ΔPA4834 mutant was also significantly compromised in vivo. Together, our results identify a genetic element encoding a novel iron acquisition system that plays a previously undiscovered role in P. aeruginosa airway infection.
Linking rapid erosion of the Mekong River delta to human activities
Authors: Anthony Edward J. , Brunier Guillaume , Besset Manon , Goichot Marc , Dussouillez Philippe , Nguyen Van Lap
Published: October 2015

As international concern for the survival of deltas grows, the Mekong River delta, the world’s third largest delta, densely populated, considered as Southeast Asia’s most important food basket and rich in biodiversity at the world scale, is also increasingly affected by human activities and exposed to subsidence and coastal erosion. Several dams have been constructed upstream of the delta and many more are now planned. We quantify from high-resolution SPOT 5 satellite images large-scale shoreline erosion and land loss between 2003 and 2012 that now affect over 50% of the once strongly advancing >600 km-long delta shoreline. Erosion, with no identified change in the river’s discharge and in wave and wind conditions over this recent period, is consistent with: (1) a reported significant decrease in coastal surface suspended sediment from the Mekong that may be linked to dam retention of its sediment, (2) large-scale commercial sand mining in the river and delta channels and (3) subsidence due to groundwater extraction. Shoreline erosion is already responsible for displacement of coastal populations. It is an additional hazard to the integrity of this Asian mega delta now considered particularly vulnerable to accelerated subsidence and sea-level rise and will be exacerbated by future hydropower dams.
Detection of novel CYP11A1-derived secosteroids in the human epidermis and serum and pig adrenal gland
Authors: Slominski Andrzej T. , Kim Tae-Kang , Li Wei , Postlethwaite Arnold , Tieu Elaine W. , Tang Edith K. Y. , Tuckey Robert C.
Published: October 2015

To investigate whether novel pathways of vitamin D3 (D3) and 7-dehydrocholesterol (7DHC) metabolism initiated by CYP11A1 and previously characterizedin vitro, occurin vivo, we analyzed samples of human serum and epidermis and pig adrenals for the presence of intermediates and products of these pathways. We extracted human epidermis from 13 individuals and sera from 13 individuals and analyzed them by LC/qTOF-MS alongside the corresponding standards. Pig adrenal glands were also analyzed for these steroids and secosteroids. Epidermal, serum and adrenal samples showed the presence of D3 hydroxy-derivatives corresponding to 20(OH)D3, 22(OH)D3, 25(OH)D3, 1,25(OH)2D3, 20,22(OH)2D3, 20,23(OH)2D3, 20,24(OH)2D3, 20,25(OH)2D3, 20,26(OH)2D3, 1,20,23(OH)3D3 and 17,20,23(OH)3D3, plus 1,20(OH)2D3 which was detectable only in the epidermis. Serum concentrations of 20(OH)D3 and 22(OH)D3 were only 30- and 15-fold lower than 25(OH)D3, respectively and at levels above those required for biological activity as measuredin vitro. We also detected 1,20,24(OH)3D3, 1,20,25(OH)3D3 and 1,20,26(OH)3D3 in the adrenals. Products of CYP11A1 action on 7DHC, namely 22(OH)7DHC, 20,22(OH)27DHC and 7-dehydropregnenolone were also detected in serum, epidermis and the adrenal. Thus, we have detected novel CYP11A1-derived secosteroids in the skin, serum and adrenal gland and based on their concentrations and biological activity suggest that they act as hormonesin vivo.
Correction: Corrigendum: Gap junctional protein Cx43 is involved in the communication between extracellular vesicles and mammalian cells
Authors: Soares Ana Rosa , Martins-Marques Tania , Ribeiro-Rodrigues Teresa , Ferreira Joao Vasco , Catarino Steve , Pinho Maria João , Zuzarte Monica , Anjo Sandra Isabel , Manadas Bruno , Sluijter Joost P.G. , Pereira Paulo , Girao Henrique
Published: October 2015

Intercellular communication is vital to ensure tissue and organism homeostasis and can occur directly, between neighbour cells via gap junctions (GJ), or indirectly, at longer distances, through extracellular vesicles, including exosomes. Exosomes, as intercellular carriers of messenger molecules, mediate the transfer of biological information between donor and acceptor cells. Although the biological effects of exosomes in target cells have been intensively studied, the mechanisms that govern exosomal uptake are not fully understood. Here, we show that Connexin 43 (Cx43), the most widely expressed GJ protein, is present in exosomes in the form of hexameric channels and, more importantly, that exosomal Cx43 is able to modulate the interaction and transfer of information between exosomes and acceptor cells. This study envisions a new paradigm where Cx43-containing channels mediate the release of exosomal content into cells, which constitutes a novel and unanticipated mechanism to modulate intercellular communication.
Storm deposition layer on the Fujian coast generated by Typhoon Saola (2012)
Authors: Li Yunhai , Li Haidong , Qiao Lei , Xu Yonghang , Yin Xijie , He Jianhua
Published: October 2015

Typhoons have a significant effect on the marine depositional environment and depositional process. In this paper, we used the high-resolution Chirp sonar sub-bottom profiler and radioisotope detection techniques to examine the storm-deposited layer formed in the seawater near the path of Typhoon Saola along the coast of Fujian, China. The thickness of the typhoon-deposited layer acquired using these two methods was 10–25 cm. The thickness, sediment grain size and δ13C values of the deposited sedimentary layer indicated that it was mainly matter from the re-suspension and redistribution of seafloor sediments. The particle sizes of the sediments in the storm-deposited layer became coarser, indicating that the fine-grade compositions spread over a wider range out of the coastal zone.
Origin of the structure-directing effect resulting in identical topological open-framework materials
Authors: Xin Liang , Sun Huai , Xu Ruren , Yan Wenfu
Published: October 2015

In the synthesis of zeolites and related crystalline materials with open-frameworks, a single structure is obtained in the presence of many different templates, known as the “one-structure/multiple-templates” phenomenon. However, the reasons behind this phenomenon have yet to be elucidated. By analyzing the possible starting point of crystallization in several “one-structure/multiple-templates” systems and applying the molecular dynamics simulation to such systems, we found that the template-framework binding free energy level or charge transfer (exchange) degree was the key to the structure-directing effect of a template. This discovery explains why the structure-directing effect of a template can be affected by many variables, such as the nature of the source materials, molar composition of the initial reaction mixture (recipe), mineralizers, type of solvent and heating temperature. In the synthesis of zeolites and related crystalline materials with open-frameworks, the template or organic additive played a topological structure-directing role instead of a structure-directing role.
Molecular Mechanisms for High Hydrostatic Pressure-Induced Wing Mutagenesis in Drosophila melanogaster
Authors: Wang Hua , Wang Kai , Xiao Guanjun , Ma Junfeng , Wang Bingying , Shen Sile , Fu Xueqi , Zou Guangtian , Zou Bo
Published: October 2015

Although High hydrostatic pressure (HHP) as an important physical and chemical tool has been increasingly applied to research of organism, the response mechanisms of organism to HHP have not been elucidated clearly thus far. To identify mutagenic mechanisms of HHP on organisms, here, we treated Drosophila melanogaster (D. melanogaster) eggs with HHP. Approximately 75% of the surviving flies showed significant morphological abnormalities from the egg to the adult stages compared with control flies (p < 0.05). Some eggs displayed abnormal chorionic appendages, some larvae were large and red and some adult flies showed wing abnormalities. Abnormal wing phenotypes of D. melanogaster induced by HHP were used to investigate the mutagenic mechanisms of HHP on organism. Thus 285 differentially expressed genes associated with wing mutations were identified using Affymetrix Drosophila Genome Array 2.0 and verified with RT-PCR. We also compared wing development-related central genes in the mutant flies with control flies using DNA sequencing to show two point mutations in the vestigial (vg) gene. This study revealed the mutagenic mechanisms of HHP-induced mutagenesis in D. melanogaster and provided a new model for the study of evolution on organisms.
Clostridium difficile: New Insights into the Evolution of the Pathogenicity Locus
Authors: Monot Marc , Eckert Catherine , Lemire Astrid , Hamiot Audrey , Dubois Thomas , Tessier Carine , Dumoulard Bruno , Hamel Benjamin , Petit Amandine , Lalande Valérie , Ma Laurence , Bouchier Christiane , Barbut Frédéric , Dupuy Bruno
Published: October 2015

The major virulence factors of Clostridium difficile are toxins A and B. These toxins are encoded by tcdA and tcdB genes, which form a pathogenicity locus (PaLoc) together with three additional genes that have been implicated in regulation (tcdR and tcdC) and secretion (tcdE). To date, the PaLoc has always been found in the same location and is replaced in non-toxigenic strains by a highly conserved 75/115 bp non-coding region. Here, we show new types of C. difficile pathogenicity loci through the genome analysis of three atypical clinical strains and describe for the first time a variant strain producing only toxin A (A+B−). Importantly, we found that the PaLoc integration sites of these three strains are located in the genome far from the usual single known PaLoc integration site. These findings allowed us to propose a new model of PaLoc evolution in which two “Mono-Toxin PaLoc” sites are merged to generate a single “Bi-Toxin PaLoc”.
Surface-enhanced resonance Raman scattering (SERRS) simulates PCR for sensitive DNA detection
Authors: Zhou Haibo , Lin Shenyu , Nie Yichu , Yang Danting , Wang Qiqin , Chen Weijia , Huang Ning , Jiang Zhengjin , Chen Shanze
Published: October 2015

This paper describes a novel double-stranded DNA detection method through resonance between SYBR Green I and DNA with the surface-enhanced resonance Raman scattering (SERRS) assay, which opens an avenue to the quantitative and reliable application of SERRS in DNA detection.
Selective choline biosensors based on choline oxidase co-immobilized into self-assembled monolayers on micro-chips at low potential
Authors: Rahman Mohammed M. , Asiri Abdullah M.
Published: October 2015

The fabricated choline-biosensor exhibits excellent specific and selective recognition for selected biological molecules coexisting with interferents in a buffer system at low potential.
Organic radicals for the enhancement of oxygen reduction reaction in Li–O2 batteries
Authors: Tesio A. Y. , Blasi D. , Olivares-Marín M. , Ratera I. , Tonti D. , Veciana J.
Published: October 2015

Carbon free-radicals are used as soluble redox mediators to catalyze ORR and enhance the discharge of Li–O2 batteries.
Raman/fluorescence dual-sensing and imaging of intracellular pH distribution
Authors: Cao Yue , Qian Ruo-Can , Li Da-Wei , Long Yi-Tao
Published: October 2015

A pH-sensitive probe has been designed based on DNA modified gold nanoparticles (AuNPs) for Raman/fluorescence dual-imaging of the intracellular pH distribution.
Direct C–H alkylation and indole formation of anilines with diazo compounds under rhodium catalysis
Authors: Mishra Neeraj Kumar , Choi Miji , Jo Hyeim , Oh Yongguk , Sharma Satyasheel , Han Sang Hoon , Jeong Taejoo , Han Sangil , Lee Seok-Yong , Kim In Su
Published: October 2015

The rhodium(iii)-catalyzed direct functionalization of aniline C–H bonds with α-diazo compounds for the preparation of ortho-alkylated anilines and highly substituted indoles is described.
Structural phases of adsorption for flexible polymers on nanocylinder surfaces
Authors: Gross Jonathan , Vogel Thomas , Bachmann Michael
Published: October 2015

Using Monte Carlo simulations, the thermodynamic behavior of a flexible elastic polymer model in the vicinity of an attractive nanocylinder is investigated. We systematically identify structural phases for varying nanocylinder radii and materials as a functions of temperature and construct hyperphase diagrams.
Direct versus hydrogen-assisted CO dissociation over stepped Ni and Ni3Fe surfaces: a computational investigation
Authors: Yang Kuiwei , Zhang Minhua , Yu Yingzhe
Published: October 2015

We explored direct and H-assisted CO dissociation on pure and alloyed Ni(211) and highlighted the importance of Fe locating in the step edge.
Femtosecond predissociation dynamics of the methyl radical from the 3pz Rydberg state
Authors: Balerdi Garikoitz , Woodhouse Joanne , Zanchet Alexander , de Nalda Rebeca , Senent María L. , García-Vela Alberto , Bañares Luis
Published: October 2015

Vibrationally state selected predissociation lifetimes for the methyl radical in the 3pz Rydberg state have been measured by femtosecond velocity map imaging and the results explained by ab initio theoretical calculations.
Solution based CVD of main group materials
Authors: Knapp Caroline E. , Carmalt Claire J.
Published: October 2015

Advances in the last decade in the field of AACVD of main group elements in semiconducting and TCO devices and photoelectrochemical and gas sensing materials are described.
Free-standing ultrathin CoMn2O4 nanosheets anchored on reduced graphene oxide for high-performance supercapacitors
Authors: Gao Guoxin , Lu Shiyao , Xiang Yang , Dong Bitao , Yan Wei , Ding Shujiang
Published: October 2015

Free-standing ultrathin CoMn2O4 nanosheets are successfully assembled on reduced graphene oxide via a simple trisodium citrate (TSC) assisted co-precipitation method with a post-annealing treatment.
Advances in nanoscale alloys and intermetallics: low temperature solution chemistry synthesis and application in catalysis
Authors: Jana Subhra
Published: October 2015

Advances made in the synthesis of size and shape-tunable nanoscale alloys and intermetallics using the low-temperature solution-phase synthesis approaches have been discussed in this perspective, keeping a focus on the utility of these nanomaterials in understanding the catalysis.
Heterometallic coordination polymers: syntheses, structures and heterogeneous catalytic applications
Authors: Bansal Deepak , Pandey Saurabh , Hundal Geeta , Gupta Rajeev
Published: October 2015

Heterometallic coordination polymers function as heterogeneous catalysts for various organic transformation reactions via preferential interaction with the substrates.
Magnetic nanoparticle based dispersive micro-solid-phase extraction for the determination of malachite green in water samples: optimized experimental design
Authors: Asfaram Arash , Ghaedi Mehrorang , Goudarzi Alireza , Soylak Mustafa , Mehdizadeh Langroodi Sanaz
Published: October 2015

This paper presents an extraction method based on dispersive-nanoparticle-solid phase microextraction for the preliminary preconcentration and subsequent spectrophotometric determination of trace amounts of malachite green.
Tetramethylguanidiniumchlorosulfonate ionic liquid (TMG IL): an efficient reusable catalyst for the synthesis of tetrahydro-1H-benzo[a]chromeno[2,3-c]phenazin-1-ones under solvent-free conditions and evaluation for their in vitro bioassay activity
Authors: Reddy Mudumala Veeranarayna , Valasani Koteswara Rao , Lim Kwon Taek , Jeong Yeon Tae
Published: October 2015

The scope and versatility of multi-component reaction has been demonstrated in this methodology are highly reactive, potent activity, ecologically cleaner route and reusability.
An internal charge transfer-dependent solvent effect in V-shaped azacyanines
Authors: Tasior Mariusz , Bald Ilko , Deperasińska Irena , Cywiński Piotr J. , Gryko Daniel T.
Published: October 2015

Intramolecular charge transfer dictates linear and non-linear optical properties of D–π-A+–π-D compounds.
Design, synthesis and DNA interactions of a chimera between a platinum complex and an IHF mimicking peptide
Authors: Rao Harita , Damian Mariana S. , Alshiekh Alak , Elmroth Sofi K. C. , Diederichsen Ulf
Published: October 2015

A platinum complex/peptide chimera shows specific DNA binding and covalent platination with potential as a novel chemotherapeutic.
Di(naphthalen-2-yl)-1,2-diphenylethene-based conjugated polymers: aggregation-enhanced emission and explosive detection
Authors: Gao Mengxia , Wu Yue , Chen Bin , He Bairong , Nie Han , Li Tingyan , Wu Fupeng , Zhou Wenjun , Zhou Jian , Zhao Zujin
Published: October 2015

Conjugated polymers with rotatable naphthalen-2-yl pendants show aggregation-enhanced emission characteristics and explosive detection potential.
On the properties and atmospheric implication of amine-hydrated clusters
Authors: Chen Jiao , Jiang Shuai , Miao Shou-Kui , Peng Xiu-Qiu , Ma Yan , Wang Chun-Yu , Zhang Miao-Miao , Liu Yi-Rong , Huang Wei
Published: October 2015

Amines have been recognized as important precursor species in the formation of new atmospheric particles.
Separation of toxic heavy metals from its aqueous solution using environmentally benign vegetable oil as liquid membrane
Authors: Bhatluri Kamal Kumar , Chakraborty Sushma , Manna Mriganka Sekhar , Ghoshal Aloke Kumar , Saha Prabirkumar
Published: October 2015

This paper presents an experimental investigation of simultaneous extraction and recovery of harmful heavy metals from the industrial wastewater through Bulk Liquid Membrane (BLM) based technology.
Electrodeposition of PtNi bimetallic nanoparticles on three-dimensional graphene for highly efficient methanol oxidation
Authors: Xiu Ruiping , Zhang Feifei , Wang Zonghua , Yang Min , Xia Jianfei , Gui Rijun , Xia Yanzhi
Published: October 2015

In the present work, platinum–nickel (PtNi) bimetallic nanoparticles with a uniform diameter of 40 nm were anchored onto a three-dimensional graphene (3DGN) by using the method of electrodeposition.
Facile synthesis of a polythiophene/TiO2 particle composite in aqueous medium and its adsorption performance for Pb(ii)
Authors: Chen Jie , Feng Jiangtao , Yan Wei
Published: October 2015

A polythiophene/TiO2 particle composite was synthesized by a facile and green method in aqueous medium to adsorb Pb2+ ions from aqueous solution, and both of synthesis and adsorption mechanism were proposed.
Exploring substrate promiscuity of chlorophenol hydroxylase against biphenyl derivatives
Authors: Ren Hejun , Li Qingchao , Fang Xuexun , Yu Dahai
Published: October 2015

The substrate promiscuity of 2,4-dichlorophenol hydroxylase against biphenyl derivatives was explored. This enzyme may be used as a potentially useful catalyst in the bioremediation of aromatic contaminants.
Self-assembly of adenovirus-templated platinum nanoshells and evaluation of their biocompatibilities
Authors: Xue Weili , Li Yanji , Zhou Jing , Wang Zi , Liu Yanping , Zhang Xuwu , Liu Zhiwei , Gao Faming , Gao Dawei
Published: October 2015

Highly biocompatible and monodisperse platinum nanoshells with diameters of ∼100 nm were fabricated using adenovirus as sacrificial template.
Synthesis, characterization and biological evaluation of N-(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)benzamides
Authors: Saeed Aamer , Ejaz Syeda Abida , Khurshid Asma , Hassan Sidra , al-Rashida Mariya , Latif Muhammad , Lecka Joanna , Sévigny Jean , Iqbal Jamshed
Published: October 2015

Comparison of active site residues of modelled h-GCAP with template h-PLAP.
Structural and electrochemical characterization of carbon ion beam irradiated reduced graphene oxide and its application in voltammetric determination of norepinephrine
Authors: Rosy Rosy , Singh Fouran , Goyal Rajendra N.
Published: October 2015

A high energy carbon ion beam irradiated sensor has been used for the sensitive determination of norepinephrine.
Accelerated aging test of hydrogenated nitrile butadiene rubber using the time–temperature–strain superposition principle
Authors: Zhu Zhongmeng , Jiang Chengkai , Cheng Qian , Zhang Jianwei , Guo Shaoyun , Xiong Ying , Fu Baoqiang , Yang Wenlong , Jiang Han
Published: October 2015

The long-term (~550 days) degradation of fracture strain of HNBR under the reference condition of 60 °C @ zero strain can be predicted using the time–temperature–strain superposition principle with the short-term (<10 days) test results.
Synthesis and characterization of Au–Fe alloy nanoparticles embedded in a silica matrix by atom beam sputtering
Authors: Pannu Compesh , Bala Manju , Khan S. A. , Srivastava S. K. , Kabiraj D. , Avasthi D. K.
Published: October 2015

AuFe alloy nanoparticles (NPs) embedded in a silica matrix were synthesized using an atom beam sputtering setup. Increasing the metal fraction in the thin films from 16 at% to 33 at% results in the formation of alloy NPs.
Dissimilatory nitrate reduction to ammonium as an electron sink during cathodic denitrification
Authors: Sander Elisa M. , Virdis Bernardino , Freguia Stefano
Published: October 2015

Nitrate reduction to ammonium is shown as a competitive pathway during cathodic denitrification at low potential, and is dependent on biofilm age and electron uptake capacity.
Epigenetic relevant chemical space: a chemoinformatic characterization of inhibitors of DNA methyltransferases
Authors: Gortari Eli Fernández-de , Medina-Franco José L.
Published: October 2015

The first comprehensive exploration of the epigenetic relevant chemical space is reported in this work with a special emphasis on inhibitors of DNA methyltransferases.
Synthesis and highly efficient supercapacitor behavior of a novel poly pyrrole/ceramic oxide nanocomposite film
Authors: Mohammad Shiri Hamid , Ehsani Ali , Shabani Shayeh Javad
Published: October 2015

This work introduces new nanocomposite materials (Ppy/YAG) for electrochemical redox capacitors with advantages including long life cycle and stability in an aqueous electrolyte to that of commonly used ruthenium based pervoskites.
Synthesis and characterisation of permethylindenyl zirconium complexes and their use in ethylene polymerisation
Authors: Buffet Jean-Charles , Arnold Thomas A. Q. , Turner Zoë R. , Angpanitcharoen Phakpoom , O'Hare Dermot
Published: October 2015

We report here the synthesis, characterisation and use in solution and slurry phase ethylene polymerisation of new group 4 permethylindenyl complexes.
Fast capture of methyl-dyes over hierarchical amino-Co0.3Ni0.7Fe2O4@SiO2 nanofibrous membranes
Authors: Zhu Zhigao , Li Guihua , Zeng Gaofeng , Chen Xinqing , Hu Deng , Zhang Yanfeng , Sun Yuhan
Published: October 2015

Flexible polydopamine–Co0.3Ni0.7Fe2O4@SiO2 NFMs with a hierarchical structure and strong magnetism were prepared by gelation, calcination and dopamine self-polymerization on electrospun SiO2 NFMs.
Conformally deposited NiO on a hierarchical carbon support for high-power and durable asymmetric supercapacitors
Authors: Guan Cao , Wang Yadong , Hu Yating , Liu Jilei , Ho Kuan Hung , Zhao Wei , Fan Zhanxi , Shen Zexiang , Zhang Hua , Wang John
Published: October 2015

Metal oxide based supercapacitors can provide much higher energy densities as compared with carbon-based ones.
Combined constraint for single image dehazing
Authors: He Renjie , Wang Zhiyong , Fan Yangyu , Feng David Dagan
Published: October 2015

Existing single image dehazing techniques have limitations on estimating accurate transmission maps for pixels which do not meet the assumption of the dark channel prior. A combined constraint is presented for single image dehazing by taking both geometric and natural characteristics of outdoor images into consideration. The combined constraint can be applied to various regularisation‐based optimisation frameworks. Both qualitative and quantitative comparisons with the state‐of‐the‐art dehazing approaches indicate the superiority of the proposed constraint.
Analogue multiplier using passive circuits and digital primitives with time‐mode signal representation
Authors: D'Angelo R. , Sonkusale S.
Published: October 2015

A new architecture to multiply signals with time‐mode representations is proposed. The exponential relationship between voltage and time in an RC circuit is utilised to implement the time‐mode logarithmic and exponential functions needed to realise a time‐mode analogue of the translinear principle. The addition of time‐mode variables is achieved through the natural progression of time equal to the sum of the input times. By combining these two techniques, an analogue multiplier can be implemented almost exclusively with passive circuits and digital primitives. Therefore, the circuit performance could benefit from CMOS scaling trends. The architecture is described, and simulation results are presented for an operational circuit implementing this approach.
Document image binarisation based on low‐rank modelling
Authors: Zheng Xin , Chen Yung‐Sheng
Published: October 2015

Segmentation from document images with a complex background is presented. The background component is estimated by low‐rank modelling. With the estimated background component, the original image is further transformed into a compensated image which is easily segmented with Otsu's thresholding algorithm to obtain a good binarisation result. Experiments on the Bickley diary and the DIBCO 2013 datasets validate the feasibility of the proposed method.
Low‐power digital latch circuit using magnetic logic device
Authors: Qin Tao , Cai Li , Yang Xiaokuo , Zhang Mingliang
Published: October 2015

The in‐plane magnetic logic device is a spin‐based technology which offers several advantages over charged‐based devices such as non‐volatility, ultra‐low power and greater integration density. A novel low‐power digital latch circuit is proposed by using various shaped nanomagnets. Specifically, a pipelined clocking layout is effectively constructed to ensure sequential and reliable operation. The simulation results show that the magnetic logic latch performs well. The proposed circuit is promising in building future ultra‐low power magnetic memories, and may inspire new applications (i.e. magnetic arithmetic circuits).
Multi‐wavelength channel 1.5 μm and 10 Gb/s EMBH DFB‐LD array module using SAG technology
Authors: Kwon O.K. , Oh S.H. , Kim K.S. , Lee C.W. , Leem Y.A. , Nam E.S.
Published: October 2015

A multi‐wavelength channel distributed feedback laser diode array (DFB‐LDA) for the low‐cost and low‐power consumption applications of WDM‐based datacentre networks is reported. The gain spectrum and lasing wavelength of each channel are controlled by using selective area growth and E‐beam lithography techniques, respectively. To reduce the operation current and parasitic capacitance of the proposed array, an etched mesa buried hetero‐structure (EMBH) is introduced. From this study, it was found that an eight‐channel 300 μm long λ/4‐shifted DFB‐LDA has a threshold current of 10 ± 1.5 mA and a side mode suppression ratio of over 50 dB at a current of 50 mA for all channels. A transmission test for this LDA showed a clear eye opening with a dynamic extinction ratio of over 4.5 dB at 10 Gb/s after a 2 km transmission.
Multi‐aircrafts tracking using spatial–temporal constraints‐based intra‐frame scale‐invariant feature transform feature matching
Authors: Xie Zehua , Wei Zhenzhong , Bai Chen
Published: October 2015

Although multi‐objects tracking has been improved significantly, tracking multiple aircrafts with nearly the same appearance remains a difficult task, especially when a significant pose changes and long‐time occlusions occur in the complex environment. In this study, the authors propose a new multi‐aircrafts tracker based on a structured support vector machine (SVM) and an intra‐frame scale‐invariant feature transform feature matching. The structured SVM‐based model adapts to the appearance change well, but confuses different aircrafts when occlusions between aircrafts occur. To handle occlusions, an intra‐frame matching method is applied to separate different aircrafts by matching points into different clusters. Moreover, to remove the mismatching caused by the cluttered background, the spatial–temporal constraint is applied to help improve the performance of the intra‐frame feature matching. As there is no dataset to evaluate a multi‐aircrafts tracker, they select eighteen challenging videos and manually annotate the ground truth, forming the first multi‐aircrafts tracking dataset. The experiments in the dataset demonstrate that the author's tracker outperforms the state‐of‐the‐art trackers in multi‐aircrafts tracking.
Planar, compact ultra‐wideband polarisation diversity antenna array
Authors: Khan Muhammad Saeed , Capobianco Antonio‐Daniele , Naqvi Aftab , Ijaz Bilal , Asif Sajid , Braaten Benjamin D.
Published: October 2015

A new compact multiple‐input multiple‐output (MIMO) ultra‐wideband (UWB) antenna array is presented. The antenna array initially consisted of two monopoles placed side by side at a distance of 4 mm. A strong mutual coupling was observed so the design was modified by rotating the second radiator at 90° at a distance of 1 mm. Wideband isolation is achieved by exploiting polarisation diversity of antenna elements. Simulation in HFSS and printed prototype results validate the high isolation, over 21 dB on the entire 2.5–12 GHz frequency range. A prototype was fabricated on a low loss substrate of Rogers TMM4 measuring 23 × 39.8 mm2. To evaluate the diversity performance, the envelope correlation coefficient was calculated resulting below −20 dB, thus ensuring good diversity performance. The compactness of the proposed UWB‐MIMO design is finally compared against alternative solutions already present in the literature.
Nonlinear stability research on the hydraulic system of double-side rolling shear
Authors: Wang Jun , Huang Qingxue , An Gaocheng , Qi Qisong , Sun Binyu
Published: October 2015

This paper researches the stability of the nonlinear system taking the hydraulic system of double-side rolling shear as an example. The hydraulic system of double-side rolling shear uses unsymmetrical electro-hydraulic proportional servo valve to control the cylinder with single piston rod, which can make best use of the space and reduce reversing shock. It is a typical nonlinear structure. The nonlinear state-space equations of the unsymmetrical valve controlling cylinder system are built first, and the second Lyapunov method is used to evaluate its stability. Second, the software AMEsim is applied to simulate the nonlinear system, and the results indicate that the system is stable. At last, the experimental results show that the system unsymmetrical valve controlling the cylinder with single piston rod is stable and conforms to what is deduced by theoretical analysis and simulation. The construction and application of Lyapunov function not only provide the theoretical basis for using of unsymmetrical valve controlling cylinder with single piston rod but also develop a new thought for nonlinear stability evaluation.
Nonadiabatic vibrational dynamics in the HCO2−⋅H2O complex
Authors: Hamm Peter , Stock Gerhard
Published: October 2015

Based on extensive ab initio calculations and the time-propagation of the nuclear Schrödinger equation, we study the vibrational relaxation dynamics and resulting spectral signatures of the OH stretch vibration of a hydrogen-bonded complex, HCO2−⋅H2O. Despite their smallness, it has been shown experimentally by Johnson and coworkers that the gas-phase infrared spectra of these types of complexes exhibit much of the complexity commonly observed for hydrogen-bonded systems. That is, the OH stretch band exhibits a significant red shift together with an extreme broadening and a pronounced substructure, which reflects its very strong anharmonicity. Employing an adiabatic separation of time scales between the three intramolecular high-frequency modes of the water molecule and the three most important intermolecular low-frequency modes of the complex, we calculate potential energy surfaces (PESs) of the ground and the first excited states of the high-frequency modes and identify a vibrational conical intersection between the PESs of the OH stretch fundamental and the HOH bend overtone. By performing a time-dependent propagation of the resulting system, we show that the conical intersection affects a coherent population transfer between the two states, the first step of which being ultrafast (60 fs) and irreversible. The subsequent relaxation of vibrational energy into the HOH bend and ground state occurs incoherently but also quite fast (1 ps), although the corresponding PESs are well separated in energy. Owing to the smaller effective mass difference between light and heavy degrees of freedom, the adiabatic ansatz is consequently less significant for vibrations than in the electronic case. Based on the model, we consider several approximations to calculate the measured Ar-tag action spectrum of HCO2−⋅H2O and achieve semiquantitative agreement with the experiment.
Effect of chain stiffness on the competition between crystallization and glass-formation in model unentangled polymers
Authors: Nguyen Hong T. , Smith Tyler B. , Hoy Robert S. , Karayiannis Nikos Ch.
Published: October 2015

We map out the solid-state morphologies formed by model soft-pearl-necklace polymers as a function of chain stiffness, spanning the range from fully flexible to rodlike chains. The ratio of Kuhn length to bead diameter (lK/r0) increases monotonically with increasing bending stiffness kb and yields a one-parameter model that relates chain shape to bulk morphology. In the flexible limit, monomers occupy the sites of close-packed crystallites while chains retain random-walk-like order. In the rodlike limit, nematic chain ordering typical of lamellar precursors coexists with close-packing. At intermediate values of bending stiffness, the competition between random-walk-like and nematic chain ordering produces glass-formation; the range of kb over which this occurs increases with the thermal cooling rate |Ṫ| implemented in our molecular dynamics simulations. Finally, values of kb between the glass-forming and rodlike ranges produce complex ordered phases such as close-packed spirals. Our results should provide a useful initial step in a coarse-grained modeling approach to systematically determining the effect of chain stiffness on the crystallization-vs-glass-formation competition in both synthetic and colloidal polymers.
A self-consistent phase-field approach to implicit solvation of charged molecules with Poisson–Boltzmann electrostatics
Authors: Sun Hui , Wen Jiayi , Zhao Yanxiang , Li Bo , McCammon J. Andrew
Published: October 2015

Dielectric boundary based implicit-solvent models provide efficient descriptions of coarse-grained effects, particularly the electrostatic effect, of aqueous solvent. Recent years have seen the initial success of a new such model, variational implicit-solvent model (VISM) [Dzubiella, Swanson, and McCammon Phys. Rev. Lett. 96, 087802 (2006) and J. Chem. Phys. 124, 084905 (2006)], in capturing multiple dry and wet hydration states, describing the subtle electrostatic effect in hydrophobic interactions, and providing qualitatively good estimates of solvation free energies. Here, we develop a phase-field VISM to the solvation of charged molecules in aqueous solvent to include more flexibility. In this approach, a stable equilibrium molecular system is described by a phase field that takes one constant value in the solute region and a different constant value in the solvent region, and smoothly changes its value on a thin transition layer representing a smeared solute-solvent interface or dielectric boundary. Such a phase field minimizes an effective solvation free-energy functional that consists of the solute-solvent interfacial energy, solute-solvent van der Waals interaction energy, and electrostatic free energy described by the Poisson–Boltzmann theory. We apply our model and methods to the solvation of single ions, two parallel plates, and protein complexes BphC and p53/MDM2 to demonstrate the capability and efficiency of our approach at different levels. With a diffuse dielectric boundary, our new approach can describe the dielectric asymmetry in the solute-solvent interfacial region. Our theory is developed based on rigorous mathematical studies and is also connected to the Lum–Chandler–Weeks theory (1999). We discuss these connections and possible extensions of our theory and methods.
Using Bayes formula to estimate rates of rare events in transition path sampling simulations
Authors: Terrier Pierre , Marinica Mihai-Cosmin , Athènes Manuel
Published: October 2015

Transition path sampling is a method for estimating the rates of rare events in molecular systems based on the gradual transformation of a path distribution containing a small fraction of reactive trajectories into a biased distribution in which these rare trajectories have become frequent. Then, a multistate reweighting scheme is implemented to postprocess data collected from the staged simulations. Herein, we show how Bayes formula allows to directly construct a biased sample containing an enhanced fraction of reactive trajectories and to concomitantly estimate the transition rate from this sample. The approach can remediate the convergence issues encountered in free energy perturbation or umbrella sampling simulations when the transformed distribution insufficiently overlaps with the reference distribution.
Synergistic effect of electromigration and Joule heating on system level weak-link failure in 2.5D integrated circuits
Authors: Liu Yingxia , Li Menglu , Kim Dong Wook , Gu Sam , Tu K. N.
Published: October 2015

In system level electromigration test of 2.5D integrated circuits, a failure mode due to synergistic effect of Joule heating and electromigration has been found. In the test circuit, there are three levels of solder joints, two Si chips (one of them has through-Si-via), and one polymer substrate. In addition, there are two redistribution layers; one between every two levels of solder joints. We found that the redistribution layer between the flip chip solder joints and micro-bumps is the weak-link and failed easily by burn-out in electromigration test. The failure is time-dependent with sudden resistance increase. Preliminary simulation results show that Joule heating has a positive feedback to electromigration in the redistribution layer and caused the thermal run-away failure. Joule heating becomes an important reliability issue in the future scaling of semiconductor devices.
Study and characterization of the irreversible transformation of electrically stressed planar Ti/TiOx/Ti junctions
Authors: Guillaume N. , Puyoo E. , Le Berre M. , Albertini D. , Baboux N. , Chevalier C. , Ayadi K. , Grégoire J. , Gautier B. , Calmon F.
Published: October 2015

We investigate the properties and characteristics of planar Ti/TiOx/Ti junctions, which consist of transverse TiOx lines drawn on Ti test patterns. Junctions are elaborated by means of local anodic oxidation using atomic force microscopy. An irreversible morphological transformation occurring in a reproducible manner is observed when these planar junctions are electrically stressed under ambient atmosphere. Structural and chemical analyses based on transmission electron microscopy techniques reveal the extension of the initial amorphous TiOx into a crystalline rutile phase. This irreversible transformation is proven to vanish completely if the electrical stress occurs under vacuum atmosphere. Finally, we carry out temperature dependent electrical measurements in order to elucidate their conduction mechanism: Schottky emission above an ultra-low potential barrier is assumed to dominate under vacuum atmosphere whereas ionic conduction seems to prevail in air.
Hybrid ZnO nanowire/a-Si:H thin-film radial junction solar cells using nanoparticle front contacts
Authors: Pathirane M. , Iheanacho B. , Tamang A. , Lee C.-H. , Lujan R. , Knipp D. , Wong W. S.
Published: October 2015

Hydrothermally synthesized disordered ZnO nanowires were conformally coated with a-Si:H thin-films to fabricate three dimensional hybrid nanowire/thin-film structures. The a-Si:H layer formed a radial junction p-i-n diode solar cell around the ZnO nanowire. The cylindrical hybrid solar cells enhanced light scattering throughout the UV-visible-NIR spectrum (300 nm–800 nm) resulting in a 22% increase in short-circuit current density compared to the reference planar p-i-n device. A fill factor of 69% and a total power conversion efficiency of 6.5% were achieved with the hybrid nanowire solar cells using a spin-on indium tin oxide nanoparticle suspension as the top contact.
Coherent optical transients observed in rubidium atomic line filtered Doppler velocimetry experiments
Authors: Fajardo Mario E. , Molek Christopher D. , Vesely Annamaria L.
Published: October 2015

We report the first successful results from our novel Rubidium Atomic Line Filtered (RALF) Doppler velocimetry apparatus, along with unanticipated oscillatory signals due to coherent optical transients generated within pure Rb vapor cells. RALF is a high-velocity and high-acceleration extension of the well-known Doppler Global Velocimetry (DGV) technique for constructing multi-dimensional flow velocity vector maps in aerodynamics experiments [H. Komine, U.S. Patent No. 4,919,536 (24 April 1990)]. RALF exploits the frequency dependence of pressure-broadened Rb atom optical absorptions in a heated Rb/N2 gas cell to encode the Doppler shift of reflected near-resonant (λ0 ≈ 780.24 nm) laser light onto the intensity transmitted by the cell. The present RALF apparatus combines fiber optic and free-space components and was built to determine suitable operating conditions and performance parameters for the Rb/N2 gas cells. It yields single-spot velocities of thin laser-driven-flyer test surfaces and incorporates a simultaneous Photonic Doppler Velocimetry (PDV) channel [Strand et al., Rev. Sci. Instrum. 77, 083108 (2006)] for validation of the RALF results, which we demonstrate here over the v = 0 to 1 km/s range. Both RALF and DGV presume the vapor cells to be simple Beer's Law optical absorbers, so we were quite surprised to observe oscillatory signals in experiments employing low pressure pure Rb vapor cells. We interpret these oscillations as interference between the Doppler shifted reflected light and the Free Induction Decay (FID) coherent optical transient produced within the pure Rb cells at the original laser frequency; this is confirmed by direct comparison of the PDV and FID signals. We attribute the different behaviors of the Rb/N2 vs. Rb gas cells to efficient dephasing of the atomic/optical coherences by Rb-N2 collisions. The minimum necessary N2 buffer gas density ≈0.3 amagat translates into a smallest useful velocity range of 0 to 2 km/s, which can readily be extended to cover the 0 to 10 km/s range, and beyond. The recognition that coherent optical transients can be produced within low pressure vapor cells during velocimetry experiments may offer new insights into some quantitative discrepancies reported in earlier DGV studies. Future plans include “line-RALF” experiments with streak camera detection, and two-dimensional surface velocity mapping using pulsed laser illumination and/or gated intensified CCD camera detection.
Correlating spin transport and electrode magnetization in a graphene spin valve: Simultaneous magnetic microscopy and non-local measurements
Authors: Berger Andrew J. , Page Michael R. , Wen Hua , McCreary Kathleen M. , Bhallamudi Vidya P. , Kawakami Roland K. , Chris Hammel P.
Published: October 2015

Using simultaneous magnetic force microscopy and transport measurements of a graphene spin valve, we correlate the non-local spin signal with the magnetization of the device electrodes. The imaged magnetization states corroborate the influence of each electrode within a one-dimensional spin transport model and provide evidence linking domain wall pinning to additional features in the transport signal.
Fully tuneable, Purcell-enhanced solid-state quantum emitters
Authors: Petruzzella M. , Xia T. , Pagliano F. , Birindelli S. , Midolo L. , Zobenica Z. , Li L. H. , Linfield E. H. , Fiore A.
Published: October 2015

We report the full energy control over a semiconductor cavity-emitter system, consisting of single Stark-tunable quantum dots embedded in mechanically reconfigurable photonic crystal membranes. A reversible wavelength tuning of the emitter over 7.5 nm as well as an 8.5 nm mode shift are realized on the same device. Harnessing these two electrical tuning mechanisms, a single exciton transition is brought on resonance with the cavity mode at several wavelengths, demonstrating a ten-fold enhancement of its spontaneous emission. These results open the way to bring several cavity-enhanced emitters mutually into resonance and therefore represent a key step towards scalable quantum photonic circuits featuring multiple sources of indistinguishable single photons.