bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental demonstration on the deterministic quantum key distribution based on entangled photons
Authors: Chen Hua , Zhou Zhi-Yuan , Zangana Alaa Jabbar Jumaah , Yin Zhen-Qiang , Wu Juan , Han Yun-Guang , Wang Shuang , Li Hong-Wei , He De-Yong , Tawfeeq Shelan Khasro , Shi Bao-Sen , Guo Guang-Can , Chen Wei , Han Zheng-Fu
Published: February 2016

As an important resource, entanglement light source has been used in developing quantum information technologies, such as quantum key distribution(QKD). There are few experiments implementing entanglement-based deterministic QKD protocols since the security of existing protocols may be compromised in lossy channels. In this work, we report on a loss-tolerant deterministic QKD experiment which follows a modified “Ping-Pong”(PP) protocol. The experiment results demonstrate for the first time that a secure deterministic QKD session can be fulfilled in a channel with an optical loss of 9 dB, based on a telecom-band entangled photon source. This exhibits a conceivable prospect of ultilizing entanglement light source in real-life fiber-based quantum communications.
Reproduction, abundance and survivorship of two Alveopora spp. in the mesophotic reefs of Eilat, Red Sea
Authors: Eyal-Shaham Lee , Eyal Gal , Tamir Raz , Loya Yossi
Published: February 2016

Although the study of coral reproduction has advanced tremendously over the last few decades, a particular gap exists in our knowledge of the reproductive modes of corals from ‘mesophotic coral ecosystems’ (MCEs) found at 30–150 m depth. Here, we report for the first time on the reproductive patterns, living cover and survivorship under different light treatments of two scleractinian species from the MCEs of Eilat, Red-Sea: Alveopora allingi and A. ocellata. Both species are found exclusively within MCEs and are high in both abundance and relative cover. These species display a synchronous gametogenic cycles with consecutive oocyte growth and development. Peak of reproductive activity occurs in late summer (September-October), typified by accelerated oocyte growth, coinciding with the rise in seawater temperature. Estimates of fecundity show mean monthly maxima of 48.5 ± 26.3 and 23.5 ± 11.8 (Mean ± SE) oocytes per cm2 for A. allingi and A. ocellata respectively, prior to spawning. A comparison of light and temperature regimes in the shallow vs. MCE environments is presented and the response of these species to changes in these parameters is discussed. A call encouraging the much-needed studies on the sexuality and reproductive modes of MCE coral species is expressed.
Multiple functions of Na/K-ATPase in dopamine-induced salivation of the Blacklegged tick, Ixodes scapularis
Authors: Kim Donghun , Urban Joshua , Boyle Daniel L. , Park Yoonseong
Published: February 2016

Control of salivary secretion in ticks involves autocrine dopamine activating two dopamine receptors: D1 and Invertebrate-specific D1-like dopamine receptors. In this study, we investigated Na/K-ATPase as an important component of the secretory process. Immunoreactivity for Na/K-ATPase revealed basal infolding of lamellate cells in type-I, abluminal interstitial (epithelial) cells in type-II and labyrinth-like infolding structures opening towards the lumen in type-III acini. Ouabain (10 μmol l−1), a specific inhibitor of Na/K-ATPase, abolished dopamine-induced salivary secretion by suppressing fluid transport in type III acini. At 1 μmol l−1, ouabain, the secreted saliva was hyperosmotic. This suggests that ouabain also inhibits an ion resorptive function of Na/K-ATPase in the type I acini. Dopamine/ouabain were not involved in activation of protein secretion, while dopamine-induced saliva contained constitutively basal level of protein. We hypothesize that the dopamine-dependent primary saliva formation, mediated by Na/K-ATPase in type III and type II acini, is followed by a dopamine-independent resorptive function of Na/K-ATPase in type I acini located in the proximal end of the salivary duct.
SpyRing interrogation: analyzing how enzyme resilience can be achieved with phytase and distinct cyclization chemistries
Authors: Schoene Christopher , Bennett S. Paul , Howarth Mark
Published: February 2016

Enzymes catalyze reactions with exceptional selectivity and rate acceleration but are often limited by instability. Towards a generic route to thermo-resilience, we established the SpyRing approach, cyclizing enzymes by sandwiching between SpyTag and SpyCatcher (peptide and protein partners which lock together via a spontaneous isopeptide bond). Here we first investigated the basis for this resilience, comparing alternative reactive peptide/protein pairs we engineered from Gram-positive bacteria. Both SnoopRing and PilinRing cyclization gave dramatic enzyme resilience, but SpyRing cyclization was the best. Differential scanning calorimetry for each ring showed that cyclization did not inhibit unfolding of the inserted β-lactamase. Cyclization conferred resilience even at 100 °C, where the cyclizing domains themselves were unfolded. Phytases hydrolyze phytic acid and improve dietary absorption of phosphate and essential metal ions, important for agriculture and with potential against human malnutrition. SpyRing phytase (PhyC) resisted aggregation and retained catalytic activity even following heating at 100 °C. In addition, SpyRing cyclization made it possible to purify phytase simply by heating the cell lysate, to drive aggregation of non-cyclized proteins. Cyclization via domains forming spontaneous isopeptide bonds is a general strategy to generate resilient enzymes and may extend the range of conditions for isolation and application of enzymes.
Highly efficient optogenetic cell ablation in C. elegans using membrane-targeted miniSOG
Authors: Xu Suhong , Chisholm Andrew D.
Published: February 2016

The genetically encoded photosensitizer miniSOG (mini Singlet Oxygen Generator) can be used to kill cells in C. elegans. miniSOG generates the reactive oxygen species (ROS) singlet oxygen after illumination with blue light. Illumination of neurons expressing miniSOG targeted to the outer mitochondrial membrane (mito-miniSOG) causes neuronal death. To enhance miniSOG’s efficiency as an ablation tool in multiple cell types we tested alternative targeting signals. We find that membrane targeted miniSOG allows highly efficient cell killing. When combined with a point mutation that increases miniSOG’s ROS generation, membrane targeted miniSOG can ablate neurons in less than one tenth the time of mito-miniSOG. We extend the miniSOG ablation technique to non-neuronal tissues, revealing an essential role for the epidermis in locomotion. These improvements expand the utility and throughput of optogenetic cell ablation in C. elegans.
Absence of N-terminal acetyltransferase diversification during evolution of eukaryotic organisms
Authors: Rathore Om Singh , Faustino Alexandra , Prudêncio Pedro , Van Damme Petra , Cox Cymon J. , Martinho Rui Gonçalo
Published: February 2016

Protein N-terminal acetylation is an ancient and ubiquitous co-translational modification catalyzed by a highly conserved family of N-terminal acetyltransferases (NATs). Prokaryotes have at least 3 NATs, whereas humans have six distinct but highly conserved NATs, suggesting an increase in regulatory complexity of this modification during eukaryotic evolution. Despite this and against our initial expectations, we determined that NAT diversification did not occur in the eukaryotes, as all six major human NATs were most likely present in the Last Eukaryotic Common Ancestor (LECA). Furthermore, we also observed that some NATs were actually secondarily lost during evolution of major eukaryotic lineages; therefore, the increased complexity of the higher eukaryotic proteome occurred without a concomitant diversification of NAT complexes.
Comparative assessment of methods for the fusion transcripts detection from RNA-Seq data
Authors: Kumar Shailesh , Vo Angie Duy , Qin Fujun , Li Hui
Published: February 2016

RNA-Seq made possible the global identification of fusion transcripts, i.e. “chimeric RNAs”. Even though various software packages have been developed to serve this purpose, they behave differently in different datasets provided by different developers. It is important for both users and developers to have an unbiased assessment of the performance of existing fusion detection tools. Toward this goal, we compared the performance of 12 well-known fusion detection software packages. We evaluated the sensitivity, false discovery rate, computing time and memory usage of these tools in four different datasets (positive, negative, mixed and test). We conclude that some tools are better than others in terms of sensitivity, positive prediction value, time consumption and memory usage. We also observed small overlaps of the fusions detected by different tools in the real dataset (test dataset). This could be due to false discoveries by various tools, but could also be due to the reason that none of the tools are inclusive. We have found that the performance of the tools depends on the quality, read length and number of reads of the RNA-Seq data. We recommend that users choose the proper tools for their purpose based on the properties of their RNA-Seq data.
Automatic graphene transfer system for improved material quality and efficiency
Authors: Boscá Alberto , Pedrós Jorge , Martínez Javier , Palacios Tomás , Calle Fernando
Published: February 2016

In most applications based on chemical vapor deposition (CVD) graphene, the transfer from the growth to the target substrate is a critical step for the final device performance. Manual procedures are time consuming and depend on handling skills, whereas existing automatic roll-to-roll methods work well for flexible substrates but tend to induce mechanical damage in rigid ones. A new system that automatically transfers CVD graphene to an arbitrary target substrate has been developed. The process is based on the all-fluidic manipulation of the graphene to avoid mechanical damage, strain and contamination and on the combination of capillary action and electrostatic repulsion between the graphene and its container to ensure a centered sample on top of the target substrate. The improved carrier mobility and yield of the automatically transferred graphene, as compared to that manually transferred, is demonstrated by the optical and electrical characterization of field-effect transistors fabricated on both materials. In particular, 70% higher mobility values, with a 30% decrease in the unintentional doping and a 10% strain reduction are achieved. The system has been developed for lab-scale transfer and proved to be scalable for industrial applications.
Simultaneous quantification of ion pairs in water via infrared attenuated total reflection spectroscopy
Authors: Rauh F. , Mizaikoff B.
Published: February 2016

In this study, ion pairs in aqueous solution were quantitatively and simultaneously determinedviainfrared attenuated total reflection (IR-ATR) spectroscopy in combination with multivariate data evaluation.
Effect of Ag/Au bilayer assisted etching on the strongly enhanced photoluminescence and visible light photocatalysis by Si nanowire arrays
Authors: Ghosh Ramesh , Imakita Kenji , Fujii Minoru , Giri P. K.
Published: February 2016

Array of Si nanowires fabricated by Au/Ag bilayer metal assisted etching exhibit strongly enhanced photoluminescence and efficient visible light photocatalysis and are primarily attributed to plasmon enhancement and Schottky barrier effect, respectively.
In search of non-conventional surface oxidic motifs of Cu on Au(111)
Authors: Lee Taehun , Lee Yonghyuk , Kang Kisung , Soon Aloysius
Published: February 2016

Using first-principles density-functional theory calculations, we systematically examine and analyze the detailed atomic structure and surface energetics of various oxidic motifs of Cu on Au(111), in search of new non-conventional, non-hexagonal surface oxidic structures in this system.
Heterogeneous basic catalysts for biodiesel production
Authors: de Lima Ana Lúcia , Ronconi Célia M. , Mota Claudio J. A.
Published: February 2016

We review the recent advances in the synthesis and utilization of heterogeneous basic catalysts for biodiesel production.
Bacterial lipid membranes as promising targets to fight antimicrobial resistance, molecular foundations and illustration through the renewal of aminoglycoside antibiotics and emergence of amphiphilic aminoglycosides
Authors: Mingeot-Leclercq Marie-Paule , Décout Jean-Luc
Published: February 2016

Membrane anionic lipids as attractive targets in the design of amphiphilic antibacterial drugs active against resistant bacteria: molecular foundations and examples.
Green synthesis and characterization of silver nanoparticles using Ferula latisecta leaf extract and their application as a catalyst for the safe and simple one-pot preparation of spirooxindoles in water
Authors: Rashid Zahra , Moadi Tara , Ghahremanzadeh Ramin
Published: February 2016

In this research, Ag nanoparticles were preparedviaplant extract and applied as an efficient catalyst in a three component reaction for the synthesis of spirooxindols.
Zn(ii) and Cu(ii) formamidine complexes: structural, kinetics and polymer tacticity studies in the ring-opening polymerization of ε-caprolactone and lactides
Authors: Akpan Ekemini D. , Ojwach Stephen O. , Omondi Bernard , Nyamori Vincent O.
Published: February 2016

The flexibility of ligands and their coordination chemistry with metal centers provided effective catalysts in the ring opening polymerization of cyclic esters.
SERS activity with tenfold detection limit optimization on a type of nanoporous AAO-based complex multilayer substrate
Authors: Sui Chaofan , Wang Kaige , Wang Shuang , Ren Junying , Bai Xiaohong , Bai Jintao
Published: February 2016

The flower-patterned nanostructure developed on AAO is capable of achieving greater enhancement and lower detectable limit than its template for SERS.
Doxorubicin loaded dual pH- and thermo-responsive magnetic nanocarrier for combined magnetic hyperthermia and targeted controlled drug delivery applications
Authors: Hervault Aziliz , Dunn Alexander E. , Lim May , Boyer Cyrille , Mott Derrick , Maenosono Shinya , Thanh Nguyen T. K.
Published: February 2016

Dual pH- and thermo-responsive magnetic nanocomposite as a platform for hyperthermia and controlled drug delivery in cancer treatment.
Nanopatterned polymer brushes by reactive writing
Authors: Nawroth Jonas F. , Neisser Claudia , Erbe Artur , Jordan Rainer
Published: February 2016

A self-assembled monolayer of perflourinated silanes is used to prepare nanopatterned polymer brushes and brush gradients by focused electron beam reactive writing (RW) and surface-initiated photopolymerization of vinyl monomers.
Nitropyrrole natural products: isolation, biosynthesis and total synthesis
Authors: Ding Xiao-Bo , Brimble Margaret A. , Furkert Daniel P.
Published: February 2016

A review of the isolation, biological activity, biosynthesis and chemical synthesis of nitropyrrole-containing natural products reported to date, including the pyrrolomycins, heronapyrroles and nitropyrrolins.
Analyzing the discrepancies in the activation energies of the backbiting and β-scission reactions in the radical polymerization of n-butyl acrylate
Authors: Hamzehlou S. , Ballard N. , Reyes Y. , Aguirre A. , Asua J. M. , Leiza J. R.
Published: February 2016

Activaton energies for backbiting and β-scission reactions for the polymerization of n-BA were determined by fitting experimental data to a mathematical model. The activation energy for backbiting was higher and that for β-scission lower than those accepted in the literature.
Comparison of hydrogen, halogen, and tetrel bonds in the complexes of HArF with YH3X (X = halogen, Y = C and Si)
Authors: Liu Mingxiu , Li Qingzhong , Li Wenzuo , Cheng Jianbo , McDowell Sean A. C.
Published: February 2016

Ab initio calculations were performed in order to find equilibrium structures with tetrel, hydrogen or halogen bonds on the potential energy surfaces of the complexes formed between HArF and YH3X (X = halogen, Y = C and Si).
Facile-synthesized ultrasmall CuS nanocrystals as drug nanocarriers for highly effective chemo–photothermal combination therapy of cancer
Authors: Wang Xin , Zhang Qian , Zou Li , Hu Huishan , Zhang Mengxin , Dai Jianwu
Published: February 2016

Combinational chemo–photothermal therapy has been considered as a promising strategy to enhance antitumor efficiency via synergistic effects for cancer treatments.
3-(5-(Benzylideneamino)thiazol-3-yl)-2H-chromen-2-ones: a new class of alkaline phosphatase and ecto-5′-nucleotidase inhibitors
Authors: Saeed Aamer , Ejaz Syeda Abida , Shehzad Muddasar , Hassan Sidra , al-Rashida Mariya , Lecka Joanna , Sévigny Jean , Iqbal Jamshed
Published: February 2016

Most plausible binding mode of 7h against h-TNAP.
One step synthesis of MOF–polymer composites
Authors: Calvez C. Le , Zouboulaki M. , Petit C. , Peeva L. , Shirshova N.
Published: February 2016

One step synthesis of metal organic framework–polymer composites is achieved via emulsion templating approach which allows simultaneous MOF crystallization and polymerization of the internal phase of the emulsion.
ZnO coated CoFe2O4 nanoparticles for multimodal bio-imaging
Authors: Venkatesha N. , Qurishi Yasrib , Atreya Hanudatta S. , Srivastava Chandan
Published: February 2016

The potential of CoFe2O4–ZnO core–shell nanoparticles for fluorescence optical imaging and as a contrast agent for magnetic resonance imaging (MRI) is demonstrated.
Antimicrobial and toxicological evaluations of binuclear mercury(ii)bis(alkynyl) complexes containing oligothiophenes and bithiazoles
Authors: Lam P. L. , Lu G. L. , Choi K. H. , Lin Z. , Kok S. H. L. , Lee K. K. H. , Lam K. H. , Li H. , Gambari R. , Bian Z. X. , Wong W. Y. , Chui C. H.
Published: February 2016

We investigated the antimicrobial activity of bis-(alkynyl)mercury(ii) complexes with oligothiophene and bithiazole linking units against MRSA and C. albicans, and their cytotoxicity was tested on NIH 3T3 cells.
The effect of sol–gel surface modified silver nanoparticles on the protective properties of the epoxy coating
Authors: Ghazizadeh Alireza , Haddadi Seyyed Arash , Mahdavian Mohammad
Published: February 2016

In this study, the effect of surface modified silver nanoparticles on the corrosion protection of an epoxy coating on mild steel was studied.
Competition-driven selection in covalent dynamic networks and implementation in organic reactional selectivity
Authors: Kovaříček P. , Meister A. C. , Flídrová K. , Cabot R. , Kovaříčková K. , Lehn J.-M.
Published: February 2016

Competition among reagents in dynamic combinatorial libraries of increased complexity leads to reactional self-sorting. This fundamental principle allowed development of selective dynamic protecting groups for controlled sequential derivatization of polyamines.
Super-ion inspired colorful hybrid perovskite solar cells
Authors: Fang Hong , Jena Puru
Published: February 2016

Hybrid perovskites viewed as super alkali halides with alkali and halogen ions replaced by super alkalis and super halogens, respectively. The basic properties of these materials are determined by the bonding ionicity and effective ionic radii of the super-ions. New colorful hybrid perovskites can be invented with super-ions as the building block.
The improved efficiency of quantum-dot-sensitized solar cells with a wide spectrum and pure inorganic donor–acceptor type polyoxometalate as a collaborative cosensitizer
Authors: Chen Li , Chen Weilin , Tan Huaqiao , Li Jiansheng , Sang Xiaojing , Wang Enbo
Published: February 2016

Wide spectrum and pure inorganic donor–acceptor type polyoxometalate was assembled on TiO2 as a collaborative cosensitizer of QDSCs, which tremendously improved the performance of QDSCs to 6.59%.
Microwave-assisted synthesis of multiply-twinned Au–Ag nanocrystals on reduced graphene oxide for high catalytic performance towards hydrogen evolution reaction
Authors: Qin Yuchen , Dai Xiaoping , Zhang Xin , Huang Xingliang , Sun Hui , Gao Daowei , Yu Yanbing , Zhang Pengfang , Jiang Yan , Zhuo Hongying , Jin Axiang , Wang Hai
Published: February 2016

Multiply-twinned Au–Ag NCs/rGO are prepared by a one-pot method under microwave irradiation and exhibit excellent HER activity and stability.
Enhanced mid-temperature thermoelectric performance of textured SnSe polycrystals made of solvothermally synthesized powders
Authors: Li Yiwen , Li Fu , Dong Jinfeng , Ge Zhenhua , Kang Feiyu , He Jiaqing , Du Hongda , Li Bo , Li Jing-Feng
Published: February 2016

A highZTof up to 0.6 at 773 K with improved mid-temperature thermoelectric performance is achieved for textured SnSe polycrystals without deliberate doping.
Highly efficient and selective isolation of rare tumor cells using a microfluidic chip with wavy-herringbone micro-patterned surfaces
Authors: Wang Shunqiang , Thomas Antony , Lee Elaine , Yang Shu , Cheng Xuanhong , Liu Yaling
Published: February 2016

We present a microfluidic chip with wavy-herringbone micro-patterned surfaces for highly efficient and selective isolation of viable rare tumor cells.
Color polymorphs of aldose reductase inhibitor epalrestat: configurational, conformational and synthon differences
Authors: Swapna Battini , Suresh Kuthuru , Nangia Ashwini
Published: February 2016

Color polymorphs of aldose reductase inhibitor epalrestat also exhibit configurational, conformational and synthon differences. Form I is the stable modification under temperature and humidity conditions.
A simple aptamer-functionalized gold nanorods based biosensor for the sensitive detection of MCF-7 breast cancer cells
Authors: Li Yuan , Zhang Yulong , Zhao Man , Zhou Qianqian , Wang Lili , Wang Huizhong , Wang Xiaohui , Zhan Linsheng
Published: February 2016

Herein, we describe a novel approach for the rapid diagnosis of human breast carcinoma MCF-7 cells with a detection limit of 100 cells mL−1.
Development of an antibody-binding modular nanoplatform for antibody-guided targeted cell imaging and delivery
Authors: Kim Hansol , Kang Young Ji , Min Junseon , Choi Hyeokjune , Kang Sebyung
Published: February 2016

A polyvalent antibody-binding lumazine synthase protein cage nanoparticle (ABD–AaLS) is constructed by genetically fusing lumazine synthase and antibody-binding domains. ABD–AaLS effectively displays targeting antibodies in an orientation-controlled manner.
Using Rasch measurement to validate an instrument for measuring the quality of classroom teaching in secondary chemistry lessons
Authors: He Peng , Liu Xiufeng , Zheng Changlong , Jia Mengying
Published: February 2016

This study intends to develop a standardized instrument for measuring classroom teaching and learning in secondary chemistry lessons. Based on previous studies and interviews with expert teachers, the progression of five quality levels was constructed hypothetically to represent the quality of chemistry lessons in Chinese secondary schools. The measurement instrument was revised from the Evaluation Scale of Effectiveness of Primitive System of Classroom Teaching (ESEPrSCT). 90 videotaped chemistry lessons were collected and measured to validate the instrument in the pilot and field stage. By means of Rasch modeling, the instrument consisting of 18 items with five response categories was finally validated in this study. The results provide the validity and reliability evidence for using this measurement instrument to assess the quality of chemistry lessons.
Surfactant-facilitated crystallisation of water-soluble foldamers
Authors: Collie G. W. , Pulka-Ziach K. , Guichard G.
Published: February 2016

Common surfactants promote the crystallisation of a series of water-soluble oligourea foldamers which had previously proven resistant to crystallisation efforts.
One-pot synthesis of multifunctional magnetic ferrite–MoS2–carbon dot nanohybrid adsorbent for efficient Pb(ii) removal
Authors: Wang Jing , Zhang Wentao , Yue Xiaoyue , Yang Qingfeng , Liu Fangbing , Wang Yanru , Zhang Daohong , Li Zhonghong , Wang Jianlong
Published: February 2016

Multifunctional MFe2O4 (M = Mn, Co)–MoS2–carbon dot nanohybrid composites were fabricated using a one-pot solvothermal method and applied for efficient Pb(ii) removal.
Influence of the composition of hybrid perovskites on their performance in solar cells
Authors: Albero Josep , Asiri Abdullah M. , García Hermenegildo
Published: February 2016

The chemical composition of hybrid perovskites in photovoltaic devices is revised and some insights are provided to improve device efficiencies and stability by control of the composition.
On the design of atropisomer-separable photochromic diarylethene-based metal–organic framework linkers
Authors: Cox Jordan M. , Walton Ian M. , Benedict Jason B.
Published: February 2016

The relative stability and accessibility of atropisomers plays a prominent role in the efficacy of diarylethene-based photochromic materials.
Dual reference phase shifted pulse width modulation technique for a N‐level inverter based grid connected solar photovoltaic system
Authors: Kartick Jana Chandra , Sujit Biswas K. , Suparna KarChowdhury
Published: February 2016

This study presents a control algorithm of a grid tied solar photovoltaic (PV) system using a dual reference phase shifted pulse width modulation technique for a single‐phase cascaded N‐level inverter. The grid tied inverter consists of several five‐level hybrid inverter modules which are connected to the solar PV panels having equal DC voltage magnitudes. The proposed control technique for the multilevel inverter generate the near‐sinusoidal current with near‐unity power factor to the grid and balance the capacitor voltages across the DC links. The voltage and frequency of the multilevel inverter can be adjusted using closed loop control, such that, the maximum power flow to the grid can be achieved even under varying grid voltage. The performance of the complete system has been verified under different transient states. Experimental results verify the effectiveness of the proposed technique.
Stochastic security‐constrained economic dispatch for random responsive price‐elastic load and wind power
Authors: Yang Shengchun , Zeng Dan , Ding Hongfa , Yao Jianguo , Wang Ke , Li Yaping
Published: February 2016

Price‐elastic load (PEL) is a typical demand response resource. PEL provides an effective option to address the challenge of wind power output fluctuation. This study proposes a stochastic scheduling model, considering uncertainties of variable wind power and PEL response. A PEL stochastic security‐constrained economic dispatch model using chance‐constrained programming is presented for scheduling. The authors propose that the chance‐constrained transmission interface flow constraints should be considered to control the probability of transmission interface flow limit violation via the parameter of security probability. An approach is suggested to transform the stochastic model into a deterministic quadratic programming problem via linearising the branch flow constraints and transmission interface flow constraints with sensitivity analysis method. Then, the probabilistic transmission interface flow constraints are equivalently transformed into conventional constraints. Case simulations on a provincial power system with 151 buses demonstrate the effectiveness and feasibility of the proposed mechanism, models, and methods.
Status of ECR ion sources for the Facility for Rare Isotope Beams (FRIB) (invited)
Authors: Machicoane Guillaume , Felice Helene , Fogleman Jesse , Hafalia Ray , Morgan Glenn , Pan Heng , Prestemon Soren , Pozdeyev Eduard , Rao Xing , Ren Haitao , Tobos Larry
Published: February 2016

Ahead of the commissioning schedule, installation of the first Electron Cyclotron Resonance (ECR) ion source in the front end area of the Facility for Rare Isotope Beam (FRIB) is planned for the end of 2015. Operating at 14 GHz, this first ECR will be used for the commissioning and initial operation of the facility. In parallel, a superconducting magnet structure compatible with operation at 28 GHz for a new ECR ion source is in development at Lawrence Berkeley National Laboratory. The paper reviews the overall work in progress and development done with ECR ion sources for FRIB.
Stochastic stimulated electronic x-ray Raman spectroscopy
Authors: Kimberg Victor , Rohringer Nina
Published: February 2016

Resonant inelastic x-ray scattering (RIXS) is a well-established tool for studying electronic, nuclear, and collective dynamics of excited atoms, molecules, and solids. An extension of this powerful method to a time-resolved probe technique at x-ray free electron lasers (XFELs) to ultimately unravel ultrafast chemical and structural changes on a femtosecond time scale is often challenging, due to the small signal rate in conventional implementations at XFELs that rely on the usage of a monochromator setup to select a small frequency band of the broadband, spectrally incoherent XFEL radiation. Here, we suggest an alternative approach, based on stochastic spectroscopy, which uses the full bandwidth of the incoming XFEL pulses. Our proposed method is relying on stimulated resonant inelastic x-ray scattering, where in addition to a pump pulse that resonantly excites the system a probe pulse on a specific electronic inelastic transition is provided, which serves as a seed in the stimulated scattering process. The limited spectral coherence of the XFEL radiation defines the energy resolution in this process and stimulated RIXS spectra of high resolution can be obtained by covariance analysis of the transmitted spectra. We present a detailed feasibility study and predict signal strengths for realistic XFEL parameters for the CO molecule resonantly pumped at the O1s→π* transition. Our theoretical model describes the evolution of the spectral and temporal characteristics of the transmitted x-ray radiation, by solving the equation of motion for the electronic and vibrational degrees of freedom of the system self consistently with the propagation by Maxwell equations.
The upgraded Large Plasma Device, a machine for studying frontier basic plasma physics
Authors: Gekelman W. , Pribyl P. , Lucky Z. , Drandell M. , Leneman D. , Maggs J. , Vincena S. , Van Compernolle B. , Tripathi S. K. P. , Morales G. , Carter T. A. , Wang Y. , DeHaas T.
Published: February 2016

In 1991 a manuscript describing an instrument for studying magnetized plasmas was published in this journal. The Large Plasma Device (LAPD) was upgraded in 2001 and has become a national user facility for the study of basic plasma physics. The upgrade as well as diagnostics introduced since then has significantly changed the capabilities of the device. All references to the machine still quote the original RSI paper, which at this time is not appropriate. In this work, the properties of the updated LAPD are presented. The strategy of the machine construction, the available diagnostics, the parameters available for experiments, as well as illustrations of several experiments are presented here.
Squeeze flow between a sphere and a textured wall
Authors: Chastel T. , Mongruel A.
Published: February 2016

The motion of a millimetric sphere, translating in a viscous fluid towards a wettable textured wall, is investigated experimentally. The textures consist of square arrays of cylindrical or square micro-pillars, the height, width, and spacing of which are varied, keeping the periodicity small compared to the sphere radius. An interferometric device is used to measure the sphere vertical displacement, for distances between the sphere and the base of the pillars smaller than 0.1 sphere radius, and with a resolution of 200 nm. At a given distance from the top of the pillars, the sphere velocity is found to be significantly larger than the corresponding velocity for a smooth solid wall. A squeeze flow model of two adjacent fluid layers is developed in the lubrication approximation, one fluid layer having an effective viscosity that reflects the viscous dissipation through the array of pillars. The pressure field in the gap between the sphere and the textured surface is then used to obtain the drag force on the sphere and hence its velocity. Adjustment of the model to the velocity measurements yields the effective viscosity for a given texture. Finally, a correlation between the effective viscosity and the geometry of the pillar array is proposed.
On the structure of crystalline and molten cryolite: Insights from the ab initio molecular dynamics in NpT ensemble
Authors: Bučko Tomáš , Šimko František
Published: February 2016

Ab initio molecular dynamics simulations in isobaric-isothermal ensemble have been performed to study the low- and the high-temperature crystalline and liquid phases of cryolite. The temperature induced transitions from the low-temperature solid (α) to the high-temperature solid phase (β) and from the phase β to the liquid phase have been simulated using a series of MD runs performed at gradually increasing temperature. The structure of crystalline and liquid phases is analysed in detail and our computational approach is shown to reliably reproduce the available experimental data for a wide range of temperatures. Relatively frequent reorientations of the AlF6 octahedra observed in our simulation of the phase β explain the thermal disorder in positions of the F− ions observed in X-ray diffraction experiments. The isolated AlF63−, AlF52−, AlF4−, as well as the bridged Al2Fm6−m ionic entities have been identified as the main constituents of cryolite melt. In accord with the previous high-temperature NMR and Raman spectroscopic experiments, the compound AlF52− has been shown to be the most abundant Al-containing species formed in the melt. The characteristic vibrational frequencies for the AlFn3−n species in realistic environment have been determined and the computed values have been found to be in a good agreement with experiment.
Structural characterization of nanostructures grown by Ni metal induced lateral crystallization of amorphous-Si
Authors: Radnóczi G. Z. , Dodony E. , Battistig G. , Vouroutzis N. , Kavouras P. , Stoemenos J. , Frangis N. , Kovács A. , Pécz B.
Published: February 2016

The nickel metal induced lateral crystallization of amorphous silicon is studied by transmission electron microscopy in the range of temperatures from 413 to 521 °C. The structural characteristics of the whiskers grown at 413 °C are compared to the grains grown at 600 °C, where both Metal Induced Lateral Crystallization (MILC) and Solid Phase Crystallization (SPC) are involved. At 413 °C, long whiskers are formed at any crystallographic direction almost free of defects. In contrary, whiskers grown by MILC around 600 °C are crystallized along the ⟨111⟩ directions. These differences are attributed to the low crystallization rate and suppression of the SPC process. The activation energy of the pure MILC was measured in the order of 2 eV. The effect of Ni on the crystallization rate is studied by in-situ heating experiments inside the microscope. The role of contamination that can inhibit MILC is discussed. The cases of MILC process under limited Ni and unlimited Ni source were studied and compared to in-situ annealing experiments. The crystallization rate is strongly influenced by the neighbouring Ni sources; this long-range interaction is attributed to the requirement of a critical Ni concentration in amorphous silicon before the initiation of the MILC process. The long-range interaction can enhance crystallization along a certain direction. The transition from MILC to SPC and the change of the crystallization mode due to the lack of Ni are discussed. The beneficial effect of long annealing at 413 °C is also discussed.
Velocity synchronization of multi-agent systems with mismatched parameters via sampled position data
Authors: Sun Wen , Huang Chunli , Lü Jinhu , Li Xiong , Chen Shihua
Published: February 2016

Power systems are special multi-agent systems with nonlinear coupling function and symmetric structures. This paper extends these systems to a class of multi-agent systems with mismatched parameters, linear coupling function, and asymmetric structures and investigates their velocity synchronization via sampled position data. The dynamics of the agents is adopted as that of generators with mismatched parameters, while the system structures are supposed to be complex. Two distributed linear consensus protocols are designed, respectively, for multi-agent systems without or with communication delay. Necessary and sufficient conditions based on the sampling period, the mismatched parameters, the delay, and the nonzero eigenvalues of the Laplacian matrix are established. It is shown that velocity synchronization of multi-agent systems with mismatched parameters can be achieved if the sampled period is chosen appropriately. Simulations are given to illustrate the effectiveness of the theoretical results.
Second harmonic generation in composites: Theoretical and numerical analyses
Authors: Zhao Jinling , Chillara Vamshi K. , Ren Baiyang , Cho Hwanjeong , Qiu Jinhao , Lissenden Cliff J.
Published: February 2016

Second harmonic generation in a transversely isotropic plate and a symmetric composite laminate is analyzed from a theoretical perspective. The strain energy function for a nonlinear elastic transversely isotropic material is expressed in terms of the five invariants of the Green-Lagrange strain tensor. Internal resonance conditions for the generation of cumulative second harmonics indicate that a cumulative second harmonic exists when the primary-secondary mode pair satisfies the phase matching and non-zero power flux criteria. In particular, for transversely isotropic plates, when the primary mode propagates along the material principal direction, only symmetric second harmonic Lamb-like wave modes can be cumulative. Also, when the primary wave propagates along other directions, only symmetric second harmonic modes can be generated. Additionally, for the case of symmetric composite laminates, only symmetric modes can be generated as cumulative second harmonics regardless of the propagation direction of the primary mode. To validate the above theoretical predictions, finite element simulations were conducted for mode pairs that are: (i) phase matched but have zero power flux, (ii) not phase matched but have non-zero power flux, and (iii) internally resonant i.e., satisfying both phase matching and non-zero power flux criterion. The results obtained from the simulations corroborate the theoretical findings for both transversely isotropic plates and symmetric composite laminates.
Diverse wave-particle interactions for energetic ions that traverse Alfvén eigenmodes on their first full orbit
Authors: Heidbrink W. W. , Persico E. A. D. , Austin M. E. , Chen Xi , Pace D. C. , Van Zeeland M. A.
Published: February 2016

Neutral-beam ions that are deflected onto loss orbits by Alfvén eigenmodes (AE) on their first bounce orbit and are detected by a fast-ion loss detector (FILD) satisfy the “local resonance” condition proposed by Zhang et al. [Nucl. Fusion 55, 22002 (2015)]. This theory qualitatively explains FILD observations for a wide variety of AE-particle interactions. When coherent losses are measured for multiple AE, oscillations at the sum and difference frequencies of the independent modes are often observed in the loss signal. The amplitudes of the sum and difference peaks correlate weakly with the amplitudes of the fundamental loss-signal amplitudes but do not correlate with the measured mode amplitudes. In contrast to a simple uniform-plasma theory of the interaction [Chen et al., Nucl. Fusion 54, 083005 (2014)], the loss-signal amplitude at the sum frequency is often larger than the loss-signal amplitude at the difference frequency, indicating a more detailed computation of the orbital trajectories through the mode eigenfunctions is needed.
Switching between attractive and repulsive Coulomb-interaction-mediated drag in an ambipolar GaAs/AlGaAs bilayer device
Authors: Zheng B. , Croxall A. F. , Waldie J. , Das Gupta K. , Sfigakis F. , Farrer I. , Beere H. E. , Ritchie D. A.
Published: February 2016

We present measurements of Coulomb drag in an ambipolar GaAs/AlGaAs double quantum well structure that can be configured as both an electron-hole bilayer and a hole-hole bilayer, with an insulating barrier of only 10 nm between the two quantum wells. Coulomb drag resistivity is a direct measure of the strength of interlayer particle-particle interactions. We explore the strongly interacting regime of low carrier densities (2D interaction parameter rs up to 14). Our ambipolar device design allows a comparison between the effects of the attractive electron-hole and repulsive hole-hole interactions and also shows the effects of the different effective masses of electrons and holes in GaAs.
Numerical simulation of systems of shear bands in ductile metal with inclusions
Authors: Plohr JeeYeon N. , Plohr Bradley J.
Published: February 2016

We develop a method for numerical simulations of high strain-rate loading of mesoscale samples of ductile metal with inclusions. Because of its small-scale inhomogeneity, the composite material is prone to localized shear deformation (adiabatic shear bands). This method employs the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. 127–139, 1992] to ensure that the micro mechanical behavior of the metal and inclusions is reflected properly in the behavior of the composite at the mesoscale. To find the effective plastic strain rate when shear bands are present, we extend and apply the analytic and numerical analysis of shear bands of Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31–41, 1996]. Our tests of the method focus on the stress/strain response in uniaxial-strain flow, both compressive and tensile, of depleted uranium metal containing silicon carbide inclusions. We use the Preston-Tonks-Wallace viscoplasticity model [J. Appl. Phys., vol. 93, pp. 211–220, 2003], which applies to the high strain-rate regime of an isotropic viscoplastic solid. In results, we verify the elevated temperature and thermal softening at shear bands in our simulations of pure DU and DU/SiC composites. We also note that in composites, due the asymmetry caused by the inclusions, shear band form at different times in different subcells. In particular, in the subcells near inclusions, shear band form much earlier than they do in pure DU.
Low-frequency metamaterial absorber with small-size unit cell based on corrugated surface
Authors: Wang Nan , Dong Xiaochun , Zhou Weicheng , He Chuanwang , Jiang Wei , Hu Song
Published: February 2016

In this paper, we report the design, analysis, and simulation of the low-frequency perfect metamaterial absorber (MMA) based on corrugated surface, which has very small unit-cell size. The proposed MMA consist of a regular square-array and a metallic background plane, separated by a corrugated surface with periodic square-pillar-array. Through the optimized design, the ratios between lattice constant and resonance wavelength for nearly-perfect and high absorption MMA are close to 1/15 and 1/21, respectively. To explain the absorption mechanism of suggested structures, the surface current and electromagnetic field distributions are given. Moreover, the absorption peaks remain high with large angles of incidence for both transverse electric and transverse magnetic polarizations, which provide more efficient absorptions for oblique incident electromagnetic wave.
Displacement measurement of the compliant positioning stage based on a computer micro-vision method
Authors: Wu Heng , Zhang Xianmin , Wang Ruizhou , He Zhenya
Published: February 2016

We propose a practical computer micro-vision-based method for displacement measurements of the compliant positioning stage. The algorithm of the proposed method is based on a template matching approach composed of an integer-pixel search and a sub-pixel search. By combining with an optical microscopy, a high resolution CCD camera and the proposed algorithm, an extremely high measuring precision is achieved. Various simulations and experiments are conducted. The simulation results demonstrate that the matching precision can reach to 0.01 pixel when the noise interference is low. A laser interferometer measurement system (LIMS) is established for comparison. The experimental results indicate that the proposed method possesses the same performance as the LIMS but exhibits a greater flexibility and operability. The measuring precision can theoretically attain to 2.83 nm/pixel.
Optical evidences for an intermediate phase in relaxor ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals
Authors: Zhang Xiaolong , Zhang Jinzhong , Xu Guisheng , Jiang Kai , Hu Zhigao , Chu Junhao
Published: February 2016

The mechanism of low-temperature structural transformation and evolution of polar nano-structures in relaxor ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-xPbTiO3 (x = 0.33, 0.35, and 0.42) single crystals have been investigated with the aid of temperature dependent low-wavenumber Raman scattering (LWRS) and photoluminescence (PL) spectra. The E(TO1) phonon mode reveals the characteristic relaxational polarization fluctuations associated with the reorientation of either polar nano-regions or polar nano-domains. It was found that these mechanisms are not independent and they can be ascribed to the phonon localization. In addition, a short-range monoclinic phase (Mc) can be found below 250 K in the tetragonal phase region by LWRS, which is always associated with the morphotropic phase boundary (MPB) and excellent electromechanical properties. It is interesting that PL spectra confirm these results. The present work indicates that external field modulation and change of composition can result in the monoclinic phase and co-existence of multi-phase.
Enhancement of Oxidation of Formic Acid in Acid Medium on Zirconia-Supported Phosphotungstate-Decorated Noble Metal (Pd, Pt) Nanoparticles
Authors: Rutkowska Iwona A.
Published: February 2016

Palladium and platinum nanoparticles have been modified at sub-monolayer level with Keggin-type phosphododecatungstate (by spontaneous adsorption of H3PW12O40) and considered as catalysts for the electrooxidation of formic acid in sulfuric acid electrolyte. The presence of phosphotungstate adsorbates has been confirmed using Fourier transform infrared spectroscopy (by reflectance). The enhancement effect (described in terms of the oxidation current increases) is even more pronounced when the catalytic centres have been supported on nanostructured ZrO2. In the case of Pd catalysts, a large population of hydroxyl groups and a high mobility of interfacial protons (on zirconia) seem to favour the direct oxidation path to CO2, whereas in the case of Pt-based systems, the enhancement effect is related to the oxidative removal of otherwise passivating CO adsorbates (indirect oxidation path). The role of polytungstate adsorbates on Pd or Pt nanoparticles relates to their ability to interact competitively with the CO adsorbates at noble metal catalytic sites (‘third-body’ effect).
Cell–cell communication enhances the capacity of cell ensembles to sense shallow gradients during morphogenesis
Authors: Ellison David , Mugler Andrew , Brennan Matthew D. , Lee Sung Hoon , Huebner Robert J. , Shamir Eliah R. , Woo Laura A. , Kim Joseph , Amar Patrick , Nemenman Ilya , Ewald Andrew J. , Levchenko Andre
Published: February 2016

Significance

What new properties may result from collective cell behavior, and how may these emerging capabilities influence shaping and function of tissues, in health and disease? Here, we explored these questions in the context of epithelial branching morphogenesis. We show experimentally that, whereas individual mammary epithelial cells are incapable of sensing extremely weak gradients of a growth factor, cellular collectives in organotypic cultures exhibit reliable, gradient-driven, directional growth. This underscores a critical importance of collective cell–cell communication and computation in gradient sensing. We develop and verify a biophysical theory of such communication and identify the mechanisms by which it is implemented in the mammary epithelium, quantitatively analyzing both advantages and limitations of biochemical cellular communication in collective decision making.