bluuebunny/crossref_metadata_2025 huggingface dataset:
A microarray for assessing transcription from pelagic marine microbial taxa
Authors: Shilova Irina N , Robidart Julie C , Tripp H James , Turk-Kubo Kendra , Wawrik Boris , Post Anton F , Thompson Anne W , Ward Bess , Hollibaugh James T , Millard Andy , Ostrowski Martin , Scanlan David J , Paerl Ryan W , Stuart Rhona , Zehr Jonathan P
Published: January 2014

Metagenomic approaches have revealed unprecedented genetic diversity within microbial communities across vast expanses of the world’s oceans. Linking this genetic diversity with key metabolic and cellular activities of microbial assemblages is a fundamental challenge. Here we report on a collaborative effort to design MicroTOOLs (Microbiological Targets for Ocean Observing Laboratories), a high-density oligonucleotide microarray that targets functional genes of diverse taxa in pelagic and coastal marine microbial communities. MicroTOOLs integrates nucleotide sequence information from disparate data types: genomes, PCR-amplicons, metagenomes, and metatranscriptomes. It targets 19 400 unique sequences over 145 different genes that are relevant to stress responses and microbial metabolism across the three domains of life and viruses. MicroTOOLs was used in a proof-of-concept experiment that compared the functional responses of microbial communities following Fe and P enrichments of surface water samples from the North Pacific Subtropical Gyre. We detected transcription of 68% of the gene targets across major taxonomic groups, and the pattern of transcription indicated relief from Fe limitation and transition to N limitation in some taxa. Prochlorococcus (eHLI), Synechococcus (sub-cluster 5.3) and Alphaproteobacteria SAR11 clade (HIMB59) showed the strongest responses to the Fe enrichment. In addition, members of uncharacterized lineages also responded. The MicroTOOLs microarray provides a robust tool for comprehensive characterization of major functional groups of microbes in the open ocean, and the design can be easily amended for specific environments and research questions.
Development of a novel multi-layer microfluidic device towards characterization of drug metabolism and cytotoxicity for drug screening
Authors: Wu Qin , Gao Dan , Wei Juntong , Jin Feng , Xie Weiyi , Jiang Yuyang , Liu Hongxia
Published: January 2014

A multi-layer microfluidic device was developed for characterization of drug metabolism and cytotoxicity assays on a single device that overcomes many limitations of existing methods. And it also shows potential for high-throughput drug screening.
An unusual linker and an unexpected node: CaCl2dumbbells linked by proline to form square lattice networks
Authors: Lamberts Kevin , Porsche Sven , Hentschel Bernd , Kuhlen Torsten , Englert Ulli
Published: January 2014

Extensive database searches using the network approach underline that thesql-topology is unusual for carboxylato bridged networks.
Novel luminescent hybrids prepared by incorporating a rare earth ternary complex into CdS QD loaded zeolite Y crystals through coordination reaction
Authors: Duan Tian-Wei , Yan Bing
Published: January 2014

Novel luminescent hybrids were assembled by incorporating a rare earth (Eu, Tb), mercaptan acid and 1,10-phenanthroline ternary complex into CdS loaded zeolite Y through coordination reaction.
Heat storage properties of organic phase-change materials confined in the nanospace of mesoporous SBA-15 and CMK-3
Authors: Kadoono Tomosuke , Ogura Masaru
Published: January 2014

A mesoporous carbon CMK-3 composite with phase-change materials (PCMs) showed unique properties for heat storage/release.
Preparation and evaluation of carborane-derived inhibitors of prostate specific membrane antigen (PSMA)
Authors: El-Zaria Mohamed E. , Genady Afaf R. , Janzen Nancy , Petlura Christina I. , Beckford Vera Denis R. , Valliant John F.
Published: January 2014

Carborane-derived inhibitors of prostate specific membrane antigen are reported. Compounds were prepared from C-hydroxy-carboranes and screened in vitro and in vivo.
Theory, synthesis and reactivity of quintuple bonded complexes
Authors: Nair Anokh K. , Harisomayajula N. V. Satyachand , Tsai Yi-Chou
Published: January 2014

Recent achievements in the area of metal–metal quintuple bonding are highlighted, including synthesis of quintuple bonded complexes, metal-to-metal bonding schemes, and their reactivity.
Personal nitrogen footprint tool for the United Kingdom
Authors: Stevens Carly J. , Leach Allison M. , Dale Sarah , Galloway James N.
Published: January 2014

A nitrogen footprint calculator tool for the UK is described together with a historical and international comparison of N footprints. Scenarios show how reductions in individual footprints can be made.
The two-step mechanochemical synthesis of porphyrins
Authors: Shy Hannah , Mackin Paula , Orvieto Andrea S. , Gharbharan Deepa , Peterson Geneva R. , Bampos Nick , Hamilton Tamara D.
Published: January 2014

Porphyrin synthesis under solvent-free conditions represents the “greening” of a traditional synthesis that normally requires large amounts of organic solvent, and has hindered the industrial-scale synthesis of this useful class of molecules. We have found that the four-fold acid-catalysed condensation of aldehyde and pyrrole to yield a tetra-substituted porphyrin is possible through mechanochemical techniques, without a solvent present. This represents one of the still-rare examples of carbon–carbon bond formation by mechanochemistry. Specifically, upon grinding equimolar amounts of pyrrole and benzaldehyde in the presence of an acid catalyst, cyclization takes place to give reduced porphyrin precursors (reversible), which upon oxidation form tetraphenylporphyrin (TPP). The approach has been found to be suitable for the synthesis of a variety of meso-tetrasubstituted porphyrins. Oxidation can occur either by using an oxidizing agent in solution, to give yields comparable to those published for traditional methods of porphyrin synthesis, or through mechanochemical means resulting in a two-step mechanochemical synthesis to give slightly lower yields that are still being optimized. We are also working on “green” methods of porphyrin isolation, including entrainment sublimation, which would hopefully further reduce the need for large amounts of organic solvent. These results hold promise for the development of mechanochemical synthetic protocols for porphyrins and related classes of compounds.
Capturing CO2 for cellulose dissolution
Authors: Xie Haibo , Yu Xue , Yang Yunlong , Zhao Zongbao Kent
Published: January 2014

The design of organic liquids in DMSO after CO2 capture created a new solvent capable of dissolving up to 10 wt% of cellulose under mild conditions.
Selenium effects on the metabolism of a Se-metabolizingLactobacillus reuteri: analysis of envelope-enriched and extracellular proteomes
Authors: Mangiapane E. , Lamberti C. , Pessione A. , Galano E. , Amoresano A. , Pessione E.
Published: January 2014

Fixation of selenium byLactobacillus reuteriLb2 BM DSM 16143 into secreted proteins as selenocysteine.
Rhodamine-based molecular clips for highly selective recognition of Al3+ions: synthesis, crystal structure and spectroscopic properties
Authors: Dhara Anamika , Jana Atanu , Guchhait Nikhil , Ghosh Prasanta , Kar Susanta K.
Published: January 2014

A novel fluorescent chemosensor based on a rhodamine derivative (L) was designed, synthesized, and used as a selective Al+3ion sensor.
Effect of non-covalent interaction on the diastereoselective self-assembly of Cu(ii) complexes containing a racemic Schiff base in a chiral self-discriminating process
Authors: Jena Himanshu Sekhar
Published: January 2014

The effects of π⋯π interactions between benzene–pyridine rings on the diastereoselective self-assembly of Cu(ii) compounds in the chiral self-discrimination process are studied.
Transition metal-catalyzed direct nucleophilic addition of C–H bonds to carbon–heteroatom double bonds
Authors: Zhang Xi-Sha , Chen Kang , Shi Zhang-Jie
Published: January 2014

Compared with the traditional Grignard reaction, direct insertion of polar double bonds to C–H bondsviatransition-metal catalysis is ideal from the viewpoint of atom-, step- and cost-economy and the avoidance of the waste emission, as well as of the complex manipulation of sensitive reagents.
Encapsulation of γ-Fe2O3decorated reduced graphene oxide in polyaniline core–shell tubes as an exceptional tracker for electromagnetic environmental pollution
Authors: Singh Avanish Pratap , Mishra Monika , Sambyal Pradeep , Gupta Bipin Kumar , Singh Bhanu Pratap , Chandra Amita , Dhawan S. K.
Published: January 2014

High performance γ-Fe2O3decorated rGO–polyaniline core–shell tubes demonstrated exceptional EMI shielding which could be an ultimate choice for future building block material in EMI SE applications.
Novel core–shell structured superparamagnetic microspheres decorated with macrocyclic host molecules for specific recognition and magnetic removal of Pb(ii)
Authors: Yi Rong , Ye Gang , Pan Dengfang , Wu Fengcheng , Wen Mingfen , Chen Jing
Published: January 2014

Specific recognition and highly-efficient magnetic separation of Pb(ii) by a new class of core–shell structured superparamagnetic microspheres bearing calixcrown host molecules with size-fitted cavities.
Ultra-small fluorescent inorganic nanoparticles for bioimaging
Authors: Li Zhen , Sun Qiao , Zhu Yian , Tan Bien , Xu Zhi Ping , Dou Shi Xue
Published: January 2014

The recent advances of ultra-small fluorescence inorganic nanoparticles including quantum dots, metal nanoclusters, carbon and graphene dots, up-conversion nanocrystals, and silicon nanoparticles have been comprehensively reviewed.
Probing the interfacial molecular packing in TIPS-pentacene organic semiconductors by surface enhanced Raman scattering
Authors: Xu Jie , Diao Ying , Zhou Dongshan , Mao Yisha , Giri Gaurav , Chen Wei , Liu Nan , Mannsfeld Stefan C. B. , Xue Gi , Bao Zhenan
Published: January 2014

TIPS-pentacene crystal lattices assume a non-equilibrium packing state near the substrate interface, which gradually relaxes towards equilibrium packing near the top of the interface.
A coral-like film of Ni@NiS with core–shell particles for the counter electrode of an efficient dye-sensitized solar cell
Authors: Chuang Hui-Min , Li Chun-Ting , Yeh Min-Hsin , Lee Chuan-Pei , Vittal R. , Ho Kuo-Chuan
Published: January 2014

A novel coral-like film with core–shell particles of Ni@NiS is obtained on an FTO glass by a two-step electrochemical deposition technique. An efficiency of 7.84% is achieved, which is comparable to that of a DSSC with a platinum counter electrode (8.11%).
Flexible CoO–graphene–carbon nanofiber mats as binder-free anodes for lithium-ion batteries with superior rate capacity and cyclic stability
Authors: Zhang Ming , Yan Feilong , Tang Xuan , Li Qiuhong , Wang Taihong , Cao Guozhong
Published: January 2014

Flexible mats composed of CoO–graphene–carbon nanofibers have been prepared by electrospinning and subsequent thermal treatment as binder-free anodes for lithium-ion batteries with superior rate capacity and cyclic stability.
PAK4 confers cisplatin resistance in gastric cancer cells via PI3K/Akt- and MEK/ERK-dependent pathways
Authors: Fu Xueqiong , Feng Jiarui , Zeng Duan , Ding Yu , Yu Changshou , Yang Bing
Published: January 2014

CDDP [cisplatin or cis-diamminedichloroplatinum(II)] and CDDP-based combination chemotherapy have been confirmed effective against gastric cancer. However, CDDP efficiency is limited because of development of drug resistance. In this study, we found that PAK4 (p21-activated kinase 4) expression and activity were elevated in gastric cancer cells with acquired CDDP resistance (AGS/CDDP and MKN-45/CDDP) compared with their parental cells. Inhibition of PAK4 or knockdown of PAK4 expression by specific siRNA (small interfering RNA)-sensitized CDDP-resistant cells to CDDP and overcome CDDP resistance. Combination treatment of LY294002 [the inhibitor of PI3K (phosphoinositide 3-kinase)/Akt (protein kinase B or PKB) pathway] or PD98509 {the inhibitor of MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] pathway} with PF-3758309 (the PAK4 inhibitor) resulted in increased CDDP efficacy compared with LY294002 or PD98509 alone. However, after the concomitant treatment of LY294002 and PD98509, PF-3758309 administration exerted no additional enhancement of CDDP cytotoxicity in CDDP-resistant cells. Inhibition of PAK4 by PF-3758309 could significantly suppress MEK/ERK and PI3K/Akt signalling in CDDP-resistant cells. Furthermore, inhibition of PI3K/Akt pathway while not MEK/ERK pathway could inhibit PAK4 activity in these cells. The in vivo results were similar with those of in vitro. In conclusion, these results indicate that PAK4 confers CDDP resistance via the activation of MEK/ERK and PI3K/Akt pathways. PAK4 and PI3K/Akt pathways can reciprocally activate each other. Therefore, PAK4 may be a potential target for overcoming CDDP resistance in gastric cancer.
Enzyme kinetics and distinct modulation of the protein kinase N family of kinases by lipid activators and small molecule inhibitors
Authors: Falk Matthew D. , Liu Wei , Bolaños Ben , Unsal-Kacmaz Keziban , Klippel Anke , Grant Stephan , Brooun Alexei , Timofeevski Sergei
Published: January 2014

The PKN (protein kinase N) family of Ser/Thr protein kinases regulates a diverse set of cellular functions, such as cell migration and cytoskeletal organization. Inhibition of tumour PKN activity has been explored as an oncology therapeutic approach, with a PKN3-targeted RNAi (RNA interference)-derived therapeutic agent in Phase I clinical trials. To better understand this important family of kinases, we performed detailed enzymatic characterization, determining the kinetic mechanism and lipid sensitivity of each PKN isoform using full-length enzymes and synthetic peptide substrate. Steady-state kinetic analysis revealed that PKN1–3 follows a sequential ordered Bi–Bi kinetic mechanism, where peptide substrate binding is preceded by ATP binding. This kinetic mechanism was confirmed by additional kinetic studies for product inhibition and affinity of small molecule inhibitors. The known lipid effector, arachidonic acid, increased the catalytic efficiency of each isoform, mainly through an increase in kcat for PKN1 and PKN2, and a decrease in peptide KM for PKN3. In addition, a number of PKN inhibitors with various degrees of isoform selectivity, including potent (Ki<10 nM) and selective PKN3 inhibitors, were identified by testing commercial libraries of small molecule kinase inhibitors. This study provides a kinetic framework and useful chemical probes for understanding PKN biology and the discovery of isoform-selective PKN-targeted inhibitors.
Conditional inference tree‐based analysis of hazardous traffic conditions for rear‐end and sideswipe collisions with implications for control strategies on freeways
Authors: Li Zhibin , Wang Wei , Chen Ruoyun , Liu Pan
Published: January 2014

Identifying hazardous traffic conditions related to traffic collisions is important to the development of real‐time traffic control measures for preventing collision occurrences. The primary objective of this study is to explore the hazardous traffic situations on freeways for rear‐end and sideswipe collisions to assist the development of control strategies for mitigating collision risks using the conditional inference tree method. Based on the 3‐year crash data and traffic data from a freeway corridor on the Interstate 880 in California, the conditional inference tree was developed and validated for each collision type separately. Results showed that the hazardous traffic conditions were different between different types of collisions. The occurrence of rear‐end collision was mainly related to the magnitude of lengthwise traffic variation between upstream and downstream locations. The occurrence of sideswipe collision was related to the type of freeway segment as well as the crosswise traffic variation between adjacent lanes. The control strategies for the mitigation of collision potentials were discussed according to the appearances of the conditional inference trees developed in this study.
Research on low‐order current harmonics rejections for grid‐connected LCL‐filtered inverters
Authors: Xu Jinming , Tang Ting , Xie Shaojun
Published: January 2014

The current quality is an important indicator to evaluate the performance of a grid‐connected inverter. In practice, many factors including the grid voltage distortion, dead‐time effect, non‐ideal switches and dc‐link disturbances would result in many low‐order harmonics in the injected grid current. The inverter with either the typical grid voltage feedforward or the harmonic resonant (HR) control had some difficulties in rejecting the impact of multi‐harmonic sources. In this study, the combination of the grid voltage feedforward and the multi‐HR control is proposed to suppress low‐order harmonics. It is found that all those harmonic sources are classified into two kinds, and a general way is provided to analyse the harmonic rejection of the inverter with the typical or the proposed strategy. The low‐order current harmonics of the inverter with different strategies are clearly explained. The comparative analysis, simulations and experiments all indicate that the proposed strategy greatly improves the ability of the inverter to reject the current harmonics induced by multi‐harmonic sources as long as the grid feedforward and the resonant control are complementary.
Accurate reliability evaluation using quantum‐dot cellular automata probabilistic transfer matrix
Authors: Chen Xiangye , Cai Li , Jia Kaixiang , Wang Zhichun , Cui Huanqing
Published: January 2014

The probabilistic transfer matrix (PTM) plays an important role in analysing the transient faults and the reliability of digital logic circuits. Proposed a modified PTM (QPTM) for quantum‐dot cellular automata (QCA). It has two features different from the previous PTM model: (i) finding more accurate matrices for the wires; and (ii) dividing the QCA circuits more reasonably. Simultaneously, the wire's correct probability is curved by a Gaussian function to enable it to emerge successfully. By using this QPTM, the detailed and extensive simulation results gained reveal that the reliabilities obtained from the PTM analysis of the same circuit could differ at 9%. As for the reliabilities achieved from the PTM and the QPTM, the difference rises to 30%. The simulations obtained have proved that the PTM has weaknesses when presenting the effects of the wire's length and division on the circuit reliabilities.
Frequency scaling with miniature COmpact MIcrowave and Coaxial ion sources
Authors: Sortais Pascal , André Thomas , Angot Julien , Bouat Sophie , Jacob Josua , Lamy Thierry , Sole Patrick
Published: January 2014

We will present recent basic developments about possible extension of the COMIC (for COmpact MIcrowave and Coaxial) devices up to 5.8 GHz in place of the present 2.45 GHz operation [P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81, 02B314 (2010)]. New applications associating multiple COMIC devices for thin film deposition will be described and we will explain why an increase of the current density delivered by each individual ion source could lead to the increase of the deposition rate. For this purpose, we will present results of about two devices working at 5.8 GHz. The first one is a tiny ion source, the world smallest microwave ion source, exactly similar to COMIC but operating at 5.8 GHz with a quarter wave cavity structure and a few watts microwave power consumption. We will show that the frequency scaling effect is effective inside such small machines. The second one is a more ambitious ion source designed around a three quarter wave structure that works with a few tens of watts at 5.8 GHz.
Metallic beam development for the Facility for Rare Isotope Beam
Authors: Machicoane Guillaume , Cole Dallas , Leitner Daniela , Neben Derek , Tobos Larry
Published: January 2014

The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum (98Mo), and selenium (82Ser).
Si
3
N
4
optomechanical crystals in the resolved-sideband regime
Authors: Davanço M. , Ates S. , Liu Y. , Srinivasan K.
Published: January 2014

We demonstrate sideband-resolved Si3N4 optomechanical crystals supporting 105 quality factor optical modes at 980 nm, coupled to ≈4 GHz frequency mechanical modes with quality factors of ≈3000. Optomechanical electromagnetically induced transparency and absorption are observed at room temperature and in atmosphere with intracavity photon numbers in excess of 104.
Silver nanoplates with ground or metastable structures obtained from template-free two-phase aqueous/organic synthesis
Authors: Zhelev Doncho V. , Zheleva Tsvetanka S.
Published: January 2014

Silver has unique electrical, catalytic, and plasmonic characteristics and has been widely sought for fabrication of nanostructures. The properties of silver nanostructures are intimately coupled to the structure of silver crystals. Two crystal structures are known for silver: the stable (ground) state cubic face centered 3C-Ag structure and the metastable hexagonal 4H-Ag structure. Recently, Chackraborty et al. [J. Phys.: Condens. Matter 23, 325401 (2011)] discovered a low density, highly reactive metastable hexagonal 2H-Ag structure accessible during electrodeposition of silver nanowires in porous anodic alumina templates. This 2H-Ag structure has enhanced electrical and catalytic characteristics. In the present work we report template-free synthesis of silver nanoplates with the metastable 2H-Ag crystal structure, which appears together with the ground 3C-Ag and the metastable 4H-Ag structures in a two-phase solution synthesis with citric acid as the capping agent. The capacity of citric acid to stabilize both the stable and the metastable structures is explained by its preferential binding to the close packed facets of Ag crystals, which are the (111) planes for 3C-Ag and the (0001) planes for 4H-Ag and 2H-Ag. Nanoplate morphology and structure are characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The synthesized nanoplates have thickness from 15 to 17 nm and edge length from 1 to 10 μm. Transmission electron microscopy selected area electron diffraction is used to uniquely identify and distinguish between nanoplates with 2H-Ag or 4H-Ag or 3C-Ag structures.
Propagation of ultra-short solitons in stochastic Maxwell's equations
Authors: Kurt Levent , Schäfer Tobias
Published: January 2014

We study the propagation of ultra-short short solitons in a cubic nonlinear medium modeled by nonlinear Maxwell's equations with stochastic variations of media. We consider three cases: variations of (a) the dispersion, (b) the phase velocity, (c) the nonlinear coefficient. Using a modified multi-scale expansion for stochastic systems, we derive new stochastic generalizations of the short pulse equation that approximate the solutions of stochastic nonlinear Maxwell's equations. Numerical simulations show that soliton solutions of the short pulse equation propagate stably in stochastic nonlinear Maxwell's equations and that the generalized stochastic short pulse equations approximate the solutions to the stochastic Maxwell's equations over the distances under consideration. This holds for both a pathwise comparison of the stochastic equations as well as for a comparison of the resulting probability densities.
Ion-modulated nonlinear electronic transport in carbon nanotube bundle/RbAg4I5 thin film composite nanostructures
Authors: Sun Jia-Lin , Zhang Wei , Wei Jinquan , Gu Bingfu
Published: January 2014

We have explored the ion-modulated electronic transport properties of mixed ionic-electronic conductor (MIEC) composite nanostructures made of superionic conductor RbAg4I5 films and carbon nanotube (CNT) bundle spiderwebs. Our experimental and theoretical studies indicate that the formation of ion-electron bound states (IEBSs) leads to strong ion-electron interference effect and interesting electronic transport of CNT, such as nonlinear current-voltage (I–V) characteristics and novel temperature dependence of the current. With increasing temperature, the hybrid nanostructures show rich phases with different dependence of current on temperature, which is related to the structural phase transition of RbAg4I5 and the transition of dissociation of IEBSs. The ion-modulation of the electric conductivity in such MIEC composite nanostructures with great tunability has been used to design new ionic-electronic composite nano-devices with function like field effect transistor.
Directivity patterns and pulse profiles of ultrasound emitted by laser action on interface between transparent and opaque solids: Analytical theory
Authors: Nikitin Sergey M. , Tournat Vincent , Chigarev Nikolay , Bulou Alain , Castagnede Bernard , Zerr Andreas , Gusev Vitalyi
Published: January 2014

The analytical theory for the directivity patterns of ultrasounds emitted from laser-irradiated interface between two isotropic solids is developed. It is valid for arbitrary combinations of transparent and opaque materials. The directivity patterns are derived both in two-dimensional and in three-dimensional geometries, by accounting for the specific features of the sound generation by the photo-induced mechanical stresses distributed in the volume, essential in the laser ultrasonics. In particular, the theory accounts for the contribution to the emitted propagating acoustic fields from the converted by the interface evanescent photo-generated compression-dilatation waves. The precise analytical solutions for the profiles of longitudinal and shear acoustic pulses emitted in different directions are proposed. The developed theory can be applied for dimensional scaling, optimization, and interpretation of the high-pressure laser ultrasonics experiments in diamond anvil cell.
Squeezed states and Hermite polynomials in a complex variable
Authors: Ali S. Twareque , Górska K. , Horzela A. , Szafraniec F. H.
Published: January 2014

Following the lines of the recent paper of J.-P. Gazeau and F. H. Szafraniec [J. Phys. A: Math. Theor. 44, 495201 (2011)], we construct here three types of coherent states, related to the Hermite polynomials in a complex variable which are orthogonal with respect to a non-rotationally invariant measure. We investigate relations between these coherent states and obtain the relationship between them and the squeezed states of quantum optics. We also obtain a second realization of the canonical coherent states in the Bargmann space of analytic functions, in terms of a squeezed basis. All this is done in the flavor of the classical approach of V. Bargmann [Commun. Pure Appl. Math. 14, 187 (1961)].
From the attempt of certain classical reformulations of quantum mechanics to quasi-probability representations
Authors: Stulpe Werner
Published: January 2014

The concept of an injective affine embedding of the quantum states into a set of classical states, i.e., into the set of the probability measures on some measurable space, as well as its relation to statistically complete observables is revisited, and its limitation in view of a classical reformulation of the statistical scheme of quantum mechanics is discussed. In particular, on the basis of a theorem concerning a non-denseness property of a set of coexistent effects, it is shown that an injective classical embedding of the quantum states cannot be supplemented by an at least approximate classical description of the quantum mechanical effects. As an alternative approach, the concept of quasi-probability representations of quantum mechanics is considered.
Three-region characteristic temperature in p-doped quantum dot lasers
Authors: Cao Yu-Lian , Ji Hai-Ming , Yang Tao , Zhang Yan-Hua , Ma Wen-Quan , Wang Qi-Jie
Published: January 2014

We have investigated the temperature dependence of threshold in p-doped 1.3 μm InAs/GaAs quantum dot (QD) lasers with ten layers of QDs in the active region. It is found that the dependence of threshold current density on the temperature within the temperature range from 10 to 90 °C can be divided into three regions by its characteristic temperature (T0): negative, infinite, and positive T0 regions. Furthermore, the T0 region width is dependent on the cavity length: the longer cavity length of the QD lasers correspondingly the wider T0 region. Additionally, for the broad area laser, the threshold modal gains of the lasers with different cavity lengths can be fitted by an empirical expression as a function of the threshold current density, when at the temperatures of 30, 50, and 70 °C. We find that the transparency current density (Jtr) remains almost unchanged under different temperatures according to the extracted parameters from these fitted results, which indicates that Jtr plays an important role in balancing the T0 between negative region and positive one.
Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University
Authors: Uchida T. , Minezaki H. , Ishihara S. , Muramatsu M. , Rácz R. , Asaji T. , Kitagawa A. , Kato Y. , Biri S. , Drentje A. G. , Yoshida Y.
Published: January 2014

In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C60 using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.
Dynamic decay of a single vortex into vortex-antivortex pairs
Authors: Lendínez Sergi , Jain Shikha , Novosad Valentyn , Fradin Frank Y. , Pearson John E. , Tejada Javier , Bader Samuel D.
Published: January 2014

A variety of metastable states, including vortices, antivortices, and their combinations, is typical for magnetically soft, thin films and patterned structures. The physics of individual spin vortices in patterned structures has been rather extensively explored. In contrast, there are few studies of the vortex–antivortex–vortex (v-av-v) system, in part because the configuration is rather challenging to obtain experimentally. We demonstrate herein how a recently proposed resonant-spin-ordering technique can be used to induce the dynamic decay of a single vortex into v-av states in elongated elements. The approach is based on first driving the system from the linear regime of constant vortex gyrations to the non-linear regime of vortex-core reversals at a fixed excitation frequency, and then subsequently reducing the excitation field back to the linear regime. This procedure stabilizes the system into a v-av-v state that is completely decoupled from the initialization excitation frequency. The newly acquired state is stable in remanence. The dynamic response of this system is expected to demonstrate a number of collective modes, depending on the combination of the vortex core polarities, and/or the excitation field direction, and, hence, is of interest for future studies.
Dielectric material degradation monitoring of dielectric barrier discharge plasma actuators
Authors: Hanson Ronald E. , Houser Nicole M. , Lavoie Philippe
Published: January 2014

It is a known phenomenon that some dielectric materials used to construct plasma actuators degrade during operation. However, the rate at which this process occurs, to what extent, as well as a method to monitor is yet to be established. In this experimental study, it is shown that electrical measurements can be used to monitor changes in the material of the plasma actuators. The procedure we introduce for monitoring the actuators follows from the work of Kriegseis, Grundmann, and Tropea [Kriegseis et al., J. Appl. Phys. 110, 013305 (2011)], who used Lissajous figures to measure actuator power consumption and capacitance. In the present study, we quantify changes in both the power consumption and capacitance of the actuators over long operating durations. It is shown that the increase in the effective capacitance of the actuator is related to degradation (thinning) of the dielectric layer, which is accompanied by an increase in actuator power consumption. For actuators constructed from layers of Kapton® polyimide tape, these changes are self-limiting. Although the polyimide film degrades relatively quickly, the underlying adhesive layer appears to remain intact. Over time, the effective capacitance was found to increase by up to 36%, 25%, and 11% for actuators constructed with 2, 3, and 4 layers of Kapton tape, respectively. A method is presented to prevent erosion of the Kapton dielectric layer using a coating of Polydimethylsiloxane oil. It is shown the application of this treatment can delay the onset of degradation of the Kapton dielectric material.
On the localized surface plasmon resonance modes in nanoporous gold films
Authors: Detsi Eric , Salverda Mart , Onck Patrick R. , De Hosson Jeff Th. M.
Published: January 2014

This work concentrates on the relation between plasmonic modes and the microstructure of nanoporous gold films. Based on experiments and computational analyses, we conclude that ligament as well as pore sizes need to be taken into account for an adequate physical description of the optical performance of a disordered nanoporous metal film as a function of its detailed microstructure.
Characteristics of low Reynolds number non-Boussinesq fountains from non-circular sources
Authors: Vinoth B. R. , Panigrahi P. K.
Published: January 2014

The behaviour of low Reynolds number, non-Boussinesq fountains from four different nozzle geometries (one circular and three rectangular nozzles) are studied. High speed laser schlieren imaging is used to study the fountain behaviour (frequency and penetration height). Bi-orthogonal decomposition and dynamic mode decomposition (DMD) are used to understand the unsteady characteristics of fountains. The flow regimes of fountains are classified as steady, flapping, and flapping-bobbing type. The DMD technique successfully separates the bobbing oscillation from the combined flapping-bobbing oscillation of the fountain. The frequency of the flapping oscillation, and the frequency of the bobbing oscillation in the flapping-bobbing regime scales as SthFrh = C1 and \documentclass[12pt]{minimal}\begin{document}$St_h Fr_h^2 = C_2$\end{document}SthFrh2=C2, respectively, where the characteristic length scale is the smallest dimension (h) of the nozzle. The mean steady state penetration heights (Zs/h) of “forced” low Reynolds number non-Boussinesq fountains are independent of nozzle shape (circular and rectangular), and scales linearly with the Froude number.
Loop Virasoro Lie conformal algebra
Authors: Wu Henan , Chen Qiufan , Yue Xiaoqing
Published: January 2014

The Lie conformal algebra of loop Virasoro algebra, denoted by \documentclass[12pt]{minimal}\begin{document}$\mathscr {CW}$\end{document}CW, is introduced in this paper. Explicitly, \documentclass[12pt]{minimal}\begin{document}$\mathscr {CW}$\end{document}CW is a Lie conformal algebra with \documentclass[12pt]{minimal}\begin{document}$\mathbb {C}[\partial ]$\end{document}C[∂]-basis \documentclass[12pt]{minimal}\begin{document}$\lbrace L_i\,|\,i\in \mathbb {Z}\rbrace$\end{document}{Li|i∈Z} and λ-brackets [Li λ Lj] = (−∂−2λ)Li+j. Then conformal derivations of \documentclass[12pt]{minimal}\begin{document}$\mathscr {CW}$\end{document}CW are determined. Finally, rank one conformal modules and \documentclass[12pt]{minimal}\begin{document}$\mathbb {Z}$\end{document}Z-graded free intermediate series modules over \documentclass[12pt]{minimal}\begin{document}$\mathscr {CW}$\end{document}CW are classified.
A white noise approach to the Feynman integrand for electrons in random media
Authors: Grothaus M. , Riemann F. , Suryawan H. P.
Published: January 2014

Using the Feynman path integral representation of quantum mechanics it is possible to derive a model of an electron in a random system containing dense and weakly coupled scatterers [see F. Edwards and Y. B. Gulyaev, “The density of states of a highly impure semiconductor,” Proc. Phys. Soc. 83, 495–496 (1964)]. The main goal of this paper is to give a mathematically rigorous realization of the corresponding Feynman integrand in dimension one based on the theory of white noise analysis. We refine and apply a Wick formula for the product of a square-integrable function with Donsker's delta functions and use a method of complex scaling. As an essential part of the proof we also establish the existence of the exponential of the self-intersection local times of a one-dimensional Brownian bridge. As a result we obtain a neat formula for the propagator with identical start and end point. Thus, we obtain a well-defined mathematical object which is used to calculate the density of states [see, e.g., F. Edwards and Y. B. Gulyaev, “The density of states of a highly impure semiconductor,” Proc. Phys. Soc. 83, 495–496 (1964)].
Multiplexed measurements by time resolved spectroscopy using colloidal CdSe/ZnS quantum dots
Authors: Kaiser U. , Jimenez de Aberasturi D. , Malinowski R. , Amin F. , Parak W. J. , Heimbrodt W.
Published: January 2014

Multiplexed measurements of analytes in parallel is a topical demand in bioanalysis and bioimaging. An interesting alternative to commonly performed spectral multiplexing is lifetime multiplexing. In this Letter, we present a proof of principle of single-color lifetime multiplexing by coupling the same fluorophore to different nanoparticles. The effective lifetime of the fluorophores can be tuned by more than one order of magnitude due to resonance energy transfer from donor states. Measurements have been done on a model systems consisting of ATTO-590 dye molecules linked to either gold particles or to CdSe/ZnS core shell quantum dots. Both systems show the same luminescence spectrum of ATTO-590 dye emission in continuous wave excitation, but can be distinguished by means of time resolved measurements. The dye molecules bound to gold particles exhibit a mono-exponential decay with a lifetime of 4.5 ns, whereas the dye molecules bound to CdSe/ZnS dots show a nonexponential decay with a slow component of about 135 ns due to the energy transfer from the quantum dots. We demonstrate the fundamental possibility to determine the mixing ratio for dyes with equal luminescence spectra but very different transients. This opens up a pathway independent of the standard optical multiplexing with many different fluorophores emitting from the near ultraviolet to the near infrared spectral region.
Improving parabolic trough mirror module qualification by FOCuS tool
Authors: Peña-Cruz Manuel I. , Arancibia-Bulnes Camilo A. , Monreal Vidal Ana , Sánchez González Marcelino
Published: January 2014

An improved tool for the shape qualification of parabolic trough mirror modules used in concentrated solar power plants was developed. The tool is based on the fringe reflection theory, in which sinusoidal fringe patterns are projected on a screen and their reflection over a specular surface is recorded by a camera. The observed distortions in the image are related directly to surface deviations from ideal geometry. Relevant aspects of the technique are its high spatial resolution (more than 1 × 106 points per mirror facet), short measurement time and easy setup. The developed tool (called FOCuS) is capable of calculating the local mirror slope deviations from its ideal design and the RMS value as a quality factor. Furthermore, the tool generates a file which can be loaded into CENER's TONATIUH ray tracing software, through a specially developed plug-in, for mirror modeling and intercept factor calculation with several tube absorber geometries.
Defect reduction in Si-doped Al0.45Ga0.55N films by SiNx interlayer method
Authors: Li Yang , Chen Shengchang , Kong Man , Li Senlin , Tian Wu , Sun Shichuang , Wu Zhihao , Fang Yanyan , Dai Jiangnan , Chen Changqing
Published: January 2014

The dislocation density in AlGaN epitaxial layers with Al content as high as 45% grown on sapphire substrates has been effectively reduced by introducing an in-situ deposited SiNx nanomask layer in this study. By closely monitoring the evolution of numerous material properties, such as surface morphology, dislocation density, photoluminescence, strain states, and electron mobility of the Si-Al0.45Ga0.55N layers as the functions of SiNx interlayer growth time, the surface coverage fraction of SiNx is found to be a crucial factor determining the strain states and dislocation density. The dependence of the strain states and the dislocation density on the surface coverage fraction of SiNx nanomask supports the very different growth models of Al-rich AlGaN on SiNx interlayer due to the reduced nucleation selectivity compared with the GaN counterpart. Compared with GaN, which can only nucleate at open pores of SiNx nanomask, Al-rich AlGaN can simultaneously nucleate at both open pores and SiNx covered areas. Dislocations will annihilate at the openings due to the 3D growth initiated on the opening area, while 2D growth mode is preserved on SiNx and the threading dislocations are also preserved. During the following growth process, lateral overgrowth will proceed from the Al0.45Ga0.55N islands on the openings towards the regions covered by SiNx, relaxing the compressive strain and bending the dislocations at the same time.
Loading and release of internally self-assembled emulsions embedded in a magnetic hydrogel
Authors: Milošević Irena , Guillot Samuel , Tadić Marin , Duttine Mathieu , Duguet Etienne , Pierzchala Katarzyna , Sienkiewicz Andrzej , Forró László , Saboungi Marie-Louise
Published: January 2014

We have investigated drug loading and release from thermosensitive gel emulsions with external triggering by an alternating magnetic field (AMF) for on-demand drug delivery. Superparamagnetic iron oxide nanoparticles dispersed in gel emulsions were used to study the loading and release capabilities, with the stable nitroxide radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) serving as the model drug. AMF activation gave similar results to temperature activation in a water bath at 37 °C, showing that the principal effect of the AMF is a temperature increase without burst release. These results suggest that the system could play an important role in the development of advanced drug delivery.
Fluorescence lifetime imaging microscopy and polar-plot analysis of gallium selenide crystals
Authors: Zahner S. , Kador L. , Allakhverdiev K. R. , Salaev E. Yu. , Huseyinoğlu M. F.
Published: January 2014

Crystals of the layered chalcogenide semiconductor gallium selenide (GaSe) were studied with fluorescence lifetime imaging microscopy in the frequency domain, the excitation source being a cw frequency-doubled Nd:YAG laser modulated between 25 and 50 MHz. The non-zero photoluminescence (PL) lifetime leads to a change of the relative modulation amplitude (m) and a phase lag (ϕ) of the luminescence with respect to the excitation. The data were analyzed with the polar-plot (or phasor) approach by plotting m sinϕ versus mcosϕ. Data points of different spots on the sample show strong inhomogeneities and form looping structures in the polar plot. Moreover, they extend distinctly outside the characteristic semi-circle. The latter point is due to the nearly quadratic variation of the PL signal with excitation intensity, whereas the looping structures indicate the presence of energy transfer processes between (at least) two different emitting states. The analysis of the data shows that the same exciton state(s) are involved in both absorption and PL emission of GaSe.
Finite-thickness effect on crystallization kinetics in thin films and its adaptation in the Johnson–Mehl–Avrami–Kolmogorov model
Authors: Očenášek Jan , Novák Petr , Agbo Solomon
Published: January 2014

The Johnson–Mehl–Avrami–Kolmogorov (JMAK) model is widely used to quantify the isothermal crystallization kinetics. The present work reports an analytical solution for the crystallization kinetics in the special case of plate-shaped samples with a finite thickness. As a result, we obtained an adapted JMAK model revealing the thickness range which influences the crystallization kinetics mode significantly. The analytical solution also provides theoretical bounds for the film thickness, where the assumption of 2D or 3D kinetics is accurate. Finally, the conclusions related to amorphous silicon and amorphous nickel-titanium thin films are reported.
Temperature dependence of the band-band absorption coefficient in crystalline silicon from photoluminescence
Authors: Nguyen Hieu T. , Rougieux Fiacre E. , Mitchell Bernhard , Macdonald Daniel
Published: January 2014

The band-band absorption coefficient in crystalline silicon has been determined using spectral photoluminescence measurements across the wavelength range of 990–1300 nm, and a parameterization of the temperature dependence has been established to allow interpolation of accurate values of the absorption coefficient for any temperature between 170 and 363 K. Band-band absorption coefficient measurements across a temperature range of 78–363 K are found to match well with previous results from MacFarlane et al. [Phys. Rev. 111, 1245 (1958)], and are extended to significantly longer wavelengths. In addition, we report the band-band absorption coefficient across the temperature range from 270–350 K with 10 K intervals, a range in which most practical silicon based devices operate, and for which there are only sparse data available at present. Moreover, the absorption coefficient is shown to vary by up to 50% for every 10 K increment around room temperature. Furthermore, the likely origins of the differences among the absorption coefficient of several commonly referenced works by Green [Sol. Energy Mater. Sol. Cells 92, 1305 (2008)], Daub and Würfel [Phys. Rev. Lett. 74, 1020 (1995)], and MacFarlane et al. [Phys. Rev. 111, 1245 (1958)] are discussed.
Effect of ultrathin gold on the Ohmic-to-Schottky transition in Al/ZnO contacts: A first-principles investigation
Authors: Catellani Alessandra , Calzolari Arrigo , Ruini Alice
Published: January 2014

By using a first principles approach based on Density Functional Theory, we present a study of the manipulation of the Al/ZnO contact, which may be turned from Ohmic to Schottky by simply including an ultrathin Au interlayer at the interface. To understand the rationale behind this contact design, we first characterize the original Al/ZnO interface, which results to be Ohmic, irrespective of the substrate termination and of eventual n-doping. Then, we identify the mechanisms that regulate the contact behavior switch upon gold insertion by highlighting the different charge transfer processes that take place at the interface.