bluuebunny/crossref_metadata_2025 huggingface dataset:
The “entropy floor” is porous – remarks on the coexistence of star formation and kinetic AGN feedback
Authors: Tremblay Grant R.
Published: July 2014

We discuss the morphology of star forming clouds and filaments in the central (≲ 50 kpc) regions of 16 low redshift (z<0.3) cool core brightest cluster galaxies (BCGs). The sample spans decades-wide ranges of X-ray mass deposition and star formation rates as well as active galactic nucleus (AGN) mechanical power, encompassing both high and low extremes of the supposed intracluster medium (ICM) cooling and AGN heating feedback cycle. Amid evidence that the gas fueling both star formation and AGN activity has condensed from the hot atmosphere, we present new and archival Hubble Space Telescope (HST) images of far ultraviolet (FUV) continuum emission directly associated with young stars, acting as a calorimeter for the degree to which the suppression of star formation by AGN mechanical feedback may be spatially or temporally inefficient. We discuss evidence for temporal and possibly cyclical variation in star formation rate, wherein elevated cooling episodes are permitted when AGN feedback is in a low-power state, and vice-versa. Several sources exhibit strong morphological evidence that low levels of star formation can survive and may indeed be triggered by the passage of a propagating radio source. We conclude by discussing the apparent coexistence of feedback and star formation. If AGN mechanical power does establish an “entropy floor”, this floor must be porous, or raise and lower as the AGN varies in power.
AGN populations in compact groups of galaxies
Authors: Amirkhanian A. S. , del Olmo A. , Egikian A. G. , Tiersch H. , Stoll D. , Perea J.
Published: July 2014

Compact groups of galaxies (CGG) have revealed some interesting problems from their origin and lifetime to the evolution of their members in such dense configurations. Some authors suppose that CGG probably are the best location for AGNs in the local Universe. According to our preliminary data about 7–10% of member galaxies in Shahbazian compact groups (SHCGs) are emission-line galaxies including the broad-line AGN and the narrow emission-line galaxies. Shahbazian 355/4 is a classical Seyfert 1 galaxy at the same redshift as host group. Moreover Shahbazian 278/4 is also a broad-line AGN in an early-type galaxy. This is the first emission-line object in SHCGs. Meanwhile there is no Seyfert 1 galaxy among the spectroscopically investigated galaxies in the South compact groups, although more than 70% of the member galaxies in these groups probably have an active nucleus. The UZC- compact groups have an excess of Seyfert 2s (but not Seyfert 1s!). Further observational studies are necessary to understand such and many other questions related to the puzzle of CGG.
Relative frequencies of supernovae versus properties of spiral hosts
Authors: Hakobyan A. A. , Nazaryan T. A. , Adibekyan V. Zh. , Petrosian A. R. , Aramyan L. S. , Kunth D. , Mamon G. A. , de Lapparent V. , Bertin E. , Gomes J. M. , Turatto M.
Published: July 2014

In this work, we present an analysis of SNe number ratios in spiral galaxies with different morphological subtypes, luminosities, sSFR, and metallicities, to provide important information about the physical properties of the progenitor populations.
The galaxy environment of a QSO at z ~ 5.7
Authors: Bañados E. , Venemans B. P. , Walter Fabian , Kurk Jaron , Overzier Roderik , Ouchi Masami
Published: July 2014

High-redshift quasars are thought to reside in the most massive halos in the early universe and should therefore be located in fields with overdensities of galaxies, which are expected to evolve into galaxy clusters seen in the local Universe. In Bañados et al. (2013), we used deep narrow-band imaging to study the environment of the z=5.72 quasar ULAS J0203 + 0012. The redshift range probed by our narrow band selection is Δz ~ 0.1. This was the first time that Lyman alpha emitters (LAEs) were searched for near a z ~ 6 quasar, to provide clues on the surroundings of quasars at the end of the epoch of reionization. The main result of this work is that no enhancement of LAEs has been found in the surroundings of ULAS J0203 + 0012. We discuss different explanations and interpretations for this non-detection of a galaxy overdensity.
IGM Heating and AGN activity in Fossil Galaxy Groups
Authors: Miraghaei H. , Khosroshahi H. G. , Klöckner H.-R. , Ponman T. J. , Jetha N. N. , Raychaudhury S.
Published: July 2014

Fossil galaxy groups are energetically and morphologically ideal environments to study the intergalactic medium (IGM) heating, because their inter-galactic gas is undisturbed due to the lack of recent group scale mergers. We study the role of active galactic nuclei (AGN) in heating the IGM in a sample of five fossil galaxy groups by employing properties at 610 MHz and 1.4 GHz. We find that two of the dominant galaxies in fossil groups, ESO 3060170 and RX J1416.4+2315, are associated with the radio lobes. We evaluate the PdV work of the radio lobes and their corresponding heating power and compare to the X-ray emission loss within cooling radius. Our results show that the power due to mechanical heating is not sufficiently high to suppress the cooling.
Spatially Resolved Spectroscopy to Confirm or Disprove Dual Active Galactic Nuclei
Authors: McGurk Rosalie C. , Max Claire E. , Medling Anne , Shields Gregory A.
Published: July 2014

When galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see dual active galactic nuclei (AGNs) in a fraction of galaxy mergers. Candidates for galaxies containing dual AGNs have been identified by the presence of double-peaked narrow [O III] emission lines and by high spatial resolution images of close galaxy pairs. 30% of double-peaked narrow [OIII] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy is needed to confirm these galaxy pairs as systems with double AGNs. With the Keck 2 Laser Guide Star Adaptive Optics system and the OSIRIS near-infrared integral field spectrograph, we obtained spatially resolved spectra for SDSS J095207.62+255257.2, confirming that it contains a Type 1 and a Type 2 AGN separated by 4.8 kpc (=1.0″). We performed similar integral field and long-slit spectroscopy observations of more spatially separated candidate dual AGNs and will report on the varied results. By assessing what fraction of radio-quiet double-peaked emission line SDSS AGNs are true dual AGNs, we can better constrain the statistics of dual AGNs and characterize physical conditions throughout these interacting AGNs.
When disks collide: major and minor mergers in disk galaxies
Authors: Mezcua M. , Lobanov A. P. , Mediavilla E. , Karouzos M.
Published: July 2014

We present the surface brightness profile fitting of a sample of double nucleus disk galaxies, minor merger candidates. We have decomposed these systems into two compact nuclear components and one or two extended galaxy disk components and estimated the luminosity of the primary and secondary nucleus and of the host galaxy and the separation between the two nuclei. Based on the ratio of nuclear luminosities we find that most of the sources qualify as major mergers despite their initial classification as minor merging systems. This is supported by the finding that 65% of the host galaxies are fitted only by one galaxy disk and that the luminosity of both the primary and the secondary nucleus decreases with decreasing nuclear separation, as expected from simulations of disk galaxy mergers. All these results indicate that these sources are most plausibly in the post-merger state of a major merger event. We also identify 19 candidates to binary active nucleus with nuclear separation ≤1 kpc.
Are the “Physically Bound Systems” beyond the Cosmological Expansion Effect? (A provocative musing on the given theme)
Authors: Harutyunian Haik A.
Published: July 2014

Influence of the dark energy at small scales is considered. Interaction and energy exchange between ordinary matter and dark energy is proposed as a working hypothesis. Some observational facts are put into the base of this consideration: the large rate of lunar retreat and the acceleration of cosmic expansion which proves the energy exchange between ordinary matter and dark energy. If the possibility of the space and matter expansion at the scales under consideration is accepted one can show that the dark energy transformed into the object's potential energy is enough to generate cluster of galaxies over the Hubble time due to matter ejection mechanism.
Optical variability of quasars: a damped random walk
Authors: Ivezić Željko , MacLeod Chelsea
Published: July 2014

A damped random walk is a stochastic process, defined by an exponential covariance matrix that behaves as a random walk for short time scales and asymptotically achieves a finite variability amplitude at long time scales. Over the last few years, it has been demonstrated, mostly but not exclusively using SDSS data, that a damped random walk model provides a satisfactory statistical description of observed quasar variability in the optical wavelength range, for rest-frame timescales from 5 days to 2000 days. The best-fit characteristic timescale and asymptotic variability amplitude scale with the luminosity, black hole mass, and rest wavelength, and appear independent of redshift. In addition to providing insights into the physics of quasar variability, the best-fit model parameters can be used to efficiently separate quasars from stars in imaging surveys with adequate long-term multi-epoch data, such as expected from LSST.
Optical microvariability of bright type 2 quasars
Authors: Polednikova Jana , Ederoclite Alessandro , Cepa Jordi , de Diego Onsurbe José Antonio , González-Serrano José Ignacio
Published: July 2014

We present results from a project focused on searching optical microvariabilty (also known as “intra-night” variability) in type 2 - obscured - quasars. Optical microvariability can be described as very small changes in the flux, typically in the order of hundredths of magnitude, which can be observed on timescales of hours. Such studies have been so far conducted for samples of blazars and type 1, unobscured, AGNs, where the optical microvariability was detected with success. We have focused on obscured targets which would pose a challenge to the AGN standard model. In the present work, however, we have observed a sample of three bright (g mag < 17) type 2 quasar, based on the catalog of type 2 quasars from SDSS of Reyes et al. (2008). The observations were carried out with the 1.5 meter telescope at San Pedro Martir observatory in Mexico. The sample was observed during an observation period of four days in Johnsons V filter, resulting in at least two continuous intervals of observations per target during the observational run. We have obtained differential light curves for our sources as well as for the comparison stars. They were analyzed using one-way analysis of variance statistical test (ANOVA), which has been repeatedly used in the past for studies of unobscured targets. Based on the results from the statistical analysis, we show that at least two out of three observed targets appear to be variable on time scales of hours. So far, this is the first study which confirmed existence of optical microvariability in type 2 quasars.
Results on Panoramic Spectroscopy of Mrk 171
Authors: Hakopian S. A. , Balayan S. K. , Movsessian T. A.
Published: July 2014

Observations of Mrk 171, aimed at conduction of panoramic spectroscopy, were undertaken with the Byurakan 2.6-m telescope using spectrograph “VAGR”. Within the two components of the galaxy, Mrk171W and Mrk171E, there were differentiated eight condensations of starforming activiity, i.e. HII-regions, and no sign of AGN activity was revealed inspite of existing suggestions.
The MASIV Legacy: Surveying AGN Intra-day Variability at Radio Wavelengths
Authors: Koay J. Y. , Macquart J.-P. , Rickett B. J. , Bignall H. E. , Jauncey D. L. , Pursimo T. , Reynolds C. , Lovell J. E. J. , Kedziora-Chudczer L. , Ojha R.
Published: July 2014

The Micro-arcsecond Scintillation-Induced Variability (MASIV) Survey and its follow-up observations have provided large datasets of AGN intra-day variability (IDV) at radio wavelengths. These data have shown that IDV arises mainly from scintillation caused by scattering in the ionized interstellar medium (ISM) of our Galaxy, based on correlation with Galactic latitudes and line-of-sight Galactic electron column densities. The sensitivity of interstellar scintillation (ISS) towards source angular sizes has provided a new tool for studying the most compact components of radio-loud AGNs at microarcsecond (μas) scale resolution - much higher than any ground-based radio interferometer. We present here key results from the MASIV Survey and its follow-up observations, and point to relevant papers where these results have been published.
The Role of Radio Loud Phase of Nuclear Activity in Galaxy Formation and Evolution
Authors: Ohanian Gabriel A.
Published: July 2014

Key questions, which arise when one tries to clear up a problem of formation and evolution of galaxies, is the question of energy: what is the energetic budget of AGN owing to form galaxies and provide its subsequent development? Hence, for understanding the formation and evolution of galaxies, it is important to estimate the energetic budget of AGN which we try to do involving radio loud phase of nuclear activity.
Alternative Models of the Outcome Questionnaire-45
Authors: Gayle Thalmayer Amber
Published: July 2014

The Outcome Questionnaire-45 (OQ) reliably quantifies level of psychological functioning and change during treatment. The three subscales, however, are not well validated. Could alternative scales, based on personality dimensions or other groupings of psychological problems better explain patterns of response? In Study 1, the intended structure and four alternative models were compared using EFA and CFA in random thirds of a community clinic intake sample (N = 1,822). Oblique and bi-level models were compared. Preferred models were tested for stability in samples from later time points. In Study 2, the models were compared in a nonclinical sample (N = 589). Most bi-level models provided adequate fit per standards previously established for the Outcome Questionnaire-45. A seven-factor model of psychological problems provided better fit than any yet reported for this inventory.
Measuring Decision-Making Regret Among French Populations
Authors: Bonaccio Silvia , Girard Annie J.
Published: July 2014

Most studies examining decision-making processes are conducted in English. As a result, the majority of scales that are used to measure relevant constructs are unavailable in other languages. The Regret Scale ( Schwartz, Ward, Monterosso, Lyubomirsky, White, & Lehman, 2002 ) consists of five items that assess an individual’s tendency to experience regret. The purpose of this study was to translate and validate this scale into French. Psychometric properties of the newly created Échelle de Regret were verified with a sample of native French-speaking participants. The properties of the translated scale were then compared to those of the original scale derived from a sample of native English-speaking participants. Results of measurement invariance analyses indicate that the measure functions similarly across both linguistic groups. Thus, the Échelle de Regret can be used with confidence to assess regret proneness in French-speaking populations.
Forced Zero Cross-Loading Misspecifications in Measurement Component of Structural Equation Models
Authors: Hsu Hsien-Yuan , Troncoso Skidmore Susan , Li Yan , Thompson Bruce
Published: July 2014

The purpose of the present paper was to evaluate the effect of constraining near-zero parameter cross-loadings to zero in the measurement component of a structural equation model. A Monte Carlo 3 × 5 × 2 simulation design was conducted (i.e., sample sizes of 200, 600, and 1,000; parameter cross-loadings of 0.07, 0.10, 0.13, 0.16, and 0.19 misspecified to be zero; and parameter path coefficients in the structural model of either 0.50 or 0.70). Results indicated that factor pattern coefficients and factor covariances were overestimated in measurement models when near-zero parameter cross-loadings constrained to zero were higher than 0.13 in the population. Moreover, the path coefficients between factors were misestimated when the near-zero parameter cross-loadings constrained to zero were noteworthy. Our results add to the literature detailing the importance of testing individual model specification decisions, and not simply evaluating omnibus model fit statistics.
Assessing Person Fit With the Information Matrix Test
Authors: Ranger Jochen , Kuhn Jörg-Tobias
Published: July 2014

In this manuscript, a new approach to the analysis of person fit is presented that is based on the information matrix test of White (1982) . This test can be interpreted as a test of trait stability during the measurement situation. The test follows approximately a χ2-distribution. In small samples, the approximation can be improved by a higher-order expansion. The performance of the test is explored in a simulation study. This simulation study suggests that the test adheres to the nominal Type-I error rate well, although it tends to be conservative in very short scales. The power of the test is compared to the power of four alternative tests of person fit. This comparison corroborates that the power of the information matrix test is similar to the power of the alternative tests. Advantages and areas of application of the information matrix test are discussed.
Direct Detection of FoxP3 Expression in Thymic Double-Negative CD4−CD8− Cells by Flow Cytometry
Authors: Liu Gang , Li Zongfang , Wei Yang , Lin Yan , Yang Cengceng , Liu Tie
Published: July 2014

Foxp3 expression is a marker of regulatory T cells (Treg), but how early it is expressed in the thymus is still not fully defined. In this study, we examined Foxp3 expression in double-negative (DN) CD4−CD8− T cell precursors in the thymus by flow cytometry. By increasing the number of collected cells from the conventional 104 cells up to more than 106 cells during flow cytometry, we found that DN cells exhibited higher Foxp3 expression than double-positive (DP) CD4+CD8+ and single-positive (SP) CD4+ or CD8+ (SP) T cells. CD44+ expression positively correlated with Foxp3 in thymic DN cells. Furthermore, TCR-β−CD25+ DN cells exhibited the highest frequency of Foxp3-expressing cells. Almost all Foxp3+ cells expressed CD25in DN cells. These results suggest that Foxp3 expression in DN cells can directly be detected by flow cytometry and it was positively corelated with CD25 and CD44 in DN cells.
Hf-Nd isotopic variability in mineral dust from Chinese and Mongolian deserts: implications for sources and dispersal
Authors: Zhao Wancang , Sun Youbin , Balsam William , Lu Huayu , Liu Lianwen , Chen Jun , Ji Junfeng
Published: July 2014

Mineral dust provenances are closely related to the orogenic processes which may have distinct Hf-Nd isotopic signatures. Here we report the clay-sized (<2 μm) Hf-Nd isotope data from Asian dust sources to better constrain the source and transport dynamics of dust deposition in the North Pacific. Our results show that there is a more positive radiogenic Hf isotopic composition with clay-sized fractions than the corresponding bulk sample and a decoupling of the Hf-Nd couplets in the clay formation during the weathering process. The clay-sized Hf-Nd isotopic compositions of the desert samples from the Sino-Korean-Tarim Craton (SKTC) are different from those of the Gobi and deserts from the Central Asian Orogeny Belt (CAOB) due to varying tectonic and weathering controls. The Hf-Nd isotopic compositions of dust in the North Pacific central province (NPC) match closely with those from the Taklimakan, Badain Jaran and adjacent Tengger deserts, implying that the NPC dust was mainly transported from these potential sources by the westerly jet. Our study indicates that dusts from the CAOB Gobi deserts either didn't arrive in NPC or were quantitatively insignificant, but they were likely transported to the North Pacific margin province (NPM) by East Asian winter monsoon.
Mapping the resting and stimulated EGFR in cell membranes with topography and recognition imaging
Authors: Zhao Weidong , Pan Yangang , Wu Jiazhen , Cai Mingjun , Tian Yongmei , Xu Haijiao , Yu Lihua , Wang Hongda
Published: July 2014

EGFR exists in membrane protein clusters both at the resting and stimulated states revealed by single molecule recognition imaging.
Sub-100 nm patterning of TiO2film for the regulation of endothelial and smooth muscle cell functions
Authors: Muhammad R. , Lim S. H. , Goh S. H. , Law J. B. K. , Saifullah M. S. M. , Ho G. W. , Yim E. K. F.
Published: July 2014

A sub-100 nm nano-imprinted TiO2layer significantly inhibited the proliferation of SMCs and increased the proliferation of HUVECs. Focal adhesions size, density and distribution were significantly modulated by nano-imprinted TiO2.
AgNO2-mediated direct nitration of the quinoxaline tertiary benzylic C–H bond and direct conversion of 2-methyl quinoxalines into related nitriles
Authors: Wu Degui , Zhang Jian , Cui Jianhai , Zhang Wei , Liu Yunkui
Published: July 2014

A unique method for AgNO2-mediated direct nitration of the quinoxaline tertiary C–H bond and direct conversion of 2-methyl quinoxalines into 2-quinoxaline nitriles under oxidative conditions has been developed.
Supramolecular pyridyl urea gels as soft matter with antibacterial properties against MRSA and/or E. coli
Authors: Pandurangan Komala , Kitchen Jonathan A. , Blasco Salvador , Paradisi Francesca , Gunnlaugsson Thorfinnur
Published: July 2014

The development of a family of twelve aryl pyridyl ureas, their crystallography and the ability of a number of these to form hydrogen bonding supramolecular gels with antimicrobial properties are described.
TBHP-promoted sequential radical silylation and aromatisation of aryl isonitriles with silanes
Authors: Wang Lei , Zhu Hui , Guo Songjin , Cheng Jiang , Yu Jin-Tao
Published: July 2014

TBHP-promoted sequential silylation and aromatisation of isonitriles was developed, where the silyl group was regioselectively installed at the 6-position of phenanthridines. The addition of a silyl radical to the isonitrile followed by an intramolecular aromatic cyclization was involved in this transformation.
Stereoselective [3+2] cycloaddition of N-tert-butanesulfinyl imines to arynes facilitated by a removable PhSO2CF2 group: synthesis and transformation of cyclic sulfoximines
Authors: Ye Wenchao , Zhang Laijun , Ni Chuanfa , Rong Jian , Hu Jinbo
Published: July 2014

An unprecedented [3+2] cycloaddition between N-tert-butane sulfinyl imines and arynes provides a stereoselective method for the synthesis of cyclic sulfoximines.
An IR modulator based on the self-assembly of gold nanoparticles on germanium
Authors: Ghosh Harekrishna , Bouhekka Ahmed , Bürgi Thomas
Published: July 2014

Germanium modified with gold nanoparticles shows a drastically increased concentration of holes near the valence band edge upon illumination with visible or near infrared light.
On the nature of non-covalent interactions in isomers of 2,5-dichloro-1,4-benzoquinone dimers – ground- and excited-state properties
Authors: Vijaya Pandiyan B. , Deepa P. , Kolandaivel P.
Published: July 2014

Impact of intermolecular NCIs (C–H⋯O, C–H⋯Cl, C–Cl⋯O, C–Cl⋯Cl–C, C–O⋯C, C–Cl⋯C and C–O⋯π) on chirality arrangement in the isomers of the 2,5-dichloro-1,4-benzoquinone (DCBQ) dimer.
Theoretical study of Δ-3-(+)-carene oxidation
Authors: Baptista Leonardo , Fernandes Francisco Lilian , Dias Jacques Fernandes , da Silva Edilson Clemente , Ferreira dos Santos Claudio Vinicius , Gil de Mendonça Felipe Simões , Arbilla Graciela
Published: July 2014

The rate-limiting steps of Δ-3-(+)-carene oxidation by ozone and OH radicals were studied by quantum-chemical methods and the atmospheric implications were discussed.
The conjugated oligoelectrolyte DSSN+ enables exceptional coulombic efficiencyviadirect electron transfer for anode-respiringShewanella oneidensisMR-1—a mechanistic study
Authors: Kirchhofer Nathan D. , Chen Xiaofen , Marsili Enrico , Sumner James J. , Dahlquist Frederick W. , Bazan Guillermo C.
Published: July 2014

Biofilm electrochemistry reveals that DSSN+ increases coulombic efficiency by enhancing the native direct electron transfer pathway ofS. oneidensisMR-1.
Combination of Pd/C and Amberlyst-15 in a single reactor for the acid/hydrogenating catalytic conversion of carbohydrates to 5-hydroxy-2,5-hexanedione
Authors: liu Fei , Audemar Maïté , De Oliveira Vigier Karine , Clacens Jean-Marc , De Campo Floryan , Jérôme François
Published: July 2014

Here we report an effective cooperation between Pd/C and Amberlyst-15 for the catalytic conversion of fructose and inulin to 5-hydroxymethyl-2,5-hexanedione in a one-pot process.
Highly efficient hybrid solar cells with tunable dipole at the donor–acceptor interface
Authors: Fu Weifei , Wang Ling , Ling Jun , Li Hanying , Shi Minmin , Xue Jiangeng , Chen Hongzheng
Published: July 2014

Effects of molecular dipole at the polymer–nanocrystal interface on the energy level alignment, the exciton dissociation process, and consequently the photovoltaic performance of bulk heterojunction hybrid solar cells are systemically studied.
Impact of optical antennas on active optoelectronic devices
Authors: Bonakdar Alireza , Mohseni Hooman
Published: July 2014

Remarkable progress has been made in the fabrication and characterization of optical antennas that are integrated with optoelectronic devices.
Dynamics and polarization of superparamagnetic chiral nanomotors in a rotating magnetic field
Authors: Morozov Konstantin I. , Leshansky Alexander M.
Published: July 2014

We present a theory of dynamic orientation and propulsion of superparamagnetic nano-screws, both showing universal dependence on scaled frequency of actuating magnetic field.
The role of a nanoparticle monolayer on the flow of polymer melts in nanochannels
Authors: Huang Long-Biao , Zhou Ye , Han Su-Ting , Yan Yan , Zhou Li , Roy V. A. L.
Published: July 2014

The flowing behaviour of polymer melts in nanochannels with diverse surface conditions were experimentally investigated and the results are presented in this paper.
Plasmon modes in graphene: status and prospect
Authors: Politano Antonio , Chiarello Gennaro
Published: July 2014

The plasmonic excitation of graphene (intraband and interband plasmons) and the composite modes formed by plasmons with other quasi-particles are reviewed.
Self-assembly: an option to nanoporous metal nanocrystals
Authors: Ying Jie , Yang Xiao-Yu , Tian Ge , Janiak Christoph , Su Bao-Lian
Published: July 2014

Self-assembly, which is as an excellent option to nanoporous metal nanocrystals with desired structure and rational performance, has been summarized.
Copper metal–organic framework nanocrystal for plane effect nonenzymatic electro-catalytic activity of glucose
Authors: Liu Yuanying , Zhang Youjuan , Chen Jing , Pang Huan
Published: July 2014

Nanocrystal plane affects nonenzymatic electro-catalytic glucose activity of [Cu3(btc)2] nanocrystals, and the activity changes from highly sensitive to general with decrease of {100} crystal planes from cubes to octahedra.
Polyalkynylanthracenes – syntheses, structures and their behaviour towards UV irradiation
Authors: Lamm Jan-Hendrik , Glatthor Johanna , Weddeling Jan-Henrik , Mix Andreas , Chmiel Jasmin , Neumann Beate , Stammler Hans-Georg , Mitzel Norbert W.
Published: July 2014

A series of 1,5-, 1,8-, 9,10- and 1,8,10-alkynyl-substituted anthracenes have been synthesised. Amongst others, 9,10-bis[(trimethylsilyl)ethynyl]anthracene was photo-dimerised. The photodimer is thermally unstable as was investigated by VT NMR spectroscopy.
Dual-cure photochemical/thermal polymerization of acrylates: a photoassisted process at low light intensity
Authors: Retailleau M. , Ibrahim A. , Allonas X.
Published: July 2014

The synergistic effect in dual-cure polymerization.
Brønsted acidic ionic liquids of aza-crown ether complex cations: preparation and applications in organic reactions
Authors: Cheng Chen , Jing Huanwang
Published: July 2014

Brønsted acidic ionic liquids ofaza-crown ether complex cations acted as versatile and efficient catalysts to facilitate several organic reactions.
Facile synthesis of flexible graphene–silver composite papers with promising electrical and thermal conductivity performances
Authors: Huang Sheng-Yun , Zhang Kai , Yuen Matthew M. F. , Fu Xian-Zhu , Sun Rong , Wong Ching-Ping
Published: July 2014

Free-standing and flexible graphene–silver (GE–Ag) composite paper has been successfully fabricated through an evaporation of graphene oxide–AgNO3 aqueous aerosol followed by a chemical reduction.
Ionization energies and photoelectron spectra of fat-soluble vitamins in the gas phase: a theoretical study
Authors: Abyar Fatemeh , Farrokhpour Hossein
Published: July 2014

The electronic structures and photoelectron spectra of several fat-soluble vitamins including A (all-trans-retinol and its two derivatives, 13-cis-retinoic acid and all-trans-retinoic acid), D2, D3, E (consisting of α-tocopherol, β-tocopherol, γ-tocopherol and δ-tocopherol) and K were studied theoretically in this work.
Diguanidinocalix[4]arenes as effective and selective catalysts of the cleavage of diribonucleoside monophosphates
Authors: Salvio Riccardo , Cacciapaglia Roberta , Mandolini Luigi , Sansone Francesco , Casnati Alessandro
Published: July 2014

Upper rim diguanidino-cone-calix[4]arenes catalyze the hydrolytic cleavage of diribonucleoside monophosphates in aqueous DMSO with good substrate selectivity and rate accelerations approaching 105-fold in the most favourable substrate-catalyst combinations.
Particle-size and morphology dependence of the preferred interface orientation in LiFePO4 nano-particles
Authors: Abdellahi Aziz , Akyildiz Oncu , Malik Rahul , Thornton Katsuyo , Ceder Gerbrand
Published: July 2014

Using calculations based on first principles, we demonstrate that the preferred interface in singles LiFePO4 particles depends both on the particle size and morphology.
Polythiophenoazomethines – alternate photoactive materials for organic photovoltaics
Authors: Bolduc Andréanne , Barik Satyananda , Lenze Martin R. , Meerholz Klaus , Skene W. G.
Published: July 2014

A solution processable all-thiophene polyazomethine used as a photoactive/donor layer in a bulk heterojunction photovoltaic device with PC60BM.
Planar heterojunction perovskite/PC71BM solar cells with enhanced open-circuit voltage via a (2/1)-step spin-coating process
Authors: Chiang Chien-Hung , Tseng Zong-Liang , Wu Chun-Guey
Published: July 2014

A two-step spin-coating process was used to synthesize perovskite films at ambient conditions. Combining a PEDOT:PSS hole-transport layer and a PC71BM acceptor, the device achieves a power conversion efficiency of 16.31% with a remarkably highVocof 1.05 V and FF of 0.78.
Tuning the composition of biocompatible Gd nanohydrogels to achieve hypersensitive dual T1/T2 MRI contrast agents
Authors: Callewaert Maité , Roullin Valérie Gaëlle , Cadiou Cyril , Millart Elodie , Van Gulik Laurence , Andry Marie Christine , Portefaix Christophe , Hoeffel Christine , Laurent Sophie , Elst Luce Vander , Muller Robert , Molinari Michael , Chuburu Françoise
Published: July 2014

A series of hydrogel nanoparticles incorporating MRI contrast agents (GdDOTP and MS325) as potential cross-linkers were elaborated by an easy and robust ionotropic gelation process.
Recent progress of liposomes in nanomedicine
Authors: Hosta-Rigau Leticia , Schattling Philipp , Teo Boon M. , Lynge Martin E. , Städler Brigitte
Published: July 2014

Liposome formulations are highlighted focusing on their chemical modification, interaction with cells, and use in substrate-mediated drug delivery and cell mimicry.
Thermal evaporation synthesis of SiC/SiOx nanochain heterojunctions and their photoluminescence properties
Authors: Liu Haitao , Huang Zhaohui , Huang Juntong , Fang Minghao , Liu Yan-gai , Wu Xiaowen
Published: July 2014

Chainlike SiC/SiOx heterojunctions were prepared on a silicon wafer by a simplified catalyst-free thermal chemical vapour deposition method.
Area‐ and power‐efficient DC–DC converter with on‐chip compensation
Authors: Liu Pang‐Jung , Chang Yi‐Hsiang
Published: July 2014

A dual‐path capacitor multiplier (DPCM) technique is proposed for on‐chip frequency compensation. The DPCM uses two currents to charge and discharge a compensation capacitor concurrently. Consequently, the equivalent capacitance is amplified dramatically with slight increase in silicon area and power. Thanks to the DPCM, the transient response of the DC–DC converter has improved significantly because of the small compensation capacitor. Experimental results demonstrate converter stability and transient response. The transient recovery time of a 450 mA step load change is <30 μs. With the proposed technique, the compensation capacitor is shrunk significantly and adding the compensation resistor would have helped in improving transient response.
Fresnel‐assisted self‐heterodyne detection for Brillouin gain spectrum characterisation in polymer optical fibres
Authors: Mizuno Y. , Hayashi N. , Nakamura K.
Published: July 2014

It has been experimentally shown that by utilising the Fresnel‐reflected light as the reference light, Brillouin signals in polymer optical fibres (POFs) can be observed with a higher signal‐to‐noise ratio (SNR) than those measured with standard self‐heterodyne detection. This method is basically the same in setup as direct detection, leading to an additional advantage of system simplicity. Moreover, it has been demonstrated that the Brillouin signal in a 1 cm‐long POF can be observed with a moderate SNR using this technique, indicating a potential feasibility of POF‐based distributed Brillouin measurement with a millimetre‐order spatial resolution.
Compact wideband and dual‐band antenna for TD‐LTE and WLAN applications
Authors: Chen Shaojian , Dong Dacheng , Liao Zhouying , Cai Qibo , Liu Gui
Published: July 2014

A novel compact wideband and dual‐band microstrip‐fed antenna is proposed. By using symmetrical inverted‐L‐shaped strips, a fork‐shaped strip, a rectangular slot and a defected ground plane, the dual‐band resonances of the antenna are generated. The measured impedance bandwidths are 1.12 GHz for the lower frequency band (1.87–2.99 GHz), and 780 MHz for the higher frequency band (5.10–5.88 GHz). The fabricated antenna can be used to cover the entire required bands for time‐division‐long‐term evolution (1880–2655 MHz) and wireless local area network 802.11 a/b/g (2.4–2.4835, 5.15–5.875 GHz). The measured gain at 2.4 and 5.5 GHz is 2.1 and 6.1 dBi, respectively. The antenna shows a compact size of 25 × 30 × 0.8 mm. The details of the antenna design, the operation mechanism and the simulated and measured results are presented.
Electric‐LC resonators at microwave for oil sensing
Authors: Yaghmaee P. , Minoofar H.
Published: July 2014

A modified electric‐LC resonators array is proposed which makes use of a capacitive gap for oil sensing. The resonator was fabricated on a Duroid 5880 substrate with a thickness of 3.05 mm. The modified resonator operates at a frequency of 6.28 GHz and has an 8 × 2 array of cells. The compared results from the prototype measurements and the fitted curves from full‐wave electromagnetic simulations indicate accurate relative permittivity sensing for this resonator at the C‐band.
Finite‐SNR diversity‐multiplexing trade‐off of inter‐vehicular cooperative diversity protocols
Authors: Perera P. , Jayalath A.D.S.
Published: July 2014

The finite‐signal‐to‐noise ratio (SNR) diversity‐multiplexing trade‐off (DMT) of cooperative diversity protocols are investigated in vehicular networks based on cascaded Rayleigh fading. Lower bounds of DMT at finite SNR for orthogonal and non‐orthogonal protocols are derived. The results showcase the first look into the achievable DMT trade‐off of cooperative diversity in volatile vehicular environments. It is shown that the diversity gains are significantly suboptimal at realistic SNRs.
Efficient pre‐equalisation strategies for the downlink of a multi‐carrier code division multiple‐access wireless network
Authors: Campos‐Delgado Daniel Ulises , Luna‐Rivera Jose Martin , Gutierrez Carlos A.
Published: July 2014

In this study, the problem of optimal synthesis of pre‐equalisation factors for a multi‐carrier code division multiple‐access wireless network is studied under different quality of service (QoS) restrictions and performance objectives. The downlink is particularly addressed, where the QoS is evaluated by the signal‐to‐interference‐noise ratio (SINR) after signal detection by matched filtering. First, the minimum energy formulation under inequality QoS constraints is analysed, and it was concluded that the optimal performance is always achieved at the lower bounds. Next, the minimisation of the peak magnitude of the pre‐equalisation factors was addressed by an optimal synthesis scheme through the infinity norm, where a linear programming strategy is proposed by using an upper bound. Finally, by combining the minimum energy and minimum peak strategies, the minimisation of an upper bound on the peak‐to‐average‐power ratio (PAPR) is suggested, which can be solved through quadratic programming by incorporating the QoS constraints. The new synthesis schemes take into account two important transmitter‐based properties: peak magnitude and PAPR. These ideas were extensively validated in simulation, where the synthesis schemes were compared by Monte Carlo tests at different load and noise levels, and objective SINRs.
Joint maximum likelihood detection and link selection for cooperative MIMO relay systems
Authors: Hesketh Thomas , de Lamare Rodrigo C. , Wales Stephen
Published: July 2014

In this study, the authors propose a cross layer design strategy that consists of a cooperative maximum likelihood detector operating in conjunction with link selection for cooperative multiple‐input multiple‐output relay networks. The system considered is a two phase relaying model, with amplify‐and forward relays. The model considers the effect of relay placement and of large scale shadowing. The authors develop a cooperative maximum likelihood detector for an arbitrary number of relays, and link selection schemes are devised for two scenarios relating to the available knowledge at the destination node, which considers relay combination, with complexity analysis. The authors also propose a cooperative list sphere decoder that processes soft information and implements an iterative detection and decoding scheme. The results of simulations of the systems are presented, with comparisons to system models used in previous literature, and show how the cooperative detector and the proposed link selection schemes affect the bit error rate performance at the destination node, for both the hard decision non‐iterative case, and the soft information iterative processing case.
Channel assignment based on bee algorithms in multi‐hop cognitive radio networks
Authors: Ghasemi Ahmad , Masnadi‐Shirazi Mohammad Ali , Biguesh M. , Qassemi Foad
Published: July 2014

Spectrum management policies are responsible for poor utilisation of the radio spectrum. By carrying out dynamic spectrum management (DSM), cognitive radio (CR) can increase the radio spectrum in wireless systems efficiently. CR technology accounts for the improvement in the spectrum utilisation significantly. One issue of DSM in CR is the assignment of frequency channels among its users. Herein, a general model and four utility functions for optimal channel assignment in open spectrum systems such as CR networks have been defined. First, a new utility function with a better fairness than the other functions is proposed. Then, two new different channel assignment methods, based on the artificial bee colony (ABC) and bee swarm optimisation (BSO) algorithms, are proposed, whereas other certain evolutionary algorithms and colour sensitive graph colouring (CSGC) are used to compare the performances. In order to decrease the search space, based on the channel availability and interference constraints a mapping process between the channel assignment matrix and the position of the bees has been proposed. Our simulation results, compared to the optimal solutions, show that our algorithms drastically improve network performance by reducing interference.
Improving the performance of cell edge users with fractional coordinated fair scheduling
Authors: Abiri Majid , Mehrjoo Mehri
Published: July 2014

In this study, the authors propose a fractional coordinated fair scheduling (FCFS) scheme for improving the performance of cell edge users in long term evolution (LTE‐advanced) networks. To enhance the network spectral efficiency and reduce co‐channel interference, they extend the inter‐cell interference coordination technique for multi‐sector cells. The sectors are coordinated in the sense that they are allowed to transmit simultaneously, if the neighbouring sectors co‐channel interference is less than a threshold value. Accordingly, a coordinated scheduling scheme is proposed to transmit to a fraction of users, located in cell edges, with good channel conditions. The proposed scheme maintains fairness among the users using alpha‐fair criterion. Furthermore, to reduce the computational complexity of the scheduling scheme, they propose a heuristic algorithm based on choosing an appropriate subset of users for scheduling computations. Performance evaluation of FCFS shows that the cell edge users’ throughput improves because of the spectral efficiency enhancement and interference reduction. Moreover, FCFS achieves a higher fairness index with respect to a non‐coordinated fair scheme.
Opportunistic relaying with analogue and digital network coding for two‐way parallel relay network
Authors: Dai Mingjun , Wang Hui , Lin Xiaohui , Zhang Shengli , Chen Bin
Published: July 2014

A pair of terminals exchanging information via a layer of parallel relay nodes under slow fading is considered. Two protocols are proposed based on the combination of opportunistic relaying (OR) with analogue network coding (ANC), named ORANC, or with digital network coding (DNC), named ORDNC, respectively. Two schemes/versions of ORDNC, including 2‐phase ORDNC (2P‐ORDNC) and 3‐phase ORDNC (3P‐ORDNC) are proposed. Their outage performances are investigated. ORANC and 2P‐ORDNC are proved to achieve optimal diversity‐multiplexing tradeoff (DMT), whereas 3P‐ORDNC is proved to be suboptimal. However, from diversity viewpoint only, all the above schemes are proven to achieve full diversity order. Simulation results verify the analysis, and show that 3P‐ORDNC and ORANC shows advantage at low‐ and high‐data rate regions, respectively.
Finite‐time attitude control for rigid spacecraft‐based on adaptive super‐twisting algorithm
Authors: Lu Kunfeng , Xia Yuanqing
Published: July 2014

This study addresses the finite‐time attitude tracking control for rigid spacecraft with external disturbances and inertia uncertainties. A novel adaptive‐gain super‐twist algorithm (STA) improves the control performance of standard STA, and the dynamically adapted control gains can resolve non‐overestimating problem. The presented controllers do not require any knowledge on inertial uncertainties and external disturbances, and are anti‐chattering and anti‐singularity. The closed‐loop spacecraft system under the proposed controllers can provide rapidity, robustness, accuracy and anti‐wasting energy simultaneously, which is largely ignored in the existing literatures. The finite‐time rigorous convergence, an estimation of the convergence time and accurate expression of convergence region are also provided. Finally, comparison results demonstrate that the presented controllers can achieve higher control performance than existing methods. Furthermore, digital simulations utilising the physical parameters of Uosat‐12 verify the effectiveness of the proposed controllers.
Adaptive fuzzy wavelet network for robust fault detection and diagnosis in non‐linear systems
Authors: Shahriari‐kahkeshi Maryam , Sheikholeslam Farid
Published: July 2014

Fault is an undesired and unexpected event that changes the system behaviour resulting in performance degradation or even instability, so how to detect and diagnose fault become a great deal in engineering community. In this study, an adaptive fuzzy wavelet network‐based fault detection and diagnosis (AFWN‐FDD) scheme is proposed for non‐linear systems subject to unstructured uncertainty. The proposed scheme is composed of a diagnostic estimator and an adaptive fuzzy wavelet network (AFWN). Diagnostic estimator is designed for residual generation and fault detection and AFWN based on multi‐resolution analysis of wavelet transform and fuzzy concept is proposed to approximate the model of fault. Learning algorithm of the proposed AFWN‐FDD scheme is derived in the Lyapunov stability sense. The proposed scheme can simultaneously detect and estimate multiple incipient and abrupt faults in the presence of uncertainty. Stability analysis for the presented fault detection and diagnosis (FDD) scheme is provided. Furthermore, an extension of the proposed scheme for a class of non‐linear systems with unmeasured states is presented. The efficiency and performance of the proposed scheme is evaluated through simulations that are performed for two well‐known case studies. Comparison results highlight the superiority and capability of the proposed scheme.
Finite‐time distributed cooperative attitude control for multiple spacecraft with actuator saturation
Authors: Lu Pingli , Gan Chao , Liu Xiangdong
Published: July 2014

In this study, the distributed cooperative attitude tracking controller based on fast terminal sliding mode and Chebyshev neural network (CNN) is proposed for multiple spacecraft formation flying (SFF) system in the presence of external disturbance. Firstly, a new modified fast terminal sliding mode manifold, which has faster convergence rate than the existing terminal sliding modes, is proposed. Then, based on the proposed terminal sliding mode manifold, the distributed cooperative attitude tracking controller is designed for the SFF system, where the time varying reference attitude can be only accessed to a subset of the group member. To guarantee that the output of CNN used in the controller is bounded by the corresponding bound of the approximated unknown function, a modified adaptive law is proposed to revise the sliding mode manifold, meanwhile, the finite‐time stability of SFF system can be also guaranteed. Finally, numerical simulations are presented to verify the validity and robustness of the proposed control algorithm.
Morphological mapping for non‐linear dimensionality reduction
Authors: Kapoor Rajiv , Gupta Rashmi
Published: July 2014

Recently, much research has been carried out on dimensionality reduction techniques that summarise a large set of features into a smaller set, leading to much less redundancy. Among the various non‐linear dimensionality reduction techniques, Isomap and local linear embedding are the most popular techniques. However, these techniques require optimisation on the size of the neighbourhood set, reducing their computational efficiency. To overcome this limitation, a computational efficient algorithm, which is not dependent on size of the neighbourhood set, has been proposed in this study. In the proposed algorithm, morphological mapping (Morphmap) has been used for visualising an image in three dimensions. Then neighbourhood graph construction is done using intensity attenuation function. The pixels in the layer which comes under the angle of divergence can form a part of group vectors and other vectors are removed. In the proposed method, neighbourhood graph construction is not dependent on size of neighbourhood set and removes all the redundant data that reduces complexity to a great extent. Various facial expression datasets have been used to evaluate the performance of the proposed method. Finally, improvement in recognition accuracy with reduced number of computations using the Morphomap algorithm has been shown in the study.