bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell fate changes induced by a Distal-less enhancer-trap transgene in the Drosophila antennal imaginal disc
Authors: Abidi Syeda Nayab Fatima , Smith-Bolton Rachel K.
Published: March 2018

The imaginal discs of the genetically tractable model organism Drosophila melanogaster have been used to study cell-fate specification and plasticity, including homeotic changes and regeneration-induced transdetermination. The identity of the reprogramming mechanisms that induce plasticity has been of great interest in the field. Here we identify a change from antennal fate to eye fate induced by a Distal-less-GAL4 (DllGAL4) P-element insertion that is a mutant allele of Dll and expresses GAL4 in the antennal imaginal disc. While this fate change is not induced by tissue damage, it appears to be a hybrid of transdetermination and homeosis as the GAL4 expression causes upregulation of Wingless, and the Dll mutation is required for the fate change. Neither GAL4 expression nor a Dll mutation on its own is able to induce antenna-to-eye fate changes. This plasticity appears to be unique to the DllGAL4 line, possibly due to cellular stress induced by the high GAL4 expression combined with the severity of the Dll mutation. Thus, we propose that even in the absence of tissue damage, other forms of cellular stress caused by high GAL4 expression can induce determined cell fates to change, and selector gene mutations can sensitize the tissue to these transformations.
In-situ measurements of rare earth elements in deep sea sediments using nuclear methods
Authors: Obhođaš Jasmina , Sudac Davorin , Meric Ilker , Pettersen Helge E. S. , Uroić Milivoj , Nađ Karlo , Valković Vlado
Published: March 2018

The prospecting activities for finding new rare earth elements (REE) sources have increased greatly in recent years. One of the main discoveries was announced in 2011 by Japanese researchers who found large quantities of REE on the ocean seafloor at the sea depths greater than 4,000 m. The classic approach to investigate REE in deep sea sediments is to obtain sediment samples by drilling that is followed by laborious laboratory analysis. This is very expensive, time consuming and not appropriate for exploring vast areas. In order to efficiently explore the ocean floor for REE deposits, the further development of affordable sensors is needed. Here, we propose two nuclear techniques for exploring REE in surface deep sea sediments: i) Passive measurement of lutetium-176 radioactivity, appropriate if long-term in-situ measurements are possible, and ii) The use of the neutron sensor attached to a remotely operated vehicle for rapid in-situ measurement of gadolinium by thermal neutron-capture. Since concentrations of lutetium and gadolinium show strong linear correlation to the total REE concentrations in deep sea sediments, it is possible to deduce the total REE content by measuring Lu or Gd concentrations only.
Effects of the novel pesticide flupyradifurone (Sivanto) on honeybee taste and cognition
Authors: Hesselbach Hannah , Scheiner Ricarda
Published: March 2018

Due to intensive agriculture honeybees are threatened by various pesticides. The use of one group of them, the neonicotinoids, was recently restricted by the European Union. These chemicals bind to the nicotinic acetylcholine receptor (nAchR) in the honeybee brain. Recently, Bayer AG released a new pesticide by the name of “Sivanto” against sucking insects. It is assumed to be harmless for honeybees, although its active ingredient, flupyradifurone, binds nAchR similar to the neonicotinoids. We investigated if this pesticide affects the taste for sugar and cognitive performance in honeybee foragers. These bees are directly exposed to the pesticide while foraging for pollen or nectar. Our results demonstrate that flupyradifurone can reduce taste and appetitive learning performance in honeybees foraging for pollen and nectar, although only the highest concentration had significant effects. Most likely, honeybee foragers will not be exposed to these high concentrations. Therefore, the appropriate use of this pesticide is considered safe for honeybees, at least with respect to the behaviors studied here.
Role of Pacific SSTs in improving reconstructed streamflow over the coterminous US
Authors: Mukhopadhyay Sudarshana , Patskoski Jason M. , Sankarasubramanian A.
Published: March 2018

Reconstructed annual streamflows using tree-ring chronologies provide useful information on moisture availability during the pre-historic period, but they have limitations in estimating high flows due to the upper bound on soil water holding capacity and trees’ metabolic growth limits. We propose a hybrid approach that uses tree-ring chronologies and climatic indices for improving high flows in 301 basins whose annual streamflows are modulated by ENSO and/or PDO. The hybrid decomposition approach relies on separating the moisture supply into the basin as outside-the-region moisture and within-the-region moisture with the former being estimated by SST indices and the latter being estimated by tree-ring chronologies. Analyses over the 301 stations from coterminous US show that the proposed approach improves the high flows and improves the overall error in the reconstructed streamflows. Potential utility of the improved reconstructed annual streamflows with improved high flows is also discussed.
Inhibition of Hedgehog signaling suppresses proliferation and microcyst formation of human Autosomal Dominant Polycystic Kidney Disease cells
Authors: Silva Luciane M. , Jacobs Damon T. , Allard Bailey A. , Fields Timothy A. , Sharma Madhulika , Wallace Darren P. , Tran Pamela V.
Published: March 2018

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is caused by mutation of PKD1 or PKD2, which encode polycystin 1 and 2, respectively. The polycystins localize to primary cilia and the functional loss of the polycystin complex leads to the formation and progressive growth of fluid-filled cysts in the kidney. The pathogenesis of ADPKD is complex and molecular mechanisms connecting ciliary dysfunction to renal cystogenesis are unclear. Primary cilia mediate Hedgehog signaling, which modulates cell proliferation and differentiation in a tissue-dependent manner. Previously, we showed that Hedgehog signaling was increased in cystic kidneys of several PKD mouse models and that Hedgehog inhibition prevented cyst formation in embryonic PKD mouse kidneys treated with cAMP. Here, we show that in human ADPKD tissue, Hedgehog target and activator, Glioma 1, was elevated and localized to cyst-lining epithelial cells and to interstitial cells, suggesting increased autocrine and paracrine Hedgehog signaling in ADPKD, respectively. Further, Hedgehog inhibitors reduced basal and cAMP-induced proliferation of ADPKD cells and cyst formation in vitro. These data suggest that Hedgehog signaling is increased in human ADPKD and that suppression of Hedgehog signaling can counter cellular processes that promote cyst growth in vitro.
Cervical microbiome is altered in cervical intraepithelial neoplasia after loop electrosurgical excision procedure in china
Authors: Zhang Hongwei , Lu Jiaqi , Lu Yingying , Cai Qingqing , Liu Haiou , Xu Congjian
Published: March 2018

Although human papillomavirus (HPV) infection is a major cause leading to the development of cervical intraepithelial neoplasia (CIN), the relationship between genital microbiome and HPV persistence/clearance is not well established. Loop electrosurgical excision procedure (LEEP) is one of standard treatments of CIN 2/3 globally, yet little is known about how the LEEP influence genital microbiota. We conducted a prospective study of 26 patients with CIN2/3 who underwent analysis of cervical microbiome before and after 3 months of LEEP treatment. Cervical swabs were collected, and microbiomes were analyzed by 16S ribosomal RNA gene sequencing. A decrease of cervical microbial diversity was observed after 3 months of LEEP treatment. Notably, a significant shift from community type of a Prevotella-containing and lack of a consistent dominant species to lactobacillus iners dominated microbiome correlated with LEEP. Particularly, Leptotrichia and clostridium were further decreased after LEEP treatment (P = 0.049 and P = 0.002, respectively). Our results suggest that the cervical microbiome is altered after LEEP treatment in patients with CIN2/3. Further studies with larger sample sizes are needed to validate these findings.
Synthesis of a ZSM-5/NaA hybrid zeolite membrane using kaolin as a modification layer
Authors: Xu Yao-Yi , Wei Xue-Ling , Liang Shuai , Sun Ya-Li , Chao Zi-Sheng
Published: March 2018

A kaolin modification layer, which makes the surface of the support smooth and covers the defects on the support, not only attracts Si/Al active materials to the surface of the ceramic tube, but also dissolves under alkaline conditions to assist the growth of zeolite membranes.
Automated flow injection method for the high precision determination of drift tube ion mobility collision cross sections
Authors: Nichols Charles M. , May Jody C. , Sherrod Stacy D. , McLean John A.
Published: March 2018

This work presents a fully automated method to generate absolute Collision Cross Sections for annotated libraries.
Highly emissive salicylidene Schiff bases (SASBs) in solution and their application in the detection of the chemical warfare agent mimic diethyl chlorophosphate
Authors: Liu Huan , Fu Yanyan , Liu Ao , Yu Yaguo , He Qingguo , Cao Huimin , Cheng Jiangong
Published: March 2018

Salicylidene Schiff bases (SASBs) have attracted significant attention because they have unique properties and can be simply synthesized by the condensation reactions; however, their poor fluorescence in solution makes them unable to be used as a fluorescent turn-off probe and limits their application fields.
Anisotropic and amphoteric characteristics of diverse carbenes
Authors: Kim Dong Yeon , Yang D. ChangMo , Madridejos Jenica Marie L. , Hajibabaei Amir , Baig Chunggi , Kim Kwang S.
Published: March 2018

The singlet/triplet stabilities and amphoteric behaviors of diverse carbenes are elucidated with the anisotropic natures of their electron configurations.
Analyzing the efficiency, stability and cost potential for fullerene-free organic photovoltaics in one figure of merit
Authors: Li Ning , McCulloch Iain , Brabec Christoph J.
Published: March 2018

Organic semiconductors with low synthetic complexity, such as P3HT, would be the preferred choice for large-scale production and commercialization.
A compact and scalable fabrication method for robust thin film composite membranes
Authors: Kim Ji Hoon , Cook Marcus , Park Sang Hyun , Moon Sun Ju , Kim Jeong F. , Livingston Andrew G. , Lee Young Moo
Published: March 2018

A compact and scalable membrane fabrication method proposes an environmentally friendly process intensification in terms of efficiently reduced production time, chemical consumption, and wastewater generation, resulting in a robust membrane.
An iron hydroxyl phosphate microoctahedron catalyst as an efficient peroxidase mimic for sensitive and colorimetric quantification of H2O2 and glucose
Authors: Yang Qimeng , Lu Shiyu , Shen Bolei , Bao Shujuan , Liu Yingshuai
Published: March 2018

An iron hydroxyl phosphate that possesses high peroxidase activity is synthesized via a one-step hydrothermal method and used for colorimetric glucose detection in human serum.
Polymer encapsulation of anticancer silver–N-heterocyclic carbene complexes
Authors: Mohamed H. A. , Khuphe M. , Boardman S. J. , Shepherd S. , Phillips R. M. , Thornton P. D. , Willans C. E.
Published: March 2018

Amphiphilic block copolymers have been developed for the encapsulation of silver anticancer drugs.
Collective motion of active Brownian particles with polar alignment
Authors: Martín-Gómez Aitor , Levis Demian , Díaz-Guilera Albert , Pagonabarraga Ignacio
Published: March 2018

The competition between self-propulsion, alignment and excluded volume gives rise to richer non-equilibrium structures than the Vicsek and the ABP models.
Reconfigurable paramagnetic microswimmers: Brownian motion affects non-reciprocal actuation
Authors: Du Di , Hilou Elaa , Biswal Sibani Lisa
Published: March 2018

Paramagnetic particles placed in an eccentric rotating magnetic field results in microscale collective propulsion in which “arm” particles orbit near larger “torso” particles.
Towards traffic matrix prediction with LSTM recurrent neural networks
Authors: Zhao Jianlong , Qu Hua , Zhao Jihong , Jiang Dingchao
Published: March 2018

This Letter investigates traffic matrix (TM) prediction that is widely used in various network management tasks. To fastly and accurately attain timely TM estimation in large‐scale networks, the authors propose a deep architecture based on LSTM recurrent neural networks (RNNs) to model the spatio‐temporal features of network traffic and then propose a novel TM prediction approach based on deep LSTM RNNs and a linear regression model. By training and validating it on real‐world data from Abilene network, the authors show that the proposed TM prediction approach can achieve state‐of‐the‐art TM prediction performance.
Adaptive integral sliding‐mode control strategy of data‐driven cyber‐physical systems against a class of actuator attacks
Authors: Huang Xin , Zhai Ding , Dong Jiuxiang
Published: March 2018

This study is concerned with the reliable and optimal control problems of data‐driven cyber‐physical systems (CPSs) against a class of actuator attacks. Consider an unknown continuous‐time linear physical system with the external disturbance, and it is assumed that control input signals transmitted via network layers are vulnerable to cyber attacks. By introducing a new integral sliding‐mode function and utilising the available data acquired by an off‐policy reinforcement learning algorithm, a novel data‐based adaptive integral sliding‐mode control strategy is presented. Different from the existing control policies, the novel one uses a data‐driven sliding‐mode compensator to eliminate the effect of the actuator attacks such that the stability and a nearly optimal performance of the CPSs can be guaranteed. Finally, the effectiveness of the proposed control strategy is verified by a numerical example.
Colour image encryption technique using differential evolution in non‐subsampled contourlet transform domain
Authors: Kaur Manjit , Kumar Vijay
Published: March 2018

The main challenges of image encryption are robustness against attacks, key space, key sensitivity, and diffusion. To deal with these challenges, a differential evolution‐based image encryption technique is proposed. In the proposed technique, two concepts are utilised to encrypt the images in an efficient manner. The first one is Arnold transform, which is utilised to permute the pixels position of an input image to generate a scrambled image. The second one is differential evolution, which is used to tune the parameters required by a beta chaotic map. Since the beta chaotic map suffers from parameter tuning issue. The entropy of an encrypted image is used as a fitness function. The proposed technique is compared with seven well‐known image encryption techniques over five well‐known images. The experimental results reveal that the proposed technique outperforms the other existing techniques in terms of security and better visual quality.
Localisation and segmentation of optic disc with the fractional‐order Darwinian particle swarm optimisation algorithm
Authors: Guo Fan , Peng Hui , Zou Beiji , Zhao Rongchang , Liu Xiyao
Published: March 2018

Automatic optic disc (OD) localisation and segmentation is still a great challenge in computer‐aided diagnosis and screening system. Here, a new OD segmentation algorithm is proposed based on the distinct features of OD in terms of its intensity and shape. The algorithm includes four stages: image preprocessing, image segmentation, ellipse fitting, and OD localisation and segmentation. In the preprocessing stage, the blood vessel in the input retinal image is removed by using the morphological operation and median filtering in HSL (hue–saturation–lightness) colour space. In the image segmentation and ellipse fitting stages, the fractional‐order Darwinian particle swarm optimisation algorithm is used to extract the brightest region, and the least‐squares optimisation is adopted to detect elliptical OD shape. Finally, the smooth OD borders are generated in the last stage. The proposed method is evaluated by the centroid difference, overlapping ratio, overlap score, and success indexes. Experimental results on the retinal images from DRION, MESSIDOR, ORIGA, and many other public databases demonstrate that the proposed method has superior performance, and may be a suitable tool for automated retinal image analysis.
Proposal of new windings for 5‐X variable reluctance resolvers
Authors: Tootoonchian Farid
Published: March 2018

Here, a new winding is proposed for 5‐X variable reluctance resolver. In the proposed winding method, all the stator teeth are devoted to the signal windings and a peripheral slot is added to the stator core including two excitation coils. The performance of the resolver is discussed using the proposed winding and all previous winding methods. It is shown the position error of the resolver is less than that of the previously proposed methods and it can offer much simpler manufacturing process and consequently lower cost. All the analyses are performed using three‐dimensional time stepping finite element method and finally, a prototype of the resolver is built and tested. The comparison between simulation and test results verifies the success of the proposed winding method.
Facile synthesis of TiO2 hollow spheres via aerosol‐assisted spray drying for photocatalysis
Authors: Wang Shumin , Yan Xiaoxia , Zhu Yan , Deng Dongmei , He Haibo , Chen Hua , Luo Liqiang
Published: March 2018

A simple and feasible aerosol‐assisted spray‐drying method was developed. High‐resolution transmission electron microscopy images demonstrated the as‐prepared TiO2 possessed hollow structure with large cavity formed by the accumulation of numerous nanoparticles. Moreover, the obtained TiO2 hollow spheres could lead to the improved light‐harvesting and low recombination of photo‐generated electron–hole carriers, as well as large specific surface area. These excellent properties contributed to the superior photocatalytic activity in degrading Rhodamine B.
The flat-spectrum radio quasar 3C 345 from the high to the low emission state
Authors: Berton M. , Liao N. H. , La Mura G. , Järvelä E. , Congiu E. , Foschini L. , Frezzato M. , Ramakrishnan V. , Fan X. L. , Lähteenmäki A. , Pursimo T. , Abate V. , Bai J. M. , Calcidese P. , Ciroi S. , Chen L. , Cracco V. , Li S. K. , Tornikoski M. , Rafanelli P.
Published: March 2018

We report simultaneous observations at different energy bands in radio, optical, UV, X-rays and γ rays of the flat-spectrum radio-quasar 3C 345. We built the light curve of the source at different frequencies from 2008, the beginning of the Fermi all-sky survey, to 2016, using new data and public archives. In particular we obtained several optical spectra, to study the behavior of emission lines and the continuum in different activity states and to derive the black hole mass. 3C 345 showed two flaring episodes in 2009, which occurred simultaneously in γ ray, optical/UV and X-rays, and were later followed in radio. The source shows an inverse Compton dominated spectral energy distribution, which moved from higher to lower frequencies from the high to the low state. The reverberation of emission lines during one outburst event allowed us to constrain the location of production of γ rays very close to the broad-line region, and possibly in the jet-base. We report the observation of an increased accretion after the outburst, possibly induced by the decrease of magnetic field intensity with respect to the low state.
Evolution of the anti-truncated stellar profiles of S0 galaxies since z = 0.6 in the SHARDS survey
Authors: Borlaff Alejandro , Eliche-Moral M. Carmen , Beckman John E. , Vazdekis Alexandre , Lumbreras-Calle Alejandro , Ciambur Bogdan C. , Pérez-González Pablo G. , Cardiel Nicolás , Barro Guillermo , Cava Antonio
Published: March 2018

Context. Anti-truncated lenticular galaxies (Type-III S0s) present tight scaling relations between their surface brightness photometric and structural parameters. Although several evolutionary models have been proposed for the formation of these structures, the observations of Type-III S0 galaxies are usually limited to the local Universe.

Aims. We aim to compare the properties of Type-III discs in a sample of S0 galaxies at 0.2 < z < 0.6 with those of the local Universe. In this paper, we study the evolution of the photometric and structural scaling relations measured in the rest-frame R-band with z and the possible differences between the rest-frame (B − R) colours of the inner and outer disc profiles.

Methods. We make use of a sample of 14 Type-III E/S0–S0 galaxies at 0.2 < z < 0.6 from the GOODS-N field identified and characterised in a previous paper. We study whether or not the correlations found in local Type-III S0 galaxies were present ~6 Gyr ago. We analyse the distribution of the surface brightness characteristic parameters (Rbreak, μbreak, hi, ho, μ0,i and μ0,o) as a function of the stellar mass and look to see if there is a significant change with z. We also derive their rest-frame (B − R) colour profiles. Finally, we compare these results with the predictions from a grid of SSP models.

Results. We find that the inner and outer scale-lengths of Type-III S0 galaxies at 0.4 < z < 0.6 follow compatible trends and scaling relations with those observed in local S0 galaxies as a function of the break radius, Rbreak. We do not detect any significant differences between the location of Rbreak between z ~ 0.6 and z ~ 0 for a fixed stellar mass of the object, whereas the surface brightness at the break radius μbreak is ~1.5 mag arcsec-2 dimmer in the local Universe than at z ~ 0.6 for a fixed stellar mass. We find no significant differences in the (B − R) colour between the inner and outer profiles of the Type-III S0 galaxies at 0.2 < z < 0.6.

Conclusions. In contrast to Type-II (down-bending) profiles, the anti-truncated surface brightness profiles of S0 galaxies present compatible Rbreak values and scaling relations during the last 6 Gyr. This result and the similarity of the colours of the inner and outer discs point to a highly scalable and stable formation process, probably more related to gravitational and dynamical processes than to the evolution of stellar populations.
Hémophilie : la thérapie génique, enfin…
Authors: Jordan Bertrand
Published: March 2018

Recent efforts at gene therapy for haemophilia A and B using AAV-derived vectors show durable expression of coagulation factors at significant levels, resulting in almost complete correction of the phenotype. This is the first success of gene therapy for a major hereditary disorder, and shows how continuous improvement of many components of the system has finally succeeded. Although these results must be confirmed with more patients and longer durations, they constitute a significant accomplishment for this approach after decades of frustration.
Evidenzbasierte Klinische Sozialarbeit: Gegenstand und Perspektiven
Authors: Deimel Daniel
Published: March 2018

Klinische Sozialarbeit hat sich in den letzten 15 Jahren als gesundheitsspezifische Profession in Deutschland etabliert. Sie bezieht sich auf ein bio-psycho-soziales Gesundheitsverständnis und arbeitet insbesondere mit schwer erreichbaren Klientengruppen. Das Konzept der Evidenzbasierung wird in Teilen der Profession und Disziplin Sozialer Arbeit kritisiert und abgelehnt. In dem Beitrag werden die Konzepte der Evidenzbasierung und der Klinischen Sozialarbeit in Verbindung gebracht und aufgezeigt, welchen Nutzen in einer evidenzbasierten Klinischen Sozialarbeit für die klinische Praxis und Professionsentwicklung beinhaltet.
Penning ionization widths by Fano-algebraic diagrammatic construction method
Authors: Yun Renjie , Narevicius Edvardas , Averbukh Vitali
Published: March 2018

We present an ab initio theory and computational method for Penning ionization widths. Our method is based on the Fano theory of resonances, algebraic diagrammatic construction (ADC) scheme for many-electron systems, and Stieltjes imaging procedure. It includes an extension of the Fano-ADC scheme [V. Averbukh and L. S. Cederbaum, J. Chem. Phys. 123, 204107 (2005)] to triplet excited states. Penning ionization widths of various He*–H2 states are calculated as a function of the distance R between He* and H2. We analyze the asymptotic (large-R) dependences of the Penning widths in the region where the well-established electron transfer mechanism of the decay is suppressed by the multipole- and/or spin-forbidden energy transfer. The R−12 and R−8 power laws are derived for the asymptotes of the Penning widths of the singlet and triplet excited states of He*(1s2s1,3S), respectively. We show that the electron transfer mechanism dominates Penning ionization of He*(1s2s 3S)–H2 up until the He*–H2 separation is large enough for the radiative decay of He* to become the dominant channel. The same mechanism also dominates the ionization of He*(1s2s 1S)–H2 when R < 5 Å. We estimate that the regime of energy transfer in the He*–H2 Penning ionization cannot be reached by approaching zero collisional temperature. However, the multipole-forbidden energy transfer mechanism can become important for Penning ionization in doped helium droplets.
Semi-local machine-learned kinetic energy density functional with third-order gradients of electron density
Authors: Seino Junji , Kageyama Ryo , Fujinami Mikito , Ikabata Yasuhiro , Nakai Hiromi
Published: March 2018

A semi-local kinetic energy density functional (KEDF) was constructed based on machine learning (ML). The present scheme adopts electron densities and their gradients up to third-order as the explanatory variables for ML and the Kohn-Sham (KS) kinetic energy density as the response variable in atoms and molecules. Numerical assessments of the present scheme were performed in atomic and molecular systems, including first- and second-period elements. The results of 37 conventional KEDFs with explicit formulae were also compared with those of the ML KEDF with an implicit formula. The inclusion of the higher order gradients reduces the deviation of the total kinetic energies from the KS calculations in a stepwise manner. Furthermore, our scheme with the third-order gradient resulted in the closest kinetic energies to the KS calculations out of the presented functionals.
Calibrating an ultra-low expansion cavity for high precision spectroscopy from 630 THz to 685 THz using molecular tellurium lines
Authors: Patterson C. , Vira A. D. , Herd M. T. , Hawkins W. B. , Williams W. D.
Published: March 2018

We report on the calibration of a temperature stabilized ultra-low expansion (ULE) cavity using previously measured molecular tellurium and atomic cesium lines. By means of a dual frequency modulation technique, the frequency dependence of the free spectral range of the ULE cavity is measured and was found to vary by less than 60 Hz over the ∼55 THz range of the calibration. This method of calibration enables the ULE cavity to measure absolute frequencies to better than 1.5 MHz.
Surface-initiated phase transition in solid hydrogen under the high-pressure compression
Authors: Lei Haile , Lin Wei , Wang Kai , Li Xibo
Published: March 2018

The large-scale molecular dynamics simulations have been performed to understand the microscopic mechanism governing the phase transition of solid hydrogen under the high-pressure compression. These results demonstrate that the face-centered-cubic-to-hexagonal close-packed phase transition is initiated first at the surfaces at a much lower pressure than in the volume and then extends gradually from the surface to volume in the solid hydrogen. The infrared spectra from the surface are revealed to exhibit a different pressure-dependent feature from those of the volume during the high-pressure compression. It is thus deduced that the weakening intramolecular H-H bonds are always accompanied by hardening surface phonons through strengthening the intermolecular H2-H2 coupling at the surfaces with respect to the counterparts in the volume at high pressures. This is just opposite to the conventional atomic crystals, in which the surface phonons are softening. The high-pressure compression has further been predicted to force the atoms or molecules to spray out of surface to degrade the pressure. These results provide a glimpse of structural properties of solid hydrogen at the early stage during the high-pressure compression.
Heterogeneous nucleation of a droplet pinned at a chemically inhomogeneous substrate: A simulation study of the two-dimensional Ising case
Authors: Trobo Marta L. , Albano Ezequiel V. , Binder Kurt
Published: March 2018

Heterogeneous nucleation is studied by Monte Carlo simulations and phenomenological theory, using the two-dimensional lattice gas model with suitable boundary fields. A chemical inhomogeneity of length b at one boundary favors the liquid phase, while elsewhere the vapor is favored. Switching on the bulk field Hb favoring the liquid, nucleation and growth of the liquid phase starting from the region of the chemical inhomogeneity are analyzed. Three regimes occur: for small fields, Hb<Hbcrit, the critical droplet radius is so large that a critical droplet having the contact angle θc required by Young’s equation in the region of the chemical inhomogeneity does not yet “fit” there since the baseline length of the circle-cut sphere droplet would exceed b. For Hbcrit<Hb<Hb*, such droplets fit inside the inhomogeneity and are indeed found in simulations with large enough observation times, but these droplets remain pinned to the chemical inhomogeneity when their baseline has grown to the length b. Assuming that these pinned droplets have a circle cut shape and effective contact angles θeff in the regime θc < θeff < π/2, the density excess due to these droplets can be predicted and is found to be in reasonable agreement with the simulation results. On general grounds, one can predict that the effective contact angle θeff and the excess density of the droplets, scaled by b, are functions of the product bHb but do not depend on both variables separately. Since the free energy barrier for the “depinning” of the droplet (i.e., growth of θeff to π − θc) vanishes when θeff approaches π/2, in practice only angles θeff up to about θeffmax≃70° were observed. For larger fields (Hb>Hb*), the droplets nucleated at the chemical inhomogeneity grow to the full system size. While the relaxation time for the growth scales as τG∝Hb−1, the nucleation time τN scales as lnτN∝Hb−1. However, the prefactor in the latter relation, as evaluated for our simulations results, is not in accord with an extension of the Volmer-Turnbull theory to two-dimensions, when the theoretical contact angle θc is used.
Morphology of size-selected Ptn clusters on CeO2(111)
Authors: Shahed Syed Mohammad Fakruddin , Beniya Atsushi , Hirata Hirohito , Watanabe Yoshihide
Published: March 2018

Supported Pt catalysts and ceria are well known for their application in automotive exhaust catalysts. Size-selected Pt clusters supported on a CeO2(111) surface exhibit distinct physical and chemical properties. We investigated the morphology of the size-selected Ptn (n = 5–13) clusters on a CeO2(111) surface using scanning tunneling microscopy at room temperature. Ptn clusters prefer a two-dimensional morphology for n = 5 and a three-dimensional (3D) morphology for n ≥ 6. We further observed the preference for a 3D tri-layer structure when n ≥ 10. For each cluster size, we quantitatively estimated the relative fraction of the clusters for each type of morphology. Size-dependent morphology of the Ptn clusters on the CeO2(111) surface was attributed to the Pt–Pt interaction in the cluster and the Pt–O interaction between the cluster and CeO2(111) surface. The results obtained herein provide a clear understanding of the size-dependent morphology of the Ptn clusters on a CeO2(111) surface.
Comparison of microrings and microdisks for high-speed optical modulation in silicon photonics
Authors: Ying Zhoufeng , Wang Zheng , Zhao Zheng , Dhar Shounak , Pan David Z. , Soref Richard , Chen Ray T.
Published: March 2018

The past several decades have witnessed the gradual transition from electrical to optical interconnects, ranging from long-haul telecommunication to chip-to-chip interconnects. As one type of key component in integrated optical interconnect and high-performance computing, optical modulators have been well developed these past few years, including ultrahigh-speed microring and microdisk modulators. In this paper, a comparison between microring and microdisk modulators is well analyzed in terms of dimensions, static and dynamic power consumption, and fabrication tolerance. The results show that microdisks have advantages over microrings in these aspects, which gives instructions to the chip design of high-density integrated systems for optical interconnects and optical computing.
Quenching oscillating behaviors in fractional coupled Stuart-Landau oscillators
Authors: Sun Zhongkui , Xiao Rui , Yang Xiaoli , Xu Wei
Published: March 2018

Oscillation quenching has been widely studied during the past several decades in fields ranging from natural sciences to engineering, but investigations have so far been restricted to oscillators with an integer-order derivative. Here, we report the first study of amplitude death (AD) in fractional coupled Stuart-Landau oscillators with partial and/or complete conjugate couplings to explore oscillation quenching patterns and dynamics. It has been found that the fractional-order derivative impacts the AD state crucially. The area of the AD state increases along with the decrease of the fractional-order derivative. Furthermore, by introducing and adjusting a limiting feedback factor in coupling links, the AD state can be well tamed in fractional coupled oscillators. Hence, it provides one an effective approach to analyze and control the oscillating behaviors in fractional coupled oscillators.
Ultrafast electric phase control of a single exciton qubit
Authors: Widhalm Alex , Mukherjee Amlan , Krehs Sebastian , Sharma Nandlal , Kölling Peter , Thiede Andreas , Reuter Dirk , Förstner Jens , Zrenner Artur
Published: March 2018

We report on the coherent phase manipulation of quantum dot excitons by electric means. For our experiments, we use a low capacitance single quantum dot photodiode which is electrically controlled by a custom designed SiGe:C BiCMOS chip. The phase manipulation is performed and quantified in a Ramsey experiment, where ultrafast transient detuning of the exciton energy is performed synchronous to double pulse π/2 ps laser excitation. We are able to demonstrate electrically controlled phase manipulations with magnitudes up to 3π within 100 ps which is below the dephasing time of the quantum dot exciton.
Analytical energy gradients for explicitly correlated wave functions. II. Explicitly correlated coupled cluster singles and doubles with perturbative triples corrections: CCSD(T)-F12
Authors: Győrffy Werner , Werner Hans-Joachim
Published: March 2018

We present an implementation of analytical energy gradients for the explicitly correlated coupled cluster singles and doubles method with perturbative triples corrections [CCSD(T)-F12]. The accuracy of the CCSD(T)-F12 analytical gradient technique is demonstrated by computing equilibrium geometries for a set of closed-shell molecules containing first- and second-row elements. Near basis-set limit equilibrium geometries are obtained with triple-zeta correlation consistent basis sets. Various approximations in the F12 treatment are compared, and the effects of these are found to be small.
Stable and simple quantitative phase-contrast imaging by Fresnel biprism
Authors: Ebrahimi Samira , Dashtdar Masoomeh , Sánchez-Ortiga Emilio , Martínez-Corral Manuel , Javidi Bahram
Published: March 2018

Digital holographic (DH) microscopy has grown into a powerful nondestructive technique for the real-time study of living cells including dynamic membrane changes and cell fluctuations in nanometer and sub-nanometer scales. The conventional DH microscopy configurations require a separately generated coherent reference wave that results in a low phase stability and a necessity to precisely adjust the intensity ratio between two overlapping beams. In this work, we present a compact, simple, and very stable common-path DH microscope, employing a self-referencing configuration. The microscope is implemented by a diode laser as the source and a Fresnel biprism for splitting and recombining the beams simultaneously. In the overlapping area, linear interference fringes with high contrast are produced. The frequency of the interference pattern could be easily adjusted by displacement of the biprism along the optical axis without a decrease in fringe contrast. To evaluate the validity of the method, the spatial noise and temporal stability of the setup are compared with the common off-axis DH microscope based on a Mach-Zehnder interferometer. It is shown that the proposed technique has low mechanical noise as well as superb temporal stability with sub-nanometer precision without any external vibration isolation. The higher temporal stability improves the capabilities of the microscope for studying micro-object fluctuations, particularly in the case of biological specimens. Experimental results are presented using red blood cells and silica microspheres to demonstrate the system performance.
Hindered rotation and nuclear spin isomers separation of molecularly chemisorbed H2 on Pd(210)
Authors: Arguelles Elvis F. , Kasai Hideaki
Published: March 2018

We investigated the hindered rotation and nuclear spin isomer separation of H2 on Pd(210) for various pre-adsorbed atomic hydrogen coverages (Θ), by total energy calculations based on density functional theory. Our results revealed that H2 is in the molecularly chemisorbed state and the adsorption is characterized by a highly anisotropic potential energy surface. Further, we found that J = 1 degenerate level splitting is insensitive to the increase in Θ from 1 to 2 ML. This is due to the comparable potential strengths hindering/restricting the polar rotations in both coverages. On a fully H passivated (3 ML) Pd(210), H2 is in a weakly physisorbed state with a negligible potential anisotropy. Our findings suggest that the activation barrier for polar rotational motion does not strongly depend on the adsorption energy but rather on the surface-molecule bond. The estimated rotational state desorption energies show a separation of ortho and para isomers by around 7.0 meV.
Structural evaluation of reduced graphene oxide in graphene oxide during ion irradiation: X-ray absorption spectroscopy and in-situ sheet resistance studies
Authors: Saravanan K. , Jayalakshmi G. , Suresh K. , Sundaravel B. , Panigrahi B. K. , Phase D. M.
Published: March 2018

We report the structural evolution of reduced graphene oxide (rGO) in graphene oxide (GO) flakes during 1 MeV Si+ ion irradiation. In-situ electrical resistivity measurements facilitate monitoring the sheet resistance with the increase in the fluence. The electrical sheet resistance of the GO flake shows the exponential decay behaviour with the increasing ion fluence. Raman spectra of the GO flake reveal the increase in the ID/IG ratio, indicating restoration of the sp2 network upon irradiation. The C/O ratio estimated from resonant Rutherford backscattering spectrometry analysis directly evidenced the reduction of oxygen moieties upon irradiation. C K–edge X-ray absorption near edge structure spectra reveal the restoration of C=C sp2–hybridized carbon atoms and the removal of oxygen-containing functional groups in the GO flake. STM data reveal the higher conductance in the rGO regime in comparison with the regime, where the oxygen functional groups are present. The experimental investigation demonstrates that the ion irradiation can be employed for efficient reduction of GO with tunable electrical and structural properties.
The noncommutative index theorem and the periodic table for disordered topological insulators and superconductors
Authors: Katsura Hosho , Koma Tohru
Published: March 2018

We study a wide class of topological free-fermion systems on a hypercubic lattice in spatial dimensions d ≥ 1. When the Fermi level lies in a spectral gap or a mobility gap, the topological properties, e.g., the integral quantization of the topological invariant, are protected by certain symmetries of the Hamiltonian against disorder. This generic feature is characterized by a generalized index theorem which is a noncommutative analog of the Atiyah-Singer index theorem. The noncommutative index defined in terms of a pair of projections gives a precise formula for the topological invariant in each symmetry class in any dimension (d ≥ 1). Under the assumption on the nonvanishing spectral or mobility gap, we prove that the index formula reproduces Bott periodicity and all of the possible values of topological invariants in the classification table of topological insulators and superconductors. We also prove that the indices are robust against perturbations that do not break the symmetry of the unperturbed Hamiltonian.
Surface Tension Effect on Harmonics of Rayleigh-Taylor Instability
Authors: Liu Wan-hai , Wang Xiang , Ma Wen-fang
Published: March 2018

Using the method of the parameter expansion up to the third order, explicitly investigates surface tension effect on harmonics at weakly nonlinear stage in Rayleigh-Taylor instability (RTI) for arbitrary Atwood numbers and compares the results with those of classical RTI within the framework of the third-order weakly nonlinear theory. It is found that surface tension strongly reduces the linear growth rate of time, resulting in mild growth of the amplitude of the fundamental mode, and changes amplitudes of the second and third harmonics, as is expressed as a tension factor coupling in amplitudes of the harmonics. On the one hand, surface tension can either decrease or increase the space amplitude; on the other hand, surface tension can also change their phases for some conditions which are explicitly determined.
Stochastic Thermodynamics of Mesoscopic Electrochemical Reactions
Authors: Xiao Tie-jun , Zhou Yun
Published: March 2018

In this work, we discussed the stochastic thermodynamics of mesoscopic electron transfer reactions between ions and electrodes. With a relationship between the reaction rate constant and the electrode potential, we find that the heat dissipation βq equals to the dynamic irreversibility of the reaction system minus an internal entropy change term. The total entropy change Δst is defined as the summation of the system entropy change Δs and the heat dissipation βq such that Δst=Δs+βq. Even though the heat dissipation depends linearly on the electrode potential, the total entropy change is found to satisfy the fluctuation theorem ⟨e−Δst⟩=1, and hence a second law-like inequality reads ⟨Δst⟩≥0. Our study provides a practical methodology for the stochastic thermodynamics of electrochemical reactions, which may find applications in biochemical and electrochemical reaction systems.
Oxygen Electroreduction Performance of Ultrasmall Gold Nanoclusters
Authors: Huang Ting , Sun Zhi-hu , Pan Guo-qiang
Published: March 2018

Ultrasmall gold nanoclusters consisting of 2–4 Au atoms were synthesized and their performance in electrocatalytic oxygen reduction reactions (ORR) was examined. These clusters were synthesized by exposing AuPPh3Cl to the aqueous ammonia medium for one week. Electrospray ionization mass spectrometry (ESI-MS), X-ray absorption fine structure (XAFS), and X-ray photoelectron spectroscopy (XPS) analyses indicate that the assynthesized gold clusters (abbreviated as Aux) consist of 2–4 Au atoms coordinated by the triphenylphosphine, hydroxyl, and adsorbed oxygen ligands. A glassy carbon disk electrode loaded with the Aux clusters (Aux/GC) was characterized by the cyclic and linear-sweep voltammetry for ORR. The cyclic voltammogram vs. RHE shows the onset potential of 0.87 V, and the kinetic parameters of JK at 0.47 V and the electron-transfer number per oxygen molecule were calculated to be 14.28 mA/cm2 and 3.96 via the Koutecky-Levich equations, respectively.
Infrared Spectra, Structures and Bonding of Binuclear Transition Metal Carbonyl Cluster Ions
Authors: Wang Guan-jun , Zhou Ming-fei
Published: March 2018

Binuclear transition metal carbonyl clusters serve as the simplest models in understanding metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporization/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric structures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metal-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.
Die Harmonisierung platonischer und aristotelischer Ontologie im
neuplatonischen Kategorienkommentar
Authors: Welt Thomas
Published: March 2018

Commentaries on Plato’s and Aristotle’s works were central to the Neoplatonic
school’s curriculum. In a fixed order, established since Jamblichus, the
Aristotelian writings were first read, then the Platonic ones. At the beginning,
the logical writings of Aristotle and particularly his
Categories were examined. But like any other work, the
Categories were construed from the perspective of
Neoplatonic anagogy. In addition, the commentator was obliged to work out the
commonalities between the two philosophical teachings. That anagogical and
harmonising approach culminates in the commentaries on the
Categories with the integration of the Aristotelian concept
of substance into the Platonic concept of ideas. While Dexippus is primarily
engaged in the right modes of predication corresponding to the sensible and the
intelligible realm respectively, Simplicius focuses on the description of a
continuous connection of being.
CV reduplication in Isbukun Bunun
Authors: Lin Hui-shan
Published: March 2018

This paper presents a novel generalization of the reduplicant (henceforth red) placement in CV reduplication in Isbukun Bunun. It is shown that the variable red placements cannot be explained in terms of the presence of a PF marker or merely by the syllable number of the root, as assumed in previous studies. Rather, the variable red placements are argued to be simultaneously governed by the size and the syllable well-formedness of the root. The red is normally prefixed to the root; however, if onsetless red is generated under normal copying, the placement of the red shifts one syllable rightward, except for shorter (bimoraic) roots. Thus, the variable placements of the red are driven by a universal tendency for the red to be unmarked and the need for the P-Root to sustain a minimal size.
NP interpretation and disposal variations among the Mandarin, Cantonese, and Shaoxing dialects
Authors: Yao Jennifer Shuiying
Published: March 2018

Corresponding to the Ba construction (S Ba-OVC) in Mandarin, Cantonese prefers a strong SVCO word order, and the Shaoxing dialect adopts an SOVC variation. This paper makes a detailed cross-linguistic study on the structure and semantic interpretations of disposal NPs and highlights the role of the disposal NPs in the formation of disposal construction in the above three dialects. It suggests that the word order variations in disposal constructions among the Mandarin, Cantonese, and Shaoxing dialects result from the different options being adopted to make the object NPs conform to the so called definiteness constraint of a disposal NP, namely, definite, specific, or generic.