bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollen and spores as biological recorders of past ultraviolet irradiance
Authors: Jardine Phillip E. , Fraser Wesley T. , Lomax Barry H. , Sephton Mark A. , Shanahan Timothy M. , Miller Charlotte S. , Gosling William D.
Published: December 2016

Solar ultraviolet (UV) irradiance is a key driver of climatic and biotic change. Ultraviolet irradiance modulates stratospheric warming and ozone production, and influences the biosphere from ecosystem-level processes through to the largest scale patterns of diversification and extinction. Yet our understanding of ultraviolet irradiance is limited because no method has been validated to reconstruct its flux over timescales relevant to climatic or biotic processes. Here, we show that a recently developed proxy for ultraviolet irradiance based on spore and pollen chemistry can be used over long (105 years) timescales. Firstly we demonstrate that spatial variations in spore and pollen chemistry correlate with known latitudinal solar irradiance gradients. Using this relationship we provide a reconstruction of past changes in solar irradiance based on the pollen record from Lake Bosumtwi in Ghana. As anticipated, variations in the chemistry of grass pollen from the Lake Bosumtwi record show a link to multiple orbital precessional cycles (19–21 thousand years). By providing a unique, local proxy for broad spectrum solar irradiance, the chemical analysis of spores and pollen offers unprecedented opportunities to decouple solar variability, climate and vegetation change through geologic time and a new proxy with which to probe the Earth system.
Evaluation of efficacy and safety for recombinant human adenovirus-p53 in the control of the malignant pleural effusions via thoracic perfusion
Authors: Biaoxue Rong , Hui Pan , Wenlong Gao , Shuanying Yang
Published: December 2016

A certain number of studies have showed that p53 gene transfer has an anti-tumor activity in vitro and in vivo. This study was to evaluate the efficacy and safety of thoracic perfusion of recombinant human adenovirus p53 (rAd-p53, Gendicine) for controlling malignant pleural effusion (MPE). We searched for the relevant studies from the database of MEDLINE, Web of Science, EMBASE, Cochrance Library and CNKI to collect the trials concerning the efficacy and safety of rAd-p53 to treat MPE. Fourteen randomised controlled trials (RCTs) with 879 patients were involved in this analysis. The rAd-p53 combined with chemotherapeutic agents significantly improved the overall response rate (ORR) (P < 0.001; odds ratio = 3.73) and disease control rate (DCR) (P < 0.001; odds ratio = 2.32) of patients with MPE as well as the quality of life (QOL) of patients (P < 0.001; odds ratio = 4.27), compared with that of chemotherapeutic agents alone. In addition, the participation of rAd-p53 did not have an obvious impact on the most of incidence of adverse reactions (AEs) (P < 0.05) except the fever (P < 0.001). However, the fever was self-limited and could be tolerated well. The application of rAd-p53 through thoracic perfusion for treating MPE had a better efficacy and safety, which could be a potential choice for controlling MPE.
Modulating the photocatalytic redox preferences between anatase TiO2{001} and {101} surfaces
Authors: Zhou Peng , Zhang Hongna , Ji Hongwei , Ma Wanhong , Chen Chuncheng , Zhao Jincai
Published: December 2016

The surface protonation/deprotonation can change the photocatalytic redox preferences of TiO2{001} and {101} surfaces.
Gold–silver@TiO2nanocomposite-modified plasmonic photoanodes for higher efficiency dye-sensitized solar cells
Authors: Lim Su Pei , Lim Yee Seng , Pandikumar Alagarsamy , Lim Hong Ngee , Ng Yun Hau , Ramaraj Ramasamy , Bien Daniel Chia Sheng , Abou-Zied Osama K. , Huang Nay Ming
Published: December 2016

Au–Ag@TiO2were prepared using a simple one-step chemical reduction method and used as photoanodes in high-efficiency DSSCs.
Structures of protonated hydrogen sulfide clusters, H+(H2S)n, highlighting the nature of sulfur-centered intermolecular interactions
Authors: Wang Dandan , Fujii Asuka
Published: December 2016

Though H2S has the same hydrogen bond coordination property as H2O, intermolecular structures of H+(H2S)n are very different from those of H+(H2O)n, indicating the competition among hydrogen bond and other intermolecular interactions.
Anisotropic intrinsic lattice thermal conductivity of borophane from first-principles calculations
Authors: Liu Gang , Wang Haifeng , Gao Yan , Zhou Jian , Wang Hui
Published: December 2016

The thermal transport of borophane is decided by phonons with very low frequency.
The total and the differential mean pore anisotropy in porous solids and the ranking of pores according to Zipf's law
Authors: Margellou Antigoni , Pomonis Philippos
Published: December 2016

The total mean pore anisotropy bmean,total = (N·b) and the distribution of differential pore anisotropies bmean,diff = (Ni·bi) in porous solids were estimated from N2 porosimetry data V = f(P/P0). The pore numbers N and volumes V are ranked according to the Zipf's law log(Ni) = A − B log(Vi).
An Au/AgBr–Ag heterostructure plasmonic photocatalyst with enhanced catalytic activity under visible light
Authors: Purbia Rahul , Paria Santanu
Published: December 2016

An efficient bimetallic–semiconductor (Au/AgBr–Ag) plasmonic heterostructure with plasmon enhanced absorption and plasmonic sensitization for visible light induced photocatalysis.
Two blue-light excitable yellow-emitting LMOF phosphors constructed by triangular tri(4-pyridylphenyl)amine
Authors: Wang Fangming , Zhou Zeyu , Liu Wei , Zhou Lei , Chen Lizhuang , Li Jing
Published: December 2016

Two luminescent metal–organic-frameworks (LMOFs) constructed by a molecular chromophore [tri(4-pyridylphenyl)amine] (tppa) emit intense yellow color under blue excitation.
Highly luminescent core–shell InP/ZnX (X = S, Se) quantum dots prepared via a phosphine synthetic route
Authors: Mordvinova Natalia , Vinokurov Alexander , Kuznetsova Tatiana , Lebedev Oleg I. , Dorofeev Sergey
Published: December 2016

A simple and fast synthetic approach to produce highly luminescent InP/ZnX (X = Se, S) core–shell QDs on the basis of a phosphine synthetic route has been realized.
Ag2Cu3Cr2O8(OH)4: a new bidimensional silver–copper mixed-oxyhydroxide with in-plane ferromagnetic coupling
Authors: Casañ-Pastor Nieves , Rius Jordi , Vallcorba Oriol , Peral Inma , Oró-Solé Judith , Cook Daniel S. , Walton Richard I. , García Alberto , Muñoz-Rojas David
Published: December 2016

A new brucitic Ag–Cu–Cr mixed oxide with bidimensional ferromagnetic coupling is obtained by soft hydrothermal methods.
{Fe3Nb25} cluster based on an Fe-centred Keggin unit
Authors: Liang Zhijie , Wang Ke , Zhang Dongdi , Ma Pengtao , Niu Jingyang , Wang Jingping
Published: December 2016

A new Fe-centred heteropolyniobate, synthesized via a combined hydrothermal and test tube diffusion method, represents the largest Fe-based polyoxoniobate yet reported.
Poly-Lewis-acids based on bowl-shaped tribenzotriquinacene
Authors: Tomaschautzky Janek , Neumann Beate , Stammler Hans-Georg , Mitzel Norbert W.
Published: December 2016

Tribenzotriquinacene is a versatile bowl-shaped hydrocarbon and a useful building block for the synthesis of poly-Lewis-acids. First derivatives bearing Lewis-acidic groups are reported.
Rare-earth metal hydrides supported by silicon-bridged boratabenzene fluorenyl ligands: synthesis, structure and reactivity
Authors: Wang Chunhong , Xiang Li , Leng Xuebing , Chen Yaofeng
Published: December 2016

The first boratabenzene derivatives of rare-earth metal hydrides were synthesized, and their reactivity was studied.
One-pot synthesis of a quantum dot-based molecular imprinting nanosensor for highly selective and sensitive fluorescence detection of 4-nitrophenol in environmental waters
Authors: Yu Jialuo , Wang Xiaoyan , Kang Qi , Li Jinhua , Shen Dazhong , Chen Lingxin
Published: December 2016

A facile surface imprinting polymerization one-pot synthesis strategy based on the electron-transfer induced fluorescence quenching mechanism for fluorescence detection of 4-nitrophenol.
Chlorohydrination of allyl chloride with HCl and H2O2 catalyzed by hollow titanium silicate zeolite to produce dichloropropanol
Authors: Peng Xinxin , Xia Changjiu , Lin Min , Yuan Hui , Zhu Bin , Zhang Yao , Wang Baorong , Shu Xingtian
Published: December 2016

A novel chlorohydrination process of allyl chloride with HCl and H2O2 catalyzed by hollow titanium silicate zeolite has been developed, overcoming the significant drawbacks of traditional Cl2-based route.
Difluoro- and trifluoro diazoalkanes – complementary approaches in batch and flow and their application in cycloaddition reactions
Authors: Hock Katharina J. , Mertens Lucas , Metze Friederike K. , Schmittmann Clemens , Koenigs Rene M.
Published: December 2016

Fluorinated diazoalkanes can be obtained in either batch or continuous-flow reactions, depending on the substitution pattern. These diazo compounds were applied in dipolar cycloadditions yielding sulfonated heterocycles.
Cu-Catalyzed electrophilic amination of internal alkynes via hydroalumination
Authors: Yoon Hongju , Kim Yuna , Lee Yunmi
Published: December 2016

A straightforward and efficient method for the synthesis of 1,2-diaryl-substituted enamines through the Cu-catalyzed electrophilic amination reaction of O-benzoyl hydroxylamines with vinylaluminum reagents generated in situ from the Ni-catalyzed hydroalumination of readily accessible internal aryl acetylenes is described.
Three metalloporphyrin frameworks containing imidazole groups: synthesis, characterization and properties
Authors: Zhang Li , Hou Lei , Zhao Xin , Zhang Zengqi , Wang Yongsong , Li Jun
Published: December 2016

Three metalloporphyrin frameworks containing imidazole groups were structurally characterized, revealing the moderate CO2 adsorption capacity and high catalytic activity for ethylbenzene oxidation.
A non-volatile resistive memory effect in 2,2′,6,6′-tetraphenyl-dipyranylidene thin films as observed in field-effect transistors and by conductive atomic force microscopy
Authors: Courté Marc , Surya Sandeep G. , Thamankar Ramesh , Shen Chao , Rao V. Ramgopal , Mhailsalkar Subodh G. , Fichou Denis
Published: December 2016

A non-volatile resistive memory effect is observed in 2,2′,6,6′-tetraphenyldipyranylidene (DIPO-Ph4), a large planar quinoïd π-conjugated heterocycle, in a field-effect transistor (FET) configuration and by conductive atomic force microscopy (c-AFM).
Retraction: 3D small molecule microarray with enhanced sensitivity and immobilization capacity monitored by surface plasmon resonance imaging
Authors: Zhu Jinsong
Published: December 2016

Retraction of ‘3D small molecule microarray with enhanced sensitivity and immobilization capacity monitored by surface plasmon resonance imaging’ by Vikramjeet Singh et al., RSC Adv., 2014, DOI: 10.1039/c4ra07306a.
Microfluidics with in situ Raman spectroscopy for the characterization of non-polar/aqueous interfaces
Authors: Pinho Bruno , Hartman Ryan L.
Published: December 2016

The design of microfluidics with in situ Raman spectroscopy is reported in the present work for the investigation of immiscible non-polar/aqueous interactions.
An albumin-based tumor-targeted oxaliplatin prodrug with distinctly improved anticancer activity in vivo
Authors: Mayr Josef , Heffeter Petra , Groza Diana , Galvez Luis , Koellensperger Gunda , Roller Alexander , Alte Beatrix , Haider Melanie , Berger Walter , Kowol Christian R. , Keppler Bernhard K.
Published: December 2016

An oxaliplatin-based platinum(iv) drug which specifically binds to albumin after i.v. application led to several complete responses in tumor-bearing mice.
Surface engineering to achieve organic ternary memory with a high device yield and improved performance
Authors: Hou Xiang , Xiao Xin , Zhou Qian-Hao , Cheng Xue-Feng , He Jing-Hui , Xu Qing-Feng , Li Hua , Li Na-Jun , Chen Dong-Yun , Lu Jian-Mei
Published: December 2016

Organic memories fabricated on surface-engineered indium tin oxide show the highest ternary yield (82%) to date and better performance.
[Ag115S34(SCH2C6H4tBu)47(dpph)6]: synthesis, crystal structure and NMR investigations of a soluble silver chalcogenide nanocluster
Authors: Bestgen Sebastian , Fuhr Olaf , Breitung Ben , Kiran Chakravadhanula Venkata Sei , Guthausen Gisela , Hennrich Frank , Yu Wen , Kappes Manfred M. , Roesky Peter W. , Fenske Dieter
Published: December 2016

The soluble 115 nuclear silver cluster [Ag115S34(SCH2C6H4tBu)47(dpph)6] was synthesized and fully characterized in solution and in the solid state.
Correction: A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes
Authors: Sun Yifei , Li Jianhui , Zeng Yimin , Amirkhiz Babak Shalchi , Wang Mengni , Behnamian Yashar , Luo Jingli
Published: December 2016

Correction for ‘A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes’ by Yifei Sun et al., J. Mater. Chem. A, 2015, 3, 11048–11056.
Chemical durability engineering of solution-processed oxide thin films and its application in chemically-robust patterned oxide thin-film transistors
Authors: Cho Sung Woon , Kim Da Eun , Kang Won Jun , Kim Bora , Yoon Dea Ho , Kim Kyung Su , Cho Hyung Koun , Kim Yong-Hoon , Kim Yunseok
Published: December 2016

The chemical durability of solution-processed oxide films was engineered via Sn-incorporation and thermal-treatment, which was applied for large-area TFT circuit integration.
Structure and lipid-binding properties of the kindlin-3 pleckstrin homology domain
Authors: Ni Tao , Kalli Antreas C. , Naughton Fiona B. , Yates Luke A. , Naneh Omar , Kozorog Mirijam , Anderluh Gregor , Sansom Mark S.P. , Gilbert Robert J.C.
Published: December 2016

Kindlins co-activate integrins alongside talin. They possess, like talin, a FERM domain (4.1-erythrin–radixin–moiesin domain) comprising F0–F3 subdomains, but with a pleckstrin homology (PH) domain inserted in the F2 subdomain that enables membrane association. We present the crystal structure of murine kindlin-3 PH domain determined at a resolution of 2.23 Å and characterise its lipid binding using biophysical and computational approaches. Molecular dynamics simulations suggest flexibility in the PH domain loops connecting β-strands forming the putative phosphatidylinositol phosphate (PtdInsP)-binding site. Simulations with PtdInsP-containing bilayers reveal that the PH domain associates with PtdInsP molecules mainly via the positively charged surface presented by the β1–β2 loop and that it binds with somewhat higher affinity to PtdIns(3,4,5)P3 compared with PtdIns(4,5)P2. Surface plasmon resonance (SPR) with lipid headgroups immobilised and the PH domain as an analyte indicate affinities of 300 µM for PtdIns(3,4,5)P3 and 1 mM for PtdIns(4,5)P2. In contrast, SPR studies with an immobilised PH domain and lipid nanodiscs as the analyte show affinities of 0.40 µM for PtdIns(3,4,5)P3 and no affinity for PtdIns(4,5)P2 when the inositol phosphate constitutes 5% of the total lipids (∼5 molecules per nanodisc). Reducing the PtdIns(3,4,5)P3 composition to 1% abolishes nanodisc binding to the PH domain, as does site-directed mutagenesis of two lysines within the β1–β2 loop. Binding of PtdIns(3,4,5)P3 by a canonical PH domain, Grp1, is not similarly influenced by SPR experimental design. These data suggest a role for PtdIns(3,4,5)P3 clustering in the binding of some PH domains and not others, highlighting the importance of lipid mobility and clustering for the biophysical assessment of protein–membrane interactions.
The application of metabolomics for herbal medicine pharmacovigilance: a case study on ginseng
Authors: Crighton Elly , Mullaney Ian , Trengove Robert , Bunce Michael , Maker Garth
Published: December 2016

Herbal medicines are growing in popularity, use and commercial value; however, there remain problems with the quality and consequently safety of these products. Adulterated, contaminated and fraudulent products are often found on the market, a risk compounded by the fact that these products are available to consumers with little or no medical advice. Current regulations and quality control methods are lacking in their ability to combat these serious problems. Metabolomics is a biochemical profiling tool that may help address these issues if applied to quality control of both raw ingredients and final products. Using the example of the popular herbal medicine, ginseng, this essay offers an overview of the potential use of metabolomics for quality control in herbal medicines and also highlights where more research is needed.
Solution state nuclear magnetic resonance spectroscopy for biological metabolism and pathway intermediate analysis
Authors: Nealon Gareth L. , Howard Mark J.
Published: December 2016

Using nuclear magnetic resonance (NMR) spectroscopy in the study of metabolism has been immensely popular in medical- and health-related research but has yet to be widely applied to more fundamental biological problems. This review provides some NMR background relevant to metabolism, describes why 1H NMR spectra are complex as well as introducing relevant terminology and definitions. The applications and practical considerations of NMR metabolic profiling and 13C NMR-based flux analyses are discussed together with the elegant ‘enzyme trap’ approach for identifying novel metabolic pathway intermediates. The importance of sample preparation and data analysis are also described and explained with reference to data precision and multivariate analysis to introduce researchers unfamiliar with NMR and metabolism to consider this technique for their research interests. Finally, a brief glance into the future suggests NMR-based metabolism has room to expand in the 21st century through new isotope labels, and NMR technologies and methodologies.
Divide‐conquer method for improving possibilistic c‐means
Authors: Yu J. , Woo W.
Published: December 2016

Possibilistic c‐means (PCM) was proposed to overcome the problem of the noise sensitivity of fuzzy c‐means, but its performance highly depends on the initialisation of cluster centres and often is degraded due to producing coincident clusters or close centres. To tackle these defects of PCM, a divide‐conquer method which not only provides appropriate cluster centres but also yields pre‐clustered and un‐clustered data information which are used to overcome the coincident or close clustering problem is presented. Experiment results on a simulated magnetic resonance brain image data corrupted by noise and bias‐field shows that the proposed method has a better clustering performance than conventional PCM clustering methods.
Platform choices and design demands for IoT platforms: cost, power, and performance tradeoffs
Authors: Chen Deming , Cong Jason , Gurumani Swathi , Hwu Wen‐mei , Rupnow Kyle , Zhang Zhiru
Published: December 2016

The rise of the Internet of Things has led to an explosion of sensor computing platforms. The complexity and applications of IoT devices range from simple devices in vending machines to complex, interactive artificial intelligence in smart vehicles and drones. Developers target more aggressive objectives and protect market share through feature differentiation; they just choose between low‐cost, and low‐performance CPU‐based systems, and high‐performance custom platforms with hardware accelerators including GPUs and FPGAs. Both CPU‐based and custom designs introduce a variety of design challenges: extreme pressure on time‐to‐market, design cost, and development risk drive a voracious demand for new CAD technologies to enable rapid, low cost design of effective IoT platforms with smaller design teams and lower risk. In this article, we present a generic IoT device design flow and discuss platform choices for IoT devices to efficiently tradeoff cost, power, performance and volume constraints: CPU‐based systems and custom platforms that contain hardware accelerators including embedded GPUs and FPGAs. We demonstrate this design process through a driving application in computer vision. We also present current critical design automation needs for IoT development and demonstrate how our prior work in CAD for FPGAs and SoCs begin to address these needs.
Querschnittsanalyse der gesundheitlichen und sozialen Lage in Deutschland auf Bundeslandebene
Authors: Wittmann Nadine , Meinlschmidt Gerhard , Czaja Mario
Published: December 2016

Ziel der Studie war es herauszufinden, wie, und wenn ja, in welchem Maße sich die deutschen Bundesländer in ihrer gesundheitlichen und sozialen Struktur unterscheiden. Der Status quo der gesundheits- und sozialwissenschaftlichen Forschung besteht hier aktuell entweder in national oder in sehr kleinräumig angelegten Ansätzen. Allerdings erscheint es hier – sowohl aus gesundheitswissenschaftlicher als auch aus -politischer Sicht – sinnvoll, zusätzlich zur Meta- und Mikroebene auch die Mesoebene einer differenzierteren Analyse zu unterziehen. Auf diese Weise wird dem spezifischen Informationsbedarf aller vorhandenen Politik- und Planungsebenen bei weiterführenden, versorgungsstrukturellen Fragestellungen umfassend Rechnung getragen. Die für die Analyse verwendete Methodik basiert dabei auf den seit nunmehr 25 Jahren in Berlin etablierten sowie auch international praktizierten Public Health basierten Methoden der Gesundheits- und Sozialberichterstattung. Es erfolgte hierzu eine Sozialraumanalyse unter Verwendung von 53 Indikatoren der amtlichen Statistik, welche entsprechend international anerkannter Kernbereiche der gesundheitswissenschaftlichen und sozialindikativen Planung selektiert wurden. Dabei zeigt sich, dass die gesundheits- und sozialstrukturelle Lage der Bundesländer anhand von 3, auf Basis einer Faktorenanalyse extrahierten, Indizes umfassend beschrieben werden kann. Dabei erklären diese 3 Faktoren insgesamt rund 80% der Gesamtvarianz, wobei rund 38% auf den ersten, gut 31% auf den zweiten sowie knapp 11% auf den dritten Faktor (Index) entfallen. Eine Prüfung der Ergebnisse mittels hierarchischer sowie K-Means Clusteranalyse bestätigt die zutage geförderten Erkenntnisse. Insgesamt divergieren die Bundesländer im Verhältnis zueinander teils stark in ihrer gesundheitlichen und sozialen Lage. Zudem sind dabei mindestens 4, eher jedoch 8 Subregionen zu unterscheiden. Dabei zeigt sich auch, dass die oftmals im Fokus stehende Ost-Westdiskrepanz kein hinreichend differenziertes Bild der Gesamtsituation darstellt. Vielmehr zeigen sind zudem – neben klaren Stadtstaaten-Flächenland Aspekten – auch verschiedene Varianten deutlicher Süd-Nord Gefälle.
Growth of viscoelastic instabilities around linear cylinder arrays
Authors: Shi Xueda , Christopher Gordon F.
Published: December 2016

Using a linear array of cylinders in a rectangular microchannel, the development of viscoelastic instabilities at moderate viscoelastic Mach numbers is investigated. Through both flow visualization and pressure drop measurements, instabilities in these channels are shown to start on the downstream face of a cylinder and grow upstream, eventually creating a vortex of slow moving fluid in front of the most upstream cylinder. Previously considered to be independent, it is shown that the downstream and upstream flow patterns all emerge due to the same mechanism related to the creation of secondary flow due to elastic waves. Furthermore, pressure drop measurements show that the relative importance of this phenomenon in terms of the excess pressure drop is mitigated for higher elasticity fluids.
Compositional dependence of charge carrier transport in kesterite Cu2ZnSnS4 solar cells
Authors: Just Justus , Nichterwitz Melanie , Lützenkirchen-Hecht Dirk , Frahm Ronald , Unold Thomas
Published: December 2016

Cu2ZnSnS4 solar cells deposited by thermal co-evaporation have been characterized structurally and electronically to determine the dependence of the electronic properties on the elemental composition of the kesterite phase, which can significantly deviate from the total sample composition. To this end, the kesterite phase content and composition were determined by a combination of X-ray fluorescence and X-ray absorption measurements. The electronic properties, such as carrier density and minority carrier diffusion length, were determined by electron beam induced current measurements and capacitance-voltage profiling. The charge-carrier transport properties are found to strongly depend on the Cu/(Sn+Zn) ratio of the kesterite phase. For the Cu-poor sample, a minority carrier diffusion length of 270 nm and a total collection length of approx. 500 nm are deduced, indicating that current collection should not be an issue in thin devices.
Simultaneous observations of electromagnetically induced transparency (EIT) and absorption (EIA) in a multi-level V-type system of 87Rb and theoretical simulation of the observed spectra using a multi-mode approach
Authors: Das Bankim Chandra , Bhattacharyya Dipankar , Das Arpita , Chakrabarti Shrabana , De Sankar
Published: December 2016

We report here simultaneous experimental observation of Electromagnetically Induced Transparency (EIT) and Electromagnetically Induced Absorption (EIA) in a multi-level V-type system in D2 transition of Rb87, i.e., F=2→F′ with a strong pump and a weak probe beam. We studied the probe spectrum by locking the probe beam to the transition F=2→F′=2 while the pump is scanned from F=2→F′. EIA is observed for the open transition (F=2→F′=2) whereas EIT is observed in the closed transition (F=2→F′=3). Sub natural line-width is observed for the EIA. To simulate the observed spectra theoretically, Liouville equation for the three-level V-type system is solved analytically with a multi-mode approach for the density matrix elements. We assumed both the pump and the probe beams can couple the excited states. A multi-mode approach for the coherence terms facilitates the study of all the frequency contributions due to the pump and the probe fields. Since the terms contain higher harmonics of the pump and the probe frequencies, we expressed them in Fourier transformed forms. To simulate the probe spectrum, we have solved inhomogeneous difference equations for the coherence terms using the Green’s function technique and continued fraction theory. The experimental line-widths of the EIT and the EIA are compared with our theoretical model. Our system can be useful in optical switching applications as it can be precisely tuned to render the medium opaque and transparent simultaneously.
Role of energy distribution in contacts on thermal transport in Si: A molecular dynamics study
Authors: Dunn Jonathan , Antillon Edwin , Maassen Jesse , Lundstrom Mark , Strachan Alejandro
Published: December 2016

We use molecular dynamics simulations to investigate how the energy input and distribution in contacts affect the thermal transport in silicon as described by the Stillinger-Webber potential. We create a temperature difference across a Si specimen by maintaining the temperature of two contacts (also made of Si) using widely used thermostats: the deterministic Nosé-Hoover approach and a stochastic Langevin bath. Quite surprisingly, the phonon thermal conductivity of the channel obtained using the two thermostats but under otherwise identical conditions can differ by a factor of up to three. The discrepancy between the two methods vanishes as the coupling strength between the thermostat and material is reduced and for long channels. A spectral analysis of the contacts and channel shows that increasing the coupling of the stochastic Langevin thermostat affects the spectral energy distribution in the contacts away from that based on the vibrational density of states, broadening peaks and smoothening the distribution. This results in contacts injecting phonons preferentially in low frequency modes and in transport through the channel away from local equilibrium. A comparison of the MD results with Boltzmann transport equation simulations provides an additional insight into the role of contacts on thermal transport in nanoscale specimens. These results stress the importance of contacts in nanoscale thermal transport in simulations and in the interpretation of experimental data.
Gamma bandgap determination in pseudomorphic GeSn layers grown on Ge with up to 15% Sn content
Authors: Gassenq A. , Milord L. , Aubin J. , Guilloy K. , Tardif S. , Pauc N. , Rothman J. , Chelnokov A. , Hartmann J. M. , Reboud V. , Calvo V.
Published: December 2016

Adding Tin (Sn) to Germanium (Ge) can turn it into a direct bandgap group IV semiconductor emitting in the mid-infrared wavelength range. Several approaches are currently being investigated to improve the GeSn devices. It has been theoretically predicted that the strain can improve their optical properties. However, the impact of strain on band parameters has not yet been measured for really high Sn contents (i.e., above 11%). In this work, we have used the photocurrent and photoluminescence spectroscopy to measure the gamma bandgap in compressively strained GeSn layers grown on Ge buffers. A good agreement is found with the modeling and the literature. We show here that the conventional GeSn deformation potentials used in the literature for smaller Sn contents can be applied up to 15% Sn. This gives a better understanding of strained-GeSn for future laser designs.
Compressed-tube pressure cell for optical studies at ocean pressures: Application to glucose mutarotation kinetics
Authors: Lamelas F. J.
Published: December 2016

A self-contained compressed-tube pressure cell is tested to 25 MPa. The cell is very simple to construct and offers stable pressure control with optical access to fluid samples. The physical path length of light through the cell is large enough to measure optical activity. The entire system is relatively small and portable, and it is vibration-free, since a compressor is not used. Operation of the cell is demonstrated by measuring the mutarotation rate of aqueous glucose solutions at 25 °C. A logarithmic plot of the rate constant vs. pressure yields an activation volume for mutarotation of −22 cm3/mol, approximately twice the value measured previously at higher pressures.
Dynamic force matching: Construction of dynamic coarse-grained models with realistic short time dynamics and accurate long time dynamics
Authors: Davtyan Aram , Voth Gregory A. , Andersen Hans C.
Published: December 2016

We recently developed a dynamic force matching technique for converting a coarse-grained (CG) model of a molecular system, with a CG potential energy function, into a dynamic CG model with realistic dynamics [A. Davtyan et al., J. Chem. Phys. 142, 154104 (2015)]. This is done by supplementing the model with additional degrees of freedom, called “fictitious particles.” In that paper, we tested the method on CG models in which each molecule is coarse-grained into one CG point particle, with very satisfactory results. When the method was applied to a CG model of methanol that has two CG point particles per molecule, the results were encouraging but clearly required improvement. In this paper, we introduce a new type (called type-3) of fictitious particle that exerts forces on the center of mass of two CG sites. A CG model constructed using type-3 fictitious particles (as well as type-2 particles previously used) gives a much more satisfactory dynamic model for liquid methanol. In particular, we were able to construct a CG model that has the same self-diffusion coefficient and the same rotational relaxation time as an all-atom model of liquid methanol. Type-3 particles and generalizations of it are likely to be useful in converting more complicated CG models into dynamic CG models.
Uncertainty quantification for generalized Langevin dynamics
Authors: Hall Eric J. , Katsoulakis Markos A. , Rey-Bellet Luc
Published: December 2016

We present efficient finite difference estimators for goal-oriented sensitivity indices with applications to the generalized Langevin equation (GLE). In particular, we apply these estimators to analyze an extended variable formulation of the GLE where other well known sensitivity analysis techniques such as the likelihood ratio method are not applicable to key parameters of interest. These easily implemented estimators are formed by coupling the nominal and perturbed dynamics appearing in the finite difference through a common driving noise or common random path. After developing a general framework for variance reduction via coupling, we demonstrate the optimality of the common random path coupling in the sense that it produces a minimal variance surrogate for the difference estimator relative to sampling dynamics driven by independent paths. In order to build intuition for the common random path coupling, we evaluate the efficiency of the proposed estimators for a comprehensive set of examples of interest in particle dynamics. These reduced variance difference estimators are also a useful tool for performing global sensitivity analysis and for investigating non-local perturbations of parameters, such as increasing the number of Prony modes active in an extended variable GLE.
Investigation of snap-through and homoclinic bifurcation of a magnet-induced buckled energy harvester by the Melnikov method
Authors: Li H. T. , Zu J. , Yang Y. F. , Qin W. Y.
Published: December 2016

Snap-through is used to improve the efficiencies of energy harvesters and extend their effective frequency bandwidths. This work uses the Melnikov method to explore the underlying snap-through mechanism and the conditions necessary for homoclinic bifurcations in a magnet-induced buckled energy harvester. First, an electromechanical model of the energy harvester is established analytically using the Euler-Bernoulli beam theory and the extended Hamilton's principle. Second, the Melnikov function of the model is derived, and the necessary conditions for homoclinic bifurcations and chaos are presented on the basis of this model. The analysis reveals that the distance between the magnets and the end-block mass significantly affect the thresholds for chaotic motions and the high-energy solutions. Numerical and experimental studies confirm these analytical predictions and provide guidelines for optimum design of the magnet-induced buckled energy harvester.
Low operational current spin Hall nano-oscillators based on NiFe/W bilayers
Authors: Mazraati Hamid , Chung Sunjae , Houshang Afshin , Dvornik Mykola , Piazza Luca , Qejvanaj Fatjon , Jiang Sheng , Le Tuan Q. , Weissenrieder Jonas , Åkerman Johan
Published: December 2016

We demonstrate highly efficient spin Hall nano-oscillators (SHNOs) based on NiFe/β-W bilayers. Thanks to the very high spin Hall angle of β-W, we achieve more than a 60% reduction in the auto-oscillation threshold current compared to NiFe/Pt bilayers. The structural, electrical, and magnetic properties of the bilayers, as well as the microwave signal generation properties of the SHNOs, have been studied in detail. Our results provide a promising path for the realization of low-current SHNO microwave devices with highly efficient spin-orbit torque from β-W.
The behavior of a magnetic filament in flow under the influence of an external magnetic field
Authors: Lüsebrink Daniel , Cerdà Joan J. , Sánchez Pedro A. , Kantorovich Sofia S. , Sintes Tomás
Published: December 2016

We present an extensive numerical study of the behaviour of a filament made of ferromagnetic colloidal particles subjected to the simultaneous action of a fluid flow and a stationary external magnetic field perpendicular to the flow lines. We found that in the presence of a shear flow, the tumbling motion observed at zero field is strongly inhibited when the external magnetic field is applied. The field is able to stabilise the filament with a well defined degree of alignment that depends on the balance between hydrodynamic and magnetic torques. In addition, for a Poiseuille flow, it has been found that the initial position has a long lasting influence on the behaviour of the magnetic filament when the external field is applied.
Sequential pulsed laser deposition of homoepitaxial SrTiO3 thin films
Authors: Groenendijk D. J. , Gariglio S.
Published: December 2016

The control of thin film stoichiometry is of primary relevance to achieve desired functionality. Pulsed laser deposition ablating from binary-oxide targets (sequential deposition) can be applied to precisely control the film composition, offsetting the importance of growth conditions on the film stoichiometry. In this work, we demonstrate that the cation stoichiometry of SrTiO3 thin films can be finely tuned by sequential deposition from SrO and TiO2 targets. Homoepitaxial SrTiO3 films were deposited at different substrate temperatures and Ti/Sr pulse ratios, allowing the establishment of a growth window for stoichiometric SrTiO3. The growth kinetics and nucleation processes were studied by reflection high-energy electron diffraction and atomic force microscopy, providing information about the growth mode and the degree of off-stoichiometry. At the optimal (stoichiometric) growth conditions, films exhibit atomically flat surfaces, whereas off-stoichiometry is accommodated by crystal defects, 3D islands, and/or surface precipitates depending on the substrate temperature and the excess cation. This technique opens the way to precisely control stoichiometry and doping of oxide thin films.
Active control of probability amplitudes in a mesoscale system via feedback-induced suppression of dissipation and noise
Authors: Gupta Chaitanya , Peña Perez Aldo , Fischer Sean R. , Weinreich Stephen B. , Murmann Boris , Howe Roger T.
Published: December 2016

We demonstrate that a three-terminal potentiostat circuit reduces the coupling between an electronic excitation transfer (EET) system and its environment, by applying a low-noise voltage to its electrical terminals. Inter-state interference is preserved in the EET system by attenuating the dissipation in the quantum system arising from coupling to the surrounding thermodynamic bath. A classical equivalent circuit is introduced to model the environment-coupled excitation transfer for a simplified, two-state system. This model provides a qualitative insight into how the electronic feedback affects the transition probabilities and selectively reduces dissipative coupling for one of the participant energy levels EET system. Furthermore, we show that the negative feedback also constrains r.m.s. fluctuations of the energy of environmental vibrational states, resulting in persistent spectral coherence between the decoupled state and vibronic levels of the complementary state. The decoupled vibronic channel therefore can serve as a probe for characterizing the vibronic structure of the complementary channel of the EET system.
Anisotropic control of thermal transport in graphene/Si heterostructures
Authors: Yousefzadi Nobakht Ali , Shin Seungha
Published: December 2016

The cross-plane interaction across interface changes phonon kinetics and spectrum near the interface, and the interaction effects on both in-plane and cross-plane thermal transport are investigated in graphene/Si heterostructure. The interaction with substrates dramatically reduces the in-plane thermal conductivity of graphene by changing the behaviors of the out-of-plane phonons as well as adding phonon-substrate scatterings. Applying pressure up to 2.6 GPa to the sandwiched graphene reduces the cross-plane interfacial thermal resistance by 50% without altering the in-plane thermal conductivity in a significant way. The pressure increases the inter-layer coupling and creates a low-energy phonon transport channel between graphene and Si with minor effects on phonons propagating along the graphene. This study suggests the anisotropic control of thermal transport, and the physics and calculation results can be used to improve the thermal design and analysis in two-dimensional nano-electronic devices.
Free energy calculations along entropic pathways. II. Droplet nucleation in binary mixtures
Authors: Desgranges Caroline , Delhommelle Jerome
Published: December 2016

Using molecular simulation, we study the nucleation of liquid droplets from binary mixtures and determine the free energy of nucleation along entropic pathways. To this aim, we develop the μ1μ2VT–S method, based on the grand-canonical ensemble modeling the binary mixture, and use the entropy of the system S as the reaction coordinate to drive the formation of the liquid droplet. This approach builds on the advantages of the grand-canonical ensemble, which allows for the direct calculation of the entropy of the system and lets the composition of the system free to vary throughout the nucleation process. Starting from a metastable supersaturated vapor, we are able to form a liquid droplet by gradually decreasing the value of S, through a series of umbrella sampling simulations, until a liquid droplet of a critical size has formed. The μ1μ2VT–S method also allows us to calculate the free energy barrier associated with the nucleation process, to shed light on the relation between supersaturation and free energy of nucleation, and to analyze the interplay between the size of the droplet and its composition during the nucleation process.
Aspects of infinite dimensional ℓ-super Galilean conformal algebra
Authors: Aizawa N. , Segar J.
Published: December 2016

In this work, we construct an infinite dimensional ℓ-super Galilean conformal algebra, which is a generalization of the ℓ = 1 algebra found in the literature. We give a classification of central extensions, the vector field representation, the coadjoint representation, and the operator product expansion of the infinite dimensional ℓ-super Galilean conformal algebra, keeping possible applications in physics and mathematics in mind.
Influence of the Sn oxidation state in ferromagnetic Sn-doped In2O3 nanowires
Authors: Maloney Francis Scott , Wang Wenyong
Published: December 2016

Sn-doped indium oxide nanowires were grown using a vapor-liquid-solid technique (VLS). The Sn content of the nanowires was tunable based on the source powder ratios used in the VLS process. The oxidation state of the Sn ions was examined using x-ray photoelectron spectroscopy. It was found that Sn2+ was the dominant ionic species in samples over 6% (atomic percentage) Sn. The nanowires were found to be ferromagnetic at room temperature, and their saturation magnetization increased with increasing Sn concentration, which could be associated with the spin-splitting of a defect band that was encouraged by the imbalance of Sn2+ to Sn4+ species at high Sn concentrations.
Amorphous pnictide semiconductor BaZn2As2 exhibiting high hole mobility
Authors: Xiao Zewen , Ran Fan-Yong , Liao Min , Ueda Shigenori , Hiramatsu Hidenori , Hosono Hideo , Kamiya Toshio
Published: December 2016

We selected BaZn2As2 as a candidate for a high-mobility p-type amorphous semiconductor because of the valence band maximum formed mainly of widely spread As 4p orbitals. The hole mobility of amorphous BaZn2As2 films increased from 1 to 10 cm2 V−1 s−1 as the annealing temperature increased from 300 to 400 °C. 500 °C annealing started crystallizing the film with the hole mobility ∼20 cm2 V−1 s−1. The optical bandgaps of amorphous BaZn2As2 were 1.04–1.37 eV, which are much larger than that of the crystalline β-BaZn2As2 (0.23 eV). It is explained by the broken symmetry at the Ba site and the weakening of the As–As direct bonds, which is supported by 6 keV hard X-ray photoemission spectroscopy measurement.
Structural enzymology using X-ray free electron lasers
Authors: Kupitz Christopher , Olmos Jose L. , Holl Mark , Tremblay Lee , Pande Kanupriya , Pandey Suraj , Oberthür Dominik , Hunter Mark , Liang Mengning , Aquila Andrew , Tenboer Jason , Calvey George , Katz Andrea , Chen Yujie , Wiedorn Max O. , Knoska Juraj , Meents Alke , Majriani Valerio , Norwood Tyler , Poudyal Ishwor , Grant Thomas , Miller Mitchell D. , Xu Weijun , Tolstikova Aleksandra , Morgan Andrew , Metz Markus , Martin-Garcia Jose M. , Zook James D. , Roy-Chowdhury Shatabdi , Coe Jesse , Nagaratnam Nirupa , Meza Domingo , Fromme Raimund , Basu Shibom , Frank Matthias , White Thomas , Barty Anton , Bajt Sasa , Yefanov Oleksandr , Chapman Henry N. , Zatsepin Nadia , Nelson Garrett , Weierstall Uwe , Spence John , Schwander Peter , Pollack Lois , Fromme Petra , Ourmazd Abbas , Phillips George N. , Schmidt Marius
Published: December 2016

Mix-and-inject serial crystallography (MISC) is a technique designed to image enzyme catalyzed reactions in which small protein crystals are mixed with a substrate just prior to being probed by an X-ray pulse. This approach offers several advantages over flow cell studies. It provides (i) room temperature structures at near atomic resolution, (ii) time resolution ranging from microseconds to seconds, and (iii) convenient reaction initiation. It outruns radiation damage by using femtosecond X-ray pulses allowing damage and chemistry to be separated. Here, we demonstrate that MISC is feasible at an X-ray free electron laser by studying the reaction of M. tuberculosis ß-lactamase microcrystals with ceftriaxone antibiotic solution. Electron density maps of the apo-ß-lactamase and of the ceftriaxone bound form were obtained at 2.8 Å and 2.4 Å resolution, respectively. These results pave the way to study cyclic and non-cyclic reactions and represent a new field of time-resolved structural dynamics for numerous substrate-triggered biological reactions.
Frequency flicker of 2.3 GHz AlN-sapphire high-overtone bulk acoustic resonators
Authors: Boudot Rodolphe , Martin Gilles , Friedt Jean-Michel , Rubiola Enrico
Published: December 2016

We report the detailed characterization of 2.3 GHz AlN-Sapphire high-overtone bulk acoustic resonators (HBARs), with a typical loaded Q-factor of 25–30 × 103, 15–20 dB insertion loss, and resonances separated by about 10 MHz. The temperature coefficient of frequency of HBARs is measured to be about −25 ppm/K. We observe at high-input microwave power a significant distortion of the HBAR resonance lineshape, attributed to non-linear effects. The power-induced fractional frequency variation of the HBAR resonance is measured to be about −5 × 10−10/μW. The residual phase noise of a HBAR is measured in the range of −110 to −130 dBrad2/Hz at 1 Hz Fourier frequency, yielding resonator fractional frequency fluctuations at the level of −205 to −225 dB/Hz at 1 Hz and an ultimate HBAR-limited oscillator Allan deviation about 7 × 10−12 at 1 s integration time. The 1/f noise of the HBAR resonator is found to increase with the input microwave power. A HBAR resonator is used for the development of a low phase noise 2.3 GHz oscillator. An absolute phase noise of −60, −120, and −145 dBrad2/Hz for offset frequencies of 10 Hz, 1 kHz, and 10 kHz, respectively, in excellent agreement with the Leeson effect, is measured.
Transitivity reinforcement in the coevolving voter model
Authors: Malik Nishant , Shi Feng , Lee Hsuan-Wei , Mucha Peter J.
Published: December 2016

One of the fundamental structural properties of many networks is triangle closure. Whereas the influence of this transitivity on a variety of contagion dynamics has been previously explored, existing models of coevolving or adaptive network systems typically use rewiring rules that randomize away this important property, raising questions about their applicability. In contrast, we study here a modified coevolving voter model dynamics that explicitly reinforces and maintains such clustering. Carrying out numerical simulations for a variety of parameter settings, we establish that the transitions and dynamical states observed in coevolving voter model networks without clustering are altered by reinforcing transitivity in the model. We then use a semi-analytical framework in terms of approximate master equations to predict the dynamical behaviors of the model for a variety of parameter settings.