bluuebunny/crossref_metadata_2025 huggingface dataset:
Fusion of the mouse IgG1 Fc domain to the VHH fragment (ARP1) enhances protection in a mouse model of rotavirus
Authors: Günaydın Gökçe , Yu Shengze , Gräslund Torbjörn , Hammarström Lennart , Marcotte Harold
Published: July 2016

A variable fragment of a heavy chain antibody (VHH) directed against rotavirus, also referred to as anti-rotavirus protein 1 (ARP1), was shown to confer protection against rotavirus induced diarrhea in infant mouse model of rotavirus induced diarrhea. In this study, we have fused the mouse IgG1 Fc to ARP1 to improve the protective capacity of ARP1 by inducing an Fc-mediated effector function. We have shown that the Fc-ARP1 fusion protein confers significantly increased protection against rotavirus in a neonatal mouse model of rotavirus-induced diarrhea by reducing the prevalence, duration and severity of diarrhea and the viral load in the small intestines, suggesting that the Fc part of immunoglobulins may be engaged in Fc-mediated neutralization of rotavirus. Engineered conventional-like antibodies, by fusion of the Fc part of immunoglobulins to antigen-specific heavy-chain only VHH fragments, might be applied to novel antibody-based therapeutic approaches to enhance elimination of pathogens by activation of distinct effector signaling pathways.
MicroRNA-mediated target mRNA cleavage and 3′-uridylation in human cells
Authors: Xu Kai , Lin Jing , Zandi Roza , Roth Jack A. , Ji Lin
Published: July 2016

MicroRNAs (miRNAs) play an important role in targeted gene silencing by facilitating posttranscriptional and translational repression. However, the precise mechanism of mammalian miRNA-mediated gene silencing remains to be elucidated. Here, we used a stem-loop array reverse-transcription polymerase chain reaction assay to analyse miRNA-induced mRNA recognition, cleavage, posttranscriptional modification and degradation. We detected endogenous let-7 miRNA-induced and Argonaute-catalysed endonucleolytic cleavage on target mRNAs at various sites within partially paired miRNA:mRNA sequences. Most of the cleaved mRNA 5′-fragments were 3′-oligouridylated by activities of terminal uridylyl transferases (TUTases) in miRNA-induced silencing complexes and temporarily accumulated in the cytosol for 5′-3′ degradation or other molecular fates. Some 3′-5′ decayed mRNA fragments could also be captured by the miRNA-induced silencing complex stationed at the specific miRNA:mRNA target site and oligouridylated by other TUTases at its proximity without involving Argonaute-mediated RNA cleavage. Our findings provide new insights into the molecular mechanics of mammalian miRNA-mediated gene silencing by coordinated target mRNA recognition, cleavage, uridylation and degradation.
Influence of transition metal electronegativity on the oxygen storage capacity of perovskite oxides
Authors: Liu Lu , Taylor Daniel D. , Rodriguez Efrain E. , Zachariah Michael R.
Published: July 2016

The selection of highly efficient oxygen carriers (OCs) is a key step necessary for the practical development of chemical looping combustion (CLC).
Crystallinity-induced shape evolution of Pt–Ag nanosheets from branched nanocrystals
Authors: Mahmood Azhar , Saleem Faisal , Lin Haifeng , Ni Bing , Wang Xun
Published: July 2016

2D Pt–Ag nanosheets and 3D Pt–Ag–Cu tetrapods have been selectively synthesized, which were determined by the crystallinity of the nanoseeds.
Rh(iii)-catalyzed C–H activation reactions forming 1H-isoindoles containing a quaternary carbon center from aryl ketones or benzylamines
Authors: Yi Yeonhui , Lee Hyejeong , Jun Chul-Ho
Published: July 2016

Rh(iii)/Cu(OAc)2 catalyzed, one-pot reactions of aryl ketones, acrylate esters and ammonium acetate or α-substituted benzylamines under microwave irradiation conditions produce 1H-isoindoles bearing a quarternary carbon center.
Synthesis of figure-of-eight helical bisBODIPY macrocycles and their chiroptical properties
Authors: Saikawa Makoto , Nakamura Takashi , Uchida Junji , Yamamura Masaki , Nabeshima Tatsuya
Published: July 2016

A macrocyclic bisBODIPY with a figure-of-eight helicity was synthesized, which was proven to be an efficient red-emitting CPL fluorophore.
Facile and efficient formation and dissociation of a pseudo[2]rotaxane by a slippage approach using pillar[5]arene-based cyclic host liquid and solvent
Authors: Ogoshi Tomoki , Tamura Yuko , Yamafuji Daiki , Aoki Takamichi , Yamagishi Tada-aki
Published: July 2016

A pillar[5]arene-based [2]rotaxane was synthesized by heating an axle with valine ends in a cyclic host liquid.
Transformation of masked benzyl alcohols to o-aminobenzaldehydes through C–H activation: a facile approach to quinazolines
Authors: Chen Xiaolan , Han Jian , Zhu Yan , Yuan Chunchen , Zhang Jingyu , Zhao Yingsheng
Published: July 2016

A decorating strategy has been developed for the synthesis of important synthetic units from benzyl alcohols through C–H functionalization.
High resolution GHz and THz (FTIR) spectroscopy and theory of parity violation and tunneling for 1,2-dithiine (C4H4S2) as a candidate for measuring the parity violating energy difference between enantiomers of chiral molecules
Authors: Albert S. , Bolotova I. , Chen Z. , Fábri C. , Horný L'. , Quack M. , Seyfang G. , Zindel D.
Published: July 2016

Our results show that this molecule is a suitable candidate for a possible first determination of the parity violating energy difference ΔpvE between enantiomers.
Characterization of the excited states of DNA building blocks: a coupled cluster computational study
Authors: Benda Zsuzsanna , Szalay Péter G.
Published: July 2016

DNA building blocks consisting of up to four nucleobases are investigated using the EOM-CCSD and CC2-LR methods in two B-DNA-like arrangements of a poly-adenine:poly-thymine (poly-A:poly-T) system.
A near-zero Poisson's ratio of Si with ordered nanopores
Authors: Yoo Yongmin , Kim Young-Joo , Kim Do-Nyun , Lee Joo-Hyoung
Published: July 2016

Significant reduction in the Poisson's ratio is predicted for Si with cylindrical nanopores through first-principles DFT calculations.
The transport properties of silicon and carbon nanotubes at the atomic scale: a first-principles study
Authors: Ma Tengying , Wen Shizheng , Yan Likai , Wu Caixia , Zhang Chunmei , Zhang Min , Su Zhongmin
Published: July 2016

We report a comparative study of the intrinsic electronic and transport properties of four pairs of SiNTs and CNTs using density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) method.
Photofragmentation mechanisms in protonated chiral cinchona alkaloids
Authors: Kumar Sunil , Lucas Bruno , Fayeton Jacqueline , Scuderi Debora , Alata Ivan , Broquier Michel , Barbu-Debus Katia Le , Lepère Valeria , Zehnacker Anne
Published: July 2016

Photo-fragmentation of protonated alkaloids results in C8–C9 cleavage accompanied or not by hydrogen migration, with a stereochemistry-dependent branching ratio.
Theoretical investigation of the broad one-photon absorption line-shape of a flexible symmetric carbazole derivative
Authors: Liu Yanli , Cerezo Javier , Santoro Fabrizio , Rizzo Antonio , Lin Na , Zhao Xian
Published: July 2016

The one-photon absorption spectrum of a carbazole derivative has been studied by employing density functional response theory combined with a mixed quantum/classical approach to simulate the spectral shape.
The methylsulfinyl radical CH3SO examined
Authors: Estep Marissa L. , Schaefer III Henry F.
Published: July 2016

Our computational investigations broaden the scope of currently available experimental results on the methylsulfinyl radical, a key atmospheric species.
An experimental and theoretical study of the aggregate structure of calix[6]arenes in Langmuir films at the water/air interface
Authors: de Lara Lucas S. , Wrobel Ellen C. , Lazzarotto Márcio , de Lázaro Sérgio R. , Camilo Alexandre , Wohnrath Karen
Published: July 2016

In this paper, the aggregate formation of para-tert-butylcalix[6]arene molecules (Calix6) in dimeric structures was investigated at the water/air interface using experimental and theoretical studies.
Flexible heterostructured supercapacitor electrodes based on α-Fe2O3 nanosheets with excellent electrochemical performances
Authors: Zheng Xin , Han Zhicheng , Chai Fang , Qu Fengyu , Xia Hui , Wu Xiang
Published: July 2016

Hybrid α-Fe2O3@Co3O4 and α-Fe2O3@MnCo2O4 composites are successfully synthesized on flexible carbon cloth, respectively. These as-obtained products as the supercapacitor electrodes show enhanced discharge areal capacitance.
Diatom silica–titania photocatalysts for air purification by bio-accumulation of different titanium sources
Authors: Van Eynde E. , Hu Z.-Y. , Tytgat T. , Verbruggen S. W. , Watté J. , Van Tendeloo G. , Van Driessche I. , Blust R. , Lenaerts S.
Published: July 2016

Diatom microalgae are used to fabricate silica–titania photocatalysts for air purification by means of a biological immobilization process into the diatom frustules.
The protective effect of resveratrol against cytotoxicity induced by mycotoxin, zearalenone
Authors: Sang Yaqiu , Li Wenzhu , Zhang Genyi
Published: July 2016

Zearalenone (ZEA), a non-steroidal estrogenic mycotoxin, is widely present in cereals and agricultural products.
Ring-locking enables selective anhydrosugar synthesis from carbohydrate pyrolysis
Authors: Chen Li , Zhao Jinmo , Pradhan Sivaram , Brinson Bruce E. , Scuseria Gustavo E. , Zhang Z. Conrad , Wong Michael S.
Published: July 2016

The nonselective nature of glucose pyrolysis chemistry can be controlled by preventing the sugar ring from opening and fragmenting.
Exploring the origin of the catalytic power and product specificity of SET domain protein methyltransferase
Authors: Lima A. H. , Alves C. N. , Prasad R. , Lameira J.
Published: July 2016

Computer simulation reveals that the origin of SET8 catalytic power is mainly due to electrostatic preorganization.
The discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening
Authors: Xiang Jinbao , Zhang Zhuoqi , Fu Renzhong , Ternansky Robert J. , Gladstone Patricia L. , Allan Amy L. , Donate Fernando , Parry Graham , Juarez Jose , Mazar Andrew P. , Bai Xu
Published: July 2016

An efficient strategy for the discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening was presented.
Osteochondral scaffold combined with aligned nanofibrous scaffolds for cartilage regeneration
Authors: Lee Paul , Manoukian Ohan S. , Zhou Gan , Wang Yuhao , Chang Wei , Yu Xiaojun , Kumbar Sangamesh G.
Published: July 2016

Osteochondral defect repair poses a significant challenge in its reconstruction as the damage is presented in both articular cartilage and the underlying subchondral bone. Thus we present a osteochondral scaffold for articular cartilage repair.
Composition-dependent structural and electrical properties of p-type SnOx thin films prepared by reactive DC magnetron sputtering: effects of oxygen pressure and heat treatment
Authors: Han Sang Jin , Kim Sungmin , Ahn Joongyu , Jeong Jae Kyeong , Yang Hoichang , Kim Hyeong Joon
Published: July 2016

The composition-dependent structural and electrical properties of p-type SnOx films prepared by reactive DC sputtering at various oxygen partial pressures (PO) and post-heat treatment temperatures (TA) were investigated.
Highly efficient near IR photosensitizers based-on Ir–C bonded porphyrin-aza-BODIPY conjugates
Authors: Zhou Jinfeng , Gai Lizhi , Zhou Zhikuan , Mack John , Xu Kejing , Zhao Jianzhang , Qiu Hailin , Chan Kin Shing , Shen Zhen
Published: July 2016

Novel orthogonally arranged Ir(iii) porphyrin-aza-BODIPY conjugates exhibit strong absorbance in the near infrared region and have unusually high singlet oxygen quantum yields, since they act as unique molecules rather than as dyads.
Interactions affecting 1JC–F SSCCs in neutral and ionic 2-, 3- and 4-fluoro-substituted piperidines: normal and reverse fluorine Perlin-like effect
Authors: Silla Josué M. , Freitas Matheus P.
Published: July 2016

We report a theoretical analysis of the 1JC–F spin–spin coupling constant (SSCC) in n-fluoropiperidines to find the dictating effects of 1JC–F and to obtain insight into the stereochemistry of organofluorine compounds using this SSCC.
Defect engineering route to boron nitride quantum dots and edge-hydroxylated functionalization for bio-imaging
Authors: Jung Jung-Hwan , Kotal Moumita , Jang Min-Ho , Lee Junseok , Cho Yong-Hoon , Kim Won-Jong , Oh Il-Kwon
Published: July 2016

A defect engineering method was developed using physical energy sources to synthesize boron nitride quantum dots (BNQDs) for bioimaging applications.
A review on the advancement of ether synthesis from organic solvent to water
Authors: Mandal Sangita , Mandal Swagata , Ghosh Sumanta K. , Sar Pintu , Ghosh Aniruddha , Saha Rumpa , Saha Bidyut
Published: July 2016

Ethers have been synthesized by different protocols, this review aims to bring the attention of scientists working in the field of industrial chemistry, green chemistry, and catalysis towards the potential future of ether synthesis in micellar media.
Pre-clinical risk assessment and therapeutic potential of antitumor lipopeptide ‘Iturin A’ in an in vivo and in vitro model
Authors: Dey Goutam , Bharti Rashmi , Banerjee Indranil , Das Anjan Kumar , Das Chandan Kanta , Das Subhayan , Jena Bikash Chandra , Misra Mridula , Sen Ramkrishna , Mandal Mahitosh
Published: July 2016

Microbial lipopeptide “Iturin A” is a versatile bio-active molecule with potent antitumor action. Pre-clinical study of this lipopeptide showed very minimum toxicity in rodent model.
Effects of cyano groups on the properties of thiazole-based β-ketoiminate boron complexes: aggregation-induced emission and mechanofluorochromism
Authors: Zhou Lin , Xu Defang , Gao Huaizhi , Han Aixia , Yang Yan , Zhang Chao , Liu Xingliang , Zhao Feng
Published: July 2016

The triphenylamine-functionalized thiazole-based β-ketoiminate boron complexBF2-TT-CNexhibited strong cyano-dependent aggregation-induced emission (AIE) and mechanofluorochromic (MFC) properties.
A concise asymmetric total synthesis for structure elucidation of 5,6-secoiridoid from Incarvillea argute
Authors: Fu Jian-Jun , Liu Zhi-Qian , Jin Hui-Zi , Zhang Shou-De , Sun Qing-Yan , Zhang Wei-Dong
Published: July 2016

A phytochemical investigation of the roots of Incarvillea arguta led to the isolation of secoarguterin (1), which is the first example of 5,6-secoiridoid.
Graphene-coated mesoporous Co3O4 fibers as an efficient anode material for Li-ion batteries
Authors: Qu Genlong , Geng Hongbo , Ge Danhua , Zheng Junwei , Gu Hongwei
Published: July 2016

The graphene-coating porous cobalt oxide fibers (Co3O4@G) were synthesized using coordination polymers as precursors through calcination and subsequent self-assembly process. The obtained materials exhibit good electrochemical performances.
Sustainable hydrogen production from electroplating wastewater over a solar light responsive photocatalyst
Authors: Su En-Chin , Huang Bing-Shun , Wey Ming-Yen
Published: July 2016

An environmentally friendly and sustainable photocatalytic hydrogen production system was successfully developed using EDTA in the wastewater as the photo-excited hole scavenger and a solar light responsive material as the photocatalyst.
High performance red organic electroluminescent devices based on a trivalent iridium complex with stepwise energy levels
Authors: Li Yanan , Zhou Liang , Cui Rongzhen , Jiang Yunlong , Zhao Xuesen , Liu Weiqiang , Zhu Qi , Cui Yingjie , Zhang Hongjie
Published: July 2016

Red EL device with maximum current efficiency of 44.76 cd A−1, power efficiency of 40.19 lm W−1, and external quantum efficiency (EQE) of 15.5% was realized. At high brightness of 1000 cd m−2, current efficiency as high as 40.59 cd A−1(EQE = 14.4%) can be retained.
Green-assisted tool for nanogold synthesis based on alginate as a biological macromolecule
Authors: Ahmed Hanan B. , Abdel-Mohsen A. M. , Emam Hossam E.
Published: July 2016

Large-scale biomedical applications of nanogold reflect the challenge faced by recent researches in the investigation of green synthesis methodologies, which are mostly complicated and/or expensive processes.
Phase structure control and optical spectroscopy of rare-earth activated GdF3 nanocrystal embedded glass ceramics via alkaline-earth/alkali-metal doping
Authors: Liu Shen , Chen Daqin , Wan Zhongyi , Zhou Yang , Huang Ping , Ji Zhenguo
Published: July 2016

Alkaline-earth/alkali-metal dopant-induced hexagonal and orthorhombic GdF3 nanocrystal embedded glass ceramics were fabricated via glass crystallization.
Advances in the FTU collective Thomson scattering system
Authors: Bin W. , Bruschi A. , D’Arcangelo O. , Grosso G. , Lubiako L. , Alessi E. , Castaldo C. , Centioli C. , De Angeli M. , Figini L. , Galperti C. , Garavaglia S. , Granucci G. , Lontano M. , Magagnino S. , Mellera V. , Minelli D. , Moro A. , Muraro A. , Nardone A. , Orsitto F. , Simonetto A. , Tartari U. ,   FTU Team
Published: July 2016

The new collective Thomson scattering diagnostic installed on the Frascati Tokamak Upgrade device started its first operations in 2014. The ongoing experiments investigate the presence of signals synchronous with rotating tearing mode islands, possibly due to parametric decay processes, and phenomena affecting electron cyclotron beam absorption or scattering measurements. The radiometric system, diagnostic layout, and data acquisition system were improved accordingly. The present status and near-term developments of the diagnostic are presented.
Bulk characterization in a Monte Carlo particle-deposition model with a novel adherence-potential barrier
Authors: Galindo Jose Luis , Huertas Rafael , Carrasco-Sanz Ana , Lapresta Alejandro , Galindo Jorge , Vasco Enrique
Published: July 2016

The aim of this work is to analyze in more depth a model of particle deposition by characterizing different parameters such as profile density, bonds and perimeter, and substrate coverage, all being involved in the description of deposits as bulk. Thus, this study is an extension of a previous work on non-equilibrium interface-growth systems where two different interface-growth models, called Standard Adherence Rule Model and Potential Adherence Rule Model, were characterized. In this work, bulk characterization is implemented for the complete range of Peclet numbers. The zones of density profile (Near-Wall, Plateau, and Active-Growth) are studied by proposing an adjustment for each of them and determining the full-setting density profile depending on the Peclet number. The density profiles are compared with other one- and two-stage models. Furthermore, an algorithm is proposed to calculate the number of bonds of the particles and the perimeter that a substrate forms over time. Finally, to analyze the coating, its temporal behavior is adjusted to an exponential function by comparing the results with those found for Random Sequential Adsorption models which describe systems like colloidal particles on solid substrates, adsorption of proteins at mineral surfaces, or oxidation of one-dimensional polymer chains.
Ferromagnetic resonance of a YIG film in the low frequency regime
Authors: Lee Seongjae , Grudichak Scott , Sklenar Joseph , Tsai C. C. , Jang Moongyu , Yang Qinghui , Zhang Huaiwu , Ketterson John B.
Published: July 2016

An improved method for characterizing the magnetic anisotropy of films with cubic symmetry is described and is applied to an yttrium iron garnet (111) film. Analysis of the ferromagnetic resonance (FMR) spectra performed both in-plane and out-of-plane from 0.7 to 8 GHz yielded the magnetic anisotropy constants as well as the saturation magnetization. The field at which FMR is observed turns out to be quite sensitive to anisotropy constants (by more than a factor ten) in the low frequency (<2 GHz) regime, and when the orientation of the magnetic field is nearly normal to the sample plane; the restoring force on the magnetization arising from the magnetocrystalline anisotropy fields is then comparable to that from the external field, thereby allowing the anisotropy constants to be determined with greater accuracy. In this region, unusual dynamical behaviors are observed such as multiple resonances and a switching of FMR resonance with only a 1° change in field orientation at 0.7 GHz.
A new intermolecular potential for simulations of methanol: The OPLS/2016 model
Authors: Gonzalez-Salgado D. , Vega C.
Published: July 2016

In this work, a new rigid-nonpolarizable model of methanol is proposed. The model has three sites, located at the same positions as those used in the OPLS model previously proposed by Jorgensen [J. Phys. Chem. 90, 1276 (1986)]. However, partial charges and the values of the Lennard-Jones parameters were modified by fitting to an adequately selected set of target properties including solid-fluid experimental data. The new model was denoted as OPLS/2016. The overall performance of this model was evaluated and compared to that obtained with other popular models of methanol using a similar test to that recently proposed for water models. In the test, a certain numerical score is given to each model. It was found that the OPLS/2016 obtained the highest score (7.4 of a maximum of 10) followed by L1 (6.6), L2 (6.4), OPLS (5.8), and H1 (3.5) models. The improvement of OPLS/2016 with respect to L1 and L2 is mainly due to an improvement in the description of fluid-solid equilibria (the melting point is only 14 K higher than the experimental value). In addition, it was found that no methanol model was able to reproduce the static dielectric constant and the isobaric heat capacity, whereas the better global performance was found for models that reproduce the vaporization enthalpy once the so-called polarization term is included. Similar conclusions were suggested previously in the analysis of water models and are confirmed here for methanol.
A multi-wavelength, high-contrast contact radiography system for the study of low-density aerogel foams
Authors: Opachich Y. P. , Koch J. A. , Haugh M. J. , Romano E. , Lee J. J. , Huffman E. , Weber F. A. , Bowers J. W. , Benedetti L. R. , Wilson M. , Prisbrey S. T. , Wehrenberg C. E. , Baumann T. F. , Lenhardt J. M. , Cook A. , Arsenlis A. , Park H.-S. , Remington B. A.
Published: July 2016

A multi-wavelength, high contrast contact radiography system has been developed to characterize density variations in ultra-low density aerogel foams. These foams are used to generate a ramped pressure drive in materials strength experiments at the National Ignition Facility and require precision characterization in order to reduce errors in measurements. The system was used to characterize density variations in carbon and silicon based aerogels to ∼10.3% accuracy with ∼30 μm spatial resolution. The system description, performance, and measurement results collected using a 17.8 mg/cc carbon based JX–6 (C20H30) aerogel are discussed in this manuscript.
Surface Al doping of 4H-SiC via low temperature annealing
Authors: Park Junbo , Kim Ki-hwan , Park Young-rak , Kim Minki , Lee Hyungseok , Jun Chi-Hoon , Koo Sangmo , Ko Sang Choon
Published: July 2016

We present a method of forming shallow p-doping on a 4H-SiC surface by depositing a thin Al layer (d = 5 nm) and then thermally annealing it at 1000 °C for 10 min. A secondary ion mass spectrometry analysis of the annealed Al/SiC sample reveals an Al concentration in excess of 1017 cm−3 up to a depth of d ≤ 250 nm. I–V measurements and CV characterizations of Ti-SiC Schottky barrier diodes (SBDs) fabricated on a n-type SiC epi-wafer indicate that the shallow Al doping increases the built-in potential of the junction and the barrier height by ΔVbi=0.51 eV and ΔϕB=0.26 eV, respectively. Assuming a rectangular doping profile, calculations of the built-in voltage shift and the Schottky barrier height indicate that partial dopant activation (activation ratio ∼2%) can induce the observed barrier height shift. The shallow doping method was then used to fabricate junction terminations in SBDs which increased the breakdown voltage and reduced the reverse leakage current. Technology CAD simulations of the SBD with and without doping verify that a reduction of peak electric field can explain the improvement of the breakdown voltage.
Lattice dynamics, electronic structure, and optical properties of LiBeSb: A hexagonal ABC-type hyperferroelectrics
Authors: Dai Jian-Qing , Zhu Jian-Hui , Xu Jie-Wang
Published: July 2016

The recently discovered hexagonal ABC-type hyperferroelectrics, in which the polarization persists in the presence of the depolarization filed, exhibit a variety of intriguing and potentially useful properties [Garrity et al., Phys. Rev. Lett. 112, 127601 (2014)]. For the existing prototype of LiBeSb, we present detailed first-principles calculations concerning the lattice dynamics, electronic structure, and optical properties. An unstable longitudinal optic mode in the high-symmetry structure and a large polarization of 0.5 C/m2 in the polar phase are reported, including the remarkable dependence of Born effective charges on structural distortion. Using the HSE06 hybrid functional, we predict that LiBeSb has a small band-gap of 1.5 eV and shows dominant asymmetric covalent bonding character. Importantly, we find that there are remarkable absorptions in the whole visible spectrum. These features, combined with the enhanced carrier mobility, make LiBeSb as well as the whole family of hexagonal ABC-type hyperferroelectrics as promising candidates for ferroelectric photovoltaic materials with large bulk photovoltaic effect in the visible spectrum.
Topological magnetoelectric effects in microwave far-field radiation
Authors: Berezin M. , Kamenetskii E. O. , Shavit R.
Published: July 2016

Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.
Design calculations for a xenon plasma x-ray shield to protect the NIF optical Thomson scattering diagnostic
Authors: Swadling G. F. , Ross J. S. , Datte P. , Moody J. , Divol L. , Jones O. , Landen O.
Published: July 2016

An Optical Thomson Scattering (OTS) diagnostic is currently being developed for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. This diagnostic is designed to make measurements of the hohlraum plasma parameters, such as the electron temperature and the density, during inertial confinement fusion (ICF) experiments. NIF ICF experiments present a very challenging environment for optical measurements; by their very nature, hohlraums produce intense soft x-ray emission, which can cause “blanking” (radiation induced opacity) of the radiation facing optical components. The soft x-ray fluence at the surface of the OTS blast shield, 60 cm from the hohlraum, is estimated to be ∼8 J cm−2. This is significantly above the expected threshold for the onset of “blanking” effects. A novel xenon plasma x-ray shield is proposed to protect the blast shield from x-rays and mitigate “blanking.” Estimates suggest that an areal density of 1019 cm−2 Xe atoms will be sufficient to absorb 99.5% of the soft x-ray flux. Two potential designs for this shield are presented.
Full-dimensional quantum dynamics of CO in collision with H2
Authors: Yang Benhui , Balakrishnan N. , Zhang P. , Wang X. , Bowman J. M. , Forrey R. C. , Stancil P. C.
Published: July 2016

Inelastic scattering computations are presented for collisions of vibrationally and rotationally excited CO with H2 in full dimension. The computations utilize a newly developed six-dimensional potential energy surface (PES) and the previously reported four-dimensional V12 PES [P. Jankowski et al., J. Chem. Phys. 138, 084307 (2013)] and incorporate full angular-momentum coupling. At low collision energies, pure rotational excitation cross sections of CO by para-, ortho-, and normal-H2 are calculated and convolved to compare with recent measurements. Good agreement with the measured data is shown except for j1 = 0 → 1 excitation of CO for very low-energy para-H2 collisions. Rovibrational quenching results are presented for initially excited CO(v1j1) levels with v1 = 1, j1 = 1–5 and v1 = 2, j1 = 0 for collisions with para-H2 (v2 = 0, j2 = 0) and ortho-H2 (v2 = 0, j2 = 1) over the kinetic energy range 0.1–1000 cm−1. The total quenching cross sections are found to have similar magnitudes, but increase (decrease) with j1 for collision energies above ∼300 cm−1 (below ∼10 cm−1). Only minor differences are found between para- and ortho-H2 colliders for rovibrational and pure rotational transitions, except at very low collision energies. Likewise, pure rotational deexcitation of CO yields similar cross sections for the v1 = 0 and v1 = 1 vibrational levels, while rovibrational quenching from v1 = 2, j1 = 0 is a factor of ∼5 larger than that from v1 = 1, j1 = 0. Details on the PES, computed at the CCSD(T)/aug-cc-pV5Z level, and fitted with an invariant polynomial method, are also presented.
The radiative transport equation in flatland with separation of variables
Authors: Machida Manabu
Published: July 2016

The linear Boltzmann equation can be solved with separation of variables in one dimension, i.e., in three-dimensional space with planar symmetry. In this method, solutions are given by superpositions of eigenmodes which are sometimes called singular eigenfunctions. In this paper, we explore the singular-eigenfunction approach in flatland or two-dimensional space.
The effect of grading the atomic number at resistive guide element interface on magnetic collimation
Authors: Alraddadi R. A. B. , Robinson A. P. L. , Woolsey N. C. , Pasley J.
Published: July 2016

Using 3 dimensional numerical simulations, this paper shows that grading the atomic number and thus the resistivity at the interface between an embedded high atomic number guide element and a lower atomic number substrate enhances the growth of a resistive magnetic field. This can lead to a large integrated magnetic flux density, which is fundamental to confining higher energy fast electrons. This results in significant improvements in both magnetic collimation and fast-electron-temperature uniformity across the guiding. The graded interface target provides a method for resistive guiding that is tolerant to laser pointing.
Nonadiabatic transition path sampling
Authors: Sherman M. C. , Corcelli S. A.
Published: July 2016

Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.
Time-dependent density-functional theory simulation of local currents in pristine and single-defect zigzag graphene nanoribbons
Authors: He Shenglai , Russakoff Arthur , Li Yonghui , Varga Kálmán
Published: July 2016

The spatial current distribution in H-terminated zigzag graphene nanoribbons (ZGNRs) under electrical bias is investigated using time-dependent density-functional theory solved on a real-space grid. A projected complex absorbing potential is used to minimize the effect of reflection at simulation cell boundary. The calculations show that the current flows mainly along the edge atoms in the hydrogen terminated pristine ZGNRs. When a vacancy is introduced to the ZGNRs, loop currents emerge at the ribbon edge due to electrons hopping between carbon atoms of the same sublattice. The loop currents hinder the flow of the edge current, explaining the poor electric conductance observed in recent experiments.
Envelope Hamiltonian for charged-particle dynamics in general linear coupled systems
Authors: Chung Moses , Qin Hong , Davidson Ronald C.
Published: July 2016

We report the discovery of an envelope Hamiltonian describing the charged-particle dynamics in general linear coupled lattices.
Resonant dipolar relaxation in poly (ε-caprolactone)—A thermally stimulated depolarization current study
Authors: Patidar M. M. , Jain D. , Nath R. , Ganesan V.
Published: July 2016

Resonant dipolar relaxation in poly(ε-caprolactone) (PCL) is reported using thermally stimulated discharge current spectroscopy. PCL is a bio-medically known shape memory polymer having a well defined γ, β, α, and α′ relaxations, respectively, centered around 125 K, 170 K, 220 K, and 270 K as seen by the measurements. By employing a new protocol variable poling temperature at constant freezing temperature, resonant dipolar relaxation in PCL could be induced, especially in the vicinity of α relaxation. Such a protocol is useful in de-convoluting the features in a more meaningful fashion. By an analysis of activation process, we could show a clear contrast enhancement of the dynamics of the participating dipoles by means of a minimum in the activation energies situated around the glass transition region. The relevant parameters of interest such as activation energies and relaxation times are estimated and discussed.
Observation of structural inhomogeneity at degraded Fe-doped SrTiO3 interfaces
Authors: Ascienzo D. , Greenbaum S. , Bayer T. J. M. , Maier R. , Randall C. A. , Ren Y. H.
Published: July 2016

We report on the detection of structural inhomogeneity across anode and cathode interfaces in electrically degraded reduced and oxidized Fe-doped SrTiO3 (Fe:STO) single crystals by optical second harmonic generation (SHG) spectroscopy. SHG spectra were collected from several regions across the anode and cathode interfaces in both degraded reduced and oxidized Fe:STO crystals. We identify the formation of defect concentration gradients along both degraded reduced and oxidized anode interfaces. While the broken symmetries decrease from the outer region towards the central region of the reduced anode, the opposite trend is seen in the degraded oxidized anode. These results are attributed to the formation of centrosymmetric Fe4+:Ti4+-O6 octahedral structures in the central region of the reduced sample's degraded anode and non-centrosymmetric Jahn-Teller distortions in the central region of the oxidized sample's degraded anode. The observed changes in SHG intensity from the outer region towards the central region of the degraded cathode interfaces is accompanied by a structural phase transition in the inner and outer regions, marked by strong changes to the s-polarized intensity spectra. We explain the SHG intensity changes by the formation of lower order symmetry Fe3+:Ti3+-O6 structures in the outer region and a modification of the second-order nonlinear susceptibility near the central regions due to the clustering of dissociated oxygen vacancies. These significant structural and spatial inhomogeneities are linked directly to the field-driven migration of oxygen ions and vacancies.
Effects of interlayer screening and temperature on dielectric functions of graphene by first-principles
Authors: Yang J. Y. , Liu L. H.
Published: July 2016

The dielectric functions of few-layer graphene and the related temperature dependence are investigated from the atomic scale using first-principles calculations. Compared with ellipsometry experiments in the spectral range of 190–2500 nm, the normalized optical constants of mono-layer graphene demonstrate good agreement and further validate first-principles calculations. To interpret dielectric function of mono-layer graphene, the electronic band structure and density of states are analyzed. By comparing dielectric functions of mono-, bi-, and tri-layer graphene, it shows that interlayer screening strengthens intraband transition and greatly enhances the absorption peak located around 1 eV. The strengthened optical absorption is intrinsically caused by the increasing electron states near the Fermi level. To investigate temperature effect, the first-principles calculations and lattice dynamics are combined. The lattice vibration enhances parallel optical absorption peak around 1 eV and induces redshift. Moreover, it is observed that the van der Waals force plays a key role in keeping the interlayer distance stable during dynamics simulations.
Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02
Authors: Sun Hui , Lu Xu , Morelli Donald T.
Published: July 2016

Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm−1 K−2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.
Bi-alkali antimonide photocathode growth: An X-ray diffraction study
Authors: Schubert Susanne , Wong Jared , Feng Jun , Karkare Siddharth , Padmore Howard , Ruiz-Osés Miguel , Smedley John , Muller Erik , Ding Zihao , Gaowei Mengjia , Attenkofer Klaus , Liang Xue , Xie Junqi , Kühn Julius
Published: July 2016

Bi-alkali antimonide photocathodes are one of the best known sources of electrons for high current and/or high bunch charge applications like Energy Recovery Linacs or Free Electron Lasers. Despite their high quantum efficiency in visible light and low intrinsic emittance, the surface roughness of these photocathodes prohibits their use as low emittance cathodes in high accelerating gradient superconducting and normal conducting radio frequency photoguns and limits the minimum possible intrinsic emittance near the threshold. Also, the growth process for these materials is largely based on recipes obtained by trial and error and is very unreliable. In this paper, using X-ray diffraction, we investigate the different structural and chemical changes that take place during the growth process of the bi-alkali antimonide material K2CsSb. Our measurements give us a deeper understanding of the growth process of alkali-antimonide photocathodes allowing us to optimize it with the goal of minimizing the surface roughness to preserve the intrinsic emittance at high electric fields and increasing its reproducibility.
Study of carbon dioxide emissions prediction in Hebei province, China using a BPNN based on GA
Authors: Sun Wei , Ye Minquan , Xu Yanfeng
Published: July 2016

With the deterioration of the global greenhouse effect, the study of carbon dioxide emissions has received more and more international attention and accurate prediction of carbon dioxide emissions is also important for the formulation of reasonable energy-saving emission reduction measures. In this paper, the genetic algorithm is used to optimize the initial connection weights and thresholds of the traditional back propagation neural network (BPNN) which can give full play to the advantages of the genetic algorithm's global search capacity and BPNN's local search. The data of Hebei province in China during the period 1978–2012 are selected to carry out the carbon dioxide emissions prediction with the established model. In the view of the choice of input variables, the coal consumption, gross domestic product, total population, and urbanization level are examined by Pearson coefficient test. Auto correlation and partial correlation are applied to analyze the inner relationships between the historic carbon dioxide emissions, thus to select the input variables of BPNN. Besides, in order to verify the validity of the built model, the residual auto correlation and partial correlation are done upon the training set. The prediction results suggest the proposed model outperforms the compared models.
Impact of built-in fields and contact configuration on the characteristics of ultra-thin GaAs solar cells
Authors: Aeberhard Urs
Published: July 2016

We discuss the effects of built-in fields and contact configuration on the photovoltaic characteristics of ultra-thin GaAs solar cells. The investigation is based on advanced quantum-kinetic simulations reaching beyond the standard semi-classical bulk picture concerning the consideration of charge carrier states and dynamics in complex potential profiles. The thickness dependence of dark and photocurrent in the ultra-scaled regime is related to the corresponding variation of both, the built-in electric fields and associated modification of the density of states, and the optical intensity in the films. Losses in open-circuit voltage and short-circuit current due to the leakage of electronically and optically injected carriers at minority carrier contacts are investigated for different contact configurations including electron and hole blocking barrier layers. The microscopic picture of leakage currents is connected to the effect of finite surface recombination velocities in the semi-classical description, and the impact of these non-classical contact regions on carrier generation and extraction is analyzed.
Matrix-assisted relaxation in Fe(phen)2(NCS)2 spin-crossover microparticles, experimental and theoretical investigations
Authors: Enachescu Cristian , Tanasa Radu , Stancu Alexandru , Tissot Antoine , Laisney Jérôme , Boillot Marie-Laure
Published: July 2016

In this study, we present the influence of the embedding matrix on the relaxation of Fe(phen)2(NCS)2 (phen = 1,10-phenanthroline) spin-transition microparticles as revealed by experiments and provide an explanation within the framework of an elastic model based on a Monte-Carlo method. Experiments show that the shape of the high-spin → low-spin relaxation curves is drastically changed when the particles are dispersed in glycerol. This effect was considered in the model by means of interactions between the microparticles and the matrix. A faster start of the relaxation for microparticles embedded in glycerol is due to an initial positive local pressure acting on the edge spin-crossover molecules from the matrix side. This local pressure diminishes and eventually becomes negative during relaxation, as an effect of the decrease of the volume of spin-crossover microparticles from high-spin to low-spin.
Inscription of 3D waveguides in diamond using an ultrafast laser
Authors: Courvoisier Arnaud , Booth Martin J. , Salter Patrick S.
Published: July 2016

Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.
Light induced suppression of Kondo effect at amorphous LaAlO3/SrTiO3 interface
Authors: Liu G. Z. , Qiu J. , Jiang Y. C. , Zhao R. , Yao J. L. , Zhao M. , Feng Y. , Gao J.
Published: July 2016

We report photoelectric properties of two-dimensional electron gas (2DEG) at an amorphous LaAlO3/SrTiO3 interface. Under visible light illumination (650 nm), an enhancement of electric conductivity is observed over the temperature range from 2 to 300 K. Particularly, a resistance upturn appearing below 25 K, which is further proved to from the Kondo effect, is suppressed by the 650 nm visible light. From the results of light-assisted Hall measurements, light irradiation increases the carrier mobility rather than carrier density in the Kondo regime. It is suggested that light induces the decoherence effect of localized spin states, hence the electron scattering is weakened and the carrier mobility is improved accordingly. Moreover, the enhancement of electrical conductivity by visible light verifies that in-gap states located in the SrTiO3 side of the interface play an important role in the electrical transport of the amorphous SrTiO3-based oxide 2DEG system. Our results provide deeper insight into the photoinduced effects in the 2DEG system, paving the way for the design of optoelectronic devices based on oxides.
Unconventional Fano effect based spectrally selective absorption enhancement in graphene using plasmonic core-shell nanostructures
Authors: Li Yan , He Xiaodan , Wan Mingjie , Wu Wenyang , Chen Zhuo
Published: July 2016

We present a design of multilayer core-shell nanostructures formed by introducing a dielectric gap shell layer between a silver core and a monolayer graphene shell for spectrally selective absorption enhancement in graphene based on an unconventional Fano effect. We demonstrate that this mechanism enables great flexibility in the choice of parameters of the proposed structures for the achievement of a relatively large and narrow-band absorption enhancement in graphene. Furthermore, we also demonstrate that such a spectrally selective absorption enhancement in graphene is highly tunable and can be optimized by controlling either the core or the shell parameters. These unique absorption properties may have applications in color-selective photodetectors and image sensors.