bluuebunny/crossref_metadata_2025 huggingface dataset:
SiO and CH3OH mega-masers in NGC 1068
Authors: Wang Junzhi , Zhang Jiangshui , Gao Yu , Zhang Zhi-Yu , Li Di , Fang Min , Shi Yong
Published: November 2014

Maser is an acronym for microwave amplification by stimulated emission of radiation; in astronomy mega-masers are masers in galaxies that are ≥106 times more luminous than typical galactic maser sources. Observational studies of mega-masers can help us to understand their origins and characteristics. More importantly, mega-masers can be used as diagnostic tracers to probe the physical properties of their parent galaxies. Since the late 1970s, only three types of molecules have been found to form mega-masers: H2O, OH and H2CO. Here we report the detection of both SiO and CH3OH mega-masers near the centre of Seyfert 2 galaxy NGC 1068 at millimetre wavelengths, obtained using the IRAM 30-m telescope. We argue that the SiO mega-maser originated from the nuclear disk and the CH3OH mega-maser originated from shock fronts. High-resolution observations in the future will enable us to investigate AGN feedback and determine the masses of central supermassive black holes in such galaxies.
Sleep apnea is not associated with worse outcomes in kidney transplant recipients
Authors: Fornadi Katalin , Ronai Katalin Zsuzsanna , Turanyi Csilla Zita , Malavade Tushar S. , Shapiro Colin Michael , Novak Marta , Mucsi Istvan , Molnar Miklos Z.
Published: November 2014

Obstructive sleep apnea(OSA) is one of the most common sleep disorders in kidney transplant recipients, however its long-term consequences have only rarely been investigated. Here, we hypothesized that the presence of OSA would be associated with higher risk of mortality and faster decline of graft function in kidney transplant recipients. In a prospective cohort study 100 prevalent kidney transplant recipients who underwent one-night polysomnography at baseline and were followed for a median 75 months. Generalized linear mixed-effects models and Cox regression models were used to assess the association between OSA and the rate of progression of chronic kidney disease(CKD) and mortality. The estimated slopes of estimated glomerular filtration rate(eGFR) in patients with and without OSA were compared using a two-stage model of eGFR change including only OSA as a variable. In this model patients with OSA (eGFR versus time was −0.93 ml/min/1.73 m2/yr(95%CI:−1.75 to−0.11) had a similar slope as compared to patients without OSA(eGFR versus time was −1.24 ml/min/1.73 m2/yr(95%CI: −1.67 to −0.81). In unadjusted Cox proportional regression analyses OSA was not associated with higher all-cause mortality risk (Hazard Ratio(HR) = 1.20; 95% Confidence Interval(CI): 0.50–2.85). No association was found between the presence of OSA and the rate of progression of CKD or all-cause mortality in prevalent kidney transplant recipients.
Significantly enhanced antibacterial activity of TiO2 nanofibers with hierarchical nanostructures and controlled crystallinity
Authors: Lee Won Seok , Park Yang-Seok , Cho Yoon-Kyoung
Published: November 2014

We report a significantly enhanced antibacterial activity of hierarchical anatase TiO2 nanofibers against Staphylococcus aureus, achieved by well-controlled crystallinity as well as an increased surface area.
Novel pyridinium-based tags: synthesis and characterization for highly efficient analysis of thiol-containing peptides by mass spectrometry
Authors: Qiao Xiaoqiang , Yang Yanjun , Liu Shijia , Chen Shiheng , Wang Xin , Li Guangyue , Yan Hongyuan , Yang Xun
Published: November 2014

Novel pyridinium-based tags were exploited for highly efficient analysis of thiol-containing peptides using mass spectrometry.
An exceptionally stable functionalized metal–organic framework for lithium storage
Authors: Lin Yichao , Zhang Qiuju , Zhao Chongchong , Li Huailong , Kong Chunlong , Shen Cai , Chen Liang
Published: November 2014

A new functionalized MOF with remarkable thermal and chemical stability, and Li storage ability has been designed and synthesized.
In situ observation of facet-dependent oxidation of graphene on platinum in an environmental TEM
Authors: Yuan Wentao , Jiang Ying , Wang Yong , Kattel Shyam , Zhang Zhengfei , Chou Lien-Yang , Tsung Chia-Kuang , Wei Xiao , Li Jixue , Zhang Xiaofeng , Wang Guofeng , Mao Scott X. , Zhang Ze
Published: November 2014

The facet-dependent oxidation reactionvia in situETEM.
General base-tuned unorthodox synthesis of amides and ketoesters with water
Authors: Khamarui Saikat , Maiti Rituparna , Maiti Dilip K.
Published: November 2014

We discovered a highly reactive λ3-hypervalent iodane species using an inorganic/organic base for the unorthodox synthesis of amides and ketoesters through grafting terminal alkynes. In contrast to the metal-catalyzed dehydrative approaches the in situ generated nonmetallic reagent efficiently created C–N/C–O and CO bonds with amines/alkynes and water at rt.
Ternary synthesis of colloidal Zn3P2quantum dots
Authors: Glassy Benjamin A. , Cossairt Brandi M.
Published: November 2014

The synthesis and characterization of crystalline colloidal zinc phosphide quantum dots with observable excitonic transitions ranging between 424–535 nm (2.3–2.9 eV) are reported.
All-solid-state Z-scheme system arrays of Fe2V4O13/RGO/CdS for visible light-driving photocatalytic CO2 reduction into renewable hydrocarbon fuel
Authors: Li Ping , Zhou Yong , Li Haijin , Xu Qinfeng , Meng Xiangguang , Wang Xiaoyong , Xiao Min , Zou Zhigang
Published: November 2014

An all-solid-state Z-scheme system array consisting of Fe2V4O13/RGO/CdS was rationally designed for visible light-driving photocatalytic CO2 reduction into CH4.
“Tschitschibabin type biradicals”: benzenoid or quinoid?
Authors: Ravat Prince , Baumgarten Martin
Published: November 2014

Revisiting the history: towards the better understanding of open shell singlet biradicaloids.
An experimental and theoretical study of the gas phase kinetics of atomic chlorine reactions with CH3NH2, (CH3)2NH, and (CH3)3N
Authors: Nicovich J. M. , Mazumder S. , Laine P. L. , Wine P. H. , Tang Y. , Bunkan A. J. C. , Nielsen C. J.
Published: November 2014

The first kinetic data for the gas phase reactions of amines with chlorine atoms.
Metastable behavior of noble gas inserted tin and lead fluorides
Authors: Pan Sudip , Gupta Ashutosh , Mandal Subhajit , Moreno Diego , Merino Gabriel , Chattaraj Pratim K.
Published: November 2014

The metastable FNgEF and FNgEF3(E = Sn, Pb; Ng = Kr–Rn) are the first reported neutral compounds possessing Ng–Sn and Ng–Pb covalent bonds.
Solvent effects on the intramolecular conversion of trimethylsulfonium chloride to dimethyl sulfide and methyl chloride
Authors: Lankau Timm , Yu Chin-Hui
Published: November 2014

M05/6-311+G(2d,p) calculations reveal the role of ion pairs in the conversion of (CH3)3SCl as a function of solvent's permittivity.
Durability, inactivation and regeneration of silver tetratantalate in photocatalytic H2 evolution
Authors: Dong Hongjun , Chen Gang , Sun Jingxue , Li Chunmei , Lv Chade , Hu Yidong
Published: November 2014

The prepared Ag2Ta4O11 photocatalyst exhibits durable activity for H2 production from water, which can achieve the dual recovery of the photocatalyst and activity.
Photoelectrochemical hydrogen evolution of tapered silicon nanowires
Authors: Li Xiaopeng , Xiao Yanjun , Zhou Keya , Wang Junna , Schweizer Stefan L. , Sprafke Alexander , Lee Jung-Ho , Wehrspohn Ralf B.
Published: November 2014

The photoelectrochemical performance of Si nanowires can be greatly improved both in photocurrent and photovoltage through a tapering process.
Size-dependent pressure-induced amorphization: a thermodynamic panorama
Authors: Machon Denis , Mélinon Patrice
Published: November 2014

The complex behavior of nanoparticles subjected to high-pressure is analyzed using different thermodynamic and geometrical approaches. The defect density and the surface states are identified as the main factors governing the pressure-induced transitions of nanoparticles.
Modulation of human IAPP fibrillation: cosolutes, crowders and chaperones
Authors: Gao Mimi , Estel Kathrin , Seeliger Janine , Friedrich Ralf P. , Dogan Susanne , Wanker Erich E. , Winter Roland , Ebbinghaus Simon
Published: November 2014

The mechanism of human IAPP aggregation is studied in the presence of three different classes of chaperones and crowding agents.
Lipase adsorption on different nanomaterials: a multi-scale simulation study
Authors: Zhao Daohui , Peng Chunwang , Zhou Jian
Published: November 2014

Adsorption orientations of lipase on different nanomaterials with different surface chemistry.
Structures of [Li(glyme)]+ complexes and their interactions with anions in equimolar mixtures of glymes and Li[TFSA]: analysis by molecular dynamics simulations
Authors: Tsuzuki Seiji , Shinoda Wataru , Matsugami Masaru , Umebayashi Yasuhiro , Ueno Kazuhide , Mandai Toshihiko , Seki Shiro , Dokko Kaoru , Watanabe Masayoshi
Published: November 2014

The coordination number of Li+ in [Li(G3)][TFSA] and [Li(G4)][TFSA].
Why genetic modification of lignin leads to low-recalcitrance biomass
Authors: Carmona Christopher , Langan Paul , Smith Jeremy C. , Petridis Loukas
Published: November 2014

Molecular dynamics simulations show genetically modified lignin to associate less with hemicellulose than does wild type.
Improved reaction conditions for the synthesis of new NKP-1339 derivatives and preliminary investigations on their anticancer potential
Authors: Kuhn P.-S. , Pichler V. , Roller A. , Hejl M. , Jakupec M. A. , Kandioller W. , Keppler B. K.
Published: November 2014

NKP-1339 and KP1019 derivatives were synthesized under mild reaction settings in high yields. The characterization and influence of the N-alkyl substitution on the aqueous stability, redox potentials, in vitro cytotoxicity and cellular accumulation are discussed.
Quinoline-2-carboimine copper complex immobilized on amine functionalized silica coated magnetite nanoparticles: a novel and magnetically retrievable catalyst for the synthesis of carbamates via C–H activation of formamides
Authors: Sharma R. K. , Dutta Sriparna , Sharma Shivani
Published: November 2014

A novel and magnetically recoverable nanocatalytic system consisting of a magnetic silica based copper complex has been fabricated and applied in the synthesis of carbamates via C–H activation of formamides.
Design and construction of three dimensional graphene-based composites for lithium ion battery applications
Authors: Luo Bin , Zhi Linjie
Published: November 2014

This review summarizes the current progress toward the synthesis of three dimensional graphene-based composites and their application in lithium ion batteries.
Analysis and understanding of amido black 10B dye degradation in aqueous solution by electrocoagulation with the conventional oxidants peroxomonosulfate, peroxodisulfate and hydrogen peroxide
Authors: Govindan Kadarkarai , Raja Mohan , Maheshwari Subramanian Uma , Noel Michael
Published: November 2014

Degradation of amido black 10B dye by electrocoagulation processes assisted by conventional oxidants: peroxomonosulfate, peroxodisulfate and hydrogen peroxide.
Synthesis of five- and six-membered heterocycles by dimethyl carbonate with catalytic amounts of nitrogen bicyclic bases
Authors: Aricò F. , Evaristo S. , Tundo P.
Published: November 2014

Five- and six-membered N- and O-heterocycles have been prepared by DMC chemistry in the presence of catalytic amounts of a homogeneous nitrogen bicyclic base under neat conditions.
Interplay of physical mechanisms and biofilm processes: review of microfluidic methods
Authors: Karimi A. , Karig D. , Kumar A. , Ardekani A. M.
Published: November 2014

A review on the physical processes involved in biofilm formation and the lab-on-a-chip techniques utilized to unravel the associated mechanisms.
Microfluidic platforms with monolithically integrated hierarchical apertures for the facile and rapid formation of cargo-carrying vesicles
Authors: Cho Hyesung , Kim Junsoo , Suga Keishi , Ishigami Takaaki , Park Hyunchul , Bang Jung Won , Seo Soonmin , Choi Mansoo , Chang Pahn-Shick , Umakoshi Hiroshi , Jung Ho-Sup , Suh Kahp-Yang
Published: November 2014

We fabricated a simple yet robust microfluidic platform with monolithically integrated hierarchical apertures.
Fine structuration of low-temperature co-fired ceramic (LTCC) microreactors
Authors: Jiang Bo , Haber Julien , Renken Albert , Muralt Paul , Kiwi-Minsker Lioubov , Maeder Thomas
Published: November 2014

We developed a novel low-temperature co-fired ceramic (LTCC) microfabrication method for making microreactors with complex fluidic structures for applications involving harsh chemicals and envir`onmental processes.
Dual tumor markers assay based on surface charged graphene
Authors: Xu Teng , Ma Jie , Ma Zhanfang
Published: November 2014

The simultaneous detection of carcinoembryonic antigen and alpha-fetoprotein was achieved by combining ionic liquid–reduced graphene oxide with two different redox probes through electrostatic adsorption.
Allylic and benzylic sp3 C–H oxidation in water
Authors: Ang Wei Jie , Lam Yulin
Published: November 2014

A copper-catalyzed method for the oxidation of allylic and benzylic sp3 C–H by aqueous tert-butyl hydroperoxide (T-Hydro) in water using a recyclable fluorous ligand has been developed.
A mild copper-catalyzed aerobic oxidative thiocyanation of arylboronic acids with TMSNCS
Authors: Sun Nan , Che Liusheng , Mo Weimin , Hu Baoxiang , Shen Zhenlu , Hu Xinquan
Published: November 2014

A facile and generalized synthesis of aryl thiocyanates has been established via the CuCl-catalyzed oxidative coupling of arylboronic acids with TMSNCS. The reaction could be conducted at RT and under an O2 atmosphere.
Synthesis and characterization of amino acid-modified adsorption resins and their adsorption properties in the purification of tabersonine from Voacanga africana seeds
Authors: Liu Xiong , Yang Dongliang , Liu Jiajia , Ren Na
Published: November 2014

The modified MARs had good adsorption of impurities but poor adsorption of tabersonine from extracts of Voacanga africana seeds.
A carboxylic acid-functionalized coumarin-hemicyanine fluorescent dye and its application to construct a fluorescent probe for selective detection of cysteine over homocysteine and glutathione
Authors: Liu Jing , Sun Yuan-Qiang , Zhang Hongxing , Huo Yingying , Shi Yawei , Shi Heping , Guo Wei
Published: November 2014

We obtained a highly selective fluorescent probe2for Cys over Hcy and GSH based on a carboxylic acid-functionalized coumarin-hemicyanine dye1platform that is inspired by coumarin, cyanine, and rhodamine dyes.
Expression ofArabidopsis thalianaS-ACP-DES3 inEscherichia colifor high-performance biodiesel production
Authors: Scaglia Barbara , Cassani Elena , Pilu Roberto , Adani Fabrizio
Published: November 2014

pET15b expression vector (a) used to cloneArabidopsisDES3 gene (b) inE. coli.
Electron localization in a mixed-valence diniobium benzene complex
Authors: Gianetti Thomas L. , Nocton Grégory , Minasian Stefan G. , Kaltsoyannis Nikolas , Kilcoyne A. L. David , Kozimor Stosh A. , Shuh David K. , Tyliszczak Tolek , Bergman Robert G. , Arnold John
Published: November 2014

One electron oxidation of a neutral diniobium benzene complex leads to a mixed-valence species. Single crystal X-ray diffraction, EPR, L3,2-edge XANES, and DFT indicate that the unpaired electron is localized on one metal center.
Van der Waals free energy model for solubilization of oil in micelles
Authors: Troncoso Americo Boza , Acosta Edgar
Published: November 2014

Lipophilic contributions to the free energy of solubilization.
Highly defective CeO2 as a promoter for efficient and stable water oxidation
Authors: Liang Fengli , Yu Ying , Zhou Wei , Xu Xiaoyong , Zhu Zhonghua
Published: November 2014

A highly defective CeO2 supported RuO2 as an electrocatalyst shows improved OER activity and stability in alkaline media. This improvement likely originates from the highly oxidative oxygen species O22−/O− formed in the defective CeO2, which can easily migrate from CeO2 and “spillover” to the surface of RuO2 during the OER process.
New efficient (thio)acetalized fullerene monoadducts for organic solar cells: characterization based on solubility, mobility balance, and dark current
Authors: Mikie Tsubasa , Saeki Akinori , Masuda Hiroyuki , Ikuma Naohiko , Kokubo Ken , Seki Shu
Published: November 2014

We report a systematic study of organic photovoltaic cells using novel spiro-acetalized and (thio)acetalized [60]fullerene monoadducts bearing five- to seven-membered rings.
Enhanced colloidal stability and antibacterial performance of silver nanoparticles/cellulose nanocrystal hybrids
Authors: Shi Zengqian , Tang Juntao , Chen Li , Yan Chuanren , Tanvir Shazia , Anderson William A. , Berry Richard M. , Tam Kam C.
Published: November 2014

Preparation of polydopamine functionalized CNCs and silver nanoparticle immobilized CNCs.
Aligned gold nanobowl arrays: their fabrication, anisotropic optical response and optical grating applications
Authors: Li Xinyang , Wu Yanchun , Hang Lifeng , Men Dandan , Cai Weiping , Li Yue
Published: November 2014

Aligned Au nanobowl arrays on a flexible film with specific optical properties were obtained by combining template-assisted self-assembly and colloidal lithography.
Asymmetric Coulomb fluids at randomly charged dielectric interfaces: Anti-fragility, overcharging and charge inversion
Authors: Naji Ali , Ghodrat Malihe , Komaie-Moghaddam Haniyeh , Podgornik Rudolf
Published: November 2014

We study the distribution of multivalent counterions next to a dielectric slab, bearing a quenched, random distribution of charges on one of its solution interfaces, with a given mean and variance, both in the absence and in the presence of a bathing monovalent salt solution. We use the previously derived approach based on the dressed multivalent-ion theory that combines aspects of the strong and weak coupling of multivalent and monovalent ions in a single framework. The presence of quenched charge disorder on the charged surface of the dielectric slab is shown to substantially increase the density of multivalent counterions in its vicinity. In the counterion-only model (with no monovalent salt ions), the surface disorder generates an additional logarithmic attraction potential and thus an algebraically singular counterion density profile at the surface. This behavior persists also in the presence of a monovalent salt bath and results in significant violation of the contact-value theorem, reflecting the anti-fragility effects of the disorder that drive the system towards a more “ordered” state. In the presence of an interfacial dielectric discontinuity, depleting the counterion layer at the surface, the charge disorder still generates a much enhanced counterion density further away from the surface. Likewise, the charge inversion and/or overcharging of the surface occur more strongly and at smaller bulk concentrations of multivalent counterions when the surface carries quenched charge disorder. Overall, the presence of quenched surface charge disorder leads to sizable effects in the distribution of multivalent counterions in a wide range of realistic parameters and typically within a distance of a few nanometers from the charged surface.
Evaluation of the constant potential method in simulating electric double-layer capacitors
Authors: Wang Zhenxing , Yang Yang , Olmsted David L. , Asta Mark , Laird Brian B.
Published: November 2014

A major challenge in the molecular simulation of electric double layer capacitors (EDLCs) is the choice of an appropriate model for the electrode. Typically, in such simulations the electrode surface is modeled using a uniform fixed charge on each of the electrode atoms, which ignores the electrode response to local charge fluctuations in the electrolyte solution. In this work, we evaluate and compare this Fixed Charge Method (FCM) with the more realistic Constant Potential Method (CPM), [S. K. Reed et al., J. Chem. Phys. 126, 084704 (2007)], in which the electrode charges fluctuate in order to maintain constant electric potential in each electrode. For this comparison, we utilize a simplified LiClO4-acetonitrile/graphite EDLC. At low potential difference (ΔΨ ⩽ 2 V), the two methods yield essentially identical results for ion and solvent density profiles; however, significant differences appear at higher ΔΨ. At ΔΨ ⩾ 4 V, the CPM ion density profiles show significant enhancement (over FCM) of “inner-sphere adsorbed” Li+ ions very close to the electrode surface. The ability of the CPM electrode to respond to local charge fluctuations in the electrolyte is seen to significantly lower the energy (and barrier) for the approach of Li+ ions to the electrode surface.
Upgrading optical information of rotating mirror cameras
Authors: Li Jingzhen , Sun Fengshan , Huang Hongbin , Gong Xiangdong , Chen Hongyi , Lu Xiaowei , Cai Yi
Published: November 2014

To date, rotating mirror (RM) cameras still serve as indispensable imaging equipment for the diagnosis of microsecond transient processes due to their excellent characteristics. This paper, for upgrading the optical information capacity of the cameras, presents the new optical acceleration principle to increase the framing frequency or scanning velocity, the new design theory without principle errors instead of the classical theories with some flaws in principle to have applied to design our simultaneous streak and framing rotating mirror camera with continuous access, and the new rotating mirror with novel structure, made of an aluminum alloy, to have considerably reduced lateral deformation of the RM and improved the performance of the camera.
A dynamic end cap technique for sound computation using the Ffowcs Williams and Hawkings equations
Authors: Nitzkorski Zane , Mahesh Krishnan
Published: November 2014

A dynamic end cap methodology is proposed to account for spurious contributions to the far-field sound within the context of the Ffowcs–Williams and Hawkings (FW–H) acoustic analogy. The quadrupole source terms are correlated over multiple planes to obtain a convection velocity which is then used to determine a corrective convective flux at the FW–H porous surface. The proposed approach is first demonstrated for a convecting potential vortex. It is then evaluated by computing the sound emitted by flow over circular cylinders at Reynolds number of 150, 10 000, and 89 000, respectively. The low Re cylinder is used to validate against direct numerical simulation (DNS) and demonstrate insensitivity to end plane location and spacing, the effect of dynamic convection velocity and to compare to commonly used end cap corrections. The Re 100 00 cylinder is used to validate at turbulent Reynolds numbers against other simulations. Finally the Re 89 000 simulations are used to compare to experiment. The proposed approach demonstrates better performance than other commonly used approaches with the added benefit of computational efficiency and the ability to query independent volumes.
Insights into DNA-mediated interparticle interactions from a coarse-grained model
Authors: Ding Yajun , Mittal Jeetain
Published: November 2014

DNA-functionalized particles have great potential for the design of complex self-assembled materials. The major hurdle in realizing crystal structures from DNA-functionalized particles is expected to be kinetic barriers that trap the system in metastable amorphous states. Therefore, it is vital to explore the molecular details of particle assembly processes in order to understand the underlying mechanisms. Molecular simulations based on coarse-grained models can provide a convenient route to explore these details. Most of the currently available coarse-grained models of DNA-functionalized particles ignore key chemical and structural details of DNA behavior. These models therefore are limited in scope for studying experimental phenomena. In this paper, we present a new coarse-grained model of DNA-functionalized particles which incorporates some of the desired features of DNA behavior. The coarse-grained DNA model used here provides explicit DNA representation (at the nucleotide level) and complementary interactions between Watson-Crick base pairs, which lead to the formation of single-stranded hairpin and double-stranded DNA. Aggregation between multiple complementary strands is also prevented in our model. We study interactions between two DNA-functionalized particles as a function of DNA grafting density, lengths of the hybridizing and non-hybridizing parts of DNA, and temperature. The calculated free energies as a function of pair distance between particles qualitatively resemble experimental measurements of DNA-mediated pair interactions.
Semiclassical Monte Carlo: A first principles approach to non-adiabatic molecular dynamics
Authors: White Alexander J. , Gorshkov Vyacheslav N. , Wang Ruixi , Tretiak Sergei , Mozyrsky Dmitry
Published: November 2014

Modeling the dynamics of photophysical and (photo)chemical reactions in extended molecular systems is a new frontier for quantum chemistry. Many dynamical phenomena, such as intersystem crossing, non-radiative relaxation, and charge and energy transfer, require a non-adiabatic description which incorporate transitions between electronic states. Additionally, these dynamics are often highly sensitive to quantum coherences and interference effects. Several methods exist to simulate non-adiabatic dynamics; however, they are typically either too expensive to be applied to large molecular systems (10's-100's of atoms), or they are based on ad hoc schemes which may include severe approximations due to inconsistencies in classical and quantum mechanics. We present, in detail, an algorithm based on Monte Carlo sampling of the semiclassical time-dependent wavefunction that involves running simple surface hopping dynamics, followed by a post-processing step which adds little cost. The method requires only a few quantities from quantum chemistry calculations, can systematically be improved, and provides excellent agreement with exact quantum mechanical results. Here we show excellent agreement with exact solutions for scattering results of standard test problems. Additionally, we find that convergence of the wavefunction is controlled by complex valued phase factors, the size of the non-adiabatic coupling region, and the choice of sampling function. These results help in determining the range of applicability of the method, and provide a starting point for further improvement.
Stability of quantum-dot excited-state laser emission under simultaneous ground-state perturbation
Authors: Kaptan Y. , Röhm A. , Herzog B. , Lingnau B. , Schmeckebier H. , Arsenijević D. , Mikhelashvili V. , Schöps O. , Kolarczik M. , Eisenstein G. , Bimberg D. , Woggon U. , Owschimikow N. , Lüdge K.
Published: November 2014

The impact of ground state amplification on the laser emission of In(Ga)As quantum dot excited state lasers is studied in time-resolved experiments. We find that a depopulation of the quantum dot ground state is followed by a drop in excited state lasing intensity. The magnitude of the drop is strongly dependent on the wavelength of the depletion pulse and the applied injection current. Numerical simulations based on laser rate equations reproduce the experimental results and explain the wavelength dependence by the different dynamics in lasing and non-lasing sub-ensembles within the inhomogeneously broadened quantum dots. At high injection levels, the observed response even upon perturbation of the lasing sub-ensemble is small and followed by a fast recovery, thus supporting the capacity of fast modulation in dual-state devices.
Modeling and simulation of energetically disordered organic solar cells
Authors: Fallahpour A. H. , Gagliardi A. , Santoni F. , Gentilini D. , Zampetti A. , Auf der Maur M. , Di Carlo A.
Published: November 2014

The aim of this work is to present a consistent model for simulation of organic solar cells (OPV) with a correct description of mobility, density of state, organic-metal contacts, and exciton. We simulate the photoconversion by means of an integration of the optical and electrical part: light absorption is calculated with a Transfer Matrix Model and the charge transport is computed using Drift Diffusion approach including the effect of energetically disorder materials. Most model parameters are directly taken from experiment. The model is used to study the effect of energetic disordered materials and cell thickness on the performance of the cell in terms of short circuit current, open circuit voltage, and fill factor. Based on the results of this model, it will be possible to design and predict the optimal thickness of OPV toward higher efficiencies.
A novel method to optimize the mode spectrum of the dynamic resonant magnetic perturbation on the J-TEXT tokamak
Authors: Yi B. , Rao B. , Ding Y. H. , Li M. , Xu H. Y. , Zhang M. , Zhuang G. , Pan Y.
Published: November 2014

The dynamic resonant magnetic perturbation (DRMP) system has been developed for the J-TEXT tokamak to study the interaction between the rotating perturbation magnetic field and the plasma. When the DRMP coils are energized by two phase sinusoidal currents with the same frequency, a 2/1 rotating resonant magnetic perturbation component will be generated. But at the same time, a small perturbation component rotating in the opposite direction is also produced because of the control error of the currents. This small component has bad influence on the experiment investigations. Actually, the mode spectrum of the generated DRMP can be optimized with an accurate control of phase difference between the two currents. In this paper, a new phase control method based on a novel all-digital phase-locked loop (ADPLL) is proposed. The proposed method features accurate phase control and flexible phase adjustment. Modeling and analysis of the proposed ADPLL is presented to guide the design of the parameters of the phase controller in order to obtain a better performance. Testing results verify the effectiveness of the ADPLL and validity of the method applying to the DRMP system.
Dewetting transition assisted clearance of (NFGAILS) amyloid fibrils from cell membranes by graphene
Authors: Liu Jiajia , Yang Zaixing , Li Haotian , Gu Zonglin , Garate Jose Antonio , Zhou Ruhong
Published: November 2014

Clearance of partially ordered oligomers and monomers deposited on cell membrane surfaces is believed to be an effective route to alleviate many potential protein conformational diseases (PCDs). With large-scale all-atom molecular dynamics simulations, here we show that graphene nanosheets can easily and quickly win a competitive adsorption of human islet amyloid polypeptides (hIAPP22-28) NFGAILS and associated fibrils against cell membrane, due to graphene's unique two-dimensional, highly hydrophobic surface with its all-sp2 hybrid structure. A nanoscale dewetting transition was observed at the interfacial region between the fibril (originally deposited on the membrane) and the graphene nanosheet, which significantly assisted the adsorption of fibrils onto graphene from the membrane. The π–π stacking interaction between Phe23 and graphene played a crucial role, providing the driving force for the adsorption at the graphene surface. This study renders new insight towards the importance of water during the interactions between amyloid peptides, the phospholipidic membrane, and graphene, which might shed some light on future developments of graphene-based nanomedicine for preventing/curing PCDs like type II diabetes mellitus.
Enhanced ferroelectricity, piezoelectricity, and ferromagnetism in Nd-modified BiFeO3-BaTiO3 lead-free ceramics
Authors: Zheng Qiaoji , Luo Lingling , Lam Kwok Ho , Jiang Na , Guo Yongquan , Lin Dunmin
Published: November 2014

Lead-free multiferroic ceramics of 0.75Bi1−xNdxFeO3 − 0.25BaTiO3 + 1 mol. % MnO2 were prepared by a conventional ceramic technique and their structure, piezoelectricity, and multiferroicity were studied. The ceramics sintered at 890–990 °C possess a pure perovskite structure. A morphotropic phase boundary of rhombohedral and monoclinic phases is formed at x = 0.05. A small amount of Nd improves the ferroelectric and piezoelectric properties of the ceramics. The ferroelectric-paraelectric phase transition becomes gradually diffusive with x increasing. After the addition of Nd, the ferromagnetism of the ceramics is greatly enhanced by ∼320%. The increase in sintering temperature improves significantly the ferroelectric, piezoelectric, and ferromagnetic properties of the ceramics. The ceramics with x = 0.05 sintered at 950–990 °C possess improved ferroelectricity, piezoelectricity, magnetism and insulation with Pr of 16.5–17.5 μC/cm2, d33 of 113–121 pC/N, Mr of 0.127–0.138 emu/g, R of ∼5 × 109 Ω·cm and high TC of 473–482 °C, indicating that the ceramic is a promising candidate for room-temperature multiferroic and high-temperature piezoelectric materials.
Modified Jeans instability in Lorentzian dusty self-gravitating plasmas with Lennard-Jones potential
Authors: Qian Y. Z. , Chen H. , Liu S. Q.
Published: November 2014

The Jeans instability in self-gravitating plasma with Kappa distributed dust grains is investigated basing on assumption that the mutual interaction among dust grains is governed by Lennard-Jones potential. It is shown that the presence of additional suprathermal particles has significant effects on the range of unstable modes and growth rate of Jeans instability. Compared with Maxwellian scenario, suprathermality stabilized the Jeans instability.
Magneto-caloric response of the Gd60Co25Al15 metallic glasses
Authors: Xia L. , Guan Q. , Ding D. , Tang M. B. , Dong Y. D.
Published: November 2014

The magneto-caloric response of the Gd60Co25Al15 amorphous alloys was investigated in this work. The amorphous rod exhibits an excellent magneto-caloric effect with a peak value of magnetic entropy change (−ΔSmpeak) up to 10 Jkg−1K−1 at 125 K under a field of 5 T, and the highest adiabatic temperature change (ΔTad = 5.3 K) under the same field among the bulk metallic glasses yet reported in the literature. In contrast, although the thin amorphous ribbons show similar −ΔSmpeak and refrigeration capacity to the as-cast rod under 5 T, the higher −ΔSmpeak of the ribbons under a lower magnetic field indicates the different magneto-caloric response between the two amorphous alloys. A more detailed investigation has been performed on the field dependence of −ΔSmpeak for a deeper insight into the physical characteristics of the amorphous materials.
Communication: HK propagator uniformized along a one-dimensional manifold in weakly anharmonic systems
Authors: Kocia Lucas , Heller Eric J.
Published: November 2014

A simplification of the Heller-Herman-Kluk-Kay (HK) propagator is presented that does not suffer from the need for an increasing number of trajectories with dimensions of the system under study. This is accomplished by replacing HK’s uniformizing integral over all of phase space by a one-dimensional curve that is appropriately selected to lie along the fastest growing manifold of a defining trajectory. It is shown that this modification leads to eigenspectra of quantum states in weakly anharmonic systems that can outperform the comparatively computationally cheap thawed Gaussian approximation method and frequently approach the accuracy of spectra obtained with the full HK propagator.
Mitigating impact of thermal and rectified radio-frequency sheath potentials on edge localized modes
Authors: Gui B. , Xu X. Q. , Myra J. R. , D'Ippolito D. A.
Published: November 2014

The mitigating impact of thermal and rectified radio frequency (RF) sheath potentials on the peeling-ballooning modes is studied non-linearly by employing a two-fluid three-field simulation model based on the BOUT++ framework. Additional shear flow and the Kelvin-Helmholtz effect due to the thermal and rectified RF sheath potential are induced. It is found that the shear flow increases the growth rate while the K-H effect decreases the growth rate slightly when there is a density gradient, but the energy loss of these cases is suppressed in the nonlinear phase. The stronger external electrostatic field due to the sheaths has a more significant effect on the energy loss suppression. From this study, it is found the growth rate in the linear phase mainly determines the onset of edge-localized modes, while the mode spectrum width in the nonlinear phase has an important impact on the turbulent transport. The wider mode spectrum leads to weaker turbulent transport and results in a smaller energy loss. Due to the thermal sheath and rectified RF sheath potential in the scrape-off-layer, the modified shear flow tears apart the peeling-ballooning filament and makes the mode spectrum wider, resulting in less energy loss. The perturbed electric potential and the parallel current near the sheath region is also suppressed locally due to the sheath boundary condition.
Dispersion relations for electromagnetic wave propagation in chiral plasmas
Authors: Gao M. X. , Guo B. , Peng L. , Cai X.
Published: November 2014

The dispersion relations for electromagnetic wave propagation in chiral plasmas are derived using a simplified method and investigated in detail. With the help of the dispersion relations for each eignwave, we explore how the chiral plasmas exhibit negative refraction and investigate the frequency region for negative refraction. The results show that chirality can induce negative refraction in plasmas. Moreover, both the degree of chirality and the external magnetic field have a significant effect on the critical frequency and the bandwidth of the frequency for negative refraction in chiral plasmas. The parameter dependence of the effects is calculated and discussed.
Ohmic contact formation of metal/amorphous-Ge/n-Ge junctions with an anomalous modulation of Schottky barrier height
Authors: Liu Hanhui , Wang Peng , Qi Dongfeng , Li Xin , Han Xiang , Wang Chen , Chen Songyan , Li Cheng , Huang Wei
Published: November 2014

The modulation of Schottky barrier height of metal/Ge inserting an amorphous Ge layer has been demonstrated. It is interested that the Schottky barrier height of Al/amorphous-Ge/n-Ge junctions is oscillated with increase of the a-Ge thickness from 0 to 10 nm, and when the thickness reaches above 10 nm, the Al/amorphous-Ge/n-Ge shows ohmic characteristics. Electron hopping through localized states of a-Ge layer, the alleviation of metal induced gap states, as well as the termination of dangling bonds at the amorphous-Ge/n-Ge interface are proposed to explain the anomalous modulation of Schottky barrier height.
Quantitative cone beam X-ray luminescence tomography/X-ray computed tomography imaging
Authors: Chen Dongmei , Zhu Shouping , Chen Xueli , Chao Tiantian , Cao Xu , Zhao Fengjun , Huang Liyu , Liang Jimin
Published: November 2014

X-ray luminescence tomography (XLT) is an imaging technology based on X-ray-excitable materials. The main purpose of this paper is to obtain quantitative luminescence concentration using the structural information of the X-ray computed tomography (XCT) in the hybrid cone beam XLT/XCT system. A multi-wavelength luminescence cone beam XLT method with the structural a priori information is presented to relieve the severe ill-posedness problem in the cone beam XLT. The nanophosphors and phantom experiments were undertaken to access the linear relationship of the system response. Then, an in vivo mouse experiment was conducted. The in vivo experimental results show that the recovered concentration error as low as 6.67% with the location error of 0.85 mm can be achieved. The results demonstrate that the proposed method can accurately recover the nanophosphor inclusion and realize the quantitative imaging.
Raman spectroscopy of GaP/GaNP core/shell nanowires
Authors: Dobrovolsky A. , Sukrittanon S. , Kuang Y. J. , Tu C. W. , Chen W. M. , Buyanova I. A.
Published: November 2014

Raman spectroscopy is employed to characterize structural and phonon properties of GaP/GaNP core/shell nanowires (NWs) grown by molecular beam epitaxy on Si substrates. According to polarization-dependent measurements performed on single NWs, the dominant Raman modes associated with zone-center optical phonons obey selection rules in a zinc-blende lattice, confirming high crystalline quality of the NWs. Two additional modes at 360 and 397 cm−1 that are specific to the NW architecture are also detected in resonant Raman spectra and are attributed to defect-activated scattering involving zone-edge transverse optical phonons and surface optical phonons, respectively. It is concluded that the formation of the involved defect states are mainly promoted during the NW growth with a high V/III ratio.
Size effects on thermoelectric behavior of ultrathin NaxCoO2 films
Authors: Brinks Peter , Rijnders Guus , Huijben Mark
Published: November 2014

Size effects in thermoelectric NaxCoO2 thin films are studied, focusing on the electrical resisitivity and Seebeck coefficient. For very thin films below 10 nm, we have observed an increase in resistivity, which is in agreement with theoretical models. In contrast to a predicted simultaneous suppression of the Seebeck coefficient for ultrathin films, we observe a constant Seebeck coefficient as a function of layer thickness due to changes in the structural properties as well as the presence of strong electron correlations. This preserved high Seebeck coefficient opens up new directions for NaxCoO2 ultrathin films as basic building blocks in thermoelectric superlattices with enhanced phonon scattering.
Reproducible bipolar resistive switching in entire nitride AlN/n-GaN metal-insulator-semiconductor device and its mechanism
Authors: Chen Yiren , Song Hang , Jiang Hong , Li Zhiming , Zhang Zhiwei , Sun Xiaojuan , Li Dabing , Miao Guoqing
Published: November 2014

Reproducible bipolar resistive switching characteristics are demonstrated in entire nitride AlN/n-GaN metal-insulator-semiconductor devices. The mechanism involved confirms to trap-controlled space charge limited current theory and can be attributed to the nitrogen vacancies of AlN serving as electron traps that form/rupture electron transport channel by trapping/detrapping electrons. This study will lead to the development of in-situ growth of group-III nitrides by metal-organic chemical vapor deposition as a candidate for next-generation nonvolatile memory device. Moreover, it will be benefit to structure monolithic integrated one-transistor-one-resistor memory with nitride high electron mobility transistors.
Perspectival Reversals of a Solid: A Phenomenal Description
Authors: Deregowski Jan B
Published: November 2014

The paper presents a phenomenal investigation of monocular perception of perspectival reversal of a conical shell. The inverted shell is seen as shorter than the stimulus, and both relative size of elements within it and movement within it appear to be affected by reversal. Similarity of the observed effects to those recorded in studies of afterimages are noted, as is similarity to reversals of Mach's Book.
Elementary Graphical Perception for Older Adults: A Comparison with the General Population
Authors: Le Thai , Aragon Cecilia , Thompson Hilaire J , Demiris George
Published: November 2014

We identified the graphical perceptual information needs of older adults (≥ 60 years of age) through a set of psychophysical experiments on bar, stacked, and pie charts. The results are compared with those of a general population (< 60 years of age). We conducted the experiments as online remote studies with 202 total participants across two experimental types: (1) comparison judgments of graphs (50 older adults, 50 general population) and (2) proportion judgments of graphs (52 older adults, 50 general population). Older adults took longer than the general population to complete tasks across both comparison (4.09 s) and proportion judgments (3.66 s). However, this translated to an approximately equal level of perceptual accuracy. Bar charts were the most effective graphical display when considering both speed and accuracy. Older adults were more accurate using pie charts compared with the general population in the comparison task.
Prey selection and diet overlap of native golden perch and alien redfin perch under contrasting hydrological conditions
Authors: Wedderburn S. D. , Bice C. M. , Barnes T. C.
Published: November 2014

Many freshwater fishes have been introduced outside their natural range. The consequences have included the decline or extinction of native fishes, principally due to competition and predation. Redfin perch (Perca fluviatilis) is a highly efficient predatory fish species that was introduced to Australia in the 1800s. It now has a broad distribution in the Murray–Darling Basin, but its impacts on native fishes are largely unstudied. It often cohabits with native golden perch (Macquaria ambigua ambigua), which is similar from a trophic ecomorphology perspective. We examine prey selection and diet overlap of adult redfin perch and golden perch under contrasting hydrological conditions in terminating lakes of the Murray–Darling Basin. Prey selection by both species varied substantially between drought and flood conditions. Diet overlap of redfin perch and golden perch was significant only during flood, and was apparently related to pelagic prey availability. There were dietary differences during drought that imply that resource partitioning occurred between the perches, possibly because competitive interactions were intensified. Conversely, the promotion of pelagic prey fishes during flooding apparently facilitated resource sharing. The findings suggest that redfin perch can directly compete with native piscivores for prey. The potential impacts on native piscivores and small-bodied fish populations warrant further experimental and field investigations.
Unusual role of epilayer–substrate interactions in determining orientational relations in van der Waals epitaxy
Authors: Liu Lei , Siegel David A. , Chen Wei , Liu Peizhi , Guo Junjie , Duscher Gerd , Zhao Chong , Wang Hao , Wang Wenlong , Bai Xuedong , McCarty Kevin F. , Zhang Zhenyu , Gu Gong
Published: November 2014

Significance

van der Waals (vdW) heterostructures of dissimilar 2D material sheets held together by vdW interactions promise new physics and applications not necessarily associated with the constituent 2D materials. Only epitaxial growth can achieve the orientational alignment in vdW heterostructures needed to obtain certain novel phenomena. As a case study of vdW epitaxy, we experimentally find that hexagonal boron nitride strictly aligns to Cu(100), whereas crystallographically similar graphene is known to exhibit a wide spread of in-plane rotations. Theoretical investigation reveals that this stark difference occurs because the C–Cu interactions are stronger than the B–Cu and N–Cu interactions. This counterintuitive discovery sheds light on orientational relationships in vdW epitaxy and their case specificity.
Multifunctional supramolecular polymer networks as next-generation consolidants for archaeological wood conservation
Authors: Walsh Zarah , Janeček Emma-Rose , Hodgkinson James T. , Sedlmair Julia , Koutsioubas Alexandros , Spring David R. , Welch Martin , Hirschmugl Carol J. , Toprakcioglu Chris , Nitschke Jonathan R. , Jones Mark , Scherman Oren A.
Published: November 2014

Significance

The preservation of cultural heritage is of widespread importance all over the world. Yet the lack of development in the field of conservation treatments means the fate of some of the most culturally important artifacts in the world remain in jeopardy. In the preservation of waterlogged wooden artifacts, conservators rely almost exclusively on poly(ethylene glycol) doped with a broad-spectrum biocide. The concept of a chemotactic consolidant, one that can adapt to the artifact it is treating, as described here has never before been described for an archaeological/conservation treatment. Additionally, the cross-links holding the consolidant together are entirely reversible, resulting in a material that is a greener, safer, and sustainable alternative to current conservation strategies.