bluuebunny/crossref_metadata_2025 huggingface dataset:
The structural evolution and tunable photoluminescence of f-element bearing coordination polymers of the 2,4,6-tri-α-pyridyl-1,3,5-triazine ligand
Authors: Yue Zenghui , Lu Huangjie , Li Zijian , Guo Shangyao , Song Junze , Ren Yiming , Huang Yu-Ying , Lin Jian , Wang Jian-Qiang
Published: July 2019

An attempt at expanding the family of f-element bearing TPTZ coordination polymers has resulted in fifteen new complexes with topologies that evolved along the periodic table and tunable photoluminescence properties.
Defect tolerant and dimension dependent ferromagnetism in MnSe2
Authors: Eren I. , Iyikanat F. , Sahin H.
Published: July 2019

By performing density functional theory-based calculations, we investigate the structural, vibrational, electronic and magnetic properties of 2D monolayers, nanoribbons and quantum dots of MnSe2.
Systematic behaviour of electron redistribution on formation of halogen-bonded complexes B⋯XY, as determinedviaXY halogen nuclear quadrupole coupling constants
Authors: Alkorta Ibon , Legon Anthony C.
Published: July 2019

Systematic behaviour of the fractional electron redistributionδifrom B to Br with ionisation energyIBon formation of B⋯BrY.
Cross-linked bond accelerated interfacial charge transfer in monolayer zinc indium sulfide (ZnIn2S4)/reduced graphene oxide (RGO) heterostructure for photocatalytic hydrogen production with mechanistic insight
Authors: Du Chun , Yan Bo , Lin Zhaoyong , Yang Guowei
Published: July 2019

By separating the photo-excited charge carriers, the cross-linked bonds enabled the monolayer ZnIn2S4/RGO heterostructure to produce more H2.
Aryl C–H amination initiated by laccase-mediated oxidation of 4-phenylurazole
Authors: Chen Yu-Jue , Zhang Guo-Yan , He Yan-Hong , Guan Zhi
Published: July 2019

A mild amination of aryl C–H initiated by laccase-mediated oxidation of 4-phenylurazole is described.
Hierarchically patterned striped phases of polymerized lipids: toward controlled carbohydrate presentation at interfaces
Authors: Davis Tyson C. , Bechtold Jeremiah O. , Hayes Tyler R. , Villarreal Terry A. , Claridge Shelley A.
Published: July 2019

Microcontact printing can be used to generate well-defined microscopic areas of striped phases of both single-chain and dual-chain amphiphiles.
Multivalent glycan arrays
Authors: Mende Marco , Bordoni Vittorio , Tsouka Alexandra , Loeffler Felix F. , Delbianco Martina , Seeberger Peter H.
Published: July 2019

In this introductory lecture we discuss the state-of-the-art glycan microarray technology, with emphasis on novel approaches to immobilize collections of glycans in a defined, multivalent manner.
Metal-free quinolylation of the primary amino groups of amino acid derivatives and peptides with dihydrooxazolo[3,2-a]quinoliniums
Authors: Liu Peng , Li Bo , Xi Mengyu , Chen Zhaoqiang , Sun Haiguo , Huan Xiajuan , Xu Xuejun , Zhang Yong , Zou Kun , Jiang Xiangrui , Miao Zehong , Liu Jinggen , Shen Jingshan , Chen Kaixian , Zhu Weiliang
Published: July 2019

A new metal-free method for theN-quinolylation of primary amino groups using novel dihydrooxazolo[3,2-a]quinoliniums showing good compatibility with other reactive moieties.
Intramolecular electrochemical dehydrogenative N–N bond formation for the synthesis of 1,2,4-triazolo[1,5-a]pyridines
Authors: Li Yong , Ye Zenghui , Chen Na , Chen Zhenkun , Zhang Fengzhi
Published: July 2019

A reagent-free electrochemical synthesis of valuable 1,2,4-triazolo[1,5-a]pyridines was developed with the N–N bond formation as the key step.
Method for quantifying and removing polyatomic interferences on a suite of moderately volatile elements (Zn, Se, Rb, Ag, Cd, In, Sb, Tl, Pb, and Bi) during solution-mode ICP-MS
Authors: Burney David , Neal Clive R.
Published: July 2019

Moderately volatile elements (MVEs: Zn, Se, Rb, Ag, Cd, In, Sb, Tl, Pb, and Bi) have condensation temperatures between 650 and 1250 K.
Microsecond charge separation at heterojunctions between transition metal dichalcogenide monolayers and single-walled carbon nanotubes
Authors: Sulas-Kern Dana B. , Zhang Hanyu , Li Zhaodong , Blackburn Jeffrey L.
Published: July 2019

Heterojunctions of transition metal dichalcogenide monolayers and single-walled carbon nanotubes are promising for photocatalysis and photocurrent generation, with microsecond timescale charge separation and sub-picosecond interfacial charge transfer.
Oxovanadium(v)-catalyzed deoxygenative homocoupling reaction of alcohols
Authors: Sakuramoto Takashi , Donaka Yosuke , Tobisu Mamoru , Moriuchi Toshiyuki
Published: July 2019

Catalytic direct hydrazination of allyl alcohol and deoxygenative homocoupling reaction of alcohols depending on hydrazine derivatives were performed by utilizing oxovanadium(v) catalysts.
Cross-conjugation increases the conductance of meta-connected fluorenones
Authors: Alanazy Asma , Leary Edmund , Kobatake Takayuki , Sangtarash Sara , González M. Teresa , Jiang Hua-Wei , Bollinger Gabino Rubio , Agräit Nicolás , Sadeghi Hatef , Grace Iain , Higgins Simon J. , Anderson Harry L. , Nichols Richard J. , Lambert Colin J.
Published: July 2019

In meta-connected fluorenones, the carbonyl group almost negates the effects of destructive quantum interference, compared with corresponding meta-connected fluorenes.
CO oxidization catalyzed by B, N, and their co-doped fullerenes: a first-principles investigation
Authors: Gao Boya , Chen Gang
Published: July 2019

The novel catalytic properties of the oxides of B and N, and their co-doped fullerenes are investigated.
Systematic study of TiO2/ZnO mixed metal oxides for CO2 photoreduction
Authors: Thompson Warren A. , Olivo Alberto , Zanardo Danny , Cruciani Giuseppe , Menegazzo Federica , Signoretto Michela , Maroto-Valer M. Mercedes
Published: July 2019

A novel example using a systematic design of experiments mixture design for developing mixed metal oxide photocatalysts for CO2 photoreduction.
Rapid generation of chemical combinations on a magnetic digital microfluidic array
Authors: Zhang Yi , Wang Tza-Huei
Published: July 2019

FlipDrop is a combinatorial screening platform. It enables rapid generation of chemical combinations by flipping and coupling two droplet arrays generated by surface energy traps on the magnetic digital microfluidic platform.
Indium sulfide nanotubes with sulfur vacancies as an efficient photocatalyst for nitrogen fixation
Authors: He Zhiyi , Wang Yu , Dong Xiaoli , Zheng Nan , Ma Hongchao , Zhang Xiufang
Published: July 2019

We have designed and manufactured In2S3 nanotubes containing sulfur vacancies as effective and stable photocatalysts for nitrogen fixation and ammonia production.
In situ autologous growth of self-supporting NiFe-based nanosheets on nickel foam as an efficient electrocatalyst for the oxygen evolution reaction
Authors: Wang Jianying , Teng Xue , Niu Yanli , Guo Lixia , Kong Jianfei , He Xiaoming , Chen Zuofeng
Published: July 2019

We report here a simple and cost-effective autologous growth method to prepare a NiFe-based integrated electrode for efficient electrocatalytic water oxidation.
CO2 reduction to formic acid at low overpotential on BDD electrodes modified with nanostructured CeO2
Authors: Verlato Enrico , Barison Simona , Einaga Yasuaki , Fasolin Stefano , Musiani Marco , Nasi Lucia , Natsui Keisuke , Paolucci Francesco , Valenti Giovanni
Published: July 2019

Nanostructured CeO2/BDD electrodes produce formic acid with good faradaic efficiency at very low overpotential (>40% at η ≈ 40 mV).
Nitrogen-rich carbon-onion-constructed nanosheets: an ultrafast and ultrastable dual anode material for sodium and potassium storage
Authors: Liu Sitong , Yang Beibei , Zhou Jisheng , Song Huaihe
Published: July 2019

Nitrogen-rich carbon-onion-constructed nanosheets prepared from Co–hexamine coordination frameworks exhibit high-rate and ultrastable Na- and K-ion storage capability.
Building highly stable and industrial NaVPO4F/C as bipolar electrodes for high-rate symmetric rechargeable sodium-ion full batteries
Authors: Chen Chengcheng , Li Tianjiao , Tian Han , Zou Yabing , Sun Jianchao
Published: July 2019

We report the synthesis of carbon coated NaVPO4F (NaVPO4F/C)viaindustrial high-temperature calcination and its application as bipolar electrodes to build symmetric sodium ion full batteries (SIFBs).
Ultrahigh energy storage and electrocaloric performance achieved in SrTiO3 amorphous thin films via polar cluster engineering
Authors: Zhang Yulei , Li Weili , Wang Zhenyu , Qiao Yulong , Yu Yang , Zhao Yu , Song Ruixuan , Xia Hetian , Fei Weidong
Published: July 2019

High energy storage density and a reversible electrocaloric effect are simultaneously achieved in Sr0.995(Na0.5Bi0.5)0.005(Ti0.99Mn0.01)O3 amorphous thin films via polar cluster engineering.
The role of PTB domain containing adaptor proteins on PICALM-mediated APP endocytosis and localization
Authors: Merthan Lisa , Haller Amelie , Thal Dietmar R. , von Einem Bjoern , von Arnim Christine A.F.
Published: July 2019

One hallmark of Alzheimer's disease (AD) is the presence of amyloid plaques, which mainly consist of the amyloid precursor protein (APP) cleavage product amyloid β (Aβ). For cleavage to occur, the APP must be endocytosed from the cell surface. The phosphatidylinositol binding clathrin assembly protein (PICALM) is involved in clathrin-mediated endocytosis and polymorphisms in and near the gene locus were identified as genetic risk factors for AD. PICALM overexpression enhances APP internalization and Aβ production. Furthermore, PICALM shuttles into the nucleus, but its function within the nucleus is still unknown. Using co-immunoprecipitation, we demonstrated an interaction between PICALM and APP, which is abrogated by mutation of the APP NPXY-motif. Since the NPXY-motif is an internalization signal that binds to phosphotryrosine-binding domain-containing adaptor proteins (PTB-APs), we hypothesized that PTB-APs can modulate the APP-PICALM interaction. We found that interaction between PICALM and the PTB-APs (Numb, JIP1b and GULP1) enhances the APP-PICALM interaction. Fluorescence activated cell sorting analysis and internalization assays revealed differentially altered APP cell surface levels and endocytosis rates that depended upon the presence of PICALM and co-expression of distinct PTB-APs. Additionally, we were able to show an impact of PICALM nuclear shuttling upon co-expression of PTB-APs and PICALM, with the magnitude of the effect depending on which PTB-AP was co-expressed. Taken together, our results indicate a modulating effect of PTB-APs on PICALM-mediated APP endocytosis and localization.
Bio‐inspired nanofunctionalisation of biomaterial surfaces: a review
Authors: Xie Chaoming
Published: July 2019

The surfaces of biomaterials determine their efficacy and hence, have an important role in clinical applications. Through bio‐inspired surface nanofunctionalisation, the surface properties of biomaterials such as physical morphology and chemical composition can be tailored using biomimicry. It is a powerful tool for improving the interactions between the physiological environment and biomaterial surfaces. Therefore, research on bio‐inspired nanofunctionalised surfaces has attracted much attention in recent years. This review focus on the recent bio‐inspired strategies based on the structure of the extracellular matrix (ECM) and composition of mussel‐inspired polydopamine (PDA). The design, preparation, and properties of ECM and PDA‐inspired nanofunctionalised biomaterial surfaces are reviewed. I have also highlighted the effects of these bio‐inspired nanofunctionalised biomaterial surfaces on bone regeneration, cartilage repair, and antibacterial activities.
Solar PV plant for supplying ancillary services in distribution systems
Authors: Yang Guangya , Zimmermann Jakob Kjaer , Frederiksen Ken H. B. , Helth Thomas , Ipsen Hans Henrik , Hansen Torben Vesth , Kjaer Søren Baekhøj
Published: July 2019

The paper reports the latest practice in the field for solar PV integration in distribution grids in Denmark, where the communication capability of solar inverters is exploited for integrating the monitoring and control functions of solar inverters into the SCADA system of the grid operator. The project demonstrates that, by implementing the enabled communication protocols of solar PV inverters in the remote terminal unit (RTU), the operator can receive measurements from the PV inverter on a variety of quantities, as well as remotely regulate the active and reactive power production for procurement of grid services. The practice demonstrates the feasibility of using solar PV plants for grid support in critical situations, where the experience is repeatable for other distribution grid operators to integrate distributed generation resources into the grid management functions. The work is carried out in cooperation with the grid operator of Bornholm, which is one of the islands in Denmark having the highest penetration of renewable energy.
Supplementary frequency control in power systems via decentralised V2G/G2V support
Authors: Gamit Mitul , Shukla Akanksha , Kumar Rajesh , Verma Kusum
Published: July 2019

One of the smartest evolution in the electrical power system is the integration of various renewable sources. It is an effective way to cater consumers growing power demands. The intermittency issues in renewable sources may lead to generation and demand imbalance. This imbalance creates various issues like frequency fluctuations, voltage variation, power quality problem and so on. This study proposes a method to reduce the frequency deviation. More the electric vehicles (EVs) in this system, then more the mobile storage devices for vehicle to grid (V2G). The charging/discharging rates of EVs are controlled as per the regulation signal coming from the system operator. The proposed scheme has been simulated using the frequency regulation data acquired from PJM. The proposed algorithm controls the total charging/discharging power based on the regulation signal and this is used to modify the charging/discharging rates of EVs. The result shows a better performance during grid to vehicle (G2V), at time 20:00 the regulation signal is −650 kW and it fully met by EVs. However, during V2G the performance is quite good, at time 08:00 the regulation signal is 800 kW and EVs meet only 180 kW due to less number of EVs for discharging.
Development of NIE networks' nodal controller project to deliver reactive power support to the wider electricity system
Authors: Pollock Jonathan , Hill David , Smyth Lee , McGuckin Donal
Published: July 2019

In 2017, 34.8% of total electricity consumption in Northern Ireland was generated from renewable sources located in Northern Ireland. Alongside other significant changes to the electricity sector this leads to an increasing need for reactive power. This paper provides an overview of NIE Networks' nodal controller project which aims to deliver reactive power support to the wider system through the utilisation of Distributed Energy Resources (DERs). The requirements and implementation of the nodal controller are outlined with future work proposed to provide additional reactive power support to the system.
Particle swarm optimisation technique to improve energy efficiency of doubly‐fed induction generators for wind turbines
Authors: Sompracha Cherngchai , Jayaweera Dilan , Tricoli Pietro
Published: July 2019

Wind energy conversion systems (WECSs) require a suitable control to maximise the power generated by wind turbines independently on the wind conditions. Variable‐speed fixed‐pitch wind turbines with doubly‐fed induction generators (DGIG) are used in WECSs for their higher reliability and efficiency compared to variable‐pitch wind turbine systems. This study proposes an effective control algorithm to maximise the efficiency of fixed‐pitch wind turbines with DFIGs using particle swarm optimisation control to compensate for the errors in the estimation of the circuit parameters of the generator. The proposed control algorithm generates an optimal speed reference to optimise the mechanical power extracted from the wind and the optimal d ‐axis rotor current through stator reactive power management to minimise the electrical losses of the doubly‐fed generator. The optimal speed reference is provided by a maximum power point tracking control below the rated wind speed and a soft‐stalling control above the rated wind speed, while the optimal d ‐axis rotor current is searched by a particle swarm optimisation algorithm. The proposed control system has been verified by numerical simulations and it has been demonstrated that the energy generated for typical wind speed profiles is greater than that of a traditional control based on a model‐based loss minimisation.
Non-LTE chemical abundances in Galactic open and globular clusters
Authors: Kovalev Mikhail , Bergemann Maria , Ting Yuan-Sen , Rix Hans-Walter
Published: July 2019

Aims. We study the effects of non-local thermodynamic equilibrium (NLTE) on the determination of stellar parameters and abundances of Fe, Mg, and Ti from the medium-resolution spectra of FGK stars.

Methods. We extended the Payne fitting approach to draw on NLTE and LTE spectral models. These were used to analyse the spectra of the Gaia-ESO benchmark stars and the spectra of 742 stars in 13 open and globular clusters in the Milky Way: NGC 3532, NGC 5927, NGC 2243, NGC 104, NGC 1851, NGC 2808, NGC 362, M 2, NGC 6752, NGC 1904, NGC 4833, NGC 4372, and M15.

Results. Our approach accurately recovers effective temperatures, surface gravities, and abundances of the benchmark stars and clusters members. The differences between NLTE and LTE are significant in the metal-poor regime, [Fe/H] ≲ −1. The NLTE [Fe/H] values are systematically higher, whereas the average NLTE [Mg/Fe] abundance ratios are ∼0.15 dex lower, compared to LTE. Our LTE measurements of metallicities and abundances of stars in Galactic clusters are in a good agreement with the literature. Though, for most clusters, our study yields the first estimates of NLTE abundances of Fe, Mg, and Ti.

Conclusion. All clusters investigated in this work are homogeneous in Fe and Ti, with the intra-cluster abundance variations of less then 0.04 dex. NGC 2808, NGC 4833, M 2, and M 15 show significant dispersions in [Mg/Fe]. Contrary to common assumptions, the NLTE analysis changes the mean abundance ratios in the clusters, but it does not influence the intra-cluster abundance dispersions.
Historical church diagnostic with regards to impact of traffic included vibrations
Authors: Kozioł Krzysztof
Published: July 2019

In the article problem of a comprehensive diagnosis of a historic building with damages is discussed. Dynamic investigations carried out in the church of St. Nicholas in the center of Krakow are an example of diagnostic tests provided to determine the causes of damage. Because the tested structure is exposed to traffic vibrations caused by wheeled vehicles and train passes, special attention has been paid to the impact of these vibrations onto a historic object. Results of measurements of these vibrations as well as dynamic analyzes obtained using FEM model of the investigated church were given.
Reduction of vibration in railway surfaces
Authors: Kozioł Krzysztof
Published: July 2019

Presented paper concerns the problem of reduction of the impact of vibrations generated by the metro on neighboring buildings and people staying inside. The issue of acceptable levels of these impacts in accordance with Polish standards and ISO (International Standard Organization) has been discussed. Basing on the example of research carried out by the author in the Warsaw Metro and his experience acquired during the design of vibroisolations of the final section of the first subway line in Warsaw, methods of testing dynamic interactions and predicting their level using FEM and simulation calculations on models were presented
Free vibration of frame structures made of Zener type viscoelastic material
Authors: Lewandowski Roman , Wielentejczyk Przemysław
Published: July 2019

A method for determining the dynamic characteristics of structures made of viscoelastic material is presented. The fractional Zener model is used to the describe the rheological properties of materials. All of the elements of a structure must be built of material with identical rheological properties. The solution to the linear eigenvalue problem for some elastic structure and the solution to a single nonlinear algebraic equation are needed to obtain the dynamic characteristics of a viscoelastic structure. Moreover, the frequency response functions are determined in a very efficient way. The results of a representative calculation are presented and briefly discussed.
Numerical model of tracked vehicle crossing inland water
Authors: Pawlak Mariusz , Sławski Sebastian , Duda Sławomir
Published: July 2019

In this paper, a numerical model of tracked vehicle with a simplified suspension and a winch forcing movement at a constant speed of 2 m / s is presented. The simplified vehicle body was created in the CAD environment, the suspension model, dry and wet obstacle, as well as the winch system and material models, were created in the LS PREPOST. The body of the vehicle was treated as a rigid, mounted by springs and dampers on tracks, the solid element was replaced by a shell element with assigned moments of inertia and mass in the node located in the centre of gravity of the vehicle. The characteristics of the resultant contact force of vehicle travel on the rigid ground for a dry and water obstacle are presented.
On dynamic interaction between mechanical systems and selected electric motors
Authors: Szolc Tomasz , Konowrocki Robert , Pochanke Andrzej
Published: July 2019

In the paper there is presented a reliable structural model of the rotating mechanical systems as well as mathematical models of the stepping, synchronous and asynchronous motors, by means of which electromechanical coupling effects can be thoroughly investigated. An importance and severity of these phenomena, not sufficiently explored till present, have been demonstrated by results obtained for transient and steady-state operational conditions in the computational examples concerning torsional vibrations of drive trains with various electric motors.
Stability of a hydraulic telescopic cylinder subjected to generalised load by a force directed towards the positive pole
Authors: Uzny Sebastian , Kutrowski Łukasz
Published: July 2019

The paper presents the boundary problem of the stability of a telescopic hydraulic cylinder subjected to a generalized load with a force directed to the positive pole. The boundary problem was formulated on the basis of the Hamilton principle. Numerical calculations were carried out, taking into account the influence of the parameters of the load heads (radii of loading and receiving head, length of bolt). On the basis of the numerical calculations, regions of load heads parameters were presented, at which the load bearing capacity of the analysed telescopic hydraulic cylinder is the largest from the buckling standpoint.
Are masters athletic performances predictive of human aging in men and women?
Authors: Senefeld Jonathon W. , Hunter Sandra K.
Published: July 2019

Human aging particularly after ∼70 years, is associated with declines in physical function and athletic performance, that are accelerated in part by age-associated declines in physical activity and exercise training. Because elite athletes maintain high levels of physical activity across the lifespan, older athletes (Masters) may present as a proxy for healthy human aging. Although longitudinal studies are most informative about human aging, there are substantial practical challenges to conducting longitudinally designed research. Masters athletic records and comparisons of performance across age groups can serve as a practical and unique probe to predict the trajectory of human function throughout the lifespan. While useful, the cross-sectional comparison of elite athletic performance across different age groups, however, has inherent limitations in predicting healthy human aging, particularly among women. This review presents evidence that (1) there is a progressive age-related decline in world class performances in freestyle swim swimming, marathon, and triathlon, that accelerates into very old age (∼70 years), and (2) lower participation rates of women relative to men results in an overestimation of the age-related decline in athletic performance particularly in very old women. Thus, while useful, there are some limitations to predicting biological aging among women using current Masters Athletic performances.
Irreducible Volar DRUJ Dislocation with Distal Radius Fracture Dislocation
Authors: Gulbrandsen Matthew T. , Putnam Jill G. , Watson J. Tracy , McKee Michael D.
Published: July 2019

Background Volar dislocations of the distal radioulnar joint (DRUJ) are rare and often missed during initial evaluation. Chronic dislocations and disability can occur when DRUJ dislocations are unrecognized and not reduced. DRUJ dislocations often occur with other wrist injuries, which may complicate reduction. Closed reduction can fail to reduce DRUJ dislocations, in which case open reduction is necessary.

Case Description This case describes a patient who had a volar dislocation of the DRUJ with an associated dorsal distal radius fracture dislocation. Initial attempts at closed reduction were unsuccessful which prompted surgical intervention. After open reduction and internal fixation of the distal radius fracture dislocation, closed reduction of the DRUJ remained unsuccessful. This prompted an open reduction of the DRUJ. Surgical exposure demonstrated that the extensor carpi ulnaris and the distal radius had prevented closed reduction of the DRUJ. Postoperatively, a splint was placed with the wrist in supination. The patient followed-up at the 2- and 4-month intervals with persistent subluxation. However, the patient also reported minimal pain and the ability to return to work and previous level of activity.

Literature Review Current literature regarding irreducible volar DRUJ dislocations with distal radius fracture dislocations includes sparse case reports, which are reviewed in this report.

Clinical Relevance This case illustrates successful treatment for an uncommon volar DRUJ dislocation associated with a dorsal distal radius fracture dislocation and can be utilized to help guide future treatment of similar complex cases.
Winfree loop sustained oscillation in two-dimensional excitable lattices: Prediction and realization
Authors: Qian Yu , Zhang Gang , Wang Yafeng , Yao Chenggui , Zheng Zhigang
Published: July 2019

The problem of self-sustained oscillations in excitable complex networks is the central issue under investigation, among which the prediction and the realization of self-sustained oscillations in different kinds of excitable networks are the challenging tasks. In this paper, we extensively investigate the prediction and the realization of a Winfree loop sustained oscillation (WLSO) in two-dimensional (2D) excitable lattices. By analyzing the network structure, the fundamental oscillation source structure (FOSS) of WLSO in a 2D excitable lattice is exposed explicitly. For the suitable combinations of system parameters, the Winfree loop can self-organize on the FOSS to form an oscillation source sustaining the oscillation, and these suitable parameter combinations are predicted by calculating the minimum Winfree loop length and have been further confirmed in numerical simulations. However, the FOSS cannot spontaneously offer the WLSO in 2D excitable lattices in usual cases due to the coupling bidirectionality and the symmetry properties of the lattice. A targeted protection scheme of the oscillation source is proposed by overcoming these two drawbacks. Finally, the WLSO is realized in the 2D excitable lattice successfully.
Capture of highly charged ions in a pseudo-hyperbolic Paul trap
Authors: Dreiling J. M. , Naing A. S. , Tan J. N. , Hanson J. M. , Hoogerheide S. F. , Brewer S. M.
Published: July 2019

The confinement of ions in a radio-frequency (RF) trap (also known as a Paul trap) has proven to be advantageous in many applications. In nearly all cases, singly- or few-times-ionized atoms are created in situ within the RF trap. Highly charged ions, on the other hand, are produced more efficiently in dedicated external sources; hence, the isolation of single highly charged species in an RF trap is more involved. In this work, highly charged ions produced by an electron beam ion trap/source are extracted in bunches via an ∼7 m long beamline, which is tuned to minimize the phase-space volume of the ion bunch. The charge-state-selected ion bunch is then captured in an RF trap constructed from cylindrically symmetric electrodes with pseudohyperbolic surfaces. The RF drive parameter space is surveyed both experimentally and computationally to investigate the dynamics and map out those regions favorable for ion capture. We find that an appreciable number of Ne10+ ions are captured using an RF frequency of 2.4 MHz and an amplitude range of 120 V–220 V, with an efficiency highly dependent on the RF field phase. An experimental capture efficiency of >20% was attained, with at least 500 ions being captured by the RF trap. This is slightly higher (∼135%) than that captured by a contiguous, compact Penning trap. However, in the absence of any cooling mechanism, the observed ion-storage lifetime in the RF trap is 69 ms, a factor of ∼30 shorter than in the Penning trap; potential improvements are discussed.
Evaluation of particle-based continuum methods for a coupling with the direct simulation Monte Carlo method based on a nozzle expansion
Authors: Pfeiffer M. , Mirza A. , Nizenkov P.
Published: July 2019

This paper investigates three different particle-based continuum methods, the ellipsoidal statistical Bhatnagar-Gross-Krook (ESBGK) and Fokker-Planck (ESFP) methods and the Low Diffusion (LD) method, for a coupling with the direct simulation Monte Carlo (DSMC) method. After a short description of the methods and their implementation, including the coupling concept for the LD-DSMC, simulation results of a nozzle expansion are compared with available experimental measurements and a DSMC simulation. Excellent agreement between ESBGK, ESFP, and DSMC can be observed in the throat of the nozzle, while the LD method fails to predict the correct velocity, temperature, and density profile. Further downstream, only the DSMC and the coupled ESBGK/ESFP-DSMC simulations are able to reproduce the measured rotational temperature profiles. A performance comparison shows the possible computational savings of a coupled ESBGK/ESFP-DSMC simulation, where a speedup of four orders of magnitude can be observed compared to a regular DSMC simulation.
Resolving different scattering effects on the thermal and electrical transport in doped SnSe
Authors: Li Shouhang , Tong Zhen , Bao Hua
Published: July 2019

Recently, it has been found that crystalline tin selenide (SnSe) holds great potential as a thermoelectric material due to its ultralow thermal conductivity and moderate electronic transport performance. As the thermoelectric application usually requires doped materials, dopants play an essential role in both the thermal and electrical transport properties in SnSe, but such an effect has never been clearly elucidated in previous theoretical and experimental studies. Here, we performed a rigorous first-principles analysis on the thermal and electrical transport in doped SnSe. Three phonon scattering mechanisms, including phonon-phonon, phonon-dopant, and phonon-electron interactions, were considered. The electron-phonon scattering is considered in the calculation of charge carrier transport properties using a mode specific calculation. Although intrinsic SnSe holds extremely low lattice thermal conductivity due to strong anharmonicity, the dopants can further reduce the lattice thermal conductivity. However, phonon-electron scattering is much weaker even at high carrier concentrations and thus has little effect on the lattice thermal conductivity. In comparison, the electronic thermal conductivity is not negligible when the carrier concentration is higher than 1019 cm−3, and the values can be as high as 1.55, 1.45, and 1.77 W m−1 K−1 on a, b, and c axes, respectively, for 1020 cm−3 electron concentration at 300 K. The strong anisotropy of electrical transport is observed, and it is attributed to the complex electronic band structure. The Lorenz number of SnSe is also calculated and it is dependent on crystal orientations, carrier concentrations, and carrier types. The simple estimation of electronic thermal conductivity using the Wiedemann-Franz law can cause large uncertainties for doped SnSe.
Photovoltage-induced blockade of charge and spin diffusion in semiconducting thin films
Authors: Park S. , Paget D. , Berkovits V. L. , Ulin V. P. , Alekseev P. A. , Kaliuzhnyi N. A. , Mintairov S. A. , Cadiz F.
Published: July 2019

In semiconductors under tightly-focused photocarrier excitation, the lateral variation of carrier concentration induces a lateral variation of photovoltage. In chemically-passivated p-type GaAs films at 300 K, we show experimentally and theoretically that the photovoltage lateral dependence is able to block the photoelectron diffusion, thus reducing the effective charge diffusion constant by a factor of ≈5 with respect to surface-free conditions and producing a self-trapping of photoelectrons. This effect is not present for surface-free and for oxidized samples, for which the photovoltage magnitude is strongly reduced. The photovoltage lateral variation also induces a coupling between charge and spin diffusion. Because of this coupling, the effective spin diffusion constant is significantly larger than the effective charge one.
Energy conversion in turbulent weakly collisional plasmas: Eulerian hybrid Vlasov-Maxwell simulations
Authors: Pezzi O. , Yang Y. , Valentini F. , Servidio S. , Chasapis A. , Matthaeus W. H. , Veltri P.
Published: July 2019

Kinetic simulations based on the Eulerian Hybrid Vlasov-Maxwell (HVM) formalism permit the examination of plasma turbulence with a useful resolution of the proton velocity distribution function. The HVM model is employed here to study the balance of energy, focusing on channels of conversion that lead to proton kinetic effects, including growth of internal energy and temperature anisotropies. We show that this Eulerian simulation approach, which is almost noise-free, is able to provide an accurate energy balance for protons. The results demonstrate explicitly that the recovered temperature growth is directly related to the role of the pressure-strain interaction. Furthermore, analysis of local spatial correlations indicates that the pressure-strain interaction is qualitatively associated with strong-current, high-vorticity structures although other local terms—such as the heat flux—weaken the correlation. These numerical capabilities based on the Eulerian approach will enable a deeper study of transfer and conversion channels in weakly collisional Vlasov plasmas.
Surface states in AlGaN/GaN high electron mobility transistors: Quantitative energetic profiles and dynamics of the surface Fermi level
Authors: Turkulets Yury , Shalish Ilan
Published: July 2019

We present a method to obtain quantitative profiles of surface state charge density and monitor its dynamics under various stress conditions in high electron mobility transistor (HEMT) devices. The method employs optical spectroscopy of the channel current at various bias conditions. We test the method on a classical AlGaN/GaN HEMT structure. To analyze the results, we propose a model, according to which the energy distribution of the surface charge density may be obtained from the derivative of the channel photocurrent. The proposed method is applied to fully fabricated transistors and can be measured under any device bias combination. This way, it is possible to explore the effect of device operating conditions on the surface state charge. This feature should be especially useful in studies of the various surface charge migration effects in nitride HEMTs. An important by-product of the method is a quantitative assessment of the energy position of the surface Fermi level and its dynamics under various bias conditions.
Reduction of glass-surface charge density slows the lipid diffusion in the proximal leaflet of a supported lipid bilayer
Authors: Otosu Takuhiro , Yamaguchi Shoichi
Published: July 2019

Understanding the effect of a solid support on the dynamical properties of a supported lipid bilayer (SLB) is a prerequisite for the applications of SLB as a model biomembrane. Here, we applied two-dimensional fluorescence lifetime correlation spectroscopy to examine the effect of solution pH on the diffusion of lipids in the proximal/distal leaflets of a zwitterionic SLB. Leaflet-specific diffusion analyses at various pH revealed that the diffusion of lipids in the proximal leaflet facing a glass surface becomes slower by decreasing pH with the transition pH of ∼7.4. We attributed it to the reduction of the surface charge density of a glass support. Furthermore, the data clearly showed that the lipid diffusion in the distal leaflet facing a bulk solution is insensitive to the change in the diffusion property of the proximal leaflet. This reflects a weak interleaflet coupling between the proximal and distal leaflets of the SLB.
An analytic expression approximating the Debye heat capacity function
Authors: Anderson William W.
Published: July 2019

It is useful to have analytic expressions for important functions in the equations of state of materials. The Debye model has been quite successful in approximating the thermal energy properties of a variety of solids, but is nonanalytic. Existing approximations suffer from various shortcomings, the most common being lack of applicability over some temperature range. A new analytic and integrable functional form that closely approximates the Debye model for the heat capacity is presented. This form, based on the mean of two Einstein heat capacity functions with a low temperature correction, exhibits deviations from the Debye model smaller than typical experimental scatter in heat capacity data.
Efficient dynamic simulations of charged dielectric colloids through a novel hybrid method
Authors: Gan Zecheng , Wang Ziwei , Jiang Shidong , Xu Zhenli , Luijten Erik
Published: July 2019

Modern particle-based simulations increasingly incorporate polarization charges arising from spatially nonuniform permittivity. For complex dielectric geometries, calculation of these induced many-body effects typically requires numerical solvers based upon boundary-element methods, which very significantly increase the required computational effort. For the special case of dielectric spheres, such as colloids or nanoparticles, we recently proposed a semianalytical spectrally accurate hybrid method that combines the method of moments, the image-charge method, and the fast multipole method. The hybrid method is efficient and accurate even when dielectric spheres are closely packed. Here, we extend the method to the evaluation of direct and induced electrostatic forces and demonstrate how this can be incorporated in molecular dynamics simulations. The choice of the relevant numerical parameters for molecular dynamics simulations is discussed in detail, as well as comparisons to the boundary-element method. As a concrete example, we examine the challenging case of binary crystal structures composed of close-packed dielectric colloidal spheres.
Advances in enhanced sampling molecular dynamics simulations for biomolecules
Authors: Wang An-hui , Zhang Zhi-chao , Li Guo-hui
Published: July 2019

Molecular dynamics simulation has emerged as a powerful computational tool for studying biomolecules as it can provide atomic insights into the conformational transitions involved in biological functions. However, when applied to complex biological macromolecules, the conformational sampling ability of conventional molecular dynamics is limited by the rugged free energy landscapes, leading to inherent timescale gaps between molecular dynamics simulations and real biological processes. To address this issue, several advanced enhanced sampling methods have been proposed to improve the sampling efficiency in molecular dynamics. In this review, the theoretical basis, practical applications, and recent improvements of both constraint and unconstrained enhanced sampling methods are summarized. Further-more, the combined utilizations of different enhanced sampling methods that take advantage of both approaches are also briefly discussed.
Meta-analysis of the Cepheid Xpert® CT/NG assay for extragenital detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections
Authors: Bristow Claire C. , Morris Sheldon R. , Little Susan J. , Mehta Sanjay R. , Klausner Jeffrey D.
Published: July 2019

Background Most studies evaluating extragenital testing performance for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) detection by the Xpert® CT/NG show high per cent agreement with comparison assays; however, the precision around positive per cent agreement is low and thus the values that have been reported are not highly informative. Therefore, a systematic review was conducted and data from five studies were combined to better assess positive per cent agreement. Methods: The literature indexed on PubMed.gov was searched. Included studies were those that were an evaluation of the Xpert CT/NG assay with rectal and/or pharyngeal specimen types compared with another nucleic acid amplification test (NAAT), the Aptima transcription mediated amplification assay. A full Bayesian method was used for bivariate fixed-effect meta-analysis of positive and negative per cent agreement and pooled estimates (and 95% confidence intervals (CI)) were presented for each. Results: The pooled positive and negative per cent agreement for detection of CT in rectal specimens was 89.72% (95% CI: 84.97%, 93.64%) and 99.23% (95% CI: 98.74%, 99.60%), and in pharyngeal specimens, they were 89.96% (95% CI: 66.38%, 99.72%) and 99.62% (95% CI: 98.95%, 99.95%) respectively. For NG detection in rectal specimens, the pooled positive and negative per cent agreement was 92.75% (95% CI: 87.91%, 96.46%) and 99.75% (95% CI: 99.46%, 99.93%), and in pharyngeal specimens, they were 92.51% (95% CI: 85.84%, 97.18%) and 98.56% (95% CI: 97.69%, 99.23%) respectively. Conclusions: It was found that the Xpert CT/NG assay performed similarly to the Aptima transcription mediated amplification assay for the detection of CT and NG in extragenital specimens. The Xpert assay has the benefit of providing faster results at the point-of-care, thus reducing the turnaround time for results, potentially enabling same-day treatment.
Cardiomyocyte orientation modulated by the Numb family proteins–N-cadherin axis is essential for ventricular wall morphogenesis
Authors: Miao Lianjie , Li Jingjing , Li Jian , Lu Yangyang , Shieh David , Mazurkiewicz Joseph E. , Barroso Margarida , Schwarz John J. , Xin Hong-Bo , Singer Harold A. , Vincent Peter A. , Zhong Weimin , Radice Glenn L. , Wan Leo Q. , Fan Zhen-Chuan , Huang Guoying , Wu Mingfu
Published: July 2019

Significance

The formation of ridge-like trabeculae from the myocardium is central to heart formation, as it allows for the increase in muscle mass before the formation of coronary circulation. We found that cardiomyocytes display spatiotemporal orientation during trabecular formation. Cardiomyocytes in the
Numb
and
Numblike
double knockout display abnormal cellular orientation. The knockout hearts display reduced membrane localized N-cadherin due to attenuated N-cadherin recycling to the membrane. When chick N-cadherin is overexpressed in the knockouts via a mosaic model, the defects of cellular orientation and trabeculation were at least partially rescued, suggesting that Numb and Numblike regulate cellular orientation and trabeculation via N-cadherin. Cellular orientation might modulate the directionality of cellular migration, mitotic spindle orientation, and cellular organization during heart morphogenesis.
The lyric present in English translations of Russian poetry
Authors: Piątkowska Józefina
Published: July 2019

Taking English translations of Anna Akhmatova’s poems as a case study, this article investigates whether the lyric
present (a specific use of simple present forms in poetry) is the preferred present tense in poetic translations from Russian into
English. Akhmatova’s verbal craft is remarkably relevant for the issue at hand because of her extensive exploration of temporal
levels. The article examines what stylistic effects stem from a translator’s choice between the lyric present and the present
progressive. In order to provide a more general view of English translations, the study includes data concerning the frequency of
progressives contained in two different English editions of Akhmatova’s poetry. These data are presented in the comparative
perspective, together with data collected from English and American poetry and from English renditions of several Russian
poets.
High Power Pulse Laser Reflection Sequence Combination with a Fast Steering Mirror*
Authors: Gong Ke-Ling , Xu Jian , Zhang Lin , Guo Ya-Ding , Wang Bao-Shan , Li Yang , Li Shuai , Chen Zhong-Zheng , Yuan Lei , Kou Yang , Xu Yi-Ting , Peng Qin-Jun , Xu Zu-Yan
Published: July 2019

We propose and demonstrate a new approach for a high power pulse laser reflection sequence combination with a fast steering mirror (FSM). This approach possesses significant advantages for lasers combining with a variety of output power, wavelength, pulse duration, repetition rates and polarization. The maximum number of laser routes participating in combination principally depends on the FSM’s adjustment time of the step response, lasers’ repetition rates and pulse duration. A proof-of-principle experiment is performed with two 2-kW level pulsed beams. The results indicate that the combined beam has an excellent pointing stability with rms pointing jitter ∼8.5 μrad. Meanwhile, a high combining efficiency of 98.6% is achieved with maintaining good beam quality.
Electron-Electron Collision Term Describing the Reflections Induced Scattering in a Magnetized Plasma*
Authors: Dong Chao , Li Ding , Jiang Chang
Published: July 2019

For an electron-electron collision with characteristic scale length larger than the relative gyro-radius of the two colliding electrons, when the initial relative parallel kinetic energy cannot surmount the Coulomb repulsive potential, reflection will occur with interchange of the parallel velocities of the two electrons after the collision. The Fokker–Planck approach is employed to derive the electron collision term

C
R

describing parallel velocity scattering due to the reflections for a magnetized plasma where the average electron gyro-radius is much smaller than the Debye length but much larger than the Landau length. The electron parallel velocity friction and diffusion coefficients due to the reflections are evaluated, which are found not to depend on the electron perpendicular velocity. By studying the temporal evolution of the H quantity due to

C
R

, it is found that

C
R

eventually makes the system relax to a state in which the electron parallel velocity distribution is decoupled from the perpendicular velocity distribution.
Magneto-Transport and Shubnikov–de Haas Oscillations in the Type–II Weyl Semimetal Candidate NbIrTe4 Flake*
Authors: Huang Xiang-Wei , Liu Xiao-Xiong , Yu Peng , Li Pei-Ling , Cui Jian , Yi Jian , Deng Jian-Bo , Fan Jie , Ji Zhong-Qing , Qu Fan-Ming , Jing Xiu-Nian , Yang Chang-Li , Lu Li , Liu Zheng , Liu Guang-Tong
Published: July 2019

We report on magnetoresistance, Hall effect, and quantum Shubnikov–de Haas oscillation (SdH) experiments in NbIrTe4 single crystals, which was recently predicted to be a type-II Weyl semimetal. NbIrTe4 manifests a non-saturating and parabolic magnetoresistance at low temperatures. The magneto-transport measurements show that NbIrTe4 is a multiband system. The analysis of the SdH oscillations reveals four distinct oscillation frequencies. Combined with the density-functional theory calculations, we show that they come from two types of Fermi surfaces: electron pocket E1 and hole pocket H2.