bluuebunny/crossref_metadata_2025_split huggingface dataset:
One-pot synthesis of double silane-functionalized carbon dots with tunable emission and excellent coating properties for WLEDs application
Authors: Cao Wenbing , Wu Yuhan , Li Xin , Jiang Xuanfeng , Zhang Yuhong , Zhan Yuan , Sun Zhengguang 
Published: December 2021

Abstract
Silane-functionalized carbon dots (SiCDs) can be exploited as effective color converting materials for the solid-state light-emitting devices. However, most of SiCDs reported thus far have shown photoluminescence emissions in the blue and green spectral range, which limit them to construct an efficient white light-emitting diodes (WLEDs) due to the lack of long-wavelength emission. Herein, a series of double silane-functionalized carbon dots (DSiCDs) were prepared via a one-step solvothermal method. The results show that the organic functional group of the silane has great influence on the optical properties of DSiCDs and the number of alkoxy group in the silane has great influence on coating properties of DSiCDs. In addition, the DSiCDs prepared by (3-aminopropyl)triethoxysilane and N-[3-(trimethoxysilyl)propyl]ethylenediamine with molar ratio of 7:3 show excellent optical properties with the maximum emission at 608 nm under 570 nm excitation. Furthermore, they can be completely cured within 1 h at room temperature to form fluorescent coating with high stability and strong adhesion to the substrate. Together with their excellent optical and coating properties, they can be directly coated on LED chips to prepare WLEDs, with a CIE coordinate of (0.33,0.31), color rendering index of 81.6, and color temperature of 5774 K.
How high is a MoSe2 monolayer?
Authors: Cowie Megan , Plougmann Rikke , Benkirane Yacine , Schué Léonard , Schumacher Zeno , Grütter Peter 
Published: December 2021

Abstract
Transition metal dichalcogenides (TMDCs) have attracted significant attention for optoelectronic, photovoltaic and photoelectrochemical applications. The properties of TMDCs are highly dependent on the number of stacked atomic layers, which is usually counted post-fabrication, using a combination of optical methods and atomic force microscopy height measurements. Here, we use photoluminescence spectroscopy, Raman spectroscopy, and three different AFM methods to demonstrate significant discrepancies in height measurements of exfoliated MoSe2 flakes on SiO2 depending on the method used. We also highlight the often overlooked effect that electrostatic forces can be misleading when measuring the height of a MoSe2 flake using AFM.
Retracted: Zeptomolar detection of 4-aminothiophenol by SERS using silver nanodendrites decorated with gold nanoparticles
Authors: Ceballos Manuel , López Israel , Arizmendi-Morquecho Ana , Sánchez-Domínguez Margarita 
Published: December 2021

Abstract
In the present work, we report a simple, fast, reproducible and cheap methodology for SERS substrate fabrication of silver dendritic nanostructures (prepared by electrodeposition) decorated with gold nanospheres by electrophoretic deposition. This is the first report where a metal dendritic nanostructure has been decorated with another type of metal nanoparticles by this technique. The decorated nanostructures were used directly as SERS substrate using 4-aminothiophenol (4-ATP) as analyte. The objective of the decoration is to create more hot-spots in order to detect the analyte in a lower concentration. Decorated nanodendrites had a detection limit one million times lower than bare silver nanodendrites and all the substrates showed an increase in the Raman intensity at concentrations below 1 nM; because this concentration corresponds to the threshold for the formation of a monolayer resulting in a triple mechanism of intensity increase, namely electric field, chemical factor and hot-spots. 4-ATP was detected in zeptomolar concentration, which is below 1 ppq, corresponding to an analytical enhancement factor in the order of 1015.
Numerical study of silicon vacancy color centers in silicon carbide by helium ion implantation and subsequent annealing
Authors: Fan Yexin , Song Ying , Xu Zongwei , Wu Jintong , Zhu Rui , Li Qiang , Fang Fengzhou 
Published: December 2021

Abstract
Molecular dynamics simulation is adopted to discover the formation mechanism of silicon vacancy color center and to study the damage evolution in 4H-SiC during helium ion implantation with different annealing temperatures. The number and distribution of silicon vacancy color centers during He ion implantation can be more accurately simulated by introducing the ionization energy loss during implantation. A new method for numerical statistic of silicon vacancy color centers is proposed, which takes into account the structure around the color centers and makes statistical results more accurate than the Wigner–Seitz defect analysis method. Meanwhile, the photoluminescence spectra of silicon vacancy color centers at different helium ion doses are characterized to verify the correctness of the numerical analysis. The new silicon vacancy color center identification method can help predicting the optimal annealing temperature for silicon vacancy color centers, and provide guidance for subsequent color center annealing experiments.
Atomic layer deposition for rutile structure TiO2 thin films using a SnO2 seed layer and low temperature heat treatment
Authors: Kim Byunguk , Choi Yeonsik , Lee Dahyun , Cheon Seonghak , Byun Younghun , Jeon Hyeongtag 
Published: December 2021

Abstract
We study the rutile-TiO2 film deposition with a high-k value using a SnO2 seed layer and a low temperature heat treatment. Generally, heat treatment over 600 °C is required to obtain the rutile-TiO2 film. However, By using a SnO2 seed layer, we obtained rutile-TiO2 films with heat treatments as low as 400 °C. The XPS analysis confirms that the SnO2 and TiO2 film were deposited. The XRD analysis showed that a heat treatment at 400 °C after depositing the SnO2 and TiO2 films was effective in obtaining the rutile-TiO2 film when the SnO2 film was thicker than 10 nm. The TEM/EDX analysis show that no diffusion in the thin film between TiO2 and SnO2. The dielectric constant of the TiO2 film deposited on the SnO2 film (20 nm) was 67, which was more than twice as high as anatase TiO2 dielectric constant (Anatase TiO2 dielectric constant : 15–40). The current density was 10−4 A cm−2 at 0.7 V and this value confirmed that the leakage current was not affected by the SnO2 seed layer.
Physics-constrained intraventricular vector flow mapping by color Doppler
Authors: Vixège Florian , Berod Alain , Sun Yunyun , Mendez Simon , Bernard Olivier , Ducros Nicolas , Courand Pierre-Yves , Nicoud Franck , Garcia Damien 
Published: December 2021

Abstract
Color Doppler by transthoracic echocardiography creates two-dimensional fan-shaped maps of blood velocities in the cardiac cavities. It is a one-component velocimetric technique since it only returns the velocity components parallel to the ultrasound beams. Intraventricular vector flow mapping (iVFM) is a method to recover the blood velocity vectors from the Doppler scalar fields in an echocardiographic three-chamber view. We improved our iVFM numerical scheme by imposing physical constraints. The iVFM consisted in minimizing regularized Doppler residuals subject to the condition that two fluid-dynamics constraints were satisfied, namely planar mass conservation, and free-slip boundary conditions. The optimization problem was solved by using the Lagrange multiplier method. A finite-difference discretization of the optimization problem, written in the polar coordinate system centered on the cardiac ultrasound probe, led to a sparse linear system. The single regularization parameter was determined automatically for non-supervision considerations. The physics-constrained method was validated using realistic intracardiac flow data from a patient-specific computational fluid dynamics (CFD) model. The numerical evaluations showed that the iVFM-derived velocity vectors were in very good agreement with the CFD-based original velocities, with relative errors ranged between 0.3% and 12%. We calculated two macroscopic measures of flow in the cardiac region of interest, the mean vorticity and mean stream function, and observed an excellent concordance between physics-constrained iVFM and CFD. The capability of physics-constrained iVFM was finally tested with in vivo color Doppler data acquired in patients routinely examined in the echocardiographic laboratory. The vortex that forms during the rapid filling was deciphered. The physics-constrained iVFM algorithm is ready for pilot clinical studies and is expected to have a significant clinical impact on the assessment of diastolic function.
Quantifying tidal expiratory flow limitation using a vector-based analysis technique
Authors: Welch Ryan , Francis Alaina , Babbage Thalia , Lardenoye Mandy , Kolbe John , Ellyett Kevin 
Published: December 2021

Abstract

Objective. Tidal expiratory flow limitation (EFLT) is commonly identified by tidal breaths exceeding the forced vital capacity (FVC) loop. This technique, known as the Hyatt method, is limited by the difficulties in defining the FVC and tidal flow-volume (TV) loops. The vector-based analysis (VBA) technique described and piloted in this manuscript identifies and quantifies EFLT as tidal breaths that conform to the contour of the FVC loop. Approach. The FVC and TV loops are interpolated to generate uniformly spaced plots. VBA is performed to determine the smallest vector difference between each point on the FVC and TV curves, termed the flow reserve vector (FRV). From the FVC point yielding the lowest FRV, the tangential angles of the FVC and TV segments are recorded. If the TV and FVC loops become parallel, the difference between the tangential angles tends towards zero. We infer EFLT as parallel TV and FVC segments where the FRV is < 0.1 and the tangential angle is within ±18 degrees for ≥5% of TV. EFLT is quantified by the percent of TV loop fulfilling these criteria. We compared the presence and degree of EFLT at rest and during peak exercise using the Hyatt method and our VBA technique in 25 healthy subjects and 20 subjects with moderate-severe airflow obstruction. Main results. Compared to the Hyatt method, our VBA technique reported a significantly lower degree of EFLT in healthy subjects during peak exercise, and in obstructed subjects at rest and during peak exercise. In contrast to the Hyatt method, our VBA technique re-classified five subjects (one in the healthy group and four in the obstructed group) as demonstrating EFLT. Significance. Our VBA technique provides an alternative approach to determine and quantify EFLT which may reduce the overestimation of the degree EFLT and more accurately identify subjects experiencing EFLT.
Near real-time streaming analysis of big fusion data
Authors: Kube R , Churchill R M , Chang C S , Choi J , Wang R , Klasky S , Stephey L , Dart E , Choi M J 
Published: December 2021

Abstract
Experiments on fusion plasmas produce high-dimensional data time series with ever-increasing magnitude and velocity, but turn-around times for analysis of this data have not kept up. For example, many data analysis tasks are often performed in a manual, ad-hoc manner some time after an experiment. In this article, we introduce the Delta framework that facilitates near real-time streaming analysis of big and fast fusion data. By streaming measurement data from fusion experiments to a high-performance compute center, Delta allows computationally expensive data analysis tasks to be performed in between plasma pulses. This article describes the modular and expandable software architecture of Delta and presents performance benchmarks of individual components as well as of an example workflow. Focusing on a streaming analysis workflow where electron cyclotron emission imaging (ECEi) data is measured at KSTAR on the National Energy Research Scientific Computing Center’s (NERSC’s) supercomputer we routinely observe data transfer rates of about 4 Gigabit per second. In NERSC, a demanding turbulence analysis workflow effectively utilizes multiple nodes and graphical processing units and executes them in under 5 min. We further discuss how Delta uses modern database systems and container orchestration services to provide web-based real-time data visualization. For the case of ECEi data we demonstrate how data visualizations can be augmented with outputs from machine learning models. By providing session leaders and physics operators, results of higher-order data analysis using live visualizations may make more informed decisions on how to configure the machine for the next shot.
Third-order transport coefficients for electrons in N2 and CF4: effects of non-conservative collisions, concurrence with diffusion coefficients and contribution to the spatial profile of the swarm
Authors: Simonović I , Bošnjaković D , Petrović Z Lj , White R D , Dujko S 
Published: December 2021

Abstract
Using a multi-term solution of the Boltzmann equation and Monte Carlo simulation technique we study behaviour of the third-order transport coefficients for electrons in model gases, including the ionisation model of Lucas and Saelee and modified Ness–Robson model of electron attachment, and in real gases, including N2 and CF4. We observe negative values in the E/n
0-profiles of the longitudinal and transverse third-order transport coefficients for electrons in CF4 (where E is the electric field and n
0 is the gas number density). While negative values of the longitudinal third-order transport coefficients are caused by the presence of rapidly increasing cross sections for vibrational excitations of CF4, the transverse third-order transport coefficient becomes negative over the E/n
0-values after the occurrence of negative differential conductivity. The discrepancy between the two-term approximation and the full multi-term solution of the Boltzmann equation is investigated for electrons in N2 and CF4. While the accuracy of the two-term approximation is sufficient to investigate the behaviour of the third-order transport coefficients in N2, it produces large errors and is not even qualitatively correct for electrons in CF4. The influence of implicit and explicit effects of electron attachment and ionisation on the third-order transport tensor is investigated. In particular, we discuss the effects of attachment heating and attachment cooling on the third-order transport coefficients for electrons in the modified Ness–Robson model, while the effects of ionisation are studied for electrons in the ionisation model of Lucas and Saelee, N2 and CF4. The concurrence between the third-order transport coefficients and the components of the diffusion tensor, and the contribution of the longitudinal component of the third-order transport tensor to the spatial profile of the swarm are also investigated. For electrons in CF4 and CH4, we found that the contribution of the component of the third-order transport tensor to the spatial profile of the swarm between approximately 50 Td and 700 Td, is almost identical to the corresponding contribution for electrons in N2. This suggests that the recent measurements of third-order transport coefficients for electrons in N2 may be extended and generalized to other gases, such as CF4 and CH4.
High-performance SiC MOSFET embedded heterojunction diode with electric field protection region
Authors: Yoon Jongwoon , Kim Kwangsoo 
Published: December 2021

Abstract
In this study, we proposed high-performance SiC metal-oxide-semiconductor field effect transistors (MOSFETs) embedded heterojunction diode (HJD) with an electric field protection (EFP) region and analyzed it using a Sentaurus TCAD simulation. The proposed device features an HJD positioned at the trench side wall in the middle of the junction field effect transistor region and a highly doped EFP region under the P+ polysilicon to features excellent static performance and high reliability. The simulation results revealed that the maximum oxide electric field (E
MOX) and the Baliga’s figure-of-merit improved by 54% and 12%, respectively, compared with those of conventional SiC MOSFETs (C-MOSFETs). In addition, the EFP region suppressed the drain induced barrier lowering effect and leakage current in the HJD interface sufficiently. The HJD suppressed the bipolar degradation of the PiN body diode effectively due to its low V
F (1.75 V). In addition, the proposed device demonstrated superior reverse-recovery characteristics, thereby improving t
rr and Q
rr by 35% and 57%, respectively, compared to the corresponding values in C-MOSFET. Moreover, the input capacitance (C
ISS) was reduced by 17.5%, and C
GD was reduced by 96%. Therefore, the high-frequency figure-of-merit improved by a factor of 25.8 in terms of R
ON × C
GD. As a result, the proposed device is a promising structure for high-frequency and high-reliability applications.
Magnetic behavior of magneto-rheological foam under uniaxial compression strain
Authors: Diguet Gildas , Sebald Gaël , Nakano Masami , Lallart Mickaël , Cavaillé Jean-Yves 
Published: December 2021

Abstract
This study reports the development of a magneto-rheological foam, which consists in a porous matrix filled by ferromagnetic particles. The porous matrix of such a composite being easily deformable, large magnetic properties changes are expected. The measurements of the magnetic properties of such a magneto-rheological foam submitted to a compressive strain are reported. Main aspect of the magnetic properties is the low field magnetic permeability as the function of the compression and filling factor. Then, larger field magnetization measurement allowed to investigate the saturation field as a function of the filling factor. Because of the large amount of pores in the material, the magnetic relative permeability, µ
r, is quite small (µ
r ∼ 1). However, these materials can be easily deformed over a large range of strain providing important relative variation of the magnetic properties under mechanical solicitation. The composite magnetic permeability is increasing under compression for all the considered filling factors. A model is then developed to understand the variation of the permeability with the strain. Hence, from a simple concept consisting of taking advantage of high deformation of foams, the present study demonstrates the interest of such a highly compressible while cheap composite for obtaining a large magneto-rheological effect.
Thermal design and analysis of a flexible solar array system based on shape memory polymer composites
Authors: Liu Zhengxian , Hao Sida , Lan Xin , Bian Wenfeng , Liu Liwu , Li Qifeng , Fu Zijian , Liu Yanju , Leng Jinsong 
Published: December 2021

Abstract
Smart structures based on shape memory polymer composites (SMPCs) have attracted extensive attention because of their unique self-deployment behavior. This study investigated the thermal design and analysis of the SMPC flexible solar array system (SMPC-FSAS). The thermal design ensured the reliability of the deployment functionality and desirable structural temperatures. The fundamental properties of the shape-memory materials were obtained by dynamic mechanical analysis and shape fixity ratio tests. Thermal experiments, including the thermal balance test (TBT), thermal vacuum test and thermal cycle test were conducted to verify the safety and reliability of the SMPC-FSAS. Additionally, the temperature distribution of the SMPC-FSAS was simulated using numerical analysis. Notably, a geostationary satellite carrying the SMPC-FSAS was successfully launched into a geosynchronous orbit and controlled deployment was accomplished for the first time. The prediction of the numerical model was consistent with the TBT and on-orbit data, thus validating the accuracy of the numerical method. The research in this work has important reference significance for ultra-large SMPC-FSAS in the future.
Effective reduction of magnetisation losses in copper-plated multifilament coated conductors using spiral geometry
Authors: Amemiya Naoyuki , Shigemasa Mao , Takahashi Akira , Wang Ning , Sogabe Yusuke , Yamano Satoshi , Sakamoto Hisaki 
Published: December 2021

Abstract
We wound copper-plated multifilament coated conductors spirally on a round core to decouple filaments electromagnetically under ac transverse magnetic fields and measured their magnetisation losses. Although the coated conductors were plated with copper, which connects all filaments electrically and allows current sharing among them, the spiral geometry decoupled filaments similar to the twist geometry, and the magnetisation loss was reduced effectively by the multifilament structure. The measured magnetisation loss of a 4 mm wide, 10-filament coated conductor with a 20 μm thick copper wound spirally on a 3 mm core was only 7% of that of the same 10-filament coated conductor with a straight shape under an ac transverse magnetic field with an amplitude and frequency of 100 mT and 65.44 Hz, respectively. We separated the measured magnetisation losses into hysteresis and coupling losses and discussed the influence of filament width, copper thickness, and core diameter on both losses. We compared the hysteresis losses with the analytical values given by Brandt and Indenbom and compared the coupling losses with the values calculated using a general expression of coupling loss with the coupling time constants and geometry factors.
A visual and full-field method for detecting quench and normal zone propagation in HTS tapes
Authors: Wang Shudan , Guan Mingzhi , Chen Jiaxiang , Wang Xingzhe , Zhou Youhe 
Published: December 2021

Abstract
A fast and effective quench detection method is especially challenging in the development of high-field high-temperature superconducting (HTS) magnets for their safe operations and reliably releasing the stored energy during a quench. The occurrence and propagation of a quench are often accompanied by strong thermal and magneto-mechanical responses within superconducting magnets. Aiming to detect a quench in the whole process and capture the thermoelastic behavior associated with it, a new detection technique with a visual and full-field perception based on the digital image correlation (DIC) method is proposed in the present study. The experiment of a quench triggered thermally by a local spot heater is conducted for a YBCO coated conductor tape in a cryogenic chamber. The evolution and characteristics of the full-field strain in the HTS tape during the processes of a non-quench, a quench occurrence and quench propagation are intuitively presented with experimental observations. For the comparison purpose, the conventional quench detection methods by monitoring temperature and voltage signals during a quench are also utilized experimentally. The results verify the visual and full-field quench detection method, which uses a criterion of thermoelastic strain-rate for the quench occurrence and the evolution of strain contours for the normal zone propagating aspect. Additionally, a numerical quench model of coupled thermoelasticity to simulate the experiment is established and solved with the aid of Comsol multiphysics software. The quantitative results are in good agreement with the experimental measurements to prove the reliability and availability of the developed detection method. Since the DIC method is non-contact and insensitive to intense electromagnetic interferences, it is expected to provide a new technique on quench issues and some basic measurements on strain/stress behaviors in extreme environments of high-field HTS magnets in the future.