bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on laser surface processing of titanium based alloy (Ti6Al4V) with titanium, carbon and a mixture of titanium and carbon
Authors: Gayen Tarun Kumar , Pityana Sisa , Akinlabi Esther , Majumdar Jyotsna Dutta 
Published: September 2023

Abstract
The present study concerns the development of titanium carbide (TiC) dispersed titanium matrix composite by laser surface processing of titanium with titanium and carbon (in the weight ratio of 90:10 and 50:50). Laser surface processing has been carried out using a 4 kW continuous wave (CW) Nd:YAG laser with a beam diameter of 2 mm, at varied applied power ranging from 600–900 W and a scan speed of 0.6 m s−1 by pre-deposition of precursor powder and its subsequent melting using laser in argon shroud. Followed by laser surface processing, a detailed characterization of the processed zone has been carried out in terms of microstructure, phase, and composition. Properties of the surface processed zone were evaluated in terms of corrosion resistance in Hank’s solution. Finally, the optimum process parameters for laser surface processing has been established through a detailed structure–property-process parameters correlation. The microstructure of the surface processed zone consists of presence of titanium carbides dispersed in α matrix, the mass fraction of carbide phase was found to vary with weight percentage of graphite present in the precursor powder. The corrosion resistance property of the surface was found to be improved in terms of decrease in corrosion rate (range of 0.001 mm to 0.03 mm per year) as compared to as-received Ti-6Al-4V (0.2 mm per year). Laser surface processing with 100% graphite shows a maximum improvement in corrosion and bio-activity.
A neural network regression model for estimating the lifespan of a Fibre Bundle
Authors: V Gokul , Singh Navin 
Published: September 2023

Abstract
Fibre Bundle Models (FBMs) use generalized distributions like the Weibull distribution to study the failure mechanics of disordered material under different load-sharing schemes. Here we attempt to use a simple neural network regression model to estimate the lifespan of Fibre Bundles for axial loading under the Global Load Sharing (GLS) scheme. We find that using neural networks can give a reliable estimate (within ∼2%) of the lifespan for different initial conditions. We also develop a semi-analytical expression for the lifespan of a bundle of fibres. The aim is to establish an empirical relationship using a neural network regression (NNR) method that helps us estimate the ultimate tensile strength. The expressions and methods developed here can be a precursor to future investigation under those cited in the following section(s).
SPR-Based refractive index sensor using BaTiO3 and WS2 with Al-Ni bimetal for glucose sensing
Authors: Uwais Mohd , Bijalwan Ashish , Rastogi Vipul 
Published: September 2023

Abstract
In this work, we propose a high-performance surface plasmon resonance (SPR)-based refractive index biosensor to determine the glucose concentration in the urine samples. To achieve the most efficient design for the sensor, four possible designs have been investigated. The proposed design of the sensor uses the Kretschmann configuration, which consists of a BK7 glass prism with Aluminum (Al) and Nickel (Ni) metallic layers separated by a dielectric layer of barium titanate (

BaTiO

3

), and a 2D material tungsten disulfide (

WS

2

) layer placed above the Ni layer. The dielectric layer of

BaTiO

3

is used to enhance the shift in the resonance angle and

WS

2

to increase the absorption of the biomolecules, which results in an increase in the sensitivity of the sensor. The performance of the sensor has been numerically investigated using the transfer matrix method at

633

nm

wavelength. Minimum reflectance at resonance is studied to show the coupling strength of the incident light with the surface plasmons. The thicknesses of the Al and Ni metallic layers have been optimized for maximum sensitivity and minimum reflectance at the resonance. The performance of the proposed sensor has been investigated to obtain sensitivity for different glucose concentrations in the urine samples. The sensor has a sensitivity of

330.5
°
/
RIU

for glucose concentration in the range

0
−
10

g\dl
.

The corresponding glucose concentration sensitivity is 0.4

°
/
(
g
/
dl
)
.

The proposed study would be helpful in designing the refractive index-based biosensor for medical diagnostics applications.
A Novel Low-frequency Radio Astronomical Observation Array (1 ∼ 90 MHz) and its First Light
Authors: Yang Wen-Jun , Wang Zhen , Wang Ming-Yuan , Yan Fa-Bao , Lu Guang , Gao Guan-Nan , Guo Shao-Jie , Shen Yu-Mei , Xu Bing-Qiang , Bai Yu , Chen Yong , Ping Jin-Song 
Published: September 2023

Abstract
The extremely low frequency (f < 40 MHz) is a very important frequency band for modern radio astronomy observations. It is also a key frequency band for solar radio bursts, planetary radio bursts, fast radio bursts detected in the lunar space electromagnetic environment, and the Earth’s middle and upper atmosphere with low dispersion values. In this frequency band, the solar stellar activity, the early state of the universe, and the radiation characteristics of the planetary magnetosphere and plasma layer can be explored. Since there are few observations with effective spatial resolution in the extremely low frequency, it is highly possible to discover unknown astronomical phenomena on such a band in the future. In conjunction with low frequency radio observation on the far side of the Moon, we initially set up a novel low-frequency radio array in the Qitai station of Xinjiang Astronomical Observatory deep in Tianshan Mountains, Xinjiang, China on 2021 August 23. The array covers an operating frequency range of 1 ∼ 90 MHz with a sensitivity of −78 dBm/125kHz, a dynamic range of 72 dB, and a typical gain value of 6 dBi, which can realize unattended all-weather observations. The two antennas due south of the Qitai Low-Frequency Radio Array were put into trial observations on 2021 May 28, and the very quiet electromagnetic environment of the station has been confirmed. So far, many solar radio bursts and other foreign signals have been detected. The results show that this novel low frequency radio array has the advantages of good performance, strong direction, and high antenna efficiency. It can play a unique role in Solar Cycle 25, and has a potential value in prospective collaborative observation between the Earth and space for extremely low frequency radio astronomy.
Prediction of Short Stellar Activity Cycles using Derived and Established Empirical Relations between Activity and Rotation Periods
Authors: Althukair A. K. , Tsiklauri D. 
Published: September 2023

Abstract
In our previous work, we investigated the occurrence rate of super-flares on various types of stars and their statistical properties, with a particular focus on G-type dwarfs, using entire Kepler data. The said study also considered how the statistics change with stellar rotation period, which in turn, had to be determined. Using such new data, as a by-product, we found 138 Kepler IDs of F- and G-type main sequence stars with rotation periods less than a day (P
rot < 1 day). On one hand, previous studies have revealed short activity cycles in F-type and G-type stars and the question investigated was whether or not short-term activity cycles are a common phenomenon in these stars. On the other hand, extensive studies exist which establish an empirical connection between a star’s activity cycle and rotation periods. In this study, we compile all available Kepler data with P
rot < 1 day, and rely on an established empirical relation between P
cyc and P
rot with the aim to provide predictions for very short 5.09 ≤ P
cyc ≤ 38.46 day cases in a tabular form. We propose an observation to measure P
cyc using a monitoring program of stellar activity (e.g., activity-related chromospheric emission S-index) or a similar means for the Kepler IDs found in this study in order put the derived empirical relations between P
cyc and P
rot derived here to the test. We also propose an alternative method for measuring very short P
cyc, using flare-detection algorithms applied to future space mission data.
Hippocampal network axons respond to patterned theta burst stimulation with lower activity of initially higher spike train similarity from EC to DG and later similarity of axons from CA1 to EC
Authors: Chen Ruiyi , Vakilna Yash Shashank , Lassers Samuel Brandon , Tang William C , Brewer Gregory 
Published: September 2023

Abstract

Objective. Decoding memory functions for each hippocampal subregion involves extensive understanding of how each hippocampal subnetwork processes input stimuli. Theta burst stimulation (TBS) recapitulates natural brain stimuli which potentiates synapses in hippocampal circuits. TBS is typically applied to a bundle of axons to measure the immediate response in a downstream subregion like the cornu ammonis 1 (CA1). Yet little is known about network processing in response to stimulation, especially because individual axonal transmission between subregions is not accessible. Approach. To address these limitations, we reverse engineered the hippocampal network on a micro-electrode array partitioned by a MEMS four-chambered device with interconnecting microfluidic tunnels. The micro tunnels allowed monitoring single axon transmission which is inaccessible in slices or in vivo. The four chambers were plated separately with entorhinal cortex (EC), dentate gyrus (DG), CA1, and CA3 neurons. The patterned TBS was delivered to the EC hippocampal gateway. Evoked spike pattern similarity in each subregions was quantified with Jaccard distance metrics of spike timing. Main results. We found that the network subregion produced unique axonal responses to different stimulation patterns. Single site and multisite stimulations caused distinct information routing of axonal spikes in the network. The most spatially similar output at axons from CA3 to CA1 reflected the auto association within CA3 recurrent networks. Moreover, the spike pattern similarities shifted from high levels for axons to and from DG at 0.2 s repeat stimuli to greater similarity in axons to and from CA1 for repetitions at 10 s intervals. This time-dependent response suggested that CA3 encoded temporal information and axons transmitted the information to CA1. Significance. Our design and interrogation approach provide first insights into differences in information transmission between the four subregions of the structured hippocampal network and the dynamic pattern variations in response to stimulation at the subregional level to achieve probabilistic pattern separation and novelty detection.
Suppression of cortical electrostimulation artifacts using pre-whitening and null projection
Authors: Lim Jeffrey , Wang Po T , Bashford Luke , Kellis Spencer , Shaw Susan J , Gong Hui , Armacost Michelle , Heydari Payam , Do An H , Andersen Richard A , Liu Charles Y , Nenadic Zoran 
Published: September 2023

Abstract

Objective. Invasive brain–computer interfaces (BCIs) have shown promise in restoring motor function to those paralyzed by neurological injuries. These systems also have the ability to restore sensation via cortical electrostimulation. Cortical stimulation produces strong artifacts that can obscure neural signals or saturate recording amplifiers. While front-end hardware techniques can alleviate this problem, residual artifacts generally persist and must be suppressed by back-end methods. Approach. We have developed a technique based on pre-whitening and null projection (PWNP) and tested its ability to suppress stimulation artifacts in electroencephalogram (EEG), electrocorticogram (ECoG) and microelectrode array (MEA) signals from five human subjects. Main results. In EEG signals contaminated by narrow-band stimulation artifacts, the PWNP method achieved average artifact suppression between 32 and 34 dB, as measured by an increase in signal-to-interference ratio. In ECoG and MEA signals contaminated by broadband stimulation artifacts, our method suppressed artifacts by 78%–80% and 85%, respectively, as measured by a reduction in interference index. When compared to independent component analysis, which is considered the state-of-the-art technique for artifact suppression, our method achieved superior results, while being significantly easier to implement. Significance. PWNP can potentially act as an efficient method of artifact suppression to enable simultaneous stimulation and recording in bi-directional BCIs to biomimetically restore motor function.
Synthesis, characterization, and fluorescence properties of SrAl2B2O7:Eu2+ and SrAl2B2O7:Eu2+, Li+
Authors: Li Sheng , Jiao Zhiwei , Guo Yanxing , Liu Shuchang , Wu Yuhao , Qin Guangcan 
Published: September 2023

Abstract
The blue-emitting phosphor SrAl2B2O7:Eu2+ has the potential to be used in full-spectrum LED devices. However, the reducing atmosphere is extremely demanding in the complex preparation process of SrAl2B2O7:Eu2+. Thereby, the synthesis of SrAl2B2O7:Eu2+ with an economic approach is important. In this work, a new synthesis route was realized; SrAl2O4:Eu2+ and H3BO3 were used as solid precursors to synthesize SrAl2B2O7:Eu2+ by solid-state reaction method, and only carbon powder is needed as a source of reducing atmosphere. The effects of different synthesis routes on the crystal structure, morphology, and luminescence properties of SrAl2O4:Eu2+ were studied, as well as the effects of Li+ doping on luminescence properties were investigated. The results show that under the new synthesis route, SrAl2B2O7:Eu2+ has good luminescence properties, and doping Li+ will improve the luminescence intensity.
Study on mechanical properties of multi-fiber reinforced fly ash concrete
Authors: Zhang Wei , Chen Chengqin , Wu Hongjuan , Mao Yuncheng 
Published: September 2023

Abstract
Aiming at the problems of low strength and easy cracking of concrete with large dosages of fly ash, SSF, ARF, and PPF were mixed into concrete respectively according to the same volume ratio. Various indexes were tested and the change rule was analyzed. Besides, the fiber spacing theory was adopted to explore the anti-cracking mechanism of fiber on concrete. The results indicate that the compressive strength and flexural strength of concrete were improved by three kinds of fiber in different dosage; the RFC of 7d was between 14% and 18%, and that of 28d was between 13% and 20%; SSF in concrete would produce strong bonding force and mechanical bite force. ARF has a small impact on the compressive strength of concrete, but a significant impact on the flexural strength of concrete. PPF can be more evenly dispersed in concrete to disperse and release a certain amount of stress and play a reinforcing role. Combined with SEM Microscopic Morphology Analysis of Concrete, a concrete mix ratio of three fibers 1:1:1 is recommended.
Experimental study on defects of needled quartz fiber reinforced phenolic aerogel composites by cryogenic milling
Authors: Zhang Yu , Han Lingsheng , Yu Qingbo , Yang Yuebing , Liu Kuo , Liu Haibo , Wang Yongqing 
Published: September 2023

Abstract
Needled quartz fiber reinforced phenolic aerogel composite (NQF/PA) is a kind of lightweight thermal protection material commonly used in the aerospace field. With the continuous development of aerospace science and technology, the design of various spacecraft is becoming more and more complex. Due to the limitation of the preparation process, thermal protection components are difficult to be directly prepared and formed. It is often necessary to carry out secondary processing in order to bond and assemble into a large-size combined thermal protection system. Because NQF/PA composites have the characteristics of high fiber toughness and easy cracking of the matrix, it is easy to cause processing defects such as burrs, tearing and edge collapse in dry machining. Cryogenic machining can improve the machinability of fiber-reinforced composites. However, there is still a lack of research on the cryogenic machining of NQF/PA composites. In order to analyze the feasibility of cryogenic machining technology for low-damage processing of NQF/PA composites, this paper carried out a comparative experimental study on dry machining and cryogenic machining of NQF/PA composites and analyzed the influence of spindle speed, feed rate and radial cutting depth on surface defects and cutting force. The research showed that under the same processing parameters, compared with dry machining, cryogenic machining can effectively reduce the cutting force and suppress processing defects.
The Effect of Trivalent Ions on Luminescent Properties of SrAl2O4:Eu2+, Dy3+ Phosphors
Authors: Guo Yanxing , Jiao Zhiwei , Cao Leigang , Li Sheng 
Published: September 2023

Abstract
Sr0.96Al2O4:Eu0.02, Dy0.02 green phosphors doped with La3+, Bi3+ and extra Dy3+ were successfully prepared by the solid-phase method. The crystal structure and luminescence properties of phosphors were characterized. The results showed that the doping of La3+ and Bi3+ and the continued increase of Dy3+ concentration in the SrAl2O4 lattice did not produce significant lattice distortion in the SrAl2O4 lattice, and the small amount of doping still maintained the presence of SrAl2O4. The photoluminescence intensity of both La3+ and Bi3+ doped samples showed an increasing and then decreasing trend within the doping amount, while the photoluminescence performance of Dy3+ doped samples did not show a decrease when increasing the same concentration of doping amount. The decay curves indicated that both La3+ and Bi3+ could decrease the afterglow time of SrAl2O4:Eu2+, Dy3+ phosphor, but increasing the concentration of Dy3+ effectively extends the afterglow time of SrAl2O4:Eu2+, Dy3+ phosphor.
Study on preparation and properties of PVDF/CB composite films
Authors: Zhen Wanqing , Nie Fu , Yang Hongcheng , Fei Hailin , Wang Peng 
Published: September 2023

Abstract
Carbon black was often used as a UV stabilizer, due to its ability to absorb high-energy ultraviolet radiation. In this study, carbon black was added to PVDF resin, and PVDF film with carbon black (PVDF/CB composite film) was fabricated using a precision co-extrusion casting mechanism. The properties of the films were characterized by differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), field emission scanning electron microscope (FESEM), water contact angle (WCA), and universal material testing machine. Furthermore, the DSC results suggested that the melting temperature (Tm) of PVDF/CB composite film was 168.7°C. The TGA results showed that the initial decomposition temperature (Td) of PVDF/CB composite film was 358.9°C. The FESEM observation showed that the surface of the PVDF/CB composite film was smooth without obvious defects. The WCA results indicated that PVDF/CB composite film had good hydrophobicity. In addition, the UV transmittance results presented that PVDF/CB composite film had higher UV aging resistance than that PVDF film.
Topology Optimization of Dual-Material Structures with Porous Materials
Authors: Zhou Yifan 
Published: September 2023

Abstract
To improve the buckling resistance of the structure and the effective utilization of materials, a topology optimization algorithm using dual materials is designed in this paper. Among them, the two materials are solid and porous, respectively. The single-material structure topology optimization algorithm in two-dimensional structures has been relatively perfect. However, the two-dimensional algorithm is limited to the topology optimization of a single material, and it cannot improve the buckling resistance of the actual compression structure. At the same time, the optimization algorithm for the three-dimensional structure still needs to be improved. The dual-material topology optimization algorithm using porous materials constructed in this paper assigns porous materials with good compressive capacity to the compression parts and solid materials with good tensile properties to the tension parts. Therefore, the structure of the compression part of the structure is strengthened, and the unnecessary structure of the tension part is simplified. In conclusion, the algorithm in this paper greatly improves the buckling resistance of the structure and maximizes the utilization of each design unit.
Synthesis of ZIF-L-derived Leaf-like Carbon Support Ultrafine Pt Nanoparticles for Oxygen Reduction Reaction
Authors: Huang Qirui 
Published: September 2023

Abstract
We prepared a two-dimensional ZIF-L-derived high-performance ORR catalyst using a mesoporous silica coating strategy. By one-step pyrolysis of mSiO2@L composite, the Pt precursors adsorbed inside ZIF-L are reduced to ultra-small Pt nanoparticles, and the SiO2 template inhibits agglomeration and collapse of ZIF-L during pyrolysis. After the template is removed, the obtained Pt/SLC exhibits outstanding activity for ORR. The half-wave potential of Pt/SLC is 0.910 V vs. RHE, which far exceeds commercial Pt/C catalyst (0.895 V vs. RHE).
Impact Resistance and Energy Absorption Characteristics of the Bionic Turtle Shell Structure
Authors: Song Yuting , Shi Weichen 
Published: September 2023

Abstract
The microstructure of the shell is a kind of “sandwich” structure with a denser outer layer and a less dense inner layer, density, which can be identified as a functional gradient material in engineering. It has excellent performance, such as earthquake resistance and shock resistance. In order to study the reliability of this kind of material, a kind of shell structure is designed in this paper. In the range of elastic deformation constraints of the material, simulate and calculate bionic structure the bionic structure. Firstly, a three-point bending analysis is carried out to investigate the mechanical properties of the bionic structure under a bending load. Secondly, through the Finite Element Analysis, the mechanical properties of the shell structure and the general structure under the same load are analyzed and compared. The simulation results show that in the three-point bending analysis, the maximum equivalent stress of the simulated shell structure under impact load is reduced by 1.4 times compared with the general structure. The energy absorption analysis showed a 1.6-fold increase.
Study on Crack Propagation in Proton Exchange Membranes with Doped Microcapsules
Authors: Yan Boru , Du Xin 
Published: September 2023

Abstract
Crack defects produced during the operation of proton exchange membrane fuel cells (PEMFCs) have a significant impact on their service life. One common approach to extend their working time is to embed self-healing microcapsules in the membrane to repair the defects. In this study, we use the extended finite element method (XFEM) to investigate the capture and control of cracks by doped microcapsules and numerically simulate the crack propagation patterns. The results show that a two-layer microcapsule distribution along the membrane cross-section can achieve complete control of cracks. In addition, the two-material microcapsules with layered, staggered arrangement exhibit the maximum distance between cracks they can attract, while minimizing their impact on the mechanical properties of the membrane. Based on these findings, we determine the theoretical doping amount of microcapsules per unit volume, which has important implications for future experimental design and engineering applications.