bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mode transition of the cylindrical Hall thruster with the near-anode cusp magnetic field
Authors: Gao Yuanyuan , Wang Weizong , Li Yifei , Cai Guobiao , Xue Shuwen 
Published: March 2022

Abstract
There are two distinct discharge modes in a 200 W cylindrical Hall thruster with the near-anode cusp magnetic field. In mode I, a divergent plume is observed at a low discharge voltage. When the discharge voltage rises over 280 V, an apparent discharge mode transition occurs along with the sharp decreasing of discharge current (by 9.9%) and electron current (by 26%) and apparent narrowing of plume angle (by 12%), bringing a convergent plume (mode II). In mode I, the most probable ion energy of ion energy distribution function declines monotonically with the increasing of plume angle. However, a non-monotonic variation characteristic of most probable ion energy is indicated in mode II, which suggests that there are two ionization regions in this mode. These novel mode transition phenomena should be attributed to the unique near-anode cusp magnetic field. In low discharge voltage conditions (mode I), as the energies of the electron population are low, they are trapped in the near-axial magnetic mirror field, and a cylindrical ionization region along thruster axis is established. When the discharge voltage rises over the threshold voltage occurring mode transition, the energies of the electron population are enhanced and the energetic electrons could escape from the mirror field and reach the upstream crossed electric and magnetic fields. As a result, an additional ionization region related to E × B drift is formed in the upstream region. The competitive relationship between the upstream ionization related to E × B drift and the near-axial ionization related with magnetic mirror field should be the leading cause of mode transition.
The distribution pattern of the electron density and the electron temperature in a weakly compressible argon plasma jet measured by a Langmuir triple probe
Authors: Cao Jinwen , Meng Xian , Han Ning , Pan Wenxia , Wu Chengkang , Huang Heji 
Published: March 2022

Abstract
High-speed plasma plays an important role in diverse areas. Plasma flow with a sufficiently high speed to arouse compression is usually not in thermal equilibrium, and the plasma characteristics are closely coupled with the flow field. The relation between the flow and the plasma parameters, especially the distributions of electron density, i.e. n
e, and the electron temperature, i.e. T
e, are of ultimate importance; however, this is not yet completely understood. In this work, a weakly compressible plasma jet produced by an arc torch is diagnosed using a Langmuir triple probe. The two-dimensional distributions of n
e and T
e are obtained consisting of 80 spatial points under arc currents of 70–100 A. The spatial patterns of the distributions demonstrate alternative expansion–compression wave structures. As the arc power increases, the wave structures remain almost unchanged, while n
e increases monotonically. Moreover, in some regions T
e decreases with the arc power, which has seldom been reported in the literature. In addition, the peaks of the radial distributions of T
e always deviate from the central axis. These results are compared with previous works of strongly compressible plasma flows. The phenomena are then analyzed and explained from the perspective of fluid wave-plasma interactions and the actions of the ambipolar field in the electrons.
Fine structure of streamer-to-filament transition in high-pressure nanosecond surface dielectric barrier discharge
Authors: Ding Ch , Jean A , Popov N A , Starikovskaia S M 
Published: March 2022

Abstract
The fine structure of a streamer-to-filament transition in a single-shot high-voltage nanosecond surface dielectric barrier discharge in molecular nitrogen at pressure P = 6 bar was studied with the help of ICCD microimaging. An intermediate discharge structure, existing for only a few nanoseconds, was observed in the time interval between two discharge modes: streamer discharge, with a typical electron density of n
e ∼ 1015 cm−3, and filamentary discharge, with n
e ∼ 1019 cm−3. The structure was observed for both polarities of the high-voltage electrode. The structure can be briefly described as a stochastic appearance of thin channels propagating a bit faster than the main ionization front of merged surface streamers, transforming in a few nanoseconds in a bi-directional ionization wave. One wave, which we associate with a feather-like structure in optical emission, propagates further away from the high-voltage electrode, and another, a backward wave of emission, propagates back towards the edge of the high-voltage electrode. When the backward wave of emission almost reaches the high-voltage electrode, the filament appears. Plasma properties of the observed structure were studied to better understand the nature of a streamer-to-filament transition. Theoretical analysis suggests that the instability of a flat front of ionization wave (Laplacian instability) triggers the streamer-to-filament transition, and that a surface stem (a tiny region with enhanced electron density) should be in the origin of the bi-directional ionization wave.
Note on the energy transport in capacitively coupled plasmas
Authors: Wu Hao , Chen Zhaoyu , Yi Lin , Jiang Wei , Zhang Ya 
Published: March 2022

Abstract
Particle and energy balance relations are the key to understanding the discharge in low-temperature plasmas. In this note, we derived the energy transport balances in capacitively coupled plasmas (CCPs) based on the electromagnetic theory. Then we calculated the energy transport terms in CCPs from particle-in-cell/MonteCarlo (PIC/MC) simulations, including the energy absorption, energy density, energy flow, and the energy dissipation terms, both for the particles and the field. The spatial-temporal dependant and averaged distributions of energy transport terms are shown at different pressure, demonstrating the correctness and the effectiveness of the method. This revisited method may be used to aid the studies of the electrons heating mechanism in CCP, as well as in some other plasma sources.
Electron spectra in double quantum wells of different shapes
Authors: Garbaczewski Piotr , Stephanovich Vladimir A , Engel Grzegorz 
Published: March 2022

Abstract
We suggest a method for calculating electronic spectra in ordered and disordered semiconductor structures (superlattices) forming double quantum wells (QWs). In our method, we represent the solution of Schrödinger equation for QW potential with the help of the solution of the corresponding diffusion equation. This is because the diffusion is the mechanism, which is primarily responsible for amorphization (disordering) of the QW structure, leading to so-called interface mixing. We show that the electron spectrum in such a structure depends on the shape of the QW, which, in turn, corresponds to an ordered or disordered structure. Namely, in a disordered substance, QW typically has smooth edges, while in ordered one it has an abrupt, rectangular shape. The present results are relevant for the heterostructures like GaAs/AlGaAs, GaN/AlGaN, HgCdTe/CdTe, ZnSe/ZnMnSe, Si/SiGe, etc, which may be used in high-end electronics, flexible electronics, spintronics, optoelectronics, and energy harvesting applications.
Proximal nitrogen reduces the fluorescence quantum yield of nitrogen-vacancy centres in diamond
Authors: Capelli Marco , Lindner Lukas , Luo Tingpeng , Jeske Jan , Abe Hiroshi , Onoda Shinobu , Ohshima Takeshi , Johnson Brett , Simpson David A , Stacey Alastair , Reineck Philipp , Gibson Brant C , Greentree Andrew D 
Published: March 2022

Abstract
The nitrogen-vacancy colour centre in diamond is emerging as one of the most important solid-state quantum systems. It has applications to fields including high-precision sensing, quantum computing, single photon communication, metrology, nanoscale magnetic imaging and biosensing. For all of these applications, a high quantum yield of emitted photons is desirable. However, diamond samples engineered to have high densities of nitrogen-vacancy centres show levels of brightness varying significantly within single batches, or even within the same sample. Here we show that nearby nitrogen impurities quench emission of nitrogen-vacancy centres via non-radiative transitions, resulting in a reduced fluorescence quantum yield. We monitored the emission properties of nitrogen-vacancy centre ensembles from synthetic diamond samples with different concentrations of nitrogen impurities. All samples were irradiated with high energy electrons to create high densities of nitrogen-vacancy centres relative to the concentration of nitrogen impurities. While at low nitrogen densities of 1.81 ppm we measured a lifetime of 13.9 ns, we observed a strong reduction in lifetime with increasing nitrogen density. We measure a lifetime as low as 4.4 ns at a nitrogen density of 380 ppm. The change in lifetime matches a reduction in relative fluorescence quantum yield from 77.4% to 32% with an increase in nitrogen density from 88 ppm to 380 ppm, respectively. These results will inform the conditions required to optimise the properties of diamond crystals devices based on the fluorescence of nitrogen-vacancy centres. Furthermore, this work provides insights into the origin of inhomogeneities observed in high-density nitrogen-vacancy ensembles within diamonds and nanodiamonds.
Purcell modification of Auger and interatomic Coulombic decay
Authors: Franz Janine , Buhmann Stefan Yoshi 
Published: March 2022

Abstract
An excited two-atom system can decay via different competing relaxation processes. If the excess energy is sufficiently high the system may not only relax via spontaneous emission but can also undergo interatomic Coulombic decay or even Auger decay. We provide analytical expressions for the rates by including them into the same quantum optical framework on the basis of macroscopic quantum electrodynamics. By comparing the rates in free space we derive the atomic properties determining which decay channel dominates the relaxation. We show that by modifying the excitation propagation of the respective process via macroscopic bodies, in the spirit of the Purcell effect, one can control the ratio between the two dominating decay rates. We can relate the magnitude of the effect to characteristic length scales of each process, analyse the impact of a simple close-by surface onto a general two-atom system in detail and discuss the effect of a cavity onto the decay rates. We finally apply our theory to the example of a doubly excited HeNe-dimer.
Cosmography with standard sirens from the Einstein Telescope
Authors: de Souza Josiel Mendonça Soares , Sturani Riccardo , Alcaniz Jailson 
Published: March 2022

Abstract
We discuss the power of third-generation gravitational wave
detectors to constrain cosmographic parameters
in the case of electromagnetically bright standard sirens focusing on the specific case of the Einstein Telescope.
We analyze the impact that the redshift source distribution, the number of detections
and the observational error in the luminosity distance have on the inference
of the first cosmographic parameters, and show
that with a few hundreds detections the Hubble constant
can be recovered at sub-percent level whereas the deceleration parameter at a few
percent level, both with negligible bias.
Enhancement of functional corticomuscular coupling after transcranial ultrasound stimulation in mice
Authors: Xie Ping , Hao Yingying , Chen Xiaoling , Jin Ziqiang , Cheng Shengcui , Li Xin , Liu Lanxiang , Yuan Yi , Li Xiaoli 
Published: March 2022

Abstract

Objective. Transcranial ultrasound stimulation (TUS), a large penetration depth and high spatial resolution technology, has developed rapidly in recent years. This study aimed to explore and evaluate the neuromodulation effects of TUS on mouse motor neural circuits under different parameters. Approach. Our study used functional corticomuscular coupling (FCMC) as an index to explore the modulation mechanism for movement control under different TUS parameters (intensity [

I

sppa

] and stimulation duration). We collected local field potential (LFP) and tail electromyographic (EMG) data under TUS in healthy mice and then introduced the time-frequency coherence method to analyze the FCMC before and after TUS in the time-frequency domain. After that, we defined the relative coherence area to quantify the coherence between LFP and EMG under TUS. Main results. The FCMC at theta, alpha, beta, and gamma bands was enhanced after TUS, and the neuromodulation efficacy mainly occurred in the lower frequency band (theta and alpha band). After TUS with different parameters, the FCMC in all selected frequency bands showed a tendency of increasing first and then decreasing. Further analysis showed that the maximum coupling value of theta band appeared from 0.2 to 0.4 s, and that the maximum coupling value in alpha and gamma band appeared from 0 to 0.2 s. Significance. The aforementioned results demonstrate that FCMC in the motor cortex could be modulated by TUS. We provide a theoretical basis for further exploring the modulation mechanism of TUS parameters and clinical application.
Monte Carlo studies of the Blume–Capel model on nonregular two- and three-dimensional lattices: phase diagrams, tricriticality, and critical exponents
Authors: Azhari Mouhcine , Yu Unjong 
Published: March 2022

Abstract
We perform Monte Carlo simulations, combining both the Wang–Landau and the Metropolis algorithms, to investigate the phase diagrams of the Blume–Capel model on different types of nonregular lattices (Lieb lattice (LL), decorated triangular lattice (DTL), and decorated simple cubic lattice (DSC)). The nonregular character of the lattices induces a double transition (reentrant behavior) in the region of the phase diagram at which the nature of the phase transition changes from first-order to second-order. A physical mechanism underlying this reentrance is proposed. The large-scale Monte Carlo simulations are performed with the finite-size scaling analysis to compute the critical exponents and the critical Binder cumulant for three different values of the anisotropy

Δ
/
J
∈

0
,
1
,
1.34

(
for

LL
)

,
1.51

(
for

DTL

and

DSC
)

, showing thus no deviation from the standard Ising universality class in two and three dimensions. We report also the location of the tricritical point to considerable precision: (Δ
t
/J = 1.3457(1); k
B
T

t
/J = 0.309(2)), (Δ
t
/J = 1.5766(1); k
B
T

t
/J = 0.481(2)), and (Δ
t
/J = 1.5933(1); k
B
T

t
/J = 0.569(4)) for LL, DTL, and DSC, respectively.
Average trapping time on a type of horizontally segmented three dimensional Sierpinski gasket network with two types of locally self-similar structures
Authors: Zhang Zhizhuo , Wu Bo 
Published: March 2022

Abstract
As a classic self-similar network model, Sierpinski gasket network has been used many times to study the characteristics of self-similar structure and its influence on the dynamic properties of the network. However, the network models studied in these problems only contain a single self-similar structure, which is inconsistent with the structural characteristics of the actual network models. In this paper, a type of horizontally segmented three dimensional Sierpinski gasket network is constructed, whose main feature is that it contains the locally self-similar structures of the two dimensional Sierpinski gasket network and the three dimensional Sierpinski gasket network at the same time, and the scale transformation between the two kinds of self-similar structures can be controlled by adjusting the crosscutting coefficient. The analytical expression of the average trapping time of a random walker by a particular site on the network model is solved, which used to analyze the effect of two types of self-similar structures on the properties of random walks. Finally, we conclude that the dominant self-similar structure will exert a greater influence on the random walk process on the network.
Indoor air quality research within a furniture factory
Authors: Corlan R V , Ionel I , Boatca M E , Draghici A , Balogh R M , Bisorca D 
Published: March 2022

Abstract
Improving conditions and quality of life depends, among others, on the environment. People spend most of their time in a day inside buildings to work, sleep, eat, rest, and do sports and other activities. The article refers to a case study based on research on indoor environment within a furniture factory; the research is achieved via instruments for collecting diverse indoor parameters, such as temperature, CO2, PM (particulate matter) concentrations, noise, and humidity levels. All data recorded are needed to evaluate the conditions of the indoor climate in which the workers are activating. The measuring methods are shortly introduced and the IAQ (indoor air quality) index is expressed. The personnel activating in this factory is working intensely, standing up, and having to wear a mask considering the Covid-19 context. Thus, it is important to depict each aspect that might trigger a concern if IAQ limits are over passed, not mentioning the synergetic context of the diverse effects. Through revealing the IAQ, and the comfort/discomfort level PMV/PPD (predicted mean vote and predicted percentage dissatisfied) employees and company management can benefit from this awareness and enhance the behaviour in such a way that one might improve the indoor condition. The rapid and irreversible climate changes, mostly due to increasing pollution level and exhaust of greenhouse gases should push humanity to make more studies of this kind and, accordingly, realize the need of improvement and development of new solutions whereby one can sustain the indoor environment as proper as possible, in addition to the outdoor climate.
Modal analysis methods usage possibilities during virtual tests of designing multimedia mobile stages
Authors: Kałaczyński T 
Published: March 2022

Abstract
The paper presents the problems related to technical state identification of the complex technical objects on the example of multimedia mobile stages. Designing modularly oriented complex stage objects is a challenge in terms of maintaining exploitations conditions as well as minimizing risk and increasing safety. The obtained results confirm identification of the state by means variable modal parameters describing the modal model. The possibility of implementing modal analysis presented in the paper made it possible to assessment state and behavior of mobile multimedia stage constructions modules. That allowed to validate the obtained results with the stages of proceeding in the research process.
A sub-picosecond digitally-controlled phase delay
Authors: Dehmeshki D. , Frahm E. , Rusack R. , Saradhy R. , Tousi Y. 
Published: March 2022

Abstract
The use of precision timing measurements will be a major tool at the HL-LHC, where it will be used to suppress pile-up and to search for long-lived particles. To control a reference clock with sub-picosecond accuracy, we have fabricated in the TSMC 65 nm process a digitally controlled phase shifter. It is composed of a chain of 66 cells, each with a digitally controlled planar wave guide with either a short or long delay. With this a reference clock’s phase can be controlled to a precision of 200 fs with dynamic range of 12 ps.
Atlantic multidecadal variability and the implications for North European precipitation
Authors: Börgel Florian , Meier H E Markus , Gröger Matthias , Rhein Monika , Dutheil Cyril , Kaiser Jan Moritz 
Published: March 2022

Abstract
The North Atlantic exhibits temperature variations on multidecadal time scales, summarized as the Atlantic multidecadal variability (AMV). The AMV plays an essential role for regional climate and is a key driver of the low-frequency variability in Northern Europe. This study analyzed the interaction between the atmosphere and the ocean using Coupled Model Intercomparison Project 6 (CMIP6) control runs. The results showed that the physical mechanisms underlying decadal or longer time scales differ among CMIP6 models, which allowed them to be sorted into two clusters. For the first cluster, a significant coherence between the North Atlantic Oscillation (NAO) and the AMV was found. Further, it showed a strong negative NAO response and decreasing precipitation over Northern Europe. In contrast, the second cluster showed no significant coherence between NAO and AMV. This non-coherent cluster developed a low-pressure anomaly in the subpolar gyre and showed increasing precipitation over Europe. Differences in the northward extension of the Atlantic meridional overturning circulation (AMOC) between the two clusters were identified and linked to the different atmospheric responses. Our findings have important implications for European climate, since predictions of an increase or decrease in precipitation over Northern Europe will be model-dependent.
Identification of Critical Nodes in Water Distribution Networks
Authors: Mosetlhe Thapelo C. , Hamam Yskandar , Shengzhi D , Monacelli Eric 
Published: March 2022

Abstract
In this work, the problem of the identification of critical nodes in water distribution networks (WDNs) is investigated. A scheme is then put forward to identify critical nodes in WDNs. Mathematical formulations for the scheme put forward are provided in this work. Results show that the application of the scheme yields consistent outputs when applied to the various WDNs test cases. Furthermore, critical nodes could be ranked in order of their criticality based on the sensitivity index.
Morphometric Analysis by Using Remote Sensing & QGIS Approach to Evaluate the Aquifer Response of Two Sub Watersheds of Coastal Kerala
Authors: Deepa Varghese G S , Chadaga Mohandas , Lathashri U A , Salim Surumi Rasia 
Published: March 2022

Abstract
Global increase in demand of water resources stepped up due to climate change and increase in population, stimulates an efficient development, management and conservation of water resources by quantifying the available water within the catchment to bridge the gap between its demand and availability. Initiated at a watershed scale, it is important to quantitatively evaluate the geomorphological parameters, since all the hydrologic and geomorphic processes may be accounted and balanced within a watershed. This study presents an excellent morphometric characterization of Payppara and Tikovil sub watersheds of Meenachil basin, in the state of Kerala, India, evaluated using SRTM DEM at 30m×30m spatial resolution as input to QGIS. The important linear morphometric aspects like stream order, length of stream segments, bifurcation ratio, Rho coefficient, the areal morphometric aspects like form factor, drainage density, stream frequency, elongation ratio, length of overland flow and relief aspects like ruggedness number, watershed relief were calculated for a comprehensive understanding of the geomorphic characteristics of the watershed. The general terrain of Tikovil was found to be steep but it was relatively mild for Payppara. The gravity flow paths traced by few 4th order, 3rd order and 2nd order stream segments of Payppara were identified as potential groundwater recharge zones. The derived morphometric characteristics benefits a better understanding of the formation of erosive and permeable surface flow paths in response to precipitation, the principal input to the hydrological budget.