bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionization and current sheet formation in inductive pulsed plasma thrusters
Authors: Little Justin M. , McCulloh Gordon I. , Marsh Cameron
Published: September 2022

Current sheet formation in inductive pulsed plasma thrusters (IPPTs) is investigated theoretically to determine how non-equilibrium ionization processes influence plasma impermeability to inductive electromagnetic fields and downstream propellant mass. Plasma impermeability to both electromagnetic fields and downstream mass is a prerequisite for efficient IPPT operation. A lumped-element circuit model of an IPPT plasma is modified to include propellant ionization and the electron energy balance under non-equilibrium conditions, neutral gas entrainment via charge exchange collisions, and electromagnetic coupling to a finite skin depth plasma. It is found that current sheets impermeable to both the accelerating fields and downstream mass—presumed to exist in all prior circuit modeling efforts—form only under specific conditions. The dynamics of electron heating during the early portion of the inductive current cycle are identified as the dominant contributors to current sheet formation. A new dimensionless scaling parameter is derived to characterize electron heating relative to inelastic ionization losses, from which it is found that impermeable current sheet formation requires Ohmic heating in the early formation phase to offset ionization losses associated with the entire propellant mass bit. This finding provides a physical explanation and generalization of the semi-empirical requirement on coil current rise rate that is commonly used in the early design phase of IPPTs to ensure current sheet formation.
A similarity scaling model for the axisymmetric turbulent jet based on first principles
Authors: Buchhave Preben , Velte Clara M.
Published: September 2022

Similarity scaling, when it can be justified, is a powerful tool for predicting properties of fluid flows and reducing the computational load when using mathematical models. Numerous publications describe different applications of this method, using often different scaling laws with one or more scaling parameters. The justification for these laws is often based on some assumptions or references to experimental results. In this paper, we base the scaling law on basic physical principles of classical Newtonian physics (Galilei group) and derive some predictions that we apply to a simple model for the axisymmetric turbulent jet. In a companion paper, we compare these predictions to careful measurements on a free jet in the laboratory and evaluate how far our model predictions are borne out by the experimental results. We have succeeded in obtaining such high-measurement quality that we can compute both second- and third-order statistical functions even far downstream and far-off axis. We can already here reveal that we find very good agreement between a simple one-parameter geometric scaling law derived from the model and numerous first-order and higher-order statistical results computed from the experimental data.
A straightforward optical alignment protocol for STM-based single molecule spectroscopy
Authors: Aiga Norihiro , Takeuchi Satoshi
Published: September 2022

A light-accessed scanning tunneling microscope (STM) is a powerful spectroscopic tool that enables chemical analysis at the single molecular level, but it requires highly precise optical alignments to pinpoint the nano-scale tunneling gap, leaving experimental challenges. Here we present straightforward procedures to align the optical setup for STM-luminescence and STM-based tip-enhanced Raman spectroscopy (TERS) performed with a reflection geometry in an ultrahigh vacuum chamber. Observing real-space images of the metal tip apex through a spectrograph set to the zeroth-order diffraction enables “in situ” optimization of the detection path and introduction of the excitation light of TERS to the nanogap. The best spatial overlap with the nanogap can be achieved by monitoring plasmon-enhanced, low-frequency inelastic scattering of the metal. This protocol allows us to overcome such difficulties in STM-based spectroscopy and facilitates physicochemical study of single adsorbates on nontransparent substrates.
Density functionals for core excitations
Authors: Park Young Choon , Perera Ajith , Bartlett Rodney J.
Published: September 2022

The core excitation energies and related principal ionization energies are obtained for selected molecules using several density functionals and compared with benchmark equation-of-motion coupled cluster (EOM-CC) results. Both time-dependent and time-independent formulations of excitation spectra in the time-dependent density functional theory and the EOM-CC are employed to obtain excited states that are not always easily accessible with the time-independent method. Among those functionals, we find that the QTP(00) functional, which is only parameterized to reproduce the five IPs of water, provides excellent core IPs and core excitation energies, consistently yielding better excitation and ionization energies. We show that orbital eigenvalues of KS density functional theory play an important role in determining the accuracy of the excitation and photoelectron spectra.
Spin and alignment effects in O2 chemisorption on Fe(110), Ni(111), and Co(0001) films grown on W(110)
Authors: Kurahashi Mitsunori
Published: September 2022

O2 has a spin triplet multiplicity in its ground state, while the effect of its electron spin on O2-surface interaction is not well understood. In this study, the spin and/or alignment effects in O2 chemisorption on surfaces of Fe(110), Ni(111), and Co(0001) films grown on W(110) have been investigated with the use of a single spin-rotational state-selected O2 beam. The results indicate that the spin effects for the Fe and Ni films are similar in that the initial sticking probability (S0) of O2 is higher when the spins of O2 and the film are antiparallel, and the spin dependence in S0, which amounts to 30%–40% at thermal energy, decays with increasing the O2 kinetic energy (E0). In the case of the Fe/O2 system, however, considerable spin dependence was found to remain even at E0 > 0.2 eV and on the oxidized surface. It has also been shown that the barrier for O2 chemisorption increases in the order of Fe(110) < Ni(111) < Co(0001), and the difference in the observed alignment effect among the samples can be understood based on the difference in the barrier.
VAMP4 regulates insulin levels by targeting secretory granules to lysosomes
Authors: Li Min , Feng Fengping , Feng Han , Hu Pengkai , Xue Yanhong , Xu Tao , Song Eli
Published: September 2022

Insulin levels are essential for the maintenance of glucose homeostasis, and deviations lead to pathoglycemia or diabetes. However, the metabolic mechanism controlling insulin quantity and quality is poorly understood. In pancreatic β cells, insulin homeostasis and release are tightly governed by insulin secretory granule (ISG) trafficking, but the required regulators and mechanisms are largely unknown. Here, we identified that VAMP4 controlled the insulin levels in response to glucose challenge. VAMP4 deficiency led to increased blood insulin levels and hyperresponsiveness to glucose. In β cells, VAMP4 is packaged into immature ISGs (iISGs) at trans-Golgi networks and subsequently resorted to clathrin-coated vesicles during granule maturation. VAMP4-positive iISGs and resorted vesicles then fuse with lysosomes facilitated by a SNARE complex consisting of VAMP4, STX7, STX8, and VTI1B, which ensures the breakdown of excess (pro)insulin and obsolete materials and thus maintenance of intracellular insulin homeostasis. Thus, VAMP4 is a key factor regulating the insulin levels and a potential target for the treatment of diabetes.
Origin of cytoplasmic GDP-fucose determines its contribution to glycosylation reactions
Authors: Sosicka Paulina , Ng Bobby G. , Pepi Lauren E. , Shajahan Asif , Wong Maurice , Scott David A. , Matsumoto Kenjiroo , Xia Zhi-Jie , Lebrilla Carlito B. , Haltiwanger Robert S. , Azadi Parastoo , Freeze Hudson H.
Published: September 2022

Biosynthesis of macromolecules requires precursors such as sugars or amino acids, originating from exogenous/dietary sources, reutilization/salvage of degraded molecules, or de novo synthesis. Since these sources are assumed to contribute to one homogenous pool, their individual contributions are often overlooked. Protein glycosylation uses monosaccharides from all the above sources to produce nucleotide sugars required to assemble hundreds of distinct glycans. Here, we demonstrate that cells identify the origin/heritage of the monosaccharide, fucose, for glycosylation. We measured the contribution of GDP-fucose from each of these sources for glycan synthesis and found that different fucosyltransferases, individual glycoproteins, and linkage-specific fucose residues identify and select different GDP-fucose pools dependent on their heritage. This supports the hypothesis that GDP-fucose exists in multiple, distinct pools, not as a single homogenous pool. The selection is tightly regulated since the overall pool size remains constant. We present novel perspectives on monosaccharide metabolism, which may have a general applicability.
Update of the BIPM comparison BIPM.RI(II)-K1.Sn-113 of activity measurements of the radionuclide 113Sn to include the 2017 result of the LNE-LNHB (France)
Authors: Michotte C , Courte S , Nonis M , Coulon R , Fréchou C , Lépy M-C
Published: September 2022

Main text

Since 1975, 7 laboratories have submitted 13 samples of 113Sn to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Sn-113. Recently, the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated to take account of the change of the 113Sn half-life value used for the SIR. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Notes on peculiarities of quantum fields in space–times with horizons
Authors: Bazarov K V
Published: September 2022

We consider a massive scalar field theory on static four-dimensional space–times with horizons. We study the near horizon behavior of the quantum expectation values of the stress–energy tensor (SET) operator for the thermal states with arbitrary temperatures. It turns out that the dependence of the expectation values on the temperature and tensor structure of the SET are different from the usual ones in the Minkowski space–time. Moreover, for non-canonical temperatures these expectation values are divergent on the horizons. We also show that the Wightman functions have additional infrared peculiarities near the horizons.
A method of performance enhancement for piezoresistive pressure sensors through diaphragm size design
Authors: Tang Xiaotian , Li Ting , Shang Haiping , Wan Xingxing , Wang Weibing
Published: September 2022

Sensitivity and nonlinearity are two of the most basic and important properties of microelectromechanical systems piezoresistive pressure sensors. In this paper, we proposed a simple method to enhance sensor performance by changing the diaphragm size, which can improve both sensitivity and linearity. To obtain close sensitivity for different diaphragms, we first fixed the ratio of the edge length to the thickness of the diaphragm. Then, the relationship between sensitivity, linearity, and diaphragm size was established by calculation, and the simulation was carried out using ANSYS. We found that both sensitivity and linearity increased with an increase in the diaphragm side length. In addition, we designed and fabricated two pressure sensors with square diaphragms in the range of 30 MPa. They have the same length-to-thickness ratio of 3.33, and the edge lengths of the diaphragms are 346 μm and 599 μm, respectively. The test results showed that the device with a larger edge length had higher sensitivity and lower nonlinearity, which is consistent with the conclusion above. Therefore, increasing the diaphragm size may be an easy and practical way to improve the performance of the pressure sensors.
Dipoles in blackbody radiation: momentum fluctuations, decoherence, and drag force
Authors: Sinha Kanu , Milonni Peter W
Published: September 2022

An expression is derived for the momentum diffusion constant due to photon scattering of a small polarizable particle in blackbody radiation, and is shown to be related to the long-wavelength collisional decoherence rate for such a particle in a thermal environment. We show how this diffusion constant appears in the steady-state photon emission rate of two dipoles induced by blackbody radiation. We consider in addition the Einstein–Hopf drag force on a small polarizable particle moving in a blackbody field, and derive its relativistic form from the Lorentz transformation of forces. We obtain an expression for the rate of change of the field energy density associated with changes in the particles’ kinetic energies and relate it to the Kompaneets equation for the case of Compton scattering by thermalized electrons.
All-optical spatio-temporal metrology for isolated attosecond pulses
Authors: He Lixin , Hu Jianchang , Sun Siqi , He Yanqing , Deng Yu , Lan Pengfei , Lu Peixiang
Published: September 2022

Characterizing an isolated attosecond pulse (IAP) is essential for its potential applications. A complete characterization of an IAP ultimately requires the determination of its electric field in both time and space domains. However, previous methods, like the widely-used RABBITT and attosecond streaking, only measure the temporal profile of the attosecond pulse. Here we demonstrate an all-optical method for the measurement of the space-time properties of an IAP. By introducing a non-collinear perturbing pulse to the driving field, the process of IAP generation is modified both spatially and temporally, manifesting as a spatial and a frequency modulation in the harmonic spectrum. By using a FROG-like retrieval method, the spatio-spectral phases of the harmonic spectrum are faithfully extracted from the induced spatio-spectral modulations, which allows a thorough characterization of the IAP in both time and space. With this method, the spatio-temporal structures of the IAP generated in a two-color driving field in both the near- and far-field are fully reconstructed, from which a weak spatio-temporal coupling in the IAP generation is revealed. Our approach overcomes the limitation in the temporal measurement in conventional in situ scheme, providing a reliable and holistic metrology for IAP characterization.
Tuning the interfacial Dzyaloshinskii–Moriya interaction in perpendicularly magnetized CoFeB system
Authors: Ravi Kumar B , Guddeti Sreekar , Anil Kumar P S
Published: September 2022

Magnetic field driven domain-wall motion in the creep regime is investigated with Kerr microscopy in out-of-plane magnetized as-deposited and annealed Ta/Pt/CoFeB/Pt multilayers. In addition to the effect of thermal annealing on the quasi-static magnetic properties of Ta (3 nm)/Pt (3 nm)/CoFeB (

t

C
o
F
e
B

nm)/Pt (2 nm) film stacks where

t

C
o
F
e
B

=
{
0.72
,
0.93
}

, the study focuses on the modified interfacial Dzyaloshinskii–Moriya interaction (iDMI) that governs the dynamics of chiral domain walls. The strength of the iDMI decreases with an increase in both

t

C
o
F
e
B

at a fixed annealing temperature and annealing temperature for a fixed

t

C
o
F
e
B

. While the former behaviour arises due to the interfacial nature of iDMI, the latter correlates with the annealing induced suppression of magnetization and enhancement of interface roughness that could be, respectively, ascribed to B-segregation and Co-Fe-Pt intermixing.
Manipulating the magnetic and transport properties by CuIr thickness in CoFeB/CuIr/IrMn multilayers
Authors: Öztürk Mustafa , Demirci Erdem
Published: September 2022

In this study, it was investigated how the magnetic and electrical properties of the exchange biased multilayers are affected by the Pt and CuIr spacer layer thicknesses. For this purpose, CoFeB/NM/IrMn sample stacks which can be used as magnetic field sensors based on the anisotropic magnetoresistance and planar Hall effect (PHE) were designed. The magnetic and electrical results showed an unexpected behavior to the variations in the spacer layer thickness when a CuIr spacer layer was used instead of a Pt spacer layer in terms of the properties of exchange bias, anisotropic magneto-resistance voltage and PHE voltage. This phenomenon is explained by the layer interdiffusion between CuIr and IrMn layers.
Vacuum barrier induced large spin polarization, giant magnetoresistance, and pure spin photocurrent in ferromagnetic zigzag graphene nanoribbons
Authors: Song Lingling , Liu Lu , Wei Canglong , Zhang Yan , Zhao Han , Ye Runlong , Zheng Xiaohong
Published: September 2022

Based on first-principle calculations combined with non-equilibrium Green’s function method, we investigate the spin-polarized transport properties of a two-probe device which consists of a vacuum barrier sandwiched between two semi-infinite ferromagnetic zigzag graphene nanoribbons (ZGNRs). It is well known that any vacuum barrier itself is not spin-polarized, and meanwhile, the infinite pristine ferromagnetic ZGNR presents no spin polarization in the transmission function around the Fermi level. However, our computational results indicate that robust large spin polarization is found in the proposed device. More interestingly, giant magnetoresistance up to

3.0
×

10
8

%

can be obtained at low bias voltage. Furthermore, the photogalvanic effect-induced fully spin-polarized photocurrent or pure spin photocurrent can be generated in such device by illumination with polarized light, depending on the symmetry of structure. Consequently, our results indicate that vacuum barrier may show interesting spin-polarized transport properties in certain systems and should be taken into consideration in the construction of molecular junctions and spintronic devices.
Energy transfer in hybrid 0D-CdSe quantum dot/2D-WSe2 near-infrared photodetectors
Authors: Meng Haotong , Zhang Fen , Mo Zhangxun , Xia Qinglin , Zhong Mianzeng , He Jun
Published: September 2022

Due to the energy transfer at the interface, the quantum dots (QDs) modification of two-dimensional (2D) materials is an effective and convenient way to improve their optoelectronic properties. In this work, we have studied the influence of the CdSe QDs on the physical properties of the 2D WSe2. After the modification of CdSe QDs, the energy transfer is observed in heterostructures which confirmed by the photoluminescence and Raman results. The WSe2/CdSe QDs heterostructure based phototransistors exhibit an ambipolar characteristic, owing to the typical type-Ⅱ band alignment. Under the illumination of 638 nm light, the performance of the device significantly improved compared with the WSe2 based device: the responsivity increased from 3.6 A W−1 to 9.27 A W−1; the detectivity increased from 7.73 × 109 Jones to 4.38 × 1010 Jones. Meanwhile, the devices exhibit good photoresponse in a wide spectral range from visible light to near-infrared light. Our work suggests that hybridizing 0D QDs and 2D material is a suitable and effective way to enhance the photodetection ability of the device and realize the ambipolar photodetection. It is a potential way to build multifunctional optoelectronic devices with broadband and high photoresponse performances.
Noncollinear magnetism in two-dimensional CrTe2
Authors: Abuawwad Nihad , dos Santos Dias Manuel , Abusara Hazem , Lounis Samir
Published: September 2022

The discovery of two-dimensional (2D) van der Waals magnets opened unprecedented opportunities for the fundamental exploration of magnetism in quantum materials and the realization of next generation spintronic devices. Here, based on a multiscale modelling approach that combines first-principles calculations and a Heisenberg model supplied with ab-initio parameters, we report a strong magnetoelastic coupling in a free-standing monolayer of CrTe2. We demonstrate that different crystal structures of a single CrTe2 give rise to non-collinear magnetism through magnetic frustration and emergence of the Dzyaloshinskii–Moriya interaction. Utilizing atomistic spin dynamics, we perform a detailed investigation of the complex magnetic properties pertaining to this 2D material impacted by the presence of various types of structural distortions akin to charge density waves.
Influence of particle wettability on foam formation in honey
Authors: Tyowua Andrew T , Echendu Adebukola M , Adejo Sylvester O , Binks Bernard P
Published: September 2022

The rising level of obesity is often attributed to high sugar and/or fat consumption. Therefore, the food industry is constantly searching for ways to reduce or eliminate sugar or fat in food products. Therefore, honey foam, which contains little sugar and no fat, can be used as cake, cracker or bread spread instead of butter or margarine which contains a substantial amount of fat or jam that contains a substantial amount of sugar. Small solid particles (nanometers to micrometers) of suitable wettability are now considered outstanding foam-stabilizing agents. However, while the degree of particle wettability necessary to obtain very stable aqueous and nonaqueous foams is well-known, that needed to obtain very stable honey foam is unknown. In this study, the influence of the degree of wettability of fumed silica particles, indicated by their % SiOH (14–100), was investigated in honey in relation to foam formation and foam stability. The honephilic particles (61%–100% SiOH) formed particle dispersion in honey, while foams were obtained with the honephobic particles (14%–50% SiOH). The thread-off between particle dispersion and foam formation occurs at 50% SiOH, meaning foam formation in honey is possible when the particles are at least 50% honephobic. At relatively low particle concentration <1 wt.%, foam volume decreases with increasing honephobicity, but increases with honephobicity at relatively high concentration >1 wt.%. Also, as particle concentration increases, the shape of the air bubbles in the foam changes from spherical to non-spherical. After a little drainage, the foams remain stable to drainage and did not coalesce substantially for more than six months. These findings will guide the formulation of edible Pickering honey foams.
The quantum dynamics of two-component Bose–Einstein condensate: an

Sp(4,R)

symmetry approach
Authors: Wang Chang-Yan , He Yan
Published: September 2022

The compact groups such as SU(n) and SO(n) groups have been heavily studied and applied in the study of quantum many body systems. However, the non-compact groups such as the real symplectic groups are less touched. In this paper, it is revealed that the quantum dynamics of two-component Bose–Einstein condensate can be described by a non-compact real symplectic group

S
p
(
4
,
R
)

. With this group, an explicit form of the wavefunction in any time of the evolution can be given, meanwhile, this whole time evolution can be shown to correspond to a trajectory in a six-dimensional manifold. By introducing a polar coordinate, we can visualize this six-dimensional manifold in 2d unit disk and reveal the relation between the behavior of the trajectory in this manifold and the eigenenergies of the Hamiltonian. Furthermore, the time evolution of expectation value of a physical observable such as number operator is proven closely related to the behavior of the trajectory in this manifold.
Utilization of focused ultrasound for opening of the blood-nerve barrier
Authors: Umansky Daniel , Bing Chenchen , Chu Tak Ho , Alzahrani Saud , Dunn Jeff F. , Pichardo Samuel , Midha Rajiv
Published: September 2022

Objective. Focused ultrasound (FUS) use with and without microbubbles (MB) for investigation of the blood-nerve barrier (BNB) within the peripheral nervous system (PNS) has been performed in this study. We evaluate the feasibility of BNB opening in a rodent sciatic nerve model by direct vision FUS treatment and provide preliminary results of magnetic resonance guided FUS (MRgFUS). Approach. Twenty rodent bilateral sciatic nerves were investigated. Rodents were treated using a benchtop FUS system to directly visualize nerve FUS studies. Definity MB, Evans blue dye (EB) and latex micro beads were injected during studies. Selected animals underwent further compound muscle action potential (CMAP) studies. Sonication peak pressure (MPa), width, duty-cycle and duration as well as MB concentration were varied to investigate effective pressure threshold. Further preliminary MRgFUS studies were performed on selected animals. Immunohistochemistry and histological analysis under florescent microscopy were performed at termination of experiments to verify treatment outcomes. Main results. Three ultrasound pressures and three microbubble concentrations at a single sonication frequency (476.5 kHz) were performed under direct open targeting. Histological analysis demonstrated nerve internal architecture disruption at 1.2 MPa with 166.7 μl kg−1 while 0.3 MPa, with 40 μl kg−1 MB concentration was the lower threshold for consistently observed disruption of the BNB without anatomical microarchitecture disruption. EB leakage was confirmed at the target region in histological evaluation of nerve following MB injection and FUS sonication. Supra-harmonic emissions were detected during FUS exposures following MB injection but not at baseline reference, indicating effective MB response and stable cavitation. CMAP amplitudes showed delayed onset latency and lower amplitudes in sonicated nerves compared to control nerves without evidence of complete conduction block, suggesting a transient BNB disruption, while at lower limit pressure subtle conduction changes were observed. In MRgFUS, targeted nerves demonstrated further contrast agent leak as well as supra-harmonic frequency detection. Significance. Opening of the BNB in the PNS was achieved using FUS and MB in a rodent model. Ongoing work aims to refine FUS parameters for drug delivery into the nerve after experimental transient BNB disruption.
Development of a deep learning network for Alzheimer’s disease classification with evaluation of imaging modality and longitudinal data
Authors: Deatsch Alison , Perovnik Matej , Namías Mauro , Trošt Maja , Jeraj Robert
Published: September 2022

Objective. Neuroimaging uncovers important information about disease in the brain. Yet in Alzheimer’s disease (AD), there remains a clear clinical need for reliable tools to extract diagnoses from neuroimages. Significant work has been done to develop deep learning (DL) networks using neuroimaging for AD diagnosis. However, no particular model has emerged as optimal. Due to a lack of direct comparisons and evaluations on independent data, there is no consensus on which modality is best for diagnostic models or whether longitudinal information enhances performance. The purpose of this work was (1) to develop a generalizable DL model to distinguish neuroimaging scans of AD patients from controls and (2) to evaluate the influence of imaging modality and longitudinal data on performance. Approach. We trained a 2-class convolutional neural network (CNN) with and without a cascaded recurrent neural network (RNN). We used datasets of 772 (N
AD = 364, N
control = 408) 3D 18F-FDG PET scans and 780 (N
AD = 280, N
control = 500) T1-weighted volumetric-3D MR images (containing 131 and 144 patients with multiple timepoints) from the Alzheimer’s Disease Neuroimaging Initiative, plus an independent set of 104 (N
AD = 63, N
NC = 41) 18F-FDG PET scans (one per patient) for validation. Main Results. ROC analysis showed that PET-trained models outperformed MRI-trained, achieving maximum AUC with the CNN + RNN model of 0.93 ± 0.08, with accuracy 82.5 ± 8.9%. Adding longitudinal information offered significant improvement to performance on 18F-FDG PET, but not on T1-MRI. CNN model validation with an independent 18F-FDG PET dataset achieved AUC of 0.99. Layer-wise relevance propagation heatmaps added CNN interpretability. Significance. The development of a high-performing tool for AD diagnosis, with the direct evaluation of key influences, reveals the advantage of using 18F-FDG PET and longitudinal data over MRI and single timepoint analysis. This has significant implications for the potential of neuroimaging for future research on AD diagnosis and clinical management of suspected AD patients.
Investigation on performance degradation due to induced interface trapped charges on HSO based FDSOI NCFET and sustaining it through back-gate bias
Authors: Shaik Rameez Raja , Pradhan K P
Published: September 2022

In this article, a variant of doped HfO2 based ferroelectric capacitor i.e. silicon doped HfO2 (hafnia-silica/HSO) is investigated for analytical feasibility and viability for negative capacitance FET (NCFET) applications. Investigations are carried out extensively using well calibrated and validated numerical simulations to find out the optimum ferroelectric thickness (tf) of HSO thin-film for the NCFET to operate in hysteresis-free regime. The optimized NCFET is then subjected to the variation of back-gate bias (V

B

) to exploit threshold-voltage (

V

T
H

) shift phenomena might further improve NCFET performance. In continuance, the optimized NCFET has been introduced with interface trap (+Nit) charges at the oxide–semiconductor interface to emphasize on the reliability deflation caused at process level design. Hence, this has allowed us to concisely observe and analyse performance degradation aspect of the NCFET with numerical simulations. Also, a feasibility to recuperate the degraded performance caused by +Nit with utilizing −V

B

is carried out. The performance metrics used in the numerical simulation for the evaluation of HSO ferroelectric NCFET are: sub-threshold slope, charge variation with gate-voltage and ferro voltage, surface potential,

V

T
H

, drain-current and amplification factor.
A DFT study of gas molecules adsorption on intrinsic and Cu-doped graphene gas nanosensors
Authors: Tohidi T , Sattarian H , Tohidi S
Published: September 2022

In this study, first-principles calculations are performed to investigate the sensitivity of intrinsic graphene sheet (GS) and Cu-doped graphene sheet (Cu-GS) gas nanosensors for adsorbing CO, H2, and H2S gas molecules using QUANTUM ESPRESSO package. The density of states (DOS), net charge transfer, adsorption energy, partial density of states (PDOS), and the most stable adsorption configuration of these molecules on GS and Cu-GS are studied. The results show the weak physical adsorption of the three gas molecules on GS. The strength of interaction between the Cu-GS system and adsorbed gas molecules is higher due to the Cu doping. It is expected that the significant increase in charge transfer and adsorption energy leads to fundamental improvement in the electrical conductivity of the Cu-GS system. The results indicate that the introduction of Cu impurity can improve the gas sensing properties of graphene-based gas nanosensors. Therefore, Cu-GS is more appropriate for detecting gas molecules compared to pure GS. The results in this study are useful for developing the design of gas nanosensors.
Probing modified gravity with integrated Sachs-Wolfe CMB and galaxy cross-correlations
Authors: Kable Joshua A. , Benevento Giampaolo , Frusciante Noemi , De Felice Antonio , Tsujikawa Shinji
Published: September 2022

We use the cross-correlation power spectrum of the integrated Sachs-Wolfe (ISW) effect in
the cosmic microwave background (CMB) temperature anisotropy and galaxy fluctuations to probe the
physics of late-time cosmic acceleration. For this purpose, we focus on three models of dark
energy that belong to a sub-class of Horndeski theories with the speed of gravity equivalent to
that of light: Galileon Ghost Condensate (GGC), Generalized Cubic Covariant Galileon (GCCG), and
K-mouflage. In the GGC and GCCG models, the existence of cubic-order scalar self-interactions
allows a possibility for realizing negative ISW-galaxy cross-correlations, while the K-mouflage
model predicts a positive correlation similar to the Λ-cold-dark-matter (ΛCDM)
model. In our analysis, we fix the parameters of each model to their best-fit values derived from
a baseline likelihood analysis with observational data from CMB, baryon acoustic oscillations, and
supernovae type Ia. Then we fit those best-fit models to the ISW-galaxy cross-correlation power
spectrum extracted from a collection of photometric redshift surveys. We find that both GGC and
GCCG best-fit models degrade the fit to the ISW-galaxy cross-correlation data compared to
ΛCDM best-fit model. This is attributed to the fact that, for their best-fit values
constrained from the baseline likelihood, the cubic-order scalar self-interaction gives rise to
suppressed ISW tails relative to ΛCDM. The K-mouflage best-fit model is largely degenerate
with the ΛCDM best-fit model and has a positively correlated ISW-galaxy power close to
that of ΛCDM.
A general study of decaying scalar dark matter: existing limits and projected radio signals at the SKA
Authors: Dutta Koushik , Ghosh Avirup , Kar Arpan , Mukhopadhyaya Biswarup
Published: September 2022

We consider a decaying scalar dark matter (DM) with mass m
χ 
in the range 10 GeV – 10 TeV and vary the branching ratios of all
possible two-body SM final states (excluding and including νν̅) 
in the range 0%-100% to derive constraints on the total
decay width Γ using the data collected by several
astrophysical and cosmological observations. We find that,
Γ ≲ 10-26 - 10-27 s-1 (excluding νν̅) 
and Γ ≲ 10-24 - 10-26 s-1 (including νν̅) 
are allowed, depending on the values of m
χ, which are most
robust upper limits on Γ for a generic decaying scalar DM.
We then investigate the prospect of the upcoming Square Kilometre
Array (SKA) radio telescope in detecting the DM decay induced radio
signals originating inside the dwarf spheroidal (dSph) galaxies.
We have classified the DM parameter space, allowed by the existing
observations, independently of the branching ratio of each individual
two-body SM final state, based on the detectability at the SKA.
Excluding the νν̅ decay mode, we find that, throughout
the DM mass range considered,
Γ ≳ 10-30 s-1 - 10-29 s-1 
is detectable for all possible branching ratio combinations
at the SKA (assuming 100 hours of observation time), with conservative
choices for the relevant astrophysical parameters.
On the other hand, when arbitrary branching ratios are allowed
also for the νν̅ decay mode, DM decays can be probed
independently of the branching ratio of each SM final state
for Γ ≳ 2 × 10-29 s-1,
provided DM masses are greater than a few hundreds of GeV.
A review on generative based methods for MRI reconstruction
Authors: Zhao Xiang , Yang Tiejun , Li Bingjie
Published: September 2022

Magnetic resonance imaging (MRI) is one of the most important methods for clinical diagnosis. However, the main drawback of MRI is the long imaging time, which will cause the moving artifact by patient movements. With the rapid development of the computing power of computer, deep learning is widely used in computer vision, natural language processing, visual recognition and so on. Meanwhile, a large number of reconstruction methods based on deep learning have also emerged. Recently, many generative models have been proposed to solve the perception quality problem that existed in fast MRI images. In this paper, we manage to survey the motivations and reconstruction strategies of generative-based methods published in journals and conferences over the past five years. First, the background and theoretical basis of MRI reconstruction are introduced. Secondly, the application of generative-based methods in MRI reconstruction field is comprehensively summarized and analyzed, including Generative Adversarial Network (GAN), Variational Autoencoder (VAE) and VAE-GAN. Then the advantages and disadvantages of the existing generative-based MRI reconstruction methods are discussed. Finally, several publicly available MR image datasets and evaluation metrics are presented, which can provide a reference for researchers and practitioners working in related domains. The conclusions and challenges are also given.
Real-time adaptive deviation assessment and synchronized Compensation in driving phase alternation scenario
Authors: Dai Mian , Zhang Guoyu , Zhao Shuai , Zhao Pengchao
Published: September 2022

The real-time synchronized compensation based on adaptive deviation evaluation is proposed as a solution to driving phase alternation scenarios, especially in departure and brake to stop period. It provides a protected control logic to ADAS (Advanced Driving Assist System) or an autonomous driving system equipped vehicle with radar sensors and DGPS (Differential Global Position System) device of non-uniform sampling rate and data quality. It is expected to avoid error computation of movement in time series such as turning angle and velocity. The comprehensive test cases of 350 driving phases in proving ground are designed for effectiveness evaluation of the synchronization correction. The result shows the method could detect and overcome the crucial imprecise signal calculation with coverage ratio of 90.2% and 78.4% in start and stopping deviation scenario so as to enhance the automatic driving function performance.
Secure data transmission between self-driving cars and cloud services through AIngle, a novel semantic distributed-ledger technology
Authors: Zhang Zhexiong , Tijerino Yuri
Published: September 2022

The realization of fully autonomous vehicles in great scale is already in sight. However, to be safe and reliable, autonomous driving requires a significant amount of communication with cloud services, which are prone to many kinds of failures and malicious attacks. This paper introduces the use of AIngle, a novel distributed-ledger technology developed to guarantee real-time encrypted communication among IoT devices. Not only AIngle tackles various kinds of malicious attacks by design, such as Sybil attacks, but it also enables semantic distributed applications (Sem D Apps). Sem D Apps decentralize supporting driving services, such as traffic and route mapping, which are typically centralized in cloud services. AIngle provides a new paradigm for Sem D Apps, that will support future-proofed, fast, reliable, intelligent distributed applications for the autonomous vehicle industry.
Research on motion distortion optimization algorithm of laser SLAM
Authors: Wu HongWei , Zhu Liucun , Cheng Jingdi , Deng Haofeng , Chen Mingyou , Dong Lutong
Published: September 2022

Aiming at the problems of inaccurate laser point cloud matching, large reference pose error and insufficient utilization of sensor observation data during 2D laser SLAM positioning and mapping, which lead to the motion distortion of lidar, a piecewise linear interpolation based method is proposed. Fusion of radar motion distortion optimization strategy and PL-ICP algorithm. The optimization algorithm first uses the piecewise linear interpolation method to fuse the data of the wheel odometer and the lidar, solve the robot pose corresponding to each laser point in the current frame of laser data, then convert all the laser points to the same coordinate system according to the solved pose, and finally the laser data scan matching is performed by the PL-ICP algorithm. In the experiment, the ICP and PL-ICP algorithms were compared for the radar data, and the SLAM algorithm equipped with the motion distortion optimization module was used for localization and mapping. The experimental results show that the motion distortion optimization algorithm effectively removes the motion distortion of low-precision lidar and improves the accuracy of mobile robot positioning and mapping.
Research on navigation and control method for inspection robot in smart substation
Authors: Wang Lei , Yuan LuHai , Zhang Xin
Published: September 2022

For the line-tracking robot navigation system used in smart substation now, combined with the camera monitoring system installed in substations, the method of inspection robot navigation based on wireless sensor network and the control of the robot under this navigation system are studied, which can improve the robot's mobility, coordination and the ability to quickly adapt to dynamic changes in the environment, enabling the robot to complete its tasks excellently.
Map-based registration of multi-LiDAR infrastructure sensor setups for real-time applications
Authors: Kloeker Amarin , Kloeker Laurent , Baumanns Tim , Eckstein Lutz
Published: September 2022

The use of infrastructure sensors has proven to be an effective method for recording large traffic datasets. In order to achieve a high data quality for such datasets, an accurate extrinsic calibration of the sensors is essential. While previous approaches are not fast enough or do not fit the use-case of infrastructure sensing, we present a method that is capable of registering LiDAR sensors to a digital map in real-time. We use a mobile infrastructure sensor setup consisting of two measurement units, which we position at different locations with real road traffic. Each measurement unit is equipped with two LiDARs at a mounting height of eight meters. Experiments have shown that our method can perform continuous registration of up to four 128-layer LiDARs. With a voxel size of 0.05 meters used, our method achieves a root-mean-square error (RMSE) of 0.13 meters at an average processing time of 0.05 seconds per frame.
Sentiment analysis based on CNN - LSTM hotel reviews
Authors: Yao Lisha
Published: September 2022

In order to obtain the implied semantic information of hotel reviews for emotional analysis, the correlation between discontinuous words is ignored in the traditional convolutional neural network (CNN) emotional analysis. Therefore, a novel sentiment analysis method based on CNN - LSTM model is proposed. In this method, CNN is used to extract semantic features from hotel review texts, and LSTM is used to add sentence structure features to enhance deep semantic learning. This model improves the accuracy and F1 value on the CHN senticorp-HTOL-BA-6000 hotel review data set, and can better solve the task of text sentiment analysis and discover the emotional orientation of text information.
Research on signal control method of deep reinforcement learning based on value distribution
Authors: Li Jianming , Chen Ting , Zhou Fengming , Lv Xiaolei , Peng Feng
Published: September 2022

In the traditional DQN (Deep Q network)-based signalized intersection control strategy, this research introduces an improved Distributional DQN to establish signal optimization decision-making model utilizing reinforcement learning based on value distribution. Different from the DQN model based on expected values, proposed model makes full use of the intersection environment information in each phase action for the distribution of the future total return. At the same time, proposed model constructs an optimization through minimizing the KL divergence between the estimated distribution and the true distribution, which makes it easier minimize the loss and accelerate the convergence speed of the model. In addition, a fixed boundary is reasonably added to the discrete distribution of the reward of the phase action, which effectively suppresses the traffic flow. The reward shock caused by large randomness reduces the instability of the algorithm. The simulation results demonstrate that the Distributional DQN proposed in this paper has a faster convergence rate than the original DQN, and the cumulative delay at the intersection is reduced by about 13.1%, and the average driving speed is increased by 7.1%, which further improves the control efficiency of signalized intersections.
Enhanced superconductivity with interlayer spacing dependent T
c in intercalated Weyl semimetal MoTe2
Authors: Zhang Haoxiong , Rousuli Awabaikeli , Zhang Kenan , Zhong Haoyuan , Wu Yang , Yu Pu , Zhou Shuyun
Published: September 2022

Manipulating the strength of the interlayer coupling is an effective strategy to induce intriguing properties in layered materials. Recently, enhanced superconductivity has been reported in Weyl semimetal MoTe2 and WTe2 via ionic liquid (IL) cation intercalation. However, how the superconductivity enhancement depends on the interlayer interaction still remains elusive. Here by inserting IL cations with different sizes into MoTe2 through this strategy, we are able to tune the interlayer spacing of the intercalated MoTe2 samples and reveal the dependence of superconducting transition temperature T
c on the interlayer spacing. Our results show that T
c increases with the interlayer spacing, suggesting that the weakened interlayer coupling plays an important role in the superconductivity. Interestingly, the intercalation induced superconductivity shows a high Ginzburg–Landau anisotropy, which suggests a quasi-two-dimensional nature of the superconductivity where the adjacent superconducting layers are coupled through Josephson tunnelling.
Preparation and investigations of PEG-AT-PEG organic nano-polymer photothermal material
Authors: Chen Haibo , He Xingli , Yang Xiaolong , Li Peng , Wu Weibing
Published: September 2022

Conjugated polymer (CPs) has good near infrared (NIR) absorption and high photothermal conversion effect, which is one of the most promising photothermal therapy (PTT) drugs for cancer therapy. Through the combination of hydrophobic conjugate component of aniline trimer (AT) and hydrophilic component of aldehyde polyethylene glycol (PEG-CHO), linear polymer (PEG-AT-PEG) is synthesized via Schiff base reaction. Self-assembly nanoparticles simply precipitated out by dropping the tetrahydrofuran solution of PEG-AT-PEG into deionized water under ultrasonic dispersion. Owing to the rigid hydrophobic conjugated structure in the middle and the hydrophilic long chain structure at both ends, the long chain material can undergo hydrophobic association and π–π stacking in deionized water to form spherical organic nanoparticle. Such self-assembly nanoparticles have strong NIR absorption at 700 ∼ 800 nm, and can significantly increase the temperature in a short time upon continuous 808 nm laser irradiation, showing good photothermal conversion efficiency. The nanoparticles of PEG-AT-PEG show good biocompatibility to Hela cells at low concentration, when exposed to laser light, the destruction of Hela tumor cells was very distinct in the concentration range of 200 to 800 ug ml−1. Synthetic strategy based on CPs will be possible to develop more effective nanomaterials for treating cancer or tumors.