bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman spectroscopy study of the slow order–order transformation of deuterium atoms: Ice XIX decay and ice XV formation
Authors: Thoeny Alexander V. , Parrichini Iside S. , Gasser Tobias M. , Loerting Thomas 
Published: March 2022

The nature of the hydrogen substructure of a deuterated and deuterium chloride (DCI)-doped ice VI sample after cooling at 1.8 GPa has been a topic of recent interest—especially because the novel ice polymorph ice XIX was discovered in the course of such studies. We here investigate deuterated samples containing 5% H2O using Raman spectroscopy to probe for transitions associated with rearrangement of D-atoms in ice XIX. The protocol involving heating at subambient pressure (10 mbar) in this study follows closely the one used in our earlier neutron diffraction study. Heating of ice XIX induces a complex cascade of processes involving both ordering and disordering of D atoms. Our Raman spectra demonstrate that the transition sequence is ice XIX → ice VI‡ → ice XV, in accordance with our earlier neutron diffraction result. First signs for ice XIX decay are evident at 100 K, while ice XV build-up is seen only at 108 K and above. Between 100 and 108 K, a transiently disordered D-substructure appears, where at 108 K, ice VI‡ forms from ice XIX and simultaneously decays to produce ice XV—thereby establishing a dynamic equilibrium. Using isothermal, time-resolved Raman spectroscopy in real time, we here determine rate constants, Avrami exponents, and activation energies for both slow processes, ice XIX decay and ice XV build-up. The first transition in this sequence, ice XIX decay, is faster than the second transition, ice XV build-up, so that ice VI‡ accumulates. On the basis of the Johnson–Mehl–Avrami–Kolmogorov data obtained from the isothermal Raman experiment, we additionally report kinetic models for the development of fractions of ices XIX, XV, and VI‡ in non-isothermal heating experiments at different heating rates. These models consider the two coupled first-order transitions as separated processes, where the phase fractions are calculated for incrementally small temperature (or time) steps. These models compare favorably with our previous observations for slowly or rapidly heated ice XIX samples, such as in calorimetry or neutron diffraction experiments.
Sensitivity ofVHLmutant kidney cancers to HIF2 inhibitors does not require an intact p53 pathway
Authors: Stransky Laura A. , Vigeant Sean M. , Huang Bofu , West Destiny , Denize Thomas , Walton Emily , Signoretti Sabina , Kaelin William G. 
Published: March 2022

SignificanceVHLtumor suppressor gene inactivation is a hallmark of clear cell renal cell carcinoma (ccRCC), the most common form of kidney cancer, and promotes tumor growth by stabilizing the hypoxia-inducible factor 2 (HIF2) transcription factor. HIF2 inhibitors appear to be helpful for some, but not all, ccRCC patients in clinical trials. Previous preclinical and clinical data suggested that only ccRCCs that can activate the p53 tumor suppressor in response to DNA damage would respond to HIF2 inhibitors. Here, we show that an intact p53 pathway is neither necessary nor sufficient for the sensitivity of ccRCCs to HIF2 inhibitors, suggesting that it would be premature to use p53 status to determine which ccRCC patients should be treated with a HIF2 inhibitor.
Uncovering the crystal defects within aragonite CaCO
3
Authors: San Xingyuan , Gong Mingyu , Wang Jian , Ma Xiuliang , dos Reis Roberto , Smeets Paul J. M. , Dravid Vinayak P. , Hu Xiaobing 
Published: March 2022

Significance
Nacre exhibits outstanding mechanical performance, which results from coordinated deformation mechanisms synergistically working in characteristic microstructures at multiple length scales. A comprehensive understanding of crystal defects within aragonite is critical for discussing the deformation behavior of nacre on microstructure at the nanoscale through atomic scale. By integrating aberration-corrected transmission electron microscopy, crystallographic analysis, and theoretical calculations, we reveal various crystal defects within aragonite at atomic scale and discuss their potential effects on deformation. Our work will serve as cornerstones for modeling analysis and in-depth discussions on nanoscale deformation mechanisms within nacre. Additionally, these atomic-scale insights will benefit theoretical evaluation of the environmental effect on defect formation, enabling defect control in synthetic aragonite and designing of stronger and tougher bioengineering materials.
The Wald–Zoupas prescription for asymptotic charges at null infinity in general relativity
Authors: Grant Alexander M , Prabhu Kartik , Shehzad Ibrahim 
Published: March 2022

Abstract
We use the formalism developed by Wald and Zoupas to derive explicit covariant expressions for the charges and fluxes associated with the Bondi–Metzner–Sachs symmetries at null infinity in asymptotically flat spacetimes in vacuum general relativity. Our expressions hold in non-stationary regions of null infinity, are local and covariant, conformally-invariant, and are independent of the choice of foliation of null infinity and of the chosen extension of the symmetries away from null infinity. While similar expressions have appeared previously in the literature in Bondi–Sachs coordinates (to which we compare our own), such a choice of coordinates obscures these properties. Our covariant expressions can be used to obtain charge formulae in any choice of coordinates at null infinity. We also include detailed comparisons with other expressions for the charges and fluxes that have appeared in the literature: the Ashtekar–Streubel flux formula, the Komar formulae, and the linkage and twistor charge formulae. Such comparisons are easier to perform using our explicit expressions, instead of those which appear in the original work by Wald and Zoupas.
Influence of crystal structure and oxygen vacancies on optical properties of nanostructured multi-stoichiometric tungsten suboxides
Authors: Višić Bojana , Pirker Luka , Opačić Marko , Milosavljević Ana , Lazarević Nenad , Majaron Boris , Remškar Maja 
Published: March 2022

Abstract
Four distinct tungsten suboxide (WO3–x
) nanomaterials were synthesized via chemical vapour transport reaction and the role of their crystal structures on the optical properties was studied. These materials grow either as thin, quasi-2D crystals with the W
n
O3n-1 formula (in shape of platelets or nanotiles), or as nanowires (W5O14, W18O49). For the quasi-2D materials, the appearance of defect states gives rise to two indirect absorption edges. One is assigned to the regular bandgap occurring between the valence and the conduction band, while the second is a defect-induced band. While the bandgap values of platelets and nanotiles are in the upper range of the reported values for the suboxides, the nanowires’ bandgaps are lower due to the higher number of free charge carriers. Both types of nanowires sustain localized surface plasmon resonances, as evidenced from the extinction measurements, whereas the quasi-2D materials exhibit excitonic transitions. All four materials have photoluminescence emission peaks in the UV region. The interplay of the crystal structure, oxygen vacancies and shape can result in changes in optical behaviour, and the understanding of these effects could enable intentional tuning of selected properties.
Long-wavelength InAs/GaSb superlattice double heterojunction infrared detectors using InPSb/InAs superlattice hole barrier
Authors: Liu Jiafeng , Zhu He , Zhu Hong , Li Meng , Huai Yunlong , Liu Zhen , Huang Yong 
Published: March 2022

Abstract
We demonstrate two double heterojunction long-wavelength infrared detectors based on InAs/GaSb superlattice on InAs substrates grown by metal-organic chemical vapor deposition. In the two structures, the hole barrier employs a novel InPSb/InAs superlattice to achieve conduction-band alignment, while the electron barrier is InAs/GaSb superlattice to achieve valence-band alignment. Two devices with n-type absorber layer and p-type absorber layer exhibit cut-off wavelengths of ∼10.4 μm and ∼12.2 μm, dark current densities of 9 × 10−4 A cm−2 and 2 × 10−2 A cm−2, and specific detectivities of ∼1.7 × 1010 cm Hz1/2 W−1 and ∼1.5 × 1010 cm Hz1/2 W−1, respectively. The device with n-type absorber has a lower dark current due to the natural valence-band alignment, but it has a low quantum efficiency (QE) resulting from the use of n-type absorber layer. In contrast, the device with p-type absorber has a higher dark current that can be possibly attributed to the conduction-band misalignment, but it achieves a higher QE due to the benefits from the p-type absorber.
Investigation of ambient temperature and thermal contact resistance induced self-heating effects in nanosheet FET
Authors: Rathore Sunil , Jaisawal Rajeewa Kumar , Suryavanshi Preeti , Kondekar Pravin N 
Published: March 2022

Abstract
Self-heating effect (SHE) is a severe issue in advanced nano-scaled devices such as stacked nanosheet field-effect transistors (NS-FET), which raises the device temperature (T
D), that ultimately affects the key electrical characteristics, i.e. threshold voltage (V
T), DIBL, subthreshold slope (SS), I
OFF, I
ON, etc. SHE puts design constraints in the advanced CMOS logic devices and circuits. In this paper, we thoroughly investigated the impact of ambient temperature and interface thermal contact resistance induced-self heating effect in the NS-FET using extensive numerical simulations. The weak electron–phonon coupling, phonon scattering, and the ambient temperature-induced joule energy directly coupled with thermal contact resistance cause the SHE-induced thermal degradation, which increases the device temperature (T
D) and affects the device reliability. The baseline NS-FET is well-calibrated with the experimental data and 3D quantum corrected drift-diffusion coupled hydrodynamic and thermodynamic transport models is used in our TCAD framework to estimate the impact of ambient temperature and interface thermal contact resistance on the device performance. Moreover, we also evaluate the SHE-induced performance comparison of NS-FET with conventional FinFET and found that thermal degradation in NS-FET potentially worsen the electrical characteristics. Thus, a detailed TCAD analysis shows that the ambient temperature and interface thermal contact resistances deteriorate the effective thermal resistance (R
eff) and device performance metrics.
Electronic structure of rare-earth mononitrides: quasiatomic excitations and semiconducting bands
Authors: Galler Anna , Pourovskii Leonid V 
Published: March 2022

Abstract
The electronic structure of the rare-earth mononitrides LnN (where Ln = rare-earth), which are promising materials for future spintronics applications, is difficult to resolve experimentally due to a strong influence of defects on their transport and optical properties. At the same time, LnN are challenging for theory, since wide semiconducting 2p and 5d bands need to be described simultaneously with strongly correlated 4f states. Here, we calculate the many-body spectral functions and optical gaps of a series of LnN (with Ln = Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) by a density-functional + dynamical mean-field theory (DFT + DMFT) approach treating the correlated Ln 4f shells within the quasi-atomic Hubbard-I approximation. The on-site Coulomb interaction in the 4f shell is evaluated by a constrained DFT + Hubbard-I approach. Furthermore, to improve the treatment of semiconducting bands in DFT + DMFT, we employ the modified Becke–Johnson semilocal exchange potential. Focusing on the paramagnetic high-temperature phase, we find that all investigated LnN are pd semiconductors with gap values ranging from 1.02 to 2.14 eV along the series. The pd band gap is direct for light Ln = La…Sm and becomes indirect for heavy rare-earths. Despite a pronounced evolution of the Ln 4f states along the series, empty 4f states are invariably found above the bottom of the 5d conduction band. The calculated spectra agree well with those available from x-ray photoemission, x-ray emission and x-ray absorption measurements.
Enforcing Levy relaxation for multi-mode fibers with correlated disorder
Authors: Li Yaxin , Cohen Doron , Kottos Tsampikos 
Published: March 2022

Abstract
Environmental perturbations and noise are source of mode mixing and interferences between the propagating modes of a complex multi-mode fiber (MMF). Typically, they are characterized by their correlation (paraxial) length, and their spectral content which describes the degree of coupling between various modes. We show that an appropriate control of these quantities allows to engineer Levy-type relaxation processes of an initial mode excitation. Our theory, based on random matrix theory modeling, is tested against realistic simulations with MMFs.
An overview of the trigger system at the CMS experiment
Authors: Das Pallabi 
Published: March 2022

Abstract
The trigger system of the Compact Muon Solenoid (CMS) experiment at CERN has been evolving continuously since the startup of the LHC. While the base of the current configuration will remain in use for the next LHC running period (Run 3 starting in 2022), new features and algorithms are already being developed to take care of higher data loads due to increasing LHC luminosity and pileup but also of new experimental signatures to be investigated, in particular, displaced decay vertices stemming from relatively long-lived particles created in proton-proton collisions. Beyond this period, the trigger system will undergo a major upgrade to prepare for the high-luminosity LHC (HL-LHC) operations, which will deliver a luminosity of 5–7.5 times the design value. It corresponds to 140-200 pileup events, defined as overlapping proton-proton interactions in the same or nearby bunch crossings. During HL-LHC, information from the silicon pixel and strip tracker will be available already for the Level-1 Trigger, detector granularity and pseudorapidity coverages will increase. Trigger rates will rise by a factor of about 7.5 both at Level-1 (to 750 kHz) and at the High Level Trigger (to 7.5 kHz) and the latency—the processing time available for arriving at the Level-1 trigger decision—will increase significantly from 3.8 μs to 12.5 μs, allowing for the use of more sophisticated algorithms at the Level-1 trigger.
Effects of neutrino masses and asymmetries on dark matter halo assembly
Authors: Wong Hiu Wing , Chu Ming-chung 
Published: March 2022

Abstract
Massive cosmological neutrinos suppress the Large-Scale Structure (LSS) in the Universe by smoothing the cosmic over-densities, and hence structure formation is delayed relative to that in the standard Lambda-Cold Dark Matter (ΛCDM) model.
We characterize the merger and mass accretion history of dark matter halos with the halo formation time a
1/2, tree entropy s and halo leaf function ℓ(X) and measure them using neutrino-involved N-body simulations. We show that a non-zero sum of neutrino masses Mν
delays the a
1/2 for halos with virial mass between 1013
M
⊙ and 3 × 1013
M
⊙, whereas a non-zero neutrino asymmetry parameter η
2 has the opposite effect. While the mean tree entropy s̅ does not depend significantly on either Mν
or η
2, the halo leaf function does. Furthermore, the dependencies of ℓ on Mν
and η
2 have significant evolution in redshift z, with the relative contributions of Mν
and η
2 showing a sigmoid-like transition as a function of z around z ≈ 0.6. Together with the matter power spectrum, these halo parameters allow us to break the parameter degeneracy between Mν
and η
2 so that they can both be constrained in principle.
Crust Cooling of Soft X-Ray Transients—the Uncertainties of Shallow Heating
Authors: Lu Xiang-Yang , Lü Guo-Liang , Liu He-Lei , Zhu Chun-Hua , Wang Zhao-Jun 
Published: March 2022

Abstract
Crust cooling of soft X-ray transients has been observed after outbursts, but an additional shallow heating during accretion in outburst is needed to explain the quiescent light curve. However, shallow heating is significantly different between sources and even within one source between different outbursts, and the source of shallow heat is as yet unknown. Using the open source code “dStar” which solves the fully general relativistic heat diffusion equation for the crust, we investigate the effect of magnitude and depth of shallow heating on crust cooling and find that some exceptional sources (Swift J174805.3-244637, MAXI J0556-332 during outburst II and GRO J1750-27) in which shallow heating may be inactive could be explained by a deeper shallow heating mechanism. We compare our results with those from previous works and find that the shallow heating is model dependent. In addition, the effects of mass and radius of a neutron star on shallow heating are studied, and it is shown that the more compact the star, the less shallow heating will be needed to fit the crust cooling light curves.
To dee or not to dee: costs and benefits of altering the triangularity of a steady-state DEMO-like reactor
Authors: Schwartz J.A. , Nelson A.O. , Kolemen E. 
Published: March 2022

Abstract
Shaping a tokamak plasma to have a negative triangularity may allow operation in an edge-localized mode-free L-mode regime and with a larger strike-point radius, ameliorating divertor power-handling requirements. However, the shaping has a potential drawback in the form of a lower no-wall ideal beta limit, found using the MHD codes chease and dcon. Using the new fusion systems code faroes, we construct a steady-state DEMO2 reactor model. This model is essentially zero-dimensional and neglects variations in physical mechanisms like turbulence, confinement, and radiative power limits, which could have a substantial impact on the conclusions deduced herein. Keeping its shape otherwise constant, we alter the triangularity and compute the effects on the levelized cost of energy (LCOE). If the tokamak is limited to a fixed B field, then unless other means to increase performance (such as reduced turbulence, improved current drive efficiency or higher density operation) can be leveraged, a negative-triangularity reactor is strongly disfavored in the model due to lower β
N limits at negative triangularity, which leads to tripling of the LCOE. However, if the reactor is constrained by divertor heat fluxes and not by magnet engineering, then a negative-triangularity reactor with higher B
0 could be favorable: we find a class of solutions at negative triangularity with lower peak heat flux and lower LCOE than those of the equivalent positive triangularity reactors.
Lower bounds for Ramsey numbers as a statistical physics problem
Authors: Wouters Jurriaan , Giotis Aris , Kang Ross , Schuricht Dirk , Fritz Lars 
Published: March 2022

Abstract
Ramsey’s theorem, concerning the guarantee of certain monochromatic patterns in large enough edge-coloured complete graphs, is a fundamental result in combinatorial mathematics. In this work, we highlight the connection between this abstract setting and a statistical physics problem. Specifically, we design a classical Hamiltonian that favours configurations in a way to establish lower bounds on Ramsey numbers. As a proof of principle we then use Monte Carlo methods to obtain such lower bounds, finding rough agreement with known literature values in a few cases we investigated. We discuss numerical limitations of our approach and indicate a path towards the treatment of larger graph sizes.
Low-noise amplification of voltage response for thermopile optical detectors
Authors: Li Chaochen , Zhao Yaru , Deng Yuqiang , Xu Tao 
Published: March 2022

Abstract
A technique is presented to amplify the voltage response of thermopile optical detectors. It is based on the parallel combination of multiple operational amplifiers. The background noise of the voltage response has been deceased, which significantly improves the repeatability of the measurement results. Thus, this technique enables the same detector to measure weaker optical power or irradiance at the same precision level. The corresponding amplifying circuit is designed and fabricated. For the same detector, the experimental results show that the standard deviation of the background noise of the combined n op-amps is about

1
/

n

lower comparing with the conventional single op-amp scheme, which is consistent with the theoretical expectations. Furthermore, the lasers of 10 μW and 1μW were also measured by the specific detector and the amplifier circuit. For a 10 μW response, the measurement repeatability of the 8-combined op-amps is about 1.4%, which is better than the 3.3% of a single op-amp. For 1 μW laser, the measurement result of voltage response of the 8-combined op-amps can be precisely quantified; however, the result of the single op-amp is hardly distinguished. The presented technique based on multiple op-amps is practical and can be potential in many applications. We hope this technique could offer help for expanding the measurement ranges of thermopile optical detectors at weaker optical power and irradiance.
Preparation of Dy3+/Tm3+ Co-doped Phosphate Glasses by Melt Method and its Luminescence Properties
Authors: Zhang Tao , Zhang Danyi , Wang Pei-an , Cui Caixia 
Published: March 2022

Abstract
In this paper, P2O5 matrix materials were used to prepare Dy3+/Tm3+ phosphate glasses with different concentrations by high temperature melt method. The emission spectrum of Dy3+/Tm3+co-doped glass samples were measured under 350nm excitation. High-efficiency green and blue down-conversion emissions were already observed. Based on the intensity of the emission peaks of samples doped with different concentrations of Dy3+/Tm3+, It can be assumed that an energy transfer process is occurring between Dy3+/Tm3+, i.e. the energy transfer process between the two kinds of ions is Dy3+ to Tm3+ and Tm3+to Dy3+, respectively. Finally, the energy transfer between Dy3+/Tm3+ was further illustrated by testing the fluorescence decay lifetime of the samples. It was found that the increased probability of cross relaxation of ions in glasses doped with 0.8mol% Dy3+/0.2mol% Tm3+ caused the fluorescence quenching of Dy3+ ions, and a fluorescence color shift from blue to white was observed in the range of 0.2-0.7mol% Dy3+. CIE coordinates of the 0.2mol% Tm3+/0.7mol% Dy3+ co-doped phosphate glasses sample are (0.33, 0.32), which is extremely approximate to the standards of equivalent energy white light for illumination (0.33,0.33). The results indicate that Dy3+/Tm3+ has a significant contribution in the down-conversion mechanism.
The temperature difference method for screening patients with COVID-19 fever symptoms
Authors: Zeng Zhiwei , Mei Guangdong , Liao Tingdi , huang Yantang 
Published: March 2022

AbstractCoronavirus disease (COVID-19), caused by the SARS-CoV-2 virus, is a potentially fatal disease of global public health concern. Fever has been reported to be a common clinical symptom in COVID-19 and current CDC recommendations for mitigation of community COVID-19 transmission include temperature screening, so prompting widespread temperature screening across multiple sectors, including hospitals, office buildings and airports. The need for no-contact and rapid measurement of body temperature during the COVID-19 pandemic emergency has led to the widespread use of thermal imaging cameras. However, the body temperature measurement is also disturbed by the environment factors, including ambient temperature, background light etc. When the ambient temperature is low, the temperature of the patient will also be low. It was difficult to screen the fever patients by using the absolute temperature criteria, and it often result in missing detection. In order to solve this problem, this paper proposed a method of screening COVID-19 symptom fever patients by the body temperature difference detection. The temperature difference detection method combined the temperature measurement of the infrared imaging camera and the visible camera face recognition. This method will eliminate environmental interference and equipment errors, to reduce the probability of the fever missed detection.