bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerium-promoted conversion of dinitrogen into high-energy-density material CeN6 under moderate pressure
Authors: Wang Yuanyuan , Li Zhihui , Niu Shifeng , Yi Wencai , Liu Shuang , Yao Zhen , Liu Bingbing 
Published: April 2023

Synthesis pressure and structural stability are two crucial factors for highly energetic materials, and recent investigations have indicated that cerium is an efficient catalyst for N2 reduction reactions. Here, we systematically explore Ce–N compounds through first-principles calculations, demonstrating that the cerium atom can weaken the strength of the N≡N bond and that a rich variety of cerium polynitrides can be formed under moderate pressure. Significantly, P1̄-CeN6 possesses the lowest synthesis pressure of 32 GPa among layered metal polynitrides owing to the strong ligand effect of cerium. The layered structure of P1̄-CeN6 proposed here consists of novel N14 ring. To clarify the formation mechanism of P1̄-CeN6, the reaction path Ce + 3N2 → trans-CeN6 → P1̄-CeN6 is proposed. In addition, P1̄-CeN6 possesses high hardness (20.73 GPa) and can be quenched to ambient conditions. Charge transfer between cerium atoms and N14 rings plays a crucial role in structural stability. Furthermore, the volumetric energy density (11.20 kJ/cm3) of P1̄-CeN6 is much larger than that of TNT (7.05 kJ/cm3), and its detonation pressure (128.95 GPa) and detonation velocity (13.60 km/s) are respectively about seven times and twice those of TNT, and it is therefore a promising high-energy-density material.
Thermal degradation comparison of delta-doped GaAs tunnel junctions using Si and Te n-type dopants
Authors: Madarang May Angelu , Chu Rafael Jumar , Kim Yeonhwa , Lung Quang Nhat Dang , Ju Eunkyo , Choi Won Jun , Jung Daehwan 
Published: April 2023

Tunnel junctions (TJs) are essential for high-performance multijunction solar cells to act as transparent low resistance paths for carriers to travel between adjacent cells. However, TJs typically exhibit highly degraded tunneling performance due to unwanted dopant out-diffusion during top cell growth. In this study, GaAs TJs with Si and Te delta-doping (δ-doping) were grown via solid source molecular beam epitaxy to investigate the tunneling performance and thermal stability. While Si δ-doped TJs exhibited typical tunneling characteristics with an Esaki peak current density of 173 A/cm2, Te δ-doped TJs revealed 1.5 A/cm2 at Vbias = 100 mV without negative resistance. It was found that the performance degradation after annealing at 600 °C for 90 min was significantly higher for TJs with Si δ-doping than for Te. Secondary ion mass spectroscopy measurements reveal that Te shows no clear signs of dopant diffusion while Si exhibited significant out-diffusion in the active TJ layer after thermal annealing. The superior thermal stability of Te compared to Si proves to be advantageous as an alternative n-type dopant for high temperature and long duration grown multi-junction solar cells.
Porting fragmentation methods to GPUs using an OpenMP API: Offloading the resolution-of-the-identity second-order Møller–Plesset perturbation method
Authors: Pham Buu Q. , Carrington Laura , Tiwari Ananta , Leang Sarom S. , Alkan Melisa , Bertoni Colleen , Datta Dipayan , Sattasathuchana Tosaporn , Xu Peng , Gordon Mark S. 
Published: April 2023

Using an OpenMP Application Programming Interface, the resolution-of-the-identity second-order Møller–Plesset perturbation (RI-MP2) method has been off-loaded onto graphical processing units (GPUs), both as a standalone method in the GAMESS electronic structure program and as an electron correlation energy component in the effective fragment molecular orbital (EFMO) framework. First, a new scheme has been proposed to maximize data digestion on GPUs that subsequently linearizes data transfer from central processing units (CPUs) to GPUs. Second, the GAMESS Fortran code has been interfaced with GPU numerical libraries (e.g., NVIDIA cuBLAS and cuSOLVER) for efficient matrix operations (e.g., matrix multiplication, matrix decomposition, and matrix inversion). The standalone GPU RI-MP2 code shows an increasing speedup of up to 7.5× using one NVIDIA V100 GPU with one IBM 42-core P9 CPU for calculations on fullerenes of increasing size from 40 to 260 carbon atoms using the 6-31G(d)/cc-pVDZ-RI basis sets. A single Summit node with six V100s can compute the RI-MP2 correlation energy of a cluster of 175 water molecules using the correlation consistent basis sets cc-pVDZ/cc-pVDZ-RI containing 4375 atomic orbitals and 14 700 auxiliary basis functions in ∼0.85 h. In the EFMO framework, the GPU RI-MP2 component shows near linear scaling for a large number of V100s when computing the energy of an 1800-atom mesoporous silica nanoparticle in a bath of 4000 water molecules. The parallel efficiencies of the GPU RI-MP2 component with 2304 and 4608 V100s are 98.0% and 96.1%, respectively.
Energy response and spatial alignment of the perturbed electron gas
Authors: Dornheim Tobias , Tolias Panagiotis , Moldabekov Zhandos A. , Vorberger Jan 
Published: April 2023

We study the linear energy response of the uniform electron gas to an external harmonic perturbation with a focus on resolving different contributions to the total energy. This has been achieved by carrying out highly accurate ab initio path integral Monte Carlo (PIMC) calculations for a variety of densities and temperatures. We report a number of physical insights into effects such as screening and the relative importance of kinetic and potential energies for different wave numbers. A particularly interesting finding is obtained from the observed non-monotonic behavior of the induced change in the interaction energy, which becomes negative for intermediate wave numbers. This effect is strongly dependent on the coupling strength and constitutes further direct evidence for the spatial alignment of electrons introduced in earlier works [T. Dornheim et al., Commun. Phys. 5, 304 (2022)]. The observed quadratic dependence on the perturbation amplitude in the limit of weak perturbations and the quartic dependence of perturbation amplitude corrections are consistent with linear and nonlinear versions of the density stiffness theorem. All PIMC simulation results are freely available online and can be used to benchmark new methods or as input for other calculations.
The gas-phase structure determination of α-pinene oxide: An endo-cyclic epoxide of atmospheric interest
Authors: Neeman E. M. , Osseiran N. , Huet T. R. 
Published: April 2023

The gas-phase rotational spectra of α-pinene oxide have been recorded using a chirped-pulse Fourier transform microwave spectrometer in the 6–18 GHz frequency range. The parent species and all heavy atom isotopologues (13C and 18O) have been observed in their natural abundance. The experimental rotational constants of all isotopic species observed have been determined and used to obtain the substitution (rs) and the effective (r0) structures of the most stable conformer of α-pinene oxide. Calculations using the density functional theories B3LYP, M06-2X, and MN15-L and the ab initio method MP2 level of theory were carried out to check their performance against experimental results. The structure of the heavy atom’s skeleton of α-pinene oxide has been compared to that of α-pinene and has shown that epoxidation does not overly affect the structure of the bicycle, validating its robustness. Furthermore, the structural features have been compared to those of other bicyclic molecules, such as nopinone and β-pinene.
Bilateral supplementary comparison of high voltage transformer measuring systems
Authors: Ayhan B , Çaycı H , Räther P , Mohns E 
Published: April 2023

Main text
A comparison of high voltage transformer measuring systems of TÜBİTAK UME (Türkiye) and PTB (Germany) was conducted between August 2021 and August 2022. The comparison was registered as EURAMET Project No: EM 1492 and EURAMET.EM - S43 in the BIPM key comparison database. Ratio error and phase displacement of the voltage transformers were measured at voltages from 3 kV to 110/√3 kV, at 50.2 Hz and 60 Hz. The main targets of the comparison were to underpin and strengthen the capabilities of the National Metrology Institutes. The results of the participants were found to be equivalent, comparable and in agreement with the comparison reference values within stated uncertainties of measurements.
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 CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Front-side releasing <110> oriented clamped–clamped beams for piezoresistive sensors
Authors: Han Jianqiang , Sun Weihua 
Published: April 2023

Abstract
Front-side releasing suspended structures made using bulk micromachining processes have the advantages of simplifying vacuum or hermetic packaging processes and reducing squeeze-film damping. This paper studies the effect of doping concentration on the etching rate (ER) of the (111) plane. The experimental results show that increasing the boron doping concentration (but to less than the self-stop etching concentration) significantly increases the ER of the (111) plane and the ER ratio of the (111) and (100) planes. This phenomenon is used to speed up the undercutting and release <110> oriented clamped–clamped beams, which can be used as piezoresistive sensitive elements. The etching depth when the microbeams have just been released and the silicon wedges under single beams, double beams and triple beams disappear is deduced and verified by experiments. This has a certain guiding significance for designing piezoresistive sensors.
A method for multiplexed and volumetric-based magnetic particle spectroscopy bioassay: mathematical study
Authors: Chugh Vinit Kumar , Liang Shuang , Yari Parsa , Wu Kai , Wang Jian-Ping 
Published: April 2023

Abstract
Magnetic particle spectroscopy (MPS) is an emerging biosensing technique that detects target analytes by exploiting the dynamic magnetic responses of magnetic nanoparticles (MNPs). Due to the ease of synthesis and surface chemical functionalization of MNPs, MPS-based bioassays have gained popularity around the globe. One limiting factor for MPS-based assay is the ability to detect multiple analytes simultaneously in a single run, namely, multiplexed bioassay. Several groups have reported the realization of multiplexed bioassays on surface-based MPS platforms by spatially separating reaction areas by using the unique magnetic responses of different MNPs. In this work, we systematically study the magnetization curves (M-H curves) of different types of MNPs and their relationship to the dynamic magnetic responses when subjected to AC magnetic driving fields. Due to the different structures, sizes, and magnetic properties of each kind of MNP, the resulting harmonics are unique. Thus, concurrent quantification (also called ‘colorization’) of each type of MNP in a mixture is possible by solving the harmonic matrix function. Our results show that the uniqueness of M-H response curves of selected types of MNP and the signal-to-noise ratio of the system can affect the accuracy of multiplexed, volumetric-based MPS bioassays. The reported method assumes that each type of MNPs nanoparticles does not interact, and that the magnetic response of the mixture is a linear combination of the responses of each kind of MNP. This assumption may not hold for very dense systems where inter-particle interactions become significant and may require more complex models.
Frequency spectrum of radiation transfer in high voltage circuit breaker arcs for polymer nozzle ablation in C4F7N and CO2 gas mixture
Authors: Zhou Mingyu , Xu Ruoyu , Esmaeili S , Ding Yi , Lei Zonghan , Yan J D 
Published: April 2023

Abstract
Arc radiation-induced polymer nozzle ablation plays a crucial role in the operation of self-blast circuit breakers. Up to now, there is no study specifically on the spectral distribution of radiated power from a switching arc towards the nozzle surface and its implication to nozzle ablation. Three-dimensional radiation transfer calculation has been performed in this study for arcs burning in the mixture of

C

4

F

7

N

+

C

O

2

+

PTFE

, a gaseous environment that is under significant focus in the development of SF6 free switching technology to aim net-zero by the middle of this century. Results show that photons from infrared to extreme ultraviolet (UV, up to 5 × 1015 Hz) are emitted from the core of high current arcs. However, the high-frequency photons are mostly absorbed within the arc column, especially at the arc edge, and only photons up to

1.7
×

10

15

Hz

(far UV, 7 eV) can penetrate the arc edge and cold gas and reach the nozzle surface. The spectral distribution of the radiative energy at different instantaneous currents (15 kA, 28 kA and 60 kA peak) and different locations of the nozzle is presented and compared in detail. The location of the radiation absorption zone at the arc edge and the radiative power reaching the nozzle wall as a function of the instantaneous current is, in particular, purposely considered.
Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals
Authors: Mehta R , Moalic M , Krawczyk M , Saha S 
Published: April 2023

Abstract
Reprogramming the structure of the magnonic bands during their operation is important for controlling spin waves in magnonic devices. Here, we report the tunability of the spin-wave spectra for a triangular shaped deterministic magnonic fractal, which is known as Sierpinski triangle by solving the Landau–Lifshitz–Gilbert equation using a micromagnetic simulations. The spin-wave dynamics change significantly with the variation of iteration number. A wide frequency gap is observed for a structure with an iteration number exceeding some value and a plenty of mini-frequency bandgaps at structures with high iteration number. The frequency gap could be controlled by varying the strength of the magnetic field. A sixfold symmetry in the frequency gap is observed with the variation of the azimuthal angle of the external magnetic field. The spatial distributions of the spin-wave modes allow to identify the bands surrounding the gap. The observations are important for the application of magnetic fractals as a reconfigurable aperiodic magnonic crystals.
Non-invasive, intelligent, and continuous monitoring of human blood glucose with UWB dual-antenna and cascade CNN
Authors: Wang Zengxiang , Xiao Xia , Pang Yanwei , Su Wenling 
Published: April 2023

Abstract
Finger-prick blood collection process has become unrealistic for a long-term and frequent blood glucose detection. Hence, an appropriate non-invasive detection system is highly desirable to effectively address this concern. A non-invasive and intelligent dual-sensing system is forwarded in this paper. The feasibility of the proposed system has been verified using glucose solution, animal serum, and human trials. In the in vivo experiments, the detection signal exhibited a high correlation (r = 0.96) with blood glucose levels. An improved cascade convolution neural network is suggested to accurately predict the BGL. For the estimation results of BGL, the root mean squared error of 7.3217 mg dl−1 and a mean absolute relative difference of 4.7209% are achieved. The estimated results also fell by 100% in the clinically acceptable zones of the Clarke error grid analysis, indicating that the proposed system could potentially be used for clinical measurements.
Infinite WARM graphs III: strong reinforcement regime
Authors: Hirsch Christian , Holmes Mark , Kleptsyn Victor 
Published: April 2023

Abstract
We study a reinforcement process on graphs G of bounded degree. The model involves a parameter α > 0 governing the strength of reinforcement, and Poisson clock rates λ

v
at the vertices v of the graph. When the Poisson clock at a vertex v rings, one of the edges incident to it is reinforced, with edge e being chosen with probability proportional to its current count (counts start from 1) raised to the power α. The main problem in such models is to describe the (random) subgraph

, consisting of edges that are reinforced infinitely often. In this paper, we focus on the finite connected components of

in the strong reinforcement regime (α > 1) with clock rates that are uniformly bounded above. We show here that when α is sufficiently large, all connected components of

are trees. When the firing rates λ

v
are constant, we show that all components are trees of diameter at most 3 when α is sufficiently large, and that there are infinitely many phase transitions as

α
↓
1

. For example, on the triangular lattice, increasingly large (odd) cycles appear as

α
↓
1

(while on the square lattice no finite component of

contains a cycle for any α > 1). Increasingly long paths and other structures appear in both lattices when taking

α
↓
1

. In the special case where

G
=

Z

and α > 1, all connected components of

are finite and we show that the possible cluster sizes are non-monotone in α. We also present several open problems.
Impact of motion correction on [18F]-MK6240 tau PET imaging
Authors: Tiss Amal , Marin Thibault , Chemli Yanis , Spangler-Bickell Matthew , Gong Kuang , Lois Cristina , Petibon Yoann , Landes Vanessa , Grogg Kira , Normandin Marc , Becker Alex , Thibault Emma , Johnson Keith , El Fakhri Georges , Ouyang Jinsong 
Published: April 2023

Abstract

Objective. Positron emission tomography (PET) imaging of tau deposition using [18F]-MK6240 often involves long acquisitions in older subjects, many of whom exhibit dementia symptoms. The resulting unavoidable head motion can greatly degrade image quality. Motion increases the variability of PET quantitation for longitudinal studies across subjects, resulting in larger sample sizes in clinical trials of Alzheimer’s disease (AD) treatment. Approach. After using an ultra-short frame-by-frame motion detection method based on the list-mode data, we applied an event-by-event list-mode reconstruction to generate the motion-corrected images from 139 scans acquired in 65 subjects. This approach was initially validated in two phantoms experiments against optical tracking data. We developed a motion metric based on the average voxel displacement in the brain to quantify the level of motion in each scan and consequently evaluate the effect of motion correction on images from studies with substantial motion. We estimated the rate of tau accumulation in longitudinal studies (51 subjects) by calculating the difference in the ratio of standard uptake values in key brain regions for AD. We compared the regions’ standard deviations across subjects from motion and non-motion-corrected images. Main results. Individually, 14% of the scans exhibited notable motion quantified by the proposed motion metric, affecting 48% of the longitudinal datasets with three time points and 25% of all subjects. Motion correction decreased the blurring in images from scans with notable motion and improved the accuracy in quantitative measures. Motion correction reduced the standard deviation of the rate of tau accumulation by −49%, −24%, −18%, and −16% in the entorhinal, inferior temporal, precuneus, and amygdala regions, respectively. Significance. The list-mode-based motion correction method is capable of correcting both fast and slow motion during brain PET scans. It leads to improved brain PET quantitation, which is crucial for imaging AD.
Inter-crystal scattering event identification using a novel silicon photomultiplier signal multiplexing method
Authors: Shim Hyeong Seok , Bae Sangjin , Lee Seungeun , Lee Jae Sung 
Published: April 2023

Abstract

Objective. Identifying the inter-crystal scatter (ICS) events and recovering the first interaction position enables the accurate determination of the line-of-response in positron emission tomography (PET). However, conventional silicon photomultiplier (SiPM) signal multiplexing methods based on two-dimensional (2D) charge-division circuits do not allow the detection of multiple gamma-ray interaction positions in a scintillation array coupled with a SiPM array. In this study, we propose a novel multiplexing method that can restore all the individual channel data from a smaller number of multiplexed channels using high-pass filters and neural networks. Approach. The number of output channels is reduced by summing the SiPM signals that have passed through high-pass filters with different time constants. Then, the signal amplitude of each SiPM channel is restored from the combined signal using an artificial neural network. This study explains the principle of this method in detail and demonstrates the results using 4:1 multiplexing as an example. The usefulness of this method was also demonstrated by its application in the identification of ICS events in 1-to-1 coupled LSO-SiPM PET detectors. Main results. The artificial neural network enabled accurate energy estimation for each SiPM channel. One of the high-pass filter sets with the lowest Cramér–Rao lower bound provided the best results, yielding R
2 value of 0.99 between the true and estimated signals. The energy and flood histograms generated using the best-estimated signals were in good agreement with the ground truth. Additionally, the proposed method accurately estimated 2D energy deposit distribution in the LSO crystal array, allowing ICS event identification. Significance. The proposed method is potentially useful for ICS event recovery with a reduced number of array signal readout channels from a SiPM array.
Critical site percolation on the triangular lattice: from integrability to conformal partition functions
Authors: Morin-Duchesne Alexi , Klümper Andreas , Pearce Paul A 
Published: April 2023

Abstract
Critical site percolation on the triangular lattice is described by the Yang–Baxter solvable dilute

A
2

(
2
)

loop model with crossing parameter specialized to

λ
=

π
3

, corresponding to the contractible loop fugacity

β
=
−
2
cos
4
λ
=
1

. We study the functional relations satisfied by the commuting transfer matrices of this model and the associated Bethe ansatz equations. The single and double row transfer matrices are respectively endowed with strip and periodic boundary conditions, and are elements of the ordinary and periodic dilute Temperley–Lieb algebras. The standard modules for these algebras are labelled by the number of defects d and, in the latter case, also by the twist

e

i

γ

. Nonlinear integral equation techniques are used to analytically solve the Bethe ansatz functional equations in the scaling limit for the central charge c = 0 and conformal weights

Δ
,

Δ
ˉ

. For the ground states, we find

Δ
=

Δ

1
,
d
+
1

for strip boundary conditions and

(
Δ
,

Δ
ˉ

)
=
(

Δ

γ

/

π
,
d

/

2

,

Δ

γ

/

π
,
−
d

/

2

)

for periodic boundary conditions, where

Δ

r
,
s

=

1
24

(

(
3
r
−
2
s

)
2

−
1

)

. We give explicit conjectures for the scaling limit of the trace of the transfer matrix in each standard module. For

d
⩽
8

, these conjectures are supported by numerical solutions of the logarithmic form of the Bethe ansatz equations for the leading 20 or more conformal eigenenergies. With these conjectures, we apply the Markov traces to obtain the conformal partition functions on the cylinder and torus. These precisely coincide with our previous results for critical bond percolation on the square lattice, described by the dense

A
1

(
1
)

loop model with

λ
=

π
3

. The concurrence of all this conformal data provides compelling evidence supporting a strong form of universality between these two stochastic models as logarithmic conformal field theories.