bluuebunny/crossref_metadata_2025_split huggingface dataset:
Double-edged sword: China’s free trade agreements reinforces embodied greenhouse gas transfers in agricultural products
Authors: Hu Yanyong , Zou Zhixiao , Wu Jiaxi , Meng Zheng 
Published: February 2024

AbstractChina, as the world’s largest importer, heavily relies on agricultural products. However, the impact of China’s free trade agreements (FTAs) on greenhouse gas (GHG) emissions embodied in agricultural product imports has been overlooked. It’s crucial to analyze changes in embodied GHG emissions resulting from FTAs. We categorize 367 agricultural products into 15 categories and construct a dataset on the embodied GHG emissions of these products imported by China from 119 countries between 2000 and 2015. Using the Propensity Score Matching (PSM)-progressive difference-in-differences (DID) method, our findings indicate that China’s FTAs have double-edged impact on agricultural product imports. It has positively influenced imports, with a 12.22% annual growth rate, promoting economic integration. However, it has negatively affected GHG emissions, leading to a 53.00% increase in emissions from agricultural imports. These findings highlight the importance of addressing production and consumption in reducing GHG strategies with agricultural products.
Same yet different
Authors: Ivaska Ilmari , Tamm Anne 
Published: February 2024

Abstract
The article compares the distributional differences in the use of the partitive object cases in Estonian and
Finnish via multifactorial modeling in contrastive research using the European Parliament parallel text corpus. Based on previous
contrastive research on Finnic, we expected the principles of object case marking to be similar for Estonian and Finnish
(confirmed), and the partitive objects to be more numerous in Estonian than in Finnish (not confirmed, as countable objects with
scalar verbs proved less likely to be partitive in Estonian). We hypothesized that multifactorial modeling in contrastive research
design could help identify the causes for variation and unfold subtle differences between related language systems. Since
preferences related to grammatical voice and constituent order revealed subtle differences between the systems, this hypothesis
was confirmed.
Multivariable calculus textbook representation of non-cartesian coordinates: a misalignment between multivariable calculus textbook content and upper-division physics application
Authors: Dalton Chaelee , Farlow Brian , Christensen Warren M 
Published: February 2024

Abstract
Upper-division undergraduate physics coursework necessitates a firm grasp on and fluid use of mathematical knowledge, including an understanding of non-cartesian (specifically polar, spherical and cylindrical) coordinates and how to use them. A limited body of research into physics students’ thinking about coordinate systems suggests that even for upper-division students, understanding of coordinate system concepts is emergent. To more fully grasp upper-division physics students’ incoming understanding of non-cartesian coordinates, the prevalence of non-cartesian content in seven popular Calculus textbooks was studied. Using content analysis techniques, a coding scheme was developed to gain insight into the presentation of coordinate system content both quantitatively and qualitatively. An initial finding was that non-cartesian basis unit vectors were absent in all but one book. A deeper analysis of three of the calculus textbooks showed that cartesian coordinates comprise an overwhelming proportion of the textbooks’ content and that qualitatively the cartesian coordinate system is presented as the default coordinate system. Quantitative and qualitative results are presented with implications for how these results might impact physics teaching and research at the middle and upper-division.
Quantitative passive imaging by iterative holography: the example of helioseismic holography
Authors: Müller Björn , Hohage Thorsten , Fournier Damien , Gizon Laurent 
Published: February 2024

Abstract
In passive imaging, one attempts to reconstruct some coefficients in a wave equation from correlations of observed randomly excited solutions to this wave equation. Many methods proposed for this class of inverse problem so far are only qualitative, e.g. trying to identify the support of a perturbation. Major challenges are the increase in dimensionality when computing correlations from primary data in a preprocessing step, and often very poor pointwise signal-to-noise ratios. In this paper, we propose an approach that addresses both of these challenges: it works only on the primary data while implicitly using the full information contained in the correlation data, and it provides quantitative estimates and convergence by iteration. Our work is motivated by helioseismic holography, a well-established imaging method to map heterogenities and flows in the solar interior. We show that the back-propagation used in classical helioseismic holography can be interpreted as the adjoint of the Fréchet derivative of the operator which maps the properties of the solar interior to the correlation data on the solar surface. The theoretical and numerical framework for passive imaging problems developed in this paper extends helioseismic holography to nonlinear problems and allows for quantitative reconstructions. We present a proof of concept in uniform media.
Measurement of steep dispersion associated with magnetically assisted gain in Zeeman degenerate two-level system of cold atoms
Authors: de Aquino Carvalho J C , Moreira R S N , Tabosa J W R 
Published: February 2024

Abstract
We report on the measurements of magnetically assisted dispersion and gain in a Zeeman degenerate two-level system associated with the closed D
2 hyperfine transition

F

g

=
3
→

F

e

=
2

cold cesium atoms. We use a Mach–Zehnder interferometer to measure the dispersive properties of this system in the presence of a magnetic field, transversal to the quantization direction, when the atomic system is excited by a coupling and probe beams with orthogonal polarizations. We have measured the spectrum of the refraction index for different magnitudes of the external magnetic field and different coupling beam intensities. A previously published theoretical model, using a simpler atomic transition

F

g

=
1
→

F

e

=
0

, accounts reasonably for the experimentally observed gain and dispersive lineshapes.
Targeted optimization in small-scale atomic structure calculations: application to Au I
Authors: Caliskan Sema , Grumer Jon , Amarsi Anish M 
Published: February 2024

Abstract
The lack of reliable atomic data can be a severe limitation in astrophysical modelling, in particular of events such as kilonovae that require information on all neutron-capture elements across a wide range of ionization stages. Notably, the presence of non-orthonormalities between electron orbitals representing configurations that are close in energy can introduce significant inaccuracies in computed energies and transition probabilities. Here, we propose an explicit targeted optimization (TO) method that can effectively circumvent this concern while retaining an orthonormal orbital basis set. We illustrate this method within the framework of small-scale atomic structure models of Au I, using the Grasp2018 multiconfigurational Dirac–Hartree–Fock atomic structure code. By comparing to conventional optimization schemes we show how a TO approach improves the energy level positioning and ordering. TO also leads to better agreement with experimental data for the strongest E1 transitions. This illustrates how small-scale models can be significantly improved with minor computational costs if orbital non-orthonormalities are considered carefully. These results should prove useful to multi-element atomic structure calculations in, for example, astrophysical opacity applications involving neutron-capture elements.
Analysis of semi-molten hollow particle spreading and deformation in plasma spraying
Authors: Zhang Mengjiao , Chen Lihua , Shan Lutong , Li Haoqun 
Published: February 2024

Abstract
Hollow yttrium-stabilized zirconia (YSZ) particles, which are often used to prepare high porosity coatings in industry, hit substrate at a fully molten state or semi-molten state due to the high temperature gradient of particles caused by the low thermal conductivity. Considering the hollow solid core large deformation and liquid solidification during the deposition of semi-molten hollow particles (SMHPs), a fluid-structure interaction model described by the coupled Eulerian and Lagrangian (CEL) method, is developed and validated to investigate the spreading results in thermal spraying. The empirical formula of dynamic viscosity based on the ABAQUS CEL method is proposed and verified for simulation of the liquid YSZ spreading and solidification. The compression ratio and plastic dissipation are calculated to reveal flattening and buckling phenomena of hollow solid core with different initial velocities and hollow radius. Moreover, a double-SMHP impact model is established to simulate the interaction of particle-particle-substrate, and the effect of flattening, buckling and structural self-contact on porosity is analyzed. Numerical simulation results show that hollow solid core large deformation induces instability accompanied by flattening, buckling or structural self-contact, which results in the reduction of layer porosity.
The physics case for neutrino–neutrino collisions
Authors: Qian Sitian , Yang Tianyi , Deng Sen , Xiao Jie , Gao Leyun , Levin Andrew Michael , Li Qiang , Lu Meng , You Zhengyun 
Published: February 2024

Abstract
Addressing the mass origin and properties of neutrinos is of strong interest to particle physics, baryogenesis and cosmology. Popular explanations involve physics beyond the standard model, for example, the dimension-5 Weinberg operator or heavy Majorana neutrinos arising from ‘seesaw’ models. The current best direct limits on the electron neutrino mass, derived from nuclei beta decay or neutrinoless double beta decay processes, are at the sub-electronvolt level. Here we propose a novel neutrino–neutrino collider where the neutrino beam is generated from TeV scale muon decays. Such collisions can happen between either neutrinos and anti-neutrinos, or neutrinos and neutrinos. We find that with a tiny integrated luminosity of about 10−5 fb−1 we can already expect to observe direct neutrino anti-neutrino annihilation,

ν

ν

¯

→
Z

, which also opens the door to explore neutrino related resonances

ν

ν

¯

→
X

. The low luminosity requirement can accommodate a relatively large emittance muon beam. Such a device would also allow for probing heavy Majorana neutrino and effective Majorana neutrino mass through ν
ν → HH to a competitive level, for both electron and muon types.
A generalized time-domain constitutive finite element approach for viscoelastic materials
Authors: Abercrombie Eric , Gregory McDaniel J , Walsh Timothy 
Published: February 2024

Abstract
Despite the existence of time domain finite element formulations for viscoelastic materials, there are still substantial ways to improve the analysis. To the authors’ knowledge, the formulation of the problem is always done with respect to a single constitutive relation and so limits the implementer to a single scheme with which to model relaxation. Furthermore, all current constitutive relations involve the finding of fitting parameters for an analytical function, which is a sufficiently painful process to warrant the study of best fitting procedures to this day. In contrast, this effort is the first full derivation of the two dimensional problem from fundamental principles. It is also the first generalization of the problem, which frees users to select constitutive relations without re-derivation or re-expression of the problem. This approach is also the first approach to the problem that could lead to the elimination of constitutive relations for representing relaxation in viscoelastic materials. Following, the full derivation, several common constitutive relations are outlined with analysis of how they may best be implemented in the generalized form. Several expressions for viscoelastic terms are also provided given linear, quadratic, and exponential interpolation assumptions.
Collapse dynamics for two-dimensional space-time nonlocal nonlinear Schrödinger equations
Authors: Cole Justin T , Aurko Abdullah M , Musslimani Ziad H 
Published: February 2024

Abstract
The question of collapse (blow-up) in finite time is investigated for the two-dimensional (non-integrable) space-time nonlocal nonlinear Schrödinger equations. Starting from the two-dimensional extension of the well known AKNS

q
,
r

system, three different cases are considered: (i) partial and full parity-time (PT) symmetric, (ii) reverse-time (RT) symmetric, and (iii) general

q
,
r

system. Through extensive numerical experiments, it is shown that collapse of Gaussian initial conditions depends on the value of its quasi-power. The collapse dynamics (or lack thereof) strongly depends on whether the nonlocality is in space or time. A so-called quasi-variance identity is derived and its relationship to blow-up is discussed. Numerical simulations reveal that this quantity reaching zero in finite time does not (in general) guarantee collapse. An alternative approach to the study of wave collapse is presented via the study of transverse instability of line soliton solutions. In particular, the linear stability problem for perturbed solitons is formulated for the nonlocal RT and PT symmetric nonlinear Schrödinger (NLS) equations. Through a combination of numerical and analytical approaches, the stability spectrum for some stationary one soliton solutions is found. Direct numerical simulations agree with the linear stability analysis which predicts filamentation and subsequent blow-up.
Measurement of the 12C(p,n)12N reaction cross section below 150 MeV
Authors: Zapien-Campos Brian , Ahmadi Ganjeh Zahra , Both Stefan , Dendooven Peter 
Published: February 2024

Abstract

Objective. Proton therapy currently faces challenges from clinical complications on organs-at-risk due to range uncertainties. To address this issue, positron emission tomography (PET) of the proton-induced 11C and 15O activity has been used to provide feedback on the proton range. However, this approach is not instantaneous due to the relatively long half-lives of these nuclides. An alternative nuclide, 12N (half-life 11 ms), shows promise for real-time in vivo proton range verification. Development of 12N imaging requires better knowledge of its production reaction cross section. Approach. The 12C(p,n)12N reaction cross section was measured by detecting positron activity of graphite targets irradiated with 66.5, 120, and 150 MeV protons. A pulsed beam delivery with 0.7–2 × 108 protons per pulse was used. The positron activity was measured during the beam-off periods using a dual-head Siemens Biograph mCT PET scanner. The 12N production was determined from activity time histograms. Main results. The cross section was calculated for 11 energies, ranging from 23.5 to 147 MeV, using information on the experimental setup and beam delivery. Through a comprehensive uncertainty propagation analysis, a statistical uncertainty of 2.6%–5.8% and a systematic uncertainty of 3.3%–4.6% were achieved. Additionally, a comparison between measured and simulated scanner sensitivity showed a scaling factor of 1.25 (±3%). Despite this, there was an improvement in the precision of the cross section measurement compared to values reported by the only previous study. Significance. Short-lived 12N imaging is promising for real-time in vivo verification of the proton range to reduce clinical complications in proton therapy. The verification procedure requires experimental knowledge of the 12N production cross section for proton energies of clinical importance, to be incorporated in a Monte Carlo framework for 12N imaging prediction. This study is the first to achieve a precise measurement of the 12C(p,n)12N nuclear cross section for such proton energies.
Observation of the low electron density and electron temperature in an unmagnetized cascaded arc helium plasma by laser Thomson scattering approach
Authors: Wang Yong , Zhou Lina , Shi Jielin , Li Yu , Li Cong , Feng Chunlei , Ding Hongbin 
Published: February 2024

Abstract
In this study, the electron density (ne
) and temperature (Te
) in an unmagnetized cascaded arc helium (He) plasma are precisely determined using cutting-edge laser Thomson scattering. In our experimental scope, ne
is only 1018 m−3 and Te
is less than 0.2 eV, both of which are substantially lower than in linear plasma devices (LPDs). The comparison of ne
and Te
values in He plasma with those in cascaded arc Ar plasma reveals that these two parameters are likewise significantly lower in He plasma than they are in Ar plasma on average. In comparison to Ar gas, the degree of ionization of He is low due to its high ionization potential, and diffusive loss dominates due to its light weight, both of which result in a lower ne
. Meanwhile, these two characteristics render the three-body recombination interaction between electrons and He+ ions in He plasma insignificant, thus the electrons cannot be heated effectively, explaining why Te
is lower. This study will provide foundational data and build the groundwork for a thorough knowledge of cascaded arc He plasma in LPDs and plasma windows.
When physics meets chemistry at the dynamic glass transition
Authors: Lu Haibao 
Published: February 2024

Abstract
Can the laws of physics be unified? One of the most puzzling challenges is to reconcile physics and chemistry, where molecular physics meets condensed-matter physics, resulting from the dynamic fluctuation and scaling effect of glassy matter at the glass transition temperature. The pioneer of condensed-matter physics, Nobel Prize-winning physicist Philip Warren Anderson referred to this gap as the deepest and most interesting unsolved problem in condensed-matter physics in 1995. In 2005, Science, in its 125th anniversary publication, highlighted that the question of ‘what is the nature of glassy state?’ was one of the greatest scientific conundrums for the next quarter century. However, the nature of the glassy state and its connection to the glass transition have not been fully understood owing to the interdisciplinary complexity of physics and chemistry, governed by physical laws at the condensed-matter and molecular scales, respectively. Therefore, the study of glass transition is essential to explore the working principles of the scaling effects and dynamic fluctuations in glassy matter and to further reconcile the interdisciplinary complexity of physics and chemistry. Initially, this paper proposes a thermodynamic order-to-disorder free-energy equation for microphase separation to formulate the dynamic equilibria and fluctuations, which originate from the interplay of the phase and microphase separations during glass transition. Then, the Adam–Gibbs domain model is employed to explore the cooperative dynamics and molecular entanglement in glassy matter. It relies on the concept of transition probability in pairing, where each domain contains e + 1 segments, in which approximately 3.718 segments cooperatively relax in a domain at the glass transition temperature. This model enables the theoretical modeling and validation of a previously unverified statement, suggesting that 50–100 individual monomers would relax synchronously at glass transition temperature. Finally, the constant free-volume fraction of 2.48% is phenomenologically obtained to achieve a condensed constant (C) of C= 0.12(1−γ) = 1.501 × 10−11 J·mol−1·K−1, where γ represents the superposition factor of free volume and is characterised using the cumulative Poisson distribution function, at the condensed-matter scale, analogous to the Boltzmann constant (k
B) and gas constant (R).
Replication and study of anomalies in LK-99—the alleged ambient-pressure, room-temperature superconductor
Authors: Habamahoro T , Bontke T , Chirom M , Wu Z , Bao J M , Deng L Z , Chu C W 
Published: February 2024

Abstract
We have studied LK-99 [Pb10−x
Cu
x
(PO4)6O], alleged by Lee et al to exhibit superconductivity above room temperature and at ambient pressure, and have reproduced all anomalies in electric and magnetic measurements that they reported as evidence for the claim of LK-99 being an ambient-pressure, room-temperature superconductor. We found that these anomalies are associated with the structural transition of the Cu2S impurity in their sample and not with superconductivity.
The sensitivity demonstration and propagation of hyper-geometric soliton waves in plasma physics of Kairat-II equation
Authors: Faridi Waqas Ali , Tipu Ghulam Hussain , Myrzakulova Zhaidary , Myrzakulov Ratbay , AlQahtani Salman A , Pathak Pranavkumar 
Published: February 2024

Abstract
This study investigates the Kairat-II equation, describing optical pulse behavior in optical fibers and plasma. To uncover new solitary wave profiles, the study employs an extended direct algebraic method. This kind of solution has never been reached in research prior to this study. This innovative approach efficiently encompasses a comprehensive set of thirty-seven solitonic wave profiles, spanning various soliton families. The investigation unveils novel solitonic wave patterns, including plane solutions, hyper-geometric solutions, mixed hyperbolic solutions, periodic and mixed periodic solutions, mixed trigonometric solutions, trigonometric solutions, shock solutions, mixed shock singular solutions, mixed singular solutions, complex solitary shock solutions, singular solutions, and shock wave solutions. To demonstrate the pulse propagation characteristics, the research presents 2-D, 3-D, and contour graphics based on parameter values, aiding in a better understanding of the phenomenon.
Electronic and transport properties of boron and nitrogen passivated zigzag graphene nanoribbons
Authors: Narwaria Premlata , Chauhan Satyendra Singh , Shrivastava A K 
Published: February 2024

Abstract
A systematic study is conducted on 8ZGNR by edge terminations with boron and nitrogen at I and II termination sites by replacing hydrogen atoms in a single layer and in two probe systems. Electronic properties were observed in the DFT framework. Non-equilibrium green’s function (NEGF) tool was used to study the transport properties. Analysis of band structure, total energy, formation energy, and projected density of states (PDOS) suggest that despite Boron and Nitrogen passivation at all the termination sites, the electronic behavior of the system remains metallic. The analysis of Transmission spectra also confirms its metallic behavior in all these cases. This study reveals that B and N passivated graphene nanoribbons are sensitive to electronic transmission. This fact makes it potentially useful for application in sensors, memory devices and many other nano-electronic devices.