bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gate voltage tuning of photo-responses in n-AlGaAs/GaAs/AlGaAs double-heterojunction
Authors: Kawazu Takuya 
Published: December 2024

We demonstrate that the gate voltage Vg tunes the Schottky photocurrent ISG for the irradiation of two lights (Light A and B) in an n-AlGaAs/GaAs/AlGaAs double-heterojunction. Light A is a 975-nm laser that illuminates the entire Schottky gate region at 280 μW/mm2. Light B is a 670-nm laser that locally illuminates the ungated region at 0.4 μW. When Vg = 0 V, Light B doubles ISG for Light A. At Vg = 87 mV, ISG is generated only when both Light A and B are irradiated simultaneously, like the logical operation A∩B. When Vg = 165 mV, ISG is induced only for the illumination of Light A alone, like A∩B̄.
Novel pseudo-hexagonal montmorillonite model and microsecond MD simulations of hydrate formation in mixed clay sediments with surface defects
Authors: Mi Fengyi , Pang Jiangtao , Li Wei , Moultos Othonas A. , Ning Fulong , Vlugt Thijs J. H. 
Published: December 2024

Both CH4 hydrate accumulation and hydrate-based CO2 sequestration involve hydrate formation in mixed clay sediments. The development of realistic clay models and a nanoscale understanding of hydrate formation in mixed clay sediments are crucial for energy recovery and carbon sequestration. Here, we propose a novel molecular model of pseudo-hexagonal montmorillonite nanoparticles. The stress–strain curves of tension, compression, and shear of pseudo-hexagonal montmorillonite nanoparticles exhibit linear characteristics, with tension, compression, and shear moduli of ∼435, 410, and 137 GPa, respectively. We perform microsecond molecular dynamics simulations to study CH4 and CH4/CO2 hydrate formation in montmorillonite–illite mixed clay sediments with surface defects. The results indicate that hydrate formation in mixed clay sediments is significantly influenced by the presence of clay defects. CH4 and CH4/CO2 mixed hydrates are challenging to form at the junction between the inside and outside clay defects. CH4 and CH4/CO2 mixed hydrates exhibit a preference for forming outside the clay defects rather than inside the clay defects. Some CH4 and CO2 molecules from the inside clay defect migrate to the outside clay defect, thereby promoting CH4 and CH4/CO2 mixed hydrate formation outside the clay defects. This molecular insight advances the development of clay particle models and expands an understanding of natural gas hydrate accumulation and hydrate-based CO2 sequestration.
Placement poverty has major implications for the future health and education workforce: a cross-sectional survey
Authors: Lambert Kelly , Austin Kylie , Charlton Karen , Heins Rebecca , Kennedy Meredith , Kent Katherine , Lutze Janna , Nicholls Natalie , O’Flynn Gabrielle , Probst Yasmine , Walton Karen , McMahon Anne 
Published: December 2024

Objective ‘Placement poverty’ refers to the financial burdens imposed upon students by the completion of mandatory professional placement. We aimed to identify the financial implications of mandatory professional placements on student wellbeing. Methods A cross-sectional online survey (August 2023 to January 2024) completed during students’ most recent professional placement in the final year of their degree. Eligible participants were health or teaching students studying at Australian and New Zealand universities in degrees requiring mandatory professional placement. Questions included total and accommodation costs, financial support, impact of finances on placement preferences, presence of food insecurity, and implications for student wellbeing. Results Participants (n = 530) were mostly health professional (65%) students (median, 25; interquartile range (IQR), 22–30 years, 95.3% domestic, 88.3% full time, 2.0% New Zealand). Health students had higher total costs (in Australian dollars) for the recent placement ($1500; IQR, 600–3453) compared to teaching students ($1200; IQR, 600–2757) (P = 0.02), likely due to longer placement duration (6 weeks for health students). A higher proportion of health students required financial support (P = 0.0001). Placement preferences were always or sometimes (63.8%) determined by cost rather than learning opportunity. Food insecurity was experienced by most students (70.2%) (10.4% marginal, 32.1% moderate, 27.7% severe), with no difference by degree type. Thematic analysis identified themes of burnout, emotional distress, inability to focus on learning, postponing care of oneself, urgent need for financial support, unanticipated family and other circumstances, and worsened societal inequity. Conclusions Our study identified widespread financial difficulty in students undertaking placement that adversely impacted personal wellbeing. Strategies are needed to support wellbeing and ameliorate the financial burden.
Assessing climate-driven glacial retreat, snow-cover reduction and GLOF risks: implications for water resource management amid rising global temperatures and CO2
Authors: Yahya Muhammad , Noreen Uzma , Attia Kotb A. , Jabeen Fariha , Aslam Afifa , Anjum Navid , Abbasi Asim , Zaidi Syed Faizan Hassan 
Published: December 2024

Context The consequences of climate change, including alterations in snow and glacier patterns and rising temperatures, pose a risk of glacial lake outburst floods (GLOFs), which can have cross-border impacts, leading to the loss of life and property downstream. Aims This research focused on the assessment of changes in snow cover within Chitral district imposed by temperature increase. Methods ArcGIS and Origin programs were used in this research to study the glacier pattern of Chitral. Results Therer was a significant increase of 266.7% in urban development and an expansion of 135.9 km2 in agricultural areas within this remote mountainous region. The findings of the study show that in the year 2000, >51.6% of Chitral district’s total land was covered by snow during early winter. However, this coverage drastically declined to ~6.8% by 2008. Across the initial two 4-year periods, ~44.7% (5694.6 km2) of the glaciated area transitioned to barren rock, whereas the overall reduction in snow-covered areas accounted for ~43.3% (5514.6 km2). Conclusion Owing to the increasing stress on freshwater resources, it is essential to conduct thorough analyses and monitoring of snow patterns to ensure sustainable freshwater availability and effective environmental risk management. Implications This study emphasises the critical consequences of climate-driven glacial retreat, waning snow cover and increased risks of glacial lake outburst floods (GLOFs) for the management of water resources with the rise in global CO2 and temperatures levels. These changes threaten the timing and availability of water supply, with impacts on agriculture, ecosystem and hydropower. Effective adaptation measures and sustainable management practices are crucial to alleviate these risks and ensure water security in a warming world.
Primordial gravitational wave backgrounds from phase transitions with next generation ground based detectors
Authors: Caprini Chiara , Pujolàs Oriol , Quelquejay-Leclere Hippolyte , Rompineve Fabrizio , Steer Danièle A 
Published: December 2024

Abstract
Third generation ground-based gravitational wave (GW) detectors, such as Einstein Telescope and Cosmic Explorer, will operate in the

(
few
−

10
4

)

Hz frequency band, with a boost in sensitivity providing an unprecedented reach into primordial cosmology. Working concurrently with pulsar timing arrays in the nHz band, and LISA in the mHz band, these 3G detectors will be powerful probes of beyond the standard model particle physics on scales

T
≳

10

7

GeV. Here we focus on their ability to probe phase transitions (PTs) in the early Universe. We first overview the landscape of detectors across frequencies, discuss the relevance of astrophysical foregrounds, and provide convenient and up-to-date power-law integrated sensitivity curves for these detectors. We then present the constraints expected from GW observations on first order PTs and on topological defects (strings and domain walls), which may be formed when a symmetry is broken irrespective of the order of the phase transition. These constraints can then be applied to specific models leading to first order PTs and/or topological defects. In particular we discuss the implications for axion models, which solve the strong CP problem by introducing a spontaneously broken Peccei-Quinn (PQ) symmetry. For post-inflationary breaking, the PQ scale must lie in the

10

8

−

10

11

GeV range, and so the signal from a first order PQ PT falls within reach of ground based 3G detectors. A scan in parameter space of signal-to-noise ratio in a representative model reveals their large potential to probe the nature of the PQ transition. Additionally, in heavy axion type models domain walls form, which can lead to a detectable GW background. We discuss their spectrum and summarise the expected constraints on these models from 3G detectors, together with SKA and LISA7

7
Invited review for a CQG Focus Issue on the science case for next generation ground based GW detectors.
.
Truncated amplitude flow with coded diffraction patterns
Authors: Li Huiping , Li Jiayi 
Published: December 2024

Abstract
The phase retrieval problem, which involves Fourier transforms with random masks, has a wide range of applications in signal and image processing, such as diffraction imaging. In recent years, various first-order methods have been explored, including truncated amplitude flow (TAF). These methods are considered to be simple and effective for solving the phase retrieval problem. However, existing convergence results for TAF mainly focus on random Gaussian measurements, which is very far from practical scenarios. In this paper, we analyze the convergence of a revised TAF (RTAF) for the phase retrieval problem. We focus on coded diffraction patterns composed of Fourier transforms and random masks. Then we justify the linear convergence behavior of such algorithm when near the true solution. By utilizing the local initializer found by a non-truncated spectral method, we establish the exact convergence rates in both the noiseless case and the bounded noise case. Further, we have shown that a general signal

x
∈

C

n

can be estimated on an optimal sampling order (specifically,

O
(
n
log
⁡
n
)

). Moreover, our demonstrations indicate that sharp stability can be maintained even when the observations are contaminated by bounded noise. Our experiments have revealed that the RTAF algorithm can reliably estimate the original signal using fewer measurements, aligning with our theoretical analysis. Additionally, numerical experiments have highlighted that the RTAF algorithm outperforms the truncated Wirtinger flow and truncated Riemannian gradient descent algorithms in terms of efficiency and stability, showcasing its superior performance over state-of-the-art algorithms.
Using an electronic balance to measure the kinetic friction coefficient in class experiment
Authors: Luo Duan-bin 
Published: December 2024

Abstract
In this paper, we propose an experimental method for measuring the kinetic friction coefficient using an electronic balance. We measured the kinetic friction coefficient of the wooden block on the paper tape using this method and compared the result with that using the force sensor method. The results of the two methods were in good agreement. This method is convenient and can be implemented in many laboratories, and at the same time it can measure the kinetic friction coefficients between different materials easily. Therefore, it is a simple and practical experimental method for high school students or first-year college students to measure the kinetic friction coefficient in class experiment.
ICRP pregnant-female mesh-type reference computational phantoms part 1: development of fetal phantoms
Authors: Shin Bangho , Kim Suhyeon , Choi Chansoo , Kim Hyeonil , Yeom Yeon Soo , Chung Beom Sun , Nguyen Thang Tat , Moon Sungho , Bolch Wesley E , Kim Chan Hyeong 
Published: December 2024

Abstract

Objective. The International Commission on Radiological Protection (ICRP) decided to develop pregnant-female reference computational phantoms, including the maternal and fetal phantoms, through its 2007 general recommendations. Acknowledging the advantages of the mesh geometry, the ICRP decided to develop the pregnant-female mesh-type reference computational phantoms (MRCPs) for 8, 10, 15, 20, 25, 30, 35, and 38 week fetal ages directly in the mesh format. As part of this process, the present study developed the mesh-type fetal phantoms. Approach. The reference blood-inclusive organ masses, elemental compositions, and densities were established based on various scientific literatures. Then, the phantoms were developed in accordance with the established reference dataset while reflecting the anatomical features of the developing fetus, such as fetal-age-specific anthropometric parameters, bone ossification, and contents formation time. Main results. The phantoms were developed in the tetrahedral-mesh format and can be implemented in the general-purpose Monte Carlo codes (i.e. Geant4, PHITS, MCNP6, and EGSnrc) without the necessity of the voxelization process. To explore the dosimetric impact of the developed phantoms, photon specific absorbed fractions (SAFs) were computed for energies between 10−2–101 MeV for the fetal liver and spleen as source regions and self-irradiation and cross-irradiation to the fetal brain, lungs, and urinary bladder wall as target regions. The SAFs showed the fetal-age-dependent dose trends (i.e. SAF decreases with increasing fetal age) due to organ masses increases via fetal growth. Significance. The mesh-type fetal phantoms, as part of the ICRP pregnant-female MRCPs, will be used to calculate reference dose coefficients for fetal members of the public for both the current and future ICRP general recommendations.
Effect of the cation-to-anion mass ratio of ionic liquid on plume neutralization characteristics for novel electrospray thruster
Authors: Han Meiting , He Jiahui , Meng Baoqing , Tian Baolin , Li Jianling 
Published: December 2024

Abstract
The ionic liquid electrospray thruster (ILET), a promising technology for space electric propulsion, has been gaining attention due to its theoretical capability to operate without an external neutralizer, which is a key component for traditional ion thrusters. Some experiments have shown that the cation-to-anion mass ratio significantly affects the self-neutralization of thruster plumes, but further depth research is still needed. Therefore, numerical simulations of ion emission process both in uni-thruster and bi-thruster modes of ILETs are conducted using particle-in-cell method, to investigate the effect of the cation-to-anion mass ratio in ionic liquid on plume neutralization characteristics. In bi-thruster mode, the anions and cations are emitted simultaneously, while in uni-thruster mode, only anions or cations are emitted under the action of electric field force. Plume neutralization characteristics of four ionic liquid propellants, with different cation-to-anion mass ratio, in bi-thruster mode are obtained and compared to the uni-thruster mode. The results show that the plume profile morphology is significantly dependent on operating mode of the thruster and the cation-to-anion mass ratio of ionic liquid. Unlike the circular profile in uni-thruster mode, the plume in bi-thruster mode exhibit distortion with vertical stratification. The contours of the high-potential region in bi-thruster mode also distort, showing stratification and a V-shape, respectively, influenced by the mass ratio. Ion beam neutralization in bi-thruster mode is primarily achieved through the horizontal displacement of anion and cation beams, as well as their interactions. The cation-to-anion mass ratio influences the oscillation effects of the mass center in anion and cation clouds during neutralization, which in turn affects the neutralization effect. Ionic liquids with a significant mass ratio difference between cations and anions necessitate a longer time and greater distance for neutralization under identical conditions. These findings are instrumental for understanding the plume neutralization process and advancing the design of ILETs.
Searches for exotic spin-dependent interactions with spin sensors
Authors: Jiang Min , Su Haowen , Chen Yifan , Jiao Man , Huang Ying , Wang Yuanhong , Rong Xing , Peng Xinhua , Du Jiangfeng 
Published: December 2024

Abstract
Numerous theories have postulated the existence of exotic spin-dependent interactions beyond the Standard Model of particle physics. Spin-based quantum sensors, which utilize the quantum properties of spins to enhance measurement precision, emerge as powerful tools for probing these exotic interactions. These sensors encompass a wide range of technologies, such as optically pumped magnetometers, atomic comagnetometers, spin masers, nuclear magnetic resonance, spin amplifiers, and nitrogen-vacancy centers. These technologies stand out for their ultrahigh sensitivity, compact tabletop design, and cost-effectiveness, offering complementary approaches to the large-scale particle colliders and astrophysical observations. This article reviews the underlying physical principles of various spin sensors and highlights the recent theoretical and experimental progress in the searches for exotic spin-dependent interactions with these quantum sensors. Investigations covered include the exotic interactions of spins with ultralight dark matter, exotic spin-dependent forces, electric dipole moment, spin-gravity interactions, and among others. Ongoing and forthcoming experiments using advanced spin-based sensors to investigate exotic spin-dependent interactions are discussed.
Database Design for SpExoDisks: A Database and Web Portal for Spectra of Exoplanet-forming Disks
Authors: Wheeler Caleb H. , Hinkel Natalie R. , Banzatti Andrea 
Published: December 2024

Abstract
Data access—or the availability of new and archival data for use by the larger community—is key for scientific advancement. How data is presented, searched, and formatted determines accessibility and it can be difficult to find a solution that fits the needs of a given subdiscipline. We present a generalized roadmap for developing a specialty astronomy database with web application based on the development of the Spectra of Exoplanet-forming Disks (SpExoDisks) database (spexodisks.com), which provides infrared spectra of protoplanetary disks. Expertise in an astronomy subdiscipline can provide two necessary components for creating a database: access to a large volume of specialized data and knowledge of how that data should be presented to the community. However, there are a variety of steps and decisions for database development that can fall outside astronomy expertise. Here we offer generalized discussions on design and process that are accompanied by real-world examples from the SpExoDisks developer team and website. Starting from the database portal design and data organization, we demonstrate on-demand data distribution and query using publicly accessible database software. These systems support interactive visualizations such that users can explore spectra directly from their browsers. We also offer details that show how the technical concepts in SpExoDisks are implemented, particularly emphasizing sustainability and long-term management of the codebase and processes. Finally, we illustrate the utility that a specialty website can offer to the community by providing a specific example of how the combined spectra from SpExoDisks can enhance our understanding of protoplanetary disks.
Non-convergence of some non-commuting double ergodic averages
Authors: Austin Tim 
Published: December 2024

Let

S
S

and

T
T

be measure-preserving transformations of a probability space

(
X
,

B

,
μ
)

(X,\mathcal {B},\mu )

. Let

f
f

be a bounded measurable function, and consider the integrals of the corresponding ‘double’ ergodic averages:
\[

1
n

∑

i
=
0

n
−
1

∫
f
(

S
i

x
)
f
(

T
i

x
)

d
μ
(
x
)

(
n
≥
1
)
.

\frac {1}{n}\sum _{i=0}^{n-1} \int f(S^ix)f(T^ix)\,d\mu (x) \qquad (n\ge 1).

\]
We construct examples for which these integrals do not converge as

n
→
∞

n\to \infty

. These include examples in which

S
S

and

T
T

are rigid, and hence have entropy zero, answering a question of Frantzikinakis and Host.

Our proof begins with a corresponding construction for orthogonal operators on a Hilbert space, and then obtains transformations of a Gaussian measure space from them.
Upper estimates for the Hausdorff dimension of the temporal singular set in chemotaxis-fluid systems
Authors: Fuest Mario 
Published: December 2024

The chemotaxis-fluid system

{

n
t

+
u
⋅
∇
n
=
Δ
n
−
∇
⋅
(
n
∇
c
)
,

c
t

+
u
⋅
∇
c
=
Δ
c
−
n
c
,

u
t

+
(
u
⋅
∇
)
u
=
Δ
u
+
∇
P
+
n
∇
Φ
,

∇
⋅
u
=
0
,

\begin{align*} \begin {cases} n_t + u \cdot \nabla n = \Delta n - \nabla \cdot (n \nabla c), \\ c_t + u \cdot \nabla c = \Delta c - nc, \\ u_t + (u \cdot \nabla ) u = \Delta u + \nabla P + n \nabla \Phi , \quad \nabla \cdot u = 0, \end{cases} \end{align*}

models aerobic bacteria interacting with a fluid via transportation and buoyancy. When posed on a three-dimensional, smoothly bounded, convex domain

Ω
\Omega

, the above equation complemented with suitable initial and boundary conditions is known to admit a global ‘weak energy solution’, which recently has been shown to be smooth (after a redefinition on a set of measure

0
0

) in

Ω
¯

×
E

\overline \Omega \times E

for some countable union of open intervals

E
E

with

|

(
0
,
∞
)
∖
E

|

=
0

|(0, \infty ) \setminus E| = 0

.

The present paper investigates further regularity properties of this solution and proves that (

E
E

can be chosen such that) the

1
2

\frac 12

-dimensional Hausdorff measure of

(
0
,
∞
)
∖
E

(0, \infty ) \setminus E

vanishes and thus that in particular its Hausdorff dimension is at most

1
2

\frac 12

. As

1
2

\frac 12

has been the best known upper estimate for the Hausdorff dimension of the temporal singular set for the unperturbed Navier–Stokes equations for quite some time, this result is the best one can hope for the above system without significant progress in the regularity theory of (homogeneous) Navier–Stokes equations.