bluuebunny/crossref_metadata_2025_split huggingface dataset:
1.3 Synthesis of Small Fluorinated Carbocycles
Authors: Peyrical L. C. , Charette A. B. 
Published: February 2025

AbstractSmall carbocycles, such as three- and four-membered rings, are highly strained motifs that represent an interesting class of organic compounds. Fluorinated analogs of these scaffolds, combining the attractive features of both small carbocycles and fluorinated groups, have been studied for several decades, particularly in the field of medicinal chemistry. In recent years, several interesting achievements and new developments have been reported in the synthesis of small fluorinated carbocycles. In particular, various fluorinated substituents have found increasing significance, such as the fluoromethyl group (CFH2), the difluoromethyl group (CF2H), the trifluoromethyl group (CF3), and the pentafluorosulfanyl (SF5) group. Reviewed herein are synthetic strategies developed between 2017 and 2024 to afford three- and four-membered rings with these emerging fluorinated substituents.
Does renewable energy reduce energy intensity? A matter of income inequality
Authors: Li Rongrong , Yang Zhuang , Wang Qiang 
Published: February 2025

Abstract
This study investigates the complex relationships between income inequality, renewable energy utilization, and energy efficiency across 104 countries from 2010 to 2020. By employing the Panel Threshold Model and Unconditional Quantile Regression based on the Re-centered Influence Function, the analysis focuses on the moderating role of income inequality in shaping the impact of renewable energy consumption on energy intensity. The results indicate a nonlinear relationship, driven by a single-threshold effect of income inequality. In contexts with low income inequality, renewable energy consumption significantly reduces energy intensity, demonstrating its potential to enhance energy efficiency. However, as income inequality increases, this positive association weakens, suggesting that income inequality can act as a barrier to achieving energy-efficient economies. The study further highlights substantial variations across regions and income levels. In high-income economies, greater financial resources enable more widespread adoption of renewable energy, mitigating the adverse effects of income inequality on energy efficiency. By contrast, in middle-income countries, severe income disparities erode the ability of renewable energy to contribute meaningfully to reducing energy intensity. These findings suggest that by incorporating equity considerations into energy strategies, nations can strengthen the synergy between renewable energy adoption and energy efficiency, fostering progress across diverse economies.
Theoretical study of mode competition including backward wave and experiment on the 28 GHz second harmonic gyrotron
Authors: Jia Kai , Niu Xinjian , Liu Yinghui , Liu Jianwei , Sun Zongzheng , Li Hongfu 
Published: February 2025

The gyrotron operates in the harmonic state, which can significantly reduce the required operating magnetic field but complicates the mode competition problem. In some situations, it is also possible for the backward wave of the fundamental wave mode to be excited to suppress the desired harmonic operating mode. Therefore, a detailed analysis of mode competition is necessary for gyrotrons operating in the harmonic state. This paper presents the theoretical research of mode competition and experimental work for the 28 GHz second harmonic gyrotron at the TE02 mode. Possible mode competition problems are analyzed in detail using the linear theory and the multimode time-dependent non-linear theory. The problem of excitation of the backward wave of the fundamental wave mode TE21, which may be present, is received focused investigation. Ultimately, the possible competition modes are successfully suppressed in the non-linear simulation by setting up a suitable startup scenario, and an interaction efficiency of 32.5% is obtained. Based on the theoretical research results, experimental verification is carried out. When the working voltage is 29.8 kV, the beam current is 1.18 A, and we obtain stable single mode operation of the gyrotron, which has an operation frequency of about 27.96 GHz and an interaction efficiency of about 30.1% from the experiment.
Two optimization problems for the Loewner energy
Authors: Wang Yilin 
Published: February 2025

A Jordan curve on the Riemann sphere can be encoded by its conformal welding, a circle homeomorphism. The Loewner energy measures how far a Jordan curve is away from being a circle, or equivalently, how far its welding homeomorphism is away from being a Möbius transformation. We consider two optimizing problems for the Loewner energy, one under the constraint for the curves to pass through n given points on the Riemann sphere, which is the conformal boundary of hyperbolic 3-space H3; the other under the constraint for n given points on the circle to be welded to another n given points of the circle. The latter problem can be viewed as optimizing positive curves on the boundary of AdS3 space passing through n prescribed points. We observe that the answers to the two problems exhibit interesting symmetries: optimizing the Jordan curve in ∂∞H3 gives rise to a welding homeomorphism that is the boundary of a pleated plane in AdS3, whereas optimizing the positive curve in ∂∞ AdS3 gives rise to a Jordan curve that is the boundary of a pleated plane in H3.
FPGA-based process, voltage, and temperature insensitive picosecond resolution timing generators with offset correction for automatic test equipment
Authors: Guo Zeyu , Gui Liangqi , Sheng Kai 
Published: February 2025

This paper presents the implementation of a picosecond resolution timing generator (TG) insensitive to process, voltage, and temperature (PVT) variations for automatic test equipment. The TG is implemented in field-programmable gate arrays (FPGAs) using two-stage time interpolation, which utilizes a multi-phase generator, IDELAY3, and carry-chain resources. To enhance the test rate, each channel of the proposed TG consists of four parallel operating edge generators. The TG performance will deteriorate severely without offset correction due to its sensitivity to PVT variations. To improve the adaptability of the TG, we design a robust offset canceler to ensure stable performance of the TG, resilient to PVT variations. With the proposed architecture and offset canceler, the PVT-insensitive TG achieves a time resolution of 5 ps and offers a maximum dynamic range of 10 s. It also shows improved worst case integral non-linearity ranging from −4.7 to +4.6 ps with the operating temperature continuously varying from 15 to 65 °C and voltage ranging from 0.95 to 1.01 V in FPGAs. The proposed TG can be implemented in the Ultrascale or Ultrascale+ FPGA platform.
From rediscovery towards recovery: a recent history of Australia’s most critically endangered marsupial, Gilbert’s potoroo (Potorous gilbertii)
Authors: Friend J. Anthony , Sinclair Elizabeth A. , Courtenay Jacqueline M. 
Published: February 2025

Context Ngilgaitch/Gilbert’s potoroo (Potorous gilbertii) was presumed extinct until its rediscovery at Two Peoples Bay Nature Reserve, Australia, in 1994. Aims Our paper summarises the history and rediscovery of Ngilgaitch/Gilbert’s potoroo, outlines the diverse research conducted to inform recovery, describes key management actions, and documents the fluctuating fortunes of the species between 1994 and 2024. Methods We summarise research and management actions to promote the species’ recovery at Two Peoples Bay Nature Reserve and nearby reserves. Key results About 40 Ngilgaitch/Gilbert’s potoroo survived in heathland on the slopes of Maardjitup Gurlin/Mount Gardner, feeding almost exclusively on the fruiting bodies of hypogeal fungi. Two ‘insurance’ populations were established between 2005 and 2014 by translocation from the original population to Bald Island (810 ha) and a mainland enclosure (380 ha). These colonies proved critical to the species’ survival when a wildfire consumed most of the habitat at Two Peoples Bay in November 2015, causing the functional extinction of the population. Efforts have begun to restore this population through translocation from the insurance populations. Conclusion Establishing new potoroo populations by translocation has been the most valuable recovery technique for this species. Current and predicted climate change must be considered when choosing translocation sites. Management of all populations requires effective fire management, feral predator control, and actions derived from genetic information. Implications The Two Peoples Bay potoroo population was effectively lost following the 2015 fire. However, the regenerating habitat at the site remains an important resource in efforts to ensure the survival of the species.
Quantum state tomography on closed timelike curves using weak measurements
Authors: Bishop Lachlan G , Costa Fabio , Ralph Timothy C 
Published: February 2025

Abstract
Any given prescription of quantum time travel necessarily endows a Hilbert space to the chronology-violating (CV) system on the closed timelike curve (CTC). However, under the two foremost models, Deutsch’s prescription (D-CTCs) and postselected teleportation (P-CTCs), the CV system is treated very differently: D-CTCs assign a definite form to the state on this system, while P-CTCs do not. To further explore this distinction, we present a methodology by which an operational notion of state may be assigned to their respective CV systems. This is accomplished via a conjunction of state tomography and weak measurements, with the latter being essential in leaving any notions of self-consistency intact. With this technique, we are able to verify the predictions of D-CTCs and, perhaps more significantly, operationally assign a state to the system on the P-CTC. We show that, for any given combination of chronology-respecting input and unitary interaction, it is always possible to recover the unique state on the P-CTC, and we provide a few specific examples in the context of select archetypal temporal paradoxes. We also demonstrate how this state may be derived from analysis of the P-CTC prescription itself, and we explore how it compares to its counterpart in the CV state predicted by D-CTCs.
Microlocal properties of the Radon transform on V-lines: a framework to reduce artifacts due to intrinsic missing data in linear Compton cameras
Authors: Rosenblatt Mariel , Morvidone Marcela , Cebeiro Javier 
Published: February 2025

Abstract
Microlocal Analysis constitutes a theoretical framework based on Fourier analysis and differential geometry that provides a precise characterization of singularities in image reconstruction in the context of the classical Radon transform theory. Accurate descriptions of artifacts together with strategies to mitigate them have been proposed since it was introduced. Artifacts due to missing data are presumably the most challenging problem addressed by microlocal analysis. Recent extensions of these analytical concepts to the field of transmission Compton tomography show the efficacy of this theoretical framework. Conversely, in the case of Compton cameras, an emission technique wherein the issue of missing data is an intrinsic problem, these ideas are still unexplored. In this work we introduce a Radon transform over double V-lines, presenting its key properties for deriving a filtered back-projection formula. This theoretical groundwork enables us to outline an initial methodology utilizing microlocal analysis to develop a framework aimed at mitigating the main artifacts produced by the limited size of detectors in linear Compton cameras.
Temperature-dependent investigation of polarisation doping in 330 nm ultraviolet light-emitting diodes
Authors: Milner P , Zubialevich V Z , Singh S M , Pampili P , Corbett B , Parbrook P J 
Published: February 2025

Abstract
Polarisation doping of

Al
x

Ga

1
−
x

N, through grading of x, has realised major improvements in p-type conductivity in ultraviolet (UV) light-emitting diodes (LEDs) compared to conventional impurity doping. However, the exact balance between the two doping regimes to achieve the best device performance is not clear, especially as a function of operating wavelength. In this work, 330 nm LEDs with varied p-doping approaches were characterised as a function of temperature: Mg doped only (reference); polarisation doped and Mg doped (co-doped); and polarisation doped only. At room temperature, the co-doped LED showed the highest electroluminescence (EL) intensity, with a similar operating voltage to the reference LED. The highest hole concentration, confirmed by Hall effect measurements, as well as improved injection efficiency revealed by simulations, are credited as the main reasons for EL improvement. A parasitic near-UV luminescence tail, analogous to the ‘blue luminescence’ in p-GaN, was observed in both the reference and co-doped LEDs, but was absent in the polarisation doped LED. The reference LED demonstrated the highest increase in operating voltage with decreasing temperature, while the LED with only polarisation doping showed a temperature-independent behaviour, demonstrating the benefits of a polarisation field-induced carrier concentration. Further optimisation of the compositional grading with concurrent Mg doping can potentially produce higher performance LEDs with cleaner spectra.
Predicting two-dimensional ferroelastic semiconductors LuX (X=N, P, As): negative Poisson’s ratio, high carrier mobility, and strong visible light absorption
Authors: Chen Zibo , Ma Fengxian , Gao Zhen , Jiao Yalong 
Published: February 2025

Abstract
Two-dimensional (2D) materials manifesting ferroelasticity have received significant attention, yet it is uncommon for single materials to exhibit ferroelasticity alongside high carrier mobilities and strong visible light absorption. In this study, we use first-principles calculations to predict three 2D semiconductors: LuX monolayers (X = N, P, As), which are distinguished by their exceptional dynamical, thermodynamic, and mechanical stability. These LuX monolayers feature band gaps ranging from 0.98 eV to 1.98 eV, placing them within the ideal range for solar cell applications, and they exhibit strong visible light absorption, reaching up to 5%. Notably, the LuP monolayer demonstrates remarkable carrier mobility, reaching 1796 cm2·s−1·V−1, surpassing that of MoS−1 and showcasing its superior transport properties. Mechanical analyses reveal a significant in-plane negative Poisson’s ratio (NPR) for these materials, as high as −0.37, which is substantially greater than that of black phosphorus. Additionally, all LuX monolayers are identified as 2D ferroelastic materials, with reversible strains ranging from 12.9% to 17.8%. Our findings highlight the exceptional electronic, mechanical, and optical properties of the LuX monolayers, making them promising candidates for a wide range of multifunctional applications.
Effect of atomic configuration and biaxial strain on the electronic properties of

Cd

x

Zn

1
−
x

Te

and

Hg

1
−
x

Cd

x

Te

alloys: a first principles study
Authors: Alowa F , Matsubara M , Schaake C , Bellotti E 
Published: February 2025

Abstract
The electronic properties of CdZnTe and HgCdTe alloys intended for ionizing radiation and infrared detection applications are studied using first-principles calculations based on density functional theory. The Heyd, Scuseria, and Ernzerhof functional and the modified Becke–Johnson potential are employed to predict the band gap and bowing parameters of the ternary alloys over the full composition range. We demonstrate the impact of the atomic disorder on the band gap energy and thermodynamic stability of the alloys by analyzing all distinct atomic arrangements of supercells up to 16 atoms. Subsequently, we investigate the impact of biaxial strain in the (001), (111) and (112) crystal planes on the electronic properties of binary ZnTe, CdTe, and HgTe compounds, as well as the ternary alloys with composition

x
=
25
%

, 50% and 75%. We observe distinct behavior of the compounds under tetragonal and trigonal deformations, particularly for the semimetal HgTe and its alloys, where we find an unexpected non-linear band gap dependence of HgCdTe on the Cd composition, strain orientation, and strain magnitude. These results can be used to aid in the design of optoelectronic devices with targeted functionality.
An IoT-based quality inspection robot for measuring conductor sag and detecting defects in ultra-high voltage overhead transmission lines
Authors: Song Jiayin , Jiang Zhuoyuan , Zhou Jiancai , Zhu Qinglin , Liao Ting , Lu Teng , Wang Jinlong , Zhou Hongwei , Yang Liusong , Song Wenlong 
Published: February 2025

Abstract
Aiming to solve the urgent problem of sag measurement in constructing ultra-high voltage (UHV) power transmission lines non-line-of-sight conditions, we have developed an internet of things-based quality inspection robot for UHV overhead transmission line conductors to assist in construction. This robot not only improves the accuracy of sag measurement but also possesses the function of detecting and locating line defects. Utilizing sensors, it monitors sag, environment, and operating conditions in real-time and uploads the results to a cloud platform. The proposed lightweight YOLOv5s-SGSW algorithm, deployed on NVIDIA Jetson TX2, detects transmission line defects with 81.9% precision at 35.62 FPS. The integration of autonomous positioning algorithms and defect detection locates the defects on the transmission line. The relative errors are 0.25% for the X-coordinate and 2.07% for the Y-coordinate of the defect localization. A new tension-based sag compensation method is proposed to compensate for the sag error caused by the robot’s weight, with experimental results showing an error of 1.3%. This indicates that the robot can meet the expected design goals and satisfy the practical engineering requirements.
Sequence equicontinuity, bounded sequence complexity and rigidity
Authors: Li Jie , Li Zhijin , Zhao Jianjie 
Published: February 2025

Abstract
In this paper, in both topological and measure-theoretical senses, various types of sequence equicontinuity and bounded sequence complexity via Furstenberg family are introduced, and the interrelationships among which and rigidity are systematically studied, which generalize many known results in the literature. In particular, it is shown that a topological dynamical system (X, T) is uniformly rigid iff it is

F

r

-equicontinuous of type 4 iff it has bounded

F

r

-complexity of type 4; And a measure-preserving system

(
X
,

B

X

,
μ
,
T
)

is rigid iff it is µ-

F

r

-mean equicontinuous of type 4 iff it has bounded µ-

F

r

-mean complexity of type 4, where

F

r

is the Furstenberg family consisting of all sequences like

q

N

(

q
∈

N

). Moreover, several examples are also constructed to distinguish the new notions or illustrate the scopes of some conclusions, while concurrently addressing a few questions posed in earlier articles.
Characterizing the magnetic noise power spectrum of dark spins in diamond
Authors: Williams Ethan Que , Ramanathan Chandrasekhar 
Published: February 2025

Abstract
The coherence times of solid-state spin qubits are often limited by the presence of a spin bath. Characterizing the spectrum of the local magnetic field fluctuations of the bath is key to understanding spin qubit decoherence. Here we use pulsed electron paramagnetic resonance (pEPR) based noise spectroscopy to measure the magnetic noise power spectra for ensembles of P1 (substitutional nitrogen) centers in diamond that typically form the bath for NV (nitrogen-vacancy) centers. The Carr-Purcell-Meiboom-Gill (CPMG) dynamical decoupling experiments on the P1 centers were performed on a low [N] CVD (chemical vapor deposition) sample and a high [N] HPHT (high-temperature, high-pressure) sample at 89 mT. We characterize the NV centers of the latter sample using the same 2.5 GHz pEPR spectrometer. All power spectra show two distinct features, a broad component that is observed to scale as approximately 1/ω^{0.7-1.0}, and a prominent peak at the 13C Larmor frequency. The behavior of the broad component is consistent with an inhomogeneous distribution of Lorentzian spectra due to clustering of P1 centers, which has recently been shown to be prevalent in HPHT diamond. We develop techniques utilizing harmonics of the CPMG filter function to improve characterization of high-frequency signals, which we demonstrate on the 13C nuclear Larmor frequency. At 190 mT this is 2.04 MHz, 5.7 times higher than the CPMG modulation frequency (<357 kHz, hardware-limited). Understanding the properties of the bath allow us to either exploit it as a quantum resource or optimize decoupling performance, while also informing sample fabrication technologies. The techniques are applicable to ac magnetometry for nanoscale nuclear magnetic resonance and chemical sensing.
Kramers–Henneberger atoms in flattened Gaussian beams
Authors: Leung Ioksang , Zhu Mingyu , Wang Pingxiao , Wei Qi 
Published: February 2025

Abstract
The dichotomy structure is one of the prominent features of Kramers–Henneberger (KH) atoms. Within a focused laser field, the wave function of KH atoms becomes polarized due to ponderomotive (PM) forces induced by light intensity gradients, leading to the disruption of the dichotomy structure. In a Gaussian-focused laser field, the PM forces are negligible only along the optical axis. To maintain the dichotomy structure of KH atoms over a broader area, we compared the result of flattened Gaussian laser beams with Gaussian-focused laser beams. By calculating the wave functions of ground KH state hydrogen atoms at various radial and angular locations in the laser focusing plane, it was demonstrated that under suitable laser parameters, the dichotomy structure can be fully or partially preserved in flattened Gaussian laser beams. Through the dichotomy structure of KH atoms, we can verify the existence of KH atoms using interference fringes of multi-photon ionization signals.
Statistical analysis of Revan topological indices for drug compounds used in treatment of tuberculosis
Authors: Shenoy B Gautham , M Vishu Kumar , Acharya Divya , H M Nagesh , Poojary Prasanna 
Published: February 2025

Abstract
One of the most infectious diseases, tuberculosis (TB) has a higher death rate than HIV/AIDS, and as a result of the COVID-19 pandemic, there is concern that the number of TB cases may increase. With the aid of QSPR models, the pharmaceutical industry is continuously searching for methods to enhance medication design procedures to stop the spread of infections and treat recently discovered syndromes or genetically based dysfunctions. QSPR models are mathematical tools that utilize structural properties to establish relationships between a molecular structure and its physicochemical attributes. One way to generate attributes from the molecular graph without the need for experimental measurements is to use topological indices. The goal of this work is to create a QSPR model for tuberculosis drugs and their many physicochemical characteristics using degree-based topological indices.