bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative efficacy of plant derived extracts with the insecticide mospilan on two whitefly species Bemisia tabaci biotype B and Trialeurodes ricini
Authors: Hussein Hanaa S. , Idriss Mamdouh H. , El-Gayar Farouk H. , Mousa Hebatullah Yehia Saad , Salem Mohamed Z. M.
Published: January 2025

The insecticidal, synergistic, and acetylcholinesterase (AChE) inhibitory effects of plant n-hexane extracts (HEs) were evaluated. The HEs from thyme (Thymus vulgaris L.) leaves, garlic (Allium sativum L.) bulbs, and weeping willow (Salix babylonica L.) leaves were used in comparison with the acetamiprid insecticide (mospilan) against two whitefly species, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B and Trialeurodes ricini (Genn.) (Hemiptera: Aleyrodidae). Furthermore, using the choice test design, the repellent efficacy of three extracts was investigated against whitefly B. tabaci biotype B. The chemical compositions of HEs were identified using gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame-ionization detection (GC-FID) analysis. The main compounds of thyme HE were thymol and geranyl-α-terpinene; in garlic bulbs HE were diallyl sulfide and allyl tetrasulfide; and in weeping willow HE were 6-phenyltridecane, 6-phenyldodecane, and 5-phenyldodecane, while the methylated fatty acids were stearic and palmitic. The HEs of weeping willow and garlic showed the maximum toxicity against B. tabaci, while the HEs of thyme and garlic showed the highest toxicity against T. ricini. Mospilan with HEs resulted in a potentiating effect, with co-toxicity factors ranging between 21.47 for a mixture of garlic HE + mospilan against B. tabaci and 37.65 for weeping willow HE + mospilan against T. ricini. The mix of mospilan + weeping willow HE recorded the highest acetylcholinesterase (AChE) inhibitory effect 48 h after treatment. The highest expulsion effect was recorded by 2% thyme HE, with a repellency index (RI) of 88.22%. The HE of weeping willow at 1% exhibited the highest attractant effect with an RI value of -8.94%. The current research lays the groundwork for the integrated pest management (IPM) of B. tabaci biotype B and T. ricini by employing natural extracts and pesticides blends.
Towards sustainable perovskite light-emitting diodes
Authors: Zhang Muyi , Ma Xiaotian , Esguerra John Laurence , Yu Hongling , Hjelm Olof , Li Jiashuo , Gao Feng
Published: January 2025

Perovskite light-emitting diodes (PeLEDs) are advancing to become the frontrunner candidates for the next generation of lighting and display technologies. However, despite rapid technical development, a thorough understanding of PeLEDs’ environmental and economic impacts—essential information for future commercialization—is currently lacking. Here we assess the environmental and economic performance of 18 representative PeLEDs, aiming to identify effective industrial techniques to develop sustainable PeLEDs from a life-cycle perspective. We find that, like mature organic LEDs, PeLEDs show excellent environmental performance. In addition, we demonstrate that lead is not a major source of toxicity from PeLEDs. We estimate that, to commercialize PeLEDs and improve their sustainability, their lifetime should reach the order of 10,000 hours to compensate for the relative environmental impacts. The techno-economic assessment indicates that the cost of future PeLEDs will probably be in the vicinity of US$100 m–2, comparable to that of commercial organic LED panels. Overall, this study shows the potential of PeLEDs as next-generation lighting technology from environmental, economic and technical perspectives, providing insights relevant to their future development.
Proximity-induced flipped spin state in synthetic ferrimagnetic Pt/Co/Gd heterolayers
Authors: Brandão Jeovani , Carvalho Pamela C. , Miranda Ivan P. , Mori Thiago J. A. , Béron Fanny , Bergman Anders , Petrilli Helena M. , Klautau Angela B. , Cezar Julio C.
Published: January 2025

To develop new devices based on synthetic ferrimagnetic heterostructures, understanding the material’s physical properties is pivotal. Here, the induced magnetic moment (IMM), magnetic exchange coupling, and spin textures are investigated in Pt(1 nm)/Co(1.5 nm)/Gd(1 nm) multilayers using a multiscale approach. The magnitude and direction of the IMM are interpreted in the framework of both X-ray magnetic circular dichroism and density functional theory. The IMM transferred by Co across the Gd paramagnetic thickness leads to a nontrivial flipped spin state (FSS) within the Gd layers, in which their magnetic moments couple antiparallel/parallel with the ferromagnetic Co near/far from the Co/Gd interface, respectively. The FSS depends on the magnetic field, which, on average, reduces the Gd magnetic moment as the field increases. For the Pt, in both Pt/Co and Gd/Pt interfaces, the IMM follows the same direction as the Co magnetic moment, with negligible IMM in the Gd/Pt interface. Additionally, zero-field spin spirals were imaged using scanning transmission X-ray microscopy, whereas micromagnetic simulations were employed to unfold the interactions, stabilizing the ferrimagnetic configurations, where the existence of a sizable Dzyaloshinskii-Moriya interaction is demonstrated to be crucial.
Elongator is a microtubule polymerase selective for polyglutamylated tubulin
Authors: Planelles-Herrero Vicente J , Genova Mariya , Krüger Lara K , Bittleston Alice , McNally Kerrie E , Morgan Tomos E , Degliesposti Gianluca , Magiera Maria M , Janke Carsten , Derivery Emmanuel
Published: January 2025

Elongator is a tRNA-modifying complex that regulates protein translation. Recently, a moonlighting function of Elongator has been identified in regulating the polarization of the microtubule cytoskeleton during asymmetric cell division. Elongator induces symmetry breaking of the anaphase midzone by selectively stabilizing microtubules on one side of the spindle, contributing to the downstream polarized segregation of cell-fate determinants, and therefore to cell fate determination. Here, we investigate how Elongator controls microtubule dynamics. Elongator binds both to the tip of microtubules and to free GTP-tubulin heterodimers using two different subcomplexes, Elp123 and Elp456, respectively. We show that these activities must be coupled for Elongator to decrease the tubulin critical concentration for microtubule elongation. As a consequence, Elongator increases the growth speed and decreases the catastrophe rate of microtubules. Surprisingly, the Elp456 subcomplex binds to tubulin tails and has strong selectivity towards polyglutamylated tubulin. Hence, microtubules assembled by Elongator become selectively enriched with polyglutamylated tubulin, as observed in vitro, in mouse and Drosophila cell lines, as well as in vivo in Drosophila Sensory Organ Precursor cells. Therefore, Elongator rewrites the tubulin code of growing microtubules, placing it at the core of cytoskeletal dynamics and polarization during asymmetric cell division.
Coordination Chemistry Perspectives
Authors: Ishitani Osamu , Nakai Hidetaka , Nakazawa Hiroshi , Nam Wonwoo , Ohki Yasuhiro , Yamaguchi Toshio
Published: January 2025

A series of individual volumes providing a comprehensive treatment in new developments in coordination chemistry and interdisciplinary topics.
One-step synthesis of N-coordinated Rh catalysts for efficient and stable alkene hydroformylation
Authors: Lan Yongcheng , Wang Jia , Yun Dong , Xia Chungu , Qian Bo , Liu Jianhua
Published: January 2025

A highly dispersed Rh catalyst supported on nitrogen-doped carbon nanotubes (CNTs) was prepared using a one-pot method and exhibited highly catalytic performance in the hydroformylation of olefin.
New VVO2,VVO, VVOVVO and electrogenerated VIVOVVO systems of valproic acid hydrazones: Study of catalytic activity
Authors: Patra Roumi , Sinha Debopam , Mondal Sandip , Rajak Kajal Krishna
Published: January 2025

Reaction between [VO(acac)2] and two valproic acid hydrazide ligands, H2L1 and H2L2 leads to the formation of two mononuclear dioxido complexes [VV(O2)HL1-2] (1, 2) in acetonitrile, two oxidomethoxido complexes [VVO(L1-2)(OMe)(OHMe)]...
A green and sustainable catalytic protocol for methoxymethylation of primary amides using methanol with dihydrogen release
Authors: Babu Reshma , Sivakumar Ganesan , Rekha Padhy Smruti , Balaraman Ekambaram
Published: January 2025

A highly efficient and selective catalytic method for the methoxymethylation of primary amides with the liberation of dihydrogen under Mn(i) catalysis is reported.
Retina-on-chip: engineering functional in vitro models of the human retina using organ-on-chip technology
Authors: Gensheimer Tarek , Veerman Devin , van Oosten Edwin M. , Segerink Loes , Garanto Alejandro , van der Meer Andries D.
Published: January 2025

The retina is a complex and highly metabolic tissue in the back of the eye essential for human vision. In this review, we provide insights in the field of retina-on-chip based on current research.
Fabrication of nanoparticles with precisely controllable plasmonic properties as tools for biomedical applications
Authors: Kolar-Hofer Pauline , Zampini Giulia , Derntl Christian Georg , Soprano Enrica , Polo Ester , del Pino Pablo , Kereyeva Nurgul , Eggeling Moritz , Breth Leoni , Haslinger Michael J. , Mühlberger Michael , Ertl Peter , Shoshi Astrit , Hartbaum Julian , Jurisch Michael , Pelaz Beatriz , Schrittwieser Stefan
Published: January 2025

Highly homogenous nanoparticles fabricated via nanoimprint lithography with minimal batch-to-batch size variation and tailor-made plasmonic properties. Polymer surface modification ensures functionality, good biocompatibility and minor cytotoxicity.
Preparation of ethynylsulfonamides and study of their reactivity with nucleophilic amino acids
Authors: Kyoya Tatsuhiro , Ishida Hiroaki , Saitoh Toshiaki , Itoh Toshimasa
Published: January 2025

A facile synthesis for ethynylsulfonamides was developed, and reactivity of the ethynylsulfonamides with cysteine was enhanced in PBS. Propynylsulfonamides show promise as suitable Michael acceptors for selective bioconjugation with cysteine.
A layered basic zinc acetate coating for dendrite-free Zn anodes by interface environment regulation in aqueous zinc-ion batteries
Authors: Cai Qingsong , Guan Zhenyu , Hu Yue , Zhang Jianmin , Zhang Kai , Zheng Zongmin
Published: January 2025

The artificially constructed porous layered basic zinc acetate nanosheets can effectively reduce the electric field's tip effect and hydrogen evolution reaction, leading to uniform Zn nucleation and deposition.
Prelithiation strategies for enhancing the performance of lithium-ion batteries
Authors: Zhang Yiming , Shen Huyan , Li Yanyu , Hu Yongsheng , Li Yao
Published: January 2025

This review highlights prelithiation techniques to improve efficiency and stability in lithium-ion batteries, focusing on electrode materials. It evaluates strategies to enhance coulombic efficiency and cycle capacity while addressing challenges.
Knoevenagel-IMHDA and -IMSDA sequences for the synthesis of chiral condensed O,N-, S,N- and N-heterocycles
Authors: Kajtár Mihály , Király Sándor Balázs , Bényei Attila , Kiss-Szikszai Attila , Kónya-Ábrahám Anita , Horváth Lilla Borbála , Bősze Szilvia , Kotschy Andras , Paczal Attila , Kurtán Tibor
Published: January 2025

Heterocycles containing hexahydrobenzo[j]phenanthridine and hexahydro-1H-(thio)pyrano[3,4-c]pyridine skeletons were prepared by domino Knoevenagel-styryl Diels–Alder and intramolecular hetero-Diels–Alder sequences, respectively.
In situ synthesis of ultrafine Cu(ii) metal immobilized on pectin hydrogel, modified by a CoFe2O4/Pr-SO3H nanocomposite as a green catalyst for reduction of nitro compounds and synthesis of 1H-tetrazoles
Authors: Mozafari Roya , Mohammadi Maria , Moradi Setareh , Ghadermazi Mohammad
Published: January 2025

This research introduced CoFe2O4@HPECG/Pr-SO3H·Cu(ii) MNPs as green catalyst for the aqueous reduction of nitro compounds to amines and synthesis of 1H-tetrazoles.
MAGIS (Measuring Abundances of red super Giants with Infrared Spectroscopy) project
Authors: Taniguchi Daisuke , Matsunaga Noriyuki , Kobayashi Naoto , Jian Mingjie , Thorsbro Brian , Fukue Kei , Hamano Satoshi , Ikeda Yuji , Kawakita Hideyo , Kondo Sohei , Otsubo Shogo , Sameshima Hiroaki , Tsujimoto Takuji , Yasui Chikako
Published: January 2025

Context. Given their high luminosities (L ≳ 104 L⊙), red supergiants (RSGs) are good tracers of the chemical abundances of the young stellar population in the Milky Way and nearby galaxies. However, previous abundance analyses tailored to RSGs suffer some systematic uncertainties originating in, most notably, the synthesized molecular spectral lines for RSGs.

Aims. We establish a new abundance analysis procedure for RSGs that circumvents difficulties faced in previous works, and test the procedure with ten nearby RSGs observed with the near-infrared high-resolution spectrograph WINERED (0.97−1.32 µm, R = 28 000). The wavelength range covered here is advantageous in that the molecular lines contaminating atomic lines of interest are mostly weak.

Methods. We first determined the effective temperatures (Teff) of the targets with the line-depth ratio (LDR) method, and calculated the surface gravities (log 𝑔) according to the Stefan-Boltzmann law. We then determined the microturbulent velocities (vmicro) and metallicities ([Fe/H]) simultaneously through the fitting of individual Fe I lines. Finally, we also determined the abundance ratios ([X/Fe] for element X) through the fitting of individual lines.

Results. We determined the [X/Fe] of ten elements (Na I, Mg I, Al I, Si I, K I, Ca I, Ti I, Cr I, Ni I, and Y II). We estimated the relative precision in the derived abundances to be 0.04−0.12 dex for elements with more than two lines analyzed (e.g., Fe I and Mg I) and up to 0.18dex for the other elements (e.g., Y II). We compared the resultant abundances of RSGs with the well-established abundances of another type of young star, namely the Cepheids, in order to evaluate the potential systematic bias in our abundance measurements, assuming that the young stars (i.e., both RSGs and Cepheids) in the solar neighborhood have common chemical abundances. We find that the determined RSG abundances are highly consistent with those of Cepheids within <0.1 dex for some elements (notably [Fe/H] and [Mg/Fe]), which means the bias in the abundance determination for these elements is likely to be small. In contrast, the consistency is worse for some other elements (e.g., [Si/Fe] and [Y/Fe]). Nevertheless, the dispersion of the chemical abundances among our target RSGs is comparable with the individual statistical errors on the abundances. Hence, the procedure is likely to be useful to evaluate the relative difference in chemical abundances among RSGs.
Amino acid composition, antioxidant activity and mineral content of Achatina fulica snail slimes and edible bird’s nest
Authors: Dang Tin Tin , Ong Mei Kying , Wong Seng Mei , Ong Ching Ang
Published: January 2025

This study was performed to investigate whether the snail slimes which also well-known for their anti-aging properties, can be served as an alternative for edible bird’s nest (EBN) in our daily lives. The amino acid composition of samples was evaluated using a reversed-phase High Performance Liquid Chromatography. The four major amino acids detected in snail slimes were aspartic acid (3.80 µmol/mL), glutamic acid (2.87 µmol/mL), alanine (2.23 µmol/mL) and serine (1.80 µmol/mL), while for EBN, the top four amino acids were proline (5.31 µmol/mL), serine (5.27 µmol/mL), aspartic acid (4.78 µmol/mL) and threonine (3.97 µmol/mL). In overall, EBN possessed significantly (p < 0.05) higher total amino acid content (42.63 µmol/mL) than the snail slimes (23.59 µmol/mL). Besides, the EBN was found to have significantly higher (p < 0.05) DPPH free radical scavenging activity (25.12 %) as compared to the snail slimes (16.02 %). The four major elements identified in snail slimes and EBN were sodium, calcium, potassium and magnesium. Snail slimes contained higher levels of minerals compared to EBN. In conclusion, the snail slimes can potentially be served as an alternative of EBN to those people suffered from mineral deficiencies.
The fungicidal effect of Rosa Damascena Mill extracts against fungal infections invading Plants in Al Taif
Authors: Ali Dosh Mohammed Hassan , Alamri Saleh Hamdan , Al-Ghamdi Saleh Bakheet , Al-Zahrani Salma A. , El-Sayed Sahar A. , Melebari Mohammad , Gazi Khaled S. , Alharthi Haitham Abdulrahman S. , Al-Mutairi Salman Faleh , Thabet Mohammed A. , Almiman Bandar Fahad
Published: January 2025

Plant pathogens of fungus have become of the most crucially harmful objects that may affect overall plants growth rate and crops production worldwide. This study involved the identification of six species and six genera was achieved from the ten fungal plant pathogen isolates that gathered from different sites and regions in Taif region, Saudi Arabia. The identification of these organisms was conducted using molecular markers; among the identified species, 30% were Mucor circinelloides, 20% were Penicillium crustosum, and 20% were Alternaria alternata. The remaining 30% was comprised of Cladosporium tenuissimum, Phoma macrostoma, and Fusarium equiseti. A considerable proportion of these genera are widely acknowledged for their capacity to generate mycotoxins. The linear growth regression derived by the new plant extract is higher than fungicide, it has been found that the growth inhibition percentage driven by fungicide was between (20 to 85%), whereas for plant extract was between (80 to 100%) across all isolates. This data facilitate the contributing to the exploration of a more secure alternative to fungicides. Further, it will facilitate the development of regulatory approaches aimed at alleviating the detrimental consequences of fungal infections.
Research on Comprehensive Evaluation of Food Governance Sustainable Development Based on Entropy Weight Method
Authors: Wang Zidan , Liu Hui
Published: January 2025

Based on the connotation and characteristics of food modernization governance, this paper constructs a comprehensive evaluation system for sustainable development of food governance from the three dimensions. These three dimensions include industrial development, safety risk and social co-governance. Based on the availability of data, entropy weight method is used to carry out empirical evaluation on the index data of the past three years. Variability in the index data provide suggestions for the sustainable development path of food governance in the next step.
24% Efficient TOPCon-based back contacted polyZEBRA solar cells
Authors: Linke Jonathan , Peter Christoph , Hoß Jan , Sharbaf Kalaghichi Saman , Mihailetchi Valentin , Lossen Jan , Buchholz Florian
Published: January 2025

This publication serves as an update on the progress of the back contacted polyZEBRA solar cell technology, which features Tunnel Oxide Passivating Contact (TOPCon) structures on both polarities. The solar cell efficiency mean values published by the end of last year have been improved by +1%abs to 24.0%. Following the key parameter changes, it is discussed how this improvement has been achieved. These changes are in particular the cell thickness and base resistivity, a dedicated wet-chemical cleaning step, the rear AlOx capping layer thickness and the pitch of the rear metallization pattern.
Effect of CaO based dual flux addition on iron ore pellet properties
Authors: Tekkalakote Umadevi , Sridhara Komala Shivanna , Srinidhi Bindaganavile Raghunath , Sah Rameshwar
Published: January 2025

Limestone and wollastonite are the main CaO bearing fluxes. Wollastonite is a calcium silicate (CaSiO3) and limestone is a calcium carbonate (CaCO3). Wollastonite has an LOI of 6–8%, whereas limestone has 42–44%. The CaO content in limestone and wollastonite is 50.51% and 45.30% respectively. To study the effect of wollastonite as a lime-bearing flux on iron ore pellet properties, detailed laboratory studies have been carried out by replacing the limestone with wollastonite. The Cold crushing strength (CCS) of the pellet increased from 282 to 295 kg/t, the reduction degradation index (RDI (–6.3 mm)) was reduced from 10.5% to 9.2%, and the reducibility index (RI) was reduced from 72% to 71.4% at pellet basicity (CaO/SiO2) of 0.30. The improvement in the physical and metallurgical properties of the pellets with 40% wollastonite was due to the presence of small pores with a higher pore density. The distribution of slag phase around the hematite particles is uniform throughout the pellet, and there are more recrystallized hematite particles with better slag bonding. The addition of CaO and SiO2 in the form of wollastonite improves the pellet properties in the form of slag phase. Pellet with lime-based dual flux with 40% wollastonite specific consumption of raw material was reduced by 2kg/ton of pellets due to the presence of negligible amount of loss of ignition (LOI) in wollastonite; and 7% of CO2 emissions was reduced due to the absence of carbonate.
Physiological responses to low-intensity stationary cycling with intermittent positive and negative pressure an exploratory study
Authors: Del Vecchio Luke , Climstein Mike , Beavers Rosalind
Published: January 2025

Background: This study evaluated the physiological responses to intermittent positive and negative pressure (IPNP) in 17 healthy, recreationally active individuals (10 males, average age 33.1 years, mean BMI 26.1 kg/m²) during stationary, upright cycling.

Methods: We assessed acute IPNP effects on heart rate variability (HRV), blood pressure, and cardiovascular responses during moderate-intensity exercise. Participants engaged in two exercise modalities: Monark cycle ergometry (Mc) and cycling with IPNP, ranging from ±15 to ±25 Mbar.

Results: Results indicated normal physiological responses in heart rate and systolic blood pressure (SBP) from rest to peak exercise in both modalities. A non-significant difference in SBP was observed during Mc compared to IPNP. Significant differences in mean arterial pressure were noted during recovery from IPNP cycling, highlighting a distinct cardiovascular response. HR increased in both conditions during exercise, with a more pronounced increase during Mc. Comfort and perceived exertion revealed no significant differences between the two modalities, indicating the potential acceptability of IPNP therapies.

Conclusion: The study provides valuable insights into cardiovascular dynamics during stationary cycling with intermittent positive and negative pressure and highlights key physiological responses that warrant further investigation.
Microsurgery in Motion: An Objective Assessment of Microsurgical Skill and Efficiency
Authors: Lyon Sarah M. , Zeng Weifeng , Yang Su , Wise Brett J. , Mohamadipanah Hossein , Pugh Carla M. , Poore Samuel O.
Published: January 2025

Background High levels of precision, as well as controlled, efficient motions, are important components of microsurgical technique and success. An accurate and objective means of skill assessment is lacking in resident microsurgical education. Here we employ three-dimensional, real-time motion-tracking technology to analyze hand and instrument motion during microsurgical anastomoses. We hypothesize that motion metrics can objectively quantify microsurgical skill and predict the overall level of expertise.

Methods Seventeen participants including medical students, plastic surgery residents, and attendings performed two end-to-end arterial microsurgical anastomoses in a laboratory setting. Motion tracking sensors were applied to standardized positions on participants' hands and microsurgical instruments. Motion and time parameters were abstracted using sensor-derived position data.

Results A total of 32 anastomoses were completed and analyzed. There were significant differences in time for task completion and idle time between attendings and junior residents (post-graduate year (PGY)1–3). Path length and working volume consistently differentiated between students and attendings for all phases of an anastomosis. Motion and time data were less able to consistently distinguish attendings from residents stratified by laboratory anastomosis experience.

Conclusion Quantifiable motion parameters provide objective data regarding the efficiency of microsurgical techniques in surgical trainees. These data provide a basis for microsurgical competency assessments and may inform future structured feedback through instruction, instruments, and technological interfaces.
Detection and diagnosis of unknown threats in power equipment using machine learning and Spark technology
Authors: Di Li , Chen Cen , Lv Zhuo , Li Mingyan , Li Nuannuan , Chang Hao
Published: January 2025

With the continuous advancement of network technology, attack behaviors have become increasingly diversified, giving rise to new challenges in threat detection. To effectively monitor and diagnose unknown threats, we have created an unknown threat detection model for power equipment based on Spark technology. Our research utilizes a lightweight gradient-based method for detecting known threats, and we propose a novel detection approach for unknown threats that combines classical anomaly detection methods, specifically support vector machines, with autoencoders. In addition, Spark technology is employed to achieve data parallelization, enhancing detection and diagnosis efficiency. Finally, we apply stacking techniques to integrate the two detection methods, enabling hybrid intrusion detection and diagnosis. Experimental analysis indicates that the model runs in 1.88 seconds, achieving a detection accuracy of 98.88%, a precision rate of 99.06%, and a false positive rate of 2.36%. This approach allows for more efficient and accurate detection of unknown threat attacks on power grid equipment, providing robust network security for power systems. Our findings offer a new theoretical perspective for the evolving field of network security.
Structural and optical properties of cubic GaN films on high-thermal conductivity substrates
Authors: Freitas Jaime A. , Culbertson James C. , Storm David F. , Mahadik Nadeemullah A. , Nepal Neeraj , Anderson Travis J.
Published: January 2025

A thin cubic-GaN epitaxial layer was grown by plasma-assisted molecular-beam epitaxy directly on a (100) cubic-boron-nitride nucleation layer that was previously deposited on a (100)-oriented, type IIA, single-crystal chemical-vapor deposition diamond substrate. X-ray diffraction measurements verified that (100)-plane zincblende is the dominant crystal structure of the GaN layer, with a small contribution from the wurtzite phase in some sample regions. Detailed atomic force microscopy and Raman scattering measurements confirmed the XRD findings. Low temperature photoluminescence spectra show a dominant emission line near 3.12 eV and a weaker emission line near 3.21 eV. The former is assigned to a recombination process involving electrons bound to shallow donors with holes bound to shallow acceptors (donor–acceptor pair recombination process). The latter, which becomes dominant at temperatures above 50 K, is assigned to a recombination process involving the annihilation of excitons bound to shallow impurities. Room temperature transmission measurements yielded a direct bandgap of 3.23 eV, which is close to the reported values for c-GaN. These results confirm that cubic-GaN was successfully deposited on a high thermal-conductivity diamond substrate. This opens the door to exploring the potential of cubic-GaN devices for high-power applications, given that large area diamond substrates are becoming available.
Impedance matching assistance based on frequency modulation for capacitively coupled plasmas
Authors: Yu Shimin , Wang Yu , Chen Zhipeng , Wang Zhijiang , Wang Lu , Jiang Wei , Schulze Julian , Zhang Ya
Published: January 2025

The efficiency and repeatability of capacitively coupled plasma (CCP) processes are highly dependent on achieving precise impedance matching between the plasma load and the RF power supply. This paper presents a numerical investigation of the role of frequency modulation in enhancing impedance matching of RF CCPs, a technique that can be critical to maintaining operational efficiency and plasma stability. Through a detailed simulation approach, the research explores how variations in the driving frequency impact plasma characteristics and electrical parameters, particularly focusing on the CCP’s impedance behavior. The simulations demonstrate that when impedance matching is achieved at a fixed fundamental frequency of 13.56 MHz, changes in driving frequency will lead to reduced power coupling efficiency and increased reflection. The study introduces a frequency modulation strategy that allows us to re-establish high-quality impedance matching after changes of the plasma impedance occur, e.g., due to changes of the variable capacitor settings inside the matchbox or gas pressure, thereby improving the CCP’s performance. As the driving frequency can be adjusted electrically, adjusting the impedance matching by frequency modulation is much faster than based on mechanical adjustments of variable capacitors inside the matching and could, thus, allows quicker matching. The findings underscore the impact of frequency modulation on power absorption efficiency and highlight the sensitivity of impedance matching to driving frequency fluctuations. This study provides a foundation for further exploration into the optimization of RF CCP systems with the potential to enhance process control and plasma performance across a range of industrial applications, especially pulsed CCPs.
A newly designed laser-based time- and angle-resolved photoelectron spectroscopy with a time-of-flight electron analyzer
Authors: Lu Shengyue , Zhang Yeqinbo , Li Jingze , Ma Xueyan , Deng Yongkai , Liu Yunquan
Published: January 2025

Angle-resolved photoemission spectroscopy can directly detect the energy and momentum resolved electronic structure of solids, serving as a central role in the discovery and understanding of quantum materials. Here, we report the development of a novel time-resolved ARPES setup equipped with a table-top vacuum ultraviolet laser source with a photon energy of 10.8 eV and a time-of-flight analyzer. The light source is obtained through the generation of ninth harmonics of a 1030 nm Yb fiber-based amplified laser (290 fs, 100 μJ). The photon flux can reach 5 × 1012 photons/s at 333 kHz. We demonstrate its performance in ARPES measurements of the polycrystalline gold film and the electronic structure of the topological insulator Bi2Te3. By introducing a pump beam, we make a pump–probe experiment to detect unoccupied electronic states of Bi2Te3. This setup can achieve an energy resolution of 21.6 meV and a temporal resolution of 296 fs with the tunability of the polarization and repetition rates. This system can provide an important platform to study the non-equilibrium band structure of complex quantum materials with exceptional energy resolution at high repetition rates.
Selected configuration interaction for high accuracy and compact wave functions: Propane as a case study
Authors: Craciunescu Luca , Prentice Andrew W. , Paterson Martin J.
Published: January 2025

Traditionally, because of the limit of full configuration interaction, complete active space (CAS) theory is most often used to model bond dissociation and other dynamical processes where the multi-reference character becomes important. Inconveniently, the CAS method is highly dependent on the choice of active space and, therefore, inherently non-black-box, in addition to the exponential scaling with respect to electrons and orbitals. This illustrates the need for methods that can accurately treat multi-reference electronic structure problems without significant dependence on input parameters. Selected configuration interaction (SCI) methods have experienced a revival in recent years because of their independence of these predicaments. SCI methods aim to exploit the sparsity of the full configuration interaction space to identify all relevant electronic configurations and, therefore, keep the wave function as compact as possible while still representing the total multi-reference electronic structure accurately. In this work, we take the recent achievement by Gao et al. to run full configuration interaction on the propane molecule in a minimal basis set (23 electrons in 26 orbitals) as an occasion to demonstrate that our SCI methods implemented in the GeneralSCI program package can achieve high energetic accuracy in conjunction with very compact wave functions, which considerably alleviate computational cost. Furthermore, we show the good performance of our SCI methods in reproducing a propane bond dissociation surface and energy. This illustrates that SCI methods can be readily applied to problems in chemical reactivity.
Enhanced flexoelectric properties in sodium bismuth titanate-based lead-free relaxor ferroelectrics by inducing polar nanoregions
Authors: Yi Chao , Wang Zhiguo , Rao Zhenggang , Li Chunchun , Shu Longlong
Published: January 2025

The presence of polar nanoregions (PNRs) is widely recognized as playing a crucial role in the functionalities of numerous solid dielectrics. However, the contribution of PNRs to the specific coupling between strain gradient and electric polarization (flexoelectricity) has not yet been thoroughly understood. Herein, we investigated the impact of varying PNR concentrations on the dielectric and flexoelectric properties of lead-free relaxor ferroelectric (Bi0.5Na0.5)TiO3 ceramics, achieved through stoichiometric BaTiO3 doping. The temperature-dependent dielectric properties indicated the presence of PNRs in doubly doped ceramics as compared to pure BNT. Complex impedance analysis and piezoresponse force microscopy measurements demonstrated significant differences in PNR concentrations among the different components. The reorientation of PNRs notably enhanced the flexoelectric response of the doubly doped BNT-xBT ceramics, with this enhancement being positively correlated with the concentration of PNR. Specifically, the flexoelectric coefficient was found to be approximately 10 times higher in the morphotropic phase boundary (MPB) region (x = 0.08) compared to pure BNT. These findings illustrate that adjusting the concentration of PNRs in lead-free relaxation ferroelectrics is an effective strategy for improving flexoelectric properties.
Point process analysis of geographical diffusion of news in Argentina
Authors: García L. L. , Tirabassi G. , Masoller C. , Balenzuela P.
Published: January 2025

The diffusion of information plays a crucial role in a society, affecting its economy and the well-being of the population. Characterizing the diffusion process is challenging because it is highly non-stationary and varies with the media type. To understand the spreading of newspaper news in Argentina, we collected data from more than 27 000 articles published in six main provinces during 4 months. We classified the articles into 20 thematic axes and obtained a set of time series that capture daily newspaper attention on different topics in different provinces. To analyze the data, we use a point process approach. For each topic, n, and for all pairs of provinces, i and j, we use two measures to quantify the synchronicity of the events, Qs(i,j), which quantifies the number of events that occur almost simultaneously in i and j, and Qa(i,j), which quantifies the direction of news spreading. Our analysis unveils how fast the information diffusion process is, showing pairs of provinces with very similar and almost simultaneous temporal variations of media attention. On the other hand, we also calculate other measures computed from the raw time series, such as Granger Causality and Transfer Entropy, which do not perform well in this context because they often return opposite directions of information transfer. We interpret this as due to the characteristics of the data, which is highly non-stationary, and of the information diffusion process, which is very fast and probably acts at a sub-resolution time scale.
Shared-aperture full-duplex Janus meta-lens for asymmetric focusing of electromagnetic waves
Authors: Dong Shufang , Qu Kai , Wang Shaojie , Zhao Junming , Chen Ke , Feng Yijun
Published: January 2025

Janus metasurfaces have provided a platform for multiplexing diverse electromagnetic (EM) wave functionalities, which are determined by the intrinsic propagation direction of the EM wave. However, most existing approaches only utilize half of the metasurface aperture for each EM functionality. Here, we propose a method that employs receiver–transmitter Janus meta-atom to accomplish high-efficiency transmission and asymmetric phase responses. By fully implementing the direction-duplex strategy through these meta-atoms, we can directly assign asymmetric phase profiles to the Janus meta-lens in order to achieve a direction-selective focusing configuration, thereby effectively improving aperture utilization. Experimental validation is conducted in the microwave region to demonstrate the feasibility of the proposed method, showcasing potential applications of shared-aperture Janus metasurfaces in asymmetric imaging and multichannel information processing.
The van der Waals heterostructures of blue phosphorene with GaN/GeC for high-performance thermoelectric applications
Authors: Ahmad Iqtidar , Wang Xue-Peng , Shahid Ismail , Ali Anwar , Shah Syed Hatim , Li En , Lyu Tu , Ding Keyuan , Chen Xin , Rao Feng
Published: January 2025

Thermoelectric devices have substantial potential as an environmentally compatible and sustainable power source to produce electricity straight out of waste heat. In this article, the density functional theory and Boltzmann’s transport equation are employed to investigate the thermoelectric characteristics of blue phosphorene (P)/GaN and P/GeC van der Waals heterostructures (vdWHs). Both vdWHs exhibit a small lattice thermal conductivity at 300 K because of the enhanced phonon boundary dispersion. P/GaN and P/GeC vdWHs drive an impressive boost in the figure of merit (ZT), achieving remarkable values of 5.07 and 4.67 at their respective effective temperatures. Moreover, both vdWHs possess an average ZT as high as 3.91 (P/GaN) and 3.44 (P/GeC). We also observed that these vdWHs exhibit an excellent conversion efficiency, up to 26% (P/GaN) and 25% (P/GeC) at 700 K. Our findings demonstrate that both vdWHs have practical potential for thermoelectric applications, representing significant progress in developing better thermoelectric devices.
Observation of a two-dimensional topological metal in acoustic metamaterials
Authors: Cui Zhenxing , Zhang Xuewei , Peng Mian , Wei Qiang , Yan Mou , Chen Gang
Published: January 2025

A two-dimensional topological metal with anti-helical-like edge states has been predicted recently but has not been confirmed experimentally. In this paper, we report an experimental realization of this topological metal in acoustic metamaterial by introducing a time-reversal symmetry protected square lattice. The edge states appearing in gapless bulk bands are observed by measuring the projected dispersions and acoustic pressure field distributions. Moreover, these edge states propagate in the same direction when simultaneously exciting two sources with a fixed phase difference. Interestingly, by simply changing the coupling tubes, we realized the transformation of an acoustic topological metal to a topological insulator. Our work not only pushes forward the studies of topological metals but also inspires the design of multifunctional acoustic devices.
Absolute line strength measurements of HO2 radical in the OO-stretching fundamental band between 1088 and 1124 cm−1 using time-resolved dual-comb spectroscopy
Authors: Chang Che-Wei , Chen I-Yun , Luo Pei-Ling
Published: January 2025

Absolute line strength measurements of hydroperoxyl (HO2) radical in the OO-stretching (ν3) fundamental band have been performed by means of mid-infrared time-resolved dual-comb spectroscopy. By employing two sets of dual-comb spectrometers, high-resolution time-resolved spectra of HO2 and HCl, formed in the photolysis reaction system of Cl2/CH3OH/O2, could be, respectively, measured near 1123 and 3059 cm−1. With kinetic simulations, spectral analysis of both HO2 and HCl, as well as the accurate line strength of the HCl R(9) transition at 3059.316 cm−1, an absolute line strength of the ν3 131,13 ← 121,12 F1,2 transitions in HO2 at 1122.983 cm−1 was first determined to be 1.80 × 10−20 cm molecule−1 with a small uncertainty down to 4% under the conditions with low initial concentrations of Cl radical (1.63–1.81 × 1013 molecule cm−3). Furthermore, broadband high-resolution spectra of the ν3 fundamental band of HO2 were recorded in the range of 1088–1124 cm−1 with an average spectral resolution of 0.002 cm−1. By contour fitting the measured broadband spectra with PGOPHER, the line strengths of hundreds of rovibrational transitions were obtained relative to the well-determined HO2 lines at 1122.983 cm−1, and those values were observed to be higher than those tabulated in the HITRAN database by a factor of ∼2.8. Moreover, the absolute band strength of the ν3 fundamental band in HO2 was derived to be 22.3 km mol−1 with an uncertainty of 5%. This work providing precise and detailed spectral data would be crucial in revisiting the theoretical modeling of HO2 geometry and updating the database of the HO2 radical.
Collision integrals within the Chapman–Enskog theory for a generalized Lennard-Jones potential
Authors: Perko Joseph R. , Xantheas Sotiris S.
Published: January 2025

We report the values of the collision integrals, needed for the calculation of the macroscopic transport properties such as viscosity (η) and diffusion coefficient (D) of gases within the Chapman–Enskog kinetic gas theory, for a generalized Lennard-Jones potential (gLJ), a more general potential with an adjustable long range 1/r dependence that can describe a wide range of intermolecular interactions.
Modeling shock propagation and resilience in financial temporal networks
Authors: Lillo Fabrizio , Rizzini Giorgio
Published: January 2025

Modeling how a shock propagates in a temporal network and how the system relaxes back to equilibrium is challenging but important in many applications, such as financial systemic risk. Most studies, so far, have focused on shocks hitting a link of the network, while often it is the node and its propensity to be connected that are affected by a shock. Using the configuration model—a specific exponential random graph model—as a starting point, we propose a vector autoregressive (VAR) framework to analytically compute the Impulse Response Function (IRF) of a network metric conditional to a shock on a node. Unlike the standard VAR, the model is a nonlinear function of the shock size and the IRF depends on the state of the network at the shock time. We propose a novel econometric estimation method that combines the maximum likelihood estimation and Kalman filter to estimate the dynamics of the latent parameters and compute the IRF, and we apply the proposed methodology to the dynamical network describing the electronic market of interbank deposit.
Hybrid proton acceleration with an ultra-intense laser of low contrast
Authors: Qiu Guanqi , Wu Xuezhi , Ma Qianyi , Yan Xueqing
Published: January 2025

Proton acceleration from the interaction of an ultra-intense femtosecond-class laser pulse at varying picosecond contrast levels with an ultrathin-foil target is investigated numerically. It is found that lower contrast increases the optimal target thickness without reducing the proton cutoff energy at an ultrahigh laser intensity of I∼8×1021 W/cm2, contrasting with previous experimental results at low laser intensity I<1×1021 W/cm2. By employing particle tracking techniques, we show that due to the intense radiation pressure of the main pulse, the acceleration of protons in the pre-expanded target via the Hole-Boring mechanism under low contrast surpasses that in the steep-edge target under high contrast, which is driven by a hybrid regime of light-sail and sheath acceleration before the target is penetrated. After that, a thinner optimal target thickness under high contrast results in stronger electron heating, enabling the proton energy to catch up gradually in relativistic-induced transparency enhanced acceleration. Ultimately, a similar cutoff energy is obtained for both scenarios. Our work demonstrates that high laser intensity can offer some advantages to proton acceleration at the radiation-pressure-dominated stage when laser contrast control on the picosecond level is challenging, and a thicker target is necessary. This implies that the demanding requirement for laser contrast could potentially be relaxed for multi-petawatt laser facilities, simplifying experimental setups and enhancing proton energy.
Impact of thermal crosstalk on dependent failure rates of multilayer ceramic capacitors undergoing lifetime testing
Authors: Yousefian Pedram , Shoemaker Daniel C. , Mena-Garcia Javier , Norrell Michael , Long Jeff , Choi Sukwon , Randall Clive A.
Published: January 2025

Several research studies have investigated the degradation of BaTiO3-based dielectric capacitor materials, focusing on the impact of composition, defect chemistry, and microstructural design to limit the electromigration of oxygen vacancies under electric fields at finite temperatures. Electromigration can be a dominant mechanism that controls failure rates in the individual multilayer ceramic capacitor (MLCC) components in testing the reliability of failures with highly accelerated lifetime testing (HALT) to determine the mean time to failure of MLCCs surface mounted onto printed circuit boards (PCBs). Conventional assumptions often consider these failures as independent, with no interaction between components on the PCB. However, this study employs a Physics of Failure (PoF) approach to closely examine transient degradation and its impact on MLCC reliability, emphasizing thermal crosstalk and its influence on dependent and independent failure rates. Finite element analysis thermal modeling and infrared thermography were used to assess the impact of circuit layout and component spacing on heat dissipation and thermal crosstalk under various electrical stress conditions. The study distinguishes between dependent and independent failures under a HALT, quantified through a β′ factor reflecting common cause failures due to thermal crosstalk. Through a series of experimental and statistical analyses, the β′ factor is evaluated with respect to temperature, voltage, and component spacing. These insights highlight the importance of understanding the nature of the data in reliability testing of MLCCs and optimizing the layout design of high-density circuits to mitigate dependent failures, improving overall reliability and informing better design and packaging strategies.
Origin of oxygen partial pressure-dependent conductivity in SrTiO3
Authors: Cai Zenghua , Ma Chunlan
Published: January 2025

SrTiO3 (STO) displays a broad spectrum of physical properties, including superconductivity, ferroelectricity, and photoconductivity, making it a standout semiconductor material. Despite extensive research, the oxygen partial pressure-dependent conductivity in STO has remained elusive. This study leverages first-principles calculations and systematically investigates the intrinsic defect properties of STO. The results reveal that VO, VSr, and TiSr are the dominant intrinsic defects, influencing STO's conductivity under varying O chemical potentials (oxygen partial pressures). Under O-poor condition, VO is the predominant donor, while VSr is the main acceptor. As the oxygen pressure increases, TiSr emerges as a critical donor defect under O-rich conditions, significantly affecting the conductivity. Additionally, the study elucidates the abnormal phenomenon where VTi, typically an acceptor, exhibits donor-like behavior due to the formation of O-trimer. This work offers a comprehensive understanding of how intrinsic defects tune the Fermi level, thereby altering STO's conductivity from metallic to n-type and eventually to p-type across different O chemical potentials. These insights resolve the long-standing issue of oxygen partial pressure-dependent conductivity and explain the observed metallic conductivity in oxygen-deficient STO.