bluuebunny/crossref_metadata_2025_split huggingface dataset:
Semitransparent organic solar cells based on low temperature processed PEIE as electron transport layer with enhanced charge transfer ability
Authors: Khanam Lubna , Singh Samarendra Pratap 
Published: April 2023

Abstract
In inverted structure-based semitransparent organic solar cells (OSCs), the electron transport layer (ETL) plays a crucial role in the improvement of the transparent cathode efficiency in collecting and extracting negative charge carriers. Zinc oxide (ZnO) thin film prepared by zinc acetate dihydrate precursor with various benefits is generally used as ETL. However, high temperature, less charge transfer ability, and irregular film surface due to fiber-like domain formation limit the device performance. In this work, a new approach is presented by using low-temperature processed polyethylenimine ethoxylated (PEIE) as ETL in semitransparent OSCs fabricated in an ambient environment with a blend of low-bandgap donor polymer PTB7-Th, and fullerene acceptor, PC71BM, based active layer. For semitransparent OSCs, the thickness of the silver electrode has been varied from 55 nm to 25 nm to investigate its effect on the electrical and optical properties of the devices. The power conversion efficiencies (PCE) of 5.1% and 4.6% were achieved for semitransparent devices (25 nm thickness of silver electrode) for PEIE and ZnO ETLs, respectively. Similarly, PCE of 7% and 6.7% have been achieved for opaque devices (85 nm thickness of silver electrode) using PEIE and ZnO ETLs, respectively. PEIE based devices with 25 nm Ag demonstrate about 25%–30% transparency. The impedance spectroscopy measurements indicate low interfacial contact resistance and fast charge transfer capability for PEIE interlayer-based devices compared to the ZnO based devices. The encapsulated semitransparent devices processed and stored in ambient conditions with PEIE and ZnO ETLs were found to retain ≈80% performance for up to 45 days.
Design of multi-spectral LED lighting system with high color uniformity for microscopic imaging
Authors: Li Yalin , Dong Jianfei , Zhang Yunchu 
Published: April 2023

Abstract
Multi-spectral imaging is commonly used in biomedical field to detect and recognize targets, which are in a low contrast with their background. Highly integrated multichannel light-emitting diode (LED) devices enable tuning the spectral contents of the illumination in an accurate and compact fashion, and hence make multi-spectral lighting more easily achievable even in a microscope. Besides the light source, the light mixing system is also a key to realize it. Existing light mixing devices available for multi-spectral LED lighting systems are both costly to manufacture and intricate in design, making them a challenging solution to create. This work proposes a design of multi-spectral lighting system for microscopic imaging, which can achieve a high uniformity in the effective area of illumination in terms of both the illuminance and chromaticity. Simulation results first demonstrate that the designed lighting system consisting of two rods, both containing a frosted emitting surface, managed to reduce the non-uniformity to less than 0.05 for both the illuminance and chromaticity. Experiments with a real prototype show highly uniformly illuminated microscopic images of tissue section samples. Moreover, the pathogenic fungi in the infected tissue section samples can be highlighted by the superposition of multi-spectral images. These experimental results indicate that the designed multi-spectral LED lighting system can improve the quality of microscopic imaging in terms of the illumination and image contrast.
NuSTAR View of the R − Γ Correlation in the Hard State of Black Hole Low-mass X-Ray Binaries
Authors: Dong Yanting , Liu Zhu , Cao Xinwu 
Published: April 2023

Abstract
The power law and reflection emission have been observed in the X-ray spectra of both black hole X-ray binaries (BHXRBs) and active galactic nuclei (AGNs), indicating a common physical origin of the X-ray emission from these two types of sources. The relevant parameters describing the shape of both components and the potential correlation between these parameters can provide important clues on the geometric and physical properties of the disk and the corona in these sources. In this work, we present a positive correlation between the photon index Γ and the reflection strength R for the low-mass BHXRBs in the hard state by modeling NuSTAR data, which is qualitatively consistent with the previous studies. We compare our results with the predictions from different theoretical disk-corona models. We show that the R − Γ correlation found in this work seems to favor the moving corona model proposed by Beloborodov. Our results indicate that the coronal geometry varies significantly among BHXRBs. We further compare our results with that of AGNs. We find that the reflection strength R is smaller than unity in the hard state of BHXRBs, while it can be as large as ∼5 in AGNs, which implies that the variations of the disk-coronal geometry of AGNs are more vigorous than that of the BHXRBs in the hard state.
Fermi Blazars in the Zwicky Transient Facility Survey: A Correlation Study
Authors: Sun Si-Si , Wang Zhong-Xiang , Xing Yi 
Published: April 2023

Abstract
We report on our correlation analysis for the γ-ray blazars detected with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi), for which we use the Fermi-LAT data and the optical zr and zg band data from the Zwicky Transient Facility survey in the time period approximately from 2018 July to 2022 February. We start from the full sample of the Fermi-LAT blazars and find ∼38% of them as significant variables in both γ-ray and optical bands. Among the variables, which are 705 blazars, 95 are selected as our targets based on the requirement for the γ-ray brightnesses. Then 15 out of the 95 blazars are found to show the γ-ray–optical correlations in the ∼3.7 yr time period. Most of the 15 blazars are classified as low synchrotron peaked (LSP) ones with the time lags between the γ-ray and optical bands in a range from −19 to +25 days. The results generally fit the often-considered emission scenario for the LSP blazars. Two cases of showing ∼−100 days time lags are discussed, which require further studies for confirmation. Our analysis results suggest that among the detected significant variables, ∼23% LSPs can show γ-ray and optical correlations, while their average γ-ray fluxes are above ∼4 × 10−8 photon cm−2 s−1.
Magnetoencephalographic neurofeedback training decreases β-low-γ phase-amplitude coupling of the motor cortex of healthy adults: a double-blinded randomized crossover feasibility study
Authors: Izutsu Nobuyuki , Yanagisawa Takufumi , Fukuma Ryohei , Kishima Haruhiko 
Published: April 2023

Abstract

Objective. The coupling between the beta (13–30 Hz) phase and low gamma (50–100 Hz) amplitude in the motor cortex is thought to regulate motor performance. Abnormal phase-amplitude coupling (PAC) of beta-low gamma (β-low-γ PAC) is associated with motor symptoms of Parkinson’s disease. However, the causal relationship between β-low-γ PAC and motor performance in healthy subjects is unknown. We hypothesized that healthy subjects could change the strength of the β-low-γ PAC in the resting state by neurofeedback training (NFT) to control the β-low-γ PAC, such that the motor performance changes in accordance with the changes in β-low-γ PAC in the resting state. Approach. We developed an NFT to control the strength of the β-low-γ PAC in the motor cortex, which was evaluated by magnetoencephalography (MEG) using a current source estimation technique. Twenty subjects were enrolled in a double-blind randomized crossover trial to test the feasibility of the MEG NFT. In the NFT for 2 d, the subjects were instructed to reduce the size of a black circle whose radius was proportional (down-training) or inversely proportional (up-training) to the strength of the β-low-γ PAC. The reaction times (RTs) to press a button according to some cues were evaluated before and after training. This study was registered at ClinicalTrials.gov (NCT03837548) and UMIN-CTR (UMIN000032937). Main results. The β-low-γ PAC during the resting state was significantly decreased after down-training, although not significantly after up-training. RTs tended to decrease after both trainings, however the differences were not statistically significant. There was no significant correlation between the changes in β-low-γ PAC during rest and RTs. Significance. The proposed MEG NFT was demonstrated to change the β-low-γ PAC of the motor cortex in healthy subjects. However, a relationship between PAC and RT has not yet been demonstrated.
3D printed guide tube system for acute Neuropixels probe recordings in non-human primates
Authors: Bauer Devyn Lee , Pobiel Ben , Hilber Kathryn , Verma Ajay K , Wang Jing , Vitek Jerrold , Johnson Matthew , Johnson Luke 
Published: April 2023

Abstract

Objective. Neuropixels (NP) probes are a significant advance in electrophysiological recording technology that enable monitoring of hundreds of neurons in the brain simultaneously at different depths. Application of this technology has been predominately in rodents, however widespread use in non-human primates (NHPs) such as rhesus macaques has been limited. In this study we sought to overcome two overarching challenges that impede acute NP implantation in NHPs: (1) traditional microdrive systems that mount to cephalic chambers are commonly used to access cortical areas for microelectrode recordings but are not designed to accommodate NP probes, and (2) NHPs have thick dura mater and tissue growth within the cephalic chambers which poses a challenge for insertion of the extremely fragile NP probe. Approach. In this study we present a novel NP guide tube system that can be adapted to commercial microdrive systems and demonstrate an implant method using the NP guide tube system. This system was developed using a combination of CAD design, 3D printing, and small part machining. Software programs, 3D Slicer and SolidWorks were used to target cortical areas, approximate recording depths and locations, and for in-silico implant testing. Main results. We performed in vivo testing to validate our methodology, successfully implanting, explanting, and reimplanting NP probes. We collected stable neurophysiological recordings in the premotor cortex of a rhesus macaque at rest and during performance of a reaching task. Significance. In this study we demonstrate a robust Neuropixels implant system that allows multiple penetrations with the same NP probe and share design files that will facilitate the adoption of this powerful recording technology for NHP studies.
Finite temperature phases and excitations of bosons on a square lattice: a cluster mean field study
Authors: Malakar Manali , Sinha Sudip , Sinha S 
Published: April 2023

Abstract
We study the finite temperature phases and collective excitations of hardcore as well as softcore bosons on a square lattice with nearest and next nearest neighbor interactions, focusing on the formation of various types of supersolid (SS) phases and their stability under thermal fluctuations. The interplay between the on-site, nearest, and next nearest neighbor interactions leads to various density ordering and structural transitions, which we have plotted out. Thermodynamic properties and phase diagrams are obtained by cluster mean field theory at finite temperatures, which includes quantum effects systematically, and they are compared with the single-site mean field (MF) results. We investigate the melting process of the SS phase to normal fluid (NF), which can occur in at least two steps due to the presence of two competing orders in the SS. A tetra-critical point exists at finite temperature and exhibits intriguing behavior, which is analyzed for different regimes of interactions. The phase diagrams reveal the different pathways of the thermal transition of SSs to the NF phase, for different interaction regimes, which can be accessible by thermal quench protocols used in recent experiments. We show how the phases and the transitions between them can be identified from the characteristic features of the excitation spectrum. We analyze the appearance of a low-energy gapped mode apart from the gapless sound mode in the SS phase, which is analogous to the gapped mode recently studied for dipolar SS phases. Finally, we discuss the relevance of the results of the present work in the context of ongoing experiments on ultracold atomic gases and newly observed SS phases.
Compound marine heatwaves and low sea surface salinity extremes over the tropical Pacific Ocean
Authors: Liu Hao , Nie Xunwei , Cui Chaoran , Wei Zexun 
Published: April 2023

Abstract
Marine heatwaves (MHWs) and low sea surface salinity (SSS) events can significantly impact marine ecosystems and dynamic systems, respectively. Compound marine extreme events can cause more significant damage than individual extreme events. However, the spatiotemporal patterns of compound MHW-low SSS extremes are not well understood. Daily reanalysis data were used to identify the basic patterns of compound extreme events and their drivers. These events mainly occur over the central tropical Pacific Ocean during record-breaking El Niño events. This analysis revealed that extreme sea surface warming associated with El Niño drives increased convection, which subsequently leads to increased rainfall. It ultimately causes extreme sea surface freshening. This analysis highlights the significance of air-sea interactions and low-frequency climate variability in shaping compound extreme events.
Enhanced ferroelectric and ferromagnetic properties of xNiFe2O4/(1–x)Ba0.94Ca0.06Ti0.975Zr0.025O3 nanocomposites
Authors: Linh Dinh Chi , Lam Dao Son , Thi Viet Chinh Nguyen , Dung Dang Duc , Tran Ngo , Thanh Tran Dang 
Published: April 2023

Abstract
Bi-phase multiferroic composites of NiFe2O4/Ba0.94Ca0.06Ti0.975Zr0.025O3 (BCTZ/NFO) were successfully fabricated by high-energy ball milling combined with heat treatment. X-ray diffraction patterns and Raman spectra confirmed the successful coexistence of BCTZ and NFO phases in the final composites, which had an average particle size of 50 nm. However, the number of large particles increased with the increased NFO concentration in the composites. Optical properties of the composites were also modified by the NFO content, where the absorption band tended to the visible region and band-gap energies (E
g) decreased with the increase of NFO. Ferromagnetic and ferroelectric properties of the BCTZ/NFO composites were also tuned by NFO additive content. Both saturation magnetisation (M
s) and remnant magnetisation (M
r) increased with the increase of NFO content, where the maximum values of M
s = 22.52 emu g−1 and M
r = 1.48 emu g−1 for composites with 40% NFO concentration, while coercivity (H
c) was maintained at about 60 Oe. Maximum polarisation (P
max), remnant polarisation (P
r), and coercive field (E
c) values all increased with NFO concentration, with 10% NFO providing the highest P
max (= 0.249 μC cm−2) and P
r (= 0.116 μC cm−2) values, and 30% NFO providing the highest E
c (= 1.720 kV cm−1) value with a maximum applied voltage of 1 kV. Therefore, the multiferroic properties of BCTZ/NFO composites could be enhanced with an appropriate concentration of NFO, which led to a wide range of practical applications in the advanced electronic device field.
Study on the spatio-temporal patterns of urban air pollution and its spatial mismatch with air pollutant emissions in the Yellow River Basin, China
Authors: Yang Xiaolin , Feng Zengwei , Chen Yiyan 
Published: April 2023

Abstract
In order to promote the precise governance of air pollution in the Yellow River Basin(YRB), it is of great significance to reveal the spatio-temporal patterns of urban air pollution in the basin and its spatial mismatch characteristics with air pollutant emissions. Based on spatial autocorrelation model and spatial mismatch model, this paper selected air pollution-related monitoring data from 69 cities in YRB from 2015 to 2020 as samples, and used ArcGIS, Stata, GeoDa and other softwares to analyze the spatio-temporal patterns of urban air pollution and its spatial mismatch characteristics with air pollutant emissions in YRB. The results showed that: (1) Temporally, the average annual Air Quality Index (AQI) values of cities in YRB ranged from 78.22 to 97.08 in 2015–2020, among which, the average annual AQI values of cities in the upper, middle and lower reaches of the basin decreased from 79.86, 89.23 and 122.14 in 2015 to 66.87,82.98 and 98.43 in 2020. (2) Spatially, there were obvious spatial differences in urban air pollution in YRB, and the AQI was roughly distributed in a geographical gradient of upper reaches < middle reaches < lower reaches, and there were significant spatial correlations in urban air pollution, mainly showing ‘high-high’ and ‘low-low’ aggregating characteristics. Among them, the lower reaches of YRB had formed a concentrated ‘high pollution zone’. (3) There was an obvious spatial mismatch between urban air pollution and air pollutant emissions in YRB, among which the spatial mismatch was obvious in cities such as Wuhai, Zibo, Shizuishan, Yangquan, Taiyuan, Datong, Jiyuan, Kaifeng, Puyang and Xi’an. (4) To improve the overall situation of air pollution in the cities of YRB, this paper proposed that the geographical gradient difference of air pollution in the upper, middle and lower reaches of YRB needs to be fully considered, following the principle of ‘focused treatment, gradual progress, enhanced prevention’, and according to the spatial mismatch characteristics of urban air pollution and air pollutant emissions, it is necessary to build a ‘differentiated’ governance strategy system for urban air pollution in the basin, which is ‘tailored to local conditions and categorized measures’.
Characterizing methane emissions from orphaned coalbed methane wells in the powder river basin
Authors: Nivitanont J , Robertson E P , Murphy S M , Burkhart M D , Caulton D R 
Published: April 2023

Abstract
In 2018, the U.S. EPA Greenhouse Gas Inventory (GHGI) began including methane emissions from abandoned oil and gas (AOG) wells and estimated that they may constitute up to 4% of total methane emissions from the oil and gas sector. Several studies have shown that these emissions vary by location which introduces regionally dependent uncertainty into inventory estimates. In Wyoming, there are over 1000 wells identified as ‘orphaned’ indicating that they are both abandoned and unplugged, approximately 80% of which are coalbed methane (CBM) wells. In this pilot study, 3-hour measurements of ten orphaned CBM wells were taken to support the characterization of AOG well emission rates in the Powder River Basin (PRB) in Wyoming. The mean methane emission rate measured at these wells was 653 mg CH4/hr with the majority of these wells emitting in the 100-1000mg CH4/hr range. The highest emitting well in the study was measured at 4.53 g CH4/hr. Compared to the GHGI AOG wells emission factor of 10.04 g CH4/hr, these findings suggest that AOG wells emission rate in the PRB are overestimated by national inventory methods. Finally, the addition of AOG well emissions data from this study doubles the number of sampled AOG wells in Wyoming and triples the number of sampled CBM wells in the U.S.
Symbiotic microbiota vary with breeding group membership in a highly social joint-nesting bird
Authors: Grieves Leanne A , Gloor Gregory B , Quinn James S 
Published: April 2023

Abstract
Symbiotic microbes affect the health, fitness, and behavior of their animal hosts, and can even affect the behavior of non-hosts. Living in groups presents numerous benefits and challenges to social animals, including exposure to symbiotic microbes, which can mediate both cooperation and competition. In social mammals, individuals from the same social group tend to share more similar microbes and this social microbiome, the microbial community of all hosts in the same social group, can shape the benefits and costs of group living. In contrast, little is known about the social microbiome of group living birds. We tested the predictions that communally breeding smooth-billed anis (Crotophaga ani) belonging to the same breeding group share more similar microbes and that microbial community composition differs between body regions. To test this, we used 16S rRNA gene sequencing to characterize the preen gland and body feather microbiota of adult birds from 16 breeding groups at a long-term study site in southwestern Puerto Rico. As predicted, individuals from the same breeding group shared more similar microbiota than non-group members and preen gland and body feathers harbored distinct microbial communities. Future research will evaluate whether this social microbiome affects the behavior of group living birds.
British Contributions to the Law of the Sea and the Protection of the Marine Environment, including its Natural Resources
Authors: Boyle Alan , Harrison James 
Published: April 2023

Abstract
This article explores the contribution of the United Kingdom to the development and continued evolution of the law of sea and the establishment of an international legal order for the world’s oceans. The authors consider the rise of the United Kingdom as the pre-eminent naval power until the early 20th century, and its use of international law, including the principle of the freedom of the seas, to further its national interests. Despite the relative decline in the naval power of the UK throughout the 20th century, the UK has continued to be influential in the development of the law of the sea, particularly through its participation in multilateral institutions. For example, the UK was at the forefront of the establishment of the IMO and played a leading role in the successful conclusion of the United Nations Convention on the Law of the Sea. The authors identify that it is not only UK officials that have shaped the discipline, but also UK industry, civil society, and academia. The authors conclude their piece by considering the future of the UK’s contribution to the development of the law of the sea after its withdrawal from the European Union, as it resumes its status as an independent coastal state for the first time in four decades. The authors specifically consider the implications of this development for fisheries regulation and the protection of the marine environment.