bluuebunny/crossref_metadata_2025 huggingface dataset:
Large-field CO (J= 1−0) observations toward SNR G150.3+4.5
Authors: Feng Jian-Cheng , Chen Xuepeng , Su Yang , Sun Li , Zhang Shiyu , Zhou Xin , Guo Weihua
Published: April 2024

Aims. We aim to investigate the molecular environment of the supernova remnant (SNR) G150.3+4.5, and explore its association with ambient molecular clouds (MCs).

Methods. We present large-field CO (J= 1−0) molecular line observations toward SNR G150.3+4.5, using the 13.7 m millimeter telescope of the Purple Mountain Observatory. The observations have an angular resolution of ~55″. We analyzed the spatial distribution of MCs in relation to the SNR shell detected in previous Urumqiλ6 cm radio observations and examined the CO spectra for kinematics information.

Results. We find that MCs within the velocity range of [−14, −2] km s−1are spatially distributed along the radio shell of the SNR. Line broadening and asymmetries are observed in the CO spectra of the clouds. Moreover, we find that the molecular clouds around the shell have systematic velocity gradients in the position–velocity (PV) diagram. Both the morphology alignment and gas kinematics suggest that the SNR is associated with the ambient MCs at ~740 pc. Based on the CO gas distance, the dimension and the age of the SNR are estimated to be 40 pc × 33 pc and 3.8 × 104yr, respectively. The very high energy emission of 1LHAASO J0428+5531 toward the SNR may originate from the interaction between the SNR and the surrounding MCs.
The jet of BP Tau
Authors: Dodin A. V. , Potanin S. A. , Burlak M. A. , Cheryasov D. V. , Ikonnikova N. P. , Lamzin S. A. , Safonov B. S. , Shatskii N. I. , Tatarnikov A. M.
Published: April 2024

Context. A strong global magnetic field of young low-mass stars and a high accretion rate are the necessary conditions for the formation of collimated outflows (jets) from these objects. But it is still unclear whether these conditions are also sufficient.

Aims. We aim to check whether BP Tau, an actively accreting young star with a strong magnetic field, has a jet.

Methods. We carried out narrowband [S II] 672 nm imaging and spectroscopic observations of BP Tau and its vicinity.

Results. We find that BP Tau is a source of a Herbig-Haro flow (assigned number HH 1181), which includes two HH objects moving from the star in opposite directions and a micro- (counter-) jet of ∼1″ projected length. The flow is oriented along position angle 59 ± 1°.
Understanding the thermal and magnetic properties of an X-class flare in the low solar atmosphere
Authors: Ferrente F. , Quintero Noda C. , Zuccarello F. , Guglielmino S. L.
Published: April 2024

We analyse the spatial distribution and vertical stratification of the physical parameters of the solar atmosphere when an X-class flare occurs. We made use of observations acquired by the Interferometric Bidimensional Spectropolarimeter instrument when observing the full Stokes parameters for the Fe I 6173 Å and Ca II 8542 Å transitions. We analysed the observed spectra using the newly developed DeSIRe code to infer the atmospheric parameters at photospheric and chromospheric layers over the entire observed field of view. Our findings reveal that the chromosphere is characterised by temperature enhancements and strong upflows in the flare ribbon area, which indicates that the flaring event is producing hot material that is moving outwards from the Sun. We did not detect any trace of temperature enhancements or strong velocities (of any sign) at photospheric layers, signalling that the impact of the flaring event mainly happens at the middle and upper layers. The information about the magnetic field vector revealed relatively smooth stratifications with height for both magnetic field strength and inclination. Still, when examining the spatial distribution of the magnetic field inclination, we observed the presence of large-scale mixed polarities in the regions where the flare ribbon is located. These results suggest that the interaction between those mixed polarities could be the flare’s triggering mechanism.
Probing the eccentricity in protostellar discs: Modelling kinematics and morphologies
Authors: Ragusa Enrico , Lynch Elliot , Laibe Guillaume , Longarini Cristiano , Ceppi Simone
Published: April 2024

Context. Protostellar discs are mostly modelled as circular structures of gas and dust orbiting a protostar. However, a number of physical mechanisms, for example, the presence of a (sub)stellar companion or initial axial asymmetry, can cause the gas and dust orbital motion to become eccentric. Theoretical studies have revealed that, when present, disc eccentricity is expected to occur with predictable profiles that can be long-lasting and potentially observable in protostellar systems.

Aims. We construct an analytical model predicting the typical features of the kinematics and morphology of eccentric protostellar discs, with the final goal of characterising the observational appearance of eccentricity in discs.

Methods. We validate the model using a numerical simulation of a circumbinary disc (where the binary makes the disc eccentric). We finally post-process the simulation with Monte Carlo radiative transfer to study how eccentric features would appear through the ‘eyes’ of ALMA.

Results. Besides the motion of the material on eccentric Keplerian orbits in the disc orbital plane, the most characteristic eccentric feature emerging from the analytical model is strong vertical motion with a typical anti-symmetric pattern (with respect to the disc line of pericentres). A circumbinary disc with a ≈ 40 au eccentric cavity (ecav = 0.2), carved by an abin = 15 au binary, placed at a distance d = 130 pc, is expected to host in its upper emission surface vertical oscillations up to vz ~ 400 m s−1 close to the cavity edge, that is to say, well within ALMA spectral and spatial resolution capabilities. A residual spiral pattern in the vertical velocity Δvz ~ 150 m s−1 of the simulation cannot be captured by the theoretical model, we speculate it to be possibly linked to the presence of a companion in the system.
Recovering the gas properties of protoplanetary disks through parametric visibility modeling: MHO 6
Authors: Kurtovic N. T. , Pinilla P.
Published: April 2024

Context. The composition and distribution of the gas in a protoplanetary disk plays a key role in shaping the outcome of the planet formation process. Observationally, the recovery of information such as the emission height and brightness temperature from interfer-ometric data is often limited by the imaging processes.

Aims. To overcome the limitations of image-reconstruction when analyzing gas emission from interferometric observations, we have introduced a parametric model to fit the main observable properties of the gaseous disk component in the visibility plane. This approach is also known as parametric visibility modeling.

Methods. We applied our parametric visibility modeling to the gas brightness distribution of the molecular line emission from 12CO J = 3–2 and 13CO J = 3–2 in the disk around MHO 6, a very-low-mass star in the Taurus star-forming Region. To improve the flux fidelity of our parametric models, we combined models with different pixel resolution before the computation of their visibilities, referred to as “nesting images.”

Results. When we apply our parametric visibility modeling to MHO 6, with independent fits to the emission from its CO isopoto-logues, the models return the same consistent results for the stellar mass, disk geometry, and central velocity. The surface height and brightness temperature distribution are also recovered. When compared to other disks, MHO 6 surface height is among the most elevated surfaces, consistent with the predictions for disks around very-low-mass stars.

Conclusions. This work demonstrates the feasibility of running rapidly iterable parametric visibility models in moderate resolution and sensitivity interferometric observations. More importantly, this methodology opens the analysis of disk’s gas morphology to observations where image-based techniques are unable to robustly operate, as in the case of the compact disk around MHO 6.
The galaxy group merger origin of the Cloverleaf odd radio circle system
Authors: Bulbul E. , Zhang X. , Kluge M. , Brüggen M. , Koribalski B. , Liu A. , Artis E. , Bahar Y. E. , Balzer F. , Garrel C. , Ghirardini V. , Malavasi N. , Merloni A. , Nandra K. , Ramos-Ceja M. E. , Sanders J. S. , Zelmer S.
Published: April 2024

Odd radio circles (ORCs) are a newly discovered class of extended faint radio sources of unknown origin. We report the first detection of diffuse X-ray gas at the location of a low-redshift ORC (z = 0.046) known as Cloverleaf ORC. This observation was performed with theXMM-NewtonX-ray telescope. The physical extent of the diffuse X-ray emission corresponds to a region of approximately 230 kpc by 160 kpc, lying perpendicular to the radio emission detected by ASKAP. The X-ray spectrum shows characteristics of thermal multiphase gas with temperatures of 1.10 ± 0.08 keV and 0.22 ± 0.01 keV and a central density of (4.9 ± 0.6)×10−4cm−3, indicating that the Cloverleaf ORC resides in a low-mass galaxy group. Using X-ray observations, with hydrostatic equilibrium and isothermal assumptions, we measure the galaxy group to have a gas mass and a total mass of (7.7 ± 0.8)×1011 M⊙and 2.6 ± 0.3 × 1013 M⊙within the overdensity radiusR500. The presence of a high-velocity subgroup identified in optical data, the orientation of the brightest cluster galaxy, the disturbed morphologies of galaxies toward the east of the Cloverleaf ORC, and the irregular morphology of the X-ray emission suggest that this system is undergoing a galaxy group merger. The radio power of the ORC could be explained by the shock reacceleration of fossil cosmic rays generated by a previous episode of black hole activity in the central active galactic nucleus.
Structural elucidation of Cr2O3-Al2O3 catalyst: Synthesis & characterization
Authors: Alexzman Zulaikha Athirah , Rozali Annuar Nur Hazirah
Published: April 2024

The development of active, stable, and low-cost catalysts for efficient reactions is appealing but difficult. The objectives of this study are to synthesize Cr2O3-Al2O3 catalysts and analyze their physical properties using SEM, XRD, TGA-DTA, and FTIR. The impregnation method was used to create Cr2O3-Al2O3 catalysts with five different chromium oxide loadings (3wt%, 6wt%, 9wt%, 12wt%, and 15wt%). The physical properties of the catalysts were characterized using FTIR, SEM, BET, and TGA. The FTIR spectra and SEM images of the samples confirmed that Cr2O3 was successfully incorporated on Al2O3 support. TGA was used to evaluate the weight loss and thermal stability of the catalysts during the calcination process. The hydroxyl groups of alumina, as well as its water affinity, cause more mass loss when heated because water molecules are released. The addition of chromium oxide, on the other hand, alters thermal interactions, resulting in different mass loss behavior for chromium oxide alumina. The surface area changes seen by BET analysis gave insights into the structural flexibility of the catalyst across varied loading levels. The physical properties of synthesized catalysts demonstrated their ability to be utilized in a variety of catalytic reactions.
Development of Pairwise Force Smoothed Particle Hydrodynamics for Capillary Rise Modelling
Authors: Hakim Ridwan , Marthanty Dwinanti Rika , Prakoso Widjojo A.
Published: April 2024

This research conducted a series of numerical experiments employing the Pair-Wise Force Smoothed Particle Hydrodynamics (PF-SPH) model to simulate the capillary action of water in the soil column. Initially, analytical relationships were formulated to connect various PF-SPH model parameters to surface tensions, static contact angles, and pore radius. Subsequently, the model was utilized to investigate PF-SPH equations and develop a modified function between numerical and physical parameters that incorporate the pore radius variable. The findings of this research reveal that capillary rise profiles in a steady state condition and Soil Water Characteristic Curve (SWCC) profiles closely align with empirical data obtained from published laboratory experiments. In conclusion, we observed that the PF-SPH model could simulate the capillary rise of water through the soil column by adjusting parameters such as surface tension, contact angle, and soil particle properties.
A Qualitative Review on the Strategies to Reduce the Buildings’ Carbon Emissions
Authors: Ayuningtias Dwi Sari , Berawi Mohammed Ali , Sarojin Gunawan , Sari Mustika
Published: April 2024

As stated in the Nationally Determined Contribution (NDC) document, which establishes emission reduction objectives for 2030, the Government of Indonesia has ratified the Paris Agreement, a worldwide agreement to decrease emissions of greenhouse gases (GHG) and to address the consequences of climate change. This was accomplished through Law No. 16 of 2016. To achieve zero emissions, Indonesia focuses on reducing the use of fossil fuels, adopting environmentally friendly technologies, and increasing the utilization of renewable energy. Global environmental challenges, driven by climate change, have far-reaching implications, including severe health and economic consequences. This study aims to explores the strategies globally performed to reduce the carbon emissions of buildings. To obtain that objective, this study uses a qualitative literature review. The study shows that strategies that can help reduce the buildings carbon emissions include population dynamics, solar photovoltaic, solar water heaters, material use, energy consumption, building stock, and economic considerations. The finding presents a unique opportunity for prioritizing green building practices and carbon emission reduction strategies in Indonesia.
Energy-Water-Food-Environment Nexus and Circular Economy: A Systematic Review
Authors: Nugraha Nurmuntaha Agung , Pudyastuti Purwanti Sri
Published: April 2024

The increasing demand for essential resources such as water, food, and energy will hurt the environment. Nexus thinking emerges as a way of thinking about the interdependence of multiple resource flows within a specific temporal and spatial context, such as energy, water, and food flows in a region. The nexus approach is a type of systems thinking that focuses on natural resource interdependence and how that interdependence can be managed and steered into more integrated and sustainable configurations. The goals of this paper are to systematically review existing research on the energy-water-food-environment nexus and circular economy implementation globally published in the last five years (2019 – 2023) and to identify future research needs in the context of Indonesia. The Scopus database was used in this study. Microsoft Excel and VOS viewer software were applied for the bibliometric analysis. Almost all of the articles reviewed in this study were taken place in other countries. Energy, water, and food security as well as environmental sustainability have become major challenges in Indonesia. Therefore, research regarding the energy-waterfood-environment nexus and circular economy to support the SDGs for Indonesia context is required in the future.
Analysis of Production Planning of Cocoa Products Using Workload Analysis and Operation Scheduling
Authors: Chie Ho Hwi , Tjolleng Amir , Agustiawan Putra Muh
Published: April 2024

The fluctuating demand levels each period is a significant challenge in the company’s production. Production scheduling stands out as a crucial process in the production system. PT XYZ, a privately-owned company specializing in cocoa plantations in Indonesia, faced problem in production planning, leading to delays in chocolate product output. This study delved into the workload experienced by the production operator and the production schedule using the workload analysis and the Campbell Dudek Smith (CDS). Data were collected through observations and interviews. The results revealed that the total workload for the current eight production operators in each production room was 988.1%. The existing production schedule was not optimal as indicated with an excessively high makespan of 170. Implementing the CDS method reduced the makespan to 151, enhancing performance by 19% and saving 12% of time. The findings suggest that introducing two additional workers could alleviate the overall workload for production operators. In addition, the proposed production schedule prioritizes chocolate powder, followed by chocolate butter, chocolate liquid, and chocolate bars. The implications of this research extend to potential benefits for the company, including improved work quality, enhanced production efficiency, and an overall enhancement of the company’s performance.
Biodiesel Synthesis from Nyamplung (Calophyllum Inophyllum) Oil Using Heterogenous Modified Geopolymer Catalyst Derived from Kaolin
Authors: Utama Panca Setia , Syahada Nabil , Prawiranegara Barata Aditya , Saputra Edy
Published: April 2024

This work aims to develop a new type of solid base catalyst for biodiesel synthesis from “nyamplung” oil. A heterogenous catalyst was synthesized by modifying kaolin into a geopolymer. The geopolymer catalyst was activated using ammonium nitrate. The microstructure, specific surface area, pore diameter, pore volume, and crystalline phase of the catalyst were characterized. It was possible to achieve the highest biodiesel yield of 95.14%. The effects of reaction temperature, reaction time, oil-to-methanol molar ratio, and catalyst loading on the yield of biodiesel were examined. As per ASTM D6751 and SNI 7182:2015 standards, the biodiesel obtained is of satisfactory quality.
Expatriates’ boundary-spanning: double-edged effects in multinational enterprises
Authors: Liu Ting , Sekiguchi Tomoki , Qin Jiayin , Shen Ya Xi
Published: April 2024

Expatriates typically perform boundary-spanning to address challenges related to functional, linguistic, and cultural variations within multinational enterprises (MNEs), which in turn influences their relationships with host-country employees. Integrating social capital and role theory perspectives, this study explores the relational dynamics between expatriates and host-country employees by developing a novel theoretical framework that examines the double-edged effects of expatriates’ boundary-spanning. We propose that expatriates’ boundary-spanning nurtures mutual trust between expatriates and host-country employees, further facilitating expatriates’ identification with subsidiaries and host-country employees’ identification with MNEs. On the other hand, we propose that boundary-spanning increases expatriates’ role stressors, causing expatriates’ emotional exhaustion and outgroup categorization by host-country employees. We further categorize expatriates’ boundary-spanning into three types (functional, linguistic, and cultural) and theorize about their varying effects on the cognitive and affective bases of mutual trust and on role stressors. With data from 177 expatriate–host-country coworker dyads in Chinese MNEs, our double-edged framework is generally supported. Our findings suggest that cultural boundary-spanning exhibits the strongest double-edged effect, while functional boundary-spanning shows asymmetric effects, with negative outcomes surpassing positive ones, and linguistic boundary-spanning demonstrates the weakest effect. This study offers realistic and comprehensive insights into expatriates’ boundary-spanning, particularly in expatriate–host-country employee relationships.
Anti-capitalist subjectivity: considerations of fantasy, (in)action, and solidarity building
Authors: Malherbe Nick
Published: April 2024

Anti-capitalist subjectivities are produced through politically generative refusals of the divisive, profit-oriented, and manageable subject positions made available by capitalism’s socio-symbolic order. Pushing back against liberal political theories which presume subjectivity to be a priori or coherent, this article employs psychoanalytic theory to grapple with the flowing, changing, patterned, and disjointed nature of anti-capitalist subject formations. Although mainstream psychoanalysis has, historically, aligned with the dictates of capital, I argue that psychoanalytic theory nonetheless offers a useful resource for understanding how anti-capitalist refusal can foster emancipatory desires and situated political commitments within and among subjects. In fleshing out these arguments, I engage with the role that fantasy plays in forming anti-capitalist subjectivities. I also consider what solidarity building and political action mean with respect to anti-capitalist subjectivity. By way of conclusion, I argue why we should make the case for anti-capitalist subjectivity, offering some directions that future work may take.
Quantifying the diffusion history of Yangmingism
Authors: Lin Xiaobiao , Wu Shidai , Wu Bowei , Wang Jiawei
Published: April 2024

Yangmingism, a crucial component of Chinese Confucianism, has profoundly impacted the development of Eastern civilization throughout history and gained new significance within modern contexts. This study employs social network and GIS spatial analyses to investigate the spatio-temporal evolution and patterns of Yangmingism during the Ming and Qing dynasties. Conclusions drawn include: (1) Yangmingism spread during the Ming and Qing dynasties followed five phases (rise-peak-decline-revival-trough), consistent with general cultural diffusion processes. (2) The spatial structure of regions accepting Yangmingism changed from polycentric to localized ribbon-polycentric, then to monocentric, polycentric, and ultimately, fragmented distribution. Diffusion began with a point-axis structure along traffic routes, transitioned to a core-periphery spatial structure, and returned to a point-axis structure due to reduced diffusion potential energy. (3) Yangmingism diffusion exhibited distance decay characteristics, with the most extensive diffusion in the Han cultural region, primarily located within the middle and lower reaches of the Ganjiang River basin and the Yangtze River Delta. (4) Yangmingism diffusion reflected influences from local administrative hierarchies and cultural development. During the rise-to-peak phase, Yangmingism reached areas with higher administrative and cultural levels, while during the peak-to-decline phase, it disseminated from higher to lower hierarchy regions. (5) The spatial diffusion of Yangmingism is mainly relocation diffusion, followed by expansion diffusion. In the process of relocation diffusion, Yangmingism may reverse the diffusion from the “target regions” to the “source regions” due to the influence of the radiation of the high-ranking regions and the cultural innovation of the “target regions”.
The application of the “inverse problem” method for constructing confining potentials that make N-soliton waveforms exact solutions in the Gross–Pitaevskii equation
Authors: Cooper Fred , Khare Avinash , Dawson John F. , Charalampidis Efstathios G. , Saxena Avadh
Published: April 2024

In this work, we discuss an application of the “inverse problem” method to find the external trapping potential, which has particular N trapped soliton-like solutions of the Gross–Pitaevskii equation (GPE) also known as the cubic nonlinear Schrödinger equation (NLSE). This inverse method assumes particular forms for the trapped soliton wave function, which then determines the (unique) external (confining) potential. The latter renders these assumed waveforms exact solutions of the GPE (NLSE) for both attractive (g<0) and repulsive (g>0) self-interactions. For both signs of g, we discuss the stability with respect to self-similar deformations and translations. For g<0, a critical mass Mc or equivalently the number of particles for instabilities to arise can often be found analytically. On the other hand, for the case with g>0 corresponding to repulsive self-interactions which is often discussed in the atomic physics realm of Bose–Einstein condensates, the bound solutions are found to be always stable. For g<0, we also determine the critical mass numerically by using linear stability or Bogoliubov–de Gennes analysis, and compare these results with our analytic estimates. Various analytic forms for the trapped N-soliton solutions in one, two, and three spatial dimensions are discussed, including sums of Gaussians or higher-order eigenfunctions of the harmonic oscillator Hamiltonian.
Influence of interposed graphene sheets on mechanical and electronic properties of Al/graphene superlattice
Authors: Jang Jong-Hyok , Ri Kum-Chol , Kim Song-Jun , Jon Sin-Hyok , Yu Chol-Jun
Published: April 2024

Graphene-reinforced aluminum matrix composites have drawn remarkable attention in several fields of high-tech industries, but the understanding of their material properties remains unclear. This work reports a first-principles study of interface binding nature, mechanical strength, and electronic properties of aluminum/graphene (Al/G) composites using superlattice models as varying graphene content. Our calculations reveal the weak binding between Al and graphene layers with no new chemical bonding at the interface and the gradual decrease in binding strength as increasing graphene content. While demonstrating the enhancement of mechanical strength by interposing graphene layers, the critical value of graphene content for keeping ductility is determined to be 14.7%. Atom-projected band structures and local density of states are analyzed to get an insight into electronic conductance of superlattices.
Experimental validation of the analytic model for the temporal decay of the density auto-correlation function in a strongly coupled dusty plasma
Authors: Dhaka Ankit , Bandyopadhyay P. , Subhash P. V. , Sen A.
Published: April 2024

In a recent theoretical work [Dhaka et al. Sci. Rep. 12, 21883 (2022)], the method of determining the transport coefficients of a system from the time dynamics of the density auto-correlation function (DAF) was extended to complex plasma systems using the framework of a generalized hydrodynamics model. An exact analytical form of the density auto-correlation function of the thermal level spontaneous fluctuations of a Yukawa system was obtained. In the present work, we provide the first experimental validation of this analytical model for a strongly coupled dusty plasma system. The dusty plasma is produced by introducing micron-sized melamine formaldehyde particles in radio frequency argon discharges, and the DAF of the spontaneous dust density fluctuations is determined by optically tracking the trajectories of the dust particles. The experimentally obtained DAF is found to show a trend that is consistent with our earlier theoretical and numerical predictions. It is further used to determine the microscopic rate of heat diffusion for various values of the fluctuation wave-number k and obtain an extrapolated value of the macroscopic heat diffusion rate in the limit k →0. The experimental validation lends strong support to our generalized theoretical model, which can be usefully employed now in a variety of strongly coupled systems.
Photodriven electron-transfer dynamics in a series of heteroleptic Cu(I)–anthraquinone dyads
Authors: Phelan Brian T. , Xie Zhu-Lin , Liu Xiaolin , Li Xiaosong , Mulfort Karen L. , Chen Lin X.
Published: April 2024

Solar fuels catalysis is a promising route to efficiently harvesting, storing, and utilizing abundant solar energy. To achieve this promise, however, molecular systems must be designed with sustainable components that can balance numerous photophysical and chemical processes. To that end, we report on the structural and photophysical characterization of a series of Cu(I)–anthraquinone-based electron donor–acceptor dyads. The dyads utilized a heteroleptic Cu(I) bis-diimine architecture with a copper(I) bis-phenanthroline chromophore donor and anthraquinone electron acceptor. We characterized the structures of the complexes using x-ray crystallography and density functional theory calculations and the photophysical properties via resonance Raman and optical transient absorption spectroscopy. The calculations and resonance Raman spectroscopy revealed that excitation of the Cu(I) metal-to-ligand charge-transfer (MLCT) transition transfers the electron to a delocalized ligand orbital. The optical transient absorption spectroscopy demonstrated that each dyad formed the oxidized copper–reduced anthraquinone charge-separated state. Unlike most Cu(I) bis-phenanthroline complexes where increasingly bulky substituents on the phenanthroline ligands lead to longer MLCT excited-state lifetimes, here, we observe a decrease in the long-lived charge-separated state lifetime with increasing steric bulk. The charge-separated state lifetimes were best explained in the context of electron-transfer theory rather than with the energy gap law, which is typical for MLCT excited states, despite the complete conjugation between the phenanthroline and anthraquinone moieties.
Exploring the influence of the contact resistance on perovskite phototransistors
Authors: Chen Lijian , Chen Quanhua , Zhu Hong , Wang Runfeng , Wu Yiping , Li Run , Zhu Li , Yang Guangan , Wan Xiang , Zhao Xing , Yu Zhihao , Li Binhong , Tan Chee Leong , Sun Huabin , Xu Yong
Published: April 2024

Organic–inorganic hybrid perovskites are widely used in photodetection owing to their high optical absorption coefficients. A variety of research has been conducted on perovskite phototransistors and their optoelectronic properties, but the exploration of the influence of contact resistance remains limited. In this work, we employed the transmission-line method to separate the contact resistance Rc × W (ranging from 4.81 × 104 to 4.77 × 103 Ω cm) and the channel resistance Rch × W (ranging from 1.93 × 104 to 1.16 × 104 Ω cm) of (PEA)2SnI4 perovskite phototransistors at different light intensities (520 nm, ranging from 0 to 2550 μW/cm2). Further analysis reveals that illumination-induced accumulation of charge carriers at the metal/semiconductor interface reduces the Schottky barrier. Approximately 90% of the observed increase in photocurrent can be attributed to the reduction in the contact resistance. Our finding underscores the crucial role of charge injection in influencing perovskite-based phototransistors.
Deep field-of-view and passive tomography based on Airy light field
Authors: Wang Siyuan , Guo Zonglin , Zhao Yu , Pei Yanbo , Shi Hongyan , Zhang Jingbo , Wang Jian
Published: April 2024

We introduce a passive tomography method with deep field of view up to 90 m based on the self-acceleration characteristics of Airy beams. A post-modulation long-distance imaging system was proposed and optimized in its optical configuration and phase modulation parameters. The resolution was analyzed based on theoretical simulation. Experimentally, three LEDs at various distances around 10 m and two outdoor road lamps with distance of 67 and 90 m were reconstructed using the Airy-beam tomography algorithm, respectively, demonstrating excellent tomographic characteristics. This work presents a feasible candidate for the 3D passive detection for long-distance targets.
Optical assembly of multi-particle arrays by opto-hydrodynamic binding of microparticles close to a one-dimensional chain of magnetic microparticles
Authors: Zhang Xian-Feng , Meng Chun , Bai Wen , Shao Meng , Ji Feng , Zhong Min-Cheng
Published: April 2024

Two-dimensional materials possess a large number of interesting and important properties. Various methods have been developed to assemble two-dimensional aggregates. Assembly of colloidal particles can be achieved with laser-heating-induced thermal convective flow. In this paper, an opto-hydrodynamic binding method is proposed to assemble colloidal particles dispersed in a solution into multilayer structures. First, we use polystyrene (PS) microspheres to study the feasibility and characteristics of the assembly method. PS microspheres and monodispersed magnetic silica microspheres (SLEs) are dispersed in a solution to form a binary mixture system. Under the action of an external uniform magnetic field, SLEs in the solution form chains. An SLE chain is heated by a laser beam. Due to the photothermal effect, the SLE chain is heated to produce a thermal gradient, resulting in thermal convection. The thermal convection drives the PS beads to move toward the heated SLE chain and finally stably assemble into multilayer aggregates on both sides of the SLE chain. The laser power affects the speed and result of the assembly. When the laser power is constant, the degree of constraint of the PS microbeads in different layers is also different. At the same time, this method can also assemble the biological cells, and the spacing of different layers of cells can be changed by changing the electrolyte concentration of the solution. Our work provides an approach to assembling colloidal particles and cells, which has a potential application in the analysis of the collective dynamics of microparticles and microbes.
Visual explanations of machine learning model estimating charge states in quantum dots
Authors: Muto Yui , Nakaso Takumi , Shinozaki Motoya , Aizawa Takumi , Kitada Takahito , Nakajima Takashi , Delbecq Matthieu R. , Yoneda Jun , Takeda Kenta , Noiri Akito , Ludwig Arne , Wieck Andreas D. , Tarucha Seigo , Kanemura Atsunori , Shiga Motoki , Otsuka Tomohiro
Published: April 2024

Charge state recognition in quantum dot devices is important in the preparation of quantum bits for quantum information processing. Toward auto-tuning of larger-scale quantum devices, automatic charge state recognition by machine learning has been demonstrated. For further development of this technology, an understanding of the operation of the machine learning model, which is usually a black box, will be useful. In this study, we analyze the explainability of the machine learning model estimating charge states in quantum dots by gradient weighted class activation mapping. This technique highlights the important regions in the image for predicting the class. The model predicts the state based on the change transition lines, indicating that human-like recognition is realized. We also demonstrate improvements of the model by utilizing feedback from the mapping results. Due to the simplicity of our simulation and pre-processing methods, our approach offers scalability without significant additional simulation costs, demonstrating its suitability for future quantum dot system expansions.
A flexible thermal-coupled InGaZnO adaptive synapse
Authors: Xu Mingtao , Long Haotian , Fu Chuanyu , Mao Huiwu , Wan Changjin , Wan Qing
Published: April 2024

The development of neuromorphic sensory systems necessitates synaptic devices with adaptivity to a wide range of stimuli. Furthermore, the introduction of multimodal adaptivity is highly favorable, which holds immense potential for improving the processing capability of the neuromorphic system under complex environments. In this work, we report a thermal-coupled adaptive synapse (TCAS) by integrating an IGZO-based synaptic transistor with a laser-induced graphene micro-heater. This synapse enables active modulation of nonlinear short-term plasticity gains through temperature and voltage co-mediated ion/electron coupling, which facilitates the high adaptivity for image denoising. The images with multilevel signals can be effectively denoised with an average reduction of ∼84.0% in the Euclidean distance in comparison with the noisy images. This outcome indicates the effectiveness of TCASs in complex sensory processing and offers a promising solution for the development of neuromorphic systems with multimodal adaptability.
The stability analysis of In–Ga–ZnO thin film transistors with polyimide substrates based on Maxwell–Wagner effect
Authors: Bao Zongchi , Liu Bin , Liu Xianwen , Zhang Shuo , Weng Le , Sun Haoran , Zhang Xi , Yao Qi , Yuan Guangcai , Guo Jian , Ning Ce , Shi Dawei , Wang Feng , Yu Zhinong
Published: April 2024

Flexible organic light-emitting diode display devices fabricated on polyimide (PI) substrates have more obvious residual image problems due to the abnormal threshold-voltage (Vth) shifts of a thin film transistor (TFT). In this paper, the Vth shift of TFT fabricated on a PI substrate was analyzed. We explained the worse bias stability and worse recovery of TFT with a PI substrate compared with TFT with a glass substrate, by an interlayer charging effect (Maxwell–Wagner effect) and a technology computer-aided design (Silvaco). When bias stress was applied for a long time, the interface between the PI substrate and the buffer layer will have a charging effect under the action of an electric field, and the charging charge will react on the channel and hinder the formation of the channel. We found that there are differences in the scale of charge under different voltage stress conditions, and this will result in different Vth shifts of driving TFTs for displays units.
Lagrangian perspective on the expansion dynamics and shielding effect of femtosecond laser-induced copper plasma plumes
Authors: Zhan Ningwei , Jiang Lan , Zhang Tianyong , Lian Yiling , Guo Baoshan
Published: April 2024

Femtosecond laser ablation of metals generates a strongly ionized plasma plume near the irradiated surface. The resulting plasma shielding effect can reduce subsequent laser energy deposition and lower nanomachining efficiency, especially during multi-pulse irradiation. Understanding the spatiotemporal evolution of the laser-induced plasma and its associated shielding effect is, therefore, crucial. A hybrid two-temperature and direct simulation Monte Carlo (TTM-DSMC) computational model is developed in this study, which synergistically couples the ultrafast laser–metal interaction physics and the plasma collisional transport. The model simulates the plasma properties including electron density, temperature dynamics, reflectivity, and energy attenuation throughout the plume expansion process from femtosecond to nanosecond timescales. A complex “penguin-shaped” plasma plume with internal shockwaves is observed due to the effects of double-pulse irradiation. Significantly enhanced plasma reflectivity and reduced laser energy deposition demonstrate the accumulated shielding effect, which increases with higher plasma density accumulation when the pulse separation is insufficient. Our model provides valuable theoretical guidance for optimizing processing parameters to enhance efficiency and precision in femtosecond laser machining. The integrated TTM-DSMC approach could also facilitate the study of laser-induced plasmas in other contexts like material characterization and nanoparticle synthesis.
Unraveling the impact of initial choices and in-loop interventions on learning dynamics in autonomous scanning probe microscopy
Authors: Slautin Boris N. , Liu Yongtao , Funakubo Hiroshi , Kalinin Sergei V.
Published: April 2024

The current focus in Autonomous Experimentation (AE) is on developing robust workflows to conduct the AE effectively. This entails the need for well-defined approaches to guide the AE process, including strategies for hyperparameter tuning and high-level human interventions within the workflow loop. This paper presents a comprehensive analysis of the influence of initial experimental conditions and in-loop interventions on the learning dynamics of Deep Kernel Learning (DKL) within the realm of AE in scanning probe microscopy. We explore the concept of the “seed effect,” where the initial experiment setup has a substantial impact on the subsequent learning trajectory. Additionally, we introduce an approach of the seed point interventions in AE allowing the operator to influence the exploration process. Using a dataset from Piezoresponse Force Microscopy on PbTiO3 thin films, we illustrate the impact of the “seed effect” and in-loop seed interventions on the effectiveness of DKL in predicting material properties. The study highlights the importance of initial choices and adaptive interventions in optimizing learning rates and enhancing the efficiency of automated material characterization. This work offers valuable insights into designing more robust and effective AE workflows in microscopy with potential applications across various characterization techniques.
Domain reorientation due to smectic layer instability in high tilt angle-based surface stabilized ferroelectric liquid crystal cell
Authors: Yadav Neha , Kumar Suraj , Choudhary Amit , Thakur Anil K. , Rajesh  , Singh Surinder P. , Biradar Ashok M.
Published: April 2024

High tilt angle (45°) ferroelectric liquid crystal (FLC) in surface stabilized geometry, having no chiral smectic A (SmA∗) phase, has been studied for the reorientation of the smectic layers near the transition temperature (Tc). The electro-optical studies have shown the stripe domain formation in which the liquid crystal molecules are aligned along the rubbing direction, but the smectic layers are tilted away from the rubbing direction at room temperature. In such high tilt angle FLCs, the molecular alignment and smectic layer formation start from bottom and top rubbed grooves at Tc. The domain formation of the FLC takes place in the middle of the top and bottom surfaces due to the frustration of the dipolar interaction. The smectic layer switching is observed by optical microscopy and confirmed by the dielectric spectroscopy method near Tc of SmC∗ and chiral nematic phases. Domain switching has shown a larger switching angle than the molecular tilt angle within the smectic layer. These studies are expected to be significant for understanding the smectic layer structure and the domain switching process, which may pave the way for large optical switching devices.
Short-term photovoltaic power prediction model based on hierarchical clustering of K-means++ algorithm and deep learning hybrid model
Authors: Wang Man , Ma Xiaojing , Wang Ru , Kari Tusongjiang , Tang Zihan
Published: April 2024

In order to further improve the accuracy of photovoltaic (PV) power prediction and the stability of power system, a short-term PV power prediction model based on hierarchical clustering of K-means++ algorithm and deep learning hybrid model is proposed in this paper. First, hierarchical clustering of the K-means++ algorithm is used to cluster historical data into different weather scenes according to different seasons. Second, a hybrid model combining convolutional neural network (CNN), squeeze-and-excitation attention mechanism (SEAM), and bidirectional long short-term memory (BILSTM) neural network is constructed to capture long-term dependencies in time series, and the improved pelican optimization algorithm (IPOA) is used to optimize the hyperparameters in the prediction model. Finally, an example for modeling analysis is conducted by using the actual output and meteorological data of a PV power station in the Ili region of Xinjiang, China. The effectiveness and accuracy of the proposed model are verified by comparing with LSTM, BILSTM, CNN-BILSTM, and POA-CNN-SEAM-BILSTM models, and the superiority of IPOA is verified by comparing with particle swarm optimization and whale optimization algorithm. The results show that the proposed model can obtain better results under different weather scenes in different seasons, and the prediction accuracy of the model optimized by IPOA is further improved.
Ultrafast self-transportation and efficient separation of organic droplets on semi-conical asymmetric structure
Authors: Yang Yi , Zou Qinrui , Ren Hesong , Wang Yuan , Yao Xiao , Guo Chenghong , Zhuo Lijie , Xu Yuanchong , Song Yuegan , Xiang Kefeng , Li Guoqiang
Published: April 2024

Manipulating oil droplets in an aqueous solution is highly desirable for organic multiphase liquid separation. Despite substantial works in the realm of organic multiphase liquid manipulation and separation, the ultrafast transportation and efficient and precise separation of these liquids, especially those with varied surface tensions, encounters significant challenges due to little driving forces. To address this issue, a semi-conical structure with pine-needlelike features and incorporated wedge-shaped grooves is fabricated, which could support the ultrafast transport and separation of organic droplets. For pre-wetted superhydrophobic surfaces, organic liquids with lower surface tension can be transported at a speed of 305.6 mm/s. The Laplace pressure difference caused by the conical structure determines the direction of transport of organic liquids, and the capillary force caused by flat wedge-shaped grooves increases the transport speed of organic droplets on the surface. Based on the characteristics of “differential” transportation and directional transportation, the separation of mixed organic liquids is realized. This biomimetic design concept will pave a path for microfluidics, liquid manipulation, and the separation of various organic liquids.
Design and fabrication of a sandwich detector for material discrimination and contrast cancellation in dual-energy based x-ray imaging
Authors: Alikunju Rimcy Palakkappilly , Buchanan Ian , Esposito Michela , Morehen Jason , Khan Asmar , Stamatis Yiannis , Iacovou Nicolas , Bullard Edward , Anaxagoras Thalis , Brodrick James , Olivo Alessandro
Published: April 2024

Dual-energy imaging represents a versatile and evolving technology with wide-ranging applications in medicine and beyond. Recent technological developments increased the potential for improved diagnostic accuracy and expanded imaging capabilities across various fields. The purpose of this work is to design and develop an energy-integrating multilayer detector, known as a sandwich detector, aimed at single-shot dual-energy imaging tasks such as material discrimination and contrast cancellation. The sandwich detector uses two complementary metal oxide semiconductor advanced pixel sensors of 50 μm pixel size. The top and bottom sensors detect low-energy (LE) and high-energy (HE) photons, with sensors coupled with 250 and 600 μm scintillators, respectively. For better spectral separation between layers without excessively affecting the detected statistic in the bottom layer, the insertion of a 0.25-mm Cu filter between the layers was found to be the optimal choice, from among the tested 0-, 0.25-, and 0.5-mm filter options. The thickness selection for scintillator and intermediate Cu filter was carried out through a dual-energy simulation model. The experiments confirmed the model's reliability in selecting the optimal thicknesses of the intermediate Cu filter, thereby providing reassurance also on the choice of the top scintillator.
Time-traceable micro-taggants for anti-counterfeiting and secure distribution of food and medicines
Authors: Park Cheolheon , Jeong Yunjin , Yeom Huiran , Song Seo Woo , Park Wook , Lee Daewon
Published: April 2024

This study presents an innovative solution for the enhanced tracking and security of pharmaceuticals through the development of microstructures incorporating environmentally responsive, coded microparticles. Utilizing maskless photolithography, we engineered these microparticles with a degradable masking layer with 30 μm thickness that undergoes controlled dissolution. Quantitative analysis revealed that the protective layer's degradation, monitored by red fluorescence intensity, diminishes predictably over 144 h in phosphate-buffered saline under physiological conditions. This degradation not only confirms the microparticles' integrity but also allows the extraction of encoded information, which can serve as a robust indicator of medicinal shelf life and a deterrent to tampering. These findings indicate the potential for applying this technology in real-time monitoring of pharmaceuticals, ensuring quality and authenticity in the supply chain.