bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical piezoelectric composite film for self-powered moisture detection and wearable biomonitoring
Authors: Dai Jing , Xie Guangzhong , Chen Chunxu , Liu Yulin , Tai Huiling , Jiang Yadong , Su Yuanjie
Published: January 2024

Moisture detection plays a crucial role in physiological monitoring and wearable electronics. Nevertheless, most of the humidity sensors were restricted by the power supply, hindering their applicability in internet of things and mobile healthcare. Herein, we reported a hierarchical piezoelectric composite film for active humidity detection and wearable biomonitoring. The as-electrospun piezoelectric transducing textile consists of samarium-modified lead magnesium niobate lead titanate piezoceramic fillers and polyvinylidene fluoride matrix, while the spin coated polyimide film serves as the humidity sensitive layer. By tuning the thickness ratio between transducing layer and the humidity sensing layer as well as the porosity of the electrode, an optimal moisture-sensing performance was accomplished with a high response of ∼500% and rapid response/recovery time of 23 s/31 s. Furthermore, a theoretical modeling of active humidity sensing mechanism was established by combining thermodynamic derivation and finite element calculation.
Enhanced fault diagnosis via stochastic resonance in a piecewise asymmetric bistable system
Authors: Li Yongge , Zhu Qixiao , Xu Yong , Tian Ruilan
Published: January 2024

Weak fault signals are often overwhelmed by strong noise or interference. The key issue in fault diagnosis is to accurately extract useful fault characteristics. Stochastic resonance is an important signal processing method that utilizes noise to enhance weak signals. In this paper, to address the issues of output saturation and imperfect optimization of potential structure models in classical bistable stochastic resonance (CBSR), we propose a piecewise asymmetric stochastic resonance system. A two-state model is used to theoretically derive the output signal-to-noise ratio (SNR) of the bistable system under harmonic excitations, which is compared with the SNR of CBSR to demonstrate the superiority of the method. The method is then applied to fault data. The results indicate that it can achieve a higher output SNR and higher spectral peaks at fault characteristic frequencies/orders, regardless of whether the system operates under fixed or time-varying speed conditions. This study provides new ideas and theoretical guidance for improving the accuracy and reliability of fault diagnosis technology.
A detailed analysis on the heat generated inside c-Si solar cell
Authors: Lu Xiaodong , Li Haixia , Lun Shuxian , Ni Yanan
Published: January 2024

The heat generated inside solar cells is one of the important factors influencing the operational stability of a photovoltaic system composed of solar cells. In this work, based on the influencing factors of four main heat-generated mechanisms inside c-Si solar cells, i.e., the energy relaxation process of the hot carrier, Joule heat, recombination heat, and Peltier and Thomson effects, the distribution features of the heat generated by each mechanism are first discussed, and then, considering two common working conditions of c-Si solar cells in module form, i.e., the variations of environmental temperature and output voltage, the changing rules of the distributions of heat generated by different mechanisms are analyzed. The general features of the heat distributions of c-Si solar cells are that the obviously absorbed and released heat only exists in the regions near the front and back surfaces; the four mechanisms all release heat in the narrow n region close to the front surface; and Peltier and Thomson effects are the only mechanism of absorbed heat in the wide p region. The offset effects between released and absorbed heat make the total heat generated by the four mechanisms very small in the wide p region. With the environmental temperature increasing, the heat distribution features of each heat mechanism will remain unchanged, and except for the heat generated by the energy relaxation of the hot carrier, the released and absorbed heat generated by other mechanisms will increase in the whole c-Si active layer. With the output voltage increasing from 0 to 0.68 V, aside from the heat distribution of the energy relaxation of the hot carrier, the distributions of heat generated by other mechanisms show obvious threshold voltage effects, and only when the output voltage is larger than the threshold voltage will the heat distributions of different mechanisms be significantly changed by the variations of the output voltage.
Chromatic properties of InGaN-based red, green, and blue micro-LEDs grown on silicon substrate
Authors: Zheng Xi , Xu Xiongfei , Tong Changdong , Fu Yi , Zhou Mingbing , Huang Tao , Lu Yijun , Chen Zhong , Guo Weijie
Published: January 2024

The optical and chromatic characteristics of InGaN-based micro-light-emitting diodes (micro-LEDs) grown on silicon substrates with blue, green, and red emissions have been investigated. The red micro-LEDs exhibited a large full-width at half maximum and a strong blueshift upon increasing current density. The 20 μm blue, green, and red micro-LEDs achieve a maximum external quantum efficiency of 8.2% at 2.65 A/cm2, 5.1% at 5 A/cm2, and 0.62% at 0.1 A/cm2, respectively, which is superior to their 8 μm counterparts. The dependences of a color gamut on the temperature and current density of InGaN-based tri-color micro-LEDs can provide guidance for improving the performance of full-color micro-LED displays.
Electric chiral magnonic resonators utilizing spin–orbit torques
Authors: Au Yat-Yin
Published: January 2024

The recently proposed concept of electric chiral magnonic resonator (ECMR) has been extended to include usage of spin–orbit torques (SOT). Unlike the original version of ECMR which was based on voltage controlled magnetic anisotropy (VCMA), the spin wave amplification power by this new version of ECMR (pumped by SOT) no longer depends on the phase of the incident wave, which is highly desirable from an application point of view. The performance of the SOT pumped ECMR has been compared with the case of amplification by applying SOT pumping directly to a waveguide (without any ECMR involved). It is argued that at the expense of narrowing the bandwidth (i.e., slower amplifier response), the advantage of the former configuration (amplification by a SOT pumped ECMR) over the latter (amplification by direct SOT pumping the waveguide) is to offer gain, while at the same time, maintaining system stability (avoidance of auto-oscillations). Non-linear behavior of the SOT pumped ECMR has been analyzed. It is demonstrated that by cascading a SOT ECMR operating in an off-resonance mode together with a VCMA biased passive ECMR, it is possible to produce a magnonic neuron with a transmitted signal magnitude larger than the input in the firing state.
Reassessing the role of urban green space in air pollution control
Authors: Venter Zander S. , Hassani Amirhossein , Stange Erik , Schneider Philipp , Castell Núria
Published: January 2024

The assumption that vegetation improves air quality is prevalent in scientific, popular, and political discourse. However, experimental and modeling studies show the effect of green space on air pollutant concentrations in urban settings is highly variable and context specific. We revisited the link between vegetation and air quality using satellite-derived changes of urban green space and air pollutant concentrations from 2,615 established monitoring stations over Europe and the United States. Between 2010 and 2019, stations recorded declines in ambient NO
2
, (particulate matter) PM
10
, and PM
2.5
(average of −3.14% y
−1
), but not O
3
(+0.5% y
−1
), pointing to the general success of recent policy interventions to restrict anthropogenic emissions. The effect size of total green space on air pollution was weak and highly variable, particularly at the street scale (15 to 60 m radius) where vegetation can restrict ventilation. However, when isolating changes in tree cover, we found a negative association with air pollution at borough to city scales (120 to 16,000 m) particularly for O
3
and PM. The effect of green space was smaller than the pollutant deposition and dispersion effects of meteorological drivers including precipitation, humidity, and wind speed. When averaged across spatial scales, a one SD increase in green space resulted in a 0.8% (95% CI: −3.5 to 2%) decline in air pollution. Our findings suggest that while urban greening may improve air quality at the borough-to-city scale, the impact is moderate and may have detrimental street-level effects depending on aerodynamic factors like vegetation type and urban form.
The clustered gamma protocadherin PcdhγC4 isoform regulates cortical interneuron programmed cell death in the mouse cortex
Authors: Leon Walter R. Mancia , Steffen David M. , Dale-Huang Fiona R. , Rakela Benjamin , Breevoort Arnar , Romero-Rodriguez Ricardo , Hasenstaub Andrea R. , Stryker Michael P. , Weiner Joshua A. , Alvarez-Buylla Arturo
Published: January 2024

Cortical inhibitory interneurons (cINs) are born in the ventral forebrain and migrate into the cortex where they make connections with locally produced excitatory glutamatergic neurons. Cortical function critically depends on the number of cINs, which is also key to establishing the appropriate inhibitory/excitatory balance. The final number of cINs is determined during a postnatal period of programmed cell death (PCD) when ~40% of the young cINs are eliminated. Previous work shows that the loss of clustered gamma protocadherins (Pcdhgs), but not of genes in the
Pcdha
or
Pcdhb
clusters, dramatically increased BAX-dependent cIN PCD. Here, we show that
PcdhγC4
is highly expressed in cINs of the mouse cortex and that this expression increases during PCD. The sole deletion of the PcdhγC4 isoform, but not of the other 21 isoforms in the
Pcdhg
gene cluster, increased cIN PCD. Viral expression of the
PcdhγC4,
in cIN lacking the function of the entire
Pcdhg
cluster, rescued most of these cells from cell death. We conclude that
PcdhγC4
plays a critical role in regulating the survival of cINs during their normal period of PCD. This highlights how a single isoform of the
Pcdhg
cluster, which has been linked to human neurodevelopmental disorders, is essential to adjust cIN cell numbers during cortical development.
Probing the dynamics and bottleneck of the key atmospheric SO
2
oxidation reaction by the hydroxyl radical
Authors: Yuan Dao-Fu , Liu Yang , Trabelsi Tarek , Zhang Yue-Rou , Li Jun , Francisco Joseph S. , Guo Hua , Wang Lai-Sheng
Published: January 2024

SO
2
(Sulfur dioxide) is the major precursor to the production of sulfuric acid (H
2
SO
4
), contributing to acid rain and atmospheric aerosols. Sulfuric acid formed from SO
2
generates light-reflecting sulfate aerosol particles in the atmosphere. This property has prompted recent geoengineering proposals to inject sulfuric acid or its precursors into the Earth’s atmosphere to increase the planetary albedo to counteract global warming. SO
2
oxidation in the atmosphere by the hydroxyl radical HO to form HOSO
2
is a key rate-limiting step in the mechanism for forming acid rain. However, the dynamics of the HO + SO
2
→ HOSO
2
reaction and its slow rate in the atmosphere are poorly understood to date. Herein, we use photoelectron spectroscopy of cryogenically cooled HOSO
2

–

anion to access the neutral HOSO
2
radical near the transition state of the HO + SO
2
reaction. Spectroscopic and dynamic calculations are conducted on the first ab initio-based full-dimensional potential energy surface to interpret the photoelectron spectra of HOSO
2

–

and to probe the dynamics of the HO + SO
2
reaction. In addition to the finding of a unique pre-reaction complex (HO⋯SO
2
) directly connected to the transition state, dynamic calculations reveal that the accessible phase space for the HO + SO
2
→ HOSO
2
reaction is extremely narrow, forming a key reaction bottleneck and slowing the reaction rate in the atmosphere, despite the low reaction barrier. This study underlines the importance of understanding the full multidimensional potential energy surface to elucidate the dynamics of complex bimolecular reactions involving polyatomic reactants.
Extraislet expression of islet antigen boosts T cell exhaustion to partially prevent autoimmune diabetes
Authors: Selck Claudia , Jhala Gaurang , De George David J. , Kwong Chun-Ting J. , Christensen Marie K. , Pappas Evan G. , Liu Xin , Ge Tingting , Trivedi Prerak , Kallies Axel , Thomas Helen E. , Kay Thomas W. H. , Krishnamurthy Balasubramanian
Published: January 2024

Persistent antigen exposure results in the differentiation of functionally impaired, also termed exhausted, T cells which are maintained by a distinct population of precursors of exhausted T (T
PEX
) cells. T cell exhaustion is well studied in the context of chronic viral infections and cancer, but it is unclear whether and how antigen-driven T cell exhaustion controls progression of autoimmune diabetes and whether this process can be harnessed to prevent diabetes. Using nonobese diabetic (NOD) mice, we show that some CD8+ T cells specific for the islet antigen, islet-specific glucose-6-phosphatase catalytic subunit–related protein (IGRP) displayed terminal exhaustion characteristics within pancreatic islets but were maintained in the T
PEX
cell state in peripheral lymphoid organs (PLO). More IGRP-specific T cells resided in the PLO than in islets. To examine the impact of extraislet antigen exposure on T cell exhaustion in diabetes, we generated transgenic NOD mice with inducible IGRP expression in peripheral antigen-presenting cells. Antigen exposure in the extraislet environment induced severely exhausted IGRP-specific T cells with reduced ability to produce interferon (IFN)γ, which protected these mice from diabetes. Our data demonstrate that T cell exhaustion induced by delivery of antigen can be harnessed to prevent autoimmune diabetes.
Modeling the locative alternation in Mandarin Chinese
Authors: Xu Mengmin , Li Fuyin , Szmrecsanyi Benedikt
Published: January 2024

The current study investigates the probabilistic conditioning of the Mandarin locative alternation. We adopt a
corpus-based multivariate approach to analyze 2,836 observations of locative variants from a large Chinese corpus and annotated
manually for various language-internal and language-external constraints. Multivariate modeling reveals that the Mandarin locative
alternation is not only influenced by semantic predictors like affectedness and telicity, but also by previously unexplored
syntactic and language-external constraints, such as complexity and animacy of locatum and location, accessibility of locatum,
pronominality, definiteness of location, length ratio and register. Notably, the effects of affectedness, definiteness and
pronominality are broadly parallel in both the Mandarin locative alternation and its English counterpart. We thus contribute to
theorizing in corpus-based variationist linguistics by uncovering the probabilistic grammar of the locative alternation in
Mandarin Chinese, and by identifying the constraints that may be universal across languages.
Politeness, speech acts and socio-cultural change
Authors: Haselow Alexander
Published: January 2024

This paper studies the long-term diachronic development of the speech act of expressing gratitude in the history
of English in Britain. The speech act underwent a considerable transformation from a religious-devotional practice and an
expressive act with a high illocutionary weight addressed to a fellow human being towards a predominantly phatic routine in
everyday conversation. Based on empirical data it is suggested that this development is characterised by the interplay of four
processes: recontextualisation, functional expansion, attenuation/reduction of illocutionary force, and routinisation. Since, as
will be shown, these changes run parallel to major changes in the organisation of society in the social history of Britain, they
appear to be part of more general socio-cultural transformational processes that affected behavioural conventions, including
politeness conventions and communicative routines.
The copycat paradigm
Authors: Donzelli Aurora
Published: January 2024

This article describes how the copycat implementation of foreign protocols of assessment is transforming the
production of knowledge within the Italian social sciences. Focusing on the gatekeeping process whereby the national agency for
the evaluation of university research (ANVUR) publishes yearly lists of “Class‑A” journals, my analysis draws on interviews,
first-hand observations, my own experience as a returning migrant-scholar, as well as comparisons with historical Italian
journals. My aim is twofold: on the one hand, I reflect on the parallel misrecognition of scale and context underlying neoliberal
capitalism; on the other hand, I describe the paradoxes of excellence and the forms of reflexive alienation engendered by the
contemporary knowledge economy.
The Realities of Peripheral Handicraft Livelihoods in the Face of Disasters in Vanuatu
Authors: Clissold Rachel , Westoby Ross , McNamara Karen E. , Obed Viviane
Published: January 2024

The South Pacific Islands region faces unique challenges and heightened impacts from disasters, which are influenced by structural characteristics of remoteness, smallness, insularity, peripherality, low elevations, and urban primacy. The combined catastrophic impacts of the COVID-19 pandemic, border closures, and multiple cyclones, have recently devastated livelihoods, especially those dependent on tourism, in Vanuatu. The voices of women and those working in the ‘informal tourism sector’ are rarely heard. This is an oversight considering marginalised groups need improved resilience-building prospects and well-targeted risk management and social protection initiatives. Drawing from 13 unstructured interviews with handicraft vendors in 2018 and 2021, this case study aims to investigate the lived experiences of female informal workers in a multi-hazard environment. Intersecting hazards causing significant loss included tropical cyclones, COVID-19, and the inequities and marginalising forces of being women in the informal sector. Women’s voices, knowledge, and needs are often sidelined by government, particularly through a lack of social protection policies and crisis responses. The gendered burdens thus accumulate, resulting in heavy workloads and emotional burdens. Evidence of handicraft vendors developing coping and response strategies without formal support include livelihood diversification, returning to traditional subsistence lifestyles, and collective financial risk-sharing, which have led to informal resilience-building outcomes.

Information

© The Authors 2024
Unraveling the Tcrb interactome
Authors: Ollikainen Noah , Sen Ranjan
Published: January 2024

In this issue of JEM, Allyn et al. (https://doi.org/10.1084/jem.20230985) provide mechanistic insights into the nuclear organization of the Tcrb locus that permits long-range genomic rearrangements.
A research-informed graphical tool to visually approach Gauss’ and Stokes’ theorems in vector calculus
Authors: Hahn L , Blaue S A , Klein P
Published: January 2024

Gauss’ and Stokes’ theorems are fundamental results in vector calculus and important tools in physics and engineering. When students are asked to describe the meaning of Gauss’ divergence theorem, they often use statements like this: ‘The sum of all sources of a vector field in a region gives the net flux out of the region’. In order to raise this description to a mathematically sound level of understanding, we present an educational approach based on the visual interpretation of the vector differential operators, i.e. divergence and curl. As a starting point, we use simple vector field diagrams for a qualitative approach to connect both sides of the integral theorems, and present an interactive graphical tool to support this connection. The tool allows to visualise two-dimensional vector fields, to specify vector decomposition, to evaluate divergence and curl point wise, and to draw rectangles to determine surface and line integrals. From a meta-perspective, we situate this educational approach into learning with (multiple) representations. Based on prior research, the graphical tool addresses various learning difficulties of vector fields that are connected to divergence and curl. The tool was incorporated into the weekly lecture-based recitations of Physics II (electromagnetism) in 2022 and 2023, and we assessed various educational outcome measures. The students overall reported the tool to be intuitive and user-friendly (level of agreement 76%,

N
=
125

), considered it helpful for understanding and recommended its use for introductory physics courses (level of agreement 65%,

N
=
65

).
Effect of a flat band on a multiband two-dimensional Lieb lattice with intra- and interband interactions
Authors: Faúndez Julián , Magalhães S G , Riseborough P S , Reyes-Lillo Sebastian E
Published: January 2024

In this study, we explore the effect of a single flat band in the electronic properties of a ferromagnetic two-dimensional Lieb lattice using the multiband Hubbard model with polarized carriers, spin-up and spin-down. We employ the self-consistent dynamical mean field theory and a Green functions cumulant expansion around the atomic limit to obtain the correlated densities of states while varying the intra- and interband interactions. Our findings demonstrate a renormalization of the correlated density of states in both the spin-up and spin-down carriers as we varied the intra- and interband interactions. We conclude that the presence of a flat band enables the system to maintain a metal state with itinerant ferromagnetism in the spin-up carrier.
The structure of chemical vapor deposited graphene substrates for graphene-enhanced Raman spectroscopy
Authors: Faggio G , Politano G G , Lisi N , Capasso A , Messina G
Published: January 2024

Defects and nanocrystalline grain structures play a critical role in graphene-enhanced Raman spectroscopy (GERS). In this study, we selected three types of few-layer, polycrystalline graphene films produced by chemical vapor deposition (CVD), and we tested them as GERS substrates. The graphene structure was controlled by decreasing the CVD temperature, thus obtaining (i) polycrystalline with negligible defect density, (ii) polycrystalline with high defect density, (iii) nanocrystalline. We applied rhodamine 6G as a probe molecule to investigate the Raman enhancement. Our results show that nanocrystalline graphene is the most sensitive GERS substrate, indicating that the GERS effect is primarily connected to the nanocrystalline structure, rather than to the presence of defects.
An adaptive robust strategy based on hypothesis testing for satellite clock bias short-term forecasting
Authors: Su Jia , Gao Mengjia , Yi Qingwu , Wang Binbin , Ma Zhiwei
Published: January 2024

The study of short-term forecasting of satellite clock bias (SCB) is important to promote the development of real-time precise point positioning, and the Kalman filter model has certain advantages over other models in the single forecast model. However, the filtering performance will be degraded by the model bias, and a fading factor is constructed to control the effect brought by the model bias. Considering that the fading factor may cause the covariance matrix to be abnormally inflated or even invalid when the observed information is unreliable, the chi-square test is introduced as a test indicator. At the current epoch moment, the fading factor or robust estimation is conditionally applied based on the result of the hypothesis test. An improved IGGIII weight function is used by the robust estimation, which simplifies the solution of the parametric robust solution. BeiDou satellite navigation system-3 satellite clock bias data with different clock types were selected for the analysis of fitting accuracy and forecasting accuracy, and the experimental results showed that the proposed algorithm can well eliminate the anomalous perturbation phenomenon caused by model deviation and improve the fitting accuracy. The comparison of forecast accuracy between the proposed strategy and GM(1,1), quadratic polynomial, and autoregressive integrated moving average (ARIMA) models at 3, 6, and 12 h intervals reveals that the proposed strategy consistently demonstrates optimal forecast accuracy.
Growth optimization and crossover of transport mechanisms in Bi2Se3 thin films
Authors: Malasi Megha , Rathod Shivam , Lakhani Archana , Kumar Devendra
Published: January 2024

We report the growth, structural characterization, and transport studies of Bi2Se3 thin film on single crystalline silicon (Si), Si/SiO2, quartz, and glass substrates by thermal evaporation method. Our results show that 300 °C is the optimum substrate temperature to obtain the c-axis (001) oriented Bi2Se3 films on all the substrates. The film grown on the Si substrate has the minimum crystalline disorder. The energy-dispersive x-ray spectroscopy results show that film on Si substrate is bismuth deficient, the film on Si/SiO2 substrate is selenium deficient, and the film on quartz substrate is near perfect stoichiometric providing a way to tune the electronic properties of Bi2Se3 films through substrate selection. The film grown on quartz shows the highest mobility (2.7 × 104 cm2 V-1s−1) which drops to 150 cm2 V-1s−1 for Si, 60 cm2 V-1s−1 for Si/SiO2, and 0.9 cm2 V-1s−1 for glass substrate. Carrier concentration is n-type for Bi2Se3 films on Si (∼1018 cm−3), quartz (∼1018 cm−3) and Si/SiO2 (∼1019 cm−3) substrate with a clear indication of frozen out effect around 50 K for Si/SiO2 and Si substrate. Longitudinal resistivity of Bi2Se3 film on Si/SiO2 substrate shows different behavior in three different temperature regions: temperature dependent resistivity region due to electron–phonon scattering, a nearly temperature independent resistivity region due to electron–phonon and electron–ion scattering, and a quantum coherent transport region.
Parametric analysis of electron beam quality in laser wakefield acceleration based on the truncated ionization injection mechanism
Authors: Maity Srimanta , Mondal Alamgir , Vishnyakov Eugene , Molodozhentsev Alexander
Published: January 2024

Laser wakefield acceleration (LWFA) in a gas cell target separating injection and acceleration section has been investigated to produce high-quality electron beams. A detailed study has been performed on controlling the quality of accelerated electron beams using a combination of truncated ionization and density downramp injection mechanisms. For this purpose, extensive two-dimensional particle-in-cell simulations have been carried out considering a gas cell target consisting of a hydrogen and nitrogen mixture in the first part and pure hydrogen in the second part. Such a configuration can be realized experimentally using a specially designed capillary setup. Using the parameters already available in the existing experimental setups, we show the generation of an electron beam with a peak energy of 500–600 MeV, relative energy spread less than

5
%

, normalized beam emittance around 1.5 mm-mrad, and beam charge of 2–5 pC/µm. Our study reveals that the quality of the accelerated electron beam can be independently controlled and manipulated through the beam loading effect by tuning the parameters, e.g. laser focusing position, nitrogen concentration, and gas target profile. These simulation results will be useful for future experimental campaigns on LWFA, particularly at ELI Beamlines.
Operational significance of nonclassicality in nonequilibrium Gaussian quantum thermometry
Authors: Mirkhalaf Safoura , Mehboudi Mohammad , Nafari Qaleh Zohre , Rahimi-Keshari Saleh
Published: January 2024

We provide new operational significance of nonclassicality in nonequilibrium temperature estimation of bosonic baths with Gaussian probe states and Gaussian dynamics. We find a bound on the thermometry performance using classical probe states. Then we show that by using nonclassical probe states, single-mode and two-mode squeezed vacuum states, one can profoundly improve the classical limit. Interestingly, we observe that this improvement can also be achieved by using Gaussian measurements. Hence, we propose a fully Gaussian protocol for enhanced thermometry, which can simply be realized and used in quantum optics platforms.
An adaptive Bayesian approach to gradient-free global optimization
Authors: Yu Jianneng , Morozov Alexandre V
Published: January 2024

Many problems in science and technology require finding global minima or maxima of complicated objective functions. The importance of global optimization has inspired the development of numerous heuristic algorithms based on analogies with physical, chemical or biological systems. Here we present a novel algorithm, SmartRunner, which employs a Bayesian probabilistic model informed by the history of accepted and rejected moves to make an informed decision about the next random trial. Thus, SmartRunner intelligently adapts its search strategy to a given objective function and moveset, with the goal of maximizing fitness gain (or energy loss) per function evaluation. Our approach is equivalent to adding a simple adaptive penalty to the original objective function, with SmartRunner performing hill ascent on the modified landscape. The adaptive penalty can be added to many other global optimization schemes, enhancing their ability to find high-quality solutions. We have explored SmartRunner’s performance on a standard set of test functions, the Sherrington–Kirkpatrick spin glass model, and Kauffman’s NK fitness model, finding that it compares favorably with several widely-used alternative approaches to gradient-free optimization.
Electronic and optical properties for Li1-xAgxAlTe2 alloys: potential transparent conductive material
Authors: Kang Sixin , Wang Jiayuan , Yang Lei , Fan S W
Published: January 2024

Using the hybrid functionals combining the special quasi-random structure methods, the properties of LiAlTe2, AgAlTe2, and their alloys (Li1-xAgxAlTe2) are studied. Our study confirms that both LiAlTe2 and AgAlTe2 are direct wide-band gap semiconductors. Moreover, LiAlTe2 possesses high transmittance in the visual light region. Lattice constants and volume of Li1-xAgxAlTe2 alloys satisfy Vegard’s law. The band gaps express nonlinear behavior with the component x, and the optical bowing parameter (b

Eg
) is 0.13. The carriers’ effective mass for Li1-xAgxAlTe2 alloys is rapidly decreased by the presence of Ag. When Ag component reaches 0.125, the electron (hole) effective mass is 0.225 (0.271) m0 (m0: static electron’s mass), and the band gap is 3.034 eV. Low transition temperature suggests Li1-xAgxAlTe2 alloys are stable under experimental conditions. Meanwhile, the Li1-xAgxAlTe2 alloys express excellent ductility, which is beneficial for future flexible device applications. Wide band gap, smaller electron (hole) effective mass, thermodynamic stability, and high transmittance in the visual light region indicate Li0.875Ag0.125AlTe2 alloy is a promising transparent conductive material.
High-efficiency top-emitting organic light-emitting diodes based on metal/ITO composite electrodes
Authors: Zhao Ben , Pi Jinzhi , Gu Jialu , Lin Yang , Shui Xinfeng , Zhang Jianhua , Shi Wei , Wei Bin
Published: January 2024

High-performance top-emitting organic light-emitting diodes (TEOLEDs) integrating the metal/ITO composite anodes were developed. The results revealed that covering the surface of Al anode with ITO layer could effectively improve the charge injection efficiency and balance the hole–electron charge. The effect of the thickness of ITO on the performance of TEOLEDs with Al/ITO anodes was further studied. The TEOLEDs with Al/ITO (5 nm) anode showed optimized performance, with the current efficiency (CE) and external quantum efficiency (EQE) enhanced by 40.0% and 34.5% compared to that of the OELD with pure Al anode, and increased by 93.1% and 33.5% compared to that of bottom-emitting OLEDs. In addition, the full width at half maximum (FWHM) was narrowed to 36 nm due to the micro-cavity effect of the top-emitting structure and the turn-on voltage decreased to as low as 2.3 V owing to the efficient charge injection and well-matched energy level. In addition, TEOLEDs using Ag/ITO as anode exhibited a slow roll-off of CE and EQE and a narrower FWHM of 30 nm, greatly improving the color purity. The strategy is simple and can significantly improve the efficiency of the TEOLEDs, which promotes the applications of OLEDs in the fields of ultra-high-definition displays and micro-displays.
Thin photonic crystal templates for enhancing the SERS signal: a case study using very low concentrations of dye molecules
Authors: Narayanan Saranya , Sahani Pratyasha , Rathod Jagannath , Soma Venugopal Rao , Yalla Ramachandrarao , Tata B V R
Published: January 2024

A single monolayer photonic crystal (PhC) of polystyrene(PS) colloidal particles with gold nanoparticles drop-casted on the surface have been employed as templates for the detection of dye molecules (methylene blue is taken as analyte for the case study) at very low concentrations using the surface-enhanced Raman scattering (SERS) technique. Results obtained from the SERS investigations clearly reveal that PhC templates significantly enhance the Raman peak, lowering the detection limits of dye molecules (viz., Methylene Blue, Rhodamine 6G, and Malachite Green) to ∼50 nM. The results are understood by performing finite element method (FEM) based electromagnetic numerical simulations. Simulations have shown that the electric field locally gets redistributed, and significant enhancement occurs at wedge regions formed by touching PS spheres, which gets further enhanced in the presence of a gold nanoparticle at the wedge region. Gold nanoparticles sitting at the wedge regions serve as hot spots and are responsible for enhanced SERS signals.
Spectroscopic properties and laser cooling feasibility with the
X1∏21/2↔X2∏23/2
transition for the PbX (X = F, Cl, Br, and I) molecules
Authors: Luan Jing-Zhen , Yang Chuan-Lu , Li Xiaohu , Liu Wen-Wang , Liu Yu-Liang , Zhao Wen-Kai
Published: January 2024

The highly diagonal Frank–Condon factors (FCFs) are necessary for the laser cooling scheme, which means that only the molecules with the appropriate ground and excited electronic states can become candidates. Here, the laser cooling feasibility of the PbX (X = F, Cl, Br, and I) molecules is explored through four-component relativistic calculations. The potential energy curves and transition dipole moments of five Ω states are calculated and used to solve the Schrödinger equation of nuclear motion to obtain the rovibrational energy levels, spectroscopic parameters, the Einstein coefficients, and FCFs. Using the X1
2Π1/2 ↔ X2
2Π3/2 transition with highly diagonal FCFs, we construct optical schemes that can provide 104 ∼ 105 scattering phonons with four pumping lasers for PbX. The Doppler/recoil temperatures of PbX are 419.05 / 57.55, 9.63 / 61.20, 4.95 / 49.98, and 0.71 / 40.17 nK, respectively. Since the 10−4 s of the long spontaneous emission lifetime, the temperatures below microkelvin orders of magnitude can be achieved only if the adequate pre-cooling temperature is satisfied.
The multi-impurity system in CdSe nanoplatelets: electronic structure and thermodynamic properties
Authors: Baghdasaryan D A , Harutynyan V A , Kazaryan E M , Sarkisyan H A
Published: January 2024

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical, electrical, and statistical properties of CdSe nanoplatelets (NPLs). An image charge-based model of electron-impurity interaction is proposed. The charge-carrier energy spectra and corresponding wave functions depending on the impurity number and configuration are calculated. The electron binding energies are calculated for different NPL thicknesses. It is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into account. Also, it is demonstrated that the binding energies are increasing with the number of impurities. We calculate the canonical partition function using the energy levels of the electron, which in turn is used to obtain the mean energy, heat capacity, and entropy of the non-interacting electron gas. The thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPL, impurity number, configuration, and temperature are studied.
Revisiting the spin effects induced by thermal vorticity*
Authors: Gao 高 Jian-Hua 建华 , Yang 杨 Shi-Zheng 诗正
Published: January 2024

We revisit the spin effects induced by thermal vorticity by calculating them directly from the spin-dependent distribution functions. For spin-1/2 particles, we provide the polarization up to the first order of thermal vorticity and compare it with the usual results calculated from the spin vector. For spin-1 particles, we show that all the non-diagonal elements vanish and there is no spin alignment up to the first order of thermal vortcity. We present the spin alignment at second-order contribution from thermal vorticity. We also show that the spin effects for both Dirac and vector particles receive an extra contribution when the spin direction is associated with the momentum of the particle.
Gamma/Hadron Separation Method for the HADAR Experiment
Authors: Ren Yang-Zhao , Chen Tian-Lu , Feng You-Liang , Luo-Bu Dan-Zeng , Guo Yi-Qing , Liu Cheng , Gao Qi , Liu Mao-Yuan , Qian Xiang-Li , Wang Ya-Ping , Zhang Zi-Hao , Li Xin-Long , Hou Qing-Yuan , Liu Heng-Jiao , Zhou Qing-Qian , Shu Shan-Jie
Published: January 2024

Ground-based arrays of imaging atmospheric Cherenkov telescopes (IACTs) are the most sensitive γ-ray detectors for energies of approximately 100 GeV and above. One such IACT is the High Altitude Detection of Astronomical Radiation (HADAR) experiment, which uses a large aperture refractive water lens system to capture atmospheric Cherenkov photons (i.e., the imaging atmospheric Cherenkov technique). The telescope array has a low threshold energy and large field of view, and can continuously scan the area of the sky being observed, which is conducive to monitoring and promptly responding to transient phenomena. The process of γ-hadron separation is essential in very-high-energy (>30 GeV) γ-ray astronomy and is a key factor for the successful utilization of IACTs. In this study, Monte Carlo simulations were carried out to model the response of cosmic rays within the HADAR detectors. By analyzing the Hillas parameters and the distance between the event core and the telescope, the distinction between air showers initiated by γ-rays and those initiated by cosmic rays was determined. Additionally, a Quality Factor was introduced to assess the telescope’s ability to suppress the background and to provide a more effective characterization of its performance.
The extremality of disordered phases for the mixed spin-(1,1/2) Ising model on a Cayley tree of arbitrary order
Authors: Akin Hasan , Mukhamedov Farrukh
Published: January 2024

This paper continues the exploration of translation-invariant splitting Gibbs measures (TISGMs) within the framework of the Ising model with mixed spin-(1,1/2) (abbreviated as (1,1/2)-MSIM) on a Cayley tree of arbitrary order. Building upon our prior work (Akin and Mukhamedov 2022 J. Stat. Mech. 053204), where we extensively elucidated TISGMs and investigated the extremality of disordered phases employing a Markov chain indexed by a tree on a semi-infinite Cayley tree of order two, our current research extends this analysis. In the present study, we begin by constructing TISGMs and tree-indexed Markov chains tailored to the (1,1/2)-MSIM. Notably, we extend our scope to encompass Cayley trees of varying orders, thereby affording a comprehensive examination of the extremality characteristics inherent to disordered phases. Utilizing the Kesten–Stigum condition, we delve into the non-extremality aspects of disordered phases by scrutinizing the eigenvalues of the stochastic matrix associated with the (1,1/2)-MSIM on Cayley trees with order k (

k
⩾
3

). This approach allows for a nuanced exploration of the model’s behavior and stability under different conditions.
Kondo screening cloud scaling: impurity entanglement and magnetization
Authors: Sørensen Erik S
Published: January 2024

The screening of an impurity spin in the Kondo model occurs over a characteristic length scale ξ

K
, that defines the size of the Kondo screening cloud or ‘mist’. The presence of such a length scale in experimental and numerical results is rather subtle. A consistent way to show the presence of the screening cloud is to demonstrate scaling in the spatial correlations in terms of the single variable,

r

/

ξ
K

instead of the correlations depending on r and ξ

K
separately. Here we study the paradigmatic one channel Kondo model using a spin chain representation, with an impurity spin at one end of the chain coupled with a strength

J
K

′

. Using Fermi liquid theory combined with numerical results, we obtain new high precision estimates of the non-universal terms in the entanglement entropy which leads to a verification of the expected non-integer ground-state degeneracy, g. This then allows us to study the impurity contribution to the entanglement in detail. If the impurity coupling

J
K

′

is varied, a precise determination of ξ

K
can then be obtained. The length scale, ξ

K
, is then shown to characterize the scaling of both the uniform and alternating part of a measure of the magnetization of part of an odd length chain.
Pilot study on the application of collaborative online tools and technologies in physics instruction
Authors: Babayeva M , Widenhorn R
Published: January 2024

Current work is about technology-based curricula part assessment in the form of a pilot study. The developed activity was implemented in a high school in the USA. About 50 students participated in the pilot. The research team received 5 written surveys from the students who completed the whole activity part and a written teacher’s survey; conducted an in-person interview with the teacher and classroom observation. Based on the feedback the activity was revised, new hardware and software tools were implemented, and the updated activity was presented during two conference workshops for physics teachers and educational researchers. The paper discusses the conditions of implementation of technology in the classroom, presents background information on the pilot and workshops, implemented changes, and overall outcomes. The results show general interest and prospects for implementation of the technologies used with several conditions.
Comparing Simulations to Improve Physics Students’ Education
Authors: Bologna V , Koenig P , Longo F
Published: January 2024

Deepening the authentic inquiry process framework, we analysed and compared some simulations used in physics teaching/learning activities and covering different topics in secondary schools’ curricula. The analysis focused on cognitive processes activated by exploring the simulation and using the proposed material for teachers/learners. While evaluating the inquiry tasks in the simulations analysed, we recognised some features that could become a starting point for identifying simulation patterns targeting learning outcomes and scientific abilities. But more interestingly, we tried to focus on which could improve physics students’ education in an epistemologically authentic inquiry process. With the performed analysis and the collected data, we chose some simulations that better fulfilled the inquiry goal. Then, we tried to develop teaching/learning materials based on the ISLE (Investigative Science Learning Environment) approach. We adopted this framework because it is an example of epistemologically authentic inquiry. Lastly, we shared the results of our analysis and the developed materials with a community of in-service physics teachers to collect their feedback and reflections on this use of simulations.
Study of damped oscillations using Phyphox and Arduino controlled Hall-sensor
Authors: Csernovszky Z , Hömöstrei M , Kurucz K
Published: January 2024

The paper presents physics education activities organized around the topic of damped oscillations. We used the Phyphox smartphone application for secondary school physics classes. These activities served as a basis for a physics education workshop, where an Arduino-controlled Hall-sensor and the Phyphox Magnetometer were presented. The problem of a damped pendulum, a vertical oscillation in water, and an LCr oscillating circuit was examined as part of a Phyphox project. Mechanical and electromagnetic damped oscillations can be demonstrated with our devices. Using our data, we could compare Hall-sensors of different devices, estimate some characteristics of the waves and help plan an LCr oscillating circuit. Activities for secondary school physics classes are suggested, based on the pedagogical goals.
Teaching colour addition with a STEM educational resource based on Arduino and Processing Development Environment
Authors: Hahn Marcelo , Carvalho Paulo Simeão , Cruz Frederico , Rodrigues Marcelo
Published: January 2024

STEM Education is an important topic in today’s educational paradigm. The knowledge in the STEM area will be important to everyone because to solve real-world problems it is necessary to have information from different areas of knowledge. In this perspective we present an educational resource that combines the contents of physics (colour addition with LEDs), engineering (circuit assembly), technology (Arduino platform and Processing, an open-source programming language and integrated development environment), and mathematics (number handling and unit conversion). Although there are many examples in the literature regarding the study of colour addition, the educational resource here presented brings a novelty for the students. With a very intuitive setup and a simulation, students are able to understand colour addition perceived by the human eyes from two different mechanisms simultaneously: the colour seen on a computer screen and the colour produced by an RGB LED. This STEM activity uses a very simple and affordable experimental setup (less than 30 dollars, excluding the computer) and it is a clear example of how technology enhanced learning in science can be incorporated in the classroom for teaching physics in a very engaging context.
Smartphone-based undergraduate research projects in an introductory mechanics course
Authors: Lahme Simon Z. , Klein Pascal , Müller Andreas
Published: January 2024

At the University of Göttingen, we implemented undergraduate research projects into a first-year mechanics course for physics majors and teacher-training students. Our primary goal was to foster students’ affective factors and higher-order thinking skills in a self-directed, crosslinking, inquiry-based learning setting. A total of 160 students were organized into 40 small groups which worked on one of six open-ended experimental tasks, utilizing smartphone sensors for flexible first-hand data collection outside laboratories. The tasks originate from the Erasmus+ project DigiPhysLab and were significantly modified and opened to be used for undergraduate research projects. In this manuscript, we present the underlying rationales behind this program, outline the core concepts behind the developed experimental tasks, and explain the actual implementation. Additionally, we offer insights into the assessment process for the project work, including the evaluation of scientific posters and responses to eight reflection questions. To facilitate this, we have employed two rubrics to ensure a comprehensive evaluation process.