bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact and implications of Artificial Intelligent-Generated Content (AIGC) on marketing campaigns based on social media
Authors: Luo Liguo
Published: December 2024

With the development of AIGC technology, more and more enterprises apply AIGC technology to marketing activities. Nowadays, with the gradual maturity of the Internet industry, marketing based on social media is more and more occupying the mainstream of marketing activities. Many enterprises and commercial influencers are beginning to use AIGC to empower their marketing operations in social media. However, the current technical level of AIGC only enables a part of the business, so it is very important to discuss what kind of scenarios AIGC is suitable for in the emerging stage, how different industries can make good use of AIGC in social media marketing, and the iterative direction of AIGC products with more development potential in the future. In this paper, the writer will use various indicators to judge video quality, compare the contents of influent accounts mainly operated by AI and those mainly operated by humans, and find out the advantages and disadvantages of AIGC technology in social media marketing. In addition, the writer will also provide advice to AIGC technology users and developers based on current AI trends.
Bilibili’s stock trajectory: Insights and strategies for digital platforms
Authors: Sun Kecheng , Wu Zixuan
Published: December 2024

This study delves into the stock performance of Bilibili, a vibrant online platform launched on June 26, 2009, that has captivated the youth in China. By examining a multitude of factors such as market trends, competitive dynamics, industry outlook, macroeconomic influences, user demographics, content diversity, creator engagement, commercialization strategies, and international expansion efforts, the research forecasts Bilibili’s trajectory in the stock market. It also scrutinizes the company’s operational paradigm, bolstered by insights from a comprehensive questionnaire that underscores the psychological appeal and operational tactics that draw users to the platform. These tactics include strategic repositioning, effective communication of information, leveraging big data for targeted content delivery, understanding consumer and creator motivations, fostering a rich content creation environment, and employing precision marketing techniques. The paper concludes with strategic recommendations derived from the analysis, aimed at enhancing the platform’s market presence and stock performance. The findings offer invaluable insights for other platforms seeking to emulate Bilibili’s success.
Digital Technology, Green Finance and Sustainable Development: A Case Study of Ant Group’s Voluntary Carbon Neutrality Efforts
Authors: Chen Yuxi
Published: December 2024

This study explores the critical role of green financial innovation and digital technology in achieving carbon neutrality through a case study of Ant Group’s voluntary carbon neutrality efforts. The study reveals that Ant Group has raised substantial funds for environmental projects by issuing green bonds and offering green credit products. At the same time, it has leveraged blockchain, big data, and other digital technologies to enhance the transparency and efficiency of carbon emissions tracking and management. However, the company also faces challenges, such as ensuring the accuracy of carbon emissions data, managing cost pressures, dealing with policy uncertainties, and navigating industry competition. The findings of this study provide valuable insights for other companies, highlighting the importance of developing green financial products, setting clear carbon neutrality roadmaps, and maintaining strong communication with stakeholders. Moreover, it is suggested that policymakers introduce more supportive policies for green finance and sustainable development to further global progress toward sustainability goals.
Exploring the impact of internet ugly on social media users using a multi-case study approach
Authors: Meng Huanyu
Published: December 2024

With the development of social media platforms, a phenomenon called ‘internet ugly’ has emerged on social media platforms. Ugly content is the antithesis of aesthetics, spreading intuitively pompous, strange content that may negatively impact users. Based on the phenomenon of ‘internet ugly’ in several popular social media platforms, the research uses a multiplecase research method to analyze three cases, collecting data on audience sentiment. The study finds that visually ugly online content, whether it is eating or acting ugly, does not have a significant negative impact on users. Even to some extent, it has a considerable positive impact on a large portion of the audience, even though a few users believe that ugly content negatively influences their moods. The importance of this research is that it can help regulators of social media platforms get a better grasp of the developments, even if they adjust their regulatory standards. Additionally, it may also help social media users understand the real purpose of ugly content on the Internet so that they can enjoy a better online environment.
Differences between Chinese Mobile Payment and Foreign Mobile Payment
Authors: Yang Kangrui
Published: December 2024

Modern times have seen the emergence of creative payment methods thanks to technological advancements, with mobile payments becoming a major global influence. However, each country has a very different acceptance and trend for these digital transactions. The first section of this thorough analysis looks at how mobile payment systems have developed in China over the years and how they stand now in comparison to other nations. It explores the relationship between consumer behavior, regulatory settings, and technology improvements to understand the fundamental causes for the widespread use of mobile payments. The research then carefully examines the differences in mobile payment methods between China and other areas using Porter’s Diamond Model as a theoretical lens. It also looks at the difficulties foreign mobile payment apps have when tried to break into the Chinese market, such as the strong presence of well-established local rivals, the complexity of currency conversion rates, and the deeply ingrained user habits. The goal of this research is to present a comprehensive picture of the state of mobile payments and the many elements affecting their worldwide trend.
Research on the Problem of Interbank Competition of Subsidiaries in the Process of Merger and Acquisition and Integration of Companies
Authors: Lyu Yuxuan
Published: December 2024

In the context of economic globalization, mergers and acquisitions (M&A) have become a key means for enterprises to expand markets, acquire resources and enhance competitiveness. Nevertheless, especially when large firms acquire small firms and involve the integration of subsidiaries, the problem of inter-firm competition has become an unavoidable challenge. The core task of this paper is to explore in depth the competition problem among subsidiaries during M&A integration and its impact on the success of integration. Through analysis, this paper reveals that subsidiary competition not only affects the reallocation of market share, but also leads to business overlap, resource waste and management complication. Taking Baowu Group as a case study, this paper thoroughly researches how it copes with and solves the subsidiary competition problem in M&A integration, and proposes effective strategies to manage peer competition. The conclusions of the study show that successful M&A integration requires optimizing resource allocation while avoiding internal competition in order to improve the competitiveness and market performance of the integrated enterprise.
The Impact of Government Subsidies on Electric Vehicle Sales: A Regression analysis of BYD in China
Authors: Shan Jierui
Published: December 2024

This study aims to investigate the impact of Chinese government subsidies on BYD’s electric vehicle sales. Since 2009, the Chinese government has continued to subsidize electric vehicle companies in order to promote low-carbon emissions and boost consumption. As a leading company in China’s new energy vehicle industry, BYD received a total of US$3.7 billion in direct government subsidies between 2018 and 2022, including US$2.2 billion in a single year in 2022. Through a regression analysis model, this study examines the relationship between Chinese government subsidies and BYD’s EV sales. The results show that there is a strong positive correlation between government subsidies and BYD’s EV sales, with increased subsidies significantly driving sales growth. Although BYD achieved partial growth without subsidies, the absence of subsidies may negatively affect the sustained sales growth. This study reveals the importance of government subsidies in driving EV market expansion and provides a strong basis for future policy formulation.
Infrastructure for Charging Electric Vehicles’ Effect on Sales in China: Regional Variations and Policy Implications
Authors: Chen Yuqi
Published: December 2024

The market for electric vehicles in China has grown quickly. However, the impact of the quantity and distribution of charging infrastructure on electric vehicle sales has not been thoroughly investigated. This study examines infrastructure for charging electric vehicles’ impact on sales using monthly sales data and charging station data from January 2016 to December 2019. The number of charging stations and sales of electric vehicles have a weak countrywide association, according to regression and correlation analysis. Nevertheless, there is a strong positive association between the quantity of charging stations and the sales of electric vehicles in southern regions like Guangdong and Sichuan, indicating that enhanced charging infrastructure substantially boosts sales. In contrast, in central and northern provinces like Ningxia and Hubei, this effect is more limited, reflecting regional disparities. The study suggests that while improvements in charging infrastructure significantly impact electric vehicle sales in southern regions, other factors such as regional economic development and climate conditions affect northern regions.
A Study on the Impact of the Aging Population-Driven Silver Economy on Social Development and Healthcare Systems in Russia
Authors: Hua Maowei
Published: December 2024

Russia, the largest country in the world by land area, holds significant geopolitical influence in Eastern Europe and beyond. Its tumultuous history, marked by events such as World War II, widespread famine, and the disintegration of the Soviet Union, has led to complex social and economic challenges. Understanding Russia’s economic policies and their impacts is crucial for anticipating future trends on the European continent. This article seeks to explore the implications of Russia’s aging population on its social and economic development. The analysis begins by compiling comprehensive data on Russia’s demographic shifts, focusing on the increasing proportion of elderly citizens. It also reviews the perspectives of various scholars on the issue of population aging, highlighting both the challenges and opportunities this demographic trend presents. Utilizing the SWOT model, the article systematically examines the opportunities and vulnerabilities associated with Russia’s aging population, identifying key issues that require attention. The analysis then integrates SWOT with strategic frameworks to propose targeted measures that could mitigate the challenges and leverage the potential benefits of an aging society. In conclusion, the article offers insights into the broader implications of Russia’s demographic changes, providing a nuanced understanding of how these shifts may shape the nation’s future trajectory and influence the wider European landscape.
The Impact of COVID-19 on Global Retail Consumer Behavior: Regression model and graphical approach
Authors: Zhu Hanqing
Published: December 2024

During the COVID-19 pandemic, consumers increasingly reduced their visits to offline stores due to safety concerns and the closure of most physical retail stores. As a result, the share of global online retail sales surged significantly. This study uses representative examples from seven retail companies to analyze the changes in their e-commerce sales share before and after the pandemic, utilizing regression models and graph analysis to explore future trends. The main objective is to verify whether the changes in consumer behavior during the pandemic were significant and to provide recommendations for the future development of the retail industry based on the findings. The results show that the pandemic significantly increased the share of e-commerce sales, and this shift in consumer behavior is likely to persist. Therefore, retailers should focus more on developing their online shopping platforms and enhancing the customer experience, elevating the importance of online shopping to at least the same level as offline shopping.
Impact of New Energy Vehicles on Traditional Automotive Manufacturers: The Case of BMW
Authors: Liu Chang
Published: December 2024

This study examines the impact of the rapid development of new energy vehicles on traditional automakers, especially luxury brands such as BMW. As the market for NEVs is expanding rapidly due to increased global environmental awareness and government policy support, traditional automakers are facing fierce competition from emerging electric vehicle companies such as Tesla. BMW has responded positively to the market changes by investing in electrification technologies, launching a series of electric models, and building dedicated production facilities. However, despite the progress BMW has made in the field of new energy vehicles, it still needs to face the challenge of the cost structure of electric vehicles, especially the cost of batteries, which takes up a large proportion of the cost of the entire vehicle. In addition, BMW needs to continuously adjust its pricing strategy and brand positioning to remain competitive in a market that increasingly values environmental protection and technological innovation.
Freins et leviers à la mise en place et à la pérennisation des pratiques éducatives dans les maisons et centres de santé pluri-professionnels : l’exemple du département de l’Isère
Authors: Guillot Eva , Uhlenbusch Sophie , Debaty Isabelle , Lissot Clotilde , Llerena Catherine , Allenet Benoît
Published: December 2024

Introduction : Le déploiement des programmes d’éducation thérapeutique (ETP) hors les murs hospitaliers reste insuffisant sur le territoire. La création des maisons (MSP) et des centres de santé (CDS) pluriprofessionnels semble une opportunité pour initier ou conforter des dispositifs éducatifs. Mais qu’en est-il sur le terrain ? Objectif : Décrire les leviers et freins identifiés par les professionnels travaillant en MSP et CDS dans la mise en place et la pérennisation des pratiques éducatives. Méthodes : Nous avons réalisé une enquête exploratoire qualitative via des entretiens semi-directifs réalisés à distance. Résultats : Au total 15 professionnels ont été interrogés, représentant 9 MSP et 2 CDS. Discussion et conclusion : Il ressort que le développement de l’ETP dans ces structures est facilité par une approche volontariste des professionnels, un travail en équipe pluriprofessionnelle, le fait de s’appuyer sur des projets préexistants et d’être accompagné par des entités expertes en ETP. Parmi les difficultés rapportées, le manque de temps et des ressources nécessaires, les contraintes matérielles inhérentes à la mise en œuvre des actions, la difficulté de collaboration avec les infirmières Asalée et les défauts d’assiduité des patients, mettent en difficulté la pérennité des actions.
Median Nerve Displacement during Hardware Removal after Distal Radius Fractures
Authors: Ninomiya Hiroshi , Watanabe Makito
Published: December 2024

Background This retrospective study aimed to evaluate median nerve displacement observed during hardware removal procedures following volar plating for distal radius fractures.

Methods We reviewed all cases involving removal of distal radial volar locking plates at our institution by two surgeons from 2016 to 2021. Plating procedures and hardware removals were performed using the flexor carpi radialis (FCR) approach. We examined the position of the median nerve at the time of hardware removal.

Results Median nerve displacement to the radial side of the FCR occurred in 17 out of 67 cases (25%). There were no significant differences in the degree of fracture severity or involved surgeons between the normal position and displaced groups.

Conclusions The median nerve may be displaced radially from the FCR during hardware removal, and care should be taken to avoid causing iatrogenic nerve injury.

Level of Evidence Level II.
Regulating legislative lobbying in Switzerland: superfluous or overdue?
Authors: Ammann Odile
Published: December 2024

Compared to global lobbying hubs like the USA and the European Union and to its neighboring countries, Switzerland hardly regulates legislative lobbying, i.e., lobbying that targets the legislative branch. Only three types of legal provisions apply to lobbying in the Swiss legislature: First, legislators must disclose their ties to interest groups. Second, access to the parliamentary building is limited and granted at the discretion of each legislator, who may give an entry pass to two individuals of his or her choice. Third, legislative lobbying is illegal if it violates the criminal law provisions on bribery. Proposals to enact more comprehensive regulation have failed, often after several years of legislative debate. Pursuant to the classification proposed by Chari et al. (Regulating Lobbying: A Global Comparison, 2nd ed., Manchester University Press, Manchester, 2019), the Swiss legal framework governing legislative lobbying qualifies as a ‘low-robustness’ regime at best. Yet, Switzerland ranks high in Transparency International’s Corruption Perceptions Index (6/180 in 2023). Is more extensive regulation superfluous or overdue in Switzerland? While the Swiss legal and political order is exceptional in some respects, these characteristics do not justify ‘Swiss exceptionalism’ with regard to the regulation of legislative lobbying, as some of these specificities pose distinctive threats that the law needs to tackle.
Modification on electrical characteristics of interface states by using nitrogen and phosphorus co-doped polysilicon in tunnel oxide passivation contact silicon solar cells
Authors: Yang Lei , Hu Zechen , Liu Zunke , Lv Xiang , Zhu Xiaodong , Zeng Yuheng , Yu Xuegong , Yang Deren
Published: December 2024

The influence on electrical characteristics of interface states by using nitrogen (N) and phosphorus (P) co-doped polysilicon (poly-Si) in tunnel oxide passivation contact silicon solar cells has been investigated. We find that the introduction of N co-doping in P heavily doped poly-Si decreases its own work function; thus, the built-in potential of the poly-Si (n+)/tunnel SiOx/c-Si (p) junction is notably enhanced. The electrical characteristics of interface states at tunnel SiOx/c-Si in the junction have been investigated by current/capacitance–voltage deconvolution. The measured results suggest that the interface state density is reduced, and the corresponding capture cross section ratio σe/σh is increased by three orders of magnitude in the junction with N co-doped poly-Si. The obtained results not only reveal the underlying mechanism of the enhanced contact passivation effect by introducing N co-doped poly-Si but also give an enlightening idea for the design of passivation contact structure in crystalline silicon solar cells.
Metasurface polarization optics: From classical to quantum
Authors: Li Feng-Jun , Wang Shuai , Zhong Rui , Hu Meng-Xia , Jiang Yue , Zheng Meijiu , Wang Mu , Li Xiangping , Peng Ruwen , Deng Zi-Lan
Published: December 2024

Metasurface polarization optics, manipulating polarization using metasurfaces composed of subwavelength anisotropic nanostructure array, has enabled a lot of innovative integrated strategies for versatile and on-demand polarization generation, modulation, and detection. Compared with conventional bulky optical elements for polarization control, metasurface polarization optics provides a feasible platform in a subwavelength scale to build ultra-compact and multifunctional polarization devices, greatly shrinking the size of the whole polarized optical system and network. Here, we review the recent progresses of metasurface polarization optics in both classical and quantum regimes, including uniform and spatially varying polarization-manipulating devices. Basic polarization optical elements such as meta-waveplate, meta-polarizer, and resonant meta-devices with polarization singularities provide compact means to generate and modulate uniform polarization beams. Spatial-varying polarization manipulation by employing the pixelation feature of metasurfaces, leading to advanced diffraction and imaging functionalities, such as vectorial holography, classic and quantum polarization imaging, quantum polarization entanglement, quantum interference, and modulation. Substituting conventional polarization optics, metasurface approaches pave the way for on-chip classic or quantum information processing, flourishing advanced applications in displaying, communication, imaging, and computing.
A waveguide branch-line crossover based on metal gratings
Authors: Liao Xiaoyi , Yang Rongyu , Zheng Yongheng , Qian Xiangcheng , Zhao Chen
Published: December 2024

A waveguide branch-line crossover with broad bandwidth is designed for beam-forming networks in millimeter wavebands. To realize the power coupling between two parallel branch lines, a substrate with metal gratings patched replaces the common E-plane waveguide wall. Compared with the traditional crossover with coupling vias, the metal gratings achieve continuous and efficient power coupling, endowing the proposed crossover with advantages in compactness and broad bandwidth. A simulation-assisted transfer-matrix approach is used to rapidly estimate and optimize the parameters of the crossover. The coupling obtained from the simulation is over −0.5 dB from 32.1 to 39.1 GHz, with isolation greater than 15 dB and reflection less than −20 dB. A prototype is fabricated, and the measurement results agree with the simulation results, demonstrating that the proposed crossover is a promising candidate for millimeter-wave beamforming networks.
High-sensitivity integrated terahertz sensor with large dynamic range based on adjustable high-Q microring resonator
Authors: Hou Zhibo , Chen Liao , Gao Xiaoyan , Liu Rongwu , Du Yufan , Zhang Chi , Wu Xiaojun , Zhang Xinliang
Published: December 2024

Terahertz (THz) sensors play an essential role in terahertz sensing, and the whispering gallery mode resonator (WGMR) is one of the competitive platforms to enhance sensitivity. The traditional on-chip WGMRs are challenging with sensing degradation resulting from the deviation in practical fabrication. The adjustable THz sensor based on a silicon Mach–Zehnder interferometer-coupled microring resonator (MZI-MRR) is proposed and designed in this work. With the different heating power, the THz-MZI-MRR can be precisely switched between three coupling states with high repeatability. The maximum extinction ratio and Q are adjusted to 51.2 dB and 1322, respectively. The sensing characteristics of three different states are systematically demonstrated for the first time, exhibiting various unique capabilities. By adjusting the coupling state, the sensor maintains fantastic sensing ability in a larger measurement range. The proposed adjustable THz-MZI-MRR is suitable for complex and practical detection scenarios and should promote the prosperity of THz sensing.
Self-cleaning of photovoltaic modules: The role of liquid droplets on hydrophobic surfaces in surface dust removal
Authors: Fan Caijin , Zeng Jingya , Yan Xinlong , Shen Yue , Chen Jinghan , Wang Ping
Published: December 2024

Dust accumulation on photovoltaic (PV) panels reduces their energy efficiency. Although droplets play a crucial role in the self-cleaning of dust on the surface of PV panels, the underlying mechanism of surface dust self-cleaning in the presence of droplets has not been fully understood. This study aims to investigate the dust removal mechanisms on the surface of blank and coated PV panels and analyze the effects of factors such as dust particle size, PV panel tilt angle, and ash density on droplet self-cleaning efficiency. Our experiments show that superhydrophobic coatings can significantly improve the droplet self-cleaning efficiency and output power of PV panels. The maximum relative power recovery rate of the coated sample is 78.53%, which is much higher than 27.83% of the blank sample. To better understand the droplet self-cleaning mechanism, we analyze the differences in droplet self-cleaning between blank and coated PV panels from a mechanical perspective. Our model explains the main forces and motion modes of dust particles in the presence of droplets, and we find that smaller dust particles are easier to remove than larger particles. Additionally, we find that a smaller inclination angle of the PV panel surface inhibits the dust particle removal process. Finally, we conduct a comparative study between droplet self-cleaning and other self-cleaning methods to evaluate their effectiveness. Our results show that droplet self-cleaning is a more efficient and effective method for removing dust from PV panels.
Dielectric properties of nanoconfined water
Authors: Mondal Sayantan , Bagchi Biman
Published: December 2024

The dielectric function of a dipolar liquid exhibits a strong wavenumber dependence in the bulk homogeneous state. Such a behavior seems to suggest the possibility of a strong system size dependence of the dielectric constant (DC) of a nanoconfined liquid, although details have been revealed only recently. The dielectric properties of nanoconfined water, indeed, show a marked sensitivity not only to the size and shape (dielectric boundaries) of confinement but also to the nature of surface–water interactions. For geometries widely studied, namely, water confined in a narrow slit, nanocylinder, and nanospherical cavity, the asymptotic approach to the bulk value of the DC with the increase in confinement size is found to be surprisingly slow. This seems to imply the appearance of a dipolar cross correlation length, much larger than the molecular length-scale of water. In narrow slits and narrow cylinders, the dielectric function becomes both inhomogeneous and anisotropic, and the longitudinal and transverse components display markedly different system size dependencies. This sensitivity can be traced back to the dependence of the DC on the ratio of the mean square dipole moment fluctuation to the volume of the system. The observed sensitivity of collective dipole moment fluctuations to the length scale of confinement points to the possibility of using DC to estimate the orientational correlation length scale, which has been an elusive quantity. Furthermore, the determination of volume also requires special consideration when the system size is in nanoscale. We discuss these and several other interesting issues along with several applications that have emerged in recent years.
Studies of gas ionization by high-power, sub-nanosecond microwave pulses
Authors: Maksimov V. , Cao Y. , Haim A. , Asmedianov N. , Kostinskiy A. , Leopold J. G. , Krasik Ya. E.
Published: December 2024

This study investigates the ionization pressure threshold of a gas (air, helium, argon, and SF6 across a wide pressure range) filled dielectric tube when a ∼300 MW, ∼0.7 ns, 9.6 GHz high-power microwave (HPM) pulse propagates through it. The thresholds are determined as the pressure for which the energy of the transmitted HPM pulse decreases to ∼30%, which is close to the same HPM pulse's transmission coefficient when a metal rod fills the tube. These thresholds are found to be 0.4 × 105 Pa,105 Pa, 1.8 × 105 Pa, and 0.2 × 105 Pa, for air, argon, helium, and SF6, respectively. The measured intensity of the plasma light emission starts to decrease at a pressure which coincides with the pressure threshold determined by HPM pulse propagation. Additionally, at gas pressures <5 × 104 Pa, it is shown that time- and space-resolved images of the light emission display a diffused plasma which at higher pressures >105 Pa transforms into streamer like plasma. Simplified numerical simulations of a microwave discharge in air at 1 × 105 Pa and 4 × 105 Pa are consistent with the experimental plasma light observations.
On the fluid dynamics of spin-over in a partially filled cylinder
Authors: Atanasova Gergana G. , Klettner Christian A. , Micheletti Martina , Ducci Andrea
Published: December 2024

This work provides a comprehensive account of the flow within a cylinder with a free surface and an intermediate aspect ratio (liquid height to cylinder radius, L/R=0.5), undergoing spin-over: the rotation of the entire cylinder about its vertical axis is impulsively reversed from solid body rotation to the same angular velocity in the opposite direction. The transient unstable fluid flow arising from this has not previously been characterized. This study employs two-dimensional, two-component particle image velocimetry, planar laser-induced fluorescence, and three-dimensional computational fluid dynamics side by side to capture the spin-over process in full. A thorough investigation of the fluid flow established within the bulk of the fluid, as well as in the endwall and sidewall boundary layers, is provided to reveal the intricate interplay between those regions in time. The investigation goes through the various flow stages during spin-over, including the primary and secondary endwall boundary layer separations, the generation of type I/type II waves, and the behavior of the Taylor–Görtler vortices in the sidewall boundary layer, as well as the late-stage establishment of geostrophic flow through Ekman pumping. The impact of increasing the Reynolds number, Re, and Froude number, Fr, is also investigated (2504<Re<25 043; 0.02<Fr<1.07), shedding light on secondary endwall boundary layer separations and the onset of three-dimensional turbulence. The findings have implications for diverse fields, from the fluid dynamics in rotating bioreactors to geophysical and astrophysical systems.
Transition mechanism and loss analysis of a separated flow over herringbone riblets in a compressor cascade using the lattice Boltzmann method
Authors: Liu Qiang , Song Xinsheng , Wang Dingxi
Published: December 2024

Herringbone riblets were regarded as a promising approach to control the separation bubble on the compressor blade. However, the underlying mechanism requires further elucidation. And numerical simulations with body-fitted meshes often face challenges in mesh generation due to the tiny and complex geometries involved. In the present research, high-fidelity simulations using the Lattice Boltzmann Method and Immersed Boundary Method were performed to investigate the effects of herringbone riblets on separated flow in a compressor cascade. At a low Reynolds number of 90 000, a separation bubble appears on the blade suction surface. The application of herringbone riblets on the suction side surface shows that it effectively reduces the bubble length from 0.24c to 0.12c and reduces the loss coefficient by 11%. A counter-rotating mode of secondary flow occurs before the separation, with a near-wall spanwise motion from the divergent region to the convergent region and a compensating flow from the convergent region to the divergent region in the outer layer of the boundary layer. Transition occurs earlier on the suction side surface due to the complex flow patterns. Four different mechanisms are responsible for the earlier transition. Over the divergent region, engulfing of a high momentum fluid from the outer layer to the inner layer of the boundary layer suppresses the separation bubble, forcing a high-momentum passage where an attached boundary layer is observed. This thinner boundary layer leads to an earlier natural transition. Second, the discharge of fluid from the herringbone cusp causes the overflow from the riblet channel beside the divergent line, i.e., overflow transition. Meanwhile, the transition over the converging region is attributed to the accumulation of disturbance. Finally, in the middle region with yawed riblets, transition in a separated shear layer occurs earlier under the influence of adjacent transition mechanisms over the divergent/convergent region. These mechanisms also bring about a serrated structure in the downstream wake. Overall, this research confirms the role of the counter-rotating mode produced by herringbone riblets in separation control and reveals the transition mechanisms for loss production. The findings suggest that proper utilization of herringbone riblets can provide significant improvement on the compressor blade performance.
Experimental study on the slosh-induced force generated by a partially filled spherical capsule
Authors: Qu Xiaohang , Sui Hui , Lai Kanghui , Qi Xiaoni
Published: December 2024

When a capsule is partially filled with liquid, the internal inconsistent movement will result in its flow dynamics deviating a lot from a fully filled capsule. In this study, an equivalent slosh-induced force that originates from the internal moving liquid is proposed and experimentally tested. A designated linear acceleration of more than twice the gravity is exerted on the spherical capsule by a servo motor driven synchronous belt. The instantaneous force from spheres of different sizes and filling ratios is obtained based on the measured external forces. Water and tetradecane are used to test the effect of liquid properties. Slosh-induced force of magnitude from less to larger than the inertial force of the capsule can be generated, and it persists with an attenuating fluctuating feature even if the acceleration stops. Fast Fourier transformation confirms the existence of a dominant frequency, which decreases with the sphere diameter, increases with the filling ratio, and decreases with the viscosity of the liquid. All the obtained peak values of slosh-induced force in this study have been fitted into a correlation, which can be used to make predictions based on known factors. These findings shed light on the dynamic behavior of liquid in moving small or micro spherical capsules, which are important to the design and operation of related equipment.
Capacitance characterization and current transport mechanism of ZnSnN2 heterojunctions
Authors: Ye Fan , Zhao Zi-Cheng , He Cang-Shuang , Liang Jian-Lin , Gao Qian , Xie Yi-Zhu , Zhang Dong-Ping , Cai Xing-Min
Published: December 2024

The trap and defect energy levels of ZnSnN2 and the current transport mechanism of its heterojunctions are studied. A shallow energy level at 105 meV below the conduction band minimum (Ec) of ZnSnN2 is detected and its possible origin is the intrinsic antisite defect of SnZn (Sn occupy the position of Zn in ZnSnN2), besides the traps located at 0.67, 1.03 and 1.06 to 1.21 eV below Ec. The interface states of ZnSnN2 heterojunctions form two discrete energy levels with one at Ec + 0.05 eV and another at Ec−0.03 eV. The current of ZnSnN2 heterojunctions is controlled by thermionic emission at relatively low bias voltage and limited by space charge at higher bias voltage. The barrier height of the heterojunctions is inhomogeneous, which obeys Gaussian distribution and possibly results from interface roughness.
Direct measurement of current-dependent optical losses in interband cascade lasers
Authors: Piotrowski Mikołaj , Windischhofer Andreas , Fuchsberger Johannes , Arigliani Elena , David Mauro , Herzanova Kristina , Nauschütz Josephine , Weih Robert , Szedlak Rolf , Strasser Gottfried , Schwarz Benedikt
Published: December 2024

Interband cascade lasers (ICLs) are becoming increasingly valuable in mid-infrared applications due to their low power consumption and compatibility with silicon photonic integration, particularly for trace gas sensing. ICLs have demonstrated room-temperature continuous-wave operation in the 3–6 μm range, with excellent performance around 3.3 μm. A key factor limiting ICL performance at longer wavelengths is optical loss, i.e., caused by the intervalence band transitions. These losses increase with hole concentration in the active region, leading to a pronounced current-dependence of the optical losses in ICLs. Conventional methods that infer optical losses from length-dependent variations in parameters such as slope efficiency or threshold current require the assumption of constant optical loss. In this study, we present a direct optical transmission measurement technique to determine waveguide losses. Our experiments confirm strongly increasing waveguide losses with current density, directly impacting the quantum efficiency of ICLs. This approach offers a precise evaluation of optical losses and bears a functional alternative compared to traditional methods, addressing the limitations of assuming constant losses and providing enhanced insight into ICL performance across various wavelengths.
Investigating the influence of magnetic field on heat transfer in turbulent ferromagnetic fluid over a backward-facing step
Authors: Sharifi Mehran
Published: December 2024

In this research, we present a computational investigation into the behavior of turbulent ferromagnetic fluids flowing over a backward-facing step, influenced by an external magnetic field. Our model is subjected to a rigorous validation process to prevent error masking across various submodels. The study encompasses a range of Reynolds numbers (ReH) from 5000 to 80 000, expansion ratios (Er) from just above 1 to 2, Prandtl numbers (Pr) from 4 to 8, and Hartmann numbers (Ha) from 0 to 100. We introduce innovative correlations for the average Nusselt number, applicable in both the presence and absence of a magnetic field. These novel correlations are meticulously compared with existing empirical formulas, and their compatibility and discrepancies are critically analyzed. By incorporating a broader spectrum of physical phenomena, such as the braking effect of magnetohydrodynamics, the impact of the step geometry, the resulting recirculation zones, and the potential inaccuracies in calculating average velocity and Reynolds number, our new correlations substantially enhance the predictive accuracy of the average Nusselt number compared to previous models.
Kirchhoff's law violation within the main solar wavelength range
Authors: Park Yubin , Fan Shanhui
Published: December 2024

Recently, nonreciprocal structures that violate Kirchhoff's law of thermal radiation have attracted considerable interest for their potential in solar energy harvesting applications. However, previous research has primarily focused on mid-infrared wavelengths rather than on the main solar wavelength range where sunlight intensity is concentrated. In this work, we theoretically demonstrate a nonreciprocal structure operating within the main solar spectrum, specifically tailored to meet the requirements of solar cell applications.
Origin and evolution of auxin-mediated acid growth
Authors: Zeng Hai Yue , Deng Shiyu , Jin Congcong , Shang Zhiyun , Chang Le , Wang Jiajun , Han Xue , Wang Ao , Jin Dan , Wang Yubo , He Hang , Li Lanxin , Deng Xing Wang , Wei Ning
Published: December 2024

The classical acid growth theory suggests that auxin stimulates cell expansion by triggering apoplast acidification via plasma membrane (PM)-localized H
+
-ATPase. Here, we reconstructed the origin and evolutionary history of auxin-mediated acid growth. Comparative phylogenomic analysis showed that most core components of acid growth originated in Charophyta and then underwent subclass expansion and functional innovation during plant terrestrialization. In Charophyceae algae
Chara braunii,
we found that PM H
+
-ATPase has formed a core regulatory module with TMK and PP2C.D, which can be activated by photosynthesis-dependent phosphorylation through light rather than auxin. Despite the lack of canonical auxin receptor TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB), auxin elicits significant internodal elongation and transcriptional reprogramming in
C. braunii
, implying the existence of an ancient auxin-mediated growth mechanism. We propose that the evolution of acid growth represents a neofunctional adaptation to terrestrial environments, in which PM H
+
-ATPase in carbon concentrating for photosynthesis was utilized to acidify apoplast for cell expansion, and the core components responsible for acid growth eventually established a regulatory network in land plants by connecting with the TIR1/AFB pathway.
A complete DNA repair system assembled by two endosymbionts restores heat tolerance of the insect host
Authors: Ling Xiaoyu , Guo Huijuan , Di Jian , Xie Liqiang , Zhu-Salzman Keyan , Ge Feng , Zhao Zihua , Sun Yucheng
Published: December 2024

DNA repair systems are essential to maintain genome integrity and stability. Some obligate endosymbionts that experience long-term symbiosis with the insect hosts, however, have lost their key components for DNA repair. It is largely unexplored how the bacterial endosymbionts cope with the increased demand for mismatch repairs under heat stresses. Here, we showed that ibpA, a small heat shock protein encoded by
Buchnera aphidicola
, directly interacted with the cytoskeletal actin to prevent its aggregation in bacteriocytes, thus reinforcing the stability of bacteriocytes. However, the succession of 11 adenines in the promoter of
ibpA
is extremely prone to mismatching error, e.g., a single adenine deletion, which impairs the induction of
ibpA
under heat stress. Coinfection with a facultative endosymbiont
Serratia symbiotica
remarkably reduced the mutagenesis rate in the
Buchnera
genome and potentially prevented a single adenine deletion in
ibpA
promoter, thereby alleviating the heat vulnerability of aphid bacteriocytes. Furthermore,
Serratia
encoded mutH, a conserved core protein of prokaryotic DNA mismatch repair (MMR), accessed to
Buchnera
cells, which complemented
Buchnera
mutL and mutS in constituting an active MMR. Our findings imply that a full complement of a prokaryotic MMR system assembled by two bacterial endosymbionts contributes significantly to the thermostability of aphid bacteriocytes in an ibpA-dependent manner, furnishing a distinct molecular link among tripartite symbioses in shaping resilience and adaptation of their insect hosts to occupy other ecological niches.
Exploring perturbative constraints in higher-order curvature gravity theories
Authors: Molano Daniel , Bargueño Pedro
Published: December 2024

In the realm of general relativity (GR) and extended theories of gravity, obtaining solutions for scenarios of physical interest is a highly intricate challenge. By employing the formalism of mathematical perturbation theory within the GR framework, we demonstrate that, for a significant class of vacuum

f
(
R
,

R

μ
ν

R

μ
ν

)

theories, the corresponding solutions do not yield additional effects beyond those predicted by GR’s perturbation theory. However, models characterized by terms of the form

f
(
R
,

R

μ
ν

R

μ
ν

,

R

μ
ν
σ
δ

R

μ
ν
σ
δ

)

exhibit distinctive contributions not present in GR. We assert that fundamental limitations exist, explaining why solutions of certain

f
(
R
,

R

μ
ν

R

μ
ν

)

models can deviate from their GR counterparts, indicating non-connected solutions or non-analytic behavior. Conversely, in the models

f
(
R
,

R

μ
ν

R

μ
ν

,

R

μ
ν
σ
δ

R

μ
ν
σ
δ

)

, the solutions seamlessly connect with those of GR. This distinction highlights the nuanced interplay between higher-order curvature terms and their impact on gravitational dynamics, offering new insights into the landscape of modified gravity theories.
A smooth surface measurement method by flexible contact using multiple fingers device
Authors: Gong Jiale , Li Ziyang , Wang Hong , Zhang Cuiping , Guan Jinling , Li Jin
Published: December 2024

Contact measurement technology is commonly used for analysis and modeling of three-dimensional (3D) object. This paper presents a contact measurement method, using a claw type probe based on a set of rotary encoders that can flexibly contact objects with efficiently multi-lines scanning. In this paper, a 3D measurement system by flexible contact of multiple fingers was built. The claw probe was set on a coordinate measurement machine. By moving the position of the claw for interpolation detection to improve the sampling rate, higher precision 3D reconstruction was achieved. Also, a compensation algorithm was proposed for this type detector to improve measuring accuracy. In the experiments, two surface models were produced by 3D printing as the test objects. By comparing the designed surface with the reconstructed surface, it is demonstrated that this system can effectively and softly measure smooth surface, like the back of human body, which is valuable for further study and use in rehabilitation massage, apparel design, and etc.
Neural network-based method for structured light phase-shifted fringe denoising and phase-to-height calibrations
Authors: Li Chengcheng , Mao Junjie , Zhang Xinna
Published: December 2024

The monocular structured light measurement system is widely applied across various fields due to its simple structure, low cost, and extensive measurement range. However, measurement accuracy can be affected by noise, non-linear intensity variations, variations in object surface reflectance, and calibration precision, leading to unstable or inaccurate results. Traditional filtering methods are limited in effectively addressing complex noise and non-linear issues, and phase-to-height calibration often depends on high-precision motion platforms, which increases system costs, complexity, and calibration uncertainty. To address these challenges, this paper proposes a neural network-based approach for monocular structured light measurement. An iterative denoising algorithm based on a denoising autoencoder (DAE) is developed for phase-shift fringe images. By optimizing the iteration count, denoised phase-shift fringes are regenerated to de noise to reduce image noise and enhance phase computation accuracy effectively. Additionally, leveraging the high-precision absolute phase calculated from the denoised phase-shift fringe images, a multilayer feedforward neural network (FNN) algorithm is proposed for absolute phase-to-height calibration. This method directly maps the phase-to-height relationship, integrating both intrinsic and extrinsic camera parameters to achieve high-precision calibration without requiring a high-precision motion platform. Consequently, it significantly mitigates errors related to the motion platform and reduces operational errors during calibration. The DAE enhances the quality of phase images, providing more precise input for the FNN calibration and further improving measurement accuracy. Experimental results demonstrate that the proposed method achieves effective 3D reconstruction from low-quality phase-shift fringes and maintains robust performance when measuring objects with varying reflectances.