Basic Research Research Articles

Speed control for traction motor of urban electrified train in field weakening region based on backstepping method

Tractor motors always operate in the speed region higher than rated speed, but is limited to the module of the stator current, stator voltage vectors. Additionally, mathematical model of traction motor has shown nonlinearity through the product of the state variables 𝑖𝑠𝑑, 𝑖𝑠𝑞 with the input variable 𝜔𝑠:𝜔𝑠𝑖𝑠𝑞, 𝜔𝑠𝑖𝑠𝑑. Therefore, this paper focuses on the study of speed control of traction motors in weakening field region while optimizing torque control, and choosing the backstepping method in designing speed–flux controller in order to solve the nonlinear structure. The simulation results of the responses: speed, torque, power, and flux performed on MATLAB/Simulink software with parameters collected from metro Nhon-Hanoi Station, Vietnam have proven the correctness in theoretical research.

Behavioral Bias for Exploration Is Associated with Enhanced Signaling in the Lateral and Medial Frontopolar Cortex.

Should we keep doing what we know works for us, or should we risk trying something new as it could work even better? The exploration-exploitation dilemma is ubiquitous in daily life decision-making, and balancing between the two is crucial for adaptive behavior. Yet, we only have started to unravel the neurocognitive mechanisms that help us to find this balance in practice. Analyzing BOLD signals of healthy young adults during virtual foraging, we could show that a behavioral tendency for prolonged exploitation was associated with weakened signaling during exploration in central node points of the frontoparietal attention network, plus the frontopolar cortex. These results provide an important link between behavioral heuristics that we use to balance between exploitation and exploration and the brain function that supports shifts from one tendency to the other. Importantly, they stress that interindividual differences in behavioral strategies are reflected in differences in brain activity during exploration and should thus be more in the focus of basic research that aims at delineating general laws governing visual attention.

Customer Service Through AI-Powered Human-Robot Relationships: Where are we now? The case of Henn na Cafe, Japan

Throughout history, interactions between humans and robots, and robots themselves have experienced profound shifts, generating a plethora of literature within the domains of manufacturing and services. Despite the abundance of scientific publications, consensus regarding these relationships remains elusive, fostering ambiguity within and between these domains. This article aims to present an encompassing and widely accepted perspective on the existing body of literature, seeking to unravel the nature of these relational paradigms. Our objective revolves around analyzing that zeroes in on the enhancement of Artificial Intelligence (AI) within Human-Robot relationships, particularly in the context of services. Henceforth, our research pivots toward a specialized body of literature exploring the domain of technical-biosocial systems, which encompasses human-technology-social structures. By doing so, we aim to analyze AI within a more delimited context, thereby mitigating the critique that a gap persists in scholarly discourse owing to the predominant analysis of AI within a global purview. Mindful of the potential drawbacks associated with a purely holistic and aggregated conceptual theoretical model, we have opted to subject our model to empirical validation. To achieve this, a case study was employed, with a specific focus on the avant-garde Henn na Cafe in Japan. The findings underline that currently, Henn na Cafe employs Human-Robot Interaction and Collaboration (HRI-C). However, there is an expectation that service companies will embrace an evolving HRI-C by integrating AI to enhance service delivery activities. Alternatively, they may opt for a Robot-Robot Interaction and Collaboration (RRI-C) approach with improved social capabilities or multi-human/multi-robot systems. The empirical findings are consistent with existing literature, which indicates a contemporary scholarly interest in investigating complex and emotional systems within service-oriented environments. These environments, characterized by elevated levels of AI, present challenges for AI systems in executing service functions effectively. Recent research endeavors aim to synthesize and assess the prevailing understanding and research directions within this domain. This convergence of findings not only reinforces theoretical research but also provides supplementary perspectives on human-robot relations and the complexities involved in service delivery within technologically sophisticated settings. Subsequent research endeavors could pivot towards a heightened focus on the services sector, exploring potential relationships and how AI might either fortify the services domain or pivot towards a vantage point centered on multi-robot systems.

Evaluation of T-stress in an infinite plate with double-crack under compression and shear

The T-stress at the crack tip under compression and shear has received more and more attention, but most of the theoretical researches have focused on single-crack, with little reported on the closed form solutions of T-stress at the double-crack or multi-crack tips. Therefore, the single-crack problem under compression and shear is first analyzed in this paper, the formulas for calculating the three components of T-stress (Tx, Ty and Txy) are obtained. According to the principle of superposition, the origins of the three components of T-stress are examined. Then the basic equations for solving the double-crack problems under compression and shear are established, leading to the formulas for calculating the three components of T-stress at the double-crack tips. Finally, the effects of the spacing between two cracks, the ratio of double-crack half-length, the dip angle of rock-bridge and the absolute angle between two cracks on the three components of T-stress are discussed. The results indicate that the Tx and Ty are unaffected by the friction on the crack surface, but the Txy is significantly correlated with it. Each component of T-stress at the inner and outer tips of double-crack is influenced by different geometrical factors and shows a different variation curve, which may be a potential factor contributing to the complexity of the double-crack or multi-crack problems under compression shear.

5-hydroxymethylfurfural and its Downstream Chemicals: A Review of Catalytic Routes.

Biomass assumes an increasingly vital role in the realm of renewable energy and sustainable development due to its abundant availability, renewability, and minimal environmental impact. Within this context, 5-hydroxymethylfurfural (HMF), derived from sugar dehydration, stands out as a critical bio-derived product. It serves as a pivotal multifunctional platform compound, integral in synthesizing various vital chemicals, including furan-based polymers, fine chemicals, and biofuels. The high reactivity of HMF, attributed to its highly active aldehyde, hydroxyl, and furan ring, underscores the challenge of selectively regulating its conversion to obtain the desired products. This review highlights the research progress on efficient catalytic systems for HMF synthesis, oxidation, reduction, and etherification. Additionally, it outlines the techno-economic analysis (TEA) and prospective research directions for the production of furan-based chemicals. Despite significant progress in catalysis research, and certain process routes demonstrating substantial economics, with key indicators surpassing petroleum-based products, a gap persists between fundamental research and large-scale industrialization. This is due to the lack of comprehensive engineering research on bio-based chemicals, making the commercialization process a distant goal. These findings provide valuable insights for further development of this field. This article is protected by copyright. All rights reserved.

The high power laser facility at beamline ID24-ED at the ESRF

ABSTRACT This paper describes technical details and new scientific opportunities offered by the new High Power Laser Facility at the ESRF, opened to users since 2022. This facility enables laser-induced dynamic compression experiments probed by ultra-fast X-ray Absorption Spectroscopy at beamline ID24-ED. This capability allows to reach and probe more extreme pressure and temperature states and higher strain rates with respect to static compression, addressing open questions in fundamental, planetary and material science.

Design of Novel Synthetic RNA Replicons Based on Emesvirus zinderi.

Self-replicating RNAs (srRNAs) are synthetic molecules designed to mimic the self-replicating ability of viral RNAs. srRNAs hold significant promise for a range of applications, including enhancing protein expression, reprogramming cells into pluripotent stem cells, and creating cell-free systems for experimental evolution. However, the development of srRNAs for use in bacterial systems remains limited. Here, we demonstrate how a srRNA scaffold from Emesvirus zinderi can be engineered into a self-encoding srRNA by incorporating the coding region of the catalytically active replicase subunit. With the help of in vitro replication assays, including an in vitro translation-coupled replication approach, we show that the resulting system enables complete replication cycles of RNA both in cis and trans, including long cargo RNAs such as tethered 5S, 16S, and 23S rRNAs. In summary, our findings suggest that these srRNAs have significant potential for fundamental research, synthetic biology, and general in vitro evolution.

Signalling cascades choreographing petal cell death: implications for postharvest quality.

Senescence is a multifaceted and dynamic developmental phase pivotal in the plant's lifecycle, exerting significant influence and involving intricate regulatory mechanisms marked by a variety of structural, biochemical and molecular alterations. Biochemical changes, including reactive oxygen species (ROS) generation, membrane deterioration, nucleic acid degradation and protein degradation, characterize flower senescence. The progression of senescence entails a meticulously orchestrated network of interconnected molecular mechanisms and signalling pathways, ensuring its synchronized and efficient execution. Within flowering plants, petal senescence emerges as a crucial aspect significantly impacting flower longevity and postharvest quality, emphasizing the pressing necessity of unravelling the underlying signalling cascades orchestrating this process. Understanding the complex signalling pathways regulating petal senescence holds paramount importance, not only shedding light on the broader phenomenon of plant senescence but also paving the way for the development of targeted strategies to enhance the postharvest longevity of cut flowers. Various signalling pathways participate in petal senescence, encompassing hormone signalling, calcium signalling, protein kinase signalling and ROS signalling. Among these, the ethylene signalling pathway is extensively studied, and the manipulation of genes associated with ethylene biosynthesis or signal transduction has demonstrated the potential to enhance flower longevity. A thorough understanding of these complex pathways is critical for effectively delaying flower senescence, thereby enhancing postharvest quality and ornamental value. Therefore, this review adopts a viewpoint that combines fundamental research into the molecular intricacies of senescence with a practical orientation towards developing strategies for improving the postharvest quality of cut flowers. The innovation of this review is to shed light on the pivotal signalling cascades underpinning flower senescence and offer insights into potential approaches for modulating these pathways to postpone petal senescence in ornamental plants.

Evaluation of marine economic development demonstration zone policy on marine industrial structure optimization: a case study of Zhejiang, China

The marine economic development demonstration zone (MEDDZ) is the regional marine functional policy that assumes the significant tasks of innovation in the system and mechanism of the marine economy, optimization of the marine industrial structures, and the construction of marine ecological civilization. This paper constructs a panel database of 11 coastal provinces in China from 2006 to 2019, takes the Zhejiang Marine Economy Development Demonstration Zone Plan officially approved by the State Council of China in 2011 as a quasi-natural experiment, applies the synthetic control method (SCM) to evaluate the effect of implementation of the MEDDZ policy on marine industrial structure optimization in Zhejiang. The results show that: (1) The MEDDZ policy significantly promotes the structure optimization of the marine industry in Zhejiang and the existence of the policy lag phenomenon. (2) Based on the results of the robustness tests, we find that the fitted path of policy effects is better when the time of MEDDZ implementation is adjusted to 2012. (3) Government financial support and marine cargo capacity play a role in implementing the MEDDZ policy, positively affecting and optimizing the coastal marine industry’s structure. Therefore, we make some suggestions from the perspectives of strengthening the policy implementation process, focusing on the policy lag phenomenon, and broadening funding sources, thus enriching theoretical research on policies in the field of the marine industry and providing practical references for the development of other coastal demonstration zones.

The view of synthetic biology in the field of ethics: a thematic systematic review

Synthetic biology is designing and creating biological tools and systems for useful purposes. It uses knowledge from biology, such as biotechnology, molecular biology, biophysics, biochemistry, bioinformatics, and other disciplines, such as engineering, mathematics, computer science, and electrical engineering. It is recognized as both a branch of science and technology. The scope of synthetic biology ranges from modifying existing organisms to gain new properties to creating a living organism from non-living components. Synthetic biology has many applications in important fields such as energy, chemistry, medicine, environment, agriculture, national security, and nanotechnology. The development of synthetic biology also raises ethical and social debates. This article aims to identify the place of ethics in synthetic biology. In this context, the theoretical ethical debates on synthetic biology from the 2000s to 2020, when the development of synthetic biology was relatively faster, were analyzed using the systematic review method. Based on the results of the analysis, the main ethical problems related to the field, problems that are likely to arise, and suggestions for solutions to these problems are included. The data collection phase of the study included a literature review conducted according to protocols, including planning, screening, selection and evaluation. The analysis and synthesis process was carried out in the next stage, and the main themes related to synthetic biology and ethics were identified. Searches were conducted in Web of Science, Scopus, PhilPapers and MEDLINE databases. Theoretical research articles and reviews published in peer-reviewed journals until the end of 2020 were included in the study. The language of publications was English. According to preliminary data, 1,453 publications were retrieved from the four databases. Considering the inclusion and exclusion criteria, 58 publications were analyzed in the study. Ethical debates on synthetic biology have been conducted on various issues. In this context, the ethical debates in this article were examined under five themes: the moral status of synthetic biology products, synthetic biology and the meaning of life, synthetic biology and metaphors, synthetic biology and knowledge, and expectations, concerns, and problem solving: risk versus caution.

Influencing factors and realization paths for smart community construction in China.

The analysis of influencing factors serves as the cornerstone for the research on smart community construction. Drawing upon both field research and extensive literature study, this paper explores the influencing factors of China's smart community construction and its effective paths by taking 52 national pilot zones for community governance and service innovation in China as examples. In the constructed analytical framework of influencing factors, elements such as economic development, capital investment, information infrastructure, community governance, public support system, and smart platform are included. By the use of the qualitative comparative analysis (QCA) method, the results of the study show that community governance, public support system, and smart platform are necessary conditions for smart community construction, while economic development, capital investment and information infrastructure play a leading role in the four combined paths. Finally, this study provides a new perspective for theoretical research, a reference forgovernmental departments to make decisions, and experience for the construction of smart communities in other developing countries.

Approach to Spirocyclohexadienes via Visible Light‐Mediated ipso‐Cyclization of Amino Acid Derivatives with N‐(2‐Phenyl)benzoyl Groups

AbstractSpirocycles are important structural motifs, found in natural and pharmaceutical compounds, which have attracted considerable interest in modern drug discovery research. Herein, we describe the development of a visible light‐mediated ipso‐cyclization of amino acid derivatives with N‐(2‐phenyl)benzoyl groups, allowing easy access to a variety of spirocyclohexadienes. The addition of water was found to be beneficial in promoting the reaction progress. Investigation of the substrate scope revealed that incorporating an electron‐donating moiety at the 3′‐position of the biphenyl group resulted in a more favorable outcome for spirocycle formation.

Electrochemical Oxidation of Small Molecules for Energy‐Saving Hydrogen Production

AbstractElectrochemical water splitting is a promising technique for the production of high‐purity hydrogen. Substituting the slow anodic oxygen evolution reaction with an oxidation reaction that is thermodynamically more favorable enables the energy‐efficient production of hydrogen. Moreover, this approach facilitates the degradation of environmental pollutants and synthesis of value‐added chemicals through the rational selection of small molecules as substrates. Strategies for small‐molecule selection and electrocatalyst design are critical to electrocatalytic performance, with a focus on achieving a high current density, selectivity, Faradaic efficiency, and operational durability. This perspective discusses the key factors required for further advancement, including technoeconomic analysis, new reactor system design, meeting the requirements of industrial applications, bridging the gap between fundamental research and practical applications, and product detection and separation. This perspective aims to advance the development of hybrid water electrolysis applications.

Influence of proteins on the dielectric characteristics of 5CB and 8CB liquid crystals

ABSTRACT In this paper, we study the influence of the protein Bovine Serum Albumin (BSA) on the dielectric properties of liquid crystals (LCs) such as 4-cyano-4-pentyl biphenyl (5CB) and Octyl-4-biphenylcarbonitrile (8CB). Studying the effect of proteins on the dielectric properties of LC is essential for both fundamental research and practical applications in material science, biomedical engineering, biotechnology, and optoelectronic devices. It helps understand the protein behaviour on the surface of LCs, which offers an opportunity to develop novel sensing platforms. A polarising optical microscope (POM) was used to examine the correlation between textures formed by LCs interacting with different concentrations of BSA. In the dielectric studies, dielectric parameters such as impedance (Z), real (Z’) and imaginary (Z’’) parts of the impedance, and the tangential loss (tan δ) were measured. The investigation involved analysing relaxation times using the collected data, revealing distinct behaviours between 5CB and 8CB liquid crystals. Bode and Nyquist’s plots were constructed and analysed to investigate the changes LCs undergo while interacting with BSA. An equivalent electrical circuit (EEC) was constructed using Bode and Nyquist data, from which circuit element values were successfully extracted. The results obtained from the POM studies and the interferences drawn from the EIS can help enhance the performance of protein-based liquid crystal devices.

Experimental and Theoretical Research on Photocatalytic Nitrogen Reduction Using MoS2 Nanosheets with Polysulfide Vacancies.

MoS2 nanosheets with different concentrations of S vacancies (VS-MoS2) were synthesized and used for photocatalytic nitrogen reduction reactions (pNRR), and the mechanism of S vacancies enhancing the activity of MoS2 was explored through DFT calculation. The material characterization confirmed the successful construction of S vacancies at different concentrations on the spherical cluster structure of MoS2. The experimental results show that the introduction of S vacancies significantly improves the activity of pNRR, and it increases significantly with the increase of vacancy number, consistent with the trend of photoelectric performance. VS-MoS2-3 exhibits the highest pNRR efficiency, which is 3.5 times higher than that of pristine MoS2, and after being reused three times, the activity only decreased by about 11%. DFT calculation results indicate that the exposed Mo atoms generated by S vacancies alter the charge layout on the MoS2 surface while providing abundant Mo active sites. Meanwhile, the band gap structure will narrow with the increase of S vacancies, which is beneficial for the transfer of surface charges. In addition, the increase of S vacancies, on the one hand, strengthens the adsorption of MoS2 on N2, weakens the adsorption of H, improves the selectivity of nitrogen, and is conducive to the progress of NRR. On the other hand, more electrons can be transferred from MoS2 to the adsorbed N2 molecules, enhancing the hybridization between them and better activating N2.

Network pharmacology, molecular docking, and dynamics analyses to predict the antiviral activity of ginger constituents against coronavirus infection.

COVID-19 is a global pandemic that caused a dramatic loss of human life worldwide, leading to accelerated research for antiviral drug discovery. Herbal medicine is one of the most commonly used alternative medicine for the prevention and treatment of many conditions including respiratory system diseases. In this study, a computational pipeline was employed, including network pharmacology, molecular docking simulations, and molecular dynamics simulations, to analyze the common phytochemicals of ginger rhizomes and identify candidate constituents as viral inhibitors. Furthermore, experimental assays were performed to analyze the volatile and non-volatile compounds of ginger and to assess the antiviral activity of ginger oil and hydroalcoholic extract. Network pharmacology analysis showed that ginger compounds target human genes that are involved in related cellular processes to the viral infection. Docking analysis highlighted five pungent compounds and zingiberenol as potential inhibitors for the main protease (Mpro), spike receptor-binding domain (RBD), and human angiotensin-converting enzyme 2 (ACE2). Then, (6)-gingerdiacetate was selected for molecular dynamics (MD) simulations as it exhibited the best binding interactions and free energies over the three target proteins. Trajectories analysis of the three complexes showed that RBD and ACE2 complexes with the ligand preserved similar patterns of root mean square deviation (RMSD) and radius of gyration (Rg) values to their respective native structures. Finally, experimental validation of the ginger hydroalcoholic extract confirmed the existence of (6)-gingerdiacetate and revealed the strong antiviral activity of the hydroalcoholic extract with IC of 2.727 . Our study provides insights into the potential antiviral activity of (6)-gingerdiacetate that may enhance the host immune response and block RBD binding to ACE2, thereby, inhibiting SARS-CoV-2 infection.

Potential molecular patterns for tuberculosis susceptibility in diabetic patients with poor glycaemic control: a pilot study.

Type 2 diabetes (DM2) is an increasingly prevalent disease that challenges tuberculosis (TB) control strategies worldwide. It is significant that DM2 patients with poor glycemic control (PDM2) are prone to developing tuberculosis. Furthermore, elucidating the molecular mechanisms that govern this susceptibility is imperative to address this problem. Therefore, a pilot transcriptomic study was performed. Human blood samples from healthy controls (CTRL, HbA1c < 6.5%), tuberculosis (TB), comorbidity TB-DM2, DM2 (HbA1c 6.5-8.9%), and PDM2 (HbA1c > 10%) groups (n = 4 each) were analyzed by differential expression using microarrays. We use a network strategy to identify potential molecular patterns linking the differentially expressed genes (DEGs) specific for TB-DM2 and PDM2 (p-value < 0.05, fold change > 2). We define OSM, PRKCD, and SOCS3 as key regulatory genes (KRGs) that modulate the immune system and related pathways. RT-qPCR assays confirmed upregulation of OSM, PRKCD, and SOCS3 genes (p < 0.05) in TB-DM2 patients (n = 18) compared to CTRL, DM2, PDM2, or TB groups (n = 17, 19, 15, and 9, respectively). Furthermore, OSM, PRKCD, and SOCS3 were associated with PDM2 susceptibility pathways toward TB-DM2 and formed a putative protein-protein interaction confirmed in STRING. Our results reveal potential molecular patterns where OSM, PRKCD, and SOCS3 are KRGs underlying the compromised immune response and susceptibility of patients with PDM2 to develop tuberculosis. Therefore, this work paved the way for fundamental research of new molecular targets in TB-DM2. Addressing their cellular implications, and the impact on the diagnosis, treatment, and clinical management of TB-DM2 could help improve the strategy to end tuberculosis for this vulnerable population.

Giant magneto-optical effect in van der Waals room temperature ferromagnet Fe3GaTe2

Abstract The discovery of ferromagnetic two-dimensional (2D) van der Waals (vdWs) materials provides an opportunity to explore intriguing physics and develop innovative spin electronic devices. However, the main challenge for practical applications of vdWs ferromagnetic crystals lies in the weak intrinsic ferromagnetism and small perpendicular magnetic anisotropy (PMA) above room temperature. Here, we report the intrinsic vdWs ferromagnetic crystal Fe3GaTe2, synthesized by the self-flux method, exhibiting a Curie temperature (TC) of 370 K, a high saturation magnetization of 33.47 emu/g, and a large PMA energy density of approximately 4.17 × 105 J/m3. Furthermore, for the first time, the magneto-optical effect has been systematically investigated in Fe3GaTe2. The doubly degenerate E2g(Γ) mode reverses the helicity of incident photons, indicating the existence of pseudoangular momentum (PAM) and chirality. Meanwhile, the non-degenerate non-chiral A1g(Γ) phonon exhibits a significant magneto-Raman effect under an external out-of-plane magnetic field. These results lay the groundwork for studying phonon chirality and magneto-optical phenomena in 2D magnetic materials, providing the feasibility for further fundamental research and application in spintronic devices.

Future proofing a long-term agricultural experiment for decades to come: Relocation and redesign

We took land encroachment for urban development that threatened a 60-year-old field experiment as an opportunity to transport and redesign an entire experiment to more effectively address contemporary challenges. The field experiment comprised long-term pH plots, established for agronomic demonstration in 1961, but used over the years for both applied and fundamental research. We redesigned the experimental layout to add strength to the statistical design through randomisation. Continuation and enrichment of the long-term pH experimental platform lends a unique resource for microbiome research per se. Here we have provided a rationale for why the decision was made to move the soils from the former Woodlands Field pH experiment. Moving soil on the scale of a field experiment requires costs and benefits to be weighed up in that the realisation of the transfer costs and the costs for the ongoing maintenance can outweigh the costs of a new experimental set up or indeed closing the experiment and walking away. It is important to recognise that much of the value is in assets that are not monetary. Considerations include the availability of a site suitable from a biophysical perspective but also considering ownership and future access. The topsoil (0–20 cm to plough depth) was moved to a new location in a similar environment and within the same soil association. The soil was disturbed under very dry conditions and placed back into the earth in the new location within 90 minutes, and thus as near to normal cultivation as possible. Additional plots were added to the experiment that will be amended to the pH treatments in the long-term experiment providing an exciting opportunity to assess how soil microbial communities change over time. Soil samples taken 2 years after the relocation of the soils indicate that the soil pH gradient (4.5–7.5) has been maintained. Safeguarding this long-term resource on soil pH helps us to predict the impacts of changed practice with regard to liming on productivity and also to address wider contemporary and future issues surrounding net zero, food security and soil protection.

Design method and seismic vulnerability of bridges using UHPC-NSC composite pier

The focus of this investigation is the application of ultra-high-performance concrete (UHPC) and normal strength concrete (NSC) in constructing composite piers. The UHPC-NSC composite pier, comprising the external UHPC jacket and internal NSC, demonstrates a marked enhancement in both load-bearing capacity and control of seismic damage. However, the lack of suitable seismic design methodologies presents a significant barrier to the practical application of the composite pier. Drawing on extensive experimental and theoretical research, this paper proposes an optimization formula that determines the diameter of the composite pier and the thickness of the UHPC jacket. This formula aims to maximize the use of UHPC material, manage the damage, and equalize sectional moment resistance with the original reinforced concrete section. Utilizing the proposed design approach, UHPC-NSC composite piers were implemented in a typical continuous beam bridge. Seismic vulnerability analyses were conducted to quantitatively substantiate the performance of the composite pier following the aforementioned design approach. The analysis affirmed that the composite pier effectively reduced the exceeding probability of all damage levels under small and moderate earthquakes, and extensive damage level under strong earthquakes.