Structural Principles Research Articles

Theoretical Study of an Authentic Hydrocarbon Ion Pair.

For many years researchers believed that hydrocarbons only contain covalent bonds. However, since 1985 Okamoto et al. demonstrated the formation of hydrocarbon salts in several systems, demolishing the structural principle that hydrocarbons only contain covalent bonds. Despite the great importance of this outcome to the study of chemical bonds, quantum chemical calculations on these systems are essentially nonexistent. The stability of the hydrocarbon ions along with the steric hindrance associated with the formation of the covalent bond contribute to their occurrence either in solution (dissociated) or in the solid state. These facts along with the common formation of ion pairs in solvents of low polarity motivated us to search for hydrocarbon ion pairs in the gas phase. Its energetics has also been studied in four nonprotic solvents, through a continuum solvation model (CPCM). DFT and CASSCF calculations indicate a metastable and highly polar ion pair between the tricyclopropylcyclopropenylium cation and a simplified Kuhn's anion. The barrier to the covalent structure varies from ∼4.8 to 14.4 kcal/mol, while the energy difference between the ion pair and the covalent form varies from ∼4.3 to 25.4 kcal/mol. The obtained theoretical results along with previous experimental results suggest the following strategy to obtain kinetically and thermodynamically stable hydrocarbon ion pairs: choose very stable hydrocarbon ions and systematically increase the steric hindrance between them.

Clausal agreement on adverbs in Andi

Abstract Andi (Nakh-Daghestanian; Russia) displays a typologically remarkable phenomenon: adverbs of numerous morphological and functional types inflect for agreement with a clause-level controller. To the extent that adverb agreement has been observed elsewhere, it is commonly taken to signal that the items involved are semantically oriented towards the participants they agree with, aligning the phenomenon with secondary predication. This paper demonstrates that Andi works differently: the widespread clausal agreement seen on Andi adverbs is insensitive to participant orientation. While agreement exponence on adverbs is morphologically complex, a simple structural principle (modelled here in Minimalist terms) ensures that clause-level agreement is always with the absolutive-case argument. The Andi facts thus provide evidence for a typological distinction between those languages where clausal agreement on adverbs can serve a semantic function and those where it cannot. A potential challenge is posed by the exceptional “biabsolutive” construction, where both subject and object appear in absolutive case and either may control adverb agreement, suggesting a role for some additional non-structural factor. However, on independent grounds this paper identifies the two arguments as belonging to distinct structural layers; this apparent flexibility in controller choice merely reflects the ability of certain adverbs to modify either layer.

Structural switch in acetylcholine receptors in developing muscle.

During development, motor neurons originating in the brainstem and spinal cord form elaborate synapses with skeletal muscle fibres1. These neurons release acetylcholine (ACh), which binds to nicotinic ACh receptors (AChRs) on the muscle, initiating contraction. Two types of AChR are present in developing muscle cells, and their differential expression serves as a hallmark of neuromuscular synapse maturation2-4. The structural principles underlying the switch from fetal to adult muscle receptors are unknown. Here, we present high-resolution structures of both fetal and adult muscle nicotinic AChRs, isolated from bovine skeletal muscle in developmental transition. These structures, obtained in the absence and presence of ACh, provide a structural context for understanding how fetal versus adult receptor isoforms are tuned for synapse development versus the all-or-none signalling required for high-fidelity skeletal muscle contraction. We find that ACh affinity differences are driven by binding site access, channel conductance is tuned by widespread surface electrostatics and open duration changes result from intrasubunit interactions and structural flexibility. The structures further reveal pathogenic mechanisms underlying congenital myasthenic syndromes.

Review of Energy Storage Capacitor Technology

Capacitors exhibit exceptional power density, a vast operational temperature range, remarkable reliability, lightweight construction, and high efficiency, making them extensively utilized in the realm of energy storage. There exist two primary categories of energy storage capacitors: dielectric capacitors and supercapacitors. Dielectric capacitors encompass film capacitors, ceramic dielectric capacitors, and electrolytic capacitors, whereas supercapacitors can be further categorized into double-layer capacitors, pseudocapacitors, and hybrid capacitors. These capacitors exhibit diverse operational principles and performance characteristics, subsequently dictating their specific application scenarios. To make informed decisions in selecting capacitors for practical applications, a comprehensive knowledge of their structure and operational principles is imperative. Consequently, this review delved into the structure, working principles, and unique characteristics of the aforementioned capacitors, aiming to clarify the distinctions between dielectric capacitors, supercapacitors, and lithium-ion capacitors.

Structural Principles of Ion-Conducting Mineral-like Crystals with Tetrahedral, Octahedral, and Mixed Frameworks

Materials with high ion mobility are widely used in many fields of modern science and technology. Over the last 40 years, they have thoroughly changed our world. The paper characterizes the structural features of minerals and their synthetic analogs possessing this property. Special attention is paid to the ionic conductors with tetrahedral (zincite- and wurtzite-like), octahedral (ilmenite-like), and mixed (NASICON-like) frameworks. It is emphasized that the main conditions for fast ionic transport are related to the size and positions occupied by a mobile ion, their activation energy, the presence and diameter of conduction channels running inside the structure, isomorphic impurities, and other structural peculiarities. The results of the studies of solid electrolytes are dispersed in different editions, and the overview of new ideas related to their crystal structures was the focus of this paper.

Research on finite element simulation and full-scale-vehicle crash test of B750HL bridge barrier

How to raise the bridge barrier with a concrete base height of only 51 cm to SS level of protection is not yet studied. In order to effectively retrofit an existing concrete barrier design to meet new crash testing criteria, the structural dimensions and concrete strength of the existing bridge barrier were investigated, and finite element simulation analysis was carried out, and simulation suggested the existing barrier was insufficient. Based on the structural dimension design principles of bridge barriers, the existing structure of bridge barrier was designed after adding lightweight and high-strength B750HL material crossbeams and posts on top of the concrete base, and the bearing capacity of the bridge barrier was calculated based on the yield line theory. Then, a finite element simulation analysis model was established to study and analyze the blocking, guiding, and cushioning functions of the improved design of bridge barrier. Finally, full-scale-vehicle crash tests were conducted with the SS-level small car, bus, and tractor-van trailer for this bridge barrier design scheme. This paper is the world’s first to use B750HL steel as the material for the crossbeam and post of a bridge barrier with a concrete base height of only 51 cm. According to the research results, the B750HL bridge barrier, which was designed based on the calculation of structural dimension design and yield line theory, effectively reduces the increased constant load on the bridge deck caused by the extra crossbeams and posts. At the same time, it can reduce material costs and save engineering costs. After being verified by finite element simulation crash tests and full-scale-vehicle crash tests, the protective capacity of the B750HL bridge barrier was proven to meet the SS-level evaluation requirements of the Standard for Safety Performance Evaluation of Highway Barriers (JTG B05-01-2013). The research findings of this paper is that the finite element simulation crash tests can effectively simulate full-scale-vehicle crash test, and the finite element simulation crash tests is reliable. If the safety performance of the barrier in the finite element simulation crash tests meets the requirements, the probability of passing the full-scale-vehicle crash test is higher. Therefore, a design scheme is proposed for the B750HL bridge barrier to improve hybrid bridge barriers at a height of 51 cm or more based on various design methods.

Algebraic Structures and Their Applications in Modern Cryptography

Modern cryptography relies heavily on the principles of algebraic structures to ensure the security and integrity of data. This paper explores the fundamental algebraic structures that underpin contemporary cryptographic systems, including groups, rings, fields, and lattices. We provide a detailed examination of how these structures are employed in various cryptographic algorithms and protocols, such as public-key cryptography, digital signatures, and hash functions. an overview of basic algebraic concepts and their properties, followed by an in-depth analysis of their applications in cryptographic schemes. For instance, the use of elliptic curve groups in Elliptic Curve Cryptography (ECC) offers enhanced security with smaller key sizes compared to traditional systems like RSA. Similarly, lattice-based cryptography presents promising solutions for post-quantum security, leveraging the hardness of lattice problems to resist attacks by quantum computers. the role of algebraic structures in the development of advanced cryptographic techniques, such as homomorphic encryption, which allows computations on encrypted data without decryption, and zero-knowledge proofs, which enable the verification of information without revealing the information itself. Through these examples, we illustrate the critical importance of algebraic structures in achieving robust and efficient cryptographic systems.

A new empirical mass flow correlation and mass flow rate characteristics of R600a through novel rotary-baffle curved-channel electronic expansion valve

The novel rotary-baffle curved-channel electronic expansion valve (RBCC-EEV) has appeared in industry to replace a capillary tube as the variable expansion device in household refrigerators. However, due to the structure differences between the RBCC-EEV and the traditional orifice-type EEV, the previous empirical mass flow correlation inapplicable. In this paper, a new empirical correlation is proposed based on the structure and regulation principle of the novel RBCC-EEV, and the effects of different operating conditions on the mass flow rate of R600a flowing through two different RBCC-EEVs are experimentally investigated. The new empirical correlation introduces a centrifugal force coefficient and a variable length coefficient to represent the effect of asymmetric cavitation phenomenon and super-linear mass flow rate characteristics. The experimental results show a rise in the mass flow rate with increasing inlet pressure, inlet subcooling and opening ratio. Under the test range, the flow pattern of R600a flowing through the RBCC-EEV is chocked flow. Moreover, the proposed new empirical mass flow correlation agrees well with the experimental data. For 95.7 % of the prediction value, the relative deviation is below 15 %, while 89.0 % exhibit a relative deviation less than 10 %. The average deviation and standard deviation stand at 6.52 % and 4.56 %, respectively.

Design-informed generative modelling of skeletal structures using structural optimization

Although various structural optimization techniques have a sound mathematical basis, the structural robustness and practical constructability of optimal designs pose a great challenge in the manufacturing stage. This paper presents an automated novel approach stemming from structural optimization and engineering principles, where discrete members of the structurally optimized designs are driven towards optimal utilization. The developed workflow unifies topology, layout and size optimization in a single parametric platform, which subsequently outputs a ready-to-manufacture CAD skeletal model which can be manufactured either additively or by assembly. All such outputs are checked and validated for structural requirements; strength, stiffness and stability in accordance with standard codes of practice. In the implementations, first, a topology-optimal model is generated and converted to a one-pixel-wide chain model using skeletonization. Herein, this paper uses a novel efficient method to extract the skeleton by using pixel-padding near the domain borders. Secondly, a spatial frame is extracted from the skeleton for its member size and layout optimization. Finally, the CAD model is generated using constructive solid geometry trees and the structural integrity of each member is assessed to ensure structural robustness prior to manufacturing. Various examples presented in the paper showcase the validity of the presented workflow across various structural engineering applications.

Structural literacy in architectural studio learning

ABSTRACT Architectural education encompasses a multidisciplinary curriculum including design, theory, history, technology, environmental considerations, urban planning, social aspects, and professional practice. This study aims to investigate the extent to which students can effectively integrate structural concepts into architectural design. This examination takes place within the framework of a third-year architectural design studio course, where students advance their design processes with input from architectural design instructors and experts in structural concepts. To facilitate this endeavour, a simple visual screening form was introduced to aid in the learning process. The study utilises a newly generated survey, namely ‘Structural System Control Form’, which is inspired by the rapid visual screening forms, to assess the students’ comprehension of structural concepts during a 14-week architectural design studio. Employing a descriptive and correlational research approach, the study assesses the effectiveness of this integrated strategy in enhancing the students’ understanding of structural principles. The findings revealed a notable development among students who participated in the integrated approach, highlighting the value of feedback and evaluation from instructors versed in construction. Furthermore, the use of simplified structural models in students’ projects improved their understanding of structural concepts and their ability to incorporate them into their architectural representations.

Design and Simulation of Adiabatic–Damping Dual–Function Strut for LH2 Storage Tank

In the process of the on–board transportation of liquid hydrogen storage and transportation tanks, apart from considering the support strength and adiabatic performance, it is imperative to take into account the vibration characteristics of the carrying platform. The present work introduces a versatile support structure comprising a damping module and a ball contact insulation structure, enabling effective isolation of external vibrations while simultaneously providing support and insulation. The first step involves describing the principle of a flexible support structure and designing the mechanical structure. Subsequently, a damping analysis is conducted based on dynamic theory to establish the relationship between the spring and damping. Finally, the structural parameters of the dual–function strut are determined, followed by simulation of heat transfer performance. The results demonstrate that the dual–function strut exhibits exceptional vibration damping performance by reducing the amplitude of external vibrations greater than 5 Hz to less than 6%. Moreover, owing to the compact linear diameter spring structure of the vibration damping module and its ball contact effect, the thermal resistance of the dual–function strut is significantly enhanced, resulting in a mere heat leakage of only 22 W/m2 in a single rod section.

Exploring Mentoring through Ecoliteracies

The article initiates with a theoretical exploration of fields of practice, followed by an introduction to the domain of mentoring and its foundational principles. A concise overview of Gestalt perception methodology facilitates the reconfiguration of the model of Theoretical Foundations of the Induction Year, aligning it with the European Commission Handbook for developing comprehensive induction programs for novice educators. This restructuring provides deeper insights into mentoring support concepts, prompting an inquiry into requisite abilities for effective mentoring. This investigation transitions to the broader context of ecologies of practice and the underlying principles of ecological structures. Drawing from established ecological dimensions, the article presents four influential figures crucial to mentoring, developed through Gestalt perception methodology. These figures serve to enhance mentoring experiences by leveraging the visual and memorable aspects of perception. Finally, the article provides a summary evaluation of its contributions.

Recent Advances on Principles of Concurrent Data Structures

Recent Advances on Principles of Concurrent Data Structures

Macrocyclic peptides derived from AcPHF6* and AcPHF6 to selectively modulate the Tau aggregation

Ten macrocyclic peptides, each comprising 14 amino acids, were designed and synthesized based on the Tau aggregation model hexapeptides AcPHF6* and AcPHF6. The design took into account the aggregation tendencies of each residue in AcPHF6* and AcPHF6, their aggregation models, while employing peptide-based structural design principles including N-methylation to promote turns and to block hydrogen bond propagation and elongation of the aggregation chain. NMR analysis supported that all these peptides adopted an antiparallel β-sheet conformation. Self-aggregation studies characterized the aggregation properties of these peptides, identifying two peptides with the highest (P3) and lowest (P8) aggregation tendencies. In cross-aggregation studies with the parent peptides AcPHF6* and AcPHF6, P3 and P8 were found to promote and reduce aggregation, respectively. Furthermore, P3 and P8 demonstrated an enhancement and diminution effect on the aggregation of K18wt, indicating their capacity to modulate aggregation even at the macromolecular level. Thus, the two simple peptides, P3 and P8 selectively exhibit pro- or anti-aggregation effects on PHF peptides and Tau. This study, has thus developed structurally well-defined non-complex peptides, derived from AcPHF6* and AcPHF6, to modulate Tau aggregation as desired, offering applications in Tau model studies and the development of Tau aggregation inhibitors or promoters.

Unraveling the multilayer solid-electrolyte interphase in lithium batteries through depth-sensitive plasmon-enhanced Raman spectroscopy: A theoretical and experimental study

The solid-electrolyte interphase (SEI) plays a crucial role in determining the lithium deposition/dissolution behaviors, thus influencing the reversible operation of Li metal batteries renowned for their ultrahigh specific capacity. Recently, we developed a depth-sensitive plasmon-enhanced Raman spectroscopy (DS-PERS) method enabling the in situ and nondestructive characterization of the nanostructure and chemistry of SEI through synergistic plasmonic structures. However, a lack of comprehensive elucidation of the enhancement mechanisms has impeded a detailed understanding of the depth-resolved signal contributions. In this study, we integrate theoretical computations with experimental methodologies to systematically unravel the working principles of the synergistic plasmonic structures, demonstrating that hot spots can effectively detect Raman signals at key locations across various stages of SEI layer evolution. Following Li deposition, the hot spots transfer from the Cu interfaces to the Li interfaces. With the thickening of the deposited Li, the localized surface plasmon resonance of Cu is gradually shielded, leading to the disappearance of hot spots originated from Li-Li coupling. Subsequently, we propose the utilization of Cu@Li-multilayer shell-isolated nanoparticles to compensate and introduce new hot spots, thereby enhancing the depth sensitivity. Our work provides theoretical insights essential for achieving precise depth-resolved PERS characterization.

Fabrication of a multiple-self-healing and self-cleaning polymer coating for mechanical-damaged optical glass surface

Mobile screens and optical glass devices encounter formidable engineering and technological bottlenecks in achieving irreversible restoration from surface mechanical scratches. Conventional methodologies involving glass surface micromachining and coatings technology have proven inadequate in effectively addressing the multiple recovery of optical transparency. Here, the synergistic integration principle of inorganic rigid cage-like structures and organic flexible chain segments is employed. A bionic “octopus” textured surface pattern, featuring ordered arrays of nano nodes acting as “post stations” and micro-nano wrinkles serving as “channels”, is one-step fabricated by a dipping-curing coating process. The polymer coating exhibits smooth, transparent, and multiple-self-healing function with patterned antifouling. Introducing and matching the coating onto mobile screens, transparency of wiped/scratched glass is significantly restored by the synergistic use of protonic/non-protonic solvent systems in a dipping-assisted healing process. Intriguingly, the coating achieves surface/internal pattern reconstruction along with excellent transparency, antifouling, and interfacial adhesion mechanical properties, characterized by surface micro-nano textures and internal micro-nano spheres organization, after undergoing multiple treatments with the biocompatible disinfectant and cleaning agent ethanol. In the future, it is expected to develop highly versatile engineering materials for mobile screens, optical lenses and automotive glass, enabling multiple self-healing, self-cleaning, and antifouling properties with broad industrial applications.

Optimal design of low frequency rubber vibration isolator

Abstract Low frequency vibration isolator is a common structure vibration control device, widely used in transportation and machinery manufacturing fields. This paper is centered around enhancing the optimization design of rubber isolators operating at low frequencies. In the initial section, the paper introduces the structural framework and operational principles of rubber isolators. Furthermore, it delves into the analysis of their significance and potential applications within engineering contexts. Subsequently, the paper narrows its focus to address the design challenges concerning rubber isolators with low-frequency capabilities. A comprehensive three-dimensional model is constructed using ANSYS software, employing finite element analysis techniques. The paper employs a multi-objective optimization algorithm through a direct optimization module to facilitate the optimization design process. Within this study, the NSGA-II algorithm was employed to drive the optimization of design, with the objective of achieving a 10 Hz frequency for a series of dual rubber isolators, while simultaneously constraining static deformation to within 8 mm. The outcomes of this investigation emphasize the successful attainment of optimization goals by meticulously fine-tuning the structural dimensions of the isolators.

Game psychotherapy intervention based on entertainment interactive robots for preventing depression in university students

This study designs an entertainment interactive robot system for gaming psychotherapy intervention and evaluates its effectiveness in preventing depression in students. In terms of the architecture and hardware of the entertainment interactive robot system, the robot adopts high-performance processors and sensors to achieve the ability to quickly respond and accurately perceive user actions. In terms of software, a mathematical model was established based on the structure and kinematic principles of the robot to describe its motion. Preprocess user gesture data by analyzing the features and patterns of user gestures, extracting key action information, and using machine learning algorithms or deep learning models to classify and recognize gestures to determine user intent and action types. Evaluate action recognition and effectiveness, and verify the accuracy and reliability of the gesture interaction module through comparison and testing with actual user gestures. The study designed an entertainment interactive robot assisted game that provides a fun and interactive experience to attract students’ attention and stimulate positive emotions. Through game design and behavioral pattern evaluation, the research team evaluated the preventive effect of entertainment interactive robot assisted games on depression and proposed optimization strategies.

Research on Failure Characteristics of Electric Logistics Vehicle Powertrain Gearbox Based on Current Signal

As a core component of the powertrain system of Electric Logistics Vehicles (ELVs), the gearbox is crucial for ensuring the reliability and stability of ELV operations. Traditional fault diagnosis methods for gearboxes primarily rely on the analysis of vibration signals during operation. This paper presents research on diagnosing gear tooth wear faults in ELV powertrains using motor current signals. Firstly, an experimental test platform was constructed based on the structural principle of the powertrain of ELV models. Subsequently, a pure electric light truck powertrain gearbox with tooth wear was tested. Time–frequency domain analysis, amplitude analysis, ANOVA analysis, kurtosis analysis, and zero−crossing points analysis were used to analyze the U−phase current of the motor connected to the gearbox to study the characteristics of the phase current of the drive motor after tooth wear. The results indicate that while the time–frequency domain characteristics of the U−phase currents are not significantly altered by tooth wear faults, the amplitude, variance, and kurtosis of the current increase with the severity of the wear. Conversely, the number of zero−crossing points decreases. These findings provide valuable insights into new methodologies for diagnosing faults in ELV powertrain systems, potentially enhancing the efficiency and effectiveness of troubleshooting processes.

TYPES OF ALLUSIONS IN BOHDAN TOMENCHUK’S POETRY ABOUT THE WAR

The paper examines allusions in Bohdan Tomenchuk’s poetry collection “Embroider, Mother, a bulletproof vest.” The various types of allusions are grouped based on their functions (activation of historical memory, adherence to literary tradition, text-structuring), themes (historical, mythological), and typology (ranging from nominal and quotation-type to associative). An attempt was made to differentiate the concept of allusion from quotation and reminiscence, while also juxtaposing it with intertext and intertextuality for comparison. In the poet’s texts about the modern Russian-Ukrainian war, the references to literary works are accompanied by numerous allusions to historical reality. These are references of the nominal type (topographical or proper names connected with certain historical events in the reader's mind). The author's distinctive approach involves overlapping different types of allusions, namely those of historical and literary nature, as well as historical and mythological. Behind a direct allusion, an associative one may emerge, linking to a text from a different time period through shared words, phrases, or thematic aura. The involvement of allusion in Tomenchuk’s poetry often occurs on the basis of the allegation (the new text ‘absorbs’ the previous one, without entering into a controversy with the original text). In this case, we deal with intertext (a text within a text). When an allusion entering a new text gets engaged in a dialogue with the original text, we deal with intertextuality as a process of textual interaction. By involving an allusion, the author makes it an element of the structure that serves as an impetus for the reader to navigate within a receptive context, searching among known texts relevant for interpreting the allusion while disregarding distant ones. Intertextuality engages cognition here. Sometimes allusion is not just an element of a structure but a structural principle, and it is proper to name it a structuring allusion. Various allusions in B. Tomenchuk’s poetry make it possible to fit the widest range of emotions and thoughts in a small textual space, to integrate the new experience of war into a broad historical and literary canvas with a biblical and mythological background.