Structural Parameters Research Articles

Study on Microstructure Evolution Characteristics of Coal in Low Temperature Oxidation Stage in Goaf of Longfeng Coal Mine

ABSTRACT Low temperature oxidation of coal is the nature of oxidation of coal with oxygen molecules at temperatures below its oxidation critical point or ignition point, usually from ambient temperature to about 200°C. Air leakage and uneven oxygen distribution significantly impact coal spontaneous combustion in goaf. Understanding the changes in free radicals and functional groups during low-temperature oxidation of coal under different oxygen concentrations is crucial for preventing and controlling residual coal self-ignition. This study employs Fourier transform infrared spectroscopy to analyze the effects of varying oxygen concentrations (3%, 5%, 9%, 15%, 21%) on functional groups and structural parameters during coal’s low-temperature oxidation. Results indicate that increasing oxygen concentration promotes the consumption of oxygen-containing functional groups, reducing their content from 71.9% to 52%. Concurrently, the activity and content of aromatic hydrocarbon functional groups rise rapidly from 4.8% to 52.6%. The aliphatic hydrocarbon structure shows a downward trend, indicating its minimal presence. Aromatic ring condensation increases coal sample aromaticity, suggesting higher maturity and weaker hydrocarbon generation potential, with minimal effect from oxygen concentration. Early-stage reactions show little change in coal’s basic structure, and coal-oxygen reactions remain low in low oxygen environments. This study provides an important basis for understanding the mechanism of coal spontaneous combustion in goaf and formulating effective prevention measures for coal spontaneous combustion.

Impact of tool nose size on the performance and wear behavior of carbide tool when boring 1Cr17Ni2 martensitic stainless-steel parts

Purpose This study aims to examine the cutting performance of a coated carbide tool during the boring of 1Cr17Ni2 martensitic stainless steel, with a focus on how the tool’s structural parameters, particularly the nose radius, affect the wear patterns, wear volume and lifetime of the cutting tool, and related mechanisms. Design/methodology/approach A full factorial boring experiment with three factors at two levels was conducted to analyze systematically the impact of cutting parameters on the tool wear behavior. The evolution of tool wear over the machining time was recorded, and the influences of the cutting parameters and nose radius on wear behavior of the tool were examined. Findings The results show that higher cutting parameters lead to significant wear or plastic deformation at the tool nose. When the cutting depth is less than the nose radius, the tool wear tends to be minimized. Larger nose radius tools have weaker chip-breaking but greater strength and wear resistance. Higher cutting parameters reduce wear for the tools with larger nose radius, maintaining their integrity. Wear mechanisms are primarily abrasive, adhesive and diffusion wear. Furthermore, the full-factorial analysis of variance revealed that for the tool with rε = 0.4 mm and 0.8 mm, the factors contributing the most to tool wear were cutting speed (38.76%) and cutting depth (86.43%), respectively. Originality/value This study is of great significance for selection of cutting tools and cutting parameters for boring 1Cr17Ni2 martensitic stainless-steel parts. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0266/

Correlation Analysis of Subjective and Objective Texture Properties: Color and Heterocyclic Amine Content of Grilled Chicken Breast Fillet

The present study discusses the technofunctional properties (color, texture) of grilled chicken with both objective (colorimeter, texture profile) analysis and subjective (sensory) analysis. Besides them, the total content of potentially carcinogenic heterocyclic amines (HCAs) was also monitored by the applied grilling time–temperature combinations. The same samples were analyzed during the heat treatment of chicken breast samples for 5–15 min at 150–230 °C on an electric contact grill. The grilling variables included the effect of skin cover. Among the structural parameters, hardness exhibited a significant difference between the groups of skin-covered and not-covered ones, and in this case, a linear connection was also found with the time and temperature values, respectively. The structural parameters obtained by sensory and instrumental analysis were compared to each other. In addition, the structural parameters were compared to the color ones (sensory, color according to the CIELAB system: brightness, redness, and yellowness) and to the total HCA content. In the case of closed grilling, sensory-evaluated parameters such as juiciness and tenderness showed a strong negative correlation to instrumentally measured hardness (R = −0.879; −0.749) and chewiness (R = −0.872; −0.718) due to the water loss from the increase in grilling temperature and time. The total HCA content positively correlated to chewiness (R = 0.789). The sensory color parameter and the brightness had a strong connection with juiciness (R = 0.738; 0.723), hardness (R = −0.795; −0.706), and chewiness (R = −0.843; −0.818); redness showed positive correlation to cohesiveness (R = 0.764) and chewiness (R = 0.829). Accordingly, juiciness and chewiness showed a connection to the total HCA levels, which makes it possible to carry out further research on instrumental and sensory parameters that may predict the formation of hazardous amounts of carcinogenic heterocyclic amines.

Scalable robust photothermal superhydrophobic coatings for efficient anti-icing and de-icing in simulated/real environments.

Photothermal superhydrophobic coatings are supposed promising to prevent ice accumulation on infrastructures but often experience significant performance degradation in real icing conditions and lack mechanical robustness. Here, we report design of robust photothermal superhydrophobic coatings with three-tier hierarchical micro-/nano-/nanostructures by deposition of nanosized MOFs on natural attapulgite nanorods, fluorination, controlled phase separation of a hydrophobic adhesive and spraying assembly. Phase separation degree and adhesive content significantly influence the coatings' properties by regulating the structural parameters and morphology. In simulated/real icing environments, the coatings simultaneously show (i) high superhydrophobicity and stable Cassie-Baxter states due to their low-surface-energy, three-tier micro-/nano-/nanostructure, (ii) excellent photothermal effect primarily due to nanosized MOFs, and (iii) good mechanical robustness by the phase-separated adhesive, reinforcement with attapulgite and the coatings' self-similar structure. Accordingly, combined with low thermal conductivity, the coatings exhibit remarkable anti-icing/frosting (e.g., no freezing in at least 150 min and almost free of frost in 25 min) and de-icing/frosting performances (e.g., fast de-icing in 12.7 min and fast de-frosting in 16.7 min) in such environments. Furthermore, we realize large-scale preparation of the coatings at reasonable costs. The coatings have great application potential for anti-icing and de-icing in the real world by efficiently using natural sunlight.

A FRACTAL PORE-SCALE MODEL OF STRESS-DEPENDENT THERMAL CONDUCTIVITY IN A RECTANGULAR CROSS-SECTION TREE-LIKE MICROFRACTURE NETWORK

Stress is an important external element influencing effective thermal conductivity (ETC). However, previous theoretical investigations of stress-dependent effective thermal conductivity have used a simplified parallel plate model, overlooking the complex structure of rock fracture networks. Therefore, this paper establishes a new fractal model for the stress-dependent ETC of a rectangular cross-section tree-like microfracture network. The model derives a constitutive equation between the stress-dependent ETC and the microscopic geometry structural parameters of the microfracture network. The model’s validity is confirmed by the error of less than 0.291% between the theoretical predictions and the experimental data. The influence of geometry structural parameters of the microfracture network (length ratio, width ratio, height ratio, angle, total number of branches and ratios of soft part, hard part, etc.) on the ETC under the low-stress state has been analyzed. It was discovered that the soft part of the rock microfracture network has the most impact on ETC. The fractal pore-scale model clarifies heat transfer mechanism in rock microfracture network under effective stress, with each parameter physically defined and independent of empirical constants.

Research on the Configuration Optimization of All-Metal Micro Resonant Hemisphere

As the core component of the all-metal micro resonant gyroscope, the structural parameters and form and position errors of the resonator significantly influence its vibration characteristics, and consequently, the accuracy of the gyroscope. By establishing the finite element model of an ideal hemispherical resonator and optimizing the meshing method, we refined the frequency difference to 0.1 Hz, enhancing the accuracy of the simulation model. Through finite element simulation, we examined the impact of various structural parameters and processing errors on the natural frequencies of each mode. We analyzed how form and position errors, including shell thickness error, central axis error, equatorial plane error, and edge rectangular tooth position error, affect the frequency splitting of the resonator. We provided optimization suggestions for the structural parameters, ensuring frequency splitting variations of less than 1 Hz. Theoretical modeling and simulation analysis indicated that the primary factors influencing the vibration modes and frequency splitting are the rectangular tooth structure and shell thickness. Following the optimized parameters, the frequency splitting of the All-Metal Micro Resonant Hemisphere was reduced by an order of magnitude to 14 Hz, demonstrating that these optimized conditions can significantly enhance the resonator’s performance.

Multiple surface lattice resonances in symmetric nanocuboid dimer arrays

Abstract Surface lattice resonances based on nanoparticle arrays have significant characteristics such as localized field enhancement and high quality factor, and can be applied in fields such as optical sensors and lasers. In this work, we propose a symmetric Si/SiO2 nanocuboid dimer array that can generate and regulate two surface lattice resonances. One of the surface lattice resonances (named SLR1) is mainly due to the coupling between the electric dipole resonance of single Si/SiO2 nanocuboid dimers and the diffraction waves perpendicular to the applied electric field. Another surface lattice resonance (named SLR2) mainly originates from the coupling between the magnetic dipole resonance of single Si/SiO2 nanocuboid dimers and the diffraction waves parallel to the direction of the applied electric field. The research results indicate that the polarization direction of the incident field, the period of the array, the gap between the nanocuboids in the dimer, particle size, and the medium environment are all important for regulating the two surface lattice resonances. The sensing application of multiple surface lattice resonances is also investigated. The results show that under appropriate structural parameters, SLR1 can provide good stability for sensing applications, its sensitivity and figures of merit are 472 nm/RIU and 104, respectively. However, SLR2 is very weak or suppressed when the refractive index of the medium environment is greater than or equal to 1.2. This characteristic limits the application range of SLR2 in sensing. This work is of great significance for the design of micro-nano photonic devices based on multiple surface lattice resonances.

Intermetallic Compounds for Hydrogen Storage: Current Status and Future Perspectives.

Intermetallic compounds are an emerging class of materials with intriguing hydrogen activation and storage capabilities garnering attention for their application in low-temperature hydrogen storage and metal hydride batteries. However, none of the existing intermetallic compounds have met the gravimetric hydrogen storage capacity target of 5.5wt.%. Some A2B-type intermetallic compounds, like Mg2Ni, Mg2Co, and Mg2Fe, approach this target but require high temperatures for hydrogen desorption limiting their use in low-temperature hydrogen storage and automotive applications. Conversely, some intermetallic compounds like ZrV2 and LaNi5, exhibit hydrogen desorption at ambient conditions but with comparatively lower hydrogen storage capacities. This review article provides a comprehensive account of the different types of intermetallic compounds, their synthesis using different solidification-based and solid-state diffusion-based approaches, and their metallurgical and structural properties. It examines the complex interdependencies between the structural parameters of intermetallic compounds and hydrogen storage performance. A definitive but non-linear correlation is identified between void volume and gravimetric hydrogen storage capacities while lattice structure, evolution of lattice structure with hydrogen absorption, enthalpy of hydride formation, and hydrogen activation reactivities of intermetallic compounds are identified as critical parameters governing hydrogen storage performance.

Towards Achilles Tendon Injury Prevention in Athletes with Structural MRI Biomarkers: A Machine Learning Approach.

Recent advancements in artificial intelligence have proven their effectiveness in orthopaedic settings, especially in tasks like medical image analysis. This study compares human musculoskeletal radiologists to artificial intelligence in a novel, detailed, short, and cost-effective examination of Achilles tendon magnetic resonance images to uncover potential disparities in their reasoning approaches. Aiming to identify relationships between the structured assessment of the Achilles tendon and its function that could support injury prevention. We examined 72 athletes to investigate the link between Achilles tendon structure, as visualised in magnetic resonance images using a precise T2*-weighted gradient echo sequence with very short echo times, and its functional attributes. The acquired data were analysed using advanced artificial intelligence techniques and reviewed by radiologists. Additionally, we conducted statistical assessments to explore relationships with functional studies in four meaningful groups: dynamic strength, range of motion, muscle torque and stabilography. The results show notable linear or non-linear relationships between functional indicators and structural alterations (maximal obtained Spearman correlation coefficients ranged from 0.3 to 0.36 for radiological assessment and from 0.33 to 0.49 for artificial intelligence assessment, while maximal normalised mutual information ranged from 0.52 to 0.57 for radiological assessment and from 0.42 to 0.6 for artificial intelligence assessment). Moreover, when artificial intelligence-based magnetic resonance assessment was utilised as an input, the associations consistently proved more robust, or the count of significant relationships surpassed that derived from radiological assessment. Ultimately, utilising only structural parameters as inputs enabled us to explain up to 59% of the variance within specific functional groups. This analysis revealed that structural parameters influence four key functional aspects related to the Achilles tendon. Furthermore, we found that relying solely on subjective radiologist opinions limited our ability to reason effectively, in contrast to the structured artificial intelligence assessment. Cross-sectional studies.

Analysis and Design of a Recyclable Inductive Power Transfer System for Sustainable Multi-Stage Rocket Microgrid with Multi-Constant Voltage Output Characteristics—Theoretical Considerations

After a traditional one-time rocket is launched, most of its parts will fall into the atmosphere and burn or fall into the ocean. The parts cannot be recycled, so the cost is relatively high. Multi-stage rockets can be recovered after launch, which greatly reduces the cost of space launches. Moreover, recycling rockets can reduce the generation of waste and reduce pollution and damage to the environment. With the reduction in rocket launch costs and technological advances, space exploration and development can be carried out more frequently and economically. It provides technical support for the sustainable use of space resources. It not only promotes the sustainable development of the aerospace field but also has a positive impact on global environmental protection, resource utilization, and economic development. In order to adapt to the stage-by-stage separation structure of the rocket, this paper proposes a new multi-stage rocket inductive power transfer (IPT) system to power the rocket microgrid. The planar coil structure is used to form wireless power transfer between each stage of the rocket, reducing the volume of the magnetic coupling structure. The volume of the circuit topology structure is reduced by introducing an auxiliary coil. An equivalent three-stage S/T topology is proposed, and the constant voltage output characteristics of multiple loads are analyzed. A multi-stage coil structure is proposed to supply power to multiple loads simultaneously. In order to eliminate undesired magnetic coupling between coils, ferrite cores are added between coils for effective electromagnetic shielding. The parameters of the magnetic coupling structure are optimized based on the finite element method (FEM). A prototype of the proposed IPT system is built to simulate a multi-stage rocket. A series of experiments are conducted to verify the advantages of the proposed IPT system, and the three-stage rocket system efficiency reached 88.5%. This project is theoretical. Its verification was performed only in the laboratory conditions.

DFT molecular modeling investigation and optical properties characterization of CR-39 films

Abstract In this study, the structural and optical characteristics of CR-39 films were investigated both theoretically and experimentally. A number of parameters for the CR-39 structure were theoretically computed by the density functional theory (DFT) method at B3LYP/6–311 G (p, d) level of theory. FTIR and UV/Vis spectroscopy were used to determine the structure compositions and the optical parameters of the CR39 film, respectively. The computed and experimental findings show good concordance. It was found that the CR-39 compound’s total energy, dipole moment, and energy difference between the LUMO and HOMO were, respectively, −994.575 a.u., 2.772 Debye, and 7.045 eV. The MEP showed a progressive change in color, with blue signifying a low electron density and red denoting a high electron density linked to nucleophilic reactivity and electrophilic reactivity. Further, the positive charges on all hydrogen atoms, which range from 0.16506 to 0.22032 a.u., imply that they are acceptors. The positive H34 is strongly produced when electrons from the negatively charged C17 are taken up. Because they are donor atoms, part of the carbon atoms in the structure is negative, while the other atoms are positive. The highest electronegative atoms H23 and H24 were substituted, resulting in the extremely negative carbon atom C7 (−0.32436). According to the experimentally determined absorption coefficient and energy gap values, CR-39 films may find application in optoelectronic devices.

Predictive Model of the Effects of Skin Phototype and Body Mass Index on Photobiomodulation Therapy for Orofacial Disorders

Monte Carlo techniques have been extensively used for planning laser-based clinical procedures such as photobiomodulation. However, the effects of several biological tissue characteristics regarding its morphological structure and physiological parameters have not been carefully addressed in many applications. Specifically, many questions remain concerning the effect of skin phototype and body mass index on the effectiveness of photobiomodulation for extraoral therapies. To address these questions, a Monte Carlo simulation model of the effects of body mass index-dependent skin structure on different Fitzpatrick skin types was developed, specifically tailored for the morphological characteristics of cheek tissue. The model describes the settings of a typical oral photobiomodulation treatment protocol for pain relief, namely the use of 660 nm and 808 nm laser wavelengths and a therapeutic dose of 2.0J/cm2 on the masseter muscle. The simulations were used to train a machine learning predictive model aimed at accelerating the treatment planning stage and assessing the importance of patient-specific parameters. A multiple-regression approach was adopted to predict muscle dose and treatment time for effective delivered dose. Body mass index had little effect on epidermal energy deposition, but an important impact on muscle dose parameters. Phototype also influenced muscle dose, but to a lesser extent than body mass index. The results of this study can be used to develop customized dosimetry phototherapy protocols to promote more effective and safe clinical outcomes.

Analysis of Vibration Characteristics for Rotating Braided Fiber-Reinforced Composite Annular Plates with Perforations

In the current study, a comprehensive numerical model for analyzing the vibrational characteristics of braided fiber-reinforced composite (BFRC) rotating annular plate with perforations under diverse boundary constraints was introduced. This model employs the differential quadrature finite element method (DQFEM), which was developed based on the first-order shear deformation theory (FSDT) and coordinate transformation approach. The BFRC material, specifically a two-dimensional biaxial orthogonal fabric, was utilized to fabricate the annular plate with two distinct types of holes: circular and sector-shaped. The model’s convergence, accuracy, numerical stability, and reliability were confirmed through comparative assessments utilizing data from the literature, from ABAQUS software, and from experimental findings. The analysis focuses on studying the influences of structural properties, material parameters, and boundary restraints on the frequencies of vibration for BFRC rotating annular plates with holes. This theoretical model helps provide scientific basis and technical guidance for the stability and lightweight design of rotating annular plates, such as rotor structures in aircraft engines.

Improvement of the functional layouts of multifunctional soil-cultivating sowing units

BACKGROUND: With the technology evolution, the use of combined machines and units has become more in demand. From the numerous studies that were carried out during the operation of machines of this type, it can be seen that the cost of raw materials and financial costs have been significantly reduced, and the number of other advantages has been identified as well. AIM: Improvement of the functional layouts of multifunctional tillage sowing units for a more optimal combination of structural layouts and parameters of its use. METHODS: Engineers use the method of changing working bodies designed as layouts aiming to turn the machines into the modules capable of performing various types of operations based on working conditions. Thanks to this method, sets of individual working bodies and combinations are prepared for any kind of conditions (soil, climate, etc.). In addition to the advantages, this system has a number of disadvantages. One of these is that at the factory-built modules that are part of the original basis of the unit cannot be fully adapted to environmental conditions and economic factors of production. In this regard, combination of structural layouts and selection of the necessary parameters become problem causing. It is difficult to choose necessary parameters that are capable of ensuring minimal losses and adjusting the unit to the necessary operating mode. The objects of study are the devices and production processes, the main task of which is performing tillage and sowing operations. The practical value of this study presented in the form of: building the algorithm capable of structuring the analysis and synthesis of the structural layout of the tillage-sowing unit to find the working links for various types of unit functions; finding the methods and improved combinations of working bodies, comparison of similar mechanical analogues with the original properties of systems. RESULTS: When studying the studies of Wilde, who gave a description of the combined units, as well as the studies of Runchev, who determined the generalization of the combined machines, the relevant typology of agricultural machinery was developed. In this typology, one of the most important characteristics is multifunctionality, which has developed from the need for the versatility of units and the compilation of combinations of several units. The developed technology contains a number of characteristics that are fundamental for the choice of agricultural machinery. CONCLUSION: As a result of the study, it was determined at which velocity of the unit the system is balanced.

Optimization design of a two-step microreactor with spiral structure for high-performance catalytic reactions

Abstract In order to enhance the efficiency of diphenyldimethoxysilane preparation in microreactors, this study utilized the computational fluid dynamics simulation based on the finite element method to explore the impact of the internal structural parameters of the spiral two-step microreactor (STMR) on the reaction outcomes, with the aim of optimizing its structure for high-performance catalytic reactions. By designing a microreactor based on the Archimedean spiral shape and introducing two ribbed obstacles, the structure was optimized through adjusting the relevant ratios. The effects of different-sized structures and obstacles within the reaction zone and non-reaction zone on the product concentration and reaction results were discussed. The results demonstrate that lower obstacle heights and smaller aspect ratios (P = 2:7, R = 5:6) are beneficial for improving the reaction efficiency and product concentration. This study offers a theoretical foundation for microreactor design and is anticipated to further drive the development of microreactor technology.

Synthesis and characterization of p-CuO/n-ZnO heterostructured composite thin films for the detection of formaldehyde gas.

We report the synthesis and characterization of pure CuO and CuO-ZnO nanostructured composite thin films sprayed on particle-free glass substrates using chemical spray pyrolysis method. The films were systematically analyzed through microstructural, morphological, chemical, and gas-sensing studies. X-ray diffraction (XRD) studies confirmed the polycrystalline nature of the films, with a predominant monoclinic phase along the (002) direction. Key structural parameters, such as crystallite size, dislocation density, strain, and the number of crystallites per unit area, were reported from XRD analysis. Field emission scanning electron microscopy (FESEM) revealed a bundled-like morphology with uniform particle distribution, enhancing the surface area for effective gas interaction. X-ray photoelectron spectroscopy (XPS) results indicated that Cu and Zn ions existed predominantly in the 2+ oxidation state, contributing to the films' reactivity. Significantly, the gas sensing studies were investigated with static liquid distribution method, highlighting the remarkable performance of the 30 wt.% CuO-ZnO composite thin film. This composite exhibited a substantial response to 5 ppm formaldehyde at ambient conditions, showing a recovery time of 22 seconds and a response time of 15 seconds. These findings underscore the potential of CuO-ZnO composites for efficient formaldehyde gas sensing applications, marking a notable advancement in the field of environmental monitoring.

Thermal equation of state of rhodium characterized by XRD in a resistively heated diamond anvil cell

The high-pressure and high-temperature structural, mechanical, and dinamical stability of rhodium has been investigated via synchrotron X-ray diffraction using a resistively heated diamond anvil cell and density functional theory. The isothermal compression data have been fitted with a Rydberg-Vinet equation of state (EoS) with best-fitting parameters V0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$V_0$$\\end{document} =55.046(16) Å3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}, K0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K_0$$\\end{document} = 251(3) GPa, and K0′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K'_0$$\\end{document} = 5.7(2). The thermal equation of state has been determined based upon the data collected following four different isotherms and has been fitted to a Holland and Powell thermal equation-of-state model with α0=\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha _0=$$\\end{document}3.36(7)x10-5\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-5}$$\\end{document}K-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document}. The measured equation of state and structural parameters have been compared to the results of ab initio simulations. The agreement between theory and experiments is generally quite good. The present results solve controversies between previous studies which reported values of the bulk modulus from 240 to 300 GPa.

Lipid-mediated adaptation of proteins and peptides in cell membranes

The paper overviews the results of computational studies of the molecular mechanisms underlying the adaptation of model cell membranes taking place during their interaction with proteins and peptides. We discuss changes in the structural and dynamic parameters of the water–lipid environment, the hydrophobic/hydrophilic organization of the lipid bilayer surface (the so-called “mosaicity”), etc. Taken together, these effects are called the “membrane response” (MR) and constitute the most important ability of the cell membranes to respond specifically and consistently to the incorporation of extraneous agents, primarily proteins and peptides, and their subsequent functioning. The results of the authors’ long-term research in the field of molecular modeling of MR processes with various spatial and temporal characteristics are described, from the effects of binding of individual lipid molecules to proteins to changes in the integral macroscopic parameters of membranes. The bulk of the results were obtained using the “dynamic molecular portrait” approach developed by the authors. The biological role of the observed phenomena and potential ways of rationally designing artificial membrane systems with specified MR characteristics are discussed. This, in turn, is important for targeted changes in the activity profile of proteins and peptides exerting action on biomembranes, not least as promising pharmacological agents.

Design and Test of a Traction Side-Pull Square Straw Bale Pick-Up-and-Stack Truck

To address the issues of limited one-time loading capacity, single functionality, and low automation level in existing square straw bale pickers, a large automated square straw bale pick-up-and-stack truck that integrates picking, stacking, transporting, and bundling functions has been developed, combining the technical advantages of one-time field removal and storage of bales. We innovatively designed a side-pulling traction mechanism that can realize the rapid transition between the transporting state and working state of the machine; a picking device that can complete the continuous action of forking, lifting, turning positioning, and de-forking; and a bundling device that can realize the adjustment of the attitude of square straw bales. Response surface tests were conducted on the prototype to determine the key structural and operational parameters, using the bundle completion rate and regular bale rate as evaluation indicators. Regression and significance tests were performed on the machine’s forward speed, chassis frame offset, and the ground clearance of the fork tine to determine the influence and priority of these factors on the evaluation indicators. Through multi-objective function optimization of the regression model, the optimal parameter combination was found to be a machine forward speed of 15.5 km/h, a chassis frame offset of 2126 mm, and a fork tine ground clearance of 225 mm, resulting in a bundle completion rate of 98.85% and a regular bale rate of 96.96%. Subsequent field tests with the optimized parameters showed that at a machine forward speed of 15.5 km/h, a chassis frame offset of 2126 mm, and a fork tine ground clearance of 225 mm, the bundle completion rate was 98.37% and the regular bale rate was 95.83%, meeting the relevant design requirements. This study can provide a reference for the design and development of straw collection and storage machinery.

Observing vibronic coupling in a strongly hydrogen bonded system with coherent multidimensional vibrational-electronic spectroscopy.

The coupled structural and electronic parameters of intramolecular hydrogen bonding play an important role in ultrafast chemical reactions, such as proton transfer processes. We perform one- and two-dimensional vibrational-electronic (1D and 2D VE) spectroscopy experiments to understand the couplings between vibrational and electronic coordinates in 10-Hydroxybenzo[h]quinoline, an ultrafast proton transfer system. The experiments reveal that the OH stretch (νOH) is strongly coupled to the electronic excitation, and Fourier analysis of the 1D data shows coherent oscillations from the low frequency backbone vibrational modes coupled to the νOH mode, resulting in an electronically detected vibronic signal. In-plane low-frequency vibrations at 242 and 386 cm-1 change the hydrogen bond distance and modulate the observed electronic signal in the polarization-selective 1D VE experiment through orientation-dependent coupling with the νOH mode. Resolution of the excitation frequency axis with 2D VE experiments reveals that excitation frequency, detection frequency, and experimental delay affect the frequency and strength of the vibronic transitions observed. Our results demonstrate evidence of direct coupling of the high frequency νOH mode with the S1 ← S0 electronic transition in 10-Hydroxybenzo[h]quinoline (HBQ), and orientation-dependent couplings of the low-frequency 242 and 386 cm-1 modes to the νOH mode and the electronic transition. This demonstration of multidimensional VE spectroscopy on HBQ reveals the potential of using 1D and 2D VE spectroscopy to develop a quantitative understanding of the role of vibronic coupling in hydrogen bonding and ultrafast proton transfer for complex systems.