Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

The utilization of iron coke provides a green pathway for low-carbon ironmaking.To uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was investigated.Furthermore,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric method.The findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and interconnect.This provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron coke.Accelerating the heating rate in non-isothermal gasification can enhance the reactivity of iron coke.The metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon atoms.The kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore structure.Moreover,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

The multiple roles of crop structural change in productivity,nutrition and environment in China:A decomposition analysis

China's crop structure has undergone significant changes in the last two decades since 2000,with an increase in the share of cereals,vegetables,and fruit,squeezing out other crops.As a result,land productivity,nutrient supply,and carbon emissions have changed.How to reallocate limited farmland among crops to achieve the multiple goals of agrifood systems becomes an important issue.This study explores the sources of land productivity and nutrition supply growth and carbon emissions reduction,and identifies the multiple roles of crop structural change from 2003 to 2020 based on a decomposition analysis.The results reveal that the growth within crops is still the primary driver in land productivity and nutrition supply and the reduction in carbon emissions.However,structural change also plays various roles at different periods.From 2003 to 2010,crop structural change increased the total calorie supply but lowered land productivity and contributed at least 70%of the total growth of carbon emissions.The crop structure was relatively stable,and their effects were modest from 2010 to 2015.From 2015 to 2020,the crop structural change began to play a greater role and generate synergistic effects in improving land productivity,micronutrient supply,and reducing carbon emissions,contributing to approximately a quarter of the growth of land productivity and 30%of total carbon emissions reduction.These results suggest that strategies for crop structural change should comprehensively consider its multiple impacts,aiming to achieve co-benefits while minimizing trade-offs.

Structural analysis of silk using solid-state NMR

Silkworms and spiders are capable of generating fibers that are both highly durable and elastic in a short span of time,using a silk solution stored within their bodies at room temperature and normal atmospheric pressure.The dragline silk fiber,which is essentially a spider's lifeline,surpasses the strength of a steel wire of equivalent thickness.Regrettably,humans have yet to replicate this process to produce fibers with similar high strength and elasticity in an eco-friendly manner.Therefore,it is of utmost importance to thoroughly comprehend the extraordinary structure and fibrillation mechanism of silk,and leverage this understanding in the manufacturing of high-strength,high-elasticity fibers.This review will delve into the recent progress in comprehending the structure of silks derived from silkworms and spiders,emphasizing the distinctive attributes of solidstate NMR.

Structural Controls Analysis and Its Correlation with Geothermal Occurrence at Barrier Volcanic Complex (BVC), Turkana, Kenya

Geothermal is a clean energy source that is freely available in the subsurface. The exploitation of this vital resource needs intensive exploration in order to identify and quantify its occurrence. The three parameters considered when assessing the viability of a geothermal system include;heat source, fractures and fluids. Geological structures are important in transportation of fluids to and from the heat source aiding in recharge of the geothermal system and enhancing productivity. Remote sensing method was applied in mapping the structures at Barrier Volcanic Complex (BVC) by using hill shading technique which utilized four illumination angles of the sun (azimuth) i.e. 45°, 90°, 150°, and 315°, constant elevation of 45° and exaggeration of 10. The data used was Shuttle Radar Topographic Mission (SRTM) Satellite Imagery. ArcGIS Software was used for lineaments delineation and density mapping, PCI Geomatica was used to generate major faults, while Georose and Rockworks 17 were used to generate the rose diagrams. Geological structural analysis was done by delineating lineaments, determining the density distribution of lineaments and finally determining the structural trends of lineaments. The generated major faults in the area and the location of the occurrence of surface manifestations were compared with the generated lineaments. A total of 260 lineaments were generated whereby at 45° there was a total of 60 lineaments, at 90° 95 lineaments, at 150° 61 lineaments, and at 315° 44 lineaments. The results of structural analysis in the area as shown by the rose diagrams indicate an NNE-SSW and N-S trending of structures. In conclusion, the study area is highly fractured as indicated by the presence of numerous lineaments. These lineaments provide good recharge to the geothermal system and enhance the geothermal reservoir in the area.

Genetic Analysis of Structural Styles in the Makran Accretionary Wedge–Insight from Physical Simulations

The Makran accretionary wedge has the smallest subduction angle among any accretionary prism in the world. The factors controlling the spacing and morphological development of its deep thrust faults, as well as the formation mechanism of shallow normal faults, remain unclear. Meanwhile, the factors affecting the continuity of plane faults must be comprehensively discussed. Clarifying the development characteristics and deformation mechanisms of the Makran accretionary wedge is crucial to effectively guide the exploration of gas hydrate deposits in the area. This study aims to interpret seismic data to identify typical structures in the Makran accretionary wedge, including deep imbricate thrust faults, shallow and small normal faults, wedge-shaped piggyback basins, mud diapirs with fuzzy and disorderly characteristics of reflection, décollements with a northward tilt of 1° – 2°, and large seamounts. Physical simulation-based experiments are performed to comprehensively analyze the results of the plane, section, and slices of the wedge. Results reveal that the distances between and shapes of thrust faults in the deep parts of the Makran accretionary wedge are controlled by the bottom décollement. The uplift of the thrust fault-related folds and the upwelling of the mud diapirs primarily contribute to the formation of small normal faults in the shallow part of the area. The mud diapirs originate from plastic material at the bottom, while those that have developed in the area near the trench are larger. Seamounts and mud diapirs break the continuity of fault plane distribution.

Insights into the dwarfing mechanism of pear(Pyrus betulaefolia) based on anatomical and structural analysis using X-ray scanning

The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.

Analysis of optical axis deviation caused by structural stiffness in equatorial telescopes

The impact of structural stiffness on optical axis deviation poses a significant challenge in the design of equatorial telescope structures.A comprehensive analysis during the design process can reduce the reliance of a telescope on advanced control technologies,thereby improving its economic feasibility.Although full-system finite element analyses are reliable,they are encumbered by significant time requirements and limitations in covering all possible telescope orientations.Therefore,we propose an efficient and comprehensive analytical method to evaluate the optical axis deviation of equatorial telescopes across a full range of angles.To address the challenge of ensuring that the analysis covers all possible positions of an equatorial telescope,based on a model from SiTian project,we analyze the optical axis deviations caused by the fork arm at 25 different angles and then use fitting methods to obtain results for all angles.Based on the analysis results of the optical axis deviation caused by the stiffness of the optical tube in the horizontal position,we derive the results for the tube at any position using geometric relationships.Finally,we calculate the coupling factors and combine these impacts.Furthermore,we identify six discrete feature points to reflect possible telescope orientations and conduct comprehensive finite element analyses.The results are in alignment with those acquired through a comprehensive computational approach.

Comparative Analysis of ARIMA and LSTM Model-Based Anomaly Detection for Unannotated Structural Health Monitoring Data in an Immersed Tunnel

Structural Health Monitoring(SHM)systems have become a crucial tool for the operational management of long tunnels.For immersed tunnels exposed to both traffic loads and the effects of the marine environment,efficiently identifying abnormal conditions from the extensive unannotated SHM data presents a significant challenge.This study proposed amodel-based approach for anomaly detection and conducted validation and comparative analysis of two distinct temporal predictive models using SHM data from a real immersed tunnel.Firstly,a dynamic predictive model-based anomaly detectionmethod is proposed,which utilizes a rolling time window for modeling to achieve dynamic prediction.Leveraging the assumption of temporal data similarity,an interval prediction value deviation was employed to determine the abnormality of the data.Subsequently,dynamic predictive models were constructed based on the Autoregressive Integrated Moving Average(ARIMA)and Long Short-Term Memory(LSTM)models.The hyperparameters of these models were optimized and selected using monitoring data from the immersed tunnel,yielding viable static and dynamic predictive models.Finally,the models were applied within the same segment of SHM data,to validate the effectiveness of the anomaly detection approach based on dynamic predictive modeling.A detailed comparative analysis discusses the discrepancies in temporal anomaly detection between the ARIMA-and LSTM-based models.The results demonstrated that the dynamic predictive modelbased anomaly detection approach was effective for dealing with unannotated SHM data.In a comparison between ARIMA and LSTM,it was found that ARIMA demonstrated higher modeling efficiency,rendering it suitable for short-term predictions.In contrast,the LSTM model exhibited greater capacity to capture long-term performance trends and enhanced early warning capabilities,thereby resulting in superior overall performance.

Generalized nth-Order Perturbation Method Based on Loop Subdivision Surface Boundary Element Method for Three-Dimensional Broadband Structural Acoustic Uncertainty Analysis

In this paper,a generalized nth-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems.The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field,and the nth-order discretization formulation of the boundary integral equation is derived.In addition,the computation of loop subdivision surfaces and the subdivision rules are introduced.In order to confirm the effectiveness of the algorithm,the computed results are contrasted and analyzed with the results under Monte Carlo simulations(MCs)through several numerical examples.

Dynamic Interaction Analysis of Coupled Axial-Torsional-Lateral Mechanical Vibrations in Rotary Drilling Systems

Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.

Structural failure analysis with CMS-based ground motion selection using innovative cost function and weight factors

The selection and scaling of ground motion records is considered a primary and essential task in performing structural analysis and design.Conventional methods involve using ground motion models and a conditional spectrum to select ground motion records based on the target spectrum.This research demonstrates the influence of adopting different weighted factors for various period ranges during matching selected ground motions with the target hazard spectrum.The event data from the Next Generation Attenuation West 2(NGA-West 2)database is used as the basis for ground motion selection,and hazard de-aggregation is conducted to estimate the event parameters of interest,which are then used to construct the target intensity measure(IM).The target IMs are then used to select ground motion records with different weighted vector-valued objective functions.The weights are altered to account for the relative importance of IM in accordance with the structural analysis application of steel moment resisting frame(SMRF)buildings.Instead of an ordinary objective function for the matching spectrum,a novel model is introduced and compared with the conventional cost function.The results indicate that when applying the new cost function for ground motion selection,it places higher demands on structures compared to the conventional cost function.Moreover,submitting more weights to the first-mode period of structures increases engineering demand parameters.Findings demonstrate that weight factors allocated to different period ranges can successfully account for period elongation and higher mode effects.

Contribution of mechanical forces to structural synaptic plasticity:insights from 3D cellular motility mechanisms

Cells,tissues,and organs are constantly subjected to the action of mechanical forces from the extracellular environment-and the nervous system is no exception.Cell-intrinsic properties such as membrane lipid composition,abundance of mechanosensors,and cytoskeletal dynamics make cells more or less likely to sense these forces.Intrinsic and extrinsic cues are integrated by cells and this combined information determines the rate and dynamics of membrane protrusion growth or retraction(Yamada and Sixt,2019).Cell protrusions are extensions of the plasma membrane that play crucial roles in diverse contexts such as cell migration and neuronal synapse formation.In the nervous system,neurons are highly dynamic cells that can change the size and number of their pre-and postsynaptic elements(called synaptic boutons and dendritic spines,respectively),in response to changes in the levels of synaptic activity through a process called plasticity.Synaptic plasticity is a hallmark of the nervous system and is present throughout our lives,being required for functions like memory formation or the learning of new motor skills(Minegishi et al.,2023;Pillai and Franze,2024).

Research status and prospects of the fractal analysis of metal material surfaces and interfaces

As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.

A Survey Study on TPACK Framework for Normal Students of English Major in Ethnic Colleges and Universities:Empirical Analysis Based on Structural Equation Modeling

With the continuous advancement of education informatization,Technological Pedagogical Content Knowledge(TPACK),as a new theoretical framework,provides a novel method for measuring teachers’informatization teaching ability.This study takes normal students of English majors from three ethnic universities as the research object,collects relevant data through questionnaires,and uses structural equation modeling to conduct data analysis and empirical research to investigate the differences in the TPACK levels of these students at different grades and the structural relationships among the elements in the TPACK structure.The technological pedagogical knowledge element of the TPACK structure was not obtained by exploratory factors analysis but through path analysis and structural equation modeling,the results show that the one-dimensional core knowledge of technological knowledge(TK),content knowledge(CK),and pedagogical knowledge(PK)have a positive effect on the two-dimensional interaction knowledge of technological content knowledge(TCK)and pedagogical content knowledge(PCK);furthermore,TCK and PCK have a positive effect on TPACK;and TK,CK,and PK indirectly affect TPACK through TCK and PCK.On this basis,suggestions are provided to ethnic colleges and universities to develop the TPACK knowledge competence of normal students of English majors.

Structural Modal Parameter Recognition and Related Damage Identification Methods under Environmental Excitations: A Review

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.

From single to combinatorial therapies in spinal cord injuries for structural and functional restoration

Spinal cord injury results in paralysis, sensory disturbances, sphincter dysfunction, and multiple systemic secondary conditions, most arising from autonomic dysregulation. All this produces profound negative psychosocial implications for affected people, their families, and their communities;the financial costs can be challenging for their families and health institutions. Treatments aimed at restoring the spinal cord after spinal cord injury, which have been tested in animal models or clinical trials, generally seek to counteract one or more of the secondary mechanisms of injury to limit the extent of the initial damage. Most published works on structural/functional restoration in acute and chronic spinal cord injury stages use a single type of treatment: a drug or trophic factor, transplant of a cell type, and implantation of a biomaterial. Despite the significant benefits reported in animal models, when translating these successful therapeutic strategies to humans, the result in clinical trials has been considered of little relevance because the improvement, when present, is usually insufficient. Until now, most studies designed to promote neuroprotection or regeneration at different stages after spinal cord injury have used single treatments. Considering the occurrence of various secondary mechanisms of injury in the acute and sub-acute phases of spinal cord injury, it is reasonable to speculate that more than one therapeutic agent could be required to promote structural and functional restoration of the damaged spinal cord. Treatments that combine several therapeutic agents, targeting different mechanisms of injury, which, when used as a single therapy, have shown some benefits, allow us to assume that they will have synergistic beneficial effects. Thus, this narrative review article aims to summarize current trends in the use of strategies that combine therapeutic agents administered simultaneously or sequentially, seeking structural and functional restoration of the injured spinal cord.

Multilevel analysis of the central-peripheral-target organ pathway:contributing to recovery after peripheral nerve injury

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and disabilities.Research on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites,neglecting multilevel pathological analysis of the overall nervous system and target organs.This has led to restrictions on current therapeutic approaches.In this paper,we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective,covering the central nervous system,peripheral nervous system,and target organs.After peripheral nerve injury,the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves;changes such as neuronal apoptosis and axonal demyelination occur in the spinal cord.The nerve will undergo axonal regeneration,activation of Schwann cells,inflammatory response,and vascular system regeneration at the injury site.Corresponding damage to target organs can occur,including skeletal muscle atrophy and sensory receptor disruption.We then provide a brief review of the research advances in therapeutic approaches to peripheral nerve injury.The main current treatments are conducted passively and include physical factor rehabilitation,pharmacological treatments,cell-based therapies,and physical exercise.However,most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ pathway.Therefore,we should further explore multilevel treatment options that produce effective,long-lasting results,perhaps requiring a combination of passive(traditional)and active(novel)treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

Theoretical research on structural damage alarming of long-span bridges using wavelet packet analysis

The state equation and observation equation of the structural dynamic systems under various analysis scales are derived based on wavelet packet analysis. The time-frequency properties of structural dynamic response under various scales are further formulated. The theoretical analysis results reveal that the wavelet packet energy spectrum （WPES） obtained from wavelet packet decomposition of structural dynamic response will detect the presence of structural damage. The sensitivity analysis of the WPES to structural damage and measurement noise is also performed. The transfer properties of the structural system matrix and the observation noise under various analysis scales are formulated, which verify the damage alarming reliability using the proposed WPES with preferable damage sensitivity and noise robusticity.

Autodesk Revit与Robot Structural Analysis应用在高桩码头的信息互通技术研究

本文提出Autodesk Revit与Robot structural analysis应用在高桩码头的信息互通技术,介绍了信息互通工具,比较了常见的信息传递流程,提出了利用软件优势互补,分布建模,多次传递的BIM三维建模与计算分析模型的传递流程,实现三维建模与计算分析的双向链接,并提出了现阶段高桩码头三维建模与计算分析中无法实现无缝链接的原因和解决方案。

Structural Complexity Analysis of Information Systems Based on Petri Nets

Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in general net theory(GNT), a quantitative method for structure description and analysis of information systems was introduced. Results The structural complexity index and two related factors, i.e. element complexity factor and connection complexity factor were defined, and the relations between them and the parameters of the Petri net based model of the system were derived. Application example was presented. Conclusion The proposed method provides a theoretical basis for quantitative analysis and evaluation of the structural complexity and can be applied in the general planning and design processes of the information systems.