Operation Mechanism Research Articles

Mn vacancy engineering design of Fe/Mn based cathodes for breaking the spell between “sodium limiting” in air-stabilization and “sodium promoting” on kinetics

Fe/Mn-based cathode is considered a viable choice for sodium-ion batteries (SIBs) because of its affordability and high theoretical capacity. Nonetheless, bad actually comprehensive performance still impede its commercial application. In this work, based on the systematic study of P2-Na2/3Fe1/2Mn1/2O2 cathode materials with fewer Mn vacancies (NFM-Q), we realized a superior rate, cycling performance, air stability and more importantly unraveled the operation mechanism. Specifically, dual function of fewer Mn vacancies were explicitly clarified, which included the effect of shrinking sodium layers and the sodium-ion diffusion promoting effect, as confirmed by combining XRD, XANES, XAFS, EIS and GITT. So Mn vacancy engineering had the potential to break the contradiction between “sodium limiting” based on air-stabilization mechanism and “sodium promoting” based on kinetics. This has rarely been found before. And a series of characterizations strongly declared rapidly cooling rate could effectively regulated the creation of Mn vacancies. As a result, NFM-Q cathode not only delivered outstanding discharge capacity (192.7 mAh/g), cycling stability (123.8 mAh/g, 65 %, after 50 cycles) and energy density (574.0 Wh Kg−1), but also possessed splendid air stability (185.8 mA h/g, 61.8 % after 50 cycles and immersion). Moreover, ex-situ XRD and XAS further expounded structural evolution and charge compensation mechanism of NFM-Q cathode, confirming its superior performance. This work might offer fresh understanding about the roles of Mn vacancy engineering, which could open up new possibilities on the material design and the property improvement of Fe/Mn-based cathodes.

Impact of piezoelectric driving waveform on performance characteristics of vibrating mesh atomizer (VMA)

Vibrating mesh atomizer (VMA) is a specific type of ultrasonic atomizer known for its low power consumption and production of uniformly fine droplets. While previous research has provided a basic understanding of VMA operation, it has primarily focused on driving the piezoelectric actuator with continuous and symmetrical waveforms, such as sine and square waveforms. This study aims to experimentally investigate the impact of different driving waveforms on the ultrasonic atomization process and the associated performance characteristics. Specifically, the effects of pulse waveforms (Gauss and Lorentz pulse) were analyzed with high rates of energy deposition and asymmetrical hybrid waveforms (trapezia and absolute sine), featuring distinct negative cycles, by comparing them with conventional symmetrical waveforms (sine and square). Pulse waveforms suppress the growing stage but provide a high flux of input energy, facilitating the detachment of liquid into fine droplets, resulting in uniformly distributed droplets with VMDs of 5.84 μm and 4.71 μm for Gauss and Lorentz waveforms, respectively. Conversely, shorter negative cycles in asymmetrical hybrid waveforms reduce liquid suction into the micronozzle, leading to higher energy flux during subsequent positive cycles that promote the growing stage, producing larger droplets with VMDs of 10.82 μm and 11.86 μm for trapezia and absolute (abs) sine waveforms, respectively. Additionally, high-speed imaging reveals irregular pulsating behaviors in the atomization process when using pulse waveforms, suggesting a reciprocating-pump-like operation mechanism in VMA atomization. These new insights contribute to an improved understanding of the atomization mechanism in VMAs.

Recent Advancements in Nanomaterials for Near‐Infrared to Long‐Wave Infrared Photodetectors

AbstractNanomaterials have superior electronic, optical, and mechanical properties making them highly suitable for a range of applications in optoelectronics, biomedical fields, and photonics. Nanomaterials‐based IR detectors are rapidly growing due to enhanced sensitivity, wide spectral range, and device miniaturization compared to commercial photodetectors. This review paper focuses on the significant role of nanomaterials in infrared detection, an area critical for enhancing night vision and health monitoring technologies. The latest advancements in IR photodetectors that employ various nanomaterials and their hybrids are discussed. The manuscript covers the operational mechanisms, device designing, performance optimization strategies, and material challenges. This review aims to provide a comprehensive overview of the current developments in nanomaterial‐based IR photodetectors and to identify key directions for future research and technological advancements.

Microscopic Origin of Polarity-Dependent VTH Shift in Amorphous Chalcogenides for 3D Self-Selecting Memory.

Ovonic threshold switching (OTS) selectors based on amorphous chalcogenides can revolutionize 3D memory technology owing to their self-selecting memory (SSM) behavior. However, the complex mechanism governing the memory writing operation limits compositional and device optimization. This study investigates the mechanism behind the polarity-dependent threshold voltage shift (ΔVTH) through theoretical and experimental analyses. By examining the physical principles of threshold switching and conducting defect state analysis, the ΔVTH as a memory window is confirmed to be attributed to the dynamics of charged defects and their gradient near electrodes, influenced by the nonuniform electric field after threshold switching. This study provides critical insights into the operational mechanism of OTS-based SSM, known as selector-only memory, highlighting its advantages for developing high-density, low-cost, and energy-efficient memory technologies in the artificial intelligence era.

A Comprehensive Review of Unmanned Aerial Vehicle (UAV) Sprayers Used in Modern Agriculture

Global demand for food is increasing daily due to increase in population growth. Hence to meet these food demands for the growing population crop productivity must be enhanced. Plant pests and diseases are major threats to crop productivity causing an annual reduction of 20 to 40% in global crop production. For management of these pest and diseases spraying using manual sprayers is quite laborious and also not precise. Further manual spraying is hazardous to farmer’s health, World Health Organization (WHO) reported one million incidences of illness as a result of manually application of insecticides to crop fields. As a result, new automated drone technology techniques were unveiled. This review examines the application of Unmanned Aerial Vehicle (UAV) sprayers in modern agriculture, highlighting their transformative role in enhancing crop management and increasing efficiency. UAV technology has emerged as a vital tool for precision agriculture, offering benefits such as targeted pesticide and fertilizer application, reduced labor costs, and minimized environmental impact. This paper discusses the various types of UAV sprayers, their operational mechanisms, and the advantages they provide over traditional methods. Additionally, we explore challenges associated with UAV adoption, including regulatory issues, technical limitations, and the need for operator training. The review emphasizes the future potential of UAV sprayers in sustainable agriculture, suggesting that continued advancements in technology and regulatory frameworks will further integrate UAVs into mainstream agricultural practices.

Design and Fabrication of SCARA for Image Processing in Industry

The scope of our project is the design and fabrication of SCARA (Selective Compliance Articulated Robot Arm) robots optimized for image processing tasks within industrial environments. This report presents a comprehensive review of the design, control, and applications of SCARA robots, focusing on their integration with image processing technologies to enhance industrial automation. We delve into the underlying principles governing the kinematics and dynamics of SCARA robots, elucidating their operational mechanisms and capabilities. Advancementsin end-effector design and sensor integration have enhanced the adaptability of SCARA robots, enabling them to tackle complex tasks in unstructured environments.

RF NEMS switches based on graphene for low pull-in voltage and excellent RF performance

This study introduces a novel graphene RF NEMS capacitive switch and conducts an extensive analysis of its RF performance using CST and COMSOL Multiphysics software. The switch’s characteristic impedance matching is accomplished through a coplanar waveguide (CPW) structure, incorporating a dielectric layer topped with conductive graphene beam electrodes. Simulation results reveal that the monolayer graphene RF NEMS switch maintains an insertion loss of 0.003 ~ 0.015 dB and an isolation greater than 40 dB across an ultra-wideband (UWB) frequency range of DC ~ 140 GHz. Moreover, the switch demonstrates a switching time of 4.03 ps at a pull-in voltage of 1 V. The performance of multilayer graphene RF NEMS switches was also evaluated. The study further investigates the operational mechanism of the graphene RF NEMS switch and performs finite element analysis on the proposed design. The graphene RF NEMS switch discussed herein offers significant advantages, including minimal size, lightweight, cost-effectiveness, low pull-in voltage, rapid response time, excellent RF performance, and reduced space consumption in circuitry. Its potential applications span a range from L to F bands, encompassing data storage, communication systems, sensors, remote sensing and military uses.

Synthesis of dynamic modelling framework and optimal control strategy for virtually coupled train sets with guaranteed safety

Virtual coupling represents a novel railway operational mechanism, wherein several trains share state information and adjust their behaviours based on control objectives, which include safety (collision avoidance) assurance and stability (uniform velocity and constant spacing between trains) maintenance. However, the conflict between safety and stability requirements becomes more apparent, as the closer spacing between trains. Moreover, the hybrid nature of the train platoon operation, which involves both discrete events and continuous dynamics, also poses a significant barrier to the control strategy synthesis. This paper presents the Virtually Coupled Train Sets (VCTS) dynamic modelling framework and strategy synthesis approach to address these problems. A Hybrid Markov Decision Process (HMDP) is adopted for relative longitudinal dynamics modelling of trains, considering the influence of the uncertainty dynamic of trains ahead. A Stackelberg game-based strategy synthesis algorithm is applied for the safe guarantee by overcoming the uncertainty, and a Q-learning method is used for stability strategy selection from the safe strategy. The results showed a 17.95% expansion in the safe state space when compared to the general relative braking scheme (which assumes maximal acceleration during the delay horizon). In a four-train tracking operation scenario, compared with Q-learning without safe constraints, our approach gives similar stability performance; compared with Q-learning with general relative braking safe constraints, our approach not only assurance safety but has a better stability performance.

Analysis of knowledge services efficiency and influencing factors of public libraries in China: a mixed study based on the SBM model and dynamic QCA

PurposeThe core objective of this study is to provide an in-depth quantitative assessment of the efficiency of public library knowledge services (PLKS) in China and to scrutinize the factors that have a significant impact on the efficiency of PLKS. Furthermore, this study also aims to examine the characteristics and evolving patterns of PLKS in China and to propose strategies for enhancing the quality of services provided by public libraries. The findings of this paper are expected to provide valuable references for current academic research and practice areas, guiding and promoting exploration and development in related fields.Design/methodology/approachTo analyse and evaluate the operation mechanism and efficiency of PLKS, this study creatively constructs a multi-stage PLKS efficiency evaluation model and provides related indicators. Based on this process, the super-efficiency network slacks-based measure model was used to analyse the efficiency, and dynamic qualitative comparative analysis was adopted to analyse the recipes about the influencing factors of PLKS. Ultimately, through a comprehensive interpretation of the measured data and the integration of extant societal development conditions, the authors put forth relevant recommendations.FindingsIn the first stage, PLKS in China meets the basic requirements, but in the second stage, there is evident resource wastage. In addition, there are five recipes in PLKS of China. These five recipes reveal the configuration relationship between the factors that affect PLKS. The results show that PLKS in China are different in different regions, and the effects of the influencing factors are also different.Originality/valueIn this study, the authors provide an exhaustive deconstruction and interpretation of PLKS, thereby proposing a three-stage PLKS efficiency conversion process. Furthermore, the authors have identified a set of readily accessible and quantifiable indicators. It is worth emphasizing that the authors have taken a unique approach to analyse the elements affecting PLKS from the perspective of configuration, which has significantly broadened the boundaries and depth of PLKS research.

Empowerment of Farmers Through GAPOKTAN to Improve Farmers' Welfare

The general background the empowerment of farmers is crucial for improving their welfare and ensuring sustainable agricultural development. Specific background This study focuses on the role of Farmer Group Associations (GAPOKTAN) in Dukuhsari Village as a platform for farmer empowerment. Knowledge gap Despite the recognized importance of farmer groups in community development, there is limited understanding of how these associations function to enhance farmers' welfare in specific contexts. Aims the research aims to analyze and describe the effectiveness of GAPOKTAN in empowering farmers within Dukuhsari Village. Results the findings indicate that GAPOKTAN has successfully facilitated the fulfillment of farmers' basic needs, improved access to resources, and fostered critical awareness among farmers. Participation of farmers in group activities has been instrumental in enhancing their involvement in agricultural management and empowerment processes. Novelty this study contributes to the existing literature by providing empirical evidence on the operational mechanisms of GAPOKTAN in a local context, highlighting its multifaceted role in promoting welfare among farmers. Implications the results suggest that strengthening GAPOKTAN and similar associations can lead to more effective agricultural policies and community development initiatives, ultimately contributing to better living standards for farmers and sustainable agricultural practices. Highlights: GAPOKTAN plays a crucial role in fulfilling farmers' basic needs. Participation in farmer groups enhances farmers' involvement in agricultural management. Critical awareness among farmers leads to better access to resources and support. Keywords: Farmer Empowerment, GAPOKTAN, Welfare, Participation, Community Development

Fault isolation considering real mechanical coupling effects with application to liquid oxygen/kerosene staged combustion rocket engines

Liquid rocket engines are crucial for space exploration, necessitating reliable fault diagnosis systems. This paper focuses on fault isolation in liquid oxygen (LOX)/kerosene staged combustion rocket engines. Addressing deficiencies in current methods, we first propose a theorem to evaluate the adaptability between the analytical model and fault factors based on available sensors. Through the analysis of fault mechanisms, this paper defines fault modes using an innovative multi-factor coupling approach based on engine operational principles. Moreover, a fault isolation method with two steps is established, incorporating the optimal selection of sensors to accommodate robust requirements. This method features a clear process, low computational complexity, and comprehensive fault coverage, and it can also be applied to systems with similar complex operational mechanisms.

A novel and effective method for characterizing time series correlations based on martingale difference correlation.

Analysis of correlation between time series is an essential step for complex system studies and dynamical characteristics extractions. Martingale difference correlation (MDC) theory is mainly concerned with the correlation of conditional mean values between response variables and predictor variables. It is the generalization and deepening of the Pearson correlation coefficient, Spearman correlation coefficient, Kendall correlation coefficient, and other statistics. In this paper, on the basis of phase space reconstruction, the generalized dependence index (GDI) is proposed by using MDC and martingale difference divergence matrix theories, which can measure the degree of dependence between time series more effectively. Moreover, motivated by the theoretical framework of the refined distance correlation method, the corresponding dependence measure (DE) is employed in this paper to construct the DE-GDI plane, so as to comprehensively and intuitively distinguish different types of data and deeply explore the operating mechanism behind the relevant time series and complex systems. According to the performances tested by the different simulated and real-world data, our proposed method performs relatively reasonably and reliably in dependence measuring and data distinguishing. The proposal of this complex data clustering method can not only recognize the features of complex systems but also distinguish them effectively so as to acquire more relevant detailed information.

Core Technologies of Sugarcane Chopper Harvester Extractor: A Critical Review

This review has systematically assessed the critical technologies of impurity removal fans in segmental sugarcane harvesters, highlighting their impact on minimizing harvester impurity rates. The analysis was conducted from three perspectives: Firstly, the physical properties of flexible sheet-like materials were thoroughly examined, including the methodologies for material parameter measurement, the utilization of technical approaches, and the constraints of existing methods. Secondly, the operational mechanisms of impurity removal fans were elucidated, encompassing their working principles, research subjects, and technical methodologies, and compared with the mechanisms of analogous fluid machinery. Lastly, a review of the structural design and parameters of impurity removal fans was undertaken, analyzing the interplay between operational modes, structural optimization designs, and aerodynamic characteristics. The review identified key issues in the design and performance of impurity removal fans and recognized the challenges in technological advancement. Through this triadic analytical framework, the review has identified salient design and performance deficiencies within existing impurity expulsion fan technologies and has underscored the formidable challenges confronting technological evolution in this domain. Synthesizing these insights, the review proffered prospective research vectors and avant-garde technological interventions poised to augment the operational efficacy of impurity expulsion fans, with the overarching goal of enhancing the operational proficiency of sugarcane harvesting machinery.

Economic Development and the Development of the Securities Market: A Study of China's CSI 300 Index

The Chinese securities market has experienced over two decades of development and has emerged as a significant global investment market. However, compared to other developed securities markets, it still faces issues such as an inadequate institutional framework, irrational investor behavior, and imperfect mechanisms. To explore the relationship between China's economic development and its securities market, this paper employs Eviews time series analysis and VAR modeling for empirical research, aiming to uncover the relationship and operational mechanisms between the two. The findings indicate a certain correlation between economic development and securities market development in China. The variance decomposition reveals that the contribution of economic development to the securities market is relatively low, highlighting a major issue within the Chinese securities market. Consequently, this paper proposes reform suggestions from various perspectives, including institutional, investor, and listed company aspects, to guide the healthy growth of the Chinese securities market and create a favorable environment for economic development.

A descriptive study of differential stuck pipe problem in Nahr Umr oil field: principles and treatments

Differential-pressure pipe sticking is one of the main problems that occurs during drilling operations, leading to an increase in the non-productive time (NPT). To address this problem, the industry uses a range of spotting fluids to enable the recovery of a differentially stuck pipe effectively. Thus, any delay in solving this problem can turn into a difficult rescue operation that can eventually lead to the abandonment of the well in extreme conditions. Therefore, it is crucial to choose the appropriate spotting fluid that is suitable for the specific mud composition, as using an unsuitable spotting fluid may result in dangerous conditions. Additionally, other factors can further complicate the process of freeing a stuck pipe. Therefore, for prevention, remediation, and enhancing the recovery of stuck pipes, it is important to understand the root causes of the pipe sticking issue, the conditions that lead to it, and the operational mechanisms of various spotted fluids and their application areas. This paper studies the challenges of pipe sticking during drilling operations, particularly emphasizing differential pipe sticking, and the role of spotting fluids in releasing pipe sticking. It discusses the testing and evaluation methods used to choose appropriate spotting fluids while rejecting the inferior options, highlighting the benefits and disadvantages. This study, which was conducted at Well NR-A in the Nahr Umr field in southeastern Iraq, aims to address the problem of differential stuck pipes. By employing a stuck pipe list check table, the mechanism of this problem was diagnosed, resulting in a thorough analysis of the causes of differential stuck pipe and subsequent steps necessary to release the stuck pipe. Finally, recommendations are presented to improve testing and evaluation methods, overcoming the limitations of conventional methods.

Research on Mechanisms for University Connotation Construction and High-Quality Employment in the Context of New Quality Productivity

The introduction of the concept of new quality productivity has attracted a great deal of attention in the educational community. However, there is an urgent need to align it with policy orientation and advancements in science and technology moving forward. Colleges and universities themselves should be the leaders of advanced thinking and scientific and technological development, and play their due roles in line with the development of the times to provide quality and urgent talents and intellectual support. For this reason, this paper proposes that universities should consciously establish a set of regular operation mechanisms, namely, the linkage mechanism between “social demand” and “connotation construction,” and operate regularly under the guarantee of the system. This enables universities to lead or grasp the pulse of scientific and technological development, constantly improve the level of connotation construction, promote high-quality employment, and provide high-quality services for modernization and the great rejuvenation of the Chinese nation.

The Operation Strategy of a Multi-Microgrid Considering the Interaction of Different Subjects’ Interests

As the share of renewable energy generation continues to increase, the new-type power system exhibits the characteristics of coordinated operation between the main grid, distribution networks, and microgrids. The microgrid is primarily concerned with achieving self-balancing between power sources, the network, loads, and storage. In decentralized multi-microgrid (MMG) access scenarios, the aggregation of distributed energy within a region enables the unified optimization of scheduling, which improves regional energy self-sufficiency while mitigating the impact and risks of distributed energy on grid operations. However, the cooperative operation of MMGs involves interactions among various stakeholders, and the absence of a reasonable operational mechanism can result in low energy utilization, uneven resource allocation, and other issues. Thus, designing an effective MMG operation strategy that balances the interests of all stakeholders has become a key area of focus in the industry. This paper examines the definition and structure of MMGs, analyzes their current operational challenges, compiles existing research methods and practical experiences, explores synergistic operational mechanisms and strategies for MMGs under different transaction models, and puts forward prospects for future research directions.

Operating Mechanism Principles and Advancements for Halide Perovskite-Based Memristors and Neuromorphic Devices.

With the advent of the generation of artificial intelligence (AI) based on big data-processing technologies, next-generation memristor and memristive neuromorphic devices have been actively studied with great interest to overcome the von Neumann bottleneck limits. Among various candidates, halide perovskites (HPs) have been in the spotlight as potential candidates for these devices due to their unique switching characteristics with low energy consumption and flexible integration compatibility across various sources for scalability. We outline the characteristics and operating principles of HP-based memristors and their neuromorphic devices. We explain filamentary- and interface-type switching according to the type of conducting pathway occurring inside the active HP layer and the operating mechanisms depending on the species that make up this conducting pathway. We summarize the types and mechanisms of current changes beneficial for neuromorphic device applications and finally organize various suggested analysis tools and physical models to enable experimental determination of switching mechanisms from various perspectives.

The Function of International Law in Modern International Relations: A Constructivist Perspective

Following World War II, the ongoing process of globalisation led to a proliferation of international conflicts and disputes, prompting an increase in the application and regulation of international law. International law, as a legally binding framework for the rights and responsibilities of sovereign states and other entities with international status, has been crucial in reducing global strife, maintaining peace and promoting cooperation. The post-Cold War era coincided with the rise of constructivist theory, which offers a sociological perspective on world politics, emphasising social normative structures over economic material ones. This perspective underscores the influential role of ideas, norms, and culture in shaping state behaviour constructively. Theoretically, constructivist theories within international relations elucidate the legal function of international law while bolstering its authority and status; thereby further explaining its significance within global affairs. The research encompasses three main components: First, an exploration of the theoretical underpinnings of international law and an analysis of constructivism within the field of international relations will be presented. Secondly, a detailed examination of specific operational mechanisms in modern international relations and their contribution to establishing an orderly framework will be undertaken; and thirdly case analysis to examine how these mechanisms have influenced specific events thus revealing their practical impact. Ultimately concluding that as a normative institutional construct, international law has significantly contributed towards rule-making processes conflict resolution efforts as well as maintaining order within global relations while also highlighting that its construction is an ongoing evolutionary process necessitating continual adjustment within the broader context.

Analyzing the innovation ecosystem of China's major science and technology projects: From the ecological and systems science perspective

The National Major Science and Technology Projects in China are characterized by government leadership, interdisciplinary collaboration, and international cooperation. However, challenges such as insufficient innovation capacity and inadequate commercialization of scientific achievements are becoming increasingly prominent. This paper adopts the conceptual framework of natural ecology to examine these projects. By utilizing theories and methods from ecology and systems science, we draw an analogy between the innovation ecosystem of China's national major science and technology projects and the structure of ecological systems, analyzing the interrelationships among the components of the innovation ecosystem and establishing the four-level model. The findings indicate that collaboration and policy guidance among the enterprise, research, and auxiliary innovation layers promote scientific output and innovation, while the external environmental layer provides robust support and safeguards, collectively driving the development of the innovation ecosystem. We study the operational mechanisms of the innovation ecosystem in depth, identifying mechanisms of competitive symbiosis, coordination, and sharing. These mechanisms work together throughout the project management process, offering new insights for enhancing the scientific and effective management of these projects. The national innovation ecosystem and high-quality development mutually reinforce and complement each other. As a critical pathway to high-quality development, our study provides new approaches to addressing the challenges of insufficient innovation capacity and the difficulty in translating scientific achievements into practice, contributing to the optimization of resource allocation, and the deep integration of technological innovation with economic and social development.