Optimal Configuration of Fault Location Measurement Points in DC Distribution Networks Based on Improved Particle Swarm Optimization Algorithm

The escalating deployment of distributed power sources and random loads in DC distribution networks hasamplified the potential consequences of faults if left uncontrolled. To expedite the process of achieving an optimalconfiguration of measurement points, this paper presents an optimal configuration scheme for fault locationmeasurement points in DC distribution networks based on an improved particle swarm optimization algorithm.Initially, a measurement point distribution optimization model is formulated, leveraging compressive sensing.The model aims to achieve the minimum number of measurement points while attaining the best compressivesensing reconstruction effect. It incorporates constraints from the compressive sensing algorithm and networkwide viewability. Subsequently, the traditional particle swarm algorithm is enhanced by utilizing the Haltonsequence for population initialization, generating uniformly distributed individuals. This enhancement reducesindividual search blindness and overlap probability, thereby promoting population diversity. Furthermore, anadaptive t-distribution perturbation strategy is introduced during the particle update process to enhance the globalsearch capability and search speed. The established model for the optimal configuration of measurement points issolved, and the results demonstrate the efficacy and practicality of the proposed method. The optimal configurationreduces the number of measurement points, enhances localization accuracy, and improves the convergence speedof the algorithm. These findings validate the effectiveness and utility of the proposed approach.

公众参与合作生产的动机图谱及其影响——价值共创视角下的混合研究

“以人民为中心”的发展理念引领着社会治理创新。如何与公众有效互动,从而更好地实现公共价值,是政府决策部门高度关注的问题。论文基于以价值共创为新趋势的合作生产理论,围绕激励公众深度参与合作生产这一核心议题,采用混合研究方法,重新审视和解释公众合作生产行为,并挖掘行为背后的微观机理——合作生产动机。研究发现,为实现合作生产的公共价值最大化,既需要公众通过参与型合作生产行为回应政府期望,也依赖于公众表现出超越政策遵从的公民型合作生产行为。利益权衡型动机、互动体验型动机和价值引领型动机是促使公众参与合作生产的关键动机归因,不同动机之间的相互作用也会共同影响公众合作生产行为的尺度和水平。论文将建立在价值共创基础上的合作生产理论拓展到微观的行为公共管理领域,丰富了价值共创视角下公众参与合作生产的本土化研究,也为培育积极的公众主体提供了重要指引。

玄武岩及其混合料断裂性能浅析

本文对钢—玄武岩混杂纤维混凝土的增韧效果进行了试验研究。钢纤维掺量为0%,1%,1.3%,1.6%,玄武岩纤维掺量为0%,0.05%,0.1%,0.15%,每组三个试件。通过预制缺口梁的P-CMOD曲线计算得出了混杂纤维混凝土的断裂能和断裂韧度。

Automatic extraction method of force chain information and its application in the flow photoelastic experiment of granular matter

The force chain is the core of the multi-scale analysis of granular matter.Accurately extracting the force chain information among particles is of great significance to the study of particle mechanics and geological hazards caused by particle flow.However,in the photoelastic experiment,the precise identification of the branching points of force chains has not been effectively realized.Therefore,this study proposes an automatic extraction method of force chain key information.First,based on the Hough transform and the Euclidean distance,a particle geometric information identification model is established and geometric information such as particle circle center coordinates,radius,contact point location,and contact angle is extracted.Then,a particle contact force information identification model is established following the color gradient mean square method.The model realizes the rapid calibration and extraction of a large number of particle media contact force information.Next,combined with the force chain composition criterion and its quasilinear feature,an automatic extraction method of force chain information is established,which solves the problem of the accurate identification of the force chain branch points.Finally,in the photoelastic experiment of ore drawing from a single drawpoint,the automatic extraction method of force chain information is verified.The results show that the macroscopic distribution of force chains during ore drawing from a single drawpoint is left–right symmetrical.Strong force chains are mostly located on the two sides of the model but in small numbers and they mainly develop vertically.Additionally,the ends are mostly in a combination of Y and inverted Y shapes,while the middle is mostly quasilinear.Weak force chains are abundant and mostly distributed in the middle of the model,and develop in different directions.The proposed extraction method accurately extracts the force chain network from the photoelastic experiment images and dynamically characterizes the force chains of granular matter,which has significant advantages in particle geometry information extraction,force chain branch point discrimination,force chain retrieval,and force chain distribution and its azimuthal characterization.The results provide a scientific basis for studying the macroscopic and microscopic mechanical parameters of granular matter.

Design and evaluation of the traveling wave piezoelectric beam actuators

Traveling wave piezoelectric beam actuators(TWPBAs)present an advantageous structural configuration for self-moving actuators and hold significant promise for operation in confined spaces.However,current research on TWPBAs faces several limitations,including deficient design methods of excitation and structural parameters,inadequate evaluation metrics,and lack of a quantitative relationship between these parameters and evaluation metrics.This study presents a systematic approach to determining TWPBAs'structure and excitation parameters,proposes criteria for determining the excitation parameters through an established analytical model,and introduces an effective evaluation method for TWPBAs'driving.Through the analytical model and evaluation metrics,we reveal:(1)the coupling relationship between excitation parameters and structural parameters,(2)the influence of participating mode pairs on vibration response,(3)the quantitative relationship between the evaluation metrics and excitation parameters is also revealed.These conclusions are substantiated by the results of finite element analysis,laser vibration measurements,and motion test experiments.Notably,the practical application of TWPBAs in pipeline operations underscores their potential for use in endoscopy and precision instruments.

附生蕨类植物的克隆性研究进展

石松类及蕨类植物在高等植物中处于比较特殊的进化与系统发育地位,同时具有孢子植物(孢子)与种子植物(维管束)的双重特征。附生蕨类植物是蕨类植物中占据独特生境的一个大类群,其生活史策略及进化历史与其附生生长的森林生态系统紧密相关。大部分附生蕨类植物的克隆生长习性及克隆生活史性状在其生态适应中具有重要作用,但这方面未引起广泛关注。本文主要综述了中国山地森林中附生蕨类植物的根状茎克隆生长、克隆性与生态适应性、不同克隆生长方式与进化等方面,并展望了蕨类植物克隆性在森林生态系统过程与功能中的作用,以及今后如何将蕨类植物生态学研究与气候变化、植被恢复、土地利用变化等全球变化的主流方向进行结合。

Implementing fractional Fourier transform and solving partial differential equations using acoustic computational metamaterials in space domain

Metamaterials can control incident waves in the sub-wavelength range through the design of artificial structures, and realize the functions that natural materials cannot achieve. The study of metamaterials has important theoretical value and application prospects. In recent years, the proposal of computational metamaterials has opened up a brand-new direction for analog computing, providing high-throughput, energy-free computing methods for special computing tasks. However, the development of acoustic computing metamaterials is relatively preliminary, and it is necessary to develop design theories. There is no work to solve partial differential equations and realize fractional Fourier transform in spatial domain acoustic computing metamaterials. In this paper, the acoustic wave computational metamaterial is designed, and the simulation realizes the spatial domain fractional Fourier transform and partial differential equation calculation. It is expected that acoustic computational metamaterials will enable new capabilities in signal acquisition and processing, network computing, and drive new applications of sound wave.

Engineered nanoparticles for precise targeted drug delivery and enhanced therapeutic efficacy in cancer immunotherapy

The advent of cancer immunotherapy has imparted a transformative impact on cancer treatment paradigms by harnessing the power of the immune system.However,the challenge of practical and precise targeting of malignant cells persists.To address this,engineered nanoparticles(NPs)have emerged as a promising solution for enhancing targeted drug delivery in immunotherapeutic interventions,owing to their small size,low immunogenicity,and ease of surface modification.This comprehensive review delves into contemporary research at the nexus of NP engineering and immunotherapy,encompassing an extensive spectrum of NP morphologies and strategies tailored toward optimizing tumor targeting and augmenting therapeutic effectiveness.Moreover,it underscores the mechanisms that NPs leverage to bypass the numerous obstacles encountered in immunotherapeutic regimens and probes into the combined potential of NPs when co-administered with both established and novel immunotherapeutic modalities.Finally,the review evaluates the existing limitations of NPs as drug delivery platforms in immunotherapy,which could shape the path for future advancements in this promising field.