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关键词： Least squares approximations  

摘要： Since DC transient fault signals lack a fundamental frequency component and line parameters exhibit significant frequency-dependent characteristics, the R-L or Π type line-model based methods struggle to achieve accurate fault location in DC distribution lines. Leveraging the characteristic that voltage is evenly distributed along the healthy line, this paper proposes an accurate fault location method for DC distribution systems by utilizing voltage signals from both ends of the line and two additional measurement points along the line. A distance backup protection scheme based on this fault location method is also designed. The proposed approach applies a least squares algorithm to solve an overdetermined system of equations, thus enhancing the accuracy and reliability of fault location. A three-terminal DC distribution simulation model is built in PSCAD/EMTDC using a frequency-dependent phase-domain line model, and the effectiveness and robustness of the proposed fault location method are verified under different fault positions, fault resistances, noise environments, and positions of the voltage signal. © 2025 Power System Protection and Control Press. All rights reserved.

关键词： Smart Biomaterials  

摘要： Dynamic fluorescent materials capable of stimulus-responsive emission modulation have emerged as pivotal components in next-generation information security systems. This study presents a novel photoresponsive fluorescent composite system in which spiropyran (SP) was covalently grafted onto naphthalimide-functionalized silica aerogel matrices. These architectures exhibit reversible fluorescence resonance energy transfer between the naphthalimide donors and merocyanine-form of SP acceptors under ultraviolet irradiation, enabling dynamic emission shifting from green (blue) to red. The aggregation-induced emission characteristics of SP were used to engineer a smart material system that can reversibly regulate its distinct red fluorescence by precisely controlling the dispersion of amino groups on naphthalimide-functionalized silica aerogels. This spatial manipulation directly governs the molecular packing state of SP, enabling dynamic fluorescence modulation. A programmable control over the fluorescence chromatic transitions in the composite material was achieved by systematically adjusting the SP grafting densities (1%, 2%, and 3% w/w). A unique mode of dynamic information encryption technology was developed by utilizing dynamic fluorescence variations. These materials can substantially enhance information encryption levels due to their precisely adjustable fluorescence properties in response to external stimuli over time. This makes the encryption process even more unpredictable and complex, thereby exponentially increasing the difficulty for unauthorized parties to replicate or decode the encrypted information. (Figure presented.) © Science China Press 2025.

关键词： Energy utilization  

摘要： A digital twin model of an integrated energy system (IES) is established, incorporating an integrated energy system operator (IESO), an energy supplier (ES) equipped with carbon capture system (CCS), and a load aggregator (LA) that considers demand response. First, the IES system model is constructed, with tailored constraints for different system components and the introduction of a penalty mechanism for wind and solar curtailment. Then, an IES distributed cooperative optimal operation strategy based on a leader-follower (Stackelberg) game is adopted, and the strategy is solved by combining genetic algorithm and quadratic programming algorithm to obtain the optimal IES scheduling scheme. In this game theory framework, IESO acts as the lead player, while the CCS-based ES and the demand response LA act as followers, jointly optimize the IESO’s pricing strategy, ES contribution plan, and user demand schedules. Real-time IES data is obtained by the digital twin system. After the data of different dimensions and formats are processed and analyzed in a unified manner, the proposed method is used to optimize the IES optimal decision scheme. Finally, by using the digital twin model to obtain the basic operation data, simulation experiments based on the extended IEEE 39-node system and 6-node heating system yield IESO optimal price strategy, ES optimal output plan, and LA optimal energy use plan, leading to more economical energy supply and more rational energy consumption. The leader-follower game-based decision-making method based on a digital twin model, allows the power grid to move beyond heavy reliance on historical data, reduces extrapolation errors in decision-making, and enables a technical upgrade in IES optimization strategies. © 2025 Power System Protection and Control Press. All rights reserved.

关键词： 新课标   初中篮球教学   信息化教学   实践研究   体育与健康  

摘要： 在新课标背景下初中篮球教学有效融合信息化教学手段,能提升教学效率、增强学生兴趣,并全面培育学生的篮球技能与综合素养.鉴于信息技术的飞速发展与新课标实施的双重驱动,初中篮球教学正迎来前所未有的变革机遇.文章通过深度实践分析,重点考察信息化教学在初中篮球教学中的实施策略、成效评估及存在问题,并据此提出有针对性的改进建议.此外,文章尝试构建一套符合体育与健康新课标要求的信息化篮球教学模式,旨在为初中篮球教学的改革与创新提供坚实的理论依据与实践路径.

关键词： 信息化教学   中职英语   课程思政  

摘要： 中职英语课程思政是落实立德树人根本任务的核心举措.因此,中职英语教师需借助丰富的信息化教学手段,在教育理念、教学目标、教学内容、教学手段、教学评价等方面做出改进和调整,将思想政治教育有机融入中职英语课程教学的全过程,发挥中职英语课程的育人功能,以培养全面发展的高素质技能人才.

关键词： 产业链   协同创新   高质量发展   制造业  

摘要： 为推动制造业高质量发展,以产业链上下游协同创新模式为背景,探讨了制造业高质量发展的重要路径.首先阐述了造业发展的必然性,然后对产业链上下游协同创新模式进行研究,并分析了产业链上下游协同创新对制造业发展的作用机制,最后提出相关的对策及建议,以期为相关人员提供一定的参考和借鉴.

关键词： 信息技术   小学数学   个性化分层教学  

摘要： 信息化背景下,信息技术在小学教育领域引起广泛关注与应用.文章聚焦小学数学课堂,深入探讨信息技术支持下个性化分层教学实践策略.通过对教学目标、内容、方法、评价进行分层,发挥信息技术不同优势,确保信息技术融入教学各环节,提升教学质量,激活课堂活力,加快因材施教目标的实现.同时,明确信息技术应用要点,为课堂不断升级做好准备,确保学生在分层教学中充分受益,最终实现与时俱进发展.

关键词： System theory  

摘要： With the advancement of the construction process of new power systems, the problem of insufficient local consumption capacity in the northwest region has become prominent. After considering the requirements of local power and hydrogen energy needs, a new energy external transmission and consumption prediction system dynamics model was constructed. First, starting from the development potential of new energy, the characteristics of electricity consumption in various industries, and the characteristics of hydrogen consumption in various fields,we divided the new energy outsourcing prediction system into three subsystems, namely,new energy, electric power load and hydrogen energy load, and constructed wind power and photovoltaic,respectively. New energy development potential prediction models include hydrogen energy load prediction models in the four fields of industry, electricity, heat, and transportation, and electric power load prediction models covering primary industry, secondary industry, tertiary industry, and urban and rural domestic electricity consumption. Secondly, the three subsystems and their interactive relationships and feedback mechanisms with the scale of new energy delivery were clarified, and a new energy delivery prediction system dynamics model was formed. Finally, taking the Gansu region as an example, we analyzed manpower, investment, transportation and hydrogen storage. Four development models are used to conduct scenario analysis that affects the scale of new energy delivery. The results show that, under the human-oriented and investment-oriented models, the scale of new energy delivery in 2030 will increase by 83.9% and 91.5%;moreover, driven by transportation demands and hydrogen storage demands, the scale of new energy delivery in 2030 will decrease by 6.8% and 12.2%. © 2025 Science Press. All rights reserved.

关键词： 建筑节能   建筑设计   新能源   应用价值  

摘要： 应用新能源可以减少传统能源使用,保护生态环境,为建筑行业持续发展打下坚实基础.从目前的状况来看,尽管新能源在建筑节能方面已经展现出了一定的效果,但在多个方面仍然存在明显的不足.因此,有必要加强对新能源应用技术的深入研究,以实现新能源在建筑节能方面的最大化利用.对建筑节能领域中新能源的应用进行了深入分析,以期为建筑节能的未来发展提供有价值的参考.