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关键词： 新文科   师范类院校   创新创业教育   课程体系构建  

摘要： 随着"新文科"理念的兴起,近年来,高等教育领域迎来了一场深刻的变革,这不仅是对传统学科边界的跨越,更是对教育模式、教学内容以及人才培养目标的重新定义.在此背景下,师范类院校作为培养未来教育者的摇篮,其创新创业教育课程体系的构建与实践,显得尤为重要且迫切.在时代的浪潮中,教育作为社会进步的基石,其形态与内涵总是随着时代的发展而不断革新.本文将在梳理新文科建设对师范类院校创新创业教育的时代要求的基础上,分析师范类院校创新创业教育课程体系的构建策略以及实践探索,以期为新文科背景下师范教育创新发展提供参考.

关键词： Z-classified higher-order topology   0D topological states localized in the bulk   Acoustic measurements  

摘要： Z-classified topological phases lead to a larger-than-unity number of topological states. However, these multiple topological states are only localized at the corners in nonlocal systems. Here, first, we rigorously prove that the multiple topological states of nonlocal Su-Schrieffer-Heeger (SSH) chains can be inherited and realized by local aperiodic chains with only the nearest couplings. Then, we report a new class of higher-order topological insulators constructed with the local aperiodic chains, which can have any integer number of 0D topological states localized at arbitrary positions in the whole domain of the insulators, including within the bulk. The 0D topological states are protected by the local topological marker in each direction, instead of the bulk multipole chiral numbers in existing work. We experimentally demonstrate these multimode topological states in designed acoustic coupled-resonators systems. Our work enables multiple combinations of localized corner-bulk topological states, which leads to programmable lasers and sasers by selecting the excitation sites without altering the structure, and thus opens a new avenue to signal enhancement for computing and sensing. (c) 2025 Science China Press. Published by Elsevier B.V. and Science China Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Metal-organic cages   Supramolecular recognition   Node engineering   Radioactive strontium   Selective removal  

摘要： Tailored design of organic linkers or metal nodes can introduce desirable functionalities into metalorganic cages (MOCs), significantly expanding their potential applications. In this study, we present a viable approach for engineering acyl-type metal nodes to create interior oxygen-rich sites within MOCs, enabling specific recognition of metal ions, including radioactive contaminants, while maintaining the structural integrity of the MOCs. A novel MOC featuring a uranyl-sealed calix[4]resorcinarene (C[4]R)based multisite cavity, referred to as UOC, is synthesized as a prototype. In UOC, peroxide-bridged dimeric uranyl units at both ends of the coordination cage provide abundant oxygen sites for coordination, forming a cryptand-like cavity that facilitates efficient recognition and encapsulation of Sr2* due to the size-matching effect. Additionally, hydrophobic binding cavities at both ends of UOC promote the coinclusion of two different guest species. Inspired by the strong binding affinity of UOC for Sr2* , it is employed as a solid adsorbent for capturing low concentrations of Sr2* in strontium-contaminated simulated groundwater. A removal efficiency of 99.7% for Sr2* at an initial concentration as low as 0.013 mmol L 1 is achieved, demonstrating its significant potential for the selective removal of trace amounts of radioactive 90 Sr2* . This work demonstrates the feasibility of incorporating acyl-type metal nodes into MOCs for the recognition and encapsulation of metal ions, offering a novel strategy for developing new MOC-based functional materials. (c) 2024 Science China Press. Published by Elsevier B.V. and Science China Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Total solar eclipse   Ionosphere   Total electron content (TEC)   Ionospheric electron density   Global Navigation Satellite System (GNSS)  

摘要： Using data from nearly 2,000 ground-based GNSS observation stations, the response of two-dimensional total electron content (TEC) and three-dimensional electron density in the ionosphere during the solar eclipse on April 8, 2024 was investigated. The eclipse resulted in TEC decrease that lasted for over 7 h, covering the entire United States. Approximately 60 % of the obscuration region along the eclipse path experienced TEC depletes ranging from 20-40 %. Following the eclipse, a widespread TEC enhancement was observed, propagating from high-latitude regions towards the equator. After the TEC enhancement, a secondary large-scale TEC depletion phenomenon was observed for the first time, with the depletion belt mainly concentrated near the eclipse path. The TEC enhancement and TEC secondary depletion exhibit distinct variations in latitude and longitude, respectively. The overall three-dimensional electron density in the ionosphere displayed consistent behavior with TEC, but exhibits significant altitude-dependent characteristics. The maximum electron density decrease occurred near the F2 peak at an altitude of 300 km, with a magnitude of up to 30 %. Ionospheric plasma disturbances triggered by the eclipse may be associated with dynamic processes related to plasma flux from the upper ionosphere. (c) 2024 Published by Elsevier B.V. on behalf of COSPAR.

关键词： X射线光电子能谱   东曲煤   亚辰煤   元素   赋存特征  

摘要： 煤中常量元素的赋存特征是了解煤结构及其反应性的重要途径,其中,碳、氧、氮和硫的赋存特征是煤结构研究中的重要内容.通过对煤级相近的东曲煤矿与亚辰煤矿的煤样品进行X射线光电子能谱仪(XPS)、扫描电镜(SEM)和X射线衍射仪(XRD)分析,揭示了这两种煤的微观形貌特征和所含矿物质的种类,以及在分子水平上两种煤中碳、氧、氮和硫赋存特征存在差异的原因.研究结果显示,东曲煤和亚辰煤表面均有黏附的矿物质颗粒,且两者的颗粒表面形貌相似.此外,这两种煤中,碳元素以C—C、C—O、C=O和COO—四种形态存在.其中,C—C为碳元素的主要存在形式,且两种煤中的C=O和COO—含量都很低.与亚辰煤相比,东曲煤C—H含量较高,而C—O含量较低.氧元素以COO—、C—O和C=O三种形态存在.分析发现,COO—含量较低和C—O含量较高的东曲煤比亚辰煤的热解效率更高.另外,氮元素以吡咯氮、吡啶氮、质子化吡啶和氮氧化物四种形态存在.与亚辰煤相比,东曲煤氮氧化物含量较高.东曲煤可以使用选择性催化还原法(SCR)等进行脱氮处理.而亚辰煤中主要含有吡啶氮、吡咯氮和质子化吡啶.考虑到氮氧化物的含量非常低,可以使用活性炭吸附等进行脱氮处理.硫元素以硫醚(硫醇)、噻吩硫、亚砜硫、砜硫、硫酸盐硫和硫铁矿硫六种形态存在.东曲煤和亚辰煤的硫结构均以有机硫为主,无机硫为辅,噻吩硫和(亚)砜硫占各自煤种硫含量的百分比都在 80%左右.两种煤中均含有大量结构不稳定的矿物成分,因此,脱硫的重点可放在无机硫上.对东曲煤矿和亚辰煤矿可以使用燃烧后烟气脱硫法和湿法脱硫法进行脱硫.该研究对提高煤的精细加工利用、减少环境污染、促进煤的循环利用和环保发展、扩大煤的用途等具有重要意义.

关键词： Choquard system   Hénon type   Liouville theorem   Pohozaev identity  

摘要： In this paper, our purpose is to study the following Hénon type Choquard system (Formula presented) where 0 < μ < 3, α > 0. We will show that there are no positive classical solutions in three dimension-space ℝ³ for p, q > 2 and (Formula presented). © 2025 Chinese Academy of Sciences. All rights reserved.