The Dual of the Two-Variable Exponent Amalgam Spaces (Lq(),lp())(Ω)

Wiener amalgam spaces are a class of function spaces where the function’s local and global behavior can be easily distinguished. These spaces are ex-tensively used in Harmonic analysis that originated in the work of Wiener. In this paper: we first introduce a two-variable exponent amalgam space (Lq(),lp())(Ω). Secondly, we investigate some basic properties of these spaces, and finally, we study their dual.

3D MERGE与3D SPACE STIR序列在腰椎间盘突出症检查中的应用比较

目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。

BIG HANKEL OPERATORS ON HARDY SPACES OF STRONGLY PSEUDOCONVEX DOMAINS

In this article,we investigate the(big) Hankel operator H_(f) on the Hardy spaces of bounded strongly pseudoconvex domains Ω in C^(n).We observe that H_(f )is bounded on H~p(Ω)(1 <p <∞) if f belongs to BMO and we obtain some characterizations for Hf on H~2(Ω) of other pseudoconvex domains.In these arguments,Amar's L~p-estimations and Berndtsson's L^(2)-estimations for solutions of the ■_(b)-equation play a crucial role.In addition,we solve Gleason's problem for Hardy spaces H~p(Ω)(1 ≤p≤∞) of bounded strongly pseudoconvex domains.

MAXIMAL FUNCTION CHARACTERIZATIONS OF HARDY SPACES ASSOCIATED WITH BOTH NON-NEGATIVE SELF-ADJOINT OPERATORS SATISFYING GAUSSIAN ESTIMATES AND BALL QUASI-BANACH FUNCTION SPACES

Assume that L is a non-negative self-adjoint operator on L^(2)(ℝ^(n))with its heat kernels satisfying the so-called Gaussian upper bound estimate and that X is a ball quasi-Banach function space onℝ^(n) satisfying some mild assumptions.Let HX,L(ℝ^(n))be the Hardy space associated with both X and L,which is defined by the Lusin area function related to the semigroup generated by L.In this article,the authors establish various maximal function characterizations of the Hardy space HX,L(ℝ^(n))and then apply these characterizations to obtain the solvability of the related Cauchy problem.These results have a wide range of generality and,in particular,the specific spaces X to which these results can be applied include the weighted space,the variable space,the mixed-norm space,the Orlicz space,the Orlicz-slice space,and the Morrey space.Moreover,the obtained maximal function characterizations of the mixed-norm Hardy space,the Orlicz-slice Hardy space,and the Morrey-Hardy space associated with L are completely new.

Metallurgical performance evaluation of space-weathered Chang’e-5 lunar soil

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.

Space/Air Covert Communications:Potentials,Scenarios,and Key Technologies

Space/air communications have been envisioned as an essential part of the next-generation mobile communication networks for providing highquality global connectivity. However, the inherent broadcasting nature of wireless propagation environment and the broad coverage pose severe threats to the protection of private data. Emerging covert communications provides a promising solution to achieve robust communication security. Aiming at facilitating the practical implementation of covert communications in space/air networks, we present a tutorial overview of its potentials, scenarios, and key technologies. Specifically, first, the commonly used covertness constraint model, covert performance metrics, and potential application scenarios are briefly introduced. Then, several efficient methods that introduce uncertainty into the covert system are thoroughly summarized, followed by several critical enabling technologies, including joint resource allocation and deployment/trajectory design, multi-antenna and beamforming techniques, reconfigurable intelligent surface(RIS), and artificial intelligence algorithms. Finally, we highlight some open issues for future investigation.

From“Car Priority”to“People Priority”: Exploring New Ideas for Refined Road Space Design

Roads are crucial public spaces in cities and serve as a window to showcase the city’s characteristics.They serve not only as a means of urban transportation but also as a crucial spatial carrier for urban communication activities and a significant location for meeting the increasing demands of people for a better quality of life.The current road infrastructure prioritizes the right of way for cars,neglecting the design of sidewalks and green belts within the road’s boundaries,and extension spaces between buildings and boundary lines of roads.There is a pressing need to improve street space in response to the demand for development transformation and the creation of a warmer city.This paper summarizes common problems in current road spaces,draws on the experience of excellent urban road spaces in foreign countries,discusses new ideas for the refined design of road spaces based on the transformation of road planning concepts,and suggests a reference standard for guiding detailed design.Simultaneously,the review of road construction will incorporate the detailed design of road space to enhance the role of planning in guiding and controlling the construction of road works.

Space Topologies and Their Dual Space Topologies for Conventional Functional Space Topologies

In this paper, we have studied the topology of some classical functional spaces. Among these spaces, there are standard spaces, spaces that can be metrizable and others that cannot be metrizable. But they are all topological vector spaces and it is in this context that we have chosen to present this work. We are interested in the topology of its spaces and in the topologies of their dual spaces. The first part, we presented the fundamental topological properties of topological vector spaces. The second part, we studied Frechet spaces and particularly the space S(Rn) of functions of class C∞ on Rn which are as well as all their rapidly decreasing partial derivatives. We have also studied its dual S'(Rn) the space of tempered distributions. The last part aims to define a topological structure on an increasing union of Frechet spaces called inductive limit of Frechet spaces. We study in particular the space D(Ω) of functions of class C∞ with compact supports on Ω as well as its dual D' (Ω) the space distributions over the open set Ω.

Motion and Special Relativity in Complex Spaces

A natural extension of the Lorentz transformation to its complex version was constructed together with a parallel extension of the Minkowski M4 model for special relativity (SR) to complex C4 space-time. As the [signed] absolute values of complex coordinates of the underlying motion’s characterization in C4 one obtains a Newtonian-like type of motion whereas as the real parts of the complex motion’s description and of the complex Lorentz transformation, all the SR theory as modeled by M4 real space-time can be recovered. This means all the SR theory is preserved in the real subspace M4 of the space-time C4 while becoming simpler and clearer in the new complex model’s framework. Since velocities in the complex model can be determined geometrically, with no primary use of time, time turns out to be definable within the equivalent theory of the reduced complex C4 model to the C3 “para-space” model. That procedure allows us to separate time from the (para)space and consider all the SR theory as a theory of C3 alone. On the other hand, the complex time defined within the C3 theory is interpreted and modeled by the single separate C1 complex plane. The possibility for application of the C3 model to quantum mechanics is suggested. As such, the model C3 seems to have unifying abilities for application to different physical theories.

基于Cite Space可视化分析我国多发伤急救研究热点及趋势

目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作者、关键词进行分析。结果最终纳入多发伤急救研究文献2519篇,整体发文数量较平稳,以2016年为小高峰;发文量最高的机构是华中科技大学附属同济医院。多发伤急救研究热点包括院前急救、并发症护理、风险因素分析和预后效果评估,研究前沿包括不同多发伤人群的诊断、治疗、手术和护理体会等方面。结论本文通过可视化分析国内多发伤急救研究的热点及趋势,指明了多发伤目前研究存在的问题和未来研究发展的方向,为进一步完善多发伤急救卫生服务和管理体系提供指导。

体育教师信念的国际研究现状与趋势——基于CiteSpace的文献计量分析

高质量教师是高质量教育发展的中坚力量。教师信念作为教师专业素养构成的关键要素,对促进教师专业发展、提升教师质量具有重要作用与影响。为借鉴国际体育教师信念研究的成果与经验,促进国内对体育教师信念的研究,研究利用CiteSpace软件,对Web of Science核心合集数据库中1960—2022年的英文文献进行可视化研究。发现:体育教师信念研究高潮出现于2021年,载文数量最多的期刊是Journal of Teaching in Physical Education;研究中心度最高的国家是美国,核心圈层的代表学者是Richards KAR、Kulinna PH和Curtner-smith MD等人;研究热点趋势集中于体力活动促进、职业社会化、批判性教学法、职前体育教师、专业发展等方面。启示:国内未来研究应重点关注体育教师信念对课程改革的影响以及促进职前、职后阶段体育教师信念的发展。

基于CiteSpace知识图谱的智慧养老领域研究文献综述

“十四五”规划将发展智慧养老产业上升为国家战略高度。文章借助Cite Space和Vosviewer绘图软件对2012-2022年国内外智慧养老领域研究的发文量、突现词等进行可视化分析。发现国内外研究都经历了三个发展阶段,国外研究起步早,研究成果丰富;国内研究虽然起步较晚,但进展快速。总结出“智慧养老内涵”“智慧养老模式”“智慧养老产业”“智慧养老平台”“智慧养老产品”“智慧养老用户”六大国内外都重点关注的研究议题,发现技术赋能智慧养老发展是近年来国内外共同关注的研究热点,大数据、物联网、养老金融、数字技术、区块链等成为围绕智慧养老文献的关键词。

基于CiteSpace和VOSviewer的我国中西医骨科研究生教育论文比较研究

目的 探讨并比较我国中西医骨科研究生教育的研究现状、热点和趋势,为后续研究提供科学依据与参考。方法 检索中国知网、万方数据知识服务平台、维普网、Web of Science核心合集数据库收录的中西医骨科研究生教育期刊论文。统计年度、期刊及研究机构发文情况,采用VOSviewer 1.6.19软件绘制作者合作及关键词共现图谱,采用Cite Space 6.2.R4软件绘制机构合作、关键词聚类、突现及时间线图谱。结果 共纳入文献252篇。中医和西医均经历了由早期探索到波动增长的阶段;中医刊文量最高期刊为《中医教育》,西医为《中国继续医学教育》;中医和西医的代表作者分别为韦贵康和王新伟;中西医均以临床能力教学为主要研究内容,中医较为关注理论思辨研究,西医更集中于技术应用研究;未来教学改革可能基于教学方法创新、数字技术迭代等方面展开。结论 中西医骨科研究生教育仍有巨大发展空间和潜力,后续应着重开展促进研究主体交流、聚焦前沿技术应用、打造特色传承模式等研究。

基于CiteSpace对近10年国内外护理不良事件的可视化分析

为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示,从发文量看,国内外学者对护理不良事件的关注度整体较高,可视化分析结果并未发现作者之间、机构之间的联系。未来减少护理不良事件的方法一定会越来越紧贴科学技术,越来越多的新型信息化平台、App等会用于医疗行业,降低护理不良事件预防的难度,但护理人员仍要重视护理安全。

基于Cite Space对近5年发酵领域的研究进展与热点分析

近年来,我国生物产业快速发展,且发酵对身体和胃肠道健康具有很多益处,有关微生物发酵的研究逐渐增多。为探讨发酵领域近5年的研究现状与发展前景,对中国知网和Web of Science数据库中2019—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队、研究热点进行图谱分析。结果表明,近5年国内发酵领域发文量偏少,年发文量平稳上升;国外发文量较多,年发文量超过100篇,2023年发文量达到200篇;国内外研究群体主要是中医药高校和研究机构;国内外研究热点集中在抗氧化和肠道菌群,国内研究重点为发酵技术,而国外研究范围较广,重点为益生菌的研究;国内外学者间合作较为密切,但研究机构间尚未形成紧密的合作关系。高校和研究机构应突破地区间的限制,促进发酵研究领域的融合。肠道菌群是近5年发酵的研究热点,也是未来发酵研究深入的对象。

基于CiteSpace的城市公共空间活力研究进展

城市公共空间活力是城市发展潜力和空间品质的重要体现,空间活力的营造和提升是助推城市更新、营造宜居城市的重要条件。借助文献计量与CiteSpace知识图谱分析工具,回顾2003—2022年间Web ofScience和中国知网数据库关于城市公共空间活力的研究,梳理了城市公共空间活力研究阶段与热点并展开评述与比较,得出以下结论:发文量与时间分布方面,全球范围内城市公共空间活力研究数量整体呈现上升趋势,数量上英文文献多于中文文献;国家与机构学术合作方面,中国相关研究热度最高,美国相关研究影响力最强,且国家与机构之间总体合作网络较为密切;所涉期刊与发文量方面,相关研究所涉期刊丰富,英文文献发文量高于中文文献,且英文相关研究所涉学科领域种类较多;研究主题方面,城市公共空间活力研究热点不断更新,全球范围内相关研究关于城市设计对活力的营造关注时间最长,建成环境和大数据的运用是近年来中英文文献共同关注的热点。因此,立足于城市更新与大数据的时代背景,未来应创新多学科交叉下的城市公共空间活力理论体系和系统性评价框架,关注城市公共空间活力的动态演化路径,注重城市公共空间活力引起的多重效应研究。

我国户外运动研究现状、热点与趋势——基于CNKI和Cite Space可视化分析

运用CNKI和Cite Space6.2.R2软件,对来源于中国知网数据库(CNKI)所收录有关户外运动主题的283篇核心文献的发文量、作者、机构、期刊来源和关键词进行了可视化分析。结果表明:1)从研究现状看,我国户外运动经历了萌芽阶段、快速增长阶段和稳定增长阶段,作者之间合作不够紧密;2)从研究热点来看,近年来我国户外运动研究主题集中于户外运动产业、户外运动教育和户外运动生态共享这三个方面;3)从研究趋势来看,我国户外运动发展趋势偏向于健康中国、乡村振兴、产业融合、中国式现代化、高质量发展和生态文明建设等方面。

基于Cite space的我国蔬菜制种产业研究热点与趋势分析

运用可视化工具Cite Space和文献计量方法,对刊载在中国知网数据库所有与蔬菜制种相关主题的1212篇相关文献进行分析,并总结了我国蔬菜制种产业的热点及发展趋势。研究发现,蔬菜制种产业的研究热点主要集中在制种技术、杂交制种、种子产量、杂交授粉、杂种纯度等方面。我们建议后续应加强核心技术攻关,加快生物技术在蔬菜制种上的应用、强化基地建设,提高蔬菜制种产业化水平、加强研究主体间的合作与交流,重视制种人才培养,打造智慧农业。本研究可为进一步完善我国蔬菜制种产业提供借鉴。

基于CiteSpace的中国红枣产业研究现状及展望知识图谱分析

为了解中国红枣产业的研究进展、热点及趋势,基于中国知网数据库,依据文献计量学理论,运用Cite Space软件对1994~2023年红枣产业领域的759篇文章进行共被引聚类分析、关键节点分析以及突现词分析等可视化展示。结果表明年红枣产业领域相关文章在2012年达到最高;塔里木大学、巴州林业科学技术推广中心和新疆农业大学发表文章数量居前三。从国内的研究进展看,经历了缓慢发展期、波动攀升期和骤落衰减阶段三个阶段,研究热点主要集中于红枣产业、红枣加工生产和产业对策。从作者及研究机构分布说明大学在学术、科研上起着重要作用,但机构间的合作较为缺乏,不利于红枣产业领域的深度研究。综合中国当前研究现状及关注热点,未来的研究趋势将集中于红枣产业与乡村振兴、产业发展及新疆红枣等方面的研究。

基于Cite Space的村落空间结构研究文献计量与知识图谱分析

国家先后通过人居环境整治、统筹城乡发展、乡村振兴等一系列顶层设计战略把控和指导乡村建设。由于乡村建设的加快和保护意识的缺乏,全国各地的古村落正在逐渐消失,而村落空间结构作为乡村空间的重要构成部分,对其保护传承与优化利用刻不容缓。以文献计量工具Cite Space为研究工具,以“CNKI”数据库“、Web of Science”数据库中2013-2023年的中英文文献作为研究对象进行可视化分析。通过分析国内外村落空间结构的研究概况、研究趋势、研究热点,旨在梳理该领域的研究现状和发展趋势,形成客观总结并提出展望:构建学科交叉研究平台、实践导向创新研究视角、创新研究方式与手段。为下一步我国村落空间结构的优化保护与设计利用提供参考。