Runge-Kutta scheme is one of the versatile numerical tools for the simulation of engineering systems. Despite its wide and acceptable engineering use, there is dearth of relevant literature bordering on visual impress...Runge-Kutta scheme is one of the versatile numerical tools for the simulation of engineering systems. Despite its wide and acceptable engineering use, there is dearth of relevant literature bordering on visual impression possibility among different schemes coefficients which is the strong motivation for the present investigation of the third and fourth order schemes. The present study capitalise on results of tedious computation involving Taylor series expansion equivalent supplemented with Butcher assumptions and constraint equations of well-known works which captures the essential relationship between the coefficients. The simulation proceeds from random but valid specification of two out of the total coefficients possible per scheme. However the remaining coefficients are evaluated with application of appropriate function relationship. Eight and thirteen unknown coefficients were simulated respectively for third and fourth schemes over a total of five thousand cases each for relevant distribution statistics and scatter plots analysis for the purpose of scheme comparison and visual import. The respective three and four coefficients of the slope estimate for the third and fourth schemes have mix sign for large number of simulated cases. However, none of the two schemes have above three of these coefficients lesser than zero. The percentages of simulation results with two coefficients lesser than zero dominate and are respectively 56.88 and 77.10 for third and fourth schemes. It was observed that both popular third and fourth schemes belong to none of the coefficients being zero classification with respective percentage of 0.72 and 3.28 intotal simulated cases. The comparisons of corresponding scatter plots are visually exciting. The overall difference between corresponding scatter plots and distribution results can be used to justify the accuracy of fourth scheme over its counterpart third scheme.展开更多
土壤遗留效应是介导植物群落和土壤特性之间相互作用的重要机制,不仅影响着植物群落动态和物种共存,同时在土地利用和管理方面也发挥着重要作用。本文基于Web of Science数据库中检索到的2000~2022年发表的相关文献进行计量学分析,探讨...土壤遗留效应是介导植物群落和土壤特性之间相互作用的重要机制,不仅影响着植物群落动态和物种共存,同时在土地利用和管理方面也发挥着重要作用。本文基于Web of Science数据库中检索到的2000~2022年发表的相关文献进行计量学分析,探讨此研究领域的研究现状以及热点问题。结果表明:土壤遗留效应的发文量总体呈现上升趋势,美国农业部是发文量最多的机构(646篇),以中国科学院为代表的国内科研机构对该领域的发展也做出了积极贡献;生态学、环境科学、土壤学和植物学是该领域的主要发文学科,这些学科的交叉合作对深入了解土壤遗留效应起着关键作用;在国际合作方面,该领域已显示出全球交流和联系日益密切的趋势,但考虑到地理位置等因素,未来各研究团队仍需保持密切合作,共同加强该领域高水平、高认可度研究成果的产出;目前,该领域的热点问题集中在土壤遗留效应对土壤微生物群落、农业土地管理和不同生态系统恢复的影响,以及气候因素在驱动遗留效应中的作用。未来的研究可以进一步探讨这些问题,并结合新兴技术手段,如遥感技术、GIS技术和模型模拟等,推动土壤遗留效应的定量评估和预测,为实现可持续土地管理和生态系统发展提供支撑。展开更多
目的:文章从文献计量学角度分析生地黄相关研究分布、来源出版物、研究机构以及引文情况,为了解生地黄相关文献的研究热点和研究方向提供参考依据。方法:采用PubMed核心合集数据库和中国知网数据库获得文献数据,运用文献计量学的方法和C...目的:文章从文献计量学角度分析生地黄相关研究分布、来源出版物、研究机构以及引文情况,为了解生地黄相关文献的研究热点和研究方向提供参考依据。方法:采用PubMed核心合集数据库和中国知网数据库获得文献数据,运用文献计量学的方法和CiteSpace软件对有关生地黄这一研究主题的文献、期刊以及关键词等进行可视化分析。结果:近40年在生地黄领域研究热点为生地黄拥有调节免疫功能、抗衰老、促进造血、抗肿瘤、抗氧化的药效。共搜索到有效中英文文献1 071篇,其中中国知网中收录676篇,PubMed中收录395篇;在中国知网中生地黄相关文献发文量最多的作者为谢宁(28篇),在PubMed核心合集数据库中生地黄相关文献发文量最多为WANG J(13篇);中国知网中重要发文期刊为《中国实验方剂学杂志》(46篇),PubMed中重要发文期刊为《Zhongguo Zhong Yao Za Zhi》(21篇);资助文献量最多的基金为国家自然科学基金,共资助文献244篇。结论:深入了解该领域重要作者、文献、期刊、机构等信息可以获得更多突破性的成果及思路,为今后临床上的科研工作者提供理论依据。在近40年生地黄研究过程中,研究热点随着时间在不断变化,近些年来主要热点为地黄寡糖、细胞增殖、胰岛素抵抗、化学成分、药理作用等方面。目前对于生地黄研究仍有不足,各研究作者联系不强,生地黄研究主观性较强,缺乏统一标准,作用机制尚不明确,有待进一步研究以得到深入的研究数据。展开更多
Security during remote transmission has been an important concern for researchers in recent years.In this paper,a hierarchical encryption multi-image encryption scheme for people with different security levels is desi...Security during remote transmission has been an important concern for researchers in recent years.In this paper,a hierarchical encryption multi-image encryption scheme for people with different security levels is designed,and a multiimage encryption(MIE)algorithm with row and column confusion and closed-loop bi-directional diffusion is adopted in the paper.While ensuring secure communication of medical image information,people with different security levels have different levels of decryption keys,and differentiated visual effects can be obtained by using the strong sensitivity of chaotic keys.The highest security level can obtain decrypted images without watermarks,and at the same time,patient information and copyright attribution can be verified by obtaining watermark images.The experimental results show that the scheme is sufficiently secure as an MIE scheme with visualized differences and the encryption and decryption efficiency is significantly improved compared to other works.展开更多
文摘Runge-Kutta scheme is one of the versatile numerical tools for the simulation of engineering systems. Despite its wide and acceptable engineering use, there is dearth of relevant literature bordering on visual impression possibility among different schemes coefficients which is the strong motivation for the present investigation of the third and fourth order schemes. The present study capitalise on results of tedious computation involving Taylor series expansion equivalent supplemented with Butcher assumptions and constraint equations of well-known works which captures the essential relationship between the coefficients. The simulation proceeds from random but valid specification of two out of the total coefficients possible per scheme. However the remaining coefficients are evaluated with application of appropriate function relationship. Eight and thirteen unknown coefficients were simulated respectively for third and fourth schemes over a total of five thousand cases each for relevant distribution statistics and scatter plots analysis for the purpose of scheme comparison and visual import. The respective three and four coefficients of the slope estimate for the third and fourth schemes have mix sign for large number of simulated cases. However, none of the two schemes have above three of these coefficients lesser than zero. The percentages of simulation results with two coefficients lesser than zero dominate and are respectively 56.88 and 77.10 for third and fourth schemes. It was observed that both popular third and fourth schemes belong to none of the coefficients being zero classification with respective percentage of 0.72 and 3.28 intotal simulated cases. The comparisons of corresponding scatter plots are visually exciting. The overall difference between corresponding scatter plots and distribution results can be used to justify the accuracy of fourth scheme over its counterpart third scheme.
文摘土壤遗留效应是介导植物群落和土壤特性之间相互作用的重要机制,不仅影响着植物群落动态和物种共存,同时在土地利用和管理方面也发挥着重要作用。本文基于Web of Science数据库中检索到的2000~2022年发表的相关文献进行计量学分析,探讨此研究领域的研究现状以及热点问题。结果表明:土壤遗留效应的发文量总体呈现上升趋势,美国农业部是发文量最多的机构(646篇),以中国科学院为代表的国内科研机构对该领域的发展也做出了积极贡献;生态学、环境科学、土壤学和植物学是该领域的主要发文学科,这些学科的交叉合作对深入了解土壤遗留效应起着关键作用;在国际合作方面,该领域已显示出全球交流和联系日益密切的趋势,但考虑到地理位置等因素,未来各研究团队仍需保持密切合作,共同加强该领域高水平、高认可度研究成果的产出;目前,该领域的热点问题集中在土壤遗留效应对土壤微生物群落、农业土地管理和不同生态系统恢复的影响,以及气候因素在驱动遗留效应中的作用。未来的研究可以进一步探讨这些问题,并结合新兴技术手段,如遥感技术、GIS技术和模型模拟等,推动土壤遗留效应的定量评估和预测,为实现可持续土地管理和生态系统发展提供支撑。
文摘目的:文章从文献计量学角度分析生地黄相关研究分布、来源出版物、研究机构以及引文情况,为了解生地黄相关文献的研究热点和研究方向提供参考依据。方法:采用PubMed核心合集数据库和中国知网数据库获得文献数据,运用文献计量学的方法和CiteSpace软件对有关生地黄这一研究主题的文献、期刊以及关键词等进行可视化分析。结果:近40年在生地黄领域研究热点为生地黄拥有调节免疫功能、抗衰老、促进造血、抗肿瘤、抗氧化的药效。共搜索到有效中英文文献1 071篇,其中中国知网中收录676篇,PubMed中收录395篇;在中国知网中生地黄相关文献发文量最多的作者为谢宁(28篇),在PubMed核心合集数据库中生地黄相关文献发文量最多为WANG J(13篇);中国知网中重要发文期刊为《中国实验方剂学杂志》(46篇),PubMed中重要发文期刊为《Zhongguo Zhong Yao Za Zhi》(21篇);资助文献量最多的基金为国家自然科学基金,共资助文献244篇。结论:深入了解该领域重要作者、文献、期刊、机构等信息可以获得更多突破性的成果及思路,为今后临床上的科研工作者提供理论依据。在近40年生地黄研究过程中,研究热点随着时间在不断变化,近些年来主要热点为地黄寡糖、细胞增殖、胰岛素抵抗、化学成分、药理作用等方面。目前对于生地黄研究仍有不足,各研究作者联系不强,生地黄研究主观性较强,缺乏统一标准,作用机制尚不明确,有待进一步研究以得到深入的研究数据。
基金Project supported by the National Natural Science Foundation of China(Grant No.62061014)the Natural Science Foundation of Liaoning province of China(Grant No.2020-MS-274).
文摘Security during remote transmission has been an important concern for researchers in recent years.In this paper,a hierarchical encryption multi-image encryption scheme for people with different security levels is designed,and a multiimage encryption(MIE)algorithm with row and column confusion and closed-loop bi-directional diffusion is adopted in the paper.While ensuring secure communication of medical image information,people with different security levels have different levels of decryption keys,and differentiated visual effects can be obtained by using the strong sensitivity of chaotic keys.The highest security level can obtain decrypted images without watermarks,and at the same time,patient information and copyright attribution can be verified by obtaining watermark images.The experimental results show that the scheme is sufficiently secure as an MIE scheme with visualized differences and the encryption and decryption efficiency is significantly improved compared to other works.
