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天体、地球、生物的一种自相似律——对数螺线 被引量:5
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作者 彭玉鲸 《吉林地质》 1999年第3期1-10,共10页
自相似是指自然和社会现象中, 部分与整体之间, 广泛存在着的放大对称 (dilatation sym metry) 。它们不仅在形态上、时空关系上, 而且在信息、功能和能量等各个方面都表现出的自相似特征。天体中, 从众多的... 自相似是指自然和社会现象中, 部分与整体之间, 广泛存在着的放大对称 (dilatation sym metry) 。它们不仅在形态上、时空关系上, 而且在信息、功能和能量等各个方面都表现出的自相似特征。天体中, 从众多的硕大的旋涡状星云, 到坠落于地球上的微小的陨砂、陨尘, 普遍存在着螺旋状的结构形态。地球上从变形矿物的包体至巨型的旋涡状构造,从岩石圈表层, 直至外地核的深处, 也都能发现螺旋形结构的存在。生物世界从植物到动物, 从低级到高级, 对数螺线结构形态更是绚丽多姿。而最为令人惊奇的是在天地生中均发现了与我国古代科学典籍 《周易》 的形象标志太极图相似的双螺旋结构形体。我们将其称之为 “天地生对数螺线自相似律”。它们反映了宇宙万物形成的科学整体观, 受宇宙全息律的规律所支配。有助于将中国古代有机论自然观与系统科学相结合, 深入开展天地生基础理论和预测科学的研究及应用。 展开更多
关键词 对数螺线 自相似律 天体 地球 生物
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自相似律及其在地学中的运用 被引量:2
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作者 李强 《地质科技管理》 1992年第2期45-49,共5页
关键词 自相似律 地学 地质学 矿物学
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壁湍流扩展的自相似标度律的实验研究 被引量:12
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作者 姜楠 王玉春 《实验力学》 CSCD 北大核心 2002年第1期28-34,共7页
对风洞中零压力梯度平板湍流边界层进行了实验研究 ,用热线风速仪测量了不同法向位置的脉动速度 ,研究了湍流边界层不同法向位置速度结构函数的扩展的自相似标度律 .
关键词 壁湍流 扩展 自相似标度 风洞 湍流边界层 热线风速仪 法向位置 脉动速度
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自由湍射流边界层标度律的实验测量
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作者 苏锋 姜楠 舒玮 《实验力学》 CSCD 北大核心 2003年第3期324-330,共7页
用IFA300热线风速仪以低于最小低湍流时间尺度的高分辨率,精细测量了圆自由射流中同一流向断面内不同径向位置的流向速度分量,研究了不同径向位置的非均匀、非各向同性对充分发展湍流速度结构函数自相似标度律及其层次结构模型的影响.
关键词 自由湍流 自由射流 边界层 实验测量 非均匀各向同性 自相似标度 层次结构模型 速度结构函数
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静态混合器内瞬态壁压波动特性实验研究 被引量:4
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作者 孟辉波 禹言芳 +1 位作者 吴剑华 陈旭 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2011年第5期690-696,共7页
为了探讨静态混合器内非线性流动特性,利用动态数据采集系统对SK型静态混合器管壁脉动压力进行测量,研究湍流状态下壁压的脉动幅值、功率谱以及结构函数的扩展的自相似标度律.实验研究表明:SK型静态混合器各点压力的最大波动幅值大于125... 为了探讨静态混合器内非线性流动特性,利用动态数据采集系统对SK型静态混合器管壁脉动压力进行测量,研究湍流状态下壁压的脉动幅值、功率谱以及结构函数的扩展的自相似标度律.实验研究表明:SK型静态混合器各点压力的最大波动幅值大于125 Pa,并与进口流量呈二次函数关系逐渐增大;瞬态壁压脉动信号的一阶主频率低于0.5 Hz,功率谱随着频率的增加呈幂函数关系衰减;壁压波动信号的k阶结构函数与3阶结构函数的双对数存在线性关系;当进口流量Q>400 L.h-1时,压力结构函数的标度指数ξ(k)大于相对标度指数ξ(k,3);当进口流量Q≤400 L.h-1时,壁压波动信号的压力结构函数的标度指数ξ(k)小于相对标度指数ξ(k,3).但k阶结构函数相对标度指数ξ(k,3)与均匀各向同性湍流惯性子区的标度指数ξ(k)存在较大差别. 展开更多
关键词 静态混合器 壁压波动 结构函数 扩展的自相似标度
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阵发混沌导致反常标度 被引量:3
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作者 姜丽娜 吴炜 《辽宁大学学报(自然科学版)》 CAS 2007年第2期112-115,共4页
研究了Gledzer-ohkitani-Yamada(或GOY)模型的阵发湍流.通过相平面分析方法研究了惯性区各壳相空间的轨道,发现阵发轨道部分的随机性导致不稳定准周期轨道的随机转动、反转和锁定现象.计算了阵发轨道扩展自相似标度律,指出阵发性能量传... 研究了Gledzer-ohkitani-Yamada(或GOY)模型的阵发湍流.通过相平面分析方法研究了惯性区各壳相空间的轨道,发现阵发轨道部分的随机性导致不稳定准周期轨道的随机转动、反转和锁定现象.计算了阵发轨道扩展自相似标度律,指出阵发性能量传递方式是导致反常标度的原因. 展开更多
关键词 阵发性 混沌 惯性区 扩展自相似标度
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On the scaling law of ramp structures in scalar turbulence 被引量:1
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作者 CHEN Dong-Wei HU Fei XU Jing-Jing 《Atmospheric and Oceanic Science Letters》 CSCD 2018年第4期372-377,共6页
Ramp structures widely exist in scalar turbulence,such as temperature,water vapor,and carbon dioxide(CO2),which refer to the phenomenon that the physical quantity increases slowly with time and then suddenly drops.ram... Ramp structures widely exist in scalar turbulence,such as temperature,water vapor,and carbon dioxide(CO2),which refer to the phenomenon that the physical quantity increases slowly with time and then suddenly drops.ramp structures lead to large gradients on a small scale and result in intermittency and anisotropy of turbulent flows.in this paper,wavelet analysis is used to analyze observed data from the beijing 325-m meteorological tower to extract ramp structures in temperature,water vapor,and CO2 signals.ramp structures in CO2 signals are different from those in temperature and water vapor in terms of the averaged temporal scale and normalized amplitude,and the ramp duration almost equals the cliff duration,which means ramp structures in CO2 signals are not easy to generate and different physical mechanisms may exist.in addition,both the ascending and descending part of ramp structures are linearly fitted.it is found that a scaling law exists between the slope and duration in the ascending part in the three scalar signals.the corresponding power exponents are slightly different.furthermore,the same rule exists in the descending part of ramp structures,which indicates that self-similarity may be a universal law in scalar turbulence.moreover,the maxima of selected ramp structures show the same pattern,i.e.there are ramp structures in the maximum sequence,which proves that small-scale ramp structures are superimposed on large-scale ramp structures. 展开更多
关键词 Scalar turbulence ramp structure scaling law selfsimilarity
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Kant's Respect for the Law and Habermas's Redemption as a Source of Freedom?
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作者 Domenic Garcia 《Journal of Philosophy Study》 2014年第3期216-223,共8页
As the title of this paper suggests, I intend to draw attention to what, in my opinion, lies at the core of the shared notion in both Kant and Habermas. This will be the concern of the first part of my paper. My focus... As the title of this paper suggests, I intend to draw attention to what, in my opinion, lies at the core of the shared notion in both Kant and Habermas. This will be the concern of the first part of my paper. My focus will then shift, in the second part, to Habermas's views on freedom. In due time, however, as the provocative question mark in the title suggests, the notion of freedom becomes questionable. I will conclude by examining Frankfurt's notion of coercion in order to show that Habermas's notion of freedom is not only questionable but can, at times, be coercive. Throughout this paper, the reader shall be encouraged to see and possibly appreciate that there is a degree of similarity between the two thinkers. Shall the reader be hard put to gauge this similarity or shall the reader promptly appreciate it and take it into consideration? I will argue--and demonstrate--that a certain amount of similarity can readily be drawn between the two. I will leave it up to the reader to decide whether this similarity is a forced similarity or whether this is a similarity that one perceives at a first glance and thus ought to consider. This paper could better be appreciated if the reader has reasonable knowledge of the Hegelian critique of Kant's Categorical Imperative. 展开更多
关键词 validity claims discourse ethics quasi-transcendental FREEDOM coercion
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Self-Similar Characteristic for the Ramp Structures of Wind Speed
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作者 SONG Zong-Peng HU Fei +1 位作者 XU Jing-Jing CHENG Xue-Ling 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第4期320-323,共4页
Time series of wind speed are composed of large and small ramp structures. Data analysis reveals a power law relation between the linear slope of ramp structures and the time scale. This suggests that these ramp struc... Time series of wind speed are composed of large and small ramp structures. Data analysis reveals a power law relation between the linear slope of ramp structures and the time scale. This suggests that these ramp structures of wind speed have a self-similar characteristic. The lower limit of the self-similar scale range was 2 s. The upper limit is unexpectedly large at 27 rain. Data are collected from grassland, city, and lake areas. Although these data have different underlying surfaces, all of them clearly show a power law relation, with slight differences in their power exponents. 展开更多
关键词 ramp structure SELF-SIMILARITY power law time series of wind speed
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