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
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
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
基金supported by the National Key R&D Program of China(Grant No 2016YFC0208802)the National Natural Science Foundation of China(Grant Nos 11472272,41605010,and 41675012)
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China (Grant No. 91215302)"One-Three-Five" Strategic Planning (wind power prediction) of the Institute of Atmospheric Physics, Chinese Academy of Sciences (CAS) (Grant No. Y267014601)the Strategic Project of Science and Technology of CAS (Grant No. XDA05040301)
文摘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.