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We consider (classical and generalized) Massey products on the Chekanov homology of a Legendrian knot, and we prove that they are invariant under Legendrian isotopies. We also construct a minimal A∞-algebra structure on the Chekanov algebra of a Legendrian knot, we prove that this structure is invariant under Legendrian isotopy, and we observe that its higher multiplications allow us to find representatives for classical Massey products. Finally, we consider differential equations: we remark that the Massey product Legendrian invariants admit a “dynamical interpretation”, in the sense that they provide solutions for a Maurer-Cartan equation posed on an infinite-dimensional bigraded Lie algebra, and we show how to set up and solve a (twisted) Kadomtsev-Petviashvili hierarchy of equations starting from the Chekanov algebra of a Legendrian knot. 相似文献
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A thin radar-infrared stealth-compatible structure:Design,fabrication,and characterization
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A thin radar-infrared stealth-compatible structure with reflectivity below -10 dB in the whole radar X wave band and infrared emissivity less than 0.3 in the infrared region of 8μm-14 μm is reported. The designed stealth-compatible structure consists of metallic frequency selective surface (MFSS), resistive frequency selective surface (RFSS), and metal backing from the top down, and it is only 2. l-mm thick. The MFSS is made up of some divided low infrared emissivity metal copper films, and the RFSS consists of a capacitive array of square resistive patches. They are placed close together, working as an admittance sheet because of a mutual influence between them, and the equivalent admittance sheet greatly reduces the thickness of the whole structure. The proposed stealth-compatible structure is verified both by simulations and by experimental results. These results indicate that our proposed stealth-compatible structure has potential applications in stealth fields. 相似文献
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Ultrasound induced cavitation (acoustic cavitation) process is found useful in various applications. Scientists from various disciplines have been exploring the fundamental aspects of acoustic cavitation processes over several decades. It is well documented that extreme localised temperature and pressure conditions are generated when a cavitation bubble collapses. Several experimental techniques have also been developed to estimate cavitation bubble temperatures. Depending upon specific experimental conditions, light emission from cavitation bubbles is observed, referred to as sonoluminescence. Sonoluminescence studies have been used to develop a fundamental understanding of cavitation processes in single and multibubble systems. This minireview aims to provide some highlights on the development of basic understandings of acoustic cavitation processes using cavitation bubble temperature, sonoluminescence and interfacial chemistry over the past 2–3 decades. 相似文献
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Michel Talagrand 《Journal of statistical physics》2007,126(4-5):837-894
We investigate the problem of computing $$\lim_{N \to \infty}\frac{1}{aN}\log EZ_N^a$$ for any value of a, where Z N is the partition function of the celebrated Sherrington-Kirkpatrick (SK) model, or of some of its natural generalizations. This is a natural “large deviation” problem. Its study helps to get a fresh look at some of the recent ideas introduced in the area, and raises a number of natural questions. We provide a complete solution for a ≥ 0. 相似文献
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Dr Tim Evans 《Contemporary Physics》2013,54(2):187-188
The present state of theory and experiment on the gravity-induced electric field in metallic conductors and the electric field in accelerated metal conductors is reviewed. The relevant equations are derived in very simple approximations. The results depend on whether the deformation of the lattice of positive ions is neglected or is taken into account. Experimental results obtained with freely falling electrons in a cavity in the metal do not agree with the measurements of potentials on rapidly spinning metal rotors. Older direct measurements of the specific charge of carriers in metallic conductors are also mentioned. 相似文献
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The 333.6-, 351.1-, and 363.8-nm lines of a cw argon ion laser are found to coincide with the BaS B1Σ+-X1Σ+ (12, 0) R(17), (6, 0) P(35), and (3, 0) R(125) transitions, respectively. Fluorescence transitions from the laser-prepared upper levels terminating in X1Σ+v = 0–28, A1Σ+v = 1–3, A′1Π v = 1–13, and a3Π1v = 3–12 are assigned. These results are combined with a previous analysis of the extensively perturbed BaS A1Σ+-X1Σ+ system [R. F. Barrow, W. G. Burton, and P. A. Jones, Trans. Farad. Soc.67, 902–906 (1971)]. Every observed perturbation of the BaS A1Σ+ state is electronically and vibrationally assigned. The levels a3Π0v = 10–13, a3Π1v = 12–14, a3Π2v = 15, and A′1Π v = 10–13 are sampled via their perturbations of A1Σ+v = 0–2. Although the mutual interactions of the a3Π, A′1Π, and A1Σ+ states approach Hund's case (c) limit, a complete deperturbation is performed from a case (a) starting point. Of the five lowest energy electronic states of BaS, only b3Σ+ remains uncharacterized. Principal deperturbed molecular constants are (in cm?1, 1σ uncertainties in parentheses):
14 498.6(1) | 287.7(1) | 1.15(5) | 9.365(5) | 5.0(10) | 2.633 | |
12 095(6) | 258.9(5) | 0.7 | 8.21(5) | 3.6(5) | 2.813 | |
11 835(6) | 259.6(5) | 0.7 | 8.21 | 3.6 | 2.813 | |
0 | 379.50(4) | 0.91(1) | 10.334(1) | 3.4(2) | 2.507 |