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Si tratta di una memoria in cui si espongono alcuni progressi matematici recentemente compiuti nello studio delle equazioni di strato limite de Prandtl. Gli argomenti principali trattati sono la derivazione rigorosa delle equazioni stesse, la teoria matematica del problema di valore iniziale associato e la teoria delle soluzioni di similarità.

Abstract

Этa-излoжитeльнaя paбoтa o нeкoтopых мaтeмaтихecких ycпeхaх в изyхeнии ypaвнeний гpaнихнoгo cлoя Пpaндтля. Ocнoвныe paccмaтpывaeмыe вoпpocы: cтpoгий вывoд ypaвнeний, мaтe-мaтихecкaя тeopия cвязaннoй зaдaхи нaхaльнoгo знaхeния, и тeopия пoдoбнocтых pэшeний.
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View Record in Scopus
doi:10.1016/j.physd.2009.07.007    
Copyright © 2009 Elsevier B.V. All rights reserved.
Singularity formation for Prandtl’s equations
F. Garganoa, , M. Sammartino, a, and V. Sciaccaa,
aUniversity of Palermo, Department of Mathematics, Via Archirafi 34, 90123 Palermo, Italy  相似文献   

5.
Nanoscale heat conduction at a silicon–superfluid helium boundary     
J. Amrit 《Superlattices and Microstructures》2004,35(3-6):187
  相似文献   

6.
Magnetostatische eigenschwingugen an gestreckten rotationsellipsoiden bei beliebiger magnetisierungsrichtung     
W Harnischmacher 《Journal of magnetism and magnetic materials》1976,2(1-3)
  相似文献   

7.
Optical characterisation of solar concentrator     
P. Sansoni  F. Francini  D. Fontani 《Optics and Lasers in Engineering》2007,45(3):351
Pa;бo;тa; пp;e;дпp;инятa; c; цe;лью пo;кa;зa;ть пo;тe;нциa;льнy;ю вo;змo;знo;c;ть иc;пo;льзo;вa;ния “пo;вe;p;хнo;c;тнo;й плe;нки” для интe;нc;ификa;ции “мe;зфa;знo;гo; тe;плo;o;бмe;нa;”. B khcy;a;c;тнo;c;ти, p;a;c;c;мa;тp;ивa;лa;c;ь вo;змo;знo;c;ть интe;нc;ификa;ции тe;плo;пe;p;e;нo;c;a; к o;тдe;льным линзa;м лe;тy;khcy;e;й зидкo;c;ти, плa;вa;ющим нa; нe;пo;двизнo;й пo;вe;p;хнo;c;ти вo;ды, и их иc;пa;p;e;ниe;. Пo;пe;p;e;мe;ннo; p;a;c;тягивa;я и c;зимa;я (c; пo;мo;щью нp;илo;зe;ннo;й извнe; c;илы) пo;вe;p;хнo;c;тнy;ю плe;нкy; нa; пo;вe;p;хнo;c;ти вo;ды вo;кp;y;г кa;здo;й линзы, o;кa;зa;лo;c;ь вo;змo;зным пe;p;иo;диkhcy;e;c;ки p;a;c;тягивa;ть и c;зимa;ть линзы, khcy;тo; знa;khcy;итe;льнo; c;o;кp;a;щa;лo; вp;e;мя их иc;пa;p;e;ния.
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View Record in Scopus
doi:10.1016/j.optlaseng.2005.02.009    
Copyright © 2006 Elsevier Ltd All rights reserved.
Optical characterisation of solar concentrator
P. Sansoni, a, , F. Francinia and D. Fontania
aIstituto Nazionale di Ottica Applicata L.go E. fermi 6, ARCETRI, 50125 Firenze, Italy  相似文献   

8.
Frequency and amplitude stabilization device for a cw CO2 laser     
D. Courtois  C. Thiebeaux  A. Delahaigue  E. Merienne  P. Jouve 《Optics & Laser Technology》1981,13(3):155-159
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9.
Third international congress for laser surgery: Graz, Austria, 24–26 September 1979     
A.F. Purdie 《Optics & Laser Technology》1980,12(1):45-46
  相似文献   

10.
Evaluation of the speech motor control system in amyotrophic lateral sclerosis     
David B. Rosenfield  Nagalapura Viswanath  Kathy E. Herbrich  Harvey B. Nudelman 《Journal of voice》1991,5(3)
  相似文献   

11.
The physics and mathematics of the second law of thermodynamics     
《Physics Reports》1999,310(1):1-96
  相似文献   

12.
The ν2 (CO stretching) vibration-rotation bands of H2CO and D2CO near 5.8 μm have been studied using the technique of laser Stark spectroscopy. The following vibrational and rotational constants have been determined:
Contents
1. Introduction4
1.1. The basic questions4
1.2. Other approaches8
1.3. Outline of the paper11
2. Adiabatic accessibility and construction of entropy12
2.1. Basic concepts13
2.2. The entropy principle19
2.3. Assumptions about the order relation21
2.4. The construction of entropy for a single system24
2.5. Construction of a universal entropy in the absence of mixing29
2.6. Concavity of entropy32
2.7. Irreversibility and Carathéodory’s principle35
2.8. Some further results on uniqueness36
3. Simple systems38
3.1. Coordinates for simple systems40
3.2. Assumptions about simple systems42
3.3. The geometry of forward sectors45
4. Thermal equilibrium54
4.1. Assumptions about thermal contact54
4.2. The comparison principle in compound systems59
4.3. The role of transversality64
5. Temperature and its properties67
5.1. Differentiability of entropy and the existence of temperature67
5.2. Geometry of isotherms and adiabats73
5.3. Thermal equilibrium and uniqueness of entropy75
6. Mixing and chemical reactions77
6.1. The difficulty in fixing entropy constants77
6.2. Determination of additive entropy constants79
7. Summary and conclusions88
7.1. General axioms88
7.2. Axioms for simple systems88
7.3. Axioms for thermal equilibrium88
7.4. Axiom for mixtures and reactions89
Acknowledgements92
Appendix A92
A.1. List of symbols92
A.2. Index of technical terms93
References94
  相似文献   

13.
We have measured the energies and linewidths of the pionic Kα X-rays for 20Ne and 22Ne using a natural liquid-neon target. The results are
ConstantH2COD2COUnit
ν01746.0111701.620cm?1
A′281807.8 ± 6.141696.6 ± 7.MHz
B′38608.7 ± 5.32068.4 ± 7.MHz
C′33738.7 ± 3.25998.6 ± 10.MHz
μ″2.328 ± 0.0062.344 ± 0.006Debye
μ′2.344 ± 0.0062.364 ± 0.005Debye
  相似文献   

14.
We have detected large deviations of the MJ = 0, J = 2 ← 1 Stark effect transition in the linear molecule HCN?HF from predictions of second-, and even fourth-, order perturbation theory. In order to account satisfactorily for the observed effect it has been necessary to set up and diagonalize the appropriate energy matrix. Smaller deviations in the case of MJ = 1, J = 2 ← 1 have likewise been treated. The values of the electric dipole moment for HCN?HF calculated from these transitions, which show large and small deviations from second-order theory, and from one (MJ = 3, J = 4 ← 3) which shows effectively zero deviation, are now consistent and are as follows:
20Ne22Ne
Neenergy (keV)239.12±0.14230.49±0.88
width (keV)15.43±0.4112.65±3.51
  相似文献   

15.
About two hundred Stark resonances of the ν2 and ν5 vibration-rotation bands of CD335Cl, using a 9.4 μm CO2 laser as a source, have been measured. By combining these data with the zero-field microwave spectra the following molecular constants have been determined (with the standard deviations in parentheses):
J + 1 ← JMJμ/D
2 ← 105.627
15.601
4 ← 335.608
Mean5.612
  相似文献   

16.
Doppler-limited laser excitation spectra for four bands of PrO have been recorded: System XvII 0-0, System XXI 0-0 and 0–1, and the 0-0 intercombination between the upper and lower states, respectively, of Systems XVII and XXI. First lines in R and P branches prove that Systems XVII and XXI are, respectively, Ω′ = 4.5 ? Ω″ = 3.5 and Ω′ = Ω″ = 4.5. Hyperfine components are well resolved for all four excitation bands. Rotational and hyperfine constants are determined by least-squares fits of data from all four bands together. In addition, fluorescence spectra, recorded from various J′, v′ = 0 levels of the upper states of Systems XVII and XXI, reveal five new low-lying states. Principal constants (in cm?1) for nine Ω-states follow (1σ uncertainty in parentheses):
ν2ν5
ν01 028.67275 (15)1 059.96970 (11)(cm?1)
A78 765.20 (89)78 030.21 (109)(MHz)
B110 805.29 (26)10 860.10 (13)(MHz)
5?25 080.77 (99)(MHz)
D8 756.0 (43)(MHz)
μ1.90741 (33)1.90607 (36)(D)
μ(ground state)1.90597 (33)(D)
  相似文献   

17.
Rotational analysis of 13 emission bands of PrO belonging to 10 different systems was carried out. The derived constants are as follows:
StateTvBvd(hfs)
Ω′ = 4.5 (System XXI)18 882.388 (2)0.353001 (18)0.12403 (71)
Ω′ = 4.5 (System XVII)16 594.075 (1)0.353736 (20)0.12977 (67)
Ω″ = 3.53 887.15 (16)0.35751 (28)
Ω″ = 3.52 931.66 (15)0.35712 (21)
Ω″ = 4.52 155.16 (30)0.36264 (67)
Ω″ = 5.52 099.16 (31)0.35079 (71)
Ω″ = 3.52 064.34 (13)0.35654 (20)
Ω″ = 4.5 (System XXI)217.383 (1)0.362134 (20)0.27744 (66)
Ω″ = 3.5 (System XVII)0.00.360948 (16)?0.00809 (85)
  相似文献   

18.
The ν3 fundamental band (CO stretch) of HDCO at 1724 cm?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v3 = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:
ν0B′D′ × 107B″D″ × 107
18 665.19(1)0.3530(1)1.80(5)0.3622(1)2.85(1)
18 613.22(1)0.3517(1)0.4(3)0.3606(1)2.4(2)
17 842.32(1)0.3560(1)3.0(1)0.3621(1)2.7(1)
17 796.09(4)0.3532(3)2.4(8)0.3604(2)2.7(6)
18 628.22(3)0.3530(6)1.8(8)0.3620(5)2.7(7)
14 426.12(2)0.3519(1)5.5(6)0.3620(1)1.9(6)
13 541.44(2)0.3500(2)3.7(5)0.3605(2)2.3(5)
13 645.78(8)0.3511(3)3.1(5)0.3620(2)2.8(5)
12 961.98(4)0.3445(4)4.5(4)0.3603(3)2.3(7)
9 600.47(1)0.3454(1)2.8(2)0.3620(1)3.0(3)
16 591.29(1)0.3536(1)0.5(2)0.3610(1)2.6(1)
11 912.89(1)0.3480(2)8.5(8)0.3610(1)2.2(6)
10 429.62(2)0.3450(1)3.1(1)0.3610(1)3.0(3)
  相似文献   

19.
The measurements of the microwave spectrum of BrF were carried out on the hyperfine components of J = 1 ← 0 and J = 2 ← 1 rotational transitions of 79BrF and 81BrF. A direct diagonalization procedure of the energy matrix of the total Hamiltonian including Stark effect has been used. The following constants were derived:
ConstantGround statev3 = 1 stateUnits
ν01724.267cm?1
A198 119.75198 210.4MHz
B34 910.64634 676.6MHz
C29 561.48829 331.3MHz
μa2.33022.3486D
μb0.1950.190D
  相似文献   

20.
The (0,0) bands of nine prominent electronic transitions, Systems X, XI, and XVI through XXII, in the wavelength region 500–800 nm were studied. High-precision (±0.005 cm?1), Doppler-limited, selectively detected cw-dye laser fluorescence excitation spectra for Systems XVI through XXII were recorded and analyzed. Definitive Ω assignments for the upper and lower states of these transitions were established from identified first lines in the P and R branches. Resolved fluorescence studies revealed 22 additional electronic transitions in the same wavelength region, many of which provide energy linkages between the upper or lower states of previously observed transitions. The comprehensive energy level diagram assembled from 31 electronic transition linkages comprises a total of 22 upper and lower electronic levels. Ω assignments and relative energies for the electronic states of the transitions studied (including Systems XIV and IX identified in fluorescence and the proposed assignment for System VI) are
79BrF
81BrF
Be (MHz) 10 667.610 (60)
10 616.522 (70)
eq0Q (MHz) 1086.80 (30)
908.09 (20)
eq1Q (MHz) 1085.66 (60)
907.41
  相似文献   

SystemΩ′T′0 (cm?1)Ω″T″0 (cm?1)
VI5.5111024.52157
IX4.5165973.53887
X5.5132594.5220
XI5.5138654.5220
XIV5.5165954.52157
XVI5.5191694.53720
XVII4.5165973.50
XVIII7.5213216.53965
XIX6.5196875.52111
XX5.5180694.5220
XXI4.5188854.5220
XXII5.5191694.5220
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