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INGLÊS

Low Temperature Physics Ii / Kaltephysik Ii

de S. Flugge

59,61€ + 10% EM CARTÃO

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 In the case of low impedance (high current and low voltage) few turns of thick metal should be used. In the case of high impedance (low current and high voltage) many turns of thin material are needed. A nice system for low impedance coils was deve- loped by BITTER.
INGLÊS

Electron-Emission Gas Discharges I / Elektronen-Emission Gasentladungen I

de S. Flugge

118,59€ + 10% EM CARTÃO

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 v. Formation of negative ions by processes other than attachment in the gaseous phase at low X/po 17. Introduction. As early as 1912, J. J. THOMSON [32J in his first mass spectro graph observed negative ions of 0-, Cl-, H- and what he believed to be N-. He at first ascribed these to possible dissociation of polar gaseous compounds by electron impact but control studies using ionization at low energies in glow discharges indicated that this was not the origin. O. W. RICHARDSON [33J in his book on emission of electricity from hot bodies reported negative ions to come from hot salts. From there on many experimental studies over the years indicated that negative ions could be formed by various processes. By the middle nineteen hundred and thirties the data fairly clearly identified several processes as being active and MASSEY and SMITH [34J developed the theory underlying some of them. More data are summarized in MASSEY''S excellent little monograph on Negative Ions and in )L\SSEY and BURHOP''S recent book [35]. Since that period, stimulated by various investigations and certain industrial problems, very careful studies of the appearance of such ions by mass spectrograph have been carried out in the laboratory of K. G. EMELEUS in Belfast by SLOANE and his co-workers [3J that haw clarified the questions and indicated what ions have been observed and something of the processes at work.
INGLÊS

Structural Research / Strukturforschung

de Dr. Andre Guinier, Dr. G. R. Ringo, Dr. Gerard Fournet, Dr. Gerard Von Eller, Dr. J. Bouman, Dr. J. W. Anderegg, Dr. M. B. Webb, Professor Dr. H. Raether, Professor Dr. P. Kaesberg e Professor Dr. W. W. Beeman

118,59€ + 10% EM CARTÃO

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 107 In this way the absolute values of the structure factors may be found, not the phases (6. 8). The problem to find these phases is the phase problem. The present article will treat the following topics. At first the description of the ideal crystal will be given in Chap. B. The underlying principles of this description are the concepts of reciprocal lattice, FOURIER synthesis and sym metry. The evaluation of the intensity will then follow in Chap. C and D. Chap. E is concerned with the phase problem and related topics. Though this article treats the analysis of crystal structures, the fundamental concepts for other structures will here be found too. But these topics, and the experimental methods, will l find their place elsewhere . B. Description of the crystalline state. I. Lattice theory. a) The direct lattice. 8. Introduction. In Sect. 3, a description of the ideal crystal was given: The space, occupied by a crystal, is divided into congruent parallelepipeds, each with the same orientation. This parallelepiped is defined by the three basic vectors, a, band c, drawn from an origin 0 (Fig. 2), and is called the primitive cell. This cell is filled with atoms (or ions), and the same configuration of atoms is repeated in space. It has been aptly called a three-dimensional wallpaper, as on a wallpaper the same pattern is repeated again and again.
INGLÊS

Structure Of Atomic Nuclei / Bau Der Atomkerne

de S. Flugge

118,59€ + 10% EM CARTÃO

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 This explains why only light nuclei (A < 20) and isolated groups of nuclei higher in the Periodic Table were thus treated. Usually such calculations were rewarded by agreement with experiment especially those for light nuclei 2 and 20S nuclei near the double closed shell at Pb 3.
INGLÊS

Geophysik Ii / Geophysics Ii

171,59€ + 10% EM CARTÃO

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 45 downwards because (j on the average increases with height; but this conclusion does not follow from (18.3) when the dependency of Kc upon ~o is taken into consideration. s 2 ERTELl and PRIESTLEY and SWINBANK have shown that the upward eddy flux of sensible heat must be larger than indicated by (18.3), because this formula does not account for the fact that rising eddies are systematically warmer than sinking eddies because of the effect of buoyancy. The reader is referred to the reviews by SUTTON [22], [23] and PRIESTLEY and SHEP PARD [15) for further details concerning eddy-flux of heat and turbulent diffusion. 19. RICHARDSON''S criterion. The right-hand side of (15.10) represents the rate of production of eddy energy. The last term represents energy loss by dissipation; in order that the eddy energy shall be maintained, it is therefore necessary that P div V" - (! V" v" . grad. v > O.
INGLÊS

Astrophysik Ii: Sternaufbau / Astrophysics Ii: Stellar Structure

de Armin J. Deutsch, Cecilia Payne-Gaposchkin, E. Margaret Burbidge, E. Schatzman, F. Zwicky, G. R. Burbidge, H. C. Arp, Hans E. Suess, Harold C. Urey, Lawrence H. Aller, Marshal H. Wrubel, P. Ledoux e Th. Walraven

118,59€ + 10% EM CARTÃO

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 Sects. 12, 13. 89 sequence and that subgiant and fainter stars in globular clusters have ultraviolet excesses. When dealing with stars whose physical properties are imperfectly under stood, such as in globular cluster stars, we cannot rely too heavily on the empiri cal calibration by the kinds of stars used to define Fig. 5, to determine their true, unreddened U-B, B-V curve. But if by a combination of arguments, principally the reddening in the region of the stars we do known about, we can assign a fairly probable unreddened U-B, B-V curve to a group of stars about which we know little, the argument may be turned around. In this case some information may be gained about the energy envelope of the stars by examining the differences between the normal two-color index curves for the unknown group of stars compared to the known. In general there seem to be two possible causes for different stars defining different normal sequences in the U-B, B-V plane. One, the relative energy distribution in the continuum in the U, B and V photometry bands are different. An example of this is the effect of the Balmer depression in supergiants. This, of course, requires deviation from black body radiation curves for one or both groups of stars. This cause seems to be the dominant effect for very blue, hot stars where the depression of the continuum by absorption lines is at a minimum.
INGLÊS

Fluid Dynamics I / Stromungsmechanik I

171,59€ + 10% EM CARTÃO

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 IV we have established the equations for compressible flow of gases and these can of course be used to deterÂ mine when density changes in a gas flow are in fact negligible.
INGLÊS

Atoms Iii - Molecules I / Atome Iii - Molekule I

de S. Flugge

118,59€ + 10% EM CARTÃO

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 dissociation, E, of a dimer into two monomers and that, E', of a trimer into a dimer and a monomer. The separate distributions for the monomer, dimer, and trimer required to fit the data are shown as is the sum of these distributions.
INGLÊS

Neutrons And Related Gamma Ray Problems / Neutronen Und Verwandte Gammastrahlprobleme

de Edoardo Amaldi, L. V. Spencer, M. J. Berger e U. Fano

171,59€ + 10% EM CARTÃO

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 On the high energy side, this artic1e does not cover the cascade shower processes which are dealt 2 with in cosmic ray studies * In this connection it is recalled that the cascade shower process, which involves electrons and positrons besides X rays, becomes predominant above 10 Mev in heavy elements, and above 100 Mev in light ones.
INGLÊS

Fluid Dynamics / Stromungsmechanik

118,59€ + 10% EM CARTÃO

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 Sect 2. 317 tinuity surfaces 1. This suggests that a wake pressure Pw be associated with each flow past a bluff body, and that a wake parameter (2. 4) which plays the same role as the cavitation parameter (2. 1), be defined for the flow. This idea has been made the basis of a modified wake theory (ef. Sect. 11) which proves to be in good qu- titative agreement with pressure and drag measurements. It should be emphasized, however, that un h like the cavitation number, the wake parameter is a quantity which is not known a priori, and must be empirically determined in each case. (3) Jet flows. The problem of jet efflux from an orifice is one of the oldest in hydrodynamics and the first to be treated by Fig. 3a. the HELMHOLTZ free streamline theory. Of particular importance for engineering applications is the discharge coefficient Cd'' which is defined in terms of the discharge Q per unit time, the pressure P, and the cross-sectional area A of the orifice, by the formula, (2. 5) where e is the fluid density. Two methods of measuring Cd have been most fre quently adopted. In the first the liquid issues from an orifice in a large vessel under the influence of gravity _,-____________ . , (Fig. 3 a), while in the second it 1 L is forced out of a nozzle or pipe under high pressure (Fig. 3 b).
INGLÊS

Structure Of Liquids / Struktur Der Flussigkeiten

de Frank P. Buff, H. S. Green, Sohei Kondo e Syu Ono

59,61€ + 10% EM CARTÃO

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 Although all the relations for a plane interface can be deduced from the cor- responding ones for a spherical interface by putting the curvature equal to zero, the planar and the spherical cases are considered separately because of the prac- tical importance and easy physical visualization of a plane interface.
INGLÊS

Principles Of Electrodynamics And Relativity / Prinzipien Der Elektrodynamik Und Relativitatstheorie

de S. Flugge

59,61€ + 10% EM CARTÃO

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 will be "asymptotically integrable", that is to say, if we displace a vector parallel to itself along a closed curve whose total length is proportional to r, then, as we remove the curve to infinity, the change of the vector that results from the circuit about the curve will tend to zero.
INGLÊS

Light And Matter Ia / Licht Und Materie Ia

de L. Genzel

118,59€ + 10% EM CARTÃO

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 159 elements only between states which differ in one of the single-electron wave functions, in short, HeR induces only one-electron transitions. The matrix elements 1mn and Pmn reduce to matrix elements between the single-electron wave functions. We are interested primarily in crystalline solids for which the band model is a good approximation. The Bloch single-electron wave function in this model has the form: N''I ili-'';; U. r.;;) ( (1.14) ""nk r, =e nh\r , where n is the band index and U (r) has the periodicity of the lattice. The form of the Bloch function follows from the translational symmetry of the crystal, and the matrix elements between Bloch states are subject to the condition of wave-vector conservation: k''=k, for
INGLÊS

Light And Matter Id / Licht Und Materie Id - Infrared And Raman Spectra Of Non-Metals

de D. Strauch, H. Bilz e R.K. Wehner

118,59€ + 10% EM CARTÃO

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 The main task is to arrive at a physically correct treatment of electronic degrees of freedom, as for example in an electronic 'shell' model, which leads to the description of phonon spectra in terms of long-range polarizabilities and short-range deformabilities.
INGLÊS

Geophysik Iii / Geophysics Iii

de G. Schmidtke, K. Rawer e K. Suchy

118,59€ + 10% EM CARTÃO

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 With this as goal, the writers were asked to present their specific field in such a way that access is possible to any scientist without special a priori information in that field;
INGLÊS

Light And Matter Ic / Licht Und Materie Ic

de Hermann Haken

95,40€ + 10% EM CARTÃO

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 The concept of the laser came into existence more than a decade ago when ScHAWLOW and TowNES showed that the maser principle could be extended to the optical region. Since then this field has developed at an incredible pace which hardly anybody could have foreseen. The laser turned out to be a meeting place for such different disciplines as optics (e.g. spectroscopy), optical pumping, radio engineering, solid state physics, gas discharge physics and many other fields. The underlying structure of the laser theory is rather simple. The main questions are: what are the light intensities (a), what are the frequencies (b), what fluctua tions occur (c), or, in other words, what are the coherence properties. Roughly speaking these questions are treated by means of the rate equations (a), the semiclassical equations (b), and the fully quantum mechanical equations (c), respectively. The corresponding chapters are written in such a way that they can be read independently from each other. For more details about how to proceed, the reader is advised to consult Chap. I.4.
FRANCÊS

Light And Matter Ii / Licht Und Materie Ii

de S. Flugge

117,26€ + 10% EM CARTÃO

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FRANCÊS

Spectroscopy I / Spektroskopie I

de S. Flugge

82,14€ + 10% EM CARTÃO

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INGLÊS

Low Temperature Physics I / Kaltephysik I

de John Gilbert Daunt

59,61€ + 10% EM CARTÃO

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INGLÊS

Dielectrics / Dielektrika

de P. W. Forsbergh, W. Franz e William Fuller Brown

118,59€ + 10% EM CARTÃO

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INGLÊS

Optics Of Corpuscles / Korpuskularoptik

de Detlef Kamke, Heinz Ewald, Siegfried Leisegang, Tor Ragnar Gerholm e W. Glaser

59,61€ + 10% EM CARTÃO

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INGLÊS

Geophysik I / Geophysics I

59,61€ + 10% EM CARTÃO

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INGLÊS

Rontgenstrahlen / X-Rays

de Arne Eld Sandstrom, D. H. Tomboulian, H. H. Pattee, P. Kirkpatrick, S. Town Stephenson e W. Schaaffs

118,59€ + 10% EM CARTÃO

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INGLÊS

Atoms I / Atome I

de E. E. Salpeter, E. Richard Cohen, H. A. Bethe e Jesse W. M. Dumond

118,59€ + 10% EM CARTÃO

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