摘要:

AbstractDas freie Spinteilchen wird als eine pol‐dipolartige Massendistribution mit zeitartigem Linienträger in einer sonst leeren MINKOWSKI‐Welt aufgefaßt. Die Erhaltungssätze für Impulsvektor und Momententensor legen nicht die Weltlinie des Spinteilchens (Mikrobewegung) fest, sondern beziehen sich auf den – mit dem Teilchen im allgemeinen nicht zusammenfallenden – Schwerpunkt (Makrobewegung). Der Momentensatz zerfällt kovariant in einen Erhaltungssatz für den Spinvektor und einen solchen für das Bahnmoment der Schwerpunktsbewegung. Im ganzen ist das Spinteilchen weitgehend das Analogon eines Systems, dessen Zustände eine irreduzible unitäre Darstellung der POINCARÉ‐Gruppe aufspannen: Der willkürlichen Zitterbewegung entspricht die Willkür bei der Auswahl einer der unitär äquivalenten Darstellungen. Abschließend werden zwei durch Nebenbedingungen ausgesonderte spezielle Formen der

ISSN:0003-3804    

DOI:10.1002/andp.19674750302

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe temperature dependence of the transverse optic (T.O.) mode with wave numberk∼ 0, and of its contribution to the electric susceptibility, is discussed both in zero and in finite field, in terms of the renormalization of a Hamiltonian proposed by SILVERMAN and JOSEPH. The renormalization proceeds in two steps: (a) a canonical transformation is introduced which removes linear terms and also quadratic and cubic terms nondiagonal in the normal mode coordinates for whichk>0; (b) a thermal average is made of quartic terms proportional to the square of the ferroelectric mode frequency, giving rise to an effective frequency which depends on temperature. In zero field, it is shown that the contributions of T. O. modes to the renormalized frequency become large at low‐temperature, preventing this frequency from vanishing at any temperature, and thus rendering impossible a ferroelectric transition. In finite field of sufficient magnitude the optical branch frequencies are all raised, reducing their stabilizing effect. It is shown that if the stabilization is reduced sufficiently, there will exist two phases of which one is metastable, has a ferroelectric mode frequency which vanishes, and is capable of two opposed states of polarization. The second phase is stable, with a frequency which does not vanish and a susceptibility which exhibits a maximum independently of the properties of the first phase. Such a maximum has been observed by HEGENBA

ISSN:0003-3804    

DOI:10.1002/andp.19674750303

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractThe internal conversion electron spectrum of transitions in the decays of the (86 min)197mPt and the (18 h)197Pt have been studied by means of an iron‐free, double focussing beta‐ray spectrometer. Conversion electrons were observed for transitions of 268.2 ± 0.2 and 269.1 ± 0.2 keV, the first ascribed to the decay of (18 h)197Pt while the second ascribed to the decay of (86 min)197mPt. An energy level in197Au at 548 keV has also been observed for the first time from the decay of197mPt, de‐excited by the 269–279 keV cascade and a direct 548.4 ± 0.4 keV transition to the ground state. A new gamma transition of energy 202.5 ± 0.1 keV was found, decays from the 279 keV excited level in197Au, with anE2 character. The internalK‐conversion coefficients of most transitions in197Pt and197Au were determined by the internal‐external conversion method. TheK‐internal conversion coefficient of the 191 keV transition in197Au indicated noE0 contribution. Multipolarity data, obtained from the absolute or ratios measurements of conversion coefficients, were utilized for assigning possible spins and parities to the levels

ISSN:0003-3804    

DOI:10.1002/andp.19674750304

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractTotal yields and angular distributions of 380 keV gamma rays from the Cr53(p,n γ) Mn53reaction have been measured for proton energies below 2.5 MeV. The experimental results are in good agreement with predictions of the statistical compound‐nucleus theory. The angular distributions of 560 keV gamma rays upon the proton inelastic scattering on Cr53atEp= 2.3, 2.4 and 2.5 MeV are isotropic, which is commensurate with a ½−assignment to the first excited state of

ISSN:0003-3804    

DOI:10.1002/andp.19674750305

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractA spectrometer is described allowing the measurement of transverse relaxation times ≳ 30 ms at 40 kc/s and of longitudinal relaxation times ≳ 0,1 s within the range of 40 kc/s to 1 Mc/s at any frequency. The relative large sample volume of 800 cm3and the premagnetisation of the sample in a strong magnetic field (⩽ 800 Oe) assure a sufficient signal intensity.The longitudinal proton relaxation time in aqueous solutions of Mn2+‐ions determined in a temperature range of 15…95°C at frequencies between 15 kc/s and 1 Mc/s indicates an important influence of the hyperfine coupling. The experimental results are in good agreement with the result of the calculations of SAMES and MICHEL in Part I of this paper. The doubling of electron relaxation time and the decrease of scalar contribution of the relaxation rates for high temperatures during passing from high to low fields is evident. Furthermore, the theoretically predicted large range of validity of the weak field formula which describes the experimental results up to 1 Mc/s is noteworthy. However, it is not possible to give a reasonable interpretation of the experimental results by means of the theory of Solomon and Bloembergen.From the experimental results the till now always assumed temperature independence of the coupling constant of the scalar interaction in aqueous solutions of Mn2+‐ions could clearly be proved between 0 and 100°C.Studies on solutions of Mn2+‐ions in formic acid and methanol, respectively, show that the dipole contribution of the relaxation rates for sufficient long correlation times will be also affected by the hyperfine coupling during passing from high to weak

ISSN:0003-3804    

DOI:10.1002/andp.19674750306

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractEs werden die von radial auf die SCHWARZSCHILD‐Singularität (beir= 0) frei fallenden Beobachtern registrierten Rot‐ bzw. Violettverschiebungseffekte betrac

ISSN:0003-3804    

DOI:10.1002/andp.19674750307

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

摘要:

AbstractA theory of the gravitation field is proposed in connection with a new spinorial formulation of EINSTEIN'S equivalence principle and HEISENBERG'S unified quantum theory of fields. In the gravitation theory the gravitational field is given by the coefficientshAi(xl) of the matrix of the anholonomic non‐Lorentzian transformations from the Lorentzian metric ηABto the physical metricgik(xl) of the Riemannian space‐timeV4. The field equations and the commutation rules for thehAiare working in the Lorentzian space. The metric of the RiemannianV4is given by the averagegik= 〈|hAi,hBk|〉ηAB. For all matter fields (and for HEISENBERG's “Urfeld”) the field equations are equations in this RiemannianV4. The interaction between the gravitational fieldhAiand the matter‐tensor is given by a potential‐like coupling‐term.We prove that this new theory of gravitation gives for makroscopic matter the same linear approximation equations like general relativity and that a perihel‐motion δφ ≈ 76 δφ EINSTEIN results in the second approximation. But, we are finding essential differences to general relativity for the theory of gravitation radiation and for the theory of interaction of matter wit

ISSN:0003-3804    

DOI:10.1002/andp.19674750308

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0003-3804    

DOI:10.1002/andp.19674750309

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY

ISSN:0003-3804    

DOI:10.1002/andp.19674750301

出版商:WILEY‐VCH Verlag    

年代:1967

数据来源: WILEY