Experimental Test of a Time-Temperature Formulation of the Uncertainty Principle Via Nanoparticle Fluorescence

No Heading The uncertainty in the measured fluorescence decay lifetimes of 30 nm particles of YAG:Cc was used to evaluate the predictions of a novel form of the Heisenberg uncertainty principle suggested by de Sabbata and Sivaram, T t h/k. The worst-case uncertainty in temperature of 4.5 °K (as derived from the relationship between temperature and lifetime) and the measured uncertainty in decay lifetime, 0.45 ns, yielded an internal estimate of T t = 2.0 × 10^–9 °K s, which is 263 times larger than /k = 7.6 × 10^–12 °K s. An external estimate of T t = 4.5 × 10¹¹ °K s (which is = 6 times /k) is derived from the independently measured uncertainty in the temperature of the sample and the experimentally determined uncertainty in lifetime. These results could be low by a factor of 5.6 if signal averaging must be taken into account. If valid, the findings are consistent with the predictions of this version of the uncertainty principle and they imply the existence of a type of thermal quantum limit.     

Hard gamma radiation in the decay of Lu176m

Gamma lines 1·05 MeV(4 × 10^–6 quanta/decay) and 1·14 MeV (9 × 10^–6 quanta/decay), giving evidence of the existence of a new level in Hf¹⁷⁶ with an energy of 1·14 MeV, were found in the decay of Lu^176m with a half-life of 3·7 hours, using the scintillation method. The component of the beta spectrum, exciting this level, has a maximum energy of 0·17 MeV and logft=8·3. The spin of this level proved to be equal to one. The level was interpreted as a single-particle neutron level withn ₀: 5/2^– (512),n ₁: 7/2^– (514);I=1⁺.

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- Lu^176m

Lu^176m 3,7 - 1,05 MeV (4.10^–6 /) 1,14 MeV (9.10^–6 / /), Hf¹⁷⁶ 1,14 MeV. -, , 0,17 MeV logft = =8,3. . cn ₀: 5/2^– (512),n ₁: 7/2^– (514);I = 1⁺h

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The authors thank L. K. Peker from the Leningrad State University for a helpful discussion of their results.     

Equilibrium state of toroidal electron beam

The paper deals with the collective behaviour of electrons which rotate in a magnetic field used in a betatron. It is shown experimentally that there exists strong interaction between the electrons, which leads to the rapid formation of the equilibrium state with characteristic distribution of the charge density in the cross-section of the toroidal beam. The corresponding relaxation time is of the order of 1 sec. A statistical theory of the equilibrium beam is elaborated. Its main result is that the effective radius of the beam is a function of two parameters, one of which is proportional to the thermal energy of the electrons and the other to the perveance of the beam. The charge contained in a toroidal beam of given effective cross-section is equal to the product of the charge the beam would contain at zero temperature and a coefficient, which is a function of the temperature of the beam. Its value is unity at zero temperature and rapidly decreases with increasing temperature. The cause of cooling of the beam is shown.

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, . , , . 1S. . , , — I/(E₀/q)^3/2 (I — , ₀ — q ). , , , , , . . .

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Now Institute of Vacuum Electronics, Czechosl. Acad. Sci., Prague.

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In conclusion the author thanks J. Luká and L. Hyttych for invaluable help in the experiments, A. Rajský for constructing the electronic apparatus and J. Sokol for preparing the miniature probe.     

К ВОПРОСУ O КРИТИЧЕСКО Й ЧАСТОТЕ ПРИ ПРЕРЫВИСТОМ ОСВЕ ЩЕНИИ

c , c n , n AgBr. .     

Energy relaxation in aϕ 4 with long range interactions

We investigate the influence of long range interactions on the relaxation behaviour of a lattice model with an on-site potential of ⁴-type and infinite range harmonic interactions. For finite number of particlesN, it is shown that the autocorrelation functions <E _n(t)E _n > of the fluctuations of the one-particle energiesE _n(t) decays exponentially. The corresponding relaxation time is proportional toN and is given by (T, N) =N₀(T). The temperature dependent time scale ₀ can explicitly be related to the dynamics of a one-particle correlator of the noninteracting system. The results are derived using Mori-Zwanzig projection formalism. The corresponding memory kernel is calculated within a mode coupling approximation and by a perturbative approach. Both results agree in leading order in 1/N. It is speculated that any interaction of range generates a timescale .     

The distribution of ions and their valencies in manganese ferrites I. MnFe2O4+γ ferrites

A model for the distribution of cations in the spinel lattice of manganese ferrites MnFe₂O₄₊ was elaborated on the basis of the experimental studies of the basic magnetic quantities, electrical conductivity and magnetic relaxation of the given ferrites, taking into consideration their crystallographic properties. The conclusions following from this model are in good agreement with the experimental results obtained by us and by other authors both for stoichiometric manganese ferrite and for a ferrite where 0.

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I. MnFe₂O₄₊

, MnFe₂O₄₊ . , , , , , 0.

     

Локалъная чувствите лъностъ фотокатодов фотоумножителей

. . .

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The local sensitivity of photo-multiplier photo-cathodes

The influence of the non-uniform distribution of the sensitivity of a photo-multiplier photo-cathode on the spectrum shape of the output pulses from a scintillation detector is studied. Methods of scanning the local sensitivity and determining its distribution function are described. The theory was compared qualitatively with measurement on a slow-neutron detector from a mixture of zinc sulphate and boric acid.

     

Three variations in the intensity of cosmic radiation in the first half of 1958

The time courses are given of three variations in the intensity of cosmic radiation, which occurred in the first half of 1958. The measuring apparatus is described and the energies of the particles recorded a reestimated. The paper is the partial result of systematic measurements of the intensity of cosmic radiation carried out in Czechoslovakia in the International Geophysical Year.

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1958

, 1958 . . , .

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The authors heartily thank the Institute of Geomagnetism in Krasnaja Pachra, near Moscow, and especially its director, Prof. M. B. Pukov, and Dr Ju. M. Kopylov for the neutron counters.The authors wish to thank Prof. V. Petrílka, corresponding member of the Czechoslovak Academy of Sciences, and Prof. L. Jurkiewicz, from the Academy of Mining and Heavy Industry in Cracow for help in the work and Academician J. Novák, who made possible the numerical evaluation of the data in the Mathematical Institute of the Czechoslovak Academy of Sciences. Especial thanks go to F. Pilát and B. Slavík for their great help in setting up the apparatus and to all colleagues who took part in the measurements.     

BЛИЯHИE CBETA HA MOHOКPИCTAЛЛИЧECКИE ПЛACTИHКИ AgCl

The paper deals with the influence of light,=403 m, on the absorption of single-crystal plates of AgCl, grown by the capillary method. It was found that crystals with blue luminescence show no maximum in the region measured. For crystals with green luminescence a broad absorption maximum was found at – 590 m, which is partly bleached during further irradiation by light from the region of the absorption maximum. Measurements were preformed at room temperature.

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КРУЧЕНИЕ ПРИЗМАТИЧЕ СКИХ СТЕРЖНЕЙ ШВЕЛЛЕ РНОГО ПОПЕРЕЧНОГО СЕЧЕНИЯ

- [3], [4], U(x, y) . - U(x, y) -, . B § 10 - . , - , - D, . - .     

Ferromagnetic resonance in thin cobalt films

The paper gives the results of measuring ferromagnetic resonance on thin cobalt films, vacuum deposited on unheated glass slides. The values of the (g-factor, the width of the curve, the effective stress and uniaxial induced anisotropy were determined as a function of the thickness of the film from measurements of the ferromagnetic absorption in a magnetic field normal and parallel to the surface of the film. Measurements were carried out on a frequency of 9200 MHz and on film thicknesses of 180 to 1800 Å. A qualitative explanation of the observed dependences is given.

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, . , , g-, , , . 9200 MHz 180–1800 Å. .

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The author thanks V. Kamberský and Z. Málek, C. Sc., for providing some of the cobalt films and for help in depositing and measuring the thicknesses, S. Kadeková and M. Polcarová for valuable advice in determining the structure of the films, J. Míová for carefully plotting the results of measurements and Z. Málek and O. tirand for carefully reading the paper and for valuable discussions.     

Determination of parameters in equation for ferromagnetic resonance of ferrites

The paper describes a new method for determining the parameters in the equation for ferromagnetic resonance — the internal effective field, the spectroscopic splitting factor and the saturation magnetization in polycrystalline magnetically isotropic ferrites. Relations are derived for calculating these parameters by means of the values of the resonance external static fields, which are obtained by measuring on samples having different geometrical shapes and differently arranged static and microwave magnetic fields. The advantages and disadvantages of the method and remarks on the experimental method are given. The paper ends with an example of measurement.

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: , . , . . .

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The determination of the saturation magnetization of ferrites by the method described here was reported on at the Seminary on Ferrites in Microwave Technique, held by the Institute of Technical Physics, Czechoslovak Academy of Sciences, and the Research Institute of Communications Engineering of A. S. Popov, on November 25, 1959.     

Domain structure of cobalt whiskers

An experimental investigation is made into the domain structure of cobalt whiskers by the colloid technique. A new type of domain structure was found; the width of the domains is studied as a function of the thickness of the whisker. This dependence follows a two-thirds power law and does not agree with existing theories which predict a half power law.

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. . , .

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In conclusion the authors wish to thank V. Janovec and F. Kroupa for valuable remarks and A. Tahalová for help in growing the whiskers.     

A note on the Watanabe theory of weak interactions

It is shown that according to the Watanabe theory of weak interactions a resonant scattering of electrons by protons must take place. The resonant energy depends on the massm _B of the intermediate boson. Form _B=2300m _e this energy is about 213 MeV in the centre of the mass system (c. m. s.). The energy width at resonance is 1·4 MeV.

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, . , , . _{m B}=2300_{m B} , 213 MeV -. 1,4 MeV.

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The author would like to thank Professor V. Votruba for suggesting this note and for valuable advice and help during the work.     

Berry's phase,density matrices and incompatible observables

Adiabatically time-varying parameter-dependent cyclic Hamiltonians are known to generate Berry's phase in state vectors in addition to the usual dynamical phase. Using the standard algorithm for collapse into a mixture following a quantum measurement process, we investigate the general nature of measurements in which the effects of Berry's phase, introduced at some intermediate stage of the measurement process, persist in the final collapsed density matrix. We find that it is possible to construct a sequence of a preparation followed by a measurement of an observable incompatible with the prepared state, where the collapsed density operator carries intermediate changes of phase in pure states; hence unitary time evolution alone is not essential for the observation of geometrical phases. This result confirms similar suggestions made by other investigators.     

More inequalities for critical exponents

A variety of rigorous inequalities for critical exponents is proved. Most notable is the low-temperature Josephson inequalitydv +2 2–. Others are 1 1 +v, 1 1 , 1,d 1 + 1/ (for d),dv, ₃ + (for d), ₄ , and _{2m 2m+2} (form 2). The hypotheses vary; all inequalities are true for the spin-1/2 Ising model with nearest-neighbor ferromagnetic pair interactions.NSF Predoctoral Fellow (1976–1979). Research supported in part by NSF Grant PHY 78-23952.     

A contribution to the domain structure of iron whiskers

The paper contains an interpretation of the domain patterns found on iron whiskers. An explanation of the closure structure at the end of a whisker grown in the [111] direction is given on the basis of a quantitative analysis. Structures, which form on whiskers strained by axial pressure and bending, are also dealt with. The results are in good agreement with experiment.

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, . [111]. , . .

     

The influence of compression on the absorption of AgBr single crystals

The influence of compression on the edge of self absorption of AgBr single crystals was studied. The measurements were performed at a temperature of –180°C. The shift of the edge of self absorption was studied both in the field of elastic and plastic deformations. The shift of the absorption edge towards the UV end of the spectrum was determined in the field of elastic deformations and towards the i.r. end in the field of plastic deformations. After the ending of the deformation and after unloading the crystal the return of the absorption edge towards the original position was observed.

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AgBr

AgBr. –180°C. , . , — . .

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The author thanks Prof. Dr. L. Zachoval and K. K. Vacek C. Sc. for their interest in this work and for many comments given during the work.     

Der OberflÄchenmartensit und die Plastische Deformation

Zusammenfassung In der vorliegenden Arbeit wird der Einflu\ des OberflÄchenmartensits auf die plastische Verformung des Austenits gezeigt. Es wurde festgestellt, da\ der OberflÄchenmartensit im Einklang mit seiner unansehnlicher Tiefe den Verlauf der plastischen Verformung des Austenits nur ganz unbedeutend beeinflu\t. Nur schwache Gleitlinien werden an den Teilchen des OberflÄchenmartensits aufgehalten; starke Gleitlinien verlaufen unabhÄngig von dem OberflÄchenmartensit. Aus der Verschiebung der OberflÄchenmartensitteilchen bei der Dehnung der Kristalle folgt ihr individuelles Verhalten und ihre gegenseitige UnabhÄngigkeit.

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. , , . , . .

     

Влияние сильного выс окочастотного поля на расслоение положи тельного столба постоянного тлеющег о разряда

. . , .

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The influence of a strong high-frequency field on the stratification of the positive column of a D-C glow discharge

An experimental study is made of the damping of moving striations in a d-c glow discharge by a strong high-frequency field. The results of measurement are in agreement with existing conceptions on the production and mechanism of propagation of moving striations. Apart from the process of damping the paper also describes the standing stratification of the positive column of a d-c discharge as a result of a superposed high-frequency discharge.

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