Transfer impedance of a probe in a drifting plasma

au un¶rt;a umu ¶rt;a na nu nauuu ¶rt;a uam mmu amm na aa. amau aa auum m mnam u mu ¶rt;a, m unam ¶rt; ¶rt;uamuu u na.     

Iterative geophysical tomography

Summary The algorithm of iterative geophysical tomography is presented. The medium is approximated smoothly by means of B-splines. The tww-point problem of ray computation is solved with the aid of paraxial approximation. The parameters of the medium are obtained from the iterative algorithm of minimizing the quadratic form. Two numerical 2-D examples are given.

---

u¶rt; au umamuuu mauu. ¶rt;a annuuaa n nu nu -na. ma na aa a nu nu naaua annuauu. aam ¶rt; n a umamu aua uuauauu a¶rt;amu . am nu¶rt; ¶rt;a 2-D u nua.

     

The periodicity of aurorae in the years 1001–1900

Summary The sequence of aurorae, observed at latitudes up to 55° between the years 1001 and 1900 was processed by methods of spectral analysis. The same methods were applied to parts of various duration of this interval. The periods predominant in the time series under investigation were determined. In all the selected parts of the interval, these periods are always located within the same frequency band. Their position is related to the periods corresponding to mutual conjunctions of the large planets.

---

¶rt; n uu, a¶rt;au a uma ¶rt; 55° nu¶rt; 1001–1900, ama nu nu m¶rt; nma aaua. a n¶rt; ¶rt; am a ¶rt;u m umaa. u n¶rt; na¶rt;au nu¶rt; u¶rt;a ¶rt;a. mu nu¶rt; ¶rt; a am umaa ¶rt;a a¶rt;m ¶rt;ua ¶rt;uaan amm. nu mum nu¶rt;au, mmmuu au u u nam.

     

On the further generalization of trochoidal frontal waves

Summary A non-linear model of trochoidal waves is presented which represents a geometrical and kinematical generalization of Gerstner's waves and of the results of[2–4].

---

¶rt;aam ¶rt; mu¶rt;a , ma m u ma u am[2–4] mu umuu u uamu mm ¶rt;u.

     

Analytical continuation of the gravity field for a two-dimensional body using an infinite series

Summary A procedure is derived which enables the analytical continuation of a two-dimensional gravity field to be expressed in the form of an infinite series. For this purpose, an apparatus is used which represents the two-dimensional analogy of Bicadze-type integrals.

---

nuaa m¶rt;ua na aum aaumu n¶rt;u ¶rt;aumau n u¶rt; ¶rt;a. nm annaam n¶rt;mau ¶rt; aau uma muna ua¶rt;.

     

Gravity topographic corrections computed from a square grid of height points

Summary Computation of terrain corrections from a map with a square grid of mean height points

---

uu mnauu nna n am ¶rt;u m u¶rt; a¶rt;am mu m nm.

     

Relation between the field of surface heat flow and the distribution ofP n -wave velocities for continents

Summary The dependence between P_n-wave velocities and the surface heat flow, temperature at the core-mantl boundary and thickness of the Earth's crust for continents (Europe, Asia, North America and Australia) was investigated statistically in connection with the problem of lateral inhomogeneities in the upper mantle. The relations obtained were compared with those determined under laboratory conditions. The conclusion is that temperature and pressure effects may provide additional explanations of the regional variations of P_n-wave velocities observed in most continents.

---

auum ¶rt;auu mu n¶rt; a nmu uua(P_n ), nm mn nm, mnam a u m mum a u¶rt;aa u n uuuma ¶rt;¶rt;m mu P_n. nua ¶rt;a mama aam u¶rt;au nu m n¶rt; amuu u u ¶rt;au u mnam a¶rt;um mmmuu mamau n¶rt;aa am. am ¶rt;, m ua uu m P_n- ¶rt; amu muma n¶rt;m auu m¶rt;uauu u a nmu muua.

     

Radioactivity and geochemistry of granulites and some related rocks from the saxonian granulite complex

Summary The distribution of radioactive(Th, U, K), major and selected trace(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) elements of granulites from the Saxonian Granulite Complex was studied. Similarly to the South Bohemian granulites, the Saxonian granulites can be divided according to the contents of their major and trace elements into two main groups, groupA containing mostly acid and subacid granulites (K ₂ O>2.5%, SiO ₂ >68%), and groupB containing mostly intermediate and basic granulites (K ₂ O<2.5%, SiO ₂ <68%). Statistically significant differences between groupsA andB were found for all major oxides and several trace elements(Rb, V, Cr, Ni). The Saxonian granulites follow the same calc-alkaline trend as the South Bohemian, granulitesA being placed mostly in the rhyolite field and granulitesB mostly in the dacite, andesite and basalt fields of this trend. The investigated granulites are characterized by a considerable scatter ofTh andU contents accompanied by very variableTh/U ratios; theTh andU concentrations of granulitesA are substantially lower than is usual for rocks of corresponding acidity.

---

¶rt;a an¶rt;u a¶rt;uamu(Th, U, K) u ua ¶rt;u(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) m aum n¶rt;a aaum na. naa, m u¶rt;aum n uu aam n aaum u ¶rt;u am aua, u u uu. aum n u uu ma a¶rt;um ¶rt; ¶rt;nn; nnA nua¶rt;ama a au¶rt; u au¶rt;aum (K ₂ O>2,5%, Si O ₂ >68%), nnB ¶rt;u u aum (K ₂ O<2,5%, SiO ₂ <68%). ¶rt; muunnau mm mamumuu m au ¶rt; a u u ¶rt; m ¶rt;u m(Rb, V, Cr, Ni). auaum n¶rt;¶rt;m um- m¶rt; a u -uaum;aumA a¶rt;ma a uum n, uaumB a a ¶rt;aum, a¶rt;um u aam n m m¶rt;a. ¶rt;aum — u unnA — aamum uu ¶rt;au da¶rt;uamu mTh uU.

     

A contribution to the parameterization of total radiation

Summary To be able to parameterize vertical heat and water vapour fluxes in the boundary layer of the atmosphere, it is necessary to determined, among other factors, the amount of incident total radiation under a generally arbitrary condition of the atmosphere at any instant of time. This paper deals with a simple model for computing the total radiation based on known solar elevation, total cloud cover and the atmospheric turbidity parameter. This variant of the model was formulated on the basis of a two-year series of total radiation observations made in the radiation network of the Czech Hydrometeorological Institute, and on the measurements and observations made at the observatory of the Institute of the Physics of the Atmosphere in Kopisty. An example of comparing the observed and theoretical values of total radiation will also be given.

---

¶rt;um naamuauu mua nm mna u amu nzau am mm ¶rt; nu n¶rt;u au a nm numa a a¶rt;uauu m u. mam auam n naamuauu a a¶rt;uauu n ¶rt;a m a, ammu am u mnu az na. ¶rt;azaa ¶rt; nma a mam ¶rt;mu uu auau mu z zu¶rt;mzu z umumma u a amuu mumma uuu am numa. mam ma nu¶rt; nu au u u n n¶rt; ¶rt;u u au a a¶rt;uauu.

     

Analysis and optimization of wide-band force-balance seismometer responses

¶rt; aau n¶rt;am uu, umu,au mummu u ¶rt;uau ¶rt;uanaa mu um. am n a nmua amm aamumuu um ¶rt; au uu nuu. ¶rt;ma ummuu m¶rt; nmuau mu um a a¶rt;a an¶rt;u n n¶rt;am uu n nmu.     

Flow of a homogeneous electric field round a non-conducting hemisphere perpendicular to the axis of symmetry

au ¶rt; nmuaa mu n, a¶rt;u a, ¶rt;a ¶rt;¶rt; maua mu n na n¶rt;a na umuu, nn¶rt;u m nmmu ma nu n. a¶rt;aa a u um ¶rt;uam. a u ¶rt;m um u au. u m amamu n¶rt;¶rt; u u nu¶rt;um au nmuaa u¶rt; ¶rt;a nu¶rt;u u a¶rt;a mu uumau A _2k u B _2k+1 , n¶rt;mau au uua uum u uuu nmn au ¶rt; u nma a¶rt;au.     

Sensitivity of the Gs 12 gravity meter to vibrations

nuaa m¶rt;ua u mam unmauaumaGs 12 No. 129 a uauu ¶rt;uana amm 0.02–30. a uu a uau nam auu au u auma naamauma a mua ma u n¶rt;a mumm a ¶rt;uu ¶rt;ama ammau uu .     

Derived geometrical constants of the geodetic reference system 1980

Summary A large number of the users of the geomtrical constants of the reference ellipsoid know only the IAG resolutions and not the related special publications; consequently, the numerical values of the derived geometrical constants may be interpreted differently. Some values of possible differences (max. 32 mm) are given, and it is proposed that the GRS-80 geometrical constants be defined by the values of a and f ^–1 with unlimited accuracy in the next IAG resolution.

---

¶rt;a um nam zmuuu nmu n-unu¶rt;a am m uu ¶rt;a¶rt; auauu n z¶rt;uu, a nua nuauu; nm m num a mau u au nu¶rt; zmuu nm. mam nu¶rt;m m au am (a. 32 ) u n¶rt;azam n¶rt; uu n¶rt;m muu nm GRS-80 uuau a, f ^–1 zau mm.

     

Axially symmetric flow round a non-conducting obstacle in the shape of a hemisphere by a homogeneous electrical current field

m amamu n¶rt;ma au ¶rt; nmuaa mu n ma a, ¶rt;a ¶rt;¶rt; maua mu n ¶rt; nmam ¶rt;um n¶rt; nnmmu n. u m umau n aa mau a, m m nmmu ma nu ¶rt;¶rt; n naa u umuu n. maa a¶rt;aa a u um ¶rt;uam. a u nu¶rt;m um ua u au, nu u n a auu mam, n¶rt;ma [5, 6]. m um nu num m amamu au ¶rt; nmuaa mu n, n¶rt;mau u¶rt; ¶rt;a nu a¶rt;a.     

On the problem of standardization of the magnitude-frequency relation

au u uu mu a amu am a¶rt; mum ma¶rt;amuauau nmm m a, ¶rt;a m u ¶rt;u naam — aum¶rt; a, nu¶rt; a¶rt;u uu na¶rt;u am — nu muaua muam ¶rt; m ¶rt;a. ¶rt;aa n ma¶rt;amuauu nm naam ¶rt;u munaua nmmu ¶rt;.     

Study of the velocity conditions in the earth's crust in the regions of the Bohemian massif and the carpathian system along international profiles VI and VII

u¶rt;m n uu ¶rt;u m n u ma n¶rt;aa, nu m¶rt;u u ¶rt;uau. n nuu uu ¶rt;u m n ¶rt;a¶rt; nu NoNo VI, VII. u au u n m a (x, H), ¶rt;auu an¶rt;u ¶rt;u m ¶rt; m¶rt; nu, u mua m nuu (H), aamuu an¶rt;u m a mua ¶rt;¶rt; uu ¶rt;uua u a. u a ¶rt;u m (x, H) amm ¶rt;uuu (u) a m¶rt; nu. m¶rt; u, auuu aau, om aamuam muau an¶rt;u ¶rt;u m, uu , n m u m nu aamuu a nmu, am ma a¶rt;am aa uu ¶rt;u m. aa u a¶rt;u n nu NoNo VI u VII u umuu ¶rt;a. mua m nu (H) num m ¶rt;u amu aua u anam um, ¶rt;a amu ¶rt;aua u ¶rt;- nma (nu No VII). ma ¶rt; ¶rt; aua, maa numa nm m u numa nm ma¶rt;um, a unaa nuu umnmauu a¶rt;uu ¶rt;uau amu aua.     

On the possibility of long-range forecasts of geomagnetic activity

Summary The relation between geomagnetic activity and solar activity is studied in long intervals and in individual 11-year cycles, characterized by certain basic parameters, in connection with investigating the prognostic significance of long-term fluctuations of geomagnetic activity [1, 2]. A number of properties as well as sufficiently close relations with a prognostic significance have been found, such as the secular variation of geomagnetic activity, the 22-year cycle of change in the form of the behaviour of geomagnetic activity in 11-year cycles, long-term concurrence of solar and geomagnetic activity and its changes within the 11-year cycle, relations between solar and geomagnetic parameters characterizing the 11-year cycle.

---

a auu uu u ¶rt; uaum amum ¶rt;u nma u u m¶rt; 11-mu ua am mu ¶rt; ¶rt;m nuauaum amumu.

     

ЧИСЛЕННЫЕ ЭКСПЕРИМЕНТЫ С ИСКУССТВЕННЫМИ ЯДРАМИ СУБЛИМАЦИИ В СТРУЙНОЙ МОДЕЛИ КУЧЕВОГО ОБЛАКА

nuam aau ¶rt; amu a um ¶rt; ¶rt;a uauu. ¶rt; ¶rt;a, ¶rt;mu auumu m mnam u nu mum ¶rt;a, umam m ¶rt;u z aa n¶rt; uuu, a aau. u¶rt; auum ¶rt;au z naa m mauu ¶rt; amu, naam, m ¶rt;au ¶rt;z naa zauuam u amu ¶rt;.

---

Summary A formation of ice particles on artificial deposition INis described. INacting in dependence on the temperature and supersaturation over the ice are considered in the 1 D SSconvection cloud model with detailed microphysics including freezing. The limiting influence of the water vapour pressure upon the concentration of active INis shown resulting from the dependence of water vapour pressure on the ice particle concentration.

     

Induction vector estimates in the Bohemian Massif and in the transition zone to the Carpathians

u¶rt;m mam m u¶rt;uu n n mau au u n¶rt; anama. am m auu u au am aua ¶rt;a, m m unam ¶rt; u¶rt;au ua aau mn¶rt;mu n.     

Accuracy of integral migration transformation in dependence on space-time sampling

Summary The accuracy of wave field extrapolation is studied with respect to the discretization of field data and integral extrapolator. Assuming a far-field approximation of the Rayleigh-Sommerfeld solution for a two-dimensional scalar wave equation, the minimum and the maximum transmitted frequency are expressed as functions of the sampling intervals t, x, and the half-width x₀ and angle _a of the migration aperture. The theoretical limitation of the transmitted frequency band is tested on numerical examples.

---

aamuam mm manuu auumu m ¶rt;umuauu n u uma manu nama. ¶rt; u uma u -¶rt;a ¶rt; ¶rt; a au, ¶rt; nuuuu ¶rt;a n mu ¶rt; uua u aua n¶rt;aa amm a uu m a -nmam ¶rt;umuauu t u , nuu ₀ u a _a uau anm. mu n¶rt;u amm ¶rt;uanaa mmua a u nua.