Ευρετικές προσεγγίσεις του μοναδιάστατου προβλήματος πακετοποίησης

Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this species will be considered as synonyms. The older generic epithet takes priority over the younger name. Any widely used younger names proposed for use, must comply with Art. 57.2 and their usage should be approved by the Nomenclature Committee for Fungi (NCF). In this paper, we list all genera currently accepted by us in Dothideomycetes (belonging to 23 orders and 110 families), including pleomorphic and non-pleomorphic genera. In the case of pleomorphic genera, we follow the rulings of the current ICN and propose single generic names for future usage. The taxonomic placements of 1261 genera are listed as an outline. Protected names and suppressed names for 34 pleomorphic genera are listed separately. Notes and justifications are provided for possible proposed names after the list of genera. Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes. A phylogenetic tree based on four gene analyses supported 23 orders and 75 families, while 35 families still lack molecular data

On External Radio Emission from the Earth's Outer Atmosphere

The possibility is considered that cyclotron radiation, generated by fast bunched electrons in the Earth's outer atmosphere, may be observable outside the geomagnetic field. It is shown that the intensity and other properties of such external radiation may be deduced from the known characteristics of v.1.f. hooks. It appears likely that the radiation will occur as short bursts in the frequency range from 200 to 1000 kc/s. The total radiated power may be from 1 to 1000 W, depending on the electron energy.</jats:p

The F2 Component of Cosmic Radio Noise Absorption

The attenuation of cosmic radio waves expected in the F region is calculated. It is shown that by using an F-region model obtained from electron backscatter measurements the attenuation obtained agrees well with observation. The amount of attenuation is generally less than 0�2 dB, providing the wave frequency is greater than twice f OF2 for wave frequencies less than 10 Mc/s.</jats:p

Observations of the Jupiter S-bursts between 3·2 and 32 MHz

Observations of the Jupiter S-bursts in the frequency range 3� 2-32 MHz are described. Their general properties including bandwidth, time duration, frequency-time behaviour, and rate of occurrence within this frequency range are analysed and discussed.</jats:p

Fine Structure in the Spectra of Solar Radio Bursts

Observations are described of solar radio burst spectra in the frequency range 25-100 MHz with a time resolution of 0�02 sec. The types of bursts that were observed included (1) fast drift storm bursts with a mean frequency-time slope of 1�9 MHzsec-1, a mean bandwidth !!.f'"-' 0�03 MHz, and a mean duration !!.T of 0�6sec; (2) drift pair bursts with dffdt = 1�2MHzsec-1 and !!.f= 0�45 MHz; and (3) split pair bursts with dffdt = 0�08 MHzsec-1, !!.f = 0�05 MHz, and !!.T = 1�4 sec. In addition, chains of split pa.ir bursts were frequently observed, the chain resembling a type I burst with fine structure.</jats:p

An Automatic Dynamic Spectrum Analyser for Video Tape Recorded Signals

A time-expansion sweep frequency spectrum analyser is described for signals in the 0-3 MHz frequency range. It is based on a standard video tape recorder used in the single frame replay mode. With a time-expansion ratio of 400 between the record time and replay time, a frequency resolution of 10 kHz together with a time resolution of 0�5 ms is realized. An example of the spectra of Jupiter radio bursts made with the analyser is presented.</jats:p

Cyclotron Radiation From Jupiter

Cyclotron radiation from bunches of electrons trapped in ,a planetary magnetic field is discussed as a possible cause of the decametric wavelength radio emissions of Jupiter. By assuming the existence of an exospheric ionized medium, similar to that of the Earth, many of the observed properties of the radiation may be obtained by this process.</jats:p

The Radio Emissions from Jupiter and the Density of Jovian Exosphere

The properties of cyclotron radiation from bunches of electrons trapped in a Jovian exosphere are discussed. It is shown that, if the polar magnetic field intensity is 15 gauss and the magnetic axis is inclined 10� to the rotation axis, the calculated properties agree with those observed for the decametric radiation providing Jupiter is surrounded by an extensive exosphere. The electron density of the exosphere varies mainly as the magnetic field intensity and at l'5Rj is equal to 103/cm3.</jats:p

Geomagnetic Micropulsations

This paper describes simultaneous observations of geomagnetic micropulsations at three places ranging from 280 S. to 51 0 S. geomagnetic latitude. It is shown that there is no observable change in the micropulsation period with latitude although there is a monotonic increase in the amplitude with latitude for all periods between 10 and 100 sec. The interpretation of these results in terms of existing theories is discussed.</jats:p