86 research outputs found
Double giant resonances in deformed nuclei
We report on the first microscopic study of the properties of two-phonon
giant resonances in deformed nuclei. The cross sections of the excitation of
the giant dipole and the double giant dipole resonances in relativistic heavy
ion collisions are calculated. We predict that the double giant dipole
resonance has a one-bump structure with a centroid 0.8 MeV higher than twice
energy for the single giant dipole resonance in the reaction under
consideration. The width of the double resonance equals to 1.33 of that for the
single resonance.Comment: 5 pages, 2 postscript figure
Quenching of excitations in the double giant resonance
The electromagnetic excitation of the two-phonon isovector giant dipole
resonance in relativistic projectiles incident on heavy targets can be proceed
via several intermediate one-phonon giant resonance states. In two step
electric dipole transitions the population of , , and
two-phonon states are possible. We calculate the amplitude distribution of
excitations with an RPA formalism, and use it to calculate the
electromagnetic excitation of two-phonon states in second order perturbation
theory and coupled-channels. We show that a conspiracy between angular momentum
coupling and the strength of the electromagnetic fields suppresses
contributions of states to the total cross sections.Comment: 10 pages, 2 Postscript figures available upon reques
Review of the spider genus Tegenaria Latreille, 1804 (Aranei: Agelenidae) of the Russian Caucasus and Ciscaucasia. II. A new species and an interesting record
A new spider species from the family Agelenidae Tegenaria terskovi Ponomarev, sp. n. is described from the south part of Russia (Stavropol Region). It is close to T. podoprygorai (Kovblyuk, 2006) and T. lehtineni (Guseinov, Marusik et Koponen, 2005), from which it differs in the shape of the retrolateral tibial apophysis, the conductor, the position of the embolic base. The holotype is deposited in the Zoological Museum of the Moscow State University (Moscow, Russia). The first record of Tegenaria hasperi Chyzer, 1897 from Dagestan is also provided; the species is illustrated
A new species and new records of spiders (Aranei) in the south of European Russia
A new species of spider from the family Gnaphosidae Marinarozelotes ponticus Ponomarev, sp. n. is described from the south of Russia (Krasnodar Region). The new species is close to the Mediterranean species Marinarozelotes bardiae (Caporiacco, 1928), from which it differs in the greater length of the retrolateral loop of the embolar base and the presence of the distal protrusion of the embolus. The holotype is deposited in the Zoological Museum of the Moscow State University (Moscow, Russia), the paratypes are kept in the mentioned institution and in the personal collection of A.V. Ponomarev (Razdorskaya, Rostov Region, Russia). Data on the first records of Callilepis schuszteri (O. Herman, 1879) in Volgograd Region, Heliophanus simplex Simon, 1868 and Synema ornatum (Thorell, 1875) in Rostov Region are give
New species and new records of spiders (Aranei) in the south of Russia
Three new species of spiders from the families Gnaphosidae and Titanoecidae are described from the south of the European part of Russia (Astrakhan Region, Dagestan). Talanites alexeevi Ponomarev, sp. n. is characterized by the lamellar embolus, the narrow embolar base with the acute tooth-like outgrowth directed ventro-apically, the double-apex median apophysis, the epigyne with rounded fovea at the posterior margin and the anterior epigynal triangular-shaped hood with the wide arcuate posterior margin, the transverse oval contiguous spermathecae. Talanites thorelli Ponomarev, sp. n. has the following diagnostic characters: the tibia of the palp is with two processes; the embolar base is narrow, not wider than its distal part; the inner apical margin of the embolus is transformed into a long point; the double-apex median apophysis. Titanoeca caspia Ponomarev, sp. n. differs from congeners by the following characters: the tibia of the palp has a large, wide, complicated outgrowth pro-laterally, extending far beyond the lateral margin of the cymbium; tegulum with the large embolic pocket; the anterior margin of the embolic pocket bears a distinct tubercle; the process of the tegulum is large, retro-laterally shifted; the embolar haematodocha is large, protruding; the epigyne is with the narrow transverse slightly curved sclerotized plate; spermathecae are large, single, with short copulatory ducts. A new faunistic data are given for 14 species of spiders from the families Dictynidae, Gnaphosidae, Lycosidae, Mimetidae, Segestriidae, Theridiidae, Thomisidae. The following seven species of spiders are recorded for the fauna of Russia for the first time: Anagraphis ochracea (L. Koch, 1867), Gnaphosa haarlovi Denis, 1958, Zelotes fulvaster (Simon, 1878), Alopecosa kuntzi Denis, 1953, Alopecosa spasskyi Ponomarev, 2008, Lasaeolla dbari Kovblyuk, Marusik et Omelko, 2012, Ozyptila rigida (O. Pickard-Cambridge, 1872)
Two new species and new records of spiders (Aranei) in Dagestan (Russia)
Two new spider species from the families Gnaphosidae and Zodariidae are described from the south of Russia (Republic of Dagestan). Haplodrassus nabozhenkoi Ponomarev, sp. n. is similar to H. signifer (C.L. Koch, 1839) and H. pseudosignifer Marusik, Hippa et Koponen, 1996, from which it differs in the shape of the embolic apophysis (slightly curved, almost straight in the new species), the structure of the embolus, the shape of the lateral pockets and the fovea of epigyne, the size of spermathecae (they are relatively larger in the new species). Zodariellum dagestanum Ponomarev, sp. n. is similar to Z. volgouralense Ponomarev, 2007, from which it differs in the smaller size and details in the structure of the male palp, and colouration. Data on the first records of Clubiona caucasica Mikhailov et Otto, 2017, Diaea livens Simon, 1876 in Dagestan and Titanoeca caucasica Dunin, 1985 in Russia and Georgia are also provided.ZooBank Article LSID: urn:lsid:zoobank.org:pub:F629F136-0AC9-4811-9965-1796B2198BF
A review of spiders of the genera Trachyzelotes Lohmander, 1944 and Marinarozelotes Ponomarev, gen. n. (Aranei: Gnaphosidae) from the southeast of the Russian Plain and the Caucasus
The species composition and taxonomy of Trachyzelotes Lohmander, 1944 s. l. from the Russian Plain and the
Caucasus (8 species) are reviewed. The new genus Marinarozelotes Ponomarev, gen. n. (type species: Melanophora barbata L. Koch, 1866) is described. This genus differs from other Zelotinae by the following characters of the copulative organs: large distally rounded base of the embolus; terminal apophysis is obliquely oriented or distally rounded; loop-like embolus; epigina with an M-shaped median ridge. New combinations are established: Marinarozelotes adriaticus (Caporiacco, 1951), comb. n., Marinarozelotes ansimensis (Seo, 2002), comb. n., Marinarozelotes baiyuensis (Xu, 1991), comb. n., Marinarozelotes barbatus (L. Koch, 1866), comb. n., Marinarozelotes bardiae (Caporiacco, 1928), comb. n., Marinarozelotes chybyndensis (Tuneva et Esyunin, 2002), comb. n., Marinarozelotes cumensis (Ponomarev, 1979), comb. n., Marinarozelotes fuscipes (L. Koch, 1866), comb. n., Marinarozelotes glossus (Strand, 1915), comb. n., Marinarozelotes holosericeus (Simon, 1878), comb. n., Marinarozelotes huberti (Platnick et Murphy, 1984), comb. n., Marinarozelotes jaxartensis (Kroneberg, 1875), comb. n., Marinarozelotes kulczynskii (Bösenberg, 1902), comb. n., Marinarozelotes lyonneti (Audouin, 1826), comb. n., Marinarozelotes malkini (Platnick et Murphy, 1984), comb. n., Marinarozelotes manytchensis (Ponomarev et Tsvetkov, 2006), comb. n., Marinarozelotes miniglossus (Levy, 2009), comb. n., Marinarozelotes minutus (Crespo, 2010), comb. n., Marinarozelotes mutabilis (Simon, 1878), comb. n., Marinarozelotes ravidus (L. Koch, 1875), comb. n., Marinarozelotes stubbsi (Platnick et Murphy, 1984), comb. n. The distribution patterns in the southeast of the Russian Plain and the Caucasus are analyzed for Trachyzelotes pedestris (C.L. Koch, 1837), Marinarozelotes adriaticus, M. barbatus, M. chybyndensis, M. cumensis, M. jaxartensis,
M. malkini, M. manytchensis. A key to species of the genera Trachyzelotes and Marinarozelotes Ponomarev, gen. n. occurring in the studied region is given. Marinarozelotes lyonneti is excluded from the list of species of the region
Micaria micans (Blackwall, 1858) and M. pulicaria (Sundevall, 1831) (Aranei: Gnaphosidae) in the southeast of the Russian Plain and the Russian Caucasus
Morphological features, spatial biotopic and altitudinal distribution of Micaria micans (Blackwall, 1858) and M. pulicaria (Sundevall, 1831) in the southeast of the Russian Plain and the Russian Caucasus were studied. Te material for this work was collected from 1978 to 2021. Micaria micans was found from Belgorod Region to North Ossetia, extending to the semi-deserts of the Caspian Sea. Micaria pulicaria was recorded from Belgorod Region to Adygea; the species does not reach the semi-desert zone. Micaria micans prefers plain open habitats, occurring also in mesophytic forest cenoses. Micaria pulicaria inhabits woodlands of various types, along with moist herbaceous biotopes, and ascends to the subalpine mountain belt. Te characteristics of the copulatory organs are suitable for distinguishing between two closely related species; as an additional character, the presence or absence of a dark stripe on the femora of the third and fourth pairs of legs is suitable. A map of the distribution of these species in the studied area is given, as well as microphotographs of diagnostic characters (palps and epigynes, fourth pair of legs
Spiders (Aranei) of the Terek River valley in Mozdok District of the Republic of North Ossetia–Alania, Russia
Two hundred and forty species of spiders from 29 families are reported from the Terek River valley (Mozdok District, North Ossetia, Russia). Three families (Anyphaenidae, Trachelidae, Zodariidae) and 87 species are recorded for the first time from the territory of North Ossetia. Two new species are described. Tegenaria prisnyi Ponomarev, sp. n. (Agelenidae) is similar to T. lyncea Brignoli, 1978 and differs by the shorter median apophysis, the shape and location of the prolateral arm of the conductor, the shape of the tibial apophysis, the relatively short patella of the male; widely spaced epigynal ducts and spirally twisted accessorial glands. Zora osetica Ponomarev, sp. n. (Miturgidae) is characterized by the presence of two pairs of ventral spines on metatarsi I and II, like in Z. alpina Kulczyński, 1915, Z. manicata Simon, 1878, and Z. silvestris Kulczyński, 1897. From all listed species Z. osetica Ponomarev, sp. n. differs in the shape of the tibial apophysis of the male palp, in the darker colouration of the body, colouration of legs
Non-Linear Vibrations in Nuclei
We have perfomed Time Dependant Hartree-Fock (TDHF) calculations on the non
linear response of nuclei. We have shown that quadrupole (and dipole) motion
produces monopole (and quadrupole) oscillations in all atomic nuclei. We have
shown that these findings can be interpreted as a large coupling between one
and two phonon states leading to large anharmonicities.Comment: 4 pages, 3 figure
- …