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We study the recent claim that the intranuclear cascade model exhibits collective sidewards flow. 4000 intranuclear cascade simulations of the reaction Nb(400 MeV/nucleon)+Nb are performed employing bound and unbound versions of the Cugnon cascade. We show that instability of the target and projectile nuclei in the unbound cascade produces substantial spurious sidewards flow angles, for spectators as well as for participants. Once the nuclear binding is included, the peak of the flow angle distributions for the participants alone is reduced from 35° to 17°. The theoretical ‘‘data’’ are subjected to the experimental multiplicity and efficiency cuts of the plastic ball 4π electronic spectrometer system. The flow angular distributions obtained from the bound cascade—with spectators and participants subjected to the plastic ball filter—are forward peaked, in contrast to the plastic ball data. We discuss the uncertainties encountered with the application of the experimental efficiency and multiplicity filter. The influence of the Pauli principle on the flow is also discussed. The lack of flow effects in the cascade model clearly reflects the absence of the nuclear compression energy that can cause substantially larger collective sidewards motion—there is too little intrinsic pressure built up in the cascade model.
The influence of fluctuations of the shape degree of freedom in collisions of deformed nuclei with energies between 0.8 and 2.1 GeV/nucleon is analyzed on the basis of an intranuclear cascade simulation for the strongly deformed systems 46Ti+ 46Ti and 166Er+ 166Er. While there is a considerable sensitivity of the global event variables to the orientation for polarized beams and targets, this dependence disappears in the average over all orientations for impact parameter selected and integrated events. The dependence of the nuclear stopping and thermalization on the size of the system under consideration and on the bombarding energy is also investigated.
Time dependent dirac equation with relativistic mean field dynamics applied to heavy ion scattering
(1986)
We treat the relativistic propagation of nucleons coupled to scalar- and vector-meson fields in a mean-field approximation. The time-dependent Dirac and mean-meson-field equations are solved numerically in three dimensions. Collisions of 16O(300, 600, and 1200 MeV/nucleon) + 16O are studied for various impact parameters. The results are compared to other recent theoretical approaches. The calculations predict spallation, large transverse-momentum transfer, and positive-angle sidewards flow, in qualitative agreement with the data in this energy regime.
The novel momentum analysis technique introduced by Danielewicz and Odyniec can be used to detect and exhibit collective flow in the light system Ar(1800 MeV/nucleon) + KCl where the usual kinetic energy flow analysis fails. The microscopic Vlasov-Uehling-Uhlenbeck theory which includes the nuclear mean field, two-body collisions, and Pauli blocking is used to study this phenomenon. The resulting transverse momentum transfers turn out to be quite sensitive to the nuclear equation of state. From a comparison with experimental data, evidence is presented for a rather stiff nuclear equation of state. The cascade model is unable to describe the data.
The inelastic excitation of the (1/2)+ (871 keV) state of 17O in the reaction of 13C on 17O is described by a time-dependent quantum mechanical model with two diabatic states and a classical treatment of the radial relative motion. The structures in the angle-integrated cross section are interpreted as caused by the barriers of the angular momentum-dependent potentials. The transition strength is enhanced by the Landau-Zener effect between the levels considered.
We formulate a group-theoretical projection technique for the quantum-statistical description of systems with exactly conserved charges corresponding to local non-Abelian gauge symmetries. The formalism is specified for SU(N) internal symmetry and a partition function related to a mixed canonical–grand-canonical ensemble is defined. Its perturbation expansion is derived, and we point out potential applications. We also study single-particle Green’s functions for the calculation of mixed ensemble averages with the help of a generalized Wick’s theorem and find that a connected-graphs expansion is impossible.
If the local color symmetry in a quark-gluon matter is broken, the expectation value of the gluon field 〈Aμa(x)〉 may be different from zero. Such a gluon-condensed phase has been found in mean field approximation. The gluon-condensed phase is characterized by a static, periodic chromomagnetic field, which is coupled to a periodic spin-color density distribution of quarks and antiquarks. Transitions of first and second order type have been found between the gluon-condensed and normal phases, the latter characterized by the vanishing value of the mean gluon field.
We discuss the possibility that nuclei with very large baryon numbers can exist in the form of large quark blobs in their ground states. A calculation based on the picture of quark bags shows that, in principle, the appearance of such exotic nuclear states in present laboratory experiments cannot be excluded. Some speculations in connection with the recently observed anomalous positron production in heavy-ion experiments are presented.
"Noch bevor man in Europa genau wußte, wo China geographisch zu lokalisieren war, beschrieb man schon, wie es dort zuging [...]. Nicht den wahrheitsgetreuen Berichten des Marco Polo (1298), sondern den daraus zusammenphantasierten Abenteuer des Ritters Mandeville (1366) wurde Glauben geschenkt. Wer >China< beschrieb, wollte seinen Lesern vor allem ein Bild von etwas anderem vor Augen führen, wollte etwas schildern, das abschrecken oder vorbildlich sein sollte und so weit entfernt war, daß man es mangels exakterer Zeugnisse einfach glauben mußte - oder wollte. China war literarische Metapher für den Kontrast zum Abendland [...]."
Die Seele und das Geld : kulturtheoretische Implikationen in Georg Simmels „Philosophie des Geldes“
(1986)
"Das schöne Gedicht auf den Vogel ..." : Anmerkungen zu Hofmannsthals Rezeption Walt Whitmans
(1986)
Die Bedeutung des amerikanischen Dichters Walt Whitman (1819-1892) für Hugo von Hofmannsthal im einzelnen ausmachen zu wollen, ist nicht einfach und kann auch nicht Ziel dieser Ausführungen sein. Vielmehr soll es darum gehen, Spuren zu verfolgen, die einer solchen Untersuchung dienlich sein können. Dem kurzen Überblick über die Rezeption Whitmans im 19. und beginnenden 20. Jahrhundert folgen eine genauere Untersuchung des Briefwechsels zwischen Hofmannsthal und Ottonie von Degenfeld, welcher gegenüber Hofmannsthal Whitmans Gedicht "Out of the Cradle Endlessly Rocking" wohl als das "schöne Gedicht auf den Vogel, der um seine Frau klagt" erwähnte, sowie der vollständige Abdruck des Gedichtes und dessen deutsche Übersetzung von Johannes Schlaf.
Für die Literatur der Jahrhundertwende werden Werke der bildenden Kunst auf eine Weise bedeutsam, die sich wesentlich von der Kunstrezeption früherer Epochen unterscheidet: Im Zusammenhang mit den literarischen Neigungen zur Symbolisierung kommt dem Bild bzw. der BiIdhaftigkeit des Ausdrucks eine zentrale Rolle zu. Bildende Kunst als Medium visueller Vergegenwärtigung erhält einen neuen Stellenwert innerhalb des literarischen Produktionsprozesses. Am Beispiel Hofmannsthals läßt sich dies besonders gut verdeutlichen, da er sich zeitlebens intensiv mit der Kunsttradition auseinandersetzte und Bild"vorgaben" in hohem Maße in sein Werk einbezog. Diese "produktive Rezeption" (G. Grimm) der bildenden Kunst bei Hofmannsthal läßt sich durch sein gesamtes literarisches Schaffen verfolgen. Sie ist nicht nur konkret faßbar in den lyrischen Dramen und den Kunstaufsätzen. Sie ist auch erkennbar in elementaren Erfahrungen (wie dem Van-Gogh-Erlebnis in den Briefen des "Zurückgekehrten" und dem Anblick der archaischen Koren im dritten Teil der "Augenblicke in Griechenland") und schlägt sich nieder in grundsätzlichen philosophischen und kunstästhetischen Fragestellungen.
The genus Squamidium, a group of mosses with a tropical to subtropical American-African distribution, consists of two sections and seven species (prior to this study 27 species were recognized): sect. Squamidium (S. leucotrichum, S. livens, S. isocladum, S. nigricans, S. brasiliense) and sect. Macrosquamidium (S. macrocarpum and S. diversicoma). Twenty-four names are treated as syn. nov., three are provisionally excluded pending an examination of their types, and one new combination is made: Orthostichopsis pilotrichelloides (Sehnem) Allen & Crosby. Section Squamidium ist characterized by immersed capsules, stolon leaves with entire margins, and a relatively high basal membrane. Section Macrosquamidium is characterized by exserted capsules, stolon leaves with sharply recurved marginal teeth, and a relatively low basal membrane. The genus is retained in the Meteoriaceae. Within the Meteoriaceae Squamidium, is most closely related to Zelotmeteorium from which it differs only by its lack of squarrose-recurved leaves and its more well-developed alar cells. Squamidium, which in the absence of sporophytes has been confused consistently with Orthostichopsis, is separated from that genus on the basis of its lack of pseudoparaphyllia, weaker costae, lack of a distinct region of reddish cells across the leaf base, and strongly decurrent alar cells.
Conversion processes in light nuclei with transition energies above the e+, e- pair creation threshold are investigated within an analytical framework. In particular, we evaluate the ratio of electron transition probabilities from the negative energy continuum into the atomic K shell and into the positive energy continuum, respectively. The possible role of monoenergetic positron conversion with respect to the striking peak structures observed in e+ spectra from very heavy collision systems is examined.
Phenomenological consequences of a hypothetical light neutral particle in heavy ion collisions
(1986)
We discuss the possibility that the line structure observed in the spectrum of the positrons produced in heavy ion collisions is due to the decay of a new neutral elementary particle. We argue that this can be ruled out unless one is willing to accept fine tuning of parameters, or to assume the dominance of nonlinear effects.
A detailed study of pion production in inelastic and central nucleus-nucleus collisions was carried out using a 2 m streamer spectrometer. Nuclear targets mounted inside the streamer chamber were exposed to nuclear beams of 4.5 GeV/c/nucleon momentum. A systematic study of the influence of the central trigger on observed data is performed. The data on multiplicities, rapidities, transverse momenta, and emission angles of negative pions are presented for various pairs of colliding nuclei. Intercorrelations between various characteristics are studied and discussed. The results are compared with predictions of some theoretical models. It is shown that the main features of the pion production in nuclear collisions can be satisfactorily described by a model assuming independent nucleon-nucleon collisions with subsequent cascading process. However, the observed correlation between Lambda and pion characteristics seems to be unexplained by this picture.
A recently found fossil from the old Scudder pit (?) appears to be a large female horntail. It shows the ventral aspect. Compared with modern Siricidae, the length of its ovipositor in relation to the body proper suggests modern Xeris spectrum. Unfortunately the venation is incompletely preserved on both wings. In addition to this the forewings and hindwings overlap to some extent on each side. What venation is decipherable is seen in the two sketches. It does not seem to agree with any of the modern genera examined but approaches that of Sirex more closely than any other. Both antennae are faintly indicated. They are stout, many-segmented and in keeping with those of Siricidae. Both hind legs are preserved faintly almost throughout their length. They are stout, and the individual segments are clearly defined.
The recently increased importance of sunflowers (Helianthus annuus Linnaeus) as a crop has brought with it an increased interest in the sunflower maggot, a long-recognized common name for Strauzia longipennis (Wiedemann). The larva of this species bores downward in the stem and feeds upon the pith of sunflowers. Until recently the genus Strauzia was considered to include only the type-species S. longipennis, with 7 varieties (Foote, 1965). It is now known that some of these varieties should be classed as distinct species, differing morphologically and biologically.
Descriptions of species in the genus Sclerosococcus are primarily based on the female morphology (McKenzie 1958, Lambdin 1980). The lack of descriptions for males is attributed to their brief seasonal appearances (lasting only a few hours) and their small size that makes collection of adult specimens difficult. As a result, adequate descriptions for only a few males of Asterolecaniidae are available for comparisons. Of those species where males are known, most descriptions are of the tests or general morphological aspects (Russell, 1941). The most comprehensive descriptions for adult males in the family were provided for Asterolecanium proteae (Giliomee 1968) and for two species of Grammococcus (Miller and Lamdin 1978). The genus Sclerosococcus contains 4 species known from the Neotropical Region where they feed on bromelid hosts. Until now, no reference was made as to the existence of males of the species. My objective was to provide a description of the adult male of this rare species to better define the taxa. Measurements and illustration were made by microscopic examination of the allotype male. Terminology used to describe the external morphology, with few exceptions, was adapted from Theron (1958). All measurements are presented in micrometers.
El género Priocnemis SchiØdte no se puede considerar como caracteristico de la Región Neotropical y son pocas las especies descritas que se conocen de ella. Sin embargo en el área extra-tropical sudamericana se halla bastante bien representado por un grupo de especies que presenta características particulares, como veremos más adelante. Son varias las especies presentes en la Argentina, Uruguay y Chile, pero por el momento vamos a referirnosala fauna de este último país. Debemos aclarar que no consideramos aquí las especies correspondientes a Sphictostethus Kohl, que han sido tratadas como Priocnemis por algunos autores, ya que constituye un género bien definido por sí.
GLYPHICNEMIS Foerster is a small Holarctic genus in the subtribe Endaseina of the Gelini. Nearctic species were placed in PHYGADEUON Gravenhorst until Townes (1944) placed them in the subgenus GLYPHICNEMIS within ENDASYS Foerster. However, earlier Cushman (1925) had transferred PHYGADEUON CRASSIPES Provancher, a junior synonym of G. MANDIBULARIS (Cresson), to GLYPHICNEMIS, and the Palearctic species, at first placed in PHYGADEUON, were included by Habermehl (1916) i n GLYPHICNEMIS, reduced t o a subgenus within STYLOCRYPTUS Thomson (1873). This status was continued until Townes (1970) listed and described GLYPHICNEMIS as a seperate genus.
A number of years ago we received a large lot of material collected by Robert G. and Clo M. Wind during their 1939-1940 expedition to the “East Indies” and published on the Danaidae and Satyridae of that trip (L. and J. Miller, 1978). One of the insects that the Winds considered to be of special significance was a male of a thecline that Bob Wind had intended to describe for his then wife. Both Bob and Clo asked us to describe the butterfly, but before we had an opportunity to describe the insect both Bob and Clo died. We now dedicate the description of this magnificent insect to their memories.
This paper is a catalog of the Ephemeroptera known from the British Crown Colony of Hong Kong. It includes all known references for each species, along with an indication of the type localities and depositions of type specimens. For each reference the stage (male, female, or nymph) is indicated if relevant. Keys which include the species also are indicated. The recorded distribution for each species is listed. For each genus are given the reference to the original description, information on the type species, and any synonyms. Abbreviations of places of type deposition are as follows: (BMNH), British Museum (Natural History), London; (Cornell), Cornell University, Ithaca, New York; (DEI), Deutsches Entomologisches Institut, Eberswalde; (Hamburg), Zoologisches Staatsinstitut und Zoologisches Museum, Hamburg; (Hsu), personal collection of Y.-C. Hsu [the late Prof. Hsu indicated (personal communication) that because of events in China over the past few decades these specimens should be considered destroyed or lost]; (Utah), University of Utah, Salt Lake City. Although the taxonomic knowledge of the Hong Kong mayflies is still somewhat sketchy, there are substantial ecological studies ongoing at this time. Therefore, in order to facilitate future studies and comparisons of data, I have included in this catalog the "morphospecies" of Dudgeon (1982a, b, 1983, 1984a, b). The reader should be aware that many of the taxonomic assignments of these morphospecies are preliminary and actual placement will have to await future taxonomic studies. This paper is one in a continuing series of catalogs of the Ephemeroptera (cf. Hubbard & Peters 1978, Hubbard & Pescador 1978, Hubbard & Savage 1981, Hubbard 1982a,b).
Presently, only a single species of the genus Diplocentrus is known from northeastern Mexico, D. whitei (Gervais) (Hoffman 1931 ). This species is dark brown to black and is quite large, with adults 65-75 mm long. Recent collecting in the mountains near Monterrey and El Potosi, Nuevo Leon, Mexico has revealed the presence of a much smaller, more lightly-colored species. The description of this new species is the subject of the present paper. Nomenclature and mensuration essentially follows that of Stahnke (1970), with the following exceptions: carinal terminology and cheliceral measurements are after Francke (1975, 1977) and trichobothrial terminology is after Vachon (1974). All measurements were taken with an American Optical Model 569 dissecting microscope equipped with an ocular micrometer calibrated at 10x.
This paper updates and summarizes the ant fauna of Alachua County, Florida, with two basic objectives. The first objective is presentation of a current, documented check-list consistent with existing taxonomy and an insight on species groups where taxonomic changes are likely in subsequent revisions. The second objection objective seeks to identify changes in the fauna since Van Pelt’s pioneer survey of 1948, and provide a basis for similar comparisons in the future. The county consists of 902 square miles in north-central Florida and embraces essentially all inland habitats of the northern peninsula. This rich habitat variability is reflected in its ant fauna of 110 species. Few other regions of comparable size and latitude support a larger ant diversity also documented in part for greater than 50 years. A review of the earlier work, current taxonomic authorities, and questionable or rejected records precede the new list.
Crepidodera Chevrolat is a genus of small metallic-colored flea beetles belonging to the family Chrysomelidae. Although these insects are quite common in the field and numerous in museum collections, the members of the genus in North America are, until now, poorly known. Heikertinger (1948-1950) recognized 4 taxa and recently, Lazorko (1974) described 3 additional species. These 7 species were recognized primarily on the basis of genital differences and were otherwise difficult to identify. Examination of a large accumulation of museum material and investigations in the field have indicated the presence of several additional species in the North American fauna. A detailed study of external characters, male genitalia and female spermathecae has revealed, in material previously referred to the Palaearctic species, C. fulvicornis (F.), a complex of closely related species. Essentially nothing was known about the biology of the North American species. General information on host plants was available and the general seasonal occurrence and habits of adults were described by Loan (1967b). However, the immature stages and life histories of all members of the genus were unknown. This has now been remedied with the discovery, during the course of this study, of the larvae of two species. The main purpose of this paper, therefore, is to consolidate the existing information on the genus in North America, describe 8 new species, redefine the previously described species, provide a key and illustrations to aid in their identification, and to describe the immature stages for 2 species. A discussion of the host plant relationships and the general life history of members of the genus is also presented.
The genera Paratella and Sephena were established by Melichar (1902) for complexes of species having distribution principally in New Guinea. However, three of Melichar’s new species of Paratella, i.e., fumaria, fusconigra and modesta, were known only from localities in Australia and/or New Zealand. Kirkaldy (1906) described Sephena argue, cinerea and rubida from specimens collected in Australia. He commented that they had the appearance of Paratella while having the characters of Sephena assigned by Melichar. Melichar (1923) and Metcalf (1957) each retained the above named species in Paratella and Sephena The type specimens of the species named above were examined in connection with my research on Kirkaldy and Melichar types, results of which are given in articles that have been submitted for publication elsewhere. To avoid duplicate citation of new synonymies, all synonymies given in this article should be considered to have prior designation by Medler, in press.
Praestochrysis Linsenmaier contains those species of Chrysidinae with five teeth on the posterior margin of tergum III, first flagellomere (F-I) less than 3 times as long as broad (often much shorter), and clypeal length below antennal sockets (subantennal distance) not more than diameter of the midocellus (MOD). The genus is widespread in the Old World, but a majority of the known species are in the Ethiopian Region. Host records are rather few, but it is likely that nearly all species attack moth larvae and emerge from their cocoons. Praestochrysis shanghaiensis (F. Smith) is a well known parasitoid of the silk moth in the Far East.
The receipt, recently, of several requests for information and assistance in rearing blister beetles (Meloidae) has prompted me to prepare the following account of the rearing method used in my laboratory. In order to make the account as useful as possible to new students. I have included a considerable amount of information on meloid bionomics. Larval phases are designated as triungulin (TI, first grub (FG), coarctate (C), and second grub (SG). Where necessary, instar is indicated by a numerical subscript. The pupa and adult are symbolized by P and A, respectively. I assume that the reader has some knowledge of the taxonomy of the Meloidae.