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The mission of the Compressed Baryonic Matter (CBM) experiment is to investigate the phase diagram of strongly interacting matter in the region of high net-baryon densities and moderate temperatures. According to various transport models, matter densities of more than 5 times saturation density can be reached in collisions between gold nuclei at beam energies between 5 and 11 GeV per nucleon, which will be available at FAIR. The core detector of the CBM experiment is the Silicon Tracking System (STS), which is used to measure the tracks of up to 700 particles per collision with high efficiency (>95%) and good momentum resolution (<1.5%). The technological and experimental challenge is to realize a detector system with very low material budget, in order to reduce multiple scattering of the particles, and a free-streaming data readout chain, in order to achieve reaction rates up to 10 MHz together with an online event reconstruction and selection.
The STS comprises 8 tracking stations positioned between 30 cm and 100 cm downstream the target inside a magnetic field, covering polar emission angles up to 25 degrees. A station consists of vertical structures with increasing number (between 8 and 16, depending on station number), each structure carrying between 2 and 10 double-sided microstrip silicon sensors, which are connected through low-mass microcables to the readout electronics placed at the detector periphery outside the active detector area.
The work presented in this thesis focuses on the detector performance simulation and local hit pattern reconstruction in the STS. For efficient detector design and reconstruction performance, a reliable detector response model is of utmost importance. Within this work, a realistic detector response model was designed and implemented in the CBM software framework. The model includes non-uniform energy loss of an incident particle within a sensor, electric field of a planar p-n junction, Lorentz shift of the charge carriers, their diffusion, and the influence of parasitic capacitances. The developed model has been verified with experimental data from detector tests in a relativistic proton beam. Cluster size distributions at different beam incident angles are sensitive to charge sharing effects and were chosen as an observable for the verification. Taking into account parasitic capacitances further improves the agreement with measured data.
Using the developed detector response model, the cluster position finding algorithm was improved. For two-strip clusters, a new, unbiased algorithm has been developed, which gives smaller residuals than the Centre-Of-Gravity algorithm. For larger clusters, the head-tail algorithm is used as the default one. For an estimate of the track parameters, the Kalman Filter based track fit requires not only hit positions but their uncertainties as an input. A new analytic method to estimate the hit position errors has been designed in this work. It requires as input neither measured spatial resolution nor information about an incident particle track. The method includes all the sources of uncertainties independently, namely: the cluster position finding algorithm itself, the non-uniform energy loss of incident particles, the electronics noise, and the discretisation of charge in the readout chip.
The verification with simulations shows improvements in hit and track pull distributions as well as x²-distributions in comparison to the previous simple approach. The analytic method improves the track parameters reconstruction by 5-10%.
Several STS module prototypes have been tested in a relativistic proton beam. A signal to-noise ratio was obtained at the level of 10-15 for modules made of 30 cm long microcable and of either one or two 6.2 x 6.2 cm² CiS sensors.
First simulations have shown that this signal-to-noise ratio is sufficient to reach the required efficiency and momentum resolution. The high-radiation environment of CBM operation will deteriorate the sensor performance. Radiation hardness of sensors has been studied in the beam with sensors irradiated to 2 x 10[hoch 14] 1MeV [neq/cm²], twice the lifetime dose expected for CBM operation. Charge collection efficiency drops by 17-25%, and simultaneously noise levels increase 1.5-1.75 times. The simulations show that if all sensors in the STS setup are exposed to such a fluence uniformly, the track reconstruction efficiency drops from 95.5% to 93.2% and the momentum resolution degrades from 1.6% to 1.7%.
Es wird das Computerprogramm HITAB vorgestellt, das die Eingabe pflanzensoziologischer Daten stark erleichtert (rasches, fehlerfreies Eintippen), und die so erfassten Daten in die Formate einiger gängiger Programme konvertiert (TAB, TWINSPAN, DECORANA, CANOCO, SYN-TAX, VEGBASE, FLORA D), sowie die Ausgabe von Aufnahmelisten und Artenlisten in Textformat (ASCII) ermöglicht.
Nicht nur in Kinofilmen wie "Der Untergang", sondern auch in Fernsehfilmen und Dokumentationen sind Hitler und seine Paladine längst zu Stars geworden, die für hohe Einschaltquoten sorgen. Peter Zimmermann stellt die aktuelle "Hitleritis" in die Tradition medialer "Vergangenheitsbewältigung" in der Geschichte von BRD und DDR. Die Täter des NS-Regimes, die seit Mitte der 90er Jahre in das Zentrum der Fernseharstellungen rücken, sind nicht diejenigen, die nach 1945 in Deutschland wieder Karriere gemacht haben, sie bleiben auf die Person "Hitler" (ZDF 1995) bzw. "Hitlers Helfer" (ZDF 1996) beschränkt. Neuerdings wird dabei auch die menschliche Seite der Täter gezeigt. Mit der Personalisierung historischer Prozesse werden, so Zimmermann, Personenkult und Ikonographie des Dritten Reichs nicht aufgebrochen sondern vielmehr - kritisch gewendet - wieder neu reproduziert.
Der folgende Beitrag nimmt den Film „Der Untergang“ von Bernd Eichinger und Oliver Hirschbiegel gegen seine Kritiker in Schutz und zeigt auf, wie dieser Film auf innovative Weise die paradoxe Struktur von Hitlers Herrschaft erklären kann, indem er den 'Bunker' als – im Untergang des Dritten Reiches – verdichteter Mikrokosmos mit Modellcharakter für das NSRegime vorführt.
Nazi döneminden kalma orjinal belgelerin detaylı incelenmesinin yanısıra, soykırımdan kurtulmus Yahudi ögrencilerin okul gerçeklikleri üzerine yazdıkları mektuplar, elinizde tuttugunuz kitabın odak noktasını olusturuyor. "asırtıcı oldugu kadar çok da üzücü ifadeler içeren bu mektuplarda, yalnızca Nazi örgütlenmeleri olan SS ve SA’nın adamlarının ya da Yahudi ögrencileri sınıflarının önünde asagılayan kötü niyetli ögretmenlerin degil, aynı zamanda Nazi propagandaları ile kıskırtılmıs sınıf arkadaslarının da Yahudi ögrencilerin yasamını cehenneme çevirmis oldugu açıga çıkıyor
Hittite ammuk 'me'
(2005)
In the Indo-European department of Leiden University, Alwin Kloekhorst has initiated a discussion on Hittite ammuk ‘me’. The central question is: where did the geminate come from? This has led me to reconsider the origin of the Indo-European personal pronouns against the background of my reconstruction of Indo-Uralic (2002: 221-225). For the historical data I may refer to Schmidt (1978).
In an earlier study (1983) I argued that unlike aorists and athematic presents, Indo-European perfects and thematic presents originally had a dative subject, as in German mir träumt ‘me dreams’ for ich träume ‘I dream’, e.g. Greek oida ‘I know’ < ‘it is known to me’, édomai ‘I will eat’ < ‘it is eatable to me’. On the basis of Oettinger’s epoch-making book (1979), I proposed that the Hittite hi-flexion originated from a merger of the perfect, where *-i was added to 3rd sg. *-e in order to supply a new present, with the thematic flexion of causatives and iteratives, where the final *-e of 3rd sg. *-eie was dropped before the loss of intervocalic *-i- (1983: 315).
Hitzeschäden an Moosen?
(2008)
In den letzten Jahren sind mir eigenartige Schäden an Moosen aufgefallen, speziell an Epiphyten auf Holundern. Die darauf wachsenden Moose, hauptsächlich von Orthotrichum affine, waren bräunlich verfärbt. Zunächst hielt ich dies für Frostschäden aus dem Winter, doch waren diese Effekte im Sommer zu beobachten und in der Zeit seit dem letzten Winter hätten sich die Moose wahrscheinlich wieder erholt. Zur Hauptsache war Orthotrichum affine betroffen; eigenartigerweise zeigten die ansonsten als empfindlich geltenden Lebermoose wie z.B. Metzgeria fruticulosa keine Effekte. An Erd- oder Gesteinsmoosen in der Umgebung waren solche Schädigungen nicht festzustellen. In dem besonders heißen und trockenem Sommer 2003 fiel mir dieser Effekt auch an Wassermoosen (Cinclidotus ssp.) am Rheinufer auf, die gelbbraun verfärbt waren. Ich hielt das zunächst für Folgen eines Umweltschadens.