Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 1999-1999 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The development of storage rings for synchrotron radiation have now arrived at so-called third-generation and have straight sections with optical functions optimized for undulators and electron beams of very small emittances. The beam optics of the ring is chosen so as to minimize the quantum excitation of betatron oscillations which determine the emittance. This can be achieved with a ring containing many cells with a small bending angle and with strong focusing in each cell. The first point results in large and expensive rings and both points require strong sextupole magnets for the chromaticity correction which can limit the dynamic acceptance. The optimization of storage rings with these points in mind lead to lattices which have achromatic cells with two, three, or more bending magnets. Studies for future rings consider further methods like the use of wigglers, combined function magnets, increased transverse damping partitions, etc. in order to obtain even smaller emittances which approach the diffraction limit. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 750-752 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A Stern–Gerlach atomic-beam ion source (ABS) with an electron cyclotron resonance (ECR) ionizer and a Cs gas target as charge exchange units will replace the Munich Lamb–Shift polarized hydrogen source. The goal is to achieve intense negative beams of polarized H− and D− of high brightness for injection into the 14 MV MP tandem accelerator and beam intensity of about 2 μA on the target. At the entrance of the ECR ionizer the observed intensity of the neutral beam of polarized atoms is 6.4±0.4×1016 H/s, equivalent to 10 particle/mA before ionization. Comparing beam transport calculations with beam intensity measurements under various conditions allows a consistent description of the beam formation in the ABS with respect to the degree of dissociation ((similar, equals)80%), peaking ((similar, equals)1.6), beam absorption ((similar, equals)40%), and pumping speeds to be made. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1365-3121
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The Kostomuksha greenstone belt consists of two lithotectonic terranes, one mafic igneous and the other sedimentary, separated by a major shear zone. The former contains submarine 2.8 Gyr old komatiite-basalt lavas and volcaniclastic lithologies with trace element and isotopic compositions resembling those of recent oceanic flood basalts [ɛNd(T) =+ 2,8, μ.1= 8.73 (Nb/Th)N= 1.5–2.1 (Nb/La)N= 1.0–1.5]. We suggest that the mafic terrane is a remnant of the upper crustal part of an Archaean oceanic plateau derived from partial melting of a mantle plume head. When the plateau reached the continental margin, it collided with the sedimentary terrane but was too buoyant to subduct. As a result, the volcanic section of the plateau was imbricated and obducted thus becoming a new piece of continental crust. The deeper zones were subducted and disappeared from the geological record.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 3450-3462 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The velocities of neutral and charged photofragments of the rare gas trimers He+3, Ar+3, and Xe+3 have been examined in a comprehensive study for photon energies ranging from 1.5 to 6 eV. For this purpose, a novel time-of-flight technique has been applied which allows the simultaneous examination of both neutral and charged fragments. The general fragmentation pattern of all three species was that of a linear trimer with a parallel transition moment and a totally repulsive excited state: In the course of the dissociation, two of the particles gain high velocities in opposite directions, while the third particle (the middle particle of the linear trimer) only obtains a small velocity. The positive charge generally localizes on one of the fast outer particles, as can be expected from the symmetry properties of the excited state. For Ar+3 and Xe+3, however, also localization of the charge on the slow particle can be observed. This effect strongly depends on the energy of the absorbed photon, and can be quenched by decreasing the vibrational excitation of the trimer. Comparison of the results with new potential energy surface calculations indicate that mainly spin–orbit coupling induced conical intersections are responsible for this charge redistribution phenomenon. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 111 (1999), S. 2513-2518 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ionized rare gas clusters Ar4+ and Xe4+ have been studied by photofragmentation. Center-of-mass velocities of the neutral and ionized photofragments have been measured for photon energies between 1.6 and 4.4 eV. In almost all of the examined photon energy region, both clusters exhibit fragment velocity distributions which show that they consist of a linear ionized trimer with an additional atom loosely attached to its side. For the lowest photon energies, however, fragmentation patterns are observed which can only be explained by a linear tetramer structure. This demonstrates that stable linear isomers of the ionized rare gas tetramers exist. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 385 (1997), S. 219-229 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Basaltic volcanism 'samples' the Earth's mantle to great depths, because solid-state convection transports deep material into the (shallow) melting region. The isotopic and trace-element chemistry of these basalts shows that the mantle contains several isotopically and chemically distinct ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Hydrous, silica-rich melts migrating through the mantle are preserved as glass inclusions in mantle minerals in xenoliths from Philippine arc lavas. These melts, with chemistries that indicate an origin by very low degrees of melting of the subducted ocean crust, have altered their host ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0630
    Keywords: PACS: 68.55.-a
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. A new development of the pulsed laser ablation (PLA) technique based on variable azimuth ablation (VAA) is reported. The VAA itself is based on periodic variations of the azimuth of the laser beam relative to the target at a constant angle of beam incidence. Such variations result in a suppression of cone–valley surface structures which tend to develop in the case of a fixed azimuth. VAA leads to high-level stabilization of the laser plume during a long-term deposition process. As a result, the VAA method stabilizes the deposition rate with a tolerance of only 3–6% instead of a 90% decrease in the rate as in conventional PLA. Different possibilities for the realization of the VAA technique based on 2- and 3-way target scans are discussed. In the case of large areas, VAA technique with a meander beam target scan is capable of the deposition of high-quality multicompositional superconducting films on tubes and tapes more than 1 m in length.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1433-0385
    Keywords: Key words: Colorectal carcinoma ; Outcome ; Quality management ; Ranking ; Surrogate endpoint. ; Schlüsselwörter: Ergebnisqualität ; Colorectales Carcinom ; Qualitätsmanagement ; Ranking ; Surregatendpunkt.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung. Anhand der Daten der prospektiven deutschen Multizenterstudie der Studiengruppe Kolorektales Karzinom (SGKRK) wurden die Klinikunterschiede im 5-Jahres-Überleben mit speziellen für ein sog. Ranking geeigneten biometrischen Methoden unter Wahrung der Anonymität analysiert. Weiterhin wurde nach sog. Surrogatendpunkten gesucht, die bereits früher als 5 Jahre nach Ersttherapie eine Aussage über die Ergebnisqualität der chirurgischen Therapie ermöglichen. Hierzu ist eine gesonderte Analyse für Rectum- und Coloncarcinompatienten erforderlich. Für das Rectumcarcinom ist die Kombination von Häufigkeit örtlicher Tumorzelldissemination bei Tumorresektion (intraoperativer Einriß im Tumor und/oder Schnitt in oder durch Tumorgewebe) und Rate locoregionärer Rezidive (innerhalb von 2 Jahren) nach Operation als verläßlicher Surrogatendpunkt anzusehen. Beim Coloncarcinom konnte ein solcher nicht gefunden werden. Die postoperative Morbidität ist als Indikator für die definitive Ergebnisqualität ungeeignet. Eine sehr niedrige Rate postoperativer Todesfälle bietet keine Gewähr auf zufriedenstellende Langzeitergebnisse in der colorectalen Carcinomchirurgie.
    Notes: Summary. The data of the German Prospective Multicenter Study of the Study Group Colorectal Carcinoma (SGCRC) were analyzed with regard to interinstitutional differences in 5-year survival by statistical methods adequate for ranking and observing anonymity. Furthermore, possible so-called surrogate endpoints that allow an assessment of definite outcome after surgical treatment earlier than after 5 years were also analyzed. This requires a separate analysis for rectal and colon carcinoma patients. For rectal carcinoma, the combination of the frequency of local tumor cell spillage during tumor resection (iatrogenous tumor perforation and/or incision into or through tumor tissue) and the rate of locoregional recurrences (within 2 years after surgery) could be demonstrated as realiable surrogate endpoint. For colon carcinoma, no reliable surrogate endpoint could be found. Surgical morbidity is not an indicator of definite outcome. A very low rate of surgical mortality does not ensure satisfactory long-term results in colorectal cancer surgery.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1433-0458
    Keywords: Schlüsselwörter TNM-Klassifikation (4. Aufl.) ; TNM-Klassifikation (5. Aufl.) ; UICC ; Kopf- und Halstumoren ; Tumorstaging ; Key words TNM classification (4th edition) ; TNM classification (5th edition) ; Head and neck cancer ; Tumor staging ; UICC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The 5th edition of the TNM classification entails a number of changes concerning head and neck tumors. The division of stage IV tumors into three subcategories marks a significant expansion of the stage grouping procedure. Methods: In a retrospective study the clinical course of 3247 patients with head and neck carcinomas were comparatively evaluated according to the 4th and 5th editions of the new TNM classification. In particular it was the aim of the study to test the prognostic relevance of the subdivision of stage IV especially in mucosal cancer. Results: In classifying the primary tumor the most extensive changes were noted for supraglottic and salivary gland tumors. On the basis of the 4th edition of the TNM classification the following recurrence-free 5-year survival rates for 3033 cases of mucosal cancer were calculated: stage I 91,0%, stage II 78,6%, stage III 61,4%, stage IV 31,0%. The calculations based on the 5th edition yielded: stage I 91,0%, stage II 77,2%, stage III 61,2%, stage IVA 32,4%, stage IVB 25,3%, stage IVC 3,6%. Conclusions: The adequacy of the revised stage classification in establishing a prognostic hierarchy was confirmed. However, a significant prognostic distinction between N2- (stage IVA) and N3-metastasis (stage IVB) could not be found.
    Notes: Zusammenfassung Die 5. Aufl. der TNM-Klassifikation bringt einige Änderungen im Bereich der Kopf-Hals-Tumoren mit sich. Eine wesentliche Erweiterung der Stadiengruppierung besteht in der Unterteilung von Stadium IV in 3 Unterstadien. In einer retrospektiven Studie wurden die Krankheitsverläufe von 3247 Patienten mit Karzinomen der Mundhöhle, des Oro- und Hypopharynx, des Larynx, der Speicheldrüsen und der Kieferhöhle ausgewertet. Hierbei kamen die 4. und die 5. Aufl. der TNM-Klassifikation vergleichend zur Anwendung. Insbesondere wurde geprüft, ob der Unterteilung von Stadium IV eine prognostische Relevanz zukommt. Bei der Klassifikation des Primärtumors ergaben sich die umfassendsten Änderungen bei Tumoren der Supraglottis und der Speicheldrüsen. Nach der 4. Aufl. der TNM-Klassifikation errechneten sich folgende rezidivfreien Fünfjahresüberlebensraten: Stadium I 89,7%, Stadium II 78,9%, Stadium III 60,3%, Stadium IV 31,0%, nach der 5. Aufl.: Stadium I 90,8%, Stadium II 77,1%, Stadium III 61,3%, Stadium IVA 32,2%, Stadium IVB 25,8%, Stadium IVC 7,9%. Die Eignung der neuen Stadieneinteilung zur Schaffung einer prognostische Hierarchie konnte bestätigt werden. Allerdings ließ sich kein signifikanter Prognoseunterschied zwischen einer N2- (Stadium IVA) und einer N3-Metastasierung (Stadium IVB) finden.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...