@misc{3733, author = {{Dohmann, Joachim and Keldenich, Kai}}, pages = {{3}}, title = {{{Absorber}}}, year = {{1998}}, } @inproceedings{4085, abstract = {{This paper deals with an advanced speed control scheme for inverter-fed travelling waveultrasonic motors. It is implemented as an additional outer control loop of an underlaid voltage andtravelling bending wave vector controller and verified by measurements on a prototype drive. Thenovel speed control is using an inverse contact model by a neural network, trained by measured valuesof speed and torque, in order to compensate the nonlinear torque generation of the motor. Since thereference values of the bending wave control are calculated from the desired torque value by the neu-ral network, first an open loop control of the drive ́s torque is feasible and second common speed con-trol schemes, well performing in common electrical drives, can be applied. Thus, the so equippedultrasonic motor-drive meets requirements for applications in the field of servo-drives e.g. robotics. }}, author = {{Maas, Jürgen and Schulte, Thomas and Grotstollen, H.}}, location = {{Harrogate (UK)}}, pages = {{701 -- 708}}, title = {{{Controlled Ultrasonic Motor for Servo-Drive Applications}}}, year = {{1998}}, } @article{734, abstract = {{We report on investigations of platinum clusters with about five to 400 atoms that are deposited from a cluster beam on to crystalline graphite surfaces. Scanning tunneling spectroscopy in an UHV environment at liquid helium temperatures reveals the existence of distinct peaks in the conductivity of the cluster-on-surface system. For negative voltages, the peak separations scale with the inverse particle height, which hints at a quantum size effect in these metallic “quantum dots”.}}, author = {{Bettac, A. and Köller, Lars and Rank, V. and Meiwes-Broer, Karl-Heinz}}, issn = {{0039-6028}}, journal = {{Surface Science : a journal devoted to the physics and chemistry of interfaces}}, keywords = {{Clusters, Conductivity, Platinum, Quantum size effect, Scanning tunneling, spectroscopy}}, pages = {{475--479}}, publisher = {{Elsevier}}, title = {{{Scanning Tunneling Spectroscopy on Deposited Platnium Clusters}}}, doi = {{10.1016/S0039-6028(98)00028-4}}, volume = {{402-404}}, year = {{1998}}, } @article{740, abstract = {{A pinhole grid spectrometer is used to measure the light emission from the plasma of the pulsed arc cluster ion source (PACIS). Spectra of various metals and carbon have been measured between 20 and 100 nm. In the case of carbon the average electron temperature is estimated to about 0.69 eV. Higher temperatures up to 0.79 eV are measured when inserting seeding gas which flushes the discharge volume with approx. one atmosphere of helium. An operation under this source conditions leads to the generation of an intense charged cluster beam. The application of the source as a bright light source in the VUV region is discussed.}}, author = {{Seeger, K. and Köller, Lars and Tiggesbäumker, J. and Meiwes-Broer, Karl-Heinz}}, issn = {{1434-6060 }}, journal = {{The European physical journal : D, Atomic, molecular, optical and plasma physics }}, number = {{2}}, pages = {{179--182}}, publisher = {{Springer}}, title = {{{VUV-Spectroscopy of the Plasma Light Emission Generated by the Pulsed Arc Cluster Ion Source (PACIS)}}}, doi = {{10.1007/s100530050162}}, volume = {{3}}, year = {{1998}}, } @article{4351, author = {{Kutz, Gerd}}, issn = {{0031-7136}}, journal = {{Pharmazeutische Zeitung : PZ ; die Zeitschrift der deutschen Apotheker ; Zentralorgan für die Apotheker der Bundesrepublik Deutschland}}, number = {{45}}, pages = {{11--15}}, publisher = {{Avoxa, Mediengruppe Deutscher Apotheker }}, title = {{{Galenische Charaktersisierung ausgewählte Hautpflegeprodukte }}}, volume = {{142}}, year = {{1997}}, } @article{743, abstract = {{We report measurements of the photodestruction cross sections of small sputtered negatively charged silver clusters (AgN−, 5 ≤ N ≤ 19). Resonance-like peaks are observed in the optical spectra which can be attributed to collective electron excitations. In contrast to neutral and positively charged clusters, the resonance energies are far above the electron emission threshold. With decreasing cluster size the resonance positions distinctly shift towards lower energies. This red-shift is explained by an extension of a semi-empirical model by Liebsch which we previously used to interpret the blue-shift in AgN+ [J. Tiggesbäumker, L. Köller, K.H. Meiwes-Broer and A. Liebsch, Phys. Rev. A 48 (1993) R1749], now including the polarizabilities of small metal clusters.}}, author = {{Tiggesbäumker, Josef and Köller, Lars and Meiwes-Broer, Karl-Heinz}}, issn = {{0009-2614 }}, journal = {{Chemical Physics Letters}}, number = {{3-4}}, pages = {{428--432}}, publisher = {{Elsevier}}, title = {{{Bound-Free Collective Electron Excitations in Negatively Charged Silver Clusters}}}, doi = {{https://doi.org/10.1016/0009-2614(96)00950-5}}, volume = {{260}}, year = {{1996}}, } @article{6787, author = {{Gerken, Bernd and Wienhöfer, Mathias}}, issn = {{0723-6514}}, journal = {{Libellula}}, number = {{3/4}}, pages = {{249--267}}, publisher = {{Gesellschaft Deutschsprachiger Odonatologen}}, title = {{{Biozönologische Betrachtungen an Libellen einer französischen Flußaue im Rahmen eines tierökologischen Geländepraktikums}}}, volume = {{12}}, year = {{1993}}, } @article{742, abstract = {{The collinear ion-beam depletion technique is used to measure absolute photofragmentation cross sections of small silver-cluster ions in the range from 2.3 to 5.7 eV. Giant resonances are found which can be interpreted in terms of a collective electron oscillation. The optical spectra of spherical Ag+9 and Ag+21 show a large blue-shift of the resonance energy relative to the respective experimental surface value. For non-spherical clusters, a splitting of the giant resonance is found, in qualitative accordance with jellium calculations.}}, author = {{Tiggesbäumker, J. and Köller, Lars and O. Lutz, H. and Meiwes-Broer, Karl-Heinz}}, issn = {{0009-2614 }}, journal = {{Chemical Physics Letters}}, number = {{1-2}}, pages = {{42--47}}, publisher = {{Elsevier}}, title = {{{Giant Resonances in Silver-Cluster Photofragmentation}}}, doi = {{https://doi.org/10.1016/0009-2614(92)86099-4}}, volume = {{190}}, year = {{1992}}, } @inbook{745, abstract = {{Positive and negative silver cluster ions are produced by sputtering of solid silver by 25 keV Xe+ bombaxdment. After mass selection, collinear ion beam depletion is used to measure absolute photofragmentation cross-sections in the photon energy range from ħω = 2.0 to 5.7 eV. Giant resonances are found which can be interpreted in terms of a collective electron oscillation. For spherical clusters (e.g., Ag19−, Ag21+) single resonances dominate the spectra, whereas deformation (e.g., Ag9−, Ag11+) induces a splitting into two components.}}, author = {{Tiggesbäumker, J. and Köller, Lars and O. Lutz, H. and Meiwes-Broer, Karl-Heinz}}, booktitle = {{Nuclear Concepts in Atomic Cluster Physics}}, editor = {{Schmidt, Rüdiger}}, isbn = {{978-3-540-55625-1}}, location = {{Bad Honnef}}, pages = {{245--253}}, publisher = {{Springer}}, title = {{{Collective Excitation in Silver Cluster Anions and Kations}}}, doi = {{https://doi.org/10.1007/3-540-55625-7_27}}, volume = {{404}}, year = {{1992}}, }