506056 SzGeCERN 20151106222916.0 oai:cds.cern.ch:506056 cerncds:CERN CERCER 2261363 eng SIS-2001-112 Hilf, E Distributed Information Services in Physics 2001 Geneva CERN Jun 2001 The concept of distributed information services maintained by a distributed work force for scientific information is described. Realizations and experiences for Physics (since 1995), Marine Sciences, and dissertation theses in physics are presented. Technically the information is gathered from the local web servers of the worldwide distributed research institutes and departments, by distributed Harvest-gatherers, under the control of national learned societies or regional other institutions. Queries are answered by a network of mirrors of Harvest-brokers. For PhysNet, a Charter sets the rules to assure a noncommercial, free full-text access service, under the control of the set of national national learned societies involved, but unbiased to any single one. CERN EDS SzGeCERN Information Transfer and Management ARTICLE CERN Hohlfeld, M Severiens, T Zimmermann, K CERN? 2 High Energy Phys. Libr. Webzine 4 2001 sis.prepteam@cern.ch n 200126 y2005 13 20071114 2042 CER01 20010628 PUBLIC 002261363CER ARTICLE 494506 SzGeCERN 20171109141452.0 2249037CERCER chem-ph/9412003 eng Borrmann, P Specific heat in the thermodynamics of clusters 1994 29 Dec 1994 12 p The thermodynamic properties such as the specific heat are uniquely determined by the second moments of the energy distribution for a given ensemble averaging. However for small particle numbers the results depend on the ensemble chosen. We calculated the higher moments of the distributions of some observables for both the canonical and the microcanonical ensemble of the same van der Waals clusters. The differences of the resulting thermodynamic observables for the two ensembles are calculated in terms of the higher moments. We demonstrate how for increasing particle number these terms decrease to vanish for bulk material. For the calculation of the specific heat within the microcanonical ensemble we give a new method based on an analysis of histograms. LANL EDS SzGeCERN Chemical Physics and Chemistry PREPRINT LANL EDS Chemical Physics Gloski, D Hilf, E R Borrmann, Peter Gloski, Dorian Hilf, Eberhard R. http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=chem-ph&id=9412003 Access to fulltext document borrmann@merlin.physik.uni-oldenburg.DE (Peter Borrmann) Dept. of Physics, University of Oldenburg n 200115 11 20060609 2033 CER01 20010409 PUBLIC 002249037CER PREPRINT Hidden 456649 SzGeCERN 20160331235451.0 2208556CERCER cond-mat/0009048 eng Borrmann, P Paradoxical Magnetic Cooling in a Structural Transition Model 2001 In contrast to the experimentally widely used isentropic demagnetization process for cooling to ultra-low temperatures we examine a particular classical model system that does not cool, but rather heats up with isentropic demagnetization. This system consists of several magnetite particles in a colloidal suspension, and shows the uncommon behavior of disordering structurally while ordering magnetically in an increasing magnetic field. For a six-particle system, we report an uncommon structural transition from a ring to a chain as a function of magnetic field and temperature. LANL EDS SIS LANLPUBL2002 SIS:2002 PR/LKR added SzGeCERN Condensed Matter ARTICLE LANL EDS Statistical Mechanics LANL EDS Condensed Matter Stamerjohanns, H Hilf, E R Tománek, D Borrmann, Peter Stamerjohanns, Heinrich Hilf, Eberhard R. Tomanek, David 117-119 Eur. Phys. J. B 19 2001 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=0009048 Access to fulltext document stamer@uni-oldenburg.de n 200036 13 20060828 2034 CER01 20000905 PUBLIC 002208556CER ARTICLE Hidden 450259 SzGeCERN 20160331235424.0 2201302CERCER cond-mat/0008071 eng Borrmann, P Calculation of thermodynamic properties of finite Bose-Einstein systems 1999 We derive an exact recursion formula for the calculation of thermodynamic functions of finite systems obeying Bose-Einstein statistics. The formula is applicable for canonical systems where the particles can be treated as noninteracting in some approximation, e.g. like Bose-Einstein condensates in magnetic traps. The numerical effort of our computation scheme grows only linear with the number of particles. As an example we calculate the relative ground state fluctuations and specific heats for ideal Bose gases with a finite numbers of particles enclosed in containers of different shapes. LANL EDS SzGeCERN Condensed Matter ARTICLE LANL EDS Statistical Mechanics LANL EDS Mesoscopic Systems and Quantum Hall Effect LANL EDS Condensed Matter Harting, J Mülken, O Hilf, E R Borrmann, Peter Harting, Jens Muelken, Oliver Hilf, Eberhard R. 1519 Phys. Rev. A 60 1999 http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=0008071 Access to fulltext document muelken@egoiste.physik.uni-oldenburg.de n 200032 13 20060916 0014 CER01 20000807 PUBLIC 002201302CER ARTICLE Hidden 416329 SzGeCERN 0402956CERCER eng LBL-642 SIS-74-2999 Küpper, W A Thermostatic properties of nuclear matter 1974 Berkeley, CA Lawrence Berkeley Nat. Lab. Feb 1974 45 p SIS INDIA2000 SzGeCERN General Theoretical Physics PREPRINT Hilf, E R Wegmann, G Wegmann, G no 2 Hilf, E R no 3 Küpper, W A no 1 Nucl. Phys. LBL München Univ. München Univ. TH Darmstadt n 197400 11 20080628 0005 CER01 20000520 PUBLIC 000402956CER PREPRINT 295164 SzGeCERN 20160331164113.0 0216681CERCER cond-mat/9601138 eng UOL-THEO-96-2-3 Borrmann, P Thermodynamics of finite magnetic two-level systems 1996 Oldenburg Oldenburg Univ. 29 Jan 1996 4 p paper We use Monte Carlo simulations to investigate the thermodynamical behaviour of aggregates consisting of few superparamagnetic particles in a colloidal suspension. The potential energy surface of this classical two-level system with a stable and a metastable `ring' and `chain' configuration is tunable by an external magnetic field and temperature. We determine the complex `phase diagram' of this intriguing system and analyze thermodynamically the nature of the transition between the ring and the chain `phase'. LANL EDS SzGeCERN Condensed Matter PREPRINT Stamerjohanns, H Hilf, E R Jund, P Kim, S G Tománek, D Borrmann, Peter Stamerjohanns, Heinrich Hilf, Eberhard Jund, Philippe Kim, Seon Gon Tomanek, David http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=9601138 Access to fulltext document borrmann@uni-oldenburg.de n 199606 11 20051226 0018 CER01 19960130 PUBLIC 000216681CER PREPRINT Hidden 292190 SzGeCERN 20170920225048.0 oai:cds.cern.ch:292190 cerncds:FULLTEXT 0213541CERCER SLAC 3262472 SPIRES 3262472 Inspire 402857 quant-ph/9511042 eng UO-PHYS-THEO-28 Dullweber, A Simple quantum mechanical phenomena and the Feynman real time path integral 1995 29 Nov 1995 6 p paper The path integral formalism gives a very illustrative and intuitive understanding of quantum mechanics but due to its difficult sum over phases one usually prefers Schr\"odinger's approach. We will show that it is possible to calculate simple quantum phenomena by performing Feynman's sum over all paths staying entirely in real time. Once the propagator is obtained it is particularly easy to get the energy spectrum or the evolution of any wavefunction. LANL EDS SzGeCERN General Theoretical Physics PREPRINT Hilf, E R Mendel, E CERN Central Library quant-ph/9511042 http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=quant-ph&id=9511042 Access to fulltext document http://cds.cern.ch/record/292190/files/9511042.pdf Access to fulltext document mendel@darkstar.physik.uni-oldenburg.de (Eduardo Mendel) n 199549 11 20100426 0852 CER01 19951130 PUBLIC 0001 000213541CER PREPRINT Hidden 274439 SzGeCERN 20160331145510.0 0194101CERCER cond-mat/9412123 eng Diekmann, B Structures and stabilities of H3+(H2)n clusters (n=1-11) 1994 31 Dec 1994 9 p Geometries and energies for H3+(H2)n clusters (n = 0, ..., 11) have been calculated using standard "ab initio" methods. Up to clusters with n = 6, four different Pople basis sets (DZ, TZ, TZP) have been used in the calculations. For larger cluster sizes, the calculations have been carried out with one basis set (DZ) using the HF/CISD method. We discuss here only the nice counterplay of polarisation effects between the central H3+ ion and the adsorbed H2 molecules, which naturally governs both the geometric structure and the energy of the clusters. LANL EDS SzGeCERN Condensed Matter PREPRINT Borrmann, P Hilf, E R Diekmann, B Borrmann, P Hilf, E R http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=9412123 Access to fulltext document diekmann@merlin.physik.uni-oldenburg.DE (Bernd Diekmann) n 199502 11 20051224 0756 CER01 19950104 PUBLIC 0001 000194101CER PREPRINT Hidden 274437 SzGeCERN 20160331145509.0 0194099CERCER cond-mat/9412121 eng Borrmann, P Magnetism of small transition metal clusters and the effects of isomerisation 1994 30 Dec 1994 10 p We investigate the magnetic properties of small transition metal clusters using a simple statistical model, which requires some input data from ab initio spin-density functional calculations. In our study we consider a thermodynamically equilibrated ensemble of clusters with different structures, spin multiplicities, and ground state energies. We calculate the physical properties of this system by weighting the individual configurations according to the Boltzmann statistics. We find that presence of isomers with very similar ground state energies, yet very different magnetic properties, gives rise to a rich magnetic behaviour of the system which differs significantly from what would be expected for single configurations. We apply the present model to to determine the magnetic susceptibility of a cluster ensemble of Langevin paramagnets. Our results show that some of the anomalies in the magnetic behaviour of transition metal clusters might be understood in the framework of our model which is, of course, limited by the extremely high computational effort needed to obtain the input data. LANL EDS SzGeCERN Condensed Matter PREPRINT Diekmann, B Hilf, E R Tománek, D Borrmann, Peter Diekmann, Bernd Hilf, Eberhard R Tomanek, David http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=9412121 Access to fulltext document borrmann@merlin.physik.uni-oldenburg.DE (Peter Borrmann) n 199502 11 20051224 0756 CER01 19950104 PUBLIC 0001 000194099CER PREPRINT Hidden 274378 SzGeCERN 20160331145509.0 0194040CERCER cond-mat/9412113 eng Borrmann, P New enhancements to Feynman's path integral for fermions 1994 27 Dec 1994 7 p We show that the computational effort for the numerical solution of fermionic quantum systems, occurring e.g., in quantum chemistry, solid state physics, field theory in principle grows with less than the square of the particle number for problems stated in one space dimension and with less than the cube of the particle number for problems stated in three space dimensions. This is proven by representation of effective algorithms for fermion systems in the framework of the Feynman Path Integral. LANL EDS SzGeCERN Condensed Matter PREPRINT Hilf, E R Borrmann, Peter Hilf, Eberhard R http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cond-mat&id=9412113 Access to fulltext document borrmann@merlin.physik.uni-oldenburg.DE (Peter Borrmann) n 199502 11 20051224 0756 CER01 19950104 PUBLIC 0001 000194040CER PREPRINT Hidden 169151 SzGeCERN 20150210213423.0 SPIRES 1531883 Inspire 230806 eng UO-PHYS-THEO-06 Kleihaus, B Wilson action in terms of the Kogut-Susskind fermion matrix 1986 Oldenburg Oldenburg Univ. May 1986 6 p paper SzGeCERN Particle Physics - Theory PREPRINT Polley, L Wendel, M H Hilf, E R CERN Central Library UO PHYS THEO 06 h 198630 11 20100727 1734 CER01 19900129 PUBLIC 0001 000080536CER PREPRINT