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
Filter
  • crystal structure  (5)
  • 25.70.Jj  (2)
  • Nuclear Reactions  (2)
  • 1
    ISSN: 0375-9474
    Keywords: Nuclear Reactions
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: 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
    Amsterdam : Elsevier
    Nuclear Physics, Section A 329 (1979), S. 157-191 
    ISSN: 0375-9474
    Keywords: Nuclear Reactions
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 326 (1987), S. 313-326 
    ISSN: 1434-601X
    Keywords: 25.70.Jj
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fission-fragment angular distributions were measured in the reaction of40Ar with208Pb near the fusion barrier. For nearly symmetric mass-/charge splits we find angular distributions symmetric around θ=90 degrees, however, with unusually large anisotropies. These develop gradually into forward-backward asymmetric distributions as one moves away from mass-/charge symmetry. This indicates that non-compound fission (‘quasi-fission’) competes with true fusion-fission. The relative contribution of quasi-fission to the total fission cross section is somewhere between 51 and 85%. In the framework of the extra-push model this is equivalent to an extra-extra push energy for compound-nucleus formation inside the true fission saddle point of 4〈E xx 〈9 MeV in agreement with a recent empirical parametrization of fusion-barrier shifts based on fusion-fission cross sections. On the basis of cross sections for fusion-evaporation residues it had previously been concluded that fusion of40Ar with Pb isotopes occurs unhindered. Possible reasons for this apparent discrepancy are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1434-601X
    Keywords: 25.70.Cd ; 25.70.Jj ; 25.70.Lm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Mass and charge distributions for binary reaction channels have been measured for the reactions86Kr with76Ge,104Ru and130Te at the Coulomb barrier using chemical separations andγ-ray spectroscopy. These systems span the region where dynamical hindrance to complete fusion sets in. The binary reactions can be subdivided into two components associated withi) reflection from the outer potential barrier (quasielastic), andii) reseparation after passing the barrier (complex reactions). The sum of complex-reaction channels and evaporation residues from complete fusion can be reproduced by a barrier passing calculation. The fraction of the barrier passing flux leading to reseparation increases from 26±10% for the lightest system to more than 90% for the heaviest system. The data indicate that fusion hindrance is primarily caused by reseparation shortly after passage of the barrier before Swiatecki's conditional saddlepoint is overcome, resulting in partitions close to the entrance channel configuration. In addition, for the heaviest system, a quasifission component representing somewhat less than 20% of the barrier-passing flux was observed. From the missing masses of fragment pairs we can deduce that the reseparating complex-reaction products have kinetic energies well below the fusion barrier and share the excitation energy in a way similar to the sawtooth-like curve known from low-energy fission. The quasielastic, predominantly one- and two-nucleon transfer channels, have strongly varying cross sections for the three systems despite similar effectiveQ-values. A systematics of one-neutron transfer cross sections at the Coulomb barrier is established and shown to differ considerably from the smooth behaviour observed at energies 20–30% above the barrier. The connection to nuclear polarization phenomena and orbit matching is pointed out.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 663-669 
    ISSN: 0044-2313
    Keywords: Dicopper(I)-octa-μ3-halogeno-hexahalogeno-octahedro-hexamolybdate(II) ; crystal structure ; Mo6X14-group ; trigonal planar CuX3-group ; ionic conduction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trigonal Planar CuX3-Groups in Cu2Mo6X14, X = Cl, Br, ICu2Mo6Cl14 (I), Cu2Mo6Br14 (II) and Cu2Mo6I14 (III) were synthesized by thermal treatment of corresponding mixtures of copper(I) and molybdenum(II) halides. The crystal structures were determined by single crystal X-ray analyses. I and II show isotypism, cubic, Pn3 (no. 201, sec. setting), Z = 4, I: a = 12.772(3) Å, II: a = 13.350(2) Å. III shows a new structural type, orthorhombic, Pbca (No. 61), Z = 4, a = 16.058(3) Å, b = 10.643(2) Å, c = 16.963(3) Å. Trigonal planar CuX3 units were found in I—III. Structural behaviour relations are discussed, especially with regard to ionic conductivity.
    Notes: Cu2Mo6Cl14 (I), Cu2Mo6Br14 (II) und Cu2Mo6I14 (III) wurden durch thermische Behandlung der Gemenge der binären Halogenide CuX und Mo6X12 im molaren Verhältnis 2:1 in einkristalliner Form erhalten. Röntgenographische Strukturbestimmung wurde an Einkristallen durchgeführt. I und II zeigen Isotypie, Pn3 (Nr. 201, sec. setting) Z = 4, I: a = 12,772(3) Å, II: a = 13,350(2) Å. III weist eigenen Strukturtyp auf: Pbca (Nr. 61), Z = 4, a = 16,058(3) Å, b = 10,643(2) Å, c = 16,963(3) Å. In I—III liegen trigonal planare CuX3-Gruppen vor. Bindungsverhältnisse und Meßergebnisse der Ionenleitfähigkeit werden diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 1231-1235 
    ISSN: 0044-2313
    Keywords: Dilead(II)-hexahalogenopalladate(II) ; crystal structure ; strongly elongated PdX6 octahedra ; DTA, IR/RAMAN, 207Pb MAS NMR ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pb2PdX6 (X = Cl, Br) - Compounds with Elongated [PdX6] OctahedraIn contradiction to published data new compounds in the systems PbX2 - PdX2 (X = Cl, Br) with the formula Pb2PdCl6 (I) and Pb2PdBr6 (II) were found. These were synthesized by thermal treatment of the corresponding mixtures of PbX2 and PdX2 (X = Cl, Br). X-ray single crystal structure analysis shows isotypism of I and II, monoclinic, P21/c (No. 14), Z = 2, I: a = 9.037(2) Å, b = 6.224(1) Å, c = 8.162(1) Å, β = 90.31(7)β, II: a = 9.512(7) Å, b = 6.584(8) Å, c = 8.383(3) Å, β = 90.07(5)º. Strongly elongated PdX6 octahedra are found in the crystal structure. Additional characterisation of the compounds was done by DTA, IR/RAMAN spectra and 207Pb MAS NMR investigations. Remarcable low field shifts were found for 207Pb.
    Notes: Entgegen Literaturangaben wurden in den Systemen PbX2 - PdX2 (X = Cl, Br) die neuen Verbindungen Pb2PdCl6(I) und Pb2PdBr6(II) aufgefunden. Sie wurden durch thermische Behandlung der binären Halogenide PbX2 und PdX2 im molaren Verhältnis 2:1 dargestellt (Einkristalle). Die Kristallstrukturen wurden mit Einkristallröntgenuntersuchungen ermittelt. I und II sind isotyp, monoklin, P21/c (Nr. 14), Z = 2, I: a = 9,037(2) Å, b = 6,224(1) Å, c = 8,162(1) Å, β = 90,31(7)º, II: a = 9,512(7) Å, b = 6,584(8) Å, c = 8,383(3) Å, β = 90,07(5)º. In Pb2PdX6 werden stark gestreckte PdX6-Oktaeder beobachtet. Die Verbindungen wurden außerdem mittels DTA, IR/RAMAN-Spektren und 207Pb-MAS-NMR-Untersuchungen charakterisiert. Für 207Pb wurde eine bemerkenswerte Tieffeldverschiebung beobachtet.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 977-980 
    ISSN: 0044-2313
    Keywords: Mercury(II) lead(II) oxide chloride ; synthesis ; crystal structure ; structural comparison ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: HgPb2O2Cl2, a “Perforated” Lead(II) OxideSingle crystals of HgPb2O2Cl2 were grown in a HgCl2 flux by reaction of PbO with HgCl2. Crystal structure analysis by single crystal X-ray methods were carried out. HgPb2O2Cl2 crystallizes monoclinic with a = 11.788(2) Å, b = 3.910(1) Å, c = 7.749(2) Å, β = 122.64(3)°, space group C2/m (No. 12) and Z = 2. HgPb2O2Cl2 is the first member of a new structure type, closely related to the structure of PbO.
    Notes: Einkristalle von HgPb2O2Cl2 wurden durch Umsetzung von PbO und HgCl2 in HgCl2-Schmelzen gezüchtet. An ihnen wurde der Aufbau mittels Einkristallröntgenstrukturanalyse bestimmt. HgPb2O2Cl2 kristallisiert monoklin mit a = 11,788(2) Å, b = 3,910(1) Å, c = 7,749(2) Å, β = 122,64(3)°, Raumgruppe C2/m (Nr. 12) und Z = 2. HgPb2O2Cl2 ist der erste Vertreter eines neuen Strukturtyps, der kristallchemisch von der Struktur von PbO ableitbar ist.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 597 (1991), S. 151-161 
    ISSN: 0044-2313
    Keywords: Silver lead oxybromide ; crystal structure ; layer structure ; crystal chemistry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: AgPbOBr  -  a New Sillén Type? Preparation and Crystal StructureAgPbOBr was prepared for the first time. Its crystal structure was explored by single crystal X-ray diffraction. AgPbOBr crystallizes with tetragonal symmetry in space group P 4/nmm - No. 129 with a = 3.891(1) Å, c = 11.07(1) Å and two formulas per unit cell. Least squares refinement yields an weighted R-value of 0.065. AgPbOBr shows a layered structure with components of the crystal structure of red PbO as well as AgBr. Emphasized differences between the crystal structures of AgPbOBr and the X2-types after Sillén's notation [1] are characteristic. AgPbOBr is the first member of a new structure type, arranged between Sillén- and Aurivilliusphases [2].
    Notes: AgPbOBr wurde erstmalig dargestellt und die Kristallstruktur an Einkristallen aufgeklärt. Es kristallisiert tetragonal (Raumgruppe P4/nmm  -  No. 129) mit a = 3,891(1) Å, c = 11,07(1) Å und z = 2. Die Verfeinerung (LSQ) der Einkristallmessung liefert Rw = 0,065. AgPbOBr ist schichtförmig aufgebaut mit aus PbO und AgBr bestehenden Bereichen, die nahezu unverändert dem Bau von PbO und AgBr gleichen. Die Unterschiede zur Kristallstruktur der Sillén-Phasen vom X2-Typ [1] sind charakteristisch. AgPbOBr nimmt kristallchemisch eine Stellung zwischen den Sillén- und den Aurivillius-Phasen [2] (z. B. BiOCl und γ-Bi2 WO6) ein.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 603 (1991), S. 69-76 
    ISSN: 0044-2313
    Keywords: Dicesium mercury(II) palladium(II) hexachloride ; preparation ; crystal structure ; group-subgroup relation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of Cs2HgPdCl6, a Distorted Variant of ChloroperovskitsCs2HgPdCl6 single crystals show tetragonal symmetry with the space group I 4/m m m (No. 139) with 2 formular units per unit cell. The lattice parameters are a = 7.432(4) Å, c = 10.874(7) Å. The atomic arrangement of Cs2HgPdCl6 is explored by X-ray crystal structure analysis. The important polyhedrons are square-planar PdCl4 groups and HgCl2 dumbbells. The PdCl4 group is completed by two further chlorine atoms to a elongated octahedron and four further chlorine atoms form with the HgCl2 dumbbell a compressed octahedron. The crystal structure of Cs2HgPdCl6 is compared with the arrangement in halogenoperovskits and in Rb2PdCl4 [3].
    Notes: Die Verbindung Cs2HgIIPdIICl6 läßt sich durch Festkörperreaktion phasenrein darstellen. Sie kristallisiert in der Raumgruppe I 4/m m m (No. 139) mit a = 7,432(4) Å, c = 10,874(7) Å, Z = 2. Die Kristallstruktur wurde mit röntgenographischen Methoden an Einkristallen ermittelt. Pd2+ ist quadratisch-planar und Hg2+ hantelförmig von Cl-umgeben. In zweiter Nachbarschaft ergänzen weitere Cl- zu gestreckten bzw. gestauchten Oktaedern. Dieses Bauprinzip entspricht dem Aufbau von Cs2AuIAuIIICl6 [1, 2]. Es besteht direkte kristallchemische Beziehung zur Kristallstruktur der Halogenoperowskite bzw. des K2PdCl4-Typs.
    Additional Material: 4 Ill.
    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...