The spectrum and structure of the He2 molecule: Characterization of the triplet states associated with the UAO's 4pπ and 5pπ

The He₂ band systems $\text{4pπ i}{}^3\text{Π}{}_{\mathrm{g}}\text{→ 2s a}{}^3\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ and $\text{5pπ l}{}^3\text{Π}{}_{\mathrm{g}}\text{→ 2s a}{}^3\text{Σ}{}_{\mathrm{u}}{}^{\mathrm{+}}$ are described in detail, and the i and l states characterized. A number of significant perturbations in the i and l states are identified, and the possible perturber states discussed. The following molecular constants (cm^?1) are reported:

     

22.

Zur Kenntnis von Tripraseodym‐hexanitridotriborat Pr3B3N6: Neue Synthese und Verfeinerung der Kristallstruktur     

Michael Orth  Wolfgang Schnick 《无机化学与普通化学杂志》1999,625(4):551-554

On Tripraseodymium Hexanitridotriborate Pr₃B₃N₆: New Synthesis and Crystal Structure Refinement Single‐crystalline Pr₃B₃N₆ was obtained by the reaction of praseodymium and BN_x(NH)_y(NH₂)_z in a NaCl melt under N₂ atmosphere in a high‐frequency furnace at 1250 °C. Contrary to literature data, Pr₃B₃N₆ crystallizes in the centrosymmetric space group R 3 c as revealed by single‐crystal X‐ray diffraction (a = 1211.95(9), c = 701.53(7) pm, Z = 6, R1 = 0.0258, wR2 = 0.0658). In the solid, Pr₃B₃N₆ contains Pr³⁺ and planar cyclotrinitridoborate units B₃N₆^9–. The anions represent motifs from the structure of hexagonal boron nitride (h‐BN) and they are stacked analogously along [001]. Both the bond lengths B–N (average value 147.8 pm) and the interionic distances between the anions (350.8 pm) are comparable with the values in h‐BN.     

23.

Orthonitridoborate ions [BN3]6- in oxonitridosilicate cages: synthesis, crystal structure, and magnetic properties of Ba4Pr7[Si12N23O][BN3], Ba4Nd7[Si12N23O][BN3], and Ba4Sm7[Si12N23O][BN3     

Orth M  Hoffmann RD  Pöttgen R  Schnick W 《Chemistry (Weinheim an der Bergstrasse, Germany)》2001,7(13):2791-2797

The isotypic title compounds Ba4Pr7[Si12N23O][BN3], Ba4Nd7[Si12N23O][BN3], and Ba4Sm7[Si12N23O][BN3] were prepared by reaction of Pr, Nd, or Sm, with barium, BaCO3, Si(NH)2, and poly(boron amide imide) in nitrogen atmosphere in tungsten crucibles using a radiofrequency furnace at temperatures up to 1650 C. They were obtained as main products (approximately 70%) embedded in a very hard glass matrix in the form of intense dark green (Pr), orange-brown (Sm), or dark red (Nd) large single crystals, respectively. The stoichiometric composition of Ba4Sm7[Si12N23O][BN3] was verified by a quantitative elemental analysis. According to the single-crystal X-ray structure determinations (Ba4Ln7[Si12N23][BN3], Z= , P6 with Ln = Pr: a = 1225.7(1), c = 544.83(9) pm, R1 = 0.013, wR2 = 0.030; Ln = Nd: a = 1222.6(1), c = 544.6(1) pm, R1 = 0.017, wR2 = .039; Ln = Sm: a = 1215.97(5), c = 542.80(5) pm, R1 = 0.047, wR2 = 0.099) all three compounds are built up by a framework structure [Si12N23O]23- of corner-sharing SiX4 tetrahedrons (X = O, N). The oxygen atoms are randomly distributed over the X positions. The trigonal-planar orthonitridoborate ions [BN3]6- and also the Ln(3)3+ are situated in hexagonal cages of the framework (bond lengths Si-(N/O) 169-179 pm for Ln=Pr). The remaining Ba2+ and Ln3- ions are positioned in channels of the large-pored network. The trigonal-planar [BN3]6- ions have a B-N distance of 147.1(6) pm (for Ln = Pr). Temperature-dependent susceptibility measurements for Ba4Nd7[Si12N23O][BN3] revealed Curie-Weiss behavior above 60 K with an experimental magnetic moment of muexp = 3.36(5) microB/Nd. The deviation from Curie-Weiss behavior below 60 K may be attributed to crystal field splitting of the J = 9/2 ground state of the Nd3+ ions. No magnetic ordering is evident down to 4.2 K.     

24.

Muon spin rotation in superconductors     

M. Gladisch  D. Herlach  H. Metz  H. Orth  G. zu Putlitz  A. Seeger  H. Teichler  W. Wahl  M. Wigand 《Hyperfine Interactions》1979,6(1-4):109-112

By means of the muon spin rotation technique (⁺SR), the temperature dependence of the magnetic field inside the normal-conducting domains of high-purity tantalum crystals in the intermediate state has been measured in the temperature range 2.36K+SR. Possible applications of these findings to the study of long-range diffusion of positive muons at low temperatures are indicated.     

25.

Der Tetracyclin‐Repressor – das Musterbeispiel für einen biologischen Schalter     

Wolfram Saenger  Peter Orth  Caroline Kisker  Wolfgang Hillen  Winfried Hinrichs 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2000,112(12):2122-2133

     

26.

A spectrum of rhenium oxide     

Walter J Balfour  F.B Orth 《Journal of Molecular Spectroscopy》1980,84(2):424-430

The arc emission spectrum of the ReO molecule has been photographed in the region 590–860 nm and three bands of a single electronic transition have been rotationally analyzed. The separation of lines of the isotopic molecules ¹⁸⁵ReO and ¹⁸⁷ReO leads to the conclusion that the vibrational assignments for these bands are 1-0, 0-0, and 0–1. It is conceivable that an electronic isotope shift of ～0.08 cm^?1 exists. The following vibrational and rotational data (cm^?1) have been determined: ν₀(0-0) = 14 038.42, $\text{Δ}\text{G′(}\text{1}\text{2}\text{) = 867.85}$, $\text{Δ}\text{G″(}\text{1}\text{2}\text{) = 979.14}$; B′_e = 0.3889, α′_e = 0.0019, B″_e = 0.4257, α″_e = 0.0043. It is concluded that Λ′ ? Λ″ = +1 with Λ″ ≥ 2.     

27.

Quantum mechanical resonance and limiting absorption: The many body problem     

Andreas Orth 《Communications in Mathematical Physics》1990,126(3):559-573

We introduce a notion of quantum mechanical resonance that does not rely on analytic continuation of resolvent or scattering matrix and relate it to slow temporal decay of certain distinguished resonant states. We proceed to prove existence of resonances for the generalized many body Schrödinger operator for a rather large class of potentials containing Coulomb and Yukawa, but also nonsymmetric and nonanalytic potentials with Coulomblike singularities at the origin and certain differentiability and decay properties.Most of this work was done while the author was at Fachbereich Mathematik der Universität Frankfurt, D-6000 Frankfurt, Federal Republic of Germany     

28.

New spectroscopic analyses and potential energy curves for the X1Σ+ and A1Σ+ states of NaH     

F.B. Orth  W.C. Stwalley  S.C. Yang  Y.K. Hsieh 《Journal of Molecular Spectroscopy》1980,79(2):314-322

The emission spectrum of NaH has been photographed in the ～6000–7300-Å region. Additional bands of the A¹Σ⁺ electronic transition have been analyzed and in particular the observed vibrational structure of the excited A state has been extended down to v′ = 0. New spectroscopic constants have been obtained, the v′ = 0 data leading to especially large changes in the constants of the anomalous A¹Σ⁺ state. New Rydberg-Klein-Rees (RKR) potential energy curves have been calculated up to v″ = 8 of the X¹Σ⁺ state and up to v′ = 20 in the A¹Σ⁺ state.     

29.

Zur Struktur verstreckter Folien und Fäden sowie aus verdünnten Lösungen hergestellter Einkristalle aus Polyacrylnitril     

G. Hinrichsen  H. Orth 《Colloid and polymer science》1971,247(1-2):844-850

Zusammenfassung Kolloid- und Kristallstruktur von verstreckten Folien und Fäden und aus verdünnten Lösungen hergestellten Einkristallen von Polyacrylnitril wurden mit Hilfe von Röntgenklein- und -weitwinkeluntersuchungen, Elektronenbeugung und Elektronenmikroskopie untersucht. Es kann gezeigt werden, da entgegen den bisher publizierten Ergebnissen bei dem verstreckten Polyacrylnitril eine periodische Abfolge von besser und schlechter geordneten Bereichen erzielt werden kann, die sich in dem Auftreten einer röntgenografisch erfaßbaren Langperiode äußert und, wie die vergleichenden Untersuchungen an Einkristallen zeigen, durch eine Zwei-Phasen-Struktur beschrieben werden kann. Innerhalb der besser geordneten Bereiche ordnen sich die Ketten, indem ein zwar stark gestörtes, aber dreidimensionales Gitter mit der orthorhombischen Elementarzellea=10,6 Å,b=11,6 Å,c=5,04 Å aufgebaut wird. Kristallisationsfähig sind nur die syndiotaktischen Kettensequenzen des Polyacrylnitrils.

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Summary Colloidal and crystallographic structure of drawn films and solution grown single crystals of polyacrylonitrile were investigated by small and wide angle X-ray scattering, electron scattering and electron microscopical observations. In contrast to the published results it is shown that in the case of drawn polyacrylonitrile there exists a periodical arrangement of more and less ordered regions which manifests in the appearance of a so called long period and which — as shown by comparative investigations on single crystals — can be described by a two-phase-model. Within the ordered regions chains are arranged building up a strongly disturbed but three-dimensional crystal lattice. The orthorhombic unit cell has the dimensiona=10,6 Å,b=11,6 Å,c=5,04 Å. Only the syndiotactic chain sequences are able to crystallize.

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Vorgetragen auf der Arbeitssitzung des Fachausschusses Physik der Hochpolymeren in der Frühjahrstagung Berlin 1971 vom 9. bis 13. März des Regionalverbandes Physikalische Gesellschaft zu Berlin.

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Für die Hilfe bei den experimentellen Arbeiten danken die Verfasser FräuleinM. Collatz und den HerrenE. Vey undH. Gladbach.     

30.

Low-energy positrons from metallic moderators in a back scattering mode     

S. Pendyala  P.W. Zitzewitz  J.Wm. McGowan  P.H.R. Orth 《Physics letters. A》1973,43(3):298-300

The energy spectra of thermalized positrons emitted in the “back scattering mode” from Cu, Au, and Al moderators are reported.     

[首页] « 上一页 [1] [2] 3 [4] [5] [6] [7] [8] [9] 下一页 » 末  页»

State	$\text{ω}{}_{\mathrm{e}}$	$\text{xω}{}_{\mathrm{e}}$	$\text{B}{}_{\mathrm{e}}$	$\text{α}{}_{\mathrm{e}}$	$\text{r}{}_{\mathrm{e}}\text{(}\text{A}\text{?}\text{)}$
$\text{i}{}^3\text{Π}{}_{\mathrm{g}}$	1707.95	35.00	7.242g	0.222	1.0782
$\text{l}{}^2\text{Π}{}_{\mathrm{g}}$	1703.86	34.97	7.2264	0.2188	1.0794

Zur Kenntnis von Tripraseodym‐hexanitridotriborat Pr3B3N6: Neue Synthese und Verfeinerung der Kristallstruktur

On Tripraseodymium Hexanitridotriborate Pr₃B₃N₆: New Synthesis and Crystal Structure Refinement Single‐crystalline Pr₃B₃N₆ was obtained by the reaction of praseodymium and BN_x(NH)_y(NH₂)_z in a NaCl melt under N₂ atmosphere in a high‐frequency furnace at 1250 °C. Contrary to literature data, Pr₃B₃N₆ crystallizes in the centrosymmetric space group R 3 c as revealed by single‐crystal X‐ray diffraction (a = 1211.95(9), c = 701.53(7) pm, Z = 6, R1 = 0.0258, wR2 = 0.0658). In the solid, Pr₃B₃N₆ contains Pr³⁺ and planar cyclotrinitridoborate units B₃N₆^9–. The anions represent motifs from the structure of hexagonal boron nitride (h‐BN) and they are stacked analogously along [001]. Both the bond lengths B–N (average value 147.8 pm) and the interionic distances between the anions (350.8 pm) are comparable with the values in h‐BN.     

Orthonitridoborate ions [BN3]6- in oxonitridosilicate cages: synthesis, crystal structure, and magnetic properties of Ba4Pr7[Si12N23O][BN3], Ba4Nd7[Si12N23O][BN3], and Ba4Sm7[Si12N23O][BN3

The isotypic title compounds Ba4Pr7[Si12N23O][BN3], Ba4Nd7[Si12N23O][BN3], and Ba4Sm7[Si12N23O][BN3] were prepared by reaction of Pr, Nd, or Sm, with barium, BaCO3, Si(NH)2, and poly(boron amide imide) in nitrogen atmosphere in tungsten crucibles using a radiofrequency furnace at temperatures up to 1650 C. They were obtained as main products (approximately 70%) embedded in a very hard glass matrix in the form of intense dark green (Pr), orange-brown (Sm), or dark red (Nd) large single crystals, respectively. The stoichiometric composition of Ba4Sm7[Si12N23O][BN3] was verified by a quantitative elemental analysis. According to the single-crystal X-ray structure determinations (Ba4Ln7[Si12N23][BN3], Z= , P6 with Ln = Pr: a = 1225.7(1), c = 544.83(9) pm, R1 = 0.013, wR2 = 0.030; Ln = Nd: a = 1222.6(1), c = 544.6(1) pm, R1 = 0.017, wR2 = .039; Ln = Sm: a = 1215.97(5), c = 542.80(5) pm, R1 = 0.047, wR2 = 0.099) all three compounds are built up by a framework structure [Si12N23O]23- of corner-sharing SiX4 tetrahedrons (X = O, N). The oxygen atoms are randomly distributed over the X positions. The trigonal-planar orthonitridoborate ions [BN3]6- and also the Ln(3)3+ are situated in hexagonal cages of the framework (bond lengths Si-(N/O) 169-179 pm for Ln=Pr). The remaining Ba2+ and Ln3- ions are positioned in channels of the large-pored network. The trigonal-planar [BN3]6- ions have a B-N distance of 147.1(6) pm (for Ln = Pr). Temperature-dependent susceptibility measurements for Ba4Nd7[Si12N23O][BN3] revealed Curie-Weiss behavior above 60 K with an experimental magnetic moment of muexp = 3.36(5) microB/Nd. The deviation from Curie-Weiss behavior below 60 K may be attributed to crystal field splitting of the J = 9/2 ground state of the Nd3+ ions. No magnetic ordering is evident down to 4.2 K.     

Muon spin rotation in superconductors

By means of the muon spin rotation technique (⁺SR), the temperature dependence of the magnetic field inside the normal-conducting domains of high-purity tantalum crystals in the intermediate state has been measured in the temperature range 2.36K+SR. Possible applications of these findings to the study of long-range diffusion of positive muons at low temperatures are indicated.     

A spectrum of rhenium oxide

The arc emission spectrum of the ReO molecule has been photographed in the region 590–860 nm and three bands of a single electronic transition have been rotationally analyzed. The separation of lines of the isotopic molecules ¹⁸⁵ReO and ¹⁸⁷ReO leads to the conclusion that the vibrational assignments for these bands are 1-0, 0-0, and 0–1. It is conceivable that an electronic isotope shift of ～0.08 cm^?1 exists. The following vibrational and rotational data (cm^?1) have been determined: ν₀(0-0) = 14 038.42, $\text{Δ}\text{G′(}\text{1}\text{2}\text{) = 867.85}$, $\text{Δ}\text{G″(}\text{1}\text{2}\text{) = 979.14}$; B′_e = 0.3889, α′_e = 0.0019, B″_e = 0.4257, α″_e = 0.0043. It is concluded that Λ′ ? Λ″ = +1 with Λ″ ≥ 2.     

Quantum mechanical resonance and limiting absorption: The many body problem

We introduce a notion of quantum mechanical resonance that does not rely on analytic continuation of resolvent or scattering matrix and relate it to slow temporal decay of certain distinguished resonant states. We proceed to prove existence of resonances for the generalized many body Schrödinger operator for a rather large class of potentials containing Coulomb and Yukawa, but also nonsymmetric and nonanalytic potentials with Coulomblike singularities at the origin and certain differentiability and decay properties.Most of this work was done while the author was at Fachbereich Mathematik der Universität Frankfurt, D-6000 Frankfurt, Federal Republic of Germany     

New spectroscopic analyses and potential energy curves for the X1Σ+ and A1Σ+ states of NaH

The emission spectrum of NaH has been photographed in the ～6000–7300-Å region. Additional bands of the A¹Σ⁺ electronic transition have been analyzed and in particular the observed vibrational structure of the excited A state has been extended down to v′ = 0. New spectroscopic constants have been obtained, the v′ = 0 data leading to especially large changes in the constants of the anomalous A¹Σ⁺ state. New Rydberg-Klein-Rees (RKR) potential energy curves have been calculated up to v″ = 8 of the X¹Σ⁺ state and up to v′ = 20 in the A¹Σ⁺ state.     

Zur Struktur verstreckter Folien und Fäden sowie aus verdünnten Lösungen hergestellter Einkristalle aus Polyacrylnitril

Zusammenfassung Kolloid- und Kristallstruktur von verstreckten Folien und Fäden und aus verdünnten Lösungen hergestellten Einkristallen von Polyacrylnitril wurden mit Hilfe von Röntgenklein- und -weitwinkeluntersuchungen, Elektronenbeugung und Elektronenmikroskopie untersucht. Es kann gezeigt werden, da entgegen den bisher publizierten Ergebnissen bei dem verstreckten Polyacrylnitril eine periodische Abfolge von besser und schlechter geordneten Bereichen erzielt werden kann, die sich in dem Auftreten einer röntgenografisch erfaßbaren Langperiode äußert und, wie die vergleichenden Untersuchungen an Einkristallen zeigen, durch eine Zwei-Phasen-Struktur beschrieben werden kann. Innerhalb der besser geordneten Bereiche ordnen sich die Ketten, indem ein zwar stark gestörtes, aber dreidimensionales Gitter mit der orthorhombischen Elementarzellea=10,6 Å,b=11,6 Å,c=5,04 Å aufgebaut wird. Kristallisationsfähig sind nur die syndiotaktischen Kettensequenzen des Polyacrylnitrils.

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Summary Colloidal and crystallographic structure of drawn films and solution grown single crystals of polyacrylonitrile were investigated by small and wide angle X-ray scattering, electron scattering and electron microscopical observations. In contrast to the published results it is shown that in the case of drawn polyacrylonitrile there exists a periodical arrangement of more and less ordered regions which manifests in the appearance of a so called long period and which — as shown by comparative investigations on single crystals — can be described by a two-phase-model. Within the ordered regions chains are arranged building up a strongly disturbed but three-dimensional crystal lattice. The orthorhombic unit cell has the dimensiona=10,6 Å,b=11,6 Å,c=5,04 Å. Only the syndiotactic chain sequences are able to crystallize.

---

---

Vorgetragen auf der Arbeitssitzung des Fachausschusses Physik der Hochpolymeren in der Frühjahrstagung Berlin 1971 vom 9. bis 13. März des Regionalverbandes Physikalische Gesellschaft zu Berlin.

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Für die Hilfe bei den experimentellen Arbeiten danken die Verfasser FräuleinM. Collatz und den HerrenE. Vey undH. Gladbach.     

Low-energy positrons from metallic moderators in a back scattering mode

The energy spectra of thermalized positrons emitted in the “back scattering mode” from Cu, Au, and Al moderators are reported.