Exact and approximate solutions for the one-dimensional transfer of polarized radiation, and applications to X-ray pulsars

1980 ◽  
Vol 238 ◽  
pp. 1066 ◽  
Author(s):  
P. Meszaros ◽  
W. Nagel ◽  
J. Ventura
Keyword(s):  
Approximate Solutions ◽  
One Dimensional ◽  
X Ray ◽  
The One ◽  
Polarized Radiation

Polysulfonylamine, CXXV [1]. Neue Komplexe von Disulfonylaminen mit Kronenethern - im voraus entworfen oder zufällig entdeckt / Polysulfonylamines, CXXV [1]. New Complexes of Disulfonylam ines with Crown Ethers - Preconceived or Discovered by Serendipity

2000 ◽  
Vol 55 (3-4) ◽  
pp. 299-316 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
Ladder Structure ◽  
Triclinic Space Group ◽  
One Dimensional ◽  
X Ray ◽  
Bonding System ◽  
Supramolecular Aggregate ◽  
Guest Species ◽  
The One

Abstract In a study aim ed at the „deconstruction“ of the supramolecular aggregate 3(18C6) · 2HN( SO2Me)2 (1,18C6 = 18-crown-6), which is known to display a ladder structure with two isotactic [18C6 - Me SO2N(H)SO2Me···)∞ polymers forming the uprights and symmetrically N - H···O bonded 18C6 rings providing the rungs, the following crystalline complexes were isolated and (except for 2b) characterized by low-temperature X-ray diffraction: 18C6-ClN (SO2Me)2 (2a, triclinic, space group P1̅, Z = 2), 18C6-PhN (SO2Me)2 (2b), 18C6 -MeN(SO2Me)2 (3, monoclinic, P21/c, Z = 8), Bz18C6-HN(SO2Me)2 (4, Bz18C6 = benzo-18-crown-6, monoclinic, P21/n, Z = 4), 18C6-2 MeN (SO2Me)2 (5, triclinic, P1̅, Z = 1), 18C6-Me2SO- HN( SO2Me) (SO2Ph) (13, triclinic, P1̅, Z = 2), and 18C6-H2OMe2SO·2HN(SO2Me)2 (14, triclinic, P1̅, Z = 2). Each of the one-dimensional polymers 2a (syndiotactic), 3 (disyndiotactic) and 4 (isotactic) mimics a single upright of 1; in contrast to 1 and 2a, where the intra-catemer connectivity solely relies on S - Me ··· crow n and crown ··· O = S hydrogen bonds, this bonding system is reinforced in 3 by N -Me ··· crown and in 4 by N - H ··· crown hydrogen bonds. Complex 5 is monomeric and matches a fragment formally extruded from the catemer 3; moreover, 3 and 5 represent a rare case of two structurally characterized 18C6 complexes containing the same uncharged guest species in distinct molecular ratios. The surprising structure of the quaternary adduct 14 exhibits an [18C6 ··· MeSO2N(H)SO2Me ··· ]∞ chain, which can be regarded both as an isolated, though unmodified upright from the ladder 1 and, being syndiotactic, as a stereochemical analogue of 2a; the potentially rung-forming *NH functions in the chain are blocked by hydrogenbonded side chains of the type * N - H ··· water ··· sulfoxide ··· H - N (SO2Me)2. The ternary complex 13 consists of chains [18C6 ··· Me2SO ··· H - N (SO2Ph)SO2Me···]∞ and is not closely related to the other structures

APPLICATION OF A ONE-DIMENSIONAL POSITION SENSITIVE CHAMBER ON SYNCHROTRON RADIATION

2014 ◽  
Vol 27 ◽  
pp. 1460142
Author(s):  
HUIRONG QI ◽  
MEI LIU
Keyword(s):  
Synchrotron Radiation ◽  
Low Cost ◽  
Large Area ◽  
Position Resolution ◽  
One Dimensional ◽  
X Ray ◽  
High Position ◽  
Standard Data ◽  
Wire Chamber ◽  
The One

In the last few years, wire chambers have been frequently used for X-ray detection because of their low cost, large area and reliability. X-ray diffraction is an irreplaceable method for powder crystal lattice measurements. A one-dimensional single-wire chamber has been developed in our lab to provide high position resolution for powder diffraction experiments using synchrotron radiation. There are 200 readout strips of 0.5 mm width with a pitch of 1.0 mm in the X direction, and the working gas is a mixture of Ar and CO2 (90/10). The one-dimensional position of the original ionization point is determined by the adjacent strip's distribution information using the center of gravity method. Recently, a study of the detector's performance and diffraction image was completed at the 1W1B laboratory of the Beijing Synchrotron Radiation Facility (BSRF) using a sample of SiO2. Most of the relative errors between the measured values of diffraction angles and existing data were less than 1%. The best position resolution achieved for the detector in the test was 71 μm (σ value) with a 20 μm slit collimator. Finally, by changing the detector height in incremental distances from the center of the sample, the one-dimensional detector achieved a two-dimensional diffraction imaging function, and the results are in good agreement with standard data.

Synthesis, Structures and Magnetic Properties of a Family of One-Dimensional Oxides

1996 ◽  
Vol 453 ◽  
Author(s):  
H.-C. Zur Loye ◽  
P. Núñez ◽  
M. A. Rzeznik
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rietveld Refinement ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
One Dimensional ◽  
X Ray ◽  
Susceptibility Data ◽  
The One

AbstractThe one-dimensional compounds Sr3MgPtO6, Sr3MgIrO6, Sr3MgRhO6, Sr3GdRhO6, have been synthesized and structurally characterized by Rietveld refinement of powder X-ray diffraction data. All four compounds are isostructural with the rhombohedral K4CdCl6-type structure. The structure consists of infinite one-dimensional chains of alternating face-shared MO6 octahedra (M = Pt, Ir, Rh) and M′O6 (M′ = Gd, Mg) trigonal prisms. The strontium cations are located in a distorted square antiprismatic environment. Magnetic susceptibility data show that both Sr3MgIrO6 and Sr3MgRhO6 obey the Curie-Weiss law with θ = −6(1) K, and θ= −15(3)K, respectively. Sr3GdRhO6 obeys the Curie law with μeff = 7.80 B.M, consistent with an oxidation state of +3 for both rhodium and gadolinium.

Synthese und Aggregatbildung eines 5-Hydroxy-2,5-dihydropyrrols. Enantiomerenreine, eindimensionale Stränge durch Wasserstoffbrückenbindungen und chiroselektive Selbstorganisation/Synthesis and Aggregation of a 5-H ydroxy-2,5-dihydropyrrole. Enantiomerically Pure, One-dimensional Strands via Hydrogen Bonds and Chiroselective Self Organization

1999 ◽  
Vol 54 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Jochen Nachtrab ◽  
Stephan Reck
Keyword(s):  
Hydrogen Bonds ◽  
Ring Opening ◽  
Self Organization ◽  
Nucleophilic Attack ◽  
X Ray Diffraction ◽  
Enantiomerically Pure ◽  
One Dimensional ◽  
X Ray ◽  
Self Selection ◽  
The One

Reaction of dimethyl 1,3-acetonedicarboxylate 8 with oxalylchloride 2 and magnesium chloride as catalyst yielded 2,3-dioxo-2,3-dihydrofuran 9, which is in equilibrium with tautomer 10 (9:10 = 1:2). Addition of thionyl chloride to a mixture of 9/10 afforded 3-chloro-2(5H)-furanone 11. The structure of 11 was unequivocally established by X-ray diffraction, which indirectly proved the structure of 10 as well. Ring opening of 11 by nucleophilic attack with benzylamine 14 in C2-position and subsequent recyclization led to racemic 3-chloro-5-hydroxy-2-oxo-2,5-dihydropyrrole 15. According to a single crystal X-ray analysis, 15 aggregates via stereospecific self selection through hydrogen bonds to give chiroselectively the one-dimensional strands ∞1[(S)-15] and ∞1[( R)-15]

A one-dimensional cobalt(II) coordination polymer based on 2,4′-oxydibenzoic acid: poly[[[diaquabis[2-(4-carboxyphenoxy)benzoato-κO1]cobalt(II)]-μ-4,4′-bipyridine-κ2N:N′] dihydrate]

2014 ◽  
Vol 70 (7) ◽  
pp. 654-658 ◽  
Author(s):  
Long Tang ◽  
Feng Fu ◽  
Ji-Jiang Wang ◽  
Qi-Rui Liu ◽  
Hang-Hang Zhao
Keyword(s):  
Coordination Polymer ◽  
Hydrothermal Condition ◽  
Dimensional Chain ◽  
Supramolecular Architecture ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
The One ◽  
Two Sides

The reaction of CoSO4with 2,4-oxydibenzoic acid (H2oba) and 4,4′-bipyridine (bipy) under hydrothermal condition yielded a new one-dimensional cobalt(II) coordination polymer, {[Co(C14H9O5)2(C10H8N2)(H2O)2]·2H2O}n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, magnetic properties and single-crystal X-ray diffraction. The CoIIions are connected by bipy ligands into infinite one-dimensional chains. The Hoba−ligands extend out from the two sides of the one-dimensional chain. O—H...O hydrogen bonding extends these chains into a two-dimensional supramolecular architecture.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LXXIV Synthesis and Structure of the 1 : 1 Adduct of Silver(I) Nitrate with Triphenylstibine

1997 ◽  
Vol 50 (6) ◽  
pp. 671 ◽  
Author(s):  
Effendy ◽  
John D. Kildea ◽  
Allan H. White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Related Species ◽  
Room Temperature ◽  
Structural Data ◽  
Lewis Base ◽  
One Dimensional ◽  
X Ray ◽  
The One

The synthesis and room-temperature single-crystal X-ray structure determination of the 1 : 1 adduct of silver(I) nitrate with triphenylstibine, AgNO3/SbPh3 (1 : 1), is recorded, being monoclinic, Cc,a 12·824(2), b 15·794(4),c 9·796(2) Å, β 117·50(1)°, Z= 4; conventional R on F was 0·030 for 2881 independent ‘observed’ (I > 3σ(I)) reflections. The complex is a one-dimensional polymer with bridging nitrate groups, resembling in this respect its phosphine and arsine analogues. The completion of this study, along with related species recorded in accompanying papers, means that full structural data are now available for the complete array AgNO3/EPh3 (1 : n), E = P, As, Sb, n = 1–4, with the one exception of E = Sb, n = 2.

Including lateral velocity variations into true-amplitude common-shot wave-equation migration

Geophysics ◽  
2010 ◽  
Vol 75 (5) ◽  
pp. S175-S186 ◽  
Author(s):  
Daniela Amazonas ◽  
Rafael Aleixo ◽  
Gabriela Melo ◽  
Jörg Schleicher ◽  
Amélia Novais ◽  
...  
Keyword(s):  
Wave Equations ◽  
Heterogeneous Media ◽  
Synthetic Data ◽  
Approximate Solutions ◽  
Vertical Gradient ◽  
Correct Description ◽  
Lateral Velocity ◽  
One Dimensional ◽  
Velocity Variations ◽  
The One

In heterogeneous media, standard one-way wave equations describe only the kinematic part of one-way wave propagation correctly. For a correct description of amplitudes, the one-way wave equations must be modified. In media with vertical velocity variations only, the resulting true-amplitude one-way wave equations can be solved analytically. In media with lateral velocity variations, these equations are much harder to solve and require sophisticated numerical techniques. We present an approach to circumvent these problems by implementing approximate solutions based on the one-dimensional analytic amplitude modifications. We use these approximations to show how to modify conventional migration methods such as split-step and Fourier finite-difference migrations in such a way that they more accurately handle migration amplitudes. Simple synthetic data examples in media with a constant vertical gradient demonstrate that the correction achieves the recovery of true migration amplitudes. Applications to the SEG/EAGE salt model and the Marmousi data show that the technique improves amplitude recovery in the migrated images in more realistic situations.

The Na—O bond in sodium fenamate

2019 ◽  
Vol 75 (5) ◽  
pp. 766-774 ◽  
Author(s):  
Marta S. Krawczyk ◽  
Irena Majerz
Keyword(s):  
Noncovalent Interaction ◽  
Sodium Cation ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Surrounding Water ◽  
Polymeric Structure ◽  
One Dimensional ◽  
X Ray ◽  
The One ◽  
Intramolecular Hydrogen

The one-dimensional polymeric structure of sodium diaquafenamate–water (1/1) was studied by X-ray diffraction. The sodium cation is coordinated to one oxygen atom of the carboxylate group and to four water oxygen atoms. To characterize the Na—O bonds, the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction (NCI) approaches have been used. Both methods confirmed that the Na—O bonds are very weak, comparable with the weak N—H...O intramolecular hydrogen bond. The polymeric structure is stabilized by the interaction of the sodium cation with the surrounding water molecules.

A high-resolution X-ray diffractometer for the study of imperfect materials

2002 ◽  
Vol 35 (5) ◽  
pp. 606-614 ◽  
Author(s):  
A. Boulle ◽  
O. Masson ◽  
R. Guinebretière ◽  
A. Lecomte ◽  
A. Dauger
Keyword(s):  
High Resolution ◽  
Optical Element ◽  
Strong Increase ◽  
Rocking Curve ◽  
One Dimensional ◽  
X Ray ◽  
Rapid Acquisition ◽  
Order Of Magnitude ◽  
Position Sensitive ◽  
The One

A high-resolution X-ray diffractometer devoted to the study of imperfect materials (mainly oxides and ceramics) is presented. It is based on a rotating anode generator, a four-bounce monochromator, a five-movement sample holder and a curved position-sensitive detector (PSD). This setup allows rapid acquisition of a reciprocal-space map (in less than 10 h) even for very poorly diffracting materials. The two-dimensional instrumental profile is calculated taking into account each optical element in the beam path. The one-dimensional instrumental profiles corresponding to widely used scans (ω scan, θ–2θ scan, rocking curve and powder scan) are also calculated. In the three former cases, the setup exhibits an excellent angular resolution (0.003°), whereas in the latter case the resolution is lowered by one order of magnitude at the benefit of a strong increase in the collected intensity. The possibilities of this diffractometer are illustrated with three examples: an epitaxic layer, a microstructured single crystal and a powder.

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