Independent structural and valence state transitions in the cation-ordered double perovskites Ba2−xSrxTbIrO6

2005 ◽  
Vol 178 (11) ◽  
pp. 3589-3594 ◽  
Author(s):  
Qingdi Zhou ◽  
Brendan J. Kennedy
Keyword(s):  
Valence State ◽  
State Transitions ◽  
Double Perovskites

ChemInform Abstract: Electronic Properties in Intrinsically Disordered Double Perovskites: Sr3MnMo2O9and Ba3MnMo2O9with Mo5+Valence State.

ChemInform ◽  
2016 ◽  
Vol 47 (11) ◽  
pp. no-no
Author(s):  
C. A. Lopez ◽  
M. E. Saleta ◽  
J. C. Pedregosa ◽  
R. D. Sanchez ◽  
D. G. Lamas ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Valence State ◽  
Double Perovskites ◽  
Intrinsically Disordered

Study of the valence state and electronic structure in Sr2FeMO6 (M = W, Mo, Re and Sb) double perovskites

2010 ◽  
Vol 12 (41) ◽  
pp. 13616 ◽  
Author(s):  
M. Retuerto ◽  
F. Jiménez-Villacorta ◽  
M. J. Martínez-Lope ◽  
Y. Huttel ◽  
E. Roman ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Valence State ◽  
Double Perovskites

Electronic properties in intrinsically disordered double perovskites: Sr 3 MnMo 2 O 9 and Ba 3 MnMo 2 O 9 with Mo 5+ valence state

2016 ◽  
Vol 661 ◽  
pp. 411-418 ◽  
Author(s):  
C.A. López ◽  
M.E. Saleta ◽  
J.C. Pedregosa ◽  
R.D. Sánchez ◽  
D.G. Lamas ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Valence State ◽  
Double Perovskites ◽  
Intrinsically Disordered

SYNTHESIS, STRUCTURAL AND MAGNETIC PROPERTIES OF DOUBLE PEROVSKITES Sr2CrWO6

2005 ◽  
Vol 19 (01n03) ◽  
pp. 537-540 ◽  
Author(s):  
T. S. CHAN ◽  
R. S. LIU ◽  
C. Y. HUANG
Keyword(s):  
Crystal Structure ◽  
Valence State ◽  
Room Temperature ◽  
Standard Sample ◽  
Double Perovskite ◽  
Lattice Parameter ◽  
Double Perovskites ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
X Ray Absorption

The double perovskite ( Sr 2 CrWO 6) has been prepared in polycrystalline state by solid state reaction. At room temperature, the crystal structure is cubic (space group: Fm3m) with lattice parameter of 7.8200(2) (Å). Both ρ( H =0) and ρ( H =5 T ) show a semiconductor-like behavior over the whole temperature range up to 5 K. The highest MR(magnetoresistance) value of 55% ( H =5 T ) was observed at 25 K. The valence state of Cr was determined by the X-ray absorption spectroscopy at Cr -L edge. The results, compared to the standard sample, show that the valence state of Cr is 3+.

Valence state analysis of elements by EPMA and its application

1990 ◽  
Vol 48 (2) ◽  
pp. 230-231
Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei
Keyword(s):  
Valence State ◽  
Line Intensities ◽  
Valence States ◽  
Valence Electrons ◽  
Fe And Mn ◽  
Intensity Ratios ◽  
State Analysis

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.

Macroorganisation and flexibility of thylakoid membranes

2019 ◽  
Vol 476 (20) ◽  
pp. 2981-3018 ◽  
Author(s):  
Petar H. Lambrev ◽  
Parveen Akhtar
Keyword(s):  
Light Harvesting ◽  
Current Knowledge ◽  
Three Dimensional ◽  
Photosynthetic Apparatus ◽  
Dynamic Responses ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Light Harvesting Complex ◽  
Complex Ii ◽  
Light Harvesting Complex Ii

Abstract The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.

Hysteresis in spectral state transitions – a challenge for theoretical modeling

2005 ◽  
Vol 432 (1) ◽  
pp. 181-187 ◽  
Author(s):  
E. Meyer-Hofmeister ◽  
B. F. Liu ◽  
F. Meyer
Keyword(s):  
Theoretical Modeling ◽  
State Transitions ◽  
Spectral State

Theory for the mixed-valence state

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-374-C5-374 ◽  
Author(s):  
C. M. Varma
Keyword(s):  
Valence State ◽  
Mixed Valence ◽  
Mixed Valence State

MIXED VALENCE STATE OF Sm ON THE SURFACE OF AMORPHOUS La80-xSmxAu20 ALLOYS

1980 ◽  
Vol 41 (C8) ◽  
pp. C8-799-C8-802 ◽  
Author(s):  
G. Krill ◽  
A. Amamou ◽  
A. Berrada ◽  
J. Durand ◽  
N. Hassanain
Keyword(s):  
Valence State ◽  
Mixed Valence ◽  
Mixed Valence State

Tc-99m Labeled Complexes of Aldehydes and Glutamate as Cholescintigraphic Agents

1975 ◽  
Vol 14 (04) ◽  
pp. 330-338
Author(s):  
L. G. Colombetti ◽  
J. S. Arnold ◽  
W. E. Barnes
Keyword(s):  
Nuclear Medicine ◽  
Gall Bladder ◽  
Rose Bengal ◽  
Valence State ◽  
Monosodium Glutamate ◽  
Kinetic Studies ◽  
Scintillation Camera ◽  
Blood Clearance ◽  
Lower Valence ◽  
Wire Basket

SummaryTc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used 1-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130° C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde — glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.

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