Recent Advances in Wireless Measuring Instruments

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

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Concept of a new PZT

International Astronomical Union Colloquium ◽

10.1017/s0252921100074212 ◽

1978 ◽

Vol 48 ◽

pp. 271-278

Author(s):

Chr. Kühne

Keyword(s):

Mirror System ◽

Measuring Instruments

The PZT according to MARKOWITZ, undoubtedly one of the most accurate measuring instruments, has become an integral part of astronomy in the last years. Yet there are two reasons why I still tried to improve the MARKOWITZ basic idea.For the MARKOWITZ process the use of a lens objective is imperative. Because of the diameter limitations of the lens objectives the magnitude is reduced. Although a 65 cm PZT has been put into operation in Washington recently, the thermal difficulties encountered made it necessary to control the temperature actively. In addition, the 65 cm diameter of a lens equipped with 4 elements can be considered as the very limit, but not for a mirror system.In addition there are still more disadvantages using lens objectives. The useable field is restricted by astigmatism, reducing the range of declination. The transmission, especially in the blue wavelengths, decreases very rapidly with the thickness of lenses. For large multilens objectives the transmission is less than for a mirror system.

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Chelation-assisted transition metal-catalysed C–H chalcogenylations

Organic Chemistry Frontiers ◽

10.1039/c9qo01497g ◽

2020 ◽

Vol 7 (8) ◽

pp. 1022-1060 ◽

Cited By ~ 7

Author(s):

Wenbo Ma ◽

Nikolaos Kaplaneris ◽

Xinyue Fang ◽

Linghui Gu ◽

Ruhuai Mei ◽

...

Keyword(s):

Transition Metal ◽

Recent Advances ◽

Site Selectivity ◽

Transition Metal Catalyzed ◽

Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

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Nucleosome dynamics

Biochemical Society Symposium ◽

10.1042/bss0730109 ◽

2006 ◽

Vol 73 ◽

pp. 109-119 ◽

Cited By ~ 2

Author(s):

Chris Stockdale ◽

Michael Bruno ◽

Helder Ferreira ◽

Elisa Garcia-Wilson ◽

Nicola Wiechens ◽

...

Keyword(s):

High Resolution ◽

Chromatin Structure ◽

Current Knowledge ◽

Dynamic Properties ◽

Structure And Dynamics ◽

Nucleosome Dynamics ◽

Sharp Focus ◽

Recent Advances ◽

Insight Into ◽

Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

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