a method is described by which it is possible to determine the high barrier to ring inversion and hindered rotation by neat racemization of optically active compounds when the racemization is caused by ring inversion or hindered rotation. the method is based preparation of sufficiently pure enantiomers, mainly by chromatography on swollen microcrystalline triacetylcellulose (tac). by this techn...

uterine inversion is shortly described as the indentation and depression of the fundic area extending downwards up to the different levels of the birth canal till vaginal opening. clinical diagnosis of uterine inversion is difficult due to its non-specific symptoms and physical examination. ultrasonography is the most practical modality for radiological evaluation, but it is inadequate to deter...

Nitrogen oxides affect health and climate. Their emissions, in the form of nitric oxide, from inland waters such as lakes are generally considered negligible absent air quality climate models. Here we find unexpected high emissions oxide remote on Tibetan Plateau, based satellite observations tropospheric nitrogen dioxide vertical column densities subsequent emission inversion at a fine resolut...

it is very important to study and simulate s-wave structure for near surface (alluvium parts, in particular) owing to its direct relationship to urban facilities in geotechnical and earthquake engineering studies. so, in seismic microzonation, the first step is to study and identify s-wave pattern in alluvium in order to categorize different parts of cites according to s-wave velocity. current ...

We investigate the interfaces and polarity domains at atomic scale in epitaxial AlN GaN/AlN grown by hot-wall metal organic chemical vapor epitaxy on carbon face of SiC. X-ray diffraction, potassium hydroxide (KOH) wet etching, scanning transmission electron microscopy combined provide an in-depth understanding evolution with film thickness, which is crucial to optimize growth. The a 3D mode fo...

The Rukwa Rift Basin, Tanzania is regarded as a modern example of cratonic rift zone despite complex polyphase extensional and episodic inversion structures. We interpret 2D seismic reflection data tied to wells identify describe structures controlling stratigraphic sequences (Late Carboniferous Pleistocene) in two main segmented domains, A B, which are controlled by the Chisi Saza shear zones....