The reactions of neutral vanadium oxide clusters with alkenes (ethylene, propylene, 1-butene, and 1,3-butadiene) are investigated by experiments and density function theory (DFT) calculations. Single photon ionization through extreme ultraviolet radiation (EUV, 46.9 nm, 26.5 eV) is used to detect neutral cluster distributions and reaction products. In the experiments, we observe products (V(2)O...

Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass sp...

I n o r d e r t o r e p r e s e n t u n c e r t a i n knowledge e s p e c i a l l y i n f e r e n c e r u l e s m a t c h i n g u n c e r t a i n knowledge s t r u c t u r e s s e v e r a l e x t e n s i o n s o f a r e p r e s e n t a t i o n schema a r e d e s c r i b e d . F i r s t a t w o d i m e n s i o n a l e v i d e n c e space i s i n t r o d u c e d t o e x p r e s s p o s i t i v e ...

C O N J U G A T I O N . . . . . . . . . . . . 3 8 9 F o r m a t i o n a n d d i v i s i o n o f t h e p r o t o c o n j u g a n t . . . . . . . 3 8 9 B e h a v i o u r o f t h e m i c r o c o n j u g a n t . . . . . . . . . 3 9 1 N u c l e a r p h e n o m e n a i n t h e m i c r o a n d m a c r o c o n j u g a n t s . . . . . 3 9 2 T h e m a t u r a t i o n a n d t h e first d i s t r i b u t i...

A computer ized f l ow v i s u a l i z a t i o n techn ique capab le o f q u a n t i f y i n g t h e f l o w f i e l d a u t o m a t i c a l l y has been developed. T h i s techn ique uses a f t e r g l o w i n g e f f e c t o f o p t i c a l l y a c t i v a t e d phosphorescent p a r t i c l e s t o r e t r i e v e v e c t o r i a l i n f o r m a t i o n on each t r a c e . By u s i n g r h i ...

G a u g e i n v a r i a n c e i s t h e b a s i s o f t h e m o d e r n t h e o r y o f e l e c t r o w e a k a n d s t r o n g i n t e r a c t i o n s ( t h e s o c a l l e d S t a n d a r d M o d e l ) . T h e r o o t s o f g a u g e i n v a r i a n c e g o b a c k t o t h e y e a r 1 8 2 0 w h e n e l e c t r o m a g n e t i s m w a s d i s c o v e r e d a n d t h e f i r s t e l e c t r o d...

R E S U M O — A v a n ç o s t e c n o l ó g i c o s r e c e n t e s b e n e f i c i a r a m o d i a g n ó s t i c o do ac iden te v a s c u l a r c e r e b r a l ( A V C ) , r e d u z i r a m os r i s cos e a u m e n t a r a m a f r e q ü ê n c i a d e e s t u d o s a c e r c a dos m e c a n i s m o s do A V C . P r o j e t o s b a s e a d o s e m b a n c o s de d a d o s c o m p u t a d o r i ...