3-(2-furanyl)-2-propenoic acid has been used to prepare a new series of organotin complexes of general formula r3snl (r=me, et, n-bu, ph and cy) and r2snl2 (r=me and n-bu). these complexes have been characterized by elemental analyses, ir, 1h-nmr, mass and mössbaure spectroscopy.

tetrahydrobenzo[b]pyran derivatives 1 were utilized for the synthesis of several new pyrano[2,3-d]pyrimidine derivatives 2. compound 2 was obtained in the presence of ac2o/h2so4 (as a catalyst) and was confirmed by spectroscopic data such as ir, 1h nmr and 13c nmr. ab initio calculation was carried out to study geometric optimization, thermodynamic parameters, aromaticity and dynamic process of...

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 ...

CO L L E G E L I B R A R I A N S c a n n o t d e p e n d u p o n p r o f e s s i o n a l l i b r a r y l i t e r a t u r e a l o n e f o r b u i l d i n g u p t h e i r b o o k c o l l e c t i o n s . T h e f a c u l t i e s o f c o l l e g e s a n d u n i v e r s i t i e s p l a y a n i m p o r t a n t r o l e i n t h e s e l e c t i o n o f b o o k s f o r t h e c o l l e g e l i b r a r y a ...

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...

T h e L i e b r e M o u n t a i n s f o r m a d i s c r e t e u n i t o f t h e T r a n s v e r s e R a n g e s o f s o u t h e r n C a l i f o r n i a . G e o g r a p h i c a l l y , t h e r a n g e i s t r a n s i t i o n a l t o t h e S a n G a b r i e l M o u n t a i n s , I n n e r C o a s t R a n g e s , T e h a c h a p i M o u n t a i n s , a n d M o j a v e D e s e r t . A t o t a l o f...

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T h i s paper i s concerned w i t h a p l a n n i n g system f o r a r o b o t w i t h a hand and an eye w h i c h can m a n i p u l a t e b l o c k s . Two d i f f e r e n t k i n d s o f p r o b l e m s o l v e r s a r e used . One i s m a i n l y composed of a theorem p r o v e r based on t h e r e s o l u t i o n p r i n c i p l e , and the o t h e r c o n s i s t s o f a theorem p r o v e ...

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 ...