Reaction of 3-benzylthiopregna-3,5-dien-20-one or of pregna-3,5-dien-20-one with W-2 Raney nickel in acetone afforded a mixture of 20-ketopregnanes with different degrees of insaturation on rings A and B, of which the main component was identified as pregn-2-en-20-one. When deactivated Raney nickel was used, the main product was the expected pregna-3,5-dien-20-one with minor amounts of pregn-4-...

We demonstrate a 67 GHz bandwidth silicon-contacted germanium waveguide p-i-n photodetector operating at -1 V with 6.8 fF capacitance. The dark current is below 4 nA. The responsivity is 0.74 A/W at 1550 nm and 0.93 A/W at 1310 nm wavelength. 56 Gbps on-off-keying data reception is demonstrated with clear open eye diagrams in both the C-band and O-band.

We present a deterministic polynomial-time algorithm that decides whether a power product n¿=i ff is a umt m tne ring of integers of K , where K isa number field, y, are nonzero elements of K and n¡ are rational integers. The main algorithm is based on the factor refinement method for ideals, which might be of independent interest.

A b s t r a c t u m a n c a p i t a l a s s e t s , b u t a l s o a c t a s s i g n a l s t h a t (p a r t i a l l y) r e v e a l t h e t y p e s o f a g e n t s w h o b e c o m e a p p r e n t i c e s. T h e t y p e o f a g e n t w h o s e p r o d u c t i v i t y i s m o s t a ff e c t e d b y t h i s a s s e t w i l l o u t b i d a g e n t s f o r w h o m t h i s a s s e t h a s a l o w e r a...

a non-profit institution devoted to research on network industries, electronic commerce, telecommunications, the Internet, " virtual networks " comprised of computers that share the same technical standard or operating system, and on network issues in general. I n c o l la b o r a t ion w i t h Introduction C h a p t e r 1 : A s u m m a r y o f f i n d in g s 4 C h a p t e r 2 : Evolution of in...

A generalization of Schm udgen s Positivstellensatz is given which holds for any basic closed semialgebraic set in R compact or not The proof is an extension of W ormann s proof The Positivstellensatz proved by G Stengle in is a standard tool in real algebraic geometry see In his solution of the K moment problem in Schm udgen proves a surprisingly strong version of the Positivstellensatz in the...

We consider settings providing the existence of stable two-dimensional (2D) dissipative solitons with zero and nonzero vorticity in optical media quadratic ($\chi^{(2)}$) nonlinearity. To compensate spatially uniform loss both fundamental-frequency (FF) second-harmonic (SH) components system, a strongly localized amplifying region ("hot spot",HS), carrying linear gain, is included, acting onto ...

In the bin packing problem, a list L of n items is to be packed into a sequence of unit capacity bins with the goal of minimizing the number of bins used. First Fit (FF) is one of the most natural on-line algorithms for this problem, based on the simple rule that each successive item is packed into the rst bin of the sequence that currently has room for it. We present an average-case analysis o...