268 research outputs found
Radical Rings with Engel Conditions
AbstractAn associative ring R without unity is called radical if it coincides with its Jacobson radical, which means that the set of all elements of R forms a group denoted by R∘ under the circle operation r∘s=r+s+rs on R. It is proved that, for a radical ring R, the group R∘ satisfies an n-Engel condition for some positive integer n if and only if R is m-Engel as a Lie ring for some positive integer m depending only on n
Evanescently-coupled hybrid III-V/silicon laser based on DVS-BCB bonding
© 2014 IEEE. Controllable electrical breakdown of multiwall nanotubes (MWNTs) is studied utilizing the atomic force microscopy (AFM). Electrical breakdown has been known as the way to fundamentally understand the electrical properties of nanotubes and an approach to develop MWNT based transistors and sensors. Normally, electrical breakdown was known to be happened in the center of MWNT because of the thermal accumulation. However, considering the effect of thermal dissipation, the electrical breakdown could be mechanically controlled by an additional heat sink, which could be the substrate of MWNT device. Therefore, the electrical breakdown process is controllable through controlling Joule heating and thermal dissipation. In this research, we study the crucial factors that affect the electrical breakdown. The AFM based nano robot is used to measure the conductance distribution, and manipulate the three dimensional structure of MWNT in order to change the position of heat sink to control the location where electrical breakdown happened. The controllable electrical breakdown is an alternative approach for conducting bandgap engineering in nanodevice and fabricating high performance nano sensors and transistors.Link_to_subscribed_fulltex
Hybrid III-V/Si distributed-feedback laser based on adhesive bonding
A hybrid evanescently coupled III-V/silicon distributed-feedback laser with an integrated monitor photodiode, based on adhesive divinyl siloxane-benzocyclobutene bonding and emitting at 1310 nm, is presented. An output power of similar to 2.85 mW is obtained in a continuous wave regime at 10 degrees C. The threshold current is 20 mA and a sidemode suppression ratio of 45 dB is demonstrated. Optical feedback is provided via corrugations on top of the silicon rib waveguide, while a specially developed bonding procedure yields 40-nm-thick adhesive bonding layers, enabling efficient evanescent coupling
On nilpotent Lie algebras of derivations with large center
Let K be a field of characteristic zero and A an associative commutative K-algebra that is an integral domain. Denote by R the quotient field of A and by W(A)=RDerA the Lie algebra of derivations on R that are products of elements of R and derivations on A. Nilpotent Lie subalgebras of the Lie algebra W(A) of rank n over R with the center of rank n−1 are studied. It is proved that such a Lie algebra L is isomorphic to a subalgebra of the Lie algebra un(F) of triangular polynomial derivations where F is the field of constants for L
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