Synchronization through system interconnections

An interconnection strategy with built-in adaptive controllersis presented which achieves synchronization of scalar linearsystems: the closed-loop network forces all outputs to followthe same signal asymptotically while maintaining the open-loopcharacteristics. In the design of the output feedback controllers,no knowledge of system parameters is assumed, but each systemmust have the same poles and be high-gain-stable. The proofof the main theorem relies critically on derived systems-theoreticresults and the special system topology as a network of interconnectedsystems. The topology is explained by first solving the simplerproblem of signal synchronization.     

Crystal Chemistry of Ternary and Quaternary Transition Metal Nitrides

Nitrides are fascinating materials. Although the air we breathe is 78% nitrogen, essentially 100% of the land we walk upon are made of oxides. It would take an encyclopaedia to review oxide crystal chemistry, on the other hand we can present here a comprehensive review of ternary and quaternary solid state nitrides. In the ternary and quaternary solid state nitrides (IA,IIA)-M-N, unusual low valence M⁺ were found for copper, nickel, cobalt, iron and manganese, and various MN_n transition metal-nitrogen coordination polyhedra with CN=2(linear), 3(trigonal-planar), 4(tetrahedral and square planar), 5(square pyramidal), and 6(octahedral and trigonal prismatic) and different fashions of connection make nitrides an important family of inorganic solid state materials. A suitable classification is made on the basis of the correlation between coordination numbers (CN), the connection fashions and oxidation states of the anionic principal structures.     

MECHANISTIC STUDIES OF THE PHOTOREACTION OF FLAVIN WITH N, N-DIMETHYLPROPARGYLAMINE

Abstract Both photoexcited free flavin and protein-bound flavin react with N, N-dimethylpropargyla-mine (DMPA) to yield dihydroflavin-adducts which are not reoxidizable by oxygen. The mechanism of the photoreaction was reinvestigated by flash photolysis and continuous illumination experiments. We suggest that a mechanism occurs in which a flavosemiquinone and a DMPA radical result in the first photoinduced reaction. The flavin-DMPA adducts are then formed by combinations of the two radicals.     

On a Maximal Inequality of Rosenblatt and Wierdl

We give various refinements and generalizations of a recentmaximal equality of Rosenblatt and Wierdl.     

Unusual Monovalent Transition Metals (M=Cu,Ni, Co,Fe, Mn,and Cr) Stabilized in Nitrides Li2(Li1-xMx)N with Chain Structure

Chain compounds often exhibits specific physical phenomena owing to interactions between repeating units in one dimension alone. The simple topology of a chain allows more easily to establish chemical correlations between structure and properties.     

Optimal control of a one product recovery system with backlogging

In this paper a product recovery system for one product is investigated.The system contains one inventory for returned and recoverableitems and one for serviceable items. Demands are satisfied fromserviceable inventory where backlogging of demands is allowed.In addition, there is the possibility of disposal for the returnedproducts. We assume deterministic but dynamic return and demandrates and a linear cost structure. The Pontryagin maximum principleis used to determine the optimal production, remanufacturingand disposal policy.     

Long-lived diatomic dications: potential curves and radiative lifetimes for CaBr2+ and CaI2+ including relativistic effects

Relativistic effective core potential calculations have been employed in the framework of a spin–orbit configuration interaction to compute the lowest-lying electronic states of the CaBr²⁺ and CaI²⁺ dications, and the results are compared with the data for the isovalent CaCl²⁺ system studied earlier. The ground X²Π state in all three dications arises from a strong polarization of X(²P°)(X= Cl, Br or I) by the Ca²⁺(¹S) ion and is bound by 0·96–1·55eV with respect to the corresponding diabatic dissociation limits. It is split by the spinorbit interaction into the X₁ ²Π_3/2 and X₂ ²Π_1/2 components, with the energy splittings calculated to be 647 cm^-1(CaCl²⁺), 2115 cm^-1(CaBr²⁺) and 3544 cm^-1(CaI²⁺). The X₁ and X₂ states are found to be thermodynamically stable in CaCl²⁺ and CaBr²⁺, while in CaI²⁺ the lowest dissociation limit, Ca⁺+(²S)+ I^{+ 3}P₂), lies 1700 and 5200 cm^-1 lower than the X₁ and X₂ minima respectively. The X₁ and X₂ states in CaI²⁺ are extremely long-lived, however, owing to the high and very broad potential barriers to dissociation. The first electronic excited state, A²σ⁺, is also bound in all the above systems, although it is pre-dissociated in CaBr²⁺and CaI²⁺ at large internuclear distances. All other low-lying electronic states of CaX²⁺ are repulsive. Electric-dipole moments are calculated for the A→ X₁, X₂ transitions. The corresponding radiative lifetimes are found to be very long in CaCl²⁺ : τ(A→X₁) = 19·3 ms and τ(A→X₂) = 9·9 ms (the values are given for ν' = 0), and become very significantly shorter for CaBr²⁺ and CaI²⁺ because of the stronger spin-orbit interaction in the heavier systems. This effect is especially noticeable for the A →X₂ transitions, for which the values are computed to be 364 μs in CaBr²⁺ and 50·3 μs in CaI²⁺. The theoretical data obtained should aid in the future spectroscopic detection of these species. To data no experiment of this type has been successfully carried out for any of the thermodynamically stable diatomic dications.