Using metallic interlayers to stabilize abrupt,epitaxial metal-metal interfaces

An approach is described for stabilizing metal-metal epitaxial interfaces using a thin metallic interlayer. Rutherford backscattering and channeling techniques along with low-energy electron diffraction and keV He+ ion backscattering are used to demonstrate that an atomically thin layer of Ti deposited at the Fe-Al interface, a system well known for considerable intermixing at room temperature, forms a thin interface alloy that prevents interdiffusion and improves epitaxial growth of Fe on Al(100). The structure is stable up to about 200 degrees C.     

Ortho effects in organic molecules on electron impact. IV—Ortho interaction of the carboxyl group with the olefinic bond in substituted benzoic acids

Fragments ions involving hydrogen migration from the –COOH group to the olefinic bond in the mass spectra of stilbene-2-carboxylic acid and ortho-carboxylbenzalaniline are discussed.     

Ortho effects in organic molecules on electron impact. V—ortho effects of the nitro group in n-substituted anilines

Some very interesting ortho effects are observed in the mass spectra of N-benzyl-o-nitroaniline and N,N-dibenzyl-2,4-dinitroaniline. Fragment ions arising from the transfer of oxygen from the nitro group to the benzylic carbon are seen in these spectra.     

An exact duality theory for semidefinite programming and its complexity implications

In this paper, an exact dual is derived for Semidefinite Programming (SDP), for which strong duality properties hold without any regularity assumptions. Its main features are: (i) The new dual is an explicit semidefinite program with polynomially many variables and polynomial size coefficient bitlengths. (ii) If the primal is feasible, then it is bounded if and only if the dual is feasible. (iii) When the primal is feasible and bounded, then its optimum value equals that of the dual, or in other words, there is no duality gap. Further, the dual attains this common optimum value. (iv) It yields a precise theorem of the alternative for semidefinite inequality systems, i.e. a characterization of theinfeasibility of a semidefinite inequality in terms of thefeasibility of another polynomial size semidefinite inequality. The standard duality for linear programming satisfies all of the above features, but no such explicit gap-free dual program of polynomial size was previously known for SDP, without Slater-like conditions being assumed. The dual is then applied to derive certain complexity results for SDP. The decision problem of Semidefinite Feasibility (SDFP), which asks to determine if a given semidefinite inequality system is feasible, is the central problem of interest, he complexity of SDFP is unknown, but we show the following: (i) In the Turing machine model, the membership or nonmembership of SDFP in NP and Co-NP is simultaneous; hence SDFP is not NP-Complete unless NP=Co-NP. (ii) In the real number model of Blum, Shub and Smale, SDFP is in NP∩CoNP.