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81.
In this paper we prove that the language of all primitive (strongly primitive) words over a nontrivial alphabet can be generated by certain types of Marcus contextual grammars. 相似文献
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We propose different nonparametric tests for multivariate data and derive their asymptotic distribution for unbalanced designs in which the number of factor levels tends to infinity (large a, small ni case). Quasi gratis, some new parametric multivariate tests suitable for the large a asymptotic case are also obtained. Finite sample performances are investigated and compared in a simulation study. The nonparametric tests are based on separate rankings for the different variables. In the presence of outliers, the proposed nonparametric methods have better power than their parametric counterparts. Application of the new tests is demonstrated using data from plant pathology. 相似文献
84.
Palevski A. Solomon P.M. Kuech T.F. Tischler M. Umbach C. 《Electron Device Letters, IEEE》1990,11(11):535-537
The authors have fabricated for the first time heterostructure field-effect transistors where the two-dimensional electron gas (2-DEG) channel is directly contacted by selectively regrown epitaxial GaAs contacts. Both modulation-doped FETs (MODFETs) and semiconductor-insulator-semiconductor FETs (SISFETs) were fabricated. Contact resistances were low, as evidenced by high transconductances and improvements to the transconductance at low temperatures. The low resistance and shallow nature of the regrown contacts should permit scaling of these structures to very small dimensions 相似文献
85.
Xinnan Zhang Gang‐Chi Chen Andrew Collins Solomon Jacobson Paul Morganelli Yadunandan L. Dar Osama M. Musa 《Journal of polymer science. Part A, Polymer chemistry》2009,47(4):1073-1084
New thermosetting materials were developed for reworkable adhesive applications by introducing acetal ester groups as thermally degradable linkages into maleimide compounds. The synthesis of compounds containing maleimide functionality and acetal ester linkages was conducted by a one‐step neat reaction from commercially available materials. The polymerization process and thermal degradation of the synthesized materials were studied. It was found that the acetal ester linkage degraded rapidly above 225 °C, and introduction of this linkage into the adhesive formulation led to improved reworkability of adhesively bonded substrates. A mechanism for reworkability was proposed based on the insight provided by experimental and modeling work. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1073–1084, 2009 相似文献
86.
We prove that the length of the boundary of a J-holomorphic curve with Lagrangian boundary conditions is dominated by a constant times its area. The constant depends on the symplectic form, the almost complex structure, the Lagrangian boundary conditions and the genus. A similar result holds for the length of the real part of a real J-holomorphic curve. The infimum over J of the constant properly normalized gives an invariant of Lagrangian submanifolds. We calculate this invariant to be \({2\pi}\) for the Lagrangian submanifold \({\mathbb{R} P^n \subset \mathbb{C} P^n.}\) We apply our result to prove compactness of moduli of J-holomorphic maps to non-compact target spaces that are asymptotically exact. In a different direction, our result implies the adic convergence of the superpotential. 相似文献
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Solomon Feferman 《Logica Universalis》2012,6(3-4):535-552
This is a critical reexamination of several pieces in van Heijenoort??s Selected Essays that are directly or indirectly concerned with the philosophy of logic or the relation of logic to natural language. Among the topics discussed are absolutism and relativism in logic, mass terms, the idea of a rational dictionary, and sense and identity of sense in Frege. 相似文献