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991.
Submodular subgroups in finite groups 总被引:1,自引:0,他引:1
Irene Zimmermann 《Mathematische Zeitschrift》1989,202(4):545-557
992.
Daiyo Sawada Michael D. Piburn Eugene Judson Jeff Turley Kathleen Falconer Russell Benford Irene Bloom 《School science and mathematics》2002,102(6):245-253
The National Science Foundation has funded 22 Collaboratives for Excellence in Teacher Preparation. Despite the remarkable allocation of resources to this effort, it has proven exceptionally difficult to demonstrate the effectiveness of collaborative reform. In large part, this has resulted because of the difficulty of defining and measuring reform. The Reformed Teaching Observation Protocol (RTOP) was designed by the Evaluation Facilitation Group of the Arizona Collaborative for Excellence in the Preparation of Teachers (ACEPT). It is a 25‐item classroom observation protocol that is (a) standards based, (b) inquiry oriented, and (c) student centered. This instrument has provided the definition for reform and the basis for evaluation of the ACEPT collaborative. The data upon which this report is based were collected over a period of more than 2 years from 153 public school, college, and university mathematics and science classrooms. A trained team of observers consisting of two faculty members and seven graduate students was able to achieve exceptionally high levels of interrater reliability. Internal consistency, as estimated by Cronbach's alpha, was also remarkably high. Correlation coefficients ranging from 0.88 to 0.97 between RTOP scores for classrooms, and mean normalized gain scores for students in those classrooms on achievement measures demonstrate that reform, as defined by ACEPT and measured by the RTOP, has been effective. 相似文献
993.
Bernard Dacorogna Irene Fonseca 《Calculus of Variations and Partial Differential Equations》2002,14(2):115-149
The study of existence of solutions of boundary-value problems for differential inclusions
where , is an open subset of , is a compact set, and B is a -valued first order differential operator, is undertaken. As an application, minima of the energy for large magnetic bodies
where the magnetization is taken with values on the unit sphere is the induced magnetic field satisfying and is the anisotropic energy density, and the applied external magnetic field is given by , are fully characterized. Setting with , it is shown that E admits a minimizer with if and only if either 0 is on a face of or , where denotes the convex hull of Z.
Received: 6 November 2000 / Accepted: 23 January 2001 / Published online: 23 April 2001 相似文献
994.
995.
K. H. Bürger B. Burghardt S. Büttgenbach R. Harzer H. Hoeffgen G. Meisel F. Träber 《Zeitschrift für Physik A Hadrons and Nuclei》1982,307(3):201-209
Fourteen transitions in ReI, starting from high-lying metastable states belonging to the configurations (5d+6s)7, have been studied by laser-induced fluorescence in a collimated atomic beam, and accurate values for the isotope shifts in these transitions as well as for the hyperfine structure constants of 13 metastable and 9 excited states have been obtained. In addition, high precision measurements of the hyperfine structure of the states 5d 5 6s 2 4 D 7/2 and 5d 6 6s 6 D 1/2, 3/2, 5/2, 9/2 have been performed using the atomic beam magnetic resonance technique coupled with laser-induced state-selective detection of metastable atoms. The analysis of the hyperfine structure data yields experimental evidence for far configuration mixing effects on the off-diagonal spin-dipole matrix elements. The phenomenological interpretation of the isotope shifts shows the significance of off-diagonal field-shift effects. 相似文献
996.
Matthias Pailer Eveline Schaffer Irene Schläger 《Monatshefte für Chemie / Chemical Monthly》1979,110(3):589-592
The synthesis of the ,-unsaturated ketones4, 5 und6
via the regiospecific aldol- andWittigreaction with some indolealdehydes is described.4 and5 are stable enough for NaBH4-reduction to the corresponding alcohols. 相似文献
997.
998.
Irene Pieper 《Journal of Geometry》1972,2(1):35-68
In the first part a derivation method for incidence-groups is developed. The connections to the usual derivations of near-rings are shown in part 2 and examples are constructed. We characterize those finite slit incidence-groups with special affine kernel which are derivations of abelian incidence-groups. Applying these results to special classes of finite incidence-groups we show that there are 2-sided non-abelian finite incidence-groups with abelian affine kernel. The class of derivations of abelian finite incidence-groups contains all splitting a-2-sided incidence-groups with abelian kernel and no splitting kernel-2-sided non-2-sided incidence-group with abelian kernel. In the last part the a-2-sided incidence-groups are algebraically described.The results were partly communicated at the Conference on Geometry in March 1971 at the University of Waterloo, Ontario, Canada. 相似文献
999.
1000.