Ueber den Nachweis und die quantitative Bestimmung der Milchs?ure in physiologischen und pathologischen F?llen

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Zum Nachweise von Pikrotoxin in Bier, Porter u. s. w.

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Anwendung von Boraxl?sung zum Ausziehen von Farbstoffen

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Ueber einige Reagentien auf Pflanzenalkaloide

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Ueber ein neues Unterscheidungsmittel von Chinin- und Cinchoninsalzen

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First rate constants for reactions of OH radicals with amides

Rate constants have been measured for the reaction of OH radicals with four amides, R₁N(CH₃)—C(O)R₂ (R₁ = H or Methyl, R₂ = Methyl or Ethyl), at 300 and 384 K using flash photolysis/resonance fluorescence. Reactants are introduced under slow flow conditions and are controlled by two independent methods, gas saturation and continuous injection. It turns out that the reactivities of the amides are considerably lower than those of the corresponding amines. The pattern of rate constants obtained at 300 K: 14, 21, 5.2, and 7.6 · 10⁻¹² cm³/s for N,N-Dimethylacetamide (dmaa), N,N-Dimethylpropionamide (dmpa), N-Methylacetamide (maa), and N-Methylpropionamide (mpa), respectively, indicates a single, dominating reaction center and strong electronic effects of the substituents at both sides of the amide function. Correspondingly, the observed negative temperature dependence (E/R = − 400 to − 600 K) excludes a direct abstraction mechanism. © 1997 John Wiley & Sons, Inc.     

Mathematical Reasoning Requirements in Swedish Upper Secondary Level Assessments

We investigate the mathematical reasoning required to solve the tasks in the Swedish national tests and a random selection of Swedish teacher-made tests. The results show that only a small proportion of the tasks in the teacher-made tests require the students to produce new reasoning and to consider the intrinsic mathematical properties involved in the tasks. In contrast, the national tests include a large proportion of tasks for which memorization of facts and procedures are not sufficient. The conditions and constraints under which the test development takes place indicate some of the reasons for this discrepancy and difference in alignment with the reform documents.