Long range interaction mechanism for the collisioninduced electronic relaxation of single rotational levels of SO2 (A1 A 2) J. Chem. Phys. 76, 3341 (1982); 10.1063/1.443334Pressure dependence of fluorescence quantum yields and collisioninduced rotational relaxation of single rotational levels of H2CO(A1 A 2, 41)A semiclassical, nonperturbative approach to collisioninduced transitions between rotational levels for the N2-Ar system The electronic quenching cross sections (u Q.M) of SO, excited to single rotational levels (SRL's) of the "B" band (J' = 9, K' = 9) and the "E" band (J' = 6, K' = 6) were measured from the shortening of the fluorescence decay times by the addition of a variety of nonpolar and polar collision partners (M) at room temperature. u Q • M for the B band SRL varied from 32;'" for M = He to 863 ;,., for M = CHlNO,. A similar variation of U Q.M for the E band SRL was also observed. Eighteen observed values of U Q.M are compared to the values calculated from various theoretical models of electronic quenching including collision complex formation. Temperature dependence of the electronic quenching cross section for the collision complex is presented.

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Rotational analyses have been carried out for 11 bands of the [Formula: see text](π*–n) system of 13C2H2O2 in absorption. Approximately 12 000 lines have been assigned, and rotational and vibrational constants have been evaluated. The following vibrational frequencies have been determined: ν2′ = 1365.17 cm−1, ν4′ = 918.81 cm−1, ν5′ = 502.48 cm−1, ν7′ = 229.40 cm−1, ν7″ = 124.61 cm−1Using the rotational constants for C2H2O2, C2HDO2, C2D2O2, 13C2H2O2, and C2H218O2, the following geometrical parameters have been evaluated: in the Ã1Au excited state, r0(CH) = 1.115 ± 0.010 Å, r0(CO) = 1.252 ± 0.016 Å, r0(CC) = 1.460 ± 0.025 Å, [Formula: see text], [Formula: see text]; in the [Formula: see text] ground state, r0(CH) = 1.109 ± 0.008 Å, r0(CO) = 1.202 ± 0.012 Å, r0(CC) = 1.527 ± 0.017 Å, [Formula: see text], [Formula: see text]. The ground state parameters are in excellent agreement with earlier electron diffraction results.

Can. J. Chem. 71, 1595 (1993).Rotational analyses have been carried out for the 510, 5 7 , and 5 ' ) bands of the A'B,-X'A s stem of cis-glyoxal, where v, is the totally symmetric C-C=O bending frequency. The vibrational frequencies 1; ' = 302.81 cm-' and v; = 284.51 cm-I are smaller than the corresponding frequencies for tratzs-glyoxal by nearly a factor of two. A vibronically induced band with a different type of rotational structure has been analysed and shown to be an a-type band. The coupling vibration is the out-of-plane C-H wagging vibration v6(a2) and is similar in form and frequency to the vibronically active vg(bg) vibration for trans-glyoxal. [Traduit par la redaction]

We describe an inquiry-based course in physics and chemistry for preservice K-8 teachers developed at California State University Fullerton. The course is one of three developed primarily to enhance the science content understanding of prospective teachers. The course incorporates a number of innovative instructional strategies and is somewhat unusual for its interdisciplinary focus. We describe the course structure in detail, providing examples of course materials and assessment strategies. Finally, we provide research data illustrating both the need for the course and the effectiveness of the course in developing student understanding of selected topics. Student responses to various questions reflect a lack of understanding of many relatively simple physical science concepts, and a level of performance that is usually lower than that in comparable courses serving a general education audience. Additional data suggest that course activities improve student understanding of selected topics, often dramatically.