The authors provide a copious literate review on powertrain design optimization for electric vehicle (EV) powertrains. The review shows a gap in the state of science regarding the consideration of all customer relevant requirements. Existing approaches either focus on performance and energy consumption or concentrate on vehicle dynamics. Based on this insight, the authors analyze customer requirements and derive all vehicle properties that are influenced by the powertrain concept. They find that costs, longitudinal performance, lateral dynamics, off-road capabilities and energy consumption are key vehicle properties. The powertrain concept affects all these properties and thus determines the satisfaction of customer requirements. Subsequently the authors describe a vehicle simulation model that represents all predefined customer requirements in dependence on the powertrain concept design.

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We have measured the conductivity xx of GaAs/ GaAlAs Corbino devices under nonequilibrium conditions in the quantum Hall regime at low frequencies from dc up to 10 kHz. At very low frequencies up to 10-20 Hz, xx shows a steep decrease from its dc value towards a reduced saturation value. Measurements of the temperature dependence of xx from 70 mK to 4.2 K revealed a dominance of a conductivity with a temperature dependence xx ϳ exp͕−͑T 0 / T͒ 1/2 ͖ typical for variable-range hopping ͑VRH͒ at temperatures below 1 K and an additional contribution of thermal activation above 2 K. The characteristic temperature T 0 as determined from the VRH-like temperature plot of the conductivity showed also an increase with the frequency and a pronounced decrease with increasing voltage below the breakdown of the quantum Hall effect ͑QHE͒. We attribute these results to an effective suppression of the delocalization of electrons in alternating external fields due to a reduced heating and scattering between localization centers. The time scale for this process can be as long as 100 ms. Our data show that the background conductivity xx at subcritical voltages affects the critical voltage for the breakdown of the QHE.

An alternative approach to evaluating the performance of computational methods for predicting chemical shifts is presented. The influence of the theoretical level and basis set on the accuracy in calculating both proton and carbon NMR spectra of a large number of heterocyclic molecules is assessed using a linear regression method, thus omitting the need for a reference (as a potential source of error). The best theoretical levels employed herein (GIAO-PBE0/6-31G(d)//ωB97xD/6-31G(d) or GIAO-ωB97xD/6-31G(d)//ωB97xD/6-31G(d)) approach the accuracy of the most elaborate benchmark-quality calculations. One interesting observation is an unexplained distortion of the derived chemical shifts when an internal reference is used: It leads to larger relative shifts and deviations when the "quality" (size) of the basis set employed is increased. This effect can be corrected by using simple linear regression, but a lack of a systematic correlation between the quality of the basis set and the accuracy of the calculated shifts can still be observed; in fact, very good results can be achieved with modest basis sets. Although the general reliability of this approach needs to be evaluated for other theoretical levels and other substance classes, the abovementioned levels of theory appear robust enough for wider applicability. Graphical Abstract Correlation between computed chemical shieldings and experimental chemical shifts for various heterocyclic compounds.

Quantum Hall systems can show a bistability in the hysteresis of the breakdown. We realized a relaxation oscillator based on a quantum-Hall device with Corbino geometry. Investigations of the performance of such an oscillator revealed an increase of the hysteresis of the current-voltage curve of the device in comparison with the width of hysteresis at dc voltages. By direct measurements of the hysteresis of the current-voltage curve at different frequencies, we found a marked increase of the breakdown hysteresis at low frequencies of some Hz. We explain the observed dynamical enhancement of the breakdown hysteresis applying an electron heating model with a background (delocalization-related) component of conductivity, which decreases with increasing frequency, indicating a more effective localization already at low frequencies.