Browsing by Author "Wang, Hui"
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- Energy storage for power factor correction in battery charger for electric-powered vehicles(United States Patent and Trademark Office, 2018-03-13)Switches of a switching circuit used to control operation of an electric motor such as in an electrically powered vehicle connect respective windings of the electric motor as a single phase inductor during battery charging. The inductor can then store inherent low frequency, second order ripple power and return that power to a load presented by a battery during battery charging to deliver substantially constant current. Storage of ripple power in the inductor allows the capacitance value, size, weight and cost of a filter capacitor of a power factor correction circuit providing input power to a battery charger to be reduced by an order of magnitude or more. Direction of current flow through the inductor is periodically reversed to avoid magnetizing the motor.
- Localized management of non-indigenous animal domesticates in Northwestern China during the Bronze AgeVaiglova, Petra; Reid, Rachel E. B.; Lightfoot, Emma; Birch, Suzanne E. Pilaar; Wang, Hui; Chen, Guoke; Li, Shuicheng; Jones, Martin; Liu, Xinyi (Springer, 2021-08-26)The movements of ancient crop and animal domesticates across prehistoric Eurasia are well-documented in the archaeological record. What is less well understood are the precise mechanisms that farmers and herders employed to incorporate newly introduced domesticates into their long-standing husbandry and culinary traditions. This paper presents stable isotope values (δ13C, δ15N) of humans, animals, and a small number of plants from the Hexi Corridor, a key region that facilitated the movement of ancient crops between Central and East Asia. The data show that the role of animal products in human diets was more significant than previously thought. In addition, the diets of domestic herbivores (sheep/goat, and cattle) suggest that these two groups of domesticates were managed in distinct ways in the two main ecozones of the Hexi Corridor: the drier Northwestern region and the wetter Southeastern region. Whereas sheep and goat diets are consistent with consumption of naturally available vegetation, cattle exhibit a higher input of C4 plants in places where these plants contributed little to the natural vegetation. This suggests that cattle consumed diets that were more influenced by human provisioning, and may therefore have been reared closer to the human settlements, than sheep and goats.