291 research outputs found
MODELING AND SIMULATION OF PM MOTOR TESTING ENVIRONMENT TOWARDS EV APPLICATION CONSIDERING ROAD CONDITIONS
The electric vehicle (EV) performance testing is an indispensable aspect of the design study and marketing of electric vehicle. The development of a suitable electric motor testing environment for EVs is very significant. On the one hand, it provides a relatively realistic testing environment for the study of the key technologies of electric vehicles, and it also plays an essential role in finding a reasonable and reliable optimization scheme. On the other hand, it provides a reference to the evaluation criteria for the products on the market. This thesis is based on such requirements to model and simulate the PM motor testing environment towards EV applications considering road conditions. Firstly, the requirements of the electric motor drive as a propulsion system for EV applications are investigated by comparing to that of the traditional engine as a propulsion system. Then, as the studying objective of this work, the mathematical model of PMSM is discussed according to three different coordinate systems, and the control strategy for EV application is developed. In order to test the PM motor in the context of an EV, a specific target vehicle model is needed as the virtual load of the tested motor with the dyno system to emulate the real operating environment of the vehicle. A slippery road is one of the severe driving conditions for EVs and should be considered during the traction motor testing process. Fuzzy logic based wheel slip control is adopted in this thesis to evaluate the PM motor performance under slippery road conditions. Through the proposed testing environment, the PM motor can be tested in virtual vehicle driving conditions, which is significant for improving the PM motor design and control
Higher education, high-impact research, and world university rankings: A case of India and comparison with China
AbstractTo date, this paper is probably the first to compare Indian and Chinese universities on educational performance metrics such as high-impact research and world university rankings. The study, therefore, examines the current state of higher education, high-impact research metrics, and world university rankings in an emerging market of India. First, we present an overview of the higher education system, government schemes for academic research, and related educational statistics. Second, we compare India and China on various academic-research metrics (citable documents, number of citations, cites per document, and H-index in three categories), and world university rankings. Special attention is devoted to revealing the progress of management research metrics, business school accreditations and rankings, and abstracting and indexing of publishing journals. Last, we discuss several challenges in university education and recommend policy guidelines pertaining to research funding, collaborative research projects, and research assessment council for imparting quality academic practices and standards in a higher education environment. Our exploratory analysis indicates that for citable documents in the ‘all subjects’ category, the United States is ranked first, followed by China in second, the United Kingdom in third, and India in ninth. Overall, world university rankings and research metrics of Indian universities are found to be far behind those of Chinese universities
Nickel-Catalyzed Sonogashira Coupling Reactions of Nonactivated Alkyl Chlorides under Mild Conditions
OPT3 is a component of the iron-signaling network between leaves and roots and misregulation of OPT3 leads to an over-accumulation of cadmium in seeds.
Plants and seeds are the main dietary sources of zinc, iron, manganese, and copper, but are also the main entry point for toxic elements such as cadmium into the food chain. We report here that an Arabidopsis oligopeptide transporter mutant, opt3-2, over-accumulates cadmium (Cd) in seeds and roots but, unexpectedly, under-accumulates Cd in leaves. The cadmium distribution in opt3-2 differs from iron, zinc, and manganese, suggesting a metal-specific mechanism for metal partitioning within the plant. The opt3-2 mutant constitutively up-regulates the Fe/Zn/Cd transporter IRT1 and FRO2 in roots, indicative of an iron-deficiency response. No genetic mutants that impair the shoot-to-root signaling of iron status in leaves have been identified. Interestingly, shoot-specific expression of OPT3 rescues the Cd sensitivity and complements the aberrant expression of IRT1 in opt3-2 roots, suggesting that OPT3 is required to relay the iron status from leaves to roots. OPT3 expression was found in the vasculature with preferential expression in the phloem at the plasma membrane. Using radioisotope experiments, we found that mobilization of Fe from leaves is severely affected in opt3-2, suggesting that Fe mobilization out of leaves is required for proper trace-metal homeostasis. When expressed in yeast, OPT3 does not localize to the plasma membrane, precluding the identification of the OPT3 substrate. Our in planta results show that OPT3 is important for leaf phloem-loading of iron and plays a key role regulating Fe, Zn, and Cd distribution within the plant. Furthermore, ferric chelate reductase activity analyses provide evidence that iron is not the sole signal transferred from leaves to roots in leaf iron status signaling
Solvent-Free Hydrosilylation of Alkenes Catalyzed by Well-Defined Low-Valent Cobalt Catalysts
Nonparaxiality-triggered Landau-Zener transition in topological photonic waveguides
Photonic lattices have been widely used for simulating quantum physics, owing
to the similar evolutions of paraxial waves and quantum particles. However,
nonparaxial wave propagations in photonic lattices break the paradigm of the
quantum-optical analogy. Here, we reveal that nonparaxiality exerts stretched
and compressed forces on the energy spectrum in the celebrated
Aubry-Andre-Harper model. By exploring the mini-gaps induced by the finite size
of the different effects of nonparaxiality, we experimentally present that the
expansion of one band gap supports the adiabatic transfer of boundary states
while Landau-Zener transition occurs at the narrowing of the other gap, whereas
identical transport behaviors are expected for the two gaps under paraxial
approximation. Our results not only serve as a foundation of future studies of
dynamic state transfer but also inspire applications leveraging nonparaxial
transitions as a new degree of freedom.Comment: 17 pages, 4 figure
The Effect of Substituents on the Formation of Silyl [PSiP] Pincer Cobalt(I) Complexes and Catalytic Application in Both Nitrogen Silylation and Alkene Hydrosilylation
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