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Creators/Authors contains: "Zhang, Ziyan"

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  1. Abstract Palladium hydrides are traditionally employed in hydrofunctionalization (i.e. monofunctionalization) of conjugated dienes and enynes, owning to its facile protic hydropalladation of electron‐rich (or neutral) unsaturated bonds. Herein, we report a mild PdH‐catalyzed difunctionalization of conjugated dienes and enynes. This protocol is enabled by the chemoselectivity switch of the initial hydropalladation step achieved by visible light enhancement of hydricity of PdH species. This method allows for cascade annulation of dienes and enynes with various easily available and abundant substrates, such as acrylic acids, acrylic amides, and Baylis–Hillman adducts, toward a wide range of alkenyl or alkynyl lactones, lactams, and tetrahydrofurans. This protocol also provides an easy access to complex spiro‐fused tricyclic frameworks. 
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  2. ABSTRACT AimThe consistency of patterns in ontogenetic differences in plant traits across the globe has not been thoroughly studied. Environmental conditions affect leaf functional traits, and these effects can differ between adult trees and saplings due to varying environmental conditions in their aerial and soil environments. Our integrative analysis aims to reveal the global universality of woody plants' ontogeny and explores influencing factors. LocationGlobal. Time PeriodStudies published in 1989–2023. Major Taxa StudiedWoody plants. MethodsWe performed a global meta‐analysis of woody plants with different plant functional types at 64 sites around the world, assessed the ontogenetic differences in nine key leaf traits and explored the environmental factors that affected the ontogenetic differences. ResultsWe observed that (1) leaf traits differed significantly between adult trees and saplings, with environmental factors playing varying roles. Photosynthetic capacity per unit area (Aa) and nitrogen content per unit dry mass (Nm) were lower in saplings than in adults under low solar radiation, but this trend reversed with increased solar radiation. Differences in stomatal density (SD) and stable carbon isotope composition (δ13C) between adults and saplings were greatest under low solar radiation; (2) ontogenetic differences in leaf thickness (LT), leaf dry mass per area (LMA) and stomatal conductance (gs) were greater at lower mean annual temperature (MAT); (3) at high mean annual precipitation (MAP), adults had higher nitrogen content per unit area (Na), while saplings had higherNmthan adults; (4) soil conditions were strongly correlated with ontogenetic differences in LT and SD, with soil pH as a key driver of variation inAa, LT, SD,NaandNm. Main ConclusionsOur findings indicate that ontogeny strongly modifies leaf functional traits and that multiple environmental factors influence the magnitude of ontogenetic differences in leaf traits. This underscores the importance of considering ontogeny when predicting trait values across plant developmental stages, modelling vegetation composed of individuals of different ages and forecasting vegetation responses to environmental changes. 
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  3. null (Ed.)
    This study presents a time-efficient modelling approach for dynamic behavior and efficiency analysis of a Switched Reluctance Machines (SRM). It employs a hybrid model combining Simulink, finite element analysis (FEA), and hardware measurements to create an accurate behavioral model of the machine. In order to enhance accuracy of the estimated performance, Steinmetz equation is employed to characterize core loss in the machine across different operating points. This approach serves as a template for developing a time-efficient model to analyze performance of any SRM with a high degree of accuracy. Simulation and experimental results are used to show effectiveness of the proposed approach. 
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  4. null (Ed.)
    This study presents a computationally cost-effective modeling approach for a switched reluctance machine (SRM) towards predicting vibration and acoustic noise. In the proposed approach, the SRM is modeled using Finite Element (FE) software for capturing magnetic snapshots from static simulations. Using an advanced field reconstruction method (FRM), these snapshots are used to develop basis functions to estimate magnetic fields under any arbitrary stator excitation and at any desired rotor position. This method includes magnetic properties of the machine and can estimate flux density at once instead of partially predicting it. The vibration model is built in FE software while the acoustic noise is predicted using the analytical method. The proposed study can significantly reduce the computational time for vibration and noise analysis with decent accuracy. Dynamic simulation by finite-element analysis (FEA) software and experimental verification have been carried out to verify the effectiveness of the proposed hybrid model. 
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  5. null (Ed.)