Both biological and industrial nitrogen reduction catalysts activate N2 at multinuclear binding sites with constrained Fe–Fe distances. This contrasts molecular diiron systems, which routinely form linear bridges to minimize steric interactions. Model compounds that capture the salient geometric features of by nitrogenase enzymes Mittasch would contribute understanding their high N2-reduction activity. It is shown in present study use a geometrically flexible, dinucleating macrocycle allows...

Input current around zero-crossing point is distorted and the reduction of ripple limited when applying space-vector modulation (SVM) to interleaved Vienna rectifier. In this article, a hybrid SVM method for two- channel rectifier developed reduce harmonics distortion ripple. The topology two-channel introduced. characteristics peak with are analyzed. Then, clamped used eliminate in sectors point. To ripple, phase-shifted angle carriers between two channels modified current. Furthermore,...

Abstract Grid enterprises need to assess the risk caused by multiple uncertainties such as market trading volume and price fluctuations when acting a proxy for customers purchase electricity in multitimescale markets. To this end, paper constructs measurement grading evaluation model power grid agency purchase. First of all, multidimensional risks corresponding uncertainty factors agent participation transactions are analyzed. Based on this, three-dimensional multilevel system is established...

Despite their connection to ammonia synthesis, little is known about the ability of iron-bound, bridging nitrides form N-H bonds. Herein we report a linear diiron nitride complex supported by redox-active macrocycle. The unique ligand scaffold adapt geometric preference species was found facilitate formation bonds via proton-coupled electron transfer generate μ-amide product. structurally analogous μ-silyl- and μ-borylamide complexes were shown from net insertion into E-H (E=B, Si)....

Three-phase three-level Vienna rectifier using powder core inductors has been widely used for power conversion. Inductor current ripple analysis of is essential pulsewidth modulation method optimization, loss estimation, filter inductor design, etc. However, it hard to analyze the rectifier. Moreover, inductance varies with sinusoidal input current, which makes even more complicated. In this article, a three-phase considering variation presented. The distribution constant studied based on...

This report describes the first examples of unassisted C(sp)–C(sp2) and C(sp)–C(sp3) bond oxidative addition reactions to give thermodynamically favorable products. Treatment a diiron complex supported by geometrically electronically flexible macrocyclic ligand, (3PDI2)Fe2(μ-N2)(PPh3)2 ([Fe2N2]0), with stoichiometric amounts various 4,4′-disubstituted diphenylacetylenes (ArX–C≡C–ArX; X = OMe, H, F, CF3) yielded When Ph–C≡C–R substrates were used as (R Me, Et, iPr, tBu), products either or...

Abstract Despite their connection to ammonia synthesis, little is known about the ability of iron‐bound, bridging nitrides form N−H bonds. Herein we report a linear diiron nitride complex supported by redox‐active macrocycle. The unique ligand scaffold adapt geometric preference species was found facilitate formation bonds via proton‐coupled electron transfer generate μ ‐amide product. structurally analogous ‐silyl‐ and ‐borylamide complexes were shown from net insertion into E−H (E=B, Si)....

For three level VIENNA rectifier, several low-order harmonics will emerge in the input current due to distortion near zero-crossing point and fluctuation output voltage. In this paper, a new control strategy, including dual-loop balance loop is established based on state-space average model stationary αβ frame achieve reduced harmonics. As inner loop, proportional-resonant(PR) selected for it does not require complicated transformation can track AC signals with zero error. Moreover, design...

Cross-coupling polymerizations have fundamentally changed the field of conjugated polymers (CPs) by expanding scope accessible materials. Despite prevalence cross-coupling in CP synthesis, almost all rely on mononuclear Ni or Pd catalysts. Here, we report a systematic exploration mono- and dinuclear Fe precatalysts with pyridine diimine ligand scaffold for Kumada polymerization donor thiophene an acceptor benzotriazole monomers. We observe that variation metal identity from to produces...

SiC wind power energy conversion system (WECS) can operate at higher switching frequency, compared to Si IGBT systems. This will broaden the regular design range of converter. Based on efficiency and density, a scheme considering speed profile is developed for typically WECS. The components are analyzed regarding tradeoffs between volumetric density all feasible frequencies ripple current. At nominal profile, curves have same trend so that valid be achieved using condition. In 400 kW system,...

Abstract. Constructive mathematics involves numbers and objects that can be constructed computed through algorithmic methods. In this paper we prove there is no algorithm to determine if the homotopy group _n trivial or not for all constructive compact spaces. beginning introduce topology theory. Then spaces describe space in way, calculate certain groups. Finally, use an unextendible partially computable function always triviality of their groups by contradiction.

To improve the dynamic performance against load disturbance, a current feed-forward(LCFF) control scheme for Vienna Rectifier using no load-current sensor is presented in this paper. The basic feed-forward terms derived by block diagram and explained based on input-output power balance. Then closed loop observer designed estimating load-current. Nevertheless, disturbance estimated caused deviation of capacitor parameter, sampling error PWM voltage distortion will deteriorate input heavily....

In this paper, the demonstration application project of non-intrusive load monitoring (NILM) technology is introduced, including NILM-based smart meter, low voltage residential power information acquisition system Jiangsu Province, data and display, etc. On basis, considering practical conditions, four technical characteristics NILM are expounded, which processing in different devices, pushing with time delays, interacting users, improving performance continuously. A research platform called...

The rapid evolution of electric vehicles (EVs) has prompted extensive exploration into higher voltage regimes to enhance their overall performance. Within an 800-volt architecture, the 48-volt level emerged as next frontier for auxiliary power supply enhancement. This paper introduces 800V 48V Auxiliary Power Unit (APU). To efficiently manage elevated input while alleviating primary-side device stress by 50%, a stacked half-bridge (SHB) LLC converter is designed, capitalizing on favorable...

CI (Critical infrastructure) is a kind of complex and huge network system, its operating failure will cause serious impact on national interest.Evaluating emergency capacity from the perspective shortage helps directly discover weak links response improve effectiveness evaluation.Under background scenario uncertainty, it's hard to predict disaster scenarios in future.That causes difficulty presuming for analysis.This paper proposes presuming-based method analyzing terms evaluation...