Analysis of longitudinal-vertical coupling vibration of four hub motors driven electric vehicle under unsteady condition

The influence of hub motor unbalanced magnetic force (UMF) on the vibration of electric vehicle under steady state conditions has been known, but under unsteady conditions, the hub motor UMF will change with the vehicle operation condition, and there would exist complex coupling vibration for the hub motors driven electric vehicle. Here, the longitudinal-vertical coupling dynamics of the four hub motors driven electric vehicle under unsteady condition is studied. Integrating the motor electromagnetic excitation and electric vehicle dynamics, a longitudinal-vertical coupling dynamics model of the four hub motors driven electric vehicle is established. Based on the variable switching frequency field-oriented control model, analytical model of the UMFs acting on the motor stator and rotor parts under unsteady condition are developed. For model validation, a four hub motors driven electric vehicle has been tested, the accuracy of the longitudinal-vertical coupling dynamics model established in this paper was verified. Then, longitudinal-vertical coupling vibration characteristics of the four hub motors driven electric vehicle under road excitation and coupling excitation are analyzed. The results show that the longitudinal and vertical movement of the four hub motors driven electric vehicle is coupled by hub motor. In addition, under unsteady condition, the motor UMFs will cause vertical vibration of the electric vehicle body and hub motor stator, the vibration shows order characteristics including low order harmonic hfc and inverter switching frequency sideband harmonic k1fs±k2fc (fc = pn/60, fs is inverter switching frequency, k1 and k2 are positive integers, p is the number of pole pairs and n is motor speed.). The motor electromagnetic torque will cause longitudinal vibration of the electric vehicle body, the vibration shows order characteristics including harmonics fs±3fc and 2fs. The main harmonic of vehicle body pitch angle acceleration is 2fs.</p

Prediction and Diagnosis for Unsteady Electromagnetic Vibroacoustic of IPMSMs for Electric Vehicles Considering Rotor Step Skewing and Current Harmonics

Purpose: This study provides a detailed investigation on the prediction and diagnosis of unsteady electromagnetic vibroacoustic performance of IPMSMs for electric vehicles under typical unsteady operating conditions with consideration of rotor step skewing and current harmonics. Methods: Firstly, the control model considering the influence of PWM carrier modulation and rotor step skewing is established. Based on this, the currents of the IPMSM under unsteady operating conditions (driving condition and feedback braking condition) are obtained. Accordingly, the currents calculated through the control model are used as the excitation source of electromagnetic finite element. Then, the electromagnetic vibroacoustic performance under unsteady operating conditions is calculated through electromagnetic force subsection mapping and acoustic transfer vector (ATV) method. Moreover, the conditions where resonance vibroacoustic occurs are diagnosed. Finally, the results of prediction and diagnosis are fully verified by experiments of multiple physical fields. Results and Conclusions: The amplitude errors between prediction results and test results are less than 3.2%. The influence of current harmonics on electromagnetic vibroacoustic can be predicted. The frequency range and speed range of predicted peak vibroacoustic are consistent with the experimental results. The rotor step skewing can be used to weaken the vibroacoustic amplitude of IPMSMs under typical unsteady conditions in the full speed range. This study provides guidance for prediction and diagnosis for electromagnetic vibroacoustic performance of IPMSMs under typical unsteady operating conditions.</p

Portable Dual-Modular Immunosensor Constructed from Bimetallic Metal–Organic Framework Heterostructure Grafted with Enzyme-Mimicking Label for Rosiglitazone Detection

Immunosensor with photoelectrochemistry and fluorescence responsibility is widely used in biomedical detection, health monitoring, and food safety inspection. The cumbersome configuration and low integration of the current immunosensors, however, have brought challenges for their practical applications. To address these challenges, a portable and phone-APP controlled dual-modular immunosensor based on a bimetallic metal–organic framework (MOF) heterostructured photoelectrode, ZnO/NiZn-MOF/CdS, grafted with an enzyme-mimicking Au@CuO/Cu2O label is constructed to achieve simultaneous photoelectrochemistry and fluorescence signage. In the electrode design, the construction of a bimetallic NiZn metal–organic framework (NiZn-MOF) into the common ZnO/CdS photoresponsive structure achieves significant and stable photocurrent output under a very low-power LED light source for not only accelerating the transfer of photogenerated electrons from CdS to ZnO, but also stabilizing the holes of CdS to improve its photocorrosion resistance. After the graft of multifunctional enzyme-mimicking Au@CuO/Cu2O label clusters, a portable dual-modular immunosensor is built for the detection of rosiglitazone, a common antidiabetic drug and strictly restricted food residual, over a range from 10−3 to 1 µg L−1. This MOF-based immunosensor offers insights into highly sensitive dual-modular responsive material innovations and provides miniaturized biomedical detectors with promising commercialization potentials.</p

Near-Infrared Molecular Logic Gate for <i>In Situ</i> Construction and Quantification of Cell–Macromolecule Conjugates

Engineering cell surfaces with macromolecules offers the potential to manipulate and control their phenotype and function for cell-based therapies. In situ construction and real-time evaluation of cell–macromolecule conjugates are vital for characterizing their dynamics, mobility, and function but remain a great challenge. Herein, we design a near-infrared (NIR) heptamethine cyanine (LS)-bearing dibenzocyclooctyne (DBCO) and norbornene (NB) in its structure for rapid and selective bioorthogonal “click” coupling to azide-labeled cells and tetrazine-functionalized macromolecular precursors. Specifically, only orthogonal dual “click” cell–macromolecule conjugates turn on NIR fluorescence, in which LS behaves as an AND logic gate, with azide- and tetrazine-derivatives being “input” and the emission intensity as the output. LS enables in situ construction and real-time evaluation of the process and functional effects that macromolecules “graft to” cells with high cytocompatibility. This probe is tailor-made for live-cell microscopy technologies, which may open new opportunities for promoting further developments in cell-tracking and cell-based therapies

Pyrogenic temperature affects the particle size of biochar-supported nanoscaled zero valent iron (nZVI) and its silver removal capacity

Particle size of nanoscaled zero valent iron (nZVI) in nanocomposites can be affected by support materials. In this work, nZVI was supported by bamboo-derived biochars produced at 450 °C (BBL) and 600 °C (BBH). Total iron (Fe) contents were 14.4 and 11.9% for nZVI immobilized in BBL (nZVI/BBL) and BBH (nZVI/BBH), respectively. The resultant nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analyses (SEM/EDS). The nZVI was successfully embedded in biochar pores and surfaces as confirmed by SEM/EDS and XRD. TEM revealed that particle sizes of nZVI in nZVI/BBL and nZVI/BBH were roughly 26 and 40 nm, respectively. The Ag+ sorption isotherms (25–300 mg L−1 Ag+) suggested that 1 kg of nZVI in nZVI/BBL and nZVI/BBH removed as much as 745.5 and 534.5 g Ag+, respectively. The results suggested that Ag+ removal capacity was related to particle size of nZVI, which was also affected by pyrogenic temperature