Preparation and characterization of ZnO microcantilever for nanoactuation

Zinc oxide [ZnO] thin films are deposited using a radiofrequency magnetron sputtering method under room temperature. Its crystalline quality, surface morphology, and composition purity are characterized by X-ray diffraction [XRD], atomic force microscopy [AFM], field-emission scanning electron microscopy [FE-SEM], and energy-dispersive X-ray spectroscopy [EDS]. XRD pattern of the ZnO thin film shows that it has a high c-axis-preferring orientation, which is confirmed by a FE-SEM cross-sectional image of the film. The EDS analysis indicates that only Zn and O elements are contained in the ZnO film. The AFM image shows that the film's surface is very smooth and dense, and the surface roughness is 5.899 nm. The microcantilever (Au/Ti/ZnO/Au/Ti/SiO2/Si) based on the ZnO thin film is fabricated by micromachining techniques. The dynamic characterizations of the cantilever using a laser Doppler vibrometer show that the amplitude of the cantilever tip is linear with the driving voltage, and the amplitude of this microcantilever's tip increased from 2.1 to 13.6 nm when the driving voltage increased from 0.05 to 0.3 Vrms. The calculated transverse piezoelectric constant d31 of the ZnO thin film is -3.27 pC/N. This d31 is high compared with other published results. This ZnO thin film will be used in smart slider in hard disk drives to do nanoactuation in the future

Salt stress perception and metabolic regulation network analysis of a marine probiotic Meyerozyma guilliermondii GXDK6

IntroductionExtremely salt-tolerant microorganisms play an important role in the development of functional metabolites or drug molecules.MethodsIn this work, the salt stress perception and metabolic regulation network of a marine probiotic Meyerozyma guilliermondii GXDK6 were investigated using integrative omics technology.ResultsResults indicated that GXDK6 could accept the salt stress signals from signal transduction proteins (e.g., phosphorelay intermediate protein YPD1), thereby contributing to regulating the differential expression of its relevant genes (e.g., CTT1, SOD) and proteins (e.g., catalase, superoxide dismutase) in response to salt stress, and increasing the salt-tolerant viability of GXDK6. Omics data also suggested that the transcription (e.g., SMD2), translation (e.g., MRPL1), and protein synthesis and processing (e.g., inner membrane protein OXA1) of upregulated RNAs may contribute to increasing the salt-tolerant survivability of GXDK6 by improving protein transport activity (e.g., Small nuclear ribonucleoprotein Sm D2), anti-apoptotic ability (e.g., 54S ribosomal protein L1), and antioxidant activity (e.g., superoxide dismutase). Moreover, up to 65.9% of the differentially expressed genes/proteins could stimulate GXDK6 to biosynthesize many salt tolerant-related metabolites (e.g., β-alanine, D-mannose) and drug molecules (e.g., deoxyspergualin, calcitriol), and were involved in the metabolic regulation of GXDK6 under high NaCl stress.DiscussionThis study provided new insights into the exploration of novel functional products and/or drugs from extremely salt-tolerant microorganisms.Graphical Abstrac

Development of a typical driving cycle for an intra-city hybrid electric bus with a fixed route

Intra-city buses have become an effective way to alleviate urban traffic congestion. Developing the driving cycle for an intra-city hybrid electric bus is of great importance for energy economy and emissions performances tests, as well as control strategy optimization to enhance fuel economy and reduce emissions. In the construction of the bus driving cycle using the adapted regular method based on kinematic segments with fixed time-steps, the transition of partial kinematic segments leads to velocity fluctuation, which does not reflect the actual driving characteristics. This study initially collects driving data from a hybrid electric bus in Shanghai, and constructs its typical driving cycle by the k-means clustering method. Considering the characteristics of frequent stopping and repetition during the bus driving cycle, the bus-station-based driving cycle segment division method and the whole-trip-based bus driving cycle construction method are proposed. A typical hybrid electric bus driving cycle is then constructed using the proposed methods. Finally, the typical hybrid electric bus driving cycles developed by two methods are compared and analyzed. The 2-norm value of the characteristic parameter error vector is decreased from 0.249 for the typical hybrid electric bus driving cycle based on the adapted regular method to 0.163 for the improved method. It is shown that the whole-trip-based bus driving cycle construction method reflects the actual driving characteristics better, has lighter computation burden, and lays the foundation for the development of an adaptive control strategy for the hybrid electric bus as well as tests of its energy economy and emissions

Nurse managers' experience during the COVID‐19 pandemic in China: A qualitative study

Abstract Aims The aim of the study was to explore the experiences of female new nurse managers during the COVID‐19 pandemic. Design This was a phenomenological study, and qualitative descriptive analysis was used. Methods New nurse managers were defined as new nurse managers with less than 3 years of management experience in this study. During November and December of 2021, 18 female new nurse managers were interviewed face‐to‐face with a semi‐structured interview guide in three municipal hospitals. The study followed the Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines for evaluating qualitative research reports. Data analysis was performed using Colaizzi's seven‐step method. Results Four main themes and 10 sub‐themes were extracted from the collected data. The four major themes were as follows: (1) a shift in stress; (2) work‐related physical and psychological discomfort; (3) reflection on the cause; (4) coping and struggles. Conclusions New nurse managers were experiencing great stress and exhaustion in their roles. It is important that they are helped to handle situations. Providing them with readily accessible support, addressing their psychosocial needs and addressing exhaustion is necessary. Considering their short management time, the hospital should provide adequate support in human, financial and material areas and provide training to help new nurse managers better adapt to their new roles. In addition, nurse directors should create a culture of mutual respect, identify workplace bullying and create a harmonious and cooperation‐oriented work environment for new nurse managers. Patient or Public Contribution No patient or public contribution

Deposition, characterization and optimization of zinc oxide thin film for piezoelectric cantilevers

In this work, piezoelectric zinc oxide (ZnO) thin films are deposited under different deposition conditions using RF magnetron sputtering method. The influence of RF power, O2/(Ar + O2) gas ratio and sputtering pressure on the deposition rate, crystalline structures, surface roughness and composition purity of ZnO film are investigated by X-ray Diffractometer (XRD), scanning electron microscopy (SEM), atom force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS). All the fabricated ZnO films have a preferred ZnO(0 0 2) orientation. When the gas ratio of O2/(Ar + O2) is 25% and the working pressure is 0.8 Pa, the grain size in the ZnO thin film is of the largest and the ZnO film has a very smooth and dense surface. The SEM cross-sectional image of the ZnO film confirms that the ZnO thin film has a columnar structure and the c-axis is perpendicular to the substrate surface. The EDS analysis shows the ZnO film has only Zn and O elements. Different ZnO film based piezoelectric micro cantilevers are fabricated using micromachining techniques and the dynamic response of these piezoelectric cantilevers are measured by laser Doppler vibrometer (LDV). The tested results from LDV show that the deflection of the piezoelectric cantilever is linear with the driving voltage. The transverse piezoelectric constant d31 of the ZnO thin film deposited under best conditions is calculated as −3.21 pC/N by the LDV data. This value is higher than other published works. In future, these ZnO thin films will be used in our ongoing project for the design, simulation and fabrication of smart slider with a built-in ZnO sensor/actuator in the hard disk drives

Optimization of Key Parameters of Energy Management Strategy for Hybrid Electric Vehicle Using DIRECT Algorithm

The rule-based logic threshold control strategy has been frequently used in energy management strategies for hybrid electric vehicles (HEVs) owing to its convenience in adjusting parameters, real-time performance, stability, and robustness. However, the logic threshold control parameters cannot usually ensure the best vehicle performance at different driving cycles and conditions. For this reason, the optimization of key parameters is important to improve the fuel economy, dynamic performance, and drivability. In principle, this is a multiparameter nonlinear optimization problem. The logic threshold energy management strategy for an all-wheel-drive HEV is comprehensively analyzed and developed in this study. Seven key parameters to be optimized are extracted. The optimization model of key parameters is proposed from the perspective of fuel economy. The global optimization method, DIRECT algorithm, which has good real-time performance, low computational burden, rapid convergence, is selected to optimize the extracted key parameters globally. The results show that with the optimized parameters, the engine operates more at the high efficiency range resulting into a fuel savings of 7% compared with non-optimized parameters. The proposed method can provide guidance for calibrating the parameters of the vehicle energy management strategy from the perspective of fuel economy