Search

A light truck 3.5 t parallel shaft electric drive axle was taken as the research object, and the NVH test was carried out to it. In order to find out the main cause of howling and carry out optimization lifting, the method of combining experiment with simulation was adopted. Based on the test results, it is found that the main reason of the howling is the meshing excitation of the first gear of the electric drive axle, and then the rigid-flexible coupling multi-body dynamic simulation model of the electric drive axle was established based on the Romax Designer software. Through the calculation of transmission error and load distribution on the gear surface of the reducer, the vibration response of the shell was obtained. In order to reduce the fluctuation of transmission error of the gear, the micro modification of the reducer gear was carried out by using genetic algorithm, thus the excitation of the electric drive axle caused by the gear meshing was reduced, and the NVH performance of the electric drive axle was further improved. The aim is to provide reference for technical research in this field.

To guarantee the security and high-efficiency of image transmission, a novel triple-image encryption scheme based on chaotic system, S-box and image compressing is proposed in this paper. Firstly, the combination process is performed by compressing three plain images to 25% and combining the compressed images with a stochastic matrix generated by the 2D-LSCM system to construct a new image. This process makes the proposed image encryption scheme have higher image transmission efficiency comparing to that of the state-of-the-art methods. Then, Z-scan and the proposed coded lock scrambling algorithm with low time complexity is used to randomly scramble the positions of pixels in the new construct image. Next, a cipher image is obtained by performing the diffusion operation on the scrambled image through S-box and chaotic sequences. In addition, the added stochastic matrix in the combination process makes the cipher image dynamic. In other words, the generated cipher images are always different to each other even when they are generated by the proposed encrypt scheme with identical plain images under the same secret keys, which can resist chosen-plaintext attacks. Finally, experimental results and simulation analysis are performed, which shows the proposed scheme can effectively resist common kinds of attacks.

With the rapid development of modern industry, it is urgently needed to measure the biotoxicity of complex chemicals. Microbial electrochemical biotoxicity sensors are an attractive technology; however, their application is usually limited by their stability and reusability after measurements. Here, we improve their performance by encapsulating the electroactive biofilm with polydopamine (PDA), and we evaluate the improvement by different concentrations of heavy metal ions (Cu2+, Ag+, and Fe3+) in terms of inhibition ratio (IR) and durability. Results indicate that the PDA-encapsulated sensor exhibits a more significant detection concentration than the control group, with a 3-fold increase for Cu2+ and a 1.5-fold increase for Ag+. Moreover, it achieves 15 more continuous toxicity tests than the control group, maintaining high electrochemical activity even after continuous toxicity impacts. Images from a confocal laser scanning microscope reveal that the PDA encapsulation protects the activity of the electroactive biofilm. The study, thus, demonstrates that PDA encapsulation is efficacious in improving the performance of microbial electrochemical biotoxicity sensors, which can extend its application to more complex media. [ABSTRACT FROM AUTHOR]

Dearomative 1,3-dipolar cycloadditions of 1-Boc-pyrroles with in situ generated silver α-bromo alkylidenenitronates delivered a series of 3a,6a-dihydro-4-Boc-pyrrolo[2,3-d]isoxazole-2-oxides (17–91% yields) under very mild conditions. N-Deoxygenation of the cycloaddition product gave a dihydro-pyrrolo[2,3-d]isoxazole, elaborations of which produced various functionalized 2,3-dihydropyrroles and pyrrolidines, showcasing the potential utilities of our new strategy of pyrrole dearomatization. [ABSTRACT FROM AUTHOR]

Background: CircRNA‐encoded proteins (CEPs) are emerging as new players in health and disease, and function as baits for the common partners of their cognate linear‐spliced RNA encoded proteins (LEPs). However, their prevalence across human tissues and biological roles remain largely unexplored. The placenta is an ideal model for identifying CEPs due to its considerable protein diversity that is required to sustain fetal development during pregnancy. The aim of this study was to evaluate circRNA translation in the human placenta, and the potential roles of the CEPs in placental development and dysfunction. Methods: Multiomics approaches, including RNA sequencing, ribosome profiling, and LC‐MS/MS analysis, were utilised to identify novel translational events of circRNAs in human placentas. Bioinformatics methods and the protein bait hypothesis were employed to evaluate the roles of these newly discovered CEPs in placentation and associated disorders. The pathogenic role of a recently identified CEP circPRKCB119aa in preeclampsia was investigated through qRT‐PCR, Western blotting, immunofluorescence imaging and phenotypic analyses. Results: We found that 528 placental circRNAs bound to ribosomes with active translational elongation, and 139 were translated to proteins. The CEPs showed considerable structural homology with their cognate LEPs, but are more stable, hydrophobic and have a lower molecular‐weight than the latter, all of which are conducive to their function as baits. On this basis, CEPs are deduced to be closely involved in placental function. Furthermore, we focused on a novel CEP circPRKCB119aa, and illuminated its pathogenic role in preeclampsia; it enhanced trophoblast autophagy by acting as a bait to inhibit phosphorylation of the cognate linear isoform PKCβ. Conclusions: We discovered a hidden circRNA‐encoded proteome in the human placenta, which offers new insights into the mechanisms underlying placental development, as well as placental disorders such as preeclampsia. Key points: A hidden circRNA‐encoded proteome in the human placenta was extensively identified and systematically characterised.The circRNA‐encoded proteins (CEPs) are potentially related to placental development and associated disorders.A novel conserved CEP circPRKCB119aa enhanced trophoblast autophagy by inhibiting phosphorylation of its cognate linear‐spliced isoform protein kinase C (PKC) β in preeclampsia. [ABSTRACT FROM AUTHOR]