Efficient Phytase Secretion and Phytate Degradation by Recombinant Bifidobacterium longum JCM 1217

Genetic engineering of probiotics, like bifidobacteria, may improve their microbial cell factory economy. This work designed a novel shuttle plasmid pBPES, which bears exogenous appA and is stable within Bifidobacterium longum JCM 1217. Cloning of three predicted promoters into pBPES proved that all of them drive appA expression in B. longum JCM 1217. Transformation of plasmids pBPES-tu and pBPES-groEL into B. longum JCM1217 resulted in much more phytase secretion suggests Ptu and PgroEL are strong promoters. Further in vitro and in vivo experiments suggested B. longum JCM 1217/pBPES-tu degrades phytate efficiently. In conclusion, the study screened two stronger promoters and constructed a recombinant live probiotic strain for effectively phytase secretion and phytate degradation in gut. The strategy used in the study provided a novel technique for improving the bioaccessibility of phytate and decreasing phosphorus excretion

Research on Longitudinal Control Algorithm of Adaptive Cruise Control System for Pure Electric Vehicles

The vehicle longitudinal control algorithm is the core function of the adaptive cruise control system, whose main task is to convert vehicle acceleration and deceleration requirements into vehicle driving and braking commands so that the vehicle can quickly and accurately track the desired acceleration. Traditional longitudinal control algorithms rely on accurate vehicle dynamic modeling or complex controller parameter calibrations. To overcome those difficulties, a longitudinal control algorithm based on RBF-PID is proposed in this paper. The algorithm uses the RBFNN (radial basis function neural network), which can simply and quickly approximate any complex nonlinear system, to identify the Jacobian information of the vehicle and perform parameter tuning for PID control and achieve vehicle longitudinal control with self-tuning capability. Finally, the algorithm of this paper is verified by the joint simulation of Matlab/Simulink and Carsim. The results show that this algorithm has a better response rate and anti-jamming capability than the traditional PID control and can achieve accurate and rapid tracking of the desired acceleration

Research on Longitudinal Control Algorithm of Adaptive Cruise Control System for Pure Electric Vehicles

The vehicle longitudinal control algorithm is the core function of the adaptive cruise control system, whose main task is to convert vehicle acceleration and deceleration requirements into vehicle driving and braking commands so that the vehicle can quickly and accurately track the desired acceleration. Traditional longitudinal control algorithms rely on accurate vehicle dynamic modeling or complex controller parameter calibrations. To overcome those difficulties, a longitudinal control algorithm based on RBF-PID is proposed in this paper. The algorithm uses the RBFNN (radial basis function neural network), which can simply and quickly approximate any complex nonlinear system, to identify the Jacobian information of the vehicle and perform parameter tuning for PID control and achieve vehicle longitudinal control with self-tuning capability. Finally, the algorithm of this paper is verified by the joint simulation of Matlab/Simulink and Carsim. The results show that this algorithm has a better response rate and anti-jamming capability than the traditional PID control and can achieve accurate and rapid tracking of the desired acceleration

Development of a Cooperative Braking System for Front-Wheel Drive Electric Vehicles

Most electric vehicles adopt cooperative braking systems that can blend friction braking torque with regenerative braking torque to achieve higher energy efficiency while maintaining a certain braking performance and driving safety. This paper presented a new cooperative regenerative braking system that contained a fully-decoupled hydraulic braking mechanism based on a modified electric stability control system. The pressure control algorithm and brake force distribution strategy were also discussed. Dynamic models of a front wheel drive electric car equipped with this system and a simulation platform with a driver model and driving cycles were established. Tests to evaluate the braking performance and energy regeneration were simulated and analyzed on this platform and the simulation results showed the feasibility and effectiveness of this system

A CNT-Toughened Strategy for In-Situ Repair of Aircraft Composite Structures

This study aimed to develop an in-situ field-repair approach, especially for aircraft composite structures, to enhance the interlaminar toughness of plain-woven composites (PWCs) by adding multi-walled carbon nanotubes (MWCNTs). MWCNTs were dispersed at each interface between prepreg layers by means of solvent spraying, with a density of 1.58 g/m2. Then, the layers were stacked with the predefined sequence and cured at 120 °C and 1 bar pressure, using a heat-repairing instrument. A standard double cantilever beam (DCB) test was used to investigate the interlaminar toughening effect that was due to the MWCNTs. For comparison, original samples were also prepared. The results indicated that the introduction of MWCNTs can favorably enhance the interlaminar toughness of PWCs in a field-repair approach and the Mode I fracture energy release rate, GIC, increased by 102.92%. Based on the finite element method (FEM) of continuum damage mechanics, the original samples and the MWCNTs toughening specimen under DCB Mode I fracture were modeled and analyzed. The simulation and the experiment were in good agreement. Finally, when the toughening mechanism of MWCNTs was explored with a scanning electron microscope (SEM), we found that a large amount of fiber-matrix (F-M) interface debonding and matrix cracking in mountain shape were the major modes of fracture, accompanied by a small amount of fiber breakage and matrix peeling for the MWCNTs-toughening specimens

Freestanding layer-structure selenium cathodes with ultrahigh Se loading for high areal capacity Li-Se batteries

In this work, a freestanding layer-structure Se cathode, composed of alternant barrier layers and active layers, is synthesized via a facile syringe-filtration strategy. With employing the barrier layers simultaneously acting as polyselenide-interception barriers and as highly conductive current collectors, the active layers with 3D porous architecture are endowed with strong polyselenide-trapping capability and fast redox-conversion capability. Such novel Se cathode readily achieves a high Se loading up to 13.5 mg cm−2. The optimized Se cathode with a high Se loading of 4.5 mg cm−2 exhibits high specific capacity/areal capacity (794 mA h g−1/3.6 mA h cm−2), excellent cycling stability (508 mA h g−1@300 cycles), and remarkable rate capability (389 mA h g−1@800 mA g−1), which is superior to conventional Se cathodes. Keywords: Lithium-selenium batteries, Se cathode, Alternant layer structure, Syringe-filtration method, Areal capacit

Histological, Physiological, and Comparative Proteomic Analyses Provide Insights into Leaf Rolling in <i>Brassica napus</i>

Moderate leaf rolling is important in ideotype breeding, as it improves photosynthetic efficiency and therefore increases crop yields. To understand the regulatory network of leaf rolling in <i>Brassica napus</i>, a down-curved leaf mutant (<i>Bndcl1</i>) has been investigated. Physiological analyses indicated that the chlorophyll contents and antioxidant enzyme activities were remarkably increased and the photosynthetic performance was significantly improved in <i>Bndcl1.</i> Consistent with these findings, 943 differentially accumulated proteins (DAPs) were identified in the <i>Bndcl1</i> mutant and its wild-type plants using iTRAQ-based comparative proteomic analyses. Enrichment analysis of proteins with higher abundance in <i>Bndcl1</i> revealed that the functional category “photosynthesis” was significantly overrepresented. Moreover, proteins associated with oxidative stress response and photosystem II repairing were also up-accumulated in <i>Bndcl1</i>, which might help the mutant to sustain the photosynthetic efficiency under unfavorable conditions. Histological observation showed that the mutant displayed defects in adaxial-abaxial patterning. Important DAPs associated with leaf polarity establishment were detected in <i>Bndcl1</i>, including ribosomal proteins, proteins involved in post-transcriptional gene silencing, and proteins related to brassinosteroid. Together, our findings may help clarify the mechanisms underlying leaf rolling and its physiological effects on plants and may facilitate ideotype breeding in <i>Brassica napus</i>