Optimized Lightweight Frame for Intelligent New-energy Vehicles

In this paper, a joint optimization method based on multi-objective response surface approximation model and finite element simulation program is proposed to realize the lightweight optimization of new-energy vehicle frames. Under the premise of satisfying the constraints of strength, frequency and vibration, the thickness of different important parts is optimized to achieve the goal of minimizing the quality of intelligent vehicles. In order to obtain the stress distribution of each part and the vibration frequency of the frame, various finite element analyses of the intelligent vehicle frame are analyzed. In order to achieve optimization, this paper adopts the response surface method for multi-objective optimization. Sample data was generated by the central composite design, and the response surface optimization method was used to filter out 5 design variables that had a large impact on the frame. As a result, the weight of the frame was reduced from 25.05 kg to 19.86 kg, a weight reduction of 20.7%, achieving a significant weight reduction effect. This method provides important reference value and guiding significance for the optimization of frame and its lightweight. In this way, the design of the frame can be better optimized to make it lighter, thereby improving the performance of the smart car. At the same time, this method can also be applied to optimization problems in other fields to achieve more efficient and accurate optimization goals. Citation: Wu, P. (2023). Optimized Lightweight Frame for Intelligent New-energy Vehicles. Trends in Renewable Energy, 9(2), 157-166. doi:http://dx.doi.org/10.17737/tre.2023.9.2.0015

Towards a Better Understanding of the Molecular Mechanisms Underlying Plant Development and Stress Response

The spectacular array of diverse plant forms as well as the predominantly sessile life style of plants raises two questions that have been fascinating to scientists in the field of plant biology for many years: 1) how do plants develop to a specific size and shape? 2) how do plants respond to environmental stresses given its immobility? Plant organ development to a specific size and shape is controlled by cell proliferation and cell expansion. While the cell proliferation process is extensively studied, the cell expansion process remains largely unknown, and can be affected by several factors, such as cell wall remodeling and the incorporation of new wall materials. To better understand the genetic basis of plant development, we identified an Arabidopsis T-DNA insertion mutant named development related Myb-like 1 (drmy1), which showed altered size and shape in both vegetative and reproductive organs due to defective cell expansion. We further demonstrated that the defective cell expansion in the drmy1 mutant is linked to the change in cell wall composition. Complementation testing by introduction of DRMY1 into the mutant background rescued the phenotype, indicating that DRMY1 is a functional regulator of plant organ development. The DRMY1 protein contains a single Myb-like DNA binding domain and is localized in the nucleus, and may cooperate with other transcription factors to regulate downstream gene expression as DRMY1 itself does not possess transactivation ability. DRMY1 expression analysis revealed that its expression is reduced by the plant hormone ethylene (a negative regulator of cell expansion) while induced by ABA (a positive regulator of cell expansion). Furthermore, whole transcriptome profiling suggested that DRMY1 might control cell expansion directly by regulating genes related to cell wall biosynthesis/remodeling and ribosome biogenesis or indirectly through regulating genes involved in ethylene and ABA signaling pathways. Plants cannot “escape” from salinity stress but have evolved different mechanisms for salt tolerance over the time of adaptation to salinity. About 1% of plant species named halophytes can survive and thrive in environments containing high salt concentrations, which makes it important to understand their salt tolerance mechanisms and the responsible genes. Here, we investigated salt tolerance mechanisms in Supreme, the most salt-tolerant cultivar of a halophytic warm-seasoned perennial grass, Seashore paspalum (Paspalum vaginatum) at the physiological and transcriptomic levels by comparative study with another cultivar Parish, which possesses moderate salinity tolerance. Our results suggest that Na+ accumulation under normal conditions and further increased accumulation under high salinity conditions (400 mM NaCl), possibly by vacuolar sequestration is a crucial mechanism for salinity tolerance in Supreme. Our data suggests that Na+ accumulation in Supreme under normal conditions might trigger the secondary messenger Ca2+ for signal transduction and the resulting upregulation of salt stress related transcription factors in addition to serving as cheap osmolytes to facilitate water uptake. Moreover, the retention of K+ under salt treatment, which can counteract the toxicity of Na+, is a protective mechanism for both cultivars. A strong oxidation-reduction process and nucleic acid binding activity under high salinity conditions are two other contributors to the salinity tolerance in both cultivars. We also identified ion transporters including NHXs and H+-PPases for Na+ sequestration and K+ uptake transporters, which can be used as candidate genes for functional studies and potential targets to engineer plants for enhanced salinity tolerance, opening new avenues for future research

A high-resolution marine mercury model MITgcm-ECCO2-Hg with online biogeochemistry

Mercury (Hg) is a global persistent contaminant. Modeling studies are useful means of synthesizing a current understanding of the Hg cycle. Previous studies mainly use coarse-resolution models, which makes it impossible to analyze the role of turbulence in the Hg cycle and inaccurately describes the transport of kinetic energy. Furthermore, all of them are coupled with offline biogeochemistry, and therefore they cannot respond to short-term variability in oceanic Hg concentration. In our approach, we utilize a high-resolution ocean model (MITgcm-ECCO2, referred to as “high-resolution-MITgcm”) coupled with the concurrent simulation of biogeochemistry processes from the Darwin Project (referred to as “online”). This integration enables us to comprehensively simulate the global biogeochemical cycle of Hg with a horizontal resolution of 1/5∘. The finer portrayal of surface Hg concentrations in estuarine and coastal areas, strong western boundary flow and upwelling areas, and concentration diffusion as vortex shapes demonstrate the effects of turbulence that are neglected in previous models. Ecological events such as algal blooms can cause a sudden enhancement of phytoplankton biomass and chlorophyll concentrations, which can also result in a dramatic change in particle-bound Hg (HgaqP) sinking flux simultaneously in our simulation. In the global estuary region, including riverine Hg input in the high-resolution model allows us to reveal the outward spread of Hg in an eddy shape driven by fine-scale ocean currents. With faster current velocities and diffusion rates, our model captures the transport and mixing of Hg from river discharge in a more accurate and detailed way and improves our understanding of Hg cycle in the ocean.</p

Observation of a thermoelectric Hall plateau in the extreme quantum limit

The thermoelectric Hall effect is the generation of a transverse heat current upon applying an electric field in the presence of a magnetic field. Here we demonstrate that the thermoelectric Hall conductivity $\alpha_{xy}$ in the three-dimensional Dirac semimetal ZrTe$_5$ acquires a robust plateau in the extreme quantum limit of magnetic field. The plateau value is independent of the field strength, disorder strength, carrier concentration, or carrier sign. We explain this plateau theoretically and show that it is a unique signature of three-dimensional Dirac or Weyl electrons in the extreme quantum limit. We further find that other thermoelectric coefficients, such as the thermopower and Nernst coefficient, are greatly enhanced over their zero-field values even at relatively low fields.Comment: 17+21 pages, 3+14 figures; published versio

The clinical feature of silent infections of novel coronavirus infection (COVID‐19) in Wenzhou

Here were reported clinical features of silent infected COVID‐19 patients. Our study showed that the prevalence of the silent infection of COVID‐19 is 5.8% (95% CI: 3.4‐9.9%), which is much higher than 1.2% which from the report in China CDC. The silent infection patients were more likely to be young adults, the patients without chronic disease. All of the cases in the presented study was found because they were traced as close contact of confirmed cases. Our study indicated that traced the close contract of confirmed case, long time self‐quarantine, and screening is necessary to prevent the secondary cases in community