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Summary Drought is an abiotic stress that affects plant growth, and lipids are the main economic factor in the agricultural production of oil crops. However, the molecular mechanisms of drought response function in lipid metabolism remain little known. In this study, overexpression (OE) of different copies of the drought response genes LEA3 and VOC enhanced both drought tolerance and oil content in Brassica napus and Arabidopsis. Meanwhile, seed size, membrane stability and seed weight were also improved in OE lines. In contrast, oil content and drought tolerance were decreased in the AtLEA3 mutant (atlea3) and AtVOC‐RNAi of Arabidopsis and in both BnLEA‐RNAi and BnVOC‐RNAi B. napus RNAi lines. Hybrids between two lines with increased or reduced expression (LEA3‐OE with VOC‐OE, atlea3 with AtVOC‐RNAi) showed corresponding stronger trends in drought tolerance and lipid metabolism. Comparative transcriptomic analysis revealed the mechanisms of drought response gene function in lipid accumulation and drought tolerance. Gene networks involved in fatty acid (FA) synthesis and FA degradation were up‐ and down‐regulated in OE lines, respectively. Key genes in the photosynthetic system and reactive oxygen species (ROS) metabolism were up‐regulated in OE lines and down‐regulated in atlea3 and AtVOC‐RNAi lines, including LACS9,LIPASE1,PSAN,LOX2 and SOD1. Further analysis of photosynthetic and ROS enzymatic activities confirmed that the drought response genes LEA3 and VOC altered lipid accumulation mainly via enhancing photosynthetic efficiency and reducing ROS. The present study provides a novel way to improve lipid accumulation in plants, especially in oil production crops.

The promotion of the level of social urbanization puts forward higher requirements for the functionality of the city, and it is the most important auxiliary for the city function to play and reflect. The utilization of PPGIS in urban-rural schematization incalculably accelerates the improvement and development of urban-rural schematization level. Based on this, this paper first analyses the connotation, typical features and functions of PPGIS, then studies the utilization of PPGIS in urban-rural schematization, and finally gives the utilization strategies of PPGIS and network info tech in urban-rural schematization.

At present, the classification system of urban and rural planning land still lacks the division of land functions, especially the in-depth study of land data conversion, which leads to the lack of effective use of land spatial classification data and the failure to establish effective classification system criteria. Based on this, this paper first analyses the construction of urban-rural planning land classification system and land type conversion convergence criteria, then studies the land type recognition based on multi-source data of IoT, and finally gives the optimization strategy of urban-rural planning land classification recognition based on multi-source data of IoT.

Broadband low-frequency vibration and shock energies are ubiquitous such as biomechanical motion, which can be harvested to power wearable electronics. This paper proposes a compact design of V-shaped piezoelectric vibration energy harvester (V-PVEH) with impact stopper. To demonstrate V-PVEH having high power density, Euler beam model is proposed for qualitative comparison between V-PVEH and cantilevered piezoelectric vibration energy harvester (C-PVEH). FEA model in COMSOL for V-PVEH structure design is proposed especially for the stress check. Modal analysis, two bimorphs connection style, tip mass thickness, and acceleration amplitude are discussed in the experimental vibration validation. A peak voltage of 11.5 V at a low resonant frequency of 12 Hz and a maximum power of 0.442 mW are shown in experiments under the excitation of 0.1 g. A lumped parameters model with nonlinearity analysis for impact induced broadband and shock input is discussed comprehensively. The stopper design in V-PVEH can not only limit the vibration amplitude and prevent overload, but also form broadband of 8−15 Hz and generate large voltage output of 5−19 V when impact occurs at an acceleration of 0.4 g. Except for resonating excitation, biomechanical shock energy harvesting with ultra-low frequency of 1 Hz is testified for wearable V-PVEH to charge a 10 μF capacitor to 10 V in 5 s by stamping feet. Above all, V-PVEH with stopper is believed to show good performance in broadband low-frequency vibration and biomechanical shock energy harvesting.