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To explore the occurrence dynamics and infection characteristics of citrus target spot, and screen effective fungicides and provide data support for citrus safe production. Two orchards with different altitudes and different management levels in Shuangshi community and Baiyan Village of Wanzhou District Chongqing city were selected to follow up the occurrence of citrus target spot. At the same time, the inhibition effects of 6 compound fungicides to Pseud of abraea Citricarpa (Citrus Target spot) were determined by the mycelial growth rate inhibition method. The results showed that, in December of 2021 to March of 2022, in the 2 orchards, the average disease spot, number of falling leaf showed a trend of reduce after the first rise, and incidence and disease index were characterized by rising gradually along with the passage of time. From late to the end of January, there were more rainy and foggy days, and the temperature dropped sharply, which aggravated the defoliation. Orchard 1 was with higher altitude 750 m and loose management, and the disease outbreak came more rapidly and severely. While in orchard 2, the lower altitude, higher management level and stronger tree made the disease be later and lighter than orchard 1. Further studies of compound fungicide screening showed that the EC50 against Ps. Citricarpa, from low to high, was 40% Tebuconazole·Prochloraz (0.03295)

In recent years, with the rapid development of the sericulture industry, the pests of mulberry trees are also increasing. Diaghania pyloalis Walker is one of the main pests of mulberry trees, has strong fecundity and very large food intake, especially in Sichuan and Chongqing areas. In order to find out the insecticides which can effectively control D. pyloalis, the screening test of high-efficiency control efficacy was carried out. In the summer of 2020, the 3rd instar larvae of D. pyloalis were selected as the test objects, and the indoor bioassay of 10 insecticides on D. pyloalis was carried out, and the results of the indoor bioassay were tested by field experiments in the autumn. The results show that 2000 times liquid of Dursban, Spinetoram, Chlorantraniliprole, and 1000 times liquid of Dichlorvos and Phoxim had the best control effect on D. pyloalis. Secondly, 2000 times liquid of Imidacloprid and Chlorfenapyr had the better control effect on D. pyloalis. Finally 2000 times liquid of Pymetrozine and Cyromazine had poor control effect, and 1000 times liquid of Azadirachtin had the worst control effect on D. pyloalis. To control D. pyloalis, 2000 dilution of Dursban and Spinetoram, and 1000 times liquid of Dichlorvos can be used in sericultural production. When using Chlorantraniliprole to control D. pyloalis, the leaves of mulberry should be picked with long interval to avoid affecting the quality of cocoons, and it is not recommended to use Cyromazine, Azadirachtin to control D. pyloalis.

MXenes were outstanding materials for aqueous environment remediation, MXenes with a high capacity for radionuclides uranium (U(VI)) remains a challenge. In this study, a noval polydopamine functionalized MXene (defined as MXene@PDA) was successfully synthesised and evaluated for the aggregation towards U(VI) from wastewater. Versatile PDA owing functional groups provided more sites to capture contaminant ions. The mechanism research with MXene@PDA was explored by batch experiments toghther with the XPS analyses. The results revealed MXene@PDA with abundant functional groups exhibited superior elimination ability (90.4 mg/g) at pH = 5.0. The mechanism of U(VI) on MXene@PDA was primarily ascribed to the surface complexation force between the UO22+ and -OH, NH2 groups. The PDA modification of MXene materials are proved to be excellent materials for the extraction of radionuclides in the aqueous solution.

The dual pressure of energy crisis and environmental pollution has prompted the world’s energy sector to change in the direction of clean, efficient, sustainable and pollution-free, and RIES (Regional Integrated Energy System) has emerged. The deployment of energy storage devices in the RIES can deepen the connection of each energy system, release the spatial and temporal constraints of multiple energy sources, and thus improve the energy utilization and economy of the integrated energy system. Based on the infrastructure and model of the RIES, this paper studied the synergistic optimal configuration of electricity storage, power-to-gas (P2G) technology, cooling storage and heating storage in the case of multi-energy complementation operation of combined cooling, heating and power supply (CCHP) unit and other equipment. Firstly, an optimal configuration model of multiple energy storage in the RIES based on the optimal operational economy was proposed. Then, the economics and feasibility of configuring different energy storage combinations in the system were analyzed. Finally, the benefits of energy storage devices in the regional integrated energy system were quantified and analyzed by the economic indicators and low carbon emissions reduction indicators. By employing an industrial district RIES in northern China as the study case, the operation scheduling scheme and energy storage allocation scheme were solved by the optimization model proposed in this paper. The results show that the RIES containing multiple types of energy storage can consume more distributed new energy, improve economic efficiency and reduce carbon emissions. And this model has a good application prospect.

Hazard and operability study (HAZOP), which is applied to identify the hazards of a system and its operability, finds application in identifying unsafe behaviors of operators after redefining the “guide words” and “process requirements”. In this paper, unsafe behaviors of lifting workers on the construction site and the risk they brought were identified using the redefined HAZOP. Then, the causes of these behaviors were revealed after sorting and analysing these behaviors.. Finally, based on these causes, appropriate management measures were developed for effectively reducing accidents in lifting operations.

Narrow-beamwidth antenna is applied to LEO satellite constellations to provide high-speed internet services for the globe. Low-altitude, limited coverage region of single satellite and large scale are the main features of them. In this paper, under the constraint of specified half-beam angle of antenna, both inclined and polar orbit constellations are analysed based on Streets-of-Coverage method to provide continuous coverage. The results indicate that the coverage performance of single satellite is the key factor which can affect the configuration and number of constellations. When the orbit altitude is 1200 km and half-beam angle is 32 degrees, up to thousands of satellites are required for constellations providing internet services for zonal region 60 degrees from the equator. Non-symmetrical polar constellations show the best performance of continuous coverage and require approximately half of the satellites of inclined orbit constellations. The required satellites with different single coverage performance are also investigated as a reference for future research.

To develop a coupled rotor/flexible fuselage model for vibration reduction studies, the equation of coupled rotor-fuselage is set up based on the theory of multi-body dynamics, and the dynamic analysis model is established with the software MSC.ADMAS and MSC.NASTRAN. The frequencies and vibration acceleration responses of the system are calculated with the model of coupled rotor-fuselage, and the results are compared with those of uncoupled modeling method. Analysis results showed that compared with uncoupled model, the dynamic characteristic obtained by the model of coupled rotor-fuselage are some different. The intrinsic frequency of rotor is increased with the increase of rotational velocities. The results also show that the flying speed has obvious influence on the vibration acceleration responses of the fuselage. The vibration acceleration response in the vertical direction is much higher at the low speed and high speed flight conditions.