Feature Refinement Method Based on the Two-Stage Detection Framework for Similar Pest Detection in the Field.

Efficient pest identification and control is critical for ensuring food safety. Therefore, automatic detection of pests has high practical value for Integrated Pest Management (IPM). However, complex field environments and the similarity in appearance among pests can pose a significant challenge to the accurate identification of pests. In this paper, a feature refinement method designed for similar pest detection in the field based on the two-stage detection framework is proposed. Firstly, we designed a context feature enhancement module to enhance the feature expression ability of the network for different pests. Secondly, the adaptive feature fusion network was proposed to avoid the suboptimal problem of feature selection on a single scale. Finally, we designed a novel task separation network with different fusion features constructed for the classification task and the localization task. Our method was evaluated on the proposed dataset of similar pests named SimilarPest5 and achieved a mean average precision (mAP) of 72.7%, which was better than other advanced object detection methods.

Population dynamics of migrant wheat aphids in China's main wheat production region and their interactions with bacterial symbionts.

Sitobion miscanthi, Rhopalosiphum padi, and Schizaphis graminum are the three main pests in Chinese wheat-producing regions. In 2020, they are classified into the Chinese Class I list of agricultural diseases and pests, due to their severe harm to wheat plantings. S. miscanthi, R. padi, and S. graminum are migrant pests, and understanding their migration patterns and simulating their migration trajectories would improve forecasting and controlling them. Furthermore, the bacterial community of the migrant wheat aphid is also less known. In this study, we employed a suction trap to uncover the migration patterns of the three wheat aphid species in Yuanyang county, Henan province, during 2018 to 2020. And then the migration trajectories of S. miscanthi and R. padi were simulated using the NOAA HYSPLIT model. The interactions between wheat aphids and bacteria were further revealed by specific PCR and 16S rRNA amplicon sequencing. The results showed that the population dynamics of migrant wheat aphids was varied. Most of the trapped samples were identified to be R. padi, and S. graminum was the least collected sample. Typically, R. padi had two migration peaks in the 3 years, whereas S. miscanthi and S. graminum only exhibited one migration peak in 2018 and 2019. Moreover, the aphid migration trajectories varied over the years. Generally, the aphids originated from the south and migrated to the north. Herein, the infections of three main aphid facultative bacterial symbionts, Serratia symbiotica, Hamiltonella defensa, and Regiella insercticola, were detected in S. miscanthi and R. padi with specific PCR. Rickettsiella, Arsenophonus, Rickettsia, and Wolbachia were further identified with 16S rRNA amplicon sequencing. Biomarker searching indicated that Arsenophonus was significantly enriched in R. padi. Furthermore, diversity analyses showed that the bacterial community of R. padi had a higher richness and evenness than that of S. miscanthi. In conclusion, this study expands our knowledge about the migration patterns of aphids in the main wheat plant region of China and reveals the interactions between bacterial symbionts and migrant aphids.

Research on the identification and detection of field pests in the complex background based on the rotation detection algorithm.

As a large agricultural and population country, China's annual demand for food is significant. The crop yield will be affected by various natural disasters every year, and one of the most important factors affecting crops is the impact of insect pests. The key to solving the problem is to detect, identify and provide feedback in time at the initial stage of the pest. In this paper, according to the pest picture data obtained through the pest detection lamp in the complex natural background and the marking categories of agricultural experts, the pest data set pest rotation detection (PRD21) in different natural environments is constructed. A comparative study of image recognition is carried out through different target detection algorithms. The final experiment proves that the best algorithm for rotation detection improves mean Average Precision by 18.5% compared to the best algorithm for horizontal detection, reaching 78.5%. Regarding Recall, the best rotation detection algorithm runs 94.7%, which is 7.4% higher than horizontal detection. In terms of detection speed, the rotation detection time of a picture is only 0.163s, and the model size is 66.54MB, which can be embedded in mobile devices for fast detection. This experiment proves that rotation detection has a good effect on pests' detection and recognition rate, which can bring new application value and ideas, provide new methods for plant protection, and improve grain yield.

Cleaning Disposal of High-Iron Bauxite Residue Using Hydrothermal Hydrogen Reduction.

The hydrothermal hydrogen reduction process for treating high-iron bauxite residue (red mud) was investigated, and the optimum conditions of alumina extraction as well as the enrichment of iron minerals were verified by experiments. Results show that the surface magnetization of Al-goethite under the function of hydrogen reduction accelerates its conversion to hematite and/or magnetite. This conversion releases the substituted Al in goethite as well as the undigested gibbsite/boehmite and further enriches the iron content in residue. After hydrothermal hydrogen reduction with H2/Red mud ratio of 0.085 mol/20 g at 270°C for 60 min, the alumina relative recovery ratio reaches 95.40% and the grade of iron (total iron in the form of iron element) in the residue can be enriched to 55.85%. Further, co-processing of the obtained iron-rich residue in the steel industry can achieve a significant reduction of red mud discharge.

Low-temperature thermal conversion of Al-substituted goethite in gibbsitic bauxite for maximum alumina extraction.

The conversion of Al-substituted goethite (Al-goethite) to hematite in gibbsitic bauxite is conducive to alumina extraction during the Bayer process and the enrichment of iron minerals in red mud. In this work, mineralogical characteristics of gibbsitic bauxite were identified by AMICS analysis, and the low-temperature thermal conversion behavior of both synthetic Al-goethite and natural Al-goethite in gibbsitic bauxite were investigated through thermal gravity analysis, phase transformation, and microstructure studies. Results show that the proportion of aluminum in Al-goethite reached 12.68% of the total aluminum content in gibbsitic bauxite. The conversion of synthetic Al-goethite to hematite starts at ∼280 °C, while that of natural Al-goethite starts at ∼320 °C, and the addition of NaOH can accelerate the conversion. The formed hematite inherits the needle-like appearance of the original Al-goethite, has many holes on the surface due to dehydroxylation, and no migration of aluminum elements occurs during the roasting process, indicating that Al-goethite transformed into porous Al-substituted hematite (Al-hematite), which is beneficial to the extraction of the aluminum retained in the hematite structure during Bayer digestion. To confirm the above results, digestion experiments (without or with roasting for typical Bayer digestion or low-temperature roasting-Bayer digestion) were carried out with gibbsitic bauxite and the one roasted at 400 °C for 30 min as raw materials, respectively. Compared to the typical Bayer digestion, the relative alumina recovery of low-temperature roasting-Bayer digestion increased from 90.06% to 95.65%, the red mud yield decreased from 36.32% to 34.08%, and the grade of Fe in red mud increased from 48.45% to 52.88% at 270 °C for 60 min. Enhanced transformation of Al-goethite significantly improves alumina recovery and the resultant iron-rich red mud can be easily co-processed in the steel industry, thus significant emission reduction of red mud from the Bayer system might be achieved.

Dealing with pandemics: An investigation of the effects of COVID-19 on customers' evaluations of hospitality services.

The hospitality industry is highly vulnerable to pandemics. However, little is known about how pandemics alter travelers' evaluations of hospitality services. Therefore, this study investigates the changes in travelers' expectations and perceptions of hotel services during different stages of the novel coronavirus 2019 (COVID-19) pandemic. 98,163 Chinese hotel reviews were collected and scrutinized via text mining and sentiment analysis techniques to derive new implications for service optimization. The results reveal shifts in consumers' evaluations well beyond hygienic requirements. Insights obtained from this research can help guide hospitality practice in organizing its priorities during acute pandemic situations and adjusting to possibly longer-lasting shifts in consumer preferences.