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Mastering the changes in the planting area of crops are critical for formulating sustainable agricultural development strategies. The Landsat 9 satellite provides continuous observational data for crop mapping. It is necessary to evaluate the potential of Landsat 9 images for canola mapping. According to literatures, some canola indices have been proposed in relation to the spectral features of the yellow canola flower, such as the canola ratio index (CRI), normalised difference yellowness index (NDYI), canola index (CI), canola flower index (CFI), normalised difference rapeseed flower index (NRFI) and winter rapeseed index (WRI). However, it is unclear which index has more potential to extract canola based on the Landsat 9 images. Therefore, the potentials of these indices for canola mapping were quantitatively compared by using different classification methods including supervised and unsupervised classification methods. For supervised classification methods and the CFI, the overall accuracy of canola mapping was above 90% and the kappa coefficient was above 0.8. For unsupervised classification methods, CFI also performs best. It was demonstrated that the CFI outperformed the other five indices for canola mapping. It was also confirmed that Landsat 9 images and the CFI exhibit promising potential for canola mapping via quantitative comparison. [ABSTRACT FROM AUTHOR]

Landsat-9 is the latest satellite of the Landsat program and provides useful agricultural remote sensing data. The earlier the crop distribution data is obtained, the greater the value of the data. However, whether Landsat-9 image is suitable for the early-season mapping of winter garlic and winter wheat is a problem worthy of attention. Therefore, this study evaluates the potential to use two Landsat-9 images, acquired on 13 December 2021 and 30 January 2022, for the early-season identification of winter garlic and winter wheat in China. According to J-M (Jeffries-Matusita) distances, we evaluated the separability of winter garlic, winter wheat, and other ground objects based on the two Landsat-9 images. Then, winter garlic and winter wheat were extracted by using unsupervised classification method, i.e. the IsoData and K-means clustering algorithms, and supervised classification method, i.e. the Random Forest (RF), and Support Vector Machine (SVM) algorithms. The separability between garlic and wheat in January is stronger than that in December. The classification overall accuracy based on the Landsat-9 image on 30 January 2022 is 92.03% with a kappa coefficient of 0.87 using the SVM algorithm. This period is about 4 months earlier than the crop harvest period. Landsat-9 images have good potentiality for early-season mapping of winter garlic and winter wheat. [ABSTRACT FROM AUTHOR]

In this paper, by using the Riccati transformation and integral inequality technique, we establish several oscillation criteria for second-order Emden–Fowler neutral delay differential equations under the canonical case and non-canonical case, respectively. Compared with some recent results reported in the literature, we extend the range of the neutral coefficient. Therefore, our results generalize to some of the results presented in the literature. Furthermore, several examples are provided to illustrate our conclusions. [ABSTRACT FROM AUTHOR]

In view of the large proportion of thin and poor layers in the weak-alkali ternary flooding block, the statistical analysis method is used to optimize the division of well groups with injection capacity, establish a strategy chart for different types of groups to maintain injection and tap potential, and optimize the well groups of different sand body connectivity types. The fracturing method strengthens the whole process of fracturing in the well area with poor injection capacity. The effective thickness water absorption ratio is over 80%, the maximum water cut reduction in the stage is 9.65%, the low water cut stable period is 16 months, and the recovery factor is increased by 8.77 percentage points. development effect.

The development of heterogeneous Fenton catalysts with good performance and stability is a challenge in the field of wastewater treatment. In this work, MgAlFe hydrotalcite-like compounds (MgAlFe-HTLcs) were prepared by solid phase reaction at room temperature and modified via a hydrothermal process. The experimental results showed that MgAlFe-HTLcs had a good layered structure with the same proportion of iron and aluminium, 18 h of crystallisation time and 110°C of crystallisation temperature and the lamellar structure was more uniform by solid grinding. Furthermore, the addition of iron can activate H2O2 more effectively to generate active oxygen which is •OH. The degradation experiments demonstrated that nearly 99.0% degradation efficiency was achieved for 10 mg/L Malachite Green (MG) solution within 60 min at the conditions of 0.10 g·L−1 MgAlFe-HTLcs, 0.10 mol·L-1 H2O2 and a natural pH of 6.3. Total organic carbon (TOC) removal reached 72.2% in a 70 min reaction. BET and XRD were measured to further discuss the stability and durability. Finally, a possible mechanism for the degradation of MG was presumed. [ABSTRACT FROM AUTHOR]