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In order to effectively reduce and control the non-metallic inclusions in a GCr15 bearing steel produced by BOF→LF→VD→CC process and improve its product quality， the characteristics and evolution mechanism of inclusions in bearing steel produced by the whole process were analyzed firstly by methods of systematic sampling， automatic analysis and scanning of inclusions and thermodynamic calculation in the present study. The results show that the inclusions in molten steel are mainly MgO-Al2O3 and Al2O3 after the slag melting during LF stage， and they are transformed into CaO-MgO-Al2O3 and CaO-Al2O3 with the size of 1-5 μm in the end of the LF stage. The type of inclusions remains unchanged after VD soft blowing. However， the inclusion density decreases from 16.53 pcs/mm2 in the end of the LF stage to 14.02 pcs/mm2， resulting in an inclusion removal rate of approximately 15.2%. The number density of inclusions in the tundish increases to 16.39 pcs/mm2. The types of inclusions are still mainly CaO-MgO-Al2O3 and CaO-Al2O3， of which 1-2 μm and ＞ 2-5 μm size accounted for 62.8% and 35.6%， respectively. The number of CaS-containing compound inclusions in the billet increases significantly. Thermodynamic calculation explains the evolution causes of the above inclusions. It is found that when the w［Al］s is at 0.02%， the stable existence of MgO-Al2O3 is associated with a significant variation in Mg content， ranging from 0.000 3% to 0.01%， which facilitates the formation of MgO-Al2O3 or CaO-MgO-Al2O3 type inclusions during the production of GCr15 bearing steel. The T.Ca/T.O ratios of the molten steel in LF ending， VD soft blowing process， and tundish were observed to be 0.39， 1.0， and 0.62， respectively； these values align with the theoretical （T.Ca）/（T.O） ratio range （0.13 to 1.25） conducive to the formation of five distinct types of calcium aluminate. As a result， a substantial quantity of calcium aluminate inclusions was detected. During the cooling process of the molten steel， a transformation of inclusions occurs. The liquid calcium aluminate inclusions diminishes， while the quantities of MgO·Al2O3 and CaS inclusions markedly increases.

A coal gangue detection method in coal preparation plant based on YOLOv5s-FSW model is proposed to address the problems of insufficient feature extraction, large parameter quantity, low detection precision, and poor real-time performance in existing coal gangue detection models. This model is improved on the basis of YOLOv5s. Firstly, the C3 module in the Backbone section is replaced with a FasterNet Block structure, which improves detection speed by reducing the number of model parameters and computation. Secondly, in the Neck section, a parameter free SimAM attention mechanism is introduced to enhance the model's attention to important targets in complex environments, further improving the model's feature extraction capability. Finally, in the Prediction layer, the CIoU bounding box loss function is replaced with Wise-IoU, and the model focuses on ordinary quality anchor boxes to improve convergence speed and bounding box detection precision. The results of the ablation experiment indicate that compared with the YOLOv5s model, The mean average precision (mAP) of the YOLOv5s-FSW model has been improved by 1.9%, the model weight has been reduced by 0.6 MiB, the number of parameters has been reduced by 4.7%, and the detection speed has been improved by 19.3%. The comparative experimental results show that the YOLOv5s-FSW model has a mAP of 95.8%, which is 1.1%, 1.5%, and 1.2% higher compared to the YOLOv5s-CBC, YOLOv5s-ASA, and YOLOv5s-SDE models, respectively, and compared to YOLOv5m, YOLOv6s improved by 0.3%, 0.6% respectively. The detection speed of the YOLOv5s-FSW reaches 36.4 frames per second, which is 28.2% and 20.5% higher than the YOLOv5s-CBC and YOLOv5s-ASA models, respectively. Compared to YOLOv5m, YOLOv6s and YOLOv7, the detection speed of the YOLOv5s-FSW has increased by 16.3%, 15.2%, and 45.0%, respectively. The visualization experiment results of the thermal map show that the YOLOv5s-FSW model is more sensitive to the target feature areas of coal gangue and has higher attention. The detection experiment results show that in complex scenes with dim environments, blurred images, and mutual occlusion of targets, the YOLOv5s-FSW model has a higher confidence score for coal gangue target detection than the YOLOv5s model, and effectively avoids the occurrence of false positives and missed detection.

Cysteine (Cys) is closely associated with many physiological and pathological processes in organisms and cells. The establishment of a molecular tool for the rapid and simple selective recognition of Cys would be of great benefit in the diagnosis and prevention of related diseases. In this paper, we developed a turn-on fluorescent probe BMBA, 3-(benzo[d]thiazol-2-yl)-4′-morpholino-[1,1′-biphenyl]-4-yl acrylate, designed with an acryloyl ester group to initiate the reaction and a benzothiazole moiety serving as the fluorescent component. Compared with other biological thiols, the probe BMBA possessed exceptional sensitivity and specificity for detecting Cys, boasting a low detection limit at 28.6 nM and a response duration of merely 5 min. The single-crystal data for the probe BMBA and compound 2 were successfully obtained and the recognition mechanism of Cys was investigated by FTIR spectroscopy and 1H NMR. Most importantly, we effectively utilized BMBA for the detection of Cys in calf serum and living cells. [ABSTRACT FROM AUTHOR]

Timely and accurate tree species mapping is crucial for forest resource inventory, supporting management, conservation biology, and ecological restoration. This study utilized Sentinel-1 and Sentinel-2 data to classify five dominant tree species in Chengde and Beijing. To effectively capture the influence of multi-temporal data, data were acquired in March, June, September, and December 2020, extracting various features, including bands, spectral indices, texture features, and topographic variables. The optimal input variable combination was explored using 1519 field survey samples for training and testing datasets. Classification employed Random Forest, XGBoost, and deep learning models, with performance evaluated through out-of-bag estimation and cross-validation. The XGBoost model achieved the highest accuracy of 81.25% (kappa = 0.74) when using Sentinel-1 and Sentinel-2 bands, indices, texture features, and DEM data. Results demonstrate the effectiveness of using Sentinel data for tree species classification and emphasize the value of machine learning algorithms. This study underscores the potential of combining synthetic aperture radar (SAR) and optical data for large-scale tree species classification, with significant implications for forest monitoring and management. [ABSTRACT FROM AUTHOR]

The effect of cerium content (0, 0.011, 0.017, 0.075 wt%) on non-metallic inclusions and solidification microstructures of 55SiCr high-strength spring steel was experimentally studied, along with thermodynamic calculations. The results show that Ce addition changes the type and size of inclusions in this steel and influences the characteristics of the solidification microstructure. In the sample without Ce addition, the main inclusions are MnS, SiO2, SiO2–MnS, and CaO–SiO2–MgO, and the equiaxed ratio in the solidification structure is 44.63%. However, when Ce content increases to 0.011 wt%, the inclusions in the steel become mainly Ce–S, Ce–O–S, and a small amount of MnS, and the equiaxed ratio increases to 50.42%. As the Ce content increases to 0.017 wt%, the inclusions are predominantly Ce–S, Ce–O–S, and Ce–O–S–Ca, while some Ce–P and Ce–O–P–C inclusions are also observed. The equiaxed ratio increases to 67.63%, showing the best effect on heterogeneous nucleation during solidification. When Ce content in the steel reaches 0.075 wt%, the Ce-containing inclusions are Ce–S, Ce–O, Ce–P, Ce–P–O, and Ce–O–S–As, and the size becomes larger. The formation mechanism of inclusions is explained by Gibbs free energy calculations and thermodynamic diagrams. [ABSTRACT FROM AUTHOR]

To study the flame propagating characteristic and its coupling effect with other parameters in the LPG pipeline, a typical pipeline model with two equal‐length branches perpendicular to each other is designed for experiment and simulation. Then, gas explosion scenarios are experimentally tested and numerically simulated, which is followed by the analysis of flame shape changing with time and peak temperature changing with space. Results show that when passing through the bifurcation, flame propagates to vertical branch B in a sharp knife shape affected by the strong vortex, reflected airflow, and compressed pressure wave in the pipeline with a diameter of 0.125 m. At the monitoring point that is 0.4 m away from the bifurcation point, the peak temperature of the vertical branch B is 57.87% bigger than that of the horizontal branch C, and its arrival time is 80% longer than that of the horizontal branch C, due to the existence of flame in vertical branch B. What's more, in both branches, the coupling results between peak temperature and peak velocity agree very well with the growth function, while the coupling results between peak temperature and peak pressure agree well with the decay function, providing aids to the optimal layout design of industrial pipeline branches as well as to the explosion suppression measures. [ABSTRACT FROM AUTHOR]

Using 4-carboxyl-1-(3-carboxybenzyl) pyridinium chloride (H2LCl) as the organic ligand, a new complex {[Cd2(L)2Cl2(H2O)4]·3H2O} was self-assembled at room temperature with Cd2+ through ambient temperature volatilization. The structure and properties of the complex 1 were characterized by single crystal X-ray diffraction, Hirshfeld surface and two-dimensional fingerprint, powder X-ray diffraction, thermogravimetric analysis, and solid-state fluorescence. The study showed that the complex crystallized in the monoclinic P21/c space group, with two Cd2+ metal centers connected by fully deprotonated ligands, forming two mirror-symmetrical "S" shaped double-chain structures. The rich intermolecular forces such as H…H and O…H helped the complex form a stable three-dimensional supramolecular structure. Thermogravimetric analysis showed that the complex had a good thermal stability. In addition, room temperature fluorescence testing showed that the complex 1 also had a good fluorescence emission ability. [ABSTRACT FROM AUTHOR]