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The intermittent and fluctuating generation power of PV power plants has an increasingly prominent impact on the safe， stable， and economical operation of power grids. Therefore， it is required to continuously improve the accuracy of PV power prediction to provide accurate information for flexible grid dispatching and planning. First， the prediction algorithm， characteristic equation， prediction process， and evaluation index of short-term PV generation power are introduced. Afterward， the features constructed in the training set are analyzed and filtered using the SHAP， and the training is performed using the CatBoost. Finally， by comparing the prediction accuracy with other machine learning algorithm models using the same features， the paper indicates that the proposed method can improve the prediction performance and confirms the advantages of the CatBoost that incorporates multidimensional feature models in PV power prediction.

Stable nickel (Ni) isotopes have shown great potential for investigating planetary accretion processes, mantle–crust magmatism, and paleo-marine evolution. The development of an economical and time-efficient separation method for Ni isotope analysis holds significant value within the realm of Ni isotope research. Previous purification methods for Ni isotope analysis have typically relied on either multi-column procedures or the utilization of significant quantities of organic reagents, such as acetic acid, acetone, and dimethylglyoxime. In this study, a novel two-column chromatographic separation procedure was presented for the determination of Ni isotope compositions in geological materials. A cation resin (AG50W-X8) was utilized in conjunction with diluted HCl and HF to effectively remove a substantial portion of matrix elements. Subsequently, trace amounts (100–200 μL) of Ni-spec resin were used for further purification of Ni. This relatively simple purification scheme for Ni isotope analysis effectively reduces the use of organic reagents and the amount of Ni-spec resin compared to previous methods that relied on multi-column separation and organic reagent extraction. Ni isotopic compositions were analyzed using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The instrumental mass discrimination of Ni isotopic ratios was corrected for using the double spike (DS) combined with the sample–standard bracketing (SSB) method. The Ni isotope compositions (δ60Ni) of in-house standards (SCP and CUG) were −0.06 ± 0.05‰ (2 SD, n = 104) and 0.36 ± 0.06‰ (2 SD, n = 97), respectively. Furthermore, the measured δ60Ni values of various geological reference materials (BCR-2, BHVO-2, BIR-1, DTS-1, DTS-2b, SDO-1, GSP-2, and W-2a from the USGS; JB-1b from the GSJ; GSR-2, GSR-3, GSR-4, GSR-5, and GSR-10 from the NRCGA) were consistent with previous studies within measurement error. Additionally, the δ60Ni values of AGV-1 from the USGS, as well as those of GSR-10, GSR-12, GSR-15, GSR-17, GSR-18, and GSR-19 from the NRCGA are reported here for the first time. Based on repeated measurements of pure solutions and reference materials, the long-term reproducibility of δ60Ni values was better than ± 0.06‰ (2 SD). Consequently, our study presents a relatively straightforward purification method for Ni for its isotopic analysis using only trace amounts of organic reagents and Ni-spec resin. [ABSTRACT FROM AUTHOR]

Abstract Background Enhanced recovery after surgery (ERAS) pathway in spine surgery is increasingly popular which can reduce the length of hospital stay (LOS). However, there are few studies on the safety and effectiveness of ERAS pathway in the treatment of single-level lumbar disc herniation (LDH) by percutaneous endoscopic transforaminal discectomy (PETD). The aim of this study was to investigate whether ERAS can reduce LOS of patients with single segment LDH treated by PETD. Methods We reviewed the outcomes of all LDH patients (L4/5) who had been treated with PETD at our institution. Quasi-experimental study was adopted between patients treated in an ERAS after PETD with those rehabilitated on a traditional pathway. The two groups were analyzed for LOS, operation time, complications, visual analog scale (VAS), Oswestry Dysfunction Index (ODI), hospitalization expenses (HE), and improved MacNab efficacy assessment criteria (MacNab). Results A total of 120 single segment LDH patients (ERAS pathway 60 cases, traditional care pathway 60 cases) who were selected from January 2019 to January 2021 met the inclusion criteria. There was a significant difference in mean LOS postoperative VAS scores and ODI on the 3rd day after surgery between the two groups (P < 0.05). The incidence of complications and HE were similar in the two groups (P > 0.05). The mean LOS decreased from 3.47 ± 1.14 days to 5.65 ± 1.39 days after application of ERAS pathway (P < 0.05). Conclusions The ERAS pathway reduced LOS without resulting in additional complications after PETD. These findings support the application of the perioperative ERAS pathway in the treatment of single-level LDH with PETD. Level of evidence Level IV, therapeutic