A development potential assessment method for clean energy stations

Clean energy is expected to enter a new stage of large-scale development along with the growing demand for building regional clean energy stations. However, as many regional clean energy stations comprise multiple stations with different output characteristics and complementary coupling, the development potential of these stations cannot be simply based on the superposition of outputs, as this method lacks reasonable assessment results. This study proposes a method of combining Grey relational analysis (GRA), artificial neural network (ANN), and XGBoost algorithm for the potential assessment of clean energy stations. First, GRA and ANN are used for the relational analysis between the output of clean energy stations and meteorological factors. Second, the meteorological factors with high correlation and the existing historical data are used to predict the future outputs of new clean energy stations via XGBoost. Finally, according to the predicted output, an assessment method that includes available capacity coefficient (AOC) and other evaluation indicators is proposed. The case studies in this research prove the effectiveness and applicability of the proposed method

Will power company be profitable from non-utility-owned distributed generators planning with peer-to-peer strategy?

With the high penetration of renewable energy integrated into distribution networks, distributed generators (DGs) are encouraged to participate in market competition with a “peer-to-peer” (P2P) strategy. The operation strategy of the distribution network is increasingly characterized by weak centralization and decentralization. The traditional centralized operation strategy of the distribution network is difficult to ensure the efficiency and effectiveness of terminal energy consumption calculation and equipment regulation, which increases the complexity of distributed energy interactive operation cost calculation and subsequent planning scheme evaluation. Consequently, to enhance the penetration of DGs in distribution networks and ensure their economic operation, the distribution network planning calls for market-oriented integration reform and theoretical innovation. Hence, this paper investigates whether P2P strategy has a profitable and attractive point for power companies if non-utility-owned DGs are integrated into distribution networks. An investment planning scheme of the distribution network is presented to improve the profit of the power company. Network usage charges (NUC) is introduced to provide charge service for both parties of power transaction and optimize the distribution network planning and operation strategy. The profit of power companies is maximized by NUC while the economic benefit of non-utility-owned DGs is also taken into account. The effectiveness and availability of non-utility-owned DGs planning with P2P strategy on investment planning profit are illustrated by the numerical case studies

Isolation of N-Ethyl-2-pyrrolidinone-Substituted Flavanols from White Tea Using Centrifugal Countercurrent Chromatography Off-Line ESI-MS Profiling and Semi-Preparative Liquid Chromatography

N-Ethyl-2-pyrrolidinone-substituted flavanols (EPSF) are marker compounds for long-term stored white teas. However, due to their low contents and diasteromeric configuration, EPSF compounds are challenging to isolate. In this study, two representative epimeric EPSF compounds, 5'''R- and 5'''S-epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone (R-EGCG-cThea and S-EGCG-cThea), were isolated from white tea using centrifugal partition chromatography (CPC). Two different biphasic solvent systems composed of 1. N-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v) and 2. N-hexane-ethyl acetate-acetonitrile-water (0.7:3.0:1.3:5.0, v/v/v/v) were used for independent pre-fractionation experiments; 500 mg in each separation of white tea ethyl acetate partition were fractionated. The suitability of the two solvent systems was pre-evaluated by electrospray mass-spectrometry (ESI-MS/MS) analysis for metabolite distribution and compared to the results of the CPC experimental data using specific metabolite partition ratio KD values, selectivity factors α, and resolution factors RS. After size-exclusion and semi-preparative reversed-phase liquid chromatography, 6.4 mg of R-EGCG-cThea and 2.9 mg of S-EGCG-cThea were recovered with purities over 95%. Further bioactivity evaluation showed that R- and S-EGCG-cThea possessed in vitro inhibition effects on α-glucosidase with IC50 of 70.3 and 161.7 μM, respectively

Screening and evaluation of selenium-rich maize cultivars in Ziyang area

To study selenium (Se)-enriched characteristics of maize in Ziyang area and to select cultivars, six cultivars were planted on three different soils with high-Se, middle-Se and low-Se. The Se content of grain, stalk & leaf and cob were tested separately, and the relationship between Se content in soil and the capability of Se-enrichment in different organs of six cultivars were analyzed. The result showed that the Se content of maize organs is positively correlated with the Se in soil. Meanwhile, on the soil with different Se content, the trends of Se-enriching capacity in different organs of maize cultivars were as follows: stalk & leaf > grain > cob. Further comparison of the ratio of the Se content of various organs to the Se content of soil showed that, the maize planted on the middle-Se soil has the highest capability of Se-enrichment. Considering the biomass, the accumulation of Se in the grains of sweet maize Shaan K512 and waxy maize Shaan K818 were relatively higher. This study has implications for Se-rich maize and comprehensive utilization of Se in Ziyang

Pygo2 Associates with MLL2 Histone Methyltransferase and GCN5 Histone Acetyltransferase Complexes To Augment Wnt Target Gene Expression and Breast Cancer Stem-Like Cell Expansion▿

Resent studies have identified Pygopus as a core component of the β-catenin/T-cell factor (TCF)/lymphoid-enhancing factor 1 (LEF) transcriptional activation complex required for the expression of canonical Wg/Wnt target genes in Drosophila. However, the biochemical involvement of mammalian Pygopus proteins in β-catenin/TCF/LEF gene activation remains controversial. In this study, we perform a series of molecular/biochemical experiments to demonstrate that Pygo2 associates with histone-modifying enzymatic complexes, specifically the MLL2 histone methyltransferase (HMT) and STAGA histone acetyltransferase (HAT) complexes, to facilitate their interaction with β-catenin and to augment Wnt1-induced, TCF/LEF-dependent transcriptional activation in breast cancer cells. We identify a critical domain in Pygo2 encompassing the first 47 amino acids that mediates its HMT/HAT interaction. We further demonstrate the importance of this domain in Pygo2's ability to transcriptionally activate both artificial and endogenous Wnt target genes and to expand breast cancer stem-like cells in culture. This work now links mechanistically Pygo2's role in histone modification to its enhancement of the Wnt-dependent transcriptional program and cancer stem-like cell expansion