Hybrid energy storage configuration method for wind power microgrid based on EMD decomposition and two-stage robust approach.

Data centers are usually characterized by high energy loads, which raises increasing sustainability concerns in both academic and daily usage. To mitigate the uncertainty and high volatility of distributed wind energy generation, this paper proposes a hybrid energy storage allocation strategy by means of the Empirical Mode Decomposition (EMD) technique and the two-stage robust method. First, this paper conducts the evolution analyses for the over- and under-evaluated uncertainty of wind power fluctuation under different time scales. Second, we employ the EMD technique to configure a high-frequency flywheel energy storage device, realizing the wind power transformation from large fluctuations to small fluctuations and the convergence of the wind power fluctuation curves in minute- and hour levels. Finally, based on the hour-level wind energy stable power curves, we carry out two-stage robust planning for the equipment capacity of low-frequency cold storage tanks and lithium bromide chillers. The case study on a data center microgrid in northeastern China confirms the effectiveness of our proposed strategy.

Expression and Clinical Significance of Ki67 and SOX2 in Colorectal Cancer.

The purpose of the paper is to explore the expression levels and clinical significance of Ki67 and sex-determining region Y-box 2 (SOX2) in colorectal cancer. From January 2013 to December 2016, 176 patients with colorectal cancer who were pathologically diagnosed after surgery in the Department of General Surgery in Xiamen Chinese Medical Hospital are included in this study. The pathological parameters, including gender, age, pathological stage, depth of tumor invasion, lymph node metastasis, and distant metastasis, are recorded. Immunohistochemistry is used to detect the correlation between Ki67 and Sox2 protein expression and clinicopathological parameters in colorectal cancer. Immunohistochemistry shows that in each stage of colorectal cancer, the positive rate of SOX2 is higher than that of Ki67, and the sensitivity of SOX2 is relatively high. Moreover, the levels of Ki67 and SOX2 in the cancerous tissues are not related to gender, age, lymph node metastasis and distant metastasis (p > 0.05).