A Novel Z-Type Self-Balancing Modular Multilevel Converter for Flywheel Driving Applications

With the development of flywheel technology, the speed and the voltage level of flywheel continue to increase. The Z-type self-balancing modular multilevel converter can have a wide frequency range at medium voltage and is suitable for flywheel driving application. However, the voltage and current characteristics of the flywheel and the variable frequency drive still affect capacitor voltage balance in each phase-leg. The new balance of capacitor voltage can be achieved by controlling the circulating current. This paper proposed a control algorithm of the novel Z-type self-balancing modular multilevel converter for flywheel driving applications. Simulation results are presented to validate the theoretical analysis

Multi-scenario simulation of spatial structure and carbon sequestration evaluation in residential green space

As an important component of urban green space, residential green space is crucial in improving the carbon sequestration performance of urban ecosystem. At present, there is a lack of spatial analysis on the carbon sequestration performance of residential green space. Taking the main urban area of Nanjing as an example, the study firstly adopted ENVI-met, normalized difference vegetation index (NDVI) and net primary productivity (NPP) remote sensing estimation model to calculate the carbon sequestration performance of residential green space, and then carried out the coupling analysis on the results with the spatial characteristics of green space. Results showed that the residential green space with scattered layout present higher carbon sequestration performance; the ratio of trees and shrubs was the most critical factor affecting the carbon sequestration performance of residential green space; a suitable microclimate environment was a prerequisite to ensure high carbon sequestration performance of green space. The study revealed the spatial characteristics of residential green space that affected carbon sequestration performance, and provided a new method to calculate carbon sequestration performance of green space at microclimate scales, which pointed out a new direction for future sustainable urban development

A Novel Z-Type Self-Balancing Modular Multilevel Converter for Flywheel Driving Applications

With the development of flywheel technology, the speed and the voltage level of flywheel continue to increase. The Z-type self-balancing modular multilevel converter can have a wide frequency range at medium voltage and is suitable for flywheel driving application. However, the voltage and current characteristics of the flywheel and the variable frequency drive still affect capacitor voltage balance in each phase-leg. The new balance of capacitor voltage can be achieved by controlling the circulating current. This paper proposed a control algorithm of the novel Z-type self-balancing modular multilevel converter for flywheel driving applications. Simulation results are presented to validate the theoretical analysis

Carbon Sink Performance Evaluation and Socioeconomic Effect of Urban Aggregated Green Infrastructure Based on Sentinel-2A Satellite

Aggregated green infrastructure is the only element that has a relatively concentrated and well-functioning carbon sink in the city. It plays an important role in achieving carbon neutrality in urban areas with dense functions and scarce carbon sink resources. However, in contrast to other regions, aggregated green infrastructure carbon sink performance is more influenced by socioeconomic activities in urban centres. There is a lack of research on the impact between carbon sink performance and socioeconomic activities at the urban scale. In this study, we evaluated the carbon sink performance (i.e., carbon sink and location entropy) of aggregated green infrastructure and its interaction with socioeconomic activities at the urban scale based on Sentinel-2A satellite. The results showed that: (1) Aggregate green infrastructures with high carbon sink performance have significant aggregation characteristics in urban areas. (2) Aggregated green infrastructure with poor carbon sink performance tended to be surrounded by dense socioeconomic activities. Our study provides a new approach to the assessment of carbon sink performance of aggregated green infrastructure at the urban scale. More importantly, we make a new attempt to assess the association between carbon sink performance and socioeconomic activities of urban aggregated green infrastructure. These results point to a new direction for the realization of carbon neutrality in cities

Table_1_Causal relationship of genetically predicted gut microbiota with thyroid cancer: a bidirectional two-sample mendelian randomization study.xls

BackgroundPrevious investigations have demonstrated a correlation between the composition of gut microbiota and the development of thyroid cancer (TC). Nonetheless, there was no consensus on the causal effect of gut microbiota composition on TC risk. Therefore, the present study aimed to perform a bidirectional two-sample Mendelian randomization (MR) analysis to explore potential causal associations between gut microbiota and TC risk.MethodsUtilizing data from the MiBioGen consortium’s genome-wide association studies (GWAS) meta-analysis involving a sample size of 18,340, we identified instrumental variables for 211 gut microbiota taxa. The summary statistics for TC was from relevant large-scale GWAS conducted by the FinnGen consortium. In the first stage, the Inverse-variance weighted (IVW) method was used as the primary estimate method, and the stability of estimations was tested by a battery of sensitivity analyses. In the second stage, a reverse MR analysis was applied to determine whether reverse causality existed.ResultsAccording to the IVW method, we identified 9 genetically predicted gut microbiota that were causally correlated with TC risk. Among them, we observed a positive causal effect of Family Christensenellaceae (OR = 1.664, 95% CI: 1.103–2.511, P = 0.015), Family Victivallaceae (OR = 1.268, 95% CI: 1.009–1.594, P = 0.042), Genus Methanobrevibacter (OR = 1.505, 95% CI: 1.049–2.159, P = 0.027), Genus Ruminococcus2 (OR = 1.846, 95% CI: 1.261–2.704, P = 0.002), Genus Subdoligranulum (OR = 1.907, 95% CI: 1.165–3.121, P = 0.010), Phylum Verrucomicrobia (OR = 1.309, 95% CI: 1.027–1.668, P = 0.029) on TC risk, while Class Betaproteobacteria (OR = 0.522, 95% CI: 0.310–0.879, P = 0.015), Family Family XI (OR = 0.753, 95% CI: 0.577–0.983, P = 0.037), Genus Sutterella (OR = 0.596, 95% CI: 0.381–0.933, P = 0.024) might be correlated with a decreased risk of TC. Subsequently, various sensitivity analyses indicated no heterogeneity, directional pleiotropy or outliers. In addition, reverse analysis demonstrated a negative causal effect of TC risk on the abundance of the gut microbiota (Genus Ruminococcus2, OR = 0.947, 95% CI: 0.907–0.989, P = 0.014).ConclusionGenetic evidence suggested that bidirectional causal associations of specific bacteria taxa and the risk of TC, highlighting the association of the “gut-thyroid” axis. Further exploration of the potential microbiota-related mechanisms might have profound implications for public health in terms of the early prevention and treatment of TC.</p

Additional file 1 of Efficacy and safety of Xian-Lian-Jie-Du optimization decoction as an adjuvant treatment for prevention of recurrence in patients with stage IIIB/IIIC colon cancer: study protocol for a multicentre, randomized controlled trial

Additional file 1