A Hybrid Master–Slave Control Strategy for Multiple Distributed Generators in Microgrid

The problem of insufficient regulation ability in isolated microgrid operations in traditional master–slave control is targeted in this research. A hybrid master–slave control strategy is proposed to operate multiple distributed generators (DGs) in a microgrid with alleviated regulation characteristics. Firstly, a virtual synchronous generator control is adopted in the master DG to provide voltage and frequency support for the system; however, the lack of participation of the slave DG control in traditional PQ droop control in the system regulation makes a master DG susceptible to any load variation. The problem is resolved by proposing an improved droop control strategy, which ensures that the slave DG has similar output droop characteristics as the master DG and thus can respond to system load disturbances alongside the master DG. Secondly, virtual coordinate transformation and virtual impedance control are introduced to realize the decoupling and precise distribution of output power of multiple DGs. Finally, a simulation and experimental platform for a multi-DGs parallel system are established to verify the effectiveness of the proposed strategy

Cross-comparison between China HJ1A-CCD and Landsat TM data

Considering there is great similarity between the wave-band design and spatial resolution of the China HJ1A/1B satellite CCD Camera and Landsat TM data, this paper conducts comparison and analysis to the data from the aspects of track parameter, spectral response characteristics and imaging quality. The orbital parameters have little difference. But HJ satellite has two satellites constellations in A/B, and its width is bigger than that of Landsat, which enables it to conduct two-day earth coverage observation, so it is higher than Landsat 5 in time resolution. Radiation precision evaluation results show that in the 4 wavebands of blue, green, red and near-infrared, HJ1A-CCD1 is more sensitive to low radiance, and has a stronger capability to receive low radiance value than TM; in the blue and red wavebands, it also has a stronger capability to receive high radiance value than TM, from which we can conclude that HJ1A-CCD1 has a wider threshold value range than TM in the blue and red wavebands; it has a weaker capability to receive high radiance than TM in the green and near- infrared wavebands; from the perspective of imaging effect, the information amount, texture feature and definition of various wavebands of HJ1A-CCD1 data are not as good as Landsat TM data

Telmisartan protects chronic intermittent hypoxic mice via modulating cardiac renin-angiotensin system activity

Abstract Background To explore the effects of chronic intermittent hypoxia (CIH), which mimics sleep apnea syndrome, on the cardiac renin angiotensin system (RAS), and to investigate the cardiac protection of an angiotensin receptor blocker (ARB)telmisartan (TERT) against CIH. Methods 32 healthy male C57B6J mice were randomly divided into CIH, ARB, blank and air control groups. CIH lasted for 12 weeks. Cardiac angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE 2) and angiotensin II (Ang II) were evaluated by immunohistochemistry. Myocardial apoptosis were assessed by TUNEL assay and myocardial cell ultrastructure were observed under transmission electron microscope. Results Cardiac ACE expression was higher in the CIH group than in blank and air control groups, which was decreased with TERT treatment. TERT treatment elevated the expression of cardiac ACE 2 and Ang II compared with CIH group. Myocardial cell and capillary endothelial cell apoptosis, mitochondrial injury were most severe in CIH groups, which were mitigated with TERT treatment. Conclusions CIH changes the expression of cardiac ACE, ACE2 and Ang II, which may cause myocardial damage. TERT protects mice from CIH-linked cardiac damage via modulating the activity of RAS in the hearts

Spatial Variation of Soil Organic Carbon from Bamen Bay Mangrove in Southern China

Mangrove forests are large pools of soil organic carbon (SOC) found across the world, and play a vital role in global carbon (C) cycling. In this study, to investigate the effects of spatial factors on SOC in mangrove forests, soil samples at different depth layers from upper estuary (UE), lower estuary (LE), and tidal inlet (TI) in the Qinglangang mangrove forest in Southern China were collected and the differences in SOC among the layers and geomorphological settings were compared. The mean SOC content showed a pattern of LE (4.63 ± 1.28%) > UE (2.94 ± 0.73%) > TI (1.44 ± 0.33%). SOC content and storage decreased with soil depth in TI, but increased in UE. The total SOC storages (0–80 cm) of sites TU, UE, and LE, were 104.41 ± 16.63, 207.14 ± 44.83, and 228.78 ± 19.37 Mg/ha, respectively. The results suggested that top- and subsoil organic C content and storage were largely dependent on their specific location, which underwent different river-sea interactions and human activities. The SOC of the soil profile varied at different sites, implying that the current C storage of mangrove ecosystems can be accurately estimated by quantifying the C of sediments at sites

Spatial Variation of Soil Organic Carbon from Bamen Bay Mangrove in Southern China

Mangrove forests are large pools of soil organic carbon (SOC) found across the world, and play a vital role in global carbon (C) cycling. In this study, to investigate the effects of spatial factors on SOC in mangrove forests, soil samples at different depth layers from upper estuary (UE), lower estuary (LE), and tidal inlet (TI) in the Qinglangang mangrove forest in Southern China were collected and the differences in SOC among the layers and geomorphological settings were compared. The mean SOC content showed a pattern of LE (4.63 ± 1.28%) > UE (2.94 ± 0.73%) > TI (1.44 ± 0.33%). SOC content and storage decreased with soil depth in TI, but increased in UE. The total SOC storages (0–80 cm) of sites TU, UE, and LE, were 104.41 ± 16.63, 207.14 ± 44.83, and 228.78 ± 19.37 Mg/ha, respectively. The results suggested that top- and subsoil organic C content and storage were largely dependent on their specific location, which underwent different river-sea interactions and human activities. The SOC of the soil profile varied at different sites, implying that the current C storage of mangrove ecosystems can be accurately estimated by quantifying the C of sediments at sites

C3-TGAN- Controllable Tabular Data Synthesis with Explicit Correlations and Property Constraints

GAN-based tabular synthesis methods have made important progress in generating sophisticated synthetic data for privacypreserving data publishing. However, existing methods do not consider explicit attribute correlations and property constraints on tabular data synthesis, which may lead to inaccurate data analysis results. In this paper, we propose a Controllable tabular data synthesis framework with explicit Correlations and property Constraints, namely C3-TGAN. It leverages Bayesian networks to learn explicit correlations among attributes and model them as control vectors. Such control vectors can guide C3-TGAN to generate synthetic data with complicated property constraints. By conducting comprehensive experiments on 14 publicly available benchmark datasets, we showcase C3-TGAN’s remarkable performance advantage over state-of-the-art methods for synthesizing tabular data.</p