Challenges of developing a power system with a high renewable energy proportion under China’s carbon targets

For China, one of its most important commitments is to realize its “3060” targets of achieving a CO2 emission peak by 2030 and carbon neutrality by 2060. However, for a developing country with heavy carbon utilization, achieving carbon neutrality in a short period necessitates tough changes. This paper briefly introduces energy and electricity scenarios and analyzes the challenges based on the current power system in China. Moreover, it summarizes the six characteristics of China’s future power grid and highlights some partially representative projects in the country

A SOM based Anomaly Detection Method for Wind Turbines Health Management through SCADA Data

In this paper, a data driven method for Wind Turbine system level anomaly detection and root sub-component identification is proposed. Supervisory control and data acquisition system (SCADA) data of WT is adopted and several parameters are selected based on physical knowledge in this domain and correlation coefficient analysis to build a normal behavior model. This model which is based on Self-organizing map (SOM) projects higher-dimensional SCADA data into a two-dimension-map. Afterwards, the Euclidean distance based indicator for system level anomalies is defined and a filter is created to screen out suspicious data points based on quantile function. Moreover, a failure data pattern based criterion is created for anomaly detection from system level. In order to track which sub-component should be responsible for an anomaly, a contribution proportion (CP) index is proposed. The method is tested with a two-month SCADA dataset with the measurement interval as 20 seconds. Results demonstrate capability and efficiency of the proposed method

Is hepatic resection always a better choice than radiofrequency ablation for solitary hepatocellular carcinoma regardless of age and tumor size?

In this study, we aimed to compare survival outcomes after receiving radiofrequency ablation (RFA) and hepatic resection (HR) for solitary hepatocellular carcinoma (HCC) with stratification by tumor size and age. A retrospective cohort was obtained from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Patients were grouped by tumor size (0-2, 2-5, and > 5 cm) and age (>65 and ≤65). Overall survival (OS) and disease-specific survival (DSS) were assessed. For patients >65 with tumors measuring 0-2 and 2-5 cm, the HR group had better OS and DSS compared with the RFA group. For patients >65 with tumors > 5 cm, OS and DSS did not differ significantly between the RFA and HR groups (p = 0.262 and p = 0.129, respectively). For patients ≤65, the HR group had better OS and DSS compared with the RFA group regardless of tumor size. For patients with resectable solitary HCC, regardless of age, HR is the better choice not only for tumors ≤ 2 cm, but also for tumors 2-5 cm. For resectable solitary HCC with tumors ＞5 cm, HR is the better choice for patients ≤65 but for patients >65, the issue of treatment choice needs to be further studied

Hawthorn with “homology of medicine and food”: a review of anticancer effects and mechanisms

Over the past few years, there has been a gradual increase in the incidence of cancer, affecting individuals at younger ages. With its refractory nature and substantial fatality rate, cancer presents a notable peril to human existence and wellbeing. Hawthorn, a medicinal food homology plant belonging to the Crataegus genus in the Rosaceae family, holds great value in various applications. Due to its long history of medicinal use, notable effects, and high safety profile, hawthorn has garnered considerable attention and plays a crucial role in cancer treatment. Through the integration of modern network pharmacology technology and traditional Chinese medicine (TCM), a range of anticancer active ingredients in hawthorn have been predicted, identified, and analyzed. Studies have shown that ingredients such as vitexin, isoorientin, ursolic acid, and maslinic acid, along with hawthorn extracts, can effectively modulate cancer-related signaling pathways and manifest anticancer properties via diverse mechanisms. This review employs network pharmacology to excavate the potential anticancer properties of hawthorn. By systematically integrating literature across databases such as PubMed and CNKI, the review explores the bioactive ingredients with anticancer effects, underlying mechanisms and pathways, the synergistic effects of drug combinations, advancements in novel drug delivery systems, and ongoing clinical trials concerning hawthorn’s anticancer properties. Furthermore, the review highlights the preventive health benefits of hawthorn in cancer prevention, offering valuable insights for clinical cancer treatment and the development of TCM with anticancer properties that can be used for both medicinal and edible purposes

Evaluating the sustainable cultivation of 'Fuji' apples: suitable crop load and the impact of chemical thinning agents on fruit quality and transcription

The optimal load capacity provides sustainable production and high quality in 'Fuji' apple production. Determining optimal crop loads with simple and affordable thinning methods is critical for apple. We set different load capacities on different apple tree rootstocks and evaluated their effects on tree development, fruit yield and quality. The optimal load capacity for vigorous stock, dwarfing rootstock, and dwarfing interstock were 240, 90, and 100 for apples above 80 mm in diameter, respectively. To explore the optimal strategies of diverse fruit thinning agents (carbaryl, 6-BA, NAA, and Metamitron) used in the 'Fuji' apple tree, we assess from thinning agents' types, varying spraying concentrations, and application time in the most widely used dwarfing interstock. The results showed that the best use of fruit thinning agents is 2,000 mg/L carbaryl at 10 d after flowering could significantly reduce fruit set rate and improve the fruit quality in the dwarfing interstock. During the research, only the fruit thinner NAA treatment suppresses fruit development. Thus, we performed the transcriptome analysis on the NAA-treated and control fruits at 60 (FS1), 90 (FS2), 120 (FS3), and 150 (FS4) days after flowering stages to investigate the potential transcriptional regulations of NAA on fruit development and ripening. Transcriptome results showed that genes related to fruit expansion (expansin A15, expansin B3), phytohormone-related genes (HVA22C, PRE1, AHP1, etc.), fruit coloring-related genes (PAL), and many ripening-related transcription factors (EIN3, ERF, ARF, etc.) might be regulated by exogenous NAA. Our results provide an important reference for the sustainable production and optimal use of fruit thinning agents

A miniature vision-based localization system for indoor blimps

The blimp, a self-floating airship, has received increasing attention among the robotic community. In the past decade, most research focused on the blimp structure and control system design, while few researchers have shown interest in the blimp localization system. Here I propose developing an incremental vision-based localization system to enable blimps to localize themselves in an indoor environment autonomously. The localization system estimates a camera trajectory with input video sequences and a prebuilt map. Before running the system, I initially reconstruct an indoor environment by employing Structure from Motion with SuperPoint visual features. Next, with the previously built sparse point cloud map, the system generates camera poses by continuously employing pose estimation on matched visual features observed from the map. In this project, the blimp only serves as a reference mobile platform that constraints the weight of the perception system. The perception system contains one monocular camera and a WiFi adaptor to capture and transmit visual data to a ground PC station where the algorithms will be executed. The success of this project will transform remote control indoor blimps into autonomous indoor blimps, which can be utilized for applications such as entertainment, surveillance, and advertisement.M.S

Dynamic interaction between synchronous machine and DC-power-modulated LCC in electromechanical timescale

Active power modulation of line-commutated converter (LCC)-based high-voltage direct current (HVDC) system is increasingly utilised, especially for the case of damping low-frequency oscillation associated with synchronous machine (SM) in electromechanical timescale (around 1 Hz). Many papers have tried to analyse the mechanism of damping effects, but almost rely on numerical studies, which cannot reveal the dynamic interaction between SM and DC-power-modulated LCC. This study proposes a small-signal model of DC-power-modulated LCC based on motion equation concept. With this model, analytical investigation of low-frequency oscillation from the scope of damping and synchronising powers is presented. Comparisons of analytical results and eigenvalues draw some general conclusions which offer insight into the dynamic behaviour. By examining the case of an SM connected to a DC-power-modulated LCC, simulations in MATLAB/Simulink are conducted to verify the analytical results

Investigation of the moisture classification and moisture removal behavior of diamond wire saw silicon powder waste cake

When processing silicon wafers for photovoltaic power generation, approximately 35 % of high-purity silicon is lost as a diamond wire saw silicon powder (DWSSP) waste cake with a high moisture content. The high moisture content of DWSSP results in the oxidation of high-purity silicon, which hinders the recovery and utilization of silicon resources. Disappointingly, a method for the removal of moisture from the DWSSP waste cake, which is crucial for silicon recovery, has not yet been revealed. In the present study, a novel investigation was conducted to determine the moisture classification of a DWSSP waste cake and to reveal the moisture removal behavior. The results indicate that the moisture content in the DWSSP waste cake can be divided into two distinct categories: surface adsorbed water and capillary water. Moreover, the kinetics analysis and simulation demonstrated that the elimination of moisture predominantly takes place during the constant-rate period and the falling-rate period. Increasing the drying temperature and reducing the equivalent diameter of the DWSSP waste cake will contribute to improving the efficiency of moisture removal. The application of the findings of this study can help to reduce the harmful environmental impacts of DWSSP and achieve the efficient recovery of silicon resources

Silicon recycling and iron, nickel removal from diamond wire saw silicon powder waste: Synergistic chlorination with CaO smelting treatment

During the processing of silicon wafers for photovoltaic power generation, nearly 30-40% of silicon ingot will be lost as diamond wire saw silicon powder (DWSSP) waste; this can result in reduced profits, potential danger, and environmental pollution. Driven by the rapid development of the photovoltaic industry, the demand for highpurity silicon and the production of silicon waste generated during silicon processing will continue to increase. Against this trend, the recycling of silicon from DWSSP waste is a desirable alternative to meet the growing demand for high-purity silicon. In this study, a novel process of chlorination with CaO smelting treatment is first proposed for the recycling of silicon and the removal of Fe and Ni from DWSSP waste. The results of this research indicate that the SiO2 shell can be absorbed by the added CaO, while eutectic NaCl-MgCl2 has a significant effect on the maximum recovery of silicon by reducing the viscosity of the molten slag and the removal of metals through the micro concentration cells. CaO and eutectic NaCl-MgCl2 play a synergistic role in the promotion of silicon separation and the removal of Fe and Ni. Silicon with a purity of 99.83% and a recovery rate of nearly 98.96% was obtained under the smelting conditions of DWSSP:CaO:NaCl:MgCl2 = 150.0:23.42:7.50:8.85 with a holding time of 2 h at 1823 K. This process overcomes the technical bottleneck of the removal of Fe and Ni via smelting treatment, which is favorable for the recycling of silicon from DWSSP waste at the industrial scale

Investigation of Na2CO3-CaO-NaCl (or Na3AlF6) additives for the remanufacturing of silicon from diamond wire saw silicon powder waste

The demand for high-quality silicon for solar cell preparation will continue to grow due to shortages of silicon feedstock driven by the photovoltaic industry. Consequently, the silicon lost in diamond wire saw silicon powder waste during silicon wafer production must be recovered for silicon production. Depending on the current yield of silicon and level of residual impurities, an optimization treatment for the increase of the recovery rate and purity of silicon collected from diamond wire saw silicon powder should be further developed. In this study, NaCl and Na3AlF6 are designed as additives to optimize Na2CO3-CaO to increase the silicon recovery rate and purity. The action mechanisms of NaCl and Na3AlF6 for silicon recovery and the removal of metal during the direct smelting process are investigated. It is found that NaCI and Na3AlF6 improve the silicon migration channels and stabilize the impurities in slag by reducing the slag viscosity and tuning the slag composition. After induction smelting at 1823 K for 2 h with the furnace feed mass ratios of Na2CO3 :CaO:NaCl = 12.8:1.7:8.6 and Na2CO3:CaO:Na3AlF6 = 12.8:1.7:8.6, the obtained silicon recovery rates were respectively 76.39% and 79.25%, and the silicon purities were respectively 99.985% and 99.986%. Therefore, NaCl and Na3AlF6 could be used as potential additives to promote the efficient remanufacturing of silicon collected from diamond wire saw silicon powder waste, and are technically and economically feasible for large-scale application. (C) 2020 Elsevier Ltd. All rights reserved