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Deep within coal gangue hills, there is a substantial amount of wasted thermal energy. Prolonged accumulation of these hills leads to significant damage to the atmosphere and soil. Gravity heat pipes, as efficient heat transfer components, can safely, efficiently, and conveniently extract the accumulated heat in gangue hills to achieve effective thermal control. In this study, we first analyzed the optimal height of the heat dissipation fins through a single fin heat dissipation model. Then, we determined the optimum spacing between the heat dissipation fins through analysis with multiple fins. The results showed that when the height of the heat dissipation fins was 80 mm and the spacing between fins was 80 mm, the heat dissipation performance and economic costs were most reasonable. Through an engineering trial conducted for 143 days at the Maotergou coal mine gangue hill, it was found that the average heat dissipation rate of a single gravity heat pipe ranged from 243.52W to 494.32W. The total heat dissipation during the entire experimental process was 54.39 kJ, and the total heat dissipation at the elevation of 890 meters was 1087.71 kJ. This indicates that managing the internal temperature accumulation in coal gangue hills using gravity heat pipes is entirely feasible. [ABSTRACT FROM AUTHOR]

A variable flux leakage starter‐generator structure designed for helicopters is proposed. The research focuses on investigating the current distribution mechanism of the d‐q axis to determine the feasibility of incorporating variable flux leakage (FL) in the machine model. By investigating the magnetic circuit models of machines under various operating conditions, we aim to uncover the performance advantages of variable FL starter‐generator for helicopters in different scenarios. Subsequently, a variable flux leakage starter‐generator is designed, and a prototype is implemented successfully. The experimental results validate the accuracy of the theoretical analysis conducted. [ABSTRACT FROM AUTHOR]

This article analyzes the factors causing the precision error of the robot joint module, such as gear meshing disturbance, output elastic deformation, and load mutation. An improved active disturbance rejection control (ADRC) algorithm is proposed to overcome the uncertainty of nonlinear factors and variables of this research topic. The output precision loss of the joint module is introduced as a new input variable of ADRC, combined with the input variable of torque current of the joint module. The extended state observer is redesigned, and the online estimation of disturbance is realized. According to the disturbance estimation results, the current loop algorithm of permanent magnet synchronous motors is improved to compensate the torque disturbance of the robot joint module. The experimental results show that the improved ADRC algorithm can obviously suppress the disturbance of the joint module, weaken the meshing error and torque output deformation of the harmonic reducer gear, and improve the control accuracy of the joint module. [ABSTRACT FROM AUTHOR]

Improving the recovery of fine copper oxides is an important problem to be solved in the efficient utilization of copper ore resources. It is of great significance to study the selective flocculation separation of fine malachite and quartz for efficient recovery of copper ore resources. Using xanthan gum as flocculant, the selective flocculation and settlement behavior of malachite and quartz were studied. The results show that when pH value is 4, xanthan gum concentration is 10 mg/L, Cu2+ concentration is 20 mg/L, the recovery of single mineral malachite is 91.81%, the difference of settlement rate between the two minerals is 64.73 percentage points, the settlement rate of the minerals mixture is 66.61%, the recovery malachite is 72.44% and the Cu grade is 30.18%. The results of microscope observation show that the adsorption capacity of xanthan gum for malachite is stronger than that of quartz. Xanthan gum can selectively flocculate fine malachite particles and agglomerate them into large size of particle floes, which is conducive to settlement. The determination of adsorption capacity and Zeta potential analysis showed that xanthan gum had electrostatic interaction with malachite and physical adsorption with quartz, and Cu2+ would have electrostatic interaction with xanthan gum covered on the surface of quartz, but had little effect with quartz; The results of FTIR test show that xanthan gum can be adsorbed on malachite surface for chemical reaction. When Cu2+ and xanthan gum are added, there is hydrogen bond between xanthan gum and malachite, and xanthan gum can also form stable complex of Cu2+. The interaction between xanthan gum and quartz is mainly physical adsorption. XPS test results showed that xanthan gum adsorbed Cu2+ on malachite surface, bonded to Cu site on malachite surface, and obtained electrons from malachite -OH and C = O groups. The adsorption between xanthan gum and quartz is weak. Xanthan gum can effectively separate malachite from quartz, improve the grade of malachite product. This study provides theoretical guidance for the recovery and utilization of fine malachite. [ABSTRACT FROM AUTHOR]

Bilobalide has shown strong anti-inflammatory activity. Colorectal cancer (CRC) is closely associated with inflammation. However, no studies have reported on the use of bilobalide for treating CRC. This study aims to evaluate the effect of bilobalide on CRC prevention. Enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (RT-qPCR), Western blotting, and immunofluorescence showed that bilobalide significantly inhibits the M2 polarization of macrophages dependent on phorbol 12-myristate 13-acetate (PMA) and interleukin-4 (IL-4). Analysis of signaling pathways showed that the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and signal transducer and activator of transcription 3 (STAT3) was regulated. In particular, human CRC organoids were established. Western blotting, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL), and analysis of cell viability and morphology further supported the hypothesis that the anti-CRC effects of bilobalide could be explained by its ability to suppress M2 macrophage polarization and promote M1 transformation. C57BL/6 mice treated with azoxymethane (AOM)/dextran sodium sulfate (DSS) were divided into three groups, i.e., control, AOM/DSS, low (2.5 mg/kg), and high (5 mg/kg). High-dose bilobalide markedly inhibited the progression of CRC, as evidenced by the increased body weight, decrease in disease activity index (DAI) death rate, and alleviation of colon length reduction and tumorigenesis. According to the in vivo results, reduced levels of inflammatory cytokines in the serum included tumor necrosis factor (TNF-α), IL-6, IL-1β, and IL-10. Bilobalide reduced oxidative stress indices, lipid peroxide (LPO), and malondialdehyde (MDA) and increased reduced glutathione (GSH). In addition, the expression of proliferating cell nuclear antigen (PCNA), Ki67, cellular Myc (c-Myc), and CD206 was downregulated in the drug-treated groups, as confirmed by the immunohistochemical staining. Collectively, these results indicated that bilobalide administration improve experimental CRC by inhibiting M2 macrophage polarization and oxidative stress. Thus, bilobalide may prevent CRC and serve as a potential therapeutic target for CRC. [ABSTRACT FROM AUTHOR]

In the paper, two adaptive control schemes based on characteristic model (CM) method are proposed to achieve great dynamic performance for servo motor drive applications. Two second‐order CMs of permanent magnet synchronous motors (PMSMs) are established based on the difference equation method. An adaptive controller consisting of four control laws is designed based on CMs. The proposed controller implements an improved maintaining/tracking control law that considers load torque ripple, plus a golden‐section adaptive control law, a logic differential control law, and a logic integral control law. In addition, two different servo systems using adaptive controllers are established, both of which are simple to implement and can achieve accurate position‐tracking or speed‐tracking in a servo drive system. The feasibility and effectiveness of the proposed adaptive control schemes are experimentally tested and verified on a servo motor drive platform. [ABSTRACT FROM AUTHOR]