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INTRODUCTION: Photovoltaic power generation, as a rapidly developing new energy technology, is increasingly receiving attention from countries around the world. However, the efficiency of photovoltaic power generation systems is influenced by various factors. Local shadows have become one of the bottlenecks restricting the development of photovoltaic systems. OBJECTIVES: The research aims to improve the maximum power tracking performance of photovoltaic systems under local shadow conditions. METHODS: A maximum power tracking system based on ant colony optimization fuzzy algorithm is proposed. Research can effectively solve local optimal problems caused by local shadows through ant colony algorithm. Combining fuzzy algorithms can not only improve the tracking accuracy of the maximum power tracking system, but also enhance the adaptability to complex environments. RESULTS: In the simulation experiment results, the error between the ant colony optimization fuzzy algorithm and the actual maximum power in four local shadow environments was 0.21W, 0.55W, 0.27W, and 0.98W, respectively. Both stability and accuracy were superior to ant colony algorithm, fuzzy algorithm, and perturbation observation method. CONCLUSION: Research has confirmed the potential value of ant colony optimization fuzzy algorithm in maximum power tracking of photovoltaic power generation, providing a new solution for the operation and management of photovoltaic power plants.

Background The right to health of children has been a general concern of the society. The rate of systematic health management for children is a core indicator effectively reflecting the monitoring and management of children's physical growth and psycho-behavioral development. Most of the studies on systematic health management for children use an empirical design, mainly focusing on explorations of management models, while few have made in-depth analysis of the national status from temporal and geographical perspectives. Objective To analyze the temporal changes and regional differences in terms of the rate of systematic health management of children under three years old from 2010 to 2019, providing valuable evidence for the consolidation and improvement of the health management level in this group, and for promoting health level in children. Methods In November 2021, data about health management of children under three years old in China during 2011—2020 were extracted from 10 volumes of China Health Statistics Yearbook published annually from 2011 to 2020. A descriptive analysis was used to conduct temporal and geographical analysis of the systematic health management for children. Results As a whole, the national health management rate for children under three years old showed a continuous upward trend increased from 81.5% in 2010 to 91.9% in 2019, with a 12.8% increase. The annual rate of systematic health management of the children during the period was greater than 90.0% in Beijing, Inner Mongolia Autonomous Region, Liaoning Province, Shanghai, Jiangsu Province, Zhejiang Province, Shandong Province, Guangdong Province and Shaanxi Province, but was relatively low in the Tibet Autonomous Region (71.9% in 2019) , indicating that there was still a certain gap between the local level and policy goals in this region. The analysis from temporal changes and regional differences as well as regional perspective revealed the following findings: the rate of systematic health management for children under three years during 2010—2019 was higher than the national level in 13 (41.9%) out of 31 regions in China, lower than the national level in 7 regions (22.6%) , and moved around the national level in 11 regions (35.5%) . The systematic health management rate of children under 3 years old varied greatly between regions during 2010—2012, but the inter-regional differences gradually narrowed after 2015. The rate of systematic health management for children under 3 years old was the highest in northeast China, followed by eastern China, western China and central China. In 2019, there was still large differences in the rate of systematic health management for these children among regions in western China. Conclusion China has achieved remarkable results in systematic health management for children under 3 years old. More attention should be given to the regions in western China, especially the Tibet Autonomous Region during the improvement of the management for these children. To further improve and consolidate the health management level of children, it is suggested to make efforts to improve the equity and accessibility of essential medical services, narrow the inter-regional differences between health resource allocation and public health services, learn and apply relevant good management methods from advanced regions, make full use of big data and internet techniques, and strengthen the construction of community pediatric health management team.

When a large amount of heat is produced during the operation of a MRF (magnetorheological fluid) testing device, the temperature of the device will increase, which will in turn affect the characteristics of the MRF. Exploring the temperature field characteristics of the MRF yield stress testing device is necessary to improve the accuracy of the device. In this study, first, the yield stress testing device is designed, and then its temperature field model, including enameled wire and assembly gap, is established. Second, simulation software is used to simulate the temperature field change. Finally, a test platform is developed to test the simulation results, especially for two factors, namely, thermal conductivity of the coil winding and assembly gap, which demonstrate considerable influence. Comprehensive thermal conductivity and assembly clearance are determined, and the optimum temperature field of the device for measuring yield stress is resulted.

Magnetorheological fluids (MRFs) have a wide range of applications in automotive and other industrial fields. As one of the main performance parameters of MRFs, static yield stress is the demarcation point of solid-liquid performance conversion. Therefore, yield stress is important to the study of MRFs. In this work, a new type of MRF testing device was designed. Three types of material blocks, namely, steel, copper, and aluminum, were tested to determine wall slippage using MRF-122E and MRF-132D. The results indicate that the best pulling blocks were the 1-mm copper rectangular channel and the 2-mm aluminum triangle channel. Identity distance was also tested, and the result indicated that the 1-mm copper pulling block and identity distance of 5-mm curve were nearest to the Lord Corporation yield curve with a maximum relative error within 5 %. [ABSTRACT FROM AUTHOR]

The article examines the analytical method on the combination of content and citation characteristics of scientific feature of documents. It emphasizes the efficiency of different weight based on experimental research. It also cites the demand to choose suitable weight for the collection of scientific feature in the specific literature.

The flat-wire motor has the characteristics of small size, low noise, high slot fill factor and good thermal conductivity in the slot. It can significantly improve the power density of the motor and is widely used in electric vehicles. The skin effect and proximity effect of the flat wire under high-speed conditions lead to high loss. Based on the established finite element model of a two-dimensional flat-wire motor, this paper first studies the high-frequency loss of different winding layers and the conductor sizes of each layer. Secondly, the influence of the magnetic field on AC loss is reduced by optimizing the tooth-tip height and tooth-tip width. Finally, it is verified that the high-frequency loss is reduced by 16% with the optimized layers, conductor sizes and tooth-tip sizes under the drive condition of the CLTC-P (China Light-duty Test Cycle—Passenger). [ABSTRACT FROM AUTHOR]

This paper aims to improve the internal heat distribution and effective thermal management of a proton-exchange membrane fuel cell (PEMFC) while reducing its volume. A novel embedded liquid cooling channel was designed to achieve this, and a three-dimensional, multiphase numerical model of the PEMFC was established. Compared with the conventional straight-through channel, which features straight channels for both the anode and cooling runners, the embedded cooling channel demonstrates a lower temperature difference and pressure drop, reducing both by 17.5% and 71.9%, respectively. The embedded channel structure was studied based on indicators such as the index of uniform temperature distribution (IUT), average cooling channel walls heat flux, H2 mole fraction distribution, H2 flow channel pressure drop, and net power. The results show that increasing the contact length (L) between the anode plate and the anode diffusion layer is beneficial for the diffusion of anode gas, controlling fuel-cell temperature, and improving net power. Furthermore, it is recommended that the angle of the embedded channel be greater than 60°, and L should be greater than 8/16 of the PEMFC width. This study provides a new solution to the problem of PEMFC thermal management and valuable references for PEMFC engineering design. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The composition of a magnetorheological fluid (MRF) usually includes magnetic particles, a carrier fluid, and additives. Among them, the magnetic particles and carrier fluid are the main sources of the mechanical properties of the MRF. The changes of the related properties of the two will affect the mechanical properties of the MRF directly or indirectly. Herein, first, the temperature–magnetic field characteristics are analyzed during the MRF working process. Then, the influence mechanism of temperature and magnetic field changes on the properties of the magnetic particles and carrier liquid are analyzed. On this basis, the traditional Bingham model is improved and optimized, in which the temperature variable is introduced to represent the effect of temperature–magnetic field coupling on the shear stress of the MRF. Finally, parameter fitting and simulation are carried out for the optimized model, and the self‐made shear stress of the MRF measuring device with temperature‐control function is used to experimentally verify the accuracy of the optimized model. The comparison and verification of the results show that the optimized model can better represent the variation of shear stress of an MRF with temperature and magnetic field than the traditional Bingham model. [ABSTRACT FROM AUTHOR]

Magnetorheological fluid is a new type of smart material that is sensitive to magnetic fields and has controllable performance. It is widely regarded for its unique magnetorheological effect and good rheological properties. For materials, the microstructure determines its macroscopic properties. In order to better study its macroscopic properties, it is necessary to have a more comprehensive understanding and deep understanding of its microstructure. In this paper, the magnetization process of magnetorheological fluid is analyzed from a microscopic point of view. Based on Newton's second law, the dynamic model of particle motion is established. The magnetic force, repulsive force, and viscous resistance of magnetic particles are analyzed. The finite difference numerical calculation method is used. The velocity-Verlet algorithm simulates the static microstructure chaining process of the magnetorheological fluid and the dynamic chaining process under shear force under different influencing factors. At the same time, a static observation device and a shear observation device were developed to observe the microstructure chaining morphology of magnetorheological fluid under different influencing factors, and to study the dynamic chaining law of magnetorheological fluid under the action of a shear force. Therefore, a reasonable contrast index is established, and the numerical simulation results are compared with the experimental observation results. [ABSTRACT FROM AUTHOR]

An abstract of the article "Baseline Characteristics of Myocardial Infarction Secondary Prevention Study in Traditional Chinese Medicine (Misps-Tcm)" by Xu Hongjuan, Ren Ming, Zhang Junhua, Cao Hongbo, Wang Hui, Zheng Wenke and Zhang Boli is presented.

Taking two typical rivers in high mountains and steep gorge areas as example, this paper analyzes the spatiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes. Firstly, based on the species-environmental data processing, this paper adopts canonical correspondence analysis (CCA) method to identify the environmental factors influencing the distribution of river bank vegetation. Secondly, this study uses the ecological diversity index to represent the spatiotemporal variability of ecological characteristics. Thirdly, this paper uses the multiple correlation method to analyze the relationship between the hydrological factors and meteorological factors, and to identify the key factors leading to the hydrological regime changes. At last, based on the analysis of basin water quality data, this paper analyzes the regularity of spatiotemporal variability and its driving forces. By the systematic analysis on the outcome, we could get that the spatiotemporal distribution of eco-hydrological characteristics shows the regular changes from the upstream to downstream (from the north to the south), and the spatiotemporal variability of eco-hydrological characteristics is typical from the east to the west. Altitude, aspect and water distribution are the primary natural driving forces leading to the spatiotemporal variability of eco-hydrological characteristics; and exploitation and operation of hydroelectric power station, construction of road on the river bank, and basin land utilization are the main human driving forces. [ABSTRACT FROM AUTHOR]

An abstract of the article "Anklebrachial Index As a Predictor for the Severity of Coronary Artery Stenosis" by Chang Xuewei, Pan Guangjie, Gu Yunfei, Ma Huifang, Tian Liping, Zhang Shouyan, Wei Yidong and Wei Jinghan is presented.

An abstract of the article "Relationship Between Brain Natriuretic Peptide Levels in Patients With Acute Coronary Syndrome After Percutaneous Coronary Intervention and Cardiovascular Events" by Liao Wei and Zhou Aiqin is presented.

An abstract of the article "The Analysis Of Clinical And Coronary Angiographic Characteristics For Pre-Menopausal Women With Coronary Heart Disease" by Ting Wang, Peiling Cong and Xiaofei Sun is presented.