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Notably Accelerated Nano-Bainite Transformation via Increasing Undissolved Carbides Content on GCr15Si1Mo Bearing Steel

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 703-712页

作者： Yan-hui Wang Hua-Qiang Sun Wen-Jing Feng Lei-Jie Zhao Xiang Chen Qing-An Chen Hai-Tao Sun Jian-jun Wang Zhi-Nan yang Key Laboratory of Intelligent Industrial Equipment Technology of Hebei Province School of Mechanical and Equipment EngineeringHebei University of EngineeringHandan056038China Collaborative Innovation Center for Modern Equipment Manufacturing of Jinan New Area Hebei University of EngineeringHandan056038China School of Materials Science and Engineering Tsinghua UniversityBeijing100084China Avic Shang da Superalloys Company Limited Xingtai054800China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004China

In this study, a high-carbon nano-bainitic GCr15Si1Mo bearing steel was investigated. Specifically, the effects of content and size of undissolved carbides on the microstructure and transformation kinetics of nano-bainite were analyzed. The results demonstrated that after prolonged austempering at low temperatures, the mixed microstructure composed of nano-bainite (NB), undissolved carbides (UC), and retained austenite (RA) was obtained in GCr15SiMo steel. When the experimental steel was austenitized at 900 ℃, the undissolved carbides gradually dissolved until reaching a stable state with increasing holding time. Furthermore, at the same austempering temperature, despite different volume fractions of undissolved carbides in the substrate, the volume fractions of nano-bainite in the final microstructures remained essentially the same. Moreover, the higher the content of undissolved carbides in steel, the faster the transformation rate of nano-bainite and the shorter the total transformation time.

关键词： Nano-bainite Undissolved carbides Bainitic transformation kinetics Carbon concentration

Oxidized LDL upregulated ATP binding cassette transporter-1 in THP-1 macrophages

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Acta Pharmacologica Sinica 2004年第5期 39-44页

作者： Chao-ke TANG, Guang-hui YI, jun-hao yang, Lu-shan LIU,Zuo WANG, Chang-geng RUAN, Yong-zong yang2Institute of Cardiovascular Disease of Nanhua University, Hengyang 421001, China

AIM: To study the effect of oxidized low density lipoprotein (ox-LDL) on ATP binding cassette transporter A1(ABCA1) in THP-1 macrophages. METHODS: After exposing the cultured THP-1 macrophages to ox-LDL fordifferent periods, cholesterol efflux was determined by FJ-2107P type liquid scintillator. ABCA1 mRNA and proteinlevel were determined by reverse trancriptase-polymerase chain reaction (RT-PCR) and Western blot, *** cholesterol level in THP-1 macrophage foam cells was detected by high performance liquid ***: ox-LDL elevated ABCA1 in both protein and mRNA levels and increased apolipoprotein (apo) A-I-medi-ated cholesterol efflux in a time- and dose-dependent manner. 22(R)-hydroxycholesterol and 9-cis-retinoic acid didsignificantly increase cholesterol efflux in THP-1 macrophage foam cells (P<0.05), respectively. Both of themfurther promoted cholesterol efflux (P<0.01). As expected, liver X receptor (LXR) agonist decreased content ofesterified cholesterol in the macrophage foam cells compared with control, whereas only a slight decrease of freecholesterol was observed. LXR activity was slightly increased by oxidized LDL by 12 % at 12 h compared with 6 ***, LXR activity was increased about 1.8 times at 24 h, and oxidized LDL further increased LXR activity byabout 2.6 times at 48 h. CONCLUSION: ABCA1 gene expression was markedly increased in cholesterol-loadedcells as a result of activation of LXR/RXR. ABCA1 plays an important role in the homeostasis of cholesterol in themacrophages.

关键词： ATP-binding cassette transporters apolipoprotein A-I hydroxycholesterols LDL lipoproteins oxi-dation-reduction macrophages

Nanopore design of sulfur doped hollow carbon nanospheres for superior potassium-ion battery anodes

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Rare Metals 2024年第5期43卷 2103-2114页

作者： Zhen-Dong Liu hui-Yan Feng Yu-Chen Wang Fei Wang Yue Liu Jian-Xiao yang Yue Gu jun Tan Chong Ye Cheng-Zhi Zhang Ji Hua Laboratory Foshan 528000China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha 410082China

Sulfur doped carbonaceous materials are promising anodes for potassium-ion batteries because of their ability to bridge active sites and induce C/S electron coupling,resulting in increased ion storage capacitance However,the large potassium ions could cause significant volume expansion and structure collapse during operation in sulfur doped carbonaceous anodes,which lead to rapidly capacity sacrifice during long-term *** design for anchoring sulfur atom in carbon skeleton is a novel way to alleviate the structure collapse and maintain the cycling ***,this study developed a controlled nanopore and sulfur doped carbon sphere structure(S-NPHCSs).In potassium-ion batteries S-NPHCSs anode demonstrated exceptional performance with a high reversible capacity of 247 mAh·g^(–1)after 50 cycles at 0.2 A·g^(–1)and delivered a long cycle stability of 600 cycles at a high current density of 1.0 A·g^(–1).Interconnected nanopores and doped sulfur structure not only expand the accumulation space and offer ample active sites for diffusion and adsorption of potassium ions,but also build stable channels through nanopore structure to ensure the cyclic *** finding provides a fundamental theory for designing nanopore structures and introducing sulfur doped carbonaceous materials to enhance capacitive potassium storage and long cycle stability.

关键词： Nanopore Carbon materials Sulfur doping Anode Potassium-ionbatteries

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Spatial-temporal differentiation and influencing factors of rural settlements in mountainous areas: an example of Liangshan Yi Autonomous Prefecture, Southwestern China

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Journal of Mountain Science 2024年第1期21卷 218-235页

作者： WANG Yumeng DENG Qingchun yang Haiqing LIU hui yang Feng ZHAO Yakai School of Geographical Sciences China West Normal UniversityNanchong 637009China Sichuan Provincial Engineering Laboratory of Monitoring and Control for Soil Erosion in Dry Valleys China West Normal UniversityNanchong 637009China Liangshan Soil Erosion and Ecological Restoration in Dry Valleys Observation and Research Station Xide 616753China

Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization. Based on land use data of Liangshan Yi Autonomous Prefecture(hereinafter referred to as Liangshan Prefecture) in Sichuan Province, China from 1980 to 2020, compactness index, fractal dimension, imbalance index, location entropy and the optimal parameters-based geographical detector(OPGD) model are used to analyze the spatial-temporal evolution of the morphological characteristics of rural settlements, and to explore the influence of natural geographical factors, socioeconomic factors, and policy factors on the spatial differentiation of rural settlements. The results show that:(1) From 1980 to 2020, the rural settlements area in Liangshan Prefecture increased by 15.96 km^(2). In space, the rural settlements are generally distributed in a local aggregation, dense in the middle and sparse around the periphery. In 2015, the spatial density and expansion index of rural settlements reached the peak.(2) From 1980 to 2020, the compactness index decreased from 0.7636 to 0.7496, the fractal dimension increased from 1.0283 to 1.0314, and the fragmentation index decreased from 0.1183 to 0.1047. The spatial morphological structure of rural settlements tended to be loose, the shape contour tended to be complex, the degree of fragmentation decreased, and the spatial distribution was significantly imbalanced.(3) The results of OPGD detection in 2015 show that the influence of each factor is slope(0.2371) > traffic accessibility(0.2098) > population(0.1403) > regional GDP(0.1325) > elevation(0.0987) > poverty alleviation(0). The results of OPGD detection in 2020 show that the influence of each factor is slope(0.2339) > traffic accessibility(0.2198) > population(0.1432) > regional GDP(0.1219) > poverty alleviation(0.0992) > elevation(0.093). Natural geographical facto

关键词： Rural settlements Location entropy Geographical detector Spatiotemporal differentiation Influencing factors

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Stromal thrombospondin 1 suppresses angiogenesis in oral submucous fibrosis

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International Journal of Oral Science 2024年第1期16卷 163-172页

作者： Xiao yang hui Zhao Rui Li yang Chen Zhi Xu Zhengjun Shang State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei Key Laboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhanChina Department of Oral and Maxillofacial-Head and Neck Oncology School of Stomatology–Hospital of StomatologyWuhan UniversityWuhanChina Department of Stomatology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina

A decline in mucosal vascularity is a histological hallmark of oral submucous fibrosis (OSF), a premalignant disease that is largely induced by betel quid chewing. However, the lack of available models has challenged studies of angiogenesis in OSF. Here, we found that the expression of thrombospondin 1 (THBS1), an endogenous angiostatic protein, was elevated in the stroma of tissues with OSF. Using a fibroblast-attached organoid (FAO) model, the overexpression of THBS1 in OSF was stably recapitulated in vitro. In the FAO model,treatment with arecoline, a major pathogenic component in areca nuts, enhanced the secretion of transforming growth factor (TGF)-β1 by epithelial cells, which then promoted the expression of THBS1 in fibroblasts. Furthermore, human umbilical vein endothelial cells (HUVECs)were incorporated into the FAO to mimic the vascularized component. Overexpression of THBS1 in fibroblasts drastically suppressed the sprouting ability of endothelial cells in vascularized FAOs (v FAOs). Consistently, treatment with arecoline reduced the expression of CD31in v FAOs, and this effect was attenuated when the endothelial cells were preincubated with neutralizing antibody of CD36, a receptor of THBS1. Finally, in an arecoline-induced rat OSF model, THBS1 inhibition alleviated collagen deposition and the decline in vascularity in vivo. Overall, we exploited an assembled organoid model to study OSF pathogenesis and provide a rationale for targeting THBS1.

关键词： angiogenesis elevated endogenous

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Alkyl Radical Initiated Cyclization/Cascade for Synthesizing Lactam-Substituted Alkyl Sulfones

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Chinese Journal of Chemistry 2024年第16期42卷 1853-1859页

作者： Li-jun Wu Kai-Yi Zhang Pei yang Chuan-Chong Peng Jin-hui Liu Qing Li Da-Zhi Sun Shuangfeng Yin College of Sciences Central South University of Forestry and TechnologyChangshaHunan410004 China School of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhotInner Mongolia010021 China

An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite(K_(2)S_(2)O_(5))as a connector is developed for the synthesis of various lactam-substituted alkyl ***,this process does not require a metal catalyst or metal powder reductant,highlighting its environmentally friendly *** reaction demonstrates outstanding substrate adaptability and a high tolerance towards diverse functional ***,the biologically active molecules and commercially available drugs with a late-stage modification are also highly compatible with this *** studies revealed that the reaction proceeds through a single-step process involving intramolecular radical cyclization,"SO_(2)"insertion,and external alkyl incorporation.

关键词： Alkyl radical Metal-free catalyzed Cyclization/cascade Potassium metabisulphite Electrophiles Alkyl sulfones Lactams Alkyl bromides Sodium formate

The abundance, distribution, and enrichment mechanism of harmful trace elements in coals from Guizhou, Southwestern China

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Acta Geochimica 2024年第05期43卷 889-903页

作者： hui Hou Wei Cheng Ruidong yang Yan Zhang College of Mining National and Local Joint Laboratory of Engineering for Eff ective Utilization of Regional Mineral Resources from Karst Areas Guizhou Key Laboratory of Comprehensive Utilization of Non-Metallic Mineral Resources College of Resource and Environment Engineering Guizhou University

Coal seams can enrich a variety of harmful trace elements under specifi c geological conditions. The spatial distribution of harmful trace elements in coal is extremely uneven, and the distribution characteristics of each element content are diff erent. The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body. It is of great resource signifi cance to study the geochemistry of coal that aff ects the enrichment and distribution characteristics of harmful trace elements. Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators, this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou, and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou. The results show that the average contents of Cd, Pb, Se, Cu,Mo, U, V, As, Hg, and Cr in coal of Guizhou are higher than those in Chinese coal and world coal. A variety of harmful trace elements in the coal of Guizhou have high background values, especially in Liupanshui, Xingyi and Qianbei coalfi eld. The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors. The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.

关键词： Distribution characteristics Enrichment law Geological and geochemical features Guizhou Harmful trace elements

Resource Allocation for Space-Air-Ground Integrated Networks:A Comprehensive Review

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Journal of Communications and Information Networks 2024年第1期9卷 1-23页

作者： hui Liang Zhiqing yang Guobin Zhang Hanxu Hou School of Electrical Engineering and Intelligentization Dongguan University of TechnologyDongguan 523808China Peng Cheng Laboratory Shenzhen 518055China School of Electronics and Information Engineering Shenzhen UniversityShenzhen 518061China School of Electrical Engineering and Intelligentization Dongguan University of TechonologyDongguan 523808China School of Information and Communication Engineering Guangzhou Maritime UniversityGuangzhou 510725China

The space-air-ground integrated networks (SAGIN) has emerged as a critical paradigm to address the growing demands for global connectivity and enhanced communication services. This paper gives a thorough review of the strategies and methodologies for resource allocation within SAGIN, focusing on the challenges and solutions within its complex structure. With the advent of technologies such as 6G, the dynamics of resource optimization have become increasingly complex, necessitating innovative approaches for efficient management. We examine the application of mathematical optimization, game theory, artificial intelligence (AI), and dynamic optimization techniques in SAGIN,offering insights into their effectiveness in ensuring optimal resource distribution, minimizing delays, and maximizing network throughput and stability. The survey highlights the significant advances in AI-based methods,particularly deep learning and reinforcement learning, in tackling the inherent challenges of SAGIN resource allocation. Through a critical review of existing literature, this paper categorizes various resource allocation strategies, identifies current research gaps, and discusses potential future directions. Our findings highlight the crucial role of integrated and intelligent resource allocation mechanisms in realizing the full potential of SAGIN for next-generation communication networks.

关键词： space-air-ground integrated networks resource allocation 6G optimization theory game theory artificial intelligence

A 27 GHz,simple 2-bit 1×8 phased array

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Journal of Electronic Science and Technology 2024年第3期22卷 26-34页

作者： jun-Xian Liu Yun-Ying Man Hao yang Peng yang School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

This study demonstrates a simple 2-bit phased array operating at 27 GHz that supports one-dimensional beam scanning with left-handed circular polarization(LHCP).The antenna is constructed using a compact four-layer printed circuit board(PCB)structure,consisting of a 90°phase shifter layer with microstrip structures,a ground(GND)layer,a direct current(DC)control layer,and a circularly polarized annular radiation patch layer with 1-bit phase *** on the proposed unit structure,a 1×8 array with half-wavelength inter-element spacing was designed and *** results show that the array achieves a peak gain of 10.23 dBi and is capable of beam scanning within±50°.

关键词： 27 GHz 2-bit P-i-n diodes Phased array Reconfigurable antennas