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Exploring the interaction mechanisms between oxygen plasma and silicon carbide for non-defect oxidation

Materials science in Semiconductor Processing 2025年 194卷

作者： Li, Junting Shi, Pengfei Huang, Yiqin Zhong, Xingde He, Zhihuang Xu, Huajie Xiao, Chen Xu, Jingxiang Wang, Yang Research Institute of Frontier Science Southwest Jiaotong University Chengdu610031 China Tribology Research Institute School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China School of Mechanics and Aerospace Engineering Southwest Jiaotong University Chengdu610031 China School of Engineering Science and Technology Shanghai Ocean University Shanghai201306 China

Understanding the energy-dependent plasma oxidation mechanism of 4H-SiC is crucial for advancing the development of high-performance devices. However, due to the lack of in-situ characterization techniques and the limitations in precisely controlling the plasma energy during experiments, the reaction mechanism between 4H-SiC and the oxygen plasma at the atomic scale remains unclear. This paper investigates the energy-dependent plasma oxidation mechanism of 4H-SiC using reactive molecular dynamics simulations, revealing four distinct oxidation regimes as the energy increases. In regime I (below 1.2 eV), only Si-O terminals formed on the SiC surface. In regime II (1.2 eV–4.7 eV), carbon is removed as a gaseous product, while silica-like Si-O-Si groups are formed on the surface. In regime III (4.7 eV–30 eV), the Si-O-Si groups begin to be etched, although the number of etched Si-O-Si groups are less than the generated ones, allowing the silica to be retained. Finally, in regime IV (>30 eV), oxygen atoms are implanted in the subsurface of the slab, leading to significant displacement damage. These findings contribute to a further understanding of the plasma oxidation mechanism of SiC and provide scientific guidance for optimizing the plasma oxidation process. © 2025 Elsevier Ltd

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Metagenomic insights into the response of rhizosphere microbial to precipitation changes in the alpine grasslands of northern Tibet

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science OF THE TOTAL ENVIRONMENT 2023年第1期892卷 164212页

作者： Liu, Yanling Yan, Yan Fu, Lijiao Li, Xueqin Chinese Acad Sci Inst Mt Hazards & Environm Key Lab Mt Surface Proc & Ecol Regulat 189 QunXianNan St TianFu New Area Chengdu 610299 Sichuan Peoples R China Univ Chinese Acad Sci 1 East Yanqi Lake Rd Beijing 101408 Peoples R China

Water changes caused by precipitation may affect the elemental cycle of ecosystems by influencing soil microorganisms. In this study, precipitation control experiment was conducted in semi-arid alpine grasslands in northern Tibet, and plots were set up and divided into increased water (IW) and decreased water (DW) plots. Moreover, the link between functional genes and soil environmental factors, and the responses of the microbial community functions to precipitation-induced water variations were studied using metagenomic sequencing. To clarify the roles of various proteins and metabolites in the semi-arid alpine grasslands of northern Tibet, functional annotations of clusters of orthologous groups of proteins, Kyoto Encyclopedia of Genes and Genomes, and carbohydrate-active enzyme of the sequencing data were conducted. The results showed that the absolute abundance of microbial functional genes in IW was significantly higher than that in the control check (CK, natural precipitation) and DW. However, the absolute abundance did not significantly differ between CK and DW. There was no significant difference among the four plant species (Stipa purpurea, Carex moocroftii, Othropis microphylla, and Artemisia capillaris) considered in this study. These results indicated that microbial functions were mainly affected by water and do not depend on the species, and that the effect of IW was greater than that of DW. Further, we found that soil C, N, K, and other nutrients play vital roles in microbial growth, microbial functional genes were not affected by pH;however, soil C, N, and K nutrients and functional genes were negative correlated. Overall, this study enhances our understanding of the responses of microorganisms to precipitation and can be used as a valuable reference for understanding the drought resistance of soil microorganisms in semi-arid and alpine regions.

关键词： Qinghai -Tibet Plateau CAZy COG KEGG functional genes Microbial functional gene annotation Water variations

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Solution-processable core/shell structured nanocellulose/poly(o-Methoxyaniline) nanocomposites for electrochromic applications

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CELLULOSE 2020年第16期27卷 9467-9478页

作者： Ren, Junye Zhang, Sihang Yan, Bin Yao, Guo Lin, Yi Zhou, Mi Gu, Yingchun Chen, Sheng Sichuan Univ Coll Biomass Sci & Engn Chengdu 610065 Peoples R China Sichuan Univ State Key Lab Polymer Mat & Engn Polymer Res Inst Chengdu 610065 Peoples R China

In this research, core/shell structured nanocellulose (NC)/poly(o-Methoxyaniline) (POANI) nanocomposites for electrochromic applications were synthesized by controllable in situ chemical oxidative polymerization. The NC/POANI nanocomposites with different contents of NC can be obtained simply by controlling the relative proportions of the monomers and NC in the polymerization system with hydrochloric acid as the dopant and ammonium persulfate as the oxidant. Films based on the NC/POANI nanocomposites were successfully fabricated by spray-coating technique. The nanocomposite films showed the combination of good film-forming properties and excellent electrochromic behavior. The film based on NC/POANI nanocomposites containing 40% NC exhibited higher optical contrast (81% at 665 nm) and better cycling stability (sustaining 84% of its initial optical contrast after 500 times cyclic test) compared with pure POANI film. Such NC/POANI nanocomposites with excellent electrochromic performance demonstrate great promise towards achieving the ideal electrochromic applications.

关键词： Poly(o-Methoxyaniline) Nanocellulose Nanocomposites Electrochromism Core-shell nanostructures

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Device design and data processing strategies for self-powered cardiovascular sensors

Device

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Device 2025年

作者： Lin, Zhiming Zou, Mingjun Lu, Yanpeng Deng, Yulong Nie, Shijin Yang, Jin Guo, Hengyu School of Instrument Science and Technology Xi'an Jiaotong University Xi'an 710049 China School of Electronics and Information Engineering Southwest University Chongqing 400715 China Yibin Academy of Southwest University Yibin 644000 China School of Physics Chongqing University Chongqing 400044 China

Continuous and effective cardiovascular monitoring leveraging wearable pressure sensors attached to human epidermis has gained attention for early diagnosis and mortality prevention in cardiovascular-related diseases. A triboelectric sensor featuring high sensitivity, rapid response time, wearability, and versatility can help improve the functionalities of cardiovascular monitoring devices. This review delves into the fundamental sensing mechanisms, various wearable and implantable triboelectric sensors, and relevant cardiogenic parameters associated with cardiovascular monitoring. Furthermore, it highlights the challenges and opportunities in utilizing triboelectric sensors to acquire cardiogenic information. © 2025 Elsevier Inc.

关键词： cardiovascular monitoring DTI-1: Understand self-powered sensor triboelectric nanogenerator triboelectric sensor

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A systematic comparison of the extraction and adsorption of theophylline by new amino acid ester-based ionic liquids

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NEW JOURNAL OF CHEMISTRY 2022年第9期46卷 4198-4211页

作者： Liu, Na Teng, Juan Yohannes, Alula Song, Hang Yao, Shun Sichuan Univ Sch Chem Engn Chengdu 650061 Peoples R China Wolkite Univ Coll Nat Sci POB 07 Wolkite Ethiopia

For the extraction of theophylline from a water phase, four hydrophobic ionic liquids (ILs) were designed and synthesized which included various amino acid ester cations and the same bis(trifluoromethyl)sulfonimide anion. After screening, l-phenylalanine ethyl ester bis(trifluoromethyl)sulfonimide ([PheC(2)][Tf2N]) showed the highest distribution coefficient and it was then applied to further investigations focused on the extraction conditions. It was also immobilized through a simple procedure and used for the adsorption of theophylline for comparison. The new sorbent was characterized via infrared spectroscopy (IR), scanning electron microscopy (SEM), elemental analysis, thermogravimetric analysis, and particle size analysis. In addition, thorough investigations into the adsorption conditions, kinetics, isotherms, and thermodynamics were carried out, together with selective separation studies. The post-treatment and reuse of the IL were also explored using the two separation approaches. A comprehensive comparison was made between these approaches and reported methods.

关键词： Ionic liquids

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Exploring publications in 3 major orthodontic journals: A comparative bibliometric analysis of two 10-year periods (2002-2011 and 2012-2021)

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AMERICAN JOURNAL OF ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS 2024年第1期166卷 81-91页

作者： Gao, Hongyu Fu, Di Wang, Shuhua Wei, Mingying Zou, Ling Liu, Jun Sichuan Univ West China Hosp Stomatol State Key Lab Oral Dis Chengdu Sichuan Peoples R China Sichuan Univ Natl Ctr Stomatol Chengdu Sichuan Peoples R China Sichuan Univ West China Hosp Natl Clin Res Ctr Oral Dis Dept Orthodont Chengdu Sichuan Peoples R China Sichuan Univ Dept Endodont West China Hosp Stomatol Chengdu Sichuan Peoples R China

Introduction: This study aimed to perform a bibliometric analysis examining contributing countries and collaborative networks, authors and collaborative relationships, the performance of the institutions, and cocited journals and references in 3 major orthodontic journals (American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, and Angle Orthodontist) over two 10-year periods (2002-2011 and 20122021). Methods: In this study, 4432 publications in the first decade and 4012 publications in the second decade were quantitatively analyzed and visualized using visualization software such as VOSviewer (Leiden University, Spain). Results: Institutions in the United States had the highest number of publications through the 2 decades, whereas Brazil, South Korea, and China achieved significant improvements in performance in the second decade compared with the first. Closer collaborative networks among scholars were revealed in the second decade. The cocitation analysis of the journals showed that highly cited journals included more professional orthodontic journals in the second decade than in the first decade. Conclusions: Bibliometric analysis of publications in 3 major orthodontic journals over two 10-year periods revealed a trend of diversification in countries and institutions participating in publishing, international collaborations, and collaboration networks among authors in the field of orthodontics during the 2 decades. (Am J Orthod Dentofacial Orthop 2024;166:81-91)

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Antitumor effects of Bulbus Fritillariae cirrhosae on Lewis lung carcinoma cells in vitro and in vivo

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INDUSTRIAL CROPS AND PRODUCTS 2014年第0期54卷 92-101页

作者： Wang, Dongdong Wang, Shu Feng, Yong Zhang, Li Li, Zu Ma, Jing Luo, Yuanqing Xiao, Wei Sichuan Univ West China Coll Pharm Dept Pharmacognosy Chengdu 610041 Peoples R China Sichuan Acad Med Sci Chengdu 610072 Peoples R China Sichuan Prov Peoples Hosp 32 Chengdu 610072 Peoples R China

Bulbus Fritillariae cirrhosae (BFC) is used in China both for food and folk medicine due to its powerful biological activities. Initially we assayed antitumor effects of different fractions from BFC using MU assay. Data indicated that chloroform extracts (CE) and total alkaloids of BFC (TAF) showed higher inhibition of proliferation of LLC cells than other extracts. We further determined contents of total alkaloids and three main alkaloids monomers in CE and TAF, and measured inhibitory effects of three main alkaloids monomers on LLC cells, it suggested that alkaloids might be responsible for all or part of the antitumor activity. Besides, we analyzed the cell cycle and sub-G1 group of LLC cells treated with TAF and found that TAF promoted the cell cycle arrest and apoptosis. Moreover, we defined antitumor activity of TAF in vivo and investigated its preliminary antitumor mechanism by histological and immunohistochemical staining technique. These results showed that TAF exhibited significant antitumor activity and low toxicity in vivo. Meanwhile, TAF significantly inhibited tumor angiogenesis and induced apoptosis through activating caspase-3. Overall, the potent antitumor activity of BFC suggests that it may be developed for treatment of cancer in the future. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Bulbus Fritillariae cirrhosae Lewis lung carcinoma Antitumor activity Caspase-3 Anti-angiogenesis Cell cycle

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Synthesis and Design of a Highly Selective Band-5 SAW Filter Using Cascaded DMS With Nonuniform Polarities

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IEEE MICROWAVE AND WIRELESS technology LETTERS 2024年第6期34卷 725-728页

作者： Tian, Hanyu Zheng, Yan Dong, Yuandan Univ Elect Sci & Technol China Sch Elect Sci & Engn Chengdu 611731 Peoples R China

In this article, a novel compact Band-5 RX surface acoustic wave (SAW) bandpass filter with high selectivity is proposed. The filter is composed of two identical double-mode SAW (DMS), which are symmetrically placed and cascaded. Every single DMS consists of five interdigital transducer (IDT) blocks and the polarities between each pair of adjacent blocks are not uniform. The unique arrangement of the polarity sequence introduces transmission zeros (TZs) on each side of the filter passband. Therefore, by exclusively employing DMS rather than a combination of DMS and synchronous SAW resonators, steep near-band skirt and excellent out-of-band rejection performance are achieved. The in-line extracted-pole topology is applied to characterize the resonance and transmission properties of the proposed DMS. The operating mechanism of the dual-track DMS filter is revealed by the transversal coupling routing diagram with three odd-mode and three even-mode resonances. The filter is implemented on a standard Y-X 42(degrees) LiTaO3 wafer with a center frequency of 882 MHz, a 3-dB bandwidth of 32 MHz, a measured minimum in-band insertion loss of 1.3 dB, and a better-than-45-dB suppression level within the frequency ranges of dc-0.851 GHz and 0.912-3 GHz.

关键词： Double mode SAW (DMS) extracted-pole high selectivity interdigital transducer (IDT) polarity surface acoustic wave (SAW)

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Gene-Activating Framework Nucleic Acid-Targeted Upregulating Sirtuin-1 to Modulate Osteoimmune Microenvironment for Diabetic Osteoporosis Therapeutics

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ACS NANO 2024年第52期18卷 35214-35229页

作者： Cai, Zhengwen Bai, Long Li, Qiumei Li, Yong Cai, Xiaoxiao Lin, Yunfeng Sichuan Univ West China Hosp Stomatol Natl Ctr Stomatol State Key Lab Oral DisNatl Clin Res Ctr Oral Dis Chengdu 610041 Sichuan Peoples R China Sichuan Prov Engn Res Ctr Oral Biomat Chengdu 610041 Sichuan Peoples R China Southwest Med Univ Affiliated Stomatol Hosp Dept Oral Implantol Luzhou 646000 Peoples R China Shanghai Jiao Tong Univ Natl Ctr Translat Med Shanghai 200240 Peoples R China

Diabetic osteoporosis, a prevalent chronic complication of diabetes, is marked by reduced bone mass, increased bone fragility, and susceptibility to fractures. A significant cause of this condition is the disruption of osteoblastic homeostasis due to prolonged hyperglycemia, which impedes bone regeneration and remodeling. Despite its prevalence, no effective treatments specifically target diabetic osteoporosis. Recently, small-activating RNA (saRNA) therapy has attracted attention for its targeting capacity, high efficacy, and minimal side effects. However, RNA's inherent properties, such as structural instability, susceptibility to degradation, and poor penetration, limit its applications. To address these limitations, a gene-activating tetrahedral framework nucleic acid (tFNA) with sirtuin-1 (SIRT1) gene activation function is developed, termed Tsa. Tsa exhibits an RNA-protecting effect and can effectively penetrate cell membranes to upregulate SIRT1 gene expression. At the histological level, Tsa treatment alleviates diabetic osteoporosis by increasing bone trabecular density and promoting new bone formation. At the cellular level, it switches macrophage polarization toward the anti-inflammatory M2 phenotype while inhibiting the inflammatory M1 phenotype, creating a favorable bone immune microenvironment for osteoblasts. At the genetic level, Tsa activates SIRT1 expression, which deacetylates Acetyl-p65 to block the NF-kappa B pathway and restore the osteoimmune environment. Overall, this research demonstrates a nanodrug "Tsa", capable of activating SIRT1 and modulating the bone immune environment, thereby showcasing its immense potential for diabetic osteoporosis treatment.

关键词： tetrahedral framework nucleic acid small-activatingRNA sirtuin-1 osteoimmunology diabeticosteoporosis macrophage osteoblast

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Improved microstructure and optical properties of Nd:YAG ceramics by hot isostatic pressing

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CERAMICS INTERNATIONAL 2023年第19期49卷 31939-31947页

作者： Li, Xiao Yin, Jun Lai, Yuanming Zhang, Xi Yu, Shengquan Chengdu Univ Technol Sch Mech & Elect Engn Chengdu 610059 Peoples R China China Acad Engn Phys Inst Chem Mat Mianyang 621900 Peoples R China

Hot isostatic pressing (HIP) has unique advantages in the preparation of high-density, fine-grained ceramics. In this work, 1.0 at.% neodymium-doped yttrium aluminum garnet (Nd:YAG) powders were prepared via solid-state reaction (SSR) and co-precipitation (CP) methods, and differences in their microstructure after being subjected to the same sintering process were compared. After calcination of raw materials at different temperatures, there was significant phase change at 800 degrees C-1400 degrees C for SSR powders. However, this process did not occur for CP powders. Average grain size of Nd:YAG ceramics prepared via CP method was smaller than that of ceramics prepared via SSR method. HIP provided significant improvement in both microstructure and in-line transmittance of ceramics. Ceramics pre-fired under vacuum at 1700 degrees C showed slight increase in grain size after HIP, with densities close to 100%, and clean, narrow grain boundaries. Moreover, in-line transmittance of ceramics increased from 69.91% to 80.37% (at 1064 nm) via HIP.

关键词： Nd:YAG ceramics Solid-state reaction Co-precipitation Hot isostatic pressing Microstructure

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