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宣肺败毒颗粒临床应用专家共识 被引量:1
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作者 刘清泉 张洪春 +5 位作者 王成祥 苗青 杨丰文 黄宇虹 郑文科 FBD专家共识工作组 《Acupuncture and Herbal Medicine》 2023年第1期1-6,共6页
宣肺败毒颗粒是在经典名方基础上化裁而成的用于治疗新型冠状病毒感染的有效方药。为进一步规范临床医师对宣肺败毒颗粒的合理使用,提高临床疗效,提高合理用药水平,发挥更大作用,特邀请来自临床一线专家,针对宣肺败毒颗粒的功能主治、... 宣肺败毒颗粒是在经典名方基础上化裁而成的用于治疗新型冠状病毒感染的有效方药。为进一步规范临床医师对宣肺败毒颗粒的合理使用,提高临床疗效,提高合理用药水平,发挥更大作用,特邀请来自临床一线专家,针对宣肺败毒颗粒的功能主治、用法用量、不良反应及注意事项等进行讨论,形成共识。共识认为:宣肺败毒颗粒具有宣肺化湿、清热透邪、泻肺解毒的功效;可用于治疗新冠病毒感染轻型、普通型、重型患者及流感等其他常见上呼吸道感染性疾病;急性气管炎-支气管炎及社区获得性下呼吸道感染性疾病等属湿毒郁肺者;可缓解慢性阻塞性肺疾病急性加重所引发的咳嗽、咯痰等症状,临床疗效确切,安全性好。按照循证医学原则,该专家共识将会定期进行更新。 展开更多
关键词 临床应用 新冠肺炎 专家共识 宣肺败毒颗粒
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Efficient Expressive Attribute-Based Encryption with Keyword Search over Prime-Order Groups
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作者 qing miao Lan Guo +1 位作者 Yang Lu Zhongqi Wang 《Intelligent Automation & Soft Computing》 SCIE 2023年第3期2737-2754,共18页
Attribute-based encryption with keyword search(ABEKS)is a novel cryptographic paradigm that can be used to implementfine-grained access control and retrieve ciphertexts without disclosing the sensitive information.It i... Attribute-based encryption with keyword search(ABEKS)is a novel cryptographic paradigm that can be used to implementfine-grained access control and retrieve ciphertexts without disclosing the sensitive information.It is a perfect combination of attribute-based encryption(ABE)and public key encryption with keyword search(PEKS).Nevertheless,most of the existing ABEKS schemes have limited search capabilities and only support single or simple conjunctive keyword search.Due to the weak search capability and inaccurate search results,it is difficult to apply these schemes to practical applications.In this paper,an effi-cient expressive ABEKS(EABEKS)scheme supporting unbounded keyword uni-verse over prime-order groups is designed,which supplies the expressive keyword search function supporting the logical connectives of“AND”and“OR”.The proposed scheme not only leads to low computation and communica-tion costs,but also supports unbounded keyword universe.In the standard model,the scheme is proven to be secure under the chosen keyword attack and the cho-sen plaintext attack.The comparison analysis and experimental results show that it has better performance than the existing EABEKS schemes in the storage,com-putation and communication costs. 展开更多
关键词 Searchable encryption expressive keyword search attribute-based encryption unbounded keyword universe prime-order group
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1980—2030年石羊河流域生态系统碳储存服务对土地利用变化的响应 被引量:13
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作者 卿苗 赵军 +3 位作者 冯超 黄治化 温媛媛 张伟婕 《生态学报》 CAS CSCD 北大核心 2022年第23期9525-9536,共12页
陆地生态系统碳储量是表征碳储存服务的重要指标,其变化与土地利用变化存在着密不可分的关系。预测未来土地利用变化对认识区域生态系统服务及其变化具有重要的意义。利用石羊河流域1980—2020年土地利用数据,运用InVEST模型和FLUS模型... 陆地生态系统碳储量是表征碳储存服务的重要指标,其变化与土地利用变化存在着密不可分的关系。预测未来土地利用变化对认识区域生态系统服务及其变化具有重要的意义。利用石羊河流域1980—2020年土地利用数据,运用InVEST模型和FLUS模型,探究了石羊河流域在过去40年间和未来自然变化、生态保护、耕地保护3种情景下的土地利用变化对碳储量的影响。结果表明:石羊河流域在1980—2020年间耕地、草地、建设用地呈增加趋势,林地、水域、未利用地呈减少的趋势。40年间石羊河流域碳储量增加了7.98×10^(6)t,增幅为1.44%。石羊河流域碳储量呈现明显的空间分异,碳储量较高的地区主要分布在上游祁连山区和中下游绿洲地区,这种分布格局与流域内土地利用类型的空间分布密切相关。至2030年,自然变化、生态保护、耕地保护情景下石羊河流域碳储量分别为563×10^(6)t、563.43×10^(6)t、564.98×10^(6)t,较2020年分别增加了0.45%、0.53%和0.80%,其中生态保护情景与其他两种情景相比既保护了生态环境还保障了生产,对未来土地利用规划有一定指导意义。 展开更多
关键词 碳储量 生态系统服务 InVEST模型 FLUS模型 土地利用 石羊河流域
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城市活力视角下全国地级资源型城市转型效率评价研究 被引量:4
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作者 冯超 赵军 +1 位作者 卿苗 张伟婕 《资源开发与市场》 CAS 北大核心 2022年第9期1043-1051,1080,共10页
从城市活力这个新颖的评价角度能够很好地体现城市发展的质量和潜力,契合中国转向高质量发展阶段的时代背景。在分析我国资源型城市活力时空分布格局的基础上,利用对抗型交叉DEA模型构建城市活力视角下的资源型城市转型效率评价体系,对2... 从城市活力这个新颖的评价角度能够很好地体现城市发展的质量和潜力,契合中国转向高质量发展阶段的时代背景。在分析我国资源型城市活力时空分布格局的基础上,利用对抗型交叉DEA模型构建城市活力视角下的资源型城市转型效率评价体系,对2008—2018年我国114个地级资源型城市的转型效率进行定量评价,并使用Global Malmquist-Luenberger指数研究了11年间转型效率的动态变化及其因素分解。结果表明:(1)研究期间我国资源型城市整体的城市活力在迅速增长的同时,表现出明显的地区分异。(2)各城市的转型效率排名发生巨大变动,转型效果差距明显,不同地区和不同类型城市的转型效率体现出很大的差异性。(3)自2013年《全国资源型城市可持续发展规划(2013—2020年)》发布后,我国资源型城市的转型效率对比之前有了明显提高,但大部分资源型城市转型效率进步的主要驱动因素是技术进步,技术效率变化的作用较小,因此需要重视资源投入的优化配置。 展开更多
关键词 资源型城市 城市活力 转型效率 DEA模型 Global Malmquist-Luenberger指数
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Creep feed grinding induced gradient microstructures in the superficial layer of turbine blade root of single crystal nickel-based superalloy 被引量:3
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作者 qing miao Wenfeng Ding +5 位作者 Jiuhua Xu Lijie Cao Hongcai Wang Zhen Yin Chenwei Dai Weijie Kuang 《International Journal of Extreme Manufacturing》 SCIE EI 2021年第4期89-102,共14页
The service performance of the turbine blade root of an aero-engine depends on the microstructures in its superficial layer.This work investigated the surface deformation structures of turbine blade root of single cry... The service performance of the turbine blade root of an aero-engine depends on the microstructures in its superficial layer.This work investigated the surface deformation structures of turbine blade root of single crystal nickel-based superalloy produced under different creep feed grinding conditions.Gradient microstructures in the superficial layer were clarified and composed of a severely deformed layer(DFL)with nano-sized grains(48–67 nm)at the topmost surface,a DFL with submicron-sized grains(66–158 nm)and micron-sized laminated structures at the subsurface,and a dislocation accumulated layer extending to the bulk material.The formation of such gradient microstructures was found to be related to the graded variations in the plastic strain and strain rate induced in the creep feed grinding process,which were as high as 6.67 and 8.17×10^(7)s^(−1),respectively.In the current study,the evolution of surface gradient microstructures was essentially a transition process from a coarse single crystal to nano-sized grains and,simultaneously,from one orientation of a single crystal to random orientations of polycrystals,during which the dislocation slips dominated the creep feed grinding induced microstructure deformation of single crystal nickel-based superalloy. 展开更多
关键词 gradient microstructure creep feed grinding single crystal nickel-based superalloy DISLOCATION
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Transcriptome Analysis of Ten-DPA Fiber in an Upland Cotton (<i>Gossypium hirsutum</i>) Line with Improved Fiber Traits from Phytochrome A1 RNAi Plants 被引量:1
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作者 qing miao Peng Deng +6 位作者 Sukumar Saha Johnie N. Jenkins Chuan-Yu Hsu Ibrokhim Y. Abdurakhmonov Zabardast T. Buriev Alan Pepper Din-Pow Ma 《American Journal of Plant Sciences》 2017年第10期2530-2553,共24页
Silencing phytochrome A1 gene (PHYA1) by RNA interference in Upland cotton (Gossypium hirsutum L. cv. Coker 312) had generated PHYA1 RNAi lines with improved fiber quality (longer, stronger and finer fiber). To reveal... Silencing phytochrome A1 gene (PHYA1) by RNA interference in Upland cotton (Gossypium hirsutum L. cv. Coker 312) had generated PHYA1 RNAi lines with improved fiber quality (longer, stronger and finer fiber). To reveal molecular mechanisms that govern fiber development with positive fiber traits, a study of global gene expression profiling of 10-DPA fibers in a PHYA1 RNAi line and its parent Coker 312 was conducted by high-throughput RNA sequencing. A comparative analysis of transcriptomes between the two lines had identified 142 genes that were differentially expressed in the 10-DPA fiber of the RNAi line. Gene Ontology analysis showed that these differentially expressed genes were mainly involved in metabolic pathways, heterocyclic/organic cyclic compound binding and multiple enzyme activities, and cell structures which were reported to play important roles in fiber development. Twenty-eight KEGG pathways were mapped for the 142 genes, and the pathways related to glycolysis/gluconeogenesis and pyruvate metabolism were the most abundant and followed by cytochrome P450-involved pathways, suggesting that fiber improvement could be through the regulation of proteins involved in cytochrome P450 pathways. Genes encoding WRKY transcription factors, sucrose synthase, xyloglucan endotransglucosylase hydrolase, udp-glucuronate: xylan alpha-glucuronosyltransferase, and genes involved in lipid metabolism and ABA/brassinosteroid signal transduction pathways were found differentially expressed in the RNAi line. These genes have direct impacts on cotton fiber quality. The results of this study elucidate molecular signatures and possible mechanisms of fiber improvement in the background of PHYA1 RNAi in cotton and should help for future fine-tuning and programming of cotton fiber development. 展开更多
关键词 FIBER Development PHYTOCHROME A1 RNA Interference RNA-Seq Transcriptome
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Discussion on “One Belt One Road” Construction and International Financial Cooperation 被引量:1
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作者 qing miao Christian Asmussen 《Proceedings of Business and Economic Studies》 2020年第3期61-64,共4页
Under the grand economic vision of opening up and cooperation among countries,the world economy is gradually recovering,and economic and trade exchanges between countries are increasing,which is an important sign of s... Under the grand economic vision of opening up and cooperation among countries,the world economy is gradually recovering,and economic and trade exchanges between countries are increasing,which is an important sign of sound economic development.At the same time,we need the joint efforts of all countries to move towards the goal of mutual benefit and common development.We should fully develop one of the"one belt one road"in the economic construction.At the same time,we need to deepen economic cooperation,improve the investment and financing system and credit system,and China International Finance is particularly important.International financial cooperation is one of the difficulties things and“One belt one road”is the same.The financial market's influence on the economic outflow of funds is not to be ignored.Based on this background,one will take the"one belt one road"as the starting point to explore the problems of international financial cooperation. 展开更多
关键词 One belt one road CONSTRUCTION International finance
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A nonlinear creep damage model for gelled waxy crude
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作者 Hong-Ying Li qing-Bo Xie +7 位作者 Hao Sun Wei Guo Feng Yan qing miao Chao-Fei Nie Yu Zhuang Qian Huang Jin-Jun Zhang 《Petroleum Science》 SCIE CAS CSCD 2022年第4期1803-1811,共9页
Yielding behaviors of waxy crude oil is one of the key issues of flow assurance challenges. The yielding of waxy crude under constant stress is actually a creep process of strain accumulation to structural failure,to ... Yielding behaviors of waxy crude oil is one of the key issues of flow assurance challenges. The yielding of waxy crude under constant stress is actually a creep process of strain accumulation to structural failure,to describe the process completely and accurately is the basis of numerical simulation of restart process of the pipeline. The creep and yield behaviors of two gelled waxy crudes were investigated experimentally under different constant applied stresses. The results clearly show that the creep process of waxy crude is related to the applied stress and time. The greater the applied stress, and the longer the loaded time, the more obvious the nonlinear features. Based on the fractional calculus theory, a fractional viscous element was developed to describe the decelerated and steady creep process of gelled waxy crude. On the basis of the damage theory, an elastic damage element was proposed to describe the accelerated creep after the yielding. According to the idea of mechanical analogy, a nonlinear creep model was established by a fractional viscous element, an elastic damaged element, and an elastic element in series, which can accurately describe the whole creep and yielding process of gelled waxy crude. 展开更多
关键词 Waxy crude oil RHEOLOGY YIELD CREEP Constitutive model Mechanical analogy
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Transcriptome Analysis of Ten Days Post Anthesis Elongating Fiber in the Upland Cotton (<i>Gossypium hirsutum</i>) Chromosome Substitution Line CS-B25
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作者 Chuan-Yu Hsu Mark A. Arick II +6 位作者 qing miao Sukumar Saha Johnie N. Jenkins Mirzakamol S. Ayubov Ibrokhim Y. Abdurakhmonov Daniel G. Peterson Din-Pow Ma 《American Journal of Plant Sciences》 2018年第6期1334-1361,共28页
A chromosome substitution line, CS-B25, was developed by the substitution of chromosome pair 25 of Gossypium hirsutum TM-1 with the homologous pair of chromosome 25 from G. barbadense, a double haploid Pima 3-79 line.... A chromosome substitution line, CS-B25, was developed by the substitution of chromosome pair 25 of Gossypium hirsutum TM-1 with the homologous pair of chromosome 25 from G. barbadense, a double haploid Pima 3-79 line. CS-B25 has improved fiber traits compared to its parent TM-1. To explore the molecule mechanisms underlying improved fiber traits, deep sequencing of total RNA was used to compare gene expression in fibers of CS-B25 and TM-1 at 10 days post anthesis (10-DPA). A total of 1872 differentially expressed genes (DEGs) were detected between the two lines, with 1175 up-regulated and 697 down-regulated in CS-B25. Gene Ontology (GO) enrichment analysis of the expression data by Generally Applicable Gene-set Enrichment (GAGE) and ReviGO indicated that the most prevalent Biological Process GO terms associated with DEGs included DNA-templated transcription, response to oxidative stress, and cellulose biosynthesis. Enriched Molecular Function GO terms included structural constituents of cytoskeleton, peroxidase activity, cellulose synthase (UDP-forming) activity, and transcription regulatory region sequence-specific DNA binding factors. GAGE was also used to find enriched KEGG pathways, and the highly represented pathways were Biosynthesis of Amino Acids, Starch and Sucrose Metabolism, Phenylpropanoid Biosynthesis, Protein Processing in Endoplasmic Reticulum, and Plant Hormone Signal Transduction. Many of the identified DEGs are involved in cytoskeleton and cell wall metabolism. The results of gene expression data have provided new insight into the molecular mechanisms of fiber development during the fiber elongation stage and would offer novel candidate genes that may be utilized in cotton fiber quality improvement. 展开更多
关键词 CHROMOSOME Substitution Lines Differentially Expressed Genes FIBER Development Quantitative Real-Time PCR RNA Sequencing Upland Cotton
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基于IRSEI的石羊河流域生态环境质量时空变化及驱动力分析 被引量:5
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作者 颉金凤 赵军 +2 位作者 卿苗 张佘淑 孙紫云 《干旱区资源与环境》 CSCD 北大核心 2023年第5期104-111,共8页
基于绿度、湿度、热度、盐度、荒漠化程度五个指标,构建了改进遥感生态指数IRSEI,提出了完全基于遥感数据的石羊河流域生态环境质量综合评价方法。以2000-2020年为时间序列,对石羊河流域生态环境质量时空分布特征和驱动因素进行了分析... 基于绿度、湿度、热度、盐度、荒漠化程度五个指标,构建了改进遥感生态指数IRSEI,提出了完全基于遥感数据的石羊河流域生态环境质量综合评价方法。以2000-2020年为时间序列,对石羊河流域生态环境质量时空分布特征和驱动因素进行了分析。结果表明:石羊河流域生态环境质量整体偏低,空间差异显著;近20年间,流域生态环境质量整体有所改善,绿洲边缘、上游林地和草地区域改善较显著;流域生态环境质量受自然因素和人为因素共同影响,年平均气温、年降水量、海拔、土地利用类型是流域生态环境质量空间分异的主要驱动力因子,驱动因子之间的交互作用表现为双因子增强和非线性增强,土地利用类型和其他驱动因子的交互作用最为明显。 展开更多
关键词 石羊河流域 改进遥感生态指数 生态环境质量 地理探测器
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(Hf_(0.5)Ta_(0.5))C ultra-high temperature ceramic solid solution nanowires
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作者 Hui Chen Yulei Zhang +4 位作者 Yanqin Fu Jiachen Meng qing miao Jianhua Zhang Hejun Li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第16期91-101,共11页
Ultra-high temperature ceramic(UHTC)nanowires are potential reinforcement materials due to it combines the perfect properties of bulk materials and unique geometric properties of one-dimensional(1D)nanostructures.Thus... Ultra-high temperature ceramic(UHTC)nanowires are potential reinforcement materials due to it combines the perfect properties of bulk materials and unique geometric properties of one-dimensional(1D)nanostructures.Thus,developing 1D nanomaterials that have excellent morphology and structure retention in ultra-high temperature environments is of prime importance to bring their outstanding performance into full play.Herein,we report the novel solid solution((Hf_(0.5)Ta_(0.5))C)ceramic nanowires,which could not only maintain morphological and structural stability at 1900°C but also exhibit 1D nanostructures under oxyacetylene scouring and ablation at 2300°C.The morphology evolution of nanowires obeys the Rayleigh instability mechanism,and the internal structure and element distribution of nanowires remain unchanged even if the surface atoms are rearranged.The fascinating nanowires are demonstrated to have great potential as ideal reinforcement materials of composite materials and toughening phases of ceramics that are applied in ultra-high temperature environments,as well as excellent performance enhancement phases of functional materials.Our work may provide new insights into the development of ceramic nanowires and widen their applications. 展开更多
关键词 (Hf_(0.5)Ta_(0.5))C solid solution nanowires Vapor-liquid-solid mechanism Catalyst/nanowire interface High-temperature stability Ablation resistance
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Single-source precursor derived high-entropy metal–carbide nanowires:Microstructure and growth evolution
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作者 Junhao Zhao Yulei Zhang +4 位作者 Hui Chen Yanqin Fu qing miao Jiachen Meng Jiachen Li 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第11期2041-2052,共12页
In recent years,high-entropy metal carbides(HECs)have attracted significant attention due to their exceptional physical and chemical properties.The combination of excellent performance exhibited by bulk HEC ceramics a... In recent years,high-entropy metal carbides(HECs)have attracted significant attention due to their exceptional physical and chemical properties.The combination of excellent performance exhibited by bulk HEC ceramics and distinctive geometric characteristics has paved the way for the emergence of one-dimensional(1D)HECs as novel materials with unique development potential.Herein,we successfully fabricated novel(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C nanowires derived via Fe-assisted single-sourced precursor pyrolysis.Prior to the synthesis of the nanowires,the composition and microstructure of(Ti,Zr,Hf,Nb,Ta)-containing precursor(PHECs)were analyzed,and divinylbenzene(DVB)was used to accelerate the conversion process of the precursor and contribute to the formation of HECs,which also provided a partial carbon source for the nanowire growth.Additionally,multi-branched,single-branched,and single-branched bending nanowires were synthesized by adjusting the ratio of PHECs to DVB.The obtained single-branched(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C nanowires possessed smooth surfaces with an average diameter of 130–150 nm and a length of several tens of micrometers,which were a single-crystal structure and typically grew along the[11¯1]direction.Also,the growth of the(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C nanowires was in agreement with top-type vapor–liquid–solid mechanism.This work not only successfully achieved the fabrication of HEC nanowires by a catalyst-assisted polymer pyrolysis,but also provided a comprehensive analysis of the factors affecting their yield and morphology,highlighting the potential application of these attractive nano-materials. 展开更多
关键词 (Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C nanowires high-entropy metal carbides(HECs) (Ti Zr Hf Nb Ta)-containing precursors vapor–liquid–solid(VLS)mechanism
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基于天然低共熔溶剂的甜叶菊中甜菊糖绿色提取方法及优化 被引量:4
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作者 缪晴 萨比哈·帕合尔丁 +1 位作者 曾思瑀 潘琪芳 《植物学报》 CAS CSCD 北大核心 2021年第6期722-731,共10页
尝试利用天然低共熔溶剂(NADES)提取甜叶菊(Stevia rebaudiana)中的甜菊糖,探索一种高效、绿色和环保的甜菊糖提取新方法。以甜叶菊干叶为原料,对照传统提取溶剂水,以甜菊糖中甜菊苷和莱鲍迪苷A的提取浓度作为指标,筛选出最优的NADES提... 尝试利用天然低共熔溶剂(NADES)提取甜叶菊(Stevia rebaudiana)中的甜菊糖,探索一种高效、绿色和环保的甜菊糖提取新方法。以甜叶菊干叶为原料,对照传统提取溶剂水,以甜菊糖中甜菊苷和莱鲍迪苷A的提取浓度作为指标,筛选出最优的NADES提取配方,然后通过Box-Behnken响应面法对NADES提取甜叶菊中甜菊糖的工艺条件进行筛选优化。结果表明,提取效率最高的NADES配方为1,2-丙二醇:甘油:水=8:1:1(v/v/v),提取的甜菊苷浓度为2.59 mg·mL^(-1),比水提取高16.40%,提取的莱鲍迪苷A浓度为1.06 mg·mL^(-1),比水提取高12.62%;通过响应面法得到最优提取条件:提取时间90分钟,提取温度60℃,超声功率为80 J·s^(-1),预测甜菊苷提取浓度为3.49 mg·mL^(-1),莱鲍迪苷A提取浓度为1.43 mg·mL^(-1),与实验验证值(甜菊苷浓度为3.48 mg·mL^(-1),莱鲍迪苷A浓度为1.42 mg·mL^(-1))接近。在最优条件下,甜菊苷提取浓度比初始条件提高了34.36%,莱鲍迪甘A提取浓度比初始条件提高了33.96%。NADES绿色环保,且提取效率高于传统溶剂,可用于甜叶菊中甜菊糖的绿色提取;同时,该提取方法可为后续推广至其它大宗经济植物类天然产物的绿色工业生产提供参考。 展开更多
关键词 天然低共熔溶剂 甜叶菊 甜菊苷 莱鲍迪苷A 绿色提取
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Grinding force and surface quality in creep feed profile grinding of turbine blade root of nickel-based superalloy with microcrystalline alumina abrasive wheels 被引量:12
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作者 qing miao Wenfeng DING +1 位作者 Weijie KUANG Changyong YANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2021年第2期576-585,共10页
Creep feed profile grinding of the fir-tree blade root forms of single crystal nickel-based superalloy was conducted using microcrystalline alumina abrasive wheels in the present study. The grinding force and the surf... Creep feed profile grinding of the fir-tree blade root forms of single crystal nickel-based superalloy was conducted using microcrystalline alumina abrasive wheels in the present study. The grinding force and the surface quality in terms of surface topography, subsurface microstructure,microhardness and residual stress obtained under different grinding conditions were evaluated comparatively. Experimental results indicated that the grinding force was influenced significantly by the competing predominance between the grinding parameters and the cross-sectional root workpiece profile. In addition, the root workpiece surface, including the root peak and valley regions, was produced with the large difference in surface quality due to the nonuniform grinding loads along the root workpiece profile in normal section. Detailed results showed that the surface roughness, subsurface plastic deformation and work hardening level of the root valley region were higher by up to25%, 20% and 7% in average than those obtained in the root peak region, respectively, in the current investigation. Finally, the superior parameters were recommended in the creep feed profile grinding of the fir-tree blade root forms. This study is helpful to provide industry guidance to optimize the machining process for the high-valued parts with complicated profiles. 展开更多
关键词 Creep feed profile grinding Fir-tree blade root Grinding force Single crystal nickel-based superalloy Surface quality
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Characterization of the aerosol chemical composition during the COVID-19 lockdown period in Suzhou in the Yangtze River Delta,China 被引量:8
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作者 Honglei Wang qing miao +7 位作者 Lijuan Shen Qian Yang Yezheng Wu Heng Wei Yan Yin Tianliang Zhao Bin Zhu Wen Lu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第4期110-122,共13页
To control the spread of COVID-19,rigorous restrictions have been implemented in China,resulting in a great reduction in pollutant emissions.In this study,we evaluated the air quality in the Yangtze River Delta during... To control the spread of COVID-19,rigorous restrictions have been implemented in China,resulting in a great reduction in pollutant emissions.In this study,we evaluated the air quality in the Yangtze River Delta during the COVID-19 lockdown period using satellite and ground-based data,including particle matter(PM),trace gases,water-soluble ions(WSIs) and black carbon(BC).We found that the impacts of lockdown policy on air quality cannot be accurately assessed using MODIS aerosol optical depth(AOD) data,whereas the tropospheric nitrogen dioxide(NO_(2)) vertical column density can well reflect the influences of these restrictions on human activities.Compared to the pre-COVID period,the PM_(2.5),PM_(10),NO_(2),carbon monoxide(CO),BC and WSIs during the lockdown in Suzhou were observed to decrease by 37.2%,38.3%,64.5%,26.1%,53.3% and 58.6%,respectively,while the sulfur dioxide(SO_(2)) and ozone(O_(3)) increased by 1.5% and 104.7%.The WSIs ranked in the order of NO_(3)~->NH_(4)^(+)>SO_(4)^(2-)>Cl~->Ca^(2+)>K^(+)>Mg^(2+)>Na + during the lockdown period.By comparisons with the ion concentrations during the pre-COVID period,we found that the ions NO 3-,NH 4 +,SO_(4)^(2-),Cl~-,Ca^(2+),K^(+) and Na^(+) decreased by 66.3%,48.8%,52.9%,56.9%,57.9% and 76.3%,respectively,during the lockdown,in contrast to Mg^(2+),which increased by 30.2%.The lockdown policy was found to have great impacts on the diurnal variations of Cl~-,SO_(4)^(2-),Na^(+) and Ca^(2+). 展开更多
关键词 COVID-19 Lockdown Satellite data Chemical composition Diurnal variation
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溶解润湿动力学的物理力学
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作者 苗青 杨锦鸿 +1 位作者 袁泉子 赵亚溥 《科学通报》 EI CAS CSCD 北大核心 2018年第28期2985-2993,共9页
溶解润湿涉及润湿、扩散及对流多个复杂的物理过程.本文采用物理力学方法研究了溶解润湿的动态过程,分析了溶质粒子进入液体内部对于液滴铺展、溶剂结构以及液滴内部流场造成的影响,结合理论得到了溶解润湿过程中的标度律.研究结果表明... 溶解润湿涉及润湿、扩散及对流多个复杂的物理过程.本文采用物理力学方法研究了溶解润湿的动态过程,分析了溶质粒子进入液体内部对于液滴铺展、溶剂结构以及液滴内部流场造成的影响,结合理论得到了溶解润湿过程中的标度律.研究结果表明在液滴铺展前期界面张力驱动占主导,标度关系满足Tanner律.随着溶解的进行,溶质粒子进入液滴内部一方面造成溶剂分子结构的变化,另一方面浓度梯度的存在加快了液滴的铺展速度并改变了液滴内部的流场,且液滴内部流场中有无对流对于液滴铺展标度律会产生显著的影响.因此,溶解润湿对于液滴的内部结构、流场及铺展过程都会产生重要的影响,其研究对于理解、控制和优化涉及溶解润湿的实际问题具有十分重要的意义. 展开更多
关键词 溶解润湿 移动接触线 标度律 液滴 界面动力学
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An investigation on machined surface quality and tool wear during creep feed grinding of powder metallurgy nickel-based superalloy FGH96 with alumina abrasive wheels 被引量:8
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作者 Ben-Kai Li qing miao +2 位作者 Min Li Xi Zhang Wen-Feng Ding 《Advances in Manufacturing》 SCIE CAS CSCD 2020年第2期160-176,共17页
In this study,the machined surface quality of powder metallurgy nickel-based superalloy FGH96(similar to Rene88DT)and the grinding characteristics of brown alumina(BA)and microcrystalline alumina(MA)abrasive wheels we... In this study,the machined surface quality of powder metallurgy nickel-based superalloy FGH96(similar to Rene88DT)and the grinding characteristics of brown alumina(BA)and microcrystalline alumina(MA)abrasive wheels were comparatively analyzed during creep feed grinding.The infuences of the grinding parameters(abrasive wheel speed,workpiece infeed speed,and depth of cut)on the grinding force,grinding temperature,surface roughness,surface morphology,tool wear,and grinding ratio were analyzed comprehensively.The experimental results showed that there was no significant difference in terms of the machined surface quality and grinding characteristics of FGH96 during grinding with the two types of abrasive wheels.This was mainly because the grinding advantages of the MA wheel were weakened for the difficult-to-cut FGH96 material.Moreover,both the BA and MA abrasive wheeIs exhibited severe tool wear in the form of wheel clogging and workpiece material adhesion.Finally,an analytical model for prediction of the grinding ratio was established by combining the tool wear volume,grinding force,and grinding length.The acceptable errors between the predicted and experimental grinding ratios(ranging from 0.6 to 1.8)were 7.56%and 6.31%for the BA and MA abrasive wheels,respectively.This model can be used to evaluate quantitatively the grinding performance of an alumina abrasive wheel,and is therefore helpful for optimizing the grinding parameters in the creep feed grinding process. 展开更多
关键词 Creep feed grinding Powder metallurgy nickel-based superalloy Surface quality Alumina abrasive wheel Tool wear
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Fretting wear behaviour of machined layer of nickel-based superalloy produced by creep-feed profile grinding 被引量:3
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作者 Weijie KUANG qing miao +4 位作者 Wenfeng DING Yanjun ZHAO Biao ZHAO Xuebing WEN Shaopeng LI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第10期401-411,共11页
Fretting wear has an adverse impact on the fatigue life of turbine blade roots.The current work is to comparatively investigate the fretting wear behaviour of the nickel-based superalloy surfaces produced by polishing... Fretting wear has an adverse impact on the fatigue life of turbine blade roots.The current work is to comparatively investigate the fretting wear behaviour of the nickel-based superalloy surfaces produced by polishing and creep-feed profile grinding,respectively,in terms of surface/subsurface fretting damage,the friction coefficient,wear volume and wear rate.Experimental results show that the granulated tribolayer aggravates the workpiece wear,while the flat compacted tribolayer enhances the wear resistance ability of workpiece,irrespective of whether the workpiece is processed by polishing or grinding.However,the wear behaviors of tribolayers are different.For the polished surface,when the normal load exceeds 100 N,the main defects are crack,rupture,delamination and peeling of workpiece materials;the wear mechanism changes from severe oxidative wear to fatigue wear and abrasive wear when the loads increase from 50 to 180 N.As for the ground surface,the main wear mechanism is abrasive wear.Particularly,the ground surface possesses better wear-resistant ability than the polished surface because the former has the lower values in coefficient friction(0.23),wear volume(0.06×10^(6)μm^(3))and wear rate(0.25×10^(-16)Pa^(-1)).Finally,an illustration is given to characterize the evolution of wear debris on such nickel-based superalloy on the ground surface. 展开更多
关键词 Creep-feed profile grinding Fretting wear Nickel-based superalloy TRIBOLAYER Wear debris
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白头翁皂苷及其单体抗肿瘤作用及机制的研究进展 被引量:3
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作者 宋慧慧 向卓 +3 位作者 薛淑一 苗青 赵丽艳 李明春 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2021年第5期381-392,共12页
白头翁是我国中医中一味传统的中药材,广泛应用于中医临床。近年来的医学研究发现,从白头翁中提取的天然产物白头翁皂苷及其单体化合物具有多种生物活性,尤其是从中分离得到的三萜类皂苷,具有显著且广谱的抗肿瘤作用,其潜在抗肿瘤分子... 白头翁是我国中医中一味传统的中药材,广泛应用于中医临床。近年来的医学研究发现,从白头翁中提取的天然产物白头翁皂苷及其单体化合物具有多种生物活性,尤其是从中分离得到的三萜类皂苷,具有显著且广谱的抗肿瘤作用,其潜在抗肿瘤分子机制包括抑制肿瘤细胞的生长和增殖、抑制肿瘤细胞的迁移、侵袭和转移、阻滞肿瘤细胞周期、调控癌细胞能量代谢、抗肿瘤血管生成、诱导癌细胞分化、凋亡和自噬、逆转癌细胞耐药、调节多种相关信号通路及改善肿瘤细胞的炎症微环境等。本文对白头翁皂苷及其单体在不同肿瘤中的相关抗癌机制进行综述,旨在为白头翁及其单体的抗肿瘤新药研发及临床应用提供理论基础。 展开更多
关键词 白头翁 白头翁皂苷 单体 抗肿瘤作用 分子机制
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钙钛矿上单原子位点实现高灵敏定量化表面拉曼增强 被引量:2
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作者 冯冉 苗清 +18 位作者 张翔 崔培昕 王聪 冯奕博 甘立勇 傅加兴 王仕博 戴子忆 胡利明 罗云敬 孙伟海 张小娴 肖家文 巫金波 周冰朴 邹明强 何大伟 周小元 韩晓东 《Science China Materials》 SCIE EI CAS CSCD 2022年第6期1601-1614,共14页
表面增强拉曼散射(SERS)是一种快速且无损的化学和生物分子检测技术.高灵敏且定量化的SERS检测技术对其在实际中的应用至关重要,尤其是对生物分子如氨基酸和碱基的便携化检测.但是鲜有技术手段能够实现对这些最基本的生物分子进行高灵... 表面增强拉曼散射(SERS)是一种快速且无损的化学和生物分子检测技术.高灵敏且定量化的SERS检测技术对其在实际中的应用至关重要,尤其是对生物分子如氨基酸和碱基的便携化检测.但是鲜有技术手段能够实现对这些最基本的生物分子进行高灵敏且定量化的拉曼检测.我们提出了一种无需贵金属的单原子位点修饰芯片策略,用钨单原子氧化物修饰铅卤钙钛矿芯片,实现了多种检测物的高灵敏定量化识别,包括罗丹明、酪氨酸和胞嘧啶.芯片上单原子位点技术能够实现对罗丹明、酪氨酸和胞嘧啶的线性检测,相应的定量化区间分别为:10^(−6)–1 mmol L^(−1),0.06–1 mmol L^(−1)和0.2–45 mmol L^(−1),同时我们的拉曼增强芯片对这三种分子的增强因子在非等离子激元半导体中是最高的.我们通过实验测试结合理论模拟揭示了由可控单原子位点实现拉曼增强的机理:束缚由钙钛矿基底产生的光生电子,同时高效且定量地将这些电子转移到待测分子上.不仅如此,芯片上单原子位点技术可以在便携式拉曼设备下得到与台式拉曼设备类似的增强效果,这意味着这项技术有机会应用于多种生物分子的低成本、广谱、即时检测和体外检测. 展开更多
关键词 SERS single-atom site point-of-care testing in-vitro diagnosis charge-transfer mechanism lead halide perovskite
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