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基于Tv-SECOND的自动驾驶场景下的3D目标检测
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作者 魏海跃 杨奎河 毕江峰 《无线电通信技术》 北大核心 2024年第4期823-830,共8页
针对自动驾驶场景中复杂环境下的3D目标检测任务,特别是远距离和遮挡条件下,为提高模型的检测准确率,在SECOND的基础上提出了Tv-SECOND两阶段算法。该算法提出一种基于Transformer架构的提案框特征提取模块,并在传统体素特征编码基础上... 针对自动驾驶场景中复杂环境下的3D目标检测任务,特别是远距离和遮挡条件下,为提高模型的检测准确率,在SECOND的基础上提出了Tv-SECOND两阶段算法。该算法提出一种基于Transformer架构的提案框特征提取模块,并在传统体素特征编码基础上提出可变形的体素特征编码模块。在KITTI数据集上进行测试,结果显示,所提出的算法相比SECOND在远距离和遮挡严重的情况下分别提高了7.49%、9.72%。同时与其他先进的两阶段方法相比,检测精度有不同程度的提升,证明了Tv-SECOND算法的有效性。新算法能够建立特征之间的依赖关系,聚合周边广域的上下文信息,增强模型的学习推理能力,有效提升了模型在远距离和遮挡的情况下的检测性能。 展开更多
关键词 自动驾驶 3D目标检测 TRANSFORMER second
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适用于SLA型3D打印机的隐身功能油墨性能研究
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作者 刘创纪 徐英杰 +2 位作者 黄蓓青 赵星宇 王雨欣 《包装工程》 CAS 北大核心 2024年第13期292-299,共8页
目的制备可适用于SLA型3D打印机的隐身功能油墨,并研究油墨性能、3D打印样品的力学性能和隐身性能(吸波性能)。方法以光敏树脂作为树脂连接料,加入不同含量的MWNTs/PPy/Fe_(3)O_(4)复合材料,得到适用于SLA型3D打印机的隐身功能油墨,并... 目的制备可适用于SLA型3D打印机的隐身功能油墨,并研究油墨性能、3D打印样品的力学性能和隐身性能(吸波性能)。方法以光敏树脂作为树脂连接料,加入不同含量的MWNTs/PPy/Fe_(3)O_(4)复合材料,得到适用于SLA型3D打印机的隐身功能油墨,并进行流变性能、分散性能等测试。3D打印制备测试样品,进行力学性能、电磁性能和隐身性能分析。结果不同电磁吸收剂含量对隐身功能油墨的黏度、分散性有较大影响,对表面张力影响较小。吸收剂质量分数为0.4%的3D打印样品力学性能和隐身性能都较好,最大反射损耗为-23.36dB。结论本研究制备的隐身功能油墨满足SLA型3D打印机使用要求,打印的材料隐身性能良好。 展开更多
关键词 立体光固化成型 3D打印 隐身材料 微波吸收
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Researching Creativity in Second Language Acquisition:Book Review
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作者 SHEN Rong-xi ZENG Hai-xiang 《Journal of Literature and Art Studies》 2024年第3期215-219,共5页
In the realm of psychology and language acquisition,the exploration of“individual differences”-encompassing attributes such as personality traits,motivation,and language aptitude-has long been a focal point of schol... In the realm of psychology and language acquisition,the exploration of“individual differences”-encompassing attributes such as personality traits,motivation,and language aptitude-has long been a focal point of scholarly investigation.Within this sphere,the book“Researching Creativity in Second Language Acquisition”by Ashleigh Pipes offers a fresh perspective on the role of creativity as a significant individual difference in Second Language Acquisition(SLA).Positioned against the backdrop of extensive empirical research on individual differences,this book stands out by focusing on the often overlooked aspect of creativity,which Pipes argues,holds paramount importance in SLA. 展开更多
关键词 second Language Acquisition(sla) CREATIVITY
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基于SLA工艺的汽车开口检具研究
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作者 王洪乐 张森 +1 位作者 张瑞要 史铭 《模具工业》 2024年第7期58-63,共6页
针对汽车制造过程中工装支具检具数量多、机械加工费用高和生产周期长等问题,采用了SLA工艺进行汽车开口检具制造的研究。使用FDM工艺和SLA工艺分别打印了汽车后三角窗开口检具,对该开口检具进行了尺寸测量和精度分析,尺寸精度在0.2 mm... 针对汽车制造过程中工装支具检具数量多、机械加工费用高和生产周期长等问题,采用了SLA工艺进行汽车开口检具制造的研究。使用FDM工艺和SLA工艺分别打印了汽车后三角窗开口检具,对该开口检具进行了尺寸测量和精度分析,尺寸精度在0.2 mm以内;基于汽车开口检具使用环境,对比了多种液态光敏树脂材料的性能参数,最后从成本角度对比分析了多款设备和多种材料,在综合考虑变形、变色和成本等因素,使用SLA工艺打印汽车开口检具是经济可行的,为SLA工艺在汽车生产制造过程中的应用提供了实践参考案例。 展开更多
关键词 3D打印 sla工艺 开口检具 尺寸精度 光敏树脂
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Understanding the catalytic performance and deactivation behaviour of second-promoter doped Pt/WO_(χ)/γ-Al_(2)O_(3) catalysts in the glycerol hydrogenolysis for selective and cleaner production of 1,3-propanediol
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作者 Rafik Rajjak Shaikh Sittichai Damruang +2 位作者 Rais Ahmad Khan Supareak Praserthdam Piyasan Praserthdam 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期486-507,共22页
The selective aqueous-phase glycerol hydrogenolysis is a promising reaction to produce commercially useful 1,3-propanediol(1,3-PDO).The Pt-WOx bifunctional catalyst can catalyse the glycerol hydrogenol-ysis but the ca... The selective aqueous-phase glycerol hydrogenolysis is a promising reaction to produce commercially useful 1,3-propanediol(1,3-PDO).The Pt-WOx bifunctional catalyst can catalyse the glycerol hydrogenol-ysis but the catalyst deactivation via sintering,metal leaching,and coking can predominantly occur in the aqueous phase reaction.In this work,the effect of reaction temperature,pressure and second promoter(Cu,Fe,Rh,Mn,Re,Ru,Ir,Sn,B,and P)on catalytic performance and deactivation behaviour of Pt/WOx/-Al2O3 was investigated.When doped with Rh,Mn,Re,Ru,Ir,B,and P,the second promoter boosts catalytic activity by promoting great dispersion of Pt on support and increasing Pt surface area.The increased Bronsted acid sites lead to selective synthesis of 1,3-PDO than 1,2-propanediol(1,2-PDO).The characterization studies of fresh and spent catalysts reveal that the main cause of catalyst deactivation is the Pt sintering,as interpreted based on XRD,CO chemisorption,and TEM analyses.The Pt sintering is affected depending on the second promoter that can either or reduce the interaction between Pt,WO_(χ)/γ and Al_(2)O_(3).As an electron acceptor of Pt in Pt/WO_(χ)/γ-Al_(2)O_(3),Re and Mn as second promoters resulted in increased Pt^(2+) on the catalytic surface,which strengthens the contact between Pt andγ-Al_(2)O_(3) and WO_(χ),resulting in a decrease in Pt sintering.The metal leaching and coking are not affected by the presence of second promoter.The catalyst modified with a second promoter possesses improved catalytic activity and 1,3-PDO production,however the stability continues to remain a challenge.The present work unrav-elled the determining parameters of catalytic activity and deactivation,thus providing a promising pro-tocol toward effective catalysts for glycerol hydrogenolysis. 展开更多
关键词 Glycerol hydrogenolysis 1 3-PROPANEDIOL Metal-support interaction second promoter Liquid phase Catalyst deactivation
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A Review of Research on Second Language Acquisition from a Positive Psychology Perspective
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作者 Yanhui Wu 《Journal of Contemporary Educational Research》 2024年第6期189-193,共5页
This paper reviews the research on second language acquisition from the perspective of positive psychology.First,it introduces the background and purpose of the study and discusses the significance of the application ... This paper reviews the research on second language acquisition from the perspective of positive psychology.First,it introduces the background and purpose of the study and discusses the significance of the application of positive psychology in the field of language acquisition.Then,the basic theories of positive psychology,including the core concepts and principles of positive psychology,are summarized.Subsequently,the theory of second language acquisition is defined and outlined,including the definition,characteristics,and related developmental theories of second language acquisition.On this basis,the study of second language acquisition from the perspective of positive psychology is discussed in detail.By combing and synthesizing the literature,this paper summarizes the current situation and trend of second language acquisition research under the perspective of positive psychology and puts forward some future research directions and suggestions. 展开更多
关键词 Positive psychology second language acquisition Language learning motivation Positive emotion Positive mindset
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Research on the Application of Second Language Acquisition Theory in College English Speech Teaching
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作者 Hui Zhang 《Journal of Contemporary Educational Research》 2024年第3期173-178,共6页
The teaching of English speeches in universities aims to enhance oral communication ability,improve English communication skills,and expand English knowledge,occupying a core position in English teaching in universiti... The teaching of English speeches in universities aims to enhance oral communication ability,improve English communication skills,and expand English knowledge,occupying a core position in English teaching in universities.This article takes the theory of second language acquisition as the background,analyzes the important role and value of this theory in English speech teaching in universities,and explores how to apply the theory of second language acquisition in English speech teaching in universities.It aims to strengthen the cultivation of English skilled talents and provide a brief reference for improving English speech teaching in universities. 展开更多
关键词 second language acquisition theory Teaching English speeches in universities Practical strategies
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Research on Practical Teaching of Ideological and Political Courses in Colleges and Universities and Collaborative Education in the Second Classroom
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作者 Luhua Xiao Pingping Liu Zimeng Li 《Journal of Contemporary Educational Research》 2024年第1期214-220,共7页
In today’s society,the need for talent training is of utmost importance due to rapid development.To achieve high-quality talent training,we need to focus on building a collaborative education mechanism.Practical teac... In today’s society,the need for talent training is of utmost importance due to rapid development.To achieve high-quality talent training,we need to focus on building a collaborative education mechanism.Practical teaching and the second classroom,which serve as important carriers of educational talents,must align their educational goals and complement each other.This article explores the collaborative education mechanism of the second classroom and practical teaching for the ideological and political courses in colleges and universities.It proposes reasonable construction measures to provide some guidelines for teaching work. 展开更多
关键词 Colleges and universities Ideological and political courses Practical teaching second classroom Collaborative education
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The Convergence Rate of Fréchet Distribution under the Second-Order Regular Variation Condition
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作者 Xilai Dai 《Journal of Applied Mathematics and Physics》 2024年第5期1597-1605,共9页
In this article we consider the asymptotic behavior of extreme distribution with the extreme value index γ>0 . The rates of uniform convergence for Fréchet distribution are constructed under the second-order ... In this article we consider the asymptotic behavior of extreme distribution with the extreme value index γ>0 . The rates of uniform convergence for Fréchet distribution are constructed under the second-order regular variation condition. 展开更多
关键词 Convergence Rate second-Order Regular Variation Condition Fréchet Distribution Extreme Value Index
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Analysis of Second Language Acquisition in Lost in Translation a Life in a New Language from the Perspective of Sociolinguistics
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作者 蒋馨 《海外英语》 2013年第19期186-187,共2页
Eva Hoffman’s Lost in Translation:A life in a New Language is prominent in that it spares no effort elaborating on the author’s personal experience in acquiring her second language(L2)English from the view of sociol... Eva Hoffman’s Lost in Translation:A life in a New Language is prominent in that it spares no effort elaborating on the author’s personal experience in acquiring her second language(L2)English from the view of sociolinguistics.In this vein,by in vestigating the underlined relationship between language learners’cultural identity and language identity from the perspective of sociolinguistics,the paper aims to explore the possibilities of assisting L2 learners reach a balance in their biological,cultural,so cial,and psychological domains of life. 展开更多
关键词 second language ACQUISITION IDENTITY sociolinguist
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SLA-Bio处理对纯钛表面MC3T3-E1细胞黏附行为的影响 被引量:1
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作者 周冠军 于晴 +2 位作者 赵甜甜 王叶青 梅双 《河北医药》 CAS 2023年第1期52-55,共4页
目的在传统喷砂酸蚀(SLA)处理基础上对纯钛表面进行喷砂、蚀刻和生物矿化(SLA-Bio)处理,观察其表面MC3T3-E1前成骨细胞的黏附铺展行为,以期为纯钛种植体表面改性提供更多研究方向。方法将纯钛片分为SLA组(TiO_(2)砂粒喷砂+HCI/H_(2)SO_... 目的在传统喷砂酸蚀(SLA)处理基础上对纯钛表面进行喷砂、蚀刻和生物矿化(SLA-Bio)处理,观察其表面MC3T3-E1前成骨细胞的黏附铺展行为,以期为纯钛种植体表面改性提供更多研究方向。方法将纯钛片分为SLA组(TiO_(2)砂粒喷砂+HCI/H_(2)SO_(4)混合液酸蚀)和SLA-Bio组(SLA处理后再进行矿化处理14 d),通过SEM-EDS观察钛片表面形貌并分析其表面元素构成。于2组钛片表面接种MC3T3-E1细胞,分别于接种后1 h、6 h、24 h取出钛片,MTT法计算并比较2组钛片表面细胞黏附率,通过荧光染色观察、Image Pro Plus软件分析计算,比较不同表面MC3T3-E1细胞铺展行为及形态因子的差异。结果SLA组钛片表面呈蜂窝状、大小不一、深浅不等的不规则孔洞结构,SLA-Bio组钛片表面可见多孔微纳米球状羟磷灰石(hydroxyapatite,HA)沉积物,球体表面可见针状纳米微粒;MC3T3-E1细胞接种后1 h、6 h、24 h时,SLA-Bio组细胞黏附率均明显高于SLA组(P<0.05),SLA-Bio组细胞形态因子均明显低于SLA组(P<0.05);细胞荧光染色结果显示,与SLA组相比,SLA-Bio组在接种后各个时间段均呈现更好的黏附伸展形态。结论SLA-Bio处理可在纯钛表面形成多孔微纳米球状HA沉积物;SLA-Bio表面较SLA表面更有利于MC3T3-E1细胞的黏附和伸展,可能促进种植体骨结合的过程。 展开更多
关键词 sla-Bio表面处理 MC3T3-E1细胞 细胞黏附 细胞形态因子
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实验用荣昌猪SLA-1等位基因鉴定及分子遗传特征分析 被引量:1
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作者 刘弘毅 罗霆宇 +5 位作者 李昌文 于海波 路小野 陈洪岩 夏长友 高彩霞 《畜牧兽医学报》 CAS CSCD 北大核心 2023年第7期3064-3077,共14页
旨在明确实验用荣昌猪SLA遗传背景,深入研究SLA-1分子相关的抗原递呈和免疫应答机制,本研究对27头荣昌猪采集抗凝血,分离外周血淋巴细胞,提取总RNA,设计特异性引物对SLA-1基因进行RT-PCR扩增、克隆和测序,对获得序列的分子特征进行分析... 旨在明确实验用荣昌猪SLA遗传背景,深入研究SLA-1分子相关的抗原递呈和免疫应答机制,本研究对27头荣昌猪采集抗凝血,分离外周血淋巴细胞,提取总RNA,设计特异性引物对SLA-1基因进行RT-PCR扩增、克隆和测序,对获得序列的分子特征进行分析。结果显示,荣昌猪中共获得11个SLA-1等位基因,其中,9个为新等位基因,全部获得GenBank登录号和ISAG SLA命名委员会官方命名,SLA-1^(*)24:01等位基因在该群体中频率最高。SLA-1基因编码区全长1086 bp,存在127个核苷酸多态位点,非同义单核苷酸多态性位点数高于同义单核苷酸多态性位点数。核苷酸多样度为0.0449,单倍型多样度为1,平均核苷酸差异数为48.782,G+C含量为64.9%。SLA-1基因编码的361个氨基酸中,有75个氨基酸变异位点;第2和第3外显子编码区多态性最高,且第2外显子区域的氨基酸变异程度高于第3外显子区,组成抗原肽结合槽6个口袋的33个关键氨基酸位点中,11个在人与荣昌猪之间高度保守,与β2-微球蛋白结合的19个关键氨基酸位点中,10个保持一致,CD8分子与MHC结合的关键氨基酸位点中,只有225(Thr/Ser)和228(Thr/Met)位点不同。同源性和系统进化树分析表明,SLA-1^(*)10:03和SLA-1^(*)18:03分别与人HLA-A^(*)02:01和HLA-A^(*)11:01等位基因的同源性最高,荣昌猪与亚洲野猪、巴马小型猪和融水小型猪等亚洲猪种具有较近的亲缘关系。本研究成功获得了中国地方猪种荣昌猪SLA-1基因,发现其具有极为丰富的多态性,为揭示荣昌猪的SLA遗传背景和开展异种移植研究奠定了遗传学基础。 展开更多
关键词 荣昌猪 sla-1等位基因 鉴定 分子特征
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5G网络切片SLA监控及保障研究 被引量:2
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作者 刘惜吾 黄蓉 王笃炎 《信息通信技术》 2023年第1期64-70,共7页
文章针对5G切片网络质量保障的典型需求展开研究,通过分析5G切片SLA监控及保障面临的挑战,提出了一种切片MOS值智能训练框架及模型,结合端到端切片SLA指标采集、切片指标智能分析,构建了5G确定性服务监控及质量保障体系。同时,针对行业... 文章针对5G切片网络质量保障的典型需求展开研究,通过分析5G切片SLA监控及保障面临的挑战,提出了一种切片MOS值智能训练框架及模型,结合端到端切片SLA指标采集、切片指标智能分析,构建了5G确定性服务监控及质量保障体系。同时,针对行业客户对切片SLA的自运维需求,研究并开发了三种SLA能力开放共享方式,该方案已在现网部署,为5G网络切片质量监控提供了一种有效的可视、可管、可控工具,有效满足行业客户数智化转型需求。 展开更多
关键词 5G切片网络质量保障 切片MOS值 sla自运维 能力开放
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Translating new data to the daily practice in second line treatment of renal cell carcinoma:The role of tumor growth rate 被引量:1
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作者 Enrique Grande Olga Martínez-Sáez +1 位作者 Pablo Gajate-Borau Teresa Alonso-Gordoa 《World Journal of Clinical Oncology》 CAS 2017年第2期100-105,共6页
The therapeutic options for patients with metastatic renal cell carcinoma(mRCC) have completely changed during the last ten years. With the sequential use of targeted therapies, median overall survival has increased i... The therapeutic options for patients with metastatic renal cell carcinoma(mRCC) have completely changed during the last ten years. With the sequential use of targeted therapies, median overall survival has increased in daily practice and now it is not uncommon to see patients surviving kidney cancer for more than four to five years. Once treatment fails with the first line targeted therapy, head to head comparisons have shown that cabozantinib, nivolumab and the combination of lenvatinib plus everolimus are more effective than everolimus alone and that axitinib is more active than sorafenib. Unfortunately, it is very unlikely that we will ever have prospective data comparing the activity of axitinib, cabozantinib, lenvatinib or nivolumab. It is frustrating to observe the lack of biomarkers that we have in this field, thus there is no firm recommendation about the optimal sequence of treatment in the second line. In the absence of reliable biomarkers, there are several clinical endpoints that can help physicians to make decisions for an individual patient, such as the tumor burden, the expected response rate and the time to achieve the response to each agent, the prior response to the agent administered, the toxicity profile of the different compounds and patient preference. Here, we propose the introduction of the tumor-growth rate(TGR) during first-line treatment as a new tool to be used to select the second line strategy in m RCC. The rapidness of TGR before the onset of the treatment reflects the variability between patients in terms of tumor growth kinetics and it could be a surrogate marker of tumor aggressiveness that may guide treatment decisions. 展开更多
关键词 AXITINIB EVEROLIMUS Cabozantinib Kidney cancer Nivolumab RENAL cell Sequence second line SORAFENIB TUMOR-GROWTH rate
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苏紫猪SLA-1基因多态性及其抗病潜能分析 被引量:1
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作者 王泽平 王飞飞 +6 位作者 张芮铭 付言峰 赵为民 戴超辉 程金花 廖超 李辉 《中国畜牧兽医》 CAS CSCD 北大核心 2023年第5期1918-1927,共10页
【目的】探究苏紫猪白细胞抗原-1(swine leukocyte antigen-1,SLA-1)基因多态性,并对其抗病潜能进行分析,以期为苏紫猪分子育种提供理论基础。【方法】以苏紫猪血细胞cDNA为模板,用PCR法扩增苏紫猪SLA-1基因并测序,利用DNAStar和Mega 5.... 【目的】探究苏紫猪白细胞抗原-1(swine leukocyte antigen-1,SLA-1)基因多态性,并对其抗病潜能进行分析,以期为苏紫猪分子育种提供理论基础。【方法】以苏紫猪血细胞cDNA为模板,用PCR法扩增苏紫猪SLA-1基因并测序,利用DNAStar和Mega 5.0软件分别进行相似性分析及系统进化树构建;利用NetMHCpan 4.1 server分析SLA-1与非洲猪瘟病毒(African swine fever virus,ASFV)抗原表位结合的能力及特征;运用生物学软件对其编码蛋白的理化性质、亲/疏水性、跨膜区、结构和功能等进行预测。【结果】试验成功扩增6条苏紫猪SLA-1等位基因序列,分别为SLA-1*sz01、SLA-1*sz02、SLA-1*sz03、SLA-1*sz04、SLA-1*sz05和SLA-1*sz06,其高变异位点主要位于肽结合沟(peptide-binding groove,PBG)α1区和α2区;相似性比对结果显示,6条苏紫猪SLA-1等位基因核苷酸、氨基酸序列相似性分别在92.9%~96.9%、87.0%~94.8%之间,与不同品种猪核苷酸、氨基酸序列相似性分别在92.8%~98.8%、84.3%~98.0%之间;ASFV来源多肽结合能力的预测结果显示,SLA-1*sz01蛋白具有较强的ASFV抗原呈递能力,与ASFV来源B354L蛋白多肽片段FIDKTTVLY具有最高亲和力;SLA-1*sz01蛋白功能域及三级结构预测结果显示,SLA-1*sz01与免疫系统相关,具有经典的SLA-1三级结构。【结论】本研究扩增得到6条苏紫猪SLA-1基因序列,其中SLA-1*sz01能够限制性结合较多的ASFV来源抗原表位多肽,与多肽片段FIDKTTVLY具有最高亲和力,可作为苏紫猪抗病育种的候选基因。研究结果为ASFV疫苗的研发提供参考基础。 展开更多
关键词 苏紫猪 sla-1基因 多态性 抗原结合位点 抗病潜能
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Low-temperatures synthesis of CuS nanospheres as cathode material for magnesium second batteries 被引量:2
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作者 Qin Zhang Yaobo Hu +1 位作者 Jun Wang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第1期192-200,共9页
Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching ... Rechargeable magnesium batteries(RMBs),as one of the most promising candidates for efficient energy storage devices with high energy,power density and high safety,have attracted increasing attention.However,searching for suitable cathode materials with fast diffusion kinetics and exploring their magnesium storage mechanisms remains a great challenge.Cu S submicron spheres,made by a facile low-temperature synthesis strategy,were applied as the high-performance cathode for RMBs in this work,which can deliver a high specific capacity of 396mAh g^(-1)at 20 mA g^(-1) and a remarkable rate capacity of 250 m Ah g^(-1)at 1000 mA g^(-1).The excellent rate performance can be assigned to the nano needle-like particles on the surface of Cu S submicron spheres,which can facilitate the diffusion kinetics of Mg^(2+).Further storage mechanism investigations illustrate that the Cu S cathodes experience a two-step conversion reaction controlled by diffusion during the electrochemical reaction process.This work could make a contribution to the study of the enhancement of diffusion kinetics of Mg2+and the reaction mechanism of RMBs. 展开更多
关键词 Magnesium second batteries Cathode material CUS Submicron spheres Low-temperature synthesis.
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Temporal electric field of a helium plasma jet by electric field induced second harmonic(E-FISH)method 被引量:2
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作者 李旭 晋绍珲 +3 位作者 宋珂 聂兰兰 刘大伟 卢新培 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第1期43-52,共10页
Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is d... Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field). 展开更多
关键词 atmospheric pressure plasma jet electric field electric field induced second harmonic
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ON THE COMPLETE 2-DIMENSIONALλ-TRANSLATORS WITH A SECOND FUNDAMENTAL FORM OF CONSTANT LENGTH
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作者 李兴校 乔瑞娜 刘洋洋 《Acta Mathematica Scientia》 SCIE CSCD 2020年第6期1897-1914,共18页
In this article we study the two-dimensional completeλ-translators immersed in the Euclidean space R^3 and Minkovski space R1^ 3.We obtain two classification theorems:one for two-dimensional completeλ-translators x:... In this article we study the two-dimensional completeλ-translators immersed in the Euclidean space R^3 and Minkovski space R1^ 3.We obtain two classification theorems:one for two-dimensional completeλ-translators x:M 2→R^3 and one for two-dimensional complete space-likeλ-translators x:M 2→R1^3,with a second fundamental form of constant length. 展开更多
关键词 singular solution mean curvature flow second fundamental form λ-translator classification
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The Second International Conference on HSLA Steels
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《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1989年第9期224-225,共2页
GENERAL INFORMATIONThe Chinese Society of Metals is pleased to announcethat The Second International Conference on HSLASteels(HSEA’90)will be held in Beijing,China inOctober 1990.Much progress in research and devel-o... GENERAL INFORMATIONThe Chinese Society of Metals is pleased to announcethat The Second International Conference on HSLASteels(HSEA’90)will be held in Beijing,China inOctober 1990.Much progress in research and devel-opment of HSLA steels has been achieved by theworld’s metallurgical and materials community sincethe previous International Conference HSLA Steels’85 was held in Beijing,The aim of the conference isto review and to consolidate the scientific,metallurgical,and economical results and to assessthe future trend of development in the fields. 展开更多
关键词 Hsla MET The second International Conference on Hsla Steels
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Preliminary Announcement for the Second International Conference on HSLA Steels
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《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1989年第2期140-141,共2页
General Information The Chinese Society of Metals ispleased to announce that The SecondInternational Conference on HSLA Steels(HSLA ’90) will be held in Beijing, Chinain October, 1990. Much progress in researchand de... General Information The Chinese Society of Metals ispleased to announce that The SecondInternational Conference on HSLA Steels(HSLA ’90) will be held in Beijing, Chinain October, 1990. Much progress in researchand development of HSLA steels has beenachieved by the world’s metallurgical andmaterials community since the previousInternational Conference HSLA Steels ’85 展开更多
关键词 Hsla Preliminary Announcement for the second International Conference on Hsla Steels
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