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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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Hydrogen Spillover Effect in Electrocatalysis:Delving into the Mysteries of the Atomic Migration
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作者 Ashish Gaur Jatin Sharma HyukSu Han 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期181-205,共25页
Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydroge... Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word"hydrogen spillover."However,there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect.Currently,the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect.The understanding of material fabrication for hydrogen spillover effect has erupted.Considering these factors,we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication.All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance.In addition,we have attempted to elucidate the spillover paths through the utilization of DFT calculations.Furthermore,we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area. 展开更多
关键词 ELECTROCATALYSIS hydrogen evolution reaction hydrogen spillover effect interfacial atomic migration metal-support interaction
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Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers
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作者 Jingyi Xie Fuli Wang +3 位作者 Yanan Zhou Yiwen Dong Yongming Chai Bin Dong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期438-449,共12页
The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous... The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h. 展开更多
关键词 Hydroxyl spillover effect Internal polarization field HETEROSTRUCTURE Oxygen reduction reaction Anion exchange membrane water electrolysis
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Spontaneous Abortions in the Second Trimester of Pregnancy: Research and Analysis of Factors Associated at Laquintinie Hospital in Douala
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作者 Henri Essome Moustapha Bilkissou +13 位作者 Merlin Boten Bounyom Sandrine Ngoumi Ingrid Doriane Ofakem Ilick Astrid Ndolo Kondo Fulbert Mangala Nkwele Michel Roger Ekono Alphonse Ngalame Nyong Robert Tchounzou Junie Ngaha Yaneu Marga Vanina Ngono Akam Gervais Mounchikpou Ngouhouo Grâce Tocki Toutou Théophile Nana Njamen Pascal Foumane 《Open Journal of Obstetrics and Gynecology》 2024年第8期1130-1143,共14页
Introduction: Spontaneous abortion of the second trimester is an interruption of pregnancy with complete expulsion or not of the product of conception between 15 and 28 weeks of pregnancy without any maneuvers. The ob... Introduction: Spontaneous abortion of the second trimester is an interruption of pregnancy with complete expulsion or not of the product of conception between 15 and 28 weeks of pregnancy without any maneuvers. The objective of our study was to determine the factors associated with second trimester spontaneous abortions at Laquintinie Hospital in Douala. Methodology for this purpose: We conducted a case-control study from January to May 2019 on pregnant women who may or may not have had spontaneous second trimester abortions. Results: In total we recorded 1609 pregnancies and recruited 184 patients, including 46 cases and 138 controls;which gave a frequency of spontaneous abortion in the second trimester of pregnancy of 2.85%. A correlative analysis showed that spontaneous abortions in the second trimester were associated with housewife status (OR = 2.89;CI = 1.21 - 6.79;p = 0.010), gestation > 5 (OR = 4.09;CI = 1.02 - 17.66;p = 0.040), multiparity (OR = 3.81;CI = 1.59 - 9.16;p = 0.002), history of endouterine maneuvers (OR = 5.64;CI = 2.43 - 13 .03;p = 0.000), malaria in pregnancy (OR = 3.99;CI = 1.1 - 14.76;p = 0.030), incompleteness on the second trimester ultrasound (OR = 2.37;CI = 1.18 - 4.70;p = 0.010), jolts when traveling (OR = 46.04;CI = 17.29 - 123.66;p = 0.000), long car journeys (OR = 7.05;CI = 1.99 - 27.77;p = 0.000). After logistic regression eliminating the confounding factors, only the following were associated with abortions: Multiparity (OR = 13.90;CI = 2.96 - 65.18;p = 0.000), endo uterine maneuvers (OR = 3.69;CI = 1. 01 - 13.44;p = 0.047), jolts when traveling (OR = 72.63;CI = 19.47 - 270.96;p = 0.000), long car journeys (OR = 15.41;CI = 2.7 - 85, 95;p = 0.000). Conclusion: Our study reveals that a set of factors contribute to the occurrence of spontaneous abortions in the second trimester of pregnancy in our context. 展开更多
关键词 Spontaneous Abortion second Trimester Associated Factors Laquintinie
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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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Impact of digital economy development on carbon productivity:An empirical analysis based on threshold effect and spatial spillover effect
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作者 XING Huai-zhen YAO Jing 《Ecological Economy》 2024年第2期123-138,共16页
Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development an... Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation. 展开更多
关键词 digital economy carbon productivity threshold effect spatial spillover effect
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Effect of Six Bacterial Strains on the Activity of Second Instar Larvae and Egg Hatching of Meloidogyne incognita
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作者 Jie LIU Li HE +4 位作者 Zixuan WANG Jianqing MA Xiaolong TONG Dandan CAO Gangyong ZHAO 《Plant Diseases and Pests》 2024年第5期15-18,共4页
[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second in... [Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second instar larvae of M.incognita,as well as on egg hatching,was evaluated.[Results]The treatment of fermentation supernatant derived from the X-2 strain exhibited a pronounced lethal effect on M.incognita,with a corrected mortality rate reaching 97%within 72 h.Additionally,this treatment significantly inhibited egg hatching,achieving an inhibition rate of 94.69%at a 20-fold dilution.The strain was identified as Bacillus velezensis,belonging to the genus Bacillus,and was designated as RKN1111.[Conclusions]This study presents alternative strains and a theoretical framework for the biological control of M.incognita. 展开更多
关键词 Meloidogyne incognita Bacterial strain second instar larvae Egg hatching
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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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Solution of the Matrix Second Semi-Tensor Product Equation A ∘ l X ∘ l B=C
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作者 Hao Zhang 《Journal of Applied Mathematics and Physics》 2024年第10期3261-3280,共20页
In this paper, the solution of the matrix second semi-tensor product equation A∘lX∘lB=Cis studied. Firstly, the solvability of the matrix-vector second semi-tensor product equation is investigated. At the same time,... In this paper, the solution of the matrix second semi-tensor product equation A∘lX∘lB=Cis studied. Firstly, the solvability of the matrix-vector second semi-tensor product equation is investigated. At the same time, the compatibility conditions, the sufficient and necessary conditions and the specific solution methods for the matrix solution are given. Secondly, we further consider the solvability of the second semi-tensor product equation of the matrix. For each part, several examples are given to illustrate the validity of the results. 展开更多
关键词 Matrix Equation The second Semi-Tensor Product Compatibility Condition Sufficient and Necessary Conditions VECTORIZATION
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Review and Analysis: Evaluation of the Impacts and Consequences of Using Agricultural Herbicides as Military Chemical Weapons in Second Indochina War
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作者 David R. Speidel Kenneth R. Olson 《Open Journal of Soil Science》 2024年第8期471-498,共28页
The legacy of the human misery caused by the application of the herbicides including Agent Purple and Agent Orange contaminated with unknown amounts of dioxin TCDD and Agent Blue, the arsenic-based herbicide, sprayed ... The legacy of the human misery caused by the application of the herbicides including Agent Purple and Agent Orange contaminated with unknown amounts of dioxin TCDD and Agent Blue, the arsenic-based herbicide, sprayed over the jungles, rice fields, and hamlets of Vietnam is still haunting us today. Why did this happen? Could it have been prevented? Was it necessary United States military strategy? Was it an intentional decision to inflict this blight on the enemy soldiers and the Vietnamese, Cambodian, and Laotian civilians, to poison their land and cause generations of harm? Alternatively, was it an unpreventable accident in the march of military history? What patterns in the U.S. government’s thought process could be identified as the cause, which led to the decision to use these herbicides as tactical chemical weapons? If the introduction of herbicide (chemical) weapons had not been made, would the outcome of the Vietnam War and the Secret Wars in Laos and Cambodia have been any different? The objective of this treatise is to outline the role of world events and backgrounds and the role of the leaders, U.S. military, CIA, USDA, U.S. State Department, the U.S. President appointed Ambassadors to Vietnam and Laos, chemical companies, and President Diệm’s Republic of Vietnam (RVN) government and military. Their collective advice led to the decision to use herbicides as military and environmental chemical weapons in the Second Indochina War. Were the National interests achieved by U.S. military strategy in the RVN using herbicide weapons worth the long-term environmental and human health consequences in Vietnam, Cambodia, and Laos? Did it impact the outcome of the Second Indochina War? 展开更多
关键词 second Indochina War Cambodia Laos South Vietnam Vietnam War Tactical Herbicides Agent Blue Agent Orange Agent Purple Dioxin TCDD Arsenic
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Research on the Impact of China’s Foreign Trade Technology Spillover on Green Total Factor Productivity of Countries Along the“Belt and Road”:Based on the Institutional Quality Threshold Effect
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作者 Li Chai Longnan Ma Lingwei Meng 《Proceedings of Business and Economic Studies》 2024年第2期120-125,共6页
China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model t... China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward. 展开更多
关键词 Technology spillover Green total factor productivity Institutional quality Threshold effect
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Analysis of an Output-Oriented Teaching Method in College English under the Second Language Acquisition Theory
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作者 Ying Li 《Journal of Contemporary Educational Research》 2024年第10期35-39,共5页
In the context of economic globalization,English has become increasingly essential for students’communication and professional activities,necessitating higher proficiency in speaking and listening.The theory of secon... In the context of economic globalization,English has become increasingly essential for students’communication and professional activities,necessitating higher proficiency in speaking and listening.The theory of second language acquisition posits that college English teaching can purposefully guide students’learning and facilitate unconscious language acquisition.By integrating an output-oriented teaching method,students are provided with opportunities to practice and apply English,thereby addressing the traditional issue of“separation of learning and use.”This paper examines the application value of the output-oriented teaching method in college English under the second language acquisition theory and proposes several strategies to enhance college English classroom teaching.The goal is to develop students’linguistic competence and improve their practical English skills. 展开更多
关键词 second language acquisition College English Output-oriented teaching
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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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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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Promoting the Learners’Motivation in Learning Chinese as a Second Language:From Demotivation to Motivational Strategies 被引量:1
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作者 ZHANG Xiangyang 《Sino-US English Teaching》 2023年第11期465-470,共6页
Motivation is a key factor that influences the outcome of second language(L2)learning.Chinese as a second language(CSL)learners,however,may experience demotivation in their Chinese learning process which will,more oft... Motivation is a key factor that influences the outcome of second language(L2)learning.Chinese as a second language(CSL)learners,however,may experience demotivation in their Chinese learning process which will,more often than not,reduce their learning interest and eventually affect their learning effect,therefore,it is necessary to enhance the learners’motivation level.This article first reviews the research literature in motivation in general,then discusses the CSL learners’demotivation in their Chinses learning process studying in China.Finally,it introduces motivational strategies to activate CSL learners’motivation in learning Chinese. 展开更多
关键词 MOTIVATION DEMOTIVATION motivational strategies Chinese as a second language(CSL)
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Tail spillover effects between cryptocurrencies and uncertainty in the gold,oil,and stock markets
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作者 Walid Mensi Mariya Gubareva +2 位作者 Hee‑Un Ko Xuan Vinh Vo Sang Hoon Kang 《Financial Innovation》 2023年第1期2339-2365,共27页
This study investigates tail dependence among five major cryptocurrencies,namely Bitcoin,Ethereum,Litecoin,Ripple,and Bitcoin Cash,and uncertainties in the gold,oil,and equity markets.Using the cross-quantilogram meth... This study investigates tail dependence among five major cryptocurrencies,namely Bitcoin,Ethereum,Litecoin,Ripple,and Bitcoin Cash,and uncertainties in the gold,oil,and equity markets.Using the cross-quantilogram method and quantile connectedness approach,we identify cross-quantile interdependence between the analyzed variables.Our results show that the spillover between cryptocurrencies and volatility indices for the major traditional markets varies substantially across quantiles,implying that diversification benefits for these assets may differ widely across normal and extreme market conditions.Under normal market conditions,the total connectedness index is moderate and falls below the elevated values observed under bearish and bullish market conditions.Moreover,we show that under all market conditions,cryptocurrencies have a leadership influence over the volatility indices.Our results have important policy implications for enhancing financial stability and deliver valuable insights for deploying volatility-based financial instruments that can potentially provide cryptocurrency investors with suitable hedges,as we show that cryptocurrency and volatility markets are insignificantly(weakly)connected under normal(extreme)market conditions. 展开更多
关键词 Cryptocurrency Uncertainty indices Quantile spillover Crossquantilogram
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