检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于SI模型的病毒传播动力学分析

许昌学院学报 2024年第2期43卷 12-16页

作者：杨文杰宋文利郑前前许昌学院数理学院河南许昌461000

创建了SI传播动力学模型,重点讨论了系统平衡点的存在性和稳定性,并运用连续动态系统分岔理论,利用MATLAB软件对系统的分岔情况进行了深入分析,同时考察了参数变化对系统的影响.在数值模拟阶段,对具有Holling IV型功能反应的病毒传播系... 详细信息

创建了SI传播动力学模型,重点讨论了系统平衡点的存在性和稳定性,并运用连续动态系统分岔理论,利用MATLAB软件对系统的分岔情况进行了深入分析,同时考察了参数变化对系统的影响.在数值模拟阶段,对具有Holling IV型功能反应的病毒传播系统进行了详细分析,研究了疾病传播的特点和演变规律.

关键词： SI传染病模型稳定性分岔常微分方程

Alignment efficient image-sentence retrieval considering transferable cross-modal representation learning

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第1期18卷 77-91页

作者： yang yang Jinyi GUO Guangyu LI Lanyu LI wenjie LI Jian yang School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Computing Hong Kong Polytechnic UniversityHong Kong 100872China State Key Lab.for Novel Software Technology Nanjing UniversityNanjing 210094China 14th Research Institute of China Electronics Technology Group Corporation Nanjing 210094China guangyu.li2017@***

Traditional image-sentence cross-modal retrieval methods usually aim to learn consistent representations of heterogeneous modalities,thereby to search similar instances in one modality according to the query from another modality in *** basic assumption behind these methods is that parallel multi-modal data(i.e.,different modalities of the same example are aligned)can be obtained in *** other words,the image-sentence cross-modal retrieval task is a supervised task with the alignments as ***,in many real-world applications,it is difficult to realign a large amount of parallel data for new scenarios due to the substantial labor costs,leading the non-parallel multi-modal data and existing methods cannot be used *** the other hand,there actually exists auxiliary parallel multi-modal data with similar semantics,which can assist the non-parallel data to learn the consistent ***,in this paper,we aim at“Alignment Efficient Image-Sentence Retrieval”(AEIR),which recurs to the auxiliary parallel image-sentence data as the source domain data,and takes the non-parallel data as the target domain *** single-modal transfer learning,AEIR learns consistent image-sentence cross-modal representations of target domain by transferring the alignments of existing parallel ***,AEIR learns the image-sentence consistent representations in source domain with parallel data,while transferring the alignment knowledge across domains by jointly optimizing a novel designed cross-domain cross-modal metric learning based constraint with intra-modal domain adversarial ***,we can effectively learn the consistent representations for target domain considering both the structure and semantic ***,extensive experiments on different transfer scenarios validate that AEIR can achieve better retrieval results comparing with the baselines.

关键词： image-sentence retrieval transfer learning semantic transfer structure transfer

基于学习通与小班个性化模式常微分方程的教学实践

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

科技风 2024年第8期 40-42页

作者：杨文杰张佳佳郑前前许昌学院数理学院河南许昌461000

常微分方程是本科阶段数学专业学生的一门必修课程,被广泛应用于物理、化学、生物、医学等方面,渗透于生活的方方面面。因此学好常微分方程显得尤为重要。将学习通平台与小班化教学相结合的教学模式运用到常微分方程的教学中,充分利用... 详细信息

常微分方程是本科阶段数学专业学生的一门必修课程,被广泛应用于物理、化学、生物、医学等方面,渗透于生活的方方面面。因此学好常微分方程显得尤为重要。将学习通平台与小班化教学相结合的教学模式运用到常微分方程的教学中,充分利用“超星学习通”这一平台,为小班中的每个学生定制个人错题本,针对其易错点,进行“培优补弱”,二者的结合能带来更好的教学效果。

关键词：超星学习通小班化教学常微分方程

Artificial Intelligence Empowering the High-Quality Development of Education:Demands,Visions,and Paths

在线全文

学校读者我要写书评

暂无评论

Frontiers of Education in China 2023年第1期18卷 1-18页

作者： HU Xiaoyong SUN Shuo yang wenjie DING Geying School of Information Technology in Education South China Normal UniversityGuangzhou 510631China

Under the background of the two-way empowerment of artificial intelligence(AI)and education development,this paper first sorts out the demands for high-quality development of education in China in the new era from the perspectives of educational equity,talent cultivation,and contradiction ***,it focuses on the vision of AI empowering the high-quality development of education,and points out that AI is spawning new patterns and characteristics from the aspects of students’learning,teachers’development,school construction,home-school cooperation,educational governance,educational evaluation,educational equity,etc.,which has provided important driving force for the high-quality development of ***,the paper proposes the paths of AI empowering high-quality development of education from the aspects of top-level design,educational reform,construction of intelligent education environment,improvement of intelligence education literacy,cultivation of innovative talent,construction of high-quality education resources,response to ethical risks,etc.,to clarify the future direction for the deep integration and development of AI and education.

关键词： artificial intelligence+education high-quality development of education educational equity talent cultivation

Synthesis of Bio-based Epoxy Containing Phosphine Oxide as a Reactive Additive Toward Highly Toughened and Fire-retarded Epoxy Resins

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第11期41卷 1733-1746,I0007页

作者： Chunxiang Wei Tianyu Gao Yu Xu wenjie yang Guangjian Dai Ruiting Li SanE Zhu Richard K.K.Yuen Wei yang Hongdian Lu School of Energy Materials and Chemical EngineeringHefei UniversityHefei 230601China Yusuf Hamied Department of Chemistry University of CambridgeCambridge CB21EWU.K. Department of Architecture and Civil Engineering City University of Hong KongHong Kong 999077China

The integration of high mechanical toughness,impact strength as well as excellent flame-retardant properties toward epoxy resins(EPs)have always been a *** inadequate overall performance of EPs severely restricts their sustainable utilization in engineering aspects over ***,a new bio-based agent(diglycidyl ether of magnolol phosphine oxide,referred as DGEMP)derived from magnolol(classified as lignan),extracted from natural plants Magnolia officinalis,was successfully synthesized and further employed as a flameretardant reactive additive to diglycidyl ether of bisphenol A(DGEBA).As demonstration,the composite resin,DGEBA/15DGEMP(15 wt%DGEMP),achieved an Underwriters Laboratories-94 V-0 rating with a high limiting oxygen index(LOI)value(41.5%).In cone calorimeter tests,it showed that heat release and smoke production were effectively inhibited during combustion,wherein the peak heat release rate(PHRR)value of DGEBA/15DGEMP was reduced by 50%compared to neat ***,it exhibited a superior tensile strength(82.8 MPa),toughness(5.11MJ/m^(3))and impact strength(36.5 k J/m^(2)),much higher than that of neat DGEBA(49.7 MPa,2.05 MJ/m^(3)and 20.9 k J/m^(2)).Thus,it is highly anticipated that DGEMP imparts significantly improved mechanical and fire-retarded properties to conventional EPs,which holds a great potential to address the pressing challenges in EP thermosets industry.

关键词： Epoxy resin Magnolol Phosphine oxide Toughness Flame retardant

Multi-UAVs Collaborative Path Planning in the Cramped Environment

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 529-538页

作者： Siyuan Feng Linzhi Zeng Jining Liu Yi yang wenjie Song School of Automation Beijing Institute of TechnologyNanjing 210039China Nanjing Research Institute of Electronics Technology Nanjing 210039China Yichang Testing Technique Research Institute Yichang 443003China IEEE

Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few *** benchmark and source code are released in https://***/inin-xingtian/multi-UAVs-path-planner.

关键词： Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning

连续重复给予含左炔诺孕酮紧急避孕药对雌性大鼠生育力及其子代健康的影响

在线全文

学校读者我要写书评

暂无评论

中华生殖与避孕杂志 2024年第6期44卷 562-573页

作者：胡颖怡倪其承钟瑞华杨文捷李国停周洁芸郭湘洁谢淑武周佳铃朱焰复旦大学药学院上海200032 上海市生物医药技术研究院国家卫生健康委生育调节药械重点实验室上海生殖健康药具工程技术研究中心上海200032 上海市实验动物研究中心上海201203 上海健康医学院药学院上海201318

目的探讨连续重复给予含左炔诺孕酮(levonorgestrel,LNG)紧急避孕药(emergency contraception pills,ECPs)对雌性大鼠生育力及其F1代仔鼠健康的影响。方法成年SPF级雌性大鼠于每个动情周期连续给予3次LNG-ECPs,分别给予3个(P-3)、6个(P... 详细信息

目的探讨连续重复给予含左炔诺孕酮(levonorgestrel,LNG)紧急避孕药(emergency contraception pills,ECPs)对雌性大鼠生育力及其F1代仔鼠健康的影响。方法成年SPF级雌性大鼠于每个动情周期连续给予3次LNG-ECPs,分别给予3个(P-3)、6个(P-6)和12个(P-12)动情周期。雌性大鼠每个给药时程下,采用Excel产生随机数按体质量分层随机分为2组,分别为LNG-ECPs组和溶媒对照组,分别灌胃给予0.12 mg/kg LNG-ECPs和等体积溶媒。各组于末次给药后4 h分别取1/2动物(12~18只)进行解剖(6~9只)和交配(6~9只);剩余1/2动物(12~18只)于停药恢复3个动情周期后再分别进行解剖(6~9只)和交配(6~9只),计算脏器系数。采用酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)检测雌性大鼠血清中卵泡刺激素(follicle-stimulating hormone,FSH)、黄体生成素(lutenizing hormone,LH)、雌激素、孕激素、睾酮、抗苗勒管激素(anti-Müllerian hormone,AMH)以及游离甲状腺激素3(free thyroid hormone,fT3)的水平。雌性大鼠卵巢组织切片苏木精-伊红(hematoxylin and eosin,HE)染色后进行卵泡计数。记录LNG-ECPs给药结束和停药恢复期雌性大鼠妊娠率及窝仔数,测定F1代仔鼠生长指数以及主动和被动运动能力等指标。取P-12大鼠卵巢组织进行转录组学测序,建立LNG-ECPs致卵巢差异表达基因谱,分析LNG-ECPs致卵巢损伤的差异基因,并进行基因本体(gene ontology,GO)和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路富集分析。结果①连续给予3个和6个动情周期后,LNG-ECPs组雌鼠的血清激素水平和生育力与溶媒对照组相比,差异均无统计学意义(均P>0.05);F1代仔鼠生长指数和行为学结果与溶媒对照组仔鼠相比差异均无统计学意义(均P>0.05)。②连续给予12个动情周期后,与溶媒对照组相比,LNG-ECPs组大鼠血清中FSH[(0.21±0.17)U/L]、LH[(0.27±0.08)U/L]和孕激素[(0.68±0.23)μg/L]水平显著低于溶媒对照组[(1.00±0.82)U/L,P=0.043;(1.00±0.50)U/L,P=0.006;(1.00±0.20)μg/L,P=0.027],雌二醇[(2.24±1.03)μg/L]和睾酮[(1.25±0.25)μg/L]水平明显高于溶媒对照组[(1.00±0.35)μg/L,P=0.019;(1.00±0.07)μg/L,P=0.044];卵巢中原始卵泡数量(4.88±2.36)显著少于溶媒对照组(16.13±9.36,P=0.005),闭锁卵泡数量(24.38±5.01)显著高于溶媒对照组(19.13±2.30,P=0.018);LNG-ECPs组中F1代仔鼠负重游泳时间[(157.13±32.29)s]明显低于溶媒对照组[(198.06±40.01)s,P=0.003]。停药恢复3个动情周期后,LNG-ECPs可造成大鼠血清中FSH[(2.48±1.18)U/L]、LH[(1.60±0.41)U/L]、睾酮[(1.37±0.23)μg/L]及FSH/LH值(1.61±0.41)显著高于溶媒对照组[(1.00±0.67)U/L,P=0.024;(1.00±0.27)U/L,P=0.014;(1.00±0.18)μg/L,P=0.011;1.00±0.49,P=0.042],且雌激素水平[(0.49±0.15)μg/L]和AMH水平[(0.79±0.15)μg/L]显著低于溶媒对照组[(1.00±0.37)μg/L,P=0.011;(1.00±0.10)μg/L,P=0.016],同时,大鼠卵巢中原始卵泡数量(6.25±5.06)仍显著少于溶媒对照组(12.00±5.56,P=0.048);F1代仔鼠在旷场中的运动总距离[(89.85±36.98)m]以及负重游泳时长[(112.00±29.52)s]均显著低于溶媒对照组[(147.55±23.13)m,P<0.001;(137.69±25.85)s,P=0.014]。③转录组测序结果表明,与溶媒对照组相比,LNG-ECPs组雌性大鼠卵巢组织中存在Cd5、Cxcr1、Lexm、Fga、Mybphl和Gstm5等显著差异表达的基因,参与萜类骨架生物合成、卵巢类固醇生成和皮质醇的合成与分泌等类固醇激素合成相关过程

关键词：左炔诺孕酮生育力行为学卵巢损伤转录组学

Regional Climate Damage Quantification and Its Impacts on Future Emission Pathways Using the RICE Model

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第9期41卷 1843-1852页

作者： Shili yang wenjie DONG Jieming CHOU Yong ZHANG Weixing ZHAO Beijing Meteorological Observation Centre Beijing Meteorological BureauBeijing 100089China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519082China Beijing Normal University Beijing 100101China CMA Institute for Development and Programme Design Beijing 100081China

This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission *** highlight varied damages depending on regional economic development and ***,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,***,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,***,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature *** China,however,sea level-induced damages are projected to exceed those from temperature ***,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively *** 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.

关键词： climate damage integrated assessment model carbon emissions sea level rise temperature change

Investigation of Projectile Impact Behaviors of Graphene Aerogel Using Molecular Dynamics Simulations

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3047-3061页

作者： Xinyu Zhang wenjie Xia yang Wang Liang Wang Xiaofeng Liu Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai200240China Department of Aerospace Engineering Iowa State UniversityAmesIA50011USA School of Materials Science and Engineering University of Science&Technology BeijingBeijing100083China Zernike Institute for Advanced Materials University of GroningenGroningen9747The Netherlands

Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical *** this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)*** study results show that the porous structure and density are key factors determining the mechanical response of GA under impact ***,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene ***,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of ***,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile *** research findings of this work demonstrate the significant potential of GA for energy absorption applications.

关键词： Graphene aerogel molecular dynamics simulation impact response energy absorption