期刊文献+
共找到90,597篇文章
< 1 2 250 >
每页显示 20 50 100
Dirichlet-to-Neumann Map for a Hyperbolic Equation
1
作者 Fagueye Ndiaye Mouhamadou Ngom Diaraf Seck 《Journal of Applied Mathematics and Physics》 2023年第8期2231-2251,共21页
In this paper, we provide an explicit expression for the full Dirichlet-to-Neumann map corresponding to a radial potential for a hyperbolic differential equation in 3-dimensional. We show that the Dirichlet-Neumann op... In this paper, we provide an explicit expression for the full Dirichlet-to-Neumann map corresponding to a radial potential for a hyperbolic differential equation in 3-dimensional. We show that the Dirichlet-Neumann operators corresponding to a potential radial have the same properties for hyperbolic differential equations as for elliptic differential equations. We numerically implement the coefficients of the explicit formulas. Moreover, a Lipschitz type stability is established near the edge of the domain by an estimation constant. That is necessary for the reconstruction of the potential from Dirichlet-to-Neumann map in the inverse problem for a hyperbolic differential equation. 展开更多
关键词 Hyperbolic Differential Equation Calderón’s Problem Schrödinger Operator POTENTIAL Inverse Potential Problem dirichlet-to-neumann map Numerical Simulations Lipschitz Stability
在线阅读 下载PDF
Bandgap calculation for mixed in-plane waves in 2D phononic crystals based on Dirichlet-to-Neumann map 被引量:7
2
作者 Ni Zhen Feng-Lian Li +1 位作者 Yue-Sheng Wang Chuan-Zeng Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第4期1143-1153,共11页
In this paper, a method based on the Dirichlet- to-Neumann map is developed for bandgap calculation of mixed in-plane waves propagating in 2D phononic crystals with square and triangular lattices. The method expresses... In this paper, a method based on the Dirichlet- to-Neumann map is developed for bandgap calculation of mixed in-plane waves propagating in 2D phononic crystals with square and triangular lattices. The method expresses the scattered fields in a unit cell as the cylindrical wave expansions and imposes the Bloch condition on the boundary of the unit cell. The Dirichlet-to-Neumann (DtN) map is applied to obtain a linear eigenvalue equation, from which the Bloch wave vectors along the irreducible Brillouin zone are calculated for a given frequency. Compared with other methods, the present method is memory-saving and time-saving. It can yield accurate results with fast convergence for various material combinations including those with large acoustic mismatch without extra computational cost. The method is also efficient for mixed fluid-solid systems because it considers the different wave modes in the fluid and solid as well as the proper fluid-solid interface condition. 展开更多
关键词 Phononic crystal Band structure Cylindrical wave expansion dirichlet-to-neumann (DtN) map Bloch theorem
在线阅读 下载PDF
An Explicit Formula of the Dirichlet-to-Neumann Map for a Radial Potential in Dimension 3
3
作者 Fagueye Ndiaye 《Journal of Applied Mathematics and Physics》 2022年第2期379-404,共26页
In this paper, we provide an explicit expression for the full Dirichlet-to-Neumann map corresponding to a radial potential for the Schr&#246;dinger equation in 3-dimensional. We numerically implement the coefficie... In this paper, we provide an explicit expression for the full Dirichlet-to-Neumann map corresponding to a radial potential for the Schr&#246;dinger equation in 3-dimensional. We numerically implement the coefficients of the explicit formulas. In this work, Lipschitz type stability is established near the edge of the domain with giving estimation constant. That is necessary for the reconstruction of the potential from Dirichlet-to-Neuman map. 展开更多
关键词 Calderón’s Problem Schrödinger Operator POTENTIAL Inverse Potential Problem Dirichlet-to-Neuman map Numerical Simulations Lipschitz Stability
在线阅读 下载PDF
Residual Attention-BiConvLSTM:一种新的全球电离层TEC map预测模型
4
作者 王浩然 刘海军 +5 位作者 袁静 乐会军 李良超 陈羿 单维锋 袁国铭 《地球物理学报》 北大核心 2025年第2期413-430,共18页
电离层总电子含量(TEC)预测对提高全球卫星导航系统(GNSS)的精度具有重要意义.现有的TEC map预测模型主要通过顺序堆叠时空特征提取单元来实现.这种模型搭建方法会因多个卷积层顺序堆叠而损失细粒度的TEC map的空间特征,导致模型精度不... 电离层总电子含量(TEC)预测对提高全球卫星导航系统(GNSS)的精度具有重要意义.现有的TEC map预测模型主要通过顺序堆叠时空特征提取单元来实现.这种模型搭建方法会因多个卷积层顺序堆叠而损失细粒度的TEC map的空间特征,导致模型精度不够;还会由于多层堆叠导致梯度消失或梯度爆炸问题.本文借鉴残差注意力(Residual Attention)的思想,在TEC map预测模型中增加了残差注意力模块,提出了Residual Attention-BiConvLSTM模型.该模型中的残差注意力模块能同时提取粗、细粒度空间特征,并对其进行加权.本文在全球TEC map数据上与ConvLSTM、ConvGRU、ED-ConvLSTM和C1PG进行了对比实验.实验结果表明,本文所提出的Residual Attention-BiConvLSTM模型的RMSE、MAE、MAPE和R^(2)在太阳活动高年和年均优于对比模型.本文还在一次磁暴事件中对比了5种模型的预测效果.实验结果表明,大磁暴发生时,本文模型与C1PG相近,优于其他3种对比模型.本文的研究工作为电离层map预测模型搭建提供一个新思路. 展开更多
关键词 电离层TEC map预测 残差注意力模块 Residual Attention-BiConvLSTM 时空预测模型
在线阅读 下载PDF
Leveraging ROTI map derived from Indonesian GNSS receiver network for advancing study of Equatorial Plasma Bubble in Southeast/East Asia 被引量:1
5
作者 Prayitno Abadi Ihsan N.Muafiry +8 位作者 Teguh N.Pratama Angga Y.Putra Suraina Gatot H.Pramono Sidik T.Wibowo Febrylian F.Chabibi Umar A.Ahmad Wildan P.Tresna Asnawi 《Earth and Planetary Physics》 EI CAS 2025年第1期101-116,共16页
This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signa... This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research. 展开更多
关键词 Equatorial Plasma Bubble(EPB) GNSS receivers’network Indonesia Continuously Operating Reference Station(Ina-CORS) ionospheric map Rate of TEC change index(ROTI)map
在线阅读 下载PDF
心脏磁共振T1 mapping在心肌病的应用及成像技术进展
6
作者 邓佳 唐惠芳 +4 位作者 周宏 余莹 杨雯敏 周锦标 田进伟 《中国动脉硬化杂志》 2025年第2期154-162,共9页
随着心脏磁共振成像技术的不断发展,T1 mapping可以无创性、可视化和定量地评估心脏疾病的心肌纤维化、水肿和浸润性。应用T1 mapping评估心肌疾病的局限性和弥漫性心肌纤维化,在疾病的诊断、鉴别、治疗和预后风险评估中发挥了重要的临... 随着心脏磁共振成像技术的不断发展,T1 mapping可以无创性、可视化和定量地评估心脏疾病的心肌纤维化、水肿和浸润性。应用T1 mapping评估心肌疾病的局限性和弥漫性心肌纤维化,在疾病的诊断、鉴别、治疗和预后风险评估中发挥了重要的临床作用。本文旨在全面介绍T1 mapping在心肌病患者中的临床应用,归纳常用的扫描技术及其成像原理。 展开更多
关键词 心脏磁共振 T1 mapping 心肌病
在线阅读 下载PDF
利用CRISPR/Cas9基因编辑技术构建斑马鱼map3k15敲除品系
7
作者 贾淳钰 沈延 +3 位作者 陈罡 郑可 秦岩 李雪梅 《基础医学与临床》 2025年第3期290-297,共8页
目的利用CRISPR/Cas9基因编辑技术构建斑马鱼map3k15敲除纯合品系,为进一步研究map3k15在肾脏疾病方面的作用提供动物模型。方法1)分析map3k15在斑马鱼中的表达模式;2)利用CRISPR/Cas9基因编辑技术构建斑马鱼map3k15敲除纯合品系;3)观察... 目的利用CRISPR/Cas9基因编辑技术构建斑马鱼map3k15敲除纯合品系,为进一步研究map3k15在肾脏疾病方面的作用提供动物模型。方法1)分析map3k15在斑马鱼中的表达模式;2)利用CRISPR/Cas9基因编辑技术构建斑马鱼map3k15敲除纯合品系;3)观察map3k15缺失对斑马鱼表型的影响。结果1)map3k15在斑马鱼前肾中表达,且MAP3K15/Map3k15蛋白在多物种间具有高度保守性;2)成功构建了斑马鱼map3k15-/-突变体,并保留+2 bp及+1 bp 2种突变品系;3)map3k15突变斑马鱼在胚胎发育过程中出现卵黄囊、心包及头部的水肿,且随发育时间延长,症状逐渐加重。结论成功构建了map3k15敲除的纯合斑马鱼品系,为未来研究map3k15在肾脏发育及疾病中的作用提供了重要的模型。 展开更多
关键词 map3k15 CRISPR/Cas9基因编辑技术 斑马鱼 肾脏发育
在线阅读 下载PDF
基于T2^(*)mapping的业余马拉松运动员足踝部关节软骨损伤及其影响因素分析
8
作者 高雅丽 兰晓川 +2 位作者 王舒 宋凌恒 陈伟 《磁共振成像》 北大核心 2025年第2期94-99,共6页
目的基于T2^(*)mapping定量分析业余马拉松运动员足踝部关节软骨的T2^(*)值,并分析其与性别、年龄、身体质量指数(body mass index,BMI)、跑龄、跑量之间的相关性。材料与方法于2023年7月份至2023年9月份招募重庆市长跑运动爱好者48名,... 目的基于T2^(*)mapping定量分析业余马拉松运动员足踝部关节软骨的T2^(*)值,并分析其与性别、年龄、身体质量指数(body mass index,BMI)、跑龄、跑量之间的相关性。材料与方法于2023年7月份至2023年9月份招募重庆市长跑运动爱好者48名,其中跑量<300 km/月的36例(中低跑量组),跑量≥300 km/月的12例(高跑量组)。所有受试者均进行单侧无症状踝关节的MRI扫描,扫描序列包括T2^(*)mapping多回波自旋回波(spin echo,SE)序列矢状位、质子密度加权成像脂肪抑制(proton density-weighted imaging fat-saturated,PDWI-FS)序列矢状位、冠状位、横轴位以及T1加权脂肪抑制成像(T1-weighted imaging fat-saturated,T1WI-FS)序列横轴位。沿关节软骨轮廓边缘勾画距骨穹窿、跟骰关节跟骨面、骰骨面及后距下关节跟骨面、距骨面软骨作为感兴趣区(region of interest,ROI),获得相应的T2^(*)值。采用线性回归分析软骨T2^(*)值与年龄、BMI、跑龄的相关性,采用独立样本t检验分析不同跑量及不同性别间的软骨T2^(*)值差异。结果(1)距骨穹窿、跟骰关节跟骨面及骰骨面、后距下关节跟骨面及距骨面软骨T2^(*)值在性别上的差异均具有统计学意义(P=0.001、P<0.001、P=0.002、P=0.008、P=0.004);(2)高跑量组的距骨穹窿、后距下关节跟骨面软骨T2^(*)值高于中低跑量组(P=0.014、0.023),不同跑量的跟骰关节跟骨面及骰骨面、后距下关节距骨面软骨T2^(*)值的差异均无统计学意义(P=0.987、0.072、0.724);(3)距骨穹窿、跟骰关节跟骨面及骰骨面、后距下关节跟骨面、距骨面软骨T2^(*)值均与BMI呈正相关(r=0.376、0.384、0.300、0.422、0.455,P=0.005、0.004、0.019、0.001、0.001)。结论在业余马拉松运动员这一跑步群体中,与中低跑量相比,高跑量更有可能导致距骨穹窿、后距下关节跟骨面软骨损伤;而与较低的BMI相比,高BMI增加了距骨穹窿、跟骰关节跟骨面、骰骨面及后距下关节跟骨面、距骨面软骨损伤的风险。 展开更多
关键词 业余马拉松 跑步 软骨 磁共振成像 T2^(*)mapping
在线阅读 下载PDF
MAP原则指导下实现考研英语线上虚拟课堂教学的研究
9
作者 宁红曼 王晔 《通讯世界》 2025年第1期56-58,共3页
多模态苹果派(multimodal APPLE PIE, MAP)基于多模态教学原则以及交互性教学原则,在教学过程中以有效性、互动性和参与性为核心,对解决当前考研英语教学中存在的问题具有重要指导意义。因此,探究考研英语教学现状,提出MAP原则指导下实... 多模态苹果派(multimodal APPLE PIE, MAP)基于多模态教学原则以及交互性教学原则,在教学过程中以有效性、互动性和参与性为核心,对解决当前考研英语教学中存在的问题具有重要指导意义。因此,探究考研英语教学现状,提出MAP原则指导下实现考研英语线上虚拟课堂的教学设计,从课堂导入、课程呈现、学生合作学习、人机互动、课堂互动5个环节探究考研英语线上虚拟课堂的教学过程,以期提高教师的教学质量以及增强学生的学习效果。 展开更多
关键词 map教学设计 考研英语 虚拟课堂 线上教学
在线阅读 下载PDF
Landslide Susceptibility Mapping Using RBFN-Based Ensemble Machine Learning Models
10
作者 Duc-Dam Nguyen Nguyen Viet Tiep +5 位作者 Quynh-Anh Thi Bui Hiep Van Le Indra Prakash Romulus Costache Manish Pandey Binh Thai Pham 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期467-500,共34页
This study was aimed to prepare landslide susceptibility maps for the Pithoragarh district in Uttarakhand,India,using advanced ensemble models that combined Radial Basis Function Networks(RBFN)with three ensemble lear... This study was aimed to prepare landslide susceptibility maps for the Pithoragarh district in Uttarakhand,India,using advanced ensemble models that combined Radial Basis Function Networks(RBFN)with three ensemble learning techniques:DAGGING(DG),MULTIBOOST(MB),and ADABOOST(AB).This combination resulted in three distinct ensemble models:DG-RBFN,MB-RBFN,and AB-RBFN.Additionally,a traditional weighted method,Information Value(IV),and a benchmark machine learning(ML)model,Multilayer Perceptron Neural Network(MLP),were employed for comparison and validation.The models were developed using ten landslide conditioning factors,which included slope,aspect,elevation,curvature,land cover,geomorphology,overburden depth,lithology,distance to rivers and distance to roads.These factors were instrumental in predicting the output variable,which was the probability of landslide occurrence.Statistical analysis of the models’performance indicated that the DG-RBFN model,with an Area Under ROC Curve(AUC)of 0.931,outperformed the other models.The AB-RBFN model achieved an AUC of 0.929,the MB-RBFN model had an AUC of 0.913,and the MLP model recorded an AUC of 0.926.These results suggest that the advanced ensemble ML model DG-RBFN was more accurate than traditional statistical model,single MLP model,and other ensemble models in preparing trustworthy landslide susceptibility maps,thereby enhancing land use planning and decision-making. 展开更多
关键词 Landslide susceptibility map spatial analysis ensemble modelling information values(IV)
在线阅读 下载PDF
Constructing, Mapping, and Analyzing Global Urban Forest Databases Using Hyperlinks: A World of Vast Unevenness and Research Challenges
11
作者 Stanley D. Brunn Olena Dronova Mahmuda Sharmin 《Natural Resources》 2025年第1期1-23,共23页
A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking an... A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking and policies related to human/environmental worlds at local, regional, and global scales. Maps are an important part of these innovative and ongoing research approaches. In this context, we consider urban forests a topic meriting more attention of scholars studying the geographic and environmental intersections of the natural sciences with the social sciences and humanities. We construct two innovative knowledge bases, one a conceptual framework based on major themes and concepts related to mapping urban forests using key words of the first 100 results of a Google Scholar query and a second using the number of Google Scholar hyperlinks about mapping urban forests in 244 capital cities. We discovered that the constructed world maps reveal vast global unevenness in our knowledge about urban forests in hyperlink numbers and ratios, results that merit further attention by disciplinary, international and interdisciplinary scholarly communities. 展开更多
关键词 Urban Forests Database mapPING Google Scholar HYPERLINKS DISPARITIES Unevenness
在线阅读 下载PDF
基于改进RTAB-Map算法的爬壁机器人导航研究
12
作者 覃超 唐东林 +3 位作者 游东潘 丁超 饶胜 何媛媛 《工程设计学报》 北大核心 2025年第1期32-41,共10页
针对爬壁机器人难以对大型石化装备壁面感知和自动化检测等难题,提出了一种改进RTAB-Map(real-time appearance-based mapping,基于外观的实时建图)算法,通过多传感器数据融合实现爬壁机器人定位、建图与导航。首先,搭建了具有壁面吸附... 针对爬壁机器人难以对大型石化装备壁面感知和自动化检测等难题,提出了一种改进RTAB-Map(real-time appearance-based mapping,基于外观的实时建图)算法,通过多传感器数据融合实现爬壁机器人定位、建图与导航。首先,搭建了具有壁面吸附能力的机器人运动底盘,以保证爬壁机器人在壁面灵活稳定运动;其次,针对爬壁机器人在壁面滑移导致的里程计累计误差问题,采用扩展卡尔曼滤波并融合编码器和惯性测量单元的数据,为建图和导航提供精确的里程计信息;再次,基于RTAB-Map算法对深度相机、激光雷达及里程计的数据进行融合,生成二维栅格和三维点云地图,实现对装备壁面的完整描述,并基于融合数据构建了爬壁机器人导航算法的框架;最后,在装备壁面进行了实验验证。结果表明:采用融合里程计算法,能显著减小航向角误差,航向角平均误差为0.78°,相对轮式里程计规划,航向角误差减少了88.94%;改进RTAB-Map算法提高了爬壁机器人在壁面环境下的建图与感知能力,结合路径规划算法,实现了机器人自主导航。研究结果对爬壁机器人自动化检测技术的研究及应用具有一定的参考意义。 展开更多
关键词 爬壁机器人 RTAB-map(基于外观的实时建图)算法 扩展卡尔曼滤波 多传感器融合 导航
在线阅读 下载PDF
T2 mapping不同测量方法在甲状腺相关眼病活动性评估中的应用
13
作者 信雨晴 潘富强 +2 位作者 王亚磊 袁玉山 张杨 《中国CT和MRI杂志》 2025年第2期71-73,共3页
目的分析T2 mapping不同感兴趣区(ROI)勾画方法在甲状腺相关眼病(TAO)活动分期中的应用价值。方法27例患者的53个眼眶纳入研究,行3.0T MR冠状位T2 mapping扫描,采用临床活动性评分(CAS)进行分期,通过三种勾画方法获得T2HS(在炎症受累最... 目的分析T2 mapping不同感兴趣区(ROI)勾画方法在甲状腺相关眼病(TAO)活动分期中的应用价值。方法27例患者的53个眼眶纳入研究,行3.0T MR冠状位T2 mapping扫描,采用临床活动性评分(CAS)进行分期,通过三种勾画方法获得T2HS(在炎症受累最重眼肌的信号较高区域勾画小的ROI,记为热点)、T2SS(单只眼肌热点层面的均值)及T2SO(单侧眼眶四条眼肌肌腹层面的均值),分析三者与CAS的相关性及其诊断效能。结果活动期T2HS、T2SS和T2SO均高于非活动期。三者均与CAS正相关,T2SO相关性最强(r=0.606,P<0.0001)。ROC曲线显示三者对TAO活动性分期均有一定的诊断效能,虽然结果显示T2SS诊断效能较优,AUC=0.833,截断值94.25ms时判断活动性敏感度为68%,特异度为91%,但Delong检验提示三者差异无统计学意义。结论T2 mapping序列的三种测量方法均可用于TAO的活动性评估,综合分析,T2SS较适合用于分期。 展开更多
关键词 GRAVES眼病 T2 mapping 磁共振成像 感兴趣区 活动性分期 动眼肌
在线阅读 下载PDF
基于MAP法的线路板重金属铜氨废水处理研究
14
作者 黄常亮 《现代工程科技》 2025年第1期77-80,共4页
随着线路板的广泛应用,其在印刷过程中产生的铜氨废水的排放问题日益突出。铜氨废水中氨氮和铜离子对环境的危害较大,为了解决该问题,提出了一种MAP法和折点氯化法相结合的方法。该方法首先向铜氨废水中加入镁盐和磷酸盐,将氨氮转化为MA... 随着线路板的广泛应用,其在印刷过程中产生的铜氨废水的排放问题日益突出。铜氨废水中氨氮和铜离子对环境的危害较大,为了解决该问题,提出了一种MAP法和折点氯化法相结合的方法。该方法首先向铜氨废水中加入镁盐和磷酸盐,将氨氮转化为MAP沉淀,降低铜氨废水中氨氮的浓度,同时可以将MAP回收再利用;然后向剩余浓液中加入过量的NaClO溶液,进一步将溶液中的氨氮浓度降低,随着NaClO溶液的增加,反应液会逐渐呈碱性,而Cu^(2+)在碱性环境中会与OH-生成Cu(OH)_(2)沉淀,进而降低Cu^(2+)的浓度,从而使铜氨废水中的氨氮和Cu2+的浓度均符合《中华人民共和国环境保护法》的排放要求;最后通过纳氏试剂分光光度法和火焰原子吸收光度法检验反应后浓液中氨氮和Cu^(2+)的浓度。经过验证得知,该方法可以显著降低氨氮和Cu^(2+)的浓度。 展开更多
关键词 map 铜氨废水 氨氮回收 线路板 折点氯化法 环保排放标准
在线阅读 下载PDF
Compiling molecular evidence from a tetraploid rose genome into a near-saturated map for the identification of pigment-related genes
15
作者 Bixuan Cheng Yanlin Sun +6 位作者 Huihua Wan Kai Zhao Lidan Sun Le Luo Huitang Pan Qixiang Zhang Chao Yu 《Horticultural Plant Journal》 2025年第1期351-366,共16页
With their high economic value and cultural significance,modern roses are one of the most important ornamental plants.Because of their complicated genetic background and tetraploid nature,the creation of high-density ... With their high economic value and cultural significance,modern roses are one of the most important ornamental plants.Because of their complicated genetic background and tetraploid nature,the creation of high-density genetic maps of roses has been a challenge that has slowed the pace of molecular breeding for modern roses.The current construction of tetraploid genetic maps based on existing diploid rose genomes could lead to inaccurate marker information and genotyping results.Therefore,we generated the first high-quality tetraploid genome of Rosa chinensis‘Yunzheng Xiawei.'Utilizing Illumina,PacBio,and Hi-C sequencing technologies,we assembled a genome of 858.59 Mb with 14pseudo-chromosomes.Mode of inheritance analysis using PolyOrigin indicated that modern roses show both quadrivalent and bivalent pairing.Based on this reference genome,high-density genetic maps were constructed using MSTmap with nearly saturated markers.Quantitative trait locus(QTL)analysis was conducted using WinQTLCart and R/qtl for flavonoids and carotenoids,and 11 QTL clusters were identified.By combining the genome annotation,phylogenetic analyses,and gene expression analyses,we were able to identify several key genes related to flavonoid and carotenoid biosynthesis.This study provides the basis for further genetic analyses of highly heterozygous tetraploid roses and could facilitate the progress of marker-assisted selection in modern roses. 展开更多
关键词 ROSA Tetraploid genome Tetrasomic inheritance Genetic linkage map Flower color
在线阅读 下载PDF
Fusion of Dual-targeting Peptides with MAP30 Promotes the Apoptosis of MDA-MB-231 Breast Cancer Cells
16
作者 YANG Yi-Xuan WANG Xin-Yi +5 位作者 CHEN Wei-Wei GAN Li SUN Yu LIN Tong ZHAO Wei-Chun ZHU Zhen-Hong 《中国生物化学与分子生物学报》 北大核心 2025年第2期260-272,共13页
Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ab... Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ability,the arginine-glycine-aspartic(RGD)peptide and the epidermal growth factor receptor interference(EGFRi)peptide were fused with MAP30,which was named ELRL-MAP30.The efficiency of targeted therapy for triple-negative breast cancer(TNBC)MDA-MB-231 cells,which lack the expression of estrogen receptor(ER),Progesterone receptor(PgR)and human epidermal growth factor receptor-2(HER2),is limited.In this study,we focus on exploring the effect and mechanism of ELRL-MAP30 on TNBC MDA-MB-231 cells.First,we discovered that ELRL-MAP30 significantly inhibited the migration and invasion of MDA-MB-231 cells and induced MDA-MB-231 cell apoptosis.Moreover,ELRL-MAP30 treatment resulted in a significant increase in Bax expression and a decrease in Bcl-2 expression.Furthermore,ELRL-MAP30 triggered apoptosis via the Fak/EGFR/Erk and Ilk/Akt signaling pathways.In addition,recombinant ELRL-MAP30 can inhibit chicken embryonic angiogenesis,and also inhibit the tube formation ability of human umbilical vein endothelial cells(HUVECs),indicating its potential therapeutic effects on tumor angiogenesis.Collectively,these results indicate that ELRL-MAP30 has significant tumor-targeting properties in MDA-MB-231 cancer cells and reveals potential therapeutic effects on angiogenesis.These findings indicate the potential role of ELRL-MAP30 in the targeted treatment of the TNBC cell line MDA-MB-231. 展开更多
关键词 arginine-glycine-aspartic peptide(RGD) epidermal growth factor receptor interference peptide(EGFRi) momordica antiviral protein(map30) MDA-MB-231 cell tumor targeting APOPTOSIS
在线阅读 下载PDF
DTI联合T2 mapping在神经根型颈椎病神经根损伤定量评价中的应用
17
作者 赵锐荣 张凤翔 张芳 《影像技术》 2025年第1期50-56,67,共8页
目的:探讨弥散张量成像(DTI)联合T2 mapping技术在定量评价神经根型颈椎病患者神经根损伤中的应用价值。方法:对82例神经根型颈椎病患者与30例健康志愿者进行颈椎间盘常规MRI、DTI、T2 mapping及T1 Vibe检查。测量所有受试者神经根的各... 目的:探讨弥散张量成像(DTI)联合T2 mapping技术在定量评价神经根型颈椎病患者神经根损伤中的应用价值。方法:对82例神经根型颈椎病患者与30例健康志愿者进行颈椎间盘常规MRI、DTI、T2 mapping及T1 Vibe检查。测量所有受试者神经根的各序列参数,包括FA(各向异性分数)、ADC(表观扩散系数)、AD(轴向扩散系数)、RD(径向扩散系数)及T2值。利用VAS评分对患者进行疼痛学评分。比较患者受压神经根与健康志愿者神经根的各序列参数值差异,并分析各序列参数值与VAS评分的相关性。结果:神经根型颈椎病患者的患侧神经根较健侧及健康志愿者神经根FA值显著减低,ADC、AD、RD、T2值显著升高(P<0.05)。患侧神经根FA平均值与VAS评分呈中度负相关(r=-0.544),ADC、AD、RD、T2平均值与VAS呈正相关(ADC:r=0.457;AD:0.249;RD:0.390;T2:r=0.497)(P<0.05)。ROC曲线分析显示,当DTI所有参数与T2值联合时,曲线下面积(AUC)最大,为0.980,对应的敏感度为95.3%,特异度为94.6%。结论:DTI及T2 mapping技术可以用于评价神经根型颈椎病患者颈神经根损伤,且当DTI与T2 mapping联合使用时可获得最佳诊断效能。 展开更多
关键词 磁共振成像 弥散张量成像 T2图谱 定量分析 颈神经根
在线阅读 下载PDF
融合Mind Map优势助力完善线上线下教学衔接--以园林树木学树种识别教学为例 被引量:3
18
作者 刘艺平 贺丹 +1 位作者 李永华 张曼 《高教学刊》 2024年第1期78-81,共4页
疫情当前,线上线下混合式教学已经成为课程教学新模式。树种识别是园林树木学教学的重点和难点,也是教学目的之一。由于课程涉及的树种种类繁多,知识点琐碎,专业术语抽象,再加上课时少任务重,使得教师在教学过程中无法将所有树种的特征... 疫情当前,线上线下混合式教学已经成为课程教学新模式。树种识别是园林树木学教学的重点和难点,也是教学目的之一。由于课程涉及的树种种类繁多,知识点琐碎,专业术语抽象,再加上课时少任务重,使得教师在教学过程中无法将所有树种的特征逐一讲解到,学生在学习过程中也容易混淆,无法有效吸收知识点。因此,在课程的教学改革中,通过引入Mind Map帮助厘清知识框架,优化知识结构,搭建知识关联,不仅使教师授课过程更顺畅,而且能够激发学生在线学习的兴趣,促使学生养成“整理知识点”的良好习惯,使学习效率大幅度提高,从而创建高效的线上课堂,有效巩固混合式教学的教学效果。 展开更多
关键词 线上线下 园林树木学 Mind map 树种识别 混合式教学
在线阅读 下载PDF
Dirichlet-to-Neumann Mapping for the Characteristic Elliptic Equations with Symmetric Periodic Coefficients
19
作者 Jingsu Kang Meirong Zhang Chunxiong Zheng 《Communications in Computational Physics》 SCIE 2014年第9期1102-1115,共14页
Based on the numerical evidences,an analytical expression of the Dirichletto-Neumann mapping in the form of infinite product was first conjectured for the onedimensional characteristic Schrodinger equation with a sinu... Based on the numerical evidences,an analytical expression of the Dirichletto-Neumann mapping in the form of infinite product was first conjectured for the onedimensional characteristic Schrodinger equation with a sinusoidal potential in[Commun.Comput.Phys.,3(3):641-658,2008].It was later extended for the general secondorder characteristic elliptic equations with symmetric periodic coefficients in[J.Comp.Phys.,227:6877-6894,2008].In this paper,we present a proof for this Dirichlet-toNeumann mapping. 展开更多
关键词 dirichlet-to-neumann mapping Schrodinger equation symmetric periodic potentials absorbing boundary conditions.
原文传递
Dirichlet-to-Neumann Map Method with Boundary Cells for Photonic Crystals Devices
20
作者 Jianhua Yuan Ya Yan Lu 《Communications in Computational Physics》 SCIE 2011年第1期113-128,共16页
In a two-dimensional(2D)photonic crystal(PhC)composed of circular cylinders(dielectric rods or air holes)on a square or triangular lattice,various PhC devices can be created by removing or modifying some cylinders.Mos... In a two-dimensional(2D)photonic crystal(PhC)composed of circular cylinders(dielectric rods or air holes)on a square or triangular lattice,various PhC devices can be created by removing or modifying some cylinders.Most existing numerical methods for PhC devices give rise to large sparse or smaller but dense linear systems,all of which are expensive to solve if the device is large.In a previous work[Z.Hu et al.,Optics Express,16(2008),17383-17399],an efficient Dirichlet-to-Neumann(DtN)map method was developed for general 2D PhC devices with an infinite background PhC to take full advantage of the underlying lattice structure.The DtN map of a unit cell is an operator that maps the wave field to its normal derivative on the cell boundary and it allows one to avoid computing the wave field in the interior of the unit cell.In this paper,we extend the DtN map method to PhC devices with a finite background PhC.Since there is no bandgap effect to confine the light in a finite PhC,a different technique for truncating the domain is needed.We enclose the finite structure with a layer of empty boundary and corner unit cells,and approximate the DtN maps of these cells based on expanding the scattered wave in outgoing plane waves.Our method gives rise to a relatively small and sparse linear systems that are particularly easy to solve. 展开更多
关键词 Photonic crystal dirichlet-to-neumann map numerical simulation
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部