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Comparison of two classification methods to identify grain size fractions of aeolian sediment
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作者 YanZai Wang YongQiu Wu +1 位作者 MeiHui Pan RuiJie Lu 《Research in Cold and Arid Regions》 CSCD 2018年第5期413-420,共8页
Grain-size class-Std(GSCStd) and Grain-size class-dD(GSCdD) methods are simple statistical approaches for classifying bulk grain-size distributions(GSDs) into grain-size fractions. Although these two methods were deve... Grain-size class-Std(GSCStd) and Grain-size class-dD(GSCdD) methods are simple statistical approaches for classifying bulk grain-size distributions(GSDs) into grain-size fractions. Although these two methods were developed based on similar statistical principles, the classification difference between these two methods has not been analyzed. In this study, GSCStd and GSCdD methods are conducted in thirteen grain-size data sequences to examine the applicability for identifying grain size fractions. Results show that, application of the GSCStd method is equivalent to that of the GSCdD method in identifying finer grain-size fractions, and the difference between the two methods mainly comes from the identification of coarse grain-size fractions. Thus, finer grain-size fractions are recommended for use in research of surface aeolian and paleo-aeolian sediments. In addition, our results do not completely agree with previous studies, coarser grain-size fractions in our case suggest that the GSCdD method may not be more applicable than the GSCStd method. 展开更多
关键词 Grain-size class-Std method Grain-size class-dD method grain-size fractions
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Application of Leading-Subject Teaching Method in Class Teaching of Landscape Type of Public Elective Course
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作者 CHEN Ruizhi YANG Qingjuan +3 位作者 CHEN Han YANG Jiao JIA Lingli WU Yan 《Journal of Landscape Research》 2017年第1期91-93,共3页
For concrete situation of class teaching of landscape type of public elective course,the application situation of leading-subject teaching method in specific landscape type of course is explored. Teaching method trans... For concrete situation of class teaching of landscape type of public elective course,the application situation of leading-subject teaching method in specific landscape type of course is explored. Teaching method transforms from "teaching as the center" to "learning as the center". By improving student's learning interest and efficiency,student's whole development and creativity are promoted. 展开更多
关键词 Leading-subject teaching method APPLICATION class teaching
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作为方法的“中国班主任”:现代化语境下基础教育学自主知识生产的一种可能范式
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作者 齐学红 任方芳 《华东师范大学学报(教育科学版)》 北大核心 2026年第1期22-33,共12页
在当下的中国人文社会科学领域,正在发生将本土分析单位从“作为对象”“作为目的”向“作为方法”的范式转换,意在寻找能够捕捉中国经验敏感性的分析单位,以此建构促进主体生成、对话世界的自主知识体系。“中国班主任”正是这样一个... 在当下的中国人文社会科学领域,正在发生将本土分析单位从“作为对象”“作为目的”向“作为方法”的范式转换,意在寻找能够捕捉中国经验敏感性的分析单位,以此建构促进主体生成、对话世界的自主知识体系。“中国班主任”正是这样一个源自本土境脉和实践的分析单位,它在中国式现代化历次转型中深度嵌入中国基础教育场域,其观念、秩序、价值和历史的创造过程,也是分工悖论、群己纠葛、管理迷思和话语间距等普适性问题的形成过程。作为一场班主任研究的自我革命,需要研究者重构“中国班主任”的总体性视野,继承和发展“从实求知”的中国传统学术研究品性、责任伦理,以“当下经验历史化”和“世界视域‘附近’化”的双向展开作为具体的实践路径。 展开更多
关键词 作为方法 中国班主任 基础教育 基础教育学 自主知识生产
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One-Class分类器研究 被引量:37
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作者 潘志松 陈斌 +1 位作者 缪志敏 倪桂强 《电子学报》 EI CAS CSCD 北大核心 2009年第11期2496-2503,共8页
传统的多类分类问题需要多类样本训练分类器,然而由于样本获取(复杂性或代价)的原因很多情况下只能获取一类样本,故只能利用这一类样本进行学习,形成数据描述从而实现分类,故称之为One-Class分类.鉴于目前单类分类研究存在领域相关方法... 传统的多类分类问题需要多类样本训练分类器,然而由于样本获取(复杂性或代价)的原因很多情况下只能获取一类样本,故只能利用这一类样本进行学习,形成数据描述从而实现分类,故称之为One-Class分类.鉴于目前单类分类研究存在领域相关方法和通用方法百花齐放的格局,本文首先给出了当前One-Class分类器的研究综述,然后重点针对基于核方法的单类分类器进行分析,将该类方法分为对偶方式和核距离方式两类,并分析各自的特点.最后论文介绍了目前的单类分类器的应用领域,指出其在故障分析、异常检测、疾病诊断和敌我识别等现实问题中的重要作用. 展开更多
关键词 单类 核方法 分类器 异常检测
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Constrained Hamilton variational principle for shallow water problems and Zu-class symplectic algorithm 被引量:2
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作者 Feng WU Wanxie ZHONG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2016年第1期1-14,共14页
In this paper, the shallow water problem is discussed. By treating the incompressible condition as the constraint, a constrained Hamilton variational principle is presented for the shallow water problem. Based on the ... In this paper, the shallow water problem is discussed. By treating the incompressible condition as the constraint, a constrained Hamilton variational principle is presented for the shallow water problem. Based on the constrained Hamilton variational principle, a shallow water equation based on displacement and pressure (SWE-DP) is developed. A hybrid numerical method combining the finite element method for spa- tial discretization and the Zu-class method for time integration is created for the SWE- DP. The correctness of the proposed SWE-DP is verified by numerical comparisons with two existing shallow water equations (SWEs). The effectiveness of the hybrid numerical method proposed for the SWE-DP is also verified by numerical experiments. Moreover, the numerical experiments demonstrate that the Zu-class method shows excellent perfor- mance with respect to simulating the long time evolution of the shallow water. 展开更多
关键词 shallow water equation (SWE) constrained Hamilton variational principle Zu-class method
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具身认知视野下吟诵法介入大班幼儿古典诗歌教学的行动研究
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作者 刘超 许家悦 《陕西学前师范学院学报》 2026年第2期45-52,共8页
古典诗歌是我国传统优秀文化的精华,古典诗歌的学习有助于幼儿文化认同感和归属感的形成。基于具身认知的理论视野,本研究对大班幼儿展开三轮古典诗歌吟诵教学的行动研究,结果显示:幼儿具备学习古典诗歌的基本接受能力;家长在幼儿古典... 古典诗歌是我国传统优秀文化的精华,古典诗歌的学习有助于幼儿文化认同感和归属感的形成。基于具身认知的理论视野,本研究对大班幼儿展开三轮古典诗歌吟诵教学的行动研究,结果显示:幼儿具备学习古典诗歌的基本接受能力;家长在幼儿古典诗歌的吟诵学习中起着不可忽视的作用;通过多维度的教学设计和多层次的教学策略;幼儿教师能够自然地教会幼儿吟诵古典诗歌。未来研究可以开发系统的幼儿园古典诗歌课程,根据地方特点选择相应的吟诵调,通过立体化的教学方法丰富幼儿古典诗歌学习的具身体验,在教学中充分调用家长资源。 展开更多
关键词 具身认知 吟诵法 古典诗歌 大班幼儿
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An Improved Double-Threshold Method Based on Gradient Histogram 被引量:2
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作者 YANG Shen CHEN Shu-zhen ZHANG Bing 《Wuhan University Journal of Natural Sciences》 CAS 2004年第4期473-476,共4页
This paper analyzes the characteristics of the output gradient histogram and shortages of several traditional automatic threshold methods in order to segment the gradient image better.Then an improved double-threshold... This paper analyzes the characteristics of the output gradient histogram and shortages of several traditional automatic threshold methods in order to segment the gradient image better.Then an improved double-threshold method is proposed,which is combined with the method of maximum classes variance,estimating-area method and double-threshold method.This method can automatically select two different thresholds to segment gradient images.The computer simulation is performed on the traditional methods and this algorithm and proves that this method can get satisfying result. 展开更多
关键词 gradient histogram image threshold selection double-threshold method maximum classes variance method
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Task-based Teaching and Learning in English Listening Class
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作者 鲍蓉芳 《科技信息》 2008年第17期226-227,241,共3页
In technical college English listening class,task-based teaching and learning method can not only create harmonious environment for students' learning,but also motivate students' enthusiasm in listening class,... In technical college English listening class,task-based teaching and learning method can not only create harmonious environment for students' learning,but also motivate students' enthusiasm in listening class,thus students can benefit a great deal in listening class and the listening can be carried out successfully. 展开更多
关键词 高校 英语 教学方法 听写能力
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提锂硫酸盐废水的资源化回收研究
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作者 周晴 胡慧萍 +2 位作者 彭奇凡 彭全凡 郑林军 《水处理技术》 北大核心 2026年第1期113-119,共7页
以湖南省某提锂硫酸盐废水为研究对象,通过差式扫描量热仪(DSC)测定该废水的共晶温度,用聚合硫酸铁除总磷(TP),用冷冻法回收废水中的硫酸钠,探究了初始TP质量浓度、冷冻温度、冷冻时间和搅拌速率等因素对硫酸钠回收效果的影响。由此获... 以湖南省某提锂硫酸盐废水为研究对象,通过差式扫描量热仪(DSC)测定该废水的共晶温度,用聚合硫酸铁除总磷(TP),用冷冻法回收废水中的硫酸钠,探究了初始TP质量浓度、冷冻温度、冷冻时间和搅拌速率等因素对硫酸钠回收效果的影响。由此获得的结晶母液1用30wt%NaOH溶液除钙镁,蒸发浓缩一定倍数后再次用冷冻法回收硫酸钠,并得到结晶母液2。采用碳酸盐沉淀法回收结晶母液2中的锂并获得沉锂后液,探究碳酸盐种类和加料方式等因素对碳酸锂回收率和纯度的影响。该沉锂后液采用溶剂萃取法进一步回收锂。结果表明,该废水共晶温度为-1.9℃;采用铁磷摩尔比1/2除磷时TP质量浓度降低至4.89 mg/L;当在冷冻温度为-1.0℃、冷冻时间为1 h和搅拌速度200 r/min时,第一次冷冻得到的无水硫酸钠回收率为85.31%,纯度为99.638%,第二次冷冻得到的无水硫酸钠回收率为53.41%,纯度为99.490%。可达到《工业无水硫酸钠》(GB/T 6009-2014)Ⅰ类优等品/一等品的要求。经过两次冷冻后,无水硫酸钠的总回收率为97.680%。当碳酸盐沉锂温度为90.0℃、搅拌速度300 r/min和反应1 h时,采用倒加法得到的碳酸锂纯度和回收率更高,分别为99.87%和67.07%。以28%HBL121(质量分数)作为萃取剂,萃取时间10 min、相比O/A=5:1和室温条件下,对沉锂后液、洗水1和洗水2的混合液进行四级逆流萃取,得到负载有机相和萃余液,锂萃取率高达99.85%,萃余液的锂含量为6.4 mg/L。将该负载有机相用7 mol/L的盐酸在室温、相比O/A=10:1和反萃时间8 min条件下经过四级逆流反萃,反萃率可达到99.37%。整个工艺流程的锂总回收率为91.39%。 展开更多
关键词 提锂硫酸盐废水 冷冻法 工业无水硫酸钠Ⅰ类优等品/一等品 碳酸锂 DSC
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k-NN METHOD IN PARTIAL LINEAR MODEL UNDER RANDOM CENSORSHIP 被引量:1
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作者 QIN GENGSHENG (Department of Mathematics,Sichuan University, Chengdu 610064). 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第3期275-286,共12页
Consider the regression model Y=Xβ+ g(T) + e. Here g is an unknown smoothing function on [0, 1], β is a l-dimensional parameter to be estimated, and e is an unobserved error. When data are randomly censored, the est... Consider the regression model Y=Xβ+ g(T) + e. Here g is an unknown smoothing function on [0, 1], β is a l-dimensional parameter to be estimated, and e is an unobserved error. When data are randomly censored, the estimators βn* and gn*forβ and g are obtained by using class K and the least square methods. It is shown that βn* is asymptotically normal and gn* achieves the convergent rate O(n-1/3). 展开更多
关键词 Partial linear model censored data class K method k-nearest neighbor weights
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OBJECT-ORIENTED NUMERICAL MANIFOLD METHOD 被引量:1
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作者 Zhang Xiangwei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2000年第2期134-139,152,共7页
The design and management of the objects about the numerical manifold method are studied by abstracting the finite cover system of numerical manifold method as independent data classes and the theoretical basis for th... The design and management of the objects about the numerical manifold method are studied by abstracting the finite cover system of numerical manifold method as independent data classes and the theoretical basis for the researching and expanding of numerical manifold method is also put forward. The Hammer integration of triangular area coordinates is used in the integration of the element. The calculation result shows that the program is accuracy and effective. 展开更多
关键词 Mould method class/object Cover
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城市幼儿园半日活动中师幼互动质量研究——基于CLASS评估系统的观察分析 被引量:5
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作者 余斯思 刘馨 《西华师范大学学报(哲学社会科学版)》 2020年第1期110-115,共6页
师幼互动是指教师与幼儿在区域活动、集体教学活动等不同活动形式以及室内、户外等不同场域中发生的一切交互动作或反应。研究证明,高质量的师幼互动对幼儿自身的发展以及学前教育质量的提高具有重要作用。本研究采用CLASS量表对城市地... 师幼互动是指教师与幼儿在区域活动、集体教学活动等不同活动形式以及室内、户外等不同场域中发生的一切交互动作或反应。研究证明,高质量的师幼互动对幼儿自身的发展以及学前教育质量的提高具有重要作用。本研究采用CLASS量表对城市地区某两所幼儿园的部分班级进行了观察评估,得出三个结论。第一,教师和幼儿之间最容易产生较为外在的互动,而涉及情感等内在维度的互动较少;第二,集体统一行动程度较低的活动类型(如区域活动)的师幼互动质量更高;第三,班级特征(普通班、混龄班)对师幼互动的质量并无影响。针对以上结论,对教师提出如下建议:一方面,教师应打破“外倾”现状,树立“内倾”意识。另一方面,教师应调整集体活动占比,发挥户外活动优势。 展开更多
关键词 幼儿园 师幼互动 class评估系统 观察法
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NDVI-Based Lacunarity Texture for Improving Identification of Torreya Using Object-Oriented Method 被引量:4
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作者 HAN Ning WU Jing +2 位作者 Amir Reza Shah Tahmassebi XU Hong-wei WANG Ke 《Agricultural Sciences in China》 CAS CSCD 2011年第9期1431-1444,共14页
Normalized Difference Vegetation Index (NDVI) is a very useful feature for differentiating vegetation and non-vegetation in remote sensed imagery. In the light of the function of NDVI and the spatial patterns of the... Normalized Difference Vegetation Index (NDVI) is a very useful feature for differentiating vegetation and non-vegetation in remote sensed imagery. In the light of the function of NDVI and the spatial patterns of the vegetation landscapes, we proposed the lacunarity texture derived from NDVI to characterize the spatial patterns of vegetation landscapes concerning the "gappiness" or "emptiness" characteristics. The NDVI-based lacunarity texture was incorporated into object-oriented classification for improving the identification of vegetation categories, especially Torreya which was the targeted tree species in the present research. A three-level hierarchical network of image objects was defined and the proposed texture was integrated as potential sources of information in the rules base. A knowledge base of rules created by classifier C5.0 indicated that the texture could potentially be applied in object-oriented classification. It was found that the addition of such texture improved the identification of every vegetation category. The results demonstrated that the texture could characterize the spatial patterns of vegetation structures, which could be a promising approach for vegetation identification. 展开更多
关键词 Torreya NDVI LACUNARITY class hierarchy object-oriented method decision tree spatial pattern
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OPTIMIZATION OF ADAPTIVE DIRECT METHOD FOR APPROXIMATE SOLUTION OF INTEGRAL EQUATIONS OF SEVERAL VARIABLES 被引量:2
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作者 马万 房艮孙 《Acta Mathematica Scientia》 SCIE CSCD 2004年第2期228-234,共7页
This paper determines the exact error order on optimization of adaptive direct methods of approximate solution of the class of Fredholm integral equations of the second kind with kernel belonging to the anisotropic So... This paper determines the exact error order on optimization of adaptive direct methods of approximate solution of the class of Fredholm integral equations of the second kind with kernel belonging to the anisotropic Sobolev classes, and also gives an optimal algorithm. 展开更多
关键词 Integral equations direct methods anisotropic sobolev classes
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基于Bagging算法构造强分类器的one class SVM导线舞动预测应用 被引量:8
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作者 程永锋 汉京善 +2 位作者 刘彬 李鹏 姬昆鹏 《振动与冲击》 EI CSCD 北大核心 2020年第9期152-158,共7页
考虑到传统物理分析方法无法解决导线舞动的预测问题,综合运用机器学习算法,对已有的舞动历史数据进行筛选和预处理,并挖掘有效信息,利用one class SVM算法解决舞动数据中负样本缺失问题,采用集成学习算法中Bagging算法建立分类器学习方... 考虑到传统物理分析方法无法解决导线舞动的预测问题,综合运用机器学习算法,对已有的舞动历史数据进行筛选和预处理,并挖掘有效信息,利用one class SVM算法解决舞动数据中负样本缺失问题,采用集成学习算法中Bagging算法建立分类器学习方法,实现了数据的随机抽样,分成不同组数据集进行相互独立的训练,避免对舞动数据过拟合,提升机器学习算法的抗噪声能力以及泛化能力,采用k折交叉验证算法进行模型的验证,并利用F1-score描述导线舞动预警模型的性能,验证了该方法在舞动预测方面的有效性。 展开更多
关键词 导线舞动 机器学习 ONE class SVM 集成学习 BAGGING算法 F1-score
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Multi-resolution EMD and classscatter matrix extracting of tank sound 被引量:1
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作者 张万君 吴晓颖 王新 《Journal of Beijing Institute of Technology》 EI CAS 2012年第1期91-95,共5页
The acoustic vibration signal of tank is disassembled into the sum of intrinsic mode function (IMF) by multi-resolution empirical mode decomposition (EMD) method. The instantaneous frequency is obtained, and featu... The acoustic vibration signal of tank is disassembled into the sum of intrinsic mode function (IMF) by multi-resolution empirical mode decomposition (EMD) method. The instantaneous frequency is obtained, and feature transformation matrix is figured out by class scatter matrix. Multi- dimensional scale energy vector is mapped into low-dimensional eigenvector, and classification extraction is realized. This method sufficiently separates of different sound target features. The test result indicates that it is effective. 展开更多
关键词 multi-resolution analysis EMD method sound feature extraction class scatter matrix
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Exploring Design Level Class Cohesion Metrics
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作者 Kuljit Kaur Hardeep Singh 《Journal of Software Engineering and Applications》 2010年第4期384-390,共7页
In object oriented paradigm, cohesion of a class refers to the degree to which members of the class are interrelated. Metrics have been defined to measure cohesiveness of a class both at design and source code levels.... In object oriented paradigm, cohesion of a class refers to the degree to which members of the class are interrelated. Metrics have been defined to measure cohesiveness of a class both at design and source code levels. In comparison to source code level class cohesion metrics, only a few design level class cohesion metrics have been proposed. Design level class cohesion metrics are based on the assumption that if all the methods of a class have access to similar para-meter types then they all process closely related information. A class with a large number of parameter types common in its methods is more cohesive than a class with less number of parameter types common in its methods. In this paper, we review the design level class cohesion metrics with a special focus on metrics which use similarity of parameter types of methods of a class as the basis of its cohesiveness. Basically three metrics fall in this category: Cohesion among Methods of a Class (CAMC), Normalized Hamming Distance (NHD), and Scaled NHD (SNHD). Keeping in mind the anomalies in the definitions of the existing metrics, a variant of the existing metrics is introduced. It is named NHD Modified (NHDM). An automated metric collection tool is used to collect the metric data from an open source software program. The metric data is then subjected to statistical analysis. 展开更多
关键词 DESIGN Metrics class COHESION Metrics COHESION among methods of a class Normalized Hamming DISTANCE Scaled NHD
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老为何所困,老因何而贫:新时代老年人口多维贫困及其影响因素研究——基于2018年CLASS数据的实证分析 被引量:12
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作者 金光照 陶涛 《人口与发展》 CSSCI 北大核心 2022年第2期70-81,共12页
新时代对老年人口贫困的考察要多维化。使用2018年中国老年社会追踪调查(CLASS)数据,基于AF方法,从稳健老年生活、宜居养老环境、健康老龄体魄和积极老化精神维度构建老年多维贫困指数,并通过剥夺圈层体系进行实证分析。研究发现,中国... 新时代对老年人口贫困的考察要多维化。使用2018年中国老年社会追踪调查(CLASS)数据,基于AF方法,从稳健老年生活、宜居养老环境、健康老龄体魄和积极老化精神维度构建老年多维贫困指数,并通过剥夺圈层体系进行实证分析。研究发现,中国老年人的多维贫困主要表现在除住房外资产积累不足、厕所和网络建设欠缺、慢性病患病率较高、孤独感较强。剥夺圈层能够为不同程度多维贫困的发生提供有力的解释,政府与社会应根据老年人所拥有的个体特征、家庭支持情况、熟人网络状况以及所在区域,改善相对贫困,完善公共支持及服务体系,关注老年人家庭与社会支持网络建设,促进新时代老年人的全面发展。 展开更多
关键词 新时代 AF贫困测量法 老年多维贫困 剥夺圈层 中国老年社会追踪调查
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杜甫组诗的题材类别及其构建方式 被引量:1
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作者 吴淑玲 韩成武 《南都学坛》 2025年第3期64-75,共12页
“组诗”用“组”命名,指向连类,故杜甫组诗实际数量比其自命名组诗数量多。其组诗的题材类别及其构建方式大体可归纳为八类:游赏组诗多呈散絮状结构,字里行间洋溢着对自然草木的深切关怀;纪实性组诗多呈放射性结构,反映生活的多面性和... “组诗”用“组”命名,指向连类,故杜甫组诗实际数量比其自命名组诗数量多。其组诗的题材类别及其构建方式大体可归纳为八类:游赏组诗多呈散絮状结构,字里行间洋溢着对自然草木的深切关怀;纪实性组诗多呈放射性结构,反映生活的多面性和深刻性;纪行组诗多呈直线性结构,呈现纪行游踪和展现生活的平面化;回忆性组诗多呈铺叙对比结构,意在深化痛伤大唐的主题;咏史组诗多呈古今勾连结构,于古事古迹中内涵寓今之意;政论性组诗构建方式是罗列其事,直言论之,是诗人讽谏情怀的传达;咏怀性组诗多呈藤萝式结构,以深化诗人的忧世嗟生情怀;文论组诗多呈摘星式结构,是诗人选择代表性观点发表对文学史问题的真知灼见。这些构建方式为杜诗更好地传情达意作出了贡献。 展开更多
关键词 组诗 连类 题材类别 构建方式
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On the Transformation of the Traditional “Blood Revenge” in the “Red Literary Classics”
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作者 Li Xin 《学术界》 CSSCI 北大核心 2015年第3期308-312,共5页
The writers of the"red literary classics"replace the Confucian tradition of the blood relation with the modern"class struggle theory",so the class attribute becomes the one and only standard for va... The writers of the"red literary classics"replace the Confucian tradition of the blood relation with the modern"class struggle theory",so the class attribute becomes the one and only standard for value evaluation,under which the modern "class revolution"is quite different from the traditional blood revenge,taking on the expansion of the revenge object,the simplification of the revenge method,ennobling of the revenge motivation and the legalization of the revenge means and so on. 展开更多
关键词 传统 文学 价值评估 类属性 合法化
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