检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

“窘”字音读考

汉语学报 2024年第2期 112-120页

作者：齐晓燕孙玉文华中科技大学人文学院 430074 北京大学中国语言文学系 100871

“窘”在唐宋以前音义配合单纯,主流读音是群母真韵合口三等上声。元明清时期,浊上变去已完成,但“窘”依然保持上声的读音,很可能在“窘”变成去声前已完成了清化,失去了发展为去声的条件。“窘”又受到声符“君”的同化作用,没有遵循... 详细信息

“窘”在唐宋以前音义配合单纯,主流读音是群母真韵合口三等上声。元明清时期,浊上变去已完成,但“窘”依然保持上声的读音,很可能在“窘”变成去声前已完成了清化,失去了发展为去声的条件。“窘”又受到声符“君”的同化作用,没有遵循全浊上声字中未变去声的字清化为送气音声母的规律,而是读为不送气音声母。民国初年“窘”维持着读书音“jǔn”的读法,随着京音取代老国音成为国音统一的标准,北京口语音“jiǒng”渐渐占据上风。新中国后,审音只保留了“jiǒng”的读音。“窘”北京口语音读“jiǒng”正与汉语部分方言臻摄阳声韵合口字与通摄合口三等阳声韵相混的现象一致,其音理是随着主元音央/■/的脱落,元音/u/的后高圆唇属性同化韵尾/-n/为/-■/。

关键词：窘历代读音北京音和读书音

《刘赜评传》:在中国语言学星空中寻找那颗璀璨的星

在线全文

学校读者我要写书评

暂无评论

长江学术 2024年第4期 89-97页

作者：孙玉文北京大学中国语言学研究中心/中文系北京100871

刘赜是我国杰出的语言文字学家,他在汉语音韵学、文字学、训学及方言学等领域都做出了独特的贡献。卢烈红、谢艳红合著的《刘赜评传》是我国第一部专门研究刘赜生平履历和学术贡献的著作。本文比较详细地研究了《刘赜评传》一书所取得... 详细信息

刘赜是我国杰出的语言文字学家,他在汉语音韵学、文字学、训学及方言学等领域都做出了独特的贡献。卢烈红、谢艳红合著的《刘赜评传》是我国第一部专门研究刘赜生平履历和学术贡献的著作。本文比较详细地研究了《刘赜评传》一书所取得的学术成就,也指出了《刘赜评传》的若干不足,分析了该书在中国语言学史和发展当今中国语言学中的价值。文章还连带探讨了评传这一文体的来龙去脉以及撰写理想的评传的基本要求,并对当下社会评传撰写中的不正之风提出批评意见,旨在完善评传这一文体的撰写。

关键词：评传体中国语言学史古音学刘博平卢烈红

在线全文

学校读者我要写书评

暂无评论

文学象征元素在玩具设计中的跨领域应用思考

玩具世界 2024年第3期 80-82页

作者：孙玉文鄂尔多斯生态环境职业学院

文学象征通过语言和形象表达深层含义，而玩具设计则以物质形态呈现创意。将文学象征元素巧妙地融入玩具设计中，可以使玩具超越单纯的娱乐功能，成为寓教于乐的媒介，进一步启发儿童的想象力和创造力。文章系统阐述文学象征的内涵、特... 详细信息

文学象征通过语言和形象表达深层含义，而玩具设计则以物质形态呈现创意。将文学象征元素巧妙地融入玩具设计中，可以使玩具超越单纯的娱乐功能，成为寓教于乐的媒介，进一步启发儿童的想象力和创造力。文章系统阐述文学象征的内涵、特性以及玩具设计的概念与表现手法等，指出二者的内在契合性，并提出具体的跨领域应用策略。

关键词：文学象征玩具设计跨领域思考寓教于乐想象力创造力

Tool path generation for 5-axis flank milling of ruled surfaces with optimal cutter locations considering multiple geometric constraints

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第12期36卷 408-424页

作者： Shuoxue sun yuwen sun Jinting XU School of Mechanical Engineering Dalian University of TechnologyDalian 116024China School of Automotive Engineering Dalian University of TechnologyDalian 116024China

Ruled surfaces found in engineering parts are often blended with a constraint surface,like the blade surface and hub surface of a centrifugal *** is significant to accurately machine these ruled surfaces in flank milling with interference-free and fairing tool path,while current models in fulfilling these goals are complex and *** this paper,a tool path planning method with optimal cutter locations(CLs)is proposed for 5-axis flank milling of ruled surfaces under multiple geometric *** be specific,a concise three-point contact tool positioning model is firstly developed for a cylindrical *** tool orientations arise when varying the three contact positions and a tool orientation pool with acceptable cutter-surface deviation is constructed using a meta-heuristic *** angular curves are derived from candidates in this pool,and then curve registration for cutter tip point on each determined tool axis is performed in respect of interference avoidance and geometric *** this basis,an adaptive interval determination model is developed for deviation control of interpolated cutter *** model is designed to be independent of the CL optimization process so that multiple CLs can be planned simultaneously with parallel computing ***,tests are performed on representative surfaces and the results show the method has advantages over previous meta-heuristic tool path planning approaches in both machining accuracy and computation time,and receives the best comprehensive performance compared to other multi-constrained methods when machining an impeller.

关键词： Flank milling Tool path Tool orientation pool Machining Ruled surface

A multi-order method for predicting stability of a multi-delay milling system considering helix angle and run-out effects

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2018年第6期31卷 1375-1387页

作者： Shanglei JIANG yuwen sun Key Laboratory for Precision and Non-Traditional Machining Technology of the Ministry of Education Dalian University of Technology

In this paper, a multi-delay milling system considering helix angle and run-out effects is firstly established. An exponential cutting force model is used to model the interaction between a work-piece and a cutting tool, and a new approach is presented for accurately calibrating exponential cutting force coefficients and cutter run-out parameters. Furthermore, based on an implicit multi-step Adams formula and an improved precise time-integration algorithm, a novel stability prediction method is proposed to predict the stability of the system. The involved time delay term and periodic coefficient term are integrated as a comprehensive state term in the integral response which is approximated by the Adams formula. Then, a Floquet transition matrix with an arbitraryorder form is constructed by using a series of matrix multiplication, and the stability of the system is determined by the Floquet theory. Compared to classical semi-discretization methods and fulldiscretization methods, the developed method shows a good performance in convergence, efficiency,accuracy, and multi-order complexity. A series of cutting tests is further carried out to validate the practicability and effectiveness of the proposed method. The results show that the calibration process needs a time of less than 5 min, and the stability prediction method is effective.

关键词： Cutting force Floquet theory Milling stability Multi-delay milling system Run-out

在线全文

学校读者我要写书评

暂无评论

网络美好生活的表达机理与困境纾解

安康学院学报 2024年第2期36卷 81-86页

作者：杨琼孙玉雯黄山学院马克思主义学院安徽黄山245041

网络美好生活作为一种现实生活转向网络空间的新方式,反映出网络社会对美好生活的需求和期盼,具有内在的表达机理。它是公众对表达权利的一种情感体验,也是对网络社会和谐交往与幸福表达的价值追求。由于虚拟网络与现实生活的特点,网络... 详细信息

网络美好生活作为一种现实生活转向网络空间的新方式,反映出网络社会对美好生活的需求和期盼,具有内在的表达机理。它是公众对表达权利的一种情感体验,也是对网络社会和谐交往与幸福表达的价值追求。由于虚拟网络与现实生活的特点,网络美好生活也存在消极面向,面临诸多表达困境,其目标的实现有赖于网络社会质量的提升和现实美好生活双重世界的创造。应在中国式现代化的文化语境中努力建构具有现实呈照与价值引领的网络场域。

关键词：网络美好生活表达机理困境纾解

VARIABLE FEEDRATE INTERPOLATION OF NURBS TOOLPATH WITH GEOMETRIC AND KINEMATICAL CONSTRAINTS FOR FIVE-AXIS CNC MACHINING

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2013年第5期26卷 757-776页

作者： sun yuwen ZHOU Jianfeng GUO Dongming Key Laboratory for Precision and Non- Traditional Machining Technology of the Ministry of Education Dalian University of Technology

Variable feedrate interpolation algorithms for five-axis parametric toolpath are very promising but still rather limited *** this paper,an off-line feedrate scheduling method of dual NURBS curve is presented with geometric and kinematical *** a given dual parametric curve,the feedrates of sampling points are first scheduled sequent with confined feedrate of cutter tip and machine pivot,chord error,normal acceleration and angular ***,the feedrate profiles of angular feed acceleration sensitive regions of the path are adjusted using a bi-directional scanning *** that,a linear programming method is used to adjust the feedrate profiles of linear feed acceleration sensitive regions and control the linear feed acceleration of both cutter tip and machine pivot within preset ***,a NURBS curve is used to fit the feedrates of sampling ***,illustrative examples are carried out to validate the feasibility of the proposed feedrate scheduling *** results show that the proposed method has the ability of effectively controlling the angular feed characters of cutter axis as well as the chord error and linear feed characters of cutter tip and machine pivot,and it has potential to be used in high accuracy and high quality five-axis machining.

关键词： Feedrate interpolation five-axis machining NURBS tool path.

在线全文

学校读者我要写书评

暂无评论

基于心流体验的文旅服务设计研究

设计 2024年第8期37卷 62-65页

作者：孙煜文裴学胜河南科技大学艺术与设计学院

为了提高游客在文旅体验时的体验满意度,提升文旅系统的服务能力,将心流体验引入到服务设计中,探索社会多方可提供文旅服务的设计方法,实现社会多方的价值共创。结合心流体验要素、文旅服务阶段的场景及用户行为,采用5级李克特量表设计... 详细信息

为了提高游客在文旅体验时的体验满意度,提升文旅系统的服务能力,将心流体验引入到服务设计中,探索社会多方可提供文旅服务的设计方法,实现社会多方的价值共创。结合心流体验要素、文旅服务阶段的场景及用户行为,采用5级李克特量表设计调查问卷,通过SPSS软件,对收集的数据进行现状、相关性与回归分析,总结心流体验三要素与文旅体验满意度之间影响程度的权重。结合影响程度的优先级别,挖掘文旅服务体系的痛点,提出文旅服务体系的优化设计策略。将心流体验应用到洛阳文旅服务体系的设计实践中,探索文旅服务体系与其他领域之间结合的可能性,以期为文旅服务设计优化提供一条新的设计思路。

关键词：心流理论服务设计文化旅游用户体验界面设计

Analytical modeling of geometric errors induced by cutter runout and tool path optimization for five-axis flank machining

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第12期54卷 3180-3190页

作者： GUO Qiang sun yuwen GUO DongMing Key Laboratory for Precision and Non-Traditional Machining Technology of the Ministry of Education Dalian University of Technology Dalian 116024 China

The cutter runout effect has significant influence on the shape of cutter swept surface and the machining surface quality. Hence,it is necessary to integrate the cutter runout effect in cutter swept surface modeling,geometric error prediction and tool path optimization for five-axis flank machining. In this paper,an envelope surface model considering cutter runout effect is first established,and geometric errors induced by runout effect are derived based on the relative motion analysis between the cutter and part in machining. In the model,the cutter runout is defined by four parameters,including inclination angle,location angle,offset value and the length of cutter axis. Then the runout parameters are integrated into the rotation surface of each cutting edge that is used to form the final cutter envelope surface for the five-axis machining process. Thus,the final resulting geometric errors of the machined surface induced by cutter runout can be obtained through computing the deviations from the nominal cutter swept surface. To reduce these errors,an iterative least square method is used to optimize the tool paths for five-axis flank machining. Finally,a validation example is given for a specific ruled surface. Results show the effectiveness and feasibility of the analytical model of geometric errors induced by cutter runout,and also show that the geometric errors can be reduced significantly using the proposed tool path planning method.

关键词： cutter runout tool path optimization envelope surface five-axis machining geometric errors