基于创新性构型设计的工程图学教学体系研究

构型设计作为空间想象和创造性思维训练的重要载体对培养学生创新思维能力具有重要作用。论文在探讨国内外工程图学教研情况基础上,构建了以构型设计为主线,突出学生创新思维能力培养的基于创新性构型设计的工程图学新课程体系。并从教学改革目标、教学改革内容和教学实践三方面进行了深入阐述。教学实践表明,该课程体系能很好地培养学生的形体构型设计创新思维能力。     

拔尖人才培养模式下的工程图学教学研究

为适应拔尖创新人才培养的需要,提高工程图学教学效果,本文提出了工程图学课程的改革方案,进行了实践研究。采用中英双语教学模式,开展基于构型创新设计的工程图学实验课与自主型交互式机械设计制图实验课。培养了学生的创新思维与工程意识,锻炼了其动手实践能力,提高了学生团队合作素质,为专业知识的学习打好基础,取得了理想的教学效果。     

基于素质教育进行工程图学的教材建设

素质教育是实施教育部"高等学校本科教学质量与教学改革工程"的主题.工程图学课程是工科院校的一门技术基础课程,分析了在工程图学课程中的素质教育,指出在课程学习中培养学生的是工程图学素质,其核心是工程图学的思维方式;通过对国外工程图学教材的研讨,借鉴其侧重于学生素质教育的精华;就如何围绕素质教育的主题,开展我国的工程图学教材建设进行了研究.     

建筑类工程图学实践创新型教学内容与方法的研究与实践

为培养学生的创新思维能力和设计表达能力,图学教育应将学生能力、素质的培养放在与知识传授同等重要的地位。论文结合教学现状与实践,对建筑类工程图学的教学内容与方法、教学效果的考核与评价进行了根本性改革,提出了以构型设计和实践创新为主线的教学模式。结果表明,新的教学、考核体系在加强学生空间思维能力、形体构型能力、创新能力和工程意识的培养方面取得了明显效果,制图课程教学质量得以提高。     

高等工程教育体系中工程图学课程的改革诌议

论文探讨如何建立适应于中国国情的高等工程教育体系中工程图学课程的改革方向。突出特色以增强图学教育在高等工程教育中的地位,把思维能力、创造性意识、实践能力培养作为工程图学教育改革的首要目标。立体造型与投影、轴系零件测绘、工业机器人传动机构的三维实体构型等实验项目在工程图学课程中的实施,对提高学生的投影绘图能力,掌握科学思维方法,增强工程和创新意识有重要的作用。     

三维工程图学课程和教材的研究与实践

三维工程图学是传统工程图学的延伸,探讨三维工程图学的教学及其教材体系是为了更好地完善工程图学的教育.在教学实践的基础上,分析了三维工程图学的性质和教学内涵,给出了教材体系和内容,说明了教材特点.通过了四届教学实践,证明了该教材在完善工程图学教育和加强学生创造性思维及创新能力的培养上是有效的.     

工程图学思维浅析

提出了形象性、严谨性、工程性和创造性的工程图学思维特征。以思维心理学和思维方法学为理论基础,结合教学经验,探讨了形象思维的一般过程,课程中形象思维的主要方法和形象记忆。探讨了工程图学中的辩证思维方法,以利于对课程的深层次把握。提出并分析了工程图学思维的智力品质,介绍了教学中培养学生形象思维能力的具体做法。     

工程图学课程中创造性构形设计教学的研究与实践

创造性构形设计教学已成为现代工程图学课程培养学生创新能力的重要手段。论文在浅析了构形设计的教学目标与设计评价的基础上,深入探讨了创造性构形设计在工程图学课程中的基本教学方法和实际效果。     

机械制图课程内容、体系改革的研究与实践

按照社会对人才的要求、图学教师对课程改革的共识和现代教育思想，确定课程改革的指导思想。在6届30个班级中，经过对制图课程内容、体系和教学方法改革的实践，确定把制图课的教学着眼点转变为培养学生的工程图学思维方式、把计算机实体造型表示法融入制图课程和运用CAI课件进行制图课教学，建立人－机协同教学模式。     

基于特征轮廓的立体构型方法

工程图学课程中大多数立体结构都可以看成是由特征轮廓经过拉伸、切割或者旋转运动而成型的。结合工程图学系列课程和三维CAD课程的教学实践,总结出一种基于特征轮廓的立体构型方法。从立体的二维视图中提取出表现立体结构形状的特征轮廓,经过拉伸、切割、旋转或者运动组合完成立体构型。提出了单特征轮廓、单向多特征轮廓、双向单特征轮廓、双向多特征轮廓等立体构型方法。特征轮廓的方法,尤其是双向特征轮廓方法可以大大简化立体的构型过程。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...