试论高等工程专科的办学特色

近几年来,我国高等工程专科教育发展很快。全日制高等工程专科学校共有73所,还有各类理工科本科院校开办的专科班,以及迅猛发展的各类成人高校、职工大学、夜大学举办的大专班,高等工程专科教育又出现了一个大发展的新高潮。然而,高等工程专科教育的大发展还存在着许多矛盾和问题。一是高等工程专科教育的性质、地位和作用不清楚,究竟是普通高等教育中的一个相对独立的层次或类型,还是职业教育中的一个高级层次,各有不同的看法和议论。二是培养目标不明确,过去有的提培养“高级技术人员”,有的提培养     

新世纪高等工程教育课程体系模式展望

新世纪高等工程教育课程体系模式展望东北大学李绍荣学科的高度综合与技术的高度密集，已成为现代科学的显著特点，这就要求我们的高等教育不仅仅单纯地传授知识信息，还必须重视学生的智力开发与能力培养，使学生具有多种能力和健全的素质。高等教育的培养模式必须与科学...     

成人高等专业,技术教育初论

成人高等专业、技术教育,是指按照学科分类或职业分工设置高等教育专业,对具有高中毕业或相当于高中毕业文化程度的成年人实施的高等教育。(一) 成人高等专业、技术教育的分类成人高等专业、技术教育,是以培养高级专业、技术人才为目的的教育层次。依据不同的划分方法,可以将成人高等专业、技术教育划分为不同的种类。按照学制分,可以划分为二年制、三年制甚至四年制、五     

对本科生导师制的思考

实行本科生导师制可以改变中国高校人才培养模式 ,进一步深化中国高等教育教学改革 ,培养出大批具有丰富个性的杰出人才。本科生导师的主要责任是培养学生的自学和独立思考的能力。要成功地实施本科生导师制 ,必须进一步完善学分制 ,大力提高教师素质 ,加快高等教育信息化进程。     

善良的科技

<正>上世纪60年代,有个普林斯顿大学的学生,得到了一次采访爱因斯坦的机会,他非常珍惜,花了很长时间琢磨该怎么提问。最后,他问爱因斯坦:"作为当代最伟大的科学家,你觉得什么是这个时代最重要的科学问题?我不要你有答案,我只想知道问题本身。"爱因斯坦认真思考了整整15分钟,然后对学生说:"我觉得最重要的科学问题是,这个世界是善良的还是邪恶的?"学生     

重视“课堂讨论”

在改革开放的形势下,高等教育必须改革。不然,我国的人才培养就不能适应国际竞争和新技术革命挑战的形势。正如李鹏总理在全国高教工作会议上所指出:“高校要注意培养学生具有改革开放意识,具有实事求是、独立思考、勇于创造的科学精神。”众所周知,衡量高等教育的标准是学生的质量及其社会适应性。随着教育改革的深化,大家都在研究如何积极推动教学领域的改革,培养出合格的人才。本文仅就缩减上课时数,增设“课堂讨论”发表一些看法。所结合的具体问题是针对《机械设计》课程而言的。     

科学教育与人文教育:历史的透析

要理解科学教育与人文教育错综复杂的关系需要用历史的眼光来审视相关的概念,这些概念分为两类：与科学教育相关的概念有科学、科学主义、科学主义教育、科学教育观、科学主义教育观,与人文教育相关的概念有人文、人文学科、人文主义、人文主义教育、人文教育观、人文主义教育观。科学与科学教育经历了从近代的崛起到当下的贬谪。人文学科与人文教育经历了从主流到退隐、从复兴到抗争的过程。     

教学管理必须适应教育思想的转变——谈实行学分制的必要性

邓小平同志提出的“教育要面向现代化,面向世界,面向未来”的方针,给高等教育的发展和改革指明了方向。《中共中央关于教育体制改革的决定》中提出,高等教育的根来任务是要培养出大批“有理想,有道德,有文化,有纪律,热爱社会主义祖国和社会主义事业,具有为国家富强和人民富裕而艰苦奋斗的献身精神,都应该不断追求新知,具有实事求是、独立思考、勇于创新的科学精神”。要达到这些要求,在教育思想上必须来一个转变,从过去那种封闭,呆板、单调、注入式的教育思想和教学方法转到开放、灵活、多样、启发式的教育思想和教学方法上来;从单纯传授知识转到在传授知识的同时开发学生智力,注重能力的培养上     

试论高等教育质量

试论高等教育质量浙江经济高等专科学校项振乐中共中央、国务院印发的《中国教育改革和发展纲要》规定９０年代高等教育发展的具体目标是：“高等学校培养的专门人才适应经济、科技和社会发展的需求，……教育质量，科学技术水平和办学效益有明显提高。”在今年召开的全国...     

把握高职教育办学特色的基本要素

高等职业教育是培养技术应用人才的高等教育,属于职业体系中的高等教育层次,具有高等教育和职业教育的双重属性。高等职业教育作为一种实践型、技术型、职业专门化类型的高等教育,具有其鲜明的办学特色。培养目标、教学计划、教学内容、实践教学、校企合作是最能体现高职教育办学特色的几个基本要素,这几个要素做好了,那么,办学特色就能得到保证。一、培养目标培养目标是办学的方向和龙头,培养目标定位不准,其它一切都无从谈起。高职教育是以培养生产、建设、管理和服务第一线需要的高等技术应用人才为培养目标和根本任务,这已成定论,无需讨…     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.