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我国的大学教育仍有一些方面可以进行改革和优化。文章根据作者在德国的德累斯顿工业大学进行访学的经历,对中德两国大学工程教育的教育体系、学生与教授的关系、课程学习结构等方面进行了对比,为提高我国的大学工程教育水平提供参考。 相似文献
2.
王秀宇 《新课程学习(社会综合)》2011,(3)
在高中地理教学中如何发展学生的地理思维能力以及如何激发学生探究地理问题的兴趣和动机,已成为地理教育者们共同关心的问题之一.传统的教学模式只注重教师教,而忽略了学生的主体地位,学生只是被动地接受知识,学习枯燥无味,而"问题解决式"教学模式却体现了"教为主导"与"学为主体"的统一性.本文将探讨如何在高中地理教学中实践"问题解决式"教学模式. 相似文献
3.
为提高企业经营管理水平和风险防范能力,促进企业可持续发展,在财务管理过程中,企业应建立严格而规范的内部控制制度。在对企业财务管理内部控制的必要性进行分析的基础上,结合目前财务管理过程中内部控制现状,提出了系统的对策和建议。 相似文献
4.
微乳液法制备纳米钴蓝颜料及粒径控制 总被引：3，自引：0，他引：3
利用动态光散射 (DLS)法 ,研究了纳米钴蓝颜料微乳液制备过程中 ,增溶水量对微乳液滴的影响 ,并讨论了微乳液滴对最终制得的粒子粒径的影响 .结果表明 ,调节增溶水量可控制纳米粒子的粒径大小 .对制得的纳米钴蓝颜料进行了XRD和TEM表征 ,并通过颜色测定与分析 ,探讨了纳米粒子的量子尺寸效应 . 相似文献
5.
High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 type thin film chip resistors when the deposition time was about 11 min and deposition films were annealed at 500 ℃ for 120 min.The morphologies of Cr-Si-TaAl film surfaces were examined by scanning electron microscopy(SEM).The analysis suggests that Ta and Al may be distributed in CrSi2 film with mixed form of several structures(e.g.,bridge-like,capillary-like or island-like structures),and such a structure distribution is responsible for high film resistance and low TCR of Cr-Si-Ta-Al film. 相似文献
6.
Phenolic resin(PF) and nano-SiO2 were used to improve the curing property and high humidity resistance of epoxy resin (EP) and methyl nadic anhydride (MNA)
resistor paint, respectively. Hydrogen bonds, formed between phenolic resin and nano-SiO2 in alcohol, made nano-SiO2 disperse easily in EP/MNA paint through phenolic resin without being treated by supersonic vibration. When the mass ratio
of PF to EP in paint is 3:7, the formed composite paint film can be cured in 2 min at 170 °C. When the mass ratio of nano-SiO2 to PF in paint is 3:100, the property of high humidity resistance of the composite paint is the best, meeting the requirement
of varying ratio of resistance less than 0.1% after experiment on high humidity resistance. SEM analysis shows the surface
of the composite paint film is smooth, glassy, tight and homogeneous, without acicular air holes. 相似文献
7.
A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80 ℃. The structure, thermal stability, humidity resistance, and morphological characteristics of the modified epoxy resin undercoat were studied by electrical tests, infrared spectra (IR) analysis, and scanning electron microscopy (SEM). The results show that more compact and steady inter-crosslinked network structures are formed in the modified epoxy resin undercoat added with nano-SiO2, which greatly improves the performance of modified epoxy resin undercoat. The undercoat with nano-SiO2 of about 2.71%, kept for six months at room temperature without flocculating and aggregating, is of good stability, and the surface of painted resistor is uniform, tight and without air holes on it. The varying ratio of resistance with such undercoat painted is less than one in a thousand after high temperature and humidity resistance tests. 相似文献
8.
Phenolic formaldehyde(PF)and epoxy(EP)resins are commonly used in electronic packaging. In this paper, high-ohmic resistors(2.2 M?, ±0.5%,)with Cr-Si film were coated by PF/EP paint, and the resulting coated resistors were used for heat and humid(HH)experiments. The experimental results show that the corrosion of bandlike resistive films is selective and isotropic, and that the corrosion spots in resistive films all form along grooves and extend in the same direction. It is revealed that OH~- ions are generated due to the electrochemical reactions of resistive film in HH experiments, so a NaOH aqueous solution with pH about 10 was used to study the effects of absorbed water and OH~- ions on PF/EP polymer film. The results indicates that the color of some part on PF/EP polymer film changes due to corrosion, and that the corrosion part of the polymer film is easy to be peeled off. It can be inferred that OH~- ions generated in HH experiments may play a catalytic role in the chemical reactions between polymer film and the absorbed water, which accelerates the degradation of PF/EP protection film for a resistor. 相似文献
9.
企业文化在企业发展中所起的作用越来越重要,更引起了企业界有识之士的高度重视。通过对企业文化含义和作用的分析,提出了企业文化建设的策略。 相似文献
10.