浅谈中职计算机课程中如何创设问题情境

在教学中,创设问题情境是一种科学有效的教学手段。通过对一堂计算机基础课《PPT动画路径》的分析,探究如何在中职计算机课程中创设问题情境,提高课堂教学实效性,并对容易出现的问题进行简单的阐述。     

Oxidative dehydrogenation of ethane over Co–BaCO3 catalysts using CO2 as oxidant: effects of Co promoter

Co–BaCO₃ catalysts exhibited high catalytic performance for oxidative dehydrogenation of ethane (ODE) using CO₂ as oxidant. The maximal formation rate of C₂H₄ was 0.264 mmol · min⁻¹ · (g · cat.)⁻¹ (48.0% C₂H₆ conversion, 92.2% C₂H₄ selectivity, 44.3% C₂H₄ yield) on 7 wt% Co–BaCO₃ catalyst at 650 °C and 6000 ml. (g · cat.)⁻¹. h⁻¹. Co–BaCO₃ catalysts were comparatively characterized by XRF, N₂ isotherm adsorption-desorption, XRD, H₂-TPR and LRs. It was found that Co⁴⁺–O species were active sites on these catalysts in ODE with CO₂. The redox cycle of Co–O species played an important role on the catalytic performance of Co–BaCO₃ catalysts. On the other hand, the co-operation of BaCO₃ and BaCoO₃ was considered to be one of possible reasons for the high catalytic activity of these catalysts.     

确定土壤背景值的Hazen概率法——以铜陵矿区Pb为例

本文选取已知土壤背景含量的铜陵矿区,基于Hazen概率曲线,探讨了土壤污染重金属元素Pb背景含量与污染叠加含量的区分方法.得到Pb元素的背景含量为28.5μg/g,与该区深层土壤样中Pb元素含量的平均值(34μg/g)比较接近.还得到了Pb元素污染叠加含量与背景含量的界线点51μg/g.基于Hazen概率曲线区分铜陵矿区土壤Pb元素背景含量与污染叠加含量的方法是有效的,有必要将该方法推广到土壤中其它重金属污染元素、其它地区作进一步研究.     

高校广告学课程教学模式改革探讨

广告行业的繁荣,使得广告业成为当今社会炙手可热的行业之一,各地高校争相开办广告类专业或开设广告学课程.作者分析了目前高校广告学课程教学的现状,指出高校广告学课程教学中存在的不合理因素,并提出了改革建议,旨在适应市场经济发展的需要,创建具有特色的广告学课程教学新模式.     

永磁同步电机伺服控制系统设计

根据永磁同步电机的特点,研究、开发了数字信号处理器(DSP)和可编程逻辑器件(CPLD)控制的数字伺服系统,并进行了电流环、转速环和位置环的闭环实验.实验结果表明,该系统无论在调速比、定位时间、定位精度和抗干扰能力等性能指标上都已达到高性能伺服系统的一般要求.     

基于HIS颜色空间颜色对的图像检索系统

提出了一种在HIS空间中进行的基于颜色对的图像检索算法.为突出颜色在画面中的位置在内容检索上的作用,算法在HIS颜色空间的上对各颜色分量进行量化,用颜色对来描述图像的颜色特征,定义了基于颜色对的相似度度量,利用图像颜色特征进行相似度匹配和检索.实验结果表明,该算法能比较快速、有效地针对图像内容进行检索.     

加快结构调整，促进经济发展方式转变

加快结构调整、促进经济发展方式转变是关系国民经济全局紧迫而重大的战略任务。本文以严谨的逻辑和充分的事实依据的基础,对成都市加快结构调整,促进经济发展方式转变的意义,方向和路径等进行了阐述。     

长沙走马楼三国吴简研究的回顾

介绍了吴简的基本内容,较为全面地回顾了吴简的研究现状,并通过分析中外专家研究长沙走马楼吴简的成果,探讨了吴简研究的本质。     

A macro-meso constitutive law for concrete having imperfect interface and nonlinear matrix

The overall behavior of concrete depends on its meso structures such as aggregate shape, interface status, and mortar matrix property. The two key meso structure characters of concrete, bond status of interface and nonlinear property of matrix, are considered in focus. The variational structure principle is adopted to establish the macro-meso constitutive law of concrete. Specially, a linear reference composite material is selected to make its effective behavior approach the nonlinear overall behavior of concrete. And the overall property of linear reference composite can be estimated by classical estimation method such as self-consistent estimates method and Mori-Tanaka method. This variational structure method involves an optimum problem ultimately. Finally, the macro-meso constitutive law of concrete is established by optimizing the shear modulus of matrix of the linear reference composite. By analyzing the constitutive relation of concrete established, we find that the brittleness of concrete stems from the imperfect interface and the shear dilation property of concrete comes from the micro holes contained in concrete. Supported by the National Natural Science Foundation of China (Grant Nos. 50679022, 90510017, 50539090) and National Basic Research Program of China (Grant No. 2007CB714104)     

信息化条件下任职士官计算机课程教学改革初探

针对任职士官计算机水平与部队信息化建设要求不相适应的现实问题,深入调查分析了某部队任职士官计算机水平的现状与实际需求,明确了士官任职教育计算机教学的目标,进而有针对性地提出了任职士官计算机课程教学改革的几点新思路,确保课程教学真正服务于部队,服务于实战。