浅谈《机床电气控制与PLC》课程教学改革

《机床电气控制与PLC》是数控等专业的一门核心课程。该课程的理论性和实践性决定了其内容繁琐、抽象、难学。为了适应国家职业资格鉴定实施"双证融合"的人才培养模式这一要求,培养学生的实践能力和创新设计能力,针对高职学生《机床电气控制与PLC》课程进行了突破性的改革,在教学过程中做到教学有法,教无定法,贵在得法。通过运用不同教学手段和方法引导学生主动学习,教学实践表明,该做法可以有效提高《机床电气控制与PLC》的授课效果。     

关于《电气控制技术与PLC》校本化研究的思考

笔者与学校多名电工电子专业教师,进行了《电气控制技术与PLC》校本化研究.在研究过程中,编成了《电气控制技术与PLC》校本教材、布置好了电气实验室和PLC实验室、制作好了配套课件、提高了电工电子教师教科研能力并积累了相关教学和研究经验,但也发现了一些问题,即任务设置有难度、教学过程难以有效监督和控制学生、实验实训投资大、加重了电工电子教师的教学负担等问题.     

电气控制与PLC技术应用课程课证融合与项目教学教法研究

随着社会对高校人才实际工作能力的需求不断提升,高校的专业课程教学也在不断尝试探索新的方式方法。电气控制与PLC技术应用课程作为机电一体化专业的核心课程,在传统教学方式的基础上,将其与课证融合及项目教学教法相结合有利于提升课程教学的实际效果,帮助学生建立更好的职业能力。重点针对电气控制与PLC技术应用课程进行了课证融合教学的实施方案设计与项目教学教法的相关研究,给出了课程优化改革的可行途径。     

中职学校电气控制教学的现状及改革策略

随着电气控制设备尤其是电力电子技术的发展,工业自动化发生了翻天覆地的变化,电气控制与PLC技术的应用在这场变革中起到了举足轻重的作用.作为为社会输送技能应用型人才的中职学校,《电气控制与PLC》这门课程不仅是中职学校机电专业的核心理论课程,也是供电技术以及数控专业的一门主干专业课程,课程内容丰富,涉及面广,具有很强的应用性,是学生考取初级维修电工和高级维修电工的核心课程.     

高职“课证融合”的电气控制系统安装调试课程改革与实践

文章对电气自动化技术专业的电气控制系统安装调试课程"课、证融合衔接"进行研究;分析电气自动化技术专业维修电工证中电气控制技术和PLC应用方面的的技能点和知识点,将知识点和技能点课程,通过项目教学强化技能训练,帮助学生形成职业规范。     

电气控制与PLC应用技术研究

在科学技术不断获得进步以及电气行业在迅猛发展的期间,对于控制系统的技术要求标准也在不断地提升。当前PLC应用于电气控制系统中愈加普遍,通过将PLC融合于电气控制,相对推动了国内的电气行业平稳发展。本文将对于电气控制同PLC应用技术展开分析,为实践工作提供有价值的指导。     

基于蓝墨云班课在高职课程中教学活动的开展与探讨——以《电气控制与PLC技术》课程为例

蓝墨云班课是在移动网络环境下,基于移动智能设备开展课堂内外即时反馈互动教学的云服务平台。《电气控制与PLC技术》课程教学实践证明,利用智能设备在蓝墨云班课这一云服务平台上开展教学活动,可以有效调动学生的学习热情,激发学习兴趣,提高学习效率,增强教学效果。     

基本电气控制线路教学方法研究

《电气控制与PLC应用技术》课程教学中发现,学生不会应用或举一反三应用基本电气控制线路去设计电路或设计能力欠佳,经调查,造成此现象的主要原因是学生对基本电气控制线路理解不透,设计时根据要求不知应用何种控制线路。采用启发式增加法和并列比较法教学方法后,学生对基本电气控制线路的来龙去脉比较清晰,能很清楚地说出各控制线路间的关系及相同点与不同点,能快速记住并掌握基本电气控制线路,能根据要求维修现场设备和快速设计电路。     

电气控制与PLC应用技术的分析

随着当前的科学技术水平的提高,我国在PLC应用技术领域的发展也比较迅速,将PLC技术应用在电气控制当中就能起到促进作用。文章就电气控制中PLC技术的应用作用以及应用问题加以阐述,然后就其的应用和优化措施详细探究。     

“互联网+”背景下电气控制与PLC应用技术课程的教学改革研究

《电气控制与PLC应用技术》是高校机电类专业核心课程。文章将互联网和教育结合起来,利用慕课(MOOC)和社交网络平台进行课前准备和课后复习工作,课堂则侧重操作和设计的教学改革,进一步完善该课程的教学模式。     

《机械制造工艺与装备》理实一体化教学改革的研究与实践

《机械制造工艺与装备》是机械专业重要的教学科目,其教学形式是机械专业教学的缩影,因此,文章基于《机械制造工艺与装备》的教学弊端进行了实际分析,提出理实一体化的教学形式,研究了有效的教学策略来提高教学上学生理论知识的应用,促进我国机械专业的高素质专业型人才的发展.     

Identification and discrimination of water stress in wheat leaves (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) by means of reflectance measurements

Available water is one of the most limiting factors in crop production. As current methods for the determination of plant water content are time-consuming and require numerous observations to characterize a field, managers could benefit from remote sensing techniques to assist in irrigation decisions and further management practices. Adoption will depend on the development of technologies, which allow real time sensing of the soil and plant water status and the discrimination of several stress factors. A greenhouse study was initiated to determine specific wavelengths and/or combinations of wavelengths indicative of water stress in wheat and to evaluate these wavelengths for discriminating water stress from other biotic stresses. Reflectance of wheat leaves from plants grown under six different water treatments ranging from 65 to 26% field capacity was determined once a week from the beginning of the fourth leaf stage until the sixth leaf stage. Reflectance measurements were performed at the fourth leaf of wheat plants with an imager (LEICA S1 Pro) under controlled light conditions. Reflectance was measured in different wavelength ranges throughout the visible and infrared spectra (380–1,300 nm). Leaf scans were evaluated within the L*a*b*-color system. Total water content of wheat leaves was calculated after the difference between total fresh and total dry weight of wheat plants. Significant reflectance changes and correlations between water status and leaf reflectance were obtained at a water content <71% and enabled the identification and quantification of water status of wheat plants. Reflectance patterns at 510₇₈₀, 540₇₈₀, 490_1,300, and 540_1,300 nm were found most suitable to describe to the water status regardless of the sampling date or growth stage. To evaluate the validity of leaf reflectance as a method for separating water stress from other biotic stresses such as nutrient deficiencies reflectance pattern of water deficient plants were compared with reflectance patterns of N, P, Mg, and Fe deficiency obtained in earlier studies by calculating the color distance ΔEab as additional reflectance parameter. ΔEab increased under different nutrient deficiencies, but remained constant under water stress, thus enabling the discrimination of the investigated stress factors. The approach indicated that various stress factors could be clearly identified by reflectance measurements, thus enhancing a better plant management by the use of remote sensing techniques.     

Response of <Emphasis Type="Italic">Sorghum bicolor</Emphasis> varieties to soil salinity for feed and food production in Karakalpakstan,Uzbekistan

Water and land salinization, caused by ill-practiced irrigation and drainage is acute and widespread in Karakalpakstan, Uzbekistan. A crop frequently grown in these marginal areas is sorghum because of its capability to adapt to saline conditions. However, the salt uptake potential of local varieties for salt-ameliorative purposes, as well as possible income-generation benefits, have not yet been studied. Therefore, field experiments on low, medium and highly saline soils were conducted using four sorghum cultivars (S. vulgare, S. cernuum, S. durra, and S. technicum). The effect of soil salinity on biomass, stover and grain yield, the baking and feed quality, and total water soluble salt (TDS) accumulation, was assessed according to varieties, plant fractions and growth phases. Results showed that S. cernuum had the highest grain yield on the low (5.13 t ha⁻¹), medium (6.05 t ha⁻¹) and highly (3.3 t ha⁻¹) saline soil. S. technicum showed the lowest growth potential under all salinity levels. TDS accumulation varied between 406 and 185 kg ha⁻¹ depending on variety, site, plant fractions and growth stage. Irrespective of the soil salinity levels and varieties, TDS was highest in stover and leaves, while highest TDS uptake, mainly chlorides and bicarbonates, occurred between booting and flowering. Baking quality of all varieties was extremely low, whereas the in-vitro feed was assessed as of medium quality. The findings indicate the scope of local sorghum varieties for phytomelioration of marginal lands in Karakalpakstan, while concurrently satisfying a wider range of rural livelihood needs.     

Improving estimates of <Emphasis Type="Italic">N</Emphasis> and <Emphasis Type="Italic">P</Emphasis> loads in irrigation water from swine manure lagoons

The implementation of nutrient management plans for confined animal feeding operations requires recording N and P loads from land-applied manure, including nutrients applied in irrigation water from manure treatment lagoons. By regulation, lagoon irrigation water nutrient records in Mississippi must be based on at least one lagoon water nutrient analysis annually. Research in Mississippi has shown that N and P levels in lagoon water, and the N:P ratio, vary significantly through the year. Nutrient estimates based on one annual analysis do not account for this variability and may overestimate or underestimate N and P loads. The present study reports an improved method to more precisely estimate N and P loads in irrigation water from swine manure lagoons. The method is based on predictable annual cycles of N and P levels in lagoon water and employs simple curve-fitting of lagoon-specific formulas derived by analyses of historical data. Similarity of curves from analyses of Mississippi lagoons and other lagoon studies suggests that the method can be applied using the often limited nutrient data for a lagoon to more precisely estimate seasonal shifts of N and P and to improve the precision of estimates for N and P in irrigation water. Although the present study focused on swine manure lagoons in the southern US, recognition that the annual N cycle in lagoon water is temperature driven, suggests that additional research incorporating temperature into future models could extend these models to other types of waste treatment lagoons and climates.     

Plant water parameters and the remote sensing <Emphasis Type="Italic">R</Emphasis><Subscript>1300</Subscript>/<Emphasis Type="Italic">R</Emphasis><Subscript>1450</Subscript> leaf water index: controlled condition dynamics during the development of water deficit stress

Plants with different abilities for osmotic adjustment (cowpea, bean, and sugarbeet) were subjected to gradually decreasing soil water content. During the development of water deficit stress, various plant water parameters were measured to characterize their relationship to the near infrared R ₁₃₀₀/R ₁₄₅₀ leaf water index, which is based on the measurement of light reflected from leaves. In all three species, leaf water thickness (LWT), leaf cell relative water content (RWC), and overall leaf thickness remained relatively constant under moderate water deficit stress. However, at the point when plants could no longer cope with the increasing level of water deficit stress, LWT, RWC, and leaf thickness were found to decrease substantially, signaling the onset of leaf dehydration. The R ₁₃₀₀/R ₁₄₅₀ leaf water index followed the RWC very closely in cowpea and bean leaves, and with some time lag in sugarbeet leaves. The R ₁₃₀₀/R ₁₄₅₀ index may therefore be used as a feedback-signal in precision irrigation control, signaling effectively the physiological response of plants when water deficit stress becomes detrimental. RWC and the R ₁₃₀₀/R ₁₄₅₀ index were linearly correlated in cowpea and bean leaves, but not in sugarbeet leaves.     

汽车电工电子技术课程的教学改革研究

作为汽车专业的一门专业基础课,汽车电工电子技术是后续汽车类专业课程的理论基础.文章通过分析该课程的主要特点,以及传统教学方法存在的不足,主要从课程内容的整合、教学方式的改变、考核制度的完善等方面实施教学改革,课堂教学实践表明该教学改革能够取得良好教学效果.     

基于"工作过程"的《PLC应用技术》课程开发思路

随着社会发展,专业人才的缺乏成为阻碍许多行业发展的重要因素,所以培养出适合发展要求的人才成为发展过程中研究和关注的重点.传统的PLC应用技术过于注重理论教学,对学生动手能力培养存在一定缺陷,培养出的学生就业后不能适应技术岗位要求.文章就当下工作过程中的实践能力要求现状进行分析,介绍PLC应用技术含义进行分析,提出促进技术进一步发展的有力措施.