《化工制图》课程存在的问题及对策

分析了化工制图课程教学的现状及存在问题。针对存在的问题,就化工制图课程内容、教学手段、计算机绘图和课程考试等方面进行了课程改革实践,指出:通过课程内容优化、课程实践应用、实践教学强化,及课程考核引导等过程能够有效提高课程教学效果。     

高职院校《导游服务技能》课程实践教学探究

《导游服务技能》课程是一门实践性强的课程,应对实践教学环节进行深入探究.本文理清了该课程实践教学的意义,并从课堂实践教学、校内实训室建设、校外实训实践三个角度对该课程的实践进行了探索,以期对我国高职院校该课程的教学实践提供借鉴和指导.     

机械制造基础实践课程体系建设的探究——以钦州学院机械工程专业为例

机械制造实践课程体系是对机械制造基础课程教学质量的巩固和检验,同时也是应用型人才培养对课程的基本要求。通过机械制造实践课程"三部曲"—启蒙实践教学、验证实践教学、总结实践教学,把实践教学落实到课程体系建设的每一个环节,满足应用型人才培养对课程实践教学的要求。     

论理工类院校"思想道德修养与法律基础"课程实践教学改革探析

当前理工类院校"思想道德修养与法律基础"实践活动开展存在理工专业特色不够鲜明、践行效果缺乏有力监督、考核考察方式较为陈旧等问题。任课教师缺乏因校备课施课意识、课程实践环节缺乏相应制度建设、课程实践考核未能体现学生特色是造成上述现状的原因。当前,应着重建立课程与院校特点结合的长效机制、建立并健全课程实践环节践行制度、建立并完善课程实践环节考核机制。     

"课程思政"视域下医药类专业金课教学模式探索——以"药物制剂岗位实训"为例

依据药物制剂相关技能在高职药品生产相关专业人才培养中的重要作用,基于"金课"的建设标准,针对目前"药物制剂岗位实训"课程实践教学中存在的问题,通过构建实践教学体系,挖掘课程思政元素,开发优质课程资源,建设混合式教学模式,改革课程考核评价方式等探索药物制剂实践课程教学改革,提升课程的高阶性、创新性和挑战度.该模式能够切实提高课程的教学效果和学生的综合实践能力,培养学生勇于创新、严谨求实的职业素养,实现"金课"的教学目标.     

对大学生社会实践课程化建设的思考

社会实践是高校教育教学的重要环节,是大学生成长成才的重要途径.实施课程化建设是发挥社会实践育人功能的必要措施.本文阐述了大学生社会实践课程化建设的概念和基本原则,提出了一套包括课程目标、课程结构、学分设置、教材选配、考核评价等内容的实施方案,构建了由指挥系统、信息系统和评价系统组成的大学生社会实践课程教学质量监控体系.     

论高职院校《会计基础》课程的教学改革与实践

近年来,高职高专院校对《会计基础》课程的教学改革与实践越来越重视.本文从课程教学理念、教学内容、教学方法、教学手段等方面分析入手,对该课程的教学改革与实践进行了探讨,以期构建更为合理的课程教学模式.     

“土木工程材料”课程教改研究

文章在总结了"土木工程材料"课程具有内容多、实践课程缺乏、教材内容及教学大纲滞后等特点的基础上,提出本课程在教学方法及内容、实践教学、考核方式等方面的一些改进措施,提高学生的综合素质和实践能力。     

课程教学中工程实践能力培养剖析

目前在校学生所学课程主要以课堂教学方式为主,实践课程所占比例很小。在课堂教学中将教学内容与工程实践联系起来,是提高学生工程实践能力的有效方式。本文以冶金工程课程教学为例,从教学内容、课程设置、教学方法、考核评价几个方面剖析培养学生工程实践能力的影响因素及产生原因、解决方法。遵循学生成长变化的自然规律,辅以相应的政策导向,切实提高学生的工程实践能力。     

依据行业需求和培养工程实践能力,深化腐蚀课程教学体系

腐蚀类课程在以石油化工为特色的高等院校中占有重要位置。我校腐蚀类课程的教学过程中还存在着"课程理论内容较为深奥,理论与实际关联性弱,实验及实践内容少,课程考核方式单一,学生工程实践能力差"等问题。我们通过组建腐蚀教学团队、精炼理论教学内容、增加实验学时比重、增设课程小论文写作和答辩环节、改进课堂授课方法、构建多角度课程考核体系、多方面培养能力等措施,提高了腐蚀类课程的教学效果和学生的工程实践能力。     

Long-term residual value of North Carolina and Queensland rock phosphates compared with triple superphosphate

The effectiveness of large single applications of North Carolina reactive rock phosphate, Queensland non-reactive rock phosphate, and Calciphos, were compared to the effectiveness of superphosphate in field experiments in south-western Australia for up to 11 years after application. As measured using plant yield, superphosphate was the most effective fertilizer in the year of application, and relative to freshly-applied superphosphate, the effectiveness of the superphosphate residues declined to be about 15 to 65% as effective in the year after application, and 5 to 20% as effective 9 to 10 years after application. Relative to freshly-applied superphosphate, all the rock phosphates were 10 to 30% as effective in the year of application, and the residues remained 2 to 20% as effective in the 10 years after application. The bicarbonate soil test reagent predicted a more gradual decrease in effectiveness of superphosphate of up to 70% 10 years after application. For rock phosphate, the reagent predicted effectiveness to be always lower than for superphosphate, being initially 2 to 11% as effective in the year after application, and from 10% to equally as effective 10 years later. Therefore rock phosphates are unlikely to be economic alternatives to superphosphate in the short or long term on most lateritic soils in south-western Australia.     

Hard Clams (Mercenaria mercenaria) Evaluate Predation Risk Using Chemical Signals from Predators and Injured Conspecifics

Hard clams, Mercenaria mercenaria, are sessile, filter-feeding organisms that are heavily preyed upon by blue crabs, which find their clam prey using chemical cues. Clams may evade blue crabs by reducing their pumping (feeding) behavior when a threat is perceived. The purpose of this study was to determine the type of signals that clams use to detect consumers. Clams decreased their pumping time in response to blue crabs and blue crab effluent, but not to crab shells, indicating that chemical signals and not mechanical cues mediated the response of clams to distant predators. Because predator diet can influence prey evaluation of predatory threats, we compared clam responses to blue crabs fed a steady diet of fish, clams, or that were starved prior to the experiment. In addition, we used injured clams as a stimulus because many organisms detect predators by sensing the odor of injured con- or heterospecifics. Clams reduced feeding in response to injured conspecifics and to blue crabs that had recently fed. Clams reacted similarly to fed crabs, regardless of their diet, but did not respond to starved blue crabs. Because blue crabs are generalist predators and the threat posed by these consumers is unrelated to the crab's diet, we should expect clam reactions to blue crabs to be independent of the crab's diet. The failure of clams to react to starved blue crabs likely increases their vulnerability to these consumers, but clam responses to injured conspecifics may constitute a strategy that allows animals to detect an imminent threat when signals emanating from blue crabs are not detectable.     

5种新型杀菌剂对4种鱼的急性毒性及安全性评价

为评价5种新型杀菌剂的环境安全性,采用半静态法测定了其对4种鱼的急性毒性。结果表明,氟醚菌酰胺对斑马鱼、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)均大于100 mg/L,对青鳉的LC_(50)(96 h)为35.25 mg/L,其急性毒性均为低毒;氟吡菌胺对斑马鱼、青鳉、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为1.49、0.56、0.35、1.04 mg/L,其对斑马鱼和凤尾鲫急性毒性为中毒,对青鳉和稀有鮈鲫为高毒;苯噻菌胺对斑马鱼、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)均大于100 mg/L,对青锵的LC_(50)(96 h)为88.23mg/L,其急性毒性均为低毒;嘧菌酯对斑马鱼、青鳉、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为106.80、0.44、85.96、4.61 mg/L,其对斑马鱼和稀有鮈鲫急性毒性为低毒,对青鳉急性毒性为高毒,对凤尾鲫为中毒;醚菌酯对斑马鱼、青鳝、稀有鮈鲫和凤尾鲫的LC_(50)(96 h)分别为0.77、0.66、0.51、0.81 mg/L,其对4种鱼急性毒性均为高毒。明确这些药剂的环境安全性对指导其科学使用,保护环境生物均有较大意义。     

安克锰锌在荔枝树上施用的残留代谢消解规律与安全性评价

安克锰锌是烯酰吗啉两个异构体和代森锰锌组成的多元混合制剂。试样经粉碎、溶剂浸泡提取、混合柱净化,用气相色谱测定烯酰吗啉和代森锰锌母体(CS2),液相色谱测定代谢物乙撑硫脲(ETU)。仪器最低检出量:烯酰吗啉为1.436×10-12g,代森锰锌母体1.326×10-10g,ETU2.5×10-10g,最低检出浓度依次为0.02、0.025、0.02mg/kg,方法回收率依次为86.4%～90.8%、89.2%～95.9%、89.10%～95.13%;标准偏差为0.53～4.34;变异系数为0.58%～4.62%。安克锰锌在果皮中的消解方程广西和广东分别为C=1.2719e-0.1975T和C=1.045e-0.1972T,半衰期(T/2)均为3.5d;土壤中分别为C=0.8734e-0.1187T和C=0.6171e-0.1146T,半衰期(T/2)=6d;最高剂量250倍、最多施3次,最短距收期7d,在果肉中均未检出,果皮和土壤中的残留仅分别为0.1385～0.1745mg/kg和0.3105～0.3415mg/kg,均低于欧共体规定代森锰锌MRL值0.5mg/kg。     

高职无机及分析化学实施多媒体教学的几点思考

高职无机及分析化学教学中,运用多媒体的优势是:能营造良好的课堂氛围、激发学生的认知、增强记、有利于实施良好的教学策略,优化课堂教学,最大限度地提高效率.但使用时还应注意一些问题:不应用电子教案代替课件、课件的信息量要适度、版面设计要合理、注意使用超链接方式、课件的设计应便于修改、在实施过程中应注意加强和学生的交流.     

环戊二烯选择加氢制环戊烯

用Pd催化剂在固定床反应器中进行了环戊二烯选择加氢制备环戊烯研究;确定了第一段加氢催化剂采用Pd含量为0．5（wt）％载体为γ-Al2O3催化剂,第二段加氢催化剂为钯含量为0．3（wt）％载体为γ-Al2O3催化剂。第一段氢烃摩尔比为2—3,反应压力为1．2MPa,空速2～4h～,温度55—60℃,第二段氢烃摩尔比为3．5～4,温度80～85℃时,环戊二烯的转化率达99．5％,环戊烯的选择性在90％以上。     

煤或天然气经甲醇制低碳烯烃工艺研究新进展

由煤或天然气经甲醇制低碳烯烃工艺是解决石油资源紧张、低碳烯烃需求量越来越大等问题的有效路线。介绍了几种有代表性的经甲醇制低碳烯烃工艺,包括美国UOP/Hydro甲醇制烯烃工艺,中国科学院大连化学物理研究所的合成气经由二甲醚制低碳烯烃(SDTO)工艺,德国Lurgi公司的甲醇制丙烯工艺,以及甲醇制烯烃与AtoFina/UOP烯烃裂解的集成工艺;分析了各工艺目前达到的技术指标及最近的技术改进,关注了各工艺近几年的工业化进程。除了SDTO工艺外,其他几种工艺有望在未来几年内实现工业化。国内甲醇制低碳烯烃工艺的开发应借助于流化催化裂化成熟的工程设计经验,同时加大甲醇制烯烃工艺流化床催化剂的开发力度。     

What Molecular Recognition Systems Do Mesenchymal Stem Cells/Medicinal Signaling Cells (MSC) Use to Facilitate Cell-Cell and Cell Matrix Interactions? A Review of Evidence and Options

Mesenchymal stem cells, also called medicinal signaling cells (MSC), have been studied regarding their potential to facilitate tissue repair for >30 years. Such cells, derived from multiple tissues and species, are capable of differentiation to a number of lineages (chondrocytes, adipocytes, bone cells). However, MSC are believed to be quite heterogeneous with regard to several characteristics, and the large number of studies performed thus far have met with limited or restricted success. Thus, there is more to understand about these cells, including the molecular recognition systems that are used by these cells to perform their functions, to enhance the realization of their potential to effect tissue repair. This perspective article reviews what is known regarding the recognition systems available to MSC, the possible systems that could be looked for, and alternatives to enhance their localization to specific injury sites and increase their subsequent facilitation of tissue repair. MSC are reported to express recognition molecules of the integrin family. However, there are a number of other recognition molecules that also could be involved such as lectins, inducible lectins, or even a MSC-specific family of molecules unique to these cells. Finally, it may be possible to engineer expression of recognition molecules on the surface of MSC to enhance their function in vivo artificially. Thus, improved understanding of recognition molecules on MSC could further their success in fostering tissue repair.     

活性剂对颜料的分散及稳定性的研究探讨

离子型活性剂能在水溶液中电离出大量带电的离子,牢固地吸附在颜料粒子的表面,并具有相同电荷,其它带相反电荷的离子则自由扩散到液体介质的周围,形成一个带电离子的扩散层。这些带相同电荷的粒子一经接触就相互排斥,从而保持分散体系的稳定。因为表面活性剂能够定向地吸附在颜料粒子的表面,形成一种单分子吸附层,这种定向缓冲层能防止粒子间的相聚,从而保持分散体系的稳定。本文采用溶液吸附法加入离子型和非离子及高分子量的表面活性剂,在颜料的表面上形成吸附层,经过反复实验后,选择出了一种分散性能较为理想的的表面活性剂,改善了涂料贮存方面的缺点,并使涂膜便于在底材上展布,降低了涂料的生产成本和提高了生产效率。     

Polymers for use in drug delivery—property and structure requirements

The purpose of this paper is to discuss some of the requirements placed on materials needed for improved administration of drugs. Emphasis is placed on macromolecules that need to be designed and prepared to perform specific pharmacological functions, particularly to act as vehicles for delivering drugs to specific locations within the body. After introducing the reasons for more selective drug delivery, and explaining the rationale for using macromolecules, practical examples of results with linking drugs to polymers, modifying polymers to increase their biological compatibility, attachment to polymers of groups that could mediate their specific recognition, modification of proteins with polymers, and the use of polymer complexes will be given to indicate the areas of need for further development of pharmaceutically useful macromolecules.