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由于化工专业大四的本科生面临考研面试或找工作等原因,毕业论文(设计)教学陷入了教学时间与研究生面试时间或找工作时间、毕业论文(设计)内容与未来工作专业不同的多种矛盾之中,如不很好的解决这些矛盾,就会造成化工专业本科毕业生本科培养计划不能全面完成,学生缺乏科研论文研究和工程设计实践的不完整。为此笔者提出了解决以上矛盾的几点建议。 相似文献
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关于化工专业实验课程建设的几点思考 总被引:1,自引:0,他引:1
《化工设计通讯》2016,(3):140-141
化工专业实验是在学习完三传一反专业主干课后,以化工生产中工程与工艺两个出发点为主要学习依据的专业必修课程,学习本课程的目的是对化工工艺或化工过程开发中存在的共性问题进行解决与探讨。文章从化工专业实验课程开设的目的、要求、内容分配和教学原则等几个方面,结合自身办学情况,给出了化工专业实验课程建设的几点建议,具有一定的教学参考价值。 相似文献
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针对化工专业硕士研究生科技论文写作的参考文献部分存在随意标引、信息不准确和过度引用等不规范性问题,结合编辑工作实践,阐述了参考文献的作用、引用原则和常见问题,分析了著录错误的原因,并提出解决的办法,为研究生科技论文写作提供参考。 相似文献
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Theory of crystallisation in practice. The use and applicability of crystallization theories for industrial crystallization practice are evaluated. The conclusion is that the plant user in particular benefits from the Population Balance Model because it allows for bug diagnostics and prediction of response on altering conditions. Also for design purposes, the available theoretical models greatly helped to increase insight into the wide range of events occurring in a crystallizer and how their interactions govern the resulting product. However, despite the enormous amount of research work done so far, the quantitative application of theoretical models has not found entrance into the design of tailor-made crystallizers for strictly defined particle size distributions. From a designer's point of view, further investments of time and money should be considered carefully because the actual state of knowledge already allows more than 80% of the encountered problems to be solved. One area of common interest that urgently deserves more attention in the near future is habit modification by additives. 相似文献
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深入讨论了聚合物熔体在不同长径比、不同角度圆锥口模的挤出胀大现象及机理。对口模长径比较小的挤出胀大,由于熔体入口拉伸弹性变形来不及松弛,产生较大的挤出胀大;对长径比较大的口模,熔体在平直流道内停留时间较长,入口弹性形变逐渐松弛,这时主要是流动剪切应变引起的弹性变形,产生较弱的挤出胀大,比长径比小的挤出胀大来得小,并且聚合物熔体的挤出胀大随着长径比的增大而趋向一恒定值。结果还表明:聚合物熔体在圆锥口模的挤出胀大受到挤出口模入口角影响。当L/D较小时,挤出胀大与口模入口角有关;当L/D较大时,口模入口角对挤出胀大影响较小。 相似文献
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Filling cold mold cavities with hot polymer melts at high pressures is of great practical interest. The transport approach to this process of solving the general equations of change with suitable equations of state to describe the flowing material has been largely ignored. No analytic solution is possible, and the non-steady state flow adds a dimension which makes digital computation discouraging because of the core storage and execution time requirements. The mold filled in this simulation is a disk which hot polymer melt enters through a tubular entrance located at the center of the top plate. The tube is 2.54 cm. long and has a radius of 0.24 cm. The plate separation and outer radius of the disk cavity may be varied. A constant pressure applied at the entrance of the tube causes the flow. The cavity walls are kept at various low temperatures. The reported results are for rigid polyvinyl chloride (PVC). The general transport equations, i.e. continuity, momentum, and energy, for a constant density power law fluid are used to solve the flow problem. Convergence to the differential solutions is guaranteed but since a lower limit was imposed on the time increment by the core storage limit of the computer facilities (27K) and long execution times, all results are semiquantitative for the problem as stated. Using the results obtained it is possible to predict “fill times”. The formation of a frozen polymer skin as the cavity fills may be followed via the velocity profiles. The temperature profiles which reflect cooling and the amount of viscous heat generated provide the basis for studying resin thermal degradation effects. Finally, because so much of the total pressure drop is disispated in the entrance tube, and so much viscous heat is generated there, this study indicates that the design of the gate and runner system is perhaps the most important facet of success in mold filling. 相似文献
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大学一年级学生的学习成绩在一定程度上会受到高中学习程度的影响。作为大学生活的第一个学期,学生学习成绩的好坏及对大学生活的适应程度将决定学生在整个大学期间的学习质量和学习幸福度。由于学生刚进入大学时,师生之间的相互了解程度不够,授、学针对性不足,会造成教学效果欠佳,而高考成绩是老师了解学生的第一手和最直接的资料,因此深入分析大学一年级学生学习成绩与高考成绩之间的相关性,对于后续大学教育教学改革和高质量人才培养具有指导性意义。在本文中,以石河子大学化学化工学院2012级部分专业和班级学生大学一年级的无机化学学习情况为例进行分析,得到无机化学期末考试成绩得分率与高考总成绩和高考理总成绩得分率之间的相关性。分析结果表明,不同专业之间无机化学期末考试成绩得分率与高考总成绩和高考理总成绩相关性系数有所差异,同一专业相关性系数变化趋势一致,说明针对不同专业,我们需从不同角度分析学生学习走势,并提出针对性的培养方案。 相似文献
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A one‐range and a two‐range model for the laminar velocity distribution in the entrance region of tubes and ducts are presented. These allow the calculation of the residence time distribution under the impact of the flow development in the hydrodynamic entrance region. For the dispersion‐free case, an analytical solution is given. A cell model with place‐changing probability (ZEMP) is applied for the consideration of dispersion. This approach allows the fast quantification of the influence of different parameters on the residence time distribution for relatively short pipes and ducts. The numerical results are compared with earlier presented results of semi‐empirical models. 相似文献
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Designing an appropriate methanol steam reformer requires detailed knowledge about the processes within such a reactor. Thus, the axial temperature and concentration gradients and catalyst ageing were investigated. It was found that for a fresh catalyst load, the catalyst located in the reactor entrance was most active during the experiment. The activity of this part of the catalyst bed decreased after some time of operation due to ageing. With further operation, the most active zone moved through the catalyst bed. From the results concerning hydrogen production and catalyst degradation, the necessary amount of catalyst for a mobile PEMFC-system can be estimated. 相似文献
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针对工业快速反应对气固进料混合过程的特殊需求,在内径140mm,高4.7m的并流下行循环流化床中,采用双光路光纤密度测量技术及磷光颗粒示踪技术,对两种不同的气固并流下行床分布器结构的流动及颗粒混合行为进行了研究.分别考察了人口段颗粒浓度径向分布沿轴向的变化规律及颗粒轴径向混合行为.实验结果表明,下行床入口段颗粒浓度随轴向位置的变化可划分为分布器影响区及湍流控制区.分布器结构对入口段颗粒密度分布有较大影响,利用侧向喷嘴并降低入口处颗粒的射流可以获得较好的径向均布效果.侧向喷嘴的分布器结构更有利于颗粒的径向混合.还考察了入口结构对颗粒混合的影响因素,给出了对Pe_a及Pe_r的关联式. 相似文献