化学振荡的机理及应用

本文介绍了典型振荡反应的特点、机理、数学模型、动力学方程式及在化学和生物学中的某些应用.     

地方院校《化学反应工程》教学中互动式教学方法的引入

化学反应工程是化工类专业的核心课程,根据化学反应工程的课程特点,分析了化学反应工程课程改革的必要性;将互动式教学引入到化学反应工程的教学过程中,介绍了互动式教学在化学反应工程教学中的应用。     

脯胺酸及其衍生物不对称催化Aldol反应的研究进展

Aldol反应是被认为是形成碳-碳键最有用的反应之一,广泛应用在许多复杂天然或非天然有机化合物的合成中。本文综述了近年来脯氨酸、脯氨酰胺、肽均相催化在有机小分子Aldol反应的研究状况。     

三维对流反应方程的高精度多重网格方法

利用一阶偏导数的四阶紧致差分逼近公式,构造了基于非等距网格上的数值求解三维对流反应方程的一种高精度紧致差分格式.为了提高离散后代数方程组的求解效率,采用多重网格加速技术.数值算例结果验证了本文方法的精确性和可靠性.     

对我国短跑运动员起跑反应速度的研究

对参加第8届全运会短跑运动员的起跑反应速度进行了研究,发现我国男、女短跑运动员起跑反应速度基本处于同一水平,从事不同专项运动员的反应速度存在显著差异,男运动员各赛次间反应时无显著差异。女运动员在部分项目赛次间反应速度有显著差异。男、女运动员反应速度都呈后一赛次快于前一赛次的趋势。     

Static and dynamic single leg postural control performance during dual-task paradigms

Combining dynamic postural control assessments and cognitive tasks may give clinicians a more accurate indication of postural control under sport-like conditions compared to single-task assessments. We examined postural control, cognitive and squatting performance of healthy individuals during static and dynamic postural control assessments in single- and dual-task paradigms. Thirty participants (female = 22, male = 8; age = 20.8 ± 1.6 years, height = 157.9 ± 13.0 cm, mass = 67.8 ± 20.6 kg) completed single-leg stance and single-leg squat assessments on a force plate individually (single-task) and concurrently (dual-task) with two cognitive assessments, a modified Stroop test and the Brooks Spatial Memory Test. Outcomes included centre of pressure speed, 95% confidence ellipse, squat depth and speed and cognitive test measures (percentage of correct answers and reaction time). Postural control performance varied between postural control assessments and testing paradigms. Participants did not squat as deep and squatted slower (P < 0.001) during dual-task paradigms (≤12.69 ± 3.4 cm squat depth, ≤16.20 ± 4.6 cm · s^?1 squat speed) compared to single-task paradigms (14.57 ± 3.6 cm squat depth, 19.65 ± 5.5 cm · s^?1 squat speed). The percentage of correct answers did not change across testing conditions, but Stroop reaction time (725.81 ± 59.2 ms; F_2,58 = 7.725, P = 0.001) was slowest during single-leg squats compared to baseline (691.64 ± 80.1 ms; P = 0.038) and single-task paradigms (681.33 ± 51.5 ms; P < 0.001). Dynamic dual-task assessments may be more challenging to the postural control system and may better represent postural control performance during dynamic activities.     

淀粉磷酸单酯的合成及取代度的测定

本就淀粉磷酸单酯的反应时间,反应温度,磷酸盐加入量三个因素对产品取代度（D,S)的影响进行了探讨,从而确定出较佳的工艺条件为：反应温度150℃,反应时间25min,磷酸盐加入量度16％。     

α-肉桂酰基环二硫缩烯酮与Grignard试剂的共轭加成反应

具有 3个亲电中心的α 肉桂酰基烯酮 1,3 亚丙二硫基缩酮 2～ ,缩酮基为六元环 ,与乙基、丙基、丁基、苯基及苄基卤化镁等的反应均得到 β′ 碳上的共轭加成产物 3～ .2～ 中环二硫缩酮基具有调控作用 .     

带电粒子自身电磁场对粒子本身的反作用

在经典电动力学的基础上,讨论了辐射阻尼力影响下非相对论性带电粒子在复合场中的运动,导出了辐射带电粒子的完整运动方程.     

Grade 12 French Students’ use of a Thermodynamic Model for Predicting the Direction of Incomplete Chemical Changes

The authors of the current chemistry curriculum—implemented in Grade 12 in France—provided a criterion of change allowing prediction of direction of chemical changes and pointed out the difference to be made between experimental facts and models. A study analysing part of the curriculum content and the effects of teaching this content on students’ reasoning was conducted. The content analysis presents the functioning of the thermodynamic model, which highlights the links to be made between the experimental situation and the model when predicting the direction of a chemical change. This functioning specifies the role of the chemical equation and that of the criterion of change (comparing the reaction quotient to the equilibrium constant) and stresses the crucial points that may lead to misunderstandings. Written tests were administered to students after teaching them to determine how they predicted the direction of a chemical change, and whether they made a relevant choice between using the chemical equation and using the criterion of change and a clear distinction between the experimental situation and the thermodynamic model. Few students had a good understanding of the respective roles of the criterion and the chemical equation. A majority used the criterion to predict the direction of chemical changes relevantly, but correct answers were not widespread. Two particular mistakes, the modification of the expression of the reaction quotient and the prediction of a change despite a missing reactant, revealed that students do not properly understand the difference and the relationship between the experimental situation and the thermodynamic model.