共查询到20条相似文献,搜索用时 218 毫秒
1.
2.
3.
科学探究是化学学科核心素养之一,而探究性试题是检验学生探究能力及思维品质的重要方式。按照科学探究的过程,结合现有的纸笔考试形式,可将探究性试题中的探究要素分为提出问题、猜想与假设、制定计划、进行验证、获取证据、解释与结论、反思与评价、迁移与应用等几个方面。命制化学探究性试题时,要根据化学学科核心素养的培养目标,科学、灵活地设计探究环节中的各要素,有效提升探究性试题的考查功效。 相似文献
4.
以“11·4福建泉港碳九泄漏事故”为测试载体,在深入挖掘和甄选考点后,结合当前《普通高中化学课程标准(2017年版)》对考试评价的有关说明和试题命制基本理论及技术要求,命制了一道高中化学考试试题,并在文中对试题的测试目标,如认知操作、核心素养和达到的学业质量水平加以详细分析,对试题命制的技术性要求辅以论证,以期能给同行以核心素养为测试宗旨的命题提供一些参考。 相似文献
5.
6.
整合课程标准和高考评价体系提出考查化学学科核心素养的试题命题流程。以“制备KClO3和NaClO并探究其氧化能力的实验题”命制为例,针对考试类别与水平确定核心素养测试目标,以2020年全国Ⅲ卷第26题实验题为激发点遴选真实情境,查阅文献资料,基于条件控制初步命制实验探究题。针对初稿中的知识覆盖面不够、能力进阶不够等问题,二次查阅文献,深度挖掘素材创新点,形成试题,并从考查情境、考查内容、考查要求等3个方面对试题进行全面解构,得出命题过程应关注真实情境的科学性、适宜性、包容性;文献资料的权威性、互证性、多元性;必备知识分布的合理性及关键能力考查的层次性。 相似文献
7.
微型实验“氯气的制备与性质”试剂用量少,有害气体排放少,实验目的达成率高,是教材编写、试题命制及学生课外活动青睐的实验素材之一。高三一轮复习中,该实验的恰当引入可以提升复习效率,实现知识、能力的双重提升。1实验方案的选择和改进 相似文献
8.
9.
在新课程标准和高考评价体系的背景下,如何提高化学学科的命题质量?通过以学术探索情境为载体命制选择题和以实验探究情境为载体命制非选择题的2例,展示了在双向细目表的指引下,检索文献、初拟试题、打磨试题和要素分析的过程,剖析了精炼试题语言表述、核实信息来源、优化信息呈现方式和调整测试任务的各环节,总结了依靠团队合作精心筛选命题素材、创设真实问题情境、科学设计测试任务、反复推敲打磨试题的命题经验。 相似文献
10.
11.
Hongbo Tan Yulin Guo Baoguo Ma Xin Li Benqing Gu 《Journal of Dispersion Science and Technology》2017,38(5):743-749
The effect of the ester group in side chain on adsorbing behavior and dispersion of polycarboxylate superplasticizer (PC) was studied by comparing the performance of two types of PC. The fluidity of cement paste was tested to discuss the dispersing ability and dispersing retention ability of PC. The total organic carbon analyzer was used to measure the adsorption amount, and the adsorption layer was obtained by x-ray photoelectron spectroscopy. Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and pH value were used to verify the stability of the ester group, and the electrokinetic properties of cement particle were confirmed using the zeta potential measurement. The results show that the ester group in side chain reduces the initial dispersing ability while it increases the dispersing retention ability. The dispersing retention ability depends on the increase of adsorption amount and adsorption layer in 5–60 minutes, and the greater increase leads to the better dispersing retention ability. The ester group can be decomposed to release carboxyl group to enhance the adsorbing ability of PC under the condition of cement hydration, which is the main reason for the greater increase of adsorption amount and adsorption layer and the improvement in dispersing retention ability. It suggests that grafting the ester group is a good way to enhance the dispersing retention ability. 相似文献
12.
利用知识图谱梳理了625篇有关实验能力研究的文献,分析了当前国内实验能力研究领域的热点关键词,围绕这些热点探讨了国内实验能力研究主题领域与现状。并尝试从共性和差异性的角度,总结基础教育领域各学科实验能力研究的内容与特点。 相似文献
13.
探讨了化学学科能力的内涵、化学学科能力的构成要素、化学学科能力水平的发展以及化学学科能力的评价等问题。基于化学学科本质及特殊要求界定了化学学科能力内涵及其核心要素, 并以“学习进程”的相关理论为基础建立了化学学科能力发展及评价框架。 相似文献
14.
15.
Siyuan Luo Jiajia Li Yiling Zhou Li Liu Shiling Feng Tao Chen Lijun Zhou Chunbang Ding 《Arabian Journal of Chemistry》2021,14(7):103225
Bergenia emeiensis is a traditional folk medicine in China. Most studies are focusing on the bioactivity of bergenin, neglecting other compounds. Therefore, in this present work, the antioxidant, antibacterial and anticancer abilities of triterpenes from B. emeiensis rhizomes (TBE) were comprehensively evaluated. The results showed that TBE could well scavenge DPPH with a lower EC50 of 0.29 mg/mL and could improve the cell viability of CHO cells against H2O2 induced cell death. Additionally, TBE also enhanced the resistance of C. elegans under thermal stress, exhibiting a strong antioxidant potential in vivo. Moreover, TBE showed a certain antibacterial ability on five kind strains such as Pseudomonas aeruginosa while TBE could not significantly inhibit the growth of plant pathogenic fungi. Furthermore, TBE possessed an excellent suppression ability on the proliferation of cancer cells especially Hela and Hep G2 cells with an IC50 of 41.79 μg/mL and 48.62 μg/mL at 48 h, respectively. After fractionally extracted with petroleum ether, ethyl acetate and ethanol, ethanol phase (EP) contained the most triterpenes, followed by ethyl acetate phase (EAP) and petroleum ether phase (PEP). Besides, EP and EAP exhibited a strong antioxidant capacity and also inhibited the proliferation of Hela and Hep G2 cells with the effect of pro-oxidation by inducing a high level of ROS and decreasing mitochondrial membrane potential, thus causing oxidative stress then inducing cell apoptosis. Therefore, these outcomes indicated the triterpenes from B. emeiensis possessed a strong antioxidant ability and an anticancer effect, thus making B. emeiensis become a promising potential alternative in pharmacological field. 相似文献
16.
17.
采用课题研究模式,指导学生完成一定课题任务,使学生学会独立思考、分析问题和解决问题,最终培养创新能力。该模式实施步骤包括选题、学生遴选、调研、实验、结项等主要步骤。课题类型包括实验型、工程(设计)型和创业型。详细分析了每一步的具体要求和实施方法,并结合近年来课题组指导学生的实例,探讨了该模式的特点和实施效果。结果表明,该模式对培养学生的创新能力是有效的、可行的,但需进一步改进完善。 相似文献
18.
以“钠的性质”为例,探究“金属钠遇水为什么会燃烧爆炸?”“遇到因金属钠而发生的事故该怎么办?”等问题,将风险认知和决策能力培养聚集于课堂,延伸至课外。 相似文献
19.
20.
简要介绍了北京大学普通化学英文小班课的教学情况,以及在培养学生自主学习能力方面进行的尝试。课程强调一对一启发式教育,力求激发学生自主探究问题的兴趣,注重培养学生的科研基本素质,引导性地提升学生全方位的学习能力。 相似文献