高中学业水平考试试题难度模型建构*

利用主成分分析方法厘清试题难度影响因素之间的关系,进而从问题表征、问题解决和结果输出等3个维度上建立了影响高中学业水平考试试题难度的主要因素。通过编写高中学业水平考试测试题进行实证研究,建立影响因素常见呈现类型的难易赋值规则。选用机器学习的线性回归方法建构试题难度分析模型,并使用高考化学江苏卷部分试题的实测难度数据进行校验,模型难度预测值和高考难度实测值具有较好的拟合度,表明模型具有较好的应用价值和推广意义。     

浙江新高考化学加试题难度研究*

在对已有试题难度量化工具进行改进的基础上,建构了化学加试题难度评估工具。对2015年至2019年国家新高考实验区浙江省的8次化学选考加试题的难度进行了量化评价。结果表明,8次化学加试题整卷难度变化较大,但同一学年、有相同学生可能参与的2次化学选考的整体难度相近;加试题能力特征和难度差异明显,“有机化学基础”加试题(第32题)难度相对稳定,而第30题(化学反应原理)与第31题(实验化学)加试题难度却表现出一定的波动性。在对8次化学加试题的难度及相关因素进行分析的基础之上,也对如何提高加试题的编制质量,提出了可行性建议。     

基于Rasch模型的上海市某区化学高考一模试题分析*

应用分部评分模型从双层面、单维度视角分析了上海市某区高考一模试题质量。通过3 864 个样本分析得出以下结论:该测试卷信度和区分度良好(试题信度为1.00、区分度为26.20);试题平均难度比个体平均能力低1.31 logits,相对偏低;试题整体单维性良好,但部分试题拟合性较差;DIF检验表明,试题对不同性别群体不存在测试功能差异,但是分别有7题和1题对不同物理选考背景群体、不同政治选考背景群体存在测试功能差异,但对试题整体评价影响不大。最后,结合专家咨询,对质量不高的试题进行分析,并从试题、评分细则以及教学3个角度对如何形成良好的测评给出相关建议。     

基于学生出错诊断的试题难度影响因素分析

以问题解决理论构建化学试题的问题解决行为图,以高考化学试题为例,通过分析构成试题的要素,收集学生作答试题时出现的主要错误,建立学生的出错原因和被试内部认知特征之间的关系,从问题解决的角度对学生的答题错误进行诊断,并据此分析得出影响试题难度的因素。     

对高中生化学成绩与其行为归因影响的研究

探索高中学生对学习化学行为归因的倾向,寻找其规律性。为今后教学中根据不同学生进行适当的心理归因训练提供依据。采用自编成绩归因问卷对高中生学习化学行为归因进行调查。结果表明:(1)努力程度、学习兴趣是对化学学习影响较大的因素;学习方法、试题难度、休息等的影响则较小;(2)成绩与内归因、稳定影响成线性关系;(3)考试失败的学生成绩与内归因有线性关系。     

高中化学教科书课后习题难度预估方法研究

在文献研究的基础上,提出14个影响高中化学教科书课后习题难度的假设因素,并对这14个因素进行检验分析,最终剔除无效因素,确定对高中化学教科书课后习题难度有显著影响的因素是:运算要求、知识量、题型和行为目标层次。结合实测难度及14个影响因素的赋值标准,建立难度预估方程。并用实测难度检验预估方程的准确性,期望为今后化学试题难度预估研究提供基础。     

坐标图对试题难度的影响及启示

2011年高考试题中有较多的以“坐标图”呈现信息的试题,试题着重考查学生的图形转换能力。信息呈现方式的变化,在多大程度上引起试题难度的变化,这种相关性的研究就显得及时和非常必要,并且能够对教学有所帮助和启发。学生信息采集能力和转换能力的培养问题业已摆在教育者的面前,由于存在不同的教育观念,于是就有着不同的取舍和迥异的教育行动。     

化学奥赛中的物质结构推断题解法探析

根据给定信息推断物质的结构是化学奥赛中一种常见的试题类型。这类题分值高、难度大,是影响选手成绩的重要因素之一。研究最近几年的相关试题,我们发现这类试题所给定的信息大致可以分成6类:与键长有关的、与化合价有关的、与原子序数有关的、与配位体数目有关的、与杂化轨道类型有关的和与同分异构体数目有关的。而且信息的种类不同,试题的解法也不尽相同。下面逐一探讨每一类试题及其解法。1根据键长验证猜想要确定物质的结构,往往需要选手充分运用有关的物质结构理论知识,并在此基础上进行猜想和假设。有关的键长信息往往作为验证猜想是…     

关注试题等值 促进课程选择——2008年江苏、广东、海南高考化学选考模块试题比较研究

试题分“必考”和“选考”,是新课程高考化学试卷结构有别于传统高考的一个特征,是课程选择性的必然体现。力求不同选考模块试题的等值,是保证受试者选择均等、得分公平的前提。以2008年实验区高考化学试卷为样例,从试题长度、难度和效度3个维度的等值性,探讨了新课程高考化学选考模块试题命制问题,为落实课程选择性和体现高考公平提供了研究视角。     

基于SOLO分类理论的高考化学主观题的结构分析

借助SOLO分类理论作为评价工具,以定量的方式对2013-2015年间山东省高考化学试题进行解构与分析,并将试题在4个SOLO能力层次上的分值分布情况与试题难度、区分度等实测数据进行了比对研究。没有采用以往常见的以定性评价为主的高考试题分析模式,而是尝试采用定量方式对山东省高考必做试题中的主观性试题进行分析和评价,进而寻找高考化学试题适宜的SOLO试题结构。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.