Rasch模型在“化学键”概念教学评价中的应用研究

运用Rasch模型探查高二学生对"化学键"概念的认知情况，运用Conquest软件和Winsteps软件对测试结果进行分析。结果表明：基于Rasch模型编制的测试卷能客观有效地检测学生对"化学键"概念的理解，为一线教师的有效教学提供学情基础。     

高效液相色谱与原子荧光光谱联用分析汞化合物形态的研究

建立了高效液相色谱与原子荧光光谱联用测定汞化合物形态的分析方法。实验对淋洗液组分浓度、氧化剂和还原剂浓度、载气流速及紫外消解管长度等操作条件进行了优化,获得了令人满意的分析结果。在优化的分离检测条件下,20μg/L的汞化合物标准溶液平行7次进样分析,甲基汞、无机汞和乙基汞的色谱峰高的相对标准偏差(RSD)分别为2.0%、2.9%和2.4%;3种汞化合物的线性范围为10~1000μg/L,25μL进样检出限分别为3、2和4μg/L。用建立的方法测定了脉红螺样品中甲基汞的含量,甲基汞和乙基汞的加标回收率分别为90%和92%。     

Determination of some reactive oxygen species scavengers based on the peroxidase-oxidase oscillator

This paper reports a new method for detection of ROS scavengers including superoxide dismutase, ascorbic acid and glutathione based on a 'probe' of peroxidase-oxidase biochemical oscillator. The oscillation period and amplitude change with different concentrations of scavengers. The linear ranges of superoxide dismutase, ascorbic acid and glutathione are respectively 1.56 x 10(-4)-1.56 x 10(-3) mg mL(-1), 1.75 x 10(-7)-1.75 x 10(-5) mol L(-1) and 9.38 x 10(-7)-7.5 x 10(-5) mol L(-1). The selectivity, linearity and precision for superoxide dismutase, ascorbic acid, and glutathione are presented and discussed. The results compared well with other standard methods for determination of superoxide dismutase, ascorbic acid and glutathione. Some possible steps in the overall reaction mechanisms are discussed.     

病毒性心肌炎与微量元素关系的探讨

应用日本岛津ＩＣＰＱ－１０１２型高频等离子体发射光谱仪测定了病毒性心肌炎组４７例和正常儿童组６０例全血中１４种元素的水平，结果表明，心肌炎组血锌、铁、铜、钴、钛、铬、镍、铅、钛、镉的含量低于正常组，两者间有显著和非常显著性差异（Ｐ〈０．０５，Ｐ〈０．０１），血钼、锶则高于正常组，且有显著性差异（Ｐ〈０．０５），血锰、镁、钙与正常组无差异（Ｐ〉０．０５），提示病毒性心肌炎的患儿存在着血锌、铁、铜、钴     

A New Silicate Clathrate Hydrate: An X-Ray Diffraction and Nuclear Magnetic Resonance Study of a System with Octameric Silicate Anions and Trivalent Cations

The first crystal structure is reported for a silicate clathrate hydrate involving a triply charged cation [C₁₈H₃₀N₃]³⁺ and an octameric cubic silicate cage. The structure is essentially a host/guest system, with the silicate cages linked into a framework by hydrogen bonding to water molecules. The space group is P with Z = 2, and the asymmetric unit includes a complete cation and half the anion, plus 21 water molecules (4 of which are in disordered positions). Solid-state (CPMAS) ²⁹Si and ¹³CNMR spectra are consistent with the diffraction-determined structure and indicate substantial distortion of the anion from cubic symmetry. Solution-state spectra of precursor solutions and of melted material are also presented and discussed.     

增强化学发光体系酶联免疫分析法测定人绒毛膜促性腺激素

应用活化鲁米诺,用优化的增强化学发光酶联免疫分析体系测定人绒毛膜促性腺激素,检测限为0.2mIU/ml。线性范围0～200mIU/ml,与放射免分析测定结果比较,相关性良好。进而又发展了一种半定量的照相测定法,通过实际血清样品测定,效果良好。     

Kinetic Spectrophotometric Determination of Ritodrine Hydrochloride in Dosage Forms

A simple and sensitive kinetic method was developed for the determination of ritodrine hydrochloride in pharmaceutical preparations. The method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permenganate at room temperature for a fixed 12.5 min; the absorbance of the colored permenganate ion was measured at 609 nm. The absorbance concentration plots were rectilinear over the range of 1.6–11.2 μg mL^?1 (r = 0.9992) with a minimum detectability of 0.096 μgmL^?1 (2.88 × 10^?7 M). The different experimental parameters affecting the development and stability of color were carefully studied and optimized. The determination of ritodrine hydrochloride by the fixed concentration and rate constant methods is also feasible with the calibration equations obtained, but the fixed time method has been found to be more applicable. The proposed method was applied successfully to the determination of ritodrine hydrochloride in tablets and ampoules with average recoveries of 100.37 ± 0.93% and 100.42 ± 0.87%, respectively. The results obtained were in good agreement with those obtained using a reference method for comparison. A proposal of the reaction pathway is also presented.     

具有超大通道结构的介孔氧化硅柱层状钛酸的合成和催化应用初探

A mesoporous (d=2.3mm) silica-pillared layered tetratitanate with a super gallery (d₀₀₁=1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine, then reacting with 20wt% NH₂(CH₂)₃Si(OC₂H₅)₃ aqueous solution, and finally calcinating the resultant solid product in air at 550℃. All the reaction was carried out hydrothermally in an autoclave at 130℃. The obtained material has a relatively high BET surface area of 204m²·g^-1 and a thermal stability beyond 600℃. The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.     

Poly[μ‐aqua‐μ4‐naphthalene‐1,8‐dicarboxylato‐zinc(II)]

In the title complex, [Zn(C₁₂H₆O₄)(H₂O)]_n, a Zn^II polymer based on naphthalene‐1,8‐dicarboxylate (1,8‐nap), the Zn^II atoms adopt an elongated octahedral coordination geometry. A zigzag chain is formed by μ₂‐aqua ligands and μ₂‐carboxylate groups of the 1,8‐nap ligands. Adjacent parallel chains are further linked by 1,8‐nap ligands, forming a twisted two‐dimensional layer structure along the (100) plane.     

A study of substituent effect on 1H and 13C nmr spectra of N‐ and C‐substituted carbazoles

¹H and ¹³C nmr spectra of several N‐ and C‐substituted carbazoles (Series 1, 2, 3 and 4) were measured. Correlations between chemical shifts and substituent constants show that these parameters describe properly the substituent effect on the nmr phenomena. Atomic charge densities for carbazoles of Series 1, 2, 3 and 4 were calculated by using the semi empirical PM3 method. These values also show a linear correlation with the ¹³C chemical shifts. The synthesis of several carbazole derivatives 1a – 1g, 2a – 2g, 3a – 3j and 4a – 4g have been carried out according to literature procedures. The carbazoles 3i, 3j and 4c have been synthesized and fully characterized for the first time.