Preparation of Highly Stable and Photoluminescent Cadmium-Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay

Indium phosphide (InP) quantum dots (QDs) are ideal substitutes for widely used cadmium-based QDs and have great application prospects in biological fields due to their environmentally benign properties and human safety. However, the synthesis of InP core/shell QDs with biocompatibility, high quantum yield (QY), uniform particle size, and high stability is still a challenging subject. Herein, high quality (QY up to 72%) thick shell InP/GaP/ZnS core/shell QDs (12.8 ± 1.4 nm) are synthesized using multiple injections of shell precursor and extension of shell growth time, with GaP serving as the intermediate layer and 1-octanethiol acting as the new S source. The thick shell InP/GaP/ZnS core/shell QDs still keep high QY and photostability after transfer into water. InP/GaP/ZnS core/shell QDs as fluorescence labels to establish QD-based fluorescence-linked immunosorbent assay (QD-FLISA) for quantitative detection of C-reactive protein (CRP), and a calibration curve is established between fluorescence intensity and CRP concentrations (range: 1–800 ng mL⁻¹, correlation coefficient: R² = 0.9992). The limit of detection is 2.9 ng mL⁻¹, which increases twofold compared to previously reported cadmium-free QD-based immunoassays. Thus, InP/GaP/ZnS core/shell QDs as a great promise fluorescence labeling material, provide a new route for cadmium-free sensitive and specific immunoassays in biomedical fields.     

宽带放大器用碲基掺铒光纤结构参量的设计考虑

利用光波导理论及均匀展宽四能级模型,研究了宽带放大器用阶跃型折射率分布碲基掺铒光纤的结构参量—纤芯半径和相对折射率差的设计考虑.理论研究表明,在单模传输条件下,为获取最大信号增益,宜选择相对折射率差大的碲基掺铒光纤来构建光纤放大器.相对折射率差一定的情况下,在高泵浦功率、小信号输入或光纤长度短于各信道最佳增益长度时,选择纤芯半径大的碲基掺铒光纤可以得到大的信号增益;反之,宜选择纤芯半径小的碲基掺铒光纤.     

连续级联喇曼光纤激光器耦合波方程的修正

从最基本的耦合波方程出发,考虑光波正反向传输的情况下,推导出了一个全面的、准确的关于连续级联喇曼光纤激光器的理论模型,描述了各级Stokes光波功率沿光纤长度的变化.指出了相关一些文献中存在的不足,并且给出了多级斯托克斯光波相互作用的有效作用面积的表达式.此模型有助于喇曼光纤激光器的设计.     

不同引发核树枝状大分子的合成

含不同分支官能团树枝状大分子的合成是目前研究的一个热点。文献报道的有两方向引发核、三方向引发核、四方向引发核、六方向引发核等结构新颖的树枝状分子。本文综述了不同引发核及其衍生物在树枝状大分子合成中的应用。     

人教版高中化学教科书“研究与实践”栏目分析与实施策略*

对人教版高中化学教科书新设计的“研究与实践”栏目的主题内容、功能价值进行分析,就如何充分发挥该栏目的教学功能和价值,发展学生的化学学科核心素养,提出了创设教学情境线索、开发为研究性学习课题、开发为校本选修课程、开发为STEM课程等实施策略。     

Synthesis and Structure Characterization of a Tetranuclear Manganese(Ⅲ) Complex:[Mn4O2(O2CMe)6(MeOH)2(dbm)2]·2MeCOOH·2CH2Cl2

The title compound, [Mn4O2(O2CMe)6(MeOH)2(dbm)2]·2MeCOOH·2CH2Cl2 (Hdbm = dibenzoylmethane), has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P(-l), with a = 10.729(3), b = 12.269(3), c =13.085(4) (A), a = 106.367(3), β = 107.643(2), γ = 94.771(2)°, V = 1547.9(7) (A)3, Z = 1,C50H64Cl4Mn4O24, Mr= 1410.57, Dc= 1.513 g/em3, F(000) = 724, Rint = 0.0147, T = 293(2) K and μ = 1.046 mm-1. The fimal R = 0.0359 and wR = 0.0938 for 5791 observed reflections with I ＞ 2( )I).The structure of the complex consists of one [Mn4(μ3-O)2]8+ core with four coplanar Mn atoms disposed in an extended "butterfly-like" arrangement and two O atoms triply bridging each "wing",and the peripheral ligation is provided by six μ2-MeCO2-, two terminalμ2-dbm- groups at the two hydrogen bonding interactions are found within the structure of the compound.     

MICRO-PHASE SAEPARATION IN EPOXY RESIN WATERBORNE PARTICLES DURING CURING PROCESS

Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification. Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature （Tg） and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles.     

二氧化钚分子的多体展式势能函数

从导出基态PuO2分子的电子状态X5Σ g正确地判断其离解极限出发,采用MP2方法,应用相对论有效原子实模型(RECP)优化出PuO2(X5Σ g)分子稳定构型为线性OPuO(D∞h),其平衡核间距Re=0.18004nm.同时也计算出振动频率,并优化出存在亚稳态的Pu-O-O(C∞v)构型.使用多体项展式理论方法,导出了基态PuO2分子的分析势能函数.该势能表面准确地再现了O-Pu-O(D∞h)平衡结构和亚稳态的Pu-O-O(C∞v)构型.然后根据势能函数等值图讨论了O(3Pg) PuO反应的势能面静态特征.     

化学学科核心素养在高中教材习题中的表现—以人教版教材为例

教材习题是落实新课标倡导的基于化学学科核心素养进行评价的重要载体。以化学学科核心素养的水平划分和学业质量水平为依据,分析人教版高中必修化学教材课后习题考查的核心素养及其水平。结果表明,2007年版和2019年版教材均注重全面考查核心素养和对基础性的考查,突出考查宏观辨识与微观探析素养,突出化学本质;但2019年版教材习题在数量上有所减少,加强了科学思维和科学实践的考查,合理拓展了核心素养考查的广度和深度。最后,依据习题特征获得相应的教学启示,以促进学生核心素养的发展。     

近5年化学奥林匹克(初赛)试题的分析及建议

从化学核心素养出发，分析近5年化学奥林匹克（初赛）试题考查的学生知识水平、能力水平、素养水平，并针对培养中学生核心素养的教学实践提出建议。