微波硫灯发射光谱的理论模拟

通过实验观测了微波硫灯的发光光谱. 利用从头计算的多组态准简并微扰理论方法, 采用cc-pVQZ基组计算了S2分子B3Σu--X3Σg-态和B″3Πu-X3Σg-态的跃迁矩及其振动态之间跃迁的弗兰克-康登因子, 导出了S2分子振动分辨发射谱. 同时, 利用含时密度泛函方法计算了Sn(n=2~8)分子的吸收谱. 将计算得到的S2分子振动分辨发射谱与实验所测得的光谱分布进行了比较分析, 解释了微波硫灯的宽谱区发光光谱的特性.     

以DNA为靶点的钌(Ⅱ)配合物的合成、晶体结构和抗肿瘤活性

为开发新型钌(Ru)抗肿瘤药物,以3-甲基-2-噻吩甲醛-4-羟基苯甲酰肼席夫碱配体(L)合成了[Ru(L)(DMSO)2Cl2](1)(DMSO=二甲基亚砜).用X射线单晶衍射法测定了1的晶体结构.配合物1的结构由1个Ru(Ⅱ)中心离子与2个DMSO分子、2个氯离子、1个L配位而成.通过MTT实验分析,1对T24细胞...     

Determination of sulfonamide residues in cultured sea cucumber by pre-column derivatization capillary electrophoresis with fluorescence detection

A simple and mild method for the separation of sulfonamide residues based on a condensation reaction with O-phthalaldehyde solution (OPA) as labeling reagent with capillary electrophoresis has been developed. A 58.5 cm × 50 μm i.d. (50 cm effective length) untreated fused-silica capillary was used. To optimize the separation conditions, the background electrolyte concentration, pH, column temperature, voltage and other factors were evaluated. The optimal separation conditions were as follows: 20 mmol L^?1 borate buffer; pH 9.1; column temperature 20 °C; separation voltage 18 kV, pressure 50 mbar and injection time 8 s. Under the optimal conditions, 10 kinds of sulfonamide derivatives could be well-separated within 8 min, and the linear ranges were 0.35–100 μg kg^?1. The detection limit (at a signal-to-noise ratio of 3) was in the range of 0.12–0.25 μg kg^?1, and the quantification limit (at a signal-to-noise ratio of 10) was in the range of 0.35–0.70 μg kg^?1. The sulfonamide residues from cultured sea cucumber samples were determined under the optimal conditions with satisfactory results.     

低能量抽运的增益开关型Cr4+∶Mg2SiO4激光器

为了研究低能量的1.06μm调Q激光脉冲抽运的增益开关型Cr4+∶Mg2SiO4激光器,对该激光器的速率方程进行数值求解,并选取合适的初始条件,得到输出的1.22μm激光脉冲的时间波形、脉冲的建立时间和脉冲宽度与抽运能量的关系,理论计算与实验研究结果基本符合.当抽运激光脉冲的能量为45mJ、脉冲宽度为30ns时,激光器输出的1.22μm激光脉冲的能量和脉宽分别是7mJ 和8.2ns.输出激光的脉冲宽度是抽运激光的脉冲宽度的近1/4,光-光转换效率为15.5%.数值计算和实验研究结果均表明,在低能量抽运情况下,激光脉冲的建立时间和脉冲宽度均随着抽运能量的增加而减小.     

化学实验教学价值的实现与教学方式的选择

教学方式对化学实验教学价值的实现程度有很大影响.在阐述教学方式的含义和类型的基础上,指出选择教学方式应遵循为三维目标服务、以学生为主体、体现学科交叉、实施STS教育和因地制宜等原则.     

藏药蕨麻多糖水解单糖的毛细管区带电泳分离研究

以1-萘基-3-甲基-5-吡唑啉酮(NMP)为柱前衍生试剂,探讨了毛细管区带电泳模式下对藏药蕨麻多糖水解液中单糖的分离条件。实验采用58.5 cm×50μm i.d.毛细管(有效长度50 cm),55 mmol/L硼酸盐缓冲溶液(pH=9.46),柱温20℃,分离电压22 kV,进样10 s。该法不加任何添加剂,9种单糖可高效、快速基线分离,实现了对藏药蕨麻多糖水解液中单糖的分离和定量分析,结果令人满意。     

探究性实验中学生提问数量与提问质量的相关研究

1问题提出实验探究活动是从问题开始的,问题在很大程度上决定着实验探究活动的质量和效益。面对同样一个实验情境,不同的学生可能提出不同的问题。这些问题既可能存在数量上的差异,也可能存在质量上的差异。那么,问题数量与问题质量之间有没有相关性?是不是学生提出的问题越多,     

Urea-based polyacetylenes as an optical sensor for fluoride ions

Novel acetylenes carrying urea groups, 1-(4-ethynylphenyl)-3-(4-nitrophenyl) urea (1), 1-(4-propargyl)-3-(4-nitrophenyl) urea (2), were synthesized and polymerized with rhodium catalyst. Polymers [poly(1) and poly(2)] with moderate molecular weights were obtained in good yields. The anion sensing ability of poly(1) and poly(2) was estimated using the tetra-n-butylammonium (TBA) salts of a series of anions in DMF. Upon the addition of F-, the color of the DMF solution of poly(1) and poly(2) immediately turned to a different color, while the color of solution changed slightly upon addition of Cl-, HSO4-, Br-, and NO3-, indicating the F- sensing ability of poly(1) and poly(2). The 1H-NMR titrations of poly(1) revealed that the colorimetric response of poly(1) was triggered by the urea/F- interaction through the hydrogen bonding and/or deprotonation process. The absorption spectra titration and Hill plot analysis were carried out to measure the F- binding ability, and the Hill coefficient in the poly(1)/F- complexation was found to be 5.8. This result clearly indicated that this binding mode between poly(1) and F- was based on a positive homotropic allosterism.     

Bovine Serum Albumin Loaded Solid Lipid Nanoparticles Prepared by Double Emulsion Method

Solid lipid nanoparticles loaded with bovine serum albumin(BSA) were prepared by a double emulsion method. As the mass fraction of the model drug BSA increased from 0 to 15%, the particle size gradually increased. The physical stability of the nanoparticles was investigated by zeta potential measurement and they were shown to be quite stable. Fluorescence spectroscopy confirmed that the loaded position of BSA was on the interface between the inner aqueous phase and the solid lipid phase. Both Fourier-transf...     

面向21世纪的纳米电子学

评论了纳米电子学的沿革路程,介绍了纳米电子学的研究内容,并预测了它的发展趋势。进而指出,纳米电子学的崛起与发展将会对21世纪的量子计算机、量子通信以及量子信息处理等产生革命性的影响。