吡咯基金属络合物的制备及其在有机合成中的应用

本文综述了近年来吡咯基金属络合物的研究进展, 详细讨论了σ~N-、σ~C-、π-型吡咯基金属络合物的制备方法, 以及各类吡咯基金属络合物在有机合成中的应用。     

Quantitative study on La~(3+) influx mediated by sodium-calcium exchanger in human lymphocytes

Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+uptake is obviously stimulated by pre-treating the cells with ouabain and by removing extracellular Na+, and intracellular La3+concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+], is 1.5×10-12 mol · L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 μmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ion     

二氯亚甲基环己烷的卤化反应和2-取代二氯亚甲基环己烷的构象

多卤代烃在有机反应机理和结构研究中有着重要意义,作为一个有用的合成中间体,其制备也受到人们重视。我们在此报道二氯亚甲基环已烷(1)与氯及溴的反应和其它有关反应的实验结果。 1 于氯作用,主要得到加成产物1—氯—1—     

Y2O3, La2O3, Sm2O3对氧化铝瓷烧结及力学性能的影响

研究了3种稀土氧化物对氧化铝陶瓷烧结性能和力学性能的影响.结果表明 含Y2O3,La2O3,Sm2O3的添加剂促进了氧化铝瓷的烧结,提高了氧化铝瓷的力学性能.Y2O3和Sm2O3掺量为0.50%,La2O3掺量为0.75%时氧化铝瓷在1600或1620 ℃保温2 h烧结,相对密度达98.9%以上,强度超过439 MPa,断裂韧性达5.15 MPa·m1/2以上.微观结构分析表明,Y2O3,La2O3,Sm2O3抑止氧化铝晶粒生长,细化晶粒,使晶粒尺寸较均匀形成致密化结构.     

多孔二氧化硅中Gd3+ → Eu3+的能量传递

通过水热反应法，获得了单掺和双掺Eu³⁺，Gd³⁺的多孔二氧化硅组装体，研究了掺杂体系的光谱特性，观察到Gd³⁺ → Eu³⁺的能量传递。分析了能量传递过程，探讨了在多孔二氧化硅中Gd³⁺→Eu³⁺的能量传递的机理，其机理主要为电偶极-电偶极相互作用。     

Synthesis,structure and the e.s.r. spectrum of the mixed-valence molybdovandate Na2(NH4)4[(VIVVV8Mo)O28] · 10H2O

The mixed-valence molybdovanadate compound Na₂(NH₄)₄[V^IVV^V ₈Mo)O₂₈] · 10H₂O [Vanadata(6-)tetradeca--oxotetra-₃-oxodi-₆-oxoheptaoxo(oxomolybdate) nonatetrammonium disodium, decahydrate] has been synthesized from sodium molybdate(VI) dihydrate and sodium metavanadate dihydrate in aqueous solution by adding NH₂OH · HCl. The molecular structure has been determined by X-ray diffraction and is based on the isopolydecavanadate structure. The molybdate atom is crystallographically disordered over 6MO₆ octahedral sites. The e.s.r. spectrum clearly indicates that one vanadium atom has the oxidation number +4.     

加速溶剂萃取同步净化-同位素内标-气相色谱-高分辨质谱测定水产品中32种多氯联苯

建立了加速溶剂萃取同步净化-同位素内标-气相色谱-高分辨质谱同时测定水产品中32种多氯联苯含量的方法。通过在加速溶剂萃取仪中加入2 g无水硫酸钠、1 g弗罗里硅土、50 g中性氧化铝作为吸附剂实现同步净化的效果，萃取溶剂为二氯甲烷-正己烷（1:1，v/v），萃取温度为100℃，循环2次。萃取结束后分别用0.5 mL浓硫酸净化两次，净化液浓缩定容后，采用气相色谱-高分辨质谱测定，同位素内标法定量。32种多氯联苯在0.1~20 μg/L范围内平均相对响应因子（RRF）的相对标准偏差（RSD）值（n=7）均小于15%，定量限（S/N=10）为0.3~1.9 ng/kg。在草鱼和海鲈鱼空白基质中做加标回收试验，添加水平为5、20和50 ng/kg，得到的平均回收率为71.9%~119.0%（n=6），RSD为3.5%~19.6%。该方法背景干扰低，灵敏度高，重现性好，回收率稳定，适用于水产品中多氯联苯的检测。     

Cd2Ge7O16中Tb的长余辉发光特性

本文研究了Cd₂Ge₇O₁₆∶Tb³⁺材料的发光及其长余辉性质。指出Tb³⁺的发光是该离子的 ⁵D₃- ⁷D_J、 ⁵D₄- ⁷D_J两种跃迁产生的；随着掺杂浓度的增加 ⁵D₄- ⁷D_J跃迁增强，发光颜色由蓝变绿。并把该材料的长余辉性质归结为基质结构中有电子陷阱和空穴陷阱。提出余辉机理模型。     

一种新型的空心镍纳米球的合成

通过以二氧化硅粒子作为模板和金纳米粒子为表面晶种的方法制备了壳厚度可控的镍空心球。采用TEM﹑XRD对二氧化硅/镍复合球和镍空心球进行了表征和研究。结果表明镍纳米壳是由似针状的面心立方的镍纳米粒子构成的，碱溶液处理过程不影响镍纳米壳的形貌。高温处理显示镍空心球具有良好的热稳定性。     

Er3+，Ho3+和Tm3+在硫氧化钆中的余辉发光

The new Er^3 , Ho^3 and Tm^3 doped gadolinium oxysulfide phosphors with the long afterglow emission were synthesized by solid-state reaction method. The synthesized phosphors were characterized by X-ray diffraction. The excitation and photolumineseenee spectra, afterglow spectra and afterglow decay curve were examined by fluorescence spectroscopy. The afterglow spectra of Gd2O2S:Er^3 , Mg, Ti showed typical transitions of Er^3 at 528(2H11/2→4I15/2), 548 (^4S3/2 →^4I15/2) and 669 nm (^4F9/2→^4I15/2). In the afterglow spectra of Gd2O2S: Ho^3 , Mg, Ti,typical transitions of Ho^3 at 546 nm (^5S2→^5I8), 651 and 661 nm (^2F5→^5I8) were observed. In Gd2O2S:Tm^3 , Mg,Ti, the afterglow emission at 800 nm (^1G4→^3H5) of Tm^3 was seen. The meehnism and model of afterglow energy transfer were proposed.