纳米晶Y_2SiO_5∶Eu的浓度猝灭研究

报道了分别用溶胶－凝胶法合成的Ｙ２ＳｉＯ５∶Ｅｕ纳米晶和用高温固相法合成常规尺度的Ｙ２ＳｉＯ５∶Ｅｕ材料的光致发光光谱和猝灭浓度的实验研究．结果表明：纳米Ｙ２－ｘＥｕｘＳｉＯ５比常规尺度的Ｙ２－ｘＥｕｘＳｉＯ５有更高的猝灭浓度和更高的发光亮度．理论分析认为这是由于在纳米材料中能量共振传递被阻断和猝灭中心在各个纳米晶内分布的涨落造成的．这个结果为高亮度的Ｙ２ＳｉＯ５∶Ｅｕ纳米材料的实际开发应用展示了广阔前景．     

在DBU存在下酞菁锰配合物的合成及溶剂影响

在强有机碱１，８－二氮杂双环［５，４，０］十一－７烯（简称ＤＢＵ）存在下，ＭｎＣｌ２与邻二氰基苯在某些二元醇溶剂中可高效合成Ｍｎ（Ⅱ）Ｐｃ（Ｐｃ表示酞菁），同时研究了不同溶剂对合成产物的物种及产率的影响和不同氧化态锰的酞菁配合物在一些醇溶剂中的互变现象     

喷雾干燥-高温固相法制备纳米LiFePO4与LiFePO4/C材料及性能研究

采用喷雾干燥-高温固相法制备纳米LiFePO₄与LiFePO₄/C正极材料，用X-射线衍射，扫描电镜等对合成材料进行了表征，并对以LiFePO₄为正极的电池进行了电化学性能测试。结果表明:材料合成最佳煅烧温度为600 ℃;合成过程中由于碳对LiFePO₄晶型的生长有一定的抑制作用，相对于纯LiFePO₄材料，LiFePO₄/C材料粒径更小;并且，在此最佳合成温度下合成的LiF     

Iron speciation related to color of Jurassic sedimentary rocks in Turpan Basin, northwest China

Mesozoic-Cenozoic reddish and green beds are widely distributed in northwest China. Mössbauer spectroscopy revealed that the composition of iron species varies with color in the middle-upper Jurassic sedimentary rocks from the Turpan Basin. Three main kinds of iron species were identified: (1) ferric iron of hematite (hem-Fe³⁺), (2) paramagnetic ferric iron (para-Fe³⁺), and (3) paramagnetic ferrous iron (para-Fe²⁺). Pyrite iron (pyr-Fe²⁺) was revealed only in a few samples. In general, there is a direct correlation between rock color, iron species and total iron content, however, in detail, this relationship is more complicated. The reddish rocks contain higher contents of total iron and hem-Fe³⁺, whereas the gray rocks contain much more para-Fe²⁺. However, relatively low hematite content cannot give red color to rocks, probably due to suppression by other pigments such as organic matter in black or chlorite in green. The dark or green rocks normally contain either only paramagnetic Fe²⁺ and paramagnetic Fe³⁺ species or these two species associated with hematite Fe³⁺, but the relative content of hematite species is lower. The variations of different iron species control lithological properties such as color and also may reflect the sedimentary conditions. Moreover, iron speciation in these rocks is one of the main factors, which result the color features of rocks in remote sensing imagery.This revised version was published online in November 2005 with corrections to the Cover Date.     

Synthesis,crystal structure and property of a novel azide-bridged one-dimensional chain copper(II) complex with a dinucleating macrocyclic polyamine

An azide-bridged polymeric cationic chain complex, [LCu₂(N₃)₂]n(ClO₄)_2n ·n(H₂O)**, where L=the dinucleating macrocyclic ligand bis-p-xylylBISDIEN, has been prepared and characterized by x-ray crystallography, u.v.-vis and i.r. spectra, and by magnetic measurements. The structure consists of cationic azide-bridged [LCu₂(N₃)₂]²⁺ (unit) chains, non-coordinated perchlorate anions and crystallized water molecules. The azide anion is bound to two copper atoms in neighboring units with an end-to-end bridging mode. In each unit, the copper atoms have a different coordination geometry; Cu(1) is a four-coordinated, distorted square-planar geometry, whereas Cu(2) is a five-coordinated, distorted square-pyramid. The electronic spectra of the title complex differ in anhydrous and in aqueous MeCN solutions, indicating that dissociation and solvation occur in aqueous solutions. The characteristic i.r. absorptions of azides and perchlorates are described. Magnetic moments vary from 2.05 (B.M.) at 300K to2.01 (B.M.) at 80K, which suggests that very weak interactions exist between the metals.     

金属硫蛋白加质子常数及与Cd(II)络合常数测定

用pH计和Cd离子选择电极测定了金属硫蛋白的加质子常数及其与Cd(Ⅱ)的络合常数, 用改进的简化络合模型处理实验结果, 得到了去金属硫蛋白(apo MT)中6类不同的加质子基团的数目及其加质子常数。对Cd(Ⅱ)滴定数据的计算表明, MT中两个结构域——α和β对Cd(Ⅱ)的络合常数相差约1000倍。从热力学定量描述了MT中两个结构域结合金属离子选择优先顺序。     

微波场中甲烷部分氧化制合成气 Ⅱ.Co/ZrO_2催化剂在微波场中的升温行为及催化活性

近年来，甲烷部分氧化制合成气（ＰＯＭ）的研究一直十分活跃［１，２］．前文报道了用于甲烷部分氧化制合成气的镍基催化剂（Ｎｉ／Ｌａ２Ｏ３）在微波场中的升温行为和催化活性［３］，发现在达到相同的ＣＨ４转化率时，微波活化方式下的催化剂床层温度比常规加热低得多...     

枳壳炮制前后微量元素的测定

采用等离子体原子发射光谱法对枳壳进行了炮制前后32种微量元素含量的测定比较．结果表明:枳壳经麸炒后，微量元素的含量有不同程度的变化。为深入研究枳壳炮制机理提供了参考依据．     

N-(1-异丙基-2-羧基-4-甲基二环[2.2.2]-5-辛烯-3-羰基)-N′-芳基(硫)脲的合成

在无溶剂绿色化学条件下,将α-萜品烯-马来酸酐加成物(1)与取代苯(硫)脲发生N-酰化反应,合成了4个N-(1-异丙基-2-羧基-4-甲基二环[2.2.2]-5-辛烯-3-羰基)-N′-芳基(硫)脲化合物(3a~3d),并由IR、UV-Vis、MS、1HNMR、13C NMR和元素分析确认了目标产物的结构。生物活性测试表明,其中3个化合物(3a、3b和3c)具有植物激素作用。