白光LED用红色荧光粉CaMoO4：Eu^3＋的制备及发光性能研究

采用柠檬酸溶胶-凝胶法制备了CaMoO4: Eu3 荧光粉,对前驱体进行了差热(DSC)分析,对样品进行了X-射线衍射(XRD)、粒度分析和荧光光谱测定. DSC 和XRD结果表明,在700℃时可得到CaMoO4纯相.粒度分析结果表明随着烧结温度的升高,产物的粒径明显增大,700℃时约为 160 nm,而用固相法在800℃制备的CaMoO4: Eu3 荧光粉的平均粒径明显增大至3μm左右.分别以393 nm 的近紫外光和 464 nm 的可见光激发样品,CaMoO4: Eu3 荧光粉发出明亮的红光,对应于Eu3 的4f - 4f跃迁,当Eu3 的掺杂浓度约为30 mol %时,在616 nm处的发光强度最大.在393,464 nm的吸收分别与目前应用的紫外光和蓝光LED芯片相匹配.因此,这种荧光粉是一种可能应用在白光LED上的红色荧光材料.     

钌多吡啶配合物的合成及结合DNA的研究

合成了咪唑并［ｆ］邻菲咯啉（ＩＰ）和２－苯基咪唑并［ｆ］邻菲咯啉（ＰＩＰ）两种新的配体及［Ｒｕ·（ｂｐ）２（ＩＰ）］￣（２＋）（简称ｂ２ＩＰ）、［Ｒｕ（ｂｐｙ）２（ＰＩＰ）］￣（２＋）（简称ｂ２ＰＩＰ）、［Ｒｕ（ｐｈｅｎ）２（ＩＰ）］￣（２＋）（简称ｐ２ＩＰ）和［Ｒｕ（ｐｈｅｎ）２（ＰＩＰ）］￣（２＋）（简称ｐ２ＰＩＰ）４种新混配物。用电子吸收、稳态发光、圆二色谱研究了配合物与小牛胸腺ＤＮＡ的结合情况。总的结合强度顺序为：ｂ２ＩＰ＜ｂ２ＰＩＰ≤ｐ２ＩＰ＜ｐ２ＰＩＰ，这与配体的平面大小、π电子扩展程度和疏水性顺序（ｂｐｙ＜＜ｐｈｅｎ＜ＩＰ＜ＰＩＰ）是一致的。证明了配合物与ＤＮＡ存在插入结合。ＣＤ谱表明这种结合有对映体选择性．     

Studying a kind of portable ultra-bright microfocus x-raysource

This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusing system and a metal target. A crystal Lanthanum Hexaboride cathode, a Wehnelt grid and an extracted electrode compose the triode electrode electron-gun system. Two equal radius cylinder electrodes form the focusing system. The key factors determining the focus properties of the electron beam such as the ratio D_w/H, grid bias V_g, and the properties of the extracted electrode are numerically studied. The calculated results reveal that when D_w/H, V_g, the length of the extracted electrode, and the distance between the grid and the extracted electrode equals 5, --0.6~kV, 10~mm, and 8~mm respectively, the electron beam focal spot can be concentrated down to 9~μm in radius and a reasonable focal length about 72.5~mm can be achieved, at the same time, the cathode emission currents can be as high as 30~mA.     

废轮胎热解半焦CO2气化反应动力学

利用热重－差热（TG－DTA）分析仪对废轮胎热解半焦进行气化反应的研究,反应气体为CO2,在20－1100度温度范围内以不同的加热速率（10℃/min,30℃/min,50℃/min对各种热解条件下制得的废轮胎半焦进行气化动力学研究,分析了升温速率,制焦条件等对半焦气化反应特性的影响,得到废轮胎热解半焦与CO2气化反应的动力学参数。建立了废轮胎半焦CO2气化反应一级动力学模型,模型与实验结果吻合良好。     

FUNCTIONS(Ⅰ)

<正>As we all know that a relation is a cor- respondence between two variables x and y. When relations are written as ordered pairs (x,y),we say that x is related to y.Often, we are interested in specifying the type of re- lation (such as an equation) that might exist between the two variables. For example,the relation between the revenue R resulting from the sale of x items     

POWER FUNCTIONS

<正>A power function is a function that is defined by monomial.(单项式) A power function of degree n is a function of the form     

单-(6-巯基)-β-环糊精修饰的CdTe量子点的合成及与中性红的相互作用

以巯基乙酸(TGA)和单-(6-巯基)-β-环糊精(mono-6-thio-β-CD)作混合稳定剂,通过优化TGA/mono-6-thio-β-CD比例及回流时间,合成出了粒径分布均匀、荧光量子产率高达81.3%的mono-6-thio-β-CD修饰的CdTe量子点(QDs),建立了一种在水相中直接合成β-CD修饰的CdTe的新方法.利用荧光光谱、紫外-可见吸收光谱、共振瑞利散射光谱(RRS)研究了mono-6-thio-β-CD-CdTeQDs与中性红的相互作用,同时通过对比单独使用TGA为稳定剂合成的TGA-CdTeQDs与中性红的相互作用并结合透射电子显微镜(TEM)对反应机理进行了讨论并提出了相应的反应模型.在pH6.1的BR缓冲溶液中,当中性红浓度为7.5×10-6mol/L时,中性红的离子型体HNR+和分子型体NR分别与mono-6-thio-β-CD-CdTeQDs表面的-SCH2COO-和mono-6-thio-β-CD结合达饱和,当中性红浓度大于7.5×10-6mol/L时,中性红开始在mono-6-thio-β-CD-CdTeQDs表面聚集,导致mono-6-thio-β-CD-CdTeQDs粒径增大、荧光急剧猝灭、RRS显著增强.     

Darboux Transformation and Soliton Solutions for a Variable-Coefficient Modified Kortweg-de Vries Model from Fluid Mechanics,Ocean Dynamics,and Plasma Mechanics

This paper is to investigate a variable-coefficient modified Kortweg-de Vries （vc-mKdV） model, which describes some situations from fluid mechanics, ocean dynamics, and plasma mechanics. By the AblowRz-Kaup-NewellSegur procedure and symbolic computation, the Lax pair of the vc-MKdV model is derived. Then, based on the aforementioned Lax pair, the Darboux transformation is constructed and a new one-soliton-like solution is obtained as weft Features of the one-soliton-like solution are analyzed and graphically discussed to illustrate the influence of the variable coefficients in the solitonlike propagation.