LaMgAl11O19∶R(R＝Tb,Mn)的真空紫外光谱特性

采用高温固相反应法合成了LaMgAl11O19∶R (R=Mn, Tb)荧光体, 测量了荧光体的真空紫外激发光谱和相应的发射光谱, 观察到基质吸收带位于170 nm附近, Mn2+离子的吸收位于170～510 nm范围, Tb3+ 离子的4f-5d吸收位于170～250 nm范围. 在147 nm激发下, 它们发射绿光. 真空紫外光谱特性的研究表明, 基质与激活离子之间存在较好的能量传递.     

Reaction Mechanism Investigation Using Vibrational Mode Analysis for the Multichannel Reaction of CH_3O+CO

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｍｅｔｈｏｘｙｒａｄｉｃａｌ (ＣＨ3Ｏ)ｉｓａｎｉｍｐｏｒｔａｎｔｉｎｔｅｒ ｍｅｄｉａｔｅｉｎｔｈｅｐｈｏｔｏｃｈｅｍｉｃａｌｏｘｉｄａｔｉｏｎｏｆｈｙｄｒｏｃａｒｂｏｎｓｉｎｔｈｅａｔｍｏｓｐｈｅｒｅ ,1 3ａｎｄｐｌａｙｓａｓｉｇｎｉｆｉｃａｎｔｒｏｌｅｉｎｔｒａｎｓ ｆｏｒｍｉｎｇｎｉｔｒｉｃｏｘｉｄｅｔｏｎｉｔｒｏｇｅｎｄｉｏｘｉｄｅ .4 Ｓｉｍｉｌａｒｌｙ ,ｔｈｅｒｅａｃｔｉｏｎｍｅｃｈａｎｉｓｍｓｏｆｈｙｄｒｏｘｙｌａｎｄｃａｒｂｏｎｍｏｎｏｘｉｄｅ5,6ａｎｄｏ…     

Photoluminescence characterization of polycrystalline n-type Cu2O films

Electrodeposition was used to deposit Cu₂O thin films on ITO substrates. Photoresponse of the film clearly indicated n-type behavior of Cu₂O in photoelectrochemical cells. The temperature dependence of photoluminescence (PL) revealed that the spectra consist of donor-acceptor pair emissions and the recombination between electrons bound to donors and free holes. We observed that the dominant intrinsic defect, oxygen vacancies, creates a donor energy level at 0.38 eV below the bottom of the conduction band. As a result, this donor level acts as a center for both PL emissions and to produce n-type conductivity in the electrodeposited Cu₂O films. In addition, an acceptor energy level at 0.16 eV from the top of the valence band was observed.     

Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation

The application of radiation technology in the en-vironmental protection was listed as one of the mostimportant research fields by the International AtomicEnergy Agency (IAEA) for the peaceful use of nuclearenergy. It has great research value and potential appli-cation. Because of their broad-spectrum antimicrobialproperties, Cholophenols (CPs) have been used aspreservative agents for wood, paints, vegetable fibersand leather and as disinfectants. In addition, they havebeen widely employed…     

Aluminum(III) complexes containing O,O chelating ligand

The stoichiometric reactions of trimethylaluminum with 2,6‐(MeOCH₂)₂C₆H₃OH (LH) revealed compounds L₃Al ( 1 ) and L₂AlMe ( 2 ). On the other hand reaction of 1 equiv. of LH with trimethylaluminum did not lead to the formation of complex LAlMe₂ ( 3 ), rather 2 together with Me₃Al were observed as a result of a disproportionation of 3 . Compounds 1 and 2 were characterized by elemental analysis, ¹H and ¹³C NMR spectroscopy and in the case of 1 by X‐ray diffraction. Derivative 2 underwent transmetalation with Ph₃SnOH, giving LSnPh₃ ( 4 ) as the result of a migration of ligand L from the aluminum to the tin atom. The identity of 4 was established by elemental analysis, ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy and ¹H, ¹¹⁹Sn HMBC experiments. The system 2 and B(C₆F₅)₃ in a 1:1 molar ratio was shown to be active in the polymerization of propylene oxide and ε‐caprolactone. Copyright © 2007 John Wiley & Sons, Ltd.     

添加助剂的钙钛矿型氧化物NdMO_3上的甲烷氧化偶联——Ⅱ.15% Li_2O/NdMO_3(M=Cr、Mn、Fe、Co、Ni)上的OCM反应研究

在添加了15%Li_2O的NdMO_3(M=Cr、Mn、Fe、Co、Ni)上进行了甲烷氧化偶联(OCM)反应研究.通过改变反应气中CH_4:O_2浓度比,在氧化态和“脱氧态”催化剂上的CH_4脉冲反应,探讨了表面吸附氧和晶格氧在OCM反应中的作用以及NdMO_3中不同金属离子(M)对OCM反应活性的影响等.     

荧光光度法直接测定高纯氧化钕中的痕量镨和铈

使用Ｐ－ＥＬＳ５０荧光光谱仪，在盐酸介质中，用同一激发波长激发，分别测定Ｐｒ（Ⅲ）（ｎｍ）和Ｃｅ（Ⅲ）（３５６ｎｍ）发射峰强度。     

Investigation of a liquid-liquid extraction system based on non-ionic surfactant-salt-H2O and mechanism of drug extraction

Based on the investigation of a non-ionic surfactant-salt-H₂O liquid-liquid extraction system, general rules concerning salt selection are concluded and the mechanism of phase separation is explained. The extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydrochloride (PCN) in such a system is studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, which means that quantitative extraction is realized, while that of PCN is 77%. This system produces distribution coefficients (K_D) of 12.3 and 2.6, respectively, for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet absorbance; and molecular fluorescence spectra change of the drugs in the system studied.     

蚕蛹甲壳素的脱色方法与机理探讨

研究了从粗甲壳素 (分离蚕蛹蛋白质后的残渣 )中提取蚕蛹甲壳素的工艺条件 ,探索了H2 O2 氧化脱色方法。实验结果表明 ,在 70℃的水浴中 ,按照m(蚕蛹渣 )∶m(5 %氢氧化钠 ) =30∶80的质量比处理 2h ,可脱净残余蛋白 ,得到黑褐色的粗蚕蛹甲壳素。用H2 O2 脱色漂白 ,工艺条件为 :6 5～ 70℃ ,pH值为 8 5± 0 5 ,时间 5h ,m (蚕蛹渣 )∶m(30 %H2 O2 ) =5 0∶130。所得甲壳素白度为 30 % ,收率为 2 5 %。双氧水脱除蚕蛹甲壳素颜色的机理可能是H2 O2 分解的O2 -2 作用于铁硫蛋白与细胞色素复合物体系中的硫 ,将体系中半胱氨酸硫氧化成亚砜 ,使得色蛋白与甲壳素相连的键断开 ,从而使色素从甲壳素上分离下来。