Ni添加对0.4Zr0.1V1.1Mn0.5Cr0.1合金的相结构和电化学性能的影响

本文通过XRD、SEM、EDS研究了Ti_0.4Zr_0.1V_1.1Mn_0.5Cr_0.1Ni_x(x=0，0.2，0.4，0.6，0.8)合金的相结构和电化学性能。该合金系由BCC结构的V基固溶体主相和六方结构的C14 Laves第二相组成，Ni能够促进第二相的生成，Ni含量的增加导致了各相中的化学组成和晶格参数的变化，并通过电化学方法研究了Ni含量对_0.4Zr_0.1V_1.1Mn_0.5Cr_0.1合金电极的最大放电容量、自放电性能、高倍率放电性能、循环稳定性能等的影响。     

Modification effect of Cu upon Pt In Pt?Cu?Al2O3 catalysts

In Pt–Cu–Al₂O₃ catalysts Cu might display either Electronic Ligand Effect or Ensemble Effect, depending on the preparation method of catalysts. For catalysts with Pt added before Cu, the latter exhibits an Electronic Ligand Effect. However, for catalysts with Cu added before Pt or with co-added Pt and Cu, Cu mainly demonstrates an Ensemble Effect.

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Pt–Cu/Al₂O₃ , . Pt Cu, , .

     

N,N,N′′-三取代氨基甲酰脲类化合物的合成

N，N－二取代脲和取代三氯乙酰胺反应合成了10种未见文献报道的标题化合物，产物结构经元素分析、IR和^1H NMR确证。初步生物活性测定表明多数化合物具有明显的除草活性。     

非水体系毛细管电泳-紫外检测法测定苯甲酸和苯甲醛

建立了用非水相体系高效毛细管电泳-紫外检测法同时测定苯甲酸和苯甲醛的新方法，考察了运行电压、非水相介质和电解质等因素的影响，在25℃下，以V（乙腈）：V（碳酸丙烯酯）=1：1的混合液为溶剂，缓冲体系中含15mmol／L十六烷基三甲基溴化铵体积分数1％乙酸，重力进样30S，运行电压20kV，毛细管总长45cm有效长度30cm，φ75μm，检测波长285nm。苯甲酸线性范围为5～40μg／mL，线性方程为：Y=13．473ρ＋13．336，相关系数r=0．9985，检出限为0．92μg／mL，RSD为3．8％。苯甲醛的线性范围75～1125μg／mL线性方程为：Y=5．2449ρ＋564．01，相关系数r=0．9997，检出限为15．60μg／mL，RSD为3．5％。已用于经空气氧化后的苯甲醛中苯甲酸和苯甲醛的测定。     

Study of structural characteristic features of phenanthriondolizidine alkaloids by fast atom bombardment with tandem mass spectrometry

The mass spectrometric behavior of phenanthroindolizidine alkaloids has been investigated in detail by positive ion fast atom bombardment tandem mass spectrometry (FAB-MS/MS) combined with collision-induced dissociation (CID). The fragmentation has been correlated with the skeleton structure and positions of substituents. The product ions arising from retro-Diels-Alder cleavages differ clearly for compounds with different skeletons. The substituents at C-14 were observed to markedly influence the fragmentation pathway of [M + H](+) ions. A diversity of dissociation behavior initiated by the variation of substituents on the aromatic ring was also observed in the CID spectra. Product ions resulting from loss of CH(4) were obtained for compounds in which both C-6 and C-7 are occupied by methoxy groups. FAB-MS/MS spectra can reflect the connection between the fragmentation behavior and structural features of these phenanthroindolizidine alkaloids rapidly and effectively, and should prove to be a powerful method to determine the structures of related compounds.     

高能工业CT用新型X射线源焦斑测量

 为了获得较高的空间分辩率，设计了一种新型小束斑驻波电子直线加速器，该加速器取消了加速腔中的鼻锥结构，而在耦合腔中设置鼻锥结构。用狭缝法代替小孔法测得X射线源的焦斑尺寸为1.4mm。讨论了射线源焦点对成像质量的影响，分析了在高能条件下小孔法不适合用于焦点测量的物理原因，用4种测量方法测量了该高能X射线源的参数，测得该系统的成像极限分辩率为2.5 lp/mm，最后对实验结果进行了分析。     

不稳定的二甲基氨基甲基二茂铁的ESI-HRMS分析条件研究

研究并优化了化合物N,N-二甲基氨基甲基二茂铁的电喷雾离子化-高分辨质谱(ESI-HRMS)分析方法。重复测定样品,目标分子离子计数的相对标准偏差(RSD,n=10)为2.4%,表明仪器重复性良好。通过对目标分子的一级质谱图与二级质谱图分析,一级质谱图中母离子的丰度低于最强子离子丰度的10%,表明目标分子在源内发生了裂解。研究了一级质谱中目标分子离子及其最强碎片离子的离子计数与干燥气温度、毛细管出口电压的变化规律,并拟合得到相应的数学方程;确定了目标分子质谱分析的最佳条件。     

固定Ionic liquid/Silica sol/Nafion膜中的联吡啶钌电化学发光行为的研究及应用

制备了Ionic liquid/Silica sol/Nafion-联吡啶钌复合物膜修饰金电极。采用循环伏安(CV)和电致化学发光(ECL)法,考察了联吡啶钌和左氧氟沙星在此修饰电极上的电化学及其发光行为。结果表明,此修饰电极表现出很好的电化学活性和电化学发光响应。基于左氧氟沙星对固定化联吡啶钌在0.1 mol/L磷酸盐缓冲液中的弱电化学发光信号有较强的增敏作用,建立了电化学发光检测盐酸左氧氟沙星的新方法。在最佳实验条件下,左氧氟沙星浓度在1.0×10-7～1.0×10-4mol/L范围内与相对发光强度呈线性关系(r2=0.998 4),检出限(S/N=3)为1.59×10-9mol/L。连续平行测定2.2×10-5mol/L的左氧氟沙星溶液10次,发光强度的相对标准偏差(RSD)为3.6%。对样品进行回收率试验,回收率在95.6%～103.5%之间,RSD(n=5)为3.0%。该方法具有较高的选择性和灵敏度,样品处理简单快速,用于盐酸左氧氟沙星的测定,结果满意。     

Some key ordered macroporous composites

This review summarizes recent progress of the ordered macroporous composites with the opals and inverse opal structure. Synthesis and performance of the composites are emphasized. Composition of the ordered composites is tunable ranging within metal, metal alloy, metal oxide, polymer, carbon and hydrogel. The ordered structure gives brilliant color effects, which is useful for sensors and photonic crystals. The interconnected macroporous structure provides easiness for mass transportation and species culturing.     

分散液液微萃取-气相色谱-质谱法测定水样中4种嗅味物质

以四氯乙烯作萃取剂,以丙酮为分散剂对水样中4种嗅味物质,二甲基异莰醇、土臭素、β-环柠檬醛和β-紫罗兰酮进行分散液液微萃取,提取液供气相色谱-质谱仪分析。在选择离子监测模式下,4种嗅味物质的线性范围均为0.05～20μg.L-1。二甲基异莰醇、土臭素、β-环柠檬醛和β-紫罗兰酮的检出限(3S/N)分别为0.03,0.01,0.02,0.01μg.L-1。方法用于自来水和河水样品分析,4种嗅味物质的回收率在87.7%～102%之间,测定值的相对标准偏差(n=6)在1.8%～7.8%之间。