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1.
提出用溶胶粒子表面修饰方法,结合溶胶凝胶技术制备无机催化膜.该方法的基本原理是利用合适的金属配合物在胶粒表面的吸附作用,经溶胶凝胶过程,将活性组分结合到无机膜中.实验测定结果表明:(NiEDTA)2-,VO-3,MoO2-4,(Pd(NH3)4)2+,PdCl2-4,PtCl2-6和RhCl3-6可用来修饰AlOOH溶胶.以Pd/γAl2O3催化膜的制备为例,经三次溶胶凝胶过程,可制得无裂缺的厚度为9μm的Pd/γAl2O3催化膜,膜材料的平均孔直径为6nm,Pd被均匀地分布在膜的顶层,其平均粒径为23nm. 相似文献
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3.
硫酸氢铵分解动力学及其分解机理的研究 总被引:1,自引:0,他引:1
为了筛选适合的化学贮能系统,Wentworth等人曾提出了十项筛选标准。照此标准衡量,硫酸氢铵的分解-合成反应是一个十分理想的贮能系统: NH_4HSO_4(l)?NH_3(g)+H_2(g)+SO_3(g)Prengle也曾就此反应应用于太阳能电站贮能系统的可行性作过理论上的探讨.但是,有关该反应的基础研究进行的还很不够,特别有关分解动力学和分解机理的研究文献尚未见报导。本文用等温热重法和程序升温热重法对硫酸氢铵的热分解动力学进行了研究,并确定了分解机理,为贮能系统的实际应用提供了基础数据。 相似文献
4.
Jinghua Zhang Toshiko Nagahama Hiroki Ohwaki Yasuhiro Ishibashi Yuji Fujita Sunao Yamazaki 《Analytical sciences》2004,20(1):37-43
To understand the cause of discoloration of the sea laver "nori," which is found in the Ariake Sea, the concentrations of pigments and elements in the normal and discolored laver samples were determined. In the discolored samples, a decrease in all of the pigments, chlorophyll a and carotenoids, and proteinous pigments, phycobiliproteins, was clearly observed. This was accompanied by a decrease in the content of Fe, Zn, Mn, Cu, and P. Good correlations between these elements and chlorophyll a, as well as between these elements and phycobiliproteins, were confirmed, indicating that, in addition to the deficiency of nitrogen and phosphorus, the deficiency of trace elements (Fe, Zn, Mn, and Cu), which are specifically required for photosynthesis, could be a reason for the discoloration of nori. The cause of elemental deficiency is also discussed. 相似文献
5.
我们已对O(~3p)原子和酮类分子化学反应速率常数进行了系列测定,分析讨论了羰基对O(~3p)抽提氢原子反应速率的影响,关于O(~3p)与醛类分子反应速率的测定也有报道。本文用流动微波放电-化学发光光子计数方法测定O(~3p)原子与丙醛和正丁醛化学反应速率常数及其与温度的关系,并由动力学数据对醛基中C—H键的离解能进行了讨论。 相似文献
6.
在242-260nm波氏范围通过CS2分子的共振增强多光子电离(REMPI)获得了母体离子CS和碎片离子的分质量激发谱.在λ<246.4nm区间,CS激发谱上呈现出来源于CS2双光子电离的弥散谱带,碎片离子激发谱的归属强烈提示多光子过程中有中性基电子态的CS和S(经由CS2的光解离)产生:(1)CS 的谱带主要来源于中性CS碎片经由单光子跃迁产生的(1+1)共振增强电离,(2)除了部分S 的谱峰来自CS 的光解外,多数S 的锐谱峰来自中性S原子经由3p3(2D0)4p,3p3(4S0)np(n=6,7,8)←3p43pJ(J=2,1,0)双光子跃迁产生的(2+1)共振增强电离. 相似文献
7.
游离氧化钙,氧化镁连续测定的电导法研究 总被引:8,自引:0,他引:8
研究了乙二醇对氧化钙,氧化镁的提取条件,利用乙二醇提取氧化钙后在催化剂存在下继续提取氧化镁,建立了电导法连续测定CaO,MgO分析方法,可用于水泥熟料中游离氧化钙,氧化镁的测定。 相似文献
8.
A very sensitive electroanalytical method was employed to determine bergenin in phosphate buffer with a pH of 6.0, bergenin was accumulated at a 4-(2-pyridylazo)-resorcinol (PAR) polymer film modified glassy carbon electrode (GCE) surface under the condition of open-circuit. In the following anodic sweep from −0.4 to 0.8 V, bergenin adsorbed at the PAR polymer film modified electrode surface, was oxidized and yielded a sensitive oxidation peak at 0.595 V. Due to its unique structure and extraordinary properties, the PAR polymer film shows higher accumulation efficiency toward bergenin compared with a bare GCE. Hence, the amount of bergenin at the PAR polymer film modified GCE surface increases significantly, and finally the oxidation peak current improves greatly. The experimental conditions, such as supporting electrolyte, pH value, accumulation time and scan rate, were optimized for the measurement of bergenin, and a sensitive electroanalytical method was proposed for bergenin determination. The oxidation peak current varies linearly with the concentration of bergenin over the range of 2.0 × 10−7 to 1.2 × 10−5 mol/L, and the detection limit is 2.0 × 10−8 mol/L after 3 min open-circuit accumulation. The relative standard deviation of the same electrode in 10 successive scans is 1.8% for 1.0 × 10−6 mol/L bergenin and 2.1% for interelectrodes, indicating excellent reproducibility. This new method was successfully demonstrated with bergenin tablets and diluted urine. 相似文献
9.
Jinghua YANG 《数学年刊B辑(英文版)》2019,40(2):227-236
In this paper, the author gives the discrete criteria and J\o
rgensen inequalities of subgroups for the special linear group on
$\overline{\mathrm{F}}((t))$ in two and higher dimensions. 相似文献
10.
Sensitive detection of human breast cancer cells based on aptamer–cell–aptamer sandwich architecture
Breast cancer is one of the most critical threats to the health of women, and the development of new methods for early diagnosis is urgently required, so this paper reports a method to detect Michigan cancer foundation-7 (MCF-7) human breast cancer cells with considerable sensitivity and selectivity by using electrochemical technique. In this method, a mucin 1 (MUC1)-binding aptamer is adopted to recognize MCF-7 human breast cancer cells, while enzyme labeling is employed to produce amplified catalytic signals. The molecular recognition and the signal amplification are elaborately integrated by fabricating an aptamer–cell–aptamer sandwich architecture on an electrode surface, thus a biosensor for the detection of MCF-7 is fabricated based on the architecture. The detection range can be from 100 to 1 × 107 cells, and the detection limit can be as low as 100 cells. The method is also cost-effective and conveniently operated, implying potential help for the development of early diagnosis of breast cancer. 相似文献