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901.
Jun Ping Xiao Qing Xiang Zhou Hua Hua Bai Department of Chemistry University of Science Technology Beijing Beijing China School of Chemistry Environmental Sciences Henan Normal University Henan Key Laboratory for Environmental pollution Control Xinxiang China 《中国化学快报》2007,18(6):714-717
A procedure for the preconcentration of copper was described in this paper using multi-walled carbon nanotubes (MWCNTs) oxidized by potassium permanganate as the adsorbent for the enrichment of trace copper in water samples. Important parameters, such as the sample pH, the concentration and volume of eluent, sample flow rate and volume, and interference of coexisting ions, were investigated. The obtained results indicated that proposed method possessed an excellent analytical performance. The linear range, the detection limit, and precison (RSD) were 1-100 ng/mL (R2 = 0.9993), 0.32 ng/mL and 2.88%, respectively. The results showed that copper could be adsorbed quantitatively on the pretreated MWCNTs with potassium permanganate, and proposed method was very useful in the monitoring of copper in the environment. 相似文献
902.
用化学还原法制备了NiB、NiB/Al2O3和NiBSm/Al2O3三种催化剂,它们都呈非晶结构.用等离子耦合发射光谱仪(ICP)对催化剂组分进行了分析,采用差示扫描量热法(DSC)对三种催化剂进行了热稳定性分析.结果表明,载体的引入使非晶态NiB合金的体相组成中B的含量降低.将非晶态NiB合金负载到γ-Al2O3上,可以明显改善非晶态合金的热稳定性,少量Sm可以进一步提高晶化温度.晶化激活能数据亦表明了载体和Sm对非晶结构具有良好的稳定作用.载体和Sm可能通过不同的作用提高了非晶态合金的热稳定性. 相似文献
903.
The aza‐Wittig reactions of benzophenone‐, acetophenone‐ and benzaldehyde l‐[(triphenylphosphoranyl‐idene)amino]ethylidenehydrazones (4) with phthalic anhydride, 2,3‐dimethylmaleic anhydride and 7‐oxabi‐cyclo[2,2,l]hept‐5‐ene‐2,3‐dicarboxylic anhydride ( 5a ) provide a new route to 5H,7H‐1,2,4‐triazolo[1,5‐c]‐[1,3]benzoxazepin‐7‐ones 8a‐c or 6H,8H‐1,2,4‐triazolo[1,5‐c][1,3]oxazepin‐6‐ones 8d‐h via the thermal reaction of the expected azinoimine lactones 6 . 相似文献
904.
Ming Xian LIU Li Hua GAN Gen CHEN Zi Jie XU Zhi Xian HAO Long Wu CHEN 《中国化学快报》2006,17(8):1085-1088
Recently the research on structures with an ordered two-dimensional(2D) pattern has attracted great attention due to its versatile applications in the fields of microelectronic and optoelectronic devices, displays, biochips and sensors, enzymatic immobilization, drug carriers, and photonic band gap materials. Various well-arrayed 2D structures have been made by the modern technique such as laser writing pattern fabrication, photoetching technique, micro-electromechanical systems based on scann… 相似文献
905.
906.
用ICP-AES法测定了东太平洋深海锰结核样品中二十多种主,次及微量元素,结果表明,表面瘤状和表面光滑两种类型锰结核的化学元素含量有较明显的区别,如表面光滑的锰结核TiO2含较高,而表面瘤状的锰结核Mn/Fe之值较高等。 相似文献
907.
The static polarizabilities and the second-order hyperpolarizabilities of a series of tri-nuclear metal cluster models MS4(M′PPh3)2(M′PPh3)(M=Mo,W;M′=Cu,Ag,Au)have been calculated within the first-principle theoretical framework. The model clusters have two fragments of rhombic units and it is the charge ransfer from one of these moieties to the other that is responsible for nonlinear optical property. This kind of electronic delocaization, differentiated from that of planar π-system, is very interesting and is worthy for further investigation. 相似文献
908.
Macrocyclic Schiff‐base ligand, bisacetylaceton‐ethylenediimine (BAE) and its transition metal complexes M(BAE) (M = Cu2+, Ni2+) were synthesized. The complexes having characteristics of aromatic systems and well‐defined one‐dimensional structures, reacted with p‐phthaloyl chloride, to obtain polymer complexes. The complexes were characterized by elemental analysis, inductively coupled plasma (ICP), FT‐IR, and thermal analysis and show good thermal stability. ESR spectra analysis discovered that there are free radicals in the chain of polymers, indicating that a weak magnetic spin‐exchange interaction operates between the metal ions and free radicals. It is found that, as the bridging p‐phthaloyl group is able to propagate the magnetic exchange interaction, the polymer complexes show paramagnetic properties by measurement of temperature dependence of the magnetic property, and obey Curie–Weiss law. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
909.
刚性微粒填充高聚物的宏观本构关系 总被引:9,自引:0,他引:9
用微观力学和统计方法研究了含损伤过程的刚性粒子填充高聚物的非线性本构关系.在材料的变形过程中,粒子与基体间界面的开裂引发微孔洞的成核与长大,这虽然弱化了材料的宏观力学性能,但是带来了宏观本构的非线性效应,这为材料的增韧奠定了基础.该文分析了刚性粒子对材料的强化作用和微孔洞演化对材料的弱化作用,以及这两种竞争机制的耦合效应对宏观本构关系的影响,并从理论上给出了界面强度,粒径分散度,平均粒径等参量对材料宏观力学行为影响的定量分析结果. 相似文献
910.
A novel method for determining different forms of human interferon-gamma (IFN-gamma) in single natural killer cells was developed by capillary electrophoresis (CE) with on-capillary immunoreaction and laser-induced fluorescence (LIF) detection. Cells were perforated with digitonin and one single cell was electrokinatically introduced into the front end of a separation capillary. The monoclonal antibody labeled with fluorescein isothiocyanate of IFN-gamma was hydrodynamically injected into the front end of the capillary around the cell introduced. After the cell was lysed by ultrasonication, the front end of the capillary was used as a microreactor to allow different forms of IFN-gamma to process the immunoreaction with their labeled antibody. Finally, the complexes of different forms of IFN-gamma with their labeled antibody were separated and detected by CE with LIF detection with a limit of detection of zeptomoles (10(-21) mol). 相似文献