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1.
《Electroanalysis》2004,16(11):897-903
The reaction of iodine, electrogenerated from iodide, is used for the detection of As(III) via electrocatalytic reaction in the diffusion layer of a boron‐doped diamond electrode. The merits of this electrode material for this purpose (over platinum, gold or glassy carbon) are demonstrated and the kinetics of the reaction between I2 and As(III) in acid reported. 相似文献
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4.
一种新型的磷化钼加氢精制催化剂的研究 总被引:8,自引:0,他引:8
通过(NH4)Mo7O24·4H2O和(NH4)2HPO4水溶液沉淀、焙烧在923K用H2还原制得磷化钼催化剂.XRD检测表明,用H2还原后有纯的磷化钼生成.在3.0MPa的高压连续微反系统中测定催化剂的加氢活性.以制备的磷化钼为活性组分、γ-Al2O3为稀释剂,考察了空速、反应温度和反应时间对模型化合物的HDN、HDS和HDY性能的影响,结果表明:在合适的条件下,其脱硫脱氮率可达到90%以上.模型化合物为吡啶、噻吩和环己烯,吡啶含量以N计(为0.2%)、噻吩含量以S计(为0.3%),环己烯含量为20%,以环己烷作溶剂. 相似文献
5.
Omar El Tall Nicole Jaffrezic‐Renault Monique Sigaud Olivier Vittori 《Electroanalysis》2007,19(11):1152-1159
Boron‐doped Diamond (BDD) electrode has become one of the important tools for heavy metal detection. By studying some analytical parameters of DPASV method, like deposition time and potential in different electrolyte concentrations (acetate buffer), the conditions for detecting very low metal ion levels (Zn, Cd, Pb, and Cu) could be chosen. Diluted electrolyte (0.01 M buffer) was one of the factors favoring low detection and quantification limits, but its quantification range is short in comparison to more concentrated media. For ?1.7 V deposition potential, the detection of single metal at ppb levels was reached in 60 s deposition time. Understanding different metal‐metal interactions shows the limits to the simultaneous determination of heavy metals at BDD. Quantification was possible for the simultaneous determination of Zn, Cd and Pb despite the overlapping of Zn and Cd peaks. The performance of the BDD was compared with that of another C‐based solid electrode: the glassy carbon electrode (without mercury plating). A lower base line current, wider potential range, higher sensitivity (3 to 5 times higher than GC) and longevity of the material were noticed for the BDD. 相似文献
6.
研究了波长、温度及表面处理对n-InP光脉冲暂态行为的影响。结果表明,波长对时间常数无影响;随着温度升高,峰值下降,衰减变快。讨论了表面处理的影响,并对实验结果作了必要的解释。 相似文献
7.
Eberhard Hohaus 《Monatshefte für Chemie / Chemical Monthly》1980,111(4):863-875
The i.r., u. v.,1H n.m.r.,13C n.m.r., and11B n.m.r. spectra of several substituted diphenylboron chelates derived from salicylaldehyde azomethines were compared with respect to the influence of the amine substituentR. O–B–N-6-ring constitution of the chelates29–32 [R=OH, NH2, NHC6H5, N(CH3)2] can be deduced from the spectra.
Als 3. Mitt. gilt:F. Umland undE. Hohaus mit Beiträgen vonW. Riepe, K. Brodte, C. Schleyerbach undD. Szonn. Untersuchungen über borhaltige Ringsysteme vom Chelattyp. Forschungsbericht des Landes Nordrhein-Westfalen Nr. 2538. Opladen: Westdeutscher Verlag. 1976. 相似文献
8.
M. Frederick Hawthorne 《Angewandte Chemie (International ed. in English)》1993,32(7):950-984
A therapeutic method that selectively destroys malignant cells in the presence of normal cells is a highly valued goal of oncologists and the possible salvation of cancer patients afflicted with some incurable forms of the disease. Selective cell destruction is, in principle, possible with a binary therapeutic strategy based upon the neutron capture reaction observed with the 10B nucleus and a neutron of low kinetic energy (thermal neutron). This nuclear fission reaction produces both 4He and 7Li+ nuclei along with about 2.4 MeV of kinetic energy and weak γ-radiation. Since the energetic and cytotoxic product ions travel only about one cell diameter in tissue one may specify the cell type to be destroyed by placing innocent 10B nuclei on or within only the doomed cells. This article describes the current status of chemical research aimed at the eventual adoption of this therapeutic method (boron neutron capture therapy or BNCT). The multidisciplinary nature of this research effort involves chemistry, biology, nuclear physics, medicine, and related specialties. Methods devised for bringing 10B nuclei to tumor cells in therapeutic amounts are correlated with the structure of a generalized cell and the various cellular compartments available for boron localization. The synthesis methods employed for the creation of boron-containing biomolecules and drugs are presented along with representative data concerning their efficacy in tumor localization. The outlook for BNCT is especially bright at this time because of rapid developments in the fields of bioorganometallic chemistry, microbiology, immunology, and nuclear science, to name but a few. Very effective boron delivery vehicles have been demonstrated, and through the interaction of chemistry and biology these species are undergoing further improvement and evaluation of their suitability for BNCT. 相似文献
9.
Y. Shacham-Diamand Y. Sverdlov V. Bogush R. Ofek-Almog 《Journal of Solid State Electrochemistry》2007,11(7):929-938
Thin cobalt alloy films have been obtained using electroless deposition solution with two reducing agents: dimethylamine borane
(DMAB) and sodium hypophosphite. This system allows spontaneous and self-activated deposition of barrier layers on Cu lines
and via contacts for ultra large scale integration (ULSI) interconnects applications. This work presents a study of the solution
composition effects on the material properties and composition of the films. First, we present the deposition rates, the electrical
resistance, the various element profiles in the thin film, and the thin film roughness. Next, we discuss the film’s composition
and its dependence on the ratio between the reducing agents composition in the solution. The experimental results suggest
that the film phosphorous and boron composition is determined by the surface adsorption rates of the reducing agents. Therefore,
a surface co-adsorption model of the two reducing agents is proposed, formulated, analyzed, and compared to the experimental
results. Finally, we discuss the model and its significance to the formation of high-quality ultra-thin barrier layers.
Dedicated to Professor Dr. Algirdas Vaskelis on the occasion of his 70th birthday. 相似文献
10.
It is the first time that boron is determined in the presence of a little methanol by discoloring spectrophotometry in this paper. A russety product can be formed by the reaction between glycine (Gly) and sodium 1,2-naphthoquinone-4-sulfonate (NQS) in alkaline solution. When boron is added to the solution, the system will be discolored, and the addition of a little methanol will improve the discoloration. Beer's law is obeyed in the range of boron concentrations of 0.86-43.24 μg ml−1 at the maximal discoloring wavelength of 382 nm. The equation of linear regression is A = −0.07581-86.79186C (mol l−1), with a linearly correlation coefficient of 0.9979. The detection limit is 0.80 μg ml−1 and R.S.D. is 4.2%. The method is successfully applied to the determination of boron in pharmaceutical and biological samples. The average recoveries are in the range of 98.2-104.1%. Analytical results obtained with this novel method are satisfactory. 相似文献