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81.
Abstract: Reaction of a number of alkyl halides with tetrathiomolybdate in water as the solvent affords the corresponding disulfides in good yields.  相似文献   
82.
Porphyrins are very important chromophores as sensitizer in solar cell. Hole and electron transport layers are being used as an important layer to move the electrons and holes away from the sensitizer molecule to electrodes. In this work, a simple process has been developed for the synthesis of one layer combination of sensitizer and hole transport, that is, polyaniline‐porphyrin (PANI‐TPPS4) system as a bulk heterojunction. Macrospheres of fluorescent PANI‐TPPS4 materials were synthesized by one‐pot as well as two step processes directly from porphyrin for the first time. The advantage of this process is no need to isolate sulfonated porphyrin (TPPS4), which is a difficult process. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012  相似文献   
83.
The effect of l-glutamic acid as complexing agent in the presence of hydrogen peroxide as oxidizer in copper chemical mechanical polishing (CMP) slurry is investigated. In the CMP process, the work surface is moved against a pad, with slurry flowing between the surface and the pad. The polish rate was found to be stable over a wide range of hydrogen peroxide concentration. High concentration of either l-glutamic acid or hydrogen peroxide leads to a reduction in polish rate, but a high concentration of both chemicals does not reduce the polish rate. In the absence of hydrogen peroxide, the Cu polish rate was 0 for all the l-glutamic acid concentrations investigated. However, potentiodynamic polarization curves do not show any sign of passivation when l-glutamic acid was present in the solution. In situ open circuit potential measurements show that copper redox reactions as well as hydrogen peroxide redox reactions contribute in determining the electrochemical behavior. We propose that l-glutamic acid inhibits the copper dissolution by adsorption onto the metallic copper, but enhances copper dissolution by complexing copper ions. The results show that it is possible to conduct controllable copper CMP in mildly acidic slurries with hydrogen peroxide as oxidizer and l-glutamic acid as complexing agent.  相似文献   
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Mesoporous aluminosilicate spheres of 0.3–0.4 Μm diameter, with different Si/Al ratios, have been prepared by surfactant templating. Surface area of these materials is in the 510–970 m2 g-1 range and pore diameter in the 15–20 ? range.  相似文献   
88.
We present the design and fabrication of a planar structure for coupling light from a multimode feed waveguide into a single-line-defect photonic-crystal waveguide. Finite-difference time-domain calculations predict a coupling efficiency of greater than 90%, and preliminary experimental results indicate successful coupling through a single-line-defect photonic-crystal waveguide. Device design, fabrication, and characterization are presented.  相似文献   
89.
[reaction: see text] Synthesis and structure of a novel [6.6]metacyclophane with enediyne bridges is reported.  相似文献   
90.
The reaction of several geminal dithiols with 3,6-dibromo-1,4-dimethyl-2,5-piperazinedione gave in good yields piperazinedione derivatives substituted at the 3,6-position with a geminal dithiol-bridging group. These sulfur-bridged piperazinediones formally represent derivatives of the 2,4-dithia-6,8-diaza-7,9-dioxobicyclo[3.2.2]nonane ring system. Attempts to transform these sulfur-bridged piperazinediones to 3,6-epidithiopiperazinediones by removal of the bridging group common to the sulfur functionality were unsuccessful. Studies also are reported of addition of thioacetic acid to 3,6-dimethylene-2,5-piperazinedione to give 3,6-diacetylthio-3,6-dimethyl-2,5-piperazinedione. Conversion of the 3,6-diacetylthio derivative to the epithiopiperazinedione ring system yielded a mixture of epimono- and epidithiopiperazinediones.  相似文献   
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