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11.
Analysis of characteristic odors from human male axillae   总被引:7,自引:0,他引:7  
A number of studies concerning the analysis of axillary odors have assumed that the characteristic odor produced in the axillae is due to volatile steroids and isovaleric acid. Organoleptic evaluation of Chromatographic eluants from axillary extracts was employed to isolate the region in the chromatogram where the characteristic odor eluted. The odor of the dissolved eluant was eliminated when it was treated with base, suggesting that acids make up the characteristic axillary odor. Subsequent extraction of the pH-adjusted axillary extract in conjunction with organoleptic evaluation of the Chromatographic eluant, preparative gas chromatography, and analysis by GC-MS as well as GC-FTIR showed the presence of a number of C6 to C11 straight-chain, branched, and unsaturated acids as important contributors to the axillary odor. The major odor component is (E)-3-methyl-2-hexenoic acid. Three homologous series of minor components are also important odor contributors; these consist of the terminally unsaturated acids, the 2-methyl-C6 to -C10 acids and the 4-ethyl-C5 to -C11 acids. These types of acids have not been reported previously as components of the human axillary secretions and have not been proposed previously as part of the principal odor components in this area.  相似文献   
12.
In order to investigate the galvanic anodic protection (GAP) of ferrous metals (such as 410, 304 and 316 stainless steels) in acid solutions by doped polyaniline (PANi), separate doped PANi powder-pressed electrodes with different surface areas (the area ratio of the PANi electrode to stainless steel is between 1:1 and 1:2) have been prepared. These were coupled with ferrous metal in the following solutions: 5 M sulphuric acid, 5 M phosphoric acid and industrial phosphoric acid (containing 5 M phosphoric acid and 0.05% chloride ion) to construct a galvanic cell, in which PANi is cathode while ferrous metal is anode. The results indicate that a PANi electrode with sufficient area can provide corrosion protection to stainless steel in these acidic solutions. A pilot scale coupling experiment was carried out. The results indicate that PANi is a promising material as an electrode for the anodic protection of ferrous metals in acidic solutions in industrial situations.  相似文献   
13.
本文介绍单光子时间分辨在线谱仪系统中的多道分析器与IBM PC/XT微型计算机接口的工作原理及控制程序。  相似文献   
14.
阿笑  于康  彭元 《食品与药品》2005,7(12B):62-65
北风起.火锅热。户外寒气逼人,屋内热气腾腾.鲜红的肉片。翠生生的青菜.在或红或白滚烫的锅中上下飞舞,仅是这灵动的姿态就让人禁受不住媚惑,抬手、举箸.一番狼吞虎咽,于是热气从心底缓缓升起,寒冷顿时一扫而空。[编者按]  相似文献   
15.
16.
Aqueous yttria-stabilized zirconia slurry was cast on a substrate to form wet coatings. Both weight loss and thickness reduction were measured, during the drying process. Lateral drying was observed by in situ monitoring of the coating surface. The drying kinetics were classified as an initial constant rate period (CRP), followed by a falling rate period (FRP). Thickness reduction occurred in the CRP stage, and was uneven across the coating because of lateral flow. As tensile stresses developed within the coating because of the constrained volume shrinkage, crack formation and propagation occurred in the FRP stage and affected the drying rate.  相似文献   
17.
简要介绍了推力矢量控制技术的概念,分析了推力矢量控制的基本原理及特点.在简要分析其技术发展历程的基础上,给出了导弹推力矢量技术的现状和发展趋势.  相似文献   
18.
In this research, Ni/SiO2 catalyst was modified with different amount of Gd2O3 and characterized with temperature-programmed desorption of CO2 (CO2-TPD) and NH3 (NH3-TPD), temperature-programmed reduction with H2 (H2-TPR) and X-ray diffraction (XRD). It was found that Gd2O3-modified Ni/SiO2 catalysts possessed higher CO2 adsorption and activation ability due to the formation of surface carbonate species. H2-TPR and XRD characterizations found that the strong interaction among nickel, Gd2O3 and SiO2 took place, which improved the dispersion of Ni. Gd2O3-modified Ni/SiO2 catalysts exhibited higher activity and stability for the combined oxy-CO2 reforming of methane in fluidized-bed reactor. The H2/CO ratio in produced syngas could be controlled via controlling reaction temperature and CO2/O2 ratio in feed.  相似文献   
19.
This article proposes a novel parallel, hardware-oriented deadlock detection algorithm for multiprocessor system-on-chips. The proposed algorithm takes full advantage of hardware parallelism in computation and maintains information needed by deadlock detection through classifying all resource allocation events and performing class specific operations, which together make the overall run-time complexity of the new method O(1). We implement the proposed algorithm in Verilog HDL and demonstrate in the simulation that each algorithm invocation takes at most four clock cycles in hardware.  相似文献   
20.
Hydrothermal Synthesis of Magnesium Aluminate Platelets   总被引:1,自引:0,他引:1  
Magnesium aluminate (MgAl2O4) platelets were first synthesized by hydrothermal treatment of γ-AlO(OH) in a magnesium nitrate aqueous solution at 400°C. The platelets are 100–200 nm in width and 25 nm in thickness. The influence of temperature, the anions of the magnesium salt, the amount of magnesium salt, and precursor pH on the formation of such structure was investigated. The experimental results indicated that the anions of the magnesium salt and precursor pH could have a significant influence on the growth of MgAl2O4. MgAl2O4 formation followed the in situ transformation mechanism, which was the reason why the MgAl2O4 crystallites had a platelet morphology.  相似文献   
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