产品样本应用文章
Carbon steels are by far the most frequently used steels. More than 85% of the steel produced in the US is carbon steel. These steels are classified by their carbon content. Table 1 shows the classification of carbon steels and some typical uses.
In the context of the present study, we have conducted chemical and lead isotope analyses on twelve ancient glass samples unearthed from Chu tombs in Changde City, Hunan Province. The results of the chemical analysis of these samples show that all samples are PbOeBaOeSiO2 glasses, thus indicating that they are all traditional ancient Chinese glasses. The chemical results also suggest that all Bi wares may either share a common source or were produced according to similar recipes. In turn, the eye beads are different from the Bi wares for their distinct chemical composition.
The Ding kilns were some of the most famous early kilns of medieval China, producing huge quantities of white and cream-white porcelains of outstanding technical and aesthetic quality. Since 1949 they have been excavated three times, in 1965, in 1987, and in 2009 respectively. In this latest study 69 white porcelain sherds from assured contexts and from the 2009 excavations were analyzed using laser ablation techniques (ICP-AES).
Stainless steels are a corrosion resistant family of iron alloys that have a minimum of 10.5% Chromium. Their corrosion resistance is largely due to the formation of a passive chromium (III) oxide (Cr2O3) layer, approximately 1 to 5 nanometers (nm) thick, on the surface of the steel. If this layer is damaged by cutting, scratching or abrasion, it will regenerate, provided sufficient oxygen is available. By contrast, Stainless steels have poor corrosion resistance in low oxygen environments since the oxide layer cannot be repaired quickly enough. In addition to chromium, Nickel, molybdenum and niobium are also alloyed to improve corrosion characteristics.
Lead-based paints have been used extensively for painting the interior and exterior surfaces of homes. These paints were applied to almost any surface; however, they were most commonly found on interior and exterior woodwork including: doors, window frames and windowsills, cupboards and interior moldings. Almost all of the homes constructed before 1970 contain some lead-based paint. Until 1950, some of these paints contained up to 50% lead (500,000 ppm) and by the late 1960s, paints containing more than 1% (10,000 ppm) were still being used.
