![]() Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide. Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gases by chemical vapor deposition (CVD). Much more recently (hundreds to tens of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites. Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle, although a few have come from as deep as 800 kilometres (500 mi). Most natural diamonds have ages between 1 billion and 3.5 billion years. Diamond also has a very high refractive index and a relatively high optical dispersion. Small numbers of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange, or red. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.īecause the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. ![]() ![]() Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Transparent to subtransparent to translucentĭiamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Less often blue, green, black, translucent white, pink, violet, orange, purple, and red. Many economists, including those at Citi, expect the growth target to match last year's at "around 5%", anticipating more policy steps to stabilize the housing market and increase liquidity.Īnalysts widely expect (Chinese premier) Li to reveal a relatively ambitious growth target of "around 5%", showing that policymakers are still focused on economic growth.Ĭhina is expected to promote its plan to achieve "new productive forces" for 2024 in the coming two sessions meetings, which will begin in early March.Typically yellow, brown, or gray to colorless. Here are some excerpts from news media coverage on the sessions:Ĭhina's parliament, the National People's Congress (NPC), will kick off its annual session on Tuesday, with all eyes on plans to support growth in the world's second largest economy. ![]() Lou Qinjian, spokesman for the second session of the 14th National People's Congress, announced on Monday the agenda of the congress and answered questions from the media. The ongoing China's annual two sessions are being closely watched by global media outlets as the meetings share how will China keep its economic growth momentum in 2024. Journalists work at a press conference of the second session of the 14th National People's Congress at the Great Hall of the People in Beijing, on March 4, 2024.
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