The kilogram is the only SI base unit that is still defined by a material object – a piece of platinum-iridium alloy kept in a vault in Sèvres, near Paris. All the other units are related to atomic or ...

The prototype kilogram – to which all scales are calibrated to – is losing weight. International efforts are striving to redefine the base unit for measuring mass and, in future, redefine the kilogram ...

Polysilicon prices dropped across the board as of 8 May, according to the latest report from metals market research company Shanghai Metals Market. The average price of mono recharging chips was ...

On April 12, the Silicon Industry Branch announced the latest solar-grade polysilicon prices, which were between RMB190-200/kg on average, with the lowest price set at RMB180/kg (US$26.2/kg). Among ...

GAITHERSBURG, MD. — Forty feet underground, secured in a temperature- and humidity-controlled vault here, lies Kilogram No. 20. It’s an espresso-shot-sized, platinum-iridium cylinder that is the ...

Researchers are a step closer to redefining the kilogram, thanks to the creation of the purest chunk of crystalline silicon-28 yet made. Today's standard kilogram is defined by a chunk of ...

The China Nonferrous Metals Industry Association (CNMIA) said that prices for monocrystalline silicon ranged from CNY 222 ($32.30)/kg to CNY 248/kg last week, up 31.37% from the middle of January.

The number of atoms in this silicon sphere is known given or taken 20 atoms each 10^9. The atom distance was measured by the X-ray interferometer on the left. Disclaimer: AAAS and EurekAlert! are not ...

In addition to other scientific units, the kilogram also is now defined by a natural constant. This is made possible by single crystals grown from highly enriched silicon-28. In addition to Ampere, ...