| 摘要 |
A cloud of solid particles at an elevated location wherein the cloud 100 comprises at least 1,000 tonnes of solid particles over a region of at least 1,000 square kilometres. The cloud may comprise at least 10,000 tonnes of particles and the area covered may be more than 300,000 square kilometres. Substantially all the particles may be titanium dioxide, sodium chloride silicon or mixtures thereof and the particles may be of sub-micron size. The particles may be coated with hydrophobic materials which comprise siloxanes |
