A collimator is a device used to transform the divergent light or other radiation from a point light source into a parallel beam, and also is an absorber device used to limit X-rays, gamma rays, or nuclear particle beams to the size and angular spread required for a specific application. Normally, special measurements in spectroscopy and geometric and physical optics require this kind of light collimation.

In recent years, photoelectrochemical (PEC) water splitting has attracted people's attention, and it is considered to have potential applications in solar energy conversion. The effectiveness of solar energy conversion mainly depends on the structure of the photoelectrode. In addition, nanostructured photoelectrodes and surface porosity have additional advantages in in improving the efficiency since they exhibit unique properties of light-harvesting, chemical stability, active surface area, and charge separation.

Many analytical and medical devices are using thorium tungsten wires as ion source. Why use thorium tungsten materials? What about tungsten or neodymium tungsten materials? 

Cemented carbide is a kind of composite material prepared with tungsten carbide (WC) powder, which is widely used in cutting tools, drilling, and other technical fields due to its high hardness, high wear resistance, high strength and good toughness. In recent years, nano tungsten carbide powder is more required than ever due to the development of nanocrystalline cemented carbide.