
Tungsten alloy needle shield is an injection instrument used in medicine to monitor drug efficacy by isotope tracer method. It has high density, good hardness, which can bear weariness, corrosion-resistant. It has good screening ability to all kinds of ray, which provides people with protection from radiation. Isotopic tracer method is a microanalysis method using radionuclides as tracers to mark the study objects. By using the nuclear physics properties of radioactive isotopes which give out characteristic rays continuously, the nuclear…