在CMUH质子疗法设施的混凝土-铁-混凝土三明治结构墙上对屏蔽和激活水平的研究

Controlled nuclear fission reactions are used to generate electricity. Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons has six components: nuclear fuel consisting of fissionable material, a nuclear moderator, a neutron source, control rods, reactor coolant, and a shield and containment system.
Nuclear Fuels
Nuclear fuel consists of a fissile isotope, such as uranium-235, which must be present in sufficient quantity to provide a...

Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...

Composite masonry walls combine multiple wythes of the same or different masonry materials to create a unified structure. These walls feature wythes that are bonded together either through mortar-filled collar joints, grouted spaces, or more commonly, with rigid metal ties and reinforcements, with the use of masonry header units being rare. Metal ties are preferred because they effectively minimize water penetration, as these walls primarily absorb moisture and then release it into the...

Cavity walls feature a hollow space between the outer and inner wythes, connected only by corrosion-resistant metal ties. When water seeps through the outer wythe, it descends within this cavity, intercepted by flashing and eventually exiting through weep holes. To enhance moisture resistance, the inner wythe's cavity side often receives damp-proofing, doubling as an air barrier. The cavity can also house insulation to mitigate heat transfer.
Maintaining a clean cavity during construction is...

Masonry curtain walls employ brick or stone veneers supported by the building's structure to form an external cladding system that is both aesthetically appealing and functional. These walls are erected through two principal techniques, first by traditional layering of masonry units and second by using prefabricated panels. Traditional construction relies on steel shelf angles attached to the spandrel beam for support, with high-bond mortars ensuring secure attachment of masonry veneer units.

Post-tensioned masonry walls use high-strength steel rods or flexible tendons to enhance the strength and efficiency of masonry structures. These elements are securely anchored to the foundation and extend vertically either within the cores of the masonry units or between the masonry wythes. The construction process involves building the wall with these tensioning elements in place and allowing the mortar to fully cure.
Following the curing process, the tensioning begins. Steel rods are...