ALBERT

Description: Porphyry Cu-Au type mineralization forms as a result of magmato-hydrothermal activity and involves the migration of hydrothermal fluids through rock fractures, a process that causes the precipitation of fracture-filling minerals with a volume that is much larger than the orebodies themselves. This means that the mineralization-related geochemical anomalies within the minerals that fill these fractures (i.e. fracture fills) can be used to identify areas prospective for deep-seated or otherwise concealed porphyry-type mineralization. This study focuses on the Shaxi deposit, a concealed porphyry Cu-Au deposit located in the Anhui Province, China, and uses singularity techniques to identify and extract geochemical anomalies associated with porphyry Cu-Au-related fracture fills. These data were used to examine the relationships between geochemical anomalies and known deep and concealed mineralization distinguished from unaltered and unmineralized wall-rock material using a concentration–volume (C–V) model in the study area. This analysis indicates that the geochemical anomalies identified in this study are associated with known areas of mineralization in the Shaxi deposit. Areas defined by fracture fills containing anomalous concentrations of Cu only effectively delineate known areas of shallower Cu mineralization, whereas areas with fracture fills containing anomalous concentrations of Au effectively delineate areas containing either Au mineralization and/or deep-seated Cu mineralization. Our study also identified several other targets that have not been explored in the peripheral areas of the Shaxi deposit, some of which should be considered high priority targets for future exploration for concealed orebodies. This indicates that combining singularity mapping with fracture fill geochemical analysis can effectively delineate geochemical anomalies associated with deep-seated or concealed porphyry-type mineralization, an approach that also may well be applicable to exploration for other types of magmato-hydrothermal or hydrothermal mineral deposits.

Description: Crystal defects of two synthesized diamonds doped with boron and phosphorus are compared by synchrotron radiation topography (SRT). The crystal defects in the specimen are mainly dislocations. The dislocations are assembled in bundles in the cone-shape and distributed in the directions approximately towards to and . The Burgers vectors of most of the dislocations are parallel to [202] and oblique to the dislocations, showing that the dislocations are of mixed type. The features of the crystal defects are quite different in several aspects compared with the diamonds without phosphorous doping. The ionic radius of phosphorous is 118.75 percent larger than that of carbon and intensive distortion may occur near the phosphorous ions. The dislocations thus originated in bundles to release the stress caused by the phosphorous doping.

Description: 〈p〉Designing topological and geometrical structures with extended unnatural parameters (negative, near-zero, ultrahigh, or tunable) and counterintuitive properties is a big challenge in the field of metamaterials, especially for relatively unexplored materials with multiphysics coupling effects. For natural piezoelectric ceramics, only five nonzero elements in the piezoelectric matrix exist, which has impeded the design and application of piezoelectric devices for decades. Here, we introduce a methodology, inspired by quasi-symmetry breaking, realizing artificial anisotropy by metamaterial design to excite all the nonzero elements in contrast to zero values in natural materials. By elaborately programming topological structures and geometrical dimensions of the unit elements, we demonstrate, theoretically and experimentally, that tunable nonzero or ultrahigh values of overall effective piezoelectric coefficients can be obtained. While this work focuses on generating piezoelectric parameters of ceramics, the design principle should be inspirational to create unnatural apparent properties of other multiphysics coupling metamaterials.〈/p〉