Insight into the structural evolution of porous and fractured media by forced aeration during heap leaching

Despite lots of techniques in improving the heap leaching performance,many constraints on the industrial applications remain.We proposed a correspondingly effective and new idea of introducing forced aeration to improve the bad permeability and leaching effect of Yangla Copper Mine(YCM)during heap leaching.The dual-media theory was employed to study the impact mechanism of forced aeration on the variations of porous and fractured media during the column leaching experiments.An X-Ray Computed Tomography(CT)set was utilized to perform the pore imaging of the specimens and the fracture morphology of the particles within the columns was analyzed by Scanning Electron Microscope(SEM)as aeration rate(AR)changed.The results show that there exists copious fine particles within the heap of YCM,the particle size distribution of which is not reasonable.The forced aeration can not only promote the development of the porous and fractured structures but effectively break the blocked seepage paths.Then the leaching degree is improved and the seepage performance of the solute within the solution is enhanced.Therefore,the forced aeration is probable of making the leaching performance greatly improved.

Micro-configuration Observation of Porous Bioceramic for Sliding on Intestinal Mucus Film

The microstructure of the prepared porous bioceramic material, including surface porosity and apparent contact area with the artificial mucus film are computed and analyzed. The surface micro-configurations of the porous material before and after sliding on the mucus film are observed in 2 D and 3 D by digital microsco py, We describe how much mucus enters and stays within different pares, and how the porous material with rough/ porous surface contacts with the mucus film （ elastic surfucel gel ） . The presented results illustrate that the material with different porous structure can lead to different mucus suction, surface scraping and changes of contact area and condition during sliding, which will be active for high friction of robotic endoscope with the intestinal wall for intestinal locomotion.

SURFACE-ENHANCED CANTILEVER SENSORS WITH NANO-POROUS FILMS

Developing surface-enhanced microcantilevers with improved sensitivities is of longstanding interest. In this paper, the design of surface-enhanced cantilever sensors using nano- （micro-） porous films as surface layers is proposed. The static deformation and resonance frequencies of these surface-enhanced sensors with the simultaneous effects of the eigenstrain, the surface stress and the adsorption mass are analyzed. It is shown that the sensitivities of these novel cantilever sensors for the static deformation and resonance frequencies can be tuned by the porosity, the size of the pores and the structure of the porous films. For the three kinds of cantilever consisting of solid films, films with aligned cylindrical micro-scale pores, and those with nano-scale pores, the nano-porous one has the highest static and dynamic sensitivities, whereas the solid one has the lowest.

Intrinsic Peroxidase-like Activity of Porous CuO Micro-/nanostructures with Clean Surface

Porous CuO micro-/nanostructures with clean surface,prepared through Cu_(2)(OH)_(2)CO_(3) precursor followed by calcination in air,were proven to be an effective peroxidase mimic.They can quickly catalyze oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of H_(2)O_(2),producing a blue color.The obtained porous CuO micro-/nanostructure have potential application in wastewater treatment.The apparent steady-state kinetic parameter was studied with TMB as the substrate.In addition,the potential application of the porous CuO in wastewater treatment was demonstrated with phenol-containing water as an example.Such investigation not only confirms the intrinsic peroxidase-like activity of micro-/nanostructured CuO,but also suggests its potential application in wastewater treatment.