Mechanical properties,components and decay resistance of Populus davidiana bioincised by Coriolus versicolor

The experiment was conducted to improve the decay resistance of wood by increasing the wood preservatives uptake and penetration depth by bioincising with Coriolus versicolor.The mechanical properties of bioincised Populus davidiana sapwood were measured.The changes of wood components(lignin,cellulose and hemicellulose)were analyzed by FTIR.The staining treatment using potassium permanganate was to measure the preservatives uptake and penetration depth in wood specimens.The decay resistance of bioincised specimens impregnated with IPBC and CA was assessed against C.versicolor and Gloeophyllum trabeum using bioincised P.davidiana sapwood and untreated controls.The results showed that the mechanical properties of the bioincised specimens were changed with the incubation time and mass loss.The mechanical strength was decreased after 17 days compared to that of the specimens bioincised<13 days.The bioincised specimens demonstrated the deeper penetration depth than the un-bioincised specimens.It was significant correlation(P<0.01)between penetration depth and incubation time.The average value of the penetration depth of the bioincised specimens was deeper than the control groups by 158.7%.By FTIR analysis,the biodegradation ability of C.versicolor to decay cellulose and hemicellulose was weaker than that of lignin.The bioincising treatment significantly increased the wood uptake of IPBC and CA,and reached the maximum uptake value at 17 and 13 days,respectively.Summarily,the bioincising pretreatment can obviously improve the wood decay resistance against C.versicolor and G.trabeum following by introducing the IPBC and CA.

Experimental observation of multiple topological nodal structure in LaSb_(2)

Unconventional fermions in the immensely studied topological semimetals are the source for rich exotic topological properties.Here,using symmetry analysis and first-principles calculations,we propose the coexistence of multiple topological nodal structure in LaSb_(2),including topological nodal surfaces,nodal lines and in particular eightfold degenerate nodal points,which have been scarcely observed in a single material.Further,utilizing angle-resolved photoemission spectroscopy,we confirm the existence of nodal surfaces and eightfold degenerate nodal points in LaSb_(2).The intriguing multiple topological nodal structure might play a crucial role in giving rise to the large linear magnetoresistance.Our work renews the insights into the exotic topological phenomena in LaSb_(2).