Lignin is one of the most important biomass resources. With the increasing consumption of petroleum resource, lignin transformation is of strategic significance and has attracted widely interest. As lignin is a random...Lignin is one of the most important biomass resources. With the increasing consumption of petroleum resource, lignin transformation is of strategic significance and has attracted widely interest. As lignin is a random construction of aromatic monomers, the degradation products are usually very complex, which limits the scaling application of lignin as feedstock for valuable chemicals. Thus, it is desperately desired to develop highly selective approach to lignin conversion. This review first gives a brief introduction to the structure of lignin, and then summarized the methods for selective transformation of lignin into phenols, aldehydes, carboxylic acids, alkanes and arenes. Finally, the challenges and opportunities of lignin selective transformation are discussed.展开更多
The transformation-induced plasticity(TRIP) effect and resistance characteristics to adiabatic shear failure at high strain rates of high-manganese steel were investigated by using scanning electron microscopy and ele...The transformation-induced plasticity(TRIP) effect and resistance characteristics to adiabatic shear failure at high strain rates of high-manganese steel were investigated by using scanning electron microscopy and electron backscattering diffraction. Results showed that the high-manganese steel exhibited excellent strain hardening effect and resistance to adiabatic shear failure because of the TRIP effect. The TRIP effect occurred during dynamic deformation and showed two distinct stages,namely,the smooth TRIP process before the formation of adiabatic shear band(ASB) and the inhibited TRIP process during further deformation. In the first stage,the martensitic transformation showed slight orientation dependence and weak variant selection,which promoted the TRIP effect. In the second stage,reverse martensitic transformation occurred. Adiabatic shear bands(ASBs) developed typical shear microtextures {111}<110>. In microtextures,two groups of fine grains are in a twin relationship and uniform distribution,which restrained the formation of holes and cracks within the ASBs and enhanced damage resistance after ASB formation.展开更多
基金supported by the National Natural Science Foundation of China (No. 21603235)National Key Research and Development Program of China (No. 2017YFA0403103)Chinese Academy of Sciences (No. QYZDY-SSW-SLH013)
文摘Lignin is one of the most important biomass resources. With the increasing consumption of petroleum resource, lignin transformation is of strategic significance and has attracted widely interest. As lignin is a random construction of aromatic monomers, the degradation products are usually very complex, which limits the scaling application of lignin as feedstock for valuable chemicals. Thus, it is desperately desired to develop highly selective approach to lignin conversion. This review first gives a brief introduction to the structure of lignin, and then summarized the methods for selective transformation of lignin into phenols, aldehydes, carboxylic acids, alkanes and arenes. Finally, the challenges and opportunities of lignin selective transformation are discussed.
基金financially supported by the National Natural Science Foundation of China (No.51271028)
文摘The transformation-induced plasticity(TRIP) effect and resistance characteristics to adiabatic shear failure at high strain rates of high-manganese steel were investigated by using scanning electron microscopy and electron backscattering diffraction. Results showed that the high-manganese steel exhibited excellent strain hardening effect and resistance to adiabatic shear failure because of the TRIP effect. The TRIP effect occurred during dynamic deformation and showed two distinct stages,namely,the smooth TRIP process before the formation of adiabatic shear band(ASB) and the inhibited TRIP process during further deformation. In the first stage,the martensitic transformation showed slight orientation dependence and weak variant selection,which promoted the TRIP effect. In the second stage,reverse martensitic transformation occurred. Adiabatic shear bands(ASBs) developed typical shear microtextures {111}<110>. In microtextures,two groups of fine grains are in a twin relationship and uniform distribution,which restrained the formation of holes and cracks within the ASBs and enhanced damage resistance after ASB formation.
