The surface deformation after fully mechanized back filling mining was analyzed.The surface deformation for different backfill materials was predicted by an equivalent mining height model and numerical simulations.The...The surface deformation after fully mechanized back filling mining was analyzed.The surface deformation for different backfill materials was predicted by an equivalent mining height model and numerical simulations.The results suggest that:(1) As the elastic modulus,E,of the backfill material increases the surface subsidence decreases.The rate of subsidence decrease drops after E is larger than 5 GPa;(2) Fully mechanized back fill mining technology can effectively control surface deformation.The resulting surface deformation is within the specification grade I,which means surface maintenance is not needed.A site survey showed that the equivalent mining height model is capable of predicting and analyzing surface deformation and that the model is conservative enough for engineering safety.Finally,the significance of establishing a complete error correction system based on error analysis and correction is discussed.展开更多
A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladd...A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladding fiber,the hollow D-section is coated with gold film and then injected in a high thermo-optic coefficient liquid to realize the high temperature sensitivity for the fiber SPR temperature sensor.The numerical simulation results show that the peaking loss of the D-shaped hole double-cladding fiber SPR is hugely influenced by the distance between the D-shaped hole and fiber core and by the thickness of the gold film,but the temperature sensitivity is almost insensitive to the above parameters.When the thermo-optic coefficient is -2.8×10^(-4)∕℃,the thickness of the gold film is 47 nm,and the distance between the D-shaped hole and fiber core is 5μm,the temperature sensitivity of the D-shaped hole fiber SPR sensor can reach to -3.635 nm∕℃.展开更多
基金provided by the National Natural Science Foundation of China (Nos. 51074165 and 50834004)
文摘The surface deformation after fully mechanized back filling mining was analyzed.The surface deformation for different backfill materials was predicted by an equivalent mining height model and numerical simulations.The results suggest that:(1) As the elastic modulus,E,of the backfill material increases the surface subsidence decreases.The rate of subsidence decrease drops after E is larger than 5 GPa;(2) Fully mechanized back fill mining technology can effectively control surface deformation.The resulting surface deformation is within the specification grade I,which means surface maintenance is not needed.A site survey showed that the equivalent mining height model is capable of predicting and analyzing surface deformation and that the model is conservative enough for engineering safety.Finally,the significance of establishing a complete error correction system based on error analysis and correction is discussed.
基金National Natural Science Foundation of China(NSFC)(61525501)
文摘A high sensitivity D-shaped hole double-cladding fiber temperature sensor based on surface plasmon resonance(SPR)is designed and investigated by a full-vector finite element method.Within the D-shaped hole doublecladding fiber,the hollow D-section is coated with gold film and then injected in a high thermo-optic coefficient liquid to realize the high temperature sensitivity for the fiber SPR temperature sensor.The numerical simulation results show that the peaking loss of the D-shaped hole double-cladding fiber SPR is hugely influenced by the distance between the D-shaped hole and fiber core and by the thickness of the gold film,but the temperature sensitivity is almost insensitive to the above parameters.When the thermo-optic coefficient is -2.8×10^(-4)∕℃,the thickness of the gold film is 47 nm,and the distance between the D-shaped hole and fiber core is 5μm,the temperature sensitivity of the D-shaped hole fiber SPR sensor can reach to -3.635 nm∕℃.
