Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement...Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement factor as functions of diameter and refractive index of inclusions are investigated, more than 10 times that of incident beam is obtained in the simulation. We model the etched crack in close proximity to a real structure, which is characterized by AFM. We find that the peak light intensity of the crack is a function of its cross sectional breadth depth ratio, providing good hints for the effective processing of fused silica samples to improve the damage threshold.展开更多
For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the c...For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the calculations of point defect properties of TiAl alloy with this potentials,it was shown that the thermal concentration of antisite defects was higher than that of other point defects.With similar formation energies,five possible interstitial configurations were stable.This model was consistent with the embedded atom method or embedded defect method and adequate for simulation of defects in TiAl alloy.展开更多
This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels s...This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels specified for different strata would be qualified for constructing the 110 m diaphragm wall with high efficiency and precision given that the quality of slurry and poured concrete can be guaranteed. The ground settlement can be effectively controlled by using the overlapping construction method. Sliding failure as a whole characterized by pronounced lateral deformation is likely to occur in the upper muddy clay layer due to its high compressibility and sensitivity. In contrast, local collapse of trench walls tends to happen in the sandy silt strata. Furthermore, careful attention should be paid to sandy silt during the entire construction period as the vertical displacement of the sandy silt continues to develop even atter concrete pouring.展开更多
The electrochemical growth of nanowires in nuclear track membranes has been studied and a strong plasma absorption of copper nanowires in the visible region of the electromagnetic spectrum is observed.The result of th...The electrochemical growth of nanowires in nuclear track membranes has been studied and a strong plasma absorption of copper nanowires in the visible region of the electromagnetic spectrum is observed.The result of the plasma absorption is qualitatively in agreement with the prediction of the appropriate formulation of effective medium theory.展开更多
The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction tec...The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction techniques. The complex of formula Nd(pipdtc)4N(CH3)4 crystallizes in the monoclinic space group P21/n with the following lattice parameters, a = 22.685(2), b = 20.332(2), c = 17.1270(10)Å, β = 100.570(10)o, Z = 8. The calculated density is 1.47g/cm3. A new derivative method is used to remove the post-edge absorption background including the multielectron excitation effect. The EXAFS results demonstrate that there are about eight S and four O atoms around Nd with the Nd-S bond length of 2.916Å and the Nd-O bond length of 2.415Å, respectively. This implies that the powder of this complex is not stable and is easy to oxidize in air. The possible change of structure before and after oxidation is discussed.展开更多
Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energ...Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energy from 10eV to 600eV by Monte Carlo methods. The ion-implanted mechanism called the subplantation （for C, N, O, W, Y, etc.） is confirmed. Obvious thermal effect could be induced by the subplantation of the incident ions. Further, the subplantation of C ions is proved by in situ reflection high energy electron diffraction （RHEED）. The observation from an atomic force microscope （AFM） indicates that the initial implantation of C ions might result in the final primitive-cell-like morphology of the smooth film （in an area of 1.2 mm× 0.9 mm, rms roughness smaller than 20 nm by Wyko）.展开更多
文摘Light intensity distribution in the vicinity of inclusions and etched cracks in polished fused silica at wavelength scale are simulated by using the finite-difference time-domain algorithm. Light intensity enhancement factor as functions of diameter and refractive index of inclusions are investigated, more than 10 times that of incident beam is obtained in the simulation. We model the etched crack in close proximity to a real structure, which is characterized by AFM. We find that the peak light intensity of the crack is a function of its cross sectional breadth depth ratio, providing good hints for the effective processing of fused silica samples to improve the damage threshold.
基金Supported by the National Natural Science Foundation of China under Grant No.59895150.
文摘For intermetallic compound TiAl,the interatomic potentials in the Finnis-Sinclair model were constructed by empirically fitting to the properties of L10 TiAl tetragonal phase and the pressure-volume relations.In the calculations of point defect properties of TiAl alloy with this potentials,it was shown that the thermal concentration of antisite defects was higher than that of other point defects.With similar formation energies,five possible interstitial configurations were stable.This model was consistent with the embedded atom method or embedded defect method and adequate for simulation of defects in TiAl alloy.
基金Funded by the National Basic Research Program of China(973 Program,No.2014CB046905)the National Natural Science Foundation of China(Grant Nos.41172249 and 51509186)+1 种基金the State Key Laboratory for Geomechanics and Deep Underground Engineering(No.SKLGDUEK1303)the funding provided by Zhuhai Da Heng Qin Company Limited(Grant No.SG25-2014-173B1)
文摘This paper presents a case study on an ultra-deep diaphragm wall with a depth of 110 m constructed in Ningbo City. The in-situ application shows that using Bauer BC40 cutter machine in conjunction with cutter wheels specified for different strata would be qualified for constructing the 110 m diaphragm wall with high efficiency and precision given that the quality of slurry and poured concrete can be guaranteed. The ground settlement can be effectively controlled by using the overlapping construction method. Sliding failure as a whole characterized by pronounced lateral deformation is likely to occur in the upper muddy clay layer due to its high compressibility and sensitivity. In contrast, local collapse of trench walls tends to happen in the sandy silt strata. Furthermore, careful attention should be paid to sandy silt during the entire construction period as the vertical displacement of the sandy silt continues to develop even atter concrete pouring.
基金Supported by the open laboratory of nuclear analysis technique of Chinese Academy of Sciencesin part by the 95 key project of Chinese Academy of Sciences.
文摘The electrochemical growth of nanowires in nuclear track membranes has been studied and a strong plasma absorption of copper nanowires in the visible region of the electromagnetic spectrum is observed.The result of the plasma absorption is qualitatively in agreement with the prediction of the appropriate formulation of effective medium theory.
基金the Foundations of the Chinese Academy of Sciences and the Chinese Ministry of Education for returned scholars back from abroad,the Doctoral Program Foundation of Higher Education in China under Grant No.95968the Postdoctoral Foundation of Chinese Academy of Sciences.
文摘The atomic structure of a novel rare earth complex consisting of Nd and the sulfur-containing ligand pipdtc (C5H10NCS-2) has been studied with extended x-ray absorption fine structure (EXAFS} and x-ray diffraction techniques. The complex of formula Nd(pipdtc)4N(CH3)4 crystallizes in the monoclinic space group P21/n with the following lattice parameters, a = 22.685(2), b = 20.332(2), c = 17.1270(10)Å, β = 100.570(10)o, Z = 8. The calculated density is 1.47g/cm3. A new derivative method is used to remove the post-edge absorption background including the multielectron excitation effect. The EXAFS results demonstrate that there are about eight S and four O atoms around Nd with the Nd-S bond length of 2.916Å and the Nd-O bond length of 2.415Å, respectively. This implies that the powder of this complex is not stable and is easy to oxidize in air. The possible change of structure before and after oxidation is discussed.
基金Supported by the Science Foundation of China Academy of Engineering Physics under Grant No 2005Z0805, and China Postdoctoral Science Foundation （No 20090451424）.
文摘Due to the local densification, high-energy C and doped ions can greatly affect the bonding configurations of diamond-like carbon films. We investigate the corresponding affection of different incident ions with energy from 10eV to 600eV by Monte Carlo methods. The ion-implanted mechanism called the subplantation （for C, N, O, W, Y, etc.） is confirmed. Obvious thermal effect could be induced by the subplantation of the incident ions. Further, the subplantation of C ions is proved by in situ reflection high energy electron diffraction （RHEED）. The observation from an atomic force microscope （AFM） indicates that the initial implantation of C ions might result in the final primitive-cell-like morphology of the smooth film （in an area of 1.2 mm× 0.9 mm, rms roughness smaller than 20 nm by Wyko）.
