Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved signifi...Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.展开更多
Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration. In this paper we propose using rigid constraints described in different coordina...Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration. In this paper we propose using rigid constraints described in different coordinate frames to iteratively estimate structural and camera pose parameters. Using geometric properties of reflected correspondences we put forward a new concept, the reflected pole of a rigid transformation. The reflected pole represents a general analysis of transformations that can be applied to both 2D and 3D transformations. We demonstrate how the concept is applied to calibration by proposing an iterative method to estimate the structural parameters of objects. The method is based on a coarse-to-fine strategy in which initial estimation is obtained through a classical linear algorithm which is then refined by iteration. For a comparative study of performance, we also implemented an extended motion estimation algorithm (from 2D-2D to 3D-2D case) based on epipolar geometry.展开更多
A multimode interference refractive index （KI） sensor based on the coreless fiber was numerically and experimentally demonstrated. Two identical single mode fibers （SMF） are spliced at both ends of a section of th...A multimode interference refractive index （KI） sensor based on the coreless fiber was numerically and experimentally demonstrated. Two identical single mode fibers （SMF） are spliced at both ends of a section of the coreless fiber which can he considered as the equivalent weakly guiding multimode fiber （MMF） with a step-index profile when the surrounding refractive index （SKI） is lower than that of the coreless fiber. Thus, it becomes the conventional single-mode multimode single-mode （SMS） fiber structure but with a larger core size. The output spectra will shift along with the changes in the SKI owing to the direct exposure of the coreless fiber. The output spectra under different SKIs were numerically studied, as well as the sensitivities with different lengths and diameters of the coreless fiber. The predication and calculation showed the good agreement with the experimental results. The proposed RI sensor proved to be feasible by verification experiments, and the relative error was merely 0.1% which occupied preferable sensing performance and practicability.展开更多
Employing unsymmetrical 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,2′-bipyridine as mixed ligands, a new low-dimensional coordination polymer [Zn(MMTA) 2 (2,2′-bipy)] n (MMTA = 2-mercapto-5-methyl-1,3,4-thiadiazole...Employing unsymmetrical 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,2′-bipyridine as mixed ligands, a new low-dimensional coordination polymer [Zn(MMTA) 2 (2,2′-bipy)] n (MMTA = 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,2′-bipy = 2,2′-bipyridine), has been synthesized under solvothermal condition and characterized by single crystal X-ray diffraction. This compound crys- tallizes in the noncentrosymmetric space group Cc, with cell parameters: a = 8.291(4) , b = 15.483(9) , c = 15.620(6) , = 96.00(5)°, V = 1994.1(2) 3 , and Z = 4. The mixed ligands link the zinc center into a mononuclear unit, which is futher linked by weak C-H···N and C-H···S hydrogen bonds into a three-dimensional noncentrosymmetric framework. The compound exhibits intense photoluminescence and distinct NLO properties at room temperature. The intensity of the green light produced by the powder sample of the compound is about 3.2 times that produced by KDP powder. On the basis of the results of TG analysis, the structure is thermally stable up to ～260 °C.展开更多
Conventional carbon materials cannot combine high density and high porosity,which are required in many applications,typically for energy storage under a limited space.A novel highly dense yet porous carbon has previou...Conventional carbon materials cannot combine high density and high porosity,which are required in many applications,typically for energy storage under a limited space.A novel highly dense yet porous carbon has previously been produced from a three-dimensional(3D)reduced graphene oxide(r-GO)hydrogel by evaporation-induced drying.Here the mechanism of such a network shrinkage in r-GO hydrogel is specifically illustrated by the use of water and 1,4-dioxane,which have a sole difference in surface tension.As a result,the surface tension of the evaporating solvent determines the capillary forces in the nanochannels,which causes shrinkage of the r-GO network.More promisingly,the selection of a solvent with a known surface tension can precisely tune the microstructure associated with the density and porosity of the resulting porous carbon,rendering the porous carbon materials great potential in practical devices with high volumetric performance.展开更多
A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n ...A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n - 1）-dimensional invariant surface called carrying simplex E as a globe attractor, hence the long term dynamics of the system is com- pletely determined by the dynamics on E. For the three-dimensional system, the whole dynamical behavior was presented. It has a unique positive equilibrium point and any limit set is either an equilibrium point or a limit cycle. The system is permanent and it is proved that the number of periodic orbits is finite and non-periodic oscillation the May Leonard phenomenon does not exist. A criterion for the positive equilibrium to be globally asymptotically stable is provided. Whether there exist limit cycles or not remains open.展开更多
基金This project is supported by Natural Science Foundation of College of Jiangsu Province , China (02KJA540001)
文摘Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.
文摘Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration. In this paper we propose using rigid constraints described in different coordinate frames to iteratively estimate structural and camera pose parameters. Using geometric properties of reflected correspondences we put forward a new concept, the reflected pole of a rigid transformation. The reflected pole represents a general analysis of transformations that can be applied to both 2D and 3D transformations. We demonstrate how the concept is applied to calibration by proposing an iterative method to estimate the structural parameters of objects. The method is based on a coarse-to-fine strategy in which initial estimation is obtained through a classical linear algorithm which is then refined by iteration. For a comparative study of performance, we also implemented an extended motion estimation algorithm (from 2D-2D to 3D-2D case) based on epipolar geometry.
文摘A multimode interference refractive index （KI） sensor based on the coreless fiber was numerically and experimentally demonstrated. Two identical single mode fibers （SMF） are spliced at both ends of a section of the coreless fiber which can he considered as the equivalent weakly guiding multimode fiber （MMF） with a step-index profile when the surrounding refractive index （SKI） is lower than that of the coreless fiber. Thus, it becomes the conventional single-mode multimode single-mode （SMS） fiber structure but with a larger core size. The output spectra will shift along with the changes in the SKI owing to the direct exposure of the coreless fiber. The output spectra under different SKIs were numerically studied, as well as the sensitivities with different lengths and diameters of the coreless fiber. The predication and calculation showed the good agreement with the experimental results. The proposed RI sensor proved to be feasible by verification experiments, and the relative error was merely 0.1% which occupied preferable sensing performance and practicability.
基金supported by the National Natural Science Foundation of China (20701023 & 51102138)the Natural Science Foundation of Shandong Province, China (BS2010NJ004 &2009ZRB019KH)
文摘Employing unsymmetrical 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,2′-bipyridine as mixed ligands, a new low-dimensional coordination polymer [Zn(MMTA) 2 (2,2′-bipy)] n (MMTA = 2-mercapto-5-methyl-1,3,4-thiadiazole, 2,2′-bipy = 2,2′-bipyridine), has been synthesized under solvothermal condition and characterized by single crystal X-ray diffraction. This compound crys- tallizes in the noncentrosymmetric space group Cc, with cell parameters: a = 8.291(4) , b = 15.483(9) , c = 15.620(6) , = 96.00(5)°, V = 1994.1(2) 3 , and Z = 4. The mixed ligands link the zinc center into a mononuclear unit, which is futher linked by weak C-H···N and C-H···S hydrogen bonds into a three-dimensional noncentrosymmetric framework. The compound exhibits intense photoluminescence and distinct NLO properties at room temperature. The intensity of the green light produced by the powder sample of the compound is about 3.2 times that produced by KDP powder. On the basis of the results of TG analysis, the structure is thermally stable up to ～260 °C.
基金This work was supported by the National Natural Science Fund for the Distinguished Young Scholars,China(51525204)the National Natural Science Foundation of China(51702229 and 51872195)the CAS Key Laboratory of Carbon Materials(KLCM KFJJ1704).
文摘Conventional carbon materials cannot combine high density and high porosity,which are required in many applications,typically for energy storage under a limited space.A novel highly dense yet porous carbon has previously been produced from a three-dimensional(3D)reduced graphene oxide(r-GO)hydrogel by evaporation-induced drying.Here the mechanism of such a network shrinkage in r-GO hydrogel is specifically illustrated by the use of water and 1,4-dioxane,which have a sole difference in surface tension.As a result,the surface tension of the evaporating solvent determines the capillary forces in the nanochannels,which causes shrinkage of the r-GO network.More promisingly,the selection of a solvent with a known surface tension can precisely tune the microstructure associated with the density and porosity of the resulting porous carbon,rendering the porous carbon materials great potential in practical devices with high volumetric performance.
文摘A competitive system on the n-rectangle： {x ∈ Rn： 0 ≤ xi ≤ li, i = 1,... ,n} was con- sidered, each species of which, in isolation, admits logistic growth with the hyperbolic structure saturation. It has an （n - 1）-dimensional invariant surface called carrying simplex E as a globe attractor, hence the long term dynamics of the system is com- pletely determined by the dynamics on E. For the three-dimensional system, the whole dynamical behavior was presented. It has a unique positive equilibrium point and any limit set is either an equilibrium point or a limit cycle. The system is permanent and it is proved that the number of periodic orbits is finite and non-periodic oscillation the May Leonard phenomenon does not exist. A criterion for the positive equilibrium to be globally asymptotically stable is provided. Whether there exist limit cycles or not remains open.
