Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesi...Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesized by the “bottle around ship” methodology in this research by regulating the dissolution rate of Cu2O and the generation rate of metal-organic framework(MOF) materials. Cu2O@HKUST-1 was carbonized to form a Cu O@porous carbon(CuO@PC) composite material. CuO@PC was synthesized into a copper azide(CA) @PC composite energetic material through a gas-solid phase in-situ azidation reaction.CA is encapsulated in PC framework, which acts as a nanoscale Faraday cage, and its excellent electrical conductivity prevents electrostatic charges from accumulating on the energetic material’s surface. The CA@PC composite energetic material has a CA content of 89.6%, and its electrostatic safety is nearly 30times that of pure CA(1.47 mJ compared to 0.05 mJ). CA@PC delivers an outstanding balance of safety and energy density compared to similar materials.展开更多
The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as templat...The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as template.The sampled particles were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption measurement,X-ray diffraction(XRD),Energy dispersive X-Ray spectroscopy(EDX),Fourier transform infrared spectroscopy(FTIR),Thermogravimetric analysis and differential scanning calorimetry(TGA-DSC),etc.It is shown that the assynthesized hollow strontium carbonate pompons with the size of about 2μm consist of flake-like particles under the optimal reaction conditions.The formation mechanism of hollow strontium carbonate pompons was preliminarily explored.展开更多
The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capaci...The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.展开更多
In the presence of p-toluene sulfonic acid (TSA) as a dopant, polyaniline (PAni) nanofibers, (about 80～165 nm in diameter) were successfully synthesized with a chemical template-free method. It was found that the for...In the presence of p-toluene sulfonic acid (TSA) as a dopant, polyaniline (PAni) nanofibers, (about 80～165 nm in diameter) were successfully synthesized with a chemical template-free method. It was found that the formation probability, morphology, and diameter of the resulting PAni-TSA nanofibers were sensitive to the synthetic conditions,such as reaction temperature, the molar ratio of TSA to aniline, and the concentration of TSA in the polymerization media. The molecular structure was characterized by using the FT-IR, Raman spectra and X-ray diffraction, which shows that the main chain structure of PAni-TSA nanofibers was in agreement with that of granular PAni.展开更多
A modified Stober method has been developed which permits the controlled growth of spherical hollow spheres with diameters between 197 and 208 nanometers by consecutively cocondensed methyltrimethoxysilane and dimethy...A modified Stober method has been developed which permits the controlled growth of spherical hollow spheres with diameters between 197 and 208 nanometers by consecutively cocondensed methyltrimethoxysilane and dimethyldimethoxysilane monomers onto microemulsion of polydimethylsiloxane and subsequently removing the templated polydimethylsiloxane by exposure to solvents. Ammonia was used as a morphological catalyst. The morphology of the polymer spheres was demonstrated by transmission electron micrographs (TEM) and atomic force microscopy (AFM).展开更多
Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washin...Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.展开更多
PEDOT nanotubes were prepared by a template synthesis method. Based on our template, it was deduced that there are two successive processes in the formation of nanotubes. The first step is soakage of the porous templa...PEDOT nanotubes were prepared by a template synthesis method. Based on our template, it was deduced that there are two successive processes in the formation of nanotubes. The first step is soakage of the porous templates by a polymer solution, and the second step is adsorption of free charged cationic groups and doped PEDOT onto the template surface with negative charges. XRD results showed that well orientated PEDOT chains were formed during the synthesis, moreover the arrange conductivity of molecular chains strongly affect the structures of PEDOT nanotubes. The nanotubes were measured to be about 5.5-17.6 S/cm, which is higher than that of nanotube pellet due to the high contact resistance between the adjacent nanotubes.展开更多
In this paper,the application of Abaqus-based particle finite element method(PFEM)is extended from static to dynamic large deformation.The PFEM is based on periodic mesh regeneration with Delaunay triangulation to avo...In this paper,the application of Abaqus-based particle finite element method(PFEM)is extended from static to dynamic large deformation.The PFEM is based on periodic mesh regeneration with Delaunay triangulation to avoid mesh distortion.Additional mesh smoothing and boundary node smoothing techniques are incorporated to improve the mesh quality and solution accuracy.The field variables are mapped from the old to the new mesh using the closest point projection method to minimize the mapping error.The procedures of the proposed Abaqus-based dynamic PFEM(Abaqus-DPFEM)analysis and its implementation in Abaqus are detailed.The accuracy and robustness of the proposed approach are examined via four illustrative numerical examples.The numerical results show a satisfactory agreement with published results and further confirm the applicability of the Abaqus-DPFEM to solving dynamic large-deformation problems in geotechnical engineering.展开更多
基金the financial support by Postgraduate Research & Practice Innovation Program from Jiangsu Science and Technology Department under Grant number KYCX19_0320。
文摘Copper azide(CA), as a primary explosive with high energy density, has not been practically used so far because of its high electrostatic sensitivity. The Cu2O@HKUST-1 core-shell structure hybrid material was synthesized by the “bottle around ship” methodology in this research by regulating the dissolution rate of Cu2O and the generation rate of metal-organic framework(MOF) materials. Cu2O@HKUST-1 was carbonized to form a Cu O@porous carbon(CuO@PC) composite material. CuO@PC was synthesized into a copper azide(CA) @PC composite energetic material through a gas-solid phase in-situ azidation reaction.CA is encapsulated in PC framework, which acts as a nanoscale Faraday cage, and its excellent electrical conductivity prevents electrostatic charges from accumulating on the energetic material’s surface. The CA@PC composite energetic material has a CA content of 89.6%, and its electrostatic safety is nearly 30times that of pure CA(1.47 mJ compared to 0.05 mJ). CA@PC delivers an outstanding balance of safety and energy density compared to similar materials.
基金Funded by the National Natural Science Foundation of China(No.22002143)the Natural Science Foundation of Shanxi Province of China(No.201901D211223)the Postgraduate Students Scientific Research Project of North University of China(No.20201766)。
文摘The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate(SDBS)and polyvinyl pyrrolidone(PVP)work together as template.The sampled particles were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption measurement,X-ray diffraction(XRD),Energy dispersive X-Ray spectroscopy(EDX),Fourier transform infrared spectroscopy(FTIR),Thermogravimetric analysis and differential scanning calorimetry(TGA-DSC),etc.It is shown that the assynthesized hollow strontium carbonate pompons with the size of about 2μm consist of flake-like particles under the optimal reaction conditions.The formation mechanism of hollow strontium carbonate pompons was preliminarily explored.
文摘The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.
文摘In the presence of p-toluene sulfonic acid (TSA) as a dopant, polyaniline (PAni) nanofibers, (about 80～165 nm in diameter) were successfully synthesized with a chemical template-free method. It was found that the formation probability, morphology, and diameter of the resulting PAni-TSA nanofibers were sensitive to the synthetic conditions,such as reaction temperature, the molar ratio of TSA to aniline, and the concentration of TSA in the polymerization media. The molecular structure was characterized by using the FT-IR, Raman spectra and X-ray diffraction, which shows that the main chain structure of PAni-TSA nanofibers was in agreement with that of granular PAni.
基金support of the Key Laboratory of Advanced Textile Materials and Manufacturing Technology(Zhejiang Sci-Tech University),Ministry of Education(No.2005QN04)the National Natural Science Foundation of China(No.20573095)is gratefully acknowledged.
文摘A modified Stober method has been developed which permits the controlled growth of spherical hollow spheres with diameters between 197 and 208 nanometers by consecutively cocondensed methyltrimethoxysilane and dimethyldimethoxysilane monomers onto microemulsion of polydimethylsiloxane and subsequently removing the templated polydimethylsiloxane by exposure to solvents. Ammonia was used as a morphological catalyst. The morphology of the polymer spheres was demonstrated by transmission electron micrographs (TEM) and atomic force microscopy (AFM).
文摘Viscose fiber templates(15 cm×15 cm×1 cm)were put into ZrOCl_(2) solutions of different concentrations(1,2 and 3 mol·L^(-1))and impregnated at different temperatures(20,40 and 60℃)for 20 h.After washing,centrifugation and drying,ZrO_(2) fiber precursors were obtained.ZrO_(2) fibers were prepared by heat treatment of the precursors at different temperatures(600,800,1000 and 1200℃)for 2 h.The effects of the impregnation temperature,the impregnation solution concentration and the heat treatment temperature on the microstructure and the phase composition of the ZrO_(2) fibers were studied.The results show that with the increase of the impregnation temperature from 20℃to 60℃and the impregnation solution concentration increase from 1 mol·L^(-1) to 3 mol·L^(-1),the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr4+on viscose fiber templates.After heat treatment,ZrO_(2) fiber mainly exists in the form of monoclinic ZrO_(2).With the increase of the heat treatment temperature,the grains in ZrO_(2) fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.
基金Funded National Natural Science Foundation of China(No.: 60372002)
文摘PEDOT nanotubes were prepared by a template synthesis method. Based on our template, it was deduced that there are two successive processes in the formation of nanotubes. The first step is soakage of the porous templates by a polymer solution, and the second step is adsorption of free charged cationic groups and doped PEDOT onto the template surface with negative charges. XRD results showed that well orientated PEDOT chains were formed during the synthesis, moreover the arrange conductivity of molecular chains strongly affect the structures of PEDOT nanotubes. The nanotubes were measured to be about 5.5-17.6 S/cm, which is higher than that of nanotube pellet due to the high contact resistance between the adjacent nanotubes.
基金the National Natural Science Foundation of China(Grant No.41807223)the Fundamental Research Funds for the Central Universities(Grant No.B210202096)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA 23090202).
文摘In this paper,the application of Abaqus-based particle finite element method(PFEM)is extended from static to dynamic large deformation.The PFEM is based on periodic mesh regeneration with Delaunay triangulation to avoid mesh distortion.Additional mesh smoothing and boundary node smoothing techniques are incorporated to improve the mesh quality and solution accuracy.The field variables are mapped from the old to the new mesh using the closest point projection method to minimize the mapping error.The procedures of the proposed Abaqus-based dynamic PFEM(Abaqus-DPFEM)analysis and its implementation in Abaqus are detailed.The accuracy and robustness of the proposed approach are examined via four illustrative numerical examples.The numerical results show a satisfactory agreement with published results and further confirm the applicability of the Abaqus-DPFEM to solving dynamic large-deformation problems in geotechnical engineering.
