The weak dielectric properties and the lack of magnetic loss of manganese-based absorbers are obstructed as the new generation of electromagnetic wave absorption(EMA)materials applying in microelectronic devices.Herei...The weak dielectric properties and the lack of magnetic loss of manganese-based absorbers are obstructed as the new generation of electromagnetic wave absorption(EMA)materials applying in microelectronic devices.Herein,the sulfuration and subsequent compounding strategies have been employed to enhance the EMA performance of multi-shell nanosphere-shaped Mn_(2)O_(3)materials.With the narrow bandgap,the as-obtained MnS possesses reinforced electrical conductivity,which is conducive to conductivity loss.More importantly,the presence of potential difference between different phases will form space charge region at the heterogeneous interface,thus favoring interfacial polarization.Additionally,the improvement of magnetic loss is attributed to the presence of Co_(3)O_(4)nanoparticles.Consequently,the composites present enhanced EMA performance than original Mn_(2)O_(3).Specifically,the minimum reflection loss of as-prepared composites is−51.4 dB at the thickness of 1.8 mm and the broad effective absorption bandwidth reaches 6.2 GHz at 1.9 mm.The low matching thickness and high absorption efficiency in this work can provide a convincing reference when designing distinguished manganese-based absorbers.展开更多
Herein,we successfully prepare highly dispersed and uniform small nano-size nickel nanoparticles embedded on core-shell carbon spheres by confined-deposition method.The mesoporous silica layer containing surfactant co...Herein,we successfully prepare highly dispersed and uniform small nano-size nickel nanoparticles embedded on core-shell carbon spheres by confined-deposition method.The mesoporous silica layer containing surfactant coated on the surface of the polymer sphere provides confined space and effectively controls the growth of nickel nanoparticles during pyrolysis.At the same time,the introduction of nickel species has an impact on structure of the obtained carbon spheres,and it can promote the deposition of carbon to realize the adjustment from hollow to core-shell and then to solid spheres.Owing to the uniform distribution of Ni nanoparticles with small size,mesoporous structure,N-doping groups,high specified surface areas,and core-shell structure,the obtained catalyst shows exciting ability for the production of CO by reduction of CO_(2)with a maximum CO Faradaic efficiency of 98%,indicating its promising prospect in electro-reduction of CO_(2).展开更多
设计了一种在FPGA中实现色彩空间转换的简易方法。先通过左移位将转换矩阵中的小数系数转换成整数,然后用Verilog HDL例化9个加法器和9个常系数乘法器并行流水实现色彩空间转换,最终通过右移位得到正确数值。并以RGB转YC b C r422为例,...设计了一种在FPGA中实现色彩空间转换的简易方法。先通过左移位将转换矩阵中的小数系数转换成整数,然后用Verilog HDL例化9个加法器和9个常系数乘法器并行流水实现色彩空间转换,最终通过右移位得到正确数值。并以RGB转YC b C r422为例,利用Modelsim进行仿真,并在Xilinx FPGA硬件平台上得到了验证。展开更多
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘The weak dielectric properties and the lack of magnetic loss of manganese-based absorbers are obstructed as the new generation of electromagnetic wave absorption(EMA)materials applying in microelectronic devices.Herein,the sulfuration and subsequent compounding strategies have been employed to enhance the EMA performance of multi-shell nanosphere-shaped Mn_(2)O_(3)materials.With the narrow bandgap,the as-obtained MnS possesses reinforced electrical conductivity,which is conducive to conductivity loss.More importantly,the presence of potential difference between different phases will form space charge region at the heterogeneous interface,thus favoring interfacial polarization.Additionally,the improvement of magnetic loss is attributed to the presence of Co_(3)O_(4)nanoparticles.Consequently,the composites present enhanced EMA performance than original Mn_(2)O_(3).Specifically,the minimum reflection loss of as-prepared composites is−51.4 dB at the thickness of 1.8 mm and the broad effective absorption bandwidth reaches 6.2 GHz at 1.9 mm.The low matching thickness and high absorption efficiency in this work can provide a convincing reference when designing distinguished manganese-based absorbers.
基金financially supported by the Natural Science Foundation of Hebei(Nos.B02020208088,H2020206514 and B2021208074)S&T Program of Hebei(Nos.20544401D,20314401D,206Z4406G,21314402D,22344402D,22373709D,22284601Z and 21344601D)Tianjin Science and Technology Project(No.19YFSLQY00070)。
文摘Herein,we successfully prepare highly dispersed and uniform small nano-size nickel nanoparticles embedded on core-shell carbon spheres by confined-deposition method.The mesoporous silica layer containing surfactant coated on the surface of the polymer sphere provides confined space and effectively controls the growth of nickel nanoparticles during pyrolysis.At the same time,the introduction of nickel species has an impact on structure of the obtained carbon spheres,and it can promote the deposition of carbon to realize the adjustment from hollow to core-shell and then to solid spheres.Owing to the uniform distribution of Ni nanoparticles with small size,mesoporous structure,N-doping groups,high specified surface areas,and core-shell structure,the obtained catalyst shows exciting ability for the production of CO by reduction of CO_(2)with a maximum CO Faradaic efficiency of 98%,indicating its promising prospect in electro-reduction of CO_(2).
文摘设计了一种在FPGA中实现色彩空间转换的简易方法。先通过左移位将转换矩阵中的小数系数转换成整数,然后用Verilog HDL例化9个加法器和9个常系数乘法器并行流水实现色彩空间转换,最终通过右移位得到正确数值。并以RGB转YC b C r422为例,利用Modelsim进行仿真,并在Xilinx FPGA硬件平台上得到了验证。
