A new method for determining the fractal dimension by STM at nanomeler scale has been proposed.Widerstrass- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed th...A new method for determining the fractal dimension by STM at nanomeler scale has been proposed.Widerstrass- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed that fractal dimen- sion obtained with this method generally outran the traditional yard method. The new method has been applied to the fractal dimension determination of the fractures of Ti3Al and Ti-24Al-11Nb alloys. The results show that the fractal dimension of Ti-24Al-11Nb alloy is higher than that of Ti3Al, and it varies with the crark extending orientation.展开更多
GaN powder of nanometer scale was prepared by metal organic chemical vapor deposition using diethylgallium azide as precursor. The resulting powder was characterized by XRD and TEM. It has been found that the particle...GaN powder of nanometer scale was prepared by metal organic chemical vapor deposition using diethylgallium azide as precursor. The resulting powder was characterized by XRD and TEM. It has been found that the particle size of the powder obtained is affected by the deposition temperature, and the fine crystals formed in temperature range 500 similar to 650 degrees C were hexagonal.展开更多
High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The...High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.展开更多
On-chip interconnect buses consume tens of percents of dynamic power in a nanometer scale integrated circuit and they will consume more power with the rapid scaling down of technology size and continuously rising cloc...On-chip interconnect buses consume tens of percents of dynamic power in a nanometer scale integrated circuit and they will consume more power with the rapid scaling down of technology size and continuously rising clock frequency, therefore it is meaningful to lower the interconnecting bus power in design. In this paper, a simple yet accurate interconnect parasitic capacitance model is presented first and then, based on this model, a novel interconnecting bus optimization method is proposed. Wire spacing is a process for spacing wires for minimum dynamic power, while wire ordering is a process that searches for wire orders that maximally enhance it. The method, i.e., combining wire spacing with wire ordering, focuses on bus dynamic power optimization with a consideration of bus performance requirements. The optimization method is verified based on various nanometer technology parameters, showing that with 50% slack of routing space, 25.71% and 32.65% of power can be saved on average by the proposed optimization method for a global bus and an intermediate bus, respectively, under a 65-nm technology node, compared with 21.78% and 27.68% of power saved on average by uniform spacing technology. The proposed method is especially suitable for computer-aided design of nanometer scale on-chip buses.展开更多
Owing to weak light-matter interactions in natural materials,it is difficult to dynamically tune and switch emission polariza-tion states of plasmonic emitters(or antennas)at nanometer scales.Here,by using a control l...Owing to weak light-matter interactions in natural materials,it is difficult to dynamically tune and switch emission polariza-tion states of plasmonic emitters(or antennas)at nanometer scales.Here,by using a control laser beam to induce a bubble(n=1.0)in water(n=1.333)to obtain a large index variation as high as|Δn|=0.333,the emission polarization of an ultra-small plasmonic emitter(~0.4λ^(2))is experimentally switched at nanometer scales.The plasmonic emitter consists of two orthogonal subwavelength metallic nanogroove antennas on a metal surface,and the separation of the two anten-nas is only s_(x)=120 nm.The emission polarization state of the plasmonic emitter is related to the phase difference between the emission light from the two antennas.Because of a large refractive index variation(|Δn|=0.333),the phase difference is greatly changed when a microbubble emerges in water under a low-intensity control laser.As a result,the emission polarization of the ultra-small plasmonic emitter is dynamically switched from an elliptical polarization state to a linear polarization state,and the change of the degree of linear polarization is as high asΔγ≈0.66.展开更多
文摘A new method for determining the fractal dimension by STM at nanomeler scale has been proposed.Widerstrass- Mandelbrot fractal curves were used to verify the accuracy and reliability. The Computer simulation showed that fractal dimen- sion obtained with this method generally outran the traditional yard method. The new method has been applied to the fractal dimension determination of the fractures of Ti3Al and Ti-24Al-11Nb alloys. The results show that the fractal dimension of Ti-24Al-11Nb alloy is higher than that of Ti3Al, and it varies with the crark extending orientation.
文摘GaN powder of nanometer scale was prepared by metal organic chemical vapor deposition using diethylgallium azide as precursor. The resulting powder was characterized by XRD and TEM. It has been found that the particle size of the powder obtained is affected by the deposition temperature, and the fine crystals formed in temperature range 500 similar to 650 degrees C were hexagonal.
文摘High performance Dynamic Light Scattering (DLS) has been used to determine the hydrodynamic di-ameters of CdSe nanocrystals as well as CdSe cluster molecules in a size range of 1 to 10 nm (Eichh鰂er et al., 2001). The method enables the determination of their particle size, including their ligand shells, in solution. The results are consistent with the blue shift of the absorption bands, as well as Transmission Electron Microscope (TEM) experiments. The sizes of the cluster molecules were estimated from space filling models constructed from the results of a single crystal X-ray structure determination. DLS gave comparable results for the size of both types of compound, indicating that it is potentially an important additional measurement technique to TEM, which uses harsh measurement conditions, and to powder X-ray diffraction, which is difficult to interpret below 5 nm.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60725415, 60971066, and 61006028)the National High-Tech Program of China (Grant Nos. 2009AA01Z258 and 2009AA01Z260)the National Key Lab Foundation,China (Grant No. ZHD200904)
文摘On-chip interconnect buses consume tens of percents of dynamic power in a nanometer scale integrated circuit and they will consume more power with the rapid scaling down of technology size and continuously rising clock frequency, therefore it is meaningful to lower the interconnecting bus power in design. In this paper, a simple yet accurate interconnect parasitic capacitance model is presented first and then, based on this model, a novel interconnecting bus optimization method is proposed. Wire spacing is a process for spacing wires for minimum dynamic power, while wire ordering is a process that searches for wire orders that maximally enhance it. The method, i.e., combining wire spacing with wire ordering, focuses on bus dynamic power optimization with a consideration of bus performance requirements. The optimization method is verified based on various nanometer technology parameters, showing that with 50% slack of routing space, 25.71% and 32.65% of power can be saved on average by the proposed optimization method for a global bus and an intermediate bus, respectively, under a 65-nm technology node, compared with 21.78% and 27.68% of power saved on average by uniform spacing technology. The proposed method is especially suitable for computer-aided design of nanometer scale on-chip buses.
基金supported by the National Key Research and Development Program of China(2018YFA0704401)the Beijing Natural Science Foundation(Z180015)the National Natural Science Foundation of China(61922002 and 91850103).
文摘Owing to weak light-matter interactions in natural materials,it is difficult to dynamically tune and switch emission polariza-tion states of plasmonic emitters(or antennas)at nanometer scales.Here,by using a control laser beam to induce a bubble(n=1.0)in water(n=1.333)to obtain a large index variation as high as|Δn|=0.333,the emission polarization of an ultra-small plasmonic emitter(~0.4λ^(2))is experimentally switched at nanometer scales.The plasmonic emitter consists of two orthogonal subwavelength metallic nanogroove antennas on a metal surface,and the separation of the two anten-nas is only s_(x)=120 nm.The emission polarization state of the plasmonic emitter is related to the phase difference between the emission light from the two antennas.Because of a large refractive index variation(|Δn|=0.333),the phase difference is greatly changed when a microbubble emerges in water under a low-intensity control laser.As a result,the emission polarization of the ultra-small plasmonic emitter is dynamically switched from an elliptical polarization state to a linear polarization state,and the change of the degree of linear polarization is as high asΔγ≈0.66.
