Dense arrays of Fe-Cr alloy clusters with different Cr ratios were fabricated by gas-phase cluster beam deposition. The complex multiphase structure and various coupling effects in the cluster arrays were studied. A l...Dense arrays of Fe-Cr alloy clusters with different Cr ratios were fabricated by gas-phase cluster beam deposition. The complex multiphase structure and various coupling effects in the cluster arrays were studied. A lattice mismatched tetragonal-like morphology of the Fe-Cr alloy cluster was observed at large Cr ratio. An exchange bias effect was observed and was shown to be dependent on the proportion of the Cr components in the alloy. With the increase of the Cr composition, the exchange bias field became smaller and stronger dipolar interactions between the clusters developed. Residual coercivity and magnetization, which were more remarkable in the tetragonal-like clusters, were observed above the ferromagnetic-superparamagnetic transition temperature. The experimental results of the coercive field and the bias field at different temperatures demonstrated that the tetragonal-like clusters had better thermal stability and greater anisotropy.展开更多
The fast growth of Internet has cre-ated the need for high-speed switches. Re-cently, the crosspoint-queue switch has at-tracted attention because of its scalability and high performance. However, the Cross-point-Queu...The fast growth of Internet has cre-ated the need for high-speed switches. Re-cently, the crosspoint-queue switch has at-tracted attention because of its scalability and high performance. However, the Cross-point-Queue switch does not perform well under non-uniform traffic. To overcome this limitation, the Load-Balanced Cross-point-Queued switch architecture has been proposed. In this architecture, a load-balance stage is placed ahead of the Cross-point-Queued stage. The load-balance stage transforms the incoming non-uniform traffic into nearly uniform traffic at the input port of the second stage. To avoid out-of-order cells, this stage employs flow-based queues in each crosspoint buffer. Analysis and simulation results reveal that under non-uniform traffic, this new switch architecture achieves a delay performance similar to that of the Out-put-Queued switch without the need for inter- nal acceleration. In addition, its throughput is much better than that of the pure cross- point-queued switch. Finally, it can achieve the same packet loss rate as the cross- point-queue switch, while using a buffer size that is only 65% of that used by the cross- point-queue switch.展开更多
Water-dispersed CdSe/Bi2Se3 core/shell QDs with a photothermal conversion coefficient of 27.09% have been synthesized by a cation exchange reaction. The microstructure and crystal structure of the QDs, which were conf...Water-dispersed CdSe/Bi2Se3 core/shell QDs with a photothermal conversion coefficient of 27.09% have been synthesized by a cation exchange reaction. The microstructure and crystal structure of the QDs, which were confirmed by TEM and XRD, showed that partial cation exchange occurred inside the CdSe QDs. Two main mechanisms are responsible for the excellent photothermal conversion： inhibition of radiative recombination of carriers due to the formation of type-II semiconductor heterostructures, and the large surface-to-volume ratio of the QDs. Photothermal conversion experiments indicated that the CdSe/Bi2Se3 QDs showed high photothermal conversion efficiency and excellent NIR photostability.展开更多
基金supported by the National Natural Science Foundation of China(No.11627806 and No.61301015)the Priority Academic Programme Development of Jiangsu Higher Education Institutions
文摘Dense arrays of Fe-Cr alloy clusters with different Cr ratios were fabricated by gas-phase cluster beam deposition. The complex multiphase structure and various coupling effects in the cluster arrays were studied. A lattice mismatched tetragonal-like morphology of the Fe-Cr alloy cluster was observed at large Cr ratio. An exchange bias effect was observed and was shown to be dependent on the proportion of the Cr components in the alloy. With the increase of the Cr composition, the exchange bias field became smaller and stronger dipolar interactions between the clusters developed. Residual coercivity and magnetization, which were more remarkable in the tetragonal-like clusters, were observed above the ferromagnetic-superparamagnetic transition temperature. The experimental results of the coercive field and the bias field at different temperatures demonstrated that the tetragonal-like clusters had better thermal stability and greater anisotropy.
文摘The fast growth of Internet has cre-ated the need for high-speed switches. Re-cently, the crosspoint-queue switch has at-tracted attention because of its scalability and high performance. However, the Cross-point-Queue switch does not perform well under non-uniform traffic. To overcome this limitation, the Load-Balanced Cross-point-Queued switch architecture has been proposed. In this architecture, a load-balance stage is placed ahead of the Cross-point-Queued stage. The load-balance stage transforms the incoming non-uniform traffic into nearly uniform traffic at the input port of the second stage. To avoid out-of-order cells, this stage employs flow-based queues in each crosspoint buffer. Analysis and simulation results reveal that under non-uniform traffic, this new switch architecture achieves a delay performance similar to that of the Out-put-Queued switch without the need for inter- nal acceleration. In addition, its throughput is much better than that of the pure cross- point-queued switch. Finally, it can achieve the same packet loss rate as the cross- point-queue switch, while using a buffer size that is only 65% of that used by the cross- point-queue switch.
基金This work has been partly supported by the National Basic Research Program of China （973 Program） No. 2011CB922204-2, and the National Natural Science Foundation of China （Nos. 11434010, 11147024, 11247025, 11304306, 11374002, and 61290303）.
文摘Water-dispersed CdSe/Bi2Se3 core/shell QDs with a photothermal conversion coefficient of 27.09% have been synthesized by a cation exchange reaction. The microstructure and crystal structure of the QDs, which were confirmed by TEM and XRD, showed that partial cation exchange occurred inside the CdSe QDs. Two main mechanisms are responsible for the excellent photothermal conversion： inhibition of radiative recombination of carriers due to the formation of type-II semiconductor heterostructures, and the large surface-to-volume ratio of the QDs. Photothermal conversion experiments indicated that the CdSe/Bi2Se3 QDs showed high photothermal conversion efficiency and excellent NIR photostability.
