Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambi...Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.展开更多
The culture of mammalian cells is closely related to the development of biotechnology, which has been used extensively in the research and application fields of biology and medical science. In this article, various fa...The culture of mammalian cells is closely related to the development of biotechnology, which has been used extensively in the research and application fields of biology and medical science. In this article, various factors affecting cell cultivation and the application of microcarrier and bioreactor on large-scale culture of mammalian ceils were reviewed.展开更多
The morphologies at the initial stages of thin film growth were studied by using Kinetic Monte Carlo techniques.A more efficient model was used to calculate the activity energy.The model involves incident atom attachm...The morphologies at the initial stages of thin film growth were studied by using Kinetic Monte Carlo techniques.A more efficient model was used to calculate the activity energy.The model involves incident atom attachment,diffusion,detachment from the surface,detached atom returning,and dimer diffusion.We edited a set of software of the model and simulated the surface morphologies by the principle of computer graphics.It is shown that the nucleuses formed at the initial stages and the surface morphologies at high temperatures are very different from those at low temperatures.The later surface growth depends on the nucleuses at the initial stages.The mechanism results from the atom thermal movement,the temperature determines the diffusion ability,and the deposition rate determines the diffusion time.展开更多
基金supported partially by the 973 Program under the Grant 2012CB316100
文摘Large-scale array aided beamforming improves the spectral efficiency(SE) as a benefit of high angular resolution.When dual-beam downlink beamforming is applied to the train moving towards cell edge,the inter-beam ambiguity(IBA) increases as the directional difference between beams becomes smaller.An adaptive antenna activation based beamforming scheme was proposed to mitigate IBA.In the district near the base station(BS),all antenna elements(AEs) were activated to generate two beams.As the distance from the train to the BS increased,only the minimum number of AEs satisfying the resolution criterion would be activated.At the cell edge,one beam was switched off due to intolerable IBA.The proposed scheme can achieve SE gain to the non-adaptive scheme and show more robustness against the direction-of-arrival(DOA) estimation error.
基金Supported by Post-doctoral Fund of China(20070410923)Youth Science Fund of Heilongjiang(QC06C014)+1 种基金Post-doctoral Fund of HeilongjiangDoctoral Fund of Northeast Agricultural University
文摘The culture of mammalian cells is closely related to the development of biotechnology, which has been used extensively in the research and application fields of biology and medical science. In this article, various factors affecting cell cultivation and the application of microcarrier and bioreactor on large-scale culture of mammalian ceils were reviewed.
基金Supported by the National Natural Science Foundation of China(Grant No.10574059)the Natural Science Foundation of Gansu Province(GrantNo.3ZSO42-B25-033)the Postdoctoral Foundation of Lanzhou University and Qinglan Talent Engineering Funds of Lanzhou Jiaotong University
文摘The morphologies at the initial stages of thin film growth were studied by using Kinetic Monte Carlo techniques.A more efficient model was used to calculate the activity energy.The model involves incident atom attachment,diffusion,detachment from the surface,detached atom returning,and dimer diffusion.We edited a set of software of the model and simulated the surface morphologies by the principle of computer graphics.It is shown that the nucleuses formed at the initial stages and the surface morphologies at high temperatures are very different from those at low temperatures.The later surface growth depends on the nucleuses at the initial stages.The mechanism results from the atom thermal movement,the temperature determines the diffusion ability,and the deposition rate determines the diffusion time.
