It is too difficult for a compacted specimen of unsaturated clay prepared and used in a laboratory test to have homogeneous water content and porosity. Although there have been many hydraulic and mechanical studies, t...It is too difficult for a compacted specimen of unsaturated clay prepared and used in a laboratory test to have homogeneous water content and porosity. Although there have been many hydraulic and mechanical studies, there are few papers related to homogeneity of specimen. However, it is clear that homogeneity of specimen influences mechanical properties. In this paper, the use of micro-waves is proposed as method for making homogeneous specimens. The study results indicate that specimens made by micro-waves are more homogeneous than compacted specimens.展开更多
GaAs-based polarization modulators （PolMs） exhibit the unique characteristic of simultaneous intensity and complementary phase modulation owing to the linear electro-optic （LEO） effect determined by crystallograph...GaAs-based polarization modulators （PolMs） exhibit the unique characteristic of simultaneous intensity and complementary phase modulation owing to the linear electro-optic （LEO） effect determined by crystallographic orientations of the device. In this paper, we reviewed the principle of operation, the design and fabrication flows of a GaAs-based PolM. Analytical models are established, from which the features of a PolM are derived and discussed in detail. The recent advances in PolM-based multifunctional systems, in particular the PolM-based optoelectronic oscillator （OEO） are demonstrated with an emphasis on the remarkable development of applications for frequency conversion, tunable microwave photonic filter （MPF）, optical frequency comb （OFC）, arbitrary waveform generation （AWG） and beamforming. Challenges in practical implementation of the PolM-based systems and their promising future are discussed as well.展开更多
It is not difficult to predict that wireless data traffic will continue to grow and new cellular systems are to be built to provide higher data rates.Thus,for 5G(fifth generation)cellular systems,various approaches ar...It is not difficult to predict that wireless data traffic will continue to grow and new cellular systems are to be built to provide higher data rates.Thus,for 5G(fifth generation)cellular systems,various approaches are studied including millimeter-wave(mm-wave)communications and HetNets(Heterogeneous Networks)with small cells.In mm-wave bands,since a much wider bandwidth is available,higher data rates can be achieved.However,mm-wave transmissions suffer from blockage.In order to take advantage of a wide bandwidth in mm-wave bands with mitigating the blockage problem,A HetNet consisting of micro-wave Base Stations(BSs)for macro cells and mm-wave BSs for small cells were consider and its energy efficiency in terms of the communication range of mm-wave BSs were studied.It is shown that the optimal communication range of mm-wave BSs can improve the energy efficiency.展开更多
文摘It is too difficult for a compacted specimen of unsaturated clay prepared and used in a laboratory test to have homogeneous water content and porosity. Although there have been many hydraulic and mechanical studies, there are few papers related to homogeneity of specimen. However, it is clear that homogeneity of specimen influences mechanical properties. In this paper, the use of micro-waves is proposed as method for making homogeneous specimens. The study results indicate that specimens made by micro-waves are more homogeneous than compacted specimens.
基金Acknowledgements This work was supported in part by the National Basic Research Program of China （No. 2012CB315705）, the National Natural Science Foundation of China （Grant Nos. 61422108 and 61527820）, Fundamental Research Funds for the Central Universities （Nos. NP2015404, NE2012002） and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘GaAs-based polarization modulators （PolMs） exhibit the unique characteristic of simultaneous intensity and complementary phase modulation owing to the linear electro-optic （LEO） effect determined by crystallographic orientations of the device. In this paper, we reviewed the principle of operation, the design and fabrication flows of a GaAs-based PolM. Analytical models are established, from which the features of a PolM are derived and discussed in detail. The recent advances in PolM-based multifunctional systems, in particular the PolM-based optoelectronic oscillator （OEO） are demonstrated with an emphasis on the remarkable development of applications for frequency conversion, tunable microwave photonic filter （MPF）, optical frequency comb （OFC）, arbitrary waveform generation （AWG） and beamforming. Challenges in practical implementation of the PolM-based systems and their promising future are discussed as well.
基金supported by The National Research Foundation of Korea(No.NRF-2014R1A1A2A16051720)The National Natural Science Foundation of China(No.91338106,No.61571025,No.61201189,No.61231011,No.61231013).
文摘It is not difficult to predict that wireless data traffic will continue to grow and new cellular systems are to be built to provide higher data rates.Thus,for 5G(fifth generation)cellular systems,various approaches are studied including millimeter-wave(mm-wave)communications and HetNets(Heterogeneous Networks)with small cells.In mm-wave bands,since a much wider bandwidth is available,higher data rates can be achieved.However,mm-wave transmissions suffer from blockage.In order to take advantage of a wide bandwidth in mm-wave bands with mitigating the blockage problem,A HetNet consisting of micro-wave Base Stations(BSs)for macro cells and mm-wave BSs for small cells were consider and its energy efficiency in terms of the communication range of mm-wave BSs were studied.It is shown that the optimal communication range of mm-wave BSs can improve the energy efficiency.
