| 1. |
- Xu, Tao, et al.
(författare)
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Epidemiology of Unintentional Injuries Among Children Under Six Years Old in Floating and Residential Population in Four Communities in Beijing : A Comparative Study
- 2014
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Ingår i: Maternal and Child Health Journal. - : Springer Science and Business Media LLC. - 1092-7875 .- 1573-6628. ; 18:4, s. 911-919
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Tidskriftsartikel (refereegranskat)abstract
- To explore and compare the epidemiological characteristics of non-fatal unintentional injury among children in floating and residential population. Using a structured survey, quantitative data were collected on a total of 352 floating and 201 residential families. Some potential influencing factors were questioned, such as socio-demographic characteristics, injury-related family environment, knowledge, attitude and behavior, and child's character. The self-reported incidence of non-fatal unintentional injuries was 11.9 % in the floating group and 12.9 % in the residential group. Unintentional injuries were more serious and caused more disease burden in floating children than residential children, with the average medical cost being over ten times in the floating group than in the residential group. Results of multiple regression analysis showed that children living in floating families have more risk of unintentional injuries than those children in residential families. Older children and children with extroverted character were more vulnerable to unintentional injuries. Risky family environment was also an important risk factor of unintentional injuries. Better household economic status and having more siblings appeared to reduce the probability of unintentional injuries among children. Floating children are more vulnerable to unintentional injuries comparing with residential children. These findings can be used as preliminary data supporting intervention strategies and activities to promote safe living environment and decrease injury incidence among floating children.
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| 2. |
- Gu, Limin, et al.
(författare)
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Case Studies on the Use of Technology in TPD (Teacher Professional Development)
- 2012
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Ingår i: US-China Education Review. A. - : David Publishing Company. - 2161-623X .- 1548-6613 .- 1930-1529. ; 2:3, s. 278-290
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the progress of a three-year cooperative project investigating the current state of TPD (teacher professional development) in Sweden and China in the area of TPD and ICT (information and communication technologies) is summarized. A brief introduction to the field of TPD is given, and thereafter, ICT is related to what in the project is referred to as TETPD (Technology Enhanced Teacher Professional Development). Thereafter, the project as such is given a short presentation, followed by findings regarding policies and initiatives related to TETPD in Sweden and China for investigating the current state of TETPD in each country respectively. The framework for investigating TETPD is presented, and four Chinese and four Swedish cases are compared to some facets showing differences in models for TETPD in the two countries.
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| 3. |
- Li, Qiang, et al.
(författare)
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Experimental Demonstration of Plasmon Propagation, Coupling, and Splitting in Silver Nanowire at 1550-nm Wavelength
- 2011
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 17:4, s. 1107-1111
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate silver-nanowire-based plasmonic devices including the nanowaveguide, the nanocoupler, and the nanosplitter at optical communication wavelength of 1550 nm. The plasmon propagation loss in a 300-nm diameter silver nanowire is measured to be 0.3 dB/mu m and the effective propagation length is 14.5 mu m. This loss is comparatively lower than that at 980 nm. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nanocouplers, and nanosplitters, are realized. For the nanocoupler, the experimental results show that the plasmonic modes can be efficiently coupled between two closely positioned nanowires. While for the nanosplitter, the plasmonic mode is split with a power ratio of 2.6:1. These demonstrations experimentally prove the feasibility of extending the operating wavelength of silver-nanowire-based plasmonic devices to current optical communication wavelength with a lower loss, which are thus important steps for potentially utilizing low-loss nanowire-based plasmonic components for photonic integrated circuits.
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| 4. |
- Li, Qiang, et al.
(författare)
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Experimental demonstration of plasmon propagation, coupling, and splitting in silver nanowire at 1550-nm wavelength
- 2011
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : IEEE. - 1077-260X .- 1558-4542. ; 17:4, s. 1107-1111
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate silver-nanowire-based plasmonic devices including the nanowaveguide, the nanocoupler, and the nanosplitter at optical communication wavelength of 1550 nm. The plasmon propagation loss in a 300-nm diameter silver nanowire is measured to be 0.3 dB/μm and the effective propagation length is 14.5 μm. This loss is comparatively lower than that at 980 nm. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nanocouplers, and nanosplitters, are realized. For the nanocoupler, the experimental results show that the plasmonic modes can be efficiently coupled between two closely positioned nanowires. While for the nanosplitter, the plasmonic mode is split with a power ratio of 2.6:1. These demonstrations experimentally prove the feasibility of extending the operating wavelength of silver-nanowire-based plasmonic devices to current optical communication wavelength with a lower loss, which are thus important steps for potentially utilizing low-loss nanowire-based plasmonic components for photonic integrated circuits.
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| 5. |
- Li, Qiang, et al.
(författare)
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Silver nanowire based plasmon propagation, coupling and splitting at 1.55 mu m wavelength
- 2011
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 7986
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate silver nanowire based plasmonic devices at optical communication wavelength 1.55 mu m. The plasmon propagation loss in a 300 nm diameter silver nanowire is measured to be 0.3 dB/mu m. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nano-couplers and nano-splitters, are realized.
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| 9. |
- Zhang, Yan, et al.
(författare)
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A General Coupling-Based Model Framework for Wideband MIMO Channels
- 2012
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 60:2, s. 574-586
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Tidskriftsartikel (refereegranskat)abstract
- A general coupling-based model framework for wideband multiple-input multiple-output (MIMO) channels is presented in this paper. Under this framework, the channel state information (CSI) tensor can be expressed by the product of a coupling tensor, a complex Gaussian tensor and three unitary matrices. The unitary matrices can be either eigenbases or steering matrices in different domains. The coupling tensor reflects the relationship between the column vectors of these unitary matrices. The complex Gaussian tensor is used to describe the small-scale fading. Several realizations of this framework are introduced, including the wideband Kronecker-based (WKB) model, the wideband eigenvalue-decomposition-based (WEB) model, the wideband virtual presentation (WVP) model and the wideband hybrid (WHY) model. To evaluate the performance of these models, channel measurements were carried out in different indoor scenarios both at Tsinghua University and Lund University. The results show that these models have good agreement with the measured data. Furthermore, we can see that the WHY model can provide a tradeoff between complexity and accuracy in channel synthesis.
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