In order to reduce economic and life losses due to terrorism or accidental explosion threats, reinforced concrete （RC） slabs of buildings need to he designed or retrofitted to resist blast loading. In this paper the...In order to reduce economic and life losses due to terrorism or accidental explosion threats, reinforced concrete （RC） slabs of buildings need to he designed or retrofitted to resist blast loading. In this paper the dynamic behavior of RC slabs under blast loading and its influencing factors are studied. The numerical model of an RC slab subjected to blast loading is established using the explicit dynamic analysis software. Both the strain rate effect and the damage accumulation are taken into account in the material model. The dynamic responses of the RC slab subjected to blast loading are analyzed, and the influence of concrete strength, thickness and reinforcement ratio on the behavior of the RC slab under blast loading is numerically investigated. Based on the numerical results, some principles for blast-resistant design and retrofitting are proposed to improve the behavior of the RC slab subjected to blast loading.展开更多
Based on the anti-jamming performance of differential frequency hopping （DFH） systems in Additive White Gaussian Noise （AWGN） channel, Fountain code is introduced to the DFH systems as the outer error correcting c...Based on the anti-jamming performance of differential frequency hopping （DFH） systems in Additive White Gaussian Noise （AWGN） channel, Fountain code is introduced to the DFH systems as the outer error correcting code in this paper to investigate the improvements against partial-band jamming over AWGN channel. The performance of Fountain coded DFH is theoretically analyzed and numerically simulated. The total frequency of hopping in the simulation is 16, and results show that, on one hand, when exact jamming state information （JSI） is available, and the number of jamming frequency is n= 16, the bit error rate （BER） of 10~3 is achieved with the signal to interference ratio （SIR） approximately 7.5 dB over AWGN channel, and the performance improves about 1-1.5dB compared with the no-coded system. When the number of jamming frequency is n=2, the performance increases 15-17dB. On the other hand, when JSI is unavailable, a joint JSI estimation and decoding algorithm is proposed. The BER of 10 3 is achieved with jamming-frequency n 16, SIR=8dB and signal noise ratio （SNR） 10dB over AWGN channel. It＇s proved that this algorithm provides robust anti-jamming pertbrmance even without JSI. The anti-jamming performance of Fountain coded DFH systems is obviously superior to no-coded DFH systems.展开更多
Plasmonic encoding composed of metallic nanostructures makes a great contribution to the practical application of information encryption.However,most reports have so far shown the preparation of single or binary plasm...Plasmonic encoding composed of metallic nanostructures makes a great contribution to the practical application of information encryption.However,most reports have so far shown the preparation of single or binary plasmonic encoding patterns because of the technical difficulty of assembling multiplex nanostructures on a single platform,which cannot satisfy the requirements of high encoding capacity for increasing information security.Herein,we developed a strategy based on plasma etching combined with in-situ growth to fabricate patterned arrays of quasi-three-dimensional(3-D)plasmonic Au nano-mushrooms with controlled morphologies,and successfully realized ideal high-capacity plasmonic encoding by arranging Au nano-mushrooms on one platform.On this basis,such multiplex encoding patterns have been transferred to the flexible substrate to realize the triple-mode encryption of the Morse code of"FUNSOM",indicating great prospects in the applications of information encryption and data storage.展开更多
基金Supported by National Natural Science Foundation of China (No. 50638030)National Key Technologies R&D Program of China (No. 2006BAJ13B02).
文摘In order to reduce economic and life losses due to terrorism or accidental explosion threats, reinforced concrete （RC） slabs of buildings need to he designed or retrofitted to resist blast loading. In this paper the dynamic behavior of RC slabs under blast loading and its influencing factors are studied. The numerical model of an RC slab subjected to blast loading is established using the explicit dynamic analysis software. Both the strain rate effect and the damage accumulation are taken into account in the material model. The dynamic responses of the RC slab subjected to blast loading are analyzed, and the influence of concrete strength, thickness and reinforcement ratio on the behavior of the RC slab under blast loading is numerically investigated. Based on the numerical results, some principles for blast-resistant design and retrofitting are proposed to improve the behavior of the RC slab subjected to blast loading.
基金the National Natural Science Foundation of China under Grant 61371125
文摘Based on the anti-jamming performance of differential frequency hopping （DFH） systems in Additive White Gaussian Noise （AWGN） channel, Fountain code is introduced to the DFH systems as the outer error correcting code in this paper to investigate the improvements against partial-band jamming over AWGN channel. The performance of Fountain coded DFH is theoretically analyzed and numerically simulated. The total frequency of hopping in the simulation is 16, and results show that, on one hand, when exact jamming state information （JSI） is available, and the number of jamming frequency is n= 16, the bit error rate （BER） of 10~3 is achieved with the signal to interference ratio （SIR） approximately 7.5 dB over AWGN channel, and the performance improves about 1-1.5dB compared with the no-coded system. When the number of jamming frequency is n=2, the performance increases 15-17dB. On the other hand, when JSI is unavailable, a joint JSI estimation and decoding algorithm is proposed. The BER of 10 3 is achieved with jamming-frequency n 16, SIR=8dB and signal noise ratio （SNR） 10dB over AWGN channel. It＇s proved that this algorithm provides robust anti-jamming pertbrmance even without JSI. The anti-jamming performance of Fountain coded DFH systems is obviously superior to no-coded DFH systems.
基金supported by the National Natural Science Foundation of China(21822202,22072104)the National Key R&D Program of China(International Collaboration program)granted by Chinese Ministry of Science and Technology(2018YFE0200700)+1 种基金project funded by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 Project,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Plasmonic encoding composed of metallic nanostructures makes a great contribution to the practical application of information encryption.However,most reports have so far shown the preparation of single or binary plasmonic encoding patterns because of the technical difficulty of assembling multiplex nanostructures on a single platform,which cannot satisfy the requirements of high encoding capacity for increasing information security.Herein,we developed a strategy based on plasma etching combined with in-situ growth to fabricate patterned arrays of quasi-three-dimensional(3-D)plasmonic Au nano-mushrooms with controlled morphologies,and successfully realized ideal high-capacity plasmonic encoding by arranging Au nano-mushrooms on one platform.On this basis,such multiplex encoding patterns have been transferred to the flexible substrate to realize the triple-mode encryption of the Morse code of"FUNSOM",indicating great prospects in the applications of information encryption and data storage.
