The secrecy performance of cooperation with an untrusted relay under a quasi-static fading channel is analyzed in this paper. An achievable secrecy rate is provided and the influence of selfish behavior of untrusted r...The secrecy performance of cooperation with an untrusted relay under a quasi-static fading channel is analyzed in this paper. An achievable secrecy rate is provided and the influence of selfish behavior of untrusted relay is analyzed. Furthermore, the secrecy performance of the scheme is discussed and compared with that of the case where the relay is just an eavesdropper. Simulation results show that the untrusted relay's cooperation in the fading case reduces the outage probability from 1/2 to 1/3 and achieves a higher outage secrecy capacity.展开更多
Deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. In the present research, generation reliability is considered, and a method for its assessment is pr...Deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. In the present research, generation reliability is considered, and a method for its assessment is proposed using game theory and NN (neural networks). Also, due to the stochastic behavior of power markets and generators' forced outages, MCS (monte carlo simulation) is used for reliability evaluation. Generation reliability merely focuses on the interaction between generation complex and load. Therefore, in the research, based on the behavior of players in the market and using game theory, two outcomes are considered: cooperation and non-cooperation. The proposed method is assessed on IEEE-Reliability Test System with satisfactory results. LOLE (loss of load expectation) is used as the reliability index and it will be shown that generation reliability in cooperation market is better than non-cooperation outcome.展开更多
Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickne...Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickness of the synthesized nanocomposite films ranged from 50 to 70 lam, having well-dispersed MWCNTs. Increasing the AEPTES concentration from 0.0196 to 0.0300 M, increased the amine content and the dispersion of MWCNTs. The film synthesized at 0.0300 M AETPES exhibited the greatest degree of dispersion among the three samples, which is consistent with a self-assembled silane group interacting with the MWCNT surface.展开更多
Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R & D (research & development) expenditure and various core technologies, and...Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R & D (research & development) expenditure and various core technologies, and therefore, international research collaboration is necessary for prompt and efficient development. The study is aimed at establishing a knowledge base that can help to prepare international research collaboration policies for solving global challenges effectively. The authors demonstrate the research capacity and international research collaboration in solar cell and fuel cell technologies, using global research network diagrams gathered from 35,322 and 33,136 academic papers, respectively. The diagrams include the data of research competency and co-authorship. More than 6,000 institutions and 100 countries are involved in each field. Based on the diagrams, the technologies are compared and international collaboration is analyzed. A valley of research collaboration in Asia is identified for both technologies. Then, science and education policies that influence the structures are discussed.展开更多
A high performance polymer solar cells(PSCs) based on polymer donor PM6 containing fluorinated thienyl benzodithiophene unit and n-type organic semiconductor acceptor IT-4 F containing fluorinated end-groups were deve...A high performance polymer solar cells(PSCs) based on polymer donor PM6 containing fluorinated thienyl benzodithiophene unit and n-type organic semiconductor acceptor IT-4 F containing fluorinated end-groups were developed. In addition to complementary absorption spectra(300–830 nm) with IT-4 F, the PM6 also has a deep HOMO(the highest occupied molecular) level(-5.50 e V), which will lower the open-circuit voltage(V_(oc)) sacrifice and reduce the E_(loss) of the IT-4 F-based PSCs. Moreover, the strong crystallinity of PM6 is beneficial to form favorable blend morphology and hence to suppress recombination. As a result, in comparison with the PSCs based on a non-fluorinated D/A pair of PBDB-T:ITIC with a medium PCE of 11.2%, the PM6:IT-4 Fbased PSCs yielded an impressive PCE of 13.5% due to the synergistic effect of fluorination on both donor and acceptor, which is among the highest values recorded in the literatures for PSCs to date. Furthermore, a PCE of 12.2% was remained with the active layer thickness of up to 285 nm and a high PCE of 11.4% was also obtained with a large device area of 1 cm^2. In addition, the devices also showed good storage, thermal and illumination stabilities with respect to the efficiency. These results indicate that fluorination is an effective strategy to improve the photovoltaic performance of materials, as well as the both fluorinated donor and acceptor pair-PM6:IT-4 F is an ideal candidate for the large scale roll-to-roll production of efficient PSCs in the future.展开更多
Mg O has not been explored as a counter electrode materials for dye-sensitized solar cells(DSSCs)due to its lack of electrical conductivity.However,herein,it is reported that Mg O insulator with conductive poly(3,4-et...Mg O has not been explored as a counter electrode materials for dye-sensitized solar cells(DSSCs)due to its lack of electrical conductivity.However,herein,it is reported that Mg O insulator with conductive poly(3,4-ethylenedioxythiophene):polysty-renesulfonate(PEDOT:PSS)exhibited excellent performance as a counter electrode for DSSCs,leading to a high power conversion efficiency of 7.45%.Furthermore,it was revealed that the interface between Mg O and PEDOT:PSS plays an important electro-catalytic role in the Mg O/PEDOT composite counter electrodes.展开更多
基金Supported by National Natural Science Foundation of China (No.60972054)
文摘The secrecy performance of cooperation with an untrusted relay under a quasi-static fading channel is analyzed in this paper. An achievable secrecy rate is provided and the influence of selfish behavior of untrusted relay is analyzed. Furthermore, the secrecy performance of the scheme is discussed and compared with that of the case where the relay is just an eavesdropper. Simulation results show that the untrusted relay's cooperation in the fading case reduces the outage probability from 1/2 to 1/3 and achieves a higher outage secrecy capacity.
文摘Deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. In the present research, generation reliability is considered, and a method for its assessment is proposed using game theory and NN (neural networks). Also, due to the stochastic behavior of power markets and generators' forced outages, MCS (monte carlo simulation) is used for reliability evaluation. Generation reliability merely focuses on the interaction between generation complex and load. Therefore, in the research, based on the behavior of players in the market and using game theory, two outcomes are considered: cooperation and non-cooperation. The proposed method is assessed on IEEE-Reliability Test System with satisfactory results. LOLE (loss of load expectation) is used as the reliability index and it will be shown that generation reliability in cooperation market is better than non-cooperation outcome.
文摘Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickness of the synthesized nanocomposite films ranged from 50 to 70 lam, having well-dispersed MWCNTs. Increasing the AEPTES concentration from 0.0196 to 0.0300 M, increased the amine content and the dispersion of MWCNTs. The film synthesized at 0.0300 M AETPES exhibited the greatest degree of dispersion among the three samples, which is consistent with a self-assembled silane group interacting with the MWCNT surface.
文摘Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R & D (research & development) expenditure and various core technologies, and therefore, international research collaboration is necessary for prompt and efficient development. The study is aimed at establishing a knowledge base that can help to prepare international research collaboration policies for solving global challenges effectively. The authors demonstrate the research capacity and international research collaboration in solar cell and fuel cell technologies, using global research network diagrams gathered from 35,322 and 33,136 academic papers, respectively. The diagrams include the data of research competency and co-authorship. More than 6,000 institutions and 100 countries are involved in each field. Based on the diagrams, the technologies are compared and international collaboration is analyzed. A valley of research collaboration in Asia is identified for both technologies. Then, science and education policies that influence the structures are discussed.
基金supported by the National Natural Science Foundation of China(51422306,51503135,51573120,91633301)Jiangsu Provincial Natural Science Foundation(BK20150332)T.P.Russell was supported by the U.S.Office of Naval Research(N00014-15-1-2244)
文摘A high performance polymer solar cells(PSCs) based on polymer donor PM6 containing fluorinated thienyl benzodithiophene unit and n-type organic semiconductor acceptor IT-4 F containing fluorinated end-groups were developed. In addition to complementary absorption spectra(300–830 nm) with IT-4 F, the PM6 also has a deep HOMO(the highest occupied molecular) level(-5.50 e V), which will lower the open-circuit voltage(V_(oc)) sacrifice and reduce the E_(loss) of the IT-4 F-based PSCs. Moreover, the strong crystallinity of PM6 is beneficial to form favorable blend morphology and hence to suppress recombination. As a result, in comparison with the PSCs based on a non-fluorinated D/A pair of PBDB-T:ITIC with a medium PCE of 11.2%, the PM6:IT-4 Fbased PSCs yielded an impressive PCE of 13.5% due to the synergistic effect of fluorination on both donor and acceptor, which is among the highest values recorded in the literatures for PSCs to date. Furthermore, a PCE of 12.2% was remained with the active layer thickness of up to 285 nm and a high PCE of 11.4% was also obtained with a large device area of 1 cm^2. In addition, the devices also showed good storage, thermal and illumination stabilities with respect to the efficiency. These results indicate that fluorination is an effective strategy to improve the photovoltaic performance of materials, as well as the both fluorinated donor and acceptor pair-PM6:IT-4 F is an ideal candidate for the large scale roll-to-roll production of efficient PSCs in the future.
基金supported by the U.S.National Science Foundation(NSF-CBET-0931587)the ACS Petroleum Research Fund(PRF-51799-ND10)
文摘Mg O has not been explored as a counter electrode materials for dye-sensitized solar cells(DSSCs)due to its lack of electrical conductivity.However,herein,it is reported that Mg O insulator with conductive poly(3,4-ethylenedioxythiophene):polysty-renesulfonate(PEDOT:PSS)exhibited excellent performance as a counter electrode for DSSCs,leading to a high power conversion efficiency of 7.45%.Furthermore,it was revealed that the interface between Mg O and PEDOT:PSS plays an important electro-catalytic role in the Mg O/PEDOT composite counter electrodes.