The economic rise of the BRICS countries(Brazil, Russia, India, China and South Africa) is closely tied to global energy politics and their increased consumption of global energy. Energy cooperation is one of the main...The economic rise of the BRICS countries(Brazil, Russia, India, China and South Africa) is closely tied to global energy politics and their increased consumption of global energy. Energy cooperation is one of the main forces behind the development of BRICS. Looking forward, energy concerns will undoubtedly remain an important influencing force for the BRICS, shaping their domestic politics and international relations. The pursuit of oil and gas(China, India, and South Africa) to support economic development and the search for stable petroleum markets(Brazil and Russia) have shaped BRICS relations with other countries and regions. This article is trying to elaborate on the reasons why BRICS Energy cooperation is beneficial for its members; also, this article regards the main challenges hindering cooperation, analyzes BRICS energy cooperation through the use of SWOT analysis and muses potential strategic points for BRICS countries up until 2050.展开更多
Over the past two decades, as the main battlefield of China's international energy cooperation, countries along the Belt and Road have had good foundations in the foreign investment. Through China's efforts to...Over the past two decades, as the main battlefield of China's international energy cooperation, countries along the Belt and Road have had good foundations in the foreign investment. Through China's efforts to build the Belt and Road, energy cooperation has enjoyed first-mover advantages. Looking ahead, the countries along the Belt and Road are predicted to enjoy a promising future in energy cooperation because of their abundant energy resources, their role as complements to China's economic development, and their vast amounts of cooperation potential. At the same time, we are also keenly aware that there are a number of risks caused by geopolitics, policy changes, price fluctuations and legal compliance in energy cooperation among the countries along the Belt and Road. Moreover, it is urgent for Chinese enterprises to enhance their international capabilities. In this context, it is necessary to further maintain and make full use of their first-mover advantages and play a guiding and demonstrating role. Enterprises should actively adapt to new changes, while the government should make progress in policy coordination, facility connectivity, unimpeded trade, financed integration and people-to-people bonds, so as to keep deepening international energy cooperation and to build an energy silk road and a community with a shared future for energy.展开更多
Bi3＋ and Yb3＋ codoped cubic Y2O3 phosphors are prepared by pechini sol-gel method. Strong near-infrared （NIR） emission around 980 nm from Yb3＋ （2F5/2＋2 F7/2） is observed under ultraviolet light excitation. A b...Bi3＋ and Yb3＋ codoped cubic Y2O3 phosphors are prepared by pechini sol-gel method. Strong near-infrared （NIR） emission around 980 nm from Yb3＋ （2F5/2＋2 F7/2） is observed under ultraviolet light excitation. A broad excitation band ranging from 320 to 360 nm, owing to the 6s2→6s6p transition of Bi3＋ ions, is recorded when the Yb3＋ emission is monitored, which suggests a very efficient energy transfer from Bi3＋ ions to Yb3＋ ions. The Yb3＋ concentration dependences of both the Bi3＋ and the Yb3＋ emissions are investigated. The decay curve of Bi3＋ emission under the excitation of 355 nm pulse laser is used to explore the Bi3＋ →＋Yb3＋ energy transfer process. Cooperative energy transfer （CET） is discussed as a possible mechanism for the near-infrared emission.展开更多
Cooperative relaying is a promising technology that can improve the spectral and energy efficiency of cellular networks. However, the deployed relays consume a lot of energy and system resources. To improve the energy...Cooperative relaying is a promising technology that can improve the spectral and energy efficiency of cellular networks. However, the deployed relays consume a lot of energy and system resources. To improve the energy efficiency of the relay-assisted cellular networks, this paper considers the use of energy harvesting(EH) on relay nodes. A random sleeping strategy is also introduced in macro base stations(MBS) as a possible method to reduce energy consumption. In this paper, an analytical model is proposed to investigate the energy efficiency of cellular networks with EH relays and sleep mode strategy. Numerical results confirm a significant energy efficiency gain of the proposed networks comparing to the cellular networks with non-EH relays and MBSs without sleep mode strategy. The effects of the density and transmit power of MBSs on energy efficiency are also given through simulations.展开更多
A novel near-infrared （NIR） downconversion （DC） phosphor KSrPO4：Eu2＋, Pr3＋ is synthesized by the conventional high temperature solid-state reaction. The Eu2＋ acts as an efficient sensitizer for Pr3＋ in the KS...A novel near-infrared （NIR） downconversion （DC） phosphor KSrPO4：Eu2＋, Pr3＋ is synthesized by the conventional high temperature solid-state reaction. The Eu2＋ acts as an efficient sensitizer for Pr3＋ in the KSrPO4 host. With broad- band near-ultraviolet light excitation induced by the 4f→5d transition of Eu2＋, the characteristic NIR emission of Pr3＋, peaking at 974 nm and 1019 nm due to 3po →1G4 and 1G4→3H4 transitions, is generated as a result of the energy transfer from Eu2＋ to Pr3＋. The luminescence spectra in both the visible and the NIR regions and the decay lifetime curves of Eu2＋ prove the energy transfer from Eu2＋ to Pr3＋. This Eu2＋ and Pr3＋ co-doped KSrPO4 phosphor may be a promising candidate to modify the spectral mismatch behavior of crystalline solar cells and sunlight.展开更多
文摘The economic rise of the BRICS countries(Brazil, Russia, India, China and South Africa) is closely tied to global energy politics and their increased consumption of global energy. Energy cooperation is one of the main forces behind the development of BRICS. Looking forward, energy concerns will undoubtedly remain an important influencing force for the BRICS, shaping their domestic politics and international relations. The pursuit of oil and gas(China, India, and South Africa) to support economic development and the search for stable petroleum markets(Brazil and Russia) have shaped BRICS relations with other countries and regions. This article is trying to elaborate on the reasons why BRICS Energy cooperation is beneficial for its members; also, this article regards the main challenges hindering cooperation, analyzes BRICS energy cooperation through the use of SWOT analysis and muses potential strategic points for BRICS countries up until 2050.
文摘Over the past two decades, as the main battlefield of China's international energy cooperation, countries along the Belt and Road have had good foundations in the foreign investment. Through China's efforts to build the Belt and Road, energy cooperation has enjoyed first-mover advantages. Looking ahead, the countries along the Belt and Road are predicted to enjoy a promising future in energy cooperation because of their abundant energy resources, their role as complements to China's economic development, and their vast amounts of cooperation potential. At the same time, we are also keenly aware that there are a number of risks caused by geopolitics, policy changes, price fluctuations and legal compliance in energy cooperation among the countries along the Belt and Road. Moreover, it is urgent for Chinese enterprises to enhance their international capabilities. In this context, it is necessary to further maintain and make full use of their first-mover advantages and play a guiding and demonstrating role. Enterprises should actively adapt to new changes, while the government should make progress in policy coordination, facility connectivity, unimpeded trade, financed integration and people-to-people bonds, so as to keep deepening international energy cooperation and to build an energy silk road and a community with a shared future for energy.
基金supported by the National Nature Science Foundation of China (Grant No. 10774140)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KJCX2-YW-M11)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education,China (Grant No. 20060358054)the Special Foundation for Talents of Anhui Province,China (GrantNo. 2007Z021)
文摘Bi3＋ and Yb3＋ codoped cubic Y2O3 phosphors are prepared by pechini sol-gel method. Strong near-infrared （NIR） emission around 980 nm from Yb3＋ （2F5/2＋2 F7/2） is observed under ultraviolet light excitation. A broad excitation band ranging from 320 to 360 nm, owing to the 6s2→6s6p transition of Bi3＋ ions, is recorded when the Yb3＋ emission is monitored, which suggests a very efficient energy transfer from Bi3＋ ions to Yb3＋ ions. The Yb3＋ concentration dependences of both the Bi3＋ and the Yb3＋ emissions are investigated. The decay curve of Bi3＋ emission under the excitation of 355 nm pulse laser is used to explore the Bi3＋ →＋Yb3＋ energy transfer process. Cooperative energy transfer （CET） is discussed as a possible mechanism for the near-infrared emission.
基金supported by National Basic Research Program of China ( No.2012CB316002 )China’s 863 Project (No.2014AA01A703)+2 种基金National Major Project (No.2014ZX03003002-002)Program for New Century Excellent Talents in University (NCET-13-0321)Tsinghua University Initiative Scientific Research Program (No.2011THZ02-2.)
文摘Cooperative relaying is a promising technology that can improve the spectral and energy efficiency of cellular networks. However, the deployed relays consume a lot of energy and system resources. To improve the energy efficiency of the relay-assisted cellular networks, this paper considers the use of energy harvesting(EH) on relay nodes. A random sleeping strategy is also introduced in macro base stations(MBS) as a possible method to reduce energy consumption. In this paper, an analytical model is proposed to investigate the energy efficiency of cellular networks with EH relays and sleep mode strategy. Numerical results confirm a significant energy efficiency gain of the proposed networks comparing to the cellular networks with non-EH relays and MBSs without sleep mode strategy. The effects of the density and transmit power of MBSs on energy efficiency are also given through simulations.
基金Project supported by the National Natural Science Foundation of China (Grant No. 20976002)the Beijing Natural Science Foundation, China (Grant No. 2122012)the Special Funding of the Ministry of Education of Guangdong Province, China (Grant No. 2011B090400100)
文摘A novel near-infrared （NIR） downconversion （DC） phosphor KSrPO4：Eu2＋, Pr3＋ is synthesized by the conventional high temperature solid-state reaction. The Eu2＋ acts as an efficient sensitizer for Pr3＋ in the KSrPO4 host. With broad- band near-ultraviolet light excitation induced by the 4f→5d transition of Eu2＋, the characteristic NIR emission of Pr3＋, peaking at 974 nm and 1019 nm due to 3po →1G4 and 1G4→3H4 transitions, is generated as a result of the energy transfer from Eu2＋ to Pr3＋. The luminescence spectra in both the visible and the NIR regions and the decay lifetime curves of Eu2＋ prove the energy transfer from Eu2＋ to Pr3＋. This Eu2＋ and Pr3＋ co-doped KSrPO4 phosphor may be a promising candidate to modify the spectral mismatch behavior of crystalline solar cells and sunlight.
