We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite cera...We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite ceramic Nd：YAG crystal is numerically analyzed and compared with that of conventional Nd：YAG crystal. By using a composite ceramic Nd：YAG rod and a type-II high gray track resistance KTP （HGTR-KTP） crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd：YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.展开更多
Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market p...Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.展开更多
Decision-making toward prudent energy conservation is a primary issue in the power utility management while con-ceiving green environment. Presented in this paper are relevant considerations and prudent ways of decisi...Decision-making toward prudent energy conservation is a primary issue in the power utility management while con-ceiving green environment. Presented in this paper are relevant considerations and prudent ways of decision-making thereof. Examples are furnished to illustrate the underlying considerations and are discussed using practical examples. Specifically green ambient is considered and the underlying payoff resulting from each combination of strategies adopted (or courses of action taken) by the technology-option participants is evaluated. Game-theoretic pursuits are followed.展开更多
Base station power consumption is the biggest power issue concerning wireless networks. Saving power in base stations is therefore the primary focus in green wireless network development. This paper discusses green ba...Base station power consumption is the biggest power issue concerning wireless networks. Saving power in base stations is therefore the primary focus in green wireless network development. This paper discusses green base stations in terms of system architecture, base station form, power saving technologies, and green technology applications. It explores effective ways of reducing power consumption in base stations.展开更多
Increasing consumption, changing nature of loads and the need to reduce carbon emission are some of the factors threatening electricity grid stability and reliability. Demand side management programs mainly work by sh...Increasing consumption, changing nature of loads and the need to reduce carbon emission are some of the factors threatening electricity grid stability and reliability. Demand side management programs mainly work by shifting consumption from peak to off-peak period, which inconveniences some consumers and possibly creates a new peak (Reverse Peak) in off-peak hours. Growing use of Photovoltaic solar power in residences provides an opportunity to manage grid reliability and stability in a more flexible manner, and mitigates reverse peaks. We propose a community based scheduling algorithm that guarantees access to shared power capacity and integrates residences’ solar power into the grid. Results indicate peak demand can be reduced by up to 32.1%, while energy costs can be reduced by up to 14.0%. Furthermore, coordinated discharging can mitigate reverse peaks by up to 23.4%. Encouraging and integrating green energy generation and storage in the consumer side is crucial to grid stability and reliability.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61107086, 61172010, and 61101058)the Science and Technology Committee of Tianjin, China (Grant No. 11JCYBJC01100)the National High Technology Research and Development Program of China (Grant No. 2011AA010205)
文摘We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite ceramic Nd：YAG crystal is numerically analyzed and compared with that of conventional Nd：YAG crystal. By using a composite ceramic Nd：YAG rod and a type-II high gray track resistance KTP （HGTR-KTP） crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd：YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.
文摘Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.
文摘Decision-making toward prudent energy conservation is a primary issue in the power utility management while con-ceiving green environment. Presented in this paper are relevant considerations and prudent ways of decision-making thereof. Examples are furnished to illustrate the underlying considerations and are discussed using practical examples. Specifically green ambient is considered and the underlying payoff resulting from each combination of strategies adopted (or courses of action taken) by the technology-option participants is evaluated. Game-theoretic pursuits are followed.
文摘Base station power consumption is the biggest power issue concerning wireless networks. Saving power in base stations is therefore the primary focus in green wireless network development. This paper discusses green base stations in terms of system architecture, base station form, power saving technologies, and green technology applications. It explores effective ways of reducing power consumption in base stations.
文摘本文主要研究了半群 S 的幂半群 P(S)上Green关系的若干性质.证明了对任意的 a∈S, a 在 S 和 P(S)中的 L 类, R 类, H 类之间的关系.同时,对完全正则半群 S,证明了 P(S)中的两个元素 A,B 在同一 R 类(或同一 L 类, H 类)时, Id A= Id B.
文摘Increasing consumption, changing nature of loads and the need to reduce carbon emission are some of the factors threatening electricity grid stability and reliability. Demand side management programs mainly work by shifting consumption from peak to off-peak period, which inconveniences some consumers and possibly creates a new peak (Reverse Peak) in off-peak hours. Growing use of Photovoltaic solar power in residences provides an opportunity to manage grid reliability and stability in a more flexible manner, and mitigates reverse peaks. We propose a community based scheduling algorithm that guarantees access to shared power capacity and integrates residences’ solar power into the grid. Results indicate peak demand can be reduced by up to 32.1%, while energy costs can be reduced by up to 14.0%. Furthermore, coordinated discharging can mitigate reverse peaks by up to 23.4%. Encouraging and integrating green energy generation and storage in the consumer side is crucial to grid stability and reliability.
