The once-through steam generator (OTSG) in concentric annuli tube is a new type of steam generator which applies double side to transfer heat. The heat flux between the water of centric tube, outside annuli tube and t...The once-through steam generator (OTSG) in concentric annuli tube is a new type of steam generator which applies double side to transfer heat. The heat flux between the water of centric tube, outside annuli tube and that of annulus channel is assumed to be equal, and then the steam generator’s model is built by lumped parameters with moving boundary. In the basis of the built model, static and dynamic characteristics are analyzed. The static characteristics are proved by experiment results in a 19-tube once-through steam generator of Babcock & Wilcox. The characteristics that the lengths of three regions (subcooled region, nucleate boiling region, superheat region) change with power can be explained by theory analysis. The dynamic characteristics accord with the heat and hydraulics and the results of analysis according to the mechanism.展开更多
利用溶胶凝胶-丝网印刷法在氧化铝基底上制备了La1-x Sr x MnO3(x=0.3、0.4和0.5)薄膜,研究了薄膜通电发热后的热辐射特性。不同掺锶量的薄膜发热温度在90℃~360℃范围内时,红外辐射波长主要集中在4000 nm^5000 nm,发热温度越高,最大辐...利用溶胶凝胶-丝网印刷法在氧化铝基底上制备了La1-x Sr x MnO3(x=0.3、0.4和0.5)薄膜,研究了薄膜通电发热后的热辐射特性。不同掺锶量的薄膜发热温度在90℃~360℃范围内时,红外辐射波长主要集中在4000 nm^5000 nm,发热温度越高,最大辐射波长越短,而掺锶量对红外辐射光谱影响较小;掺锶量x=0.4的薄膜可实现800℃以上的加热温度,控制电压使发热温度保持在500℃时,可实现长时间稳定加热。展开更多
Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulti...Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.展开更多
In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured...In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured and compared with those from references to verify the reliability of the viscometer and measuring methods,and a good agreement was observed from the comparisons.Then,two new high-temperature molten salts were made from the HITEC salt by some additives and the viscosity-temperature profiles of them were obtained by experiments.The results show that the new molten salts have much lower viscosities,thus suitable for reducing the flow resistance in transportation system of high-temperature solar thermal power generation.展开更多
文摘The once-through steam generator (OTSG) in concentric annuli tube is a new type of steam generator which applies double side to transfer heat. The heat flux between the water of centric tube, outside annuli tube and that of annulus channel is assumed to be equal, and then the steam generator’s model is built by lumped parameters with moving boundary. In the basis of the built model, static and dynamic characteristics are analyzed. The static characteristics are proved by experiment results in a 19-tube once-through steam generator of Babcock & Wilcox. The characteristics that the lengths of three regions (subcooled region, nucleate boiling region, superheat region) change with power can be explained by theory analysis. The dynamic characteristics accord with the heat and hydraulics and the results of analysis according to the mechanism.
文摘利用溶胶凝胶-丝网印刷法在氧化铝基底上制备了La1-x Sr x MnO3(x=0.3、0.4和0.5)薄膜,研究了薄膜通电发热后的热辐射特性。不同掺锶量的薄膜发热温度在90℃~360℃范围内时,红外辐射波长主要集中在4000 nm^5000 nm,发热温度越高,最大辐射波长越短,而掺锶量对红外辐射光谱影响较小;掺锶量x=0.4的薄膜可实现800℃以上的加热温度,控制电压使发热温度保持在500℃时,可实现长时间稳定加热。
文摘Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.
基金supported by the National Natural Science Foundation Key Project of China (Grant No. 50736005)the National Basic Research Program of China ("973" Program) (Grant No. 2010CB227103)
文摘In this paper several kinds of high temperature molten salts were investigated experimentally on viscosity-temperature characteristics with high-temperature viscometer.The viscosities of the molten salts were measured and compared with those from references to verify the reliability of the viscometer and measuring methods,and a good agreement was observed from the comparisons.Then,two new high-temperature molten salts were made from the HITEC salt by some additives and the viscosity-temperature profiles of them were obtained by experiments.The results show that the new molten salts have much lower viscosities,thus suitable for reducing the flow resistance in transportation system of high-temperature solar thermal power generation.
