XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire ...XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire channel have become the major bottleneck for XCTD development. Aiming at this problem, this paper puts forward with using single-mode fiber as the transmission channel of XCTD. Firstly, this paper makes a brief analysis on the problems of using enameled wire as transmission channel faces. Secondly, it analyzes the advantages of the single mode fiber technology. Finally, it makes theoretical research and experimental verification of the influence of seawater temperature change on the optical fiber transmission channel. The experimentat results show that the error rate at the transmission rate of 10 MB/S is 0, and the loss can be negligible when the single-mode fiber channel is used in the sea water and the seawater temperature changes from 0 to 20℃. This method will greatly increase the rate of signal transmission and the transmission stability. And this paper shows that using the single-mode fiber as the transmission channel of XCTD has certain feasibility.展开更多
The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change...The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is ＋1.32 ＋ 0.22 mm/a, while the sea level change rate in China is only＋1.39 ＋ 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages （periods） are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise ＋7 - ＋11 ＋ 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently.展开更多
The relationship and elevation is a hot issue between species richness in ecology and has been documented extensively. It is widely accepted that area size can significantly affect this relationship and thus mask the ...The relationship and elevation is a hot issue between species richness in ecology and has been documented extensively. It is widely accepted that area size can significantly affect this relationship and thus mask the effects of other predictors. Despite the importance of the relationship between species richness and elevation while accounting for the area effect, it is insufficiently studied. Here, we evaluated area-corrected species richness patterns of all vascular plants as well as six vascular plant subgroups （seed plants, ferns, trees, shrubs, herbs and vines） along a tropical elevational gradient （Hainan Island, China）. If assessed in equal-elevation bands, uncorrected species richness showed bell-shaped curves, while area-corrected species richness assessed in equal-area bands appeared to increase monotonically due to the small proportion of highlands on Hainan Island. The mid-domain effect （MDE） was significantly correlated with both uncorrected and area-corrected species richness. On Hainan Island, the use of equal-area elevational bands increased the explanatory power of MDE.These findings provide useful insights to adjust for the area effect and highlight the need to use equal- area bands along the elevational gradient.展开更多
基金supported by the Research Program of Application Foundation and Advanced Technology of Tianjin (No. 14JCYBJC16300)the National Natural Science Foundation of China (No. 41206031)
文摘XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire channel have become the major bottleneck for XCTD development. Aiming at this problem, this paper puts forward with using single-mode fiber as the transmission channel of XCTD. Firstly, this paper makes a brief analysis on the problems of using enameled wire as transmission channel faces. Secondly, it analyzes the advantages of the single mode fiber technology. Finally, it makes theoretical research and experimental verification of the influence of seawater temperature change on the optical fiber transmission channel. The experimentat results show that the error rate at the transmission rate of 10 MB/S is 0, and the loss can be negligible when the single-mode fiber channel is used in the sea water and the seawater temperature changes from 0 to 20℃. This method will greatly increase the rate of signal transmission and the transmission stability. And this paper shows that using the single-mode fiber as the transmission channel of XCTD has certain feasibility.
基金supported by the National Natural Foundation of China(40940025)National Science Foundation of Tianjin(07ZCGYSF02400,09JCYBJC07400)+2 种基金Program of China"973"(2007CB411807)Open Fund of the Key Lab of Global Change and Marine-Atmospheric Chemistry,SOA(GCMAC0806)National Natural ScienceFoundation(41006002)
文摘The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is ＋1.32 ＋ 0.22 mm/a, while the sea level change rate in China is only＋1.39 ＋ 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages （periods） are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise ＋7 - ＋11 ＋ 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently.
基金the support provided by the National Special Water Programs (Grant Nos. 2009ZX07210-009, 2015ZX07203-011, 2015ZX07204-007)the Department of Environmental Protection of Shandong Province (SDHBPJ-ZB-08)+2 种基金the ChinaScholarship Council (Grant No. 201306730020)the Chinese Natural Science Foundation (Grant No. 39560023)Queen Mary University of London
文摘The relationship and elevation is a hot issue between species richness in ecology and has been documented extensively. It is widely accepted that area size can significantly affect this relationship and thus mask the effects of other predictors. Despite the importance of the relationship between species richness and elevation while accounting for the area effect, it is insufficiently studied. Here, we evaluated area-corrected species richness patterns of all vascular plants as well as six vascular plant subgroups （seed plants, ferns, trees, shrubs, herbs and vines） along a tropical elevational gradient （Hainan Island, China）. If assessed in equal-elevation bands, uncorrected species richness showed bell-shaped curves, while area-corrected species richness assessed in equal-area bands appeared to increase monotonically due to the small proportion of highlands on Hainan Island. The mid-domain effect （MDE） was significantly correlated with both uncorrected and area-corrected species richness. On Hainan Island, the use of equal-area elevational bands increased the explanatory power of MDE.These findings provide useful insights to adjust for the area effect and highlight the need to use equal- area bands along the elevational gradient.
