应力对纤维增强塑料排烟内筒耐腐蚀性能的影响

针对燃煤电厂烟囱纤维增强塑料排烟内筒工程中应用的纤维增强复合材料试样S-1设置了5种实验条件,即条件A（静态浸泡）、条件B（Ⅰ型应变,应变4.61%）、条件C（Ⅰ型应变+静态浸泡）、条件D（Ⅱ型应变,应变5.89%）、条件E（Ⅱ型应变+静态浸泡）,以探究不同实验条件下试样性能的变化。力学性能测试结果表明：不同实验条件下,试样力学性能出现了不同程度的下降,相对于条件B,试样在条件D下弯曲强度保留率、拉伸强度保留率分别下降了2.98%、9.52%;相对于条件C,试样在条件E下弯曲强度保留率、拉伸强度保留率分别下降了5.92%、4.42%。扫描电子显微镜（SEM）研究发现,试样S-1在条件E下经90 d的实验周期后,表面破坏较为严重,有明显的纤维拔出现象,巴氏硬度测试也表明试样在不同条件下的表面状态发生了变化。红外图谱结果表明,试样在条件E下的水解程度大于条件C。     

The impacts of “05.6” extreme flood event on riverine carbon fluxes in Xijiang River

An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River, the main trunk stream of the Zhujlang River. Samples were systematically collected during the flood event, and water quality parameters, including total suspended sediment （TSS）, dissolved inorganic carbon （DIC）, dissolved organic carbon （DOC）, and particulate organic carbon （POC） were analyzed, and riverine carbon concentrations associated with its changing pattern through the flood process were discussed. These parameters reflect the changes in basin surface flow and subsurface flow during the flood. This flood event influenced annual flux estimations of POC, DOC, and DIC to great extents. Based on carbon flux estimations for the year 2005 and the flood event （June 21-28） in the Xijiang River, it was found that DIC, DOC, and POC fluxes during ＇05.6＇ flood event are 1.52×10^6g.km^-2.a^-1, 0.24×10^6 g.km^-2.a^-1, and 0.54×10^6 g.km^-2.a^-1, and account for 14.87%, 24.75% and 44.89% of the annual fluxes in 2005, respectively. The results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components, being important for accurate estimates of annual carbon fluxes in rivers with frequent floods.     

Retrieval of suspended sediment concentrations in the turbid water of the Upper Yangtze River using Landsat ETM+

For the remote areas like the Longitudinal Range-Gorge Region (LRGR), it is hard to measure the suspended sediment concentrations (SSC). This study attempted to estimate SSC by employing the three atmospheric correction methods: COST, iCOST (modified from COST) and TZB5 (newly proposed). TZB5 can more accurately determine the atmospheric transmittance along the sun-ground surface path (TAUz) from the solar zenith angle (TZ), and it uses Band 5 to eliminate the path radiance of Bands 1–4. The water surface reflectance at Band 4 obtained using TZB5 has a stronger relation with SSC within the range of 0–3000 mg/L. The developed algorithms could accurately estimate SSC directly from ETM+ images in the turbid Upper Yangtze River, and were also effective in the Middle Yangtze River.

     

The impacts of ‘05.6’ extreme flood event on riverine carbon fluxes in Xijiang River

An extreme flood event with a frequency of nearly 200 year occurred in June of 2005 in the Xijiang River, the main trunk stream of the Zhujiang River. Samples were systematically collected during the flood event, and water quality parameters, including total suspended sediment (TSS), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), and particulate organic carbon (POC) were analyzed, and riverine carbon concentrations associated with its changing pattern through the flood process were discussed. These parameters reflect the changes in basin surface flow and subsurface flow dur-ing the flood. This flood event influenced annual flux estimations of POC, DOC, and DIC to great extents. Based on carbon flux estimations for the year 2005 and the flood event (June 21-28) in the Xijiang River, it was found that DIC, DOC, and POC fluxes during ‘05.6’ flood event are 1.52×106 g.km?2.a?1, 0.24×106 g.km?2.a?1, and 0.54×106 g.km?2.a?1, and account for 14.87%, 24.75% and 44.89% of the annual fluxes in 2005, respectively. The results suggested that carbon exports during extreme flood events had great contributions to the total carbon fluxes and composition of various carbon components, be-ing important for accurate estimates of annual carbon fluxes in rivers with frequent floods.     

A late Mesozoic high plateau in eastern China: Evidence from basalt vesicular paleoaltimetry

Eastern China is made of a number of large and small continental fragments throughout late Paleozoic and Mesozoic time,and is still the best natural laboratory for examining kinematic models of continent tectonics.The paleoelevation history of eastern China provides direct insight into the tectonic processes in China.Here we present basalt-vesicularity based estimates of the paleoaltimetry of the early Cretaceous basalts in northern East China,which indicate that the studied basalt units were at an elevation of more than 4 kilometers in late Mesozoic.Two vesicular basaltic rocks have been collected form bottom to top along the lava flow outcrop in eastern Inner Mongolia.After the digital precessing to the sample cross-sections,and taking advantage of the stereological conversion method to acquire the bubble size distributions,paleoelevation estimate was calculated for East China in the early Cretaceous.The results show that the elevation has been near 4700±750 m when the lava flows was cooling,implying that there were highland regions in the northern part of the East China Plateau during the early Cretaceous.Combined with other geological evidence,we conclude that there was a high plateau with elevation near 5000 m above sea level in Eastern China during the late Mesozoic.This ancient high plateau in eastern China was most likely formed by the collision of the north and south China blocks.