Despite recent progress in deep-sea biodiversity assessments in the Southern Ocean （SO）, there remain gaps in our knowledge that hamper efficient deep-sea monitoring in times of rapid climate change. These include g...Despite recent progress in deep-sea biodiversity assessments in the Southern Ocean （SO）, there remain gaps in our knowledge that hamper efficient deep-sea monitoring in times of rapid climate change. These include geographical sampling bias, depth and size-dependent faunal gaps in biology, ecology, distribution, and phylogeography, and the evolution of SO species. The phenomena of species patchiness and rarity are still not well understood, possibly because of our limited understanding of physiological adaptations and thresholds. Even though some shallow water species have been investigated physiologically, community-scale studies on the effects of multiple stressors related to ongoing environmental change, including temperature rise, ocean acidification, and shifts in deposition of phytoplankton, are completely unknown for deep-sea organisms. Thus, the establishment of long-term and coordinated monitoring programs, such as those rapidly growing under the umbrella of the Southern Ocean Observing System （SOOS） or the Deep Ocean Observing Strategy （DOOS）, may represent unique tools for measuring the status and trends of deep-sea and SO ecosystems.展开更多
Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ul...Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ulle- ung Interplain Gap of the East/lapan Sea. The current below 300 m is bottom-intensified and has nearly depth-independent flow. Near bottom, the spectral peaks of the current were found near 10, 20, and 60 d. The DAC variability near 10 d and 20 d is reasonably consistent with the linear theory of topographic Rossby waves （TRWs） in the following aspects： （1） The motion is columnar and bottom-intensified; （2） the theo- retical cutoff frequency is similar to the observation; （3） The observation-based angles of the wavenumber vector are in good agreement with the theoretical ones. The wavelengths of the TRWs with periods of near 10 d and 20 d near Dokdo are significantly shorter than those with similar timescales in the open oceans （100-250 km）. It is primarily due to the weak stratification below 300 m in the East Sea. The deep cur- rent fluctuations with periods of near 10 d and 20 d were accompanied by warm events in the upper layer resulting from eddying processes and/or meandering of the Tsushima Warm Current.展开更多
以圆筒形件为研究对象,运用Abaqus/Explicit的准静态法,分别对直径为Φ80、Φ85和Φ90 mm的DC04钢板变间隙拉深进行仿真,研究了不同压边力作用下圆筒形件变间隙拉深过程中压边力对拉深制耳的影响,得到板料变间隙拉深过程中的压边力-制...以圆筒形件为研究对象,运用Abaqus/Explicit的准静态法,分别对直径为Φ80、Φ85和Φ90 mm的DC04钢板变间隙拉深进行仿真,研究了不同压边力作用下圆筒形件变间隙拉深过程中压边力对拉深制耳的影响,得到板料变间隙拉深过程中的压边力-制耳率曲线。仿真结果表明,压边力对变间隙拉深制耳有较大影响,压边力从5 k N增大至10 k N时,制耳率由3. 8%迅速降低为2. 4%,继续增大压边力至15 k N时,制耳率缓慢降低为2. 2%,说明随着压边力的增大,圆筒形件的制耳率先迅速降低再趋于平缓。结合变间隙拉深工艺试验,通过对比拉深工艺试验的制耳率,仿真结果与试验结果吻合较好。展开更多
基金supported by the Institute for Marine and Antarctic Studies (IMAS, University of Tasmania), which hosts the SOOS International Project Officesponsored by numerous international organizations (www.soos.aq/index.php/about-us/sponsors)
文摘Despite recent progress in deep-sea biodiversity assessments in the Southern Ocean （SO）, there remain gaps in our knowledge that hamper efficient deep-sea monitoring in times of rapid climate change. These include geographical sampling bias, depth and size-dependent faunal gaps in biology, ecology, distribution, and phylogeography, and the evolution of SO species. The phenomena of species patchiness and rarity are still not well understood, possibly because of our limited understanding of physiological adaptations and thresholds. Even though some shallow water species have been investigated physiologically, community-scale studies on the effects of multiple stressors related to ongoing environmental change, including temperature rise, ocean acidification, and shifts in deposition of phytoplankton, are completely unknown for deep-sea organisms. Thus, the establishment of long-term and coordinated monitoring programs, such as those rapidly growing under the umbrella of the Southern Ocean Observing System （SOOS） or the Deep Ocean Observing Strategy （DOOS）, may represent unique tools for measuring the status and trends of deep-sea and SO ecosystems.
基金The Ministry of Land, Transport and Maritime Affairs of Korean Govenment as part of the EAST-I (East Asian Seas Time-series,East/Japan Sea) and OCCAPA (Ocean Chimate Change-Analyses, Projections and Adaptation), through KIOST Project under contract No. PE98742as part of the Development of Technology for CO2 Marine Geological Storage project under contract No. PMS246B
文摘Subinertial fluctuation of a strong northward deep current, which is referred to the Dokdo Abyssal Current （DAC） by Chang et al. （2009）, is investigated from current records for about 16.5 and 8.0 months in the Ulle- ung Interplain Gap of the East/lapan Sea. The current below 300 m is bottom-intensified and has nearly depth-independent flow. Near bottom, the spectral peaks of the current were found near 10, 20, and 60 d. The DAC variability near 10 d and 20 d is reasonably consistent with the linear theory of topographic Rossby waves （TRWs） in the following aspects： （1） The motion is columnar and bottom-intensified; （2） the theo- retical cutoff frequency is similar to the observation; （3） The observation-based angles of the wavenumber vector are in good agreement with the theoretical ones. The wavelengths of the TRWs with periods of near 10 d and 20 d near Dokdo are significantly shorter than those with similar timescales in the open oceans （100-250 km）. It is primarily due to the weak stratification below 300 m in the East Sea. The deep cur- rent fluctuations with periods of near 10 d and 20 d were accompanied by warm events in the upper layer resulting from eddying processes and/or meandering of the Tsushima Warm Current.
文摘以圆筒形件为研究对象,运用Abaqus/Explicit的准静态法,分别对直径为Φ80、Φ85和Φ90 mm的DC04钢板变间隙拉深进行仿真,研究了不同压边力作用下圆筒形件变间隙拉深过程中压边力对拉深制耳的影响,得到板料变间隙拉深过程中的压边力-制耳率曲线。仿真结果表明,压边力对变间隙拉深制耳有较大影响,压边力从5 k N增大至10 k N时,制耳率由3. 8%迅速降低为2. 4%,继续增大压边力至15 k N时,制耳率缓慢降低为2. 2%,说明随着压边力的增大,圆筒形件的制耳率先迅速降低再趋于平缓。结合变间隙拉深工艺试验,通过对比拉深工艺试验的制耳率,仿真结果与试验结果吻合较好。
