共查询到20条相似文献,搜索用时 15 毫秒
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WSE对羊毛纤维具有溶胀和交联作用,将羊毛保护剂WSE应用于丝光羊毛的漂白,优化了WSE的应用工艺.通过对漂白羊毛单纤维的断裂强力和散纤维的白度测试,表明保护剂WSE可以显著降低羊毛纤维在漂白中的损伤,并提高羊毛纤维的白度. 相似文献
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G A Shelton 《Nature》1975,253(5492):558-560
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Fossil corals are widespread on the coast of northwestern Hainan Island, China. Most of these corals are exposed during low tide levels, indicating that a higher sea level may have existed during their life time. The radiocarbon data introduced by this paper in combination with those from other sources show that the corals were alive mainly during the midto late-Holocene. Mid-Holocene sea levels 1-3 m higher than the present level were confirmed for adjacent coasts; however, the emerged corals on the investigated coast are not necessarily indicators of a higher eustatic sea level. They do predict relative sea levels of 1.5-3.4 m when using 1 m below the tidal datum as the upper limit of coral growth. However, using the Mean Lower Low Water as the coral’s upper growth limit, the relative sea level on the non-volcanic coast was almost as high as the present level, whereas that on the volcanic coast was 0.4-2.0 m higher than present. Therefore, the exposure of these dead coral heads and their discrepancy in elevation may be the result of tectonic uplift caused by volcanic activities. From these results, the highest sea level of upward coral growth must be defined first when using fossil corals to reconstruct past sea levels. Meanwhile, vertical tectonics have to be taken into account as a significant factor when conducting high-resolution sea level reconstruction, although the South China coast is located in a "tectonically stable" region. 相似文献
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Duy C Hurtz C Shojaee S Cerchietti L Geng H Swaminathan S Klemm L Kweon SM Nahar R Braig M Park E Kim YM Hofmann WK Herzog S Jumaa H Koeffler HP Yu JJ Heisterkamp N Graeber TG Wu H Ye BH Melnick A Müschen M 《Nature》2011,473(7347):384-388
Tyrosine kinase inhibitors (TKIs) are widely used to treat patients with leukaemia driven by BCR-ABL1 (ref. 1) and other oncogenic tyrosine kinases. Recent efforts have focused on developing more potent TKIs that also inhibit mutant tyrosine kinases. However, even effective TKIs typically fail to eradicate leukaemia-initiating cells (LICs), which often cause recurrence of leukaemia after initially successful treatment. Here we report the discovery of a novel mechanism of drug resistance, which is based on protective feedback signalling of leukaemia cells in response to treatment with TKI. We identify BCL6 as a central component of this drug-resistance pathway and demonstrate that targeted inhibition of BCL6 leads to eradication of drug-resistant and leukaemia-initiating subclones. 相似文献
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在实验室水槽内,以光棘球海胆和中间球海胆为实验对象,选用海带、鼠尾藻、孔石莼和江蓠作为饵料,设计使用工字形和井字形增殖礁,观察了礁体对海胆选择单一饵料和多种饵料的影响.结果表明:井字形礁体的放人对光棘球海胆的饵料选择性影响较为明显,礁体与四种饵料相结合,光棘球海胆对礁体处饵料选择率均为最高,分别达22.99%、17.95%、8.33%、6.67%,且与其他组差异显著(P<0.05);礁体对中间球海胆的饵料选择性影响较小,不论礁体与何种饵料结合,中间球海胆均喜摄食海带和鼠尾藻,而工字形礁体对两种海胆选择饵料影响较小.结果显示光棘球海胆是更适宜的增殖品种.同时也应根据增殖海区的海藻种类分布状况选择适宜的增殖礁形. 相似文献
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Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement 总被引:18,自引:0,他引:18
The effect of European settlement on water quality in the Great Barrier Reef of Australia is a long-standing and controversial issue. Erosion and sediment transport in river catchments in this region have increased substantially since European settlement, but the magnitude of these changes remains uncertain. Here we report analyses of Ba/Ca ratios in long-lived Porites coral from Havannah Reef--a site on the inner Great Barrier Reef that is influenced by flood plumes from the Burdekin river--to establish a record of sediment fluxes from about 1750 to 1998. We find that, in the early part of the record, suspended sediment from river floods reached the inner reef area only occasionally, whereas after about 1870--following the beginning of European settlement--a five- to tenfold increase in the delivery of sediments is recorded with the highest fluxes occurring during the drought-breaking floods. We conclude that, since European settlement, land-use practices such as clearing and overstocking have led to major degradation of the semi-arid river catchments, resulting in substantially increased sediment loads entering the inner Great Barrier Reef. 相似文献
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