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721.
Black rockfi sh Sebastes schlegelii juveniles(30–40 mm total length) were immersed in a range of calcein(CAL) solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S(ARS) solutions at concentrations ranging from 100 to 500 mg/L in fi ltered seawater(salinity 30) for 24 h. Fluorescent marks were detected in otoliths(sagittae, asteriscus), scales, fi n rays(dorsal, pectoral, ventral, anal, and caudal fi n rays), and fi n spines(dorsal, ventral, and anal fi n spines) after a 60-d growth experiment. With the exception of 50–100 mg/L CAL, acceptable marks were produced in the otoliths and fi n spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fi n spines of fi sh immersed in 200–500 mg/L, 300–500 mg/L, and 200–500 mg/L ARS, respectively. Scales and fi n rays had acceptable marks at much higher concentrations(≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL, ≥200 mg/L ARS for fi n rays). The mark quality was highest(i.e., acceptable marks were observed in all sampled structures after immersion marking) in fi sh immersed in 150–250 mg/L CAL or 300–500 mg/L ARS. In addition, there was no signifi cant difference in survival and growth of marked fi sh compared with controls 60 d post-marking( P 0.05). 相似文献
722.
Interdecadal and Interannnual Variabilities of the Antarctic Oscillation Simulated by CAM3
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Based on four sets of numerical simulations prescribed with atmospheric radiative forcing and sea surface temperature(SST) forcing in the Community Atmospheric Model version 3(CAM3), the interannual and interdecadal variabilities of the Antarctic oscillation(AAO) during austral summer were studied. It was found that the interannual variability is mainly driven by SST forcing. On the other hand, atmospheric radiative forcing plays a major role in the interdecadal variability. A cooling trend was found in the high latitudes of the Southern Hemisphere(SH) when atmospheric radiative forcing was specified in the model. This cooling trend tended to enhance the temperature gradient between the mid and high latitudes in the SH, inducing a transition of the AAO from a negative to a positive phase on the interdecadal timescale. The cooling trend was also partly weakened by the SST forcing, leading to a better simulation compared with the purely atmospheric radiative forcing run. Therefore, SST forcing cannot be ignored, although it is not as important as atmospheric radiative forcing. 相似文献
723.
黄海冷水团海域浮游植物磷胁迫的季节变动 总被引:2,自引:0,他引:2
The Yellow Sea is located between the China Mainland and the Korean Peninsula, representing a typical shallow epicontinental sea. The Yellow Sea Cold Water Mass(YSCWM) is one of the most important physical features in the Yellow Sea. The characteristics of vertical profiles and seasonal variations of biogenic elements in the YSCWM may lead the variations of nutrient availability(e.g., phosphorus) and phosphorus stress of phytoplankton. In this study, the authors surveyed the seasonal variations of phytoplankton phosphorus stress with emphasis on the effect of the YSCWM during the four cruises in April and October 2006, March and August 2007. Using both bulk and single-cell alkaline phosphatase activity(APA) assays, this study evaluated phosphorus status of phytoplankton community, succession of phytoplankton community and ecophysiological responses of phytoplankton to phosphorus in the typical region of the YSCWM. With the occurrence of the YSCWM, especially the variations of concentration of dissolved inorganic phosphorus(DIP), the results of bulk APA appeared corresponding seasonal variations. Along Transects A and B, the mean APA in August was the highest, and that in March was the lowest. According to the ELF-labeled assay's results, seasonal variations of the ELF-labeled percentages within dominant species indicated that diatoms were dominant in March, April and October, while dinoflagellates were dominant in August. During the four cruises, the ELF-labeled percentages of diatoms except Paralia sulcata showed that diatoms were not phosphorus deficient in April 2006 at all, but suffered from severe phosphorus stress in August 2007. In comparison, the ELF-labeled percentages of dinoflagellates were all above 50% during the four time series, which meant dinoflagellates such as Alexandrium and Scrippsiella, sustained perennial phosphorus stress. 相似文献
724.
Stella Nordhagen Dan Calverley Chris Foulds Laura O’Keefe Xinfang Wang 《Climatic change》2014,125(2):149-162
For research to positively impact society, it must be scientifically credible. The researcher plays a key role in establishing and maintaining credibility, particularly in the climate change field. This paper provides a structure for relating the credibility of researchers themselves to that of research outputs, analysing ‘researcher credibility’ with reference to three overlapping domains: personal, professional, and public. The researcher’s role in each domain is considered in a reflexive way, examining the research process and the researcher’s actions. Varied definitions of researcher credibility and possible means to achieve it in each domain are discussed, drawing on relevant cross-disciplinary literature. We argue that, in certain contexts, the actions of researchers can have a direct impact on the credibility of their research. There is scope for broadening researcher credibility to include more public-oriented behaviours. This, however, may be contentious and problematic: potential conflicts exist between public action and professional credibility, with the latter usually taking precedence. By contrast, though personal action/inaction rarely affects professional credibility, researchers’ personal behaviours may influence public perceptions of research credibility and the importance of addressing climate change. 相似文献
725.
Frost-free season lengthening and its potential cause in the Tibetan Plateau from 1960 to 2010 总被引:1,自引:0,他引:1
Dan Zhang Wenhui Xu Jiayun Li Zhe Cai Di An 《Theoretical and Applied Climatology》2014,115(3-4):441-450
Frost-free season was an important index for extreme temperature, which was widely discussed in agriculture and applied meteorology research. The frost-free season changed, which was associated with global warming in the past few decades. In this study, the changes in three indices (the last frost day in spring, the first frost day in autumn, and the frost-free season length) of the frost-free season were investigated at 73 meteorological stations in the Tibetan Plateau from 1960 to 2010. Results showed that the last frost day in spring occurred earlier, significantly in 39 % of the 73 stations. For the regional average, the last frost day in spring occurred earlier, significantly at the rate of 1.9 days/decade during the last 50 years. The first frost day in autumn occurred later, significantly in 31 % of the stations, and the regional average rate was 1.5 days/decade from 1960 to 2010. The changing rate of the first frost day in autumn below 3,000 m was 1.8 times larger than the changing rate above 3,000 m. In addition, the first frost day in autumn above 3,000 m fluctuated dramatically before the early 1990s and then it was later sharply after the early 1990s. The frost-free season length increased significantly at almost all stations in the Tibetan Plateau from 1960 to 2010. For the regional average, the frost-free season lengthened at the rate of 3.1 days/decade. The changing rate of the frost-free season length below 3,000 m was more significant than the changing rate above 3,000 m. Eight indices of large-scale atmospheric circulation were employed to investigate the potential cause of the frost-free season length change in the Tibetan Plateau during the past 50 years. There was a significant relationship between the frost-free season length and the Northern Hemisphere Polar Vortex indices. The weakening cold atmospheric circulation might be an essential factor to the Tibetan Plateau warming since 1960. 相似文献
726.
727.
利用物方匹配计算模型,实现了DEM、DOM、图幅产品的分布式计算模型,极大地提高了计算精度和速度。 相似文献
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