隐甲藻藻渣醇水提取物的抗氧化活性研究     

于金慧  尤升波  边斐  张燕  陈高  黄超  马德源  贾文斌  丁汉凤  毕玉平 《海洋学报》2018,40(8):129-137

本研究采用总抗氧化能力、DPPH自由基清除能力、亚铁离子螯合能力及总还原力等抗氧化指标评价隐甲藻（Crypthecodinium cohnii）藻渣醇水提取物不同极性萃取物的抗氧化能力,采用分光光度法测定样品中总酚和总黄酮含量。结果表明隐甲藻渣不同极性萃取物均具有一定的抗氧化能力,其中乙酸乙酯相和石油醚相总抗氧化能力和亚铁离子螯合能力较高,水相和正丁醇相的DPPH自由基清除能力和总还原能力较高,且在一定质量浓度范围内存在量效关系。相关性分析结果显示,不同极性萃取物的总多酚含量与DPPH自由基清除能力和总还原能力显著正相关,而总黄酮仅与总抗氧化能力和金属离子螯合能力呈正相关关系,提示除酚类和黄酮类化合物外,可能还含有其他抗氧化成分。本研究表明隐甲藻藻渣具有较好地抗氧化活性,有待合理开发利用,其可能存在的其他抗氧化活性成分也有待于进一步明确。  相似文献   

The surge-like eruption of a miniature filament associated with circular flare ribbon     

Haidong Li  Jiayan Yang  Yunchun Jiang  Yi Bi  Zhining Qu  Hechao Chen 《Astrophysics and Space Science》2018,363(2):26

We present a study of a mini-filament erupting in association with a circular ribbon flare observed by NVST and SDO/AIA on 2014 March 17. The filament was located at one footpoint region of a large loops. The potential field extrapolation shows that it was embedded under a magnetic null point configuration. First, we observed a brightening of the filament at the corresponding EUV images, close to one end of the filament. With time evolution, a circular flare ribbon was observed around the filament at the onset of the eruption, which is regarded as a signature of reconnection at the null point. After the filament activation, its eruption took the form of a surge, which ejected along one end of a large-scale closed coronal loops with a curtain-like shape. We conjecture that the null point reconnection may facilitate the eruption of the filament.  相似文献   

北极海冰变率的独特模式及其与大气强迫的关系   总被引：1，自引：1，他引：0  

梁钰  毕海波  王云鹤  张泽华  黄海军 《海洋学报(英文版)》2020,39(9):60-72

The spatial structure of the Arctic sea ice concentration(SIC) variability and the connection to atmospheric as well as radiative forcing during winter and summer for the 1979–2017 period are investigated. The interannual variability with different spatial characteristics of SIC in summer and winter is extracted using the empirical orthogonal function(EOF) analysis. The present study confirms that the atmospheric circulation has a strong influence on the SIC through both dynamic and thermodynamic processes, as the heat flux anomalies in summer are radiatively forced while those in winter contain both radiative and "circulation-induced" components. Thus,atmospheric fluctuations have an explicit and extensive influence to the SIC through complex mechanisms during both seasons. Moreover, analysis of a variety of atmospheric variables indicates that the primary mechanism about specific regional SIC patterns in Arctic marginal seas are different with special characteristics.  相似文献   

Variations of helioseismic parameters due to magnetic field generated by a flux transport model     

Shao-Lan Bi  Tan-Da Li  Kang Liu  Jie Jiang  Ya-Guang Li  Jing-Hua Zhang  Xian-Fei Zhang  Ya-Qian Wu 《天文和天体物理学研究(英文版)》2021,(4):157-164

The change of sound speed has been found at the base of the convection during the solar cycles,which can be used to constrain the solar internal magnetic field.We aim to check whether the magnetic field generated by the solar dynamo can lead to the cyclic variation of the sound speed detected through helioseismology.The basic configuration of magnetic field in the solar interior was obtained by using a Babcock-Leighton(BL) type flux transport dynamo.We reconstructed one-dimensional solar models by assimilating magnetic field generated by an established dynamo and examined their influences on the structural variables.The results show that magnetic field generated by the dynamo is able to cause noticeable change of the sound speed profile at the base of the convective zone during a solar cycle.Detailed features of this theoretical prediction are also similar to those of the helioseismic results in solar cycle 23 by adjusting the free parameters of the dynamo model.  相似文献   

基于OLCI数据的杭州湾悬浮物浓度估算及其产品适用性分析     

李渊  郭宇龙  程春梅  张毅博  胡耀躲  夏忠  毕顺 《海洋学报》2019,41(9):156-169

悬浮物含量及其时空分布是河口海岸环境中关心的热点问题。2016年2月16日,欧洲航天局发射了新一代海洋水色传感器(OLCI),该传感器具有良好的时空及光谱分辨率。本研究结合2017年7月杭州湾同步采样数据,对比了6种大气校正算法和8种悬浮物浓度(TSM)估算模型,遴选和分析了适宜于杭州湾和OLCI数据的大气校正方法和TSM估算模型,验证了OLCI数据二级产品精度和适用性。结果表明:(1)基于紫外光谱的大气校正算法(UVAC)精度最高,同步4个采样点的大气校正平均相对误差(MAPE)分别为34.21%、13.11%、5.92%和20.28%。在除Oa1以外的14个波段的MAPE均值为15.23%,Oa4至Oa10波段的MAPE低于8%;(2)基于Oa16/Oa5的波段比值模型,具有良好的建模(MAPE为16.49%,RMSE为50.92 mg/L)和验证(MAPE为19.08%,RMSE为19.29 mg/L)精度及模型稳健性;(3)基于C2RCC算法的固有光学量和TSM含量产品及OLCI二级TSM含量产品在杭州湾精度较差,不适用于杭州湾TSM和固有光学量遥感监测应用;(4)空间上,TSM在杭州湾中部区域含量较低,在杭州湾南岸和湾口区域含量较高。  相似文献   

繁茂膜海绵对工厂化养鱼水体微生物净化作用的初步研究     

蒲红宇  唐玲  张弼  张喜昌 《广东海洋大学学报》2009,29(4):41-45

在大菱鲆(Scophthalmus maximus)工厂化养殖废水中接种繁茂膜海绵(Hymeniacidon perleve),并将繁茂膜海绵与大菱鲆同池养殖,研究繁茂膜海绵对大菱鲆工厂化养鱼水体微生物的净化作用。结果表明,接种量为7 mg/L繁茂膜海绵经过8、16、24、32、40、48 h对养鱼废水中细菌总数的清除率分别为23.18%、47.65%、66.09%、81.57%、93.80%、98.96%;对弧菌的清除率分别为48.61%、56.44%、78.13%、92.88%、97.10%、98.56%;对大肠杆菌的清除率分别为39.51%、41.90%、73.24%、92.29%、97.69%、99.14%,将繁茂膜海绵以7 mg/L的生物量与大菱鲆同池养殖24 h,水体中细菌总数、弧菌和大肠杆菌的清除率分别为61.38%、50.34%、93.47%。  相似文献   

海湾扇贝控温育苗采卵时间的预报方法   总被引：3，自引：2，他引：3  

毕庶万  徐宗发  于光溥  李烟芬  房淑珍  孙长祥  杜季畅 《海洋与湖沼》1996,27(1):93-97

于１９８８年３月－１９９３年５月，在威海崮山渔业公司和文登市海水养殖一场，采集海湾扇贝，运用二点法、最小二乘法和电动计数式积温仪测积温３种方法，进行海湾扇贝生物临界温度和控温育苗采卵时间预报方法的研究。结果表明：在升温促熟中，用３种方法求出的海湾扇贝的生物学临界温度分别为Ｔ０１＝９．００℃，Ｔ０２＝６．５４℃，Ｔ０３℃＝７．１１℃；这些结果是实验条件精度差异的反映，Ｔ０３精度较高。亲贝入池温度与促  相似文献   

黄海西部34°N断面潮生陆架锋的多年变化及跨锋断面的环流结构   总被引：5，自引：0，他引：5  

赵保仁  涂登志  毕亚文 《海洋科学》1992,16(2):41-45

本文分析了苏北浅滩外侧34°N断面上潮生陆架锋的多年变化,指出海上调查期间的日平均风速和大小潮变化是影响陆架锋多年变化的主要因素。本文还用诊断模式给出了横跨锋断面的环流结构。  相似文献   

Sedimentary record of climate change in a high latitude fjord——Kongsfjord     

Hang Wu  Binbin Deng  Jinlong Wang  Sheng Zeng  Juan Du  Peng Yu  Qianqian Bi  Jinzhou Du 《海洋学报(英文版)》2023,42(1):91-102

The sedimentary record of climate change in the Arctic region is useful for understanding global warming.Kongsfjord is located in the subpolar region of the Arctic and is a suitable site for studying climate change.Glacier retreat is occurring in this region due to climate change,leading to an increase in meltwater outflow with a high debris content.In August 2017,we collected a sediment Core Z3 from the central fjord near the Yellow River Station.Then,we used the widely used chronology method o...  相似文献   

Crystal Structure and Geometry-Optimization Study of N-（2-hydroxy-1-naphthaldene）-4-aminoantipyrine     

Feng Guo  Caifeng Bi  Yuhua Fan  Aidong Wang  Jiakun Xu  Xia Zhang 《中国海洋大学学报(英文版)》2008,7(2):166-170

N-(2-hydroxy-1-naphthaldene)-4-aminoantipyrine has been synthesized. The structure is determined by X-ray diffraction method and elemental analysis. The crystal system belongs to orthorhombic space group P(2)2(1)2(1). The geometry has been ob-tained from the density functional theory (DFT) method and the B3LYP method employing the 6-31G* basis sets. The calculated results propose that the latter is close to the experimental data. The structural parameters from the theory are close to those of the crystal and the calculated total energy of coordination is -31677.172 eV. The energy of HOMO and LUMO and the energy gap are 5.179 eV, -1.603 eV and 3.577 eV, respectively.  相似文献