黄海西部沿岸冷水在夏季南黄海西部底层冷水形成和季节演变过程中作用的化学水文学分析

CHEMICOHYDROGRAPHIC ANALYSIS OF THE ROLE OF THE YELLOW SEA WESTERN COASTAL COLD WATER IN FORMING THE SOUTHERN YELLOW SEA WESTERN BOTTOM COLD WATER AND ITS SEASONAL SUCCESSION

基于南黄海西部海域的四季水文和营养盐调查资料,从化学水文学的视角研究了黄海西部沿岸冷水在南黄海冷水团及其西部冷中心形成和季节演变中的作用,揭示了南黄海冷水团与青岛冷水团之间的内在联系,阐释了夏季黄海冷水团西部冷中心的形成机制。结果表明,冬、春季南黄海西部沿岸流沿陆架锋面南下流动。黄海西部沿岸流南下携带的冷水对春季青岛冷水团以及南黄海中层和底层冷水、夏季南黄海西部冷水团及其冷中心的形成具有重要的作用,南黄海西部底层冷水首先在青岛冷水团附近海域孕育,并在夏季发展为黄海冷水团的西部冷中心。入秋后,南黄海西部陆架锋东侧的底层冷水开始消退,同时黄海西部沿岸流也重新携带冷水南下,并逐渐为翌年的青岛冷水团水、南黄海中层和底层冷水以及夏季南黄海西部陆架锋东侧的底层冷水提供来源,由此形成夏季南黄海西部陆架锋东侧底层冷水的季节性演替。本研究深化了对黄海西部沿岸流和南黄海冷水团及其相互关系的认识,进一步揭示了南黄海西部冷水团水的来源。

The preparation of high-Fischer ratio hydrolysates from the hydrolysis of tuna meat by two-step proteases was studied. Taking degree of hydrolysis （DH） as criterion, binary-enzymes hydrolysis process was optimized by response surface methodology. Hydrolysates derived from tuna meat were statically adsorbed by activated carbon in order to remove liberated aromatic amino acids （AAA）. Detection of amino acid composition was carried out after treatment by activated carbon absorption. The results show that the optimum enzymolysis conditions selected by Design-expert 7.0 were as follows： pepsin was selected as the first enzyme, ratio of enzyme to substrate 650U/g, ratio of tuna meat to water 1∶7 （g/mL）, temperature 35.9℃; flavourzyme was selected as the second enzyme, ratio of enzyme to substrate 50700U/g, pH 6.51, temperature 51℃, the highest degree of hydrolysis was 36.87%±0.54%. The optimal absorption condition by activated carbon was ratio of 1 ： 20 （W/V）, temperature 35℃, time 3h. The Fisher value of hydrolysates （removing AAA） determined on Automatic Amino Acid Analyzer was calculated to be 30.33, and a high AAA absorption ratio was 63.18%.