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1.
A new standardization method for glass electrodes is proposed for pH measurements on the NBS scale. An expression is obtained to evaluate the apparent activity coefficient of hydrogen ions as a function of salinity and temperature, from determinations obtained by Mehrbach et al., 1973 (Limnol. Oceanogr., 18: 897–907). This expression must be used to estimate systematic errors produced by variations of residual liquid-junction potential by estimating the apparent activity coefficient of hydrogen ions. In this way, values of pH obtained in oceanographical cruises can be standardized in order to determine and compare different parameters of the CO2 system.Some experiments to study the variation of pH with temperature are carried out to compare the different series of acid constants used at present. A simple and precise polynomial equation is also obtained to determine the variation of pH with temperature. 相似文献
2.
基于2013年9月底至10月初在印尼爪哇岛南部海域调查得到的碳酸盐参数和相关水文数据,首次报道了该海域pH的分布,并重点探讨了南爪哇上升流(季风上升流)对其影响。结果显示上升流影响区表层pH低于周围非上升流影响区。通过两端元混合模型,定量讨论了上升流的物理输运和生物活动对pH的影响。研究表明,上升流的物理输运至少造成了海表层盐度增加0.4个单位,溶解无机碳(DIC)增加110μmol/kg,pH降低约0.2个单位;同时,在上升流区,强烈的生物活动(叶绿素a浓度大于0.4mg/m3)使得DIC的降低量达70μmol/kg,pH的增加量达0.15个单位。总体来看,该研究区域的物理输运作用大于生物作用,综合效应表现为DIC的增加和pH的降低。另外,同上升流的物理输运作用和生物作用相比,上升流引起的表层冷却和增盐对pH的影响较小(热力学作用)。 相似文献
3.
海水碳酸盐体系参数是反映碳循环调控机理和季节性酸化过程的重要海水化学参数.本文根据2011年3月、7月、11月和12月4个不同季节航次获取的长江口海域海水碳酸盐体系参数,探讨了长江口-东海P断面溶解无机碳(DIC)和总碱度(T A)的空间分布特征及其影响因素.结果表明:内陆架区,DIC和T A的平均值均表现为:夏季<秋季<冬季<春季;垂直分布上,夏季和秋季受长江冲淡水影响出现层化现象,春季和冬季均垂直混合较均匀.东海内陆架DIC与温度和DO呈显著负相关;T A则受温度和DO变化影响较小,与盐度呈正相关.结合2011年东海外陆架的PN断面数据分析,DIC和pH分别与表观耗氧量(AOU)呈显著正相关和负相关,东海外陆架的pH/AOU的斜率为-0.0027 pH/(μmol·kg-1);而内陆架区的pH/AOU的斜率为-0.0018 pH/(μmol·kg-1),低于黑潮次表层水中pH/AOU的斜率.东海内陆架区由于存在季节性的通风作用以及较强的海水碳酸盐体系缓冲能力,底层水体中因有机质耗氧降解导致的季节性酸化信号在一定程度上得到了缓解. 相似文献
4.
根据2011年和2013?2018年秋季在海州湾及邻近海域进行的底拖网调查数据，结合同步采集的底层水温、底层盐度、水深、资源密度、饵料生物等生物和非生物因子数据，开展长蛇鲻(Saurida elongata)栖息地适宜性的相关研究。利用提升回归树(Boosted Regression Tree, BRT)模型确定各环境因子的权重，分别采用算术平均法和几何平均法建立栖息地适宜性指数(Habitat Suitability Index, HSI)模型，并通过交叉验证确定最优模型。结果表明:海州湾长蛇鲻在秋季最适宜栖息的底层水温范围为17.5～18℃，最适底层盐度范围为31.3～32.0，最适水深范围为24～37 m；选择其3种主要饵料生物作为生物因子，即枪乌贼(Loligo spp.)、戴氏赤虾(Metapenaeopsis dalei)和六丝钝尾鰕虎鱼(Amblychaeturichthys hexanema)，与底层水温、底层盐度和水深共同作为影响因子建立HSI模型。结果显示，对长蛇鲻空间分布总偏差贡献率最高的是饵料因子，其次是水深和底层水温。通过交叉验证发现，运用算术平均算法，且赋予权重的HSI模型具有较低的赤池信息准则值(Akaike Information Criterion, AIC)。研究发现，海州湾秋季长蛇鲻的最适栖息地(HSI≥0.7)主要分布在34.5°～36°N，119°～121°E之间，其中35°～36°N海域的最适栖息地分布范围大，而且从近岸至远海，HSI指数有增加的趋势。 相似文献
5.
The ratio of dissolved cadmium (Cd) to phosphate (PO4) in the subtropical coastal area of Ishigaki Island, Okinawa, Japan, was investigated. Twenty vertical seawater samplings
were carried out once a month from May 2008 to January 2010. In order to examine how the Cd/PO4 ratio in seawater varies with the oceanographic conditions (i.e., the water temperature–salinity characteristics), the water
masses at the study sites were classified into two types: group 1 with a water temperature of >25°C and a salinity range of
34.0–34.4, and group 2 with a water temperature of <25°C and a salinity of >34.4. A different phytoplankton assemblage was
observed in each water mass defined. Different Cd/PO4 ratios were obtained for the two water mass types, due to the differences between the types in terms of the environmental
conditions such as the water temperature–salinity (T–S) characteristics and phytoplankton assemblages, as well as possible variations in the concentrations of dissolved iron, zinc,
manganese, and CO2 in seawater in each water mass. 相似文献
6.
Spatial and temporal variations in pH and total alkalinity at the beginning of the rainy season in the Changjiang Estuary, China 总被引：1，自引：0，他引：1
The results of field observation carried out in May 2003 were used to examine pH and total alkalinity behaviors in the Changjiang Estuary. It was showed that pH and total alkalinity took on clear spatial variations in values with the minima in the low salinity region. Like salinity, transect distributions of pH and total alkalinity （TA） in a downriver direction had a sharp gradient each. These gradients appeared in such a sequence that the TA gradient was earlier than salinity and pH gradients, and the salinity gradient was earlier than the pH gradient. These distribution characteristics seemed to be strongly influenced by the mixing process of freshwater and seawater, for both pH and total alkalinity had significant linear relationships with salinity and temperature. For pH, phytoplankton activities also had a significant impact upon its spatial distribution. During a period of 48 h, pH and total alkalinity changed within wide ranges for every layer of the two anchor stations, namely, Stas 13 and 20, which were located at the mixed water mass and seawater mass, respectively. For both Stas 13 and 20, pH and TA fluctuation of every layer could be very wide during a 4 h period. As a whole, the data of the two anchor stations showed that neither variations in salinity and temperature nor phytoplankton activities were the main factors strongly influencing the total alkalinity temporal variability on a small time scale. The data of Sta. 20 implied that both salinity variation and phytoplankton activities had a significant influence on pH temporal variability, but the same conclusion could not be drawn from the data of Sta. 13. 相似文献
7.
以黄海绿潮暴发的主要漂浮种类浒苔 (Ulva prolifera)为材料,在实验室条件下研究了浒苔光合参数、固碳速率及提升海水pH的作用,结果表明:浒苔光合作用半饱和常数Km为0.25 mmol/dm3,光合作用饱和时海水溶解无机碳(DIC)浓度也只需1.2 mmol/dm3,为正常海水DIC浓度(2.4 mmol/dm3)一半,故黄海绿潮暴发时藻体可以一直保持光合作用饱和与旺盛生长状态。水生条件下浒苔藻体主要吸收海水中的DIC,0.5 g/dm3培养密度下,1个光周期内净光合固碳速率为10.92 mg /(g·d)(鲜重)。连续培养5 d,0.5,1.0和2.5 g/dm3培养密度组的DIC浓度从22 mg/dm3分别降为4.85,2.62和0.66 mg/dm3,表明DIC去除率随藻体培养密度提高而增强,分别可达77.78%,88.00%,96.98%;藻体吸收海水中无机碳的同时可使海水pH升高,0.5 g/dm3培养密度下,1个光周期内净提升pH速率高达0.96/(dm3·g·d)。连续培养5 d,0.5,1.0和2.5 g/dm3培养密度组第1天其pH分别可达到9.1,9.2和9.7,表明藻体密度越高pH提升越快,而且第5天pH均可稳定在9.9左右。浒苔暴露在空气中可直接吸收空气中CO2,1个光周期内其光合固碳速率约为46.14 mg/(g·d),而在海水中的光合固碳速率为10.92 mg/(g·d),可见浒苔在空气中的光合固碳速率是水中的4.23倍。水生和气生时单位质量藻体的固碳效率因藻体间相互遮蔽而下降。结果可为今后黄海绿潮暴发机制及CO2减排和防止海洋酸化作用的评估提供技术支撑。 相似文献
8.
We compiled and analyzed past time-series data to evaluate changes in oceanographic conditions and marine ecosystems near the Ieodo ocean research station (IORS) in the East China Sea (N 31°15??C33°45??, E 124°15??C127°45??) in relation to longterm changes in climate and global warming. The environment data we used was a depth-specific time-series of temperature and salinity for the water columns at 175 fixed stations along 22 oceanographic lines in Korean waters, based on bimonthly measurements since 1961 taken by the National Fisheries Research & Development Institute. As an indicator for the ecosystem status of the waters off Ieodo, we analyzed species composition in biomass of fishes caught by Korean fishing vessels in the waters near the IORS (1984?C2010) and summarized the data in relation to the environmental changes using canonical correspondence analysis (CCA). To detect step changes in the time-series of environmental factors, we applied a sequential t-test analysis of regime shift. Correspondence analysis detected a major shift in fish assemblage structure between 1990 and 1993: the dominant species was filefish during 1981?C1992, but chub mackerel during 1992?C2007. This shift in fish assemblage structure seemed to be related to the well-established 1989 regime shift in the North Pacific, which was confirmed again with respect to temperature in the Yellow Sea and the Korea Strait (but not in the waters off the IORS). In overall from 1984 to 2010, salinity was more important than water temperature in CCA, implying that the fluctuation of the Tsushima warm current is a most important force driving the long-term changes in fish assemblage structure in the waters off the IORS. Further multidisciplinary researches are required to identify oceanographic and biological processes that link climate-driven physical changes to fish recruitment and habitat range fluctuations. 相似文献
9.
作者在 1 999年夏季的航次中 ,获得了南黄海表层海水 p CO2 的实测数据。本文结合水文、化学和生物等要素的同步观测资料 ,对影响 p CO2 分布和变化的某些重要现象进行了初步探讨。研究表明南黄海表层海水 p CO2 的分布存在较大的不均匀性 ,这是边缘海区海水中生物、物理和化学因素复合作用的结果。除长江口门外的 p CO2 高值区外 ,南黄海表层海水的 p CO2 值与叶绿素、水温大体呈负相关 ,而与海水的盐度基本上呈正相关。 相似文献
10.
[1]Cai Bingji. 1978. The taxonomy study on 相似文献
11.
Qiu Xinfang 《海洋学报(英文版)》1991,10(2):271-280
By using the expressions for the maximum absorption per wavelength (αλ),and the relaxation frequency fr of the boric acid relaxation derived previously by the author and employing the related oceanographic literatures, the effects of pressure, temperature, pH and salinity on (αλ)r and ∫r of the boric acid relaxation in sea water have been estimated. Results show that ( αλ), not only increases with pH but also increases approximately linearly with pressure and temperature, and is nearly proportional to the 1. 35 power of salinity. However, pressure, pH and salinity have negligible effect on ∫r; therefore, ∫r, can be approximately expressed as a function of temperature only. Comparisons of the predicted with the measured ( αλ)r and ∫r in different ocean areas are given. 相似文献
12.
据１９８４年５月至１９８５年２月调查资料，计算了该水体中二氧化碳体系各分量的含量，研究了它们与ｐＨ，ＨＣＯ＾－３／ＣＯ＾２－３，Ａｌｋ，ＤＩＮ，ＰＯ＾３－４－９，Ｃｈｌ－ａＤＯ，Ｓ，ｔ等环境因子的相关性。结果表明ＰＣＯ３，ＣＯ２（Ｔ），ＨＣＯ＾－３，ＣＯ＾２－３与ｐＨ，ＨＣＯ＾－３／ＣＯ＾２－３呈极显著的线性相关；ＨＣＯ＾－３，ＣＯ＾２－３ΣＣＯ２与Ａｌｋ也呈非常显著的线性相关。 相似文献
13.
胶州湾海水中一氧化碳光致生成影响因素的研究 总被引：3，自引：1，他引：2
海水中的一氧化碳(CO)主要由溶解有色有机物(CDOM)光降解产生,且CO的光致生成量受到环境因素的影响。采集了胶州湾及其河口表层水样,通过实验室模拟实验开展了不同的环境条件(辐射强度、光照时间、温度、pH和盐度)以及水体中CDOM的来源对CO光致生成的影响研究。结果表明胶州湾海水中CO的光致生成速率随辐射强度的增强、水温的升高和水体pH的增大而增大;随着光照时间的延长、水体盐度的增大而逐渐减小;不同来源的CDOM对水体中CO的光致生成速率产生了不同的影响。 相似文献
14.
海水中的一氧化碳(CO)主要由溶解有色有机物(CDOM)光降解产生,且CO的光致生成量受到环境因素的影响。采集了胶州湾及其河口表层水样,通过实验室模拟实验开展了不同的环境条件(辐射强度、光照时间、温度、pH和盐度)以及水体中CDOM的来源对CO光致生成的影响研究。结果表明胶州湾海水中CO的光致生成速率随辐射强度的增强、水温的升高和水体pH的增大而增大;随着光照时间的延长、水体盐度的增大而逐渐减小;不同来源的CDOM对水体中CO的光致生成速率产生了不同的影响。 相似文献
15.
J.V. Leyendekkers 《Marine Chemistry》1977,5(1):29-42
An equation is given for predicting the absolute refractive index of seawater as a function of wavelength (in the visible region), temperature, pressure and salinity. This equation is based on the pure-water equation of H. Eisenberg, on the Tammann hypothesis and the Tait-Gibson equation of state for seawater. Comparison with experimental results (to 1380 bars) indicate an accuracy of ca. 0.0001 or better is achieved in the range of oceanographic interest. 相似文献
16.
黄海南部和东海小黄鱼资源分布差异性研究 总被引：4，自引：0，他引：4
根据2006年6月～2007年4月黄海南部和东海底拖网监测调查资料,比较分析了2个海域小黄鱼资源密度指数(CPUE)分布、环境因子特征、CPUE与环境因子相关关系的差异.研究结果表明,黄海南部和东海小黄鱼资源密度指数分布除了秋季分布有显著差异之外(t′_((33))=2.69,P=0.011),其余季节分布均无显著差异(春季:t′_((43))=1.68,P=0.104;夏季:t′_((60))=0.31,P=0.756 7;冬季:t′_((43))=1.74,P=0.089);夏季的底层盐度分布和水深分布没有明显差异,在其他季节,黄海南部和东海的底层水温、底层盐度和水深分布等环境特征的差异明显,均达到极显著(P<0.01)或显著(P<0.05)水平;资源密度与环境因子回归分析和AIC模型选择中,2个海域夏季的小黄鱼资源密度受到有显著性影响的环境因子数最多,而冬季受到有显著性影响的环境因子最少.综合推断,黄海南部和东海小黄鱼具有不同空间分布特征和环境分布特征,2个海域的小黄鱼分属于不同种群,但在2个海域交界处有混栖种群. 相似文献
17.
Enzymatic properties of UFE, a novel marine fibrinolytic enzyme 总被引：2，自引：0，他引：2
A novel potent protease, Urechis unicinctus fibrinolytic enzyme (UFE), was firstly discovered. The enzymatic properties of UFE were further investigated. As a low molecular mass protein, UFE appeared to be very stable to heat and pH. When temperature was below 50 ℃, the remnant enzyme activity remained almost unchanged, but when temperature was raised to 60 ℃, the remnant enzyme activity began to decrease rapidly. UFE was quite stable in the range of pH value from 3 to 12, especially in slightly alkaline pH value. Mn2 , Cu2 and Fe2 ions were activators of UFE, while Fe3 and Ag ions were inhibitors of UFE. Fe2 ion along with Fe3 ion might regulate UFE activity in vivo. The optimum pH and temperature of UFE were about 8 and 50 ℃, respectively. Other characteristics of this enzyme were also studied. Systematic research results are significant when UFE is applied for medical and industrial purposes. 相似文献
18.
The conditional acid dissociation constants (pKa′) of two sulfonephthalein dyes, thymol blue (TB) and m-cresol purple (mCP), were assessed throughout the estuarine salinity range (0<S<40) using a tris/tris–HCl buffer and spectrophotometric measurement. The salinity dependence of the pKa′ of both dyes was fitted to the equations (25 °C, total proton pH scale, mol kg soln−1):The estimated accuracy of pH measurements using these calculated pKa′ values is considered to be comparable to that possible with careful use of a glass electrode (±0.01 pH unit) but spectrophotometric measurements in an estuary have the significant advantage that it is not necessary to calibrate an electrode at different salinities. pH was measured in an estuary over a tidal cycle with a precision of ±0.0005 pH unit at high (S>30) salinity, and ±0.002 pH unit at low (S<5) salinity. The pH increased rapidly in the lower salinity ranges (0<S<15) but less rapidly at higher salinities. 相似文献
19.
《中国海洋大学学报(自然科学版)》2000,30(Z1):179-182
以转基因聚球藻为材料,研究了 其在f/2培养液中培养时,培养温度、光照强度、培养液起始pH和盐度对生长的影响。结果 表明,该聚球藻培养的最适条件为：温度35℃,光照强度5000lx,培养液起始pH8.5,盐度1 5～30。 相似文献
20.
利用2019年8月获得的长江口及其邻近海域表层海水pCO2的走航观测数据,结合温度、盐度、溶解氧等理化参数,初步探讨了该区域夏末表层海水pCO2的空间分布特点及控制因素。研究结果显示,整体上pCO2呈现近岸高而离岸低的特点,其中在长江冲淡水的中盐度区域出现了一个pCO2的极低值区。去除温度的影响,温度归一化后的pCO2与溶解氧饱和度具有良好的负相关关系,这表明生物过程是造成研究区域pCO2巨大空间差异的主要原因,其中高初级生产造成了中盐度区的强汇现象。同时河、海混合区断面的温度、盐度和溶解氧的分布显示水体层化致使垂直混合作用对pCO2的影响较小。整体而言,研究区域的海 气界面CO2通量为-2.0±5.2 mmol·m-2·d-1,表现为大气CO2的汇。随着环境的改变和人为活动的干扰(如长江径流量的减少),长江口及其邻近海域可能存在由大气CO2的汇转为源的风险,需要持续关注和研究。 相似文献