DISTRIBUTION, ECOLOGY AND RESOURCE CONSERVATION OF THE SPOTTED SEAL IN THE HUANGHAI AND BOHAI SEAS

The Phoca largha is found in the coastal waters of China from the Huanghai Sea and Bohai Sea to the northern part of East China Sea. Its breeding ground is situated in ice packs in the Liaodong Gulf., from about 40°10′ to 40°45′ N, from 121 °15′ to 122°E. At the breeding season, male and female seals in pairs form many family groups. The pup is born with white lanugo fur on ice packs in Liaodong Gulf during a period from January to the middle of February, and usually carried by its mother on her back to run away. However, from February to March, it could be caught around some islands in Bohai Strait. In recent years, these species resources have been reduced rapidly. It must be strengthened to protect the seals from extinction.     

ELASTIC CLASSIFICATION OF MODIFIED WATER MASS IN SHALLOW SEA

In this paper, the principle and steps for differentiating water masses by fuzzy cluster method are introduced, and a scalar formula based on Euclidean distance and a method for determining objectively the number of water masses by F-test are proposed. Consequently, a method and specific steps for differentiating modified water masses in shallow sea according to fuzzy elastic classification are given. Computation of the membership degree in which each sample belongs to every water mass determines conveniently and quantitatively the cores, boundaries of water masses and mixed zones. An example for the Huanghai Sea and East China Sea is shown and compared with previous results.     

1976年夏季东海陆架区浮游植物生态的研究

关于东海浮游植物,虽然国内、外都有人进行过一些调査研究,取得一些成果,但因调查时间较短或调查范围較小所获资料不全,都未能代表东海浮游植物的全貌。中国科学院海洋研究所继全国海洋综合调査之后,自1976年夏季又在东海陆架区进行了综合调查。这次调查，分析了东海浮游植物的个体数量和种数的分布状况,讨论了其主要种类的生态性质、群落组成和它们与水文环境的关系,对东海浮游植物的生态状况有了进一步了解。 1976年夏季在东海陆架区进行了两次(6月25日至7月23日和8月27日至9月21日)调查,调查范围南到北纬26°30′,东到东经127°,在沿纬度安排的6个断面共44个测站上(第一航次还在黄海南部增加一斜断面),分別进行了水文观测,并用网目为64平方微米的小型浮游生物网(Juday phytoplankton net),从水底到表面垂直拖网进行浮游植物采样,以个体计数法计数分析。     

热带地区流场异常与江淮特大暴雨成因的研究

本文通过计算和对比分析，得到１９９１年春、夏江淮地区特大暴雨形成的五个基本特征：西北太平洋上副高显著偏西、偏北；较弱的西南季风与东南气流汇合成强西南气流伸向江淮地区；偏东风与强西南风形成的辐合带在江淮地区维持；江淮地区对流层中下部为强上升运动、上部为辐散；１３０°Ｅ附近南半球向北半球的较强越赤道气流持续。     

关于多项式特征值的条件数

Tisseur(2000)研究了非齐次多项式特征值问题的条件数，所得结果的不足是对无穷特征值必须另外处理；Declieu和Tisseur(2003)运用微分几何方法研究了齐次多项式特征值问题的条件数，所得结果的不足之处是与系数矩阵的尺度化(scaling)有关。这两种条件数都有各自的应用范围。本文基于投影尺度引入齐次多项式特征值问题的条件数，其优点是与系数矩阵的尺度化无关，因而也许会有较广泛的应用。     

利用卫星遥感资料对南海北部陆架海洋表层温度锋的分析

利用7年(1993～1999)月平均的SST卫星遥感资料，分析了南海北部陆架区域海洋表层温度锋在一年中的逐月变化特征，表明南海北部陆架海洋表层温度锋存在明显的季节内变化。结合风场的卫星遥感资料，分析了东北季风对南海北部陆架温度锋的影响，表明东北季风风速的增加有利于温度锋强度的增强。通过对黑潮南海流套入侵较强的1999年2月与流套入侵较弱的1998年2月的SST卫星遥感资料的对比分析，考察了黑潮南海流套的入侵对南海北部陆架温度锋的影响，结果表明黑潮流套的较强入侵能够增加陆架温度锋的强度，对温度锋的走向也会产生一定的影响。     

南海中部海区次表层NO2^——N的最大值

本文根据1983年9月至1985年1月南海中部海区综合调查所获得的NO_2~--N及有关参数的观测资料,分析了该海区NO_2~--N的分布变化特征及其与环境因子的关系。结果表明,调查海区NO_2~--N含量的变化范围在0～0.54μmol/L之间,其中小于0.05μmol/L的测定值约占测定总数的82.1%,而大于0.05μmol/L测定值基本上出现在50～150m层。文中还对该海区次表层NO_2~--N最大值形成的机理作了初步探讨,指出密度跃层的终年存在、铵的氧化和浮游植物的代谢过程是调查海区次表层NO_2~--N最大值形成的主要因素。     

二次特征值问题的最佳向后扰动分析

二次特征值问题 (QEP)的主要的求解方法之一是转化为广义特征值问题 (GEP) ,然后用求解广义特征值的方法 (比如 QZ方法 )求解。本文研究由此获得的计算解的范数意义下的最佳向后扰动分析 ,所得结果是 Tisseur最近所得结果的加强。     

塞曼石墨炉原子吸收法直接测定海水中的铬

海水基体对Cr有增感作用。本文研究了抗坏血酸、柠檬酸三铵、酒石酸、乙酸铵等有机基体改进剂对消除基体干扰效果。前二者均有效地消除基体干扰,但1％抗坏血酸 1％柠檬酸三铵混合试剂的效果更好,它不仅可以消除基体干扰,还可降低背景及噪声,Cr的吸收峰也较平滑。本法准确,相对偏差在0.7—4.4％范围内。回收率在92—109％范围内。若海水Cr含量低于定量下限时,可采用多次进样法。     

Identification of Pb sources in Yellow Sea sediments using stable Pb isotope ratios

Rapid economic developments in East Asian countries have inevitably resulted in environmental degradation in the surrounding seas, and concern for both the environment and protection from pollutants is increasing. Identification of sources of contaminants is essential to environmental pollution management. In this study, the provenance of anthropogenic lead (Pb), a major pollutant of Yellow Sea sediments, was determined for river mouth sediments, including those of the Changjiang, Huanghe, Han, and Geum Rivers, and for age-determined shelf core sediments through the measurement of Pb isotope ratios in the HCl-leached fraction using multi-collector inductively coupled plasma-mass spectrometry (MC ICP/MS). Anthropogenic Pb has accumulated in shelf core sediments since 1910, and its isotope ratios were estimated as 0.863–0.866 and 2.119–2.125 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively, from the mixing relationships of the two endmembers. River mouth sediments exhibited enough distinction in anthropogenic Pb isotope ratios to be discriminated: 0.874 (2.144) in the Huanghe, 0.856 (2.129) in the Han, 0.857 (2.122) in the Geum, and 0.854 (2.101) in the Changjiang for ²⁰⁷Pb/²⁰⁶Pb (²⁰⁸Pb/²⁰⁶Pb), respectively. Although isotope ratios of geogenic Pb in sediments dating before 1910 showed narrow ranges (0.842–0.845 and 2.088–2.100 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively), distinct isotope ratios in each core permitted source identification of sediments in the Yellow Sea based on geographic locations and the geogenic Pb of each river. By comparing the isotope ratios of the estimated anthropogenic Pb to source-related materials, the provenances of anthropogenic Pb in Chinese river sediments were presumed to be Chinese coal or ore, which is also a major source of atmospheric particulate Pb. The anthropogenic Pb in the shelf core sediments in the northern Yellow Sea originated from northern Chinese cities such as Beijing and Tianjin through atmospheric pathways. Pb isotope ratios indicated that Pb in Korean river sediments was characteristic of local Korean ores.