A comparative study on the contents of vitamins in the natural and the cultured prawn

Ａｃｏｍｐａｒａｔｉｖｅｓｔｕｄｙｏｎｔｈｅｃｏｎｔｅｎｔｓｏｆｖｉｔａｍｉｎｓｉｎｔｈｅｎａｔｕｒａｌａｎｄｔｈｅｃｕｌｔｕｒｅｄｐｒａｗｎ￥ＷａｎｇＡｎｌｉ；ＷａｎｇＷｅｉｎａ；ＬｉｕＣｕｎｑｉａｎｄＷａｎｇＳｕｏ＇ａｎ（ＲｅｃｅｉｖｅｄＦｅｂｒ...     

一种提高粘土矿物去除赤潮生物能力的新方法

在研究粘土颗粒与赤潮生物絮凝作用的基础上，建立了粘土表面改性对其絮凝作用影响的理论模型，认为改变粘土颗粒的表面性质提高其去除赤潮生物能力的主要途径，提出在粘土中引入ＰＡＣＳ（聚羟基氯化铝）的改性方法。结果表明，对于微型原甲藻（Ｐｒｏｒｏ－ｃｅｎｔｒｕｍ ｍｉｎｉｍｕｎ）体系，粘土中引入微量ＰＡＣＳ后，其去除率达９０％以上的高岭土用量由原来的２ｇ／Ｌ降至０．１ｇ／Ｌ，去除效率提高近２０倍。考察了ＰＡ     

半封闭海湾固有振动周期的数值计算

用二维数值模式,根据芝罘湾的实测水深和形状,计算了该湾的固有振动周期,与实测资料吻合较好。计算结果同时给出了当节点N=1,2,...,6时,湾内的振幅分布（合波长、波节线分布）,以及纵振动和横振动分布情况。     

英国的自然保护

就英国自然保护区的八种主要类型：国家公园、国家风景区、自然遗产区、自然风景名胜区、遗产海岸、环境敏感区、特殊科学意义区、国家自然保护区;以及自然保护区的保护管理机构分别进行了概略介绍,以便有助于对英国自然保护区的了解。     

南黄海北部B03孔沉积物的重矿物特征及物源指示意义

本文对取自南黄海北部的B03孔岩芯(330cm)沉积物进行了粒度和重矿物特征分析,并运用电子探针技术,分析了其典型层位角闪石的矿物化学特征。研究表明,B03孔柱状样为均一连续的粉砂质沉积,重矿物含量较低(平均仅0.65%),主要为云母类和闪石类矿物,岩芯以85cm处为界分为上、下2个沉积层,其重矿物组合分别为普通角闪石-云母类矿物-绿帘石和云母类矿物-普通角闪石-绿帘石。角闪石的EPMA分析显示其种属主要为镁角闪石,其次为镁钙闪石、铁镁钙闪石及阳起石,成因以中酸性侵入岩与中高级变质岩为主,上下沉积层角闪石特征元素Mg/Fe2+比值分别为2.03、1.90。综合分析认为,岩芯的主要物源为黄河源物质及山东半岛陆架基岩剥蚀产物的混源,上下沉积层的矿物特征差异暗示了沉积物源发生了变化,其分界线可能代表了黄河1855年改道事件在山东半岛东部陆架的区域响应。     

Large-scale environmental influences on the benthic macroinfauna of the southern Gulf of Mexico

The influence of large-scale natural disturbance from winter storms (‘northers’) and river runoff on the macrobenthic community structure of the southern Gulf of Mexico was investigated in both carbonate and transitional carbonate–terrigenous sedimentary environments. Samples of the infauna were obtained in three seasons from 13 stations from two 250 km transects along 80–170 and 20–50 m water depth. Samples after the northers season had the lowest total number of families and individuals, 114 and 2940, respectively, compared to the dry and rainy seasons with 129 and 132 families and 11580 and 15266 individuals, respectively. Spatial patterns of macroinfauna composition varied across and along the shelf as a response to sedimentary environments and depth. Coarser sediments from the carbonate area harboured the highest mean densities per station with 500–24,000 individuals m⁻² and 108–122 families in total, compared to the transitional sediment with 500–8200 individuals m⁻² and 56–74 families across the three seasons. Univariate and multivariate statistical techniques demonstrated that low densities and number of taxa were associated with winter storms, but storm influence was dependent on depth and sediment type. Multiple linear regression analysis and BIOENV analysis indicated that sediment mean grain size, percentage of clay and organic matter best explained the macroinfauna spatial patterns, although BIOENV indicated that depth has an overriding role. An increase in densities of opportunistic taxa (numerous polychaetes of small sizes) was observed four months after the ‘northers’ and this was more evident in the area of carbonate sediment. Additionally a combined disturbance from northers and river runoff is suspected to be responsible for a naturally impoverished macroinfauna community in the transitional sedimentary environment.     

天然气水合物成矿的沉积控制因素

天然气水合物是一种非常规的天然气矿藏，其形成与分布除了需要特定的温压条件外，还需要合适的沉积条件。截止2002年底，世界上共有l16处已直接或间接发现水合物，直接见到水合物样品的只有23处(海洋20处、陆地3处)，所以对水合物沉积条件的系统研究处于比较薄弱的阶段，文献报道也较少，目前认为其形成的沉积控制因素主要有岩性、沉积速率、有机碳含量、沉积环境及沉积相等4方面。     

中国近海的天然气勘探

据最新勘探资料，在综合分析中国近海海域天然气勘探现状、资源潜力及其区域分布规律的基础上，分析了我国近海海域天然气勘探的有利区带及目前比较现实的勘探目标，展示了我国近海海域天然气勘探的良好前景。     

苏北盐城凹陷复合含油气系统

苏北盐城凹陷含油气系统可划分为上、下2个复合含油气系统。上复合含油气系统，即Pz、K2p、K2t(生)-K2t、E1f1(储)一E1f1 E1f2(盖)，古生界、中生界浦口组和泰州组为烃源岩层，泰州组和阜宁组一段为储集层，阜宁组一段顶部至二段暗色泥岩为区域盖层，油气沿深大断裂运移，油气成藏关键时刻在古近纪晚期至新近纪早期，有利勘探区在深大断裂附近的中、新生界发育地区；下复合含油气系统，即Pz、K2p(生)-Pz、K2p(储)-K2p3 K2p4(盖)，油气通过断层或不整合运移，油气大量生成的关键时刻为古近纪早期，该系统中气藏分布在古生界被中生界覆盖地区。     

Genetic Diversity in Marine Molluscs: A Test of the Niche-Width Variation Hypothesis

Abstract. A test of the niche width variation hypothesis was conducted in the three Mediterranean littoral species of the family Trochidae: Monodonta turbinata, M. turbiformis and Gibbula richardi. Allozymic variation encoded by 26 gene loci was analyzed, and the levels of polymorphism (P), heterozygosity (H) and allele diversity per locus (A) were estimated and appear to support the niche-width variation hypothesis. The broad-niche species, M. turbiformis and G. richardi are more polymorphic and heterozygous than the relatively narrow-niche M. turbinata (P = 0.571; 0.731 and 0.417; H = 0.108; 0.116 and 0.078; A = 2.025; 2.489 and 1.965, respectively).