基于多波束测深系统的水下成像技术

为实现多波束测深系统的一体化探测功能,研究分析了利用快拍法进行多波束水下成像的基本原理,并考虑实际中的水声环境和多波束测深系统自身的复杂性,对用于成像的位置数据和散射强度数据进行了修正,湖上试验数据的处理结果表明了该方法对水中目标的探测能力,验证了其工程应用的可行性。     

海洋盐生植物海马齿(Sesuvium portulacastrum)对环境盐度胁迫的耐受性及营养价值综合评价

通过水培实验,系统研究了广泛分布于全球热带和亚热带海岸的多年生匍匐性肉质草本盐生植物海马齿(Sesuvium portulacastrum)在不同盐度培养条件下的生长,探讨其盐环境适应性和适宜栽培盐度,并测定海马齿的营养成分,对其营养价值进行评价。结果表明,海马齿在35和30盐度下的生长受到明显抑制,茎间变短,叶子肉质化程度加重。在0—20盐度条件下能快速生长,是栽培的适宜盐度。海马齿具有高蛋白低脂肪的营养特点,含有丰富的水分,肉质多汁,平均营养价值估算法得出的ANV分数为2.95—2.96,营养综合评分为2,第四类营养等级,总体营养价值高于红萝卜、马铃薯、莴苣笋、大白菜等多种常见蔬菜,属于营养价值稍高的植物。每100g海马齿食用部分,其能量为74.9—93.3k J,水分为93g,灰分为2.6g,碳水化合物为1.4g,蛋白质为3.0g,粗纤维为0.95g;含有亚麻酸和亚油酸两种必需脂肪酸;含有丰富的矿质元素,其含量大小为NaKCaMgPIMnFeZnCuSe,可为人体提供常量及微量元素的补充;维生素E含量最高,β-胡萝卜素次之;含有16种必需氨基酸,种类齐全。谷氨酸含量最高,蛋氨酸含量最低,含有丰富的鲜味氨基酸,其含量占总氨基酸的23.02%。海马齿含有配比合理的丰富必需氨基酸,占总氨基酸的比例为39.39%。其必需氨基酸RAA值为0.19—0.25,RC为0.84—1.09,SRC为90.69,是极具潜力的可开发为高营养绿色保健的野生海洋蔬菜品种。     

一株抗硅藻附着的海绵附生菌的鉴定及发酵条件优化

为了从海绵共附生微生物中寻找天然高效抗污损活性物质,本文针对前期研究获取的4株具有显著抗硅藻附着的活性菌株进行活性验证和比较,选出其中最优菌株进行菌种鉴定及发酵条件优化.比较了活性菌株对小新月菱形藻(Nitzschia closterium)、咖啡双眉藻(Amphora coffeaeformis)、碎片菱形藻(Nitzschia frustulum)附着的抑制活性,确定菌株UST050418-715为最优菌株;通过16S r DNA的测序分析,结合平板的菌落形态和扫描电镜下菌体特征,鉴定活性菌株UST050418-715为短小芽孢杆菌(Bacillus pumilus).为优化该菌株的培养条件,选择了酵母粉、蛋白胨、Na Cl、p H值进行四因素三水平的正交实验,对菌株培养条件进行优化.发现选择的4个因素对应的菌株发酵产物对硅藻附着的抑制活性大小不同,影响显著性顺序是酵母粉蛋白胨Na Clp H值,综合菌株发酵产物活性、粗提物产量和菌株生长情况进行分析,确定菌株UST050418-715基于海洋2216E培养基的最佳发酵条件为:蛋白胨含量7.5 g/dm3,酵母粉含量3 g/dm3,Na Cl含量10.45 g/dm3,p H值9.5.     

Contribution of siderite–water interaction for the unconventional generation of hydrocarbon gases in the Solimões basin,north-west Brazil

Hydrocarbon gases with unconventional carbon isotopic signatures were observed in the Solimões sedimentary basin in north-west Brazil. Siderite contents measured with a new Rock-Eval methodology in the drill-cuttings samples of the Famenian source rock were found to decrease with the increase of gas maturity and with the occurrence of the gas isotopic anomalies. Triassic diabase intrusions induced heating of the source rock, which likely resulted in the gradual oxidative dissolution of siderite as suggested by the observation of etch pits on the siderite surfaces. It is proposed that ferrous iron from the carbonate was involved in a redox reaction with water producing ferric iron and H₂, then reducing CO₂ and yielding an inverse correlation between siderite content and gas maturity. Alternatively, hydrogenation of highly mature kerogen by H₂ derived from siderite could explain the production of ¹³C-rich CH₄. Mass balance considerations suggest that these mechanisms may account for a significant fraction of the hydrocarbon gases generated from the Famenian source rock in the Solimões basin.     

The effect of river-delta system on the formation of the source rocks in the Baiyun Sag,Pearl River Mouth Basin

Source rock formation influenced by river-delta system, especially in continental margin basins, is still poorly understood. This article aimed to reveal the effect of river-delta system on the formation of the source rock by taking the Baiyun Sag of the Pearl River Mouth Basin for example. Paleo-Pearl River began to develop since the Enping Formation, providing abundant organic matter beneficial for the formation of the source rocks in the Baiyun Sag. The main controlling factor of source rock formation in the Baiyun Sag is terrestrial organic matter supply rather than the paleoproductivity or redox conditions. Low Al/Ti and P/Ti ratios suggest low marine productivity, which may be associated with a large number of terrigenous detritus input, occupying about 43.04%–94.91%. There is a positive correlation between the oleanane/C₃₀hopane ratio and the TOC value, showing that terrigenous organic matter controls the source rock formation. The size of the delta below Pearl River estuary determines the extent of terrestrial organic matter supply. Source rocks with high organic matter abundance mainly formed in delta environment, and those in neritic environment in Enping and Zhuhai Formations also have high TOC values as a result of adequate terrestrial organic matter supply.     

Changes in life cycle of the Ponto‐Caspian amphipod Pontogammarus robustoides at in the northernmost part of its range

The aim of this study was to investigate the dynamics of abundance, population structure and reproductive variables of the invasive Ponto‐Caspian amphipod Pontogammarus robustoides in its northernmost population, located in the Baltic Sea. Pontogammarus robustoides population variables were studied every month from May to October over 7 years (2002–2008) at two locations in the eastern part of the Gulf of Finland, one site in the north and one in the south. Observations of macrozoobenthos were also conducted once per year in July at 12 sites in this gulf during 2002–2014. This was to monitor the distribution area of P. robustoides and its abundance/biomass in different parts of the Gulf. The results showed that P. robustoides is a widely spread species in the Gulf, preferring to colonize stone‐sandy, vegetated and littoral habitats, from the shore to a depth of 5 m, with water salinity of 0.2–3 ppt. This species co‐exists with other amphipods, such as the Baikalian Gmelinoides fasciatus, the North Atlantic Gammarus tigrinus and the native Gammarus spp. The abundance of P. robustoides varied between the two study sites and among years (2002–2008), reaching a maximum level of 1000 ind.·m^?2 for adults and 3000 ind.·m^?2 for juveniles. The temperature‐dependent duration of egg development (embryogenesis) in the amphipod and the annual number of generations in P. robustoides populations varied among years. Three generations were recorded in most years and two generations in the coldest years. Clutch size (or fecundity) was dependent on the body length of female and averaged between 33 and 43 eggs per clutch for females ranging in body length from 11.2 to 12.2 mm. A maximum of 75 eggs were observed in a female with a body length of 16 mm. This paper concludes that life‐cycle variables change when P. robustoides spreads from the southern (Ponto‐Caspian region) to northern (Baltic Sea) range areas. In the studied northernmost location, the fecundity and number of generations of this amphipod were 1.5–2‐fold lower compared with the more southern locations. In addition, these variables and P. robustoides abundance were different between the coldest and warmest years at study sites that testify about their distinct dependence on local environmental conditions; further changes in life cycle of this species may be expected together with current climate warming.     

Note on axisymmetric consolidation of multi-layered poroelastic soils with compressible constituents

In the conventional analysis of Biot’s axisymmetric consolidation, the solid phase and the surrounding fluid were often assumed incompressible for simplicity. Such assumption in soil engineering ignored the effect of compressibility of constituents on the consolidation. In this article, the compressible fluid and solid in soil were taken into account for 3-D consolidation. The pore pressure, the displacements, and the stresses were expressed by two displacement functions, and the Laplace–Hankel transform was applied to set up the stiffness matrix between the generalized displacement and stress. The stiffness matrix consisted of negative exponential functions, ensuring that the computation is efficient and stable. Then the global stiffness matrix is extended by embracing the continuity of the interfaces and boundary conditions of soil base. The relationship between the generalized displacement and stress of the soil base reduces the number of unknowns of the global matrix. Such consideration reduced the number of unknowns of the global matrix and brought in more acceptable boundary conditions where the stiffness and the permeability of semi-infinite soil base can be taken into account. After the inversion of the Laplace–Hankel transform, the real solutions were obtained. The results show that the stiffness and permeability of the soil base can change the development consolidation and that the compressibility of solid particles has a great effect on the settlement in the beginning of consolidation.     

Fish recruitment into a South African temporarily open/closed temperate estuary during three different hydrological mouth phases

Quantitative recruitment of ichthyofauna into a South African temporarily open/closed estuary (TOCE) was investigated during three distinct hydrological phases: closed overwash, open outflow and tidal mouth conditions. Maximum recruitment densities occurred during outflow conditions and declined when the system became tidally inundated. Recruitment densities were lowest during overwash events. Selective diel variation was evident, with higher night-time densities for each phase. This study highlights the importance of seasonal timing and duration of open conditions and overwash events for structuring ichthyofaunal community composition of southern African TOCEs.     

开钻新工艺介绍及其优越性分析

介绍自升式钻井平台勘探二号在渤海某井作业中采用的一、二开合并钻进的开钻新工艺,并对新工艺与传统工艺对比分析,找出新工艺存在的优越性,以及使用新工艺的必要条件和技术要点。     

青岛近海浒苔光谱特征研究

针对从2008年以来,每年夏季我国黄海南部暴发大面积的浒苔(Enteromorpha)灾害,对海洋环境及经济造成不利影响的状况,为了进一步研究浒苔特性,为利用遥感手段监测浒苔提供一定的理论依据,通过实地测量不同条件下浒苔的光谱反射率曲线,定性分析了浒苔的光谱特征。结果表明,浒苔的基本光谱特征表现为在蓝光波段和红光波段形成反射谷,在绿光波段形成反射峰,而在近红外波段反射率明显增大,形成高反射峰。因此将红光波段和近红外波段作为敏感波段,利用NDVI(归一化植被指数)提取遥感图像上的浒苔信息,可取得较好效果,有利于浒苔监测。