Degradation in Cemented Marine Clay Subjected to Cyclic Compressive Loading

The influence of cyclic loading on the strength and deformation behavior of cemented marine clay has been studied. This marine clay is of recent Pleistocene origin and deposited in a shallow water marine environment. Open pits were dug in sheeted enclosures and from these pits, undisturbed samples were taken for strength testing. A series of standard triaxial shear tests and stress controlled one-way cyclic load tests were conducted at consolidation stress ranges below and above the preconsolidation pressure. For the stress levels below the preconsolidation pressure, the cyclic loading has brought about the collapse of the cementation bond through an increase in strains, and at higher pressure ranges, the soil behaves like typical soft clay. This experiment studied the rate of development of strain and pore water pressure and shows that rate is a function of number of cycles, applied stress, and stress history. In addition, soil degradation during cyclic loading is studied in terms of Degradation Index. Attempt has been made to predict stain, pore water pressure, and degradation index through an empirical model.     

济州岛南部海区的双跃层现象

本文分析了济州岛南部区域温度双跃层现象的类型及其成因。特别阐明了双跃层的波状现象,指出:强流锋区的侧向效应,黑潮次—中层混合水的爬升,黄海冷水团边缘密度环流引起的侧向流动,以及上、下层流速、流向不一致引起的剪切作用,是导致双跃层波状现象的主要原因。发现上、下跃层之间存在着“跃层间环流”,这是一个有趣的海洋学现象,它将导致双扩散的发生和有利于双跃层的维持。     

中华鲟配合饲料适宜蛋白质含量及最佳蛋白能量比研究

以酪蛋白和明胶为蛋白源 ,添加豆油、鱼油、糊精、纤维素以及适量的维生素和矿物质混合剂配制试验饲料 ,饲料配成5个蛋白质水平 ,每个蛋白水平分别包括5个能量级 ,以体质量增长倍数、蛋白质效率和饲料系数为评判依据 ,对体质量为8.73g±0.79g的中华鲟(Acipensersinensis)的适宜蛋白质含量及其蛋白能量比进行了研究。经过为期8周的试验 ,结果表明 :中华鲟幼鲟配合饲料中的适宜蛋白质含量范围为35.7%～41.8% ,饲料的最佳蛋白能量比范围为21.85～30.05ng/J。当试验饲料蛋白质含量为40.3% ,蛋白能量比为27.85ng/J时 ,试验鲟鱼获得最大体质量增长倍数为11.60±1.20,最低的饲料系数为1.68±0.23,以及最高的蛋白质效率为1.58%±0.14%。     

蛋白质组学的研究概况及其在海洋生物学中的应用

随着DNA序列测定技术的飞速发展，人们可以在很短的时间内获得某种生物基因组的全序列。生物体的生命活动主要依赖于基因组的产物——蛋白质组，但是蛋白质组的研究相对于基因组来说却要复杂得多。蛋白质组技术是在细胞内整体蛋白质水平上进行研究，从蛋白质整体活动的角度来研究生命活动的规律。综述了蛋白质组和蛋白质组学出现的背景、起源、概念、研究技术、研究内容、面对的挑战、开展该项研究的意义、陆生动植物和微生物蛋白质组学的研究进展及海洋生物蛋白质组学的研究概况。目前，普通生物方面的蛋白质组工作开展得较多，海洋生物方面却相对滞后。种种迹象表明，开展海洋生物蛋白质组学研究，对揭示生命的奥秘、促进海洋资源的开发都有重大的推动作用。     

Assessment of the effects of hydrocarbon contamination on the sedimentary bacterial communities and determination of the polar lipid fraction purity: Relevance of intact phospholipid analysis

This in situ study reports on the relevance of intact phospholipids as new biomarkers and highlights the limits of the classical fatty acid analysis after the hydrolysis of the polar lipid fraction. The analysis of polar lipid fractions revealed significant contributions of marine macrophytes with either non-phospholipid compounds (sulfoquinovosyl diacylglycerol) or with both non-bacterial phospholipid classes (phosphatidylcholine) and non-bacterial phospholipid molecular species (some molecular species of phosphatidylglycerol). The analysis of intact phospholipids showed also the predominance of gram-negative bacteria in sediments whereas the analysis of fatty acids alone cannot confirm such information. Lastly, as regard to the effects of petroleum hydrocarbons on the sedimentary bacterial communities, we observed a higher degree of saturation of the fatty acyl chains of the phospholipids extracted from sediment exposed to a massive and chronic crude oil contamination. Such a result was interpreted as an adaptive response resulting in higher membrane rigidity of the bacterial communities.     

烟威及石岛近海春季水团分析

本文使用1960—1980年春季的水文资料,以温度和盐度作为主要指标,根据聚类分析逼近温盐图解,结合对该海域地理环境特征的分析,对烟台、威海及石岛近海春季的水团结构演变及其和渔场、渔期的关系进行综合分析。结果表明,北黄海及青岛外海的冷水团,以及黄海暖水团的强度与位置的变动,对春季渔期的早迟以及渔场位置的变动,都有很大的影响。     

80年代我国人口性别比的变动及其省区差异

本文根据有关资料,讨论了80年代我国人口性别比的变动特点及其省区差异,认为我国人口性别比上升的主要原因是出生性别比的变化,最后分析了人口性别比上升对我国男性婚姻的影响。     

Trace gas exchange at the air/water interface: Measurements of mass accommodation coefficients

A liquid jet of 90 m diameter and variable length has been utilized to determine absorption rates and, hence, mass accommodation coefficients , of atmospheric trace gases. The compounds investigated are HCl (0.01), HNO₃ (0.01), N₂O₅ (0.005), peroxyacetyl nitrate (>0.001), and HONO (0.005). It is concluded that the absorption of these trace gases by liquid atmospheric water is not significantly retarded by interfacial mass transport. The strengths and limitations of the liquid jet technique for measuring mass accommodation coefficients are explored.     

Increasing critical sensitivity of the Load/Unload Response Ratio before large earthquakes with identified stress accumulation pattern

The Load/Unload Response Ratio (LURR) method is proposed for short-to-intermediate-term earthquake prediction [Yin, X.C., Chen, X.Z., Song, Z.P., Yin, C., 1995. A New Approach to Earthquake Prediction — The Load/Unload Response Ratio (LURR) Theory, Pure Appl. Geophys., 145, 701–715]. This method is based on measuring the ratio between Benioff strains released during the time periods of loading and unloading, corresponding to the Coulomb Failure Stress change induced by Earth tides on optimally oriented faults. According to the method, the LURR time series usually climb to an anomalously high peak prior to occurrence of a large earthquake. Previous studies have indicated that the size of critical seismogenic region selected for LURR measurements has great influence on the evaluation of LURR. In this study, we replace the circular region usually adopted in LURR practice with an area within which the tectonic stress change would mostly affect the Coulomb stress on a potential seismogenic fault of a future event. The Coulomb stress change before a hypothetical earthquake is calculated based on a simple back-slip dislocation model of the event. This new algorithm, by combining the LURR method with our choice of identified area with increased Coulomb stress, is devised to improve the sensitivity of LURR to measure criticality of stress accumulation before a large earthquake. Retrospective tests of this algorithm on four large earthquakes occurred in California over the last two decades show remarkable enhancement of the LURR precursory anomalies. For some strong events of lesser magnitudes occurred in the same neighborhoods and during the same time periods, significant anomalies are found if circular areas are used, and are not found if increased Coulomb stress areas are used for LURR data selection. The unique feature of this algorithm may provide stronger constraints on forecasts of the size and location of future large events.     

Water–rock interaction during the process of steam stimulation exploitation of viscous crude oil in Liaohe Shuguang Oil Field, Liaoning, China

In the process of steam stimulation exploitation of viscous crude oil, the injected water, at high temperature and under high pressure, reacts intensively with the host rock. This kind of water–rock interaction in Liaohe Shuguang Oil Field was studied on the basis of analysis of water composition changes, laboratory experiments, mineral saturation indices analysis, and mass balance calculation. Compared with the injected water, the changes of the composition of discharged water are mainly the distinct decrease of pH, Na⁺, SiO₂ and Cl⁻, as well as the increase of K⁺, Ca²⁺, Mg²⁺, SO ₄ ²⁻ and HCO ₃ ⁻ . Laboratory experiments under field conditions showed: the dissolution sequence of minerals quantitatively is quartz>potassium feldspar>albite, and the main change of clay minerals is the conversion of kaolinite to analcime. Mass balance calculation indicated during the process of steam stimulation, large quantities of analcime are precipitated with the dissolution of large amounts of quartz, kaolinite, potassium feldspar, and CO₂. These results correlated very well with the experimental results. The calculated results of Liaohe Shuguang Oil Field showed that during the steam stimulation for viscous crude oil, the amounts of minerals dissolved (precipitated) are huge. To control the clogging of pore spaces of oil reservoirs, increased study of water–rock interaction is needed.