Densities of Huanghe River estuary and Bohai Bay waters

The densities of 36 water samples from the Huanghe River estuary and Bohai Bay were determinedby a magnetic float densimcter under three temperatures from 15℃ to 25℃.All the measured densities ofsamples were greater than that of the values calculated from the International Equation of State of Seawater.The differences between the measured and calculated densities increased with the decrease of salinities.The dif-ferences appeared exponentially correlated with[Ca~(2+)]/s,[Mg~(2+)]/s and[SO_4~(2-)]/s,and had"s"type curverelationship with the alkalinity in all salinity range.But in the salinity ranging from 25.72 to 31.57,therelationships were all linear.The density difference can be estimated from the equation △ρ（10~3kg·m~(-3)）=（-2.79+236.5([Ca~(2+)]/s)/(-9.7464×10~（-3）+[Ca~(2+)]/s).It was the high alkalinity and[Ca~(2+)]/s that resulted in the measured densi-ties of seawaters being higher than the calculated densities in the Huanghe estuary and Bohai Bay.     

Fractural structure of thick hard roof stratum using long beam theory and numerical modeling

The thick hard rock (THR) roof of the long-wall mining face is prone to the large-sized cantilever roof, and its sudden fracture will cause serious rock dynamic disasters, such as coal and gas outburst and rockburst. In this study, based on the long beam theory, the initial fracture mechanical model for THR was established, and the first weighting characteristics and extreme fracture step distance were calculated. This study introduced a new technology called deep-hole pre-splitting blasting (DPB) which could break the THR by drilling holes with different depths and angles at different levels of roof rock and then blasting it. Field measurement analysis indicated that the immediate roof and lower thick hard strata were fully collapsed to fill the goaf, and the upper thick hard stratum was effectively cut off. The results showed that mechanical model and drilling holes method and DPB technique were so notably that would lead to a foundation for large-scale popularization and application in a Chinese Mine.     

Identification of two Skeletonema costatum-like diatoms by fluorescence in situ hybridization

A harmful algae bloom (HAB) is a dense aggregation of algae in a marine or aquatic environment that can result in significant environmental problems. To forecast the occurrence of HAB, development of a rapid and precise detection method is urgently required. In this study, two Skeletonema costatum-like diatoms (SK-1 and SK-2), were identified morphologically under a light microscope, and detected using fluorescent in situ hybridization (FISH). Strain SK-1 was isolated from a frequently HAB affected area of the East China Sea, and strain SK-2 from an aquatic farm in Qingdao, China. Fluorescent DNA probes were designed that were complementary to the ITS sequence (including 5.8S rDNA) of strain SK-1. After hybridization, strong green fluorescence was observed in cells of strain SK-1 under an epifluorescence microscope; however, no such fluorescence was observed with strain SK-2, which indicates that probes hybridized only the DNA of the target strain, SK-1, in species-specific manner, and that the two strains do not belong to a same species. This finding was confirmed by ITS sequence analysis. The FISH technique used in this study was sensitive, simple, and rapid, and is a promising tool for detecting target HAB species in natural environments.     

Karyological analysis of the sea cicada Blepharipoda liberate Shen from the Rizhao intertidal zone,China

Journal of Oceanology and Limnology - Blepharipoda liberate Shen is a commercially valuable seafood species that has important ecological significance in Shandong Province, China. Although B....     

In situ tensile fracture toughness of surficial cohesive marine sediments

This study reports the first in situ measurements of tensile fracture toughness, K _IC, of soft, surficial, cohesive marine sediments. A newly developed probe continuously measures the stress required to cause tensile failure in sediments to depths of up to 1 m. Probe measurements are in agreement with standard laboratory methods of K _IC measurements in both potter’s clay and natural sediments. The data comprise in situ depth profiles from three field sites in Nova Scotia, Canada. Measured K _IC at two muddy sites (median grain size of 23–50 μm) range from near zero at the sediment surface to >1,800 Pa m^1/2 at 0.2 m depth. These profiles also appear to identify the bioturbated/mixed depth. K _IC for a sandy site (>90% sand) is an order of magnitude lower than for the muddy sediments, and reflects the lack of cohesion/adhesion. A comparison of K _IC, median grain size, and porosity in muddy sediments indicates that consolidation increases fracture strength, whereas inclusion of sand causes weakening; thus, sand-bearing layers can be easily identified in K _IC profiles. K _IC and vane-measured shear strength correlate strongly, which suggests that the vane measurements should perhaps be interpreted as shear fracture toughness, rather than shear strength. Comparison of in situ probe-measured values with K _IC of soils and gelatin shows that sediments have a K _IC range intermediate between denser compacted soils and softer, elastic gelatin.     

赤潮生物种类特征光谱获取技术

较为系统地研究了赤潮生物水体反射率曲线获取方法。通过对 2类反射率反演方法得出的反射率曲线与实际反射率曲线进行比较 ,得出在不具备大气环境参数的情况下 ,经验线性法的反演结果与实际反射率曲线最接近的结论 ,并进一步对正常海水和赤潮生物水体的光谱特性进行分析 ,提取出赤潮生物水体的特征光谱。这是进行赤潮监测和识别的重要前提     

Water masses of the northern part of the Iceland Basin in the late Pleistocene

A core of bottom sediments AMK-4438 with a length of 320 cm was taken in the North-Eastern part of the Iceland Basin from the depth of 2240 m. The continuous sampling (every 2 cm) made it possible to study the core using the principle of high-resolving paleoceanology. For the stratigraphic partition of the core, we applied the paleotemperature analysis by planktonic foraminifera and carbonate analysis; the distribution of the iceberg rafted debris (IRD) was studied. As a result, nine isotopic stages were distinguished. The change in the complexes of benthic foraminifera indicates that the present-day deepwater circulation in the North-Eastern part of the Iceland Basin had no analogs in earlier glacial periods, including the MIS 5 age. During almost 300 ka, there were relatively warm, rich in nutrients, and poor in oxygen water masses. The formation of the modern Northern-Eastern deep water in the Iceland Basin began in the Bolling-Allerod 14 ka B.P.     

A model of the formation and development of ocean shear wave

Ａｍｏｄｅｌｏｆｔｈｅｆｏｒｍａｔｉｏｎａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｏｃｅａｎｓｈｅａｒｗａｖｅ￥ＱｉａｏＦａｎｇｌｉａｎｄＺｈａｎｇＱｉｎｇｈｕａ（ＦｉｒｓｔＩｎｓｔｉｔｕｔｅｏｆＯｃｅａｎｏｇｒａｐｈｙ，ｓｔａｔｅｏｃｅａｎｉｃＡｄｍｉｎｉｓ...     

富钴结壳中矿物组成对稀土元素分布的制约

为探讨富钴结壳中矿物组成对稀土元素分布的制约,对约翰斯顿岛富钴结壳中矿物组成及稀土元素特征进行了研究。依据主要矿物组成,富钴结壳可以分为3种类型,分别命名为A、B、C。由A到C,水羟锰矿含量逐渐降低,B类中磷灰石含量最高,C类中水钠锰矿和钙锰矿含量最高。A类结壳中富集REE3+、Ce,B类结壳中富集Ce和Y。A类富钴结壳中,REE3+、Y以专属吸附的方式富集在铁氧化物上,Ce3+氧化成Ce4+与其他REE分离,吸附在锰矿物上。B类结壳中,稀土元素主要以独立矿物的形式存在,另有部分Ce、LREE3+吸附于铁相中,部分Y存在于磷灰石中。C类结壳中,稀土元素主要赋存在锰矿物中,部分Y存在于磷灰石中。     

南海北部表层颗粒有机碳的季节和年际变化遥感分析

海洋颗粒有机碳（POC）是海洋固碳的一个关键参数。为了研究南海北部陆架及海盆表层POC浓度的时空分布特征以及变化趋势,本文利用2009-2011年4个季节的实测数据,对NASA发布的MODIS/AQUA卫星月平均POC遥感产品,进行了验证和校正;并利用校正后的遥感数据分析了2003-2014年POC的时空分布特征和变化趋势。发现POC遥感产品与南海北部实测数据具有较好的线性关系（R2=0.72）,但存在系统性偏高,需利用实测数据对遥感数据进行区域性校正。分析校正后的遥感数据发现,南海北部陆架POC浓度较高,平均为（33.34±8.02）mg/m3;吕宋海峡西南海域浓度较低,平均为（29.25±6.20）mg/m3;中央海盆区浓度最低,平均为（27.02±4.84）mg/m3。春夏季POC浓度较低,最低值一般出现在5月,冬季（12月至翌年1月）POC浓度达到最高。利用2003-2014年的长时间序列遥感叶绿素（Chl a）和海表温度（SST）、混合层深度（MLD）模式数据,以及实测数据对南海北部POC浓度的影响机制进行了分析。发现POC与Chl a在秋冬呈现较好的相关关系（R2=0.51）,但在春夏季较离散,表明秋冬季生物作用对POC影响较大。2003-2014年期间,POC与Chl a、MLD及SST存在明显的年际变化,但并没有显著的上升或下降趋势。