天然气水合物赋存区甲烷渗漏活动的地球化学响应特征

综述了天然气水合物赋存区甲烷渗漏活动的地球化学响应指标的研究进展,分析了应用单一指标识别甲烷渗漏活动各自所存在的问题,包括浅表层沉积物孔隙水中CH_4、SO_4~(2–)、Cl~–等离子浓度随深度的变化;浅层沉积物全岩W_(TOC)(W表示质量分数,TOC表示总有机碳)和W_(TS)(TS表示总硫)之间的相关性及比值;自生碳酸盐岩δ~(13)C和δ~(18)O;自生矿物重晶石、黄铁矿、自生石膏的δ~(34)S;有孔虫壳体和生物标志化合物的δ~(13)C等。结果表明孔隙水中的CH_4、SO4_~(2–)浓度及溶解无机碳的碳同位素组成可以用来识别目前正在发生的甲烷渗漏活动;而沉积物中的WTS、自生矿物的δ~(34)S、钡含量及其异常峰值和生物标志化合物的δ~(13)C等指标的联合使用可以更真实准确地反映地质历史时期天然气水合物赋存区的甲烷渗漏活动。因此,在实际研究过程中,可将孔隙水和沉积物两种介质的多种指标相结合。随着非传统稳定同位素(Fe、Ca、Mg等)和沉积物氧化还原敏感元素(Mo、V、U等)等研究的发展,甲烷渗漏活动地球化学响应指标的研究也将得到拓展,而多种地球化学指标的联合使用将为天然气水合物勘探及其形成分解过程识别研究提供重要的科学依据。     

2012年夏季楚科奇海浮游动物垂直迁移及上升流对其生物量的影响

The diel vertical migration(DVM) of zooplankton and the influence of upwelling on zooplankton biomass were examined using water column data of current velocity and mean volume backscattering strength(MVBS)collected by moored acoustic Doppler current profilers(ADCPs) deployed in the southeastern Chukchi Sea during the 5th Chinese National Arctic Research Expedition(CHINARE) in summer 2012, combined with the satellite observational data such as sea surface temperature(SST), wind, and chlorophyll a(Chl a). Hourly acoustic data were continuously collected for 49-d in the mooring site. Spectral analysis indicated that there were different migrating patterns of zooplankton, even though precisely classifying the zooplankton taxa was not available. The prevailing 24-h cycle corresponded to the normal DVM with zooplankton swimming upwards at sunrise and returning to deep waters at sunset. There was a clear DVM in the upper 17 m of the water column during the period with distinct day-night cycles, and no active DVM throughout the water column when the sun above the horizon(polar day), suggesting that light intensity was the trigger for DVM. Also there was a second migrating pattern with 12-h cycle. The upwelling event occurring in the northwest of Alaskan coastal area had important influence on zooplankton biomass at the mooring site. During the upwelling, the SST close to the mooring site dropped significantly from maximal 6.35°C to minimal 1.31°C within five days. Simultaneously, there was a rapid increase in the MVBS and Chl a level, suggesting the aggregation of zooplankton related to upwelling.     

渤海西部2次赤潮过程的气象因子对比分析

利用加密自动站资料、NCEP/NCAR 1°×1°再分析资料、海表温度(SST)资料和常规观测资料等气象资料,对2009年5月31日—6月13日和2012年5月18—28日发生在渤海西部海域的2场相似气象因子影响下的典型高影响赤潮过程进行了对比分析。初步结果表明:(1)2场高影响赤潮过程都发生在春末夏初的赤潮高发期,持续时间在10天以上;(2)赤潮爆发前期,伴随有暖湿气流影响形成适度降水,渤海西部的周平均海表温度(SST)升温明显,且SST≥16.2℃,赤潮发生海域为SST的暖脊控制,对赤潮过程的潜势预报有明显的指示意义;(3)850 h Pa以下层次的温度迅速上升,近地层西南暖湿气流的加强和地面6 m/s以下偏南、东南气流在渤海西部海域的汇合,利于渤海西部海洋浮游生物积聚和突发性繁殖,是赤潮形成的重要气象因子特征。     

50年来北海市滨海湿地景观格局变化及其驱动机制

以1955~2004年遥感影像为数据源,结合野外调查,运用景观生态学原理,研究50 a间北海市滨海湿地的景观格局及其动态变化。结果表明,50 a间北海市滨海湿地呈整体退化趋势,潮间砂质海滩、潮间淤泥质海滩、红树林滩、小型岛屿湿地减少;景观格局指数显示1977年、1998年是北海市滨海湿地较明显变化的拐点。1977年人类活动影响增加,滨海湿地稍有退化,湿地景观多样性指数减小,优势度指数增加,均匀度指数减小、景观总面积指数降至最低值。1988年湿地保护力度加大,湿地略为好转,景观多样性指数、优势度指数、均匀度指数则呈相反规律。1998年湿地受到的极端气候灾害、人类干扰程度加大,平均斑块分形维数下降,斑块密度指数、景观斑块数破碎化指数呈最高值。湿地景观格局指数的变化,反映了围垦改造、互花米草的生物入侵、城市污染、极端气候灾害等对景观格局的影响,人类活动是北海市滨海湿地景观格局变化的主要驱动因子。     

急性低氧胁迫对卵形鲳鲹选育群体血液生化指标的影响

本文研究了水环境急性低氧胁迫对卵形鲳鲹Trachinotus ovatus选育群体血液生化指标的影响。实验设计了急性低氧试验组和对照组,每组3个平行。结果显示,急性低氧胁迫后选育群体的血清离子含量与对照组相比都有不同程度的升高,其中钠、氯、钙浓度与对照组相比差异显著(p0.05),铁浓度极显著高于对照组(p0.01);血清蛋白、尿酸、肌酐、血脂、血糖等指标的差异较大,其中尿酸、肌酐极显著高于对照组(p0.01),总蛋白、总胆固醇显著低于对照组(p0.05);血清中肌酸激酶含量极显著高于对照组(p0.01),肌酸激酶同工酶显著高于对照组(p0.05),γ-谷氨酰转肽酶含量显著低于对照组(p0.05);其他指标均有不同程度的升高或降低,但差异不显著。研究表明,急性低氧胁迫造成卵形鲳鲹鳃、肾、心脏和肝脏损伤,免疫力下降。     

海豚链球菌及其胞外产物诱导的牙鲆血清抗体应答分析

海豚链球菌(Streptococcus iniae)是引起鱼类链球菌病的主要致病菌,对牙鲆(Paralichthys olivaceus)等养殖鱼类造成巨大危害。本文制备了海豚链球菌强毒株NUF849的福尔马林灭活全菌(FKC)、胞外产物(ECPs)及全菌与胞外产物的混合物(FKC+ECPs),以其免疫牙鲆,在免疫后第42天分别以海豚链球菌NUF849和NUF812攻毒,并在免疫前以及免疫后第7、14、21、28、35、42天与攻毒后第7天取样,分析3种免疫原以及免疫后再攻毒所诱发的血清抗体应答。结果显示,免疫后牙鲆体内产生了分别针对FKC和ECPs的特异性抗体,且各免疫组中FKC诱导的抗体水平较ECPs高,2种抗原间存在一定程度的交叉反应;FKC+ECPs组的两种抗体水平显著高于其他组(P0.05);攻毒后第7天2种抗体水平都显著升高(P0.05),并且免疫原来源菌株NUF849攻毒组的2种抗体水平高于非免疫原来源菌株NUF812攻毒组。攻毒后存活牙鲆的血清对NUF849、NUF812全菌蛋白及其胞外产物进行Western-blot分析,结果显示抗血清与全菌蛋白的阳性反应条带位于25~100kDa,与胞外产物的阳性反应条带位于18~100kDa。本文结果表明灭活海豚链球菌与胞外产物都能够诱发牙鲆产生特异性抗体,二者混合物的免疫效果更好,且NUF849来源的免疫原可以刺激牙鲆产生针对NUF812菌株的交叉保护抗体,为牙鲆海豚链球菌疫苗成分的筛选提供了基础资料。     

流场散度的误差估计

按照误差传递原理,推导出流场散度的误差估计式,并将其应用于赤道中东太平洋上升流区域水平散度误差的估计。应用结果表明:赤道中东太平洋上升流区多年平均流场的散度稳定,平均散度约为3.0×10-7s-1;和通常采用的误差估计公式相比,该估计公式降低了散度误差,从而提高了散度的可信度。     

基于一维综合孔径微波辐射计的海面温度反演研究

Due to the low spatial resolution of sea surface temperature(T_S) retrieval by real aperture microwave radiometers,in this study, an iterative retrieval method that minimizes the differences between brightness temperature(T_B)measured and modeled was used to retrieve sea surface temperature with a one-dimensional synthetic aperture microwave radiometer, temporarily named 1 D-SAMR. Regarding the configuration of the radiometer, an angular resolution of 0.43° was reached by theoretical calculation. Experiments on sea surface temperature retrieval were carried out with ideal parameters; the results show that the main factors affecting the retrieval accuracy of sea surface temperature are the accuracy of radiometer calibration and the precision of auxiliary geophysical parameters. In the case of no auxiliary parameter errors, the greatest error in retrieved sea surface temperature is obtained at low T_S scene(i.e., 0.710 6 K for the incidence angle of 35° under the radiometer calibration accuracy of0.5 K). While errors on auxiliary parameters are assumed to follow a Gaussian distribution, the greatest error on retrieved sea surface temperature was 1.330 5 K at an incidence angle of 65° in poorly known sea surface wind speed(W)(the error on W of 1.0 m/s) over high W scene, for the radiometer calibration accuracy of 0.5 K.     

Effect of different registration methods on precision of orientation based on RTK registration/georeferencing mode

Abstract

Compared with traditional methods, the three-dimensional laser-scanning (3D-LS) technique can efficiently acquire many high-quality geometric properties of rock discontinuities. In practice, engineers usually prefer to simplify the processing by using single-station point data and roughly orienting owing to the complexity of registration/georeferencing multi-station point data. However, prior published studies have paid little attention to the accuracy and reliability when determining discontinuity orientations using 3D-LS. We propose a reliable and accurate method with robust on-site applicability. As part of an ongoing effort, we are evaluating the precision of the commonly used coarse registration method and the fine registration method, and promoted the optimized coarse- and fine-registration methods and evaluated their precision. It is found that: (1) the common and the optimized registration method can meet our project’s engineering requirements, and the optimized registration method improved accuracy in the dip direction by approximately 1°; (2) fine registration using an iterative closest point (ICP) algorithm can correct both dip direction and dip angle; and (3) the orientation is of high precision with commonly used coarse and fine registration, whereas the optimization effect to correct the orientation is slightly limited.     

赤道暖池区漂流浮标运动轨迹分析

TOGA—COARE强化观测期间,对赤道暖池区海流作了多种方法、多层次的观测;根据美国释放的漂流浮标不同时刻位置的资料,分别对赤道及其南、北海域的表层漂流状况作了计算分析,指出:从1°N向北存在单一的北向流;从1°N～1°S这个近赤道区域内为东向流;1°N～2°S区域为过渡区,以东向流为主,个别浮标出现涡旋状运动。2°S以南为一反时针运动的大涡旋。