胶州湾秋季文石饱和度分布及控制因素分析

基于2017-10-18航次在胶州湾调查获取的水文、碳化学和叶绿素a(Chl a)等数据与资料,分析了秋季该海域文石饱和度(Ω_arag(现场))的分布状况,探讨了影响其空间分布的主要控制因素。结果显示,秋季航次期间胶州湾表层Ω_arag(现场)为1.85～2.57,平均值为(2.20±0.24);其分布具有较大的空间差异,低值位于湾的西部和东北部(<2.05),高值位于湾口(>2.45),总体上呈现出由湾口向湾顶逐步降低的趋势。除了通过分析Ω_arag(现场)与温度、盐度和Chl a的相关性来定性确定Ω_arag(现场)的主控因素外,我们还通过引入总碱度与溶解无机碳的差值作为Ω_arag(现场)的指征参数,定量确定了影响Ω_arag(现场)空间分布的主要过程及其贡献。研究发现,陆源输入是影响胶州湾秋季Ω_arag(现场)空间分布的最重要因素(>50%),而温度和生物过程的影响相对较小。     

荒沟蓄能电站地下厂房地应力状态与工程稳定性研究

为了解黑龙江荒沟抽水蓄能电站地下厂房区应力状态 ,在探洞内布置了 4个地应力测点 ,利用空芯包体应力计进行地应力测量。测量结果表明 :最大主应力近于水平 ,最大主应力量值为 9.6MPa ,最大主应力方向为N78°W。根据实测结果对该区应力作用特征进行了分析 ,测量结果与现今区域构造应力场相吻合。在地应力实测和岩石力学性质试验基础上 ,对地下厂房周边应力状态进行了有限元分析 ,为地下厂房轴线的选择提出了建设性意见。     

Sea state estimation using vessel response in dynamic positioning

This paper presents a novel method for estimating the sea state parameters based on the heave, roll and pitch response of a vessel conducting station keeping automatically by a dynamic positioning (DP) system, i.e., without forward speed. The proposed algorithm finds the wave spectrum estimate from the response measurements by iteratively solving a set of linear equations, and it is computationally efficient. The main vessel parameters are required as input. Apart from this the method is signal-based, with no assumptions on the wave spectrum shape. Performance of the proposed algorithm is demonstrated on full-scale experimental DP data of a vessel in three different sea states at head, bow quartering, beam, stern quartering and following sea waves, respectively.     

利用高频雷达海面回波中奇异峰估计浪高的方法

The popular methods to estimate wave height with high-frequency(HF) radar depend on the integration over the second-order spectral region and thus may come under from even not strong external interference. To improve the accuracy and increase the valid detection range of the wave height measurement, particularly by the smallaperture radar, it is turned to singular peaks which often exceed the power of other frequency components. The power of three kinds of singular peaks, i.e., those around ±1,±2~(1/2) and ±1(2~(1/2)) times the Bragg frequency, are retrieved from a one-month-long radar data set collected by an ocean state monitoring and analyzing radar,model S(OSMAR-S), and in situ buoy records are used to make some comparisons. The power response to a wave height is found to be described with a new model quite well, by which obvious improvement on the wave height estimation is achieved. With the buoy measurements as reference, a correlation coefficient is increased to 0.90 and a root mean square error(RMSE) is decreased to 0.35 m at the range of 7.5 km compared with the results by the second-order method. The further analysis of the fitting performance across range suggests that the peak has the best fit and maintains a good performance as far as 40 km. The correlation coefficient is 0.78 and the RMSE is 0.62 m at 40 km. These results show the effectiveness of the new empirical method, which opens a new way for the wave height estimation with the HF radar.     

Data-moderate assessments of Cape monkfish Lophius vomerinus and west coast sole Austroglossus microlepis in Namibian waters

There is global interest in providing scientific advice on optimal harvesting of all commercially exploited fish stocks. Nevertheless, many commercially important stocks lack analytical assessments. Therefore, we evaluate a data-moderate stock assessment method: the stochastic surplus production model in continuous time (SPiCT). The method was applied to two Namibian stocks: (i) the data-rich Cape monkfish Lophius vomerinus, where results are compared to a new data-rich assessment using a state–space assessment model (SAM); and (ii) the data-moderate west coast sole Austroglossus microlepis, which is an important bycatch species in the Cape monkfish fishery, but currently unassessed. The information available to the data-moderate assessment is total commercial catch, commercial catch per unit effort (CPUE), and survey CPUE. SPiCT and SAM gave largely consistent estimates of relative fishing mortality (F/F_MSY) and relative exploitable biomass (B/B_MSY) for the Cape monkfish stock, although with some discrepancies. Differences in the biomass estimates between the two assessments suggest that further investigation is required to understand the cause, and that some caution is necessary when considering the biomass of the stock. SPiCT shows that the west coast sole may be overexploited, although the confidence bounds were too wide for a firm conclusion. Similarity in the estimates of F/F_MSY for Cape monkfish in recent years, using SPiCT relative to SAM, likewise indicates the suitability of SPiCT for managing west coast sole.     

SSR改正数更新频率及中断时间间隔对实时PPP的影响分析

实验模拟服务器端不同更新频率的SSR改正数对实时精密单点定位的影响,以及客户端改正数中断时长对实时精密单点定位的影响。结果表明,服务器端SSR改正数的播发频率控制在30 s以内可获得cm级定位精度;客户端的SSR改正数中断在150 s之内可获得cm级定位精度,改正数中断200 s可获得20 cm的定位精度,改正数中断300 s可获得亚m级定位精度。     

鄂尔多斯地块周缘近期地震活动趋势分析

依据青藏块体东北缘与鄂尔多斯地块相互作用的“轮闸模型”的有关结论,结合鄂尔多斯地块周缘近年来中强地震活动特征和震源机制解以及青藏块体的地震活动特征,研究了鄂尔多斯地块的现今运动状态.结果表明,鄂尔多斯地块目前继续受青藏块体东北缘强烈左旋压扭作用的控制,其自身构造运动仍处于被完全抑制状态,致使其周缘自1815 年以来的地震活动格局基本未变,而维持着原有的活动水平.     

早前寒武纪古地热状态的构造环境意义

区域变质作用是在造山运动中地热流和动力联合作用的体现。在早前寒武纪的造山带中,随着地壳的缩短,古地热流向构造边界聚敛,形成由高温到低温的区域变质相带序列,它既指示古地热流运移的方向,又是构造边界的指向。古地热流值的高低同构造环境的性质有关,如陆内裂陷带的区域变质仅达绿片岩相,而陆缘活动带的则可高达角闪岩相。古地热流从活动带的边界向中心运移,具有向心性,随着构造层的深埋,构成地热槽,它的片段则表现为地热斜。识别这些古地热状态,可为构造环境属性的鉴定提供有力的依据     

1995—1996年云南地区三次强震前地震活动的短期异常

在地震学参量年度异常的背景＾（３）,阐述了１９９５￣１９９６年云南地区发生的孟连、武定、丽江三次强震前的地震活动短期异常,包括地震平静、小震群、窗口地震、调制地震、地震波参数以及４级左右地震向震中迁移等。结果表明,这些异常特征表现突出,其演化进程显示了强震孕育的阶段性。     

山东地区现今构造应力场与地震活动

应用现代中小地震的震源机制解,推断了山东地区的现今构造应力场,分析了区域构造应力场整体与局部变化特点。在此基础上,探讨了区域构造应力场与地震活动的关系。