经济海藻病害及防控技术的研究进展

经济海藻的病害一直是海藻人工栽培的一大障碍,往往造成严重的经济损失。目前对藻类病害的研究大多集中于病原鉴定,而病原的多样性和复杂的海区微环境增加了病原分离和鉴定的难度。本文综述了经济海藻病害发生的原因、病原的多样性和致病机制、病原的鉴定、检测和防治方法,并对未来我国海藻病害研究方向进行了展望,以期对藻类病害的防控提供参考。     

西南印度洋中脊表层沉积物非碳酸盐组分的粒度特征及其地质意义

The carbonate-free fraction of 20 surface sediments collected from the ultraslow-spreading Southwest Indian Ridge(SWIR) was studied by grain size analysis and mineralogical analysis with X-ray powder diffraction(XRD),stereo microscopy and scanning electron microscopy(SEM). The characteristics of the carbonate-free fraction of the sediments were obtained, and related influential factors were discussed. The results show that the mean grain size of this fraction is in 1.96Φ–8.19Φ, with poorly sorting and unimodal, bimodal or irregular bimodal distribution patterns. Four grain size end members of the fraction are derived with the End Member Model method. The finest end member EM1 shows a significant contribution of terrigenous materials of the aeolian input and sediment carried by the bottom current. End member EM2 with medium size mainly reflects sediment of a siliceous bioclast origin. EM3 and EM4 are interpreted as representing the coarser volcanic materials related to bedrock weathering or volcanic activities. Multi-provenance is the dominant factor controlling the grain size pattern of the carbonate-free fraction of the sediments in that area. In addition, sediment transport processes such as the bottom current and wind are the minor factors that influence the grain size distribution of the carbonate-free fraction sediments.     

基于数字全息显微的海洋浮游生物三维形貌快速重建方法研究

针对海洋浮游生物实时探测中,三维形貌特征难以快速获取的问题,本文提出了一种海洋浮游生物三维形貌快速重建的方法。基于离轴菲涅尔数字全息显微系统,通过改进相位恢复方法预消除相位畸变,直接得到正确的相位信息,进而对浮游生物三维形貌重建。该方法不需要进行后期复杂的相位补偿计算,就可以对浮游生物三维形貌进行快速重建,有利于对动态、微小尺寸的浮游生物进行实时探测及分析。论文对青岛近海岸浮游生物桡足类和夜光虫进行了三维形貌重建,分辨率可达到3.5μm。实验结果为离轴菲涅尔数字全息显微系统用于海洋浮游生物原位、实时探测的可行性提供了依据。     

天文卫星下传数据处理系统的规划

天文卫星获取的数据需要经过卫星下传数据处理系统的一系列加工,生成可以分析的数据产品,这些产品及相应软件要发布给国内外用户,同时数据处理系统还要监测载荷状态、数据质量及天体源爆发等。这样,下传数据处理系统的建设直接关系到物理成果的获取,规划该系统就变得非常有意义。从数据产品定义、子系统规划、数据流程等方面介绍卫星下传数据处理系统的规划,并提出以模块化开发方式从整体上协调各个子系统的开发,使各个系统及其软件相互配合,共同促进科学产出。     

More than two hundred and fifty thousand spectroscopic binary or variable star candidates discovered by LAMOST

About 786.4 thousand stars were observed by LAMOST twice or more during the first stage of its spectroscopic survey. The radial velocity differences for about 256 thousand targets are larger than10 km s^-1 and they are possible spectroscopic binary or variable candidates(SBVCs). It is shown that most SBVCs are slightly metal poorer than the Sun. There are two peaks in the temperature distribution of SBVCs around 5760 K and 4870 K, while there are three peaks in the distribution of the gravitational acceleration at 2.461, 4.171 and 4.621 cm s^-2. The locations of SBVCs on the [Fe/H]-T, [Fe/H]-log g, log g-T and H-R diagrams are investigated. It is found that the detected SBVCs could be classified into four groups. The first group has higher log g～4.621 and lower T ～ 4870 K which are mainly cool red dwarf binaries. The second group of SBVCs has logg around 4.171 cm s^-2 that includes binaries and pulsating stars such as δSet and γ Dor variables. The gravitational accelerations of the third group of SBVCs are higher and some of them are below the zero-age main sequence. They may be contact binaries in which the primary components are losing energy to the secondaries in the common envelopes and are at a special stellar evolutionary stage.The last group is composed of giants or supergiants with log g around 2.461 cm s^-2 that may be evolved pulsating stars. One target(C134624.29+333921.2) is confirmed as an eclipsing binary with a period of 0.65 days. A preliminary analysis suggests that it is a detached binary with a mass ratio of 0.46. The primary fills its critical Roche lobe by about 89%, indicating that mass transfer will occur between the two components.     

海洋环境对猎雷声呐探测识别的影响及对策建议

猎雷是各海军强国重点发展方向,猎雷作战中首要的就是探测识别水雷。从传播损失、混响、 目标强度以及海流、潮汐等多个方面分析了海洋环境对猎雷声呐探测识别的影响,并从猎雷作战角度提出了有关参数设置、作战方式、数据处理等对策建议,可为部队探测识别水雷等目标提供有效参考。     

Archaeal community structure in sediments from a seamount in the Mariana Volcanic Arc

Seamounts are subsurface mountains in the ocean. Examination of the abundance and distribution of Archaea in seamount ecosystems may provide a better understanding of their ecological functions. Most studies of marine archaeal assemblages in seamount area have focused on hydrothermal vents or ferromanganese crusts. We investigated the archaeal communities from a seamount of the Mariana Volcanic Arc, in the tropical western Pacific Ocean by using high-throughput sequencing. Thaumarchaeota was dominant in the sediments of all sample stations. Community diversity and species richness were greatest at stations near the top of the seamount, and lowest at the deepest station. One sample station on the steep southeast slope that faced the Yap-Mariana trench had a unique composition of Archaea. In summary, depth has an important influence on archaeal community structure, and the geographic properties and sediment characteristics may explain the unique distribution patterns of Archaea in this seamount. This study provides a foundation for future research on Archaea in seamounts.     

一种基于卫星遥感的临近预报方法

中尺度对流系统(MCS)是形成强对流天气的主要原因,云团在MCS生命周期中的分裂合并问题是临近预报的难点。为解决这一问题,本文提出了FCC方法,该方法使用质心位移和FY-2卫星数据预测多个对流单体的运动轨迹。多个案例分析证明,FCC算法在MCS的各个生命周期均能进行有效的预测,包括初生、成熟和消散阶段。此外,通过列联表方法验证了所提算法的有效性。     

偏振激光雷达探测大气—水体光学参数廓线

激光雷达在上层水体垂直廓线的遥感中展现出巨大优势。本文研制了一套高垂直分辨率的实时探测偏振激光雷达,提出了一种基于偏振激光雷达回波信号的反演算法,采用Fernald理论和多次散射原理反演非均匀大气—水体的衰减和退偏光学产品,以高效稳定地处理偏振激光雷达实验数据。展示了一个中国内陆水体激光雷达探测实例,观测到了两次气溶胶积聚现象和一次水体浑浊现象。对实验数据的分析表明,退偏比主要由前向多次散射和后向单次散射产生的退偏两部分组成。当多次散射强度较大时,退偏比的变化主要取决于多次前向散射退偏;反之,则主要依赖于单次后向散射退偏。     

CORS网区域重力场变化与地面稳定性跟踪监测方法

为了实现地面稳定性降低时间与地点、持续作用时间与空间影响分布的全面跟踪监测,该文基于卫星定位连续运行站(CORS)站网观测数据,结合地表水、大气及海平面变化资料,提出了CORS站网时变重力场及负荷形变场精化的已知负荷移去恢复法,建立了基于时变重力场的确定性地面稳定性变化定量辨识准则。以丽水温州地区为例,利用2015-2017年CORS网及有关水文观测数据进行计算分析,根据40起已发生的历史地质灾害(险情)事件对结果进行验证:丽水温州地区的CORS网具备区域重力场变化与地面稳定性跟踪监测能力,具备地质灾害灾变过程追踪与前兆捕获能力,CORS站网的地质灾害前兆提前捕获率可达92.5%。