Molecular phylogeny of the genus Clibanarius(Decapoda: Anomura: Diogenidae) based on mitochondrial and nuclear DNA sequences

Clibanarius , a genus of hermit crabs, is one of the most diverse genera within Diogenidae. However, studies on the phylogeny within Clibanarius is very limited. We reconstruct the molecular phylogeny of the genus Clibanarius based on two mitochondrial (16S rRNA and COI) and two nuclear protein-coding (NaK and PEPCK) genes using a multigene phylogenetic approach. Eleven selected Clibanarius species from the Indo-West Pacifi c are analyzed and the Bayesian and maximum likelihood analyses produced identical results in topology. Results suggest that C . rutilus and C . infraspinatus are more closely related to each other than to C . snelliusi , and C . striolatus shows a close relationship to C . longitarsus . The close association of C . merguiensis with C . englaucus and C . humilis is strongly supported by the divergence of C . virescens from them. Our phylogenetic results contradict the morphological classifi cation scheme proposed for Clibanarius and indicate that the relative length of dactyls and propodi is not phylogenetically signifi cant in Clibanarius . In addition, we speculate that the morphological characteristic of the median cleft of the telson might be phylogenetically important for Clibanarius .     

基于作战概念的深远海水下作战体系设计与评估

着眼我深远海水下作战面临的现实困难及未来可能遇到的瓶颈问题,设计深远海水下作战概念。以作战概念为驱动,分析深远海水下作战需求,在作战背景下设计行动构想,构建基于作战概念的深远海水下作战体系,评估优化完善后对研究成果进行应用。     

地基干涉雷达IBIS-S桥跨结构振动变形测量与模态分析

地基雷达干涉测量技术能够以较高的时空采样频率获取线性结构目标整体瞬时变形状态。本文将该技术引入大型桥梁桥跨结构的振动变形测量与模态分析中。对动静载试验过程中的武汉二七长江大桥东岸桥跨结构开展连续变形监测,利用频域分解法计算桥跨结构的自振频率、阻尼比和模态振型。计算结果表明,地基干涉雷达干涉测量技术能够快速探测桥跨结构竖弯模态,特别适用于灾后大型线形结构健康状态的应急检测。     

背负式移动激光扫描系统测绘大比例尺地形图精度试验研究

将背负式移动激光扫描系统应用在测绘大比例尺地形图中,其扫描精度至关重要。本文利用徕卡Pegasus Backpack对苏州工业园园区测绘地理信息大楼进行扫描,采用Inertial Explorer、Infinity、AoTumatic Processing对点云数据进行预处理,运用RealWorks提取特征点,将特征点在MicroStation V8联图中绘制成1：500地形图。通过与传统方法绘制的1：500地形图相叠合,发现两幅地形图具有很好重合度。对地物检测点精度分析后,得到点位中误差为0.026 m,高程中误差为0.041 m。研究结果表明徕卡Pegasus Backpack满足1：500地形图测量精度要求。     

结合MST划分和RHMRF-FCM算法的高分辨率遥感图像分割

针对基于像素的HMRF-FCM算法抗噪性差以及对地物复杂边界分割精度低的问题,提出一种结合形状信息的静态MST区域划分和RHMRF-FCM算法的高分辨率遥感图像分割方法。该方法定义一种静态MST同质区域划分准则,借助MST能较好表达边界和形状信息、能较好抑制几何噪声的特点,解决地物复杂边界的表达和降低分割结果中几何噪声问题。首先,利用MST静态划分将图像域划分成若干个均质区域,假设每个均质区域内光谱测度服从独立同一的多元高斯分布。然后,在此基础上构建了区域隐马尔可夫随机场模型,以及建立基于信息熵和KL信息正则化项的模糊聚类目标函数。最后,采用偏微分方法对分割模型参数进行求解,从而得到全局最优分割结果。为验证本文方法,对WorldView-3高分遥感图像进行分割试验。定性、定量分析了尺度参数、光谱相似性参数和区域紧致度参数对最优分割结果的影响,并对比分析本文算法和eCognition软件中的多分辨率分割算法、分水岭算法。     

基于引文分析法的“点-轴系统”理论研究述评

论文采用引文分析法,对陆大道院士所著《关于“点-轴”空间结构系统的形成机理分析》一文的349篇引文进行分析,从引文数量、引文作者、发文期刊、研究案例地、学科领域、研究主题、引用动机7个方面,探究“点-轴系统”理论的研究现状。结果表明：自2002年以来,“点-轴系统”理论的引文数量整体呈上升趋势,研究主题聚焦于区域经济和旅游发展;研究案例地以省级和市级中观尺度为主,多为单一型研究区,主要集中在西北丝绸之路经济带、东北辽宁经济圈、西南藏滇川渝、东部长三角四大热点区域;引文质量普遍较高,并且具有多学科交叉应用的特点,但批判性思考和创造性提升相对较少。基于此,论文从拓展研究和实践应用2个角度对“点-轴系统”理论未来发展进行了展望,以期为相关研究提供参考。     

Exploring spatial-temporal change and gravity center movement of construction land in the Chang-Zhu-Tan urban agglomeration

Urban agglomeration is caused by the continuous acceleration of the urbanization process in China. Studying the expansion of construction land can not only know the changes and development of urban agglomeration in time, but also obtain the great significance of the future management. In this study, taking Changsha-Zhuzhou-Xiangtan (Chang-Zhu-Tan) urban agglomeration in Hunan province as a study area, Landsat images from 1995 to 2014 and Autologistic-CLUE-S model simulation data were used. Moreover, several factors including gravity center, direction, distance and landscape index were considered in the analysis of the expansion. The results revealed that the construction area increased by 132.18%, from 372.28 km² in 1995 to 864.37 km² in 2014. And it might even reach 1327.23 km² in 2023. Before 2014, three cities had their own respective and discrete development directions. However, because of the integration policy implementation in 2008, the Chang-Zhu-Tan began to gather, the gravity center moved southward after 2014, and the distance between cities decreased, which was in line with the development plan of urban expansion. The research methods and results were relatively reliable, and these results could provide some reference for the future land use planning and spatial allocation in the urbanization process of Chang-Zhu-Tan urban agglomeration.

     

Developing a comprehensive evaluation method for Interconnected River System Network assessment: A case study in Tangxun Lake group

Journal of Geographical Sciences - The Interconnected River System Network (IRSN) plays a crucial role in water resource allocation, water ecological restoration and water quality improvement. It...     

Compositional Balance Analysis: An Elegant Method of Geochemical Pattern Recognition and Anomaly Mapping for Mineral Exploration

Natural Resources Research - Geochemical pattern recognition and anomaly mapping are always involved in the fields of environmental and exploration geochemistry. Principal component analysis (PCA)...     

南海大洋钻探及海洋地质与地球物理前沿研究新突破

南海是西太平洋地区规模最大且具有代表性的边缘海盆地之一。经过近几十年的研究积累,尤其是通过实施5个国际大洋钻探航次(1999–2018年)与国家自然科学基金委“南海深海过程演变”重大研究计划(2011–2019年),我国科学家获得了大量宝贵的第一手资料,取得了一系列创新进展与重大突破,标志着南海海洋地质与地球物理研究正走向国际前沿。重要研究成果包括:(1)新提出南海是“板缘张裂”盆地,与经典的大西洋型陆缘模式不同;(2)大洋钻探首次获取了基底玄武岩样品,结合中国在南海首次深拖地磁测量实验,精确测定了南海海盆玄武岩年龄,揭示南海海盆从东向西分段扩张;(3)大洋钻探结果发现南海陆缘岩石圈减薄之初岩浆迅速出现,未发现缓慢破裂造成的蛇纹岩出露;(4)发现南海扩张结束后仍存在大量岩浆活动,可能受控于多种构造与地幔因素;(5)地球化学证据与地球动力学模拟都显示南海岩浆的形成受到周边俯冲带的影响。目前我国的海洋地球科学正在进入崭新的发展阶段,有望以南海为基点,开始拓展到周边大洋,通过主导大型研究计划以及建设我国大洋钻探平台,以提升我国在南海、西太平洋与印度洋海洋地质科学研究的实质性影响力与引领地位。