中国含油气盆地沉积研究主要科学问题与发展分析

沉积相研究发展与人类的生存和矿产资源勘探开发密切相关.该文在简单回顾了近200年的沉积学发展历史的基础上,分析了国际和中国沉积学关注的学科热点问题.国际沉积学会重点关注的问题主要包括国际大洋钻探计划、深-时气候变化与全球海平面变化、源-汇系统、碳酸盐岩沉积环境、混合沉积、微生物岩、陆架边缘三角洲、重力流、细粒沉积、构造...     

线路上任意一点对应中桩平面坐标在统一模型中的计算

本文给出了交通线路任意点对应中桩平面坐标计算的统一模型,并就直线段、圆曲线段、缓和曲线段三种线型具体展开,给出其理论公式和实际计算方法。     

福建省基础空间数据管理技术研究

福建省基础地理信息中心作为福建省基础空间数据的管理和分发服务单位,管理和分发福建省多种类、多比例尺、多数据源、分布式、多时态的基础空间信息,在基础空间数据管理上存在多种形式,本文通过几种管理模式的技术分析,结合中心的管理实际,总结了福建省空间数据管理的多样性和技术特点,对比分析出各种管理模式的优势和缺点。     

基于《地理学报》创刊85年载文的中国西南地区之地理研究

西南地区以其独特的地理现象一直为国内外地理学者所关注。通过对《地理学报》创刊以来85年间西南地区研究的载文分析,可以管窥其研究脉络,并予未来研究以启示。结果表明：① 232篇论文囊括了地理研究的若干主题,但以地貌、气象气候、综合自然地理和生态环境发文量最大,而城市、民族、交通、健康则关注较少;② 研究经历了传统区域研究、任务带学科、承上启下和多元化发展4个阶段;③ 论文在数量和内容上的阶段性变化,既受国家时事格局影响,也受地理学科研究范式发展变化影响;④ 《地理学报》有关西南地区的载文具有很高的研究水平,无论是在学术视野还是研究方法手段上,区域的自然、人文、社会经济与生态环境等诸多研究都站在了学术研究前沿,代表了学界对西南地理的研究情况;⑤ 但西南地理研究论文增长速度远赶不上《地理学报》载文量增长,外来研究机构占比很大,本土力量弱;相较自然地理,人文地理研究也少而弱。可见,西南地理研究当从新区域地理视角重新审视这一地区传统与现代的碰撞、边界的接触与冲突和区际的联系与竞争,继续成就西南地区重要的地理意义。     

Predicting the entire soil-water characteristic curve using measurements within low suction range

The soil-water characteristic curve(SWCC) is widely used in the design and evaluation in the practice of geotechnical and geoenvironmental engineering such as the slope stability under the influence of environmental factors. The SWCC has distinct features in the capillary and adsorption zones due to different physical mechanisms. Measurements of the SWCC are typically limited within the capillary zone(i.e., low suction range). It is cumbersome and time-consuming to measure the SWCC in the adsorption zone(i.e., high suction range). This study presents a simple method to predict the entire SWCC within both the capillary and adsorption zones, using measured data only from low suction range(e.g., from 0 to 500 kPa). Experimental studies were performed on a completely weathered granite residual soil to determine its entire SWCC from saturated to dry conditions. The resultant SWCC, along with the SWCC measurements of 14 soils reported in the literature, were used to validate the proposed method. The results indicate that the proposed method has good consistency with a wide array of measured data used in this study. The proposed method is easy to use as it only requires a simple parameter calibration for a commonly used SWCC model. It can be used to improve the reliability in the prediction of the SWCC over the entire suction range when measurements are limited within the low suction range.     

Spatio-temporal variability of small fishes related with environmental factors in a typical domestic tap water lake,Eastern China

The knowledge of prey small ?sh stock, distribution and abundance is necessary to guide stocking of piscivorous ?sh for the biomanipulation in domestic tap water lakes. This study describes the current status of small ?sh community in Kuilei Lake(China), and examines the spatial and seasonal variations of the community in relation to key environmental factors. Based on submerged macrophyte cover and water depth, the lake was divided into ?ve major habitats:(1) macrophyte covered shallow habitat of water depth< 2.00 m,(2) uncovered or less-covered shallow habitat(2.00 m–3.50 m),(3) uncovered medium shallow habitat(3.50 m–5.00 m),(4) uncovered medium deep habitat(5.00 m–6.50 m) and(5) uncovered deep habitat(6.50 m–8.50 m). The abundance and composition of small ?sh were monitored by benthic fykenet sampling from April 2013 to January 2014. A total of 2881 individuals belonging to 5 families and 21 species were collected. Based on their abundance(accounted for 88.96% of the total) and occurrence(more than 33.33%), Acheilognathus chankaensis, Acheilognathus macropterus, Microphysogobio microstomus,Pseudorasbora parva and Rhinogobius giurinus were recognized as dominant small ?sh species. The results of correlation analysis identi?ed that species richness( Sr), Shannon-Wiener diversity index( H′)and Margalef′s richness index( D) were signi?cantly negatively correlated with water depth, but positively correlated with biomass of submerged macrophytes.Redundancy analysis(RDA) revealed that the spatial distributions of most small ?shes were negatively associated with water depth. The details of these ?ndings are bene?cial to understanding the adaptation of the small ?shes in degraded environments, and to developing suitable biomanipulation strategies for the management of ?sh resources and water quality in the lakes along the lower reach of the Changjiang(Yangtze) River basin.     

Dynamic metabolite alterations of Portunus trituberculatus during larval development

A mass mortality often occurs from molting to the megalopa stage during the larval development of the swimming crab Portunus trituberculatus. Larvae with insuffcient nutrient accumulation during the zoeal stages are probably unable to develop into juvenile swimming crabs. However, the nutritional information such as the primary metabolites is scarce for P. trituberculatus larvae. The aim of this work is to obtain an insight into the metabolite traits of P. trituberculatus at early developmental stages. 1 H nuclear magnetic resonance spectroscopy coupled with multivariate data analysis was used to determine how the metabolite pro?les shift during larval development in P. trituberculatus. Our results show that the trend of total metabolites exhibited a rise from zoea 1 to zoea 3, followed by a drop from zoea 4 to megalopa and recovery during the ?rst juvenile stage. A large-scale depletion of total metabolites in the zoea 4 and megalopa stages suggests a deep depression of metabolic activity, which may be linked to the mass mortality from molting to the megalopa stage. These ?ndings provided essential metabolic information about the larval development of P. trituberculatus and important clues for understanding the nutritional requirements of P. trituberculatus in early developmental stages.     

我国自然资源、自然资源资产监测发展现状及问题分析

自然资源、自然资源资产监测是实现自然资源统一管理和确权的基础性工作。本文通过对自然资源、自然资源资产监测概念和内涵的研究,从行政监测、航天监测、航空监测、地表监测、地下矿产监测、水资源监测、海洋监测等角度介绍了我国自然资源监测研究及工作实践的方法和手段;并对科学界定自然资源内涵与分类及监测目录、国家自然资源监测网络整合与建设、自然资源监测时空框架构建等主要问题的解决提出了建议。     

高分辨率光学遥感场景分类的深度度量学习方法

针对高分辨率光学遥感影像场景具有同类型内部差异大、不同类型间相似度高导致部分场景识别困难的问题,本文提出了一种深度度量学习方法。首先在深度学习模型的特征输出层上为每类预设聚类中心,其次基于欧氏距离方法设计均值中心度量损失项,最后联合交叉熵损失项以及权重与偏置正则项构成模型的损失函数。该方法的目标是在特征空间上使同类型特征聚集并扩大类型间的距离以提高分类准确率。试验结果表明,本文方法有效地提升了分类准确率。在RSSCN7、UC Merced和NWPU-RESISC45数据集上,与现有方法相比,分类准确率分别提高了1.46%、1.09%和2.51%。     

北极地区地缘关系研究综述

论文检索了科学引文索引(Web of Science)和中国知网(CNKI)中北极地区地缘关系的相关文献,借助CiteSpace文献分析软件的关键词共现分析功能,系统综述了2000年以来国内外关于北极地区地缘关系的研究重点。从研究内容上看,国外研究主要关注主权政治、航道利用、资源管理和原住民权益等主体性议题,而国内则着重关注地缘政治、航道交通、资源经济和地区治理等参与性议题。就研究方法上看,国内外研究中定性与定量方法兼具,但仍以定性方法和描述性方法为主。随着北极地区的发展,研究方法和研究视角有待丰富,研究领域和研究深度亟需进一步拓展和加强。北极地区具有重要的战略意义,未来应结合现代技术,借鉴国际上的地区发展理论,开展北极地区的可持续发展研究和中国参与研究,并构建新时代北极地区地缘环境理论。