北冰洋沉积物中四醚脂类来源与TEX_(86)指数初步研究

对北冰洋海域11个站位的沉积物进行了四醚脂类(GDGTs)生物标志化合物的浓度及分布特征分析,结合沉积物的TOC及TN含量及同位素组成对GDGTs的来源进行了探讨。对比TEX86-SST与WOA数据库资料,研究区内美亚海盆73°N以南站位以及欧亚海盆ARC5-BB06站的TEX86-SST与SST具有很好的符合性。楚科奇海域68~73°N站位样品和全球海洋TEX86-SST模式一致,与年平均SST具有较好的符合性。白令海区及ARC5-BB06站TEX86-SST与夏季平均SST符合性更好,可能与提供GDGT的古菌夏季的生产力更高,在全年生产力中所占比例大有关。     

基于航测、遥感影像的大比例尺地形图综合更新方法

随着经济的快速发展和城市化进程的加快,传统数字化地形图的测制和更新越来越需要新测绘手段的加入与新测绘技术的支撑.传统的大比例尺地形图具有全野外生产、投入大、周期长、更新慢且受天气影响较大等特点,伴随着遥测、遥感等技术的快速发展,利用航测遥感进行数据获取的地形图更新方式应用越来越广泛.0.22 m分辨率的遥感影像可以提供大范围较高分辨率的地表覆盖物影像信息,为大比例尺地形图更新提供较高的现势性和较高精度的外业调绘底图数据支撑;而基于无人机的航空摄影测量可以针对性地提供超高现势性和超高精度的测区内正射影像和实景三维模型.因此,采用基于航测和遥感信息相结合的方式是一种综合应用航测遥感技术进行地形图更新的新手段[1].本项目以某地区的大比例尺基础测绘地形图更新为例,测试一种新的地形图更新方法,经过精度比对,证明基于航测、遥感影像进行大比例尺地形图综合更新是一种可靠的方法,在很多时候可以替代全野外数字化测图.     

中大比例尺地形图坐标转换中图廓整饰处理研究

随着地心坐标系的推广应用,在现有地形图坐标转换的过程中,图廓整饰是一个重要环节和难点.图幅进行坐标转换时会发生平移、旋转、缩放,导致原图廓转换后不符合国家标准图式规范.为了保证输出时图廓信息的完整性,本文总结了坐标转换时图廓整饰的特点和处理方法,实现了现有地形图坐标转换中的图廓整饰处理,并已应用于三调、油田、林业、城市规划,多个省、市基础地理信息坐标转换软件的开发中.实践证明,此方法适用于大部分地形图图廓整饰的坐标转换问题.     

"四标四实"中标准地址库建设与应用

"四标四实"是由广州市委市政府提出的对于深化平安有序规范城市管理专项行动的核心工作.其中"四标"包含标准地址库,它是空间位置的结构化描述,建立统一的标准地址库可为城市的社会治理和智慧城市建设奠定基础,本文通过对广州市增城区地址库现状分析,提出采用自主研发的"众采"移动GIS平台的采集地址数据方法,阐述了标准地址数据库建设情况,并以实例说明标准数据库的建设成效.     

史前人类在青藏高原的定居与动物资源利用

定居是人类从高度移动的游猎生活发展到全年固定于一处居住的漫长过程。定居的发生和发展对人类社会的生产方式、技术演化和文明起源具有深远影响,而定居的产生受到气候变化、人口增长、资源压力、技术革新等多种因素影响。青藏高原是研究人类适应和定居高寒缺氧极端环境的理想区域,对史前人类在青藏高原的定居过程关注较多亦争议颇多。通过梳理已发表的考古学、地理学、遗传学等相关学科文献,发现目前对于史前人类定居青藏高原的研究,侧重于讨论低海拔人群或者农作物扩散的影响,对动物资源在这一过程中的作用则关注较少,定居高原的年代和驱动机制仍存在争议。遗址使用的季节性分析,是判断古人是否全年定居的关键。本文总结了如何利用青藏高原鱼类、鸟类和哺乳类等动物遗存因地制宜进行遗址季节性分析以及建立高原遗址动物资源利用时间表的方法。本文认为,开展史前人类在青藏高原定居与动物资源利用研究,首先,应全面建立和完善青藏高原现生动物骨骼形态、全基因组和蛋白质组的数据库,为考古遗址动物遗存物种鉴定提供基础;其次,在物种鉴定的基础上,研究人—动物—环境之间的关系;最后,评估人类在遗址活动的季节性以及动物资源在人类定居青藏高原过程中的作用。     

A neighbor decay cellular automata approach for simulating urban expansion based on particle swarm intelligence

Simulation and quantitative analysis of urban land use change are effective ways to investigate urban form evolution. Cellular Automata (CA) has been used as a convenient and useful tool for simulating urban land use change. However, the key issue for CA models is the definition of the transition rules, and a number of statistical or artificial intelligence methods may be used to obtain the optimal rules. Neighborhood configuration is a basic component of transition rules, and is characterized by a distance decay effect. However, many CA models do not consider the neighbor decay effect in cellular space. This paper presents a neighbor decay cellular automata model based on particle swarm optimization (PSO-NDCA). We used particle swarm optimization (PSO) to find transition rules and considered the decay effect of the cellular neighborhood. A negative power exponential function was used to compute the decay coefficient of the cellular neighborhood in the model. By calculating the cumulative differences between simulation results and the sample data, the PSO automatically searched for the optimal combination of parameters of the transition rules. Using Xiamen City as a case study, we simulated urban land use changes for the periods 1992–1997 and 2002–2007. Results showed that the PSO-NDCA model had a higher prediction accuracy for built-up land, and a higher overall accuracy and Kappa coefficient than the urban CA model based on particle swarm optimization. The study demonstrates that there exist optimal neighborhood decay coefficients in accordance with the regional characteristics of an area. Urban CA modelling should take into account the role of neighborhood decay.     

Primers to block the amplification of symbiotic apostome ciliate 18S rRNA gene in a PCR-based copepod diet study

Pelagic copepods play an important role in the marine food web. However, a full understanding of the ecological status of this zooplankton group depends on the careful study of their natural diets. In previous PCR-based copepod diet studies, we found many apostome ciliates that live symbiotically under the exoskeleton of the copepods, and their sequences were often over-represented in the 18S rRNA gene （18S rDNA） libraries. As a first step to address this issue, we designed three apostome ciliate 18S rDNA blocking primers, and tested their blocking efficiency against apostome ciliate 18S rDNA under various PCR conditions. Using a semi-quantitative PCR method, we optimized the conditions to efficiently amplify the 18S rDNA of the prey while simultaneously excluding the symbiotic apostome ciliates. This technique will facilitate PCR-based diet studies of copepods and other zooplankton in their natural environments.