Genetic analysis of selected Sargassum fusiforme (Harvey) Setchell (Sargassaceae,Phaeophyta) strains with RAPD and ISSR markers

Since the 1980s, Sargassum fusiforme has been cultivated in Zhejiang, South China, and nowadays it becomes one of the important commercial seaweeds in China. With traditions of eating habits in the East Asian countries, this brown alga is used as food, because it contained functional oligo/polysaccharides and chemical components, and was regarded playing roles in antioxidant activities and regulating immunology. Through over 15 years' selection, breeding and cultivation, we obtained three strains with good traits and testified their characters during the production, which included the cultivars with high yield and other two good characters, either all the selected strains were applied in the Sargassum production. To avoid confusion during the selection and nursery, it was preferred to establish one fingerprint for distinguishing the Sargassum cultivars from different strains. Random amplified polymorphic DNA(RAPD) and inter-simple sequence repeat(ISSR) methods were adopted to analyze the genetic diversities of the selected S. fusiforme strains. With that, one fingerprint with RAPD markers was constructed, and one sequence characterized amplified region(SCAR) marker to S.fusiforme was obtained. It is indicated that the applied fingerprint could be valid in S. fusiforme genetic and germplasm justification, and will be positive to molecular marker assistance in its selection and cultivation.     

德州市深层地下水水化学动态演化

通过分析德州市德城区、临邑县城、武城县城、齐河县城和禹城市5个代表点深层地下水近20年或近10年的水质资料,研究了深层地下水的水化学类型和主要水化学指标的动态演化。研究表明,德城区、武城县和禹城县深层地下水水化学类型比较稳定,临邑和齐河个别年份的水化学类型发生变化,但水质并未发生实质性的改变;多数水化学组分含量呈上升趋势,但变化幅度相对较小。水化学组分含量发生变化的原因主要是由其自身水化学地球环境影响所致。     

江苏省耕地细碎化评价与土地整治分区研究

在明确耕地细碎化内涵空间尺度特征的基础上,从资源规模性、空间集聚性和生产便利性3方面构建耕地细碎化空间测度体系,以江苏省为例,综合运用地理空间分析、数理统计分析等方法,开展了省域尺度耕地细碎化多维评价及相应的土地整治协同探讨。研究表明：① 江苏省资源规模属性值总体偏低,呈现苏北-苏中-苏南逐级递减的分异格局;空间集聚属性值总体较高,但区域差异明显,高值区主要集中在徐淮平原及里下河平原地区;利用便利属性值总体呈现与资源规模及集聚状况相反的格局特征,苏南明显高于苏中和苏北地区,两极分化明显,地域差异较大;② 在乡镇尺度对各分维属性进行耦合形成江苏省耕地细碎化指数,省域尺度下该指数呈现从北到南逐渐增加的格局特征,表现为北部的低值聚集区和西南部的高值聚集区;③ 基于区域耕地细碎化不同属性特征的层次组合特点,全省可划分为利用提升区、集约归并区、设施改造区、规模流转区、资源优配区和综合整治区6种类型分区,据此提出不同分区土地整治的主要整治方向及关键问题。     

空间恢复力理论支持下的人地系统动态研究进展

人地系统的概念表现了人与地在特定的地域中相互联系、相互作用而形成的一种动态结构,面向人地系统动态运行过程的复杂性,亟待构建更有力的指标体系表征地球系统和人类系统相互影响与反馈的过程。空间恢复力可以被理解为以保障人地系统结构稳定为目标的地域空间整体对自然和社会扰动的吸收、复原或转化能力,为人地系统研究中针对性理论模式和可定量化指标体系的塑造提供新途径。本文以从自然维度出发的政策与生态系统空间恢复力、从社会维度出发的环境变化与社区生产生活空间恢复力、从综合描述方式出发的空间恢复力综合指标体系三个角度梳理空间恢复力研究现状,并从结构、功能、阈值三个方面研讨不同地域功能类型下的空间恢复力指标体系,提出认知保障系统可持续性的空间状态、明晰人地系统动态过程的空间阈值、满足生态保护与社会进步国家需求三项内容可以作为人地系统动态研究的重要方向。     

张家界农户乡村旅游脆弱性评价与影响因素

以张家界7个村庄334户农户为研究对象,运用参与式农村评估法（PRA）、主成分分析法、聚类分析法和多元线性回归等方法,分析不同类型农户脆弱性指数以及脆弱性影响因素。研究结果表明：① 农户乡村旅游脆弱性类型可分为意识脆弱型、社交脆弱型、人力脆弱型、发展均衡型和全面脆弱型5种类型;② 总体脆弱性方面,不同类型农户的总体脆弱程度均为脆弱,各自脆弱性指数不一,且非旅游农户高于旅游农户;③ 因子脆弱性中除社交脆弱型农户的民俗文化因子脆弱性指数高于农户认知因子脆弱性外,其他类型农户的人力素质、社会网络、生计资本和农户认知等4个因子脆弱性指数均高于政策制度、生态环境和民俗文化等3个因子脆弱性指数;④ 人力、文化和生态等方面的因子是影响农户乡村旅游脆弱性的主要因素。最后,从提升生计资本、传承民俗文化和保护生态环境等方面提出降低农户乡村旅游脆弱性的几点建议。     

高中生地理剖面图阅读障碍的诊断分析与教学建议

地理剖面图是描绘地理事物内部结构的图形,是承载地理信息的一种重要形式。能够正确阅读地理剖面图并解决相关问题是中学生必备的素养。文章通过对高中生地理剖面图阅读障碍的诊断分析,为地理剖面图的教学提供针对性的建议。     

海洋大数据应用技术分析与趋势研究

随着各类探测设备及计算模拟的发展,科学研究进入第四范式"数据密集型发现",海洋领域亦已进入大数据时代,各类海洋大数据应用技术也成为海洋科学研究的关注焦点。本文从海洋大数据的产生到海洋大数据应用整个链条进行探讨。首先对海洋大数据的定义及特征进行了讨论;其次从技术方面,从多源感知与探测、存储与管理、分析挖掘、可视化角度对海洋大数据应用技术研究的基础和研究现状进行分析,最后从实践方面,对相关技术研究的应用现状及应用前景进行了说明,为海洋科学及技术研究发展提供重要参考依据。     

An Estimation of Ground Ice Volumes in Permafrost Layers in Northeastern Qinghai-Tibet Plateau,China

The ground ice content in permafrost serves as one of the dominant properties of permafrost for the study of global climate change, ecology, hydrology and engineering construction in cold regions. This paper initially attempts to assess the ground ice volume in permafrost layers on the Qinghai-Tibet Plateau by considering landform types, the corresponding lithological composition, and the measured water content in various regions. An approximation demonstrating the existence of many similarities in lithological composition and water content within a unified landform was established during the calculations. Considerable knowledge of the case study area, here called the Source Area of the Yellow(Huanghe) River(SAYR) in the northeastern Qinghai-Tibet Plateau, has been accumulated related to permafrost and fresh water resources during the past 40 years. Considering the permafrost distribution, extent, spatial distribution of landform types, the ground ice volume at the depths of 3.0–10.0 m below the ground surface was estimated based on the data of 101 boreholes from field observations and geological surveys in different types of landforms in the permafrost region of the SAYR. The total ground ice volume in permafrost layers at the depths of 3.0–10.0 m was approximately(51.68 ± 18.81) km~3, and the ground ice volume per unit volume was(0.31 ± 0.11) m~3/m~3. In the horizontal direction, the ground ice content was higher in the landforms of lacustrine-marshland plains and alluvial-lacustrine plains, and the lower ground ice content was distributed in the erosional platforms and alluvial-proluvial plains. In the vertical direction, the volume of ground ice was relatively high in the top layers(especially near the permafrost table) and at the depths of 7.0–8.0 m. This calculation method will be used in the other areas when the necessary information is available, including landform type, borehole data, and measured water content.     

虚拟地理环境中沉浸式多人协同交互技术研究及实现

在VGE的发展过程中,自然高效的人机交互一直是其研究的核心内容之一,但在当前众多VGE应用案例中,用户仍然是基于传统的人机交互界面与VGE进行交流,这导致了：① 用户的沉浸感不高;② 多人在VGE中协同交互的需求无法得到有效满足。因此,为了实现VGE中的沉浸式多人协同交互,本文首先综述了VGE中人机交互技术研究和应用现状,并简要阐述了动作捕捉技术发展历程、基本原理及其在提高VGE用户交互沉浸感上的优势。在此基础上,对VGE中沉浸式多人协同交互系统进行了重点设计,主要包括分析了基于动作捕捉技术的沉浸式多人协同交互模式及其对应的交互动作语义,提出了多人协同冲突控制机制,以及着重介绍了VGE中沉浸式多人协同交互系统的结构和功能。最后,以北京大学为例开发了虚拟燕园辅助规划设计原型系统,并进行了实验。研究结果表明,沉浸式多人协同交互技术的交互效果受到用户认可,它在提高化身之间及化身与VGE之间的协同交互方面具有明显的优势,可应用于地学教育、城市规划、应急救援和军事指挥等领域,具有良好的应用前景。     

地铁盾构管片姿态的水平偏差算法研究

针对管片姿态的水平偏差计算复杂、人工干预大等局限,提出一种基于设计参数的管片姿态水平偏差的自动计算方法。文中介绍地铁盾构管片姿态的测量方法,推导出直线段、圆曲线段以及缓和曲线段的姿态水平偏差的数学模型。通过工程实例,验证该方法数学模型的正确性,且能准确地、高效地反馈管片姿态水平偏差的信息。