回归分析在确定多金属硫化物矿石密度中的应用

在研究多金属硫化物矿床的特点,分析以往矿床勘查中确定矿石密度值难点的基础上,通过建立矿石密度值与矿石各组分的多元线性回归数学模型,预测矿床的矿石密度值。     

A Quantitative Evaluation of Shale Gas Content in Different Occurrence States of the Longmaxi Formation: A New Insight from Well JY-A in the Fuling Shale Gas Field,Sichuan Basin

Comprehensive quantitative evaluation of shale gas content and the controlling factors in different occurrence states is of great significance for accurately assessing gas-bearing capacity and providing effective well-production strategies. A total of 122 core samples from well JY-A in the Fuling shale gas field were studied to reveal the characteristics of S_1 l shale,15 of which were selected to further predict the shale gas content in different occurrence states, which are dependent on geological factors in the thermal evolution process. Geological parameters were researched by a number of laboratory programs, and the factors influential in controlling shale gas content were extracted by both PCA and GRA methods and prediction models were confirmed by the BE method using SPSS software. Results reveal that the adsorbed gas content is mainly controlled by TOC, Ro, SSA, PD and pyrite content, and the free gas content is mainly controlled by S_2, quartz content, gas saturation and formation pressure for S_1 l in well JY-A. Three methods, including the on-site gas desorption method, the empirical formula method, and the multiple regression analysis method were used in combination to evaluate the shale gas capacity of well JY-A, all of which show that the overall shale gas content of well JY-A is in the range of 2.0–5.0 m~3/t and that the free gas ratio is about 50%, lower than that of well JY-1. Cause analysis further confirms the tectonics and preservation conditions of S_1 l in the geological processes, especially the influence of eastern boundary faults on well JY-A, as the fundamental reasons for the differences in shale gas enrichment in the Jiaoshiba area.     

甘肃地层研究现状、存在问题及今后方向

地层学是地质学重要的基础性学科,是地质工作的基础和支撑。近年来甘肃省地层古生物研究取得重大进展,积累了一批为全省地层研究修史立典的材料,及时总结这些成果素材,按照最新的理论、方法对区域地层进行划分、对比和精准化研究,是一个省区基础地质工作的重要内容。本文通过系统总结和梳理近年来甘肃地层学研究的最新成果,按照时间顺序和学科特点,系统性提出了按照多重地层划分对比理论和《中国地层指南及中国地层指南说明书》（2016年版）和《中国地层表》（2014）的框架和序列,全面提高甘肃地层研究精准度,为全省地质调查和相关研究提供基础支撑;对全省不同地区和不同地质单元地层界线层型和单位层型进行对比研究和厘定,建立新一代甘肃地层表的建议和路径。     

一个采用多种支护技术的基坑工程

基坑支护是一种临时施工措施,目的是挡土挡水,为地下室施工创造条件,同时控制好对周边环境的影响。以一个基坑工程为例,介绍根据其不同的周边环境采用不同的支护技术及在施工过程中发生问题的解决办法,供类似基坑支护工程参考。     

青藏高原"一江两河"农区居民食物消费结构与特征

居民食物消费受自然地理环境、城镇化等因素影响,同时通过市场机制影响区域粮食安全和农牧业发展。以西藏“一江两河”地区为例,基于分层抽样,通过2019年实地入户调研,获取了262户农村居民上年度食物消费数据,对青藏高原农区居民的食物消费结构及其影响因素进行分析。结果表明：① 样本内居民的植物性食物的消费量是动物性食物的3.19倍,植物性食物以蔬菜和粮食为主,动物性食物以肉类和牛奶为主;青稞及青稞酒在藏民饮食中占有重要地位。② 居民食物消费规模和结构与食物自给率指标密切相关,自给自足特征显著。③ 不同地区、家庭规模、务工规模、收入水平以及家庭年龄之间,居民的家庭食物消费结构均有所差异,且不同家庭之间面粉和水果的消费差异最显著。④ 区域差异、家庭规模类型和家庭务工规模是影响样本农区居民食物消费综合差异的主要因素。结果可为青藏高原地区居民食物消费结构改善、膳食营养提升以及农牧业转型发展提供科学基础和决策借鉴。     

基于GPS的地基增强系统机载端完好性算法研究

针对地基增强系统（GBAS）非完好性事件的极端性,开展GBAS完好性算法研究,给出H0和H1假设下的机载端保护级计算方法,并分析GBAS中引起“虚警”和“漏警”两类非完好性事件的主要误差源。实验结果表明,机载端伪距经过差分校正后其位置精度优于1 m,可用性大于99.999 9%,满足CAT Ⅰ精密进近着陆导航需求。同时,进行非完好性事件仿真验证的结果表明,卫星几何分布和电离层风暴是引起“虚警”和“漏警”的主要误差源,未来CAT Ⅲ GBAS需将单星座扩展为包括北斗在内的多星座,将单频升级为双频,其中多星座可以优化卫星的几何布局,双频可以消除电离层风暴的影响。     

Troubling Positionality: Politics of “Studying Up” in Transnational Contexts

Drawing on research conducted in India's software industry in Bangalore, this article explores the multiple positionalities of differently situated people in the project—state officials, software firm managers and owners, software professionals, and researcher as critic. Challenging conventional notions of positionality centered on individual scholars' negotiations of their own identities, I trace the institutional, geopolitical, and social relations within which all participants are embedded. I argue that moments of tension and uncertainty are not just symbolic of multiple positionalities of both researcher and researched but also indicate the fraught nature of information technology–led development in neoliberal India. This article thus provides a particular opportunity to trouble notions of power, positionality, reflexivity, and feminist commitment to untangling the politics of knowledge production while “studying up” in transnational contexts.     

基于“多规合一”的市级国土空间优化方法——以烟台市为例

针对现阶段各规划边界交叉、空间重叠的问题,本文从提高空间价值、减少空间破碎度和协调各类空间的角度出发,在梳理现有空间优化模型及智能算法的基础上,改进多目标规划模型并适应性改造遗传算法,以此二者构建市级国土空间优化模型。以烟台市为例,设置3种情景为决策者提供方案集进行3类规划主导下的2020年国土空间优化研究,结果显示：①优化后烟台市农业、城镇和生态空间价值分别增加了23.24%、29.27%、6.30%;②不同情景下空间分布合理且较为集中,生态保护情景有利于国土空间集合连片,经济发展情景更适合于多空间协调发展。研究表明：该模型能有效地解决国土空间内容重叠问题,明显提高了国土空间价值,同时优化模型适应性强,为“多规合一”背景下市级国土空间优化提供技术支撑。     

Synchronising geometric representations for map mashups using relative positioning and Linked Data

Map mashups, as a common way of presenting geospatial information on the Web, are generally created by spatially overlaying thematic information on top of various base maps. This simple overlay approach often raises geometric deficiencies due to geometric uncertainties in the data. This issue is particularly apparent in a multi-scale context because the thematic data seldom have synchronised level of detail with the base map. In this study, we propose, develop, implement and evaluate a relative positioning approach based on shared geometries and relative coordinates to synchronise geometric representations for map mashups through several scales. To realise the relative positioning between datasets, we adopt a Linked Data–based technical framework in which the data are organised according to ontologies that are designed based on the GeoSPARQL vocabulary. A prototype system is developed to demonstrate the feasibility and usability of the relative positioning approach. The results show that the approach synchronises and integrates the geometries of thematic data and the base map effectively, and the thematic data are automatically tailored for multi-scale visualisation. The proposed framework can be used as a new way of modelling geospatial data on the Web, with merits in terms of both data visualisation and querying.     

For your eyes only? Evaluating a coordinated and multiple views tool with a map,a parallel coordinated plot and a table using an eye-tracking approach

Geographic visualization tools with coordinated and multiple views (CMV) typically provide sets of visualization methods. Such configuration gives users the possibility of investigating data in various visual contexts; however, it can be confusing due to the multiplicity of visual components and interactive functions. We addressed this challenge and conducted an empirical study on how a CMV tool, consisting of a map, a parallel coordinate plot (PCP), and a table, is used to acquire information. We combined a task-based approach with eye-tracking and usability metrics since these methods provide comprehensive insights into users’ behaviour. Our empirical study revealed that the freedom to choose visualization components is appreciated by users. The individuals worked with all the available visualization methods and they often used more than one visualization method when executing tasks. Different views were used in different ways by various individuals, but in a similarly effective way. Even PCP, which is claimed to be problematic, was found to be a handy way of exploring data when accompanied by interactive functions.