西安城市扩张及其驱动力分析

随着人口的增长与经济的发展,尤其我国西部城市在西部大开发的背景下,大中城市的扩张十分明显,深刻地影响城市周边的生态环境。如何快速准确地获取城市扩张信息,并分析其驱动力机制,对于指导城市规划,优化西部生态环境与可持续发展都具有十分重要的意义。作者分别采用了监督分类法和归一化裸露指数 (NDBI) 法提取了西安市的城市边界信息,并对二者进行对比分析,认为监督分类法提取的城市边界信息较为准确。在此基础上通过对相关统计资料的分析,认为西安市城区快速扩张与西部大开发以来西安市固定资产投资额的大幅增加以及经济的快速发展有密切的关系,此外人口的增加、交通等基础设施的发展也是重要的驱动因素。     

数字南水北调的虚拟技术应用——以中线工程河北段主干线为例

以中线工程河北段主干线为例,讲述了虚拟技术在南水北调工程中的应用设计,并利用虚拟三维模型在三维景观显示、最佳路线选择、缓冲分析、土方计算、分析表面形态、计算坡度、坡向、长度等方面进行了可行性分析。并指出今后需进一步解决的问题。     

中国电影产业时空演变特征及驱动因素

从产业环境、产业规模和产业效益3个维度构建综合评价指标体系,运用熵值法对中国2012—2018年省域尺度电影产业进行综合评价,运用GIS空间分析技术和地理探测器模型,分析其时空演变规律和影响因素.结果表明:1)2012—2018年中国电影产业发展整体水平不高,但发展速度显著提高,"T"字型空间结构逐渐形成,其发展空间格...     

Biomarker records of phytoplankton productivity and community structure changes during the last 14000 years in the mud area southwest off Cheju Island, East China Sea

The ecological environment in the East China Sea (ECS) and the Yellow Sea (YS) has changed significantly due to sea-level rising and the Kuroshio incursion since the last deglaciation. In this study, biomarker records of core F10B from the mud area southwest off Cheju Island (MSWCI) were generated to evaluate phytoplankton productivity and community structure changes in response to environmental evolution during the last 14 kyr. The contents of diatom, dinoflagellate and haptophyte biomarkers (brassicasterol, dinosterol and C₃₇ alkenones) display similar trends, with increasing phytoplankton productivity during the last 14 kyr due to the increased influences of the Kuroshio, and especially due to the eddy-induced upwelling during the late Holocene. On the other hand, the contents of terrestrial biomarkers (C₂₈ +C₃₀ +C₃₂ n-alkanols) and terrestrial organic matter (TOM) proxies (TMBR’ and BIT) all reveal decreasing TOM input into the area around the sampling site for the 14 kyr, mostly due to sea-level rising. Phytoplankton biomarker ratios reveal a shift from a haptophyte-dominated community at 6.2–2.5 kyr BP to a diatom-dominated community at 2.5–1.45 kyr BP, likely caused by a stronger cold eddy circulation system at 2.5–1.45 kyr BP in the MSWCI.     

新疆尾亚—天湖地区花岗岩类剥蚀程度估算及对区域找矿的启示

尾亚—天湖地区位于新疆中亚造山带东南部的中天山地块内,晚古生代—中生代岩浆活动强烈,产出了战略性关键矿产尾亚钒铁磁铁矿.在详细岩相学观察的基础上,对尾亚、天湖和沙泉子南岩体中的角闪石和黑云母进行了电子探针(EMPA)测试分析,限定了 3个岩体结晶的温压条件、氧逸度、含水量和含铁指数等要素,为解析中天山地块的岩浆-成矿物...     

Diurnal Variations of Hydrochemistry in a Travertine-depositing Stream at Baishuitai, Yunnan, SW China

Diurnal variations of hydrochemistry were monitored at a spring and two pools in a travertine-depositing stream at Baishuitai, Yunnan, SW China. Water temperature, pH and specific conductivity were measured in intervals of 5 and 30 min for periods of 1 to 2 days. From these data the concentrations of Ca²⁺, HCO₃⁻, calcite saturation index, and CO₂ partial pressure were derived. The measurements in the spring of the stream did not show any diurnal variations in the chemical composition of the water. Diurnal variations, however, were observed in the water of the two travertine pools downstream. In one of them, a rise in temperature (thus more CO₂ degassing) during day time and consumption of CO₂ due to photosynthesis of submerged aquatic plants accelerated deposition of calcite, whereas in the other pool, where aquatic plants flourished and grew out of the water (so photosynthesis was taking place in the atmosphere), the authors suggest that temperature-dependent root respiration underwater took place, which dominated until noon. Consequently, due to the release of CO₂ by the root respiration into water, which dominated CO₂ production by degassing induced by temperature increase, the increased dissolution of calcite was observed. This is the first time anywhere at least in China that the effect of root respiration on diurnal hydrochemical variations has been observed. The finding has implications for sampling strategy within travertine-depositing streams and other similar environments with stagnant water bodies such as estuaries, lakes, reservoirs, pools and wetlands, where aquatic plants may flourish and grow out of water.     

基于多元回归分析的铬污染地下水风险评价方法

土-水分配系数（K_d）是表征重金属污染物在土壤包气带中迁移能力的重要参数,受污染物质量浓度、pH值、有机质质量分数、铁铝氧化物质量分数等多种因素影响。本文通过实验研究了分配系数与各种影响因素之间的关系,基于多元回归分析方法得到了分配系数与影响因素的关系方程;并以分配系数、泄漏量、土壤孔隙度、初始含水率为风险因子建立了地下水污染风险评价方法。以某工厂铬废液的泄露为案例,采用构建的方法进行地下水污染风险评价。结果表明：该处地下水被污染的风险等级为中等。地下水污染风险评价方法的建立为重金属污染地下水的监测管理提供了一种有效方法。     

渤海风驱-潮致Lagrange余流的数值模拟与季相时空变异

The spatial distribution and seasonal variation of the tide-induced Lagrangian Residual Circulations (LRC hereafter), wind-driven LRC, and the coupling dynamic characteristics were simulated using ECOM, given the Hellerman and Rosenstein global monthly-mean wind stresses. The results showed that the tide-induced LRC of the harmonic constituent M2 bears an identical pattern in four seasons in the Bohai Sea: the surface one is weak with random directions; however, there exist a southeast current from the Bohai Strait to the Laizhou bay, and a weakly anticlockwise gyre in the south of the Bohai Strait for the bottom layer LRC. The magnitude of bottom layer tide-induced LRC is larger than the surface one, and moreover, it contributes significantly to the whole LRC in the Bohai Sea. Unlike the identical structure of the tide-induced LRC, the wind driven LRC varies seasonally under the prevailing monsoon. It forms a distinct gyre under the summer and winter monsoons in July and January respectively, but it seems weak and non-directional in April and September.     

湖南白马山龙潭超单元、瓦屋塘花岗岩锆石SHRIMP U-Pb年龄及其地质意义

运用阴极发光技术,对湖南白马山龙潭超单元2个样品和瓦屋塘花岗岩1个样品的锆石进行了内部结构分析,在此基础上利用锆石SHRIMP U-Pb定年方法进行了同位素年代学测定。其中,白马山龙潭超单元2个黑云母二长花岗岩样品分别给出了(215.9±1.9) Ma和(212.2±2.1) Ma的主体谐和年龄。同时还测得了一组较年轻的谐和年龄((201.0±2.8) Ma)和一组较老的锆石核部年龄(230.3~227.0 Ma),表明研究区印支晚期存在多期花岗质岩浆的侵入活动。瓦屋塘岩体黑云母二长花岗岩1个样品给出了(217.7±1.8) Ma的谐和年龄。这2个岩体的形成进一步佐证了华南大陆印支晚期岩浆活动于210~225 Ma,达到岩浆活动的峰期。地球化学测试结果显示,白马山和瓦屋塘岩体均为弱过铝-强过铝质花岗岩,具壳源型花岗岩的特征,形成于后碰撞期或碰撞晚期的构造环境,源于早元古代变质杂砂岩的部分熔融。结合区域大地构造背景认为,这2个岩体形成于秦岭-大别和松马2条印支期缝合带碰撞结束后的印支晚期伸展构造背景下,为热-应力松弛阶段,板内挤压加厚的地壳减压熔融作用的产物。     

一个灵活的海洋——大气耦合环流模式

Based on the National Center for Atmospheric Research (NCAR) Climate System Model version 1(CSM-1), a Flexible coupled General Circulation Model version 0 (FGCM-0) is developed in this study through replacing CSM-1＇s oceanic component model with IAP L30T63 global oceanic general circulation model and some necessary modifications of the other component models. After the coupled model FGCM--0 is spun up for dozens of years, it has been run for 60 years without flux correction. The model does not only show the reasonable long-term mean climatology, but also reproduce a lot of features of the interannual variability of climate, e.g. the ENSO-like events in the tropical Pacific Ocean and the dipole mode pattern in the tropical Indian Ocean. Comparing FGCM-0 with the NCAR CSM-1, some common features are found, e.g. the overestimation of sea ice in the North Pacific and the simulated double ITCZ etc.The further analyses suggest that they may be attributed to errors in the atmospheric model.