吉林南部地区老岭群变质作用特征研究

吉林南部地区老岭群变质矿物较为发育,本文通过对其中发育的变质矿物进行详细鉴定和大量探针分析,将老岭群下亚群主要变质矿物划分为两个世代,分别代表两期变质作用M1和M2.结合研究区老岭群变质矿物组合、分布特征以及变质相带的研究,认为M1为中-低温区域动力热流变质作用,可以划分为低绿片岩相和高绿片岩相,而M2为局部热变质作用...     

基于地理案例开发的研究性学习设计

案例教学是揭示地理原理和规律、启迪学生思维、引导学生自主学习、培养学生地理能力的有效载体。因此,案例教学被广泛地应用于地理教学,尤其是人文地理教学。教师是实施案例开发的主体,教师的专业视野往往决定了案例开发的质量。地理案例质量高低是实施地理案例教学的基础性条件,如何开发适合特定学生、特定内容的案例是摆在广大地理教师面前的一道难题。     

不同应力路径下岩石三轴卸荷力学特性与强度准则研究EI北大核心CSCD

基于3种不同应力路径下花岗岩三轴卸荷试验,研究了岩石的应力-应变全过程曲线和变形特征及其强度准则。试验结果表明,卸围压过程中,侧向应变与围压先呈线性后呈非线性关系,且其增长速率约为轴向应变增长速率的3-5倍,表现出明显的侧向扩容,其扩容程度与卸载路径有关;从不同围压与体积应变曲线所围面积可以看出,卸荷前围压越大,卸荷释放的能量越大;变形模量随围压卸载而逐渐减小,且随初始围压增大,总体上呈负指数分布趋势,且同一种卸荷应力路径时,变形模量的减小量随初始围压增大有所增大,泊松比随围压降低而不断增大,两者之间呈现明显的非线性关系;岩石破坏特征以剪切破坏为主;采用幂函数型摩尔强度准则很好反应了岩石的强度特征。研究结果对地下金属矿深部开采具有一定的指导意义和参考价值。     

奋战“后六九”——黑龙江省矿业集团后六九地区铜金普查工作掠影

这里是几代地质工作者梦寐以求期盼实现找矿突破的地方。他们从上个世纪50年代就开始了在这里的追梦生活。虽然心中的理想一直没．有实现，但是他们始终没有放弃对希望的追求。     

黑龙江首次发现喀斯特溶洞

近日，位于齐齐哈尔市龙江县的一处喀斯特溶洞引起人们的广泛关注，省、市有关部门准备将其作为填补我省喀斯特构造溶洞空白的旅游项目进行开发。据了解，这是在高纬度地区第一次发现喀斯特构造溶洞。。     

20世纪80年代以来中国土地利用变化的基本特征与空间格局(英文)

Land-use/land-cover changes(LUCCs) have links to both human and nature interactions. China's Land-Use/cover Datasets(CLUDs) were updated regularly at 5-year intervals from the late 1980s to 2010, with standard procedures based on Landsat TM\ETM+ images. A land-use dynamic regionalization method was proposed to analyze major land-use conversions. The spatiotemporal characteristics, differences, and causes of land-use changes at a national scale were then examined. The main findings are summarized as follows. Land-use changes(LUCs) across China indicated a significant variation in spatial and temporal characteristics in the last 20 years(1990–2010). The area of cropland change decreased in the south and increased in the north, but the total area remained almost unchanged. The reclaimed cropland was shifted from the northeast to the northwest. The built-up lands expanded rapidly, were mainly distributed in the east, and gradually spread out to central and western China. Woodland decreased first, and then increased, but desert area was the opposite. Grassland continued decreasing. Different spatial patterns of LUC in China were found between the late 20th century and the early 21st century. The original 13 LUC zones were replaced by 15 units with changes of boundaries in some zones. The main spatial characteristics of these changes included(1) an accelerated expansion of built-up land in theHuang-Huai-Hai region, the southeastern coastal areas, the midstream area of the Yangtze River, and the Sichuan Basin;(2) shifted land reclamation in the north from northeast China and eastern Inner Mongolia to the oasis agricultural areas in northwest China;(3) continuous transformation from rain-fed farmlands in northeast China to paddy fields; and(4) effectiveness of the "Grain for Green" project in the southern agricultural–pastoral ecotones of Inner Mongolia, the Loess Plateau, and southwestern mountainous areas. In the last two decades, although climate change in the north affected the change in cropland, policy regulation and economic driving forces were still the primary causes of LUC across China. During the first decade of the 21st century, the anthropogenic factors that drove variations in land-use patterns have shifted the emphasis from one-way land development to both development and conservation. The "dynamic regionalization method" was used to analyze changes in the spatial patterns of zoning boundaries, the internal characteristics of zones, and the growth and decrease of units. The results revealed "the pattern of the change process," namely the process of LUC and regional differences in characteristics at different stages. The growth and decrease of zones during this dynamic LUC zoning, variations in unit boundaries, and the characteristics of change intensities between the former and latter decades were examined. The patterns of alternative transformation between the "pattern" and "process" of land use and the causes for changes in different types and different regions of land use were explored.     

社会经济数据空间化研究进展

由于传统的社会经济数据在地学研究和使用中存在着数据结构不一致、空间单元不匹配和数据在空间单元内均一化等问题,因而需要对社会经济数据进行空间化,使其满足科学研究的需求。国内外社会经济数据空间化的研究主要集中在人口数据空间化和GDP数据空间化两方面,而其他社会经济数据空间化的研究尚不多见。经过数十年的发展,国内学者提出了至少10余种社会经济数据空间化模型。该文按照其思想及方法的不同将其归为空间插值法、土地利用/土地覆被影响模型、多源数据融合法及遥感反演法四类,分别对其做了详细介绍,并评述了各种方法的优缺点;指出了今后对社会经济数据空间化结果应用的两个方向:用于分析社会经济数据对生态交错带时空变化的影响和根据社会经济数据空间化的结果进行土地利用历史重建。     

光合细菌(PSB)饲喂海湾扇贝幼虫的试验

光合细菌(Photo Synthetic Bacteria,简称 PSB)是一种以光为能源,以CO_2或有机物质为碳源而繁殖的微生物,广泛分布于海洋、河流、土壤及污泥表层中。光合细菌具有净化水质的能力,其菌体含有丰富的蛋白质,V_(B12)、叶酸、生长素等促生物生长因子,是鱼虾、贝幼虫的良好饵料,近几年引起国内外水产界的重视。     

地质找矿中遥感信息的综合研究与深化应用——以铀矿为例

以铀矿勘查为例,通过对遥感信息进行综合研究与深化应用的思考,提出后遥感应用技术的新理念,并认为它是将遥感信息的应用“从技术层面提升到科学层面”的重要途径.在此基础上,又提出砂岩型铀矿断隆成矿的观点,进而建立了我国克拉通和大型活化盆地的铀矿区域找矿模式.在上述观点和模式指导下,利用新型遥感技术,特别是高分辨率遥感数据,在...     

Impact of Air Pollution on Summer Surface Winds in Xi’an

By analysis of observation data, this paper demonstrates that pollution particles could reduce surface wind speed through blocking solar radiation to the ground. The comparation between temperature at the lowland meteorological station Xi’an and that over the nearby highland station Mt. Hua suggests that surface solar radiation at Xi’an is reduced due to the increasing anthropogenic aerosols. The reduced surface energy suppresses the atmospheric instability and convective flows, and thus the downward transf...