印度尼西亚红土型镍矿

红土型镍矿分布在环太平洋亚热带-热带多雨地区。镍矿体产于趟基性岩上部的红土风化壳中,受地形控制明显,成因类型为红土型硅酸镍氧化矿,以褐铁矿型和腐岩型为主,矿石质量和可利用性均较好。     

红土型镍矿矿床勘查评价方法与优化

红土型镍矿为含镍基性-超基性岩体经红土化作用形成的地表风化壳型矿床, 具有矿床分布相对集中、矿床规模大、矿床勘查类型简单、找矿标志明显等显著特点。本文简要总结了红土型镍矿的成矿环境、成矿条件、地质特征, 在云南省有色地质局三〇八队“走出去”实施多个红土型镍矿找矿勘查实例的基础上, 系统对红土型镍矿的找矿、勘查评价方法进行研究和总结, 提出红土型镍矿的“三段五步法”找矿勘查程序、有效找矿方法和快速勘查评价模式, 并对红土型镍矿勘查评价中的相关问题进行了探讨。     

华北地区地壳厚度与泊松比研究

华北地区地壳结构和物理性质是研究华北克拉通破坏机制的重要依据.本文通过收集分布在华北克拉通区域的323个宽频带地震台记录到的2007年8月到2009年3月间发生在全球范围内6.5级到8.5级的共93个远震事件的波形资料,较完整地得到了华北及其周边区域台站下方的接收函数、地壳厚度和泊松比分布情况.研究发现:(1)华北克拉通地壳厚度大范围减薄不仅仅发生在东部,而是已经到达南北重力梯度带附近; (2)在鄂尔多斯的周边裂谷盆地,地壳也出现了减薄现象; 周边裂谷区的泊松比大于鄂尔多斯内部,局部区域的泊松比高达0.3左右; (3)从地壳厚度和地形的相关性来看,华北地区的地壳厚度与地表地形存在着明显负相关的关系,这与艾利均衡假说相一致,可能意味着华北地区的地壳正在经历着缓慢的破坏与均衡同时进行的过程; 而华北克拉通中西部和东北部则显示出明显的不均衡现象.     

基于加密自动气象观测站和国家气象观测站的山东省极端短时强降水时空分布特征的对比分析

利用2008—2017年4一10月山东省加密自动气象观测站(简称全部站)和国家气象观测站(简称国家站)逐小时1 mm以上降水量资料,通过对比分析,探究不同分辨率数据对极端短时强降水时空分布特征的刻画效果。结果表明如下:全部站小时降水量的偏态特征比国家站明显,若分析小时降水量的平均状态,两者均具有代表性,若分析短时强降水的极端性,全部站数据更具有优越性。将各站第99.5%分位数作为极端短时强降水的阈值最合理,全部站和国家站对于30～45 mm阈值的空间分布特征相似,45 mm以上的阈值,全部站的数值和范围均大于国家站。山东省大部地区的极端短时强降水强度集中在40～60 mm·h~(-1),全部站和国家站在此区间的空间分布特征相似。国家站数据不能刻画40 mm·h~(-1)以下和60 mm·h~(-1)以上的极端短时强降水的空间分布特征。极端短时强降水强度的空间分布特征与地理位置及地形特征密切相关。鲁东南地区的极端短时强降水强度、日最大降水量及夏季降水量、年降水量均居山东省之首,鲁西北地区虽然强降水频次高、强度大,但与年降水量和夏季降水量没有正相关关系。全部站与国家站极端短时强降水频次的月变化和日变化特征一致,但国家站不能完全代表山东省极端短时强降水强度的月变化和日变化平均状况,全部站数据能更准确地反映山东省的时间变化特征。     

Particulate Amines in the Background Atmosphere of the Yangtze River Delta,China: Concentration,Size Distribution,and Sources

Amines are important for new particle formation and subsequent growth in the atmosphere. Consequently, the processes involved are receiving more attention in recent years. Here, we conduct a field observation in order to investigate the atmospheric particulate amines at a background site in the Yangtze River Delta(YRD) during the summer of 2018.Four amines in PM_(2.5), i.e., methylamine(MA), dimethylamine(DMA), diethylamine(DEA), and trimethylamine(TMA),were collected, twice daily and analyzed. During the campaign, our measurements found the concentrations of MA, DMA,DEA, and TMA of 15.0 ± 15.0, 6.3 ± 6.9, 20.4 ± 30.1, and 4.0 ± 5.9 ng m–3, respectively, and the four amines correlated well with each other. The concentration of amines appear to be independent of whether they were collected during the day or night. Both MA and DMA exhibited a bimodal size distribution that had peaks at 0.67 and 1.1 μm, suggesting amines preferably distribute on submicron particles. Boundary layer height(BLH), relative humidity, and pH of aerosols were found have a negative relationship with amines, while aerosol liquid water content(ALWC) was found to have a positive relationship with amines. The PMF(positive matrix factorization) source apportionment results showed that the main source of amines in Chongming Island was of anthropogenic origin such as industrial and biomass emission, followed by marine sources including sea salt and marine biogenic sources. Given that the YRD region is still suffering from complex atmospheric pollution and that the knowledge on aerosol amines is still limited, more field studies are in urgent need for a better understanding of the pollution characteristics of amines.     

GNSS processing at CODE: status report

Since May 2003, the Center for Orbit Determination in Europe (CODE), one of the analysis centers of the International GNSS Service, has generated GPS and GLONASS products in a rigorous combined multi-system processing scheme, which promises the best possible consistency of the orbits of both systems. The resulting products, in particular the satellite orbits and clocks, are easily accessible by the user community. In the first part of this article, we focus on the generation of the combined global products at CODE, where we put emphasis not only on accuracy, but also on completeness. We study the impact of GLONASS on the CODE products, and the benefit of using them. Last, but not least, we introduce AGNES (Automated GNSS Network for Switzerland), a regional tracking network of small extensions (roughly 400 km East–West, 200 km North–South), which consequently tracks all GNSS satellites and analyzes their measurements using the CODE products.     

南方水库热分层消亡期混合层深度及缺氧区时空变化特征——以南宁市天雹水库为例

湖库热分层消亡引起的突发性水质恶化现象引起了广泛的关注,我国南方水库大多是暖单次混合型湖泊,每年混合一次,导致水库水质周期性下降,但目前对南方水库热分层消亡过程的高频监测研究较少。为探究我国南方水库热分层消亡期水体混合过程的时空变化规律及驱动因素,以广西南宁天雹水库为例,于冬季热分层消亡期(2019年11月—2020年2月)对水库多点位水体理化指标开展原位监测,并利用自建气象站获取气象水文数据。结果表明:(1)水库热分层消亡期间,过渡区水深较浅可在短期内达到完全混合状态且缺氧区同步消失;而湖泊区混合过程整体滞后于过渡区,混合层深度由6.85 m增加至13.65 m,缺氧区逐渐减小,缺氧指数(AI)由0.40减小至0.07,直至水体完全混合后缺氧区消失;水库过渡区较湖泊区提前约40 d达到完全混合状态。(2)气象因子是引起热分层结构变化的主要因素,气温(T)、辐射(R)与混合层深度(MLD)呈现显著负相关(R_T=0.927、R_R=0.925,P<0.01),风速(WS)与MLD呈现显著正相关(R_WS=0.728,P&...     

Assessment of Risks Relevant to Underground Measurements for Coal Mining Production and Exploration

Natural Resources Research - In underground mining establishments and in all processes of underground coal mining from investigation activities to production activities, geodetic measurements and...     

中国电子信息产业创新的集群网络模式与演化路径

流空间背景下,多空间尺度网络耦合对创新至关重要已达成学界共识。综合运用区位熵与社会网络分析,识别32个电子信息产业集群,进而基于1985—2015年合作申请发明专利数据,运用卡方检验和Infomap社区发现算法,借助Pajek和ArcGIS等软件,揭示中国电子信息产业创新合作空间模式,探讨创新网络空间组织演化规律。结果表明：① 中国电子信息产业创新合作呈现集群互联的模式,集群区域的创新主体更倾向于同本地和其他集群区域的创新主体合作,这与非集群区域的创新主体结网方式明显不同,印证了关系经济地理学者提出的全球集群网络论断。② 集群创新网络社区的空间组织从位于集群地理边界内,本地化特征显著,演化为超越集群地理边界,呈现等级差异明显的核心-边缘层级式特征,反映出地理邻近对集群主体创新结网影响程度的动态变化。