我国西北地区21世纪季节气候变化情景分析

使用各国政府间气候变化专门委员会(IPCC)数据分发中心提供的7个全球海气耦合气候系统模式(CCC、CCSR、CSIRO、DKRZ、GFDL、HADL、NCAR)的模拟结果,对我国西北地区未来21世纪考虑温室气体增加(GG)和温室气体与硫化物气溶胶共同影响(GS)时,冬夏季的气候变化情景进行了分析.模式集成结果分析表明,我国西北地区的变暖趋势与全球、东亚和中国一致,但变暖幅度明显高于全球、东亚和中国.对未来100年各个季节线性倾向的分析表明,西北地区GG和GS时都是冬季变暖最大,可高达5～8℃/100a,且整个西北地区中新疆地区为最大变暖区.21世纪由于人类活动,西北地区最低温度和最高温度都将明显升高,其线性趋势可达4～6℃/100 a.由于全球气候模式对区域尺度的模拟存在较大的不确定性,未来需要作更多的深入研究.     

冀东秦家峪中元古界高于庄组锰矿成因: 来自矿物学和地球化学的制约

冀东秦家峪锰矿赋存于中元古界蓟县系高于庄组二段底部含锰岩系内,其成因尚不明确.以秦家峪锰矿ZK58-2钻孔样品为研究对象,通过显微薄片观察、电子探针分析及全岩地球化学分析等方法,探讨了高于庄组锰矿的锰质来源和沉积环境对成矿的贡献.显微薄片观察、电子探针分析表明,原生矿带中含锰矿物主要为菱锰矿、铁镁菱锰矿、钙菱锰矿、锰方...     

Geological characteristics of the Qiaoyue Seamount and associated ultramafic-hosted seafloor hydrothermal system (～52.1°E,Southwest Indian Ridge)

Hydrothermal vent incidence was once thought to be proportional to the spreading rate of the mid-ocean ridges (MORs). However, more and more studies have shown that the ultraslow-spreading ridges (e.g., Southwest Indian Ridge (SWIR)) have a relatively higher incidence of hydrothermal venting fields. The Qiaoyue Seamount (52.1°E) is located at the southern side of segment #25 of the SWIR, to the west of the Gallieni transform fault. The Chinese Dayang cruises conducted eight preliminary deep-towed surveys of hydrothermal activity in the area during 2009 and 2018. Here, through comprehensive analyses of the video and photos obtained by the deep-towed platforms, rock samples, and water column turbidity anomalies, a high-temperature, ultramafic-hosted hydrothermal system is predicted on the northern flank of the Qiaoyue Seamount. We propose that this hydrothermal system is most likely to be driven by gabboric intrusions. Efficient hydrothermal circulation channels appear against a backdrop of high rock permeability related to the detachment fault.     

Drying increases organic colloidal mobilization in the karst vadose zone: Evidence from a 15-year cave-monitoring study

Understanding the hydrological processes of colloids within the karst vadose zone is vital to the security of karst groundwater and providing appropriate paleohydrological explanations of colloid-facilitated metals in speleothem. This study addresses the mobilization mechanisms driving colloidal organic matter (COM) transport in the karst vadose zone using a 15-year long monthly monitoring dataset from a cave drip point (HS4) in Heshang Cave, Qingjiang Valley, China. Variations in COM concentrations were reported as the fluorescence difference values of raw and filtered (<0.22 μm) samples at an excitation wavelength of 320 nm and emission wavelength of ~400 nm. A fluorescence humification index (HIX) lower than 0.8 and an autochthonous index (BIX) higher than 1.2 indicated that the origin of COM was mainly from the karst vadose zone, rather than the soil zone. The COM concentration varied from 0.001 to 0.038 Raman Unit (RU), with evident seasonal fluctuations. Rising limbs for COM values occurred prior to rising limbs within a dripwater hydrograph; moreover, the COM peak values corresponding to the beginning of the increasing hydrograph generally suggested that the mobilization of COM reflected the movement of the air–water interface (AWI) in the karst vadose zone rather than rainfall intensity or flow velocity. COM peak values were positively correlated with the antecedent drying duration and negatively correlated with HIX values. These phenomena may be explained by the increased amount of organic matter that was aggregated and absorbed on the surface of carbonate in the karst vadose zone during a longer drying duration. Moreover, the longer drying duration was also beneficial to autochthonous biological activity, which subsequently decreased the HIX value of the organic matter in the karst vadose zone. The movement of AWI and the drying duration are both controlled by the outside weather conditions. This study is therefore conducive to evaluating the security of karst groundwater in response to climate change, and challenges prevailing paleoclimate interpretations of colloid-facilitated metal abundance timeseries reported from speleothems.     

中国高尔夫球场时空演变、影响因素和扩散模式

利用空间分析和数理统计等方法探究了1984—2016年中国高尔夫球场数量时空演变、影响因素和扩散模式。结果表明：1）球场数量变化经历了低速增长期、稳定增长期、加速增长期和紧缩期；2）球场空间分布范围经历了扩张期和收缩期，向北、向西扩散较为明显；3）目前球场主要分布在经济发展水平较高且外向型经济突出的长三角、珠三角和环渤海地区；4）人均GDP、人口规模、区域开放程度、交通优势度、气候类型和土地资源稀缺性与球场空间分布均呈显著正相关，其中交通优势度相关系数最大；5）高尔夫球场空间扩散模式兼具接触性扩散和等级性扩散。     

High‐T and low‐P metamorphism in the Xilingol Complex of central Inner Mongolia,China: An indicator of extension in a previous orogeny

The Xilingol Complex comprises biotite gneisses and amphibolite interlayers with extensive migmatization. Four representative samples were documented and found to record either two or three metamorphic stages. Phase modelling using thermocalc suggests that the observed assemblages represent the final stages that underwent cooling from temperature peaks, and are consistent with a fluid‐absent solidus in P–T pseudosections. Their P–T conditions are further constrained to be 5–6 kbar/680–725°C and 4–5 kbar/650–680°C for two garnet‐bearing gneiss samples, 4–5 kbar/660–730°C for a cordierite‐bearing gneiss sample, and 4–5 kbar/680–710°C for an amphibolite sample based on mineral composition isopleths, involving measured Mg content in biotite, anorthite in plagioclase, grossular and pyrope in garnet and Ti content in amphibole. The peak temperature conditions recovered are 760–790°C or >760°C at 5–6 kbar based on the composition isopleths of plagioclase, biotite, garnet and especially the comparison of melt contents between the calculated and observed. A pre‐peak heating process with slight decompression can be suggested for some samples on the basis of the core–rim increase in the plagioclase anorthite, and the stability of ilmenite. Zircon U–Pb dating using the LA‐ICP‐MS method provides systemic constraints on the metamorphic ages of the Xilingol Complex to be 348–305 Ma, interpreted to represent the post‐peak cooling stages. Moreover, metagabbroic dykes that intruded into the Xilingol Complex yield 317 ± 3 Ma from magmatic zircon, and are considered to have played a significant role for heat advection triggering the high‐T and low‐P metamorphism. Thus, the clockwise P–T paths involving pre‐peak heating, peak and post‐peak cooling recovered for the Xilingol Complex are consistent with an extensional setting in the Carboniferous that developed on a previous orogen in response to addition of mantle‐derived materials probably together with upwelling of the asthenospheric mantle.     

中国三大城市群电子商务快递物流网络空间结构及其形成机制研究

以中国长三角、京津冀、珠三角三大城市群为案例,基于中国智能物流骨干网（China Smart Logistic Network,CSN）关系数据,采用社会网络分析、随机森林分类算法、QAP分析等研究方法,在县区尺度上探索电子商务快递物流网络空间结构特征及其形成机制。研究发现：① 三大城市群电商快递物流网络密度较高,已形成典型的网络式空间结构。其中长三角城市群网络呈圈层蛛网式结构,县区间联系强度以环杭州湾为中心向外围梯度衰减;京津冀城市群网络受制于行政藩篱,形成“北京?天津”双核心网络结构;珠三角城市群网络联系强度自区域外围由弱到强逐渐向珠江口东岸方向变化,形成“穗（广州）?莞（东莞）?深（深圳）”快递物流廊道。② 三大城市群中物流输出型县区多集中在区域中部,依托中心城市向外物流辐散,而物流输入型县区多分散于外围。③ 城市群电商快递物流网络形成主要受人均可支配收入、常住人口和距离等因素影响。研究结果对于丰富城市网络理论,促进城市群快递物流协调发展,提升现代服务业水平和城市群整体竞争力具有重要意义。     

Spatial Association Between Orogenic Gold Mineralization and Structures Revealed by 3D Prospectivity Modeling: A Case Study of the Xiadian Gold Deposit,Jiaodong Peninsula,China

Natural Resources Research - The Xiadian orogenic deposit with?~?100 t of gold resources, located in the Jiaodong Peninsula, Eastern China, shows an economically attractive gold...     

基于地面三维激光扫描强度数据的潮滩表层含水量估算

大面积潮滩表层含水量的测定是潮滩研究中的难题,传统的测量方法难以同时满足高效和精度的要求。地面三维激光扫描技术凭借其高精度、高分辨率以及主动性强等优点,已经高效运用在潮滩地形研究中。但是,对潮滩含水量进行有效分析,仅利用点云的空间几何信息是不够的,还需要对点云的强度数据进行挖掘。地面激光扫描仪提供了包含目标表面光谱反射特性的点云强度数据,利用强度数据可以有效地进行目标表面特性提取。本文提出了一种新的长距离地面激光扫描仪强度数据改正方法,对入射角和距离效应进行有效改正。利用Riegl VZ-4000长距离地面激光扫描仪建立室内含水量模型并对上海市崇明岛一处潮滩进行测试分析,同时收集26个潮滩沉积物样品并利用传统干湿称重法进行含水量验证计算。结果表明：相比于传统技术,利用改正后的激光强度值估算大面积潮滩沉积物表层含水量是一种精确和高效的方法。改正后的激光强度值与潮滩表层含水量存在幂函数关系,相关系数为0.961,估算精度为91.94%。     

冬春季东亚气溶胶流出通量年际变率的相关环流异常分析

本文使用戈达德对地观测系统（Goddard Earth Observing System,GEOS）全球三维大气化学传输模式GEOS-Chem模拟了气象场驱动下1986~2006年冬春季东亚到太平洋区域气溶胶的流出通量,分析了流出通量的年际变率及其相关的环流异常。结果表明,偏多（少）的东亚气溶胶流出对应东北亚-西太平洋区域（Northeast Asia-western Pacific,NAWP）500 hPa定常波负值中心强度变强（弱）。NAWP区域500 hPa位势高度场负（正）异常还可能造成气溶胶流出路径的变化,即更多（少）的气溶胶相对于气候态偏北5~10个纬度的路径向太平洋区域传输。这种位势高度场上的异常伴随着对流层中低层西风和大气斜压性异常,从而引起东亚到太平洋区域气溶胶流出通量及其路径的年际变化。