Optimal decision-making model of spatial sampling for survey of China’s land with remotely sensed data

For a long term,in the survey of the country land areas,how to balance the conflicts between survey cost and result accuracy,or in other words,how to acquire the highest accuracy within the capital limit or vice verse,is a major problem that couldn’t have well been solved[1].Spatial sampling,aiming this,is the preferable option and the important and the first stepin the survey of geo-analysis,including the survey of the country land resource as well in that whether the sampling scheme is good …     

新疆特克斯县林场大哈拉军山组火山岩年代学研究

首次测得了大哈拉军山组立名剖面的同位素年龄，其＾４０Ａｒ／＾３９Ａｒ的等时线年龄为３２６．８５±１５Ｍａ，在７００℃、８００℃、８７０℃和９４０℃温度区的视年龄分别为３５９．４８±３８．８４Ｍａ，３４１．７１±５８．３９Ｍａ，３４９．０６±２７．５９Ｍａ和３３３．７２±２８．８４Ｍａ。这些年龄值清楚地说明，大哈拉军山组的火山岩形成于早石炭世，并且多数年龄值属早石炭世早期。最后讨论了与其有关的热事件     

寒武纪生物爆发前的死劫难海洋

白垩纪/第三纪界线研究揭示,界线事件留下铱异常和碳同位素异常信息(Alvarez,1980;Hsü et al., 1982)。近来,二叠纪/三叠纪界线粘土中也发现了Ir-δ¹³C双异常(SunYiyin et al.,1984)。     

甘肃北山公婆泉斑岩型铜矿地质特征及成矿流体包裹体研究

公婆泉铜矿位于甘肃-蒙古-北山斑岩铜矿成矿带公婆泉岛弧区,为典型的斑岩型铜矿,赋矿围岩主要为英安斑岩、花岗闪长斑岩和石英闪长玢岩。矿石矿物主要有黄铜矿和斑铜矿,其次有少量的黄铁矿、闪锌矿、方铅矿以及蓝辉铜矿等。对含矿石英脉中流体包裹体研究表明,公婆泉铜矿主要有4类流体包裹体:纯气相包裹体(Ⅰ型)、纯液相包裹体(Ⅱ型)、原生富液相气液两相包裹体(Ⅲa型)以及次生富液相气液两相包裹体(Ⅲb型)。其中与成矿密切相关的为原生富液相气液两相包裹体(Ⅲa型)。该类包裹体的均一温度集中在100~260℃,盐度在0.18%~9.98%(NaCleq),密度为0.75~1.0g/cm3;激光拉曼探针分析表明,液相成分以H2O为主,气相成分以H2、N2以及CH4为主。成矿流体具有中低温、低盐度以及低密度的流体特征。斑岩的上升侵位为矿床的形成奠定了物质基础——Cu、S。斑岩分异出成矿流体沿早期断裂系统向上运移发生减压沸腾导致相态分离,从而造成Cu发生沉淀。因此,减压沸腾可能是导致流体中金属卸载的主要原因。     

The Influence of Pore Throat Radius on its Internal Oil and Water Wettability

<正>With the rising of energy demand and the dwindling of conventional oil and gas resources,the unconventional oil and gas resources are getting more and more attention,and has become the main contribution of global oil and gas production growth over the past five years.Compared with the North American marine tight oil,China Continental tight oil reservoir with strong heterogeneity and distribution characteristics of poor stability,and has a     

Subduction channel fluid-rock interaction:Indications from rutile-quartz veins within eclogite from the Yuka terrane,North Qaidam orogen

High-pressure(HP)or ultrahigh-pressure(UHP)rutile-quartz veins that form at mantle depths due to fluid-rock interaction can be used to trace the properties and behavior of natural fluids in subduction zones.To explore the fluid flow and the associated element mobility during deep subduction and exhumation of the continental crust,we investigated the major and trace elements of Ti-rich minerals.Additionally,U–Pb dating,trace element contents,and Lu–Hf isotopic composition of zircon grains in the UHP eclogite and associated rutile-quartz veins were examined in the North Qaidam UHP metamorphic belt,Yuka terrane.The zircon grains in the rutile-quartz veins have unzoned or weak oscillatory zonings,and show low Th/U ratios,steep chondrite-normalized patterns of heavy rare earth elements(HREEs),and insignificant negative Eu anomalies,indicating their growth in metamorphic fluids.These zircon grains formed in 431
3 Ma,which is consistent with the 432
2 Ma age of the host eclogite.As for the zircons in the rutile-quartz veins,they showed steep HREE patterns on one hand,and were different from the zircons present in the host eclogite on the other.This demonstrates that their formation might have been related to the breakdown of the early stage of garnet,which corresponds to the abundance of fluids during the early exhumation stage.The core-rim profile analyses of rutile recorded a two-stage rutile growth across a large rutile grain;the rutile core has higher Nb,Ta,W,and Zr contents and lower Nb/Ta ratios than the rim,indicating that the rutile domains grew in different metamorphic fluids from the core towards the rim.The significant enrichment of high field strength elements(HFSEs)in the rutile core suggests that the peak fluids have high solubility and transportation capacity of these HFSEs.Furthermore,variations in the Nb vs.Cr trends in rutile indicate a connection of rutile to mafic protolith.The zircon grains from both the rutile-quartz veins and the host eclogite have similar Hf isotopic compositions,indicating that the vein-forming fluids are internally derived from the host eclogite.These fluids accumulated in the subduction channel and were triggered by local dehydration of the deeply subducted eclogite during the early exhumation conditions.     

基于树木年轮信息的千烟洲人工林碳蓄积的动态分析

The authors developed a model to estimate annual tree growth based on tree-ring data (Abbr. TGTRing model) derived from the trunk at 0.5, 1.3 and 2.5 m height. This model was applied to estimate the annual biomass and carbon accumulation of a plantation in Qianyanzhou Red-Soil Hill Comprehensive Development Experimental Station of CAS in Taihe County, Jiangxi Province (Abbr. Qianyanzhou). The results showed that the inflexion points of the biomass and carbon accumulation curves occur at 17 and 18 years of age, respectively, in masson pine, whilst both inflexion points occurred at 15 years in slash pine and Chinese fir. The biomass and carbon accumulation in Chinese fir proved to be greater in the last 20 years than in the other species, with 171.697 t/hm² and 92.29 tc/hm², respectively. masson pine, with a biomass of 133.84 t/hm² and a carbon accumulation of 73.92 tc/hm² was the lowest whilst slash pine was intermediate with a biomass of 147.639 t/hm² (unturpentined) and 135.743 t/hm² (turpentined), and a carbon accumulation of 80.18 tc/hm² (unturpentined) and 73.72 tc/hm² (turpentined). In 2006, the total biomass and carbon storage of the tree stratum of masson pine in Qianyanzhou was 3324.43 t and 14,156.64 tc, respectively, whilst the values for Chinese fir were 1326.97 t and 713.27 tc. For slash pine the total biomass was 14,156.64 t (unturpentined) and 13,015.97 t (turpentined), and the total carbon storage was 7 688.21 tc (unturpentined) and 7068.78 tc (turpentined). Following the shaving of slash pine for resin, the total biomass was reduced by 1140.67 t and the total carbon storage fell by 619.43 tc.     

退耕还林还草工程对黄土高原植被总初级生产力的影响

采用Landsat解译的2000年和2015年土地利用/覆盖数据和VPM模型（Vegetation Photosynthesis Model）模拟的2000~2016年总初级生产力（Gross Primary Productivity, GPP）数据,识别出了近16 a黄土高原退耕还林还草的空间范围,并估算了GPP的年际变化趋势。在此基础上,对比分析了退耕区和未退耕区GPP年际变化的差异,从而揭示退耕还林还草工程对GPP年际变化的影响。结果显示,2000~2015年,黄土高原退耕还林还草面积约3.5万km ²,占2000年耕地面积的16.8%。期间,GPP呈增加趋势,GPP显著上升区域占全区面积的67.3%,平均增速24.1 g/(m ²?a)（以C计,下同）。虽然退耕区多年平均GPP低于未退耕区,但退耕区GPP年际增速和相对变化率明显高于未退耕区,分别提高了5.9 g/(m ²?a)和1.5%。     

社交媒体数据的获取与处理分析研究

带有地理空间信息的社交媒体数据是由众多专业和非专业用户主观发布并通过社交媒体向公众或组织提供的一种开放地理空间数据。为了高效地获取签到数据以及保证签到数据的正确性、可靠性、完整性,满足数据挖掘算法的需要,本文以微博签到数据为例,提出了获取数据的关键技术,包括调用微博API的方法、研究区域格网化的获取方法,提高了数据的获取效率。并且针对获取的原始数据提出了对其处理的方案并对获取的数据结果进行了相关的统计描述。     

海洋酸化对碳、氮和硫循环的影响

工业革命以来,大气CO_2浓度呈现快速增加的趋势,随之而来的问题是海洋酸化的程度越来越明显。与工业革命前相比,目前海洋表层海水pH降低了0.1个单位,到本世纪末估计会降低0.4个pH单位。本文综述了海洋酸化对碳、氮和硫循环的影响,包括碳循环中的溶解度泵、碳酸盐泵、软组织泵和微型生物碳泵,海洋酸化对氮循环中氮的固定、硝化作用、反硝化作用、N_2O的产生的影响,海洋酸化与硫循环中二甲基硫(DMS)的产生及其与食物网结构之间的关系。海洋酸化无论是以直接或间接方式均会在一定程度上对碳、氮和硫的生物地球化学循环产生影响,最终改变海洋系统的结构与功能。在自然界中,海洋酸化不是一个独立的过程,而是与其他物理、化学、生物变化因素相偶联共同作用于碳、氮和硫的生物地球化学循环。