Estimates of carbon stored in harvested wood products from the United States forest service northern region, 1906-2010

Background  

Global forests capture and store significant amounts of CO₂ through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux associated with harvested wood products (HWP) to meet greenhouse gas monitoring commitments and climate change adaptation and mitigation objectives. This paper uses the Intergovernmental Panel on Climate Change (IPCC) production accounting approach and the California Forest Project Protocol (CFPP) to estimate HWP carbon storage from 1906 to 2010 for the USFS Northern Region, which includes forests in northern Idaho, Montana, South Dakota, and eastern Washington.     

Mineralogy, Chemical Characteristics and Upgrading of Beach Ilmenite of the Top Meter of Black Sand Deposits of the Kafr Al-Sheikh Governorate, Northern Egypt

Egyptian beach ilmenite occurs in a relatively high content in the naturally highly concentrated superficial black sand deposits at specific beach zones in the northern parts of the Nile Delta at Rosetta. Microscopic study shows that the ilmenite occurs as fresh homogeneous black or heterogeneous multicoloured altered grains and exhibits three types (homogeneous, exsolved and altered) of ilmenite varieties. XRD data of ilmenite indicates their association with minor hematite and quartz, whereas leucoxene shows its association with Nb‐rutile, pseudorutile and hematite. Grain size distribution suggests a very fine sand size of >89% and 80% and a fine sand size of 10.5% and 18.3% for fresh and altered ilmenites, respectively. The density of fresh, altered ilmenite and leucoxene concentrates varies from 2.70, 2.50 to 2.40 ton/m³, suggesting a gradual decrease from high grade fresh to leucoxene and consistent with variation in magnetic susceptibility as a consequence of the leaching of iron. Mass magnetic susceptibility reveals 97.6% of ilmenite and 92% of the altered form are obtained at 0.20 and 0.48 ampere. Fresh ilmenite exhibits variable TiO₂ (47.18%) and Fe₂O₃^T (46.10%) with minor MnO, MgO and Cr₂O₃ (1.22, 1.10 and 0.51%). The altered ilmenite is higher in TiO₂ (76.16%) and SiO₂ (4.68%) and lower in Fe₂O₃^T (14.45%), MnO, MgO and Cr₂O₃ (0.39, 0.52 and 0.11%) compared with the fresh form. Three concentrates of ilmenites (G1, G2 and G3) were prepared from crude ore using a Reading cross belt magnetic separator under different conditions, revealing a gradual increase of TiO₂, SiO₂, Al₂O₃ and CaO accompanied by a decrease of Fe₂O₃^T, MgO and Cr₂O₃ with repetition of the separation processes. Several ore dressing techniques were carried out to upgrade the ilmenite concentrate.     

Global Paleogeography through the Proterozoic and Phanerozoic:Goals and Challenges

正Paleogeography is the merger of lithology,depositional environments,tectonic plate movements,topography,climate patterns and ecosystems (reefs,vegetation) through time (e.g.,Scotese,2014,2016,2017;Blakey,2019).The construction of paleogeographic maps using tectonic plate reconstructions requires a multi-year community effort that shares databases,standards and computer projection methods.     

南澳卡恩曼托群贱金属成矿作用的构造和变质环境

引言贱金属矿化出现在阿德雷得南50公里卡恩曼托(Kanmantoo)和斯特拉斯奥尔比(Strathalbyn)之间罗弗特(Lofty)山区东南侧,区域变质的卡恩曼托群内的几处地方。硫化物成矿作用有三种主要类型(Seccombe等,1985):1.铜矿床,有卡恩曼托矿山和布雷默(Bremer)矿山、南希尔(South Hill)勘探区和数处次要产地。2.铅-锌矿床,有阿克拉雷(Aclare)、惠阿尔埃列(Wheal Ellen)、斯特拉斯奥尔比、圣艾夫斯、     

吉林陨石钻孔样品^53Mn深度剖面

吉林陨石钻孔样品^53Mn深度剖面进一步表明吉林陨石经历了二阶段暴露历史，第一阶段母体经受2π宇宙射线辐照，时间约为10Ma，第二阶段母体经受4π宇宙射线辐照，时间约为0.5Ma。     

年青星体附近双极喷流及其块状结构的物理机制

本文用磁拉瓦尔管机制解释了双极喷流的形成。这样,喷流内部的热压力被外部纵向磁场的磁压所平衡。本文研究了这一平衡态基础上的Kelvin-Helmholtz不稳定性,得出了共振模式的分析解。这一族解可解释喷流块状结构的许多观测特点,如块状结构的间距。高本动速度及喷流膨胀段的光学不可见性等等。     

季凤:着重论述南亚和东非热带

至少在中世纪,阿拉伯航海家们就已观察到了南亚与东非之间热带海面上风向季节转换的情况。这些季节性风,就是南亚季风。季风这一名词人们相信是源自阿拉伯名词“maurim”或马来文“maurin”一词(两者都意为“季节性”)。许多世纪以后,英国人哈莱于1907年对这些季节性风(南亚季风)提出了一个直到现在仍在沿用的解释。     

利用土壤电导率测量结果探测隐伏硫化矿矿床

有人曾经提出,进入矿化期后的岩石中的以及进入覆在硫化矿矿床上面搬运来的覆盖层中的元素次生晕,可能部分是由于与自然电流有关的电化学机理所引起的。如果这种次生晕是一种持续的作用,那么在硫化矿矿体周围电场带内,相对来讲,可溶于水的离子的浓度比例应该有很大的变化。确定这种浓变的简单方法是测量含水粘土泥样品的电导率;在某硫化矿矿床的一条剖面上测量土壤粘土泥的电导率的结果,发现有明显的电导率异常。后来在实验室的试验槽内进行了研究,结果证明,在硫化矿矿体周围产生的电位和在周围脉石矿物中的元素次生晕之间,有一个经验关系(由于电化学反应的结果,在硫     

论工业系统

一、工业系统的要素一个系统包括:1.若干功能单位,2.这些单位之间的功能联系,3.这些单位及其行为和外界环境的相互作用。