Biogenic volatile compound emissions from a temperate forest,China: model simulation     

Jianhui?BaiEmail author  Tiffany?Duhl  Nan?Hao 《Journal of Atmospheric Chemistry》2016,73(1):29-59

Emissions of biogenic volatile organic compounds (BVOC) were measured using a relaxed eddy accumulation (REA) technique on an above-canopy tower in a temperate forest (Changbai Mountain, Jilin province, China) during the 2010 and 2011 summer seasons. Solar global radiation and photosynthetically active radiation (PAR) were also measured. Based on PAR energy dynamic balance, an empirical BVOC emission and PAR transfer model was developed that includes the processes of BVOC emissions and PAR transfer above the canopy level, including PAR absorption and consumption, and scattering by gases, liquids, and particles (GLPs). Simulated emissions of isoprene and monoterpenes were in agreement with observations. The averages of the relative estimator biases for the flux were 39.3 % for isoprene, and 27.1 % for monoterpenes in the 2010 and 2011 growing seasons, with NMSE (normalized mean square error) values of 0.133 and 0.101, respectively. The observed and simulated mean diurnal variations of isoprene and monoterpenes in the 2010 and 2011 growing seasons were evaluated for the validation of the empirical model. Under observed atmospheric conditions, the sensitivity analysis showed that emissions of isoprene and monoterpenes were more sensitive to changes in PAR than to water vapor content or to the magnitude of the scattering factor. The emissions of isoprene and monoterpenes in the 2010 and 2011 growing seasons (from June to September) were estimated using this empirical model along with hourly observational data, with mean hourly emissions of 1.71 and 1.55 mg m^?2 h^?1 for isoprene, and 0.48 and 0.47 mg m^?2 h^?1 for monoterpenes in 2010 and 2011, respectively. As formaldehyde (HCHO) is considered as the main oxidation product of isoprene and monoterpenes, it is necessary to investigate the link between HCHO and BVOC emissions. GOME-2 HCHO vertical column densities (VCDs) can be used to estimate BVOC emission fluxes in the Changbai Mountain temperate forest.  相似文献   

大兴安岭北部伊图里河地区二长花岗岩的成因及构造背景   总被引：1，自引：0，他引：1  

吴涛涛  陈聪  刘凯  鲍庆中  周永恒  宋万兵 《地质学报》2016,90(10):2637-2647

本文对大兴安岭北段伊图里河地区黑云二长花岗岩进行了系统的地球化学及锆石U-Pb同位素年代学研究,旨在查明其成岩时代及岩石成因,并探讨其构造意义。研究结果表明,该黑云二长花岗岩的LA-ICP-MS锆石U-Pb年龄为123.3±0.8Ma,表明其形成时代为早白垩世晚期。岩石具有具有高硅、富钾、富铝的特征,A/CNK比值较大(0.96~0.99),痕量元素具有轻稀土富集、重稀土亏损、富集Rb、K等大离子亲石元素和Th、Ce、Zr、Hf等高场强元素,贫Sr、P、Ti、Ba的特征。以上特征表明伊图里河地区花岗岩为具钾玄质系列岩石特征的铝质A型花岗岩,为中下地壳岩石部分熔融的产物,该期岩浆侵位活动可能发生在早白垩世晚期东部古太平洋板块向欧亚板块俯冲作用下的弧后伸展环境。  相似文献   

鄂尔多斯盆地渭北隆起西南缘奥陶系热演化史恢复与生烃史——以麟游-旬邑地区为例     

曹展鹏  任战利  熊平  祁凯  陈占军 《地质学报》2016,90(3):513-520

本文应用古地温恢复法及盆地模拟法,恢复鄂尔多斯盆地渭北隆起西南缘奥陶系最大古地温梯度、热演化史和生烃史。根据钻孔测温曲线求得渭北隆起现今地温梯度为3.12℃/100m。该区在二叠纪和三叠纪进入快速沉降阶段,早侏罗世早白垩世进入缓慢沉降阶段,晚白垩世以来进入抬升剥蚀阶段,剥蚀厚度在1100~1300 m。旬邑地区奥陶系烃源岩在早二叠世约270 Ma进入生油窗,晚三叠世约210 Ma进入成熟生油阶段。晚侏罗世约150 Ma开始大量生气,在早白垩世末期96 Ma左右,地层达到最大埋深及最高古地温,达到生气高峰。热史恢复及模拟结果表明旬邑地区早白垩世地温梯度最高可达到5.0℃/100 m,是主要生气期。  相似文献   

青藏高原拉萨地块西部念青唐古拉岩群的地球化学特征及构造意义   总被引：1，自引：0，他引：1  

吴勇  马绪宣  张志平  焦世文  段凯  董瀚  王小伟  马涛  李鹏举  梁志勇  曹勇刚  孔垂鹏  马亮 《地质学报》2016,90(11):3081-3098

拉萨地块西部呈断块状沿狮泉河-申扎-嘉黎蛇绿混杂岩带附近分布的念青唐古拉岩群被认为是前寒武纪变质基底。本文对念青唐古拉岩群进行了系统的岩石学、地球化学、同位素年代学及构造地质学研究。研究结果表明片岩-片麻岩-变粒岩含十字石、石榴子石等特征变质矿物,遵循粒度分异规律,其原岩可能为来自冈瓦纳古陆核北缘中新元古代弧盆体系的活动大陆边缘浊积岩。斜长角闪岩具低硅、高铁镁、富钙的基性岩特征,其原岩为岛弧型基性火山岩。念青唐古拉岩群中的花岗伟晶岩锆石LA-ICPMS U-Pb年龄为1150±13Ma,具过铝质S型花岗岩地球化学特征,可能为中元古代(1150±13 Ma)以前就开始沉积的念青唐古拉岩群基底岩石通过部分熔融形成。与花岗伟晶岩渐变过渡接触的二云斜长片麻岩第一组变质重结晶锆石U-Pb年龄为701±15 Ma,结合十字石特征变质矿物,暗示了该地区中温高压变质作用的峰期变质,变质程度达角闪岩相;第二组热液流体锆石UPb年龄为301±8.4 Ma,可能与冈瓦纳大陆北缘古特提斯洋演化过程中的岩浆热液作用有关。  相似文献   

Initiation of large-volume silicic centers in the Yellowstone hotspot track: insights from H<Subscript>2</Subscript>O- and F-rich quartz-hosted rhyolitic melt inclusions in the Arbon Valley Tuff of the Snake River Plain     

Dana?L.?DrewEmail author  Ilya?N.?Bindeman  Matthew?W.?Loewen  Paul?J.?Wallace 《Contributions to Mineralogy and Petrology》2016,171(1):10

During the onset of caldera cluster volcanism at a new location in the Snake River Plain (SRP), there is an increase in basalt fluxing into the crust and diverse silicic volcanic products are generated. The SRP contains abundant and compositionally diverse hot, dry, and often low-δ¹⁸O silicic volcanic rocks produced through time during the formation of individual caldera clusters, but more H₂O-rich eruptive products are rare. We report analyses of quartz-hosted melt inclusions from pumice clasts from the upper and lower Arbon Valley Tuff (AVT) to gain insight into the initiation of caldera cluster volcanism. The AVT, a voluminous, caldera-forming rhyolite, represents the commencement of volcanism (10.44 Ma) at the Picabo volcanic field of the Yellowstone hotspot track. This is a normal δ¹⁸O rhyolite consisting of early and late erupted members (lower and upper AVT, respectively) with extremely radiogenic Sr isotopes and unradiogenic Nd isotopes, requiring that ~50 % of the mass of these elements is derived from melts of Archean upper crust. Our data reveal distinctive features of the early erupted lower AVT melt including: variable F concentrations up to 1.4 wt%, homogenous and low Cl concentrations (~0.08 wt%), H₂O contents ranging from 2.3 to 6.4 wt%, CO₂ contents ranging from 79 to 410 ppm, and enrichment of incompatible elements compared to the late erupted AVT, subsequent Picabo rhyolites, SRP rhyolites, and melt inclusions from other metaluminous rhyolites (e.g., Bishop Tuff, Mesa Falls Tuff). We couple melt inclusion data with Ti measurements and cathodoluminescence (CL) imaging of the host quartz phenocrysts to elucidate the petrogenetic evolution of the AVT rhyolitic magma. We observe complex and multistage CL zoning patterns, the most critical being multiple truncations indicative of several dissolution–reprecipitation episodes with bright CL cores (higher Ti) and occasional bright CL rims (higher Ti). We interpret the high H₂O, F, F/Cl, and incompatible trace element concentrations in the context of a model involving melting of Archean crust and mixing of the crustal melt with basaltic differentiates, followed by multiple stages of fractional crystallization, remelting, and melt extraction. This multistage process, which we refer to as distillation, is further supported by the complex CL zoning patterns in quartz. We interpret new Δ¹⁸O(Qz-Mt) isotope measurements, demonstrating a 0.4 ‰ or ~180 °C temperature difference, and strong Sr isotopic and chemical differences between the upper and lower AVT to represent two separate eruptions. Similarities between the AVT and the first caldera-forming eruptions of other caldera clusters in the SRP (Yellowstone, Heise and Bruneau Jarbidge) suggest that the more evolved, lower-temperature, more H₂O-rich rhyolites of the SRP are important in the initiation of a caldera cluster during the onset of plume impingement.  相似文献   

基于天地图API的综合服务管理系统设计与实现   总被引：1，自引：0，他引：1  

穆凯 《测绘通报》2016,(4):114-116,132

"访民情、惠民生、聚民心"是新疆地区为了便于走访民众,了解民生,更好地做好群众路线,以及处理一些社会应急处突事件的一项具体活动。本文针对该项活动开发了综合服务管理系统,具体介绍了如何应用天地图API结合Web GIS服务技术、数据库技术来搭建活动综合服务管理系统平台,探讨了平台实现的技术路线与关键方法。使用天地图API搭建平台可以节约开发成本,缩短开发时间,带来高可靠、高性能、高质量和高效率的新系统,为实现新疆的稳定和长治久安提供技术保障和科学依据。  相似文献   

基于 GAMA 平台的多智能体应急疏散仿真模型     

周烨  魏海平  何源浩  黄凯 《测绘工程》2016,25(4):66-70

应急疏散的研究对象是一个复杂的社会系统,利用多智能体模型可以有效模拟人群复杂的社会行为。将多智能体模型应用于应急疏散领域,设计5种类型的智能体实体,构建多智能体应急疏散仿真模型,从被疏散个体的相互作用行为入手,研究整个被疏散群体的行为特征。基于GAMA平台,实现以矢量地理空间数据为基础的多智能体应急疏散仿真模型,通过仿真实验,动态呈现整个应急疏散过程。对灾害、突发事件应急疏散指挥,应急疏散设施建设、城市规划设计等工作具有重要的意义。  相似文献   

土地利用现状和规划数据建库容差浅析     

何凯  张琰  代群先 《北京测绘》2016,(5):74-77

通过对第二次全国土地调查(以下简称"二调")和土地利用总体规划数据建库过程中误差的产生和传播分析,通过误差理论和容差设置实际研究。提出现行数据建库容许误差(以下简称容差)设置不合理,设置过高引起大量无用的数据处理工作。建议合理设置容差参数,提高数据库建设和更新效率。  相似文献   

重力场数学拟合模型解的影响因素探究     

鹿荻  陈锴 《测绘科学》2016,41(3):28-33

为了提高地球重力场模型不适定方程求解的精度,该文采用谱分析方法从级数展开阶数、数据采样率及数据缺失量3个方面探索影响数学拟合效果的根本因素:从常用的三角级数及勒让德级数模型出发,引出重力场拟合模型球谐函数模型,观察在改变级数展开阶数、数据采样率及数据缺失量等情况下所对应设计矩阵谱结构的变化,并从微观上研究影响误差分配的有关因素及最小奇异值对误差的决定性作用,为探求重力场模型解不准的原因及实现更高精度的全球重力场模型的建立提供参考。  相似文献   

Recursive algorithm for fast GNSS orbit fitting   总被引：1，自引：0，他引：1  

Shuqiang?XueEmail author  Yuanxi?Yang 《GPS Solutions》2016,20(2):151-157

Gaussian elimination is an efficient and numerically stable algorithm for estimating parameters and their precision. However, before estimating the parameters, it is often prudent to perform statistical tests to achieve the best fitting model. We use Gaussian elimination to select the best fitting model among candidate models. A succinct relationship between the weighted sum of squared residuals and the previous one is revealed by a volume formula. For quick parameter estimation and determination of weighted sum of squared residuals, a recursive elimination algorithm is proposed in the context of Gaussian elimination. In order to improve the model selection efficiency, the parameter estimation and the determination of the weighted sum of squared residuals are carried out in parallel using the proposed recursive elimination algorithm in which the improvement at each recursive stage is judged by the Bayesian information criterion. Ultimately, the computational complexity and numerical stability of the recursive elimination proposed are briefly discussed, and a GNSS orbit interpolation example is used to verify the results. It shows that the proposed recursive elimination algorithm inherits the numerical stability of the Gaussian elimination, and this algorithm can be used to examine the gain from the newly introduced parameter, dynamically assess the fitting model, and fix the optimal model efficiently. The optimal fitting model with the lowest information is very close to the real situation verified by checkpoints.  相似文献