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991.
992.
Chao Huang Hao Wang Jin‐Hui Yang Jahandar Ramezani Chuan Yang Shao‐Bing Zhang Yue‐Heng Yang Xiao‐Ping Xia Lian‐Jun Feng Jie Lin Tian‐Tian Wang Qian Ma Huai‐Yu He Lie‐Wen Xie Shi‐Tou Wu 《Geostandards and Geoanalytical Research》2020,44(1):103-123
A new natural zircon reference material SA01 is introduced for U‐Pb geochronology as well as O and Hf isotope geochemistry by microbeam techniques. The zircon megacryst is homogeneous with respect to U‐Pb, O and Hf isotopes based on a large number of measurements by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and secondary ion mass spectrometry (SIMS). Chemical abrasion isotope dilution thermal ionisation mass spectrometry (CA‐ID‐TIMS) U‐Pb isotopic analyses produced a mean 206Pb/238U age of 535.08 ± 0.32 Ma (2s, n = 10). Results of SIMS and LA‐ICP‐MS analyses on individual shards are consistent with the TIMS ages within uncertainty. The δ18O value determined by laser fluorination is 6.16 ± 0.26‰ (2s, n = 14), and the mean 176Hf/177Hf ratio determined by solution MC‐ICP‐MS is 0.282293 ± 0.000007 (2s, n = 30), which are in good agreement with the statistical mean of microbeam analyses. The megacryst is characterised by significant localised variations in Th/U ratio (0.328–4.269) and Li isotopic ratio (?5.5 to +7.9‰); the latter makes it unsuitable as a lithium isotope reference material. 相似文献
993.
Acta Geotechnica - This paper is devoted to study the elastic–plastic damage behavior of heterogeneous shale rocks. The representative microstructure of this kind of rocks is first studied in... 相似文献
994.
测绘是我国进行现代化建设的先行性工作,测绘成果是国家重要的基础性、战略性资源,事关国家安全和民族利益,地理空间信息资源已成为经济社会信息化的公共基础平台。近年来,山东的测绘事业有了很大的发展,但与省委、省政府的要求相比,与国家测绘局领导同志的期望相比,与山东其他行业飞速发展的形势相比,山东的测绘工作任重道远,需要以新的精神状态、新的观念和新的工作方式,加倍工作,努力为山东的经济社会发展提供优质服务和强有力的测绘保证。 相似文献
995.
基于树木年轮信息的千烟洲人工林碳蓄积的动态分析 总被引:2,自引:0,他引:2
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. 相似文献
996.
四川盆地东部上三叠统须家河组共分7段,其中须一段与川西小塘子组为同期异相沉积。须一、须三、须五、须七段为含煤泥岩段,须二、须四、须六段为砂岩段。对区内钻井剖面及露头剖面进行分析,在须家河组中识别出区域性构造不整合面及河流下切冲刷面等层序界面,将须家河组划分为4个三级层序,分别对应于须一段、须二段—须三段、须四段—须五段、须六段—须七段。以地层的岩性、岩相变化特征细化分出低位体系域、湖侵体系域和高位体系域。其中低位体系域以广泛分布的河道砂岩沉积为特征;湖侵体系域与高位体系域以湖滨三角洲相的细砂岩、粉砂岩、泥岩及煤层互层为特征。对层序地层格架下的聚煤特征分析表明,层序Ⅲ聚煤最有利,其次为层序Ⅳ,层序Ⅱ最差;在层序Ⅲ内,高位体系域比湖侵体系域更有利于成煤。煤层厚度变化明显受泥炭堆积速率与可容空间增加速率的控制,高位体系域早期较高的可容空间增加速率与较高的泥炭堆积速率保持平衡,有利于厚泥炭(煤)层的形成。 相似文献
997.
sPn震相的多台同时测定法 总被引:1,自引:1,他引:0
利用数字台网观测技术的优势,根据sPn与Pn震相到时差与震中距无关,以及振幅和周期都比Pn大的运动学和动力学特征,提出将震中距不同的台站的Pn震相对齐后同时测定多台的sPn震相,进而计算出该地震的震源深度。这种分析和测定方法简捷准确,可在台网的日常近震分析中推广应用。 相似文献
998.
On March 13, 2007, two earthquakes with M4.7 and M4.6 occurred in Zhengfang Village, Shunchang, Fujian. The M4.7 earthquake is the most intensive one in the Fujian region since the establishment of the Fujian digital seismic networks. These two earthquakes provide us with valuable first-hand observation data for seismological research. This paper analyzes their waveforms and concludes that ( 1 ) the crustal thickness in the seismic region is estimated to be about 40km according to the observed head-wave critical distance; (2) there is a salient difference between the ratios of S-wave's maximum amplitudes of these two earthquakes; (3) the focal depth of the M4.7 earthquake is estimated to be 8.4km according to the clear depth phrase sPn in waveforms, which is the same with the result of other determination methods. 相似文献
999.
1000.
Chunjian Sun Xidong Wang Anmin Zhang Lianxin Zhang Caixia Shao Guosong Wang 《海洋学报(英文版)》2022,41(5):27-40
The statistical characteristics and mechanisms of mesoscale eddies in the North Indian Ocean are investigated by adopting multi-sensor satellite data from 1993 to 2019. In the Arabian Sea(AS), seasonal variation of eddy characteristics is remarkable, while the intraseasonal variability caused by planetary waves is crucial in the Bay of Bengal(BOB). Seasonal variation of the eddy kinetic energy(EKE) is distinct along the west boundary of AS,especially in the Somali Current region. In the BOB, lar... 相似文献