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331.
志留系是塔里木盆地第一套砂岩储层广泛分布的沉积盖层,其沉积来源与成因对志留纪构造演化及周边造山带的研究具有重要意义。塔中地区3个志留系样品的碎屑锆石LA?ICP?MS U?Pb定年研究表明,志留系具有比较集中的二期物源年龄:南华纪中期、古元古代中期。碎屑锆石测定的年龄表明塔中志留系物源均来自前寒武纪,塔中东部源区方向的塔南隆起基底在奥陶纪已隆升成为蚀源区。大量的新元古代中期锆石年龄表明塔里木板块在新元古代时期可能与Rodinia超大陆具有相似的聚合与裂解演化史。 相似文献
332.
Bao-Ke Ma Li-Xin Guo Hong-Tao Su Bei-Chen Zhang Hong-Qiao Hu 《Astrophysics and Space Science》2012,340(2):237-243
The expression of anisotropic temperature ion distribution function under the 13-moment approximation is obtained by solving a set of moment equations based on the Boltzmann equation for a relaxation collision model and with consideration of the anisotropic temperature ion distribution. And the incoherent scatter spectrum with an anisotropic temperature ion distribution is simulated in different directions based on the electromagnetic radiation theory of Sheffield. The effects of different electrical field strengths, ratios of electron temperature to ion temperature, and ion-neutral collision frequencies on the incoherent scatter spectrum are all discussed. Finally, the value of theoretical simulation is compared with the measured value of incoherent scattering spectrum. The result show that the incoherent scatter spectrum of ions seriously deviates from the form of the Maxwellian distribution in the equilibrium state. This phenomenon can be attributed to the effects of anisotropic temperature ion distribution, the larger convection electric field, and other factors in high latitude ionosphere. 相似文献
333.
Nisong Pei Wu Yong Su Rui Li Jianfeng Wang Yongqian Li Xueling Wu Zhenghao 《Geomagnetism and Aeronomy》2021,61(4):632-646
Geomagnetism and Aeronomy - To explore the global-scale coupling characteristics between ionospheric disturbances and geomagnetic storms, and research the near-Earth space environment, the time... 相似文献
334.
Domínguez Jaime Suárez Gerardo Gorbatov Alexei Segura Fabio 《Journal of Seismology》2021,25(6):1427-1439
Journal of Seismology - A three-dimensional tomographic image of the seismic velocity structure in the crust and upper mantle of northwestern Nicaragua was performed using the back-projection... 相似文献
335.
Zongjun Ning M. D. Ding K. P. Qiu H. Li Y. N. Su C. Fang 《Astrophysics and Space Science》2008,315(1-4):45-51
We present multi-wavelength observations of a complicated solar eruption event to associate with an X1.2 flare and a Coronal Mass Ejection (CME) on 2003 October 26. The soft X-ray profile shows a possibility for occurrence of two flares with peaks around 06:20 and 07:00 UT. According to our observations, there are many evidences to show that they are corresponding to two energy releases. The first one produces type II, type III, moving type IV continua, a decimetric burst (DCIM) and strong emissions at Hα, 195 and 1600 Å; While the second energy release only produces a group of RS-III bursts, DCIM and Hα emissions. It appears that the first energy release is associated with a CME, while the second CME is quiet. Such observational difference between two energy releases is found indicating two magnetic reconnection processes occurrence with different plasma situation. 相似文献
336.
337.
Natural Hazards - Based on classical mechanics and the law of energy conservation, we present a model for predicting landslide sliding distance. We conceptualize landslide movement as the movement... 相似文献
338.
Zhu Gaofeng Lu Ling Su Yonghong Wang Xufeng Cui Xia Ma Jinzhu He Jianhua Zhang Kun Li Changbin 《水文研究》2014,28(19):5093-5104
In this study, we examined the year 2011 characteristics of energy flux partitioning and evapotranspiration of a sub‐alpine spruce forest underlain by permafrost on the Qinghai–Tibet Plateau (QPT). Energy balance closure on a half‐hourly basis was H + λE = 0.81 × (Rn ? G ? S) + 3.48 (W m?2) (r2 = 0.83, n = 14938), where H, λE, Rn, G and S are the sensible heat, latent heat, net radiation, soil heat and air‐column heat storage fluxes, respectively. Maximum H was higher than maximum λE, and H dominated the energy budget at midday during the whole year, even in summer time. However, the rainfall events significantly affected energy flux partitioning and evapotranspiration. The mean value of evaporative fraction (Λ = λE/(λE + H)) during the growth period on zero precipitation days and non‐zero precipitation days was 0.40 and 0.61, respectively. The mean daily evapotranspiration of this sub‐alpine forest during summer time was 2.56 mm day?1. The annual evapotranspiration and sublimation was 417 ± 8 mm year?1, which was very similar to the annual precipitation of 428 mm. Sublimation accounted for 7.1% (30 ± 2 mm year?1) of annual evapotranspiration and sublimation, indicating that the sublimation is not negligible in the annual water balance in sub‐alpine forests on the QPT. The low values of the Priestley–Taylor coefficient (α) and the very low value of the decoupling coefficient (Ω) during most of the growing season suggested low soil water content and conservative water loss in this sub‐alpine forest. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
339.
以安庆黄梅戏会馆和再芬黄梅公馆为例,基于方法?目的链理论模型,解读文化消费者对黄梅戏展演空间属性的感知评价、层次处理和价值导向的转变。研究发现:不同层次的空间属性在文化消费者的感知与体验中实现着新的组合与重构,由此形成了基于舞台展演内容、文化呈现形式以及演出环境氛围为主体的3种空间感知模式。结合文化消费者感知的心理结构与路径,黄梅戏展演空间被消费者建构为娱乐空间、情感空间和社交空间,空间的多元化意义和价值得到彰显。方法?目的链理论从消费者的感知与需求出发,探索文化空间意义生成路径,实现了文化空间与消费者之间的双向信息交换。 相似文献
340.
依据区域气候模式RIEMS2.0输出的3 km高分辨率数据和站点降水记录分析了中国西北黑河流域降水的动力降尺度和统计—动力降尺度问题,检验了多种因子组合下多元线性回归(MLR)和贝叶斯模式平均(BMA)降尺度模型,评估了降尺度降水的均方根误差、相关系数、方差百分率及“负降水”偏差率等方面的统计特征。结果表明,动力降尺度降水相关系数最高,误差也最大,降水方差达到观测值的1.5~2倍;除相关系数外,统计—动力降尺度模型的几个统计特征均最优,纯统计模型次之。检验表明,仅用700 hPa位势高度场、经向风和比湿等构建的统计降尺度模型估计的站点降水相关系数较低,均方根误差也较大。当在统计降尺度模型中引入模式降水因子后站点降水的估计得到明显改善,其中MLR类模型的降水相关系数和方差百分率均明显高于BMA类模型,均方根误差二者相当,但前者“负降水”出现频次明显大于后者,“负降水”偏差主要出现在降水稀少的冬半年及黑河中、下游干旱或极端干旱区,上游出现频率较低,其中MLR类模型“负降水”出现频次明显高于BMA类模型,后者仅出现在黑河中、下游地区。包含模式降水因子的统计—动力降尺度模型能减少“负降水”出现... 相似文献