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撒兴昌  高天明  张艳 《地球学报》2023,44(2):341-350
随着新能源产业的快速发展, 全球碳酸锂贸易量逐渐增长, 但其出口集中于少数国家, 这意味着全球碳酸锂供应存在一定的风险。为了深入了解全球碳酸锂贸易格局演变、供应危机传播路径及影响, 本文构建了2000—2021年全球碳酸锂贸易网络和级联失效模型, 概述了主要出口国贸易流向和贸易格局演变过程, 并模拟了不同供应危机来源的雪崩规模、传播路径及其影响。我们得到: (1)20多年来全球碳酸锂贸易集中度逐渐增加, 出口前三位国家保持稳定, 而主要进口大国变化明显, 贸易格局已由南美供应全球转变为南美供应东亚; (2)碳酸锂贸易供应危机的影响范围逐渐扩大, 间接传播逐渐占据主导地位; (3)智利供应危机对中日韩的影响程度逐渐扩大, 但对欧洲的影响时间最长; 阿根廷和中国的雪崩规模在上升、传播次数增加, 而美国则相反。本文将贸易格局演变与危机传播结合, 明确了全球碳酸锂主要贸易国智利、阿根廷、中国、德国等作为供应危机来源的影响程度及其传播路径。以上分析结果将有利于维护全球碳酸锂贸易稳定和主要贸易国采取应对策略缓解供应危机。  相似文献   
13.
We present the first VLBI observations of the compact source S1 in the radio jet of NGC 1068. Roughly 1 pc in length and 0.2 pc wide, S1 resolves into clumps aligned perpendicular to the local radio jet axis. The radio continuum emission arises from a hot (Te ~ 106 K), dense (ne ~ 106 cm-3) plasma, and the source of the radio emission is either thermal free-free emission or Thomson-reflected synchrotron emission. The clouds comprising S1 are opaque to soft X-radiation, and we therefore propose that S1 is the inner, ionized region, or ‘hot zone,’ of the obscuring medium surrounding the active nucleus. The covering fraction of the hot zone is small, Cf ⋦ 10%. Since the covering fraction of the dusty, obscuring medium is probably much larger, the obscuring disk must either flare or warp outside of the hot zone. That the radio jet and hot zone axes are perpendicular also suggests that the hot zone may be considered to trace the outermost extent of the accretion disk. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
14.
基于对子午链台站地震地磁前兆异常以及地球空间环境变化等研究方向的需求分析,利用网络、大数据、云计算等新技术,结合地震数据专家(DatistEQ)软件,设计子午链台站地磁指数报告自动产出系统。该系统通过低代码、敏捷式开发工作流程,连接不同功能节点,可以实现用户定制化、数据标准化、功能智能化的系统报告产出。通过本地或者云端一键流程化工作,将不同类型的数据发送到科研工作者或其他需求者,简化工作流程,优化数据处理,实现高效率产品产出。  相似文献   
15.
Summary Semi-monthly mean sea-level pressure maps for the Mediterranean and adjacent areas are presented. Isobars have been drawn at 1-millibar intervals. The most significant features on the maps and the advantages of the mode of presentation are discussed briefly.
Zusammenfassung Es werden auf das Meeresniveau bezogene halbmonatliche mittlere Luftdruckkarten für das Mittelmeergebiet und die anstoßenden Länder vorgelegt. Die Isobaren wurden für Millibarabstände gezeichnet. Die wichtigsten Resultate der Karten und die Vorzüge der Darstellungsweise werden kurz besprochen.

Résumé Présentation de cartes de la pression moyenne semi-mensuelle, réduite au niveau de la mer, de la région méditerranéenne et des contrées voisines. Les isobares sont tracées de millibar en millibar. Brève discussion des traits principaux des cartes et des avantages de la méthode de représentation.


With 25 Figures.

The work reported in this paper has been supported by the Geophysics Research Division of the Air Force Cambridge Research Center, under Contract AF 19 (122)-466.  相似文献   
16.
We present the first results from a major HST WFPC2 imaging study aimed at providing the first statistically meaningful comparison of the morphologies, luminosities, scalelengths and colours of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies. We describe the design of this study and present the images that have been obtained for the first half of our 33-source sample. We find that the hosts of all three classes of luminous AGN are massive elliptical galaxies, with scalelengths ≃10 kpc, and R − K colours consistent with mature stellar populations. Most importantly, this is first unambiguous evidence that, just like radio-loud quasars, essentially all radio-quiet quasars brighter than M R =−24 reside in massive ellipticals. This result removes the possibility that radio 'loudness' is directly linked to host galaxy morphology, but is however in excellent accord with the black hole/spheroid mass correlation recently highlighted by Magorrian et al. We apply the relations given by Magorrian et al. to infer the expected Eddington luminosity of the putative black hole at the centre of each of the spheroidal host galaxies we have uncovered. Comparison with the actual nuclear R -band luminosities suggests that the black holes in most of these galaxies are radiating at a few per cent of the Eddington luminosity; the brightest host galaxies in our low- z sample are capable of hosting quasars with M R ≃− 28, comparable to the most luminous quasars at z ≃3. Finally, we discuss our host-derived black hole masses in the context of the radio luminosity:black hole mass correlation recently uncovered for nearby galaxies by Franceschini et al., and consider the resulting implications for the physical origin of radio loudness.  相似文献   
17.
实验采用单轴压缩循环加载方式,在地震频段内测量了莱阳大理岩的品质因数Q值.在频率为0.1-10 Hz范围内,Q值随频率变化是非线性的,而且在5 Hz附近出现峰值.用正弦波和用三角波两种方式加载所获得的Q值与频率关系很相似,并且三角波加载所测得的Q值普遍高于用正弦波加载测得的Q值.疲劳试验结果表明,正弦波循环加载大大降低了岩石的强度,三角波则对岩石强度降低较少.  相似文献   
18.
Crustal deformation shows different patterns at different depths due to changes in the physical properties of rock.Tectonic levels can be defined based on the geometry and deformation mechanisms of crustal deformation patterns. Nujiang Gorge, with a high riverbed drop, great erosion depth, and strong deformation, has rock exposures at different tectonic levels and thus provides an ideal lab for deformation study. This paper takes the Nujiang Gorge from Chawalong to Fugong as the object to identify structural deformation patterns at different depths through field study and deformation analysis. At depth, the primary form of deformation is flow deformation, as shown on the outcrops at Maji. Ductile shear deformation can be found in many outcrops within the study region, e.g., the Gaoligong dextral shear zone and Puladi-Songta sinistral shear zone that lie to the south and north of Maji, respectively. Further to the north of Puladi, the dominated deformation pattern is similar fold and dense sub-vertical foliation. In addition, brittle faults, as evidence of shallow deformation, can be seen overprinting on the deeper deformation features all over the region. Based on those observations, this paper identifies four tectonic levels from depth to the surface: flow deformation, ductile shear deformation, similar fold, and brittle fault deformation, all of which result from the NEE-SWW compressive stress field. Further evidence from studies on the region′s thermal evolution and regional tectonics suggests that the development of different tectonic levels is closely linked to the discrepant uplift or denudation since the Miocene(~21 Ma).  相似文献   
19.
利用卫星遥感资料和地面气象观测资料,基于CASA模型及其他数理方法估算了浑善达克沙地2000-2013年生长季(4-10月)植被净初级生产力(NPP),并对其时空变化特征进行了分析,讨论了气候因子和人类活动对植被净初级生产力的影响。结果表明: 14年间,研究区生长季的植被净初级生产力呈波动中增加趋势,多年平均NPP为239.8 gC·m-2·a-1。整个研究区表现为高NPP值(大于150 gC·m-2·a-1)的植被面积在增加,低NPP值(小于150 gC·m-2·a-1)的植被面积在减少。在空间分布上,研究区的北部、中部和南部边缘区域的植被NPP增加趋势较明显,而东部和西部部分区域未发生明显的趋势性变化。总体而言,研究区植被净初级生产力变化趋势与降水量的关系更密切,其相关系数达到0.86,是驱动植被NPP年际波动的最直接因素。而与温度呈负相关,相关系数为-0.42。综合考虑气候因素和人类活动对沙地NPP的影响发现,温度降低、种饲料面积、年末牲畜存栏头数和羊的数量的减少是NPP值提高的关键因素。  相似文献   
20.
The Slumgullion landslide in the San Juan Mountains of southwestern Colorado has been moving for at least the last few hundred years and has multiple ponds on its surface. We have studied eight ponds during 30 trips to the landslide between July 1998 and July 2007. During each trip, we have made observations on the variability in pond locations and water levels, taken ground‐based photographs to document pond water with respect to moving landslide material and vegetation, conducted Global Positioning System surveys of the elevations of water levels and mapped pond sediments on the landslide surface. Additionally, we have used stereo aerial photographs taken in October 1939, October 1940 and July 2000 to measure topographic profiles of the eight pond locations, as well as a longitudinal profile along the approximate centerline of the landslide, to examine topographic changes over a 60‐ to 61‐year period of time. Results from field observations, analyses of photographs, mapping and measurements indicate that all pond locations have remained spatially stationary for 60–300 years while landslide material moves through these locations. Water levels during the observation period were sensitive to changes in the local, spring‐fed, stream network, and to periodic filling of pond locations by sediment from floods, hyperconcentrated flows, mud flows and debris flows. For pond locations to remain stationary, the locations must mimic depressions along the basal surface of the landslide. The existence of such depressions indicates that the topography of the basal landslide surface is irregular. These results suggest that, for translational landslides that have moved distances larger than the dimensions of the largest basal topographic irregularities (about 200 m at Slumgullion), landslide surface morphology can be used as a guide to the morphology of the basal slip surface. Because basal slip surface morphology can affect landslide stability, kinematic models and stability analyses of translational landslides should attempt to incorporate irregular basal surface topography. Additional implications for moving landslides where basal topography controls surface morphology include the following: dateable sediments or organic material from basal layers of stationary ponds will yield ages that are younger than the date of landslide initiation, and it is probable that other landslide surface features such as faults, streams, springs and sinks are also controlled by basal topography. The longitudinal topographic profile indicated that the upper part of the Slumgullion landslide was depleted at a mean vertical lowering rate of 5.6 cm/yr between 1939 and 2000, while the toe advanced at an average rate of 1.5 m/yr during the same period. Therefore, during this 61‐year period, neither the depletion of material at the head of the landslide nor continued growth of the landslide toe has decreased the overall movement rate of the landslide. Continued depletion of the upper part of the landslide, and growth of the toe, should eventually result in stabilization of the landslide. Published in 2008 by John Wiley & Sons, Ltd.  相似文献   
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