中国单一银(-金)矿主要类型及其地质特征

对我国单一银（-金）矿床地质特征、成因类型和空间分布特点进行了总结.以成矿作用和成矿地质条件为基础,矿床成因为依据,我国单一银（-金）矿床可分为：（1）变质（混合岩化）热液型矿床;（2）火山（含次火山）热液型银（-金）矿床;（3）岩浆-热液型银（-金）矿床;（4）地热水溶滤型银（-金）矿床.     

云南锑（金）成矿带划分及有关成矿问题讨论

云南可划分11个锑（金）成矿带（区）。Sb—Au属同一成矿系列（Sb略晚）,二者常相伴产出。滇东坡脚组（D1p）与滇西三合洞组（T3s）,同为锑矿矿源层。滇东南与黔西区玄武岩喷溢早期的大厂层（P3d）、主期玄武岩组（P3β）、晚期龙潭组（P3l）,三者含Sb、Au背景值远高于全球玄武岩,构成统一的Sb—Au矿源层（岩）,在有利构造条件下,产出Sb矿（伴生Au）、Au矿（伴生Sb）或二者共存（广南堂上）,其成因都与幔源玄武岩喷溢作用有关。     

山东省损毁山体景观影响度分析

损毁山体严重影响城市和交通沿线景观,景观影响度可作为一个综合指标来反映损毁山体对城市景观的影响程度。应用专家评分综合评判法结合地理信息系统确定景观影响度分级标准,对损毁山体进行景观影响程度的评价与分析,得出景观影响度分类结果,为损毁山体的治理规划和有序整治提供科学依据。     

云南省入境旅游空间集聚性演变及灰色模型预测分析

利用标准差、市场占有率、地理集中指数、变异系数和赫芬达尔指数对云南省入境客流量的空间集聚状况进行定量分析.研究表明：云南省各市州入境旅游接待规模差异较大,入境客流量的空间集聚性较强,入境旅游市场分化程度较低,市场竞争激烈,入境客源分布较为平衡.以云南省统计年鉴2001～2012年的入境旅游数据为基础,建构GM（1,1）模型并进行精度检验.研究表明：模型预测结果与实际数据几乎一致,进而利用该模型对云南省未来入境旅游指标进行预测.     

Evolution of sedimentary environments of the middle Jiangsu coast, South Yellow Sea since late MIS 3

An evolutionary model of sedimentary environments since late Marine Isotope Stage 3 （late MIS 3, i.e., ca. 39 cal ka BP） along the middle Jiangsu coast is presented based upon a reinterpretation of core 07SR01, new correlations between adjacent published cores, and shallow seismic profiles recovered in the Xiyang tidal channel and adjacent northern sea areas. Geomorphology, sedimentology, radiocarbon dating and seismic and sequence stratigraphy are combined to confirm that environmental changes since late MIS 3 in the study area were controlled primarily by sea-level fluctuations, sediment discharge of paleo-rivers into the South Yellow Sea （SYS）, and minor tectonic subsidence, all of which impacted the progression of regional geomorphic and sedimentary environments （Le., coastal barrier island freshwater lacustrine swamp, river floodplain, coastal marsh, tidal sand ridge, and tidal channel）. This resulted in the formation of a fifth-order sequence stratigraphy, comprised of the parasequence of the late stage of the last interstadial （Para-Sq2）, including the highstand and forced regressive wedge system tracts （HST and FRWST）, and the parasequence of the postglacial period （Para-Sql）, including the transgressive and highstand system tracts （TST and HST）. The tidal sand ridges likely began to develop during the postglacial transgression as sea-level rise covered the middle Jiangsu coast at ca. 9.0 cal ka BP. These initially submerged tidal sand ridges were constantly migrating until the southward migration of the Yellow River mouth to the northern Jiangsu coast during AD 1128 to 1855. The paleo-Xiyang tidal channel that was determined by the paleo-tidal current field and significantly different from the modern one, was in existence during the Holocene transgressive maxima and lasted until AD 1128. Following the capture of the Huaihe River in AD 1128 by the Yellow River, the paleo-Xiyang tidal channel was infilled with a large amount of river-derived sediments from AD 1128 to 1855, causing the emergence of some of the previously submerged tidal sand ridges. From AD 1855 to the present, the infilled paleo-Xiyang tidal channel has undergone scouring, resulting in its modern form. The modern Xiyang tidal channel continues to widen and deepen, due both to strong tidal current scouring and anthropogenic activities.     

罕遇地震作用下的框架-摇摆刚架结构体系动力可靠度研究

针对钢筋混凝土框架结构的受力特点,采用增设摇摆刚架的抗震设计方法,以提高罕遇地震下建筑结构的安全性。建立了框架一摇摆刚架结构体系的计算模型,结合状态空间法与虚拟激励法,求解结构的平稳随机响应,并根据计算所得随机响应对框架一摇摆刚架体系的动力可靠度进行分析。以西部地区某已建成的6层框架结构为算例,探讨了罕遇地震作用下不同刚度比的摇摆刚架对新结构体系动力可靠度的影响。结果表明,通过增设不同刚度比的摇摆刚架,可以有效协调结构体系的变形模式,充分发挥结构的耗能能力,降低整体结构的条件失效概率。     

磁敏感加权成像临床应用和在血管瘤评估中的研究进展

磁敏感加权成像是一种近年发展的MRI新技术,在中枢神经系统疾病中的诊断及鉴别诊断中的重要作用已经得到了广大临床大夫的认可,具有很高的应用价值和拓展前景。SWI作为常规MRI检查的重要补充序列,采用3D梯度回波扫描,完全速度补偿,射频脉冲扰相等技术,具有三维、高分辨率、高信噪比的特点,可以更好地分析软组织血管瘤的结构成分,鉴别活动性出血、机化血栓、钙化及铁沉积等。而且SWI相位图能够清楚显示瘤体内部新生血管、瘤体周围静脉血管位置和形态改变,更有利于准确评估病变范围及程度,为血管瘤定位及定性诊断可以提供更多的影像信息,对于临床诊断及治疗方案的制定、预后评估都具有重要的应用价值。     

Impact of lateral force-resisting system and design/construction practices on seismic performance and cost of tall buildings in Dubai, UAE

The local design and construction practices in the United Arab Emirates(UAE),together with Dubai’s unique rate of development,warrant special attention to the selection of Lateral Force-Resisting Systems(LFRS).This research proposes four different feasible solutions for the selection of the LFRS for tall buildings and quantifies the impact of these selections on seismic performance and cost.The systems considered are: Steel Special Moment-Resisting Frame(SMRF),Concrete SMRF,Steel Dual System(SMRF with Special Steel Plates Shear Wall,SPSW),and Concrete Dual System(SMRF with Special Concrete Shear Wall,SCSW).The LFRS selection is driven by seismic setup as well as the adopted design and construction practices in Dubai.It is found that the concrete design alternatives are consistently less expensive than their steel counterparts.The steel dual system is expected to have the least damage based on its relatively lesser interstory drifts.However,this preferred performance comes at a higher initial construction cost.Conversely,the steel SMRF system is expected to have the most damage and associated repair cost due to its excessive flexibility.The two concrete alternatives are expected to have relatively moderate damage and repair costs in addition to their lesser initial construction cost.     

Study of the seismic response of a recycled aggregate concrete frame structure

Based on six-degree-of-freedom three-dimensional shaking table tests, the seismic response of a recycled aggregate concrete （RAC） frame was obtained. The analysis results indicate that the maximum story shear force and overturning moment reduce proportionally along the height of the model under the same earthquake wave. The story shear force, base shear coefficient and overturning moment of the structure increase progressively as the acceleration amplitude increases. The base shear coefficient is primarily controlled by the peak ground acceleration （PGA）. The relationships between the PGA and the shear coefficient as well as between the PGA and the dynamic amplification factor are obtained by mathematical fitting. The dynamic amplification factor decreases rapidly at the elastic-plastic stage, but decreases slowly with the development of the elastic-plasticity stage. The results show that the RAC frame structure has reasonable deformability when compared with natural aggregate concrete frame structures. The maximum inter-story drift ratios of the RAC frame model under frequent and rare intensity 8 test phases are 1/266 and 1/29, respectively, which are larger than the allowable value of 1/500 and 1/50 according to Chinese seismic design requirements. Nevertheless, the RAC frame structure does not collapse under base excitations with PGAs from 0.066 g up to 1.170 g.     

Condensed hyperelements method of non-vertical consistent boundaries for wave propagation analysis in irregular media

The study of wave propagation in finite/infinite media has many applications in geotechnical and structural earthquake engineering and has been a focus of research for the past few decades. This paper presents an analysis of 2D anti- plane problems （Love waves） and 2D in-plane problems （Rayleigh waves） in the frequency domain in media consisting of a near-field irregular and a far-field regular part. The near field part may contain structures and its boundaries with the far-field can be of any shape. In this study, the irregular boundaries of the near-field are treated as consistent boundaries, extending the concept of Lysmer＇s vertical consistent boundaries. The presented technique is called the Condensed Hyperelements Method （CHM）. In this method, the irregular boundary is limited to a vertical boundary at each end that is a consistent boundary at the far-field side. Between the two ends, the medium is discretized with hyperelements. Using static condensation, the stiffness matrix of the far-field is derived for the nodes on the irregular boundary. Examples of the application of the CHM illustrate its excellent accuracy and efficiency.