Yaxcopoil-1 and the Chicxulub impact

CSDP core Yaxcopoil-1 was drilled to a depth of 1,511 m within the Chicxulub crater. An organic-rich marly limestone near the base of the hole (1,495 to 1,452 m) was deposited in an open marine shelf environment during the latest Cenomanian (uppermost Rotalipora cushmani zone). The overlying sequence of limestones, dolomites and anhydrites (1,495 to 894 m) indicates deposition in various carbonate platform environments (e.g., sabkhas, lagoons). A 100-m-thick suevite breccia (894–794 m) identifies the Chicxulub impact event. Above the suevite breccia is a dolomitic limestone with planktic foraminiferal assemblages indicative of Plummerita hantkeninoides zone CF1, which spans the last 300 ky of the Maastrichtian. An erosional surface 50 cm above the breccia/dolomite contact marks the K/T boundary and a hiatus. Limestones above this contact contain the first Tertiary planktic foraminifera indicative of an upper P. eugubina zone P1a(2) age. Another hiatus 7 cm upsection separates zone P1a(2) and hemipelagic limestones of planktic foraminiferal Zone P1c. Planktic foraminiferal assemblages of Zone Plc to P3b age are present from a depth of 794.04 up to 775 m. The Cretaceous carbonate sequence appears to be autochthonous, with a stratigraphic sequence comparable to late Cretaceous sediments known from outside the Chicxulub crater in northern and southern Yucatan, including the late Cenomanian organic-rich marly limestone. There is no evidence that these sediments represent crater infill due to megablocks sliding into the crater, such as major disruption of sediments, chaotic changes in lithology, overturned or deep dipping megablocks, major mechanical fragmentation, shock or thermal alteration, or ductile deformation. Breccia units that are intercalated in the carbonate platform sequence are intraformational in origin (e.g., dissolution of evaporites) and dykes are rare. Major disturbances of strata by the impact therefore appear to have been confined to within less than 60 km from the proposed impact center. Yaxcopoil-1 may be located outside the collapsed transient crater cavity, either on the upper end of an elevated and tilted horst of the terrace zone, or even outside the annular crater cavity. The Chicxulub site thus records a large impact that predates the K/T boundary impact and mass extinction.     

Palaeogeography and tectonic structure of allochthonous units in the German part of the Rheno-Hercynian Belt (Central European Variscides)

New information on palaeogeography, orogenic evolution, tectonic structure, and boundaries of allochthonous units in the Rheno-Hercynian Belt is based on provenance analyses of clastic sediments and field studies. ⁴⁰K/⁴⁰Ar dating of detrital muscovites proved to be a particularly useful method because Cadomian, Caledonian and Early Variscan provenances of detrital material can be distinguished. Cadomian muscovite cooling ages are restricted to allochthonous units whereas Caledonian ages dominate within par-autochthonous and shortly displaced allochthonous units. The largest and uppermost preserved nappe, the Gießen-Harz Nappe, is derived from an oceanic flysch basin, which was not reached by Caledonian detritus. The other allochthonous units form a duplex-like structure sandwiched between the Gießen-Harz Nappe and par-autochthonous units at its base. The thick and heterogeneous roof- and floor-thrusts of this structure were previously often misinterpreted as olistostromes. The northern margin of allochthonous units is the steeply dipping Hörre-Gommern Zone. It consists of three sub-units derived from deep-water areas between the shelf at the southern margin of the Old Red Sandstone Continent and an oceanic basin to the south. The southeastern part of the duplex-structure (Harzgerode Zone) shows close affinities to Armorican terranes.     

酸雨观测异常数据的试验分析和处理方法

本文就酸雨观测仪器在测量操作中出现的异常状态进行了试验和分析,且对校错电极常数、测温系统故障、"后测K值"3种异常状态, 结合酸雨观测业务实践进行了试验、分析和讨论。推导出校错电极常数的电导率订正公式;制定了仪器测温系统故障的应急观测方案;指出"后测K值"会导致数据严重失真, 测量中必须严格遵循 "先测K值"规程;并建议在《酸雨观测业务规范》修订时, 增加本文有关的分析和处理方法。     

摄影测量中几种特征点提取算法比较

特征点提取技术一直是数字摄影测量和计算机视觉中的研究热点。从兴趣算子的角度研究了摄影测量中几种主流特征点提取算法,并从提取角点数、提取时间等方面,定量地比较和分析了各算法的性能、优缺点,并得出了一定的结论。     

固定铝log(Q/K)图解在温泉中的应用

为探讨常规和固定铝log(Q/K)图解法对温泉系统是否有效 ,采用WATCH程序 ,对江西 3个温度较高的温泉 ,即庐山温泉、汤湖温泉和横泾温泉 ,进行了探测性的研究 .采用常规log(Q/K)图解法计算时 ,由于参加计算的 4个水样的铝含量均未检出 ,计算结果显示只有不含铝的矿物玉髓和方解石相交于温度 1 0 0℃附近 ,热储总体上没有达到平衡 .在采用了固定铝log(Q/K)图解法并同时考虑冷水的稀释作用计算后 ,中低温地热系统中常见的蚀变矿物如浊沸石、纤蛇纹石、萤石和玉髓均显示了较好的收敛性 ,收敛的温度大致在 1 0 0～ 1 4 0℃ .并且上述矿物组合可见于某些温泉的深部钻孔中 ,计算结果与实际地质情况相吻合 .结果表明固定铝log(Q/K)图解法可以恢复温泉系统的热平衡状态     

Ordovician Granitoids and Silurian Mafic Dikes in the Western Kunlun Orogen, Northwest China: Implications for Evolution of the Proto-Tethys

The western Kunlun orogen in the northwest Tibet Plateau is related to subduction and collision of Proto-and Paleo-Tethys from early Paleozoic to early Mesozoic. This paper presents new LA-ICPMS zircon U-Pb ages and Lu-Hf isotopes, whole-rock major and trace elements, and Sr–Nd isotopes of two Ordovician granitoid plutons(466–455 Ma) and their Silurian mafic dikes(～436 Ma) in the western Kunlun orogen. These granitoids show peraluminous high-K calcalkaline characteristics, with(⁸⁷Sr/⁸⁶Sr)_i value of 0.7129–0.7224, ε_Nd(t) values of -9.3 to -7.0 and zircon ε_Hf(t) values of -17.3 to -0.2, indicating that they were formed by partial melting of ancient lower-crust(metaigneous rocks mixed with metasedimentary rocks) with some mantle materials in response to subduction of the Proto-Tethyan Ocean and following collision. The Silurian mafic dikes were considered to have been derived from a low degree of partial melting of primary mafic magma. These mafic dikes show initial ⁸⁷Sr/⁸⁶Sr ratios of 0.7101–0.7152 and ε_Nd(t) values of -3.8 to -3.4 and zircon ε_Hf(t) values of -8.8 to -4.9, indicating that they were derived from enriched mantle in response to post-collisional slab break-off. Combined with regional geology, our new data provide valuable insight into late evolution of the Proto-Tethys.     

覆盆子-红花药对与男性不育症的治疗相关机制探讨

目的：基于网络药理学探讨覆盆子-红花药对治疗男性不育症的物质基础及作用机制。方法：用TCMSP数据库检索覆盆子、红花,收集其化学成分以及靶点信息;用GeneCards和OMIM数据库筛选男性不育症的疾病靶点;应用韦恩图筛选药物与疾病的共同靶点;应用R软件进行GO富集分析及KEGG分析;应用 Cytoscape 3.7.2 软件构建药物-活性成分-疾病-靶点互作网络。结果：从覆盆子、红花得到了22个活性成分及202个药物靶点。在药物-活性成分-疾病-靶点互作网络中,degree值较高的为槲皮素及木犀草素,表明覆盆子-红花药对治疗男性不育症的主要活性成分可能为槲皮素、木犀草素等。覆盆子-红花药对治疗男性不育症的可能靶点有131个,其中核心靶点为ALB、AKT1、IL-6、VEGFA、JUN等,这些靶点主要与氧化及抗氧化生物等生物学过程相关。覆盆子-红花药对的靶点主要通过P13K/Akt信号通道治疗男性不育症。结论：覆盆子-红花药对通过多靶点、多途径治疗男性不育症。本研究为开展覆盆子-红花药对治疗男性不育症的实验提供了理论基础,为男性不育症的治疗提供了更多的思路。     

察布查尔县土壤碳氮磷钾垂直分布规律研究

以察布查尔县1 191~2 656 m不同海拔草原土壤为研究对象,研究有机质（外加热法,10.18~74.3 3 mg·kg^-1）、全氮（自动凯氏定氮仪,0.17~2.6 g·kg^-1）、碱解氮（扩散法,14.9 7~198.72mg·kg^-1）、磷元素（钼锑抗比色法,全磷：0.12~0.76 g·kg^-1、速效磷：20.7 4~153.64 mg·kg^-1）,钾元素（火焰光度计法,全钾：9.81~18.64 g·kg^-1、速效钾：659.05~1 001.45 mg·kg^-1）含量垂直分布特征。结果表明碳、氮、磷、钾均随土层深度的增加而降低;除钾元素外碳、氮、磷随海拔高度的增加而上升;相关性分析结果显示,0~20 cm土层中,海拔高度与碱解氮呈正极显著性相关（p < 0.05,R=0.838^**）,与土壤有机、全氮呈正显著性相关（p < 0.05,R=0.831^*、R=0.751^*）;有机质与碱解氮呈正极显著性相关（p < 0.05,R=0.988^**）,与全磷呈正显著性相关（p < 0.05,R=0.726^*）,20~40 cm土层中,海拔高度与有机质、碱解氮、全氮、全磷呈正相关,与速效磷、速效钾、全钾呈负相关;有机质与碱解氮、全氮成正极显著性相关（p < 0.05,R=0.867^**、R=0.970^**）,碱解氮与全氮呈正极显著相关（p < 0.05,R=0.914^**）,40~60 cm土层中,海拔高度与有机质、碱解氮、全磷呈正相关,与速效磷、全磷、速效钾、全钾呈负相关;有机质与碱解氮、全氮呈正极显著性相关（p < 0.05,R=0.884^**、R=0.966^**）,与速效磷、全钾呈正相关,与全磷、速效钾呈负相关;碱解氮与全氮呈正极显著性相关（p < 0.05,R=0.952^**）。     

Geographic Patterns of Craft Breweries at the Intraurban Scale

This article examines the intraurban geography of craft breweries in ten cities across the United States. First, through an exhaustive literature review, we outline both supply- and demand-side factors that might cause craft breweries to cluster. Second, we empirically test whether these establishments tend to cluster within cities using spatial statistical techniques. Many communities are attempting to support the establishment of more craft breweries as a way to boost tourism and economic development. The findings from this article aid in this discussion by providing insights into how craft brewers locate and the factors that could influence their location decision behavior. Our findings suggest that craft brewers do in fact cluster. There are both supply and demand factors responsible. On the supply side, the collaborative environment within the industry and the artisan nature of the industry's products allows for benefits of clustering to outweigh the costs associated with this behavior. On the demand side, the emergence of “brewery districts” allows individual brewers to enjoy the reputation benefits associated with the district in terms of increased foot traffic from locals and visitors looking to sample a variety of beers.