Relationships between bacterial-algal proliferating and mass extinction in the Late Devonian Frasnian-Famennian transition: Enlightening from carbon isotopes and molecular fossils

The five major mass extinctions which occurred in the transition of the Ordovician-Silurian (440 Ma), Late Devonian Frasnian-Famennian (F-F) (370 Ma), Permian-Triassic (250 Ma), Triassic-Jurassic (205 Ma) and Cretaceous-Paleogene (65 Ma) are significant phenomena in the Phanerozoic global environment and organic evolution. Their corresponding extinction rates of marine invertebrate at the level of genus and family are 60% (genus) and 26% (family), 57% and 22%, 82% and 51%, 53% and 22%, …     

煤田PDC钻头单喷嘴喷射试验研究

通过喷嘴喷射试验,研究了煤田PDC钻头喷嘴尺寸和喷射距离与射流动压力的关系,得出了优化喷射结构参数。     

湛江沿海大黄鱼种群的研究

徐闻和硇州两海区所产的大黄鱼,过去一直认为是同一种群—粤西种群。通过生物学测定,发现在体长组成、年龄组成、体重组成和年渔获量方面,两者有显著的差异,应分为徐闻种群和硇州种群。     

中国非金属超大型矿床分布规律及成矿地质特征

本文对中国非金属超大型矿床的种类、规模、时空分布规律、矿床成因类型与含矿建造，以及与中国板块构造和地壳演化史的关系进行了讨论，并与国外同类矿床做了对比。     

军事地理应加强区域研究

本文提出了地理学最基本的特征之一─区域性的概念及其基本特征，从现代高技术战争的需要及地理环境系统的结构特点出发论述了军事地理加强区域研究的必要性，并讨论了军事地理区域研究与ＭＧＩＳ的关系。     

1505年10月9日63／4级地震震中的再考证

１５０５年发生在南黄海的地震至今已有１２次震中定位。由于该震中位置的确定直接影响到一些重大工程的地震安全性评价工作，因此，本文通过收集大量影响场的历史资料，参考了国内ＩＸ度地震等震线资料，采用与地球物理场和构造条件相结合的方法，重新考证了该震震中位置。     

Recurrence characteristics of late-quaternary strong earthquakes on the major active faults along the northern border of Ordos block

Through study on trenches, analysis of recurrence characteristics and recurrence interval cluster/gap of strong earthquakes along the major active faults on the northern border of Ordos block, we found 62 paleoearthquakes that occurred in the late Quaternary, including 33 earthquakes occurring in the Holocene. The recurrence characteristics of the paleoearthquakes are different at three levels, segments, faults, and fault zones. The strong seismic sequence on the independent segments is mostly characterized by long- and short-interval recurrences, while that on the faults and in fault zone is characterized clearly by random and cluster recurrences. Results of the moving window test indicate that the probabilities of “temporal cluster or gap”, caused by random coincidence as opposed to intersegment contagion, are 64% and 70% for the Serteng piedmont fault and for the south-border fault of Wula Mountains, respectively, no clear interaction among the segments of each fault; while the probability is 26.8% for the whole fault zone, suggesting a clear interaction among the faults of this fault zone. These recurrence characteristics may imply an effect of the entire block motion on the recurrence of strong earthquakes. Moreover, the elapsed time for the Wujumeng Pass-Dongfeng Village segment of Serteng piedmont fault and the Tuzuo Banner-Wusutu and the Hohhot segments of Daqingshan piedmont fault has exceeded the average recurrence interval, hence these three segments may be the possible places for future strong earthquakes.     

朝阳沟油田双30-2区扶Ⅰ层裂缝发育区预测研究

通过构造裂缝形成的力学机制分析，应用弹性理论、有限单元法和岩石破坏准则等，对朝阳沟油田双30—2区块扶I层应力裂缝发育区进行预测，旨在判断裂缝性油藏区。结果表明，预测结果与现场钻探取样结果符合较好，从而为该区下一步布井和注水提供了依据。     

西秦岭糜署岭岩体镁铁质微粒包体的特征及成因

糜署岭岩体的岩石组合为灰白色似斑状二长花岗岩-花岗闪长岩-石英闪长岩，其中镁铁质微粒包体十分发育。包体密集成群、成带状分布，个体大小悬殊且有定向性。有的包体具有细粒边，有的见冷凝边；包体与寄主岩石在成分、色率以及组构上多呈弱过渡关系，界线模糊；包体中发育斜长石异常环带及针状磷灰石，常有寄主岩石中的钾长石巨晶(捕虏晶)。这些特征提供了基性岩浆与酸性岩浆混合的证据，也为探讨本区中生代壳幔混合作用和地壳增生提供了信息。     

Bundle Adjustment with Self–Calibration Using Straight Lines

Increased use of digital imagery has facilitated the opportunity to use features, in addition to points, in photogrammetric applications. Straight lines are often present in object space, and prior research has focused on incorporating straight–line constraints into bundle adjustment for frame imagery. In the research reported in this paper, object–space straight lines are used in a bundle adjustment with self–calibration. The perspective projection of straight lines in the object space produces straight lines in the image space in the absence of distortions. Any deviations from straightness in the image space are attributed to various distortion sources, such as radial and decentric lens distortions. Before incorporating straight lines into a bundle adjustment with self–calibration, the representation and perspective transformation of straight lines between image space and object space should be addressed. In this investigation, images of straight lines are represented as a sequence of points along the image line. Also, two points along the object–space straight line are used to represent that line. The perspective relationship between image– and object–space lines is incorporated in a mathematical constraint. The underlying principle in this constraint is that the vector from the perspective centre to an image point on a straight–line feature lies on the plane defined by the perspective centre and the two object points defining the straight line. This constraint has been embedded in a software application for bundle adjustment with self–calibration that can incorporate point as well as straight–line features. Experiments with simulated and real data have proved the feasibility and the efficiency of the algorithm proposed.