Environmental evolution of Zoigê Basin since 900 kaB.P. and comparison study with Loess Plateau

The Zoige Basin is located in the eastern margin of the Qinghai-Xizang Plateau, in which two cores, RH and RM, have been drilled, with the depths of 120 m and 310 m respectively. The former with the bottom age of 826 kaB. P. has been divided into 21 stages according to the multi-proxy analysis, which could be basically compared with the oxygen isotope record of deep-sea core. The palaeoclimatic and palaeoenvironmental process of the Zoigê Basin over the past 900 kaB. P. is reconstructed, and the comparison of core RH with the Luochuan Loess record is made.     

Crustal structure of Dabieshan orogenic belt

The crustal structures ofP velocity and density on the deep seismic sounding profile across the Ilabieshan orogenic belt are presented. There is a 5-km-thick crustal “root” between the Yuexi and Xiaotian where the elevation is highest on the profile. An apparent Moho offset of 4. 5 km beneath the Xiaotian-Mozitan fault marks the paleo-suture of the Triassic collision. A high-velocity anomaly zone at the depth below 3 km beneath the ultra-high pressure (UHP) zone may be correlated to the higher content of UHP metamorphic rocks. Project supported by the National Natural Science Foundation of China and the Joint Earthquake Science Foundation.     

Interpretation of S-wave data from Tai’an-Xinzhou DSS profile and its relationship with Xingtai earthquakes

On the basis of S wave information from Tai’an-Xinzhou DSS profile and with reference to the results from P-wave interpretation, the 2-D structures, including S-wave velocity V _s, ratio γ between V _p and V _s; and Poisson’ s ratio σ, are calculated; the structural configuration of the profile is presented and the relevant inferences are drawn from the above results. Upwarping mantle districts (V _s≈4.30 km/s) and sloping mantle districts (V _s≈4.50 km/s) of the profile with velocity difference about −4% at the top of upper mantle are divided according to the differences of V _s, γ and σ in different media and structures, also with reference to the information of their neighbouring regions; the existence of Niujiaqiao-Dongwang high-angle ultra-crustal fault zone is reaffirmed; the properties of low and high velocity blocks (zones) including the crust-mantle transitionalzone and the boudary indicators of North China rift valley are discussed. A comprehensive study is conducted on the relation of the interpretation results with earthquakes. It is concluded that the mantle upwarps, thermal material upwells through the high-angle fault, the primary hypocenter was located at the crust-mantle juncture 30.0∼33.0 km deep, and additional stress excited the M _S=6.8 and M _S=7.2 earthquakes at specific locations around 9.0 km below Niujiaqiao-Dongwang, the earthquakes took place around the high-angle ultra-crustal fault and centered in the brittle media and rock strata with low γ and low σ values. This subject is part of the 85-907-02 key project during the “8th Five-Year Plan” from the State Science and Technology Commission.     

40Ar/39Ar geochronology and exhumation of mylonitized metamorphic complex in Changle-Nanao ductile shear zone

New⁴⁰Ar/³⁹Ar plateau ages from rocks of Changle-Nanao ductile shear zone are 107.9 Ma(Mus), 108.2 Ma(Bi), 107.1 Ma(Bi), 109.2 Ma(Hb) and 117.9 Ma(Bi) respectively, which are concordant with their isochron ages and record the formation age of the ductile shear zone. The similarity and apparent overlap of the cooling ages with respective closure temperatures of 5 minerals document initial rapid uplift during 107–118 Ma following the collision between the Min-Tai microcontinent and the Min-Zhe Mesozoic volcanic arc. The⁴⁰Ar/³⁹ Ar plateau ages, K-Ar date of K-feldspar and other geochronologic information suggest that the exhumation rate of the ductile shear zone is about 0.18–1.12 mm/a in the range of 107–70 Ma, which is mainly influenced by tectonic extension.     

强余震持续时间的早期估计

本研究旨在解决地震序列中强余震持续时间的早期估计问题。文中首先给出了强余震的震级定义，指出：主震型与强震群型序列的强作震持续时间存在差异。使用模式识别方法对主震型序列中强余震持续时间大于１天，小于１天及无强余震等３种情况进行划分之后，给出了两类序列的强余震持续时间与序列和第一震震级的粗略相关关系。     

1995年度中国大陆及边邻MS≥7.0地震活动与华北地区的试验预报纪实之三

如实记述了１９９５年度中国大陆及边邻ＭＳ≥７．０地震活动的时、空演变与华北（φＮ３０°～φＮ４２°，λＥ１０５°～λＥ１２５°）地震活动等有关的试验预报的实况。对过去的预报办法提出了一些改进意见。     

静海地震台地磁短周期变化及其在地震短临预报中的应用

近年来的一些研究表明，由于地震前孕震区地下介质的电性结构的变化，将导致地磁短周期转换函数发生异常变化。通过对地震前后的地磁短周期转换函数的参数的计算、分析和研究，有可能提取出可靠的地震短临前兆异常（曾小苹等，１９９０）。为了进一步开展对该方法研究工作并使其在我区地震预测预报研究中得到应用，我们使用了静海台的地磁记录资料，分析计算了该台地磁短周期转换函数在地震前后的变化情况，确立了该方法应用天津地区地震预报的短临异常特征及指标，取得了较好的效果。     

图像配准和融合及其在医学影像中的应用

图像配准和融合是图像分析和处理的基本问题，在医学影像、遥感、计算机视觉等领域有着广泛的应用。本文研究它们在多模态医学影像技术中的应用。本文提出并实现了基于Ｆｏｕｒｉｅｒ变换的图像配准和基于子波变换的图像融合方法，在图像融合中，我们采用特征选择的取大原则，这种准则更适合于来自不同图像中的明显特征     

山谷冰川稳定态时积累区面积比率研究

探讨山谷冰川稳定状态时积累区面积比率，即ＡＡＲ值的大小，认为冰川物质平衡高程分布，平面形态及坡面坡度沿程变化形式是影响山谷冰川稳定态ＡＡＲ值的主要因素，并 山谷冰川稳定态ＡＡＲ值与物质平衡高程分布及平面形态之间的定量关系。山谷冰川适合于应用ＡＲ值法来研究古冰川的零平衡线高程。     

从天山乌鲁木齐河源1号冰川变化估计近百年来该地区夏季升温

通过冰川波动历史来揭示气候变化是一种重要的方法。然而，以往有关这一方面的研究大都是一些定性的。文章试图依据冰种变化来定量的研究气候变化，并且通过近百年来天山乌鲁木齐河源１号冰川的变化，揭示出本世纪以来该河源地区夏季气温上升约０．２３￣０．２５℃，同时，对于该冰川不同长度规模时的气候敏感性也进行了讨论。