多次覆盖的深地震反射剖面炮集产生的单边折射数据的模拟与反演：推导浅层速度结构的方法

地壳尺度多次覆盖的近垂直深地震反射剖面产生大量的单边炮集,因浅层折射波的交互覆盖而产生众多的数据集。我们介绍一种推导浅层速度结构的方法,该方法是通过模拟和反演单边地震折射初至走时数据来实现的。我们将该方法应用于在印度地盾西北新元古代马尔瓦尔盆地进行的炮检距为100m、长12km的剖面上获得的数据集。该方法表明,在描述浅层折射层深度、陡的倾角和速度方面是成功的,即使缺少常规的相遇折射剖面也如此。研究揭示出马尔瓦尔盆地的2层沉积建造、默拉尼火山岩和复杂基底地形,并测量出了所估算模型参数的分辨率和不确定性。发现近道选排的地震截面图在性质上与导出的盆地结构特征相一致。在布格重力剖面上观测到的相对高和低的异常进一步证实了导出的这一速度模型。本文提出的方法对那些只能获得单边、多次覆盖的地震剖面数据集的近海等地区是非常有用的。     

Macro-and Micro-Structures of Heavy Fogs and Visibility in the Dayaoshan Expressway

Belonging to the southern subtropical moist type of monsoon climate,the Nanling mountainous area experiences heavy fogs whenever quasi-stationary fronts appear there from September to May.There can be as many as 15-18 days of heavy fogs per month.Fogs have more serious consequences in the Lechang-Ruyuan section of the Beijing-Zhuhai Expressway(the longest expressway in China)that passes through the main part of the Nanling Mts.,where the road rises from 200m to more than 800m above sea level(ASL).For a major motorway in the mountainous areas of Nanling Mts.,two multidisciplinary integrated field observations were carried out,which measured visibility by the naked eyes,visibility by instrument,spectrum of fog- drops,liquid water content(LWC)of fog,tethered sounding,dual-parameter low-level sounding,turbulence diffusion within fog layers,aerosol spectra of size and composition,sampled fog water compositions,and sampled rainwater compositions.Typical cases were probed for their analyses of synoptics,micro- and macro-structures and microphysics.It is understood that heavy fogs take place with high frequency in the area and bring about serious consequences.Being typical advection and upslope fogs,they are in essence low-lying clouds appearing at high altitudes,which are closely related with the activity of South China frontal processes,especially the South China quasi-stationary fronts,and reflect on the role of local terrain as well.The heavy fogs are characteristic of long duration,extremely low visibility,well-organized lump- shaped structure,large-size fog-drops,moderate concentration,high LWC,and stronger turbulent diffusion within the fog layers than in fine sky.They differ much from radiation fogs,which are better documented in previous study in China.It is found that fog LWC is in significant anti-correlation with visibility so that large LWC is associated with small visual range.It is also noted that one of the reasons for the fluctuation of characteristic quantities of micro-structure such as the LWC of fog in the area is,in addition to the inhomogeneous structure of the fog itself,the effect of advection and inhomogeneous underlying surface; during the translation of fog with the ambient wind,irregular upslope and cross-over movement is another reason for the inhomogeneous structure and fluctuation of fog.The spectrum of the aerosol size displays itself as the power function of monotonous descent.The concentration of submicrometer particles is even higher.The high-concentration sulfate particles found in the aerosols of Nanling Mts.are actually good nuclei for condensation,which are favorable for the formation of fog.The presence of fog can help cleanse the trace compositions in the atmosphere so that fog droplets contain high levels of polluting elements.In the meantime,compared to cloud droplets,fog droplets are easier to be captured by the vertical surfaces of objects on the land surface,such as vegetation and buildings to constitute another kird of cleansing process. In vast stretches of forest like the Nanling Mts.,this kind of cleansing may be quite important.Studying the characteristic variation of fogs in the area realistically assists in setting up a forecast and warning system for local fogs and provides basic information for fog dispersal experiments.     

吉林陨石中的氨基酸

Amino acids have been separated from and identified in the Jilin meteorite No.Ⅰ and Ⅱ by gas-liquid chromatography. Eight kinds of amino acid, i.e., α-alanine,valine, glycine, isoleucine, β-alanine, leucine, proline, and threonine are observed in meteorite No. Ⅰ Ten varieties of amino acids including serine, hydroproline, lysine and etc. are noticed from meteorite No. Ⅱ. A brief diseussion is given to the origin of these acids.     

以林带为例说明统计方法在分析自然界相互关系的应用

大家知道,自1949年到1952年曾规模宏大地进行了营造农田防护林的工作。这些工作的结果远不是到处都是成功的。但是如果对这一时期的工作进行缜密的研究并对于将来作出推断,那么,不论是成功的或失败的经验都将是有用的。但直到现在为止,这样的研究工作还没有足够的规模来进行。那些取决於林带的配置和栽植方法,特别是取决     

以林带为例说明统计方法在分析自然界相互关系的应用

大家知道,自1949年到1952年曾规模宏大地进行了营造农田防护林的工作。这些工作的结果远不是到处都是成功的。但是如果对这一时期的工作进行缜密的研究并对于将来作出推断,那么,不论是成功的或失败的经验都将是有用的。但直到现在为止,这样的研究工作还没有足够的规模来进行。那些取决於林带的配置和栽植方法,特别是取决     

700毫巴西太平洋环流分型与台风路径的关系

付热带高压在西太平洋洋面上的强度变化及所在地理位置的不同,对台风路径有着直接的影响。然而,付高强度除自身有周期性变化之外,西风槽的强弱对付高脊西缘的进退也有一定的影响。因此本文试图从台风中心经过第二警戒线(以下简称“警二”)的当天700毫巴图上的付高状态及其地理位置的不同进行分类型,然后用700毫巴西风槽的位置,强度,500毫     

芙蓉洞洞穴演化形成所需历史时间估算方法及其地质意义

对芙蓉洞与芙蓉江古水面高程差进行了测量，引用洞穴古老次生化学沉积物同位素地质年代资料，通过和邻区地壳相对抬升速率对比，估算出芙蓉洞洞穴演化形成所需的历史时间约为12～18万a。相对于芙蓉洞古老次生化学沉积物同位素地质年龄（16万a）来说，洞穴演化形成是一个不可忽视的过程，进一步证明了两个清晰的洞穴发育阶段的存在。对于用洞穴古老次生化学沉积物同位素地质年龄代替洞穴发育整个历史过程是需要谨慎的。通过估算方法反演所揭示的该区地壳相对抬升速率与青藏高原相对抬升速率相比，进一步证实了扬子地台和青藏高原虽然具有相同的驱动机制，但扬子地台近代隆升速率远远低于青藏高原的隆升速度。同时，笔者还对扬子地台的隆升趋势作了一定的分析，认为近代扬子地台边缘隆升速度小，中间隆升速度稍大。     

藏北高原草甸下垫面近地层能量输送及微气象特征

利用GAME/Tibet 1998年IOP观测资料,分析研究藏北高原草甸下垫面近地层的地面加热场、地表能量平衡、地面阻曳系数CD及感热通量整体输送系数CH等特征,得到了一些有关藏北高原草甸下垫面近地层能量输送及微气象特征结构的新认识.     

断裂组合自相似性探讨

笔者在新疆东部、甘肃北山等地的研究工作中,发现该区有序地分布着不同等级和不同序次的同种断裂组合,它们不仅在几何形态和动力学特征上相似,而且在力学演化上有密切联系,在空间上构成一级套一级的有序排列.低等级或低序次断裂组合,作为高等级或高序次断裂组合的组成部分,与其整体(高等级或高序次断裂组合)具有相似性,即自相似性.本文以V型构造和工字型构造为例,对自相似断裂组合的几何特征、形成机制和变异性等作了初步探讨.     

南京栖霞山铅锌矿床流体包裹体研究

南京栖霞山铅锌矿床成矿流体为低温、低压、低盐度、低密度、偏酸性和弱还原性的仙质,成因以原生水（大气降水）为主,系陆相循环热水,由贫硫富金属的深循环水和富硫贫金属的浅循环水混合而成,从而导致了工业矿体的形成。多个成矿通道形成多个成矿中心。