Physical,chemical, and biological conditions associated with the early stages of the Lake Michigan vernal thermal front

An investigation of the thermal front in southeastern Lake Michigan during April 1988 revealed a dynamic physical, chemical, and biological environment. The front was observed approximately 4 km from the coast as a distinct gradient separating cold open-lake waters from warmer nearshore waters. Surface isotherms near the front were generally parallel to one another but skewed with respect to shore. Comparison between April 22 and 29 showed that the surface isothern pattern was modulated by wind stress. The pattern from April 29 showed signs of flow instabilities with horizontal scales of 1 km to 5 km. Surface drifter trajectories provided estimates of horizontal convergence at the fron which varied from 7×10^?6 s^?1 to 20×10^?6 s^?1. Inferred rates of downwelling, which ranged from 9.5 m d^?1 to 20.7 m d^?1, were sufficient to move a water parcel from the surface to the bottom in 2 to 6 d at the front. Convergent circulation was observed on both sampling dates despite contrasts in wind stress. Concentrations of chloride, soluble silica, and chlorophyll, which were always higher inshore, were 5% to 82% larger than offshore mean values. The aquatic environment just inshore of the thermal front was characterized by chlorphyll concentrations which exceeded 5.0 μg 1^?1 while concentrations offshore were between 1.0 μg 1^?1 and 2.0 μg 1^?1. A relatively uniform vertical structure in chlorophyll concentrations in the frontal zone was consistent with the observed convergence and inferred downwelling near the front.     

深井水位降水效率随测层深度的变化规律模拟

统计鲁北平原４井降水效率表明，地质类型相同的深井水位降水效率主要受控于测层埋深；规律性级强，笔者在统计基础上建立了模拟公式，并计算了不同深度测层的降水效率，与实际统计弥合度极好，笔者认为“对类型相同不同深度测层水位降水干扰排除过程中即可利用该式对其效率直接计算，免去了统计，修定的麻烦。     

储层毛细管压力曲线在东海油气储量计算中的应用

本文阐述了利用储层毛细管压力曲线计算含油炮和度的方法,该方法在东海油气储量计算中取得良好的结果。     

硅酸盐类样品中硅、铁、铝、钛、锰、钙、镁、钾、钠和磷的x射线荧光光谱测定

本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。     

Collision and thermal history of Indian-Sundaland-Eurasian plates as implicated by40Ar/39Ar age spectra of granodiorites

⁴⁰Ar/³⁹Ar plateau ages of biotite, plagioclase, K-feldspar and hornblende from the Biluoxueshan and Lincang plutons in the three-river area of Yunnan and the Quxu pluton in the Gandise belt of Xizang indicate that the three plutons were emplaced at 420, 234 and 43.4 Ma, respectively. Based on the study of closure temperatures and thermal histories, it is shown that the Lincang and Biluoxueshan plutons experienced the same thermodynamic event during 85–90 Ma, temporally representing the collision between the Sundaland and Eurasian plates, and that the Quxu pluton was uplifted at a much faster rate during 40–44 Ma(2.6 mm/a), marking the collision between the Indian and Eurasian plates.     

地面中—β尺度强锋区激发的特大暴雨过程分析

受0012号台风（派比安）外围影响，2000年8月30日02时至31日08时，在江苏省东北部发生了一次具有局域性、突发性、高强度、超历史、灾情重等特征的特大暴雨，分析研究发现，在台风外围第二象限，江苏东北部地面存在中-β尺度的能量锋区，此能量锋区是构成产生、维持特大暴雨的中-β尺度的天气系统。利用锋生函数对此能量锋区的发生发展进行诊断，结果表明，锋生函数的变形项起了决定性作用，辐合项也有较明显的贡献，非绝热加热在锋生初期有作用，但对锋区的维持，其贡献并不明显，进一步用二维中尺度方程对锋区进行数值模拟，结果显示，在能量锋附近驱动产生了涡旋，在涡旋上升支，将高能区的暖湿空气向上输送而成云致雨，在涡旋下沉支，通过下沉气流使雨迅速下落，同时拖曳冷空气使地面降温，使得锋区维持和加强，致使雨强增幅，综合分析表明，中-β尺度能量锋区形成以后，通过锋区附近的中-β尺度的辐合线，中低压，中高压以及锋区附近驱动的扰动涡旋等中-β尺度的天气系统间的相互作用，导致了这次江苏省东北部高强度的特大暴雨。     

断层带爆炸裂隙区范围及裂纹扩展长度的研究

常用求算岩石内爆炸裂隙区半径的计算公式中忽略了冲击波的作用、粉碎区的存在以及爆生气体的准静态作用。醉对该公式进行修正后并引和断层带应力波衰减指数α，并对尖力波损伤后的裂隙区的扩展长度进行分析计算，从而得出：考虑“预报伤”作用的爆炸裂纹长度大于不考虑“预损伤”情况下的裂纹长度。     

EVOLUTIONAL CHARACTERISTICS OF HYPER－CONCENTRATED FLOW IN BRAIDED CHANNEL OF THE YELLOW RIVER

ＥＶＯＬＵＴＩＯＮＡＬＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＨＹＰＥＲ－ＣＯＮＣＥＮＴＲＡＴＥＤＦＬＯＷＩＮＢＲＡＩＤＥＤＣＨＡＮＮＥＬＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲ￥ＱＩＰｕ；ＬＩＷｅｎｘｕｅ（Ｓｅｎｉｏｒｅｎｇｉｎｅｅｒ，ＩｎｓｔｉｔｕｔｅｏｆＨｙ...     

1986/1987厄尔尼诺期间的西风强化和海气相互作用过程分析

本文利用欧洲中期数值天气预报中心(ECMWF)西北太平洋上空(25°—35°N,110°—180°)850 hPa客观分析的西风分量,计算了1986/1987厄尔尼诺期间的西风强度.结果表明1986年12月—1987年5月西风的累计强度比1986/1987厄尔尼诺前后诸年份同期的西风更强,这种强化与历次厄尔尼诺期间西北太平洋副热带高压的加强是一致的,都反映了哈德莱环流的强化.为了探讨大气环流发生这种变化的原因,作者利用中美海气观测期间的海洋资料,说明了热带两太平洋东部对低纬度大气异常的加热和西部边界流向中纬度海洋输送热量的减少是两个十分重要的原因.