Holocene environmental change according to lake core in Fildes Peninsula of King George Island,Antarctica

Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula; 4800-4400 aB. P. , 3600-3350 aB. P. ,2100 - 1800 aB. P. and 900 aB. P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope (δC01213 ) which could be the substitute indicators of environmental temperature.     

冀西安妥岭斑岩型钼矿成矿地质条件浅析

安妥岭钼矿位于燕辽钼（铜）成矿带南端,与附近的野弧斑岩型钼矿等具有相同的地质背景和成矿条件。文章阐述了古结晶基底、中生代岩体以及NNE、NW和近EW向构造与成矿的关系,提出安妥岭钼矿是在斑岩型矿床基础上,叠加了主要沿NW向构造发育的岩浆热液成矿作用所形成的具有复杂成矿系列的非典型斑岩钼矿床。     

黄、东海近海面空气湿度分析及估算

利用1974～1982年黄、东海海洋水文气象标准断面实测资料对近海面空气湿度的分布、变化进行了分析。讨论了冬、夏季海、气温与湿度的关系,并对冬、夏季近海面空气湿度进行了估算。结果表明,夏季,空气湿度为气温的函数;冬季,除了考虑空气本身平流的水汽外,还必须考虑海洋向大气的水汽输送。     

2000年上半年全世界地震灾害综述

２０００年１～６月份全球地震活动水平为中等编高,但地震灾情较轻,半年内共发生Ｍ≥６地震７６次,其中Ｍ≥７地震８次,Ｍ≥８地震１次,全世界地震共计造成１７３人死亡,１０００多人受伤,经济损失约１亿～２亿美元,重大灾害地震主要发生在印度尼西亚。     

井水位地震效应特征研究

震后效应是较普遍和复杂的自然现象,各种物理、化学量的变化动态隐含着丰富的地壳活动的动力学信息,对其研究具有重要的理论和实际意义.本研究以典型观测井的水位震后效应为研究对象,分析震后效应的动态规律及其与构造应力环境的关系.系统的研究结果表明:①同一口井的震后效应方式与地震的强度和位置无关,对于同一口井不同地震引起的效应总是同向的,即总是上升或下降;②对于水位效应较显著震例,水位变化幅值与震级、距离之间具有很好的统计关系;③井点附近发生强震后的若干年内,井水位无后效,也就是说井水位响应灵敏度要受本地的应力状态的影响而随时间发生变化,本地发生中强以上地震后,响应灵敏度会降低;④对某些特定地区或方位的地震,井水位的后效幅值偏小.这些结果说明,井水位的地震后效除了与震级、距离有关外,更重要的是可能与水井所在地区的应力状态及地震波传播途径的地质背景有关.     

仿刺参水溶性海参皂苷的分离制备及抗真菌活性的研究

利用海洋生物资源进行天然抗真菌新药的开发,从冻干海参加工废液中提取了水溶性海参皂苷,并对其抗真菌活性进行了研究。采用大孔吸附树脂法提取水溶性海参皂苷,经Libermann Burchard反应等对提取物的性质进行鉴定后,利用管碟法对所得提取物的抗菌活性进行了测定,并利用琼脂稀释法测定了所得水溶性海参皂苷对6株供试真菌的最低抑菌浓度(MIC)。提取物在Molish反应、沉淀反应和泡沫实验中均为阳性,说明提取物中确含有皂苷类成分;在Libermann Burchard反应中,液体的颜色处在红色与紫色之间,显示提取物可能是1种三萜类皂苷。水溶性海参皂苷对6株供试真菌均具有显著的抑制作用,且在浓度为0.5~4 mg/mL的范围内,其抑菌活性与所用浓度之间呈明显的正相关性;在浓度为4 mg/mL时,水溶性海参皂苷对6株供试真菌抑制活性的大小依次为裂殖酵母菌、啤酒酵母菌、白色念珠菌、葡萄炭疽病原菌、黄瓜枯萎病原菌和黑曲霉,海参皂苷对6株真菌的MIC值依次分别为0.002,0.016,0.063,0.063,0.125,0.250 mg/mL。     

Finite element analysis of steady-state natural convection problems in fluid-saturated porous media heated from below

In this paper, a progressive asymptotic approach procedure is presented for solving the steady-state Horton–Rogers–Lapwood problem in a fluid-saturated porous medium. The Horton–Rogers–Lapwood problem possesses a bifurcation and, therefore, makes the direct use of conventional finite element methods difficult. Even if the Rayleigh number is high enough to drive the occurrence of natural convection in a fluid-saturated porous medium, the conventional methods will often produce a trivial non-convective solution. This difficulty can be overcome using the progressive asymptotic approach procedure associated with the finite element method. The method considers a series of modified Horton–Rogers–Lapwood problems in which gravity is assumed to tilt a small angle away from vertical. The main idea behind the progressive asymptotic approach procedure is that through solving a sequence of such modified problems with decreasing tilt, an accurate non-zero velocity solution to the Horton–Rogers–Lapwood problem can be obtained. This solution provides a very good initial prediction for the solution to the original Horton–Rogers–Lapwood problem so that the non-zero velocity solution can be successfully obtained when the tilted angle is set to zero. Comparison of numerical solutions with analytical ones to a benchmark problem of any rectangular geometry has demonstrated the usefulness of the present progressive asymptotic approach procedure. Finally, the procedure has been used to investigate the effect of basin shapes on natural convection of pore-fluid in a porous medium. © 1997 by John Wiley & Sons, Ltd.     

Amplification of the solar signal in the summer monsoon rainband in China by synergistic actions of different dynamical responses

A rainband meridional shift index (RMSI) is defined and used to statistically prove that the East Asian summer monsoon rainband is usually significantly more northward in the early summer of solar maximum years than that of solar minimum years. By applying continuous wavelet transform, cross wavelet transform, and wavelet coherence, it is found that throughout most of the 20th century, the significant decadal oscillations of sunspot number (SSN) and the RMSI are phase-locked and since the 1960s, the SSN has led the RMSI slightly by approximately 1.4 yr. Wind and Eliassen–Palm (EP) flux analysis shows that the decadal meridional oscillation of the June rainband likely results from both a stronger or earlier onset of the tropical monsoon and poleward shift of the subtropical westerly jet in high-solar months of May and June. The dynamical responses of the lower tropical monsoon and the upper subtropical westerly jet to the 11-yr solar cycle transmit bottom-up and top-down solar signals, respectively, and the synergistic actions between the monsoon and the jet likely amplify the solar signal at the northern boundary of the monsoon to some extent.