陕西白河县月儿潭绿松石与次生磷钙铝矾研究

对陕西省白河县月儿潭风化严重的绿松石样品进行了岩石薄片观察、化学成分测试、X射线粉晶衍射和红外吸收光谱分析等研究.结果表明,绿松石风化分解由天蓝色退色成黄绿色,最后变成白色,结构也由致密细腻变得松散多孔,主要原因是发生了硫酸根对磷酸根的交代作用,最终的交代产物主要是磷钙铝矾.     

GPS变形监测平差计算及不确定度分析

全球定位系统（GPS）是一种全天候、高精度的连续定位系统,它以速度快、方法灵活多样、操作简便等优势被广泛应用于工程测量和变形监测中。结合水厂铁矿GPS边坡变形监测实例,对GPS监测网的星历预报、基线向量平差计算、网平差计算、结果及残差不确定度进行了细致分析研究,以验证GPS技术在边坡变形监测中的可靠性和精度。     

岩石破坏前后曲线分类及脆-延转换围压研究——蚀变岩常规三轴压缩试验Ⅰ

蚀变岩是工程中少见的软弱岩类,在西南某重大水电工程中,蚀变岩处于工程的重要部位,为保证工程的长期稳定性,对蚀变岩力学特性进行了深入全面的试验研究.通过对孔隙度不同的饱水蚀变岩进行系统的常规三轴压缩试验和总结分析,提出了蚀变岩三轴压缩下破坏前应力.应变曲线可分为3大类,破坏后应力-应变曲线亦可分为3大类的形态模式.并得出结论:蚀变岩的破坏类型受围压与孔隙度的共同影响,在给定的12 MPa围压下蚀变岩以脆性破坏为主,只有孔隙度大于16%且围压大于4 MPa时才有可能进入脆-延转换状态,且脆-延转换围压随孔隙度增加而降低,临界状态应力比随孔隙度增大而增加.     

Centrifugal test of a road embankment built after new dredger fill on thick marine clay

Abstract

The construction of a 100-km road network is planned on a land reclamation area in the Oujiang Estuary in China. The embankment had a height of 4 m and a base width of 60 m. The reclamation area is newly filled by a 3-m dredger fill on a 48-m thick layer of marine clay. Estimation of the settlement of the future road network is difficult. To guide the construction of the road network, a 1/100-scale centrifuge model test was performed with a marine clay sample from the construction site to simulate the layered settlements and evaluate the drainage effect of prefabricated vertical drains in the dredger fill in the following 10 years. The results of the centrifuge modeling test are verified by 10-month in situ monitoring, which shows agreement between the centrifuge modeling test results and the in situ results. The test results indicate that additional time is needed to reinforce the newly added dredger fill by the surcharge preloading method to uplift the elevation of the reclamation area with dredger fill.     

Application of LICOM to the numerical study of the water exchangebetween the South China Sea and its adjacent oceans

1 IntroductionThe South China Sea (SCS) is the largestmarginal sea in the western Pacific (see Fig. 1). It con-nects with the SCS through the Taiwan Strait, with thePacific through the Luzon Strait, with the Sulu Seathrough the Mindoro and Balabac Straits and with theJava Sea and Andaman Sea through the Sunda Shelf(For convenience, here we refer to the section at 1.5°N,Fig. 2). It is shown that the seasonal SCS circulation ismostly affected by the summer/winter monsoon, andthe no…     

REPRODUCTIVE BEHAVIOUR AND EARLY EMBRYONIC DEVELOPMENT OF Trachypleus tridentatus

This paper reports the season, environmental conditions and pattern of spawning, fecundity and hatching amount of king crab, Trachypleus tridentatus. The egg-diameter of this animal has seasonal variations, which is different from that reported in foreign countries. The egg cleavage of the animal is in the transitional pattern from holoblastic cleavage to surface division. Egg cleavage occurs firstly on one pole with false cleavage furrows, the number of division nucleus increases continuously which move outward from the yolks to form into a layer of blastomere on the surface of the blast together with some of egg plasma. The blastomere formed into the blastoderm and the polygonal cells encircled in this cell layer is equal to the "yolk cells" of insects during the period of egg cleavage. The formation of the periblas-tula is the result of egg cleavage. This paper makes application of the technique of vital staining in exploring the properties of the stained particles. The death of the blasts after stai     

Action of Cnoidal Waves on Vertical Walls

Based on the 2nd order cnoidal wave theory, the characters of shallow water standing waves and their action on vertical walls are studied in this paper. The theoretical expressions of the wave surface elevation in front of and the wave pressure on the vertical wall are obtained. In order to verify the theoretical results, model tests were made in the State Key Laboratory of Coastal and Offshore Engineering at DUT. For the wave surface elevation in front of the wall and the wave forces on the wall at the moment when the wave surface at the wall surface goes down to the bottom of the wave trough, the calculated results coincide quite well with the experimental results. For the wave forces on the wall at the moment when the wave surface at the wall surface goes up to the top of the wave crest, the theoretical expressions are modified by the experimental results. For the convenience of practical use, calculations are made for the wave conditions which usually occur in enginering practice by use of the inves     

冬季中纬度海气相互作用与长江中下游汛期旱涝预测

中纬度海洋的热力状况对大气环流的维持和变化起着重要的作用,尤其在冬季。汛期的研究表明,冬季黑潮海域海表面水温(SST)与长江中下游和华北平原汛期降水有密切的关系(中国科学院大气物理研究所长期预报组,1978),夏季阿留申海域的SST异常与北太平洋上空大气环流场和后期秋季美国的气温和降水亦存在有意义的关系(Namias,1976)。赵永平(1986a;赵永平, McBean,1996)和Zhao and McBean(1989)曾用北太平洋海洋对大气加热场资料详细地分析了其时空分布特征,揭露了黑潮及邻近海域海洋异常加热对同期和后期半年至一年北半球大气环流的影响事实,并提出用海洋异常加热对同期和后期大气环流作用的反相性假说来进行解释。以上研究表明,冬季中纬度海洋异常加热与大气环流的异常和我国汛期旱涝之间存在一定的联系。 冬季黑潮和湾流海域是中纬度海洋的两个巨大热源,它们对同期和后期大气环流有重要影响。本文研究了冬季中纬度黑潮和湾流海域海洋异常加热对夏季副热带高压和中高纬度西风环流的影响,讨论了长江中下游汛期旱涝前期冬季和同期大气环流型。结果表明,冬季东亚和北美冷空气都强时,黑潮和湾流海域对大气异常多加热,夏季西太副热带高压、乌山和鄂海阻塞高压多趋减弱,中纬环流平直,形成长江中下游偏旱的环流形势；反之,西太副热带高压、乌山和鄂海阻塞高压多趋加强,中纬槽脊系统明显,形成长江中下游偏涝的环流场。本文还对可能的物理过程进行了讨论。     

On low-pass digital filters in oceanography

-Two types of filters are widely used to remove semidirunal and diurnal tidal signals and other high frequency noises in oceanography. The first type of filters uses moving average with weights in time domain, and can be easily operated. Some data will be lost at each end of the time series, especially for the low low-pass filters. The second type of filters uses the discrete Fourier transform filter (DFTF) which operates in the frequency domain, and there are no data loss at the ends for the forward transform. However, owing to the Gibbs phenomenon and the discrete sampling (Nyquist effect) , ringing appears in the inverse transformed data, which is especially serious at each end. Thus some data at the ends are also discarded. The present study tries to find out what causes the ringing and then to seek for methods to overcome the ringing. We have found that there are two kinds of ringings, one is the Gibbs phenomenon, as defined before. The other is the "Nyquist"ringing due to sampling Nyquist critical     

筒型基础沉贯阻力估算方法

系统地总结国外有代表性工程实践对筒型基础沉贯阻力的研究 ,并将各种方法综合起来 ,提出了加权综合估算法 ,供今后的研究和工程实践参考