现场自动过滤萃取采样技术

本文介绍国内、外现场自动过滤萃取采样技术的现状和发展水平、研究内容、研究方法以及目前所进行的研究工作,并对以后的发展趋势进行了预测。     

溶液法制备钻井泥浆用的钠羧甲基淀粉(CMS)的试验研究

淀粉是一种多羟基有机高分子化合物.利用相似相溶原理,以甲醇或乙醇为溶剂,溶解淀粉,制成的钠羧甲基淀粉不溶于乙醇,有利于生成物的分离提纯;同时一氯乙酸在醇溶液中的电离度低,对反应的影响较小,有利于反应的进行.此方法具有合成工艺简单,生产效率高,成本低等特点.     

Chemical Composition and Geologic History of Saline Waters in Aux Vases and Cypress Formations, Illinois Basin

Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/L of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.     

海浪数据高通数字滤波的一种方法

介绍了克服海浪数据低频零飘现象的一种高通数字滤波实用方法,该方法引自参考文献[1]。文章对文献[1]中提出的脉冲响应序列作了切合实际的修改,还对数字滤波器长度提出了一个适合于海浪数据处理的经验公式。近年来几个航次海上波浪测量的实际应用表明,高通数字滤波的效果是令人满意的。     

Coordinated Simultaneous Freja Satellite and Niemegk Observatory ULF Measurements

The standard FFT analysis was applied to thirteen pulsation events selected from the March–April 1993 simultaneous measurements in space (Freja satellite) and on the ground (Niemegk Observatory). The spectral processing of the six-minute sections of record in two coordinate components perpendicular to the magnetic field lines had two principal subjects in view: a) Frequency-amplitude satellite-ground relations. The average values of smoothed spectral amplitude transmission coefficients in the total Pc4-3 and, separately, in Pc4 and Pc3 bands were 0.60, 0.48 and 0.70, respectively. The maximum values were observed within the Pc3 band, near f 30 mHz. b) Estimation of frequency bands of field line resonances (FLRs) recorded on Freja. Freja's motion in a broad latitude range (±5° around Niemegk) during the measurements enabled two frequency bands of FLRs with a width of 10's of mHz to be identified on Freja. The weighted frequencies of the FLRs bands on Freja were f _wA 36 mHz and f _wB 18 mHz with fine structure separations of about 5 mHz and 4 mHz, respectively. The second band with f _wB 18 mHz was mostly not observed at Niemegk, and this could be the consequence of the satellite moving partly through regions of L greater than that of Niemegk.     

Parameter estimation and simulation of dependence of constant pressure batch dewatering on initial solids concentration

The problem of predicting dependence of constant pressure batch dewatering of particulate suspensions on feed solids concentration is considered. Scaling transformations which demonstrate that evolution in the cake consolidation stage of dewatering is governed by an underlying self-similar behavior are proposed. The self-similar master curve, which can be obtained using only one set of experimental dewatering data obtained with a feed suspension having solids concentration above the gel point, is employed for estimating dependence of key dewatering process parameters on feed solids concentration. Using the parameter estimates in a Darcy's law based dewatering model, it is shown that the complete evolution of dewatering for a desired feed solids concentration can be predicted with reasonable accuracy. The approach is simpler to implement in comparison to available pressure filtration models, which require several suspension characterization experiments.     

Assessment of groundwater pollution around Torbali,Izmir, Turkey

The Kuihe River is in Xuzhou, Jiangsu, China. It contains high concentrations of nitrogen. The water in the Kuihe River recharges the groundwater via riverbank filtration (RBF) along the Xucun and Huangqiao reaches, which are characterized by unsaturated and saturated percolations, respectively. The two sections were selected to study the effectiveness of RBF to the nitrogen removal from the infiltrating river water. The results showed that the RBF in the saturated percolation had the potential to remove the nitrogen through biochemical processes. The nitrogen-removal rates were more than 95% over the monitoring period. However, the RBF in the unsaturated percolation resulted mainly from the physical process and thus had no efficacy for nitrogen removal.     

天然河床渗滤水水质特征及净化机理研究

渗滤取水净水机理主要是利用砂砾石层表面的泥膜及砂砾石层本身过滤作用、吸附作用，微生物的降解作用达到去除水中的悬浮物质、降低水的浊度、除菌的效果。通过分析重庆江津白沙渗滤取水工程中渗透水水质表明，河水经过天然河床渗滤处理，其中的悬浮物质几乎可以被完全去除，并有较好的除菌效果。渗透水中NO3^-，COD，BOD，TOC去除率达75％以上。渗透水常量化学组分Na^ ,Cl^-浓度明显降低,Ca^2 ,Mg^2 ，HCO3有少量增加。渗滤水的水质得到大幅提高，不仅达到国家饮用水标准．而且由于水岩相互作用，使渗滤水矿化度也有所增加，产生一定矿化作用。     

高通量深海海水原位采样及分级过滤系统

深海悬浮颗粒物((含浮游微生物)的研究具有重要意义,但深海大洋中多数海域悬浮物的丰度很低,其研究需要较多水样(一次过滤水样超过200L,甚至达到1000L以上),传统方法用采水器采水后甲板过滤费时费力。基于此,本文研制了一种高通量深海海水采样及分级过滤装置,装置包括总成深海泵、过滤装置、数据采集与控制装置,以及支撑架体、供电部件、连接机构和流量计等辅助部件。过滤装置分三级过滤(分别放置0.22、1和5μm孔径的滤膜,并可根据需要更换组合),控制装置采用深度触发和时间触发两种工作模式,并可配套安装CTD、荧光计等海洋环境参数测量设备。针对调查站点,将若干套(如3套)高通量深海海水采样及分级过滤系统分一定间隔悬挂于深海绞车缆线上,可以同步进行相应水层的海水原位过滤,从而形成多水层同步高通量原位多级过滤,以获取浮游微生物等悬浮颗粒物样品。该原位取样系统具有多层同步高通量过滤和分级采样的特点,现已被应用于海洋科考航次中,为深海悬浮颗粒物(含浮游微生物等)的研究提供了一种简约高效的样品获取方法。     

基于离散点绘制等高线算法的研究

等高线图在实际工作中应用非常广泛，在离散点数据的基础上自动生成等高线图有许多算法。本文着重讨论了如何在采集离散点时加入编码的基础上，尽量减少或不进行人工干预，基于有约束的TIN构建方法一次性生成等高线图。实践表明该方法能够明显加快成图速度与提高等高线成图的精度。