粘土矿物及钻井液电动电位变化规律研究

分析了导致粘土矿物膨胀分散的原因．研究了粘土矿物的电动电位(ζ电位)变化规律；提出了粘土矿物及钻井液电性的转变方法。即有机正电处理剂法、有机正电MMH处理剂法、电解质处理法、非离子型聚合物处理法、调整pH值法等。引起粘土矿物膨胀、分散的因素较多．除取决于组成粘土矿物组分和结构外，还与颗粒表面交换阳离子成分、分散介质性质等有关；粘土矿物的分散、膨胀、收缩、坍塌、渗透等特性均与C电位的大小有密切关系．因此．可用C电位的大小来判断粘土矿物的膨胀、分散性能及钻井液的抑制性能等。只要钻井液的ζ正电位高，对粘土矿物的抑制能力就强．就能达到稳定井眼、提高钻井速度、保护油气层、减少环境污染的目的。研究结果表明，无机盐具有压缩双电层的作用．交换阳离子价越高，水化膜越薄，ζ负电位越小．抑制性增强。反之。交换离子价越低，水化膜越厚，ζ负电位越高，分散性增强；阳离子处理剂具有提高钻井液ζ正电位的作用，能使粘土-水分散体系的电性发生反转；正电胶既可使粘土颗粒电性由负向正转化．又保持粘土-水分散体系的稳定性。通过对膨胀渗透理论与双电位理论研究，认为二者是统一的。     

井-地电位成像技术研究剩余油分布

井—地电位测量是在地表向注水井中套管施加一个大电流，通过测量地表加注高矿化度的导电流体前后的电位分布，经数据处理及反演计算，求出注水各小层的电阻率分布，进而计算出各小层的剩余油饱和度分布状况，指出油藏的挖潜方向。从临17—22井区应用情况来看，与生产动态符合较好。     

Adsorption des acides humiques sur charbon active en poudre. Influence du triphosphate de sodiumAdsorption of humic acids onto powdered activated carbon. The influence of sodium triphosphate

The use of activated carbon beds for the removal of natural humic and fulvic substances found in water supplies, has recently received considerable attention in water treatment operation (Lee et al., 1980; Le Cloirec et al., 1983). Moreover, the use of carbon adsorption for the reduction of haloform precursors (Anderson et al., 1981) and trihalomethanes produced by chlorination process, has contributed to a comprehensive investigation of adsorption characteristics of natural organic compounds (McCreary and Snoeyink, 1981). Many recent works showed the influence of adsorption system characteristics, such as pH, salt type, salt concentration and ionic heterogeneity in multicomponent adsorption systems, on the removal efficiency of humic and fulvic substances by activated carbon (McCreary and Snoeyink, 1980; Randtke and Jepsen, 1982; Weber et al., 1983). The purpose of this study is to examine the effect of a main component of domestic detergents, sodium triphosphate (STP), on the adsorptive capacities of powdered activated carbon (PAC) for commercially supplied humic acids, at different pH values in distilled water. Also, the effect of STP concentration and pH on the adsorption affinity of the PAC for humic acids, is discussed in relation with electrokinetic properties of carbon particles (zeta potential measurements).A first batch equilibrium study (Figs 1 and 2), showed an effective enhancement of adsorption capacity for humic acids as a function of STP concentration, in a non buffered media (pH of distilled water, close to 5.0). For example, visible absorption analysis of humic acids indicates an increase of 93% (500 mg l^?1 PAC) and 133% (1000 mg l^?1 PAC) in the carbon adsorption efficiency for a STP concentration from 0.2 to 1.0mM. A second batch equilibrium study (Figs 3 and 4) led to adsorption isotherms for humic acids in distilled water, as a function of STP concentration and initial pH value of the non buffered multicomponent system. Freundlich isotherms showed an increase in the adsorption capacity of the PAC for humic acids, with a decrease in pH and an increase in STP concentration. However, the adsorption capacity for humic acids is quite reduced at high pH values in presence of STP, in comparison with results obtained with distilled water.Electrokinetic measurements on PAC suspensions (Fig. 5) indicates that both humic acids and STP induce a negative variation of the zeta potential of carbon particles. In such a binary system, the zeta potential is a linear function of the pH; the negative surface charge of the carbon increasing with an elevation of pH (Fig. 6). Therefore, it appears that some adsorption of triphosphate polyanion from solution could occur, contributing then to the apparent negative surface charge of PAC particles.It has been previously showed that the type of anion in sodium salts, had little effect on the enhancement of adsorptive capacities of activated carbon for humic substances (Lafrance and Mazet, 1985), due to Na⁺ ions. However, adsorption of TP anions on the carbon surface may produce a source of repulsive charges, unfavourable to the co-adsorption of humic acids as the pH of the binary system reach more basic conditions. The influence of possible electrostatic interactions between adsorbates at the carbon surface, on the adsorption efficiency for humic acids, could then be studied by zeta potential measurements of PAC particles during the adsorption process.     

宁夏灌区节水潜力的研究

通过广义水资源配置模型和平原区水循环模型的有机耦合，分析了宁夏的真实节水潜力——耗水节约量，并建立了宁夏平原区取用水节水与耗水节水二者之间的定量化关系。结果表明，宁夏耗水节水潜力远远小于取用水节水潜力。在宁夏平原区，随着水利用系数的提高，农业取用水量和耗水量不断减少，且减少幅度越来越小。随着水的利用系数的提高，农业取用水节水量和耗水量不断提高，且取用水节水量和耗水节水量的增加幅度越来越小。随着取用水量的减少，耗水量也逐渐减少，但减少幅度越来越小。当取用水达到极值点时，取用水量等于耗水量。随着取用水节水量的提高，耗水节水量也逐渐增加，但增加幅度越来越小，最后趋近于零。     

The intervalley X6→Γ6, L6 scattering time in GaAs measured by ultrafast pump-probe infrared absorption spectroscopy

A direct measurement of the dynamics of electrons in the X₆ valley for a GaAs crystal by time-resolved absorption spectroscopy is reported for the first time. IR picosecond probe pulses were used to monitor the growth and decay of the population in the X₆ valley subsequent to excitation by a 527 nm pump pulse. The intervalley X₆→Γ₆, L₆ scattering time t_x of 0.70 ± 0.50 ps is determined and the crossection for the X₆→X₇ transition is estimated to be 1.8 × 10⁻¹⁶ cm².     

Evaluation of different coating systems by electrochemical methods

Corrosion protection of organic coated steel is determined by free corrosion potential measurements and impedance spectroscopy. The results are classified by means of very basic considerations and evaluation figures are developed. These electrochemical data are correlated with the extent of the corrosion for each coating system. The evaluation figures are used for ranking coating systems and this ranking is correlated with the ranking with reference to the results of standardized and exposure tests.     

基于人工势场方法的WSN传感覆盖率提高算法

感覆盖率是WSN系统中重要的性能指标之一。Sink节点的移动性能提高系统的传感覆盖率,人工势场能描述普通节点与Sink节点之间的关系。提出了一种利用人工势场方法有效的Sink节点移动控制策略,通过Sink节点的移动能够提高系统的传感覆盖率。普通节点搜集的数据能通过多跳的方式传送给Sink节点。在最初的随机部署之后,由人工势场产生的力迫使移动Sink节点移动到整个环境中的平衡点以获得更高的传感覆盖率。在整个算法执行过程中无需事先了解环境的情况,此方法能在实时的环境中采用。给出了具体的算法步骤,最后利用一个仿真实例对控制效果进行了说明。     

裂纹对石墨烯拉伸力学性能影响的数值仿真

为研究裂纹对石墨烯力学性能的影响,以锯齿型石墨烯为研究对象,基于分子动力学方法,采用Tersoff势函数分析裂纹长度对石墨烯拉伸力学性能的影响以及含有裂纹的石墨烯在不同应变率下的拉伸变形破坏过程.结果表明,裂纹长度的增加大大减小石墨烯的抗拉强度和抗拉应变,对弹性模量有一定影响;裂纹降低石墨烯的抗拉应变对应变率的敏感性,但对于含有裂纹的石墨烯,仍可以增大加载速率来提高石墨烯的抗拉性能.     

全球水能资源评估模型与方法研究

为在全球范围开展水能资源评估,提高评估与规划的准确性与效率,通过建立水能资源评估的全球尺度参数标准、一般技术流程与方法体系,构建河流水能资源理论蕴藏量、技术可开发量评估和电站开发经济性测算模型,提出一套适用于内业工作的数字化评估方法与流程。以非洲刚果河流域为例,应用水能评估模型与数字化方法,实证评估了刚果河流域及干流的水能资源的理论蕴藏量、干流下游河段的技术可开发量,完成了刚果河下游水电基地开发成本测算。     

基于2,4-二羟基苯甲酸铜(Ⅱ)为载体的硫氰酸根电极的电位响应

制备了基于一种简单的金属铜配合物2,4-二羟基苯甲酸铜(Ⅱ)(Cu(Ⅱ)DHBA)为载体的PVC膜硫氰酸根离子(SCN-)选择性电极。该电极在1.0×10-1～1.0×10-6mol/LSCN-浓度范围内呈现斜率为-59.5mV/dec的近Nernst电位响应,检测下限为9.1×10-7mol/L。利用紫外可见光谱及交流阻抗技术初步探讨了电极对SCN-呈现的选择性电位响应机理。该电极作为直接电位分析法的指示电极,成功运用于实验室废水中硫氰酸盐含量的测定。