多元传质传能的基础和应用研究进展(Ⅳ)

<正> 许多研究者试图将多元系模型化为假二元系。这种“强迫拟合”的方法有两种:①使用“修正的”推动力;②定义各种各样的“有效”扩散系数。 Toor曾试图通过定义一种“普遍化”的推动力来近似描述三元气相扩散。他得出的近似关系(表示对Maxwell-Stefan方程     

保持鲜活生命力 促进文化落地生根

历经九载,“心相通、情相融、力相合”的“三相”企业文化,已经在大庆炼化“四大基地”建设中发挥重要作用。要保持“三相”文化的鲜活生命力,发挥持久推动力,必须促进企业文化向更深层次发展,促进企业文化落地生根。     

间歇搅拌槽中柠檬酸水溶液吸附传质动力学

柠檬酸水溶液在吸附树脂颗粒中的扩散机理与吸附树脂颗粒表面结构、微孔大小和表面能分布有关,特别是当液相浓度较高时,传质受固相内的扩散速率控制.本文采用Glueckauf和Hill建议的线性推动力近似模型和修正线性推动力近似模型,在液相浓度较高、相平衡关系呈非线性时,得到吸附和解吸阶段模型的解析解和曲线图.     

旋转窑中辐射热交换计算方法

本文根据串联和并联“热流阻力”的概念,提出了综合解决窑炉传热问题的“热流线路分析法”,并分别解决了旋窑中各项主要“热阻力”的计算公式。本文中建议把△（T~n）作为辐射传热的推动力。在讨论衬砖周期蓄热过程中,指出了适用於温度及热流的平均值的“阻抗”公式,与适用於“方均根值”的交流阻抗公式不同,并提供了一个有理论根据的近似公式。对物料粒子间的传热机理亦作了初步分析。     

粉煤气化“双高”原料气耐硫变换新工艺开发成功

为了更好地解决粉煤航天炉HT—L气化、西门子GSP气化等粉煤气化中出现的“双高”（即高浓度CO和高水气比含量）原料气变换反应推动力大、易发生甲烷化副反应、催化剂床层易超温等难题,青岛联信催化材料有限公司与河南晋开化工投资控股集团有限公司、安徽临泉化工股份有限公司近期成功开发了粉煤气化“双高”原料气耐硫变换新工艺。     

科技进步是企业发展的动力

1 前言 “科学技术是第一生产力”,经济建设必须依靠科学技术,科学技术必须面向经济建设。经济发展要以科技进步为主要推动力,科学技术发展要围绕经济发展目标,为经济发展提供强有力的支撑和保证。     

航空结构件用玻璃纤维织物的研究

航空结构件用玻璃纤维织物的研究南京玻璃纤维研究设计院赵谦１前言航空和航天工业始终是先进材料发展的巨大推动力之一。“减轻重量”和“降低成本”是航空航天材料的关键问题。复合材料由于其高的比强度和比刚度，因而在减轻重量方面具有巨大的潜力。碳纤维和ＫＥＶＬＡ...     

外场作用下多组分质量传递Maxwell-Stefan方程及其应用：电场作用下球形颗粒中的扩散

Fick扩散定律只能用于没有外场作用下的二组分扩散过程,Maxwell-Stefan（MS）方程适用于外场作用下多组分系统中的质量传递过程。阐述了MS方程的物理意义,并由此将外场作用下普遍化MS方程的表达式改写为清晰且易于使用的形式。给出了在MS方程中常用的外场作用力的数学形式。Fick扩散定律是MS方程在没有外场作用下对二元理想流体扩散的应用;MS方程对离心分离和电解质扩散等过程的描述比传统的描述方法更全面。利用MS方程导出了欧姆定律,利用该结论可以通过测量电导率计算带电粒子的扩散系数。利用MS方程研究了电场作用下球形颗粒中的扩散过程,结果表明,该方程可以对电场强化质量传递过程给出有效描述。MS方程为外场作用下的质量传递过程提供了一种有效的理论研究方法。     

贮油罐群计算机综合监测系统

从ＰＣ微机、ＳＴＤ－ＢＵＳ到罐区传感器及外场线路几方面较为详尽地介绍了贮油罐群有关参数的检测，处理等计算机自动综合监测系统技术情况。     

铬酸铅沉淀反应在凝胶中的扩散特征研究

凝胶中铬酸铅沉淀反应形成的沉淀图形，是电解质双方相对扩散的共同贡献，双方的起始扩散浓度差是主要因素；环状图形是在沉淀反应发生后沉淀微粒重新汇聚的结果，只有新生成的微粒才能发生汇聚过程。沉淀增长的推动力是参加沉淀反应后“剩余部分”电解质的继续扩散作用。在温度和凝胶介质一定时，沉淀的增长速率与电解质浓度、扩散系数及沉淀物质的溶度积常数有关。提出沉淀增长的理想模型，推导出与沉淀增长相关参数之间的关系式，并对实验现象进行了解释，得到比较满意的结果。     

A Simple Analytic Formula for the Number of Theoretical Plates in Distillation

Abstract

The Lewis equation for the number of theoretical plates in a distillation column has been simplified. The simplification is not at the expense of accuracy. On the contrary, it is shown that the simple equation leads almost exclusively to more accurate results.     

江西省永修县土地生产潜力初探

对永修县土地生产潜力的估算方法进行了阐述，并估算了永修县土地的光合生产潜力、光温生产潜力、气候生产潜力、土地生产潜力及社会生产潜力。和现实生产力进行了比较和分析，提出了一些提高土地生产力的主要途径。     

流动电位法测定中空纤维膜表面的ζ电位

根据流动电位与表面ζ电位的关系,研制了一套中空纤维膜表面ζ电位的测定装置,对NaCl、KCl、CaCl2三种电解质溶液中聚丙烯膜的流动电位进行了研究。结果表明,在中性条件下,膜表面带负电;膜丝间毛细孔径和试验操作方法对ζ电位有影响,毛细孔径越大,ζ电位的绝对值越小,降压法得到的ζ电位值大于快速升压法。ζ电位的大小与电解质溶液的浓度和种类有关,阳离子价态对ζ电位影响很大。     

粉煤灰混凝土的势能化

根据势能的观点和混凝土工程性质的要求，给出混凝土中粉煤灰经化势，固化势和免疫势的定义，以及粉煤灰砂浆体或粉煤灰混凝土材料的协同工作特性的数学表达；通过图解的方法，对粉煤灰材料的质量等级以及粉煤灰混凝土双掺技术的应用进行了势能化的初步探讨。     

Test for Estimation of Relative Stability of Suspensions by Measure of ζ‐Potential

It was found that the variation in ζ‐potential with dilution for different formulations of a suspension of a commercial yellow pigment stabilized by means of block copolymers was smaller for the formulation exhibiting longer‐term stability. Measures of the ζ‐potential of various dilutions of a sample can be performed within a day, allowing faster identification of formulations with better stability than temperature cycle tests. A ζ‐potential variation factor can be defined and may be used as a quantitative stability parameter for experimental designs. A limit in the applicability of the test is the minimum dilution required for reliable signal in the analyzer (based on light scattering and affected by opacity of the sample). The principle of the technique is based on the fact that the concentration of copolymer complexes affects its dispersing properties, and therefore the dilution shows which formulation is the more stable.     

对电位-pH曲线测定实验装置的改进

电位-pH曲线测定实验是物理化学实验的重要内容。针对多数物理化学实验教材使用很多的仪器的现象,我们改进了测定电位-pH曲线的实验装置。该实验装置的显著特点是操作简单,减轻了学生做实验时候的压力。利用该装置进行了多次实验,结果发现数据重复性好,师生评价极好。因此,利用此装置有效地提高了物理化学实验教学的效果。     

Corrosion behaviour of some stainless steels in chlorinated Gulf seawater

The corrosion resistance of conventional and high alloy stainless steels (specifically 316L, 317L, 904L, duplex 2205, 3127hMO, 1925hMO, 254SMO, 654SMO and Remanit-4565) was determined electrochemically in chlorinated and unchlorinated Arabian Gulf Seawater at 25 and 50 °C. The stainless steels 316L and 317L were used as reference alloys. The electrochemical potentiodynamic cyclic polarization method was used to determine the passive film break down potential (E _b), protection potential (E _prot) and maximum current attained on scan reversal (I _max). It was found that at 25 °C in chlorinated and unchlorinated seawater and at 50 °C in unchlorinated seawater, stainless steels 316L and 317L have poor resistance to corrosion, Stainless steels 904L and duplex 2205 at 25 °C in chlorinated and unchlorinated seawater showed good resistance to corrosion but at 50 °C these steels failed to resist. The high alloy stainless steels such as 3127hMO, 1925hMO, 254SMO, 654SMO and Remanit-4565 showed better corrosion resistance under all the test conditions.     

Controlling charge-transfer processes at semiconductor/liquid junctions

The interfacial kinetics of charge transfer at n-GaAs/liquid junctions were controlled by anchoring positively charged species, such as tetra(-4-pyridyl)porphyrinatomanganese(III), with the semiconductor surface. Unlike earlier adsorption techniques, the charges have been chemically anchored to the semiconductor surface, in this work, via a ligand. The number of charges per site (attached molecule) ranged from +1 to +5. The positive charges shifted the band-edges towards more positive potential values. The degree of shift increased with surface charge density. In the dark, the flat band potential (measured by Mott–Schottky technique) and the onset potential were shifted by up to 300 mV depending on surface charge density. Relatively less of a shift was observed during illumination of the system. Other surface characteristics, such as conversion efficiency and photoluminescence intensity, have been enhanced. The basis for these shifts and their implications with respect to control of interfacial processes are discussed.     

Removal of disinfection by-products precursors by polyaluminum chloride coagulation coupled with chlorination

The effect of coagulation coupled with chlorination (i.e., pre-, inter-, and post-chlorination) on the formation of disinfection by-products (DBPs) and the removal efficiency of DBPs precursors were investigated. Compared with coagulation coupling with pre-chlorination, coagulation coupled with inter-chlorination could lead a higher removal efficiency of dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA) and chloroacetic acids formation potential (CAAsFP). The CAAsFP/DOC value of residual DOC showed that coagulation with inter-chlorination has a beneficial effect on CAAs precursors removal. More DBPs were produced during inter-chlorination than that of pre-chlorination at pH 7.5, while less DBPs were produced during inter-chlorination than that of pre-chlorination at pH 5.5. In addition, the precipitate of humic acid (HA) after coagulation was chlorinated to study the kinetics of chlorine decay. The results showed that coagulated-HA had a higher reactivity with chlorine than aqueous-HA at pH 7.5. Furthermore, the trends of zeta potential during coagulation process suggested that the distribution of chlorine species had significant influence on the removing of DBPs precursors by coagulation coupled with chlorination.     

滤料表面电动电位的研究

根据流动电位与表面ξ电位的关系研制了一套测定滤料表面ζ电位的装置,经测定计算出了常用六种水处理滤料的表面ζ电位。结果表明:磁铁矿、沸石、石英砂、陶粒砂、核桃壳、无烟煤表面ζ电位分别为-60.85mV、-25.45mV、-24.37 mV、-21.49 mV、-14.24mV、-14.17mV。用红外光谱分析说明了各种滤料表面ζ电位存在差异的原理。