共查询到20条相似文献,搜索用时 929 毫秒
1.
2.
3.
4.
海洋环境中的石油污染物主要来自于原油开采和井喷、运输船舶的漏油以及输油管道的泄漏。随着全球能源消费的快速增长,石油的开采与运输也变得日益频繁。然而,在此过程中衍生出的石油污染问题也更加严峻。据估计,世界各地每年平均溢油量多达40万t。大规模的海上溢油处理方法主要包括物理处理法、化学处理法和生物处理法三大方法。其中原位燃烧、分散剂降解等化学方法需要高昂的成本,并且会对环境造成二次破坏;微生物分解等生物方法对自然条件要求十分苛刻;使用机械装置(如撇油器或喷杆)的物理方法需要输入能量或在高压下进行操作。这些方法均不能充分满足对溢油处理的要求。最近学者提出了一种利用磁改性超疏水/亲油的可浸湿吸油材料进行油水分离的方法。这些材料主要由粘土(二氧化硅)、沸石、活性炭、碳纳米管、聚合物、羊毛和秸秆等物质作为基材,通过四氧化三铁纳米颗粒的嵌入或涂覆以赋予材料磁响应特性。这些具有高孔隙率、高比表面积和丰富孔洞结构的吸附材料不但具有可设计调整性,而且经过磁性颗粒改性后,能够制备出在除油能力、油品回收和操作成本等方面均优于传统方法的磁性吸油材料。尤以聚合物为基材的磁响应吸油材料的研究最为广泛,被磁性纳米颗粒涂覆的聚合物海绵的吸油量最高可达50 g/g,且都具有近95%的吸油效率。其他材质的吸油材料也有所报道。这些磁性吸油材料具有三大特点:(1)吸油效率高,吸油量稳定;(2)固油性能好,吸附油不易脱附;(3)易回收,能够循环利用。本文通过阐释吸附材料的磁改性和吸油机理,分析典型磁改性复合材料的吸油性能测试实验,指出各类吸油材料在溢油处理过程中的优势和局限。特别地提出了磁改性粉煤灰沸石吸油材料,概括了固体废物资源领域的最新研究热点,以期为国内相关研究提供参考。 相似文献
5.
6.
近年来,海上石油泄漏事故和各种含油有害污水排放日益频繁,不仅造成了严重的环境污染,同时也危及到人类健康。因此,如何高效分离油水混合物成为当前材料学领域一个亟待解决的问题和研究热点。目前,具有被油或水所选择性润湿的特异浸润性材料已被广泛应用于油水分离,它们具有高效的油水分离效果,应用前景相当广阔。综述了近年来各类新型、高效的特异润湿型油水分离材料的制备方法及其吸油能力、分离效率以及重复使用性能,总结了油水分离材料领域的研究现状及尚待解决的难点,同时也展望了该领域未来研究的热点及发展方向。 相似文献
7.
8.
9.
《新型炭材料》2021,(2)
频繁的海上溢油事故和工业含油污水的肆意排放严重破坏海洋生态平衡。因此,开发先进的除油材料迫在眉睫。石墨烯(G)及其衍生物氧化石墨烯(GO)因其具有高比表面积、低密度、高孔隙率、表面功能可调等优异的理化性质,在油水分离领域成为研究热点。为充分发挥其优势,近年来,将G或GO与聚合物复合制备成功能化G/聚合物或GO/聚合物纳米复合材料,因其具有良好的除油能力、优异的机械性能、价格低廉、形貌及表面化学组分可调等优势而越来越受到人们的青睐。目前已开发出气凝胶、泡沫、海绵、膜等具有三维结构的G/聚合物或GO/聚合物复合吸油剂和过滤膜。本文系统性地总结了从表面润湿理论到G/聚合物或GO/聚合物复合吸油材料和滤膜材料的最新研究进展。此外,重点归纳了近年来有关油品回收及吸油材料再生的方法策略。最后,提出该研究领域目前面临的挑战和未来研究方向,旨在为该领域的深入探索开辟新的视角。 相似文献
10.
11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
12.
Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
13.
14.
Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献
15.
由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。 相似文献
16.
M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
17.
V. T. Kornienko 《Strength of Materials》1991,23(7):760-765
The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991. 相似文献
18.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
19.
20.
水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献