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1.
观察新型五孔PVDF共混改性纤维膜SEM形貌特征,测量改性膜的接触角和临界通量,1#(PVDF/PMMA/TPU)、2#(PVDF/PMMA/PVC)共混改性膜分别在次临界和超临界通量下进行过滤实验.结果表明:PVDF共混改性膜具有优良的微观结构,且1#共混膜性能较好;1#共混膜的接触角比2#共混膜小;1#、2#共混膜的临界通量分别为10和14L/(m2.h);1#共混膜比2#共混膜抗污染性能好;次临界通量下共混膜的运行比超临界通量下的稳定.两种共混膜分别在次临界通量下采用单独超滤和混凝+超滤工艺处理某市地表水,得出混凝+超滤工艺处理效果较好,且1#共混膜比2#共混膜处理效果好.  相似文献   

2.
聚偏氟乙烯分离膜改性研究进展   总被引:17,自引:4,他引:13  
对聚偏氟乙烯 (PVDF)功能高分子分离膜近年来在共混改性、表面改性、化学改性方面的研究进行了综述 .综合分析了相容性、制膜条件等对共混成膜过程的影响及膜性能的调节 ,概述了目前国内外在PVDF分离膜表面改性、化学改性方面的进展 ,并针对PVDF分离膜改性领域今后的研究提出建议  相似文献   

3.
强疏水性聚偏氟乙烯(PVDF)膜的亲水化改性是当前分离膜研究的热点之一.对PVDF膜近年来在共混改性、表面化学改性、表面接枝改性等方面的研究进行了综述,并针对PVDF分离膜改性领域今后的研究提出建议,指出膜材料共混改性是今后发展的主要方向.  相似文献   

4.
综述了近年来聚酰亚胺气体分离膜的主要改性方法和最新进展,其中重点介绍了交联和共混改性方法,并对聚酰亚胺气体分离膜材料今后发展方向进行了展望.  相似文献   

5.
聚偏氟乙烯膜的亲水化改性研究进展   总被引:1,自引:1,他引:1  
强疏水性聚偏氟乙烯(PVDF)膜的亲水化改性是当前分离膜研究的热点之一.从膜本体及膜表面两个角度对PVDF膜的亲水化改性进行了综述,介绍了共混、共聚、化学改性、等离子体处理及接枝改性等多种改性方法的机理、特点及改性效果.  相似文献   

6.
全生物分解PLA/PPC/改性淀粉共混薄膜拉伸性能的研究   总被引:1,自引:0,他引:1  
谢飞  何江川 《化工新型材料》2011,39(1):79-80,116
采用溶液共混的方法,用二氧化碳共聚物脂肪族聚碳酸酯(PPC)、改性淀粉对聚乳酸(PLA)改性,制备出韧性得以改善的PLA/PPC/改性淀粉共混薄膜.通过研究共混薄膜拉伸性能与共混组成配比的关系,试验结果表明,加入30%甘油对淀粉进行糊化,对淀粉改性效果较好.随着PPC组分的增加,提高了共混膜的断裂伸长率,增强了其韧性,...  相似文献   

7.
本文介绍了共混改性、自身改性、特殊处理等一些改善壳聚糖膜性能的方法,并阐述了壳聚糖在果蔬的可食性涂膜保鲜和可食性食品包装膜上的研究进展,以及壳聚糖膜今后的发展方向。  相似文献   

8.
聚氯乙烯膜分离材料改性研究进展   总被引:7,自引:2,他引:5  
从聚合物溶液共混、共聚和表面改性 3方面介绍了聚氯乙烯膜材料改性研究的进展 .并对影响膜结构与性能的因素和几种改性方法进行了对比分析 .  相似文献   

9.
将改性三聚氰胺甲醛树脂与粘胶溶液共混,经真空脱泡后,制得高强度的纤维素/改性三聚氰胺甲醛树脂共混膜。并对纤维素/改性三聚氰胺甲醛树脂共混膜进行表征。研究结果表明:当改性三聚氰胺甲醛树脂添加量为20%(wt,质量分数)时,制得的纤维素/改性三聚氰胺甲醛树脂共混膜的力学性能达到最大值,断裂强力达到116.55N,伸长率达到205.27%,拉伸强度达到97.13MPa,具有较好的性能。  相似文献   

10.
PHA/PLA生物降解共混膜的制备   总被引:3,自引:2,他引:1  
采用共混改性方法,将聚乳酸添加到聚羟基脂肪酸酯中,以提高材料的力学性能和成膜性能,制备了生物降解膜。通过对原材料进行黏度测试,确定共混加工工艺的加工温度为200℃,转速为20 r/min时,共混效果较好。对共混膜进行了力学性能测试和断面结构分析,得到当PHA与PLA质量比为100∶50时,膜的拉伸强度为30 MPa,断裂伸长率为100%,共混膜的整体性能较佳。土埋降解实验显示共混膜具有一定的降解性能。  相似文献   

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.
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   

13.
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.  相似文献   

14.
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   

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17.
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.  相似文献   

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19.
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   

20.
可燃气体检测报警器测量结果的不确定度评定   总被引:1,自引:0,他引:1  
本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。  相似文献   

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