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Search Results: 1 - 10 of 262293 matches for " 李好义 "
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纤维膜过滤特性的数值模拟
小虎,张有忱,,丁玉梅,杨卫民
环境工程学报 , 2014,
Abstract: 一个高性能过滤膜除了与纤维自身结构参数有关联外,过滤时的操作条件对其也有重要影响.为研究纤维膜过滤效率、过滤压降与过滤速度、孔隙率以及过滤膜厚度之间的关系,以更好地对实际过滤进行优化,本研究从纤维膜的过滤机理进行出发,采用FLUENT多孔介质离散相模型对纤维过滤器的流场进行模拟.结果表明,膜前后压降会随着过滤速度和膜厚度的增大而增大;一定范围内纤维膜孔隙率适度增加,截留率变化不大,但是膜压差会逐渐减小;同时过滤速度对颗粒截留率有影响,速度增大时,粒子轨迹发生偏移,导致过滤膜一部分过早发生堵死,而一部分作用减弱,影响了过滤效果.
流体微分静电纺丝喷头设计的研究进展
肖桂花,,小虎,阎华,焦志伟,杨卫民
纺织学报 , 2014,
Abstract: 随着纳米技术的发展,作为可制备纳米纤维的静电纺丝技术也受到越来越多关注。由于传统毛细管喷头生产效率极低,使纳米纤维产业化制造受到限制,而自发形成密集射流的微分喷头结构这一新型构想恰好解决了纳米纤维产量低的问题。本文就流体微分静电纺丝喷头不同结构设计的基本原理和研究进展进行综述,为进一步研制新型流体微分静电纺丝喷头和纳米纤维产业化制造提供参考。
熔体静电纺丝中电极材质和形状对电场和纤维的影响
杜琳,张有忱,丁玉梅,杨卫民,谭晶,
- , 2018, DOI: 10.13543/j.bhxbzr.2018.02.005
Abstract: 电场强度大小及分布对静电纺丝工艺的成纤形貌和接收面积具有重要影响。采用COMSOL Multiphysics分析软件建立电场分析的有限元模型,分别研究了熔体静电纺丝工艺中接收电极材质和形状对电场分布的影响,结果表明塑料在一定程度上削弱了电场强度,但是增加了电场的均匀度。通过扫描电子显微镜观测了接收电极材质和形状对纤维直径和形貌的影响,发现在不同的接收电极形状中,中空电极内环边缘电荷聚集,纤维摆动路径延长,获得较多的羊毛圈状纤维;对于方格状电极板,由于大方格的孔隙较大,削弱了电场,纤维直径较粗,中方格尺寸相对适中,可能对电场有一定的均化作用,因此降落到中方格电极板上的纤维沉积面积最大。
Abstract:The intensity and distribution of the electric field have an important influence on the fiber morphology and the deposition area in an electrospinning process. COMSOL Multiphysics analysis software has been used to model the effect of varying the material of the receiving electrode in the melt electrospinning process and a finite element analysis model of the electric field, used to study the effect of varying the shape of the receiving electrode on the electric field distribution at different electric field strengths. It was found that the use of a plastic receiving electrode rather than metal decreased the electric field strength to some extent, but increased its uniformity. The influence of varying the material and shape of the receiving electrode on the diameter and morphology of the fibers was investigated by scanning electron microscopy. It was found that by varying the receiving electrode shape, the charges on the edges of the inner hollow electrode could be aggregated and the fiber wobble path prolonged, which afforded more wool-like fibers. In the case of a grid-shaped electrode plate, due to the grid of large pores, the electric field decreased, and the fiber diameter became thicker. Using a medium sized receiving electrode resulted in some homogenization of the electric field, resulting in the fiber deposition area being the largest in this case.
熔体静电纺丝3D电场模拟
张罗,杨卫民,,陈宏波,丁玉梅,谭晶
- , 2016, DOI: 10.13543/j.bhxbzr.2016.02.013
Abstract: 采用有限元分析软件ANSYS对熔体静电纺丝平台模型进行三维电场模拟。分析了纺丝系统在不同电压下的电场分布情况,重点讨论了内锥面喷头间距对纺丝尖端电场的影响。发现在间距为100mm时,内锥面喷头纺丝尖端场强分布最为均匀|纤维路径上的场强随着喷头数量、施加电压的增加而增加,随着喷头间距增加无明显变化;场强较强处出现在纺丝尖端和接收板边缘。在模拟基础上研发了新型一分四的熔体微分静电纺丝机,制备了均匀分布的纤维,为进一步设计纳米纤维宏量化生产的纺丝设备提供参考。
Abstract:This study utilizes the finite element analysis software ANSYS to simulate a melt differential electrospinning system. The field distribution under different voltages is analyzed and the effects of changing the inner cone nozzle interval on the electric field strength of the spinning edge are discussed. The simulation results indicated that: the spinning edge had a uniform electric field distribution when the interval was 100 mm|with increasing the number of nozzles and applied voltage, the electric field of the fiber route increases, without any obvious response when changing the interval of the nozzles|the electric field intensity was a maximum on both the edge of the nozzle and the receiving board. In addition, and based on the simulation, a novel melt differential electrospinning device was developed and fibers were fabricated, and the results provide guidance for the design of future electrospinning systems for the mass production of nanofibers. 
内外双层锥面熔体微分静电纺丝实验研究
陈宏波,杨卫民,,秦永新,张艳萍,谭晶
- , 2017, DOI: 10.13543/j.bhxbzr.2017.02.010
Abstract: 为了进一步提高单喷头纤维的产量,在熔体微分静电纺丝的基础上,设计开发了一种结合内外锥面的双层熔体微分静电纺丝装置。通过COMSOL Multiphysics数值仿真软件对其电场进行对比分析,得出增加的内层锥面对外层电场有一定的削弱作用。通过实验分析了内层锥面伸出距离对内外层射流的影响,找到了最佳参数,并且在此参数下,验证了不同电压下的纺丝效果,结果表明,随着电压的增加,内外层锥面电场增加程度相同,内外层纤维直径达到了均匀分布。最后分别采用吹风和吸风辅助对纤维进行了细化,为静电纺丝法制备超细纤维的产业化提供参考。
Abstract:In order to improve the fiber yield in melt differential electrospinning when using a single nozzle, we have designed an internal and external cone combination double-layer melt differential electrospinning apparatus. By means of a comparative analysis using the numerical simulation software COMSOL Multiphysics, the additional internal cone has been shown to have a weakening effect on the electric field on the external cone. The optimum extension distance between the internal cone and the external cone has been found by experimental analysis of the jets on the cone, and the spinning effects of different voltages have been obtained for this extension distance. The results show that as the voltage increases, the electric field on the internal and external cone increases to the same extent, and the fiber diameter of the inner and outer layers are evenly distributed. The average fiber diameter can be reduced by blowing and suction assistance, which lays the foundation for industrial application of this method.
锯齿引导型无针熔体微分电纺工艺
秦永新,安瑛,杨涛,张艳萍,,杨卫民,
- , 2017, DOI: 10.13543/j.bhxbzr.2017.06.012
Abstract: 提出一种锯齿引导型无针熔体微分静电纺丝工艺方法,用来改进熔体静电纺丝纤维直径不均匀问题。首先将其与无锯齿引导型无针熔体微分静电纺丝进行对比,然后在自制的设备上进行正交试验,以探究其最佳纺丝工艺参数。试验结果表明:锯齿引导提高了纤维的均匀性,在聚丙烯(PP)进料流速一定的条件下,最佳纺丝工艺参数为纺丝温度240℃、纺丝电压65 kV以及纺丝距离105 mm;在此条件下测得最小的纤维平均直径为820 nm。
Abstract:Sawtooth-guidance type needleless melt electrospinning has been proposed as a way to improve the non-uniformity of melt electrospinning fibers. The new method was first compared with conventional melt electrospinning without sawtooth-guidance. The optimum spinning process parameters for sawtooth-guidance type needleless melt electrospinning were then determined by orthogonal experiments on self-regulating equipment. The experiments demonstrated that sawtooth-guidance type needleless melt electrospinning improves the uniformity of fiber diameter and the most appropriate spinning process parameters are as follows:a spinning temperature of 240℃, a pressure of 65 kV and a distance of 105 mm, with the mass flow rate as a constant. Moreover, Taylor-cones are distributed at the sawtooth tips, and the average minimum fiber diameter was 820 nm.
民用飞机大型模锻件的生产及其展望
,乐安
材料工程 , 1992,
Abstract: 本文通过对波音飞机钛锻件模锻工艺的研究和生产实践,以锻造实例说明大型钛锻件的模锻技术特点;介绍红原锻铸厂的近期技术改造和对未来发展的展望。
高效液相色谱法测定水产养殖底泥中呋喃唑酮残留量的研究
刁石强,吴燕燕,,杨贤庆,邵征翌,孙满,陈晓凤
南方水产科学 , 2010, DOI: 10.3969/j.issn.1673-2227.2010.02.009
Abstract: 运用高效液相色谱建立了一种测定水产养殖底泥中呋喃唑酮残留量的方法。通过比较不同提取方法获得最佳的提取条件。结果表明,底泥样品用乙酸乙酯超声波法提取,无水硫酸钠去除水分,浓缩并用流动相溶解后上机检测,方法线性范围在0.01~1.00μg?ml-1之间,相关系数为0.999,回收率为88.2%~92.6%,精密度(rsd)为0.88%~2.67%,检出限为1.0μg?kg-1。该方法操作简便、提取快捷、准确性高、重复性强,可检测出泥样中痕量的呋喃唑酮,适用于水产养殖环境底泥中呋喃唑酮残留量的测定。
航空喷洒设备及监测技术的研究 Ⅲ.喷撒设备防治马尾松毛虫
梁成杰,赵玲,黄金,蒙美琼,杨秀,吉钧
林业科学研究 , 1999,
Abstract: 在广西武鸣县的团结、直属站和定标水库林区,设定了7个试验区,首次用新研制的HU2-HPS-2型喷撒设备及用NT100GPS导航与海燕650B飞机配套,喷撒孢子100~120亿·g-1球孢白僵菌粉剂,有效喷幅为80m,粉量调节装置放在1,2,3,4挡,喷粉量依次为4,10,16.7,35kg·min-1,喷粉量均为1.3~1.5kg·hm-2,粉粒+孢子密度为84+48个·cm-2.其中6个试验区防治马尾松毛虫平均死亡率依次为65.34%,88.09%,93.60%,91.99%,80.99%和81.00%;另一防治松茸毒蛾为46.77%。
航空喷洒设备及监测技术的研究Ⅱ.喷洒设备防治松毛虫
梁成杰,赵玲,黄金,蒙美琼,杨秀,吉钧
林业科学研究 , 1999,
Abstract: 新研制的HU2-HW1型超低容量喷洒设备及NT100GPS导航系统与海燕650B飞机配套技术,首次应用于广西武鸣林区防治森林病虫害。2.5%EC溴氰菊酯用0#柴油稀释为油剂,施药量(乳油)为30、45mL·hm-2;水剂则为60mL·hm-2。航空超低容量喷洒防治松毛虫平均死亡率依次为96.4%、98.3%和97.6%;松茸毒蛾为93.6%(水剂)。1000亿孢子·g-1球孢白僵菌,施孢子量为120g·hm-2(其配比:孢子水吐温-80盐=51000.50.5).搅拌均匀,再加3.0L水稀释,航空超低容量喷洒防治马尾松毛虫和松茸毒蛾,平均死亡率依次为67.7%和50.3%。
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