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1.
春节前后,吉安市遭遇到罕见的冰冻雨雪灾害天气,连续出现了低温、阴雨和雨夹雪,成为全省灾情最严重地区之一.特别是1月25日以后,出现了持续大范围的雨雪冰冻天气.冰冻损坏了市区的电网,压垮了树枝,封锁了道路和桥梁.  相似文献   

2.
苏石 《玻璃纤维》2005,(5):42-42
欧文斯科宁公司(以下简称OC)创建66年来一直致力于开发玻璃纤维的新用途,是建筑材料和复合材料行业的领先创新者和制造商,OC进入亚太市场也已超过30年,长久以来他们专注于推广复合材料的应用领域以及扩大其供应基地.最近,欧文斯科宁在印度扩充了生产能力,并在上海设立了技术中心.至今为止,欧文斯科宁在亚太区已有超过1800名员工,从事建筑材料和复合材料的生产,销售和研发工作.  相似文献   

3.
收集了2010年7月~2011年6月世界塑料工业的相关资料,介绍了2010~2011年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、ABS树脂),工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚),特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮),通用热固性树脂(酚醛、不饱和聚酯树脂、环氧树脂、聚氨酯)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。  相似文献   

4.
花粉症又称季节性鼻炎或枯草热,是敏感个体对花粉的一种超敏反应.在美国,每一百个人当中就有两个以上的人患花粉症;现在日本有1300万人饱受花粉症折磨,超过总人口的10%[1].我国的发病率为0.5%~1%,高发区达到5%,虽没有上述一些国家那么严重,受害者亦相当可观.全世界花粉症发病人数到1999年就已有5000多万[2],可见花粉症患者是一个绝不可轻视的群体.图1显示了花粉过敏症的发病机制.  相似文献   

5.
2003~2004年国外塑料工业进展   总被引:5,自引:0,他引:5  
收集了2003年7月~2004年6月国外塑料工业的相关资料,介绍了2003年~2004年国外塑料工业的发展情况,提供了世界几大区域塑料的产量、增长率及所占份额,美国、德国、日本、韩国、法国、比利时、中国台湾、加拿大、巴西、西班牙等国家和地区的不同树脂的产量及消费量,各国、各地区塑料原料的产量、进出口量、国内消费量和人均消费量,日本塑料原料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

6.
张艳  卢文玉 《化工进展》2014,33(5):1265-1270
萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。  相似文献   

7.
随着我国国民经济的快速发展和国家"节能减排"重点项目的深入开展,各种污染源的分析及其处理措施的研究备受关注.本文在充分研究若干家电企业的钢铁喷涂制件的前处理工艺(如:预脱脂、脱脂、清洗、表调、磷化等)的基础上,分析喷涂前处理过程中的污染源,研究污染源的处理措施.  相似文献   

8.
我公司回转窑规格为Φ4.0m×60m.窑内使用的耐火砖为镁铬砖、隔热尖晶石、蓝晶石和黏土砖以及硅莫砖.镁铬砖规格为(81×90×150×200)mm,其它耐火砖规格皆为(81×90×200×200)mm.尽管每个品种的砖品质相同,但由于在镶砌和使用过程中方法不同,寿命有长有短.通过多年实践,现总结如下.  相似文献   

9.
硅酸钠缓蚀剂的研究现状与展望   总被引:4,自引:0,他引:4  
硅酸盐资源丰富,无毒,价廉,不繁殖细菌,是一种对环境友好的缓蚀剂.近年来研究的以硅酸盐为主的缓蚀剂复合配方,大大提高了硅酸盐缓蚀剂的应用范围.目前,开发缓蚀剂复合配方已成为一种发展趋势.本文综述了硅酸钠缓蚀剂的应用现状,并对其发展作了展望.  相似文献   

10.
许建元  李永娥  宋群 《玻璃与搪瓷》2004,32(6):24-25,37
为了使啤酒瓶质量与啤酒灌装质量协调统一,探讨了啤酒瓶外形设计、剩余空间和瓶壁厚度与瓶子强度和灌装质量的关系,提出啤酒瓶企业定点向啤酒企业供瓶,两企业协作互动,了解相关的技术、设备性能和工艺流程,以利同步发展.  相似文献   

11.
改性纤维球过滤器的应用性研究   总被引:2,自引:0,他引:2  
李淑华  李宝彦  马新民  路江安 《化工机械》2003,30(4):211-213,226
介绍了过滤器的结构和亲水憎油改性纤维球滤料 ,根据来水水质情况可以采用压紧式或非压紧式纤维球过滤器的结构。在大庆油田进行现场应用性试验 ,结果表明 ,改性纤维球过滤器具有滤速高、处理量大的特点 ,适用于聚驱油田含油污水深度处理 ,出水达到低渗透层注水水质标准  相似文献   

12.
长纤维高速过滤器的运行特性与性能优势   总被引:2,自引:0,他引:2  
通过对净水厂沉淀出水和长江源水的过滤试验,并与传统砂滤及已在实践中应用的两类纤维过滤器进行对比,证实了自行研制的长纤维高速过滤器的性能优势。该型过滤器在结构上的突破性改进,使纤维过滤技术更趋成熟和高效,对推动纤维过滤技术的发展和提高我国水处理水平均具有重要意义。  相似文献   

13.
To develop a simple and efficient way to recycle used cigarette filters, we report on a one-step method for preparing superhydrophobic and superoleophilic cigarette filters for oil–water separation. The robust coating layer on the surface of the cellulose acetate fiber, along with the inherent rough texture of the cigarette filter, could lead to its surface that displayed superhydrophobicity and superoleophilicity. Water droplets can retain in spherical shapes on the modified cigarette filters, while oils were immediately absorbed by the cigarette filters with high absorption capacity. As a result, free oil–water mixtures were separated with efficiency of above 98.0% by the driving force of gravity, and water-in-oil emulsion was also separated with a promising flux of about 2500 L m?2 h?1. The purity of oil for the tested emulsion was above 99.96%, indicating extremely high separation efficiency. This method for the fabrication of the superhydrophobic and superoleophilic cigarette filters would be a good candidate for recycling the solid wastes and developing an economic oil–water separation material to meet emerging needs in practical applications.  相似文献   

14.
The fractional penetration of submicrometer particles through five high-efficiency glass fiber filters, one composite fiber filter, and two membrane filters was measured for particles of 0.004–0.42-μm diameter at filter face velocities ranging from 0.5 to 20 cm/s. The glass fiber filters all had approximately the same thickness and weight per unit area, and were rated 93% to 99.999% efficient using the conventional 0.3-μm dioctyl phthalate (DOP) test. The challenge aerosols were electrically classified monodisperse DOP in the diameter range of 0.032–0.42 μm, and polydisperse silver condensation aerosols having diameters of ~ 0.004–0.01 μm. Aerosol penetration through these media was found to be generally consistent with current theory for collection by diffusion and interception over the particle size and velocity range studied. Using a filter figure of merit calculated for penetration by 0.1- and 0.3-μm particles to facilitate comparison, all of the filters except one tetrafluoroethylene membrane filter (which was slightly better) had about the same performance.  相似文献   

15.
介绍了纤维球的特点及发展。概述了纤维球过滤器的在运行过程中暴露出的反冲洗问题、过滤速度的确定、滤床压紧量的确定、纤维球大小的选择、纤维球内部积泥、纤维球反洗强度等问题,并针对这些问题的改进措施进行了总结。  相似文献   

16.
微絮凝纤维球过滤-超滤-纳滤组合工艺处理宾馆洗浴废水   总被引:3,自引:1,他引:2  
以自主研制的涤纶高弹丝纤维球为滤料,提出了微絮凝纤维球过滤-超滤-纳滤组合工艺处理综合回用洗浴废水的方法.试验结果表明,超滤出水可以回用至宾馆厕所冲洗、绿化等环节,纳滤出水可以回用至宾馆洗衣和洗浴等水质要求较高环节,同时研究发现,膜组件经复合清洗剂清洗后,水通量恢复率可达到99%以上.  相似文献   

17.
超高效过滤器设计参数的确定   总被引:1,自引:0,他引:1  
从过滤精度与比速的角度出发,讨论了过滤阻力、使用寿命等影响超高效过滤器技术经济综合性能的几个因素,为亚微米级超高效除油、除尘过滤器设计参数的选择提供了依据。  相似文献   

18.
The purpose of this study was to improve the efficiency of filters used in asbestos control systems, such as those used at asbestos removal sites. We evaluated the melt-blown (MB) filter media for their asbestos removal efficiencies. The filter grades were based on the ISO and European standards (EN 1822) of E12 (≥99.5% collection efficiency) and H13 (≥99.95% collection efficiency) with a size of <0.2?μm asbestos diameter. Based on test chamber experiments, the asbestos removal efficiency of the grade H13?MB filter (99.974%) was higher than that of the E12 grade MB filter (97.120%). In addition, the lowest level of pressure drop was observed in the case with a 3.8?mm pitch interval. The concentrations of airborne asbestos based on phase contrast microscopy in the sites with asbestos concentrations presenting high risks before turning on the asbestos control system was 0.038 fiber cm?3 at demolition site A and 0.027 fiber cm?3 at demolition site B. Chrysotile asbestos was detected at both demolition sites A and B before turning on the system, but were not detected after using the system. Therefore, MB filters present an efficient alternative to current commercial filters and should be considered for use in asbestos removal applications.

© 2018 American Association for Aerosol Research  相似文献   

19.
《分离科学与技术》2012,47(8):1955-1973
Abstract

Coalescing filters are widely used throughout industry for removal of liquid aerosols from gases or the separation of liquid droplets from emulsions. Typical filters are constructed of non-woven fibers. Fibrous filters are capable of efficient removal of micron and submicron sized droplets and particles. The filtration process is highly complex due to variability in fiber sizes, particle sizes, mixtures of particles and droplets, mixture of types of droplets (oil, water, etc.), and effects of viscosity, surface tension, and chemical reactions between components or with the filter fibers. Prediction of filter performance under such complex conditions is difficult.

Performance of a filter depends on many factors like particle and fiber sizes, flow rate, surface properties of the fibers etc. One of those parameters is the saturation of the filter medium. Saturation is a measure of the amount of liquid present in the void space. Prior models assume that the saturation is uniform along the depth of the medium. In real media, the liquid holdup at steady state need not be uniform with position. Local velocity increases when the saturation is high.

In this paper, a steady state model for a coalescing filter is used to evaluate the effects of saturation on void fraction and its subsequent effect on filter performance. Single fiber mechanisms of direct interception and diffusion deposition are used to model droplet capture efficiencies and drag forces. These mechanisms are applied to volume averaged continuum equations in which the saturation is varied linearly with position in the filter. The results show the minimum pressure drop and largest quality factor occurs with a uniform saturation profile and that variation in average saturation has a greater effect on filter performance than does the slope of the linear saturation profile. The model predicts that uniform saturation profile performs better than the other profiles.  相似文献   

20.
Although theoretical models of the filtration efficiency of fibrous filters are typically based on a single type of fiber in an ordered array, many actual fibrous filters comprises fibers that are inherently randomly distributed. It is desirable to be able to estimate the filtration efficiency of such non-uniform fibrous filters from their composition arrangement and the filtration property of individual fibers. Toward that end, we approximate the filter system as a series of cells comprising individual fibers with random distribution, deviating from the homogeneity assumption in the classical models. With better characterization of the filter structure based on the Voronoi diagram, we theoretically revisit filtration efficiency by the top-down (TD) approach and the bottom-up approach. The proposed models are compared with the existing experimental and numerical results under different fiber volume fractions, indicating the high accuracy of the TD model for the filtration of submicron aerosol particles. The influence of the degree of randomness of fiber distribution on filtration efficiency is also quantified.

Copyright 2015 American Association for Aerosol Research  相似文献   

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