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1.
抗衰老与抗衰老市场概述   总被引:1,自引:0,他引:1  
介绍了抗衰老机理和热门抗衰老成分。指出了医学对抗衰老的认识与解决方法。提出了抗衰老的新概念。同时,对抗衰老行业和抗衰老化妆品市场进行了分析,最后,指出了抗衰老化妆品市场发展趋势。  相似文献   

2.
介绍了整流机组的技术改造内容。通过改造,提高了装备技术水平,简化了操作,提高了供电的平稳性和安全性;降低了电力损耗;节约了能源。  相似文献   

3.
研究了在垂直方向上对圆筒式加热炉辐射室进行分片预制的方法,分析了辐射室分片预制方法的特点。结果表明:这种方法大大减少了现场安装组对工作量,减少了人工,机械的使用量,节约了成本。降低了工作风险,提高了施工进度,保证了工程质量。  相似文献   

4.
黄磷尾气净化脱硫模拟工艺试验   总被引:3,自引:1,他引:2  
邓聪  王学谦  宁平  陈樑 《云南化工》2003,30(1):21-23
对黄磷尾气净化脱硫进行了模拟工艺试验。测定了黄磷尾气中硫化氢的含量。对吸收、吸附条件进行了试验研究 ,用两种工艺进行了组合 ,对组合工艺进行了比较。得出了最佳的黄磷尾气净化脱硫工艺  相似文献   

5.
《上海化工》2009,(7):9-9
据庄信万丰公司最近出版的《PLATINUM 2009》报道,2008年,全球铂金市场出现了11.7t的短缺,铂金的供应量下降了9.5%,达到了185.7t。汽车尾气净化催化剂行业对铂金的需求下降了8.2%,达到了118.3t。除去回收料,全球首饰行业对铂金原材料的需求下降了6.2%,达到了42.5t。  相似文献   

6.
介绍了稳定氯、氢气系统压力的技改。通过改造提高了生产系统压力的稳定性,为生产安全奠定了基础。同时,提高了系统自动化水平,降低了劳动强度。  相似文献   

7.
文中详细介绍了几中丁二烯的生产工艺并进行了比较,总结出了它们的特点。对各地区丁二烯的生产能力以及消费状况进行了分析,并探究了丁二烯的新用途。  相似文献   

8.
简介了对二氧苯的性质、用途,详细阐述了其生产方法和工艺技术。介绍了国内外生产及消费情况,提出了发展建议。  相似文献   

9.
全钢子午线轮胎活络模的初步研究   总被引:4,自引:0,他引:4  
研究了活络模具花纹块的各种加工方法,比较了各自的优缺点。对钢制活络模花纹块的热膨胀进行了计算。得出了多种规格花纹块间隙的变化规律。提出了一套较为合理的花纹块加工工艺,并对模具各运动面的磨损进行了分析.提出了解决方案,对导套加工提出了特殊要求。  相似文献   

10.
介绍了动态可视化技术在注射充模过程中的应用。借助注射成型充模过程可视化实验装置,构造并记录了成型过程中的熔接痕缺陷的形成过程。分析了该缺陷的产生机理,并通过改变工艺条件改善了缺陷,为研究和排除制品缺陷提供了理论依据。同时,表明了可视化实验研究的意义。  相似文献   

11.
民用工业中复合材料桁架的应用和发展   总被引:1,自引:0,他引:1  
本文叙述了复合材料桁架的构造、分类和计算方法,突出了复合材料桁架的优越性能和在民用工业中的应用前景;在分析大量文献资料的基础上阐述复合材料桁架杆件的多种加工工艺,并比较不同截面形式对杆件性能的影响;探讨复合材料杆件的破坏机理和分析方法,介绍节点的类型和各自的特点,提出节点及连接部位存在的关键问题;根据国内外复合材料桁架的研究和应用现状,阐述了复合材料桁架的性能和不同的设计方法,总结归纳影响复合材料桁架性能的关键因素和设计中存在的一些问题,并提出改进杆件设计、节点设计和优化复合材料桁架的建议。  相似文献   

12.
马润梅  赵祥  李双喜  刘兴华  许灿 《化工学报》2021,72(11):5726-5737
在含有颗粒介质的工作环境中下,硬质材料配对机械密封环的热力耦合变形和摩擦磨损对机械密封的泄漏和使用寿命起着至关重要的作用。考虑动静环和颗粒介质的摩擦,试验测定了摩擦系数,建立了动静环热力耦合的有限元计算模型,研究了WC-Co硬质合金和无压烧结碳化硅(SSiC)陶瓷两种硬质材料密封的温度场和端面变形规律,分析了不同工况下的密封间隙变化规律。试验测试分析了密封环温度、磨损前后的泄漏及表面粗糙度,讨论了端面的磨损机理,验证了计算模型的准确性。结果表明:考虑动环磨粒摩擦热的有限元模型能准确地预测密封的温度和端面变形;耦合作用下动静环端面呈现外径脱离、内径贴合的变形,且变形差异程度随压差和转速的增大而加剧;变形导致端面磨痕分布不均匀,内径磨痕较严重。WC-Co硬质合金配对密封环的端面变形小、泄漏量小,高硬度WC颗粒对Co基体能产生很好的“阴影效应”,具有良好的耐磨粒磨损性能。SSiC陶瓷材料韧性差,易产生片状磨屑,形成过渡型磨粒磨损,材料耐磨性较差,泄漏量增加明显。在磨粒工况下,WC-Co硬质合金机械密封具有泄漏小、耐磨性强的特点。研究结果为颗粒介质中机械密封的材料应用及设计优化提供了参考。  相似文献   

13.
Technology and colour are viewed as interfaces between the environment, humans and human activity. Examples are provided of ways of facilitating and improving access to and use of colours by commercial users of colour coatings through improvements in the accuracy of measuring and displaying colour. By analogy, the task of providing effective interfaces within the coatings industry, between the coatings industry and the environment and between the coatings industry and the public and political domain are discussed. Examples of information shortfalls are cited to illustrate how distortions arise. Examples of more effective, integrated technological, organisational and political interfacing are culled from the author's experiences.  相似文献   

14.
木质纤维生物质资源是重要的可再生生物质资源,主要包含纤维素、半纤维素和木质素。半纤维素含量仅次于纤维素,是一种丰富、可再生的植物资源,其可水解制备重要化学品以及改性制备多功能材料。本文综述了生物质半纤维素分子模拟应用研究进展,从半纤维素大分子形态及其与纤维素结合方式的分子模拟研究和半纤维素制备化学品及材料的分子模拟研究2个方面进行阐述,从模拟结果可以看出半纤维素在细胞壁中与纤维素和木质素的相互作用及其本身的大分子形态对木质纤维生物质三大素的提取利用具有显著影响。分子模拟有利于理解过程机理,对反应效率的提高具有重要理论指导意义。最后对分子模拟在半纤维素研究的发展应用进行了展望,指出目前半纤维素分子模拟的空白领域,主要包括半纤维素液化生产生物油、木糖异构化生产木酮糖、半纤维素与木质素之间的结合方式以及其他的半纤维素基材料等,这些有待进一步的探索与研究。  相似文献   

15.
在绿色化学理念的引导下,可生物降解膜材料受到了广泛的关注,有望成为传统分离膜材料的补充和替代品。本文首先分析了传统的不可降解分离膜材料的现状及问题,然后综述了当前较为热门的几种可生物降解膜材料,讨论了它们的发展状况,详细介绍了它们在膜相关领域中的应用,并针对它们的局限性做出了说明并提出了一些解决方案。随后,分析了可生物降解膜材料的生物降解机理,从分子结构角度对膜材料的可生物降解性进行了说明,这将有利于剖析膜材料生物降解的本质,进而平衡膜材料在使用中的稳定性和生物降解性。最后,文章对可生物降解膜材料在发展中遇到的问题进行了展望,并指出随着研究的不断深入,可生物降解膜材料具有广阔的前景和深远的现实意义。  相似文献   

16.
Effectiveness of lipase in detergency was studied using three test soils (lard, artificial sebum, and olive oil) on a woven cotton fabric. Distribution of oily soil on fabrics was determined for three different treatments (unwashed, washed with detergent without lipase, and washed with detergent plus lipase). Osmium tetroxide was used to label lipid soil for analysis in the scanning electron microscope. Both longitudinal and cross-sectional backscattered electron images for unwashed samples showed that soil was present on surfaces of the cotton fibers and in interfiber spaces of the yarn bundle. Lard soiled samples had large deposits on the fabric surfaces, while artificial sebum and olive oil appeared more uniformly distributed throughout the textile. Oil was deposited in the interfiber capillaries of the yarn bundle and in the crenulation, secondary walls, and lumen of the fibers. Energy dispersive X-ray microanalysis was used to determine relative concentrations of oil at selected morphological locations within the fiber structure and at the fiber surface. Soil distributions within the fibrous structures differed with type of soil and laundry treatment. Backscattered electron images dramatically demonstrated the effect of lipase on cleaning. After washing with detergent plus lipase, yarn surfaces had much less residual soil; residual soil that remained was in the irregularities of the cotton fiber surfaces. Concentrations of oil in the secondary walls, crenulations, lumen, and the fiber surfaces were lower after lipase treatment for all three soils. While washing with detergent removed soil from the yarn and fiber surfaces and the crenulation of the cotton fiber, only the samples washed with detergent plus lipase had lower concentrations of soils within the secondary wall and lumen of the cotton fibers. Fabrics soiled with olive oil and washed with detergent plus lipase had the lowest concentrations of residual soil across the textile structure; the residual soil observed was mainly in the irregularities on the fiber surfaces.  相似文献   

17.
There is an increased demand for convenient foods including ready-to-eat and instant products. These products are desired with minimum concentration of synthetic chemicals. This creates challenges for the food industry and dryers manufactures to develop new technologies to process difficult-sensitive materials and to supply final products with high quality and improved properties. Fruits and vegetables are mainly composed of water, carbohydrates, proteins and lipids. Due to modification of chemical and physical bonds the compounds the material becomes viscous and sticky during processing. Conventional dryers have limitations in handling such sensitive materials. Heat pump dryers have been applied in the production of a diversity of ready-to-eat foods and dried instant products for the last five years at SINTEF-NTNU. Besides being energetically efficient and environmentally friendly, the heat pump drying technology provides a wide range of drying conditions as required to produce powders with improved characteristics. This work describes the new technologies and processing line for the production of instant foods as well as the measurements on the properties and quality attributes for raw, intermediate and final instant products.  相似文献   

18.
The effect of various pretreatments on drying kinetics as well as quality parameters of selected vegetables and fruits was studied experimentally in a convective dryer. The pretreatments tested include application of pinholes and drilled holes of different diameters and densities, blanching and freezing. Potato, cassava, dragon fruit and red chilli were used as the sample drying materials. As expected, increase of the diameter and density of the holes under fixed drying conditions increased the drying rate. Samples with drilled holes showed better drying performance than those with pinholes. The improvement of the drying rate was found to be dependent on the physical properties and the initial moisture content of the material. Results show that the drying performance of the products that possess a skin of low moisture diffusivity, such as chilli, can be improved significantly by blanching and making perforations in the skin. Overall changes of color and volume shrinkage during drying of the samples with and without holes were similar. The effect of different modes of heat input, such as convection, conduction and radiation, on the drying performance of the treated samples was also experimentally investigated. On-off type controllers were used to regulate the power of the heaters and maintain the product temperature within a range of pre-set values. Convection combined with radiation displayed the highest drying rate.  相似文献   

19.
为了同时分离甘草中有表面活性的甘草酸和黄芩中无表面活性的黄芩苷,开发了甘草配伍黄芩泡沫分离工艺。通过荧光光谱、紫外吸收光谱和红外吸收光谱分析表明,甘草酸与黄芩苷存在相互作用,并且甘草黄芩配伍强化了甘草酸和黄芩苷的提取。以甘草酸和黄芩苷的富集比和回收率为评价指标,当温度为40℃、气体体积流量为100 ml·min-1、甘草酸初始浓度为0.2 g·L-1、甘草黄芩质量比为3:1时,获得甘草酸的富集比和回收率分别为11.0和73.5%,黄芩苷的富集比和回收率分别为5.8和38.5%。通过甘草与黄芩配伍,利用泡沫分离获得黄芩中的黄芩苷。同时,与单独泡沫分离甘草中甘草酸相比,甘草酸的富集比提高了194.9%,回收率提高了23.3%。因此,甘草配伍黄芩能有效泡沫分离甘草酸和黄芩苷。  相似文献   

20.
The physical and hence mechanical properties of carbon fiber reinforced epoxy resin are affected by the curing conditions used in their manufacture. The relationship between the cure temperature and pressure and the density, fiber volume fraction, and the void content of cured laminates, was investigated. For the unidirectional 914C prepreg material used, an optimum cure temperature was found which gave maximum fiber volume fraction and composite density, and minimum void content. This behavior is related in the paper to resin flow and cure characteristics. A linear relationship between cure pressure and fiber volume fraction is reported and explained by reference to the void content of the laminates. It is concluded that in-house trials are required to determine the optimum size of the processing window for specific systems and components.  相似文献   

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