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41.
42.
Cryogels have been demonstrated to be efficient when applied for protein isolation. Owing to their macroporous structure, cryogels can also be used for treating particle‐containing material, e.g. cell homogenates. Another challenging development in protein purification technology is the use of molecularly imprinted polymers (MIPs). These MIPs are robust and can be used repeatedly. The paper presents a new technology that combine the formation of cryogel beads concomitantly with making imprints of a protein. Protein A was chosen as the print molecule which was also be the target in the purification step. The present paper describes a new method to produce protein‐imprinted cryogel beads. The protein‐imprinted material was characterized and the separation properties were evaluated with regard to both the target protein and whole cells with target protein exposed on the cell surface. The maximum protein A adsorption was 18.1 mg/g of wet cryogel beads. The selectivity coefficient of protein A‐imprinted cryogel beads for protein A was 5.44 and 12.56 times greater than for the Fc fragment of IgG and protein G, respectively. 相似文献
43.
介绍了2017年诺贝尔化学奖的3位获得者在冷冻电镜领域的主要贡献,同时介绍了冷冻电镜技术的用途、一般工作流程和其局限性,以及中国学者在冷冻电镜技术应用研究中的贡献。 相似文献
44.
Fatigue damage behavior of a surface-mount electronic package under different cyclic applied loads 下载免费PDF全文
This paper studies and compares the effects of pull-pull and 3-point bending cyclic loadings on the mechanical fa- tigue damage behaviors of a solder joint in a surface-mount electronic package. The comparisons are based on experimental investigations using scanning electron microscopy (SEM) in-situ technology and nonlinear finite element modeling, respec- tively. The compared results indicate that there are different threshold levels of plastic strain for the initial damage of solder joints under two cyclic applied loads; meanwhile, fatigue crack initiation occurs at different locations, and the accumulation of equivalent plastic strain determines the trend and direction of fatigue crack propagation. In addition, simulation results of the fatigue damage process of solder joints considering a constitutive model of damage initiation criteria for ductile materials and damage evolution based on accumulating inelastic hysteresis energy are identical to the experimental results. The actual fatigue life of the solder joint is almost the same and demonstrates that the FE modeling used in this study can provide an accurate prediction of solder joint fatigue failure. 相似文献
45.
繁昌窑青白瓷胎体配方工艺一直停留在理论推理阶段,尚未有确凿的测试数据和模拟实验加以证实。为深入探究繁昌窑的胎料配方工艺,选取了繁昌窑址附近的多种瓷土样品进行了测试分析,并采用了古代制瓷工艺进行了模拟烧制。主要运用了波长色散X射线荧光光谱法(WDXRF)、红外光谱(FTIR)和X射线衍射(XRD)等光谱分析方法对瓷土成分进行测试;借助同步热分析(TG-DSC)对样品烧造温度进行了探索;通过模拟烧制陶瓷样品,对繁昌窑青白瓷的烧制工艺进行了研究,并对烧制的陶瓷样品进行显微结构分析。研究表明,繁昌窑附近的几种瓷土无论是单独制胎还是添加高岭土混合制胎,其烧成温度皆接近古代繁昌窑青白瓷的烧制温度。繁昌窑附近的瓷土是可以作为制作古代青白瓷的原料之一,但由于其中的铝含量较低,不能单独用来制作青白瓷胎体的原料,繁昌窑青白瓷在制作过程中应添加了其他富铝类原料。该研究对探索古代繁昌青白瓷的生产工艺及其蕴含的科学价值,提升繁昌窑在中国陶瓷工艺技术发展史上的地位等具有重要的学术意义,并可为现代陶瓷产业技术改进提供有益启示。 相似文献
46.
Membrane technology is becoming more important for CO 2 separation from natural gas in the new era due to its process simplicity,relative ease of operation and control,compact,and easy to scale up as compared with conventional processes.Conventional processes such as absorption and adsorption for CO 2 separation from natural gas are generally more energy demanding and costly for both operation and maintenance.Polymeric membranes are the current commercial membranes used for CO 2 separation from natural gas.However,polymeric membranes possess drawbacks such as low permeability and selectivity,plasticization at high temperatures,as well as insufficient thermal and chemical stability.The shortcomings of commercial polymeric membranes have motivated researchers to opt for other alternatives,especially inorganic membranes due to their higher thermal stability,good chemical resistance to solvents,high mechanical strength and long lifetime.Surface modifications can be utilized in inorganic membranes to further enhance the selectivity,permeability or catalytic activities of the membrane.This paper is to provide a comprehensive review on gas separation,comparing membrane technology with other conventional methods of recovering CO 2 from natural gas,challenges of current commercial polymeric membranes and inorganic membranes for CO 2 removal and membrane surface modification for improved selectivity. 相似文献
47.
现有光伏系统的控制器普遍选用微控制器为核心,为使之与电子技术课程教学案例开发相结合,提出采用集成运放替代微控制器的智能太阳能控制器方案,并以直流12V/10A小功率应用为研究实例。实验结果表明该控制器方案可行,且电路简单、成本低廉,适用于实验教学与课程设计。 相似文献
48.
K.T.A.L. Burm 《等离子体物理论文集》2013,53(3):202-205
Metal surfaces can be degreased via a combustion reaction upon the metal surface by the use of a plasma torch jet. The required energy and the reaction rate of the combustion reaction are examined here. It turns out that the reaction rate can limit the cleaning performance. In such case, the cleaning performance is not improved at higher powers. It is suggested to increase the temperature at which combustion takes place such that the cleaning performance can improve again at higher powers. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
49.
Off-Line and On-Line Preconcentration Techniques for the Determination of Phenylureas in Freshwaters
M.-C. Hennion P. Subra R. Rosset J. Lamacq P. Scribe A. Saliot 《International journal of environmental analytical chemistry》2013,93(1-4):15-33
Abstract Phenylurea herbicides are analysed by reversed-phase liquid chromatography using UV detection at 244 nm after a concentration step in order to determine ppb or sub-ppb levels in drinking and river waters. With an average UV detection limit of 5 ng, a 500 ml sample volume is necessary to reach the 10 ppt level for spiked LC grade water samples and enables easy determination of concentrations below the ppb level for river water samples. Off-line and on-line methods are compared for the concentration step. Off-line concentration consists in a liquid sorption on n-octadecyl silica (C18) and elution by a suitable organic solvent. Polar phenylureas have low retention volumes on C18 silica and consequently the length of the concentration column has to be 10 cm to concentrate them at the ppb level from 100 ml of water and longer for lower levels of detection. Nevertheless, we show that increasing the size of the concentration column does not improve the limits of detection because of the numerous interferences also concentrated when percolating high volumes of water. On-line technology can be used only with short precolumns and requires a sorbent with a great retention for phenylureas. The copolymer-based PRP-1 is found to be an excellent sorbent and it is then possible to apply on-line precolumn technology with preconcentration through two precolumns (10 × 21 mm ID) in series, the first one being packed with C18 silica and the other with the PRP-1 polymer. Interfering compounds are then trapped onto the first precolumn acting as a filter and common phenylurea-breakthrough volumes on the PRP-1 precolumn are higher than 500 ml. Knowing the amounts preconcentrated on both precolumns and using UV and electrochemical detection help the identification of phenylureas in river water. 相似文献
50.