Design of electrofusion joints and evaluation of fusion strength using fusion simulation technology

Fusion simulation is one of the key techniques in designing and producing electrofusion (EF) joints for gas distribution and in evaluating fusion joint integrity. This paper describes the result of a numerical simulation of a thermal fusion process, using the finite element method. A nonlinear heat transfer computer program was used to obtain the temperature profile of a large electrofusion joint at fusion. The effects of applied voltage, heating time, wire pitch, and ambient temperature were examined for designing a 150-mm EF joint. A method to shorten the cooling time was also investigated. The fusion condition range suitable for a 150-mm EF joint was found to be slightly narrower than that suitable for a 50-mm EF joint. Examination of the effect of wire pitch revealed that if the pitch is extremely large, thermal degradation starts in the resin close to the wire before the fusion-interface strength reaches the maximum value. We have developed a program to simulate the process of closing the gap between the pipe and the joint due to resin expansion and melting after the power is supplied.     

A microfluidic toolbox for cell fusion

Cellular fusion is a key process in many fields ranging from historical gene mapping studies and monoclonal antibody production, through to cell reprogramming. Traditional methodologies for cell fusion rely on the random pairing of different cell types and generally result in low and variable fusion efficiencies. These approaches become particularly limiting where substantial numbers of bespoke one‐to‐one fusions are required, for example, for in‐depth studies of nuclear reprogramming mechanisms. In recent years, microfluidic technologies have proven valuable in creating platforms where the manipulation of single cells is highly efficient, rapid and controllable. These technologies also allow the integration of different experimental steps and characterisation processes into a single platform. Although the application of microfluidic methodologies to cell fusion studies is promising, current technologies that rely on static trapping are limited both in terms of the overall number of fused cells produced and their experimental accessibility. Here we review some of the most exciting breakthroughs in core microfluidic technologies that will allow the creation of integrated platforms for controlled cell fusion at high throughput. © 2015 Society of Chemical Industry     

基于粒子群算法的多传感器数据融合

粒子群算法是一种有效的寻找函数极值的演化计算方法,它简便易行、收敛速度快,但存在收敛精度不高、易陷入局部极值点的缺点。本文对原有算法中的固定惯性权重进行改进,着重分析了惯性权值因子在粒子群优化(PSO)算法中的作用,在现有的线性递减权值方法上,提出一种非线性权值递减策略,并将其尝试性地运用到多传感器融合的领域,运用该算法对数据融合中的加权因子进行估计。实验结果表明,改进的PSO算法能近似最优地确定数据融合中各权值因子,使融合在信息源的可靠性、信息的冗余度/互补性以及进行融合的分级结构不确定的情况下,以近似最优的方式对传感器数据进行融合,有效地从各融合数据中提取有用信息,成功排除噪声干扰,取得了良好的融合结果。     

The fusion characteristics of PVC-plasticizer mixtures

Dry blends of a PVC resin with various plasticizer mixtures were processed at different temperatures to produce samples of different degrees of fusion. The ease of fusion increased with decreasing the solid-gel transition temperature (Tm) of the plasticizer mixture. Nevertheless. Tm was not necessarily a linear function of the individual concentration of plasticizers in the mixture. Therefore, the ease of fusion showed in some cases an optimum at a given concentration of the plasticizer mixture.     

Plastic coatings for laser fusion targets

A brief review on coating techniques for laser fusion targets is presented. Specifications for plastic target coatings are given followed by details on latest advances in application techniques. Two processes, vapor-phase pyrolysis (VPP) and the low-pressure plasma (LPP) method, are described that produce conformal coatings of the required dimensional tolerances: 1% variation in coating thickness and surface smoothness with peak-to-valley values not exceeding a few 100 Å. A VPP coater with a low-temperature deposition chamber is discussed in which two main mononers were used: di(p-xylylene) and di(2-chloro-p-xylylene). For the LPP process a capacitatively coupled a.c. (1 kHz) coater with two parallel flat-plate electrodes was used. In this process the main monomers were: p-xylene, ethylene, butadiene, and perdeuterated p-xylene. The VPP process has produced coatings as thick as 350 μm with a surface smoothness of 1 μm, and both processes (VPP and LPP) are capable of producing coatings with surface smoothnesses of a few 100 Å.     

Gelation and fusion of vinyl plastisols

The gelation of vinyl plastisols at constant temperature has been found to follow the equation ln [(C ? C_e)/(U ? C_e)] = (? π²/a²)D_τ + ln (8/π²), where C is the resin phase concentration, C_e the equilibrium resin phase concentration, U the critical resin phase concentration, a the average particle size, D the diffusion constant, and τ the time required for the onsent of gelation. A light reflectance apparatus capable of measuring the gelation process is described. The effect that various resin–plasticizer parameters have on the gelation and fusion process is discussed. The light-reflectance apparatus is also useful for estimating various resin and formulating parameters.     

生物质对高灰熔点煤灰熔融特性的调控机制

为探索生物质对高灰熔点煤灰熔融特性的影响,向鹤壁煤和晋城无烟煤中分别加入不同质量比的花生壳和玉米秸秆,采用智能灰熔点测定仪测定混合灰样的灰熔点,X-射线荧光仪和X-射线衍射仪分析灰熔融特性变化的原因。结果表明:随着生物质质量分数增大混合灰熔融温度逐渐降低,选择合适生物质质量分数能使灰熔融流动温度满足液态排渣要求;鹤壁煤混合灰样和晋城无烟煤混合灰样中的高熔点矿物质与煤灰其他成分反应生成了铁橄榄石、铁尖晶石、白榴石、钙长石和微斜长石等,这些矿物之间能够形成低温共熔物,从而导致混合灰的灰熔融温度降低。     

配煤对煤灰熔点的影响及灰熔点预测模型研究

针对皖北刘桥二矿煤（A）属于高灰熔点煤,无法满足Shell气化炉液态排渣的需要。考察了采用配煤技术降低煤A的灰熔点的效果,结果表明,配煤可以显著的降低煤A的高灰熔融性。使其能够满足Shell气化炉液态排渣工艺的要求。并采用最小二乘法对灰熔点与煤灰灰成分之间建立并回归了预测模型,预测模型方程表明,若能增加配煤煤灰中MgO的含量可显著降低煤灰熔点,增加配煤煤灰中CaO的含量可使煤灰熔点降低,在煤灰中SiO2和Al2O3总含量一定的条件下,高硅低铝的配煤煤灰可进一步降低煤灰熔点。同时该模型能较好地预测三种原煤配煤的灰熔点。     

一种基于多模型融合软测量建模方法

针对锌湿法冶炼净化过程中钴离子浓度LS-SVM软测量建模方法精度低的问题,将最小二乘支持向量机（LS-SVM）和自回归滑动平均模型（ARMA）融合建立钴离子浓度融合软测量模型,首先通过离子浓度序列的小波变换获得序列的低频和高频子序列,对各子序列分别进行相空间重构,并在相空间中分别建立最小二乘支持向量机模型,然后将各模型的输出利用小波重构整合得到钴离子基于LS-SVM软测量结果,利用自回归滑动平均模型对基于LS-SVM模型输出误差信息进行建模,通过对两个模型的融合,获得融合模型的软测量估计值。将该方法应用于锌液净化除钴段入口钴离子浓度的软测量,结果表明该方法比单一的LS-SVM方法具有更好的泛化性能和测量精度,显示出良好的应用潜力。     

Measurement of PVC fusion (gelation)

PVC fusion (gelation) occurs with melting of crystallites followed by recrystallization. This recrystallization, as it occurs at the primary particle boundary, physically ties together the structure into a three dimensional network. One way of measuring the extent of this three dimensional network structure is to measure the force required to deform the material through a zero land length capillary. We examine this test method for various molecular weight PVC compounds, with and without plasticizer, and for various degrees of grinding the product.     

IgG-Fc融合蛋白的研究进展

IgG-Fc融合蛋白是将生物活性蛋白与IgG的铰链区和Fc片段进行基因重组而表达的融合蛋白。IgG-Fc融合蛋白不仅可发挥所融合蛋白的生物学活性,还赋予其类似抗体的特性,包括延长血浆半衰期以及Fc片段特有的一系列效应功能,并已广泛应用于临床治疗、生物医学研究等领域。合理优化IgG-Fc融合蛋白是未来发展趋势,选择合适的IgG亚类作为融合载体,采用Fc片段单个或多个氨基酸序列修饰、糖基化改造等,提高融合蛋白的血浆半衰期、优化融合蛋白的效应功能,最终达到最佳免疫治疗效果。本文对IgG-Fc融合蛋白的功能、相应优化策略作一综述,并介绍了其临床研究现状。     

榆林煤灰熔融特性及黏温特性

榆林煤灰分中钙、硫含量均很高,气流床气化过程中存在易于结渣的问题,实验室测量其黏温曲线波动性很大。 采用FactSage6.2软件计算三元平衡相图和煤灰高温熔融过程的物相变化规律,并结合XRD手段,分析了加入SiO₂引起的煤灰熔融特性和黏温特性改变的机理以及黏度波动的原因。结果表明,榆林煤灰熔点随着硅铝比（S/A）、酸碱比（A/B）的增大先降低后升高;钙铝黄长石与煤灰黏温曲线波动性有较强关联,通过FactSage二元相图得出,加入SiO₂至S/A=2.48可减小曲线波动性。FactSage数值计算结果与实验结果吻合良好,表明化学热力学反应平衡分析方法是研究灰渣熔融特性的一种有效手段。     

Fast image enhancement based on color space fusion

The current Retinex algorithm processes the RGB channels separately for color image enhancement. However, it changes the ratios of RGB components and also causes some serious problems, such as color distortion, color noise, and the halo artifacts. To solve these issues, we propose a novel algorithm based on color space fusion. The single scale Retinex with fast mean filtering is applied to the luminance component in hue‐saturation‐value (HSV) color space. An enhancement adjustment factor is introduced to avoid color distortion and noise amplification. Then, the surrounding function is replaced by a small scale Gaussian filter in RGB color space to eliminate the halo artifact. A parameter is involved to keep the color natural when the reflection is estimated. Finally, the enhanced color image is constructed from the weighted averaging results of these two steps. The subjective and objective evaluations of many different backlight images captured by different cameras are implemented to verify the validity of the proposed algorithm in our experiments. The experimental results show that the proposed algorithm can not only significantly suppress the halo effect and noise amplification, but can also remove color distortion. Our proposed algorithm is superior to the multi‐scale Retinex with color restoration approach and other state‐of‐the‐art methods. © 2014 Wiley Periodicals, Inc. Col Res Appl, 41, 22–31, 2016