Towards full-resolution inline electron holography

With the availability of fast computers, inline electron holography, a technique for reconstructing both amplitude and phase of the electron wave function as scattered by the sample from a set of differently aberrated transmission electron microscopy images, is becoming increasingly quantitative. While focal series reconstruction from transmission electron microscopy images has already been practiced for at least 3 decades, existing approaches can only recover a relatively small band of spatial frequencies. Here I present a reconstruction scheme which is capable of reconstructing the electron wave function for a very large range of spatial frequencies, demonstrating its performance using simulated as well as experimental data.     

In-line monitoring flow in an extruder die by rheo-optics

A new modular slit die with optical windows in two different positions and three pressure transducers flush-mounted along the wall was built and coupled to the exit of a twin-screw extruder. Thus, the birefringence and the pressure drop of polystyrene were monitored inline during extrusion. Two experimental procedures were tested: steady-state and cessation of extruder feeding. The latter proved to be very useful in the case of polystyrene since the ratio between the birefringence and the pressure drop can be quantified for a wide range of steady-state conditions with a single experiment. In fact, down to relatively lower values of pressure drop, the birefringence proved to be a function of shear stress at the wall only, depending neither on the initial feeding rate nor on the aspect ratio of the slit die, for W/h down to 5, at least.     

超滤法处理改善小鼠单抗的固定化效果

商品化小鼠单抗试剂中普遍添加了高浓度的保护蛋白,如牛血清白蛋白(BSA),这给抗体的固定化带来了严重的干扰。本研究基于超滤技术发展了一种超微量抗体试剂(用量为10μL,约含2μg抗体、100μgBSA)预处理方法,能有效去除商品化抗体试剂中的高浓度BSA,使微珠表面固定化小鼠单抗的数量显著提高,并在蛋白质检测中得到了较好的结果,为缓解抗体产品供应现状对蛋白质芯片研究工作的制约提供了一条简单实用的途径。     

不同速度混合的阵列信号速度分析*

为了考察正交偶极子测井中同向分量的速度变化规律,该文采用不同速度传播的两个相同频率的正弦波以不同幅度比进行混合来模拟同向阵列在不同方位接收到的波形,并用波形匹配方法提取混合后的波列速度。数值结果表明,同向分量的视速度一般介于两个混合的正弦波的速度之间,且与由拟合得到的双曲正切函数比较吻合。但在特殊条件下,也会出现阵列复合波形的速度会在正弦波速度范围之外,表现出一定的异常。异常出现的条件和大小与源距、频率以及速度差有关,并可用一个简单的数学关系式表达。该文的结果还可以为实际处理不同源距的混合波测速问题提供参考。     

A continuous flow-batch hybrid reactor for commodity chemical synthesis enabled by inline NMR and temperature monitoring

Inline, real time NMR and temperature measurements have been used to optimise the continuous flow synthesis of difluoromethyltrimethylsilane (TMSCF₂H) by the reduction of the Ruppert-Prakash reagent (TMSCF₃). These measurements were used to maximise the space-time-yield, while ensuring this exothermic process remains safe. In this way, a three-fold increase in space-time-yield was achieved compared to the reported batch procedure, isolating 25?g of pure TMSCF₂H after 105?min.     

Multi-analyte quantification in bioprocesses by Fourier-transform-infrared spectroscopy by partial least squares regression and multivariate curve resolution

This paper presents the quantification of Penicillin V and phenoxyacetic acid, a precursor, inline during Pencillium chrysogenum fermentations by FTIR spectroscopy and partial least squares (PLS) regression and multivariate curve resolution – alternating least squares (MCR-ALS). First, the applicability of an attenuated total reflection FTIR fiber optic probe was assessed offline by measuring standards of the analytes of interest and investigating matrix effects of the fermentation broth. Then measurements were performed inline during four fed-batch fermentations with online HPLC for the determination of Penicillin V and phenoxyacetic acid as reference analysis. PLS and MCR-ALS models were built using these data and validated by comparison of single analyte spectra with the selectivity ratio of the PLS models and the extracted spectral traces of the MCR-ALS models, respectively. The achieved root mean square errors of cross-validation for the PLS regressions were 0.22 g L⁻¹ for Penicillin V and 0.32 g L⁻¹ for phenoxyacetic acid and the root mean square errors of prediction for MCR-ALS were 0.23 g L⁻¹ for Penicillin V and 0.15 g L⁻¹ for phenoxyacetic acid. A general work-flow for building and assessing chemometric regression models for the quantification of multiple analytes in bioprocesses by FTIR spectroscopy is given.     

PFSS絮凝-膜分离法处理炼油废水

采用PFSS絮凝-膜分离法处理炼油废水.通过对PAC、PFS和PFSS的除油、CODcr、SS性能比较,确定了PFSS为较好的絮凝剂,探讨了絮凝剂用量、絮凝时间对絮凝效果的影响.通过对膜材料的分析,确定了聚氯乙烯-聚丙烯腈膜对炼油废水有较好的处理效果,探讨了进料流量、操作压力、温度对膜通量的影响.结果表明:当PFSS用量为50-70mg/L、反应时间为8min、进料流量为60L·h-1、操作压力为1.6Mpa、温度为40℃时,通过絮凝沉降、膜分离处理过程,炼油废水中的油、CODcr、SS的去除率分别达到98%、95%、93%以上.出水水质达到国家一级排放标准.     

PSF-SPES共混中空纤维超滤膜制备的研究

以聚砜(PSF)、磺化聚醚砜(SPES)和醋酸纤维素(CA)为膜材料,水为内凝胶剂,采用干湿法制备了PSF-SPES共混中空纤维超滤膜,探讨了PSF-SPES铸膜液中SPES离子交换容量(IEC)、SPES浓度、添加剂、外凝胶剂的选择和热处理对膜性能的影响。所得共混超滤膜性能如下:w=0.0 0 1的Na2SO4截留率19.9%,通量62 L/(h.m2.MPa);w=0.001的PEG4000截留率78.2%,通量85 L/(h.m2.MPa)。此外,以PSF-SPES中空纤维为支撑膜,采用醋酸纤维素作为涂层液,研究了CA/PSF-SPES复合超滤膜性能,讨论了CA/PSF-SPES共混中空纤维超滤膜结构。