In Situ Microscopy for Online Monitoring of Enzymatic Processes

In situ Microscopy (ISM) is an optical analysis method that allows non‐invasive monitoring of processes in real‐time. In this article online monitoring of enzyme carriers and the determination of their mechanical stability are presented as new application areas for ISM. As proof of principle the fragmentation of Lewatit VP OC 1600 particles in a stirred tank reactor is tracked. The image algorithm that was used to analyze the acquired image data is described and the results of the stability study are shown. Additional application possibilities of ISM in the area of two‐phase systems are demonstrated.     

In Situ Loading of Basic Fibroblast Growth Factor Within Porous Silica Nanoparticles for a Prolonged Release

Basic fibroblast growth factor (bFGF), a protein, plays a key role in wound healing and blood vessel regeneration. However, bFGF is easily degraded in biologic systems. Mesoporous silica nanoparticles (MSNs) with well-tailored porous structure have been used for hosting guest molecules for drug delivery. Here, we report an in situ route to load bFGF in MSNs for a prolonged release. The average diameter (d) of bFGF-loaded MSNs is 57 ± 8 nm produced by a water-in-oil microemulsion method. The in vitro releasing profile of bFGF from MSNs in phosphate buffer saline has been monitored for 20 days through a colorimetric enzyme linked immunosorbent assay. The loading efficiency of bFGF in MSNs is estimated at 72.5 ± 3%. In addition, the cytotoxicity test indicates that the MSNs are not toxic, even at a concentration of 50 μg/mL. It is expected that the in situ loading method makes the MSNs a new delivery system to deliver protein drugs, e.g. growth factors, to help blood vessel regeneration and potentiate greater angiogenesis.     

Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality

A novel one-step synthetic route, the double in situ approach, is used to produce both TiO₂ nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)₄) forming nano-TiO₂ in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites.     

陶瓷原位凝固胶态成形基本原理及工艺过程

陶瓷原位凝固胶态成形方法是制备净尺寸复杂陶瓷部件最具应用前景的方法，笔者主要介绍凝胶注模成形、温度诱导絮凝成形、胶态振动注模成形、直接凝固注模成形和快速凝固注射成形的基本原理及工艺过程，并展望了原位凝固胶态成形的工艺将会给传统硅酸盐工业带来成形工艺的巨大变革。     

EX Situ和In Situ Characterization辨析

前缀词“in situ”和“ex situ”在耐火材料的科技文献中频现。二者都具泛义，在许多情况下可用，弄清其确切含义并贴切地译成汉语十分必要。本文对In Situ和Ex Situ Characterization的含义及其在不同场合的应用作了分析。在表征状态时，in situ和ex situ表达了“原位”和“移位”的不同，互为反义词。用于仪器分析方面，前者表示对被测物在真实环境中的多项同步分析，也表示单项目的连续分析，其连续的意义不可忽视；而后者则指在非原始的、非综合的条件下分别进行的检测，包括用前检测、模拟试验和用后残衬分析。可把在实际正在发生中的、连续的、综合的观察和分析，统称为In Situ Characterization；而用前的检测、模拟试验和用后残衬分析，可统称为Ex Situ Characterization。如何译成中文，要弄清具体的背景和含义，无需硬译。     

Pervaporation‐Assisted Esterification of Caproic Acid with Isobutanol in Conventional,In Situ,and Ex Situ Reactors

The factors that affect the pervaporation‐assisted esterification of caproic acid and isobutanol have been investigated in a batch reactor and compared with two different pervaporation reactors, in situ and ex situ reactors, with different configurations. The operating process parameters of the pervaporation modules can be adjusted to optimize the performance, which improves the conversion of reactants and reduces the operating costs. The performances of the reactors have been extensively studied and the membrane selectivity has been investigated in terms of the flux of individual reaction species. The mass transfer limitation of both pervaporation reactors was studied and suitably eliminated. In addition, the performance of the pervaporation reactors was investigated by evaluating the ratio of water removal rate to the water production rate.     

In Situ Ultrasonic Measurements as a Tool to Characterize the Stages of the Zeolite A Crystallization Process

Zeolite A (LTA) was synthesized at 80 °C under hydrothermal conditions from a gel with the molar composition of 2.5 Na₂O : 2 SiO₂ : Al₂O₃ : 80 H₂O. In the present study, we report the use of home-made ultrasound devices as a real-time, in situ diagnostic tool for monitoring the progress of zeolite formation. In addition, the specific aim of this study was to show that the measured ultrasound parameters – ultrasonic (US) velocity and attenuation – simultaneously provide independent information about the changes in the liquid and solid phase, respectively, during the crystallization process. Both views are necessary for extracting kinetic data about the zeolite crystallization processes and allow elucidating the different stages of zeolite LTA formation process. The obtained in situ US data were compared with conventional ex situ powder X-ray diffraction measurements following the formation of zeolite LTA from dense gels. The results demonstrate that a good correlation exists between the crystallization progress of zeolite LTA in terms of crystallinity changes and the ultrasonic attenuation and velocity.     

地下水有机污染的原位生物修复技术及其应用

文章介绍了世界范围内地下水的有机污染现状,并分析了地下水中有机污染物的来源。从地下水有机污染对环境及人类健康的危害,提出了地下水有机污染修复的必要性和紧迫性。随后着重介绍了地下水有机污染的几种原位生物修复技术,即生物注射法、有机黏土法、抽提地下水系统与回注系统相结合法、生物反应器法等,说明了它们修复流程及工作原理,并对各自的修复特点进行了比较。紧接着就常见的有机污染类型,如石油烃污染、多换芳香烃污染、氯代烃污染等,提出了相应的原位生物修复方法及其应用效果。最后文章对几种原位生物修复方法进行了总结,指出了生物修复方法存在的不足,并对其更好的应用提出了建议及展望。     

In Situ Determination of the Physical State of Biological Samples during Freeze Drying

The proceeding change of water content in a freeze-drying process, as well as the physical state of cell–sugar suspensions with Lactobacillus paracasei ssp. paracasei, was monitored by means of an in situ weighing system. Due to the pressure and temperature variations in the drying chamber, the weighing system was found to be influenced. This deviation of the weighing system was quantified by means of drying simulations with drying-inert Teflon dummies. This quantified deviation could be used for correction of the following freeze-drying processes. The applicability of this correction method was verified by drying model sugar solutions with known dry matter. Taking the quantified drift of the balance into account, the measured water contents for the model solution were proved to deviate less than 5% from the actual value. Finally, this verified correction method was applied to freeze drying of cell–sugar suspensions. As a result, the drying course of the cell–sugar samples could be depicted in the appropriate state diagram. Thus, the weighing system could be used to monitor the state transitions, which the bacterial suspension experienced during freeze drying, and qualified for specific investigations on the glassy state during freeze drying.     

Demonstration of In Situ Radio‐Frequency Heating at a Former Industrial Site

In situ radio‐frequency heating (ISRFH) combined with soil vapor extraction was demonstrated at a contaminated field site of a former hydrotreatment plant in Zeitz near Leipzig. The project was carried out in several phases including cold soil vapor extraction for comparison. During the test, a soil volume of about 300 m³ was heated to an average temperature of 54 °C. As expected, the extraction rate for hydrocarbons (especially the main contaminant benzene) was markedly enhanced by soil heating. Furthermore, microbial degradation of organic compounds was supported. Although a total amount of approximately 1.4 t of hydrocarbons was removed from the soil, the demonstration project was not aimed at complete remediation of the site. Conditions limiting the extent of cleanup are discussed in detail and conclusions for an efficient application of ISRFH in soil remediation are derived whereas experiences from other sites are also implied.     

Facile Bulk Synthesis of Homogeneous and Transparent Nanocrystals Hybrids via In Situ Transformation of Ionomers into CdS Quantum-Dot-Polymer

We systemically report on a method for fabricating bulk CdS QD-polymer hybrids nanocomposites with tunable control photoluminescence (PL) by using as-prepared ionomers. Firstly, we rationally designed to synthesize well-dispersed PMMA/Cd(AA)₂ (cadmium acrylate) ionomers containing different concentrations of Cd²⁺ ion clusters via free-radical polymerization. And then, we introduced H₂S gas into the ionomer solutions to obtain transparent PMMA/CdS QD-polymers in situ. Subsequently, we employed PMMA/CdS QD-polymers to further produce claviform CdS/PMMA hybrid nanocomposites via in situ bulk polymerization. The properties of as-prepared QD-polymers and their hybrid nanocomposites were thoroughly investigated by Ultraviolet–visible (UV-vis), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), photoluminescence (PL), thermogravimetric analyses (TGA) measurements. We have found that these QD-polymers exhibit uniform dispersity, good optical property and an obvious advantage on thermal stability, along with facilely producing bulk nanocrystal/polymer hybrid nanocomposites with a large scale.     

Reactive Separations for In Situ Product Removal of Enzymatic Reactions: A Review

The topic of integrating enzymatic reactions with in situ product removal is addressed. Different integrated reactive separations structured accordingly to the corresponding unit operations, i.e., reactive distillation, reactive chromatography, reactive crystallization, and extractive biocatalysis, are discussed. Special attention is given to their realization with homogenous and heterogeneous biocatalysis. Various enzyme immobilization techniques are presented and distinct strategies for installation of heterogeneous catalysts into process equipment are discussed.     

In Situ X‐Ray Diffraction and Stress Analysis of Solid Oxide Fuel Cells

To increase the long term stability and performance of solid oxide fuel cell (SOFC) materials, it is important to understand the main degradation processes in their functional layers. In this work, the interface between electrolyte and anode material was investigated by in situ X‐ray diffraction (XRD) stress and phase analysis. It has been found that the determining process for the initial degradation of SOFC is the reduction of the anode material with hydrogen. During this process a tensile strength of 600–700 MPa is measured. These stresses are induced in the electrolyte material and produce crack networks. The reduction from nickel oxide to pure nickel was monitored by in situ phase analysis. This reaction induces tensile stress at the interface between electrolyte and anode. The stress produced in the electrolyte material was also confirmed by the observation of crack networks detected using scanning electron microscopy (SEM). Finally, the reducing process was optimized using different process gases, decreasing the destructive tensile stress level.     

膜技术用于工业废水处理的现状及进展

主要介绍了电渗析、反渗透、超滤、纳滤、膜蒸馏、乳状液膜技术等膜分离技术的基本原理及特点 ,重点报导了这些膜分离技术在工业废水处理中的应用现状 ,并讨论了它们应用于工业废水处理的可行性     

渗透汽化中试膜组件的设计及装置性能测试

介绍了年产８０吨无水乙醇渗透汽化中试装置组件的设计及装置性能的测定。结果表明，中试装置内乙醇浓度２发布和压降与设计相当一致，由物料衡算得到产品乙醇的回收率〉９６％，能耗为：耗电０．４ｋＷｈ／ｋｇ无水乙醇，耗水０．０４度／ｋｇ无水乙醇，若考虑目前动力设备容量仅利用了３９％，则其能耗与文献报导接近，为恒沸精馏的１／３左右。     

Looking on Heterogeneous Catalytic Systems from Different Perspectives: Multitechnique Approaches as a New Challenge for In Situ Studies

Adapting physico-chemical characterization techniques for in situ studies of real heterogeneous catalysts during conditioning, reaction, and deactivation processes is a research topic of growing importance. Up to now, in most studies only one single in situ technique is applied. However, new trends are focused on using a portfolio of several in situ methods to obtain comprehensive information on structure-reactivity relationships. This review discusses such application examples with the aim to point out the particular benefits that arise from multitechnique approaches for understanding processes like formation of active sites, interaction of those sites with reactant molecules, and catalyst deactivation. Except for Fourier-transform infrared spectroscopy and quasi-in situ X-ray photoelectron spectroscopy, the examples deal mainly with the combined use of bulk techniques such as electron paramagnetic resonance, ultraviolet/visible diffuse reflection spectroscopy, laser-Raman spectroscopy, temperature-programmed spectroscopy, X-ray diffraction, and X-ray absorption spectroscopy. However, although not being surface-sensitive per se, these techniques provide results relevant for the catalyzed reaction. Illustrative case studies comprise the investigation of (i) vanadia-based catalysts during selective oxidation and ammoxidation of toluene and during methanol synthesis, (ii) supported chromium oxides during octane aromatization, (iii) zeolite crystallization and catalysis, and (iv) a Cu/ZnO catalyst during methanol synthesis.     

In Situ Polymerization and Characterization of Aniline and O-Anthranilic Acid Copolymer/Pyrogenic Silica Nanocomposites

Copolymers of aniline and o-anthranilic acid/amorphous fumed silica nanocomposite are synthesized by 5:1 molar ratios of the respective monomers with different percentages of silica nanoparticles via in situ chemical co-polymerization. The electrical conductivity and spectral characteristics upon incorporation of o-anthranilic acid units into the polyaniline backbone in presence of silica nanoparticles are investigated. The results are justified by measuring the UV-Vis absorption spectra, FT-IR for PANAA copolymer, and in situ PANAA/silica nanocomposite. Also, the thermal gravimetric analysis for the copolymer powder formed in the bulk in absence and in presence of silica nanoparticles are carried out.     

In Situ Hydrogenation of CO2 by Al/Fe and Zn/Cu Alloy Catalysts under Mild Conditions

The development of efficient metal catalysts for in situ hydrogenation of CO₂ in water under mild conditions has gained considerable attention. Three Al alloys (Al/Fe, Al/Fe/Cu, Al/Cu) and three Zn/Cu alloys for in situ hydrogenation of CO₂ in aqueous bicarbonate solutions were investigated. Hydrogen was generated by reaction of Al, Fe, and Zn in the alloys with water. In situ hydrogenation of CO₂ was likely to be catalyzed by intermetallic compounds and generated metal oxides. Al alloys catalyzed the hydrogenation to methane while Zn/Cu alloys produced CO and formic acid. Zn/Cu5 possessed the highest catalytic activity, which was attributed to the CuZn5 crystal planes in the alloys. Insights are provided into the importance of compositions and structures of alloys for the selectivity for in situ hydrogenation of CO₂ in aqueous bicarbonate solutions.     

Design of a Flexible Pilot Plant Reactor for the Steam Cracking Process

A design technique for a pilot plant reactor of single diameter is presented to scale up or down steam cracking coils of different configurations like mono‐tubular, classical, and reversed splits. Using dimensional analysis, two criteria are selected in establishing partial similarity between different scales, the mean residence time, and the axial pressure profile in the reactor, in addition to preserving the flow pattern within the turbulent region. The sensitivity and accuracy of the proposed method is compared to another conceivable alternative that focuses on the lateral gradients. The pilot reactor coil is adapted for any large‐scale reactor by the adjustment of feed flow rate and the effective length exposed to the firebox heat flux. Simulation results for naphtha cracking in a commercial split coil and also the equivalent pilot plant reactors are used for verification and validation of this method.     

In Situ Formation of a Novel Nanocomposite Structure Based on MCM-41 and Polyethylene

M41S materials are prepared by in situ assembly of inorganic precursors and organic template and can be viewed as nanocomposites of the siliceous phase and organic surfactant. Calcination of these precursors gives the M41S materials that have been used to prepare novel nanocomposite structures, in which the organic phase inside the nano-sized pores is isolated by the nano-sized inorganic pore walls. The nanocomposite structures can be formed by in situ polymerization of monomers inside the channels. Polymerization of ethylene takes place inside the nano-sized pores, producing the desired nanocomposite structure. The resulting polyethylene was found to be a mixture of crystalline and amorphous phases.