Advances in layered double hydroxide (LDH)-based elastomer composites

This article reviews the advances in layered double hydroxide (LDH) materials and the synthesis of LDH-based elastomer composites. The potential of tuning the structure of LDH materials for desired properties and applications has attracted both academic and industrial interest in recent years. The modification of LDH materials and the use of such materials in the synthesis of composites with different elastomer matrices have been critically analyzed. Emphasis has been given to the use of Mg-Al LDHs and Zn-Al LDHs with different elastomers. The use of modified LDHs with elastomers substantially improves their mechanical, thermal and optical properties. Even “smart properties” of elastomers, such as reversible thermotropic optical characteristics, have been realized with the use of LDH-based multifunctional additives in rubber formulations. The flame retardance of some elastomer composites has also been enhanced with the use of modified LDHs. The possibility of replacing ZnO with LDH during rubber compounding has also been discussed, which would lead to drastic interventions in the well-established rubber processing technologies. LDH materials have also been reported to be biocompatible. Therefore, among the various possible applications of LDHs in different material development processes, their use in rubber technology offers the potential for environmentally friendly rubber products, even tires. Throughout this article, the structure, synthesis, properties and applications of elastomer/(LDH) composites are discussed, including suitable examples taken from the relevant literature.     

基于智能高分子材料的灵敏检测技术研究进展

近年来,将智能高分子材料识别响应的微小刺激信号转化并放大为方便人们读取的信号检测技术成为研究热点。本工作综述了近年来基于智能高分子材料的灵敏检测技术的研究进展,重点介绍了将智能高分子材料识别响应刺激信号转化为电信号、流量信号和光信号的检测技术。最后讨论了基于智能高分子材料的灵敏检测技术应用时需解决的关键问题,为基于智能高分子材料的灵敏检测技术的设计与应用提供了有价值的参考。     

Quantifying the uncertainty introduced by discretization and time‐averaging in two‐fluid model predictions

The two‐fluid model (TFM) has become a tool for the design and troubleshooting of industrial fluidized bed reactors. To use TFM for scale up with confidence, the uncertainty in its predictions must be quantified. Here, we study two sources of uncertainty: discretization and time‐averaging. First, we show that successive grid refinement may not yield grid‐independent transient quantities, including cross‐section–averaged quantities. Successive grid refinement would yield grid‐independent time‐averaged quantities on sufficiently fine grids. Then a Richardson extrapolation can be used to estimate the discretization error, and the grid convergence index gives an estimate of the uncertainty. Richardson extrapolation may not work for industrial‐scale simulations that use coarse grids. We present an alternative method for coarse grids and assess its ability to estimate the discretization error. Second, we assess two methods (autocorrelation and binning) and find that the autocorrelation method is more reliable for estimating the uncertainty introduced by time‐averaging TFM data. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5343–5360, 2017     

未来石化智能工厂顶层设计： 现状、对比及展望

国内石化智能工厂建设已有十年发展历史,目前正在进行智能工厂3.0的规划设计。石化智能工厂存在哪些挑战？石化智能制造有什么发展趋势？如何设计未来石化智能工厂？针对这三个问题,本文首先总结了石化智能工厂面临的挑战以及业务和技术能力需求。从工业软件、开放流程自动化、工程建设模式等三个视角分析了石化智能制造发展趋势,研究了国际灯塔工厂案例及启示。文章还阐述了石化智能制造的基本特征、内涵及演进路线,提出了未来石化智能工厂需要提升的5项关键能力和“六化”特征,提出了重点建设内容及智能场景规划思路,最后对未来发展进行了展望。     

Colour Measurement — Present Position and Future Developments

Presented at a Symposium on ‘The Next Fifty Colourful Years’, held by the Huddersfield Region at Huddersfield College of Technology, on 18 October 1968, Mr G. England in the chair The contributions to colour theory and colour measurement which have been made during the last 50 years and which led directly to some industrial end-use are reviewed briefly. Some of the more important applications are discussed and the associated difficulties for extension of use are outlined. The requirements for automated, colour-monitored dyeing processes are considered generally.     

Linking renewables and fossil fuels with carbon capture via energy storage for a sustainable energy future

Renewable energy sources and low-carbon power generation systems with carbon capture and storage (CCS) are expected to be key contributors towards the decarbonisation of the energy sector and to ensure sustainable energy supply in the future. However, the variable nature of wind and solar power generation systems may affect the operation of the electricity system grid. Deployment of energy storage is expected to increase grid stability and renewable energy utilisation. The power sector of the future, therefore, needs to seek a synergy between renewable energy sources and low-carbon fossil fuel power generation. This can be achieved via wide deployment of CCS linked with energy storage. Interestingly, recent progress in both the CCS and energy storage fields reveals that technologies such as calcium looping are technically viable and promising options in both cases. Novel integrated systems can be achieved by integrating these applications into CCS with inherent energy storage capacity, as well as linking other CCS technologies with renewable energy sources via energy storage technologies, which will maximise the profit from electricity production, mitigate efficiency and economic penalties related to CCS, and improve renewable energy utilisation.     

亚格子过滤双流体模型的网格依赖性

基于双流体方程和颗粒动力学理论的计算模型被广泛应用于流化床的气固两相流数值计算,高精度网格是其准确计算流动的必要条件。一些经典的微尺度阻力模型,其网格尺度决定其模拟结果的精度。亚格子过滤双流体模型是一种有效的适用于粗糙网格的计算模型,其包含的气固相间作用力和颗粒相应力本构方程是在高精度网格条件下,以微尺度双流体方程和颗粒动力学理论计算得到的气固流场为基础,对计算结果进行小尺度过滤后得出。使用亚格子过滤双流体模型替换基于颗粒动力学理论的双流体模型,针对同一物理问题,在不同网格尺度下进行了数值计算,结果表明此计算模型相比经典阻力模型具有较好的网格无关特性,并且和实验结果较为一致。同时也对颗粒动力学理论与之相结合进行了尝试,即仅使用亚格子过滤阻力模型,颗粒相应力仍然使用颗粒动力学模型,其计算结果的网格无关性及与实验值的吻合程度优于经典模型。     

Pullulan‐based films and coatings for food packaging: Present applications,emerging opportunities,and future challenges

Societal and industrial demands for lower environmental impact, cost effectiveness, and high‐performance goods and services are increasingly impacting the choice of technologies which are developed and deployed in consumer products. Like many other sectors, food packaging is moving to new technologies; the use of biopolymers is one of the most promising strategies toward an optimized use of traditional packaging materials (e.g., oil‐based plastics) without impairing the goal of extending shelf life. Among other food packaging materials, pullulan is attracting much attention due to its unique features. The goal of this review is to provide an overview of current and emerging applications of pullulan within the food packaging sector. In particular, the functional properties of interest for the food packaging industry will be discussed in light of the physicochemical attributes of this exopolysaccharide. Future challenges that may dictate the successful penetration of pullulan in the food packaging market are also outlined. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40539.     

炉箅设计要适应造气技术发展需要

对比分析了以煤为原料合成氨厂造气炉采用单烧法较之混烧法,使用专用炉箅较之通用型炉箅的优势;探讨了专用炉箅的结构和高度对布风的影响以及专用炉箅的边型对破渣和排灰速度的影响;提出了改进专用炉箅设计的建议。     

Silver front electrode grids for ITO-free all printed polymer solar cells with embedded and raised topographies, prepared by thermal imprint, flexographic and inkjet roll-to-roll processes

Semitransparent front electrodes for polymer solar cells, that are printable and roll-to-roll processable under ambient conditions using different approaches, are explored in this report. The excellent smoothness of indium-tin-oxide (ITO) electrodes has traditionally been believed to be difficult to achieve using printed front grids, as surface topographies accumulate when processing subsequent layers, leading to shunts between the top and bottom printed metallic electrodes. Here we demonstrate how aqueous nanoparticle based silver inks can be employed as printed front electrodes using several different roll-to-roll techniques. We thus compare hexagonal silver grids prepared using either roll-to-roll inkjet or roll-to-roll flexographic printing. Both inkjet and flexo grids present a raised topography and were found to perform differently due to only the conductivity of the obtained silver grid. The raised topographies were compared with a roll-to-roll thermally imprinted grid that was filled with silver in a roll-to-roll process, thus presenting an embedded topography. The embedded grid and the flexo grid were found to perform equally well, with the flexographic technique currently presenting the fastest processing and the lowest silver use, whereas the embedded grid presents the maximally achievable optical transparency and conductivity. Polymer solar cells were prepared in the same step, using roll-to-roll slot-die coating of zinc oxide as the electron transport layer, poly-3-hexylthiophene:phenyl-C(61)-butyric acid methyl ester (P3HT:PCBM) as the active layer and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the top electrode, along with a flat bed screen printed silver grid. The power conversion efficiency (PCE) obtained for large area devices (6 cm(2)) was 1.84%, 0.79% and 1.72%, respectively, for thermally imprinted, inkjet and flexographic silver grids, tested outside under the real sun. Central to all three approaches was that they employed environmentally friendly solvents, i.e. water based nanoparticle silver inks.     

Coated metals compatible with PVC jackets for bonded sheath cable applications

Mechanical strength in the cable sheath is particularly valuable for both fiber optical and copper pair cable. By bonding a PVC jacket to a coated metal tape, a mechanically strong sheath construction is obtained. Changes in PVC jacket technologies have created the need for PVC compatible coated metals with greater tolerance for variations in PVC jacketing materials. This need has been met by the development of a variety of coated metals having thermoplastic coatings which adhere to PVC. As a consequence of this development, new cable sheath designs for use in a variety of applications, such as riser cable and direct buried cable destined for local area networks, are possible. These cables may utilize both copper conductors and/or optical fibers for signal transmission. Data will be provided in the paper to show the effects of extrusion process conditions on adhesion for a variety of PVC resins. The properties of a variety of coated metals—aluminum, copper, and steel—will be discussed. Data on environmental tests of adhesion will be presented. Relationships between adhesion, metal characteristics, jacket properties, and mechanical performance of the sheath will be discussed. Cable applications for the PVC compatible metals will be discussed. Data on the performance of the bonded sheath in riser cable and buried local area network cable will be presented. New cable applications where coated metals in the sheath can provide lightweight armoring will also be discussed.     

Further studies on grid leakage in gas fluidized beds

Grid leakage data for single and multiorifice grids of various designs are given. The effect of the wind box volume on grid leakage has been investigated. A grid having long cylindrical nozzles can reduce solids leakage, but there is a critical nozzle length, for a given grid hole velocity, above which instabilities can occur. A method for computing this critical length is given. Implications for the design of commercial grids are discussed.     

基于18-冠-6的铅离子检测技术研究进展

铅是一种对环境和人体有严重危害的重金属污染物,研究铅离子（Pb²⁺）检测技术具有重要的实用意义。近年来,利用18-冠-6的Pb²⁺特异识别性能,研究者们设计构建了一系列智能高分子材料系统,为Pb²⁺检测提供了新的策略和途径。本文综述了近年来基于18-冠-6的Pb²⁺检测技术研究进展,重点介绍了基于智能膜、智能光学元件、智能微芯片、智能微胶囊等智能材料系统的Pb²⁺检测技术,讨论了这些Pb²⁺检测技术在实际应用中需要重点关注和解决的问题,以期为这类基于18-冠-6的Pb²⁺检测技术的进一步开发和应用提供参考。     

生物燃气净化提纯制备生物天然气技术研究进展

生物天然气是由生物燃气经过脱硫、脱碳、脱水等工艺手段净化提纯后得到的一种可再生燃气,其成分和热值与常规天然气无异,是我国重点发展的生物能源.传统生物燃气中高含量的H2S和CO2限制了其应用,因此生物燃气净化提纯技术是生物天然气实现商业化生产的关键.本工作综述了国内外生物天然气制备过程中的脱硫和脱碳技术,对各项技术的工艺...     

Application of Computational Fluid Dynamics for Simulation of Drying Processes: A Review

In recent years, computational fluid dynamics (CFD) has been used increasingly to improve process design capabilities in many industrial applications, including industrial drying processes. Drying of food and beverage products, industrial and municipal wastewater sludge, and other manufacturing and environmental products is done regularly in order to enhance the quality and life span of these products and to facilitate their use, storage, and transportation. With recent advancements in mathematical techniques and computer hardware, CFD has been found to be successful in predicting the drying phenomenon in various types of industrial dryers, which utilize all forms of drying operations including spray, freeze, and thermal drying techniques. The CFD solutions are being used to optimize and develop equipment and processing strategies in the drying industry, replacing expensive and time-consuming experimentations. However, a comprehensive review on the application of CFD for the design, study, and evaluation of industrial dryers is not yet available. A comprehensive review of the current literature on the use of CFD models in both industrial and lab-scale drying applications is presented in this article. The use of Eulerian-Eulerian and Eulerian-Lagrangian models in the study of the drying kinetics for gas–solid multiphase flow systems is fully discussed. Merits and disadvantages of using various CFD models in the design of industrial dryers are illustrated and the scope of their applicability is also discussed.     

Policy study on development and utilization of clean coal technology in China

The major obstacles to current development of clean coal technologies (CCT) are investigated, based on study of current laws, regulations and policies which have been used to accelerate CCT development in China, evaluation of implementation of these regulations, policies and economic incentives, and comparison between Chinese and foreign experiences. The evaluation of available clean coal technologies is conducted in four areas, i.e. power sector, industrial boiler, chemical production and fuel oil substitution and household use. In addition, clean coal technologies and the development plans suitable for the Chinese situation are suggested. Finally, based on technical and economic evaluation, policy and countermeasure recommendations on development of Chinese clean coal technology are made.     

Grid leakage (weeping and dumping) in a pilot plant size gas fluidized bed

Substantial grid leakage in large industrial fluidized beds is highly undesirable because it can lead, among other things, to grid erosion or plugging. Experiments have been carried out to study grid leakage using a cracking catalyst (arithmetic mean diameter 65 μm) in a 0.6 m diameter column. The flow pattern under the grid was charted with a hot wire anemometer. Micro-isokinetic probes were developed to study the particle flux returning from the windbox towards the grid. Particles were sucked in isokinetically, recovered in a filter, weighed and analyzed for particle size in a Coulter counter. Upward particle fluxes at the grid were determined by extrapolation of the flux at various distances below the grid. Grid leakage was studied for grids of various geometries which had holes of 1.27 cm diameter. Various measurement methods, a model for re-entrainment and correlations are given.     

氟表面活性剂的工业合成及应用

讨论了氟表面活性剂3种较为成熟工业合成方法,即电解氟化法、氟烯烃调聚法和氟烯烃齐聚法等,比较了3个方法的优缺及各自有待解决的问题.介绍了氟表面活性剂的特殊性能及目前在一些领域的特殊应用.认为我国研制氟表面活性剂在性能、种类、价格及应用领域上与国外相比尚有较大差距;应充分利用自身市场优势.抓住机遇.提高合成技术、工艺,降低成本.     

聚合物高效脱挥技术进展

聚合物中挥发分含量的不同导致聚合物脱挥过程遵循不同的热质传递机理，基于脱挥过程关键机制开发高能效的聚合物脱挥技术与装备具有重要工程意义。本文分别简述了闪蒸脱挥、起泡脱挥以及扩散脱挥3种脱挥方式的传递机理、过程特征以及过程模型，在此基础上从脱挥工艺和装备两个方面综述了近年来聚合物脱挥过程强化的手段与方法，并系统介绍了栅缝降膜脱挥、超重力旋转强化脱挥、超临界流体辅助脱挥、超声空化强化脱挥等过程强化新技术及其应用现状，提出了未来聚合物脱挥理论与工程实践的研究方向：一方面仍需深入研究扩散脱挥与起泡脱挥的耦合作用机制，建立精准、普适的脱挥过程模型；另一方面指出立式降膜脱挥技术因其能效优势，有望成为未来大规模工业脱挥器的重要选择。     

Electroactive phases of poly(vinylidene fluoride): Determination,processing and applications

Poly(vinylidene fluoride), PVDF, and its copolymers are the family of polymers with the highest dielectric constant and electroactive response, including piezoelectric, pyroelectric and ferroelectric effects. The electroactive properties are increasingly important in a wide range of applications such as in biomedicine, energy generation and storage, monitoring and control, and include the development of sensors and actuators, separator and filtration membranes and smart scaffolds, among others. For many of these applications the polymer should be in one of its electroactive phases. This review presents the developments and summarizes the main characteristics of the electroactive phases of PVDF and copolymers, indicates the different processing strategies as well as the way in which the phase content is identified and quantified. Additionally, recent advances in the development of electroactive composites allowing novel effects, such as magnetoelectric responses, and opening new applications areas are presented. Finally, some of the more interesting potential applications and processing challenges are discussed.