色谱反应分离器研究进展

本文介绍色谱反应分离器的原理及研究进展，概述在化学和生物工程产品制备方面的应用，并指出进一步研究的方向。     

Three-dimensional simulation using fixed coarse-grid thermal-fluid scheme and conduction heat transfer scheme in distinct element method

Three-dimensional simulation using particle-thermal-fluid coupling scheme with a mixed Lagrangian-Eulerian approach is presented and the scheme is described by extending author's previous research [Y. Shimizu, 2004. “Fluid Coupling in PFC2D and PFC3D”, numerical modeling in micromechanics via particle methods—2004, Proceeding of 2nd International PFC Conference, Balkema, 2004, pp. 281-287]. The scheme solves the continuity, Navier-Stokes (N-S) and thermal energy equations numerically in Eulerian Cartesian coordinates, then derives pressure, velocity vectors and temperature for each fixed cell by considering particle existence. On the other hand, driving forces and thermal energy from fluid are applied to the particles as external body forces and a source term in the force-displacement law and the heat transfer calculations, respectively. This paper describes the thermal scheme for both fluid and particles. Results of two- and three-dimensional simulations involving forced convective heat transfer by fluid and conduction heat transfer within particles are presented.     

改性蛋白土填充线型低密度聚乙烯的研究

对超细加工并经硅烷偶联剂处理的蛋白土填充线型低密度聚乙烯进行了研究,结果表明:采用适当的偶联剂及恰当的添加量,改性蛋白土可以降低塑料的成本。     

Isotopic Oxygen Exchange and EPR Studies of Superoxide Species on the SrF2/La2O3 Catalyst

By using the in situ IR spectroscopy, the superoxide species (O₂⁻), characterized by the O–O stretching peak at 1130 cm⁻¹, was detected on the SrF₂/La₂O₃ catalyst at temperatures up to 973 K. The introduction of ¹⁸O₂ isotope caused the 1130 cm⁻¹ peak to shift to lower wavenumbers (1095 and 1064 cm⁻¹), consistent with the assignment of the spectra to the superoxide species. A good correlation between the rate of the disappearance of the O₂⁻ species and that of the formation of C₂H₄ was observed, suggesting that O₂⁻ was the active oxygen species responsible for the oxidative coupling of methane (OCM) on the SrF₂/La₂O₃ catalyst. This conclusion was reinforced by the EPR experiments (g_xx = 2.0001, g_yy = 2.0045, g_zz = 2.0685), showing that O₂⁻ was the only paramagnetic oxygen species detectable on the O₂-preadsorbed SrF₂/La₂O₃ catalyst. These results suggest that superoxide O₂⁻ can be a stable active oxygen species, whose role in the OCM reaction cannot be overlooked.     

瓷质砖湿坯对流干燥过程的传热传质研究

引用建立于Whitaker的体积平均方程和Darcy定律基础止的多孔介质内部热质传递的等效耦合扩散模型，寻出一组关于液体饱和度、温度和气相压力的新支配方程，应用该方程组对瓷质砖坯体干燥过程进行了数值分析和实验测定。在平均含湿饱和度的变化方面，数值解与实验结果十分吻合。还改变影响坯体干燥过程的一些因素进行计算机模拟计算，通过改变这些因素的大小来考察计算结果，以期获得某些定性或定量的结论，从而用以指导实际生产过程。     

有限元方法在玻璃成形工艺研究的应用

分析了玻璃在熔融状态下的力学性质、弹粘塑性和刚粘塑性本构方程以及玻璃成形的力学特性等,并结合玻璃成形的热力学公式,介绍了对玻璃成形的热力耦合分析的基本原理,还介绍了在玻璃成形过程中玻璃和模具之间的非线性接触、摩擦问题的求解,自动网格重划分技术.为了说明玻璃成形有限元分析的过程,最后介绍了利用三维大变形有限元方法来模拟电视显像管管屏的压制成形过程和饮料瓶吹制成形过程.     

铝系阻燃剂阻燃PP的力学性能研究

将用偶联剂处理的碱式碳酸铝镁加入到聚丙烯中，通过对体系阻燃性、力学性能等研究得出：碱式碳酸铝镁能够对聚丙烯起到良好的阻燃效果，碱式碳酸铝镁的加入提高了聚丙烯的冲击强度，当碱式碳酸铝镁质量分数为23％时，体系的冲击强度最高。研究了偶联荆的用量对体系力学性能的影响，结果表明，随偶联荆用量的增加，体系的拉伸强度降低，冲击强度先升高后降低，当偶联荆质量分数为1．0％时，体系的冲击强度最高。     

甲烷氧化偶联反应制乙烯的研究进展

介绍了近年来甲烷氧化偶联制乙烯(OCM)过程的催化剂、反应机理、动力学及工程放大涉及的反应工艺、反应器等方面的研究进展,对甲烷氧化偶联法和传统裂解法的经济性进行了对比,指出目前甲烷氧化偶联制乙烯工艺的选择性和转化率还较低,因此成本上比裂解制乙烯要高。最后,对催化剂、工程放大、生产流程和分离方案等方面的研究中存在的问题进行了分析。     

Natural fiber composites of high‐temperature thermoplastic polymers: Effects of coupling agents

Our earlier paper (Jana, S.C.; Prieto, A. J Appl Polym Sci 2002, 86, 2159) on the development of natural fiber composites of high‐performance thermoplastic polymers described a new methodology for the manufacturing of composite materials of a high‐temperature thermoplastic polymer, poly(phenylene ether) (PPE) and wood flour, a cellulosic natural filler. A thermosetting epoxy, used as a reactive solvent, reduced the processing temperature of PPE/epoxy blends to well below the decomposition temperature of natural fillers. In addition, the epoxy component, upon polymerization, formed coating layers around the filler particles to provide resistance against moisture diffusion and attacks by acids and alkali. This article describes the results of an investigation on two outstanding issues: (1) the influence of cellulosic wood particles and coupling agents on the speed of epoxy curing and reaction‐induced phase separation and (2) the effects of coupling agents on the morphology of crosslinked epoxy at the surfaces of natural fillers and mechanical properties of the composites. It was found that wood particles expedited epoxy curing in the composites; the extent of epoxy curing, however, was reduced in the presence of coupling agents. Also, the coupling agents promoted complete coverage of wood flour particles by polymerized epoxy, although the mechanical properties deteriorated over systems without coupling agents. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2168–2173, 2002     

Transient and isotopic studies of the oxygen transport and exchange during oxidative coupling of methane on Sr promoted La2O3

Isotopic transient techniques were applied to study oxidative coupling of methane over lanthanum oxide and strontium promoted La₂O₃ catalysts. Results of the¹⁸O₂/¹⁶O₂ isotopic exchange experiments indicate that Sr promotion increases oxygen uptake from the lattice of the catalyst. Oxygen self diffusion coefficients, which were determined for the series of lanthana catalysts, reach a maximum for the 1% Sr/La₂O₃. Steps of¹⁸O₂ in the presence of a steady flow of methane over Sr/La₂O₃ catalysts, indicate that surface and bulk oxygen appear in the reaction products before gas-phase¹⁸O². Steps of CO₂ over catalysts in which lattice oxygen has been exchanged with¹⁸O₂, show that gas/solid exchange involves over 50% of the lattice oxygen. Under reaction conditions, methane pulses with no gas-phase oxygen yield negligible amounts of products which indicates that methane interacts with lattice oxygen only in the presence of the gas-phase oxygen.