新型颗粒状活性染料

本文阐述了颗粒状活性染料的制造特点、制造技术和品质评价，并列举了典型的商品。     

用RAP法引上技术生长KCL晶体

用RAP法(reactivo atmosphere process)处理KCl熔体,在不改变生长气氛和RAP继续处理的情况下,提拉生长KCl晶体,以解决高纯、大尺寸、生长速度快、成品率高和有较大经济效益的问题。     

不同螺杆组合对聚乙烯交联反应挤出的影响

从20世纪60年代到现在,在国外,反应挤出取得了相当巨大的进步,其应用相当广泛。而在国内,对于反应挤出研究得很少,最突出的表现在利用平行同向双螺杆、采用两步法的生产工艺来反应挤出聚乙烯交联料。这主要是由于影响交联质量的因素很多,如配方、生产工艺和反应挤出设备等等,而本文着重讨论挤出设备,通过对现有的挤出设备进行改进,以期得到一组最佳的螺杆组合和生产工艺条件。     

Optimal policies for BMA polymerization in nonisothermal batch reactor

In this paper, the optimal policies for bulk polymerization of n‐butyl methacrylate (BMA) are determined in a nonisothermal batch reactor. Four objectives are realized for BMA polymerization based on a detailed process model. The objectives are: (i) maximization of monomer conversion in a specified operation time, (ii) minimization of operation time for a specified, final monomer conversion, (iii) maximization of monomer conversion for a specified, final number average polymer molecular weight, and (iv) maximization of monomer conversion for a specified, final weight average polymer molecular weight. For each objective, the optimal temperature policy of heat‐exchange fluid inside reactor jacket is determined. The temperature of the heat‐exchange fluid is considered as a function of a specified variable. Necessary equations are provided to suitably transform the process model in terms of a specified variable other than time, and to evaluate the elements of Jacobian to help in the accurate solution of the process model. A genetic algorithm‐based optimal control method is applied to realize the objectives. The resulting optimal policies of this application reveal considerable improvements in the batch production of poly(BMA). © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 2799–2809, 2006     

Reactive‐extrusion route for the closed‐loop recycling of poly(ethylene terephthalate)

The effectiveness of the reactive extrusion technique was investigated for poly(ethylene terephthalate) to promote the concept of closed‐loop recycling, that is, the reuse of waste material in the initial application. More specifically, a chain‐extender system, consisting of pyromellitic dianhydride, polyol, and a catalyst, was employed, and its efficiency regarding the improvement of the recyclate quality was evaluated. Accordingly, rheological and thermal characterizations were performed and used as criteria of the modification induced in the polymer molecular structure during processing due to the counteracting degradation and chain‐extension reactions. In particular, the molecular weight, related to intrinsic viscosity and melt flow rate measurements, of modified poly(ethylene terephthalate) samples was found to increase with the additive content. Simultaneously, a decrease in the crystallinity was observed, attributed to the branching effect of the chain extender, which restricted the ability of the macromolecules to organize in the crystal structure. Beyond a critical concentration of the additive system, the molecular weight of the treated samples started to decrease again, and this was accompanied by a small increase in the crystallinity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1671–1678, 2007     

活性炭材料脱除烟气中SO_2的机理研究

介绍了活性炭材料的脱硫机理;论述了烟气中O2和H2O在脱硫过程中的作用,O2与炭表面作用形成的C-O中间物可氧化SO2,H2O具有洗脱H2SO4、提供质子及水解作用;活性炭材料表面的碱性对脱硫具有促进作用,炭表面的催化活性位能够有效催化转化SO2。     

Robust and stable flow shop scheduling with unexpected arrivals of new jobs and uncertain processing times

In real scheduling problems, some disruptions and unexpected events may occur. These disruptions cause the initial schedule to quickly become infeasible and non-optimal. In this situation, an appropriate rescheduling method should be used. In this paper, a new approach has been proposed to achieve stable and robust schedule despite uncertain processing times and unexpected arrivals of new jobs. This approach is a proactive–reactive method which uses a two-step procedure. In the first step an initial robust solution is produced proactively against uncertain processing times using robust optimization approach. This initial robust solution is more insensitive against the fluctuations of processing times in future. In the next step, when an unexpected disruption occurs, an appropriate reactive method is adopted to deal with this unexpected event. In fact, in the second step, the reactive approach determines the best modified sequence after any unexpected disruption based on the classical objective and performance measures. The robustness measure is implemented in the reactive approach to increase the performance of the real schedule after disruption. Computational results indicate that this method produces better solutions in comparison with four classical heuristic approaches according to effectiveness and performance of solutions.     

JITL-based concentration control for semi-batch pH-shift reactive crystallization of l-glutamic acid

Although concentration control (C-control) strategy has been shown to give effective and robust control performance for batch cooling and semi-batch antisolvent crystallizations in recent years, no research work was reported concerning the potential application of conventional C-control for the more challenging semi-batch pH-shift reactive crystallization that is common in the process industries. To this end, this paper presents detailed analysis to find out that it is not feasible to apply the C-control to semi-batch pH-shift reactive crystallization. To circumvent this problem, a variant of C-control strategy by incorporating the Just-in-Time Learning (JITL) method to cope with strong process nonlinearity inherent in the pH-shift reactive crystallization is developed in this paper. Simulation results are presented to illustrate the proposed design and a comparison with conventional optimal control is made.     

Fabrication of suspended carbon microstructures by e-beam writer and pyrolysis

A fabrication process has been developed to create suspended carbon microelectromechanical system (C-MEMS) structures. SU-8, a negative photoresist, was used as the starting material and was converted to the desired carbon microstructures using pyrolysis in an inert atmosphere. Suspended carbon-micro and nano electromechanical system (C-MEMS/NEMS) structures with feature sizes down to 500 nm were fabricated by ultra violet/electron beam (EB) lithography and pyrolysis. The problem of charging of the non-conductive SU-8 surface was solved by partially masking a thin metal layer to prevent the repulsion of negative charged electrons before EB writing. Complex suspended C-MEMS structures, such as bridges and networks have been formed. This fabrication method can accurately and reproducibly produce various suspended C-MEMS structures which have applications in microelectronics and biosensing.     

Preparation and characterization of syndiotactic polystyrene/ethylene‐propylene copolymer blends

The reactive compatibilization of syndiotactic polystyrene (sPS)/oxazoline‐styrene copolymer (RPS)/maleic anhydride grafted ethylene‐propylene copolymer (EPR‐MA) blends is investigated in this study. First, the miscibility of sPS/RPS blends is examined by thermal analysis. The cold crystallization peak (T_cc) moved toward higher temperature with increased PRS, and, concerning enthalpy relaxation behaviors, only a single enthalpy relation peak was found in all aged samples. These results indicate that the sPS/RPS blend is miscible along the various compositions and RPS can be used in the reactive compatibilization of sPS/RPS/EPR‐MA blends. The reactive compatibilized sPS/RPS/EPR‐MA blends showed finer morphology than sPS/EPR‐MA physical blends and higher storage modulus (G') and complex viscosity (η*) when RPS contents were increased. Moreover, the impact strength of sPS/RPS/EPR‐MA increased significantly compared to sPS/EPR‐MA blend, and SEM micrographs after impact testing show that the sPS/RPS/EPR‐MA blend has better adhesion between the sPS matrix and the dispersed EPR‐MA phase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2084–2091, 2002