聚氯乙烯(PVC)共混合金──(Ⅰ)聚氯乙烯(PVC)基础知识

本讲主要介绍聚氯乙烯（PVC）的基础知识，如PVC发展史、生产情况、型号、性能、用途及改性的必要性等，使读者对PVC的基本情况有一个大概的了解。     

炭分子筛概述

阐述了炭分子筛分离的原理，并分别从其制备原料、制备方法、产品用途等方面综述了近年来炭分子筛的新进展。     

粉煤灰饰面玻璃的研制

利用粉煤灰可制得粉煤灰饰面玻璃，与粉煤灰微晶玻璃相比，其优点是粉煤灰用量高，能耗低，成本低，装饰效果好。本文介绍了实验室与工业性扩大试验的结果，并对生产工艺中的几个问题作了讨论。     

Propylene epoxidation in a microreactor with electric heating

Gas phase propylene epoxidation on gold catalysts has attracted wide attention from industry and academia due to its high selectivity. However, it suffers from low propylene conversion and rapid catalyst deactivation. Experiments showed that propylene conversion could be increased by raising H₂, O₂, or C₃H₆ concentration in the feed, but the feed compositions were within the explosion limit. It was also shown that the activity of the used catalyst could be fully recovered, but the regeneration temperature was 280 °C, much higher than that for reaction. Therefore a microchannel reactor was devised to suppress explosion and was constructed with Fecralloy, to raise the temperature rapidly for catalyst regeneration by electric heating. In two minutes the temperature of the reactor could be raised from 50 to 300 °C. Catalysts were coated on the alloy belt by dip coating, and the performance of the reactor was evaluated under different operating conditions. Results showed that in the microreactor the overall reaction rate was controlled mainly by the intrinsic reaction rate, and also influenced by film diffusion to a certain extent. The deactivated catalyst was regenerated in the microchannel reactor and the activity was fully recovered.     

Sharkskin mechanism of high‐impact polystyrene (HIPS) and rheological behavior of HIPS/TiO2 composites

The rheological behaviors of high‐impact polystyrene (HIPS) and HIPS/TiO₂ composites were investigated by use of a rheometer in the present article. HIPS exhibited a constant critical stress of the sharkskin in various temperatures, and the analysis indicated that the mechanism of sharkskin of HIPS was wall–slip and its special temperature dependency was determined by weak wall–melt adsorption. The experimental results also showed that the introduction of TiO₂ into HIPS only slightly influenced the apparent viscosity (η_a) of the composites. Moreover, TiO₂ exhibited an unusual effect on the non‐Newtonian index of the composites at high shear rate. Both phenomena indicated the increase of inner free volume induced by TiO₂ in molecularly rigid HIPS. Moreover, it was noteworthy that a featured stress could be used to label the dispersion of TiO₂ in the HIPS matrix, and the numeric affinity of this featured stress and the critical stress of sharkskin revealed that both processes were relevant to the same molecular relaxation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 802–807, 2005     

熔融石英耐火材料

阐述了熔融石英耐火材料的主要性能与应用领域。     

An Elastic Architecture Adaptable to Various Application Scenarios

The quantity of computer applications is increasing dramatically as the computer industry prospers. Meanwhile, even for one application, it has different requirements of performance and power in different scenarios. Although various processors with different architectures emerge to fit for the various applications in different scenarios, it is impossible to design a dedicated processor to meet all the requirements. Furthermore, dealing with uncertain processors significantly aggravates the burden of programmers and system integrators to achieve specific performance/power. In this paper, we propose elastic architecture （EA） to provide a uniform computing platform with high elasticity, i.e., the ratio of worst-case to best-case performance/power/performance-power trade-off, which can meet different requirements for different applications. It is achieved by dynamically adjusting architecture parameters （instruction set, branch predictor, data path, memory hierarchy, concurrency, status~zcontrol, and so on） on demand. The elasticity of our prototype implementation of EA, as Sim-EA, ranges from 3.31 to 14.34, with 5.41 in arithmetic average, for SPEC CPU2000 benchmark suites, which provides great flexibility to fulfill the different performance and power requirements in different scenarios. Moreover, Sim-EA can reduce the EDP （energy-delay product） for 31.14% in arithmetic average compared with a baseline fixed architecture. Besides, some subsequent experiments indicate a negative correlation between application intervals＇ lengths and their elasticities.     

Relationship of threshold diameter and Darcean permeability in unconsolidated porous structures

Experiment was conducted on the threshold pressure for atmospheric air through unconsolidated narrow size distributed mini sphere and sand particles at low flow rates. The threshold diameter calculated from measured threshold pressure showed that it does not follow the traditional similarity theory. This is consistent with our experiment on accurate permeability measurement, and can be explained as a result of gas slip flow within such micro pore structure. Our current work tend to find the method to predict the permeability-threshold pressure relationship for unconsolidated porous structures.     

自适应门限GM-CPHD多目标跟踪算法

带有势估计的高斯混合概率假设密度滤波（GM-CPHD）作为一种杂 波环境下目标数可变的检测前跟踪方法,将复杂的多目标状态空间的运算转换为单目标状态 空间内的运算,有效避免了多目标跟踪中复杂的数据关联问题,但该方法的计算复杂度与观 测数的3次方成正比,在密集杂波情况下计算量十分巨大。针对该方法计算复杂度高的问题 ,提出利用一种最大似然自适应门限的快速算法,该算法首先利用自适应门限对观测进 行处理,然后仅利用处于门限内的有效观测进行GM-CPHD算法的更新步计算,大大降低了算 法的计算复杂度。实验结果证明,本文方法在有效降低计算复杂度的同时,在多目标跟踪效 果 方面与GM CPHD相当,优于GM-PHD滤波算法。     

ABS/镁盐晶须复合材料的研究

以（乙烯／乙酸乙烯酯／苯乙烯）三元共聚物（BS树脂）为增容荆，采用双螺杆挤出机制备了（丙烯腈／丁二烯／苯乙烯）共聚物（ABs）／镁盐晶须复合材料，研究了BS树脂、镁盐晶须用量对复合材料力学性能、流动性能的影响、结果表明，加入BS树脂有利于提高复合材料的拉伸强度和冲击强度，复合材料的熔体流动速率（MFR）随BS树脂用量增加而增大，且其MFR对温度或负荷呈非线性函数关系，比ABS对负荷更为敏感．