布尔控制网络的输出稳定与镇定

矩阵的半张量积是将逻辑变量转化为向量研究的主要工具.本文利用半张量积把逻辑控制系统表示为离散时间仿射线性系统,在逻辑系统的状态空间框架下研究了以布尔控制网络为代表的逻辑动态系统的输出稳定与镇定.首先给出布尔网络输出稳定的定义,研究了布尔网络输出稳定的充要条件;其次讨论了布尔控制网络的输出镇定,分别得到了布尔控制网络由常值输入变量、自由控制序列、状态反馈控制序列输出镇定的条件.本文讨论的系统输出稳定与镇定是(部分)变量稳定与镇定的推广.     

复合斜孔塔板在重油催化吸收稳定系统改造中的应用

金陵分公司Ⅱ重油催化吸收稳定系统设计处理能力不足 ,虽然车间对原有浮阀塔盘进行了扩大开孔处理 ,但产品质量很难满足生产要求 ,该系统已成为装置的瓶颈。通过大量的调查研究 ,最后决定在不改变原塔径的情况下 ,采用多溢流复合斜孔塔板技术对塔内构件进行改造。通过增加吸收剂来提高吸收效率 ,同时也提高了装置的处理能力。改造后的标定结果显示 ,所有产品的质量均达到了设计要求。该系统的处理能力满足了生产需要 ,并产生了显著的经济效益     

两级串联生物稳定塘处理乐果废水初探

采用厌氧水解（酸化）塘－好氧塘，兼性塘－好氧塘，好氧塘－地氧塘三种工艺分别对乐果废水进行了处理，试验结果表明，第一种工艺处理效果优于其它两种工艺。在本试验条件下，其ＣＯＤ，ＢＯＤ５，乐果的平均去除率分别为７４．３％，８５．８％和９１．０％，平均出水ＣＯＤ在２４０ｍｇ／Ｌ左右。通过综合分析得出，厌氧水解（酸化）塘－好氧塘工艺处理乐废水比普通生物稳定塘的水力停留时间短，处理效果稳定，其机理可能是幅地水     

Photooxidation and stabilization of photooxidized polyethylene and of its monopolymer blends

The increasing use of products from recycled polymers, or from blends with recycled polymers exposed to the outdoors, implies the need for good weathering resistance. This is particularly important when the recycled material comes, in turn, from products exposed during their lifetime to the sun. In this case the presence of C?O groups in the macromolecular chains strongly increases the photooxidative degradation kinetics of these secondary materials. In this work the change of the photooxidative degradation of blends of virgin and photooxidized polyethylene was evaluated as a function of the C?O content present in the material. As expected, the presence of the C?O groups strongly increases the photooxidation kinetics, as revealed by the increase of the carbonyl compounds, and by the decrease of the elongation at break. It was confirmed that the increase of C?O groups is dependent on the content of the same groups, whereas this is not true for the mechanical properties. The use of UV stabilizer strongly improves the weathering resistance of these materials, which become almost insensitive to the initial amount of C?O groups. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2244–2255, 2004     

Environmental stability of electrically conductive viologen–polyaniline systems

Viologen–polyaniline (PANI) systems were prepared by PANI being coated onto viologen‐grafted low‐density polyethylene films. PANI in this system could undergo photoinduced doping with ultraviolet irradiation. The electrical stability of the electrically conductive viologen–PANI systems was found to be stable in air, but the conductivity decreased rapidly when the sample was treated in aqueous media of pH > 5 because of the migration of the anions out of PANI into water. However, the conductivity increased by a factor of 2 after treatment in a 1M HCl solution because of the further protonation of PANI by acid. The structural changes of these systems were monitored with ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and resistance measurements. The electrical stability of the viologen–PANI system in water could be enhanced via spin coating with poly(methyl methacrylate) (PMMA) because this layer inhibited the migration of the anions out of the system. The photoinduced doping of PANI could be carried out either before or after the spin coating of PMMA. The advantages and limitations of each method were demonstrated. A PMMA coating with a thickness of approximately 10 μm allowed a significant doping level to be achieved within a short period of irradiation and, at the same time, effectively shielded the film from the effects of the aqueous medium. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2099–2107, 2002     

某些高分子受阻胺对聚丙烯稳定化作用的研究

众所周知,受阻胺光稳定剂对聚烯烃有良好的光稳定效率,已引起世界的注意。然而,小分子量的受阻胺易于挥发,从而影响它的效率发挥,为了克服这个缺点,使小分子受阻胺的高分子化是近年来受阻胺光稳定剂发展的方向,本文主要是研究三种商品化高分子受阻胺光稳定剂对聚丙烯的稳定化作用及其效率和机理。     

添加硫沥青球不熔化机理的研究

为了阐明硫促进沥青球不熔化的原因,利用红外光谱（IR）、X－射线光电子能谱（XPS）、气相色谱（GC）及元素分析等方法研究了添加硫沥青球不熔化过程的机理,证明硫与沥青发生了反应,在沥青球内部形成了硫醇、硫酸、亚砜和砜等含硫官能团,促进了沥青分子的交联,提高了沥青的软化点．缩短了沥青球的不熔化时间。同时添加硫沥青球在不熔化过程中生成了H2S、COS、CS2等含硫组分。     

Shear rheological properties of acrylic copolymers and terpolymers suitable for potentially melt processable carbon fiber precursors

In an effort to generate melt processable polyacrylonitrile (PAN) precursor fibers suitable for conversion to carbon fibers, an acrylonitrile/methyl acrylate (AN/MA) copolymer and two acrylonitrile/methyl acrylate/acryloyl benzophenone (AN/MA/ABP) terpolymers were synthesized at molar ratios of 85/15 and 85/14/1, respectively. The termonomer (ABP) was incorporated to accelerate crosslinking via UV irradiation, which serves to prevent relaxation of orientation and flow as the temperature of the fiber is raised during thermooxidative stabilization. Two molecular weights of the terpolymer and one molecular weight of the copolymer were studied to determine the effect of the termonomer, and the effect of molecular weight (MW), on the steady shear viscosity (η) and magnitude of the complex viscosity (η*). A higher rate of increase of η as a function of time was observed for the high MW terpolymer relative to that of the copolymer over the temperature range used. Using a temperature sweep and monitoring levels of η*, a minimum was observed at lower temperatures for both terpolymers. These results suggest that copolymerization with ABP significantly increased the thermally induced kinetics of crosslinking. Comparison of the η and η* data for the low and high MW terpolymers suggested that molecular weight also significantly reduced the melt stability (increased the kinetics of crosslinking). A chemorhelogical correlation was then used to quantify the effects of the termonomer and of molecular weight on the kinetics of crosslinking of the AN terpolymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2856–2865, 2004     

微波与射频电路设计课程实践教学探讨

微波与射频电路是通信电信专业的必修课程,也是学生公认的最难学习、最抽象的课程之一,为使学生能够较好地理解相关原理概念并培养一定的电路设计能力,必须激发学生的学习兴趣,使学生参与从电路设计、软件仿真、优化、实物制作、参数测量等整套电路设计的实践教学过程当中,从而形成更加深刻的印象,培养高素质的创新人才。     

《计算机控制系统》实践教学平台的构建

根据当前社会需求形势,结合本院培养应用型、复合型、外向型人才的目标,构建计算机控制系统课程的实践教学平台,文章详细介绍了组成平台的三个环节,以基础性、应用性和综合性为导向,各环节融会贯通,形成系统,为培养学生的专业知识能力和实践动手能力提供保障和支持。