串联系统的多前馈-反馈广义预测控制

为了充分利用对象的可知信息以实现串联系统的最优控制，提出了串联系统的多前馈-反馈广义预测控制算法，该算法把系统的可知外部扰动作为系统的多输入变量，把可测量的中间变量作为系统的多输出变量，运用多变量广义预测控制的思想给出了算法的控制结构。实现了前馈控制与反馈控制的有机结合，仿真结果表明，该算法能极大地改善串联系统的抗干扰性和鲁棒性。     

GPC法研究异丁烯的阳离子聚合反应

用凝胶渗透色谱仪(GPC)来测定阳离子聚合法得到的聚异丁烯,可以验证电子对给予体吡啶对T—BA/TiCl_4/IB/CH_2Cl_2体系的阳离子聚合的影响。     

一种非线性系统的鲁棒型预测控制算法

提出一种基于神经网络的鲁棒型广义预测控制（GPC）方法,该方法首先用神经网络对非线性系统进行辨识,然后在控制中将模型输出值与测量输出值进行综合,代替量测输出用于控制中,从而降低辨识器与控制器对未建模动态的敏感性,增强控制器的适应能力和鲁棒性.仿真结果表明：将本方法应用于非线性系统控制,对未建模动态具有较强的鲁棒性和控制能力.     

一种非线性系统的鲁棒型预测控制算法

提出一种基于神经网络的鲁棒型广义预测控制(GPC)方法,该方法首先用神经网络对非线性系统进行辨识,然后在控制中将模型输出值与测量输出值进行综合,代替量测输出用于控制中,从而降低辨识器与控制器对未建模动态的敏感性,增强控制器的适应能力和鲁棒性.仿真结果表明:将本方法应用于非线性系统控制,对未建模动态具有较强的鲁棒性和控制能力.     

Effect of prepolymerization on propylene polymerization

Polymerization of propylene was performed using MgCl₂. EtOH.TiCl₄.ID.TEA.ED catalyst system in hexane, where internal donor (ID) was an organic diester and external donor (ED) was a silane compound and also triethyl aluminum (TEA) as activator. A new method called isothermal/nonisothermal method (INM), a combination of isothermal and nonisothermal methods, was applied to produce the spherical polymer particles. The effects of the INM method and prepolymerization temperature on the final polymer morphology, M_w, and catalyst activity were also investigated. The morphology of the polymers was evaluated through scanning electron microscopy (SEM) images. GPC results were used for molecular weight (M_w) evaluation. It was found that the polymers had a better morphology when they were prepared using INM method. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

改进的多频自校正广义预测控制算法

针对输出采样速率比输入更新速度慢的多频系统，提出了一种的广义预测自校正控制算法。该算法将自校正机构辨识出的多频模型转化为以输入更新的为采样频率的等价单频模型，用此模型预测系统未来的输出，避免了多频模型不能预测未来输出采样点之间的信息。仿真结果表明，该方法提高了系统的动态品质，具有响应速度快的特点。     

基于GPC法的改性沥青SBS含量测试方法研究

采用GPC对不同SBS剂量的改性沥青进行了测试,建立了SBS剂量与GPC测试数值的关系,并采用已知SBS剂量的样品对该方法进行验证。结果显示,GPC测得的SBS含量与SBS真实剂量线性关系良好,SBS剂量相对偏差均在5%以内,表明GPC法是一种检测改性沥青质量的快速、可靠的测试方法。     

乙二胺改性聚乳酸溶液的性质

乙二胺改性聚乳酸(EMPLA)是一种具有支化结构的新型生物材料。文中采用GPC-MALLS技术对其在四氢呋喃(THF)中的分子量、分子量分布、半径、支化及其这些量之间的相互关系进行了分析与研究,结果表明:乙二胺改性聚乳酸在四氢呋喃中的折光指数增量dn/dc值为0.052 mL/g,第二维利系数A2为3.905e-3 mol mL/g2,重均分子量-Mw为5.753e 4,重均均方根旋转半径Rw为4.5 nm,-Mw与Rw的关系式为:Rw=0.608×-Mw0.316,通过与线性聚乳酸(PDLLA)的比较,能够得到具有与PDLLA相同分子量的EMPLA有较小的均方根旋转半径的结论,并能够推出EMPLA在四氢呋喃溶液中的分子构象为球形。     

Applications of sample preparation techniques in the analysis of pesticides and PCBs in food

Pesticides and polychlorinated biphenyls (PCBs) are found in various parts of the environment in quite small concentrations, but they accumulate and thus become a threat to human health and life. A review is focused on the application of some popular techniques for sample preparation in analysis of these compounds in food. Even with the emergence of advanced techniques of final analysis, complex matrices, such as food, require extensive sample extraction and purification. Traditional sample preparation techniques are time consuming and require large amount of solvents, which are expensive, generate considerable waste, contaminate the sample and can enrich it for analytes. There have been many sample preparation techniques proposed to meet the requirements connected with the multiplicity of food. Optimal sample preparation can reduce analysis time, sources of error, enhance sensitivity and enable unequivocal identification and quantification. Sample extraction and purification techniques are discussed and their most recent applications in food analysis are provided. This review pointed out that sample preparation is the critical step.     

凝胶渗透色谱技术在卷烟分析前处理中的应用进展

样品前处理对于保证结果的一致性与准确度至关重要。GPC凝胶净化系统的出现,使得前处理方便快捷,数据准确可靠。综述了凝胶渗透色谱在卷烟烟气中农残成分和特殊有害成分(苯并芘和NNK)实验方法中的应用,指出,凝胶渗透净化系统用于卷烟烟气中苯并芘和亚硝胺分析的前处理具有创新性和研究意义。