没食子酸异戊酯的合成研究

以壳聚糖硫酸盐为催化剂，用没食子酸与异戊酸直接酯化合成了没食子酸异戊酯，用正交试验确定了酸酸物质的量比、催化剂用量、反应时间对没食子酸异戊酯收率的影响。得到了最佳工艺条件：醇酸物质的量比为10：1，催化剂用量为1．0g，反应时间为4h，没食子酸异戊酯的收率可达96．2％。实验表明，该催化剂用于合成没食子酸异戊酯具有极好的催化活性和重复使用性。     

VideoGraph: a non-linear video representation for efficient exploration

In this paper we introduce VideoGraph, a novel non-linear representation for scene structure of a video. Unlike classical linear sequential organization, VideoGraph concentrates the video content across the time line by structuring scenes and materializes with two-dimensional graph, which enables non-linear exploration on the scenes and their transitions. To construct VideoGraph, we adopt a sub-shot induced method to evaluate the spatio-temporal similarity between shot segments of video. Then, scene structure is derived by grouping similar shots and identifying the valid transitions between scenes. The final stage is to represent the scene structure using a graph with respect to scene transition topology. Our VideoGraph can provide a condensed representation in the scene level and facilitate a non-linear manner to browse videos. Experimental results are presented to demonstrate the effectiveness and efficiency by using VideoGraph to explore and access the video content.     

在线化工设备疲劳分析专家系统的研究

运用应力分析、疲劳分析的理论，综合专家学者的知识和经验，针对现代化大型联合企业技术管理的现状，提出了建立在线化工设备及管道安全评定中疲劳分析的专家系统方法，并编制了初级的软件。用简化试验来模拟一条高温高压蒸汽管线的疲劳裂纹扩展，并用之考评本软件。     

一种改进的超宽条带噪声消除算法

针对高光谱遥感图像中的超宽条带噪声干扰现象,在深入研究高光谱图像特点和条带噪声产生机理的基础上,提出了一种新的基于最小序列值、小波变换和矩匹配相结合的滤波算法（OWM算法）。该算法主要包括灰度对比度处理、最小序列值处理、小波变换系数归零处理和矩匹配处理等四个步骤。用实际的高光谱图像进行了一系列的验证比较实验,获得了好的实验效果。实验结果表明OWM算法不仅能够有效滤除高光谱图像中的超宽条带噪声,而且还具有较好的普适性。     

基于间歇测量的状态估计稳定性和精度研究*

针对分布式控制系统状态估计过程出现的测量值丢失问题,本文量化分析测量值丢失对估计稳定性和精度的影响。首先,根据随机测量模型重新推导带测量值丢失的卡尔曼滤波器,得到估计误差协方差迭代式。然后,将随机误差协方差迭代式建模为修正的黎卡提微分方程,提出了估计稳定性和精度分析方法。最后,列举不同的系统实例,证明临界包到达率的存在性,当测量值到达率大于临界值时,平均误差协方差从发散过渡到有界,进而得到估计精度与包达率之间的函数关系。     

生物膜载体吸附剂对Zn2+的吸附

本文对生物膜吸附Zn^2＋的行为进行了准一级动力学方程和Elovich模型方程的拟合，对实验测定的吸附等温线用Langmuir与Freundlich吸附模型进行拟合；考察了pH值及温度对生物膜吸附Zn^2＋的影响。结果表明，Zn^2＋在生物膜载体吸附剂上的吸附动力学过程与Elovich方程有较好的拟合度，R^2=0．99994。单一等温吸附过程与Langmuir方程具有较好的拟合度，R^2=0．99785；pH=6～8，室温25℃对Zn^2＋分有较高的去除率。     

The compatibility of the blends of PUs with PVC and the adhesion behavior of PU to PVC

Three series of polyurethane adhesives—polyethyleneadipateurethane (PEAU), polybuthyleneadipateurethane (PBAU), and polyhexyleneadipateurethane (PHAU)—with the same MW and hard/soft segment ratio, based on the three polyesters polyethyleneadipate (PEA), polybuthyleneadipate (PBA), polyhexyleneadipate (PHA), with 4,4′-diphnylmethane diisocyanate (MDI), and butendiol were synthesized by solution polymerization. The crystallinity of these polyesters and polyurethanes (PUs) and the compatibility of blends of PUs with PVC were studied by means of wide-angle x-ray diffraction (WAXD), differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DMA), testing of solubility, and phase contrast microscopy. The results indicated that PBAU/PVC and PHAU/PVC were compatible systems, but PEAU/PVC was incompatible. The adhesive strengths of the three adhesives were quite different from one another, in the order of PBAU ≥ PHAU ? PEAU. The influences of crystallinity and compatibility on adhesion were discussed, and the Diffusion Theory for PU-PVC systems was recommended. © 1995 John Wiley & Sons, Inc.     

Benzene Alkylation with Propane over Mo Modified HZSM-5

Benzene alkylation with propane has been studied over HZSM-5 loading 3.1–15.4 wt% Mo in continuous-flow microreactor under 350 °C and atmospheric pressure with the highest activity obtained at 6.7 wt% Mo loading. C_7–9 aromatics were obtained as main products while the total amount of benzene rings kept unchanged. i-Propylbenzene and n-propylbenzene are formed primarily, while toluene, ethylbenzene, and ethyl-toluene are formed secondly from the propylbenzenes. Catalytic performance of 6.7 wt% Mo/HZSM-5(38) partially poisoned by NH₃ shows that the strong acid sites play a crucial role in the alkylation. Low SiO₂/Al₂O₃ ratio of HZSM-5 in the Mo modified catalysts gives high propane conversion. Two hydrothermal treatment methods were applied to the 6.7 wt% Mo/HZSM-5(38) catalyst, caused decrease of propane conversion but result in different product distribution. A possible reaction mechanism concerning bifunctional active centers resulted from combination of loaded Mo species and strong acid centers on HZSM-5 is proposed.     

A paraffin-fueled SOFC system design and integration

This paper addresses an integrated design of paraffin-reformer, gas separations and the electricity production with a solid oxide fuel cell (SOFC). The overall design consists of three modules. First module is a system of paraffin reformer. In this module, the paraffin feed stream is to send to a steam-reformer. In the second module, the gas separations method illustrated is the combination of a methane-permeable membrane with a pressure-swing adsorption (PSA). In the third module, the purified hydrogen is fed to the SOFC unit. To be energy efficient, this paraffin-fueled SOFC system is designed with the consideration of heat integration. The intent of this paper is to provide a possible, alternative way of cogeneration systems for refinery and petrochemical plants.     

Low temperature SCR of NO with NH3 over carbon nanotubes supported vanadium oxides

A novel multiwalled carbon nanotube (CNTs) supported vanadium catalyst was prepared. The structure of catalyst prepared was characterized by TEM, BET, FTIR, XRD and temperature-programmed desorption (TPD) methods. The results indicated that vanadium particles were highly dispersed on the wall of carbon nanotubes. The V₂O₅/CNT catalysts showed good activities in the SCR of NO with a temperature range of 373–523 K. The Lewis acid sites on the surface of V₂O₅/CNT are the active sites for the selective catalytic reduction (SCR) of NO with NH₃ at low temperatures. It was suggested that the reaction path might involve the adsorbed NH₃ species reacted with NO from gaseous phase and as well as the adsorbed NO₂ species. The diameter of CNTs showed positive effect on the activities of the catalysts. Under the reaction conditions of 463 K, 0.1 Mpa, NH₃/NO = 1, GHSV = 35,000 h⁻¹, and V₂O₅ loading of 2.35 wt%, the outer diameter of CNTs of 60–100 nm, the NO conversion was 92%.