催化剂烧炭再生模拟和分析

催化剂烧炭再生是非定态过程。本文建立了绝热反应器内催化剂烧炭模型,利用移动边界正交配置法求解。以结炭的BO2催化剂再生为工作反应,模拟预测与实验值吻合良好。模拟计算表明,用递升进口温度序列烧炭,使再生时间明显缩短。     

Enumerating maximal bicliques in bipartite graphs with favorable degree sequences

We propose an output-sensitive algorithm for the enumeration of all maximal bicliques in a bipartite graph, tailored to the case when the degree distribution in one partite set is very skewed. We accomplish a worst-case bound better than previously known general bounds if, e.g., the degree sequence follows a power law.     

Structure and properties of polyimide‐bonded magnets processed from prepolymers based on diacetyl derivatives of aromatic diamines and dianhydrides

We report a novel method of polyimide (PI) synthesis from prepolymers based on dianhydrides and diacetyl derivatives of aromatic diamines that facilitate the preparation of a melt processable mixture at 300 ± 10°C of the prepolymer and magnetic Nd‐Fe‐B alloy to provide PI‐bonded magnets with enhanced properties. It is shown that chemical structure of the prepolymers strongly influences viscosity behavior via crystallization of the oligoimide in the melt, leading to formation of PI with rigid‐rod like structure. This structural ordering of the prepolymers based on diacetyl derivative of diamine used in this study, if not controlled, leads to exponential increase of melt viscosity with time, making it practically impossible to prepare melt processable mixture of the magnetic particles and the PI prepolymers at elevated temperatures. The results obtained demonstrate that appropriate dianhydrides and diacetyl derivatives of diamines that do not lead to crystallization of oligoimides in prepolymer mixture can be used under controlled processing conditions to prepare melt‐processable PI‐bonded magnets containing rigid‐rod like PI structure that significantly increases thermal stability of the magnets. The temperature dependencies of the magnetic properties of the PI‐bonded magnets under conditions that they are likely to encounter during their service life were found to be remarkably similar to that of commercial thermoplastic magnets such as injection‐molded nylon magnets. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 478–485, 2006     

Mullitization of Diphasic Aluminosilicate Gels

Recent studies have shown that the mullitization of diphasic aluminosilicate matrices comprising transitional alumina and amorphous silica occurs via a nucleation and growth process. Nucleation is preceded by a temperature-dependent incubation period. Following this incubation period, rapid nucleation of mullite occurs, producing about 1.8 × 10¹¹ nuclei/cm³, which remains constant throughout the rest of the transformation. Both incubation and mullite growth are thermally activated processes with apparent activation energies of 987 ± 63 and 1070 ± 200 kJ/mol, respectively. The growth rate of mullite grains under isothermal conditions is time dependent. An interpretation of these results is proposed on the basis of the nucleation and growth concepts of LaMer and Dinegar which supports the concept that the growth rate of mullite grains is controlled by the dissolution of transitional alumina into the amorphous matrix.     

基于数据仓库的OLAP中的索引技术研究

数据仓库建立好后,需要对其充分高效地利用,OLAP联机分析处理就是一个很好的数据分析展现工具。人们对速度的追求是永无止境的,建立索引可以更快捷地响应用户的查询。索引的种类很多,相关研究表明位图索引既能节省空间,又能利用其进行的位运算而提高相应的查询速度,然而位图索引对字段基数较低的字段有比较好的效果,当遇到字段基数较高的字段时也会占据大量的空间,其效果不及B‐T ree索引,论文针对这种情况对位图索引进行了扩展,引入了标识符索引,并对其进行了比较讨论,最后提出可以根据维的各自特征建立不同的索引。     

CPR1000核电站三废处理控制系统仿真测试技术应用

为实现工厂测试期间,能够最大限度地模拟核电厂三废系统的工艺设备,对三废控制系统（DCS）的组态逻辑正确性进行验证,通过结构化文本语者编写仿真测试程序,对现场的工艺设备的运行状态进行仿真模拟。同时选取对核电站硼回收系统（TEP）的1号除汽器的仿真测试,验证仿真测试程序的可行性,提出了一种低成本,高效率的测试方法。     

Olfactory coding in the perception of semiochemicals

Information processing in the olfactory pathway underlying the perception of semiochemicals by insects is discussed. Both the chemical message for mates and the message for food consist of blends of chemicals. Olfactory receptors in an insect species are tuned to the detection of those compounds which comprise such chemical messages for that species. The classification of receptors as specialists or generalists coincides with two concepts of information processing, i.e., labeled lines and across-fiber patterns, respectively. The olfactory code coming from antennal receptors inPieris brassicae larvae is a combination of labeled lines and across-fiber patterning. When antennae of adult Colorado potato beetles,Leptinotarsa decemlineata, are stimulated by binary mixtures of leaf odor components, the pattern of neural activities in the olfactory receptors shows some separation into two channels, quantitative versus qualitative detection. The separation is complete in the antennal lobe of this beetle.Presented at the Symposium on Insect Chemical Communications: Unifying Concepts. ACS 194th National Meeting, New Orleans, Louisiana, August 31, 1987.     

我国煤焦油加工的现状及发展趋势

我国煤焦油加工的现状为：装置规模小；热能回收利用不合理；产品种类少；环境保护存在一定问题。从国内外焦炭市场和生产情况分析，认为我国机焦产量大幅增长是带动煤焦油加工业发展的主要因素。指出我国煤焦油集中加工格局已经形成．时机已经成熟。     

Dipole moments of copolymers in relation to the distribution of polar monomer unit sequences

A method for evaluating the dipole moments of copolymers in relation to the distribution of polar unit sequences is proposed. Experimental data on the synthesis and dipole moments of styrene-p-chlorostyrene and styrene-p-methoxystyrene copolymers were used to calculate the effective dipole moment of a polar unit in a copolymer. For this purpose, we assumed the following effective moment values for the corresponding polar unit sequences along the copolymer chains: when both of the nearest neighbours are polar, μ_PP, when one of the nearest neighbours is polar and the other is non-polar, μ_PS, and when both of the nearest neighbours are non-polar, μ_SS. The relative magnitudes of μ_SS, μ_PS and μ_PP calculated for both copolymers reflect the influence of dipole-dipole interactions on the effective dipole moment of a polar unit in a copolymer molecule.