Supported Molybdenum Carbides Lie Between Metallic and Sulfided Catalysts for Deep HDS

Hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene on alumina-supported Mo₂C has been studied. These catalysts are stable and active under deep HDS conditions (0-250 wt ppm S). However, although they are well known to have hydrogenation properties, they lead preferentially to a non-hydrogenated product of the HDS reaction: dimethylbiphenyl. For the same reaction, supported platinum and sulfided molybdenum oxide lead to the hydrogenated products dimethyldicyclohexyl and methylcyclohexyltoluene, respectively. The ranking of HDS activity is as follows: MoS₂/Al₂O₃ < Mo₂C/Al₂O₃ < Pt/SiO₂.     

单螺杆挤出过程的数值模拟

以三段七区物理模型为基础，采用面向对象程序设计语言VisualC ，对整个单螺杆挤出过程进行了数值模拟。所得压力。温度等工艺参数的模拟结果与实验值吻合较好，说明采用数学模型的正确性和数值算法的可行性。     

Visual discovery of the correlation between BGP routing and round-trip delay active measurements

Inter-domain routing data and Internet active probing measurements are two types of information commonly available in huge datasets and subject to extensive, focused analysis. However, the study of the correlation between these two complementary types of information still remains one of the most challenging problems in today’s research in networking. In this paper we describe a metaphor for the visualization of the interplay between the routing information exchanged via BGP and the round-trip delay measurements collected by several geolocated probes. We implemented a prototype based on the above metaphor. Our prototype highlights both the Autonomous System topology and the latency associated with each AS-path over time. Further, it shows how probes are partitioned into clusters associated with each border gateway, based on observed traffic patterns. The resulting visualization allows the user to explore the dynamics of the correlation between the two types of information.     

高效镇痛剂依托啡的合成

以蒂巴因为原料，经三步反应合成了高效镇痛剂依托啡，总产率由原来的１９．１％提高到３５．９％，并对各单元反应的条件及影响因素进行了探讨。     

PET/纳米SiO2复合材料的制备(Ⅱ):纳米SiO2在PET中的分散性研究

研究了分散方法、纳米材料的加入体系、分散时间、分散剂的种类及SiO2 的加入量对纳米SiO2 在PET/纳米SiO2 中分散性的影响 ,用TEM对其分散情况进行表征 ,并对其分散机理进行探讨与研究。其结果表明 :采用球磨分散法并以氨基硅烷A1 1 2 0分散剂时分散效果最佳 ;当分散时间达 7 5h时 ,分散液中SiO2 基本以纳米尺寸存在 ;将分散液加入对苯二甲酸二甲酯熔体中并在球磨状态下进行酯交换SiO2 的分散效果最好 ,1 0 0nm以下的SiO2 达 95 0 7% ;体系中随SiO2 量的增加 ,其分散性变差 ,当纳米SiO2 的加入量为 1 %～ 4 %时 ,粒径在 1 0 0nm以下的SiO2 由 88%下降到 61 %。     

不饱和聚酯树脂光固化工艺的研究-光引发剂浓度

本文选用TPO、651两种光引发剂，分别配制引发剂浓度为0．25、0．5、1、2wt％的不饱和聚酯体系。通过测定光固化试样的显微硬度分析光引发剂浓度对固化程度的影响。结果表明，提高引发剂浓度能抑制氧阻聚的作用，但对于较厚的试样，引发剂浓度过高会导致固化不完全。     

水辅助注塑大直径介质导管制品的冷却分析

采用数学分析方法，通过假设、简化分析模型，用数学模型来表述物理模型，确定了水辅助注塑(VAIM)大直径介质导臂制品的冷却时间，并运用算例和国外试验的结果进行验证。结果发现：水辅助注射成型新工艺可以更加显著地缩短注塑周期，降低制件壁厚，允许制件有更大的实际直径。因此，VAIM技术可用来高效率地生产大直径、高质量、薄壁的介质导臂。     

高效液相色谱法测定稻·噁乳油含量

采用高效液相色谱法,在同一色谱条件下对稻·噁乳油中所含有效成分稻瘟灵和噁霉灵同时进行含量测定。色谱条件为:使用Nova-PaK C18250mm×4.6mm(i.d)不锈钢色谱柱,流动相v(甲醇)∶v(水)=70∶30,流速1mL/min,检测波长为220nm。测定方法中稻瘟灵和噁霉灵的回收率分别在98.8%～100.3%和98.6%～100.0%之间,变异系数分别为0.54%和0.52%,证明本方法快速、准确、可靠。     

硼泥陶粒及其混凝土的试验研究

介绍用工业废渣硼泥作主要原料，掺一定比例的膨胀剂，生产轻质、高强、保温的硼泥陶粒及配制LC30硼泥陶粒混凝土的试验。     

Synthesis and properties of new polymerized monomer reactants matrix resins of pyrrolone–benzimidazole copolymers containing pyridine unit

A series of new polymerized monomer reactants (PMR) matrix resins of poly(pyrrolone‐benzimidazole)s containing a pyridine unit (PPBP) were synthesized by polycondensation of monoethyl ester of cis‐5‐norbornene‐endo‐2,3‐dicarboxylic acid, 2,6‐diphenyl ester pyridinedicarboxylic acid or 3,5‐diphenyl ester pyridinedicarboxylic acid, and diethyl ester of 4,4′‐oxydiphthalic acid with 3,3′‐diaminobenzidine in a mixing solution of anhydrous ethyl alcohol and N‐methylpyrrolidone under given temperature and pressure conditions. The resulting resin solutions showed good solubility in polar organic solvents and stability at room temperature. The corresponding PPBP matrix resin, molded powder, and molded plate were prepared by undergoing amidation, imidization, cyclization, and crosslinking reactions when the reaction temperature was increased from 80 to 350°C, successively; the crosslinking structure was formed by the reverse Diels–Alder reaction at 270–290°C under 50 MPa pressure (2.5–3.5 MPa displayed by the pressure meter). The chemical reactions and properties of the resulting PPBP were studied by means of FTIR, TGA, and DMA methods, and the results indicated that the kinds of PPBP materials retain excellent thermal stability and processability; when the initial decomposition temperature was above 620°C the T_g was at 413.5°C for 3,5‐PPBP‐20 molded plate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3981–3990, 2004