环氧树脂/蒙脱土纳米复合材料性能的研究

用一种新型的热稳定性较好的改性剂2，2’-二[4-(4-氨基苯氧基)苯基]-丙烷(BAPP)改性钠基蒙脱土，再与环氧树脂进行纳米复合制备了环氧树脂／蒙脱土纳米复合材料。讨论了蒙脱土用量对环氧树脂／蒙脱土纳米复合材料性能的影响，并对其结构和性能进行了表征和测试。结果表明：改性使蒙脱土层间距变大，制备出的环氧树脂／蒙脱土纳米复合材料剥离结构较好，环氧树脂／蒙脱土纳米复合材料的玻璃化转变温度和动态储能模量随改性蒙脱土用量的增加呈现较好的递增趋势。     

Selective O-methylation of phenol with dimethyl carbonate over X-zeolites

The O-methylation of phenol with dimethyl carbonate proceeds selectively in the vapor phase over alkali ion exchanged X-zeolites. Thus, a 76% yield of anisole was obtained with a 93% selectivity over NaX at 553 K. The participation of basic sites in the O-methylation is suggested.     

Novel lanthanide salicylaldimine complexes with unusual coordination mode

The one-step metal promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine in the presence of lanthanum(III) or gadolinium(III) nitrate yields new salicylaldimine complexes containing N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine as a result of the [2 + 1] Schiff base condensation. The crystal structure of the gadolinium complex reveals a dinuclear species with four unionized ligands coordinating in the monodentate and bridging bidentate fashion, using exclusively the oxygens as donor atoms with the nitrogen atoms not being involved in coordination. The coordination number of nine is achieved by involving three bidentate nitrate counterions in the coordination sphere.     

Low-pressure CO2 sorption in ammonium-based poly(ionic liquid)s

Ammonium-based ionic liquid monomers and their corresponding polymers [poly(ionic liquid)s] are synthesized and characterized for CO₂ sorption. The polymers have much higher CO₂ sorption capacities than the room-temperature ionic liquids and imidazolium-based poly(ionic liquid)s. For example, P[VBTMA][PF₆] with polystyrene backbone has a CO₂ sorption capacity of 10.67 mol%. The CO₂ sorption is selective over N₂ and O₂. The effects of cation, backbone, substituent, anion and crosslinking on CO₂ sorption are discussed. The sorption mechanism study indicates that CO₂ sorption by the poly(ionic liquid)s is a bulk and surface phenomenon.     

汽车尾气用催化剂载体研究现状及展望

汽车尾气催化净化器中，催化剂载体是实现高效尾气净化的一个关键因素。本文综述了对尾气净化催化剂载体的要求和研究现状。并提出导电型复合陶瓷是今后尾气净化载体材料研究和发展的一个新型方向。     

Electroreduction of laccase covalently bound to organothiol monolayers on gold electrodes

Cerrena unicolor laccase was immobilized on the gold electrode by covalent bonding to self-assembled monolayers of mercaptoundecanoic or mercaptopropionic acids. STM images of immobilized laccase proved high population of the laccase molecules on the monolayer modified electrode. The SERS experiments in concert with resonance Raman effect confirmed that the structure at the “blue” copper site of the immobilized protein remained intact. The accessibility of individual copper sites for electron exchange with the gold electrode surface was investigated by voltammetry. The electrode behavior of laccase is different in the presence and absence of oxygen, showing that the immobilized enzyme is reactive towards oxygen. Addition of two common mediators improved the electrical connectivity of the enzyme with the electrode, increased the catalytic efficiency of immobilized laccase and switched the onset of catalytic current to the potentials of the mediator. Immobilization of laccase on well-organized mercaptoundecanoic acid separates efficiently the enzyme from the electrode and does not allow easy access of mediators to the surface. Attachment of the enzyme at smaller distance from the electrode by means of significantly shorter spacer molecule—mercaptopropionic acid improved the efficiency of catalytic reduction of oxygen on the monolayer modified electrode.     

使用KQ-1缓蚀阻焦剂,减轻糠醛装置腐蚀和结焦

独山子炼油厂糠醛精制装置设备腐蚀状况严重 ,尤其是加工高酸值原料 ,更加剧了设备的腐蚀。通过对腐蚀原因分析 ,决定从工艺防腐上解决 ,提出了加入缓蚀剂减缓设备腐蚀的方法 ,在实验室评价和工业装置中 ,评选了四种糠醛精制装置的缓蚀剂 ,其中KQ 1作为装置缓蚀剂效果最佳 ,平均缓蚀率达到 4 4 .5 % ,并估算了KQ 1工业使用的经济效果     

江河水污垢对小管径恒壁温管内对流换热影响

为有效提高江河水冷热源的利用率,应用热力学第一、第二定律和湍流流动理论,讨论和分析了污垢对恒壁温小管径管内对流换热过程热力学性能的影响。分析结果表明,有污垢存在时,污垢层导热引起的熵产在管内对流传热熵产中占主要部分,而温差传热引起的熵产则相对较小,且在雷诺数较大,管径较小的流动中,会出现粘性流动引起的熵产大于温差传热引起的熵产;随雷诺数的增大和污垢热阻的产生,熵增率都是单调增加的。因此在利用江河水发展水源热泵时,要充分考虑污垢热阻对换热器性能的影响,尤其是污垢层导热热阻的影响。     

永磁同步电机混合非线性控制策略

永磁同步电机是一个非线性多变量强耦合系统,采用传统的线性控制方法难以在大范围运行中保持良好的动态性能和鲁棒性.针对永磁同步电机的特点,提出一种结合滑模控制和自抗扰控制的混合非线性控制策略,用于永磁同步电机矢量控制系统设计.根据指数趋近律算法设计滑模控制器,用于内环的电流控制.外环的速度采用自抗扰控制,速度控制器对负载扰动进行估计和补偿.仿真结果表明,提出的控制系统不仅具有良好的动态和静态性能,而且对负载及系统参数扰动具有较强的鲁棒性.     

Gearbox fault diagnosis of rolling mills using multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution

Fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heavy background noise under the severe condition. Thereby, a novel method based on multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution is proposed for gearbox fault diagnosis in rolling mills. The emerging multiwavelets can seize the important signal proce...