Mssbauer Spectroscopic Studies of Fe_2O_3-K_2O Based Catalysts for Ethylbenzene Dehydrogenation

利用穆斯堡尔谱在k2 O fE2 O3催化剂中检出了α fE2 O3(大晶粒及微晶 )、kfEO2 、k1+ XfE11O17、α fEOOH和γ fEOOH等物相 ,它们的相对含量取决于催化剂的含钾量及煅烧温度 ,相对含量的改变导致样品的穆斯堡尔谱图出现了复杂的变化 .与Xrd相比 ,穆斯堡尔谱可对钾与氧化铁的相互作用进行更有效的表征 ,穆斯堡尔谱和TPr研究都表明钾可延缓催化剂中fE(III)的被还原 .Fe 2O 3 K 2O Catalysts with different content of K 2O and calcined at different temperature were characterized by using Mssbauer spectroscopy.It was found from the experiments that only a sextuplet assignable to Fe 3+ of α Fe 2O 3 could be detected while the K 2O content in these catalysts were lower than 5%and the calcination temperature was below 900℃;and complex spectra ,which could be fitted with several sextuplets of trivalent irons present in α Fe 2O 3, KFeO 2, K 1+ x Fe 11 O 17 and α FeOOH ,and a doublet of Fe 3+ in γ FeOOH ,would be observed if the K 2O content were 10%～27%and the calcination temperature were 800～900℃.The γ FeOOH,as a hydrous iron oxide ,was the decomposition product of KFeO 2 which was strong hydroscopic by absorbing moisture from the atmosphere.The results also suggested that Mssbauer spectroscopy was a better mean than XRD for the characterizations of Fe 2O 3 K 2O catalysts,by which ,α FeOOH ,γ FeOOH and α Fe 2O 3 in amorphous or crystallite forms ( unable to be found by XRD ) could be detected .It was also shown from the Mssbauer spectroscopy and a TPR studies that potassium could retard the reduction of Fe(III) to Fe(II) in the Fe 2O 3 K 2O catalysts.中国石油化工总公司资助项

Mossbauer Spectroscopic Characterization on Promotion of CaO in Catalysts of Ethylbenzene Dehydrogenation

穆斯堡尔谱学研究表明，在k2O-fE2O3体系中引入CAO促进k2O与fE2O3之间的相互作用，降低k1＋XfE11O17的生成温度.而且，CAO的引入还降低了在k2O-fE2O3体系中产生“α-fEOOH“物种所必须的k2O含量（由约17%降低为约8%）.在乙苯脱氢反应条件下所发生的fE3＋被还原为fE2＋的过程，亦被钙的存在所延缓.The Promotions of CaO in the catalysts of ethylbenzene dehydrogenation to styrene were investigated by M6ssbauer studies, which showed that the interaction between K2O and Fe2O3 was enhanced and the formation temperature of K1+xFe11O17 was depressed by the introduction of CaO into K2O-Fe2O3 system.Moreover, the necessary content of K2O in K2O-Fe2O3 system for the formation of "a-FeOOH" species was reduced from about 17% to 8% by the introduction of CaO.We also found that the process of reduction from Fe3+ to Fe2+ in the Fe2O3 based catalysts under the condition of ethylbenzene dehydrogenation was retarded by the presence of Ca in the catalysts.中国石油化工集团公司资

基于Workbench的链条拆节机撞针疲劳寿命分析

链条拆节设备的撞针在载荷反复作用下极易发生疲劳损坏，威胁链产品质量。为了研究撞针疲劳破坏的规律，利用Workbench软件对撞针进行有限元分析，首先通过静强度分析确定撞针结构的薄弱部位，在此基础上进行疲劳寿命计算，获得撞针的疲劳寿命情况。将分析得到的数据与实际验证情况进行对比，结果表明，两种方法的效果基本一致，从而验证了有限元分析的有效性，也为后续设备维护和结构优化提供了一定的技术参考

社会决策中的公平准则及其神经机制

社会决策中的公平准则一直受到广泛的关注,经济学家和心理学家们分别从动机和认知的角度对这个课题进行了深入探索。在这些工作中,最为突出的是"均等","互惠"和"情绪"三个模型的提出。均等和互惠模型试图从动机角度理解个体的公平行为,而情绪模型则更强调个体在公平决策中的认知和情绪的加工过程。近年来脑成像的研究也为这些模型提供了相应的支持,其中与公平准则最密切的脑区是脑岛和背外侧前额叶:前者一般被认为是反映了个体面对不公平待遇时的负性情绪体验;而后者主要负责决策过程中的抑制控制。但这些脑区具体的功能还存在很多争议,反映了不同理论模型对特定脑区功能的不同理解。未来研究应注意三个模型之间的相互补充,以及加强多模态的脑指标的运用,并注重相关脑区的整体性,此外,公平决策行为中的个体差异,以及社会情境对其的影响也应受到重视

The Fairness Norm in Social Decision-making： Behavioral and Neuroscience Studies

社会决策中的公平准则一直受到广泛的关注,经济学家和心理学家们分别从动机和认知的角度对这个课题进行了深入探索。在这些工作中,最为突出的是"均等","互惠"和"情绪"三个模型的提出。均等和互惠模型试图从动机角度理解个体的公平行为,而情绪模型则更强调个体在公平决策中的认知和情绪的加工过程。近年来脑成像的研究也为这些模型提供了相应的支持,其中与公平准则最密切的脑区是脑岛和背外侧前额叶:前者一般被认为是反映了个体面对不公平待遇时的负性情绪体验;而后者主要负责决策过程中的抑制控制。但这些脑区具体的功能还存在很多争议,反映了不同理论模型对特定脑区功能的不同理解。未来研究应注意三个模型之间的相互补充,以及加强多模态的脑指标的运用,并注重相关脑区的整体性,此外,公平决策行为中的个体差异,以及社会情境对其的影响也应受到重视

绿洲边缘不同土地利用方式下土壤粒径分布特征

为探讨绿洲化进程中不同土地利用方式对土壤粒径分布属性的影响，基于塔里木盆地南缘策勒绿洲边缘的果园、棉田、沙拐枣林地等人为垦殖土地利用方式及自然状态骆驼刺覆被下0 ～ 20，20 ～ 40，40 ～ 60 cm 内的土壤粒径分布数据，利用分形理论及典范对应分析排序方法，分析各深度下不同土地利用方式土壤粒径分布特征变化状况，及其与土壤有机质等8 项指标的相关性，进而判别并探讨绿洲边缘合理的土地利用方式。结果表明:粒径 50. 59 μm 范围内的细粒体积分数同粒径分布分维值显著正相关，与土壤有机质、全氮含量呈显著正相关，与密度呈显著负相关; 具体分维值变化上，沙拐枣林地在各层均显著处于最低水平，其余样地总体上无显著差异，但果园相对处于高位水平; 自然状态下骆驼刺样地随着土壤深度增加分维值有增加的趋势，其对土壤养分的持有力也逐渐优于其余样地。在水资源相对有保障前提下，在绿洲边缘发展果园或棉田有利于土壤粒径分布及其余属性的提高，相反，则应保持原有的自然植被状况，而对自然植被进行替代的沙拐枣林地则会加剧土壤退化

中国心理学会会议论文集

研究目的:情绪回避对于广泛性焦虑障碍患者(GAD)维持焦虑症状具有重要意义。自传体记忆中含有丰富的情绪信息,这些情绪往往被认为是GAD的始因或结果。然而,在记忆提取时的情绪回避机制尚未明晰。因此,我们研究了GAD在自传体记忆提取过程中的情绪回避机制及神经基础。研究方法:在371名在校学生中,筛选出22名患有GAD的学生作为实验组和25名健康学生作为对照。所有被试参与了一项功能性磁共振(fMRI)研&nbsp;</p

Mossbauer spectroscopic studies of Fe2O3-K2O-based catalysts for ethylbenzene dehydrogenation

Fe2O3-K2O Catalysts with different content of K2O and calcined at different temperature Mere characterized by using Mossbauer spectroscopy. It was found from the experiments that only a sextuplet assignable to Fe3+ of alpha-Fe2O3 could be detected while the K2O content in these catalysts were lower than 5% and the calcination temperature was below 900 degrees C; and complex spectra, which could be fitted with several sextuplets of trivalent irons present in alpha-Fe2O3, KFeO2, K1+xFe11O17 and alpha-FeOOH, and a doublet of Fe3+ in gamma-FeOOH, would be observed if the K2O content were 10% similar to 27% and the calcination temperature were 800 similar to 900 degrees C. The gamma-FeOOH, as a hydrous iron oxide, was the decomposition product of KFeO2 which was strong hydroscopic by absorbing moisture from the atmosphere. The results also suggested that Mossbauer spectroscopy was a better mean than XRD for the characterizations of Fe2O3-K2O catalysts, by which, alpha-FeOOH, gamma-FeOOH and alpha-Fe2O3 in amorphous or crystallite forms ( unable to be found by XRD) could be detected. It was also shown from the Mossbauer spectroscopy and a TPR studies that potassium could retard the reduction of Fe(III) to Fe(II) in the Fe2O3-K2O catalysts

重庆市涪陵区城乡饮用水中微囊藻毒素的污染

目的探讨重庆市涪陵区城乡居民饮用水中微囊藻毒素LR(MC-LR)污染现状。方法在涪陵区市政水源水(长江水)、管网水、二次供水系统设立采样点;同时,抽取水源和水处理工艺完全相同的4个乡镇水厂,选择其水源水、管网水;在上述4个乡镇分别选择3～4个农村居民饮用水井。于2004年6&mdash;11月,采集各采样点水样。采用酶联免疫试剂盒测定MC-LR含量,采用氯化亚锡分光光度法测定水样中总磷含量,采用紫外分光光度法测定水样中总氮含量。结果6&mdash;11月市政水源水(长江水)、管网水以及6月市政二次供水、乡镇水厂水源水、管网水、