择形催化合成2,6-DMN的研究进展

介绍了2,6-二甲基萘(2,6-DMN)的制备方法,详细论述了萘、甲基萘在分子筛催化剂上择形催化合成2,6-DMN的研究进展,提出了择形催化合成2,6-DMN的研究方向。     

The effects of recent practice on task switching.

Four experiments investigated the effect of recent selective practice on the cost of switching between 2 tasks afforded by letter-digit pairs: alphabet arithmetic and shape comparison. Experiments 1 and 2 found a greater cost associated with switching to the more recently practiced task: evidence that task-set inertia contributes to switching costs. Experiment 3 found this effect to be limited to trials on which a recently trained stimulus followed another such stimulus: a result problematic for all current theories of task-set priming. Experiment 4 showed that the effect of recent practice was eliminated by active preparation for a task switch: It appears that endogenous task-set preparation reduces the effects of task-set inertia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

助剂对Pd/树脂醚化催化剂催化性能的影响 Ⅰ.铝助剂的影响

研究了不同助剂对Ｐｄ／树脂醚化催化剂在临氢条件下对催化裂化汽油Ｃ５馏份与甲醇和Ｈ２反应的催化性能的影响。结果表明，在Ｐｄ／树脂醚化催化剂中引入Ｚｒ、Ｔｉ、Ｂ、Ｓｎ和Ａｌ等助剂后，都能改善催化剂的醚化、双键异构和二烯烃选择性加氢活性，其中以Ａｌ、Ｓｎ为最好。Ａｌ助剂的体积质量和负载方式对Ｐｄ－Ａｌ／树脂醚化催化剂的活性有影响。ＢＥＴ方法和Ｘ－射线荧光光谱分析（ＸＦＳＡ）表明，Ａｌ助剂对Ｐｄ－Ａｌ／树脂醚化催化剂的表面积、孔结构和Ｐｄ离子交换量影响较小。     

乙炔在磁稳定床中的选择性加氢研究

 制备了一种磁性Pd/Al₂O₃催化剂，采用磁稳定床考察了活性组分负载量、反应条件及CO浓度对乙炔加氢反应性能的影响。结果表明，当反应温度80℃、反应压力1.5MPa、空速9000h－1、磁场强度（H）25kA/m时，乙炔转化率为100％，乙烯选择性可达81％，具有优良的乙炔加氢活性和乙烯选择性，优于相同反应条件下的进口催化剂；250h稳定性实验结果表明，磁性Pd/Al2O3催化剂具有良好的初活性和乙烯选择性，催化剂性能稳定。     

Cutting stress off at the pass: Reducing vigilance and responsiveness to social threat by manipulating attention.

Personality processes relating to social perception have been shown to play a significant role in the experience of stress. In 5 studies, the authors demonstrate that early stage attentional processes influence the perception of social threat and modify the human stress response. The authors first show that cortisol release in response to a stressful situation correlates with selective attention toward social threat. Second, the authors show in 2 laboratory studies that this attentional pattern, most evident among individuals with low self-esteem, can be modified with a repetitive training task. Next, in a field study, students trained to modify their attentional pattern to reduce vigilance for social threat showed lower self-reported stress related to their final exam. In a final field study with telemarketers, the attentional training task led to increased self-esteem, decreased cortisol and perceived stress responses, higher confidence, and greater work performance. Taken together, these results demonstrate the impact of antecedent-focused strategies on the late-stage consequences of social stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Big-Fish--Little-Pond effect on academic self-concept: A cross-cultural (26-country) test of the negative effects of academically selective schools.

Academically selective schools are intended to affect academic self-concept positively, but theoretical and empirical research demonstrates that the effects are negative. The big-fish--little-pond effect (BFLPE), an application of social comparison theory to educational settings, posits that a student will have a lower academic self-concept in an academically selective school than in a nonselective school. This study, the largest cross-cultural study of the BFLPE ever undertaken, tested theoretical predictions for nationally representative samples of approximately 4,000 15-year-olds from each of 26 countries (N=103,558) who completed the same self-concept instrument and achievement tests. Consistent with the BFLPE, the effects of school-average achievement were negative in all 26 countries (M beta=-.20, SD=.08), demonstrating the BFLPE's cross-cultural generalizability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

裂解碳五馏分分离中取代二萃单元的研究

针对目前裂解碳五馏分分离流程中第二萃取单元的诸多问题,提出采用选择性加氢除去炔烃后再进行精馏的方法代替二萃单元,得到聚合级异戊二烯产品。研究结果表明,工艺流程的改进部分是可行的,具有流程短、安全可靠、能耗低、生产成本低、环境污染少、简化溶剂回收单元等优点。     

Selective hydrogenation of oleic acid to 9-octadecen-1-ol: Catalyst preparation and optimum reaction conditions

A new catalyst, ruthenium-tin-alumina is found to selectively hydrogenate oleic acid to 9-octadecen-1-ol (oleyl + elaidyl alcohol) at low pressure with high yield. Catalyst preparation methods, catalyst raw materials and activation conditions have a significant effect on the activity of the catalyst. The optimum atomic ratio of ruthenium to tin is about 1:2. Catalyst prepared by an improved sol-gel method shows higher activity and selectivity than catalysts prepared by impregnation and coprecipitation methods. Chloride is found to have a negative effect on catalytic activity. The best catalyst is prepared from chloride-free ruthenium and tin raw materials. Under the optimum reaction conditions of 250°C and 5.6 MPa, the selectivities for 9-octadecen-1-ol and total alcohol (9-octadecen-1-ol + stearyl alcohol) formation are 80.9% and 97%, respectively, at a conversion of 81.3%.     

催化蒸馏选择加氢的数学模型和模拟

在SHBWR汽液平衡方程、幂函数型动力学方程的基础上，假定每个催化床层为－全混流反应器，建立了碳三催化蒸馏选择加氢数学模型，利用二阶P－K算法进行收敛计算。提出了给反应速率方程添加收敛引子，结合“向上逐层累加”法使模型收敛的方案。