甲基吡啶的解离萃取分离实验研究

应用解离萃取分离合成吡啶产生的3-甲基吡啶(3-MPD)与4-甲基吡啶(4-MPD)的混合物(φ(3-MPD)＝68.472 2%;φ(4-MPD)＝26.517 6%),对影响解离萃取分离的6个因素萃取剂、萃取剂的浓度及投料量、有机溶剂及投料量,以及分离温度进行了研究.选取了各因素的不同水平进行了六因素五水平的正交试验,以有机相两甲基吡啶的体积比为主要考查对象,筛选出了解离萃取分离甲基吡啶混合物的最佳工艺条件:当甲基吡啶的混合物为24 mL时,以浓度为2 mol/L的对甲基苯磺酸为萃取剂,用量为40 mL,正庚烷为溶剂,用量为48 mL,温度为0 ℃时分离效果最好.通过重复性实验,分离效果得到明显提高,说明此法具有工业化潜力.     

Teaching Young Children Self-regulation through Children’s Books

Today’s emphasis on using children’s literature as a tool to teach reading and writing sub-skills distracts teachers’ attention from looking to children’s books for their historical role in helping children navigate the intellectual, social, and emotional terrains of childhood. This article argues, first, that early childhood educators must remain fluent in the use of literature that supports young children’s psychosocial development. Second, teachers must establish criteria for choice. By way of example, it examines two popular books for young children, Sendak’s (1963) Where the Wild Things Are [New York: HarperCollins Publishers] and Shannon’s (1998) No, David! [New York: Blue Sky Press] Three theoretical perspectives guide the analysis. The first combines Dewey’s (1938/97) [Experience and education. New York:Touchstone] impetus for learning and Vygotsky’s (1978) [Mind in society. Cambridge: Harvard University Press] theory that learning precedes development through scaffolded social interaction. The second is Erikson’s (1950, 1985) [Childhood and society. New York: W. W. Norton & Company, Inc.] theory of psychosocial development in light of the 4–6-year-old’s drive towards self-regulation, control, and independence. The third is Rosenblatt’s (1978) [The reader, the text, the poem. Urbana, IL: National Council of Teachers of English] transactional nature of reading.     

四至六年级儿童家庭教养方式与儿童心理健康

小学四至六年级的儿童即9-12岁左右的儿童，是孩子一生发展最重要的关键期之一，小学儿童的家庭教养方式对于儿童的心理健康成长具有重要的现实意义。当前，我国小学中高年级儿童存在一定的心理问题，这些问题的出现与家庭错误的养育方式有关。因此，家长应掌握正确的育儿理论和育儿方式，为创设和谐的、民主的家庭氛围作出努力，以促进儿童心理的健康发展。     

Rechtliche Rahmenbedingungen für die Gestaltung universit?rer Curricula

Die bereits im Zuge der Autonomie-St?rkung der Universit?ten durch das UOG 1993 im Rahmen der Erlassung des UniStG 1997 vorgenommene Aufwertung der Selbstregelungskompetenzen der Universit?ten bei der Gestaltung des Studienrechts, findet in der Fassung der studienrechtlichen Vorgaben des UnivG 2002 seine konsequente Fortsetzung. Diese Ausweitung der Selbstregelungskompetenzen geht im rechtsstaatlichen Sinne typischerweise (als Gegengewicht) mit besonderen Anforderungen an Rechtsschutz und Rechtssicherheit einher. Insofern hat der universit?re Verordnungsgeber auch auf die in den Gesetzesgrundlagen zum Ausdruck kommenden Wertungen und Grunds?tze eingehend Bedacht zu nehmen.     

从锌锰电池中制取硫酸锰的工艺研究

研究了从废旧锌锰电池中制取硫酸锰(MnSO4)的实验原理、工艺流程及实验条件。实验结果表明:硫酸浓度和催化剂用量对反应影响很大。同时得出最佳反应条件:硫酸浓度为10%,反应温度40℃,催化剂双氧水用量1.0 mL(30%),保持固液比为1∶10和反应时间2 h,产率可达89%以上。     

五四时期的儿童文学翻译(下)

鲁迅先生除了翻译具有社会责任感和使命感的爱罗先生的童话之外,还翻译了思想性不那么沉重的作品,比如,翻译荷兰作家望·蔼覃的长篇童话《小约翰》便是一例。 还是在留学时的1906年,他在东京神田旧书店,从《文学的反响》半月刊上偶然看见《小约翰》     

A CHASE domain containing protein kinase OsCRL4, represents a new AtCRE1-like gene family in rice

AtCRE1 is known to be a cytokinin receptor in Arabidopsis. The AtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal CHASE domain of AtCRE1 contains putative recognition sites for cytokinin. Five CHASE domains containing proteins were found in rice, OsCRL1a, OsCRL1b, OsCRL2, OsCRL3, and OsCRL4. OsCRL1a, OsCRL1b, OsCRL2 and OsCRL3 contain the four domains existing in CRE1, whereas OsCRL4 only contains the CHASE domain and a putative Ser/Thr protein kinase domain. The authors cloned the encoding gene OsCRL4 and found that it represents a new member of the cytokinin receptor protein in rice.     

表面改性提高与Ti6A14V对磨材料UHMWPE摩擦学性能

Surface engineering has been emerging as one of the most promising technologies to improve the tribological properties of biomaterials with a view to extending the life span of medical implants. For example, some novel surface engineering techniques including ion implantation of ultra-high molecular weight polyethylene (UHMWPE) and thermal oxidation (TO) treatment of titanium alloy have been developed. However, the full potential of improving the wear resistance of orthopaedic implants based on the UHMWPE/ Ti6A14V system will not be realized until the tribological performance of this surface engineered tribo-system is fully characterized and the acting wear mechanisms are well understood. In this paper, a pin-on-disc tribometer was employed to evaluate the tribological response of the following three tribo-systems: (1) untreated UHMWPE/untreated Ti6A14V. (2) untreated UHMWPE/TO-treated Ti6A14V and (3) ion implanted UHMWPE/TO treated Ti6A14V under water lubricated conditions. Experimental results show that the tribological properties of UHMWPE can be significantly increased by surface enghmering its surface and/or the counterface. Tiffs can be attributed to the hardened surface of UHMWPE via molecular structure modification induced by ion bean bombardment coupled with the surface oxide layer on Ti6A14V formed during TO treatment, which has favorable tribological compatibility with UHMWPE.     

浅谈大学英语课堂教学与四级考试训练的结合

本文主要讨论大学英语课堂教学中科学结合大学英语四级考试(CET-4)训练，使学生的英语综合应用能力和应试能力同步提高。     

一种大规模合成N-(4-羟苯基)维甲酰胺的新方法

介绍了抗肿瘤药物N-（4-羟苯基）维甲酰胺（4-HPR）的合成新方法．该方法包括如下反应步骤：全反式维甲酸与二氯亚砜反应生成酰氯,再与三乙胺成盐,然后将得到的酰基铵盐与对氨基苯酚发生酰胺化反应,制得4-HPR．该方法解决了文献报道方法在大规模合成时存在的多种问题如后处理繁琐、收率低等,具有操作简单、反应条件温和以及产率高等特点．此外,研究了反应试剂的摩尔比对反应收率的影响,最佳摩尔比为二氯亚砜和对氨基苯酚物质的量分别是维甲酸物质的量的2倍和3倍,总收率为80．7％．