一水邻苯二甲酸钙的热分解及其脱水动力学分析

采用TG-DTA分析研究了一水邻苯二甲酸钙热分解过程,对其中的脱水过程进行了动力学计算. 由Friedman和Ozawa-Flynn-Friedman法得到脱水过程的活化能和指前因子,用Archar方法计算拟合了几种机理函数,确定了脱水过程的优化动力学参数及最佳机理模型. 脱水过程的活化能Ea为141.1576 kJ/mol,反应的机理模型为Bna,即f(α) =(1-α)n*αn.     

少儿英语教学与语言习得

语言学习和语言习得在学习效果上存在一定的差异.在少儿英语教学中发展儿童语言运用能力的关键在于教师应结合儿童认知能力的发展,从语言信息输入定位、输入输出定位、教学顺序定位、情感因素过滤方面来创设语言习得环境.     

Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution.     

试论《商君书》关于选任官吏的思想

《商君书》蕴含有丰富的选官思想，对于官吏的起源、地位、作用、选拔和任用以及对官吏的控制、精简等等都有阐述。它在秦国历史上产生过重要的影响，起到了积极的、进步的历史作用，在深化人事体制改革的今天，为了记取历史的经验和教训，我们仍有必要对此进行研究和总结。     

论音乐教学中的审美心理因素

音乐是听觉的艺术,它通过特殊的音乐语言-旋律,振撼人们的心灵,使人产生愉悦,激发想象,产生情感,获得美的享受.教师要懂得审美心理因素在教学中的作用,并将它贯穿、融汇在音乐教学中,方能提高学生的审美情趣和音乐素养.     

儒家恕道与中国古代法律文化

儒家恕道与中国古代法律化传统有着内在的不可分割的密切联系，使中国传统法律化表现出鲜明独特的公法化的个性特征。本从恕道的渊源、内涵及法化品性入手，阐述了其对于中国古代法律化的影响，并剖析了恕道、法律化传统与现实的关系。     

培养学生质疑问难能力策略研究

小学阶段是培养学生质疑问难能力的基础和关键。培养学生质疑问难能力是素质教育的需要，有助于学生良好个性的形成。培养学生质疑问难能力，要研究学生学习心理、学习环境和自身的知识和能力，同时也要教给学生质疑问难的方法。     

高职院校教学管理工作的探索

在新世纪新形势高职院校教学管理工作有新的要求; 目前高职院校在教学管理中存在的问题; 加强高职院校教学管理工作的建议和措施。     

Enhancing cellular immune response to HBV M DNA vaccine in mice by codelivery of interleukin-18 recombinant

Objective: To investigate the effect of interleukin-18 (IL-18) on immune response induced by plasmid encoding hepatitis B virus middle protein antigen and to explore new strategies for prophylactic and therapeutic HBV DNA vaccines. Methods: BALB/c mice were immunized with pCMV-M alone or co-immunized with pcDNA3-18 and pCMV-M and then their sera were collected for analysing anti-HBsAg antibody by ELISA; splenocytes were isolated for detecting specific CTL response and cytokine assay in vitro. Results: The anti-HBs antibody level of mice co-immunized with pcDNA3-18 and pCMV-M was slightly higher than that of mice immunized with pCMV-M alone, but there was not significantly different (P>0.05). Compared with mice injected with pCMV-M, the specific CTL cytotoxity activity of mice immunized with pcDNA3-18 and pCMV-M was significantly enhanced (P<0.05) and the level of IFN-γ in supernatant of splenocytes cultured with HBsAg in vitro was significantly elevated (P<0.05) while the level of IL-4 had no significant difference (P>0.05). Conclusion: The plasmid encoding IL-18 together with HBV M gene DNA vaccines may enhance specific TH1 cells and CTL cellular immune response induced in mice, so that IL-18 is a promising immune adjuvant.     

影响高校毕业生就业的社会资本因素分析

社会资本是近年来学术界研究较多的一个问题。本文在对社会资本及大学生就业相关文献进行梳理的基础上,利用北京大学教育学院"高等教育规模扩展与劳动力市场"课题组于2005年6月对全国34所高校调查的数据,对大学生社会资本状况,社会资本对大学生毕业去向、就业落实率、起薪及工作满意度的影响,进行了实证分析。本文的主要研究结果如下:(1)与来自社会经济地位较高的家庭的学生相比,来自社会弱势家庭的学生在家庭社会资本与个人社会资本上都比较缺乏;(2)大学生毕业选择就业或升学时,家庭社会交往广泛度对升学选择产生显著的正面影响,而个人社会交往广泛度对就业产生了显著的正面影响;(3)社会资本与大学毕业生的就业落实、起薪、工作满意度存在着显著的正面影响;(4)社会资本对大专生和本科生就业落实率有较为显著的正的影响,但是对硕士和博士的就业落实率没有显著影响。