8-R-9苄基-9H-嘌呤衍生物的合成研究

采用 (Ph3 P) 2 PdCl2 为催化剂 ,DMF为溶剂 ,对 8 碘 9 苄基 9H 嘌呤与有机锡试剂RSnBu3 (R=乙烯基、2 噻吩基、2 呋喃基、苯乙炔基和苯基等 )之间的Stille偶合反应进行了研究 ,合成出了5种 8位取代的嘌呤衍生物。在反应温度为 80℃ ,n(8 碘 9 苄基 9H 嘌呤 )∶n (RSnBu3 )∶n〔(Ph3 P) 2 PdCl2 〕 =1 0∶1 2∶0 0 5的较佳工艺条件下 ,产品收率 4 1%～ 91%。用1H NMR、13 C NMR和MS对产物进行了表征     

Pb（Sc1／2Ta1／2）O3铁电体的有序结构和介电性质）

通过铌铁矿预合成法制备Ｐｂ（Ｓｃ１／２Ｔａ１／２）Ｏ３（ＰＳＴ）陶瓷，经适当的热处理获得了钙钛矿化合物Ｂ位离子的高有序和高无序试样，ＰＳＴ陶瓷的介电性质研究结果表明，高有序试样（Ｓ＝０．７７）的居里温度为２９℃，并具有较低的介电常数表现出普通铁电体性质特征，而高元序试样（Ｓ＝０）具有很高的介电常数，并表现出明显的弥散性相转变和Ｔｍ的频率色散行为，即高介电常数的驰豫铁电体性质。文中还利用ＸＲＤ，ＳＥ     

γ—TiAl增压涡轮熔模铸造过程数值模拟研究

根据熔模型壳离心浇注的铸造工艺特点，建立了γ－TiAl增压涡轮凝固传热过程的数值模型，推导了离心压力下γ－TiAl金属间化合物的凝固收缩和补缩过程数学模型，模拟计算了γ－TiAl增压涡轮铸件的温度场和收缩缺陷，结果表明，模型能可靠计算γ－TiAl增压涡轮铸件凝固过程的温度分布和准确预测铸件的收缩缺陷，数值模拟结果与实验结果吻合良好，数值模拟结果证实了前期工作所提出的进一步减少及消除收缩缺陷的优化工艺措施的合理性。     

Ti5Nb人工钉扎中心NbTi超导体的磁通钉扎机制分析

采用棒基组合的装配方法，用热挤压和冷加工相结合的工艺制备了岛状Ti5Nb人工钉扎中心NbTi超导体，其中Ti5Nb体积含量为10％。通过对此超导体进行详细的磁通钉扎机制分析，认为样品的磁通钉扎力特征主要由正常相钉扎和Δκ扎相结合的机制决定。根据分析的结果，采用多源标度方法，很好地拟合了不同线径样品的磁通钉扎力密度随磁场变化的曲线。拟合的结果表明：样品在较低场下的性能主要由正常相钉扎机制决定，而在较高场下的性能主要由Δκ钉扎机制决定。并且随着线径的减小，正常相钉扎力密度和Δκ钉扎力密度均有不同程度的提高。     

国内广告学位论文研究现状的实证分析

此文采用文献定量分析方法,以中国国家数字图书馆、中国知网和万方数据知识服务平台中的硕博士学位论文数据库为研究平台,查询1988~2012年广告研究方向的硕博士学位论文共3967篇,分析它们的培养单位、指导教师、专业构成、学科特征、历年数量、关键词、研究内容、选题特点等方面内容,并解释其中一些特有现象的形成原因,以此从某一侧面反映当前国内广告学位教育与研究的特点。     

Self-assembled polyaniline nanorods synthesized by facile route of dispersion polymerization

We report the preparation of ordered polyaniline nanorod arrays by a simple method without the use of any template. The synthesis method is by a chemical route, viz. dispersion polymerization of aniline in polyvinyl alcohol. The nanorods obtained have a diameter of 100-500 nm and a length of a few micrometers. Films containing the nanorod assembly have been characterized by SEM, XRD and FTIR spectroscopy. We have also measured I-V characteristics and the temperature dependence of the conductivity of the films. We discuss the formation mechanism of the self-assembled nanostructures, the morphology of the films, and the crystallinity and the transport mechanism.     

关于乘法器自检特性的研究

在建立采用余了３码的自检并行乘法器结构后，完成乘法器检测分支的设计并全面讨论乘法运算分支的自检特性，给出全加器等各子电路的自检设计要求。     

Remediating Knowledge-Making Spaces in the Graduate Curriculum: Developing and Sustaining Multimodal Teaching and Research

Functional, critical, and rhetorical training in multimodal teaching and research must span all aspects of professional development within the graduate curriculum in order to best prepare emerging professionals for success in the age of digital media. The authors call upon multiple perspectives of their home program and offer a range of benchmarks for other programs that want to promote digital teaching and research as integral, sustainable components of their knowledge-making spaces.     

Predictors of support for doctoral programs in media information technologies

This study assesses interest in curricular development in new technologies among communication faculty, with a focus on doctoral-level programs. Diffusion of innovations theory explains both individual- and organizational-level factors that may account for adoption of innovations, including those stemming from new technologies. In the field of communication, media information technology programs represent an organizational-level innovation of clear importance but with uncertain faculty support, due to individual factors (e.g., interest area, age) and departmental constraints (e.g., lack of resources). In light of this, several research questions are advanced to address: (1) the current level of support for media information technology programs among communication faculty members and (2) predictors of faculty interest in having more media information technology programs. Data were collected through a random sample of faculty members who filled out a survey on the World Wide Web. Results indicate that media information technology programs are viewed by faculty as the most needed type of program in the field of communication. Findings from a logistic regression analysis also reveal several predictors of support for new technology programs, including male gender, support for organizational communication programs, support for programs focusing on mass communication, and the belief that multimedia teaching facilities are important. The implications of these findings are discussed, with an emphasis on their relevance to faculty working in communication and related fields.     

活性炭纤维的氧化还原特性及其应用前景

六十年代以来，活性炭纤维由于其优异的吸附性能而引起了科学家们的重视。近年来，人们发现活性炭纤维不仅吸附性能优异，而且还原能力良好，因此，它能够吸附大量高电位的离子，并继之将其还原成为单质金属或低氧化态离子。这种吸附－还原性能在贵重金属的富集、回收和分离，以及有害气体或溶液的处理等领域有良好的应用前景