甲醇中用氨和环氧丙烷合成异丙醇胺

研究了在甲醇介质中用氨和环氧丙烷制备异丙醇胺的新工艺.考察了原料配比、反应温度、体系中的水含量对反应的影响.     

一氧化氮与心肌再灌注损伤

一氧化氮（NO）是一种生物信息递质，广泛存在于各种细胞和组织中，具有减少血小板聚集、抑制、嗜中性粒细胞聚集等功能。NF－KB被认为是近十年最有研究潜力的调节免疫反应、应激反应、凋亡和炎症的核转录因子。充分认识一氧化氮、NF－KB与心肌再灌注损伤的机制。为对其进一步研究提供理论依据。     

Chinese Word Boundary Ambiguity and Unknown Word Resolution Using Unsupervised Methods

An unsupervised framework to partially resolve the four issues, namely ambiguity, unknown word, knowledge acquisition and efficient algorithm, in developing a robust Chinese segmentation system is described.It first proposes a statistical segmentation model integrating the simplified character juncture model (SCJM) with word formation power.The advantage of this model is that it can employ the affinity of characters inside or outside a word and word formation power simultaneously to process disambiguation and all the parameters can be estimated in an unsupervised way.After investigating the differences between real and theoretical size of segmentation space, we apply A* algorithm to perform segmentation without exhaustively searching all the potential segmentations.Finally, an unsupervised version of Chinese word-formation patterns to detect unknown words is presented.Experiments show that the proposed methods are efficient.     

Synthesis and characterization of bifunctional terbium complex-based nanoparticles

Novel bifunctional terbium complex-based nanoparticles were developed using a modified Stber method and a layer-by-layer assembly process. A magnetic core of Fe3O4 nanoparticles was coated with a silica shell to form the first layer. Then a ternary Tb3+ complex (TESPPA-Tb), which acted as a luminescent marker, was covalently bound to the silica surface by stable Si-O-Si bonds. The TESPPA monomer was synthesized by binding pyridine 2,6-dicarboxylic acid to 3-aminopropyltriethoxysilane, which was used as a ligand for coordination with the Tb3+ ions. An outer shell of silica was applied to the nanoparticles to allow for versatility with surface functionalization. The nanoparticles were characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, ultravioletvisible spectroscopy, vibration sample magnetometer, and photoluminescence spectroscopy. The bifunctional nanoparticles exhibited favorable superparamagnetic behavior and photoluminescence properties of Tb3+. These nanoparticles have potential applications in biolabeling, bioseparation, immunoassays, and pathogenic diagnosis.     

地铁与轻轨课程教学改革体会

针对地铁与轻轨课程教学存在的问题,给出了教材、课程体系、设计训练和现场实践的具体改革思路和方法。突出创新了课程考核方式转为课程创新内容、课程设计、课程实践和期末考试等综合性考察;教学方法转为要充分利用网络资源的多媒体教学,充分利用电子邮件扩大与学生的交流以及创新论文的写作答辩。     

对高校收费合理性的调查与分析

通过问卷调查的方法,揭示了目前大学生对高校收费制度合理性的看法,分析了我国高校收费制度存在的问题,提出了改革和完善我国高校收费制度的建议。     

EPS在高速公路软土地基路基拓宽中的应用数值分析

介绍了EPS的工程特性,并将其应用到高速公路软土地基拓宽工程中,采用有限元程序进行分析,得出EPS轻质路堤对减轻路堤荷裁,增大道路的稳定系数、减小路基沉降具有明显作用,对于沉降难以控制的软土地基等尤其适用,结合工程实例分析得出相关规律.     

Transmission and demodulation of multi-polarization-multiplexed signals

We propose the configuration of signal multiplexing with four polarization states and investigate its transmission performance over single-mode fiber links. Using coherent detection and digital signal processing, a demodulation scheme for four-polarization-multiplexed (4PM) system is presented. We discuss the impact of crosstalk from polarization mode dispersion and polarization beam splitter misalignment on the proposed 4PM system. Furthermore, the transmission distance could be doubled to ~50 km by employing feedback decision equalizers.     

Graphene meets biology

Graphene features a shining star in the material sciences since its discovery in 2004. Biomedical application of graphene-family materials has been driven recently. In this paper, we overviewed the cutting-edge research in the biomedical application of graphene-based biomaterials, such as bio-sensing and bio-imaging, drug/gene delivery and scaffold for tissue engineering. We emphasized on the effect of graphene substrates on cellular behaviors of adhesion, proliferation~ and differentiation. The develop- ment of three-dimensional scaffolds based on graphene- based nanomaterials and the potential of these constructs in tissue engineering are discussed. The perspectives and challenges are also addressed.     

单向关闭三部件串-并联可修系统的可靠性

研究了单向关闭先坏先修三部件串-并联可修系统的可靠性,在假定部件1的失效分布服从可变参数为λ(λ0)的指数分布条件下,利用补充变量法,得到了该系统的瞬时可用度和稳态可用度、系统的可靠度、系统的瞬时和稳态故障频度.