高速列车运行引起的墩顶垂向动反力特征分析

结合高速铁路系统特点,钢轨模拟为离散点支撑欧拉梁,桥梁采用模态综合法建立运动方程,在考虑梁轨和轮轨关系基础上建立了车桥动力分析模型,并结合常用跨度简支箱梁特点,分析了轨道不平顺、速度和跨度对墩顶动反力的影响规律.结果表明:中长波范围内轨道不平顺不会对墩顶垂向动反力产生明显影响;随着速度提高,梁的共振和消振造成墩顶动反力的放大和减小;不同跨度简支梁桥墩顶垂向反力特征差异明显,车长和轴距引起的频率都有不同程度体现.     

偏振方向对H型金纳米结构光热性质影响的研究

采用离散偶极近似方法(DDA)计算了在不同偏振方向的入射光激励下,H型金纳米结构在水介质环境中的共振吸收光谱及近区电磁场分布;在此基础上,利用付里叶热传导定律数值模拟了该结构产生的热效应。结果表明:该金属纳米结构在近红外波段存在两个主要等离激元共振模式,在单一波长的共振光激励下,改变入射光的偏振方向可调节吸收峰值大小;同时,也可以有效地调节结构的近场电磁场耦合作用,在结构周围形成高度限定的局域热增强现象,在较大的温差范围内调控该结构及其周围介质环境的局域温度。     

贵州盘县呼都金矿区成矿地质特征及找矿前景

贵州盘县呼都金矿区是该区继砂锅厂、羊禾地、小尖山金矿发现之后的又一凝灰岩金成矿潜力区，通过已开展的1：5万土壤化探测量，显示金土壤化探异常较好，针对两处金重点异常区实施地表浅部山地工程和少量钻探工程异常查证，结果显示车家槽子-猴耳包-带和哈树头-田坝头-闭塞-带金矿地表蚀变情况较好，硅化较强烈，推测其深部具有良好的找矿前景。     

Ethylene Oligomerization and Polymerization： Alternative Iron Catalysts beyond 2,6-Bisiminopyridyl Iron Complexes

Polyolefin industry arrives the option to transfer from multiple-site systems of the classical Ziegler-Natta catalysts to more sophisticated single-site catalysts. The late-transition metal compounds were traditionally assumed with poor polymerization properties due to the highly competitive chain-termination step, and produced the short-chain oligomers up to 40 carbon atoms （SHOP catalysts）. Recently the polyolefins employing latetransition metal complexes as catalysts became a hot research subject with the pioneering works by Brookhart and Gibson. It is promising for nickel catalysts to use solely ethylene as monomer for highly branched polyethylenes, and the designed nickel catalysts were not useful in industry. It is critical time to investigate the relationship of coordination modes of nickel complexes and its catalytic activities and the properties of resultant polyethylenes.     

镍基催化剂上丙酮常压气相加氢

研究了常压下丙酮的氢反应的镍基催化剂，确定了可以获得较高异丙醇选择性的催化剂较为适宜的活化时间、活化温度和反应温度等工艺条件，对于丙酮／异丙醇化学热泵的实际工业应用具有指导意义。     

La2O3对Ni/α-Mg2Al4SiO5O18催化剂表面结构作用机理的计算机图像纹理解析

应用计算机图像纹理分析的理论与方法探讨了稀土氧化物 (La2 O3 )对Ni/α Mg2 Al4 SiO5O18催化剂表面结构的影响 .研究表明 ,空间灰度值共生矩阵 (SGLCM)法所抽取的纹理熵和纹理能特征是催化剂表面镍的分散状态和稳定性的有效度量 ,将所获得的信息与催化剂表面的镍晶粒度及活性相关联 ,均取得较好的一致性 ,说明计算机图像纹理分析是催化剂设计和结构分析的新途径 .     

New Explorations for Decision Trees

1. INTannVCTIONThere axe mny techulques to rePresat and soho a decision Problem, such as deci8ion trees, game trees, strategicforms, algebric aPproathes, chence diapams, sequentiaJ decision diagrams, edation bos [1~7]. AinongtheIn, a fundameniaJ and allo the most populaI mathOd is decision tree. All Other methods are the edensionsor genertheation of decision trees. Bat nearly all these te~s are used to the an OPthoal sohibo to adecision prob1em. Whn we rePMed and sOlve a decision pro…     

二烷基膦酸载体液膜中Zn(II)的传输研究

研究了以烷基膦酸 PC-88A为流动载体的液膜中 Zn( II)的迁移规律 ,并考察了料液相 p H、温度、载体浓度及解析相组成对 Zn( II)迁移过程的影响。结果表明 ,增加载体浓度或升高温度 ,Zn( II)迁移速率明显增大 ,料液相 p H在 2 .4～ 5.1时可获得较大的 Zn( II)迁移速率。确定了最佳传质条件 ,探讨了各种因素影响机理 ,实现了 Zn( II)与 Cd( II)的分离。     

Bioaccumulation of Au(Ⅲ) by cyanobacteria Anabaena azollae

The gold accumulation efficiency of culturing Anbaena azollae (a filamentous speciees of cyanobacteria in gold bearing medium is observed. It is indicated that it is possible to produce metal combined proteins by culturing metal tolerating cyanobacteria ain metal bearing solution.