铬(Ⅲ)含β一二酮混合配体配合物的合成和表征

首次合了五种Cr(β-dik)Cl_2py_2型(其中β-dik分别为乙酰丙酮、苯甲酰丙酮、三氟乙酰丙酮、2—噻吩甲酰三氟丙酮、二苯甲酰甲烷)和一种Cr(pmbp)Cl_2(thf)混合配体配合物、一种Cr(pmbp)_3配合物。并对上述化合物进行了电子光谱、红外光谱等的表征工作。     

长江经济带新型城镇化时空格局演变及影响因素研究

从经济、人口、社会发展、基础设施、城乡统筹和生态环境等6个方面建立新型城镇化发展水平的评价指标体系,运用熵值法、空间自相关分析法和灰色关联分析法等方法对长江经济带2003年、2009年和2014年110个地级及以上城市新型城镇化水平的时空格局及影响因素进行分析.结果表明：1)长江经济带市域间新型城镇化水平差异明显,西部差异大于中部大于东部;2)新型城镇化水平整体呈现出波动上升的态势,从东西方向上看,东部发展水平较稳定,中西部发展水平波动明显;3)新型城镇化中高、中等、中低和低水平区都呈现显著的空间集聚状态,但低水平区的连续分布状态有逐渐被“冲散”且面积减小的趋势;4)长江经济带新型城镇化水平五个类型区的影响因素各异,总体差异较显著.     

二项式系数与Gauss系数

二项式系数与Ｇａｕｓｓ系数万哲先（中国科学院）第二章Ｇａｕｓｓ系数２．１Ｇａｕｓｓ系数的定义和它的组合意义定义２．１设。是非负整数，Ｑ是４１的复数，而Ｘ是未定元，令我们把ｌ－ｆ－－ｉｆ叫做Ｇａｕｓｓ系数．注意，当ｍ一０时，Ｄ“Ｉ的分子和分母都是０个因...     

负载生物活性功能基聚醚氨酯的表面自由能与表面血液相容性研究

水相接触角;负载生物活性功能基聚醚氨酯的表面自由能与表面血液相容性研究     

Ba位元素对超导电性的作用

通过 Sr,Ca 替代 Ba 对 Y-Ba-Cu-O 体系超导电性、晶格参数、氧含量、电子态以及晶格能影响的综合分析,作者发现:虽然 Sr,Ca 替代了 Ba 的位置,但对 Cu-O 面和 Cu-O 链之间的耦合程度影响很大,使 Cu 的电子态有了明显的改变,体系的晶格稳定性下降.据此,作者提出:Ba 位元素的作用在于调节 Cu-O 面和 Cu-O 链之间的耦合,从而影响超导电性.     

浅滩区大型基础施工方案比选

介绍了在浅滩区大型基础施工中基桩施工平台采用钢板桩围堰筑岛替代钢结构平台的成功经验,利用钢板桩围堰筑岛作为基桩施工平台,将承台施工阶段的钢板桩围堰提前施工,起到了减少施工成本、节省工期、降低施工难度、提高施工质量的作用。     

On the sensitive dynamical system and the transition from the apparently deterministic process to the completely random process

The detailed analysis of the dynamical process of coin tossing is made. Through calculations, it is illustrated how and why the result is extremely sensitive to the initial conditions. It is also shown that, as the initial height of the mass center of the coin increases, the final configuration, i.e. head or tail, becomes more and more sensitive to the initial parameters (the initial velocity angular velocity, and the initial orientation), the coefficient of the air drag, and the energy absorption factor of the surface on which the coin bounces. If we keep the head upward initially but allow a small range for the change of some other initial parameters, the frequency that the final configuration is head, would be 1 if the initial height h of the mass center is sufficiently small, and would be clo to 1/2 if h is sufficiently large. An interesting question is how this frequency changes continuously from 1 to 1/2 as h increases. Detailed calculations show that such a transition is very similar to the transition from laminar to turbulent flows. A basic difference between the transition stage and the completely random stage is indicated: In the completely random stage, the deterministic process of the individual case is extremely sensitive to the initial conditions and the dynamical parameters, out the statistical properties of the ensemble are insensitive to the small changes of the initial conditions and the dynamical parameters. On the contrary, in the transition stage, both the deterministic process of the individual case and the statistical properties of the ensemble are sensitive to the initial conditions and the dynamical parameters. The mechanism for this feature of the transition stage is the existence of the long-train structure in the parameter space. The illuminations of this analysis on some other random phenomena are discussed.     

~(13)C-NMR STUDY OF ETHYLENE-1-OCTENE COPOLYMERS

A ~(13)C-NMR method is presented for a quantitative determination of the respective monomercomposition and sequence distributions in ethylene-1-octene copolymers prepared with supportedtitanium/magnesium catalyst. On the basis of the sequence distributions, the ethylene-1-octenecopolymerization mechanism was studied. It was found that the observed sequence distributions inethylene-1-octene copolymers are satisfactorily predicted by the two-site model M/M,in whichthe copolymerization proceeds according to first-order Markovian statistics at the two differentsites.