Influence of The P,O-Bidentate Ligand on Ethylene Oligomerization Catalyzed by Iron Complexes

IntroductionA new area of organometallic catalysis in macromolecular chemistry has been unveiled by the discovery of the catalytic activity of late transition metal complexes containing bi- or tri-dentate ligands for the polymerization and the oligomerization of ethylene and α-olefins[1-5].As for the oligomerization of ethylene, the nickel catalysts based on phosphorus-oxygen, sul-fur-sulfur and nitrogen-nitrogen chelates have been widely investigated[6-8]. But there are on-ly limited reports…     

微生物絮凝剂产生菌絮凝活性研究(II)

从福州郊区旱田地表土壤中分离得到一株絮凝剂产生菌,根据菌落形态特征,初步鉴定为链球菌。研究表明,培养基组成如下:碳源为蔗糖,氮源为牛肉膏,培养基初始pH值为5~8.5之间能取得较好的效果,添加一定浓度的Na+、Mg2+、Ca2+对培养液的絮凝活性有促进作用,而培养液中少量的Cu2+、Fe3+、Zn2+可抑制絮凝活性,该絮凝剂对高岭土悬浮液有较好的絮凝效果。结合实验现象和双电层理论初步推测了该絮凝剂的絮凝过程模型,对进一步研究微生物絮凝剂的絮凝机理有一定的参考作用。     

白花丹的化学成分研究 Ⅱ.白花丹酸的结构测定

白花丹酸是植物白花丹(plumbago zeylanica Linn)中分离得到的一种新化合物,证明其结构为β-2,3-二羟基苯甲酰丁酸[β-(2,3-dihydroxy-benzoyl)butyric acid]。     

配位键驱动的多卟啉阵列结构在纳米SiO2表面的组装及光电性能

制备了吡啶功能化的纳米二氧化硅(nanoSiO₂BPy), 并利用配位键驱动的层层自组装技术, 以四吡啶基锌卟啉(ZnTPyP)为链接单元, 在nanoSiO₂BPy表面构筑了含有(Pd/ZnTPyP)_n多卟啉阵列结构的有机-无机杂化材料. 利用热重、 紫外-可见吸收光谱和X射线光电子能谱跟踪分析了nanoSiO₂BPy@(Pd/ZnTPyP)_n杂化材料的组装过程. 结果表明, nanoSiO₂BPy@(Pd/ZnTPyP)₃杂化材料在150~450 ℃升温区间内质量损失17%, 可归结为组装在纳米SiO₂表面的多卟啉阵列和少量有机物的热分解. 紫外-可见和荧光光谱表明, 在nanoSiO₂BPy@(Pd/ZnTPyP)_n杂化材料中, 锌卟啉Soret带的吸收峰出现在426 nm处, 其Q带的荧光发射峰出现在605和655 nm处, 荧光寿命约为1.78 ns, 光谱数据均与锌卟啉在稀的二甲亚砜溶液中的结果接近, 表明组装在nanoSiO₂BPy表面的锌卟啉环之间相互作用较弱, 没有形成聚集体. 场发射透射电镜照片显示, 由于Pd/ZnTPyP的组装, nanoSiO₂BPy@(Pd/ZnTPyP)₃杂化材料的平均直径由原料的10~16 nm增加到15~20 nm. 杂化材料修饰电极的循环伏安曲线在-0.6~-2.4 V(vs. Ag/AgCl)范围内出现了2对不可逆的氧化还原峰, 归属于卟啉被氧化的电子转移过程. 探讨了nanoSiO₂BPy@(Pd/ZnTPyP)_n杂化材料作为光敏剂在光电转换、 光催化乙基紫精的还原和显色方面的应用.     

Efficient Quantile Estimation for Functional-Coefficient Partially Linear Regression Models

The quantile estimation methods are proposed for functional-coefficient partially linear regression (FCPLR) model by combining nonparametric and functional-coefficient regression (FCR) model. The local linear scheme and the integrated method are used to obtain local quantile estimators of all unknown functions in the FCPLR model. These resulting estimators are asymptotically normal, but each of them has big variance. To reduce variances of these quantile estimators, the one-step backfitting technique is used to obtain the efficient quantile estimators of all unknown functions, and their asymptotic normalities are derived. Two simulated examples are carried out to illustrate the proposed estimation methodology.     

关于凸算子的广义Frechet可微性

本文得到如下结果：设F为从自反的Banaeh空间层到Banaeh格空间X的育有界凸算子，假若(i)X与X^*皆弱紧的区间；(ii)X有范紧区间，则F在层的某个稠子集Gδ的每一点都是Frechet可微的，推广了实值凸函数的有关结论．     

侧钻水平井轨道设计模型、算法及应用

本针对三维水平井轨道优化设计问题，建立了以非线性常微分方程为主要约束条件的最优控制模型。以均匀设计方法选初始点，并依此把允许区域分解为有限多个子域，在每个子域上构造了改进的Hooke-Jeeves优化算法，将它用于多口水平井的实际生产中，表明了本给出的模型、算法及软件的正确性与有效性。     

液晶SmC*相螺旋结构的统计理论

采用格胞模型,定义在格胞中心上的分子取向序参量、质心位置序参量和两者耦合序参量。选用双轴性并有横向电偶极矩的分子的作用两体势,求出系统的自由能,对自由能求变分得到指向矢满足的微分方程,由此方程得到SmC^*相指向矢与分子层面法线倾斜,并沿该法线作螺旋式变化,求得倾斜角和螺距的近似表示式,计算了DOBAMBC等三种典型SmC^*相液晶的倾斜角和螺距随温度的变化,结果与实验相符。     

Evolution of Cooperation in Evolutionary Games for Heterogeneous Interactions

When a population structure is modelled as a square lattice,the cooperation may be improved for an evolutionary prisoner dilemma game or be inhibited for an evolutionary snowdrift game.In this work,we investigate cooperation in a population on a square lattice where the interaction among players contains both prisoner dilemma game and snowdrift game.The heterogeneity in interaction is introduced to the population in two different ways:the heterogenous character of interaction assigned to every player(HCP) or the heterogenous character of interaction assigned to every link between any two players(HCL).The resonant enhancement of cooperation in the case of HCP is observed while the resonant inhibition of cooperation in the case of HCL is prominent.The explanations on the enhancement or inhibition of cooperation are presented for these two cases.     

弹体侵彻深度计算公式对比研究

讨论了目前应用较广的弹体对混凝土侵彻深度计算公式,并与试验结果进行对比,分析各经验公式及理论公式的计算误差。