八配位钇(Ⅲ)-反式-1,2-环己二胺四乙酸配合物NH4[Y(trans-CYDTA)(H2O)2]·4.5H2O的合成及分子结构

In this paper, the molecular and crystal structures of the NH₄[Y(trans CYDTA)(H₂O)₂]·4.5 H₂O(trans-CYDTA=trans 1,2-cyclohexanediaminetetraacetic acid) are reported. The crystal data are as follows: Triclinic system, P1space group,a=0.8599(6)nm,b=1.0021(7)nm,c=1.4370(9)nm,α =88.095(13)°,β =75.559(1)°,γ =88.344(12)°,V=1.1981(14)nm³,Z=2, M=708.68,D_c=1.570g· cm^-3, μ =2.506mm^-1 and F(000)=590. The final R₁ and wR₂ are 0.0571 and 0.1350 for 4205 [I >2.0σ (I)] unique reflections and 0.1007 and 0.1615 for all 4981 reflections, respectively. In the title complex, the anion [Y(trans-CYDTA)(H₂O)₂]^- has an eight coordination structure with distorted square antiprism. The trans CYDTA which acts as a hexadentate ligand with four Oatoms and two Natoms and two H₂O molecules directly coordinate to central metal Y(Ⅲ) ion. It can be known that the Y(Ⅲ) ion can form an eight coordinate compound with aminopolycarboxylic acid ligands in addition nine coordination structure.     

Cobalt Determination by Means of Flow Injection On-line Sorbent Preconcentration-Flame Atomic Absorption Spectrometry with 1-Nitroso-2-naphthol as a Complexing Reagent

The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the complex formation and its elution were optimized. A 2.3×10~(-3) mol/L reagent solution and the aqueous sample solution acidified with 0.1％ (volume fraction) nitric acid were on-line mixed (6.4 mL/min) on a reaction coil set at (65±1)℃ and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3—4 with HNO_3(1 mol/L) or NaOH(1 mol/L). The adsorbed complexes in the microcolumn were eluted into the nebulizer of FAAS in 10 s with ethanol acidified with 1％ HNO_3(3.0 mL/min). A good precision(1.6％ for 100μg/L Co(Ⅱ), n=10), a high enrichment factor 17.2, with detection limit (3σ) 3.2μg/L, and sample throughput (90 h~(-1)) were obtained. The method was applied to the certified reference materials(CRMs), NBS-362 and NBS-364, for the determination of cobalt and the results were in good agreement with the certified values.     

风险投资的多阶段复合实物期权定价方法

根据风险投资的多阶段连续性,建立多阶段复合实物期权定价模型,并利用条件期望和矩阵性质推导出该期权的定价公式,定价方法可用于风险投资项目的评估和决策.     

基于云理论的我国光伏产业产能过剩评估研究

基于云理论的评价方法,构建指标体系,利用云重心理论求出各指标的云模型,计算与理想状态向量的加权偏离度,以此衡量我国光伏产业产能过剩程度.该评价理论提高了评价结果的准确性,评价结果与实际情况吻合,表明该评价指标与评价方法具有较强的可操作性和科学性,并就此对光伏产业产能过剩的治理,提出了政策建议.     

威布尔分布族刻度参数的经验Bayes检验函数的收敛速度

本文研究了在"加权线性损失"下,威布尔分布族刻度参数经验Bayes (EB)检验问题.利用概率密度函数的递归核估计,构造了刻度参数的经验Bayes检验函数,并获得了它的收敛速度,在适当的条件下,收敛速度的阶可任意接近O(n^-1),推广了文献的结果.最后给出一个有关本文主要结果的例子.     

基于实物期权的油气开采许可证策略分析

石油与天然气作为我国最重要的矿产资源,其矿权管理采用许可证制度.基于我国的石油与天然气许可证体系结构,分析了石油天然气勘查与开采许可证的实物期权特性,采用实物期权思想对油气勘探开发项目进行战略经济评价,针对传统方法在颁发开采许可证时忽略了时间灵活性价值这一问题,提出了估算颁发开采许可证价值和对投资开发时机进行选择的办法.为资源管理部门和石油公司的决策提供科学依据.最后,应用实物期权法对一个算例进行了分析.     

强相依高斯序列的最大值与和的联合渐近分布

{X_n,n≥1)是标准高斯序列,T_(ij)=cov(X_i,X_j)。本文在强相依条件rijlog(j-i)→r∈(0,∞)(j-i→ ∞)下,得到了高斯序列的最大值M_n与标准化部分和S_n=sum from i=1 to n(X_i/(E(sum from i=1 to n X_i)~2)/(1/2))     

集值映射向量优化问题的ε—超有效解

本文引进了集值映射向量优化问题的ε－超有效解概念,并在集值映射为近似广义锥次似凸的假设下,建立了关于ε－超有效解的标量化定理和Lagrange乘子定理。     

L-闭包空间的c-可数性

在L-闭包空间中引入第一c-可数性和第二c-可数性等的概念,分别给出了它们的基本性质.分别证明了它们是可遗传的、可数可乘的和可数可加的,在L-同胚序同态下都保持不变等重要性质.     

基于相依函数型数据非参数回归函数的稳健核估计

本文研究了基于相依函数型数据非参数回归函数的核估计.利用稳健的方法,在一定条件下获得了与i.i.d.场合下类似的估计量的几乎完全收敛速度,推广了现有文献中的相关结论.