氟的离子选择电极瞬时电位法测定

研究了氟离子选择电极瞬时电位分析法，其检出限和Nernst响应下限均低于传统电位分析法，空白液切换到试液时瞬时电位达到稳定的峰电位Vp比传统电位法的响应快得多，可以实现小体积试液的快速准确分析；用该法测定了自来水和矿泉水中氟的含量；利用校正曲线的截距和检出限计算了LaF3的溶度积，在0.1mol/L KNO3介质中Ksp(LaF3)=10^-28.45，在0.001mol/L柠檬酸钠＋HAc-NaAc缓冲液（pH=5.50，离子强度I＝0.10mol/L)介质中溶度积K′sp(LaF3)=10^-26.26；据此，计算得柠檬酸与La^3 络合物的稳定常数K1=10^5.46和K2=10^3.99；用离子水合吉氏自由能ΔGh(F^-,g)解释了不同浓度F^-试液瞬时电位的跃迁时间。     

A Transparent Thin Film with Hexagonal Mesostructure Containing Rhodamine 6G

A transparent this film was prepared by depositing the sol-gel mixture for the synthesis of MCM-41 mesoporous molecular sieve doped with rhodamine 6G(R6G) dye on glass substrates. The film of silica-surfactant-R6G materials, which was identified to possess hexagonally ordered mesostructure,was composed of nanocrystallites about 35 nm in diameter and 1-10μm in thickness. Cleanness of the substrates, concentration of the sol-gel mixture and rate of evaporation of the solvent were the key factors affecting transparency and homogeneity of the film. Moreover,optical change and lack in dye aggregation were observed to the R6G-functionalized MCM-41 thin film in contrast with that in ethanol solution.     

改进的微波辅助无溶剂法提取薄荷和陈皮中的挥发油组分

An improved solvent free microwave extraction, in which a kind of microwave absorption medium （carbonyl iron powder） was used, was applied to the extraction of essential oil from dried menthol mint and orange peel without addition of any solvent and pretreatment. It took much less time of extraction （30 min） than microwave-assisted hydrodistillation （90 min） and conventional hydrodistillation （180 min）. The kinds of chemical compositions in essential oil extracted by different methods were almost the same and such improved solvent free microwave extraction can be a feasible way in extraction of essential oil from dried plant materials.     

自由微观粒子相对论

给出自由微观粒子的时空变换理论和自由微观粒子的相对论能量表示.     

FREE VIBRATION ANALYSIS OF LATTICE SANDWICH BEAMS UNDER SEVERAL TYPICAL BOUNDARY CONDITIONS

Free vibration problems of lattice sandwich beams under several typical boundary conditions are investigated in the present paper. The lattice sandwich beam is transformed to an equivalent homogeneous three-layered sandwich beam. Unlike the traditional analytical model in which the rotation angles of the face sheets and the core are assumed the same, different rotation angles are considered in this paper to characterize the real response of sandwich beams. The analytical solutions of the natural frequencies for several typical boundary conditions are obtained. The effects of material properties and geometric parameters on the natural frequencies are also investigated.     

1-平面图的线性荫度

图G的边分解是指将G分解成子图G₁,G₂,…,G_m,使得E(G)=E(G₁)∪…∪E(G_m),且对任意i≠j有E(G_i)∩E(G_j)=?.若一个森林的每个连通分支都是路,则称该森林为线性森林.图G的线性荫度la(G)是指使得G可以边分解为m个线性森林的最小整数m.本文利用权转移方法证明了Δ(G)≥25的1-平面图G的线性荫度为[Δ(G)/2],这里Δ(G)是图G的最大度.     

可转包的两机自由作业排序问题(英文)

本文研究两机器自由作业问题,每工件恰有两个操作,除本身两台机器用于加工外,制造商可以将部分工件转包给承包商加工.该承包商有一台机器,可以加工全部操作。一旦承担转包任务,制造商需要支付转包费用给承包商,该费用与承包商机器单位时间价格有关.制造商需要确定转包工件集及未转包工件的排序时间表,使得转包费用与时间表的加工总长最小.本文证明该问题是NP困难的,设计动态规划算法,并讨论承包商机器时间的定价方案.     

政府购买公共服务的三边匹配决策模型

针对政府购买公共服务中供应商及评估方的选择决策问题,从政府服务购买、服务供应、监管评估三方的匹配视域,利用三边匹配决策与多属性决策方法,构建基于各方评价的三边匹配模型.首先,对政府购买公共服务的三边匹配问题进行了描述,并给出了三边匹配的相关概念.然后,在三边主体多属性评价信息的基础上,定义匹配效用函数,给出了标准加权效用矩阵的计算方法.进一步地,在考虑三方加权匹配效用最优的基础上,建立了累加最优效用三边匹配模型.最后,对模型进行了算例应用及分析,研究表明模型对政府选择服务供应商及监管评估机构有实践的指导意义.