由$q$-积分算子定义的某些亚纯函数类的Fekete-Szeg\"{o}问题

本文首先引入满足如下条件$$-\frac{qzD_{q}f(z)}{f(z)}\prec \varphi (z)$$和$$\frac{-(1-\frac{\alpha }{q})qzD_{q}f(z)+\alpha qzD_{q}[zD_{q}f(z)]}{(1-\frac{\alpha}{q})f(z)-\alpha zD_{q}f(z)}\prec \varphi (z)~(\alpha \in\mathbb{C}\backslash (0,1],\ 0相似文献   

Study on iron-manganese catalysts for Fischer-Tropsch synthesis

Iron-manganese catalysts were prepared by co-precipitation method.Characterization of catalysts was carried out by using X-ray diffraction(XRD),scanning electron microscopy(SEM),temperature program reduction(TPR),N2 adsorption-desorption measurements.The results from catalytic performance tests in Fischer-Tropsch synthesis showed that the iron-manganese catalysts are supersensitive to catalyst composition and materials source.It was found that C2~4 light olefins increased while CH4 and CO2 decreased by using iron-manganese catalyst prepared from iron(II) sulfate(A catalyst).The activity and selectivity of A catalyst was studied in different operational conditions.The results showed that the best operational conditions for C2~4 light olefins production were H2/CO=1/1(GHSV=2400h-1) at 260℃ under 0.3MPa total pressure.     

Relationships of Surfactant Head Group Weight Fraction and Some Polarity Terms by Gas Chromatography

 Polarity, partition coefficient (K), methanol carbon number of surfactant ((CMeOH)S), and methanol carbon number of surfactant head group ((CMeOH)HG) are measured on six alkanolamides and five polyoxyethylenated long chain amines as stationary phases. From the measured methanol carbon numbers, polarity indices, (IP)S and (IP)HG, are calculated. The determined polarity terms are plotted against the head group weight fraction ( fHG ) of the investigated surfactants and several equations have been developed. The study reveals that the molecular structural gap between alkanolamides and polyoxyethylenated long chain amines diminished when HLB numbers of these surfactant classes are plotted against fHG values. Consequently, a general equation relating HLB and fHG is obtained.     

Inverse Gas Chromatography Used to Study Lubricating Oil Oxidation Mechanism via Changes in Kovats and Flory-Huggins Retention Parameters

Inverse gas chromatographic technique （ IGC ） was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes （ VR ） were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index （Ⅰ）, Flory-Huggins interaction parameter （ K^∞ 1,2 ）, and partial molar free energy of solution （ △GL^∞ ）, were calculated for the given test solutes from their VR. The relationships between the Ⅰ values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of Ⅰ, K^∞ 1,2 or △GL^∞ retention parameters depend on the oxidation degree of the base oil. Large differences between the Ⅰ values permit discrimination between the different oxidation steps.     

反气相色谱法测定Kovats及Flory-Huggins保留参数的变化以探究润滑油的氧化机理

 Inverse gas chromatographic technique (IGC) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes (VR) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (I), Flory-Huggins interaction parameter (κ∞1,2), and partial molar free energy of solution (ΔG∞L), were calculated for the given test solutes from their VR. The relationships between the I values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of I, κ∞1,2 or ΔG∞L retention parameters depend on the oxidation degree of the base oil. Large differences between the I values permit discrimination between the different oxidation steps.     

一致星象和凸象超几何函数的一些性质

介绍了(高斯)超几何函数属于一致星象函数和一致凸函数的某些子类的一些性质.还考虑了与超几何函数相关的算子.     

Fekete-Szeg Problems for Certain Classes of Meromorphic Functions Using q-Derivative Operator

In this paper, we introduce two subclasses Σ*q(φ) and Σ*q,α(φ) of meromorphic functions f(z) for whichqz Dq f(z)f(z)? φ(z) and     

Determination of Polarity Terms of Some Nitrogen-Containing Surfactants and Simulated Hydrophobic Tail Models by Gas Chromatography

Some polarity terms of two groups of nitrogen-containing surfactants （ six alkanolamides and nine polyoxyethylenated long chain amines） are measured through gas chromatography. The apparent methanol carbon number （CMeOH） and polarity index （IP） values are determined on the investigated surfactants as stationary phases in packed columns. Similarly, CMeOH and IP values are determined on simulated hydrophobic tail （SHT）models. The obtained results reveal that the introduction of SHT approach permits the distinction between the polarities of different surfactants and their head groups. The measured polarity terms are discussed as related to hydrophile-lipophile balance （HLB） number and the hydrophobic group carbon number （RCN）. Some equations relating the measured polarity values and these variable have been developed.