Permeation of binary gas mixture through glassy polymer membranes with concentration-dependent diffusivities

An analytical solution has been obtained for the modified dual-mode mobility model for a single gas proposed by Zhou and Stern and extended to a binary gas mixture to describe the pressure dependence of mean permeability coefficients for CO₂ and CH₄ mixtures in homogeneous cellulose triacetate membranes. The permeabilities calculated from the model fitted the corresponding experimental results quite well. Permeation experiments for equimolar CO₂ and CH₄ mixture in a homogeneous membrane of methyl methacrylate and n-sbutyl acrylate copolymer were performed along with sorption experiments for pure CO₂ and CH₄ to test the applicability of the model. The experimental permeabilities were close to those calculated from the model.     

Synthesis of Calix[4]arene with ω-Chloroalkyl Groups at the Lower Rim

杯［４］芳烃以Ｃｌ（ＣＨ２ＣＨ２Ｏ）ｎＴｓ（ｎ＝１，２）烷基化。得到６５～８７％的下缘带有２－氯乙氧基和２－（２－氯乙氧基）乙氧基杯［４］芳烃。     

TWO-DIMENSIONAL DISTRIBUTIONS OF TEMPERATURE AND OH, C_2 AND CH RADICALS IN FLAME DETECTED BY LASERINDUCED FLUORESCENCE

The in situ, high spatial resolution, two-dimensional distributions of OH(X), C_2(X) and CH(X) radicals in premixed paraffin/air flames are first reported. The measurements were done with the laser-induced fluorescence spectroscopies (LIFS) of the transitions of OH(A~Σ~+←→X~2Π), C_2(A~3Π←→X~3Π) and CH(B~2Σ←→X~2Π), (A~2△→X~2Π). The results show that OH(X) populated the edge of the outer flame, while C_2(X) and CH(X) the edge of the inner cone of the flame.The local rotational temperature of OH radical for a small zone was detected by the saturated laser-induced fluorescence spectroscopy of A~2Σ~+, v′=0←→X~2Π, v=″0 transition. The two-dimensional temperature distribution for the flame was measured through moving the position of the burner.     

There are many Kunen compact L-spaces

We prove that under CH there are non-homeomorphic Kunen compact L-spaces. Moreover there exist models of ZFC that have many non-homeomorphic Kunen spaces.

     

1,2,3-Tri(9-anthryl)benzene: Photophysical Properties and Solid-State Intermolecular Interactions of Radially Arranged,Congested Aromatic π-Planes**

We report the Negishi coupling based synthesis of 1,2,3-tri(9-anthryl)benzene derivatives containing three radially arranged anthracenes in a π-cluster. In the crystalline state of the unsubstituted derivative, intermolecular π–π and CH–π interactions between the anthracene units drive the formation of the two-dimensional packing structure. Owing to though-space π-conjugation between anthracene units, the substances have unique electronic properties. The excited-state dynamic behavior occurring between the three anthracene moieties, such as exciton localization/delocalization, was elucidated by means of transient absorption measurements and quantum chemical calculations. Interestingly, even though the three anthracenes are closely oriented with approximately 3.0 Å between their C-9 positions, exciton localization on two anthracene units is energetically favorable because of the flexible nature of the radially arranged aromatic rings.     

CH2FCF3与O(1D)反应机理的理论研究

用量子化学密度泛函理论(DFT)和G3(MP2)B3方法,对O(1↑D)与CH2FCF3的反应进行了研究．在UB3LYP/6-31G(d)计算水平上,优化了反应势能面上各驻点的几何结构,在G3(MP2)B3水平上进行了单点计算,并利用UB3LYP/6-311 G(3df,3pd)计算的波函数进行了电荷密度分析．通过内禀坐标(IRC)计算和振动分析,对反应过渡态进行了确认,并确定了反应机理．     

甲烷气体传感器的性能研究

本文研究了材料和工艺对甲烷气体传感器性能的影响。结果表明,当气体探测元件涂Pt-Pd复合催化剂而参比元件用Al2O3制作时,传感器的性能良好。     

Characterization of pure and doped potassium hydrogen tartrate single crystals grown in silica gel

Growth of pure‐, sodium‐ and lithium‐ doped potassium hydrogen tartrate single crystals by gel technique is reported. Growth conditions conducive for the growth of single crystals are worked out. The crystals are characterized by using powder XRD, SEM, FTIR, AES, EDAX, CH analysis and thermoanalytical techniques. The stoichiometric composition for the grown crystals are established as KHC₄H₄O₆.H₂O, (K)_0.98(Na)_0.02.H₂O and (K)_0.94(Li)_0.06HC₄H₄O₆.H₂O. Doping of sodium and lithium in the pure potassium hydrogen tartrate single crystals is found to influence the size, perfection, morphology, crystal structure and the thermal stability of crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)