Investigation of the Structures of the Product Ions Produced via self-CI of Acetone

TheacetoneselfCImassspectrumAcetoneselfCImassspectrumisgiveninTable1.Table1.MajorproductionsandtheirrelativeabundanceofacetoneselfCIMSTheformationofionatmlZ73AnotherproductionintheselfCIMSofacetoneistheionatm/z73.InselfCIMSofacetone-d6,thecounterpartistheionatInjz82.InselfCIMSofthemixtureofacetoneandacetone-d6inaratioofl:l,thecorrespondingionsaretheionsatInlz73,76,79and82.TheirCIDreactionresultsarelistedinTable2.Table2.TheCIDMSoftheionatIn/z73andanalogsOnthebasisofthedatainTab…     

Chemical Constituents of Ailanthus triphysa

Two new compounds,8(14),15-isopimaradiene-2α，３α，19-triol(1),and 6α，７β－dihydroxy-17(20)-cis-5α－pregna-16-one(2),together with four known copounds,a oxygenated rare phyllocladane,phyllocladan-16α，19-diol(3),kaempferol-3-0-β－Ｄ-galactopyranosied,kaempferol-3-0-α－Ｌ－rhamnopyranoside and scopoletin, were isolated from the leaves of Ailanthus tripysa.Structures of 1-3 were elucidated on the basis of spectroscopic data as compared with related compounds.     

Potentiometric pH response of membranes prepared with various aminated-poly (vinyl chloride) products

The preparation and potentiometric pH response properties of membranes formulated with various aminated-poly(vinyl chloride) (PVC-NH₂) products are described. Products containing secondary and/or primary amino functional groups are obtained by modifying PVC with mono- and/or diamines, respectively. Blank membranes prepared with either type of aminated-polymer exhibit nearly Nernstian potentiometric pH responses over different pH ranges. In general, membranes based on diamino products exhibit pH response over a wider range (5–10.5) than membranes formulated with monoamino products (<8.0). These potentiometric results are used to estimate the basicity of the various primary and secondary amino sites in the membrane phases.Dedicated to Professer W. Simon on the occasion of his 60th birthday     

Alignment of atomic autoionizing states created by slow Na++He collisions

Ejected-electron spectra have been measured for collisions of He-atoms with Na⁺-ions, whose impact energy ranged from 1.7 to 7.0 keV. The ion impact-energy dependence of the angular-differential cross-section of the ejected electrons has been investigated for an aligned autoionizing state Na**(2p ⁵ 3s ^{2 2} P), which has been created by charge transfer from the He-atoms. The alignment of the autoionizing state Na**(2p ⁵ 3s ^{2 2} P) is discussed in relation to the scattering angles of the Na⁺-ions. A complete longitudinal alignment has been observed with respect to the quasimolecular axis.     

Wild ginseng grows in Myanmar

Ginseng, the underground parts of plants of Panax species, has been used in oriental traditional medicine for centuries. Unfortunately, because of extensive exploitation over thousands of years, the natural source of these species has been almost exhausted. Recently, we have found a wild ginseng growing in Myanmar. Here, by a combination of chemical composition study and gene sequence analysis, we unambiguously demonstrate that the wild ginseng is actually P. zingiberensis, commonly known as ginger ginseng. This ginseng was an indigenous to the southwestern China. However, now it is seriously threatened to brink of extinction and is put on the highest level of protection in China. Therefore, an appropriate protection measure is highly recommended to preserve this valuable resource, since this Myanmar ginseng might turn out to be the last P. zingiberensis, which could ever be seen in the planet.     

Highly active, immobilized ruthenium catalysts for oxidation of alcohols to aldehydes and ketones. Preparation and use in both batch and flow systems

A novel, highly active immobilized ruthenium catalyst, which can be successfully used in oxidation of alcohols to aldehydes and ketones, has been developed. In contrast to most immobilized catalysts, the Ru catalyst has activity that is higher than that of the original non-immobilized catalyst. In a batch system, the Ru catalyst was recovered and reused several times without loss of activity. The catalyst was also applied to a flow system, in which excellent conversions and yields were demonstrated. No leaching of Ru was observed in both cases.     

5-(4-氯苯基)-10,15,20-三苯基卟啉及其配合物的合成、结构表征及热分解机理

合成了标题卟啉配体及其钴，镍，铜，锌和铁的五种配合物，对它们进行了元素分析，ＵＶ，ＩＲ和荧光光谱等结构表征。用ＤＴＡ，ＴＧ，ＤＳＣ等手段研究了这些新化合物的热稳定性及热分解机理，实验结果与ＨＭＯ方法计算的结果一致。     

Thermal change of Alq3, tris(8-hydroxyquinolinato) aluminum(III) studied by TG and XRD-DSC

The thermal change of the tris(8-hydroxyquinolinato)aluminum (Alq₃) is currently investigated by XRD-DSC and TG. The phase transition of Alq₃ from α-phase to γ-phase takes place at 643–669 K. A very sharp peak with the peak temperature at approx. 709 K is ascribed to the melting of the Alq₃. The decomposition of the Alq₃ was observed accompanied with the melting and evaporation at >703K. The effect of the atmospheres on the mass loss procedure was studied by TG. It was found that thermal process of Alq₃ was strongly influenced by the partial pressure of water vapor in the atmosphere instead of oxygen.     

Quantitative analysis of photoelectron angular distribution of single-domain organic monolayer film: NTCDA on GeS(0 0 1)

Angle-resolved photoelectron spectra were measured for a single-domain monolayer film of naphthalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA) prepared on a cleaved GeS(0 0 1) surface using synchrotron radiation. The observed photoelectron angular distributions were analyzed by a calculation using the single-scattering approximation combined with molecular orbital calculation. With the help of the low-energy electron diffraction pattern, the structure of the NTCDA monolayer on GeS(0 0 1) was estimated quantitatively.     

An evaluation of the performance of porous polymer monolith assisted electrospray

A novel electrospray interface, which has distinct advantages over conventional pulled silica emitters, has been developed. This novel interface can be easily fabricated by forming a porous polymer monolith (PPM) at the end of a fused-silica capillary that facilitates a stable electrospray over a wide range of flow rates with only a modest increase in back-pressure. A comparison was made between the PPM-assisted electrospray and a commercial nanosprayer in terms of sensitivity, stability and robustness. A PPM-filled electrospray tip produced a day-to-day signal variation of 23% relative standard deviation (RSD) over a 3-day period when spraying a 1.0 microM test peptide solution. Furthermore, three different capillaries fabricated by the same process produced a signal variation of 17% RSD, indicating that the fabrication process shows good reproducibility. The multiple flow paths of the PPM function to split the flow and reduce clogging. Even following the accumulation of debris after prolonged use, a stable spray could still be generated with the PPM-filled capillary while the commercial nanosprayer ceased to function properly. In terms of sensitivity, PPM-assisted electrospray showed an enhancement in sensitivity at infusion flow rates between 100 to 1000 nL/min while commercial nanosprayers performed slightly better at flow rates below 100 nL/min. A sample purification step can be combined with the PPM-assisted sprayer, using the PPM as a stationary phase to desalt and preconcentrate samples prior to mass spectrometric detection.