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41.
Two-stage capillary GC with two-stage retention index monitoring is an efficient analytical technique which can be used for detection and determination of small amounts of volatile compounds in complex mixtures of hundreds or thousands of other compounds. The system employs two capillary columns, coated with different stationary phases, connected on-line with the aid of a micro valve; the first column acts as a pre-separating unit from which unresolved fractions of interest are cut (transferred) into another column for final, interference-free separation of the compounds to be determined. This technique has been compared with selected ion monitoring capillary GC-MS using a hydrocarbon mixture as a test sample for comparing resolution, repeatability, and the practical usefulness of the techniques. Results indicate that two-stage capillary GC is very useful for mixtures containing compounds which produce mostly non-specific ions in the MS ion source whereas compounds producing specific ions can be easily analyzed by capillary GC – single ion monitoring MS even if they are not perfectly separated by a single capillary column. 相似文献
42.
Aapo U. Hrknen Markku Ahlgrn Tapani A. Pakkanen Jouni Pursiainen 《Journal of organometallic chemistry》1997,530(1-2):191-197
Three tetranuclear clusters [Ru4H4(CO)11(PPh3)] (1), [Ru4H2(CO)12(PPh3)] (2) and [Ru3IrH(CO)12(PPh3)] (3) were formed in the reaction of [Ir(CO)Cl(PPh3)2] and Na[Ru3H(CO)11] in tetrahydrofuran. Complexes 1–3 were characterized by IR and 1H and 31P NMR, and the structure of the clusters was confirmed by single crystal X-ray analysis. In 2 and 3 one of the carbonyls bridges between two ruthenium atoms; otherwise the compounds contain only terminal carbonyls. 相似文献
43.
Sari Kiviniemi Maija Nissinen Tanja Kolli Jorma Jalonen Kari Rissanen Jouni Pursiainen 《Journal of inclusion phenomena and macrocyclic chemistry》2001,40(1-2):153-159
Crown ether complexes of six-membered N-heteroaromatic cations and the closely related bicyclic purinium cation (6) have been studied by 1H NMR, mass spectrometric and crystallographic methods. The stability constants for the complexes were determined by 1H NMR titration in acetonitrile solution and the complexation stoichiometry by 1H NMR and ESI mass spectrometric methods. Altogether six crystal structures of complexes were determined to study the complexation in the solid state. Hydrogen bonding was observed to be the most important interaction for the complexation both in solution and in the solid state but – interactions also contribute to it. All crystal structures of the DB18C6 complexes with six-membered N-heteroaromatic cations, except for 4-hydroxypyridinium, are isomorphous to previously studied five-membered N-heteroaromatic cations and pyridinium complexes. Such a close resemblance is not observed in B18C6 and 18C6 complexes or DB18C6purinium (6). 相似文献
44.
Jouni Pursiainen Tapani A. Pakkanen Juhani Jääskeläinen 《Journal of organometallic chemistry》1985,290(1):85-98
A new ruthenium-rhodium mixed-metal cluster HRuRh3(CO)12 and its derivatives HRuRh3(CO)10(PPh3)2 and HRuCo3(CO)10(PPh3)2 have been synthesized and characterized. The following crystal and molecular structures are reported: HRuRh3(CO)12: monoclinic, space group P21/c, a 9.230(4), b 11.790(5), c 17.124(9) Å, β 91.29(4)°, Z = 4; HRuRh3(CO)10(PPh3)2·C6H14: triclinic, space group P, a 11.777(2), b 14.079(2), c 17.010(2) Å, α 86.99(1), β 76.91(1), γ 72.49(1)°, Z = 2; HRuCo3(CO)10(PPh3)2·CH2Cl2: triclinic, space group P, a 11.577(7), b 13.729(7), c 16.777(10) Å, α 81.39(4), β 77.84(5), γ 65.56°, Z = 2. The reaction between Rh(CO)4? and (Ru(CO)3Cl2)2 tetrahydrofuran followed by acid treatment yields HRuRh3(CO)12 in high yield. Its structural analysis was complicated by a 80–20% packing disorder. More detailed structural data were obtained from the fully ordered structure of HRuRh3(CO)10(PPh3)2, which is closely related to HRuCo3(CO)10(PPh3)2 and HFeCo3(CO)10(PPh3)2. The phosphines are axially coordinated. 相似文献
45.
46.
Mika Prunnila Jouni Ahopelto 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):281
We report on two sub-band/bi-layer transport in double gate SiO2–Si–SiO2 quantum well with 14 nm thick Si layer at 270 mK. At symmetric well potential the experimental sub-band spacing changes monotonically from 2.3 to 0.3 meV when the total electron density is adjusted by gate voltages between 0.7×1016–. The conductivity is mapped in large gate bias window and it shows strong non-monotonic features. At symmetric well potential and high density these features are addressed to sub-band wave function delocalization in the quantization direction and to different disorder of the top and bottom interfaces of the Si well. In the gate bias regimes close to second sub-band/bi-layer threshold the non-monotonic behavior is interpreted to arise from scattering from the other electron sub-system with localized or low mobility states. 相似文献
47.
Jouni Suhonen 《Czechoslovak Journal of Physics》2000,50(4):587-591
Summary of the talks presented on the fourth day of the Workshop on calculation of double-beta-decay matrix elements, MEDEX'99, and conclusions based on questions of the audience and the ensuing round-table discussion. 相似文献
48.
Riitta H. Laitinen Helena Riihimäki Jouni Pursiainen 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract In our studies we have synthesized three novel mixed ortho- and pura substituted phenyl phosphines: pSoOOP, pOoSSP and pSoSSP and a new phosphine containing pyridyl units: pS2Py. Also pOoOOP and pO2Py, which have been previously mentioned in patent literature[1,2] were prepared. 相似文献
49.
Detection of Sea Surface Temperature (SST) Using Infrared Band Data of Advanced Very High Resolution Radiometer (AVHRR) in the Gulf of Finland 总被引:1,自引:0,他引:1
Yuanzhi Zhang Jouni Pulliainen Sampsa Koponen Martti Hallikainen 《International Journal of Infrared and Millimeter Waves》2002,23(10):1407-1412
This paper presents the detection of sea surface temperature (SST) in the Gulf of Finland using infrared band data of Advanced Very High Resolution Radiometer (AVHRR). AVHRR imagery is evaluated as a main data source for monitoring SST as a measure of upwelling's dynamic. Sea surface effects (SSE), however, cause a temperature difference between the sea surface skin and water below the surface. Therefore, SSE is taken into account as one of the major error factors in the SST esimation. Further studies will be investigated using both AVHRR and MODIS in the future. 相似文献
50.
Fernando P��rez-Gonz��lez Jouni R?tty? Jari Taskinen 《Mediterranean Journal of Mathematics》2011,8(1):123-135
Natural metrics in the hyperbolic α-Bloch-, weighted Dirichlet- and Q
p
-classes are introduced, and these classes are shown to be complete metric spaces with respect to the corresponding metrics.
Then Lipschitz continuous and compact composition operators C
φ
(f) = f ◦ φ acting from the hyperbolic α-Bloch-class to the hyperbolic weighted Dirichlet- or Q
p
-class are characterized by conditions depending on the symbol φ only. 相似文献