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排序方式: 共有139条查询结果,搜索用时 15 毫秒
11.
Junko Iida Takehiro Takeda Takumi Takasuga John Moncur Phil Ireland Barry Wright 《Journal of separation science》1991,14(2):103-109
A hybrid mass spectrometer with an EBQQ configuration was used to investigate two approaches to trace dioxin analysis: high resolution gas chromatography – high resolution mass spectrometry (HRGC-HRMS) and high resolution gas chromatography – mass spectrometry – mass spectrometry (HRGC-MS-MS). It is shown that selected ion monitoring (SIM) HRGC-HRMS exhibits better selectivity for dioxins separated on a cyanopropyl column than is otherwise obtained under medium resolution mass spectrometry (3,000 resolution), while optimization of conditions for HRGC-MS-MS allowed the observation of 350 femtograms of the highly toxic 2,3,7,8-TCDF at a S/N ratio of 5:1. Both methods were applied to environmental samples with good results. 相似文献
12.
The hetero-Diels-Alder condensation between furanoid and pyranoid exocyclic vinyl ethers establishes the spiroketal system and subsequent oxidative ring contraction leads to 1.6-dioxaspiroalkane carboxylic acids. The latter are useful subunits for polyether antibiotic synthesis. 相似文献
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A method of using thermochromic liquid crystals has been developed to visualize the thermal footprints of turbulent spots convecting downstream in an otherwise laminar boundary layer over a heated surface. This technique has been employed to visualize the development of turbulent spots under the influence of adverse pressure gradients. It has also been used to visualize the transitional events that occur during unsteady wake-induced boundary layer transition typically of those occurring in multi-stage turbomachines. The results show that liquid crystal is not only capable of providing quantitative information about the growth and development of individual spots but also allows a detailed study of formation of turbulent spots occurring naturally during a complicated transition process. 相似文献
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Mehran?SohrabiEmail author Nor?Idah?Kechut Masoud?Riazi Mahmoud?Jamiolahmady Shaun?Ireland Graeme?Robertson 《Transport in Porous Media》2012,91(1):101-121
Carbonated water injection (CWI) is a CO2-augmented water injection strategy that leads to increased oil recovery with added advantage of safe storage of CO2 in oil reservoirs. In CWI, CO2 is used efficiently (compared to conventional CO2 injection) and hence it is particularly attractive for reservoirs with limited access to large quantities of CO2, e.g. offshore reservoirs or reservoirs far from large sources of CO2. We present the results of a series of CWI coreflood experiments using water-wet and mixed-wet Clashach sandstone cores and
a reservoir core with light oil (n-decane), refined viscous oil and a stock-tank crude oil. The experiments were carried out to assess the performance of CWI
and to quantify the level of additional oil recovery and CO2 storage under various experimental conditions. We show that the ultimate oil recovery by CWI is higher than the conventional
water flooding in both secondary and tertiary recovery methods. Oil swelling as a result of CO2 diffusion into the oil and the subsequent oil viscosity reduction and coalescence of the isolated oil ganglia are amongst
the main mechanisms of oil recovery by CWI that were observed through the visualisation experiments in high-pressure glass
micromodels. There was also evidence of a change in the rock wettability that could also influence the oil recovery. The coreflood
test results also reveal that the CWI performance is influenced by oil viscosity, core wettability and the brine salinity.
Higher oil recovery was obtained with the mixed-wet core than the water-wet core, with light oil than with the viscous oil
and low salinity carbonated brine than high-salinity carbonated brine. At the end of the flooding period, an encouraging amount
of the injected CO2 was stored in the brine and the remaining oil in the form of stable dissolved CO2. The experimental results clearly demonstrate the potential of CWI for improving oil recovery as compared with the conventional
water flooding (secondary recovery) or as a water-based EOR (enhanced oil recovery) method for watered out reservoirs. 相似文献
17.
Izabela Spaleniak Simon Gross Nemanja Jovanovic Robert J. Williams Jon S. Lawrence Michael J. Ireland Michael J. Withford 《Laser \u0026amp; Photonics Reviews》2014,8(1):L1-L5
The first demonstration of narrowband spectral filtering of multimode light on a 3D integrated photonic chip using photonic lanterns and waveguide Bragg gratings is reported. The photonic lanterns with multi‐notch waveguide Bragg gratings were fabricated using the femtosecond direct‐write technique in boro‐aluminosilicate glass (Corning, Eagle 2000). Transmission dips of up to 5 dB were measured in both photonic lanterns and reference single‐mode waveguides with 10.4‐mm‐long gratings. The result demonstrates efficient and symmetrical performance of each of the gratings in the photonic lantern. Such devices will be beneficial to space‐division multiplexed communication systems as well as for units for astronomical instrumentation for suppression of the atmospheric telluric emission from OH lines. 相似文献
18.
A miniaturized protein and peptide microsequencer consisting of a fused silica capillary reaction chamber is described. Extremely small volumes of reagents, 2 mul or less, were delivered directly to the reaction chamber through individual fused silica capillary lines using low pressure syringe pumps. Other than an argon gas controller, no values were used in the delivery system. The short flow path and very low dead volume were achieved by directly connecting the narrow-bore capillaries to the reaction chamber. This configuration minimized side reactions. The elimination of valves, as well as the use of capillaries for the reaction chamber and delivery lines, greatly simplified the construction of the sequencer. The performance of the sequencer was evaluated by sequencing 8-33 picomoles of myoglobin and insulin chain B that were covalently attached to Sequelon-DITC and Sequelon-AA membranes. 相似文献
19.
Iridoid glycosides from Globularia davisiana 总被引:1,自引:0,他引:1
Caliş I Kirmizibekmez H Taşdemir D Ireland CM 《Chemical & pharmaceutical bulletin》2002,50(5):678-680
From the ethanolic extract of the aerial parts of Globularia davisiana, a new iridoid glycoside, davisioside (1), was isolated. Davisioside (1) comprises a rare iridoid aglycone structure with a saturated double bond between C-3 and C-4. Nine known iridoid glycosides, asperuloside (2), alpinoside (3), geniposide (4), globularin (5), globularicisin (6), 10-O-benzoylcatalpol (7), lytanthosalin (8), melampyroside (9), agnuside (10), and three known phenylethanoid glycosides, verbascoside, isoacteoside and leucosceptoside A were also isolated and characterized. The structures of the isolates were established by spectroscopic methods (one-dimensional (1D)- and two-dimensional (2D)-NMR, MS). 相似文献
20.
Two new lucidin type anthraquinone glycosides, putorinoside A (1) and putorinoside B (2) were isolated from Putoria calabrica, in addition to two known anthraquinone glycosides, lucidin 3-O-beta-glucopyranoside (3) and lucidin 3-O-primeveroside (4). Based on spectroscopic data, putorinosides A and B were identified as 2-hydroxymethyl-1-methoxy-3,5,6-trihydroxyanthraquinone 3-O-beta-glucopyranoside and 2-hydroxymethyl-1-methoxy-3,6-dihydroxyanthraquinone 3-O-beta-glucopyranoside, respectively. 相似文献