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131.
Melting characteristics of phase change material by natural convection heat transfer inside horizontal rectangular capsules are examined experimentally. The capsules are heated isothermally and three kinds of aspect ratios (qH/W=3, 1 and 1/3) are provided. Octadecane and ice are used, respectively, as the phase change material. A method of analysis applying the empirical correlations for natural convection heat transfer in a vertical or horizontal enclosure to the melting in the rectangular capsules is presented. The predicted results show good agreement with the experimental data. For the melting of octadecane and ice, it is found that the effect of aspect ratio on the melting process is not significant for the range ofB=1/3 to 3. 相似文献
132.
Kawai K Kaneko K Yonezawa T 《Langmuir : the ACS journal of surfaces and colloids》2011,27(12):7353-7356
This Letter examines the relationship between the structures of ionic liquids and their water-solubility or osmotic pressure with a number of synthesized quaternary ammonium type ionic liquids and organic salts containing a hydroxyl group as hydrophilic substituted groups on ammonium group cations, and bromide or methylsulfonate as anions. The study found a linear relation between the amount and osmotic pressure of the water-soluble ionic liquids synthesized here, strongly indicating that these water-soluble ionic liquids are perfectly ionized in water like inorganic salts with small diameter ions. 相似文献
133.
A remarkable effect of ionic liquids in transition-metal-free aerobic oxidation of benzylic alcohols
Yoshiro OdaKoji Hirano Tetsuya SatohSusumu Kuwabata Masahiro Miura 《Tetrahedron letters》2011,52(41):5392-5394
The transition-metal-free aerobic oxidation of benzylic alcohols is uniquely accelerated by a 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6)/PhCF3 biphasic system and Cs2CO3 to afford the corresponding ketones in good yields. The reaction system is also applicable to an oxidative cross-esterification of primary benzyl alcohols with a higher aliphatic alcohol. 相似文献
134.
We proposed a low cost fabrication procedure of a poly(methylmethacrylate) (PMMA) column chip. 3D microchannel structure consisting of four columns in a chip for a mother die was fabricated using dry film photoresist and photolithography technique. Electroforming was applied to the mother die in order to obtain a Ni mold, then, the pattern was transferred to PMMA by hot press. The column had a dam structure to keep enzyme-immobilized microbeads with volume of 640 nL. The column chip was applied for a micro flow injection analysis (μFIA) system. For a demonstration, we measured lactose using two columns in series. One column was set on upper stream and filled with chitosan microbeads immobilized with β-galactosidase, the other was on downstream and filled with the beads immobilized with glucose oxidase. The lactose detection was accomplished less than 90s after the sample injection. The biosensing system also showed a high performance for lactose detection in wide range of 1 μM to 1mM. These results show that the column chip and our microfluidic biosensing system have the potential to assist minuaturization with small sample volume and short determination time for a sequential analysis. 相似文献
135.
Urita K Shiga Y Fujimori T Iiyama T Hattori Y Kanoh H Ohba T Tanaka H Yudasaka M Iijima S Moriguchi I Okino F Endo M Kaneko K 《Journal of the American Chemical Society》2011,133(27):10344-10347
An outstanding compression function for materials preparation exhibited by nanospaces of single-walled carbon nanohorns (SWCNHs) was studied using the B1-to-B2 solid phase transition of KI crystals at 1.9 GPa. High-resolution transmission electron microscopy and synchrotron X-ray diffraction examinations provided evidence that KI nanocrystals doped in the nanotube spaces of SWCNHs at pressures below 0.1 MPa had the super-high-pressure B2 phase structure, which is induced at pressures above 1.9 GPa in bulk KI crystals. This finding of the supercompression function of the carbon nanotubular spaces can lead to the development of a new compression-free route to precious materials whose syntheses require the application of high pressure. 相似文献
136.
Ogawa T Hattori H Kaneko R Ito K Iwai M Mizutani Y Arinobu T Ishii A Seno H 《Analytical and bioanalytical chemistry》2011,400(7):1959-1965
In this report, a high-throughput and sensitive method for analysis of eight central-acting muscle relaxants in human plasma
by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) in the positive and negative ionization modes
using tolbutamide as internal standard is presented. After pretreatment of a plasma sample by solid-phase extraction with
an Oasis HLB cartridge, muscle relaxants were analyzed by UPLC with Acquity UPLC BEH C18 column and Acquity TQD tandem quadrupole mass spectrometer equipped with an electrospray ionization interface. The calibration
curves for muscle relaxants spiked into human plasma equally showed good linearities in the nanogram per milliliter order
range. The detection limits (signal-to-noise ratio = 3) was as low as 0.1–2 ng/mL. The method gave satisfactory recovery rates,
accuracy, and precision for quality control samples spiked with muscle relaxants. To further validate the present method,
250 mg of chlorphenesin carbamate was orally administered to a healthy male volunteer, and the concentrations of chlorphenesin
carbamate in plasma were measured 0.5, 1, 2, 4, 6, and 8 h after dosing; their concentrations in human plasma were between
0.62 and 2.44 μg/mL. To our knowledge, this is the first report describing simultaneous analysis of over more than two central-acting
muscle relaxants by liquid chromatography–tandem mass spectrometry. This has been realized by the capability of our instrument
for simultaneous multiple reaction monitoring of the target compounds in both positive and negative ionization modes. Therefore,
the present method seems very useful in forensic and clinical toxicology and pharmacokinetic studies. 相似文献
137.
The rotational time correlation function (RTCF) of solute benzene molecules in the ionic liquid (1-butyl-3-methylimidazolium chloride) has been studied using classical molecular dynamics simulation. The effect of solvent charge on the functional form of RTCF was investigated by comparing four force fields for the solvent where the total charge on the anion and the cation was set to ±1e, ±0.7e, ±0.5e, and 0, respectively. For all three charged solvent models, the RTCF exhibits a long-time tail where the relaxation rate exhibits a significant slowdown. This feature is strengthened by higher solvent charges as well as lower temperatures, indicating the influence of the strong Coulombic fields arising from the solvent charges. The long-time tail is caused by the extraordinarily slow solvent structural relaxation of ionic liquids compared to the time scale of their local vibrational and librational dynamics. 相似文献
138.
Room temperature ionic liquids (IL) have been used in numerous applications in chemistry. Addition of water alters many of their properties making it possible to custom design solvents for specific applications. Along with experiments, computational studies using various approaches have provided key insights into the structure and dynamics of IL systems, as well as aggregate formation and phase behavior of the IL/water mixtures. These systems provide computational challenges since ILs and IL/water mixtures are viscous liquids with intrinsically slow processes and structural organization over surprisingly large length scales, which push the limits of applicability of the available techniques. Recent developments in the studies of IL/water mixtures using computational methodologies are reviewed and the future prospects for the field are briefly discussed. 相似文献
139.
Imura Y Tanuma H Sugimoto H Ito R Hojo S Endo H Morita C Kawai T 《Chemical communications (Cambridge, England)》2011,47(22):6380-6382
Straight ultrathin Au nanowires (NWs) with diameters less than 2 nm were synthesized using the lamellar structure of C18AA in an organogel and its selective adsorption for specific gold surfaces. In addition, the potential to form a bilayer structure with interdigitated hydrocarbon chains enabled the production of water-dispersible Au NWs without morphological change. 相似文献
140.