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21.
Joonho Lee Wataru Shimoda Toshihiro Tanaka 《Monatshefte für Chemie / Chemical Monthly》2005,40(10):1829-1834
Temperature dependence of the surface tension of liquid Sn–Ag and Sn–Cu base lead-free solder alloys and oxygen partial pressure
dependence of liquid Sn–Ag alloy were evaluated using the experimental data obtained, respectively, by the constrained drop
method and the sessile drop method in the previous studies [1, 2]. The temperature dependences of the surface tension have
maximum positive values when the mol fraction of Ag and Cu is about 0.7, while those for pure liquid Sn, Ag, and Cu have negative
values. The calculated values based on Butler’s equations were found to be in reasonable agreement with those of the experimental data. The oxygen partial pressure dependences
of the surface tension of liquid Sn–Ag alloys at 1253 K have a minimum value when the mol fraction of Ag is about 0.9 and
the oxygen partial pressure is less than about 10−13 atm. From this, it is considered that the oxygen adsorption increased by adding Ag to Sn when the mol fraction of Ag is less
than 0.9. 相似文献
22.
We have developed a time-reversible rigid-body (rRB) molecular dynamics algorithm in the isothermal-isobaric (NPT) ensemble. The algorithm is an extension of rigid-body dynamics [Matubayasi and Nakahara, J Chem Phys 1999, 110, 3291] to the NPT ensemble on the basis of non-Hamiltonian statistical mechanics [Martyna, G. J. et al., J Chem Phys 1994, 101, 4177]. A series of MD simulations of water as well as fully hydrated lipid bilayer systems have been undertaken to investigate the accuracy and efficiency of the algorithm. The rRB algorithm was shown to be superior to the state-of-the-art constraint-dynamics algorithm SHAKE/RATTLE/ROLL, with respect to computational efficiency. However, it was revealed that both algorithms produced accurate trajectories of molecules in the NPT as well as NVT ensembles, as long as a reasonably short time step was used. A couple of multiple time-step (MTS) integration schemes were also examined. The advantage of the rRB algorithm for computational efficiency increased when the MD simulation was carried out using MTS on parallel processing computer systems; total computer time for MTS-MD of a lipid bilayer using 64 processors was reduced by about 40% using rRB instead of SHAKE/RATTLE/ROLL. 相似文献
23.
Tsuyoshi Matsumoto Junji Furukawa Hirohisa Morimura 《Journal of polymer science. Part A, Polymer chemistry》1971,9(7):1971-1981
The π-allyl nickel halide-oxygen system was found to be active as catalyst for stereospecific polymerization of butadiene. The catalyst from π-allyl nickel chloride or π-allyl nickel bromide yields the polymer of 90% cis-1,4 content with high activity, whereas the catalyst from π-allyl nickel iodide affords a polymer of 70% or less cis-1,4 content. The catalyst systems can be fractionated into two parts on the basis of solubility in benzene. It is concluded that the catalyst activity originates essentially from the benzene-insoluble nickel complex which is composed of oxygen, halogen, σ-allyl group, and nickel. The structure of growing polymer terminal is discussed in relation to the mechanism of the stereospecific polymerization. 相似文献
24.
Wataru Sugimoto Masashi Omoto Katsunori Yokoshima Yasushi Murakami Yoshio Takasu 《Journal of solid state chemistry》2004,177(12):4542-4545
An ion-exchangeable ruthenate with a layered structure, K0.2RuO2.1, was prepared by solid-state reactions. The interlayer cation was exchanged with H+, C2H5NH3+, and ((C4H9)4N+) through proton-exchange, ion-exchange, and guest-exchange reactions. The electrical and magnetic properties of the products were characterized by DC resistivity and susceptibility measurements. Layered K0.2RuO2.1 exhibited metallic conduction between 300 and 13 K. The products exhibited similar magnetic behavior despite the differences in the type of interlayer cation, suggesting that the ruthenate sheet in the protonated form and the intercalation compounds possesses metallic nature. 相似文献
25.
Yamanaka N Kawano R Kubo W Kitamura T Wada Y Watanabe M Yanagida S 《Chemical communications (Cambridge, England)》2005,(6):740-742
Use of a new ionic liquid crystal, 1-dodecyl-3-methylimidazolium iodide, and iodine as an electrolyte of dye-sensitized solar cells leads to a high short circuit photocurrent density and a high light-to-electricity conversion efficiency, due to a self-assembled structure of the imidazolium cations, resulting in high conductivity of the electrolyte. 相似文献
26.
Photosensitized oxygenation of diethyl sulfide in the presence of α-keto carboxylic acids caused oxidative decarboxylation of the acids by persulfoxide and gave carboxylic acids, carbon dioxide, diethyl sulfoxide and diethyl sulfone. 相似文献
27.
Photooxygenation of 1,1,3,3-tetramethyl-2-indanone triphenyl-phosphazine afforded, in addition to the parent indanone and triphenylphosphine oxide, 2,2,5,5-tetramethyl-3,4-benzo-3-penten-5-olide from a carbonyl oxide intermediate and also gave light emission. 相似文献
28.
Copper-catalyzed oxonium ylide formation-[2,3] shift of (5S,7R)-5-allyloxy-1-diazo-8-(p-methoxybenzyloxy)-7-methyl-2-octanone (3) proceeded in tetrahydrofuran-dichloromethane (4 : 1) under reflux with an excellent stereoselectivity (97 : 3) to give (2R,6S)-2-allyl-6-[(2R)-3-(p-methoxybenzyloxy)-2-methylpropyl]-3-dihydropyranone (2) as a major isomer in 82% yield. The resultant pyranone (2) was converted to the key intermediate (1) of the Mulzer's laulimalide synthesis and its derivatives (14, 15). 相似文献
29.
Identification and formation mechanism of individual degradation products in lithium‐ion batteries studied by liquid chromatography/electrospray ionization mass spectrometry and atmospheric solid analysis probe mass spectrometry 下载免费PDF全文
30.