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81.
采用常数边界元对船舶与流体界面进行离散,求解船舶兴波势及船舶兴波阻力。这种方法可避免在船舶与流体自由面交线上安置节点,因而避免了这些节点建立补充方程。因为满足自由面条件的Havelock源函数的源点和场点不能同时在自由面上,使得自由面上的节点无法用Havelock源函数的建立方程。如对自由面交线上的节点建立补充方程,则要对线性自由面条件中包含的未知势函数的二阶导数用差分形式表达,引入较大误差。 相似文献
82.
The stem cell factor receptor (c‐Kit) has been known to play critical roles in regulating numerous aspects of cellular behavior including cell growth, differentiation, migration and metabolism. In this investigation, a three‐dimensional pharmacophore model of c‐Kit inhibitors has been established by using the HypoGen algorithms implemented in the catalyst software package. The best quantitative pharmacophore model, hypothesis 1, which has the highest correlation coefficient (0.989), consists of one hydrogen bond acceptor, two hydrogen bond donors and one hydrophobic feature. To our knowledge, this is the first report on the pharmacophore modeling study of c‐Kit inhibitors. The best hypothesis, hypothesis 1, was used to screen molecular structural databases, including Specs and China Natural Products Database for potential lead compounds. The hit compounds were subsequently subjected to filtering by Lipinski's rules and docking study to refine the retrieved hits and as a result to reduce the rate of false positive. Finally 28 compounds were purchased or synthesized for further in vitro assay against several human tumour cell lines including A549, MCF‐7, HepG2 and PC‐3, in which c‐Kit is overexpressed. Two compounds show very low micromolar inhibition potency against the PC‐3 and HepG2 cell lines respectively. And they were selected for further modification and testing. 相似文献
83.
An ionic liquid (IL) EPReO4 (N‐ethylpyridinium rheniumate) was prepared. The density and surface tension values of the IL were determined in the temperature range of 293.15–343.15 K. The ionic volume and surface entropy of the IL were estimated by extrapolation, respectively. In terms of Glasser's theory, the standard molar entropy and lattice energy of the IL were estimated, respectively. Using Kabo's and Rebelo's methods, the molar enthalpy values of vaporization of the IL, ΔglH0m (298 K), at 298 K and, ΔglH0m (Tb), at hypothetical normal boiling point were estimated, respectively. According to the interstice model, the thermal expansion coefficient of IL EPReO4 (α) was calculated and compared with experimental value, finding their magnitude order is in good agreement by 8.98%. 相似文献
84.
Jian‐Guo Zhang Dr. Jing‐Yu Li Yan Zang Yuan‐Jie Shu Tong‐Lai Zhang Li Yang Philip P. Power 《无机化学与普通化学杂志》2010,636(6):1147-1151
The novel high nitrogen‐containing energetic complex [Cd(DAT)6](NO3)2 was synthesized by reaction of Cd(NO3)2·6H2O with 1,5‐diamino‐tetrazole (DAT). It was characterized by elemental analysis, FT‐IR spectroscopy and single‐crystal X‐ray diffraction analysis. The central Cd2+ ion is coordinated by six nitrogen atoms from six DAT ligand molecules to form a hexacoordinate distorted octahedral compound. The [Cd(DAT)6](NO3)2 molecules are linked together through two types of hydrogen bonds thus forming a stable three‐dimensional net structure. The thermal decomposition mechanism of [Cd(DAT)6](NO3)2 was investigated by DSC and TG/DTG analyses and FT‐IR spectroscopy. The kinetic parameters of the exothermic process were studied by using Kissinger’s and Ozawa–Doyle’s methods. 相似文献
85.
Hiromasa Aono Dingy Wen Li Zang Damian Houde R. Blake Pepinsky David R.H. Evans 《Journal of chromatography. A》2010,1217(32):5225-5232
Protein trisulfide linkages are generated by the post-translational insertion of a sulfur atom into a disulfide bond. Molecular heterogeneity was detected in a recombinant IgG1 monoclonal antibody (mAb) and attributed to the presence of a protein trisulfide moiety. The predominant site of trisulfide modification was the bond between the heavy and light chains. The trisulfide was eliminated during purification of the IgG1 mAb via a cysteine wash step incorporated into Protein A affinity column chromatography. Analysis of the cysteine-treated mAb by electrophoresis and peptide mapping indicated that the trisulfide linkages were efficiently converted to intact disulfide bonds (13% trisulfide decreased consistently to 1% or less) without disulfide scrambling or an increase in free sulfhydryls. The on-column trisulfide conversion caused no change in protein folding detectable by hydrogen/deuterium exchange or differential scanning calorimetry. Consistent with this, binding of the mAb to its antigen in vitro was insensitive to the presence of the trisulfide modification and to its removal by the on-column cysteine treatment. Similar, high efficiency trisulfide conversion was achieved for a second IgG1 mAb using the column wash strategy (at least 7% trisulfide decreased to 1% or less). Therefore, trisulfide/disulfide heterogeneity can be eliminated from IgG1 molecules via a convenient and inexpensive procedure compatible with routine Protein A affinity capture. 相似文献
86.
B. Z. Li C. G. Sun A. F. Zang X. H. Zhang M. Zhao J. B. Wang G. Y. Jin 《Laser Physics》2011,21(6):988-990
We describe the output performances of the 1048 nm transition in Yb:YAG under in-band pumping with diode laser at the 968 nm wavelength. An end-pumped Yb:YAG crystal yielded 787 mW of continuous-wave (CW) output power for 9.1 W of absorbed pump power. Furthermore, 104 mW 524 nm green light was acquired by frequency doubling. Comparative results obtained for the pump with diode laser at 940 nm are given in order to prove the advantages of the in-band pumping. 相似文献
87.
Tu XL Xu HS Wang M Zhang YH Litvinov YA Sun Y Schatz H Zhou XH Yuan YJ Xia JW Audi G Blaum K Du CM Geng P Hu ZG Huang WX Jin SL Liu LX Liu Y Ma X Mao RS Mei B Shuai P Sun ZY Suzuki H Tang SW Wang JS Wang ST Xiao GQ Xu X Yamaguchi T Yamaguchi Y Yan XL Yang JC Ye RP Zang YD Zhao HW Zhao TC Zhang XY Zhan WL 《Physical review letters》2011,106(11):112501
Mass excesses of short-lived A=2Z-1 nuclei (63)Ge, (65)As, (67)Se, and (71)Kr have been directly measured to be -46,921(37), -46,937(85), -46,580(67), and -46,320(141) keV, respectively. The deduced proton separation energy of -90(85) keV for (65)As shows that this nucleus is only slightly proton unbound. X-ray burst model calculations with the new mass excess of (65)As suggest that the majority of the reaction flow passes through (64)Ge via proton capture, indicating that (64)Ge is not a significant rp-process waiting point. 相似文献
88.
89.
90.
Forsythia suspensa (Thunb.) Vahl is one of the most widely used traditional Chinese medicines, and possesses important biological activities, such as antibacterial, antiviral, anti-inflammatory and antioxidant activities. Phillyrin is the main bioactive component of Forsythia suspensa. In this paper, ultrasound-assisted extraction of phillyrin from Forsythia suspensa was studied with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extracting solvent, ratio of liquid to material, extraction temperature, and time of sonication on extraction efficiencies of phillyrin from Forsythia suspensa were evaluated. The optimal extraction conditions were 1g plant sample with 10 ml of 20% methanol and the extraction for 60 min at 60°C under ultrasonic irradiation. Under the optimum conditions, the yield of phillyrin was 0.713±0.009 mg/g. The results indicated that the ultrasound-assisted extraction is a very useful method for the extraction of important phytochemicals from plant materials. 相似文献