排序方式: 共有57条查询结果,搜索用时 531 毫秒
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Ernesto FattorussoPaolo Luciano Masteria Yunovilsa Putra Orazio Taglialatela-Scafati Angela IanaroElisabetta Panza Giorgio BavestrelloCarlo Cerrano 《Tetrahedron》2011,67(41):7983-7988
Chemical analysis of the Indonesian soft coral Sinularia sp. (order Alcyonacea, family Alcyoniidae) afforded two known and three new C-4 norcembranoids, named chloroscabrolides A (3) and B (4) and prescabrolide (5). Chloroscabrolide A is a pentacyclic norcembranoid including an unprecedented THF-type ring to connect C-13 and C-15; furthermore, it is only the second chlorinated cembranoid derivative to be reported in the literature. The relative configuration of chloroscabrolide A has been established on the basis of a comparison between experimental 13C NMR data and DFT-calculated 13C NMR chemical shifts. All the isolated norcembranoids have been evaluated for iNOS protein inhibition. 相似文献
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Yoga Satria Putra Anthony Beaudoin Germain Rousseaux Lionel Thomas Serge Huberson 《Comptes Rendus Mecanique》2019,347(2):166-180
2D numerical simulations of tidal bores were obtained using the OpenFOAM CFD software to solve the Navier–Stokes equations by means of the Finite Volume Method by applying a LES turbulence model. The trajectories of non-cohesive sediment particles beneath tidal bores were estimated using a tracker method. Using the fourth order Runge–Kutta scheme, the tracker method solves the Maxey and Riley equations, which requires the knowledge of the velocity field at time t. From 2D numerical simulations of tidal bores, we proposed a classification of tidal bores with respect to the Froude number Fr (or r the ratio of water depths). For a Froude number (), the tidal bore is undular. For a Froude number (), the tidal bore is partially breaking, which is similar to the transitional tidal bore defined by Furgerot (2014). And for a Froude number (), the tidal bore is totally breaking. The numerical results of trajectories of non-cohesive sediment particles are similar to the type of trajectories given by the analytical model proposed by Chen et al. (2012) with some modifications to take into account the effects of gravity, elevation, and attenuation. The parameters of modified Chen's model, , and , are linearly proportional to the Froude number Fr. This is because the level of turbulence for undular tidal bores is low. The flow induced by an undular tidal bore is not complex. This physical phenomenon is quasi linear. The parameter , related to the front celerity of the undular tidal bore, decreases when the Froude number Fr increases. The parameter , related to the elevation, increases when the Froude number Fr increases. And the parameter , related to the attenuation of the secondary waves, increases when the Froude number Fr increases. 相似文献
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Shinji Sakai Tetsu Yamaguchi Ryan Anugrah Putra Rie Watanabe Masaaki Kawabe Masahito Taya Koei Kawakami 《Journal of Sol-Gel Science and Technology》2012,61(2):374-380
Electrospun ultrafine silica fibers were calcined at 150–800 °C. The relation of calcination temperature to the ability to
form biomimetic apatite in a simulated body fluid solution (SBF) was evaluated. The largest apatite particles, formed on non-calcined
fibers after 1 week of soaking in SBF, were 10 μm in diameter, had a narrow size distribution (coefficient of variation 9%),
and were similar to pearls on string. The particles size decreased with increasing calcination temperature below 250 °C and
the particles formed on the fibers calcined at 250 °C were 4.5 μm in diameter. No particles were found on those calcined above
500 °C. By using a concentrated SBF at 1.5-times higher ionic concentrations than SBF, the size of apatite microparticles
increased about 50%. The fibrous substrate covered with apatite particles was effective for osteoblastic differentiation of
pre-osteoblastic cells. 相似文献
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Separation of Linear and Branched Alkanes Using Host–Guest Complexation of Cyclic and Branched Alkane Vapors by Crystal State Pillar[6]arene 下载免费PDF全文
Prof. Tomoki Ogoshi Kazuki Saito Ryuta Sueto Ryosuke Kojima Yukie Hamada Prof. Shigehisa Akine Dr. Adhitya Mangala Putra Moeljadi Dr. Hajime Hirao Dr. Takahiro Kakuta Prof. Tada‐aki Yamagishi 《Angewandte Chemie (International ed. in English)》2018,57(6):1592-1595
Activated crystals of pillar[6]arene produced by removing the solvent upon heating were able to take up branched and cyclic alkane vapors as a consequence of their gate‐opening behavior. The uptake of branched and cyclic alkane vapors by the activated crystals of pillar[6]arene induced a crystal transformation to form one‐dimensional channel structures. However, the activated crystals of pillar[6]arene hardly took up linear alkane vapors because the cavity size of pillar[6]arene is too large to form stable complexes with linear alkanes. This shape‐selective uptake behavior of pillar[6]arene was further utilized for improving the research octane number of an alkane mixture of isooctane and n‐heptane: interestingly, the research octane number was dramatically improved from a low research octane number (17 %) to a high research octane number (>99 %) using the activated crystals of pillar[6]arene. 相似文献
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Vignesh Sekar Se Yong Eh Noum Azma Putra Sivakumar Sivanesan Kok Chun Chin Yi San Wong Dg Hafizah Kassim 《声与振动》2021,55(4):343-352
This paper presents the development and performance of micro-perforated panels (MPP) from natural fiber reinforced composites. The MPP is made of Polylactic Acid (PLA) reinforced with Oil Palm Empty Fruit Bunch Fiber (OPEFBF). The investigation was made by varying the fiber density, air gap, and perforation ratio to observe the effect on the Sound Absorption Coefficient (SAC) through the experiment in an impedance tube. It is found that the peak level of SAC is not affected, but the peak frequency shifts to lower frequency when the fiber density is increased. This phenomenon might be due to the presence of porosity in the inner wall of the holes. Increasing or decreasing the air gap and perforation ratio shifts the peaks of acoustic absorption either way. 相似文献
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Dedi Satria Yhiya Amen Yasuharu Niwa Ahmed Ashour Ahmed E. Allam 《Natural product research》2019,33(2):189-195
A new lanostane-type triterpenoid, lucidumol D (1) was isolated from the fruiting bodies of Ganoderma lingzhi. Its structure was elucidated on the basis of extensive 1D- and 2D-NMR studies as well as mass spectrometry. The cytotoxicity of lucidumol D against proliferation of several cancer cells were assayed by using MTT method and the obtained result suggested selective anti-proliferative and cytotoxic effects against MCF-7, HepG2, HeLa, Caco-2, and HCT-116. In comparison to lucidumol C (2) isolated previously by our group, the structure-activity relationship indicated that carbonyl function at C-11 is necessary to enhance the cytotoxicity. 相似文献
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The unsteady shock wave diffraction over a 90° sharp corner in gases of arbitrary particle statistics is simulated using an
accurate and direct algorithm for solving the semiclassical Boltzmann equation with relaxation time approximation in phase
space. The numerical method is based on the usage of discrete ordinate method for discretizing the velocity space of the distribution
function; whereas a second order accurate TVD scheme (Harten in J. Comput. Phys. 49(3):357–393, 1983) with Van Leer’s limiter (J. Comput. Phys. 32(1):101–136, 1979) is used for evolving the solution in physical space and time. The specular reflection surface boundary condition is assumed.
The complete diffraction patterns are recorded using various flow property contours. Different range of relaxation times approximately
corresponding to continuum, slip and transitional regimes are considered and the equilibrium Euler limit solution is also
computed for comparison. The effects of gas particles that obey the Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac statistics
are examined and depicted. 相似文献