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51.
The roots of Peucedanum japonicum (Apiaceae) have been used as an alternative to the roots of Saposhnikovia divaricata (Apiaceae) to treat common cold-related symptoms in Korea. However, a variety of Peucedanum species, including the roots of P. praeruptorum or Angelica decursiva (=P. decursivum), have been used to treat phlegm–heat-induced symptoms in China. Hence, as there are differences in the medicinal application of P. japonicum roots between Korea and China, chemotaxonomic classification of P. japonicum was evaluated. Sixty samples derived from P. japonicum, P. praeruptorum, A. decursiva, and S. divaricata were phylogenetically identified using DNA barcoding tools, and chemotaxonomic correlations among the samples were evaluated using chromatographic profiling with chemometric analyses. P. japonicum samples were phylogenetically grouped into the same cluster as P. praeruptorum samples, followed by S. divaricata samples at the next cluster level, whereas A. decursiva samples were widely separated from the other species. Moreover, P. japonicum samples showed higher chemical correlations with P. praeruptorum samples or A. decursiva samples, but lower or negative chemical correlations with S. divaricata samples. These results demonstrate that P. japonicum is more genetically and chemically relevant to P. praeruptorum or A. decursiva and, accordingly, the medicinal application of P. japonicum might be closer to the therapeutic category of these two species than that of S. divaricata. 相似文献
52.
The polymorphism at codon 129 (M129V) of the human prion protein gene (PRNP) is a known risk factor for Creutzfeldt-Jakob disease (CJD) in Caucasians. There are few reports of this polymorphism's effect on memory and on the risk of Alzheimer's disease (AD). The M129V genotype distributions among Asians are very different from Caucasians. Another polymorphism, codon 219 (E219K) is not found in Caucasians. We investigated two polymorphisms of PRNP, M129V (rs1799990) and E219K (rs1800014) in 297 Korean AD patients and 217 healthy subjects. The analysis of the genotype and allele distributions showed no significant difference between the AD patients and the controls in both polymorphisms (P=0.19 genotype, P=0.51 allele for M129V; P=0.64 genotype, P=0.50 allele for E219K). Also, the PRNP polymorphisms were not significantly associated with AD when the populations were stratified for the presence or absence of apolipoprotein E-epsilon4 (ApoE-epsilon4) allele. These results suggest that the PRNP genetic variants are not associated with the risk for AD in Korean population. 相似文献
53.
54.
Chil-Hoon Doh Nallathamby Kalaiselvi Cheol Wan Park Seong-In Moon Mun-Soo Yun 《Ionics》2004,10(5-6):421-428
Among the variety of alternate anode materials being studied, the research on the exploration of 3d-metal oxide anodes gains
paramount importance in the recent time, as it is bestowed with an easy preparation method and a less complicated decomposition
mechanism. Towards this direction, an attempt to synthesize the compound CoO and to investigate the electrochemical behavior
of the same both individually and in comparison with NiO compounds was made with a view to understand the extent to which
the chosen candidates, viz., CoO and NiO can be exploited as high capacity anodes. Between the two oxides, CoO exhibited a
specific capacity of at least 550 mAh/g, against NiO with an average capacity of ∼330 mAh/g. Also, the magnitude of irreversible
capacity loss and the extent of capacity fade upon cycling corresponding to CoO anode were found to be lesser than NiO anodes.
The enhanced specific capacity values and the better cycleability properties of CoO anodes are believed to be due to the inherent
electrochemical characteristics of the compound. The type and the nature of SEI formed over the electrode surface and the
formation of possible progressive agglomeration of the products of decomposition are expected to be the factors responsible
for the difference in the electrochemical behavior of CoO and NiO anodes. In short, electrochemical characterization of the
individual oxides are studied and probable reasons for the observed difference in the charge-discharge behavior of CoO and
NiO anodes are discussed in this communication. 相似文献
55.
A modal wavelet transform, which overcomes the intrinsic data number limitation of power of two to conventional wavelet transform,
has been applied to analysis of axial and eddy pseudo velocity fields, standard PIV velocity field and experimental PIV measurement.
The modal wavelet transform is compared with the discrete wavelet transform in order to select the optimum basis function
among Neumann, Dirichlet and Green function types basis functions. Consequently, it is verified that Neumann type function
is the best basis because the correlation of Neumann type basis function is higher and the root mean square is lower than
the other basis functions. Also, the decomposition vector patterns by Neumann type are similar to that by conventional Daubechies
basis function of 4th order. 相似文献
56.
A simultaneous measurement system that can analyze the flow-structure interactions has been developed. This system consists
of four CCD cameras, two for capturing instantaneous flow fields and two for tracking a solid body. The three-dimensional
vector fields around a cylinder are measured while the motion of the cylinder forced by the flow field is measured simultaneously
with the constructed system. The cylinder is suspended in the circulating water channel and the surface of the working fluid
is forced sinusoidal to make the cylinder bounced. Reynolds number for the mean main stream is about 3500. The interaction
between the flow fields and the cylinder motion is examined quantitatively. 相似文献
57.
Z.D. Doh?evi?-Mitrovi? M.J. Š?epanovi? Z.V. Popovi? B.M. Matovi? F. Aldinger 《Solid State Communications》2006,137(7):387-390
Ultrafine Ce1−xNdxO2−δ (x=0-0.25) powders were synthesized by self-propagating room temperature synthesis. Raman spectra were measured at room temperature in the 300-700 cm−1 spectral range. The shift and asymmetric broadening of the Raman F2g mode at about 454 cm−1 in pure and doped ceria samples could be explained with combined size and inhomogenous strain effects. Increased concentration of O2− vacancies with doping is followed by an appearance of new Raman feature at about 545 cm−1. 相似文献
58.
Kyung-Hyun Choi Arshad Khan Khalid Rahman Yang-Hoi Doh Dong-Soo Kim Ki-Rin Kwan 《Journal of Electrostatics》2011,69(4):380-387
This paper presents the analysis of a triangular array of nozzles in a multi-nozzle electrohydrodynamic (EHD) inkjet printing head. A methodology has been proposed to minimize the “end effect” by changing the traditional linear array of nozzles to triangular array of nozzles in multi-nozzle EHD printing head. Interaction (cross-talk) between the electrically charged neighboring jets is investigated and analyzed both numerically and experimentally using three glass nozzles with independent voltage connections and independent ink supply to each nozzle. In order to scrutinize the performance of triangular array multi-nozzle EHD inkjet printing head, comparative study of triangular array multi-nozzle EHD inkjet printing head to the linear array multi-nozzle EHD inkjet printing head has been made on the basis of electric field simulations and experiments. Experimental results illustrate that in triangular array multi-nozzle EHD inkjet printing head, the over potential requirement is low and individual capillaries are operating with more independence as compared to linear array multi-nozzle EHD inkjet printing head. 相似文献
59.
Abstract
The tungsten inert gas (TIG) welding enables to produce high welding qualities. However, it has some problems such as a large distortion and a shallow penetration into the welding parts. To overcome those problems, there have been many studies on A-TIG welding in which active flux and a shield gas are used. The shield gas pressure, velocity, and distribution area are dominant factors in producing better welding condition which can be evaluated by the gas penetration, the gap between the nozzle tip and welding plate and the nozzle shape of the shield gas. In this study, the influences of the shield gas distribution onto the melting efficiency and penetration shape in TIG welding were investigated using a numerical simulation. The gap distances between the nozzle tip and the welding plate were changed 3, 4, 5 mm and two nozzle shapes, convergent parallel (CP) and CDP, were tested. 100% Ar gas was used as the shield gas. CDP type nozzle showed deeper penetrations and higher melting efficiency compared to those of CD type and CP type nozzles. 相似文献60.
A. Golubović M. Šćepanović A. Kremenović S. Aškrabić V. Berec Z. Dohčević-Mitrović Z. V. Popović 《Journal of Sol-Gel Science and Technology》2009,49(3):311-319
TiO2 nanopowders were produced by sol–gel technique under different synthesis conditions. XRD results have shown that obtained
nanopowders are in anatase phase, with the presence of a small amount of highly disordered brookite phase, whereas nanocrystallite
size and amount of brookite slightly depend on sol–gel synthesis conditions. Raman measurements confirm these results. The
analyses of the shift and width of the most intensive anatase E
g Raman mode by phonon confinement model suggest that anatase crystallite size should be in the range between 11 and 15 nm,
what is in excellent correlation with XRD results. Obtained results have shown that Raman spectroscopy is a highly sensitive
method for the estimation of anatase crystallite size as well as brookite content in TiO2 nanopowders synthesized by variable sol–gel synthesis conditions. 相似文献