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排序方式: 共有241条查询结果,搜索用时 15 毫秒
61.
Numerical Algorithms - In this paper, we propose and analyze high-order efficient schemes for the time-fractional Allen-Cahn equation. The proposed schemes are based on the L1 discretization for... 相似文献
62.
刘宏逸 《数学建模及其应用》2015,4(3):19-28
主要分析垃圾焚烧厂污染物的排放问题,针对排放的气体污染物,建立污染物传播的对流扩散模型,考虑到风向、风速、降雨、混合层等多方面因素,对模型加以修正,利用迎风格式的有限元素法进行数值模拟;以深圳市某垃圾焚烧厂为例,模拟得到厂区周围方圆5 km区域内污染物浓度的分布情况,并对模拟数据进行聚类分析,根据季节性特征将监测点进行归并,得到全年的动态监测方案。 相似文献
63.
64.
Jinshu Wang Yuntao Cui Hongyi Li Zhenzhen Wang Kelin Huang Guosong Sun 《Research on Chemical Intermediates》2010,36(1):17-26
Based on anodic aluminum oxide (AAO) templates prepared in different acidic solutions, highly ordered aligned titania nanotubes
array films have been successfully prepared by the liquid phase deposition method. The effect of AAO template type on the
microstructure of titania film have been studied. Using the template with a certain volume fraction of Al2O3 (less than 0.71), ordered aligned titania nanotubes were obtained, characterized with an outer diameter of 200 nm and an
inner diameter of 100 nm, respectively. However, titania existed as ordered aligned nanorods with the diameter of 100 nm when
the template with large volume fraction of Al2O3 (larger than 0.71) was used. TiO2 thin films calcined at 400°C for 4 h have an anatase phase and exhibit good photocatalytic activity, i.e., 75% methylene
blue could be degraded under ultraviolet irradiation for 2 h. 相似文献
65.
Owing to fluctuations in the financial markets from time to time, the rate λ of Poisson process and jump sequence {Vi} in the Merton’s normal jump-diffusion model cannot be expected in a precise sense. Therefore, the fuzzy set theory proposed by Zadeh [Zadeh, L.A., 1965. Fuzzy sets. Inform. Control 8, 338-353] and the fuzzy random variable introduced by Kwakernaak [Kwakernaak, H., 1978. Fuzzy random variables I: Definitions and theorems. Inform. Sci. 15, 1-29] and Puri and Ralescu [Puri, M.L., Ralescu, D.A., 1986. Fuzzy random variables. J. Math. Anal. Appl. 114, 409-422] may be useful for modeling this kind of imprecise problem. In this paper, probability is applied to characterize the uncertainty as to whether jumps occur or not, and what the amplitudes are, while fuzziness is applied to characterize the uncertainty related to the exact number of jump times and the jump amplitudes, due to a lack of knowledge regarding financial markets. This paper presents a fuzzy normal jump-diffusion model for European option pricing, with uncertainty of both randomness and fuzziness in the jumps, which is a reasonable and a natural extension of the Merton [Merton, R.C., 1976. Option pricing when underlying stock returns are discontinuous. J. Financ. Econ. 3, 125-144] normal jump-diffusion model. Based on the crisp weighted possibilistic mean values of the fuzzy variables in fuzzy normal jump-diffusion model, we also obtain the crisp weighted possibilistic mean normal jump-diffusion model. Numerical analysis shows that the fuzzy normal jump-diffusion model and the crisp weighted possibilistic mean normal jump-diffusion model proposed in this paper are reasonable, and can be taken as reference pricing tools for financial investors. 相似文献
66.
Zhang H Le Potier I Smadja C Zhang J Taverna M 《Analytical and bioanalytical chemistry》2006,386(5):1387-1394
An in-capillary derivatization of amino acids and peptides with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) was developed
for their subsequent capillary electrophoretic analysis with laser-induced fluorescence detection (λ
ex=488 nm). The in-capillary derivatization was achieved in zone-passing mode by introducing successive plugs of sample and
NBD-F into a fused silica capillary previously equilibrated with an alkaline borate buffer. To prevent NBD-F hydrolysis and
to achieve a reliable derivatization, NBD-F was prepared daily in absolute ethanol and a plug of absolute ethanol was introduced
between the sample and NBD-F reagent plugs. Various parameters influencing the derivatization efficiency were investigated
and the optimum conditions were as follows: background electrolyte (BGE), 20 mM borate buffer (pH 8.8); introduction time,
4 s for sample and 2 s for NBD-F; molar ratio of NBD-F/sample, above 215; temperature, 45 °C for amino acids and 35 °C for
peptides; applied voltage, +15 kV. The validation of the in-capillary derivatization method under optimal conditions showed
a good linearity between the heights of the derivative peaks and the concentrations of the amino acids. The intra-day relative
standard deviations of the migration times and the peak heights were less than 1.3% and 4.6%, respectively. The efficient
derivatization and separation of a mixture of valine, alanine, glutamic acid and aspartic acid were achieved using this technique.
Peptides such as buccaline and β-protein fragment 1–42 could also be derivatized using the developed in-capillary derivatization
procedure.
In‑capillary derivatization and separation of amino acids with different concentrations.
From the top to bottom the concentrations are 1.11×10−5 M, 5.55×10−6 M, 2.78×10−6 M, 6.95×10−7 M. for valine; 1.26×10−5 M, 6.30×10−6 M, 3.15×10−6 M, 7.88×10−7 M for alanine; 3.78×10−5 M, 1.89×10−5 M, 9.45×10−6 M, 2.36×10−6 M for glutamic acid;, 4.27×10−5 M, 2.14×10−5 M, 1.07×10−5 M, 2.68×10−6 M for aspartic acid.
Experiment conditions: injection order: 4s for sample, 1s for absolute ethanol, and then 2s for 5.24×10−2 M NBD‑F; BGE: 20 mM borate pH 8.77; Applied voltage: 15 kV. 相似文献
67.
We discuss the explicit form of the 2N-mode squeezing operator via N-pair entangled state. We also present the squeezing properties
of the 2N-mode squeezed state and obtain the variances of the 2N-mode quadrature operators in 2N-mode entangled state. 相似文献
68.
Capillary zone electrophoresis for the determination of average hydrodynamic velocity and diffusion coefficient 总被引:2,自引:0,他引:2
Hongyi Zhang Xiurong Song Zhihong Shi Gengliang Yang Zhide Hu 《Fresenius' Journal of Analytical Chemistry》1999,365(6):499-503
The determination of the average hydrodynamic velocity and diffusion coefficient by capillary zone electrophoresis is described.
The present simple method only requires basic experimental data, such as peak area, peak height and migration time to complete
the task of determining the diffusion coefficient and the average hydrodynamic velocity.
Received: 29 September 1998 / Revised: 14 May 1999 / Accepted: 19 May 1999 相似文献
69.
Using the MelJin inversion formulas we derive the weight function for constructing the completeness relation of the boson SU(3) charged and hypercharged coherent state. A suitable contour integration is selected for this derivation. 相似文献
70.
The amt2/m2w order supersymmetric electroweak corrections arising from loops of chargino, neu tralino and squark to top quark pair production by gg fusion at LHC are calculated in the minimal supersymmetric model. We found that the corrections amount about a few percent. 相似文献