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991.
Dejun Luo 《Potential Analysis》2014,41(3):903-915
Using the log-Sobolev inequality, we shall present in this note some estimates on the density of finite dimensional non-degenerate Wiener functionals which are independent on the dimension. We shall take the Gaussian measure as the reference measure, contrary to the customary choice of Lebesgue measure in the literature. As an application, we show that the limit in probability of a uniformly bounded sequence of non-degenerate Wiener functionals has a density with respect to the Gaussian measure. 相似文献
992.
The relative risk/prevalence ratio and odds ratio are very popular in medical research and epidemiological studies. The odds ratio is overused in practice due to its direct relation with the logistic regression. Interpreting the odds ratio in terms of “relative risk” may lead to incorrect inference on the prevalence of certain event. In this paper, we propose to estimate the relative risk using the log-binomial model by maximizing the likelihood with a linear constraint, which can be easily implemented by an existing function, such as “constrOptim” in R. Furthermore, we review other existing methods and compare their performance under a variety of settings using simulated data. We suggest the proposed and COPY methods in practice, based on its performance in the simulations. For illustration, we investigate the vigorous physical activity effects on obesity using data from the National Health and Nutrition Examination Survey, and the treatment effects on lung cancer mortality using data in R. 相似文献
993.
994.
995.
Zhiting Jiang Qionglin Liang Yong Wang Xiaoying Zheng Lijun Pei Ting Zhang Yiming Wang Guoan Luo 《Biomedical chromatography : BMC》2011,25(7):767-774
Nutritional intervention is effective in reducing the risk of neural tube defects (NTDs). To determine the effects of nutritional supplementation on human metabolism, a metabonomic study was carried out on 96 women of reproductive age. Subjects with nutritional intervention were given fortified wheat flour (containing folic acid, vitamin B1, vitamin B2, ferric sodium edetate and zinc oxide) for 8 months. Serum metabolic fingerprinting was detected via ultraperformance liquid chromatography in tandem with time‐of‐flight mass spectrometry (UPLC‐TOF MS), and data acquired was processed by multivariate statistical analysis. The result revealed a significant difference between the control and intervention group. Twenty potential biomarkers, including fructose 6‐phosphate, sphingosine 1‐phosphate, docosahexaenoic acid and hexadecanoic acid, were located and identified by the accurate mass measurement of TOF MS. These compounds are believed to be functionally related to anti‐oxidative competence in vivo. In conclusion, metabonomics study is a valuable approach in exploring the effect mechanism of nutritional intervention on NTD prevention. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
996.
Xiaofeng Luo Naiwen Kang Lei Li Jianping Deng Wantai Yang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(7):1661-1668
This article reports a class of nanoscale materials, that is, optically active nanoparticles consisting of helical‐substituted polyacetylenes. Such nanoparticles were prepared via aqueous catalytic miniemulsion polymerization, by which nanoparticles with a wide range of size (diameter: 60–400 nm) can be easily prepared. The nanoparticles could be obtained in quantitative monomer conversions. Large specific rotations and intense circular dichroism effects demonstrated that the nanoparticles possessed large optical activities; moreover, the optical activities were found to increase with a decrease in particle size. From the obtained polymer nanoparticles and with poly(vinyl alcohol) (PVA) as supporting material, composite films were further prepared and also exhibited considerable optical activities. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1661–1668, 2010 相似文献
997.
We explore the theoretical and numerical application of local regularization methods to an ill-posed inverse problem arising from financial option pricing. In addition, we provide an algorithm and show results through numerical examples. 相似文献
998.
999.
Y.F. Lu S.M. Huang C.H.A. Huan X.F. Luo 《Applied Physics A: Materials Science & Processing》1999,68(6):647-651
It is demonstrated that a liquid hydrocarbon precursor, cyclohexane, is appropriate for laser-induced carbon deposition. Amorphous
hydrogenated carbon films (a-C:H) were deposited by KrF excimer laser irradiation of single-crystal silicon surface immersed
under cyclohexane. The technique is simple and easy to operate. IR absorption spectra of the deposited films confirmed the
presence of carbon in the diamond phase. Raman and XPS studies showed diamond-like character of the deposited films. Moreover,
these two studies provided strong evidence that laser fluence played an important role in the formation of DLC bondings and
the quality of the deposited films.
Received: 15 September 1998 / Accepted: 5 January 1999 / Published online: 5 May 1999 相似文献
1000.
The energy increment spectrum method is developed for the numerical prediction of the appearance and disappearance of a primary (2M: 1)-librational or (M: 1)-rotational resonant separatrix band in a parametrically excited pendulum. The analytical conditions for the presence of such separatrix bands are also obtained. Illustrations of the analytical and numerical results for the appearance and destruction of the resonant bands are given for a comparison. 相似文献