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排序方式: 共有1413条查询结果,搜索用时 15 毫秒
991.
Yoshihiro Terashima Kei Hamazaki Miho Itomura Shin Tomita Masahiro Kuroda Hitoshi Hirata Tomohito Hamazaki Hidekuni Inadera 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(3):625-631
We have previously conducted a cohort study to investigate n‐3 polyunsaturated fatty acids (PUFAs) in red blood cells (RBCs) and risk of all‐cause mortality in hemodialysis (HD) patients over 5 years and found that n‐3 PUFAs, especially docosahexaenoic acid (DHA), might be an independent predictor of all‐cause mortality. In the present study, we extended the study for another 5 years to determine whether DHA levels in RBCs still predict the mortality of HD patients during a 10‐year study period. The study cohort consisted of 176 patients (64.1 ± 12.0 [mean ± standard deviation] years of age, 96 men and 80 women) under HD treatment. The fatty acid composition of patients' RBCs was analyzed by gas chromatography. During the study period of 10 years, 97 deaths occurred. After adjustment for 10 confounding factors, the hazard ratio of all‐cause mortality of the HD patients in the highest DHA tertile (>8.1%) was 0.52 (95% confidence interval 0.30–0.91) compared with those in the lowest DHA tertile (<7.2%). However, other n‐3 PUFAs such as eicosapentaenoic acid and docosapentaenoic acid (n‐3) did not reveal any significant correlations. The level of DHA in RBCs could be an independent predictor of all‐cause mortality in HD patients even during a long period of follow‐up. 相似文献
992.
The formation of β‐damascenone during shochu manufacture was investigated by quantifying β‐damascenone at each stage of manufacturing. Steamed sweet potato has a low level of free β‐damascenone (0.02–0.1 μg/g). During fermentation, β‐damascenone was produced in small quantities that were degraded by yeast. Thus, the second mash accumulates little free β‐damascenone (approximately 17 μg/L). The concentration profile in the fractionated distillate showed that β‐damascenone was produced during heating. Most β‐damascenone in shochu was formed during distillation, not during steam heating and fermentation. It is suggested that the level of β‐damascenone in shochu could be increased by reducing the pH of the second mash and prolonging the distillation period. Sweet potato cultivars differed in total free and hydrolyzed β‐damascenone content and there was a strong association between each cultivar and its shochu β‐damascenone content. The selection of the sweet potato cultivar is important for determining the quantity of β‐damascenone in a shochu brew. 相似文献
993.
Junji Kawata Takaaki Kinouchi Yoshihiro Yamagami Yoshifumi Nishio Akio Ushida 《International Journal of Circuit Theory and Applications》2012,40(3):247-262
We propose here a Spice‐oriented envelope analysis based on the HB (harmonic balance) method, where Fourier coefficients are assumed to be slowly varying. The Fourier expansions of nonlinear devices are executed by MATLAB in the symbolic forms. In this time, the nonlinearities need to be approximated by the polynomial functions. The determining equation of the HB method is formulated as Sine–Cosine circuit in the form of schematic diagram using ABMs (analog behavior models) of Spice. Each sub‐circuit corresponding to the higher harmonic component is almost the same circuit topology as the original one and has dynamic elements such as capacitors and inductors. The Sine–Cosine circuit can be solved by the transient analysis of Spice. Thus, our method is rather a symbolic approach in the meaning that the HB determining equation is given by the schematic diagram of Spice. Our method can be easily applied to the analysis of middle order of nonlinear communication circuits such as mixers and amplitude modulators and to the analysis of interesting phenomena in the nonlinear oscillations. After many simulation experiments, the results show that our envelope analysis is about 50 times faster than the direct transient analysis. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
994.
995.
This paper discusses a global optimization method of robust truss topology under the load uncertainties and slenderness constraints
of the member cross-sectional areas. We consider a non-stochastic uncertainty of the external load, and attempt to minimize
the maximum compliance corresponding to the most critical load. A design-dependent uncertainty model in the external load
is proposed in order to consider the variation of truss topology rigorously. It is shown that this optimization problem can
be formulated as a 0–1 mixed integer semidefinite programming (0–1MISDP) problem. We propose a branch-and-bound method for
computing the global optimal solution of the 0–1MISDP. Numerical examples illustrate that the topology of robust optimal truss
depends on the magnitude of uncertainty. The presented method can provide global optimal solutions for benchmark examples,
which can be used for evaluating the performance of any other local optimization method for robust structural optimization. 相似文献
996.
Crystal evaluation of spherical silicon produced by dropping method and their solar cell performance
Satoshi Omae Takashi Minemoto Mikio Murozono Hideyuki Takakura Yoshihiro Hamakawa 《Solar Energy Materials & Solar Cells》2006,90(20):3614-3623
The characterization of silicon spheres 1 mm in diameter, which were produced by a dropping method and solar cell performance using spheres are reported. Scanning electron microscopy observations of the Si spheres after Dash etching and X-ray pole figures indicate that the spherical Si has many defects and crystal grains. Systematic study of the crystal growth temperature and the atmosphere in the dropping area yields improvements in the crystallinity as well as a decrease in the concentrations of oxygen and carbon. Moreover, the spherical Si solar cell performance improved because these impurities are the prime factor for recombination centers. 相似文献
997.
This study compares the performance of popular sampling methods for computer experiments using various performance measures to compare them. It is well known that the sample points, in the design space located by a sampling method, determine the quality of the meta-model generated based on expensive computer experiment (or simulation) results obtained at sample (or training) points. Thus, it is very important to locate the sample points using a sampling method suitable for the system of interest to be approximated. However, there is still no clear guideline for selecting an appropriate sampling method for computer experiments. As such, a sampling method, the optimal Latin hypercube design (OLHD), has been popularly used, and quasi-random sequences and the centroidal Voronoi tessellation (CVT) have begun to be noticed recently. Some literature on the CVT asserted that the performance of the CVT was better than that of the LHD, but this assertion seems unfair because those studies only employed space-filling performance measures in favor of the CVT. In this research, we performed the comparison study among the popular sampling methods for computer experiments (CVT, OLHD, and three quasi-random sequences) with employing both space-filling properties and a projective property as performance measures to fairly compare them. We also compared the root mean square error (RMSE) values of Kriging meta-models generated using the five sampling methods to evaluate their prediction performance. From the comparison results, we provided a guideline for selecting appropriate sampling methods for some systems of interest to be approximated. 相似文献
998.
Alexandre Donizeti Alves Horacio Hideki Yanasse Nei Yoshihiro Soma 《Scientometrics》2014,98(1):173-184
Benford’s Law is a logarithmic probability distribution function used to predict the distribution of the first significant digits in numerical data. This paper presents the results of a study of the distribution of the first significant digits of the number of articles published of journals indexed in the JCR® Sciences and Social Sciences Editions from 2007 to 2011. The data of these journals were also analyzed by the country of origin and the journal’s category. Results considering the number of articles published informed by Scopus are also presented. Comparing the results we observe that there is a significant difference in the data informed in the two databases. 相似文献
999.
Study on using hydrogen and ammonia as fuels: Combustion characteristics and NOx formation 下载免费PDF全文
This paper evaluates the potential of hydrogen (H2) and ammonia (NH3) as carbon‐free fuels. The combustion characteristics and NOx formation in the combustion of H2 and NH3 at different air‐fuel equivalence ratios and initial H2 concentrations in the fuel gas were experimentally studied. NH3 burning velocity improved because of increased amounts of H2 atom in flame with the addition of H2. NH3 burning velocity could be moderately improved and could be applied to the commercial gas engine together with H2 as fuels. H2 has an accelerant role in H2–NH3–air combustion, whereas NH3 has a major effect on the maximum burning velocity of H2–NH3–air. In addition, fuel‐NOx has a dominant role and thermal‐NOx has a negligible role in H2–NH3–air combustion. Thermal‐NOx decreases in H2–NH3–air combustion compared with pure H2–air combustion. NOx concentration reaches its maximum at stoichiometric combustion. Furthermore, H2 is detected at an air‐fuel equivalence ratio of 1.00 for the decomposition of NH3 in flame. Hence, the stoichiometric combustion of H2 and NH3 should be carefully considered in the practical utilization of H2 and NH3 as fuels. H2 as fuel for improving burning performance with moderate burning velocity and NOx emission enables the utilization of H2 and NH3 as promising fuels. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
1000.