757 research outputs found

    关于二阶二、三、四点边值问题的上下解方法

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    运用上下解方法研究二阶边值问题这里0<α≤b<1,α,β,γ,δ,ζ,η>0,A,B均为给定的实数,且ρ:=αγ+αδ+βγ>0,f为满足Nagumo条件的Caratheodary函数.此问题有解当且仅当有一个上解y和一个下解x,且对所有的0≤t≤1,都有x(t)≤y(t)

    Bimetallic nano-structured glucose sensing electrode composed of copper atoms deposited on gold nanoparticles

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    We describe the preparation and sensing capabilities of a bimetallic electrode consisting of copper atoms deposited on gold nanoparticles (GNPs). The electrode was obtained by first constructing a GNP template on the surface of a glassy carbon electrode by exploiting the hydrogen-bonding interactions between pyridine groups on the surface of the GNPs and the carboxy groups of poly (acrylic acid). GNPs (60 nm in diameter) were homogeneously and densely deposited in the template (as revealed by scanning electron microscopy). The electro-deposition of copper ad-atoms on GNPs occurred at an underpotential and was proven by electrochemical techniques. The presence of GNPs in the template accelerated the deposition at low potential due to its beneficial effect on the rate of electron transfer. The new electrode was studied for its response to glucose. Highly stable and reproducible catalytic activity towards glucose oxidation is observed and attributed to the synergistic catalytic effect of the copper atoms on the surface of the GNPs. The detection limit is as low as 50 nM (at a signal-to-noise ratio of 3), and the response is between 200 nM and 10 mM of glucose

    Co-infections with Plasmodium knowlesi and Other Malaria Parasites, Myanmar

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    To determine the frequency of co-infections with Plasmodium species in southern Myanmar, we investigated the prevalence of P. knowlesi. More than 20% of patients with malaria had P. knowlesi infection, which occurred predominantly as a co-infection with either P. falciparum or P. vivax

    Sturm-Liouville边值问题的多解结果

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    利用锥映射的不动点指数证明了含参数λ>0的Sturm Liouvile边值问题至少存在两个正解大庆石油学院自然科学基

    关于奇异非线性两点边值问题的一点注记

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    在k(x)具有较强奇性的情况下证明了奇异非线性两点边值问题正解的存在性.同时提出了一个C1正解存在的充要条件

    用离散速度方法计算浅水长波方程

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    国家自然科学基金资助项目 (1970 2 0 0 5 )用离散速度法计算浅水波方程 ,将空气动力学方程和浅水波方程作了比较 ,用 Nadiga提出的近平衡流动方法模拟浅水波方程的连续和间断解。计算了一维的溃坝波问题和 Thacker提出的连续解问题 ,结果与精确解作了比较 ,并且计算了水流跃过障碍物的问

    奇异二阶三点边值问题的正解

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    应用锥中的不动点定理研究奇异二阶三点边值问题的正解的存在性· 采用一种构造Green函数的方法为出发点 ,利用分段定义算子的手法讨论更一般的奇异二阶三点边值问题· 得到了一个正解的存在性定理· 其中的非线性项可以是变号的·江苏省教育基金资助项

    Positive Entire Solutions to an Elliptic System

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    ThesecondauthorissupportedbyNNSF ( 199710 36 )ofChina

    POSITIVE SOLUTIONS TO A SINGULAR SECOND ORDER THREE-POINT BOUNDARY VALUE PROBLEM

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    the Educational Foundation of Jiangshu Provinc

    Response of innate immune factors in abalone Haliotis diversicolor supertexta to pathogenic or nonpathogenic infection

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    Cell free hemolymph from Haliotis diversicolor supertexta was prepared from fluid collected at 1, 4, 8. 12. 24, 48 96 It after injection with either Escherichia coli, Vibrio parahaemolyticus or 0.9 NaCl solution (control group). The response of selected innate immune parameters (lysozyme, antibacterial activity, alkaline phosphatase, acid phosphatase, phenoloxidase, and superoxide dismutase) was investigated. Results showed that the activities of ACP (Acid Phosphatase) from abalone injected with V. parahaemolyticus were much higher than that of the control group at 24 h after injection. The ALP (Alkaline Phosphatase) activities of abalone challenged with V. parahaemolyticus were significantly higher than those of the control group at 8 h and increased further up to 48 h after the challenge. In contrast, the activities of ALP and ACP in the E. coli-challenged group showed no statistically significant differences at any of the sampling times. The activities of SOD (Superoxide Dismutase) in cell free hemolymph from the V. parahaemolyticus-exposed group were significantly lower than those of the control group at both I h and 24 h, whereas there was no difference in SOD activity observed in the group exposed to E. coli at any of the sampling times. The activities of lysozyme and phenoloxidase in Haliotis diversicolor were relatively low in both control and bacteria-ex posed groups when compared with reports for other invertebrates no significant difference was found between the infected groups and the control for these two parameters, due to the low activities and high individual variance
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