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This paper proposes a policy enforcement framework to dynamically verify and control the collaboration process in Service-Oriented Architecture (SOA). Dynamic SOA collaboration is different from traditional service collaboration w...
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This paper proposes a policy enforcement framework to dynamically verify and control the collaboration process in Service-Oriented Architecture (SOA). Dynamic SOA collaboration is different from traditional service collaboration where the workflow is pre-defined at design time while the services used can be discovered at runtime. In dynamic collaboration, both the workflows and services can be determined at runtime. As they will be determined at runtime, many verification activities can be performed at runtime. This paper proposes a dynamic policy enforcement framework that follows the dynamic SOA collaboration process to ensure that various system constraints can be enforced at runtime. The framework includes a policy specification language, a policy completeness and consistency checking, and distributed policy enforcement. Finally, this paper presents the construction of a sample example to illustrate these features with quantitative performance data.
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Microcystins (MCs) are potent hepatotoxins and have also implicated in liver tumor promotion. The present study investigates the temporal and spatial variations of MCs in different water bodies in the Huai River Basin in China. Wa...
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Microcystins (MCs) are potent hepatotoxins and have also implicated in liver tumor promotion. The present study investigates the temporal and spatial variations of MCs in different water bodies in the Huai River Basin in China. Water samples including rivers, ponds and wells were collected every quarter during December 2008 and December 2009. MCs were determined by high pressure liquid chromatography after solid phase extraction. MCs concentrations in river samples were 0.741 ± 0.623 μg L~(-1) with maximum of 1.846 μg L~(-1). MCs in pond were 0.597 ± 0.960 μg L~(-1) with maximum of 2.298 μg L~(-1)MCs were also detected in 51.7% of the groundwater samples, MCs in groundwater were 0.060 ± 0.085 μg L~(-1) with maximum of 0.446 μg L~(-1) MCs concentrations in groundwater did not differ significantly among different depths or towns (Wilcoxon test, p > 0.05). The average MCs in groundwater in each sampling period were 0.068 μg L~(-1),0.118 μg L~(-1), 0.052 μg L~(-1), 0.059 μg L~(-1) and 0.020 μg L~(-1). Through multi linear regression, the best fit model was built on MCs in groundwater with River B (R~2 = 0.13, p < 0.05), rather than with pond water. The results suggested that MCs contamination in groundwater originated from rivers, causing potential health risk on population who drink groundwater directly.
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Phase-controlled synthesis of bismuth ferrites has been achieved via hydrothermal route by adjusting the KOH concentration. The as-prepared powders were characterized by X-ray diffraction, field-emission scanning electron microsco...
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Phase-controlled synthesis of bismuth ferrites has been achieved via hydrothermal route by adjusting the KOH concentration. The as-prepared powders were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction. The particle morphologies of the as-prepared powders evolve from nanoflakes, to self-assembled particles, and microparticles when the concentration of KOH was changed from 1.5 M, 2.5 M, to 3.5 M, and 5 M. Correspondingly, the main phase of the samples changed from orthorhombic Bi_2Fe_4O_9, both Bi_2Fe_4O_9 and BiFeO_3, to pure rhombohedral BiFeO_3. On the basis of these experiments, the phase formation and morphology evolution mechanism of the samples are discussed. Furthermore, the photocatalytic activity of the as-prepared samples was investigated by the photo-degradation of rhodamine-B solution.
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Single-crystal SrTiO_3 dendritic nanostructures were synthesized for the first time via a simple hydrothermal method without any surfactant. Structure characterizations suggest that the SrTiO_3 dendrites show preferential orientat...
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Single-crystal SrTiO_3 dendritic nanostructures were synthesized for the first time via a simple hydrothermal method without any surfactant. Structure characterizations suggest that the SrTiO_3 dendrites show preferential orientation along [110]. Additionally, it is found that KOH concentration plays an important role in the formation of SrTiO_3 dendrites, and the morphology of SrTiO_3 crystallites can vary from cubic-like, star-like to dendritic shape. A rational mechanism is proposed to illustrate the growth of SrTiO_3 dendrites.
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To investigate the expression of mRNA of leptin long-form receptor (OB-Rb) in luteinized granulosa cells of obese women with polycystic ovary syndrome (PCOS), and to determine the role of leptin in the physiopathology of PCOS, lut...
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To investigate the expression of mRNA of leptin long-form receptor (OB-Rb) in luteinized granulosa cells of obese women with polycystic ovary syndrome (PCOS), and to determine the role of leptin in the physiopathology of PCOS, luteinized granulosa cells were collected from the follicle fluid of 10 obese women who met the diagnostic criteria for PCOS and their BMI was equal to or greater than 25 kg/m~2, and at the same time, granulosa cells were collected from 10 normal women undergoing IVF-ET who served as the control group. Some luteinized granulosa cells were taken from normal women for in-vitro culture, into which human leptin of different concentrations was added (0, 10, 100 and 1000 ng/mL). After stimulation with leptin for 48 h, RT-PCR was employed for the detection of the expression of OB-R_LmRNA in the luteinized granulosa cells. Our results showed that the level of OB-R_LmRNA in luteinized granulosa cells of obese PCOS women was higher than those in the control (P< 0.05). In luteinized granulosa cells cultured in vitro and stimulated by human leptin for 48 h, the level of OB-R_LmRNA was higher than those without leptin stimulation (P< 0.01), and when leptin concentration was at 100 ng/mL, and the level of OB-R_LmRNA reached a peak. It is concluded that in obese PCOS women, the level of serum leptin is increased, which promotes the expression of OB-R_L in luteinized granulosa cells and increases the sensitivity of the granulosa cells to leptin. Leptin may contribute to anovulation in obese women with PCOS.
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