Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load tran...Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load transport rate by adopting the sedimentation pit method and resolving such key problems as weighing and desilting, which can achieve long-time, all-weather and real-time telemeasurement of the bed load transport rate of plain rivers, estuaries and coasts. Both laboratory and field tests show that this monitor is reasonable in design, stable in properties and convenient in measurement, and it can be used to monitor the bed load transport rate in practical projects.展开更多
In this paper, a novel scheduling mechanism is proposed to handle the real-time overload problem by maximizing the cumulative values of three types of tasks: the soft, the hard and the imprecise tasks. The simulation...In this paper, a novel scheduling mechanism is proposed to handle the real-time overload problem by maximizing the cumulative values of three types of tasks: the soft, the hard and the imprecise tasks. The simulation results show that the performance of our presented mechanism in this paper is greatly improved, much better than that of the other three mechanisms: earliest deadline first (EDF), highest value first (HVF) and highest density first (HDF), under the same conditions of all nominal loads and task type proportions.展开更多
Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute la...Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute largely to the unreliability of microgrid real-time operation. This paper investigates the behavior of microgrid for different intermittent scenarios of photovoltaic generation in real-time. Reactive power coordination control and load shedding mechanisms are used for reliable operation and are implemented using OPAL-RT simulator integrated with Matlab. In an islanded MG, load shedding can be an effective mechanism to maintain generation-load balance. The microgrid of the German Jordanian University (GJU) is used for illustration. The results show that reactive power coordination control not only stabilizes the MG operation in real-time but also reduces power losses on transmission lines. The results also show that the power losses at some substations are reduced by a range of 6% - 9.8%.展开更多
【目的】建立一种快速、灵敏、特异的检测甘蔗条点病毒(sugarcane striate virus,SStrV)的SYBR Green I荧光定量PCR方法。【方法】从SStrV基因组保守区域序列设计特异性扩增引物,构建含有SStrV基因组序列的重组质粒pMD19-T-SStrV-qN作...【目的】建立一种快速、灵敏、特异的检测甘蔗条点病毒(sugarcane striate virus,SStrV)的SYBR Green I荧光定量PCR方法。【方法】从SStrV基因组保守区域序列设计特异性扩增引物,构建含有SStrV基因组序列的重组质粒pMD19-T-SStrV-qN作为阳性质粒标准品,以其为模板建立SStrV荧光定量PCR检测方法,并对该方法的灵敏性、特异性、稳定性进行了测试,随后用该方法对甘蔗不同组织部位中SStrV载量进行检测。【结果】将含有SStrV基因组序列的重组质粒按10倍比稀释成标准品,将其作为模板进行荧光定量PCR,获得标准曲线y=-3.337 x+38.197,相关系数r2=0.999,说明Cq值与标准品浓度拷贝数的对数呈线性关系;建立的荧光定量PCR最低可以检测到13拷贝重组质粒/μL,是普通PCR灵敏度的100倍。该方法能特异的检测SStrV,特异性高,组内和组间的变异系数在0.13%-0.94%之间,表明该方法重复性良好。SStrV的载量在甘蔗的不同组织部位中差异较大,+4叶中SStrV的载量最高,与其他组织部位达到了显著差异。【结论】建立了能灵敏特异检测SStrV的SYBR Green I荧光定量PCR方法,明确了+4叶是甘蔗中SStrV检测的最佳采样部位。展开更多
基金supported by the special program to enhance the navigation capacity of the Golden Waterway funded by the Ministry of Transport of the People’s Republic of China"Research on Key Techniques to Monitor and Simulate the River Flow and Sediment Transport"(Grant No.2011-328-746-40)
文摘Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load transport rate by adopting the sedimentation pit method and resolving such key problems as weighing and desilting, which can achieve long-time, all-weather and real-time telemeasurement of the bed load transport rate of plain rivers, estuaries and coasts. Both laboratory and field tests show that this monitor is reasonable in design, stable in properties and convenient in measurement, and it can be used to monitor the bed load transport rate in practical projects.
基金supported by the Shanghai Applied Materials Foundation (Grant No.06SA18)
文摘In this paper, a novel scheduling mechanism is proposed to handle the real-time overload problem by maximizing the cumulative values of three types of tasks: the soft, the hard and the imprecise tasks. The simulation results show that the performance of our presented mechanism in this paper is greatly improved, much better than that of the other three mechanisms: earliest deadline first (EDF), highest value first (HVF) and highest density first (HDF), under the same conditions of all nominal loads and task type proportions.
文摘Microgrid (MG) systems effectively integrate a generation mix of solar, wind, and other renewable energy resources. The intermittent nature of renewable resources and the unpredictable weather conditions contribute largely to the unreliability of microgrid real-time operation. This paper investigates the behavior of microgrid for different intermittent scenarios of photovoltaic generation in real-time. Reactive power coordination control and load shedding mechanisms are used for reliable operation and are implemented using OPAL-RT simulator integrated with Matlab. In an islanded MG, load shedding can be an effective mechanism to maintain generation-load balance. The microgrid of the German Jordanian University (GJU) is used for illustration. The results show that reactive power coordination control not only stabilizes the MG operation in real-time but also reduces power losses on transmission lines. The results also show that the power losses at some substations are reduced by a range of 6% - 9.8%.
文摘【目的】建立一种快速、灵敏、特异的检测甘蔗条点病毒(sugarcane striate virus,SStrV)的SYBR Green I荧光定量PCR方法。【方法】从SStrV基因组保守区域序列设计特异性扩增引物,构建含有SStrV基因组序列的重组质粒pMD19-T-SStrV-qN作为阳性质粒标准品,以其为模板建立SStrV荧光定量PCR检测方法,并对该方法的灵敏性、特异性、稳定性进行了测试,随后用该方法对甘蔗不同组织部位中SStrV载量进行检测。【结果】将含有SStrV基因组序列的重组质粒按10倍比稀释成标准品,将其作为模板进行荧光定量PCR,获得标准曲线y=-3.337 x+38.197,相关系数r2=0.999,说明Cq值与标准品浓度拷贝数的对数呈线性关系;建立的荧光定量PCR最低可以检测到13拷贝重组质粒/μL,是普通PCR灵敏度的100倍。该方法能特异的检测SStrV,特异性高,组内和组间的变异系数在0.13%-0.94%之间,表明该方法重复性良好。SStrV的载量在甘蔗的不同组织部位中差异较大,+4叶中SStrV的载量最高,与其他组织部位达到了显著差异。【结论】建立了能灵敏特异检测SStrV的SYBR Green I荧光定量PCR方法,明确了+4叶是甘蔗中SStrV检测的最佳采样部位。