Dalian, Shenyang, Changchun and Harbin are the four core cities which play an essential role in terms of promoting the economic development in Northeast China. In this paper, the impact of urban agglomeration on labor...Dalian, Shenyang, Changchun and Harbin are the four core cities which play an essential role in terms of promoting the economic development in Northeast China. In this paper, the impact of urban agglomeration on labor productivity is explored by making comparisons among these four cities. The model used for analysis is a classical model derived from previous studies. Some indicators, such as population density and economic density, were selected to examine the impact of urban agglomeration on the labor productivity based on the time-series data for the four cities from 1990 to 2007. The four main conclusions are： l） The promotion from the growth rate of population density on the growth rate of labor productivity is limited. 2） The negative relationship exists between the growth rate of employment density and the growth rate of labor productivity. 3） Agglomeration effect exists in the four cities, the highest one is Dalian, Shenyang takes the second place, followed by Changchun and Harbin, and the predominant promotion exerted on the labor productivity is the output density.展开更多
Root-Knot Nematodes （RKN） Meloidogyne spp. significantly affects glasshouse tomatoes in Central Greece. Elimination or halting J2s could be an efficient strategy to control RKN. Recently, it was reported that a comm...Root-Knot Nematodes （RKN） Meloidogyne spp. significantly affects glasshouse tomatoes in Central Greece. Elimination or halting J2s could be an efficient strategy to control RKN. Recently, it was reported that a commercial product of Neem （Azadirachta indica） seed extract （Azadirachtin 1% Emulsion Concentrate-EC） significantly reduced the number of galls on tomato roots and egg masses, compared to the untreated control. In the present study neem proved to have a direct immobilising effect on RKN J2s. Different concentrations （0, 0.05, 0,1, 0.25, 0.5, I, 5, 10, 25 and 50%） of the tested neem product were applied with water containing fresh J2s and in soil naturally infected with RKN. Records of immobilised J2s were taken after 10 min, 1 h, 6 h, 24 h and 72 h of Neem application in water and after six days of neem application into the soil. Neem solution concentrations 5% and 10%, resulted in 85% ± 3.2 and 100% of immobilised J2s. The same concentrations of neem when were added in the water for nematode extraction from the soil, resulted 14.25% ± 4.01 and 1.7%, of J2s extracted from the soil with a significant concentration effect （P = 0.008）, compared to the untreated control. However, the neem product at high application dose significant damage the tomato plants caused phytoxicity.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 41071088)National Social Science Foundation of China (No. 08BJY056)
文摘Dalian, Shenyang, Changchun and Harbin are the four core cities which play an essential role in terms of promoting the economic development in Northeast China. In this paper, the impact of urban agglomeration on labor productivity is explored by making comparisons among these four cities. The model used for analysis is a classical model derived from previous studies. Some indicators, such as population density and economic density, were selected to examine the impact of urban agglomeration on the labor productivity based on the time-series data for the four cities from 1990 to 2007. The four main conclusions are： l） The promotion from the growth rate of population density on the growth rate of labor productivity is limited. 2） The negative relationship exists between the growth rate of employment density and the growth rate of labor productivity. 3） Agglomeration effect exists in the four cities, the highest one is Dalian, Shenyang takes the second place, followed by Changchun and Harbin, and the predominant promotion exerted on the labor productivity is the output density.
文摘Root-Knot Nematodes （RKN） Meloidogyne spp. significantly affects glasshouse tomatoes in Central Greece. Elimination or halting J2s could be an efficient strategy to control RKN. Recently, it was reported that a commercial product of Neem （Azadirachta indica） seed extract （Azadirachtin 1% Emulsion Concentrate-EC） significantly reduced the number of galls on tomato roots and egg masses, compared to the untreated control. In the present study neem proved to have a direct immobilising effect on RKN J2s. Different concentrations （0, 0.05, 0,1, 0.25, 0.5, I, 5, 10, 25 and 50%） of the tested neem product were applied with water containing fresh J2s and in soil naturally infected with RKN. Records of immobilised J2s were taken after 10 min, 1 h, 6 h, 24 h and 72 h of Neem application in water and after six days of neem application into the soil. Neem solution concentrations 5% and 10%, resulted in 85% ± 3.2 and 100% of immobilised J2s. The same concentrations of neem when were added in the water for nematode extraction from the soil, resulted 14.25% ± 4.01 and 1.7%, of J2s extracted from the soil with a significant concentration effect （P = 0.008）, compared to the untreated control. However, the neem product at high application dose significant damage the tomato plants caused phytoxicity.
