[Objective] The aim was to explore the effects of Ca2＋ on the negative phototropism of Chorophytum comosum root.[Method] C.comosum were cultivated in different concentration of CaCl2 solution with unilateral light il...[Objective] The aim was to explore the effects of Ca2＋ on the negative phototropism of Chorophytum comosum root.[Method] C.comosum were cultivated in different concentration of CaCl2 solution with unilateral light illuminated.[Rusult] The Ca2＋ in nutrient solution showed significant effect on the growth and tropic reaction of C.comosum;low concentration of Ca2＋ promoted root growth,while high concentrations of Ca2＋ inhibited the root growth.When the concentration of Ca2＋ was 0.4 mmol/L,the phenomenon of the negative phototropism and the root growth were the most obvious.[Conclusion] The root negative phototropism could be concluded to the comprehensive effect of the endogenous and exogenous Ca2＋.展开更多
Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the...Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest （mainly Qinghai spruce）, and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that： 1） In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2） The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3） The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.展开更多
It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV （photo voltaic）. Togeth...It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV （photo voltaic）. Together with the change on demand side that comes with the global ＂electrification＂, this can lead to serious grid congestion in low voltage grids and massive grid investments in solving this congestion. Smart charging can partly solve this issue, but with using a connected EV （electric vehicle） as a small distribution unit, combined with bi-directional charging or V2G （vehicle-to-grid） technology, these investments can be reduced to a minimum. In Lombok, Utrecht, the Netherlands, an innovative pilot was initiated with smart solar charging stations, shared electric vehicles and AC （alternating current） V2G technology. This unique combination proves that EVs are an opportunity for the grid rather than a threat. A unique partnership with OEM Renault was established to develop an AC V2G vehicle product line and work on open standardized communication between the EV, the charging station and the grid.展开更多
Using a monetary model of exchange rate determination that suggests a strong link between the nominal exchange rate and a set of monetary fundamentals, exchange rate dynamics for the Czech Republic, Hungary, and Polan...Using a monetary model of exchange rate determination that suggests a strong link between the nominal exchange rate and a set of monetary fundamentals, exchange rate dynamics for the Czech Republic, Hungary, and Poland is studied. As the cointegration relationship among exchange rate, output, and the monetary fundamentals （money supply and interest rate） is found, vector autoregressions （VAR）/vector error-correction （VEC） and two-stage least squares （2SLS） error-correction models are used in this context, since both approaches allow estimating short-run correlations between exchange rates and fundamentals while taking into account the existent long-run exchange rate constraints. Based on the quarterly data for the period of 1998-2012, it is found that for all countries, an increase in the money supply, domestic output slowdown, or stronger growth abroad are factors behind a nominal exchange rate depreciation, just as predicted by the monetary model of exchange rate. However, the effects of domestic-foreign interest rate differential are quite heterogeneous, being in line with theoretical predictions of a standard monetary model for Poland only. According to the decomposition of variance, money supply and interest rates account for 30%-46% of the exchange rate variation in the Czech Republic, from 10% to 14% in Hungary, and from 23% to 42% in Poland.展开更多
基金Supported by the Natural Science Foundation of Hubei Province (2006ABA186)the Youth Project of the Provincial Education Department of Hubei Province(Q200727004),the Natural Science Foundation for Youth and Middleages of Provincial Education Department(Q200727003)~~
文摘[Objective] The aim was to explore the effects of Ca2＋ on the negative phototropism of Chorophytum comosum root.[Method] C.comosum were cultivated in different concentration of CaCl2 solution with unilateral light illuminated.[Rusult] The Ca2＋ in nutrient solution showed significant effect on the growth and tropic reaction of C.comosum;low concentration of Ca2＋ promoted root growth,while high concentrations of Ca2＋ inhibited the root growth.When the concentration of Ca2＋ was 0.4 mmol/L,the phenomenon of the negative phototropism and the root growth were the most obvious.[Conclusion] The root negative phototropism could be concluded to the comprehensive effect of the endogenous and exogenous Ca2＋.
基金supported by the Naional 973 project (2009CB421307) the National Natural Science Foundation of China (41030528 and 40971064)
文摘Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest （mainly Qinghai spruce）, and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that： 1） In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2） The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3） The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.
文摘It is to be expected that the number of electric vehicles will be growing in the near future. This trend comes together with the development of smaller decentralized generation units, like PV （photo voltaic）. Together with the change on demand side that comes with the global ＂electrification＂, this can lead to serious grid congestion in low voltage grids and massive grid investments in solving this congestion. Smart charging can partly solve this issue, but with using a connected EV （electric vehicle） as a small distribution unit, combined with bi-directional charging or V2G （vehicle-to-grid） technology, these investments can be reduced to a minimum. In Lombok, Utrecht, the Netherlands, an innovative pilot was initiated with smart solar charging stations, shared electric vehicles and AC （alternating current） V2G technology. This unique combination proves that EVs are an opportunity for the grid rather than a threat. A unique partnership with OEM Renault was established to develop an AC V2G vehicle product line and work on open standardized communication between the EV, the charging station and the grid.
文摘Using a monetary model of exchange rate determination that suggests a strong link between the nominal exchange rate and a set of monetary fundamentals, exchange rate dynamics for the Czech Republic, Hungary, and Poland is studied. As the cointegration relationship among exchange rate, output, and the monetary fundamentals （money supply and interest rate） is found, vector autoregressions （VAR）/vector error-correction （VEC） and two-stage least squares （2SLS） error-correction models are used in this context, since both approaches allow estimating short-run correlations between exchange rates and fundamentals while taking into account the existent long-run exchange rate constraints. Based on the quarterly data for the period of 1998-2012, it is found that for all countries, an increase in the money supply, domestic output slowdown, or stronger growth abroad are factors behind a nominal exchange rate depreciation, just as predicted by the monetary model of exchange rate. However, the effects of domestic-foreign interest rate differential are quite heterogeneous, being in line with theoretical predictions of a standard monetary model for Poland only. According to the decomposition of variance, money supply and interest rates account for 30%-46% of the exchange rate variation in the Czech Republic, from 10% to 14% in Hungary, and from 23% to 42% in Poland.
