[Objective] The aim was to explore effects of silicon at different concentrations on morphology and photosynthetic physiological mechanism of japonica rice. [Method] Seedlings of japonica rice were treated with silico...[Objective] The aim was to explore effects of silicon at different concentrations on morphology and photosynthetic physiological mechanism of japonica rice. [Method] Seedlings of japonica rice were treated with silicon at different concentrations （0, 30, 80, 130 and 180 mg/L of sodium silicate）; silicon contents were measured with Molybdenum blue spectrophotometric method in root, stem and leaf; plant height, root length and number in different treatment groups were measured with tools; chlorophyll a and b, and a/b in leaf and stem of rice in different groups were measured. [Result] Silicon contents in vegetative organs were as follows： stem〉leaf〉 root; when silicon was 80 mg/L, japonica ecotype was shortest; when silicon was 30 mg/L, root length of the rice was shortest and root number was least; when silicon was 30 mg/L, contents of chlorophyll a and b were highest and chlorophyll a/b achieved the peak when silicon was 80 mg/L. [Conclusion] Silicon at proper concen- tration would improve lodging-resistance and efficiency of photosynthesis, further enhancing yield of japonica rice.展开更多
The paper deals with the energy and indoor comfort on buildings of UPF （University ofPasso Fundo）, located in southern Brazil, in order to improve the eco-efficiency concepts in the university＇s building stock, rei...The paper deals with the energy and indoor comfort on buildings of UPF （University ofPasso Fundo）, located in southern Brazil, in order to improve the eco-efficiency concepts in the university＇s building stock, reinforcing its responsibility towards sustainable development. The factors that affect thermal performance and the energy consumption of two case studies were identified, including the general characteristics of the envelope and the indoor conditions. The simulations with DesignBuilder software compare the energy and thermal performance of both cases： those results allow the identification of their positive and negative aspects, as well as making a co-relation with the students＇ sensations of comfort--obtained through PMV （predicted mean vote）. The research indicates that it will be possible to improve eco-efficiency of existing and new buildings and campuses by retrofitting and upgrading it with regard to better indoor conditions that really correspond to climate conditions （hot and humid summers, and cold and damp winters）, using passive strategies for heating and cooling and at the same time to improve rational use of natural resources and to reduce the environmental impact. Probably, giving comfortable conditions to the users will increase energy consumption, but there is a potential reduction of lighting and equipment that could minimize this impact.展开更多
We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of sp...We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of species richness,abundance,diversity and cell density.In regression analysis,all these algal attributes were negatively correlated with the depth gradients at P<0.05.In terms of species richness,the bacillariophytes showed dominance over the cyanophytes and chlorophytes;whereas with respect to standing crop,the cyanophytes showed dominance over the bacillariophytes and chlorophytes.The chlorophyll a was higher at the mid and bottom-depths than the surface-depth in both the downstream and upstream sites,which showed that vertical productivity or biomass accumulation was greater in low light irradiance.The product-moment correlation analysis showed that conductivity,turbidity,dissolved oxygen,reactive phosphate and ammonium-nitrogen were highly correlated with the algal assemblage data.However,photosynthetic active radiation(PAR) showed poor correlation with the community data.These observations have cast some light on the autoecological characteristics,habitat preferences and environmental responses of tropical periphytic communities.展开更多
The varied altitudinal gradient of climate and vegetation is further complicated by mass elevation effect(MEE), especially in high and extensive mountain regions. However, this effect and its implications for mountain...The varied altitudinal gradient of climate and vegetation is further complicated by mass elevation effect(MEE), especially in high and extensive mountain regions. However, this effect and its implications for mountain altitudinal belts have not been well studied until recently. This paper provides an overview of the research carried out in the past 5 years. MEE is virtually the heating effect of mountain massifs and can be defined as the temperature difference on a given elevation between inside and outside of a mountain mass. It can be digitally modelled with three factors of intra-mountain base elevation(MBE), latitude and hygrometric continentality; MBE usually acts as the primary factor for the magnitude of MEE and, to a great extent, could represent MEE. MEE leads to higher treelines in the interior than in the outside of mountain masses. It makes montane forests to grow at 4800–4900 m and snowlines to develop at about 6000 m in the southern Tibetan Plateau and the central Andes, and large areas of forests to live above 3500 m in a lot of high mountains of the world. The altitudinal distribution of global treelines can be modelled with high precision when taking into account MEE and the result shows that MEE contributes the most to treeline distribution pattern. Without MEE, forests could only develop upmost to about 3500 m above sea level and the world ecological pattern would be much simpler. The quantification of MEE should be further improved with higher resolution data and its global implications are to be further revealed.展开更多
基金Supported by Outstanding Young and Middle-aged Talent Program of Hubei Provincal Department of Education(Q20102501)~~
文摘[Objective] The aim was to explore effects of silicon at different concentrations on morphology and photosynthetic physiological mechanism of japonica rice. [Method] Seedlings of japonica rice were treated with silicon at different concentrations （0, 30, 80, 130 and 180 mg/L of sodium silicate）; silicon contents were measured with Molybdenum blue spectrophotometric method in root, stem and leaf; plant height, root length and number in different treatment groups were measured with tools; chlorophyll a and b, and a/b in leaf and stem of rice in different groups were measured. [Result] Silicon contents in vegetative organs were as follows： stem〉leaf〉 root; when silicon was 80 mg/L, japonica ecotype was shortest; when silicon was 30 mg/L, root length of the rice was shortest and root number was least; when silicon was 30 mg/L, contents of chlorophyll a and b were highest and chlorophyll a/b achieved the peak when silicon was 80 mg/L. [Conclusion] Silicon at proper concen- tration would improve lodging-resistance and efficiency of photosynthesis, further enhancing yield of japonica rice.
文摘The paper deals with the energy and indoor comfort on buildings of UPF （University ofPasso Fundo）, located in southern Brazil, in order to improve the eco-efficiency concepts in the university＇s building stock, reinforcing its responsibility towards sustainable development. The factors that affect thermal performance and the energy consumption of two case studies were identified, including the general characteristics of the envelope and the indoor conditions. The simulations with DesignBuilder software compare the energy and thermal performance of both cases： those results allow the identification of their positive and negative aspects, as well as making a co-relation with the students＇ sensations of comfort--obtained through PMV （predicted mean vote）. The research indicates that it will be possible to improve eco-efficiency of existing and new buildings and campuses by retrofitting and upgrading it with regard to better indoor conditions that really correspond to climate conditions （hot and humid summers, and cold and damp winters）, using passive strategies for heating and cooling and at the same time to improve rational use of natural resources and to reduce the environmental impact. Probably, giving comfortable conditions to the users will increase energy consumption, but there is a potential reduction of lighting and equipment that could minimize this impact.
基金Supported by the Goverment of Malaysia,Intensified Research in Priority Areas(IRPA Project)(No.50258-J3)
文摘We studied the depth distribution of periphyton,growing on inundated dead trees in Kenyir Lake,Malaysia in June 1995.The algal floral composition and structure manifested changes down the depth gradient in terms of species richness,abundance,diversity and cell density.In regression analysis,all these algal attributes were negatively correlated with the depth gradients at P<0.05.In terms of species richness,the bacillariophytes showed dominance over the cyanophytes and chlorophytes;whereas with respect to standing crop,the cyanophytes showed dominance over the bacillariophytes and chlorophytes.The chlorophyll a was higher at the mid and bottom-depths than the surface-depth in both the downstream and upstream sites,which showed that vertical productivity or biomass accumulation was greater in low light irradiance.The product-moment correlation analysis showed that conductivity,turbidity,dissolved oxygen,reactive phosphate and ammonium-nitrogen were highly correlated with the algal assemblage data.However,photosynthetic active radiation(PAR) showed poor correlation with the community data.These observations have cast some light on the autoecological characteristics,habitat preferences and environmental responses of tropical periphytic communities.
基金National Natural Science Foundation of China,No.41421001,No.41571099,No.41030528
文摘The varied altitudinal gradient of climate and vegetation is further complicated by mass elevation effect(MEE), especially in high and extensive mountain regions. However, this effect and its implications for mountain altitudinal belts have not been well studied until recently. This paper provides an overview of the research carried out in the past 5 years. MEE is virtually the heating effect of mountain massifs and can be defined as the temperature difference on a given elevation between inside and outside of a mountain mass. It can be digitally modelled with three factors of intra-mountain base elevation(MBE), latitude and hygrometric continentality; MBE usually acts as the primary factor for the magnitude of MEE and, to a great extent, could represent MEE. MEE leads to higher treelines in the interior than in the outside of mountain masses. It makes montane forests to grow at 4800–4900 m and snowlines to develop at about 6000 m in the southern Tibetan Plateau and the central Andes, and large areas of forests to live above 3500 m in a lot of high mountains of the world. The altitudinal distribution of global treelines can be modelled with high precision when taking into account MEE and the result shows that MEE contributes the most to treeline distribution pattern. Without MEE, forests could only develop upmost to about 3500 m above sea level and the world ecological pattern would be much simpler. The quantification of MEE should be further improved with higher resolution data and its global implications are to be further revealed.
