We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity ...We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.展开更多
This paper presents a case study on structure design and establishment of database application system for alien species in Shan-dong Province, integrating with Geographic Information System, computer network, and data...This paper presents a case study on structure design and establishment of database application system for alien species in Shan-dong Province, integrating with Geographic Information System, computer network, and database technology to the research of alien species. The modules of alien species database, including classified data input, statistics and analysis, species pictures and distribution maps, and out date input, were approached by Visual Studio.net 2003 and Microsoft SQL server 2000. The alien species information contains the information of classification, species distinction characteristics, biological characteristics, original area, distribution area, the entering fashion and route, invasion time, invasion reason, interaction with the endemic species, growth state, danger state and spatial information, i.e. distribution map. Based on the above bases, several models including application, checking, modifying, printing, adding and returning mod- els were developed. Furthermore, through the establishment of index tables and index maps, we can also spatially query the data like picture, text and GIS map data. This research established the technological platform of sharing information about scientific resource of alien species in Shandong Province, offering the basis for the dynamic inquiry of alien species, the warning technology of prevention and the fast reaction system. The database application system possessed the principles of good practicability, friendly user interface and convenient usage. It can supply full and accurate information inquiry services of alien species for the users and provide functions of dynamically managing the database for the administrator.展开更多
The restabilizing mechanisms after the onset of thermal instability in bipolar transistors are studied by theoretical analyses,computer simulations and experimental measurements.Restability conditions are described by...The restabilizing mechanisms after the onset of thermal instability in bipolar transistors are studied by theoretical analyses,computer simulations and experimental measurements.Restability conditions are described by novel analytical formulae.Furthermore,the expression of collect current in the second fly-back point is given for the first time.The effects of emitter ballast resistance,collector-emitter voltage and thermal resistance on restabilization mechanisms are expressed and investigated.展开更多
As one of the most toxic heavy metals with persistence, bioaccumulation, and toxicity in environment, mercury and its envi- ronmental problems have caused a global concern. To fully understand the behavior and fate of...As one of the most toxic heavy metals with persistence, bioaccumulation, and toxicity in environment, mercury and its envi- ronmental problems have caused a global concern. To fully understand the behavior and fate of mercury (Hg)(Ⅱ) in forest soils, a series of batch experiments were conducted to determine the adsorption and desorption characteristics of Hg(Ⅱ) by three dark brown forest soils from Mount Taishan, Laoshan Mountain, and Fanggan Village in Shandong Province, China. The adsorption solution was prepared using 0.1 mol L-1 NaNO3 as background electrolyte, with Hg(Ⅱ) at rising concentration gradients of 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mg L-1 . Fourier transform infrared (FTIR) spectroscopy was adopted to characterize the soil samples and soil-Hg complexes. It was found that Hg(Ⅱ) adsorption isotherms could be well fitted with both Langmuir and Freundlich equations. The soil from Mount Taishan had the largest potential Hg(Ⅱ) adsorption capacity, though with less adsorptive intensity. The percentages of Hg(Ⅱ) desorbed from all soil samples were less than 0.6%, which suggested that all the soils studied had a high binding strength for Hg(Ⅱ). The soil from Mount Taishan had a higher Hg(Ⅱ) desorption capacity than the other soils, which indicated that the Hg(Ⅱ) deposited on the topsoil of Mount Taishan from atmosphere may easily discharge to surface water through runoff. Results of the FTIR spectroscopy showed that the three soils contained the same functional groups. The relative absorbencies of soil-Hg complexes changed significantly compared with those of the soil samples and the adsorption of Hg(Ⅱ) mainly acted on the O-H, C-O, and C=O groups of the soils.展开更多
基金Project supported by the Outstanding Young Scientists Foundation Grant of Shandong Province (No.2005BS08010)China Geological Survey Project (No.1212010310306)Key Project of Natural Science Foundation of Shandong Province (No.Z2006D04).
基金supported by National Science Foundation of China (No.31270374)Independent Innovation Foundation of Shandong University (No.2011DX008)+1 种基金Natural Science Foundation of Shandong Province,China (No.2009ZRB01875ZR2010CM062)
文摘We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.
基金this study was supported by the Key Project of Natu-ral Science Foundation of Shandong Province(No. Z2003D05)Key Project of Environmental Protection Science of Shandong Province(No. 2004057)Outstanding Young Scientists Grants of Shandong Province(No.2005BS08010),China
文摘This paper presents a case study on structure design and establishment of database application system for alien species in Shan-dong Province, integrating with Geographic Information System, computer network, and database technology to the research of alien species. The modules of alien species database, including classified data input, statistics and analysis, species pictures and distribution maps, and out date input, were approached by Visual Studio.net 2003 and Microsoft SQL server 2000. The alien species information contains the information of classification, species distinction characteristics, biological characteristics, original area, distribution area, the entering fashion and route, invasion time, invasion reason, interaction with the endemic species, growth state, danger state and spatial information, i.e. distribution map. Based on the above bases, several models including application, checking, modifying, printing, adding and returning mod- els were developed. Furthermore, through the establishment of index tables and index maps, we can also spatially query the data like picture, text and GIS map data. This research established the technological platform of sharing information about scientific resource of alien species in Shandong Province, offering the basis for the dynamic inquiry of alien species, the warning technology of prevention and the fast reaction system. The database application system possessed the principles of good practicability, friendly user interface and convenient usage. It can supply full and accurate information inquiry services of alien species for the users and provide functions of dynamically managing the database for the administrator.
基金by the National Natural Science Foundation of China under Grant Nos 60776051,61006059 and 61006044the Beijing Municipal Natural Science Foundation under Grant No 4082007+2 种基金the Scientific Research Common Program of Beijing Municipal Commission of Education under Grant Nos KM200710005015 and KM200910005001the Ninth Technology Fund of BJUT(ykj-2011-5104 and ykj-2011-5107)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality.
文摘The restabilizing mechanisms after the onset of thermal instability in bipolar transistors are studied by theoretical analyses,computer simulations and experimental measurements.Restability conditions are described by novel analytical formulae.Furthermore,the expression of collect current in the second fly-back point is given for the first time.The effects of emitter ballast resistance,collector-emitter voltage and thermal resistance on restabilization mechanisms are expressed and investigated.
基金Supported by the National Natural Science Foundation of China(Nos.30970166 and 40801088)the Science and Technology Program for Environmental Protection of Shandong Province,China(No.2006007)the Research Award Fund for Outstanding Young Scientists of Shandong Province,China(No.2007BS08001)
文摘As one of the most toxic heavy metals with persistence, bioaccumulation, and toxicity in environment, mercury and its envi- ronmental problems have caused a global concern. To fully understand the behavior and fate of mercury (Hg)(Ⅱ) in forest soils, a series of batch experiments were conducted to determine the adsorption and desorption characteristics of Hg(Ⅱ) by three dark brown forest soils from Mount Taishan, Laoshan Mountain, and Fanggan Village in Shandong Province, China. The adsorption solution was prepared using 0.1 mol L-1 NaNO3 as background electrolyte, with Hg(Ⅱ) at rising concentration gradients of 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mg L-1 . Fourier transform infrared (FTIR) spectroscopy was adopted to characterize the soil samples and soil-Hg complexes. It was found that Hg(Ⅱ) adsorption isotherms could be well fitted with both Langmuir and Freundlich equations. The soil from Mount Taishan had the largest potential Hg(Ⅱ) adsorption capacity, though with less adsorptive intensity. The percentages of Hg(Ⅱ) desorbed from all soil samples were less than 0.6%, which suggested that all the soils studied had a high binding strength for Hg(Ⅱ). The soil from Mount Taishan had a higher Hg(Ⅱ) desorption capacity than the other soils, which indicated that the Hg(Ⅱ) deposited on the topsoil of Mount Taishan from atmosphere may easily discharge to surface water through runoff. Results of the FTIR spectroscopy showed that the three soils contained the same functional groups. The relative absorbencies of soil-Hg complexes changed significantly compared with those of the soil samples and the adsorption of Hg(Ⅱ) mainly acted on the O-H, C-O, and C=O groups of the soils.
