Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in ...Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in topsoils (0-10 cm)were quantified in two 33-year-old monoculture plantations of Castanopsis kawakamii Hayata (CK) and Cunninghamia lanceolata Lamb. (Chinese fir) (CF), and compared to a neighboring relict natural C. kawakamii forest (NF), in Sanming,Fujian. Five soil samples were collected once each in January, April, July, September and November in 2000 in each forest for laboratory analysis. Over the sampling year, there were significant differences for bacteria, fungi and actinomycetes between forests and between seasons (P ＜ 0.05). The largest bacteria and fungi populations were in NF, while CF contained the greatest number of actinomycetes. There were also significant differences (P ＜ 0.05) with microbial respiration for forests and seasons. Additionally, compared with NF, urease and acid phosphatase were significantly lower (P ＜ 0.05)in CK and CF. Also, the correlations of soil hydrolysable N and available P to soil microbial and enzymatic activities were highly significant (P ＜ 0.01). Thus, to alter the traditional Chinese fir monoculture so as to mimic the natural forest conditions, managing mixed stands of Chinese fir and broadleaf trees or conducting crop rotation of conifers and broadleaf trees as well as minimizing forest disturbances like clear-cutting, slash burning and soil preparing, could be utilized.展开更多
In production industry of Auricularia auricular, the varieties quality is most important impact factor on output. For evaluating the early quality of the edible fungus, 9 varieties of Auricularia auricular (Au9, CF09,...In production industry of Auricularia auricular, the varieties quality is most important impact factor on output. For evaluating the early quality of the edible fungus, 9 varieties of Auricularia auricular (Au9, CF09, CF05, 29, 916, chang10, chang7, Au.Japanese and 8808) were cultured on the medium consists of potato dextrose agar (PDA) and sawdust to test their mycelium growth rate, endurance to high temperature, resistance to mildew, assimilation of nutriment, and resistance to drought. The result showed that the mycelium of Chang 10, CF09, 29 and Au.Japanese varieties had the eminent characteristics such as short lifespan, stronger assimilation of nutriment, and endurance to high temperature and steady growth. These four varieties are determined as superiority varieties of Auricularia auricular in accordance with the research results.展开更多
Effects of temperature and drying and wetting alternation(DWA)on ammonium fixation in manured loessial soil were studied by means of Batch Equilibrium with Varying concentration solutions of ammonium chloride,ammonium...Effects of temperature and drying and wetting alternation(DWA)on ammonium fixation in manured loessial soil were studied by means of Batch Equilibrium with Varying concentration solutions of ammonium chloride,ammonium fixation time,and soil clay contents.The purpose of the research was to find out the pattern of ammonium fixation ted by the varying factors.The results showed a remarkable variation in ammonium fixation.Fixed ammonium increased with temperature and treatments of DWA.The ammonium fixation in manured loessial soil was characterized by the effect of temperature and DWA.展开更多
The molecular mechanism in the damage of erythrocyte membrane of the cows with hemoglobinuria was studied with the field cases and the group comparison.The field cases were devided into three groups:the hemoglobinuria...The molecular mechanism in the damage of erythrocyte membrane of the cows with hemoglobinuria was studied with the field cases and the group comparison.The field cases were devided into three groups:the hemoglobinuria group(HG),the low phosphorous group(LPG)and the control group(CG).The content of phospholipid constituents in the erythrocyte membrane and the protein constituents in membrane skeleton were determined molecularly and the shape of erythrocyte was examined with the scanning electron microscope.The result showed that:(1)the concentration of phosphatidylethanolamine(PE)in HG was lower significantly than that in LPG and CG;the concentration of sphingomyeline(SM) and phosphatidylcholine(PC)+phosphatidylserine(PS) in HG was significantly lower than that in the other groups;the content of PC+PS was lower and the concentration of SM was higher in LPG with comparing that in CG,the significant positive correlation was observed between the concentration of phosphorus in serum and the concentration of PE,respectively.The significant negative correlation was observed between the content of phosphorus in serum and the content of SM,respectively.(2)the difference of protein constituent in membrane skeleton between LPG and CG was not found,however,the concentration of spectin in band Ⅰ,Ⅱ and the content of protein in band Ⅳ 2 was lower and the concentration of protein in band Ⅲ significantly higher in HG than that in LPG and CG(P<0.01);(3)the form of erythrocyte observed with scanning electron microscope changed from discal to the spinal,to spheric form,to hemolysis ultimately following the reduction of the concentration of phosphorus in serum.It was concluded that the change of the constituent of phospholipid in erythrocyte membrane and protein in membrane skeleton and the form of erythrocyte is the most important factors in hemolysis for hypophosphatemia.展开更多
A four-point bending apparatus is used to investigate the effects of stretching on collagen synthesis, mineralization and differentiation of osteoblasts. Cells are stretched at 1500 με for 24 hours. The responses of...A four-point bending apparatus is used to investigate the effects of stretching on collagen synthesis, mineralization and differentiation of osteoblasts. Cells are stretched at 1500 με for 24 hours. The responses of osteoblasts to mechanical signal of physiological stretching are evaluated from three aspects: collagen production, extracellular inorganic calcium secretion and ALP activity. The results show that osteoblasts decrease the collagen synthesis, calcium secretion and ALP activity compared to the control cells (65.82%,73.51%,48.10% respectively), confirming that cyclic stretching at 1500 με inhabits the physiological activity of osteoblasts.展开更多
In this paper, we try to present a way in terms of which one can analytically obtain the Hartree selfconsistent potential instead of computing it by the numerical iterative procedure as usual, which is convenient for ...In this paper, we try to present a way in terms of which one can analytically obtain the Hartree selfconsistent potential instead of computing it by the numerical iterative procedure as usual, which is convenient for us to describe the current flow through a mesoscopic conductor. In our treatment, we expand the action function S(x)by Planck constant h, then the self-consistent potential and the wavefunction can be solved analytically order by order starting from the Poisson equation and quantum Hamilton-Jacobian equation, the differential conductance and quantum capacitance can thus be obtained naturally. In our paper, we show the quantum corrections up to the second order, and the electron-electron interaction is considered only at the Hartree approximation level.展开更多
GaN microcrystalline grains were grown by hot-wall chemical vapor deposition on Si(111)substrate.These grains with diameters of 2-4 μm were detected by scanning electron microscopy.X-ray diffraction,Fourier transform...GaN microcrystalline grains were grown by hot-wall chemical vapor deposition on Si(111)substrate.These grains with diameters of 2-4 μm were detected by scanning electron microscopy.X-ray diffraction,Fourier transformation infrared transmission spectroscopy and photoluminescence were used to analyze the structure, composition and the optical properties of the samples.The results show that the microcrystalline grains are hexagonal wurtzite GaN,and the property of the grains was greatly affected by the growth time.展开更多
基金the Basic Research Program of Fujian Province (No. 2000-F-004).
文摘Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in topsoils (0-10 cm)were quantified in two 33-year-old monoculture plantations of Castanopsis kawakamii Hayata (CK) and Cunninghamia lanceolata Lamb. (Chinese fir) (CF), and compared to a neighboring relict natural C. kawakamii forest (NF), in Sanming,Fujian. Five soil samples were collected once each in January, April, July, September and November in 2000 in each forest for laboratory analysis. Over the sampling year, there were significant differences for bacteria, fungi and actinomycetes between forests and between seasons (P ＜ 0.05). The largest bacteria and fungi populations were in NF, while CF contained the greatest number of actinomycetes. There were also significant differences (P ＜ 0.05) with microbial respiration for forests and seasons. Additionally, compared with NF, urease and acid phosphatase were significantly lower (P ＜ 0.05)in CK and CF. Also, the correlations of soil hydrolysable N and available P to soil microbial and enzymatic activities were highly significant (P ＜ 0.01). Thus, to alter the traditional Chinese fir monoculture so as to mimic the natural forest conditions, managing mixed stands of Chinese fir and broadleaf trees or conducting crop rotation of conifers and broadleaf trees as well as minimizing forest disturbances like clear-cutting, slash burning and soil preparing, could be utilized.
文摘In production industry of Auricularia auricular, the varieties quality is most important impact factor on output. For evaluating the early quality of the edible fungus, 9 varieties of Auricularia auricular (Au9, CF09, CF05, 29, 916, chang10, chang7, Au.Japanese and 8808) were cultured on the medium consists of potato dextrose agar (PDA) and sawdust to test their mycelium growth rate, endurance to high temperature, resistance to mildew, assimilation of nutriment, and resistance to drought. The result showed that the mycelium of Chang 10, CF09, 29 and Au.Japanese varieties had the eminent characteristics such as short lifespan, stronger assimilation of nutriment, and endurance to high temperature and steady growth. These four varieties are determined as superiority varieties of Auricularia auricular in accordance with the research results.
文摘Effects of temperature and drying and wetting alternation(DWA)on ammonium fixation in manured loessial soil were studied by means of Batch Equilibrium with Varying concentration solutions of ammonium chloride,ammonium fixation time,and soil clay contents.The purpose of the research was to find out the pattern of ammonium fixation ted by the varying factors.The results showed a remarkable variation in ammonium fixation.Fixed ammonium increased with temperature and treatments of DWA.The ammonium fixation in manured loessial soil was characterized by the effect of temperature and DWA.
文摘The molecular mechanism in the damage of erythrocyte membrane of the cows with hemoglobinuria was studied with the field cases and the group comparison.The field cases were devided into three groups:the hemoglobinuria group(HG),the low phosphorous group(LPG)and the control group(CG).The content of phospholipid constituents in the erythrocyte membrane and the protein constituents in membrane skeleton were determined molecularly and the shape of erythrocyte was examined with the scanning electron microscope.The result showed that:(1)the concentration of phosphatidylethanolamine(PE)in HG was lower significantly than that in LPG and CG;the concentration of sphingomyeline(SM) and phosphatidylcholine(PC)+phosphatidylserine(PS) in HG was significantly lower than that in the other groups;the content of PC+PS was lower and the concentration of SM was higher in LPG with comparing that in CG,the significant positive correlation was observed between the concentration of phosphorus in serum and the concentration of PE,respectively.The significant negative correlation was observed between the content of phosphorus in serum and the content of SM,respectively.(2)the difference of protein constituent in membrane skeleton between LPG and CG was not found,however,the concentration of spectin in band Ⅰ,Ⅱ and the content of protein in band Ⅳ 2 was lower and the concentration of protein in band Ⅲ significantly higher in HG than that in LPG and CG(P<0.01);(3)the form of erythrocyte observed with scanning electron microscope changed from discal to the spinal,to spheric form,to hemolysis ultimately following the reduction of the concentration of phosphorus in serum.It was concluded that the change of the constituent of phospholipid in erythrocyte membrane and protein in membrane skeleton and the form of erythrocyte is the most important factors in hemolysis for hypophosphatemia.
文摘A four-point bending apparatus is used to investigate the effects of stretching on collagen synthesis, mineralization and differentiation of osteoblasts. Cells are stretched at 1500 με for 24 hours. The responses of osteoblasts to mechanical signal of physiological stretching are evaluated from three aspects: collagen production, extracellular inorganic calcium secretion and ALP activity. The results show that osteoblasts decrease the collagen synthesis, calcium secretion and ALP activity compared to the control cells (65.82%,73.51%,48.10% respectively), confirming that cyclic stretching at 1500 με inhabits the physiological activity of osteoblasts.
文摘In this paper, we try to present a way in terms of which one can analytically obtain the Hartree selfconsistent potential instead of computing it by the numerical iterative procedure as usual, which is convenient for us to describe the current flow through a mesoscopic conductor. In our treatment, we expand the action function S(x)by Planck constant h, then the self-consistent potential and the wavefunction can be solved analytically order by order starting from the Poisson equation and quantum Hamilton-Jacobian equation, the differential conductance and quantum capacitance can thus be obtained naturally. In our paper, we show the quantum corrections up to the second order, and the electron-electron interaction is considered only at the Hartree approximation level.
文摘GaN microcrystalline grains were grown by hot-wall chemical vapor deposition on Si(111)substrate.These grains with diameters of 2-4 μm were detected by scanning electron microscopy.X-ray diffraction,Fourier transformation infrared transmission spectroscopy and photoluminescence were used to analyze the structure, composition and the optical properties of the samples.The results show that the microcrystalline grains are hexagonal wurtzite GaN,and the property of the grains was greatly affected by the growth time.
