The phenyl and methyl phenyl free radicals,formed in the oxidation-hydrolysis process of N’-acyl-N-phenylhydrazine, have been studied by ESR spectrometry.It was found that the free radical is the chief cause which pr...The phenyl and methyl phenyl free radicals,formed in the oxidation-hydrolysis process of N’-acyl-N-phenylhydrazine, have been studied by ESR spectrometry.It was found that the free radical is the chief cause which produces the feed-back inhibition effect in the hydrazine-promoted infectious development of silver halide.展开更多
Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two fiel...Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two field trials were carried out for establishing absorbed-N effects on dry matter production(ANEDr) model, using uniform design in 2010–2011and 2012–2013 winter wheat growing seasons in Hebei Province, China. Another field trial was carried out in 2010–2011for model validation. Dry matter and N concentration in leaf and non-leaf organs were measured at setting, jointing, anthesis, and maturity. Theory of best linear unbiased prediction(BLUP) was applied to analyse the N effects of leaf and non-leaf organs on dry matter production. Within ANEDr model, four N-affected phases at each stage were concerned,leaf absorbed-N effect before this stage, non-leaf organ absorbed-N effect before this stage,leaf absorbed-N effect at this stage, and non-leaf organ absorbed-N effect at this stage. In addition, developmental processes, genotype characters and temperature were three factors that determine each N effect. It was demonstrated that ANEDr model can precisely quantify absorbed-N effects on dry matter production with high correlation coefficient(r=0.95). Comparing with other models, ANEDr model considered both leaf and non-leaf organs according to developmental processes of winter wheat, showed higher flexibility and simplicity, thus could be applied to different environments, cultivars and crops after parameter adjustment.展开更多
This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper (F16CuPc)/copper phthalocyanine (CuPc) and F16CuPc/pentacene as the active...This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper (F16CuPc)/copper phthalocyanine (CuPc) and F16CuPc/pentacene as the active layers. Compared with a single-layer device, it reports that an improved field-effect mobility and a 6-fold higher drain current are observed. The highest mobility of 0.081 cm^2/(V. s) was obtained from F16CuPc/CuPc heterojunction devices. This result is attributed to the dual effects of the organic heterojunction and interface modification. Furthermore, for two heterojunction devices, the performance of the F16CuPc/CuPc-based transistor is better than that of F16CuPc/pentacene. This is attributed to the morphologic match of two organic components.展开更多
Using a previous model, which was developed to describe the light-induced creation of the defect density in the a-Si:H gap states, we present in this work a numerical modelling of the photodegradation effect in the a...Using a previous model, which was developed to describe the light-induced creation of the defect density in the a-Si:H gap states, we present in this work a numerical modelling of the photodegradation effect in the a-Si:H p–i–n solar cell under continuous illumination. We first considered the simple case of a monochromatic light beam with a wavelength λ between 530–540 nm non uniformly absorbed, then the global standard solar spectrum(AM1.5) illumination is taken into account. The photodegradation is analysed on the basis of the resulting changes in the free carrier's densities, recombination rate, band structure, electrical potential and field, space charge, and current densities. Changes in the cell's external parameters: the open circuit voltage Voc, the short circuit current density Jsc, the fill factor FF and the maximum power density Pmaxare also presented.展开更多
Two N-containing borates, BTES and BMES, were synthesized with dodecyl phenol, 2-(N-containing heterocyclic) ethan-1-ol, boric acid, and dibutylamine, and their tribological properties in rapeseed oil(RSO) were invest...Two N-containing borates, BTES and BMES, were synthesized with dodecyl phenol, 2-(N-containing heterocyclic) ethan-1-ol, boric acid, and dibutylamine, and their tribological properties in rapeseed oil(RSO) were investigated using a four-ball tester. The results showed that the load-carrying ability(P_B value) of RSO can be improved by 40.9% and 67.9%, respectively, when using 0.5 wt% BTES and BMES. Moreover, the antiwear and friction-reducing performances of the additive-containing oils increased with the additive concentration. The X-ray photoelectron spectroscopy results of the worn steel ball surfaces showed that BTES and BMES formed protective films, which contained boron oxide, iron oxide, ferrous sulfate, ferrous sulfide(for BMES), and other organic nitrogen compounds, on the metal surfaces. The better load-carrying and antiwear performances of BMES than those of BTES might be due to their different sulfur contents, which result in different tribochemical reaction films on the contact surfaces. The oxidation stability tests showed that BTES and BMES possessed synergistic antioxidation activity with N-phenyl-α-naphthylamine(T531), and consequently, the oxidation activation energy of the oil sample increased by 77.85% and 82.19%, respectively, compared with that of RSO when the oil sample contained 0.05 wt% BTES/BMES and 0.25% T531.展开更多
During the past two centuries, global changes (i.e., enhanced nitrogen deposition) have exerted profound effects on ecological processes of steppe ecosystems. We used litterbag method and mixed litters of three differ...During the past two centuries, global changes (i.e., enhanced nitrogen deposition) have exerted profound effects on ecological processes of steppe ecosystems. We used litterbag method and mixed litters of three different plant species tissues (Stipa baicalensis: Sb, Leymus chinensis: Lc and Artemisia frigid: Af), endemic to Stipa baicalensis Steppe, and measured the mass loss of mixtures over 417 days under the N addition treatment. We studied the effect of N addition (N0: no N addition;N15: 1.5 g N/m<sup>2</sup>·a;N30: 3.0 g N/m<sup>2</sup>·a;N50: 5.0 g N/m<sup>2</sup>·a;N100: 10.0 g N/m<sup>2</sup>·a;N150: 15.0 g N/m<sup>2</sup>·a) on the rate of mixed litter decomposition and nutrient dynamics change. The decomposition constant (k) of leaf mixtures was higher than that of root mixtures. The k values of leaf mixed combinations were 0.880 (Sb + Lc), 1.231 (Lc + Af), 1.027 (Sb + Lc + Af), respectively. The k value of stem was 0.806 (Lc + Af) and the root mixed combinations were 0.665 (Sb + Lc), 0.979 (Lc + Af) and 1.164 (Sb + Lc + Af), respectively. The results indicated that N addition had significantly effect on the mixed litter decomposition and nutrient releasing. The rate of plant tissues litter decomposition had different response to N addition. In the context of N addition, litter decomposition rate and nutrient dynamics were changed by synthetic effect of decaying time, specie types and N addition dose. Our findings suggested that prairie plants may adapt to environmental change by adjusting litter quality, thus retaining the stability of the steppe ecosystem.展开更多
Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the variation of the post-saddle giant dipole resonance (GDR) q-ray multiplicity of the heavy nuclei 24^240Cf, ^246Cf, ^252...Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the variation of the post-saddle giant dipole resonance (GDR) q-ray multiplicity of the heavy nuclei 24^240Cf, ^246Cf, ^252Cf and ^240U with the post-saddle friction strength (13). We find that the sensitivity of the post-saddle γ emission to β decreases considerably with increasing the neutron-to-proton ratio (N/Z) of the system. Moreover, for 240 U, the γ emission is no longer sensitive to 13. We suggest that to accurately obtain information of the post-saddle friction strength by measuring pre-scission GDR γ-ray multiplicities, it is optimal to choose among the various compound systems those with low N/Z.展开更多
The spin distribution of the evaporation residue cross section of nuclei ^194pb, ^200Pb, ^206Pb, and ^200 Os are calculated via a Langevin equation coupled with a statistical decay model. It is shown that with increas...The spin distribution of the evaporation residue cross section of nuclei ^194pb, ^200Pb, ^206Pb, and ^200 Os are calculated via a Langevin equation coupled with a statistical decay model. It is shown that with increasing the neutronto-proton ratio (N/Z) of the system, the sensitivity of the significantly. Moreover, for ^200Os this spin distribution is no spin distribution to the nuclear dissipation is decreased longer sensitive to the nuclear dissipation. These results suggest that to obtain a more accurate pre-saddle viscosity coefficient through the measurement of the evaporation residue spin distribution, it is best to yield those compound systems with low N/Z.展开更多
The mutant effects of a keV range nitrogen ion (N+) beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance (ESR) results showed that...The mutant effects of a keV range nitrogen ion (N+) beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance (ESR) results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope (SEM). The mutagenic effect on genome indicated that N+ implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms.展开更多
The objectives of this study were to evaluate the effects of different dosages of three amendments—peat,superphosphate,mixture of Mg(OH)2+H3PO4(Magnesium Hydroxide and Phosphorus Acid)on N(Nitrogen)conservation.The s...The objectives of this study were to evaluate the effects of different dosages of three amendments—peat,superphosphate,mixture of Mg(OH)2+H3PO4(Magnesium Hydroxide and Phosphorus Acid)on N(Nitrogen)conservation.The simulated composting experiment was carried out in a constant temperature water bath with pig manure and corn straw.The results showed that the ammonia volatilization could be inhibited to some extent under the treatments with fixing agents.Under the same simulated composting conditions,the nitrogen fixation effect of the three kinds of fixatives with the same proportion was as follows:Mg(OH)2+H3PO4>superphosphate>peat.The fixation effect of N increased with the increase of the additives.The N fixation rate of Mg(OH)2+H3PO4 treatment was up to 66%.Compared with the CK(Control Group),the amount of cumulative ammonia emission decreased by 90.3% and the TN(Total Nitrogen)content increased by 39.31% in this treatment.Compared with other two kinds of fixing agents,Mg(OH)2+H3PO4 treatment could not only control N loss in composting process,improve the N nutrient content of compost products,but also could increase P(Phosphorus)and Mg(Magnesium)nutrients.Therefore,it had more popularization value and application prospect.展开更多
We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion...We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type.展开更多
The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe(In)/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In...The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe(In)/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In to make a thin film on a p-Si single crystal wafer with a thickness of 100μm and a resistivity of~1.5Ω·cm at a temperature of 473 K.The short-circuit current density(jsc),open-circuit voltage(Voc),fill factor(ff) and conversion efficiency(η) under 100 mW/cm^2(AMI) intensity,are 20 mA/cm^2,0.49 V,0.71 and 6%respectively. The cells were exposed to different electron doses(electron beam accelerator of energy 1.5 MeV,and beam intensity 25 mA).The cell performance parameters are measured and discussed before and after gamma and electron beam irradiation.展开更多
Two tigogenyl glycosides containing N-acetylglucosamine were synthesized. Their structures were confirmed by ^1H and ^13C NMR spectra. The shielding effect caused by benzoyl groups was elucidated by ^1H NMR, COSY, HSQ...Two tigogenyl glycosides containing N-acetylglucosamine were synthesized. Their structures were confirmed by ^1H and ^13C NMR spectra. The shielding effect caused by benzoyl groups was elucidated by ^1H NMR, COSY, HSQC, HMBC spectroscopy.展开更多
Structural, electronic and mechanical properties of the nH-SiC (n = 2, 4, 6, 8 and 10) polytypes are calculated by using the first-principles calculations based on the density-functional theory approach. The optimiz...Structural, electronic and mechanical properties of the nH-SiC (n = 2, 4, 6, 8 and 10) polytypes are calculated by using the first-principles calculations based on the density-functional theory approach. The optimized lattice parameters of nH-SiC are in good agreement with the experimental data. The mechanical properties, including elastic constants, bulk modulus, Young's modulus, shear modulus and Poisson's ratio, are calculated. The analysis of elastic properties indicates that the effects of n on the mechanical properties of the five nil-SiC structures have no difference. The indirect band gap relationship for the live polytypes is Ebg2H 〉 Ebg4H 〉 Ebg6H 〉 Ebg10H 〉 EbgsH.展开更多
Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to o...Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.展开更多
Hard alloy were implanted with a dudl-ion of nitrogen and tatalum at temperature of 100℃ and 400℃ at a dose of 8×1017 ions cm-2 .Auger electron spectroscopy (AES) was used to determine the nitrogen and tantalum...Hard alloy were implanted with a dudl-ion of nitrogen and tatalum at temperature of 100℃ and 400℃ at a dose of 8×1017 ions cm-2 .Auger electron spectroscopy (AES) was used to determine the nitrogen and tantalum concentration profiles. Microhardness measurements were performed to evaluate the improvements in surface property. The thickness of implanted layers increased by about an order of magnitude when the temperature was elevated from 100℃ to 400 ℃. A higher surface hardness was also obtained in the higher temperature implantation. Scanning electron microscopy (SEM) image showed distinct microstructural changes, and X-ray diffiaction (XRD) analysis showed the presence of nitrides of tantalum and tungsten on the surface implanted.展开更多
文摘The phenyl and methyl phenyl free radicals,formed in the oxidation-hydrolysis process of N’-acyl-N-phenylhydrazine, have been studied by ESR spectrometry.It was found that the free radical is the chief cause which produces the feed-back inhibition effect in the hydrazine-promoted infectious development of silver halide.
基金supported by the Special Fund for Agro-Scientific Research in the Public Interest, China (201203031)the China Agriculture Research System (CARS-02-26)
文摘Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two field trials were carried out for establishing absorbed-N effects on dry matter production(ANEDr) model, using uniform design in 2010–2011and 2012–2013 winter wheat growing seasons in Hebei Province, China. Another field trial was carried out in 2010–2011for model validation. Dry matter and N concentration in leaf and non-leaf organs were measured at setting, jointing, anthesis, and maturity. Theory of best linear unbiased prediction(BLUP) was applied to analyse the N effects of leaf and non-leaf organs on dry matter production. Within ANEDr model, four N-affected phases at each stage were concerned,leaf absorbed-N effect before this stage, non-leaf organ absorbed-N effect before this stage,leaf absorbed-N effect at this stage, and non-leaf organ absorbed-N effect at this stage. In addition, developmental processes, genotype characters and temperature were three factors that determine each N effect. It was demonstrated that ANEDr model can precisely quantify absorbed-N effects on dry matter production with high correlation coefficient(r=0.95). Comparing with other models, ANEDr model considered both leaf and non-leaf organs according to developmental processes of winter wheat, showed higher flexibility and simplicity, thus could be applied to different environments, cultivars and crops after parameter adjustment.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60806007)the Shanghai ‘Post-Qi-Ming-Xing Plan’ for Young Scientists,China (Grant No. 07QA14023)the Shanghai Committee of Science and Technology (Grant Nos. 08DZ1140702 and 08520511200)
文摘This paper presents two n-channel organic heterojunction transistors with modified insulator by using hexadecafiuorophthalocyaninatocopper (F16CuPc)/copper phthalocyanine (CuPc) and F16CuPc/pentacene as the active layers. Compared with a single-layer device, it reports that an improved field-effect mobility and a 6-fold higher drain current are observed. The highest mobility of 0.081 cm^2/(V. s) was obtained from F16CuPc/CuPc heterojunction devices. This result is attributed to the dual effects of the organic heterojunction and interface modification. Furthermore, for two heterojunction devices, the performance of the F16CuPc/CuPc-based transistor is better than that of F16CuPc/pentacene. This is attributed to the morphologic match of two organic components.
文摘Using a previous model, which was developed to describe the light-induced creation of the defect density in the a-Si:H gap states, we present in this work a numerical modelling of the photodegradation effect in the a-Si:H p–i–n solar cell under continuous illumination. We first considered the simple case of a monochromatic light beam with a wavelength λ between 530–540 nm non uniformly absorbed, then the global standard solar spectrum(AM1.5) illumination is taken into account. The photodegradation is analysed on the basis of the resulting changes in the free carrier's densities, recombination rate, band structure, electrical potential and field, space charge, and current densities. Changes in the cell's external parameters: the open circuit voltage Voc, the short circuit current density Jsc, the fill factor FF and the maximum power density Pmaxare also presented.
基金the financial support provided by the National Natural Science Foundation of China(Nos.21563012 and 21363008)Jiangsu Provincial Natural Science Foundation of China(No.BK20161188)+1 种基金Jiangxi Natural Science Foundation of China(Nos.20143ACB20003,20162BCB22020 and 20171BCD40009)Jiangxi Provincial Education Department Foundation of China(No.GJJ170371)
文摘Two N-containing borates, BTES and BMES, were synthesized with dodecyl phenol, 2-(N-containing heterocyclic) ethan-1-ol, boric acid, and dibutylamine, and their tribological properties in rapeseed oil(RSO) were investigated using a four-ball tester. The results showed that the load-carrying ability(P_B value) of RSO can be improved by 40.9% and 67.9%, respectively, when using 0.5 wt% BTES and BMES. Moreover, the antiwear and friction-reducing performances of the additive-containing oils increased with the additive concentration. The X-ray photoelectron spectroscopy results of the worn steel ball surfaces showed that BTES and BMES formed protective films, which contained boron oxide, iron oxide, ferrous sulfate, ferrous sulfide(for BMES), and other organic nitrogen compounds, on the metal surfaces. The better load-carrying and antiwear performances of BMES than those of BTES might be due to their different sulfur contents, which result in different tribochemical reaction films on the contact surfaces. The oxidation stability tests showed that BTES and BMES possessed synergistic antioxidation activity with N-phenyl-α-naphthylamine(T531), and consequently, the oxidation activation energy of the oil sample increased by 77.85% and 82.19%, respectively, compared with that of RSO when the oil sample contained 0.05 wt% BTES/BMES and 0.25% T531.
文摘During the past two centuries, global changes (i.e., enhanced nitrogen deposition) have exerted profound effects on ecological processes of steppe ecosystems. We used litterbag method and mixed litters of three different plant species tissues (Stipa baicalensis: Sb, Leymus chinensis: Lc and Artemisia frigid: Af), endemic to Stipa baicalensis Steppe, and measured the mass loss of mixtures over 417 days under the N addition treatment. We studied the effect of N addition (N0: no N addition;N15: 1.5 g N/m<sup>2</sup>·a;N30: 3.0 g N/m<sup>2</sup>·a;N50: 5.0 g N/m<sup>2</sup>·a;N100: 10.0 g N/m<sup>2</sup>·a;N150: 15.0 g N/m<sup>2</sup>·a) on the rate of mixed litter decomposition and nutrient dynamics change. The decomposition constant (k) of leaf mixtures was higher than that of root mixtures. The k values of leaf mixed combinations were 0.880 (Sb + Lc), 1.231 (Lc + Af), 1.027 (Sb + Lc + Af), respectively. The k value of stem was 0.806 (Lc + Af) and the root mixed combinations were 0.665 (Sb + Lc), 0.979 (Lc + Af) and 1.164 (Sb + Lc + Af), respectively. The results indicated that N addition had significantly effect on the mixed litter decomposition and nutrient releasing. The rate of plant tissues litter decomposition had different response to N addition. In the context of N addition, litter decomposition rate and nutrient dynamics were changed by synthetic effect of decaying time, specie types and N addition dose. Our findings suggested that prairie plants may adapt to environmental change by adjusting litter quality, thus retaining the stability of the steppe ecosystem.
基金Supported by the Foundation of Nanjing University of Finance & Economics under Grant No. JGY1030
文摘Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the variation of the post-saddle giant dipole resonance (GDR) q-ray multiplicity of the heavy nuclei 24^240Cf, ^246Cf, ^252Cf and ^240U with the post-saddle friction strength (13). We find that the sensitivity of the post-saddle γ emission to β decreases considerably with increasing the neutron-to-proton ratio (N/Z) of the system. Moreover, for 240 U, the γ emission is no longer sensitive to 13. We suggest that to accurately obtain information of the post-saddle friction strength by measuring pre-scission GDR γ-ray multiplicities, it is optimal to choose among the various compound systems those with low N/Z.
基金National Natural Science Foundation of China under Grant No.10405007
文摘The spin distribution of the evaporation residue cross section of nuclei ^194pb, ^200Pb, ^206Pb, and ^200 Os are calculated via a Langevin equation coupled with a statistical decay model. It is shown that with increasing the neutronto-proton ratio (N/Z) of the system, the sensitivity of the significantly. Moreover, for ^200Os this spin distribution is no spin distribution to the nuclear dissipation is decreased longer sensitive to the nuclear dissipation. These results suggest that to obtain a more accurate pre-saddle viscosity coefficient through the measurement of the evaporation residue spin distribution, it is best to yield those compound systems with low N/Z.
基金supported by National Natural Science Foundation of China.(No,30100134)
文摘The mutant effects of a keV range nitrogen ion (N+) beam on enzyme-producing probiotics were studied, particularly with regard to the induction in the genome. The electron spin resonance (ESR) results showed that the signal of ESR spectrum existed in both implanted and non-implanted spores, and the yields of free radicals increased in a dose-dependent manner. The ionic etching and dilapidation of cell wall could be observed distinctly through the scanning electron microscope (SEM). The mutagenic effect on genome indicated that N+ implantation could make base mutation. This study provided an insight into the roles low-energy ions might play in inducing mutagenesis of micro-organisms.
文摘The objectives of this study were to evaluate the effects of different dosages of three amendments—peat,superphosphate,mixture of Mg(OH)2+H3PO4(Magnesium Hydroxide and Phosphorus Acid)on N(Nitrogen)conservation.The simulated composting experiment was carried out in a constant temperature water bath with pig manure and corn straw.The results showed that the ammonia volatilization could be inhibited to some extent under the treatments with fixing agents.Under the same simulated composting conditions,the nitrogen fixation effect of the three kinds of fixatives with the same proportion was as follows:Mg(OH)2+H3PO4>superphosphate>peat.The fixation effect of N increased with the increase of the additives.The N fixation rate of Mg(OH)2+H3PO4 treatment was up to 66%.Compared with the CK(Control Group),the amount of cumulative ammonia emission decreased by 90.3% and the TN(Total Nitrogen)content increased by 39.31% in this treatment.Compared with other two kinds of fixing agents,Mg(OH)2+H3PO4 treatment could not only control N loss in composting process,improve the N nutrient content of compost products,but also could increase P(Phosphorus)and Mg(Magnesium)nutrients.Therefore,it had more popularization value and application prospect.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60978013)the Shanghai Rising Star Project,China (Grant No. 11QA1407400)
文摘We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type.
文摘The efficiency and radiation resistance of solar cells are graded.They are then fabricated in the form of n-CdeSe(In)/p-Si heterojunction cells by electron beam evaporation of a stoichiomteric mixture of CdSe and In to make a thin film on a p-Si single crystal wafer with a thickness of 100μm and a resistivity of~1.5Ω·cm at a temperature of 473 K.The short-circuit current density(jsc),open-circuit voltage(Voc),fill factor(ff) and conversion efficiency(η) under 100 mW/cm^2(AMI) intensity,are 20 mA/cm^2,0.49 V,0.71 and 6%respectively. The cells were exposed to different electron doses(electron beam accelerator of energy 1.5 MeV,and beam intensity 25 mA).The cell performance parameters are measured and discussed before and after gamma and electron beam irradiation.
基金the National Natural Science Foundation of China (No. 20372085)
文摘Two tigogenyl glycosides containing N-acetylglucosamine were synthesized. Their structures were confirmed by ^1H and ^13C NMR spectra. The shielding effect caused by benzoyl groups was elucidated by ^1H NMR, COSY, HSQC, HMBC spectroscopy.
基金Supported by the National Natural Science Foundation of China under Grant No 51372203the National Basic Research Program of China under Grant No 2011CB605806+1 种基金the Basic Research Foundation of Northwestern Polytechnical University under Grant Nos JCY20130114 and JCY20110248the Foreign Talents Introduction and Academic Exchange Program under Grant No B08040
文摘Structural, electronic and mechanical properties of the nH-SiC (n = 2, 4, 6, 8 and 10) polytypes are calculated by using the first-principles calculations based on the density-functional theory approach. The optimized lattice parameters of nH-SiC are in good agreement with the experimental data. The mechanical properties, including elastic constants, bulk modulus, Young's modulus, shear modulus and Poisson's ratio, are calculated. The analysis of elastic properties indicates that the effects of n on the mechanical properties of the five nil-SiC structures have no difference. The indirect band gap relationship for the live polytypes is Ebg2H 〉 Ebg4H 〉 Ebg6H 〉 Ebg10H 〉 EbgsH.
基金This work was supported by the National Nature Science Foundation of China! No.19605005
文摘Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8x 1014 ions/cm2 to 6x1015 ions/cm2.The treatment of H2O2 and [ CHC13 +CH3 CH2OH ] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of MnSOD in D. radiodurans AS1.633 by N+ beam exposure . These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.
文摘Hard alloy were implanted with a dudl-ion of nitrogen and tatalum at temperature of 100℃ and 400℃ at a dose of 8×1017 ions cm-2 .Auger electron spectroscopy (AES) was used to determine the nitrogen and tantalum concentration profiles. Microhardness measurements were performed to evaluate the improvements in surface property. The thickness of implanted layers increased by about an order of magnitude when the temperature was elevated from 100℃ to 400 ℃. A higher surface hardness was also obtained in the higher temperature implantation. Scanning electron microscopy (SEM) image showed distinct microstructural changes, and X-ray diffiaction (XRD) analysis showed the presence of nitrides of tantalum and tungsten on the surface implanted.