As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and...As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China.展开更多
A coupled system of the interdecadal sea-air oscillator model is studied. The E1 Nifio-southem oscillation (ENSO) atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmo...A coupled system of the interdecadal sea-air oscillator model is studied. The E1 Nifio-southem oscillation (ENSO) atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The oscillator model is involved with the variations of both the eastern and western Pacific anomaly pat- terns. This paper proposes an ENSO atmospheric physics model using a method of the perturbation theory. The aim is to create an asymptotic solving method for the ENSO model. Employing the perturbed method, the asymptotic solution of corresponding problem is obtained, and the asymptotic behaviour of the solution is studied. Thus we can obtain the prognoses of the sea surface temperature anomaly and related physical quantities.展开更多
Although two moulds for methane gas in coal with the free state and adsorption state have been popularly considered, the derivation between the real methane gas state equation in coal and the perfect gas state equatio...Although two moulds for methane gas in coal with the free state and adsorption state have been popularly considered, the derivation between the real methane gas state equation in coal and the perfect gas state equation has been fuzzily considered and the mechanism of interaction for coal aromatics and methane gas molecules has not been understood. Then these problems have been discussed in this paper applied the principle of statistical thermo mechanics and quantum chemistry as well as based on the numerical calculating of experiential data in quantum chemistry. Therefore, it is revealed by research results that the experience state equation for real methane gas in coal, which is put forward in this paper, is closer to actual situation and the interaction process for methane gas adsorption on the surface of coal aromatics can be formulated by Morse potential function. Furthermore it is most stable through this research that the structural mould for methane gas molecule adsorption on the surface of coal nuclear with one gas molecule on top of another aromatics in regular triangle cone has been understood, and it is a physical adsorption for methane gas adsorption with single layer molecule on the surface of coal nuclear.展开更多
Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aer...Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids (MLVSS) is increased from 4055 mg.L^-1 to 4518 mg.L^-1 and the average settling volume (SV) are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand (COD) and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlates to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.展开更多
The Joule-Thomson effect reflects the interaction among constituent particles of macroscopic system.Forclassical ideal gas,the corresponding Joule-Thomson coefficient is vanishing while it is non-zero for ideal quantu...The Joule-Thomson effect reflects the interaction among constituent particles of macroscopic system.Forclassical ideal gas,the corresponding Joule-Thomson coefficient is vanishing while it is non-zero for ideal quantum gasdue to the quantum degeneracy.In recent years,much attention is paid to the unitary Fermi gas with infinite two-bodyscattering length.According to universal analysis,the thermodynamical law of unitary Fermi gas is similar to that ofnon-interacting ideal gas,which can be explored by the virial theorem P = 2E/3V.Based on previous works,we furtherstudy the unitary Fermi gas properties.The effective chemical potential is introduced to characterize the nonlinear levelscrossing effects in a strongly interacting medium.The changing behavior of the rescaled Joule-Thomson coefficientaccording to temperature manifests a quite different behavior from that for ideal Fermi gas.展开更多
A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green's function method are adopted. The result shows ...A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green's function method are adopted. The result shows that we can end up with a BCS-type theory but with a composite order parameter. Calculation shows that the Bose condensate of BCS Cooper pairs is proportional to the molecular BEC of Bose molecules. The resonance superfluid phase is indicated by the energy spectrum with an obvious interpretation of the transition mechanism.展开更多
Using SnxTi1-xO2 as carriers, CuO/Sn0.9Zi0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O...Using SnxTi1-xO2 as carriers, CuO/Sn0.9Zi0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Zi0.3O2 were examined using a microreactor-gas chromatography (GC) NO+CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Zi0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Zi0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the y peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (5) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.展开更多
Snow-cover parameters are important indicator factors for hydrological models and climate change studies and have typical vertical stratification characteristics. Remote sensing can be used for large-scale monitoring ...Snow-cover parameters are important indicator factors for hydrological models and climate change studies and have typical vertical stratification characteristics. Remote sensing can be used for large-scale monitoring of snow parameters. In SAR(Interferometric Synthetic Aperture Radar) technology has advantages in detecting the vertical structure of snow cover. As a basis of snow vertical structure detection using In SAR, a scattering model can reveal the physical process of interaction between electromagnetic waves and snow. In recent years, the In SAR scattering model for single-layer snow has been fully studied;however, it cannot be applied to the case of multi-layer snow. To solve this problem, a multi-layer snow scattering mode is proposed in this paper, which applies the QCA(Quad-Crystal Approximation) theory to describe the coherent scattering characteristics of snow and introduces a stratification factor to describe the influence of snow stratification on the crosscorrelation of SAR echoes. Based on the proposed model, we simulate an In SAR volumetric correlation of different types of multi-layer snow at the X band(9.6 GHz). The results show that this model is suitable for multi-layer snow, and the sequence of sub-layers of snow has a significant influence on the volumetric correlation. Compared to the single layer model, the multi-layer model can predict a polarization difference in the volumetric correlation more accurately and thus has a wider scope of application. To make the model more available for snow parameter inversion, a simplified multi-layer model was also developed.The model did not have polarization information compared to that of the full model but showed good consistency with the full model. The phase of the co-polarization In SAR volumetric correlation difference is more sensitive to snow parameters than that of the phase difference of the co-polarization In SAR volumetric correlation and more conducive to the development of a parameter-inversion algorithm. The model can be applied to deepen our understanding of In SAR scattering mechanisms and to develop a snow parameter inversion algorithm.展开更多
基金The research is funded by National Natural Science Foundation (40231016) and Canadian International Development Agency (CIDA).
文摘As the largest pool of terrestrial organic carbon, soils interact strongly with atmosphere composition, climate, and land change. Soil organic carbon dynamics in ecosystem plays a great role in global carbon cycle and global change. With development of mathematical models that simulate changes in soil organic carbon, there have been considerable advances in understanding soil organic carbon dynamics. This paper mainly reviewed the composition of soil organic matter and its influenced factors, and recommended some soil organic matter models worldwide. Based on the analyses of the developed results at home and abroad, it is suggested that future soil organic matter models should be developed toward based-process models, and not always empirical ones. The models are able to reveal their interaction between soil carbon systems, climate and land cover by technique and methods of GIS (Geographical Information System) and RS (Remote Sensing). These models should be developed at a global scale, in dynamically describing the spatial and temporal changes of soil organic matter cycle. Meanwhile, the further researches on models should be strengthen for providing theory basis and foundation in making policy of green house gas emission in China.
基金Under the auspices of National Natural Science Foundation of China (No.40876010)Key Direction in Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-Q03-08)+2 种基金Research and Development Special Fund for Public Welfare Industry (Meteorology) (No. GYHY200806010)LASG State Key Laboratory Special Fund, Foundation of E-Institutes of Shanghai Municipal Education Commission (No.E03004)Natural Science Foundation of Education Department of Fujian Province (No.JA10288)
文摘A coupled system of the interdecadal sea-air oscillator model is studied. The E1 Nifio-southem oscillation (ENSO) atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The oscillator model is involved with the variations of both the eastern and western Pacific anomaly pat- terns. This paper proposes an ENSO atmospheric physics model using a method of the perturbation theory. The aim is to create an asymptotic solving method for the ENSO model. Employing the perturbed method, the asymptotic solution of corresponding problem is obtained, and the asymptotic behaviour of the solution is studied. Thus we can obtain the prognoses of the sea surface temperature anomaly and related physical quantities.
文摘Although two moulds for methane gas in coal with the free state and adsorption state have been popularly considered, the derivation between the real methane gas state equation in coal and the perfect gas state equation has been fuzzily considered and the mechanism of interaction for coal aromatics and methane gas molecules has not been understood. Then these problems have been discussed in this paper applied the principle of statistical thermo mechanics and quantum chemistry as well as based on the numerical calculating of experiential data in quantum chemistry. Therefore, it is revealed by research results that the experience state equation for real methane gas in coal, which is put forward in this paper, is closer to actual situation and the interaction process for methane gas adsorption on the surface of coal aromatics can be formulated by Morse potential function. Furthermore it is most stable through this research that the structural mould for methane gas molecule adsorption on the surface of coal nuclear with one gas molecule on top of another aromatics in regular triangle cone has been understood, and it is a physical adsorption for methane gas adsorption with single layer molecule on the surface of coal nuclear.
基金Supported by the Shanghai Committee of Education (07ZZ158)
文摘Diatomite is a kind of natural low-cost mineral material. It has a number of unique physical properties and has been widely used as an adsorbent in wastewater treatment. This study was conducted to investigate the aerobic biodegradation of coal gasification wastewater with and without diatomite addition. Experimental results indicated that diatomite added in the activated sludge system could promote the biomass and also enhance the performance of the sludge settling. The average mixed-liquor volatile suspended solids (MLVSS) is increased from 4055 mg.L^-1 to 4518 mg.L^-1 and the average settling volume (SV) are changed only from 45.9% to 47.1%. Diatomite additive could enhance the efficiency of chemical oxygen demand (COD) and total phenols removal from the wastewater. The COD removal increased from 73.3% to near 80% and the total phenols removal increased from 81.4% to 85.8%. The mechanisms of the increase of biomass and pollutants removal may correlates to the improvement of bioavailability and sludge settlement characteristics by diatomite added. Micrograph of the sludge in the diatomite-activated sludge system indicated that the diatomite added could be the carrier of the microbe and also affect the biomass and pollutant removal.
基金Supported in part by Natural Science Foundation of China under Grant Nos.10875050,10675052MOE of China under Grant No.IRT0624
文摘The Joule-Thomson effect reflects the interaction among constituent particles of macroscopic system.Forclassical ideal gas,the corresponding Joule-Thomson coefficient is vanishing while it is non-zero for ideal quantum gasdue to the quantum degeneracy.In recent years,much attention is paid to the unitary Fermi gas with infinite two-bodyscattering length.According to universal analysis,the thermodynamical law of unitary Fermi gas is similar to that ofnon-interacting ideal gas,which can be explored by the virial theorem P = 2E/3V.Based on previous works,we furtherstudy the unitary Fermi gas properties.The effective chemical potential is introduced to characterize the nonlinear levelscrossing effects in a strongly interacting medium.The changing behavior of the rescaled Joule-Thomson coefficientaccording to temperature manifests a quite different behavior from that for ideal Fermi gas.
文摘A theoretical study of the BCS-BEC crossover is presented. Starting from a two-channel Boson-Fermion resonance model, the BCS-Bogoiubov mean-field method and the Green's function method are adopted. The result shows that we can end up with a BCS-type theory but with a composite order parameter. Calculation shows that the Bose condensate of BCS Cooper pairs is proportional to the molecular BEC of Bose molecules. The resonance superfluid phase is indicated by the energy spectrum with an obvious interpretation of the transition mechanism.
基金Project (No. Y504131) supported by the Natural Science Foundation of Zhejiang Province, China
文摘Using SnxTi1-xO2 as carriers, CuO/Sn0.9Zi0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Zi0.3O2 were examined using a microreactor-gas chromatography (GC) NO+CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Zi0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Zi0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the y peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (5) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41471065 & 41471066)the International Partnership Program of Chinese Academy of Sciences (Grant No. 131C11KYSB20160061)+1 种基金the Science & Technology Basic Resources Investigation Program of China (Grant No. 2017FY100502)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19070201)
文摘Snow-cover parameters are important indicator factors for hydrological models and climate change studies and have typical vertical stratification characteristics. Remote sensing can be used for large-scale monitoring of snow parameters. In SAR(Interferometric Synthetic Aperture Radar) technology has advantages in detecting the vertical structure of snow cover. As a basis of snow vertical structure detection using In SAR, a scattering model can reveal the physical process of interaction between electromagnetic waves and snow. In recent years, the In SAR scattering model for single-layer snow has been fully studied;however, it cannot be applied to the case of multi-layer snow. To solve this problem, a multi-layer snow scattering mode is proposed in this paper, which applies the QCA(Quad-Crystal Approximation) theory to describe the coherent scattering characteristics of snow and introduces a stratification factor to describe the influence of snow stratification on the crosscorrelation of SAR echoes. Based on the proposed model, we simulate an In SAR volumetric correlation of different types of multi-layer snow at the X band(9.6 GHz). The results show that this model is suitable for multi-layer snow, and the sequence of sub-layers of snow has a significant influence on the volumetric correlation. Compared to the single layer model, the multi-layer model can predict a polarization difference in the volumetric correlation more accurately and thus has a wider scope of application. To make the model more available for snow parameter inversion, a simplified multi-layer model was also developed.The model did not have polarization information compared to that of the full model but showed good consistency with the full model. The phase of the co-polarization In SAR volumetric correlation difference is more sensitive to snow parameters than that of the phase difference of the co-polarization In SAR volumetric correlation and more conducive to the development of a parameter-inversion algorithm. The model can be applied to deepen our understanding of In SAR scattering mechanisms and to develop a snow parameter inversion algorithm.