The spectrum variance m0, peak frequency ω0 and peakness factor p are expressed in terms of nondimensional fetch and duration by making use of relations which are derived through comparing and analyzing existing empi...The spectrum variance m0, peak frequency ω0 and peakness factor p are expressed in terms of nondimensional fetch and duration by making use of relations which are derived through comparing and analyzing existing empirical formulas for the growth of significant wave height and period. The main features of spectrum growth as specified by these parameters agree with those of the JONS-WAP experiments. For given wind speed and fetch, the high frequency parts beyond the peaks of shallow water spectra almost coincide with that of the corresponding deep water spectrum, whereas the low frequency parts differ appreciably. The method developed in this paper predicts smaller significant wave height as well as smaller wave period for shallow water spectra in contrast to the theoretical result of Kitaigorodskii ef al, in which the peak frequency, and consequently the significant wave period, remains basically unchanged for different water depths. Spectra are further reduced to a form in which only significant wave height and period are left as parameters, the peakness factor being replaced by the wave steepness through an empirical relation between them. Spectra in this form have been verified by observations.展开更多
We study the one-dimensional asymmetric simple exclusion process （ASEP） with generic open boundaries （in- cluding current-counting deformation）, and obtain the exact solutions of this ASEP via the off-diagonal Bet...We study the one-dimensional asymmetric simple exclusion process （ASEP） with generic open boundaries （in- cluding current-counting deformation）, and obtain the exact solutions of this ASEP via the off-diagonal Bethe ansatz method. In particular, numerical results for the small size asymmetric simple exclusion process indicate that the spectrum obtained by the Bethe ansatz equations is complete. Moreover, we present the eigenvalue of the totally asymmetric exclusion process and the corresponding Bethe ansatz equations.展开更多
Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the f...Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.展开更多
Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured eco...Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured ecological model that provide a feasible approach to describing fish communities in terms of individual dietary variation and ontogenetic niche shift. Despite the potential of ecological models in improving our understanding of ecosystems, their application is usually limited for data-poor fisheries. As a first step in implementing ecosystem-based fisheries management（EBFM）, this study built a size-spectrum model for the fish community in the Haizhou Bay, China. We describe data collection procedures and model parameterization to facilitate the implementation of such size-spectrum models for future studies of data-poor ecosystems. The effects of fishing on the ecosystem were exemplified with a range of fishing effort and were monitored with a set of ecological indicators. Total community biomass, biodiversity index, W-statistic, LFI（Large fish index）, Mean W（mean body weight） and Slope（slope of community size spectra） showed a strong non-linear pattern in response to fishing pressure, and largest fishing effort did not generate the most drastic responses in certain scenarios. We emphasize the value and feasibility of developing size-spectrum models to capture ecological dynamics and suggest limitations as well as potential for model improvement. This study aims to promote a wide use of this type of model in support of EBFM.展开更多
On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentu...On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentum flux density function for the wave spectrum, and then the parameterization scheme of the gravity waves is improved. Choosing parameter values of the background atmosphere and waves based on the observations, a more realistic equatorial quasi-biennial oscillation (QBO) driven by the incorporated drag from the planetary and gravity waves can be simulated. The numerical results indicate that the forcing magnitude of the planetary and gravity waves varies with the wind field, and in some phases of the QBO, the contribution of the gravity waves is comparable with that of the planetary waves. After the QBO is steadily formed, its amplitude and period and wind configuration are relevant to the effect of vertical diffusion and the momentum flux distribution with spectrum, however, independent of the initial background wind field. Moreover, for any given nonzero initial background wind, a steady QBO can be finally generated due to the incorporated drag from the planetary and gravity waves.展开更多
Transparent Nd: BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra o...Transparent Nd: BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra of the crystal have been measured and compared with that of 0.2 mol/L NdCl3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10?20 cm2, Ω4 = 0.1282?10?201 cm2 and Ω6 = 0.1357X10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,J’, oscillator strengths fJ,J’, radiative lifetime rand the branching ratio βJ’ have all been calculated. Based on these parameters, the properties and application perspective are discussed.展开更多
At different temperatures, the interactions between imidacloprid （IMI） and bovine serum albumin （BSA） were investigated with a fluorescence quenching spectrum, a synchronous fluorescence spectrum, a three-dimensio...At different temperatures, the interactions between imidacloprid （IMI） and bovine serum albumin （BSA） were investigated with a fluorescence quenching spectrum, a synchronous fluorescence spectrum, a three-dimensional fluorescence spectrum and an ultraviolet-visible spectrum. The average values of bonding constants （KLB： 3.424 × 10^4 L,mol^-1）, thermodynamic parameters （△H： 5.188 kJ,mol^-1, △G^（○—）：-26.36 kJ,mol^-1, △S： 103.9 J,K^-1,mol^-1） and the numbers of bonding sites （n： 1.156） could be obtained through Stern-Volmer, Lineweaver-Burk and ther- modynamic equations. It was shown that the fluorescence of BSA could be quenched for its reactions with IMI to form a certain kind of new compound. The quenching belonged to a static fluorescence quenching, with a non-radiation energy transfer happening within a single molecule. The thermodynamic parameters agree with △H〉 0, △S〉0 and△G^（○-）〈0, suggesting that the binding power between IMI and BSA should be mainly a hydrophobic interaction.展开更多
A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratifo...A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratiform cloud and convective cloud.A deep convective,anelastic and conservative system of equations with basic variables(V,θ,π')is solved by a new method to calculate dynamic field.The water substance in the cloud is divided into 6 categories and the microphysical processes are described in spectrum with two variable parameters and more reasonable particle number/size distributions.To compare with measured radar echo intensity and structure,the model may calculate echo intensity of the model cloud observed by radar.展开更多
To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrati...To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrations of Cu in the leaf cell fluid were significantly higher than those in the cell wall,and the Cu was primarily enriched in cell fluid.At the jointing and heading stages,the Cu concentration in the leaf cell wall was significantly higher than that in the cell fluid,and the main enrichment was transferred to the cell wall.During the above three growth stages,no Cu was discovered in leaf organelles.Further studies showed that the total soluble protein content in wheat leaves at the tillering and jointing stages showed a trend of first rising and then falling with increased Cu dosage.At the heading stage,under low and medium Cu stress,the total soluble protein content showed no remarkable change.Malondialdehyde(MDA)content at the tillering stage increased with the increase of Cu concentration in the soil,while MDA content did not change noticeably at the jointing and heading stages.At the tillering and heading stages,the low concentrations of Cu increased peroxidase(POD)activity.The POD activity decreased gradually with the increased Cu concentration.However,at the high concentrations of Cu,there was no significant difference in the activity of POD.At the jointing stage,the POD activity did not change significantly under the low Cu stress while it was evidently inhibited under high Cu stress.Based on the above studies,further analyses on the correlation between canopy spectral characteristics and the Cu accumulation at different growth stages of leaf cells were performed,and a new combined index SIPI/NDVI705 performed well in Cu content prediction.The results showed that at different growth stages,different sensitive spectral characteristic parameters should be used to predict the Cu content in leaf cells.展开更多
文摘The spectrum variance m0, peak frequency ω0 and peakness factor p are expressed in terms of nondimensional fetch and duration by making use of relations which are derived through comparing and analyzing existing empirical formulas for the growth of significant wave height and period. The main features of spectrum growth as specified by these parameters agree with those of the JONS-WAP experiments. For given wind speed and fetch, the high frequency parts beyond the peaks of shallow water spectra almost coincide with that of the corresponding deep water spectrum, whereas the low frequency parts differ appreciably. The method developed in this paper predicts smaller significant wave height as well as smaller wave period for shallow water spectra in contrast to the theoretical result of Kitaigorodskii ef al, in which the peak frequency, and consequently the significant wave period, remains basically unchanged for different water depths. Spectra are further reduced to a form in which only significant wave height and period are left as parameters, the peakness factor being replaced by the wave steepness through an empirical relation between them. Spectra in this form have been verified by observations.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11375141,11475135,11434013 and 11425522the Ministry of Education Doctoral Program Fund under Grant No 20126101110004the Northwest University Graduate Student Innovation Fund under Grant No YZZ14104
文摘We study the one-dimensional asymmetric simple exclusion process （ASEP） with generic open boundaries （in- cluding current-counting deformation）, and obtain the exact solutions of this ASEP via the off-diagonal Bethe ansatz method. In particular, numerical results for the small size asymmetric simple exclusion process indicate that the spectrum obtained by the Bethe ansatz equations is complete. Moreover, we present the eigenvalue of the totally asymmetric exclusion process and the corresponding Bethe ansatz equations.
文摘Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.
基金The Special Fund for Agriscientific Research in the Public Interest under contract No.201303050the Fundamental Research Funds for the Central Universities under contract Nos 201022001 and 201262004
文摘Multispecies ecological models have been used for predicting the effects of fishing activity and evaluating the performance of management strategies. Size-spectrum models are one type of physiologically-structured ecological model that provide a feasible approach to describing fish communities in terms of individual dietary variation and ontogenetic niche shift. Despite the potential of ecological models in improving our understanding of ecosystems, their application is usually limited for data-poor fisheries. As a first step in implementing ecosystem-based fisheries management（EBFM）, this study built a size-spectrum model for the fish community in the Haizhou Bay, China. We describe data collection procedures and model parameterization to facilitate the implementation of such size-spectrum models for future studies of data-poor ecosystems. The effects of fishing on the ecosystem were exemplified with a range of fishing effort and were monitored with a set of ecological indicators. Total community biomass, biodiversity index, W-statistic, LFI（Large fish index）, Mean W（mean body weight） and Slope（slope of community size spectra） showed a strong non-linear pattern in response to fishing pressure, and largest fishing effort did not generate the most drastic responses in certain scenarios. We emphasize the value and feasibility of developing size-spectrum models to capture ecological dynamics and suggest limitations as well as potential for model improvement. This study aims to promote a wide use of this type of model in support of EBFM.
基金Supported by National Natural Science Foundation of China (Grant Nos. 40731055 and 40774085)the Innovative Research Team Project, Ministry of Education, the Knowledge Innovation Program of the Chinese Academy of Sciences (IAP07315)+1 种基金the China Meteorological Administration (Grant No. GYHY200706013)the Open Programs of Key Laboratory of Geospace Environment and Geodesy, Ministry of Education
文摘On the basis of previous parameterization schemes, considering both the wave breaking and absorbed at critical level, a parameterization with a continuous spectrum of gravity waves is realized by introducing a momentum flux density function for the wave spectrum, and then the parameterization scheme of the gravity waves is improved. Choosing parameter values of the background atmosphere and waves based on the observations, a more realistic equatorial quasi-biennial oscillation (QBO) driven by the incorporated drag from the planetary and gravity waves can be simulated. The numerical results indicate that the forcing magnitude of the planetary and gravity waves varies with the wind field, and in some phases of the QBO, the contribution of the gravity waves is comparable with that of the planetary waves. After the QBO is steadily formed, its amplitude and period and wind configuration are relevant to the effect of vertical diffusion and the momentum flux distribution with spectrum, however, independent of the initial background wind field. Moreover, for any given nonzero initial background wind, a steady QBO can be finally generated due to the incorporated drag from the planetary and gravity waves.
基金the National Natural Science Foundation of China (Grant No. 59823003).
文摘Transparent Nd: BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra of the crystal have been measured and compared with that of 0.2 mol/L NdCl3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10?20 cm2, Ω4 = 0.1282?10?201 cm2 and Ω6 = 0.1357X10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,J’, oscillator strengths fJ,J’, radiative lifetime rand the branching ratio βJ’ have all been calculated. Based on these parameters, the properties and application perspective are discussed.
基金Project supported by the National Natural Science Foundation of China （Nos. 30570015, 20373051） and Natural Science Foundation of Hubei Province of China （Nos. 2005ABA067, 2005ABC002）.
文摘At different temperatures, the interactions between imidacloprid （IMI） and bovine serum albumin （BSA） were investigated with a fluorescence quenching spectrum, a synchronous fluorescence spectrum, a three-dimensional fluorescence spectrum and an ultraviolet-visible spectrum. The average values of bonding constants （KLB： 3.424 × 10^4 L,mol^-1）, thermodynamic parameters （△H： 5.188 kJ,mol^-1, △G^（○—）：-26.36 kJ,mol^-1, △S： 103.9 J,K^-1,mol^-1） and the numbers of bonding sites （n： 1.156） could be obtained through Stern-Volmer, Lineweaver-Burk and ther- modynamic equations. It was shown that the fluorescence of BSA could be quenched for its reactions with IMI to form a certain kind of new compound. The quenching belonged to a static fluorescence quenching, with a non-radiation energy transfer happening within a single molecule. The thermodynamic parameters agree with △H〉 0, △S〉0 and△G^（○-）〈0, suggesting that the binding power between IMI and BSA should be mainly a hydrophobic interaction.
文摘A 2-D slab-symmetric model of mixed convective-stratiform cloud is developed by superimposing convective cloud-size field on the convergence field,in order to simulate and study the mixed clouds consisting of stratiform cloud and convective cloud.A deep convective,anelastic and conservative system of equations with basic variables(V,θ,π')is solved by a new method to calculate dynamic field.The water substance in the cloud is divided into 6 categories and the microphysical processes are described in spectrum with two variable parameters and more reasonable particle number/size distributions.To compare with measured radar echo intensity and structure,the model may calculate echo intensity of the model cloud observed by radar.
基金This work was supported by the National Natural Science Fund of China(41471279)。
文摘To study the mechanism of Cu toxicity on wheat,the characteristics of Cu stress in pivotal growth periods of wheat were explored by field planting methods.The results showed that at the tillering stage,the concentrations of Cu in the leaf cell fluid were significantly higher than those in the cell wall,and the Cu was primarily enriched in cell fluid.At the jointing and heading stages,the Cu concentration in the leaf cell wall was significantly higher than that in the cell fluid,and the main enrichment was transferred to the cell wall.During the above three growth stages,no Cu was discovered in leaf organelles.Further studies showed that the total soluble protein content in wheat leaves at the tillering and jointing stages showed a trend of first rising and then falling with increased Cu dosage.At the heading stage,under low and medium Cu stress,the total soluble protein content showed no remarkable change.Malondialdehyde(MDA)content at the tillering stage increased with the increase of Cu concentration in the soil,while MDA content did not change noticeably at the jointing and heading stages.At the tillering and heading stages,the low concentrations of Cu increased peroxidase(POD)activity.The POD activity decreased gradually with the increased Cu concentration.However,at the high concentrations of Cu,there was no significant difference in the activity of POD.At the jointing stage,the POD activity did not change significantly under the low Cu stress while it was evidently inhibited under high Cu stress.Based on the above studies,further analyses on the correlation between canopy spectral characteristics and the Cu accumulation at different growth stages of leaf cells were performed,and a new combined index SIPI/NDVI705 performed well in Cu content prediction.The results showed that at different growth stages,different sensitive spectral characteristic parameters should be used to predict the Cu content in leaf cells.
