Influence of the effective fermion hexadecapole force newly incorporated in a microscopic sdgIBM-1 on spectra, reduced E2 and E4 transition matrix elements (T(E2)s and T(E4)s) in the even-even platinum isotopes (A = 1...Influence of the effective fermion hexadecapole force newly incorporated in a microscopic sdgIBM-1 on spectra, reduced E2 and E4 transition matrix elements (T(E2)s and T(E4)s) in the even-even platinum isotopes (A = 192,194,196,198) is investigated in terms of numerical calculations. It is found that the introduced interaction causes only limited modification to the spectrum and T(E2)s, apart from a few exceptions. However, it plays an essential role in describing E4 transitions. Thus in the case that the interaction is incorporated with certain strength, a reasonable description of all the E4 transitions in the platinum isotopes is reached in the microscopic sdgIBM-1 in comparing both to experimental data and the results calculated in phenomenological boson model.展开更多
The interacting patterns of the luteolin and guanine have been investigated by using the density functional theory B3LYP method with 6-31+G* basis set. Eighteen stable structures for the luteolin-guanine complexes h...The interacting patterns of the luteolin and guanine have been investigated by using the density functional theory B3LYP method with 6-31+G* basis set. Eighteen stable structures for the luteolin-guanine complexes have been found respectively. The results indicate that the complexes are mainly stabilized by the hydrogen bonding interactions. Meanwhile, both the number and strength of hydrogen bond play important roles in determining the stability of the complexes which can form two or more hydrogen bonds. Theories of atoms in molecules and natural bond orbital have also been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes which were corrected by basis set superposition error are 6.04-56.94 kJ/mol. The calculation results indicate that there are strong hydrogen bonding interactions in the luteolin-guanine complexes. We compared the interaction between luteolin and four bases of DNA, and found luteolin-thymine was the strongest and luteolin-adenine was the weakest. The interaction between luteolin and DNA bases are all stronger than luteolin-water.展开更多
This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The repres...This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The representation of the pipe is made by MEF using one fmite element in the cylindrical panel formulated from the theory of equivalent discrete layers (Layerwise theory), proposed by J. N. Reddy. The soil is represented by elastic continum infimite or semi-infinite and modeled using boundary elements with special curved surface, associated with cylindrical panel used to represent the soil-structure interaction within the soil, especially at the contact surface with the pipe.展开更多
The interactive effects of natural and human factors on ecosystems have been well studied, and the quantitative assessment of large-scale ecological vulnerability caused by natural and human factors is now one of the ...The interactive effects of natural and human factors on ecosystems have been well studied, and the quantitative assessment of large-scale ecological vulnerability caused by natural and human factors is now one of the most active topics in the ifeld. Taking the Guangxi Xijiang River Economic Belt in southwest China (GXEB) as a case study, we assess ecological vulnerability based on the Vulnerability Scoping Diagram (VSD) model. The indices system is decomposed into three sub objects, ten elements and 25 indicators layer by layer, which included factors from both natural and human ifelds. Results indicate that zones with lower, middle-lower, middle, middle-higher and higher vulnerability account for 11.31%, 22.63%, 27.60%, 24.39%, and 14.07%, respectively. The western and eastern parts of GXEB are more vulnerable than the central part and the mountain and urban areas are of higher vulnerability than the basins and river valleys. Compared with a vulnerability assessment based on natural factors only, it is concluded that human activities indeed cause the transition from naturally stable zones to vulnerable zones. The nature-dominated vulnerable zones are different with human-dominated ones in size and distribution, the latter being smaller, more scattered and distributed in urban areas and their surroundings. About 53%of total construction land is distributed in zones with middle and middle-higher ecological vulnerability;less vulnerable zones should attract construction in the future. Relevant suggestions are proposed on how to reduce vulnerability according to inducing factors. The VSD model has a signiifcant advantage in the quantitative evaluation of ecological vulnerability, but is insufficient to distinguish nature- or human-dominated vulnerability quantitatively.展开更多
Currently research on developing socio-cultural and linguistic competence simultaneously in the language classroom is gaining increasing attention from EFL practitioners and curriculum designers. This paper contends t...Currently research on developing socio-cultural and linguistic competence simultaneously in the language classroom is gaining increasing attention from EFL practitioners and curriculum designers. This paper contends that albeit second language learning is a complex phenomenon with different variables concerning the psychological factors of the learners and the socio-cultural elements of the contexts, an interactional approach to second language learning can ensure that a social perspective of second language development and instruction contributes to having a positive effect on the nature and quality of language learning, which activates the autonomous learning motivation and creates diversity in the learning atmosphere.展开更多
The optimal foraging theory predicts that predators choose prey with more net rate of energy intake and less energy costs if there are multiple food sources available. Toxins are found in many species in nature. Those...The optimal foraging theory predicts that predators choose prey with more net rate of energy intake and less energy costs if there are multiple food sources available. Toxins are found in many species in nature. Those toxins may be produced by prey as self- protection from predatory animals, or come from other sources such as pesticide residue. Therefore, it requires a balance between energy intake and toxicity damage. In order to study the interactive effect of prey toxin and optimal foraging strategy, we construct a predator-prey model with toxin-induced functional response and optimal foraging property. Dynamical analysis shows that the optimal strategy system presents more complex dynamical behavior than the fixed preference system. We conclude that optimal foraging strategy might play a key role in stabilizing or destabilizing the coexistence states of the species in the system, depending on the level of prey toxins.展开更多
Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrolo...Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolu- tion, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios (δ13C = 2.14%o, 8180 = -5.77‰), and was precipitated early. It was precipitated di- rectly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid( δ180 = -3‰), which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios (δ13C = -2.36%0, 8180 = -15.68‰). This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2+, Fe3+ and Mg2+ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the buri- al process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite ce- ments in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone (δ13C = 1.93%o, δ180 = -6.11‰), demonstrating that the two are from the same source that had a heavier oxygen isotope ratio (δ180 of about 2.2‰). The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different wa- ter-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles (lithic quartz sand- stone) has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.展开更多
We have investigated the structure evolution of the ^124-134Xe isotopic chain in the framework of the proton-neutron interacting model IBM2. The positive parity spectra of the ground state, quasi-β and quasi-γ bands...We have investigated the structure evolution of the ^124-134Xe isotopic chain in the framework of the proton-neutron interacting model IBM2. The positive parity spectra of the ground state, quasi-β and quasi-γ bands are reproduced well. The staggering in ^124-130Xe are almost completely removed and the ? band agree well with the experiment data, even for the high-spin quasi-3 states. The key quantities of the collective structure evolution, including level energies, the B(E2) transition branching ratios, and the M1 excitations to 11^+ mixer-symmetry states are analyzed by comparing with the experimental data. The parameters for representation of the Oπν(6) and SUπν^*(3) features in isotopes are examined. Both experimental data and theoretical results show that the shape phase transition of ^124-134Xe isotopic chain is from the SUπν^* (3) (triaxial rotation) to the Uπν(5) (vibration motion) with a considerable constituent of the Oπν(6) symmetry (γ-unstable rotation), where the shape phase transition rapidly takes place between the neutron number N = 76 and N = 78.展开更多
文摘Influence of the effective fermion hexadecapole force newly incorporated in a microscopic sdgIBM-1 on spectra, reduced E2 and E4 transition matrix elements (T(E2)s and T(E4)s) in the even-even platinum isotopes (A = 192,194,196,198) is investigated in terms of numerical calculations. It is found that the introduced interaction causes only limited modification to the spectrum and T(E2)s, apart from a few exceptions. However, it plays an essential role in describing E4 transitions. Thus in the case that the interaction is incorporated with certain strength, a reasonable description of all the E4 transitions in the platinum isotopes is reached in the microscopic sdgIBM-1 in comparing both to experimental data and the results calculated in phenomenological boson model.
文摘The interacting patterns of the luteolin and guanine have been investigated by using the density functional theory B3LYP method with 6-31+G* basis set. Eighteen stable structures for the luteolin-guanine complexes have been found respectively. The results indicate that the complexes are mainly stabilized by the hydrogen bonding interactions. Meanwhile, both the number and strength of hydrogen bond play important roles in determining the stability of the complexes which can form two or more hydrogen bonds. Theories of atoms in molecules and natural bond orbital have also been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes which were corrected by basis set superposition error are 6.04-56.94 kJ/mol. The calculation results indicate that there are strong hydrogen bonding interactions in the luteolin-guanine complexes. We compared the interaction between luteolin and four bases of DNA, and found luteolin-thymine was the strongest and luteolin-adenine was the weakest. The interaction between luteolin and DNA bases are all stronger than luteolin-water.
文摘This work deals with the analysis of soil-structure interaction modeling of pipeline problems in static behavior using the coupling between FEM (finite element method) and BEM (boundary element method). The representation of the pipe is made by MEF using one fmite element in the cylindrical panel formulated from the theory of equivalent discrete layers (Layerwise theory), proposed by J. N. Reddy. The soil is represented by elastic continum infimite or semi-infinite and modeled using boundary elements with special curved surface, associated with cylindrical panel used to represent the soil-structure interaction within the soil, especially at the contact surface with the pipe.
基金National Natural Science Foundation of China(41201110)Young Talents Foundation of Nanjing Institute of Geography and Limnology of CAS(NIGLAS2011QD03)
文摘The interactive effects of natural and human factors on ecosystems have been well studied, and the quantitative assessment of large-scale ecological vulnerability caused by natural and human factors is now one of the most active topics in the ifeld. Taking the Guangxi Xijiang River Economic Belt in southwest China (GXEB) as a case study, we assess ecological vulnerability based on the Vulnerability Scoping Diagram (VSD) model. The indices system is decomposed into three sub objects, ten elements and 25 indicators layer by layer, which included factors from both natural and human ifelds. Results indicate that zones with lower, middle-lower, middle, middle-higher and higher vulnerability account for 11.31%, 22.63%, 27.60%, 24.39%, and 14.07%, respectively. The western and eastern parts of GXEB are more vulnerable than the central part and the mountain and urban areas are of higher vulnerability than the basins and river valleys. Compared with a vulnerability assessment based on natural factors only, it is concluded that human activities indeed cause the transition from naturally stable zones to vulnerable zones. The nature-dominated vulnerable zones are different with human-dominated ones in size and distribution, the latter being smaller, more scattered and distributed in urban areas and their surroundings. About 53%of total construction land is distributed in zones with middle and middle-higher ecological vulnerability;less vulnerable zones should attract construction in the future. Relevant suggestions are proposed on how to reduce vulnerability according to inducing factors. The VSD model has a signiifcant advantage in the quantitative evaluation of ecological vulnerability, but is insufficient to distinguish nature- or human-dominated vulnerability quantitatively.
文摘Currently research on developing socio-cultural and linguistic competence simultaneously in the language classroom is gaining increasing attention from EFL practitioners and curriculum designers. This paper contends that albeit second language learning is a complex phenomenon with different variables concerning the psychological factors of the learners and the socio-cultural elements of the contexts, an interactional approach to second language learning can ensure that a social perspective of second language development and instruction contributes to having a positive effect on the nature and quality of language learning, which activates the autonomous learning motivation and creates diversity in the learning atmosphere.
基金The author thanks the referees very much for their valuable comments and suggestions. The work is supported by the Fhndamental Research Funds for the Central Universities (No. 74005701), National Natural Science Foundation of China (No. 11771033).
文摘The optimal foraging theory predicts that predators choose prey with more net rate of energy intake and less energy costs if there are multiple food sources available. Toxins are found in many species in nature. Those toxins may be produced by prey as self- protection from predatory animals, or come from other sources such as pesticide residue. Therefore, it requires a balance between energy intake and toxicity damage. In order to study the interactive effect of prey toxin and optimal foraging strategy, we construct a predator-prey model with toxin-induced functional response and optimal foraging property. Dynamical analysis shows that the optimal strategy system presents more complex dynamical behavior than the fixed preference system. We conclude that optimal foraging strategy might play a key role in stabilizing or destabilizing the coexistence states of the species in the system, depending on the level of prey toxins.
基金supported by the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Foundation (Grant No. PLC201101)the National Natural Science Foundation of China (Grant Nos. 41172119 and 41272130)
文摘Carbonate cement is the most abundant cement type in the Fourth Member of the Xujiahe Formation in the Xiaoquan-Fenggu area of the West Sichuan Depression. Here we use a systematic analysis of carbonate cement petrology, mineralogy, carbon and oxygen isotope ratios and enclosure homogenization temperatures to study the precipitation mechanism, pore fluid evolu- tion, and distribution of different types of carbonate cement in reservoir sand in the study area. Crystalline calcite has relatively heavy carbon and oxygen isotope ratios (δ13C = 2.14%o, 8180 = -5.77‰), and was precipitated early. It was precipitated di- rectly from supersaturated alkaline fluid under normal temperature and pressure conditions. At the time of precipitation, the fluid oxygen isotope ratio was very light, mainly showing the characteristics of a mixed meteoric water-seawater fluid( δ180 = -3‰), which shows that the fluid during precipitation was influenced by both meteoric water and seawater. The calcite cement that fills in the secondary pores has relatively lighter carbon and oxygen isotope ratios (δ13C = -2.36%0, 8180 = -15.68‰). This cement was precipitated late, mainly during the Middle and Late Jurassic. An important material source for this carbonate cement was the feldspar corrosion process that involved organic matter. The Ca2+, Fe3+ and Mg2+ ions released by the clay mineral transformation process were also important source materials. Because of water-rock interactions during the buri- al process, the oxygen isotope ratio of the fluid significantly increased during precipitation, by about 3‰. The dolomite ce- ments in calcarenaceous sandstone that was precipitated during the Middle Jurassic have heavier carbon and oxygen isotope ratios, which are similar to those of carbonate debris in the sandstone (δ13C = 1.93%o, δ180 = -6.11‰), demonstrating that the two are from the same source that had a heavier oxygen isotope ratio (δ180 of about 2.2‰). The differences in fluid oxygen isotope ratios during cement precipitation reflect the influences of different water-rock interaction systems or different wa- ter-rock interaction strengths. This is the main reason why the sandstone containing many rigid particles (lithic quartz sand- stone) has a relatively negative carbon isotope ratio and why the precipitation fluid in calcarenaceous sandstone has a relatively heavier oxygen isotope ratio.
基金Supported by the National Natural Science Foundation of China under Grant No.11075052the Natural Science Foundation of Zhejiang Province under Grant No.KY6100135
文摘We have investigated the structure evolution of the ^124-134Xe isotopic chain in the framework of the proton-neutron interacting model IBM2. The positive parity spectra of the ground state, quasi-β and quasi-γ bands are reproduced well. The staggering in ^124-130Xe are almost completely removed and the ? band agree well with the experiment data, even for the high-spin quasi-3 states. The key quantities of the collective structure evolution, including level energies, the B(E2) transition branching ratios, and the M1 excitations to 11^+ mixer-symmetry states are analyzed by comparing with the experimental data. The parameters for representation of the Oπν(6) and SUπν^*(3) features in isotopes are examined. Both experimental data and theoretical results show that the shape phase transition of ^124-134Xe isotopic chain is from the SUπν^* (3) (triaxial rotation) to the Uπν(5) (vibration motion) with a considerable constituent of the Oπν(6) symmetry (γ-unstable rotation), where the shape phase transition rapidly takes place between the neutron number N = 76 and N = 78.