Ericson formula represents the first formula, which was suggested to describe the partial level density (PLD) formula in pre-equilibrium region of the nuclear reactions. Then a number of corrections were added to this...Ericson formula represents the first formula, which was suggested to describe the partial level density (PLD) formula in pre-equilibrium region of the nuclear reactions. Then a number of corrections were added to this formula in order to make it more suitable to physical meaning. In this paper, there are two aims to be done: the first aim is to study the correspondence between one and two-components formulae in Ericson, Pauli, and pairing corrections;the second aim is to compare and study the results of Comprehensive formula, which contents with all corrections, with Ericson, Pauli, and pairing formulae. The Comprehensive formula was suggested to simulate the reality. To achieve these aims the 56Fe and 90Zr nuclei were chosen and the results showed that the difference between one and two-components formulae was too small which can be neglected. Furthermore, the results strongly recommended that for cross section calculations of the nuclear reaction, one must use Comprehensive formula rather than Pauli formula.展开更多
Ultrahigh-pressure（UHP） metamorphic rocks are distinctive products of crustal deep subduction,and are mainly exposed in continental subduction-collision terranes. UHP slices of continental crust are usually involved...Ultrahigh-pressure（UHP） metamorphic rocks are distinctive products of crustal deep subduction,and are mainly exposed in continental subduction-collision terranes. UHP slices of continental crust are usually involved in multistage exhumation and partial melting, which has obvious influence on the rheological features of the rocks, and thus significantly affect the dynamic behavior of subducted slices. Moreover,partial melting of UHP rocks have significant influence on element mobility and related isotope behavior within continental subduction zones, which is in turn crucial to chemical differentiation of the continental crust and to crust-mantle interaction.Partial melting can occur before, during or after the peak metamorphism of UHP rocks. Post-peak decompression melting has been better constrained by remelting experiments; however, because of multiple stages of decompression, retrogression and deformation, evidence of former melts in UHP rocks is often erased. Field evidence is among the most reliable criteria to infer partial melting. Glass and nanogranitoid inclusions are generally considered conclusive petrographic evidence. The residual assemblages after melt extraction are also significant to indicate partial melting in some cases. Besides field and petrographic evidence, bulk-rock and zircon trace-element geochemical features are also effective tools for recognizing partial melting of UHP rocks. Phase equilibrium modeling is an important petrological tool that is becoming more and more popular in P-T estimation of the evolution of metamorphic rocks; by taking into account the activity model of silicate melt, it can predict when partial melting occurred if the P-T path of a given rock is provided.UHP silicate melt is commonly leucogranitic and peraluminous in composition with high SiO_2,low MgO, FeO, MnO, TiO_2 and CaO, and variable K_2 O and Na_2 O contents. Mineralogy of nanogranites found in UHP rocks mainly consists of plagioclase ＋ K-feldspar ＋ quartz, plagioclase being commonly albite-rich.Trace element pattern of the melt is characterized by significant enrichment of large ion lithophile elements（LILE）, depletion of heavy rare earth elements（HREE） and high field strength elements（HFSE）,indicating garnet and rutile stability in the residual assemblage. In eclogites, significant Mg-isotope fractionation occurs between garnet and phengite; therefore, Mg isotopes may become an effective indicator for partial melting of eclogites.展开更多
The multiple atmospheric equilibria are studied by using a barotropic vorticity equation with thermal forcing and dissipative effects. Different low-spectral models are used to discuss the variations of theequilibrium...The multiple atmospheric equilibria are studied by using a barotropic vorticity equation with thermal forcing and dissipative effects. Different low-spectral models are used to discuss the variations of theequilibrium states, with the results that the multiple features of equilibrium states depend heavily on thetruncations of the spectra, and the low-spectral model has obvious shortcomings in solving non-linear equations,suggesting that one has to be very Careful to employ highly truncated low-spectral model in approximating partial differential equations.展开更多
技术性贸易壁垒是最难以量化的非关税壁垒之一,到目前为止对技术性贸易壁垒进行定量分析的实证研究较少。本文在Larson、Larson et al.和Larson&Scatasta等人的研究基础上,构建了局部均衡模型,运用在全国17省市开展的问卷调查对技...技术性贸易壁垒是最难以量化的非关税壁垒之一,到目前为止对技术性贸易壁垒进行定量分析的实证研究较少。本文在Larson、Larson et al.和Larson&Scatasta等人的研究基础上,构建了局部均衡模型,运用在全国17省市开展的问卷调查对技术性贸易壁垒对我国水产品出口的影响进行了定量分析。分析发现,当日本、美国、欧盟和韩国等水产品进口国检验检疫标准每提升1%,我国对这四个市场的水产品出口将分别下降0.5689、0.5094、0.9436和0.6574个百分点。展开更多
文摘Ericson formula represents the first formula, which was suggested to describe the partial level density (PLD) formula in pre-equilibrium region of the nuclear reactions. Then a number of corrections were added to this formula in order to make it more suitable to physical meaning. In this paper, there are two aims to be done: the first aim is to study the correspondence between one and two-components formulae in Ericson, Pauli, and pairing corrections;the second aim is to compare and study the results of Comprehensive formula, which contents with all corrections, with Ericson, Pauli, and pairing formulae. The Comprehensive formula was suggested to simulate the reality. To achieve these aims the 56Fe and 90Zr nuclei were chosen and the results showed that the difference between one and two-components formulae was too small which can be neglected. Furthermore, the results strongly recommended that for cross section calculations of the nuclear reaction, one must use Comprehensive formula rather than Pauli formula.
基金financially supported by the National Basic Research Program of China (Grant No. 2015CB856104)the National Natural Science Foundation of China (Grant No. 41273036)
文摘Ultrahigh-pressure（UHP） metamorphic rocks are distinctive products of crustal deep subduction,and are mainly exposed in continental subduction-collision terranes. UHP slices of continental crust are usually involved in multistage exhumation and partial melting, which has obvious influence on the rheological features of the rocks, and thus significantly affect the dynamic behavior of subducted slices. Moreover,partial melting of UHP rocks have significant influence on element mobility and related isotope behavior within continental subduction zones, which is in turn crucial to chemical differentiation of the continental crust and to crust-mantle interaction.Partial melting can occur before, during or after the peak metamorphism of UHP rocks. Post-peak decompression melting has been better constrained by remelting experiments; however, because of multiple stages of decompression, retrogression and deformation, evidence of former melts in UHP rocks is often erased. Field evidence is among the most reliable criteria to infer partial melting. Glass and nanogranitoid inclusions are generally considered conclusive petrographic evidence. The residual assemblages after melt extraction are also significant to indicate partial melting in some cases. Besides field and petrographic evidence, bulk-rock and zircon trace-element geochemical features are also effective tools for recognizing partial melting of UHP rocks. Phase equilibrium modeling is an important petrological tool that is becoming more and more popular in P-T estimation of the evolution of metamorphic rocks; by taking into account the activity model of silicate melt, it can predict when partial melting occurred if the P-T path of a given rock is provided.UHP silicate melt is commonly leucogranitic and peraluminous in composition with high SiO_2,low MgO, FeO, MnO, TiO_2 and CaO, and variable K_2 O and Na_2 O contents. Mineralogy of nanogranites found in UHP rocks mainly consists of plagioclase ＋ K-feldspar ＋ quartz, plagioclase being commonly albite-rich.Trace element pattern of the melt is characterized by significant enrichment of large ion lithophile elements（LILE）, depletion of heavy rare earth elements（HREE） and high field strength elements（HFSE）,indicating garnet and rutile stability in the residual assemblage. In eclogites, significant Mg-isotope fractionation occurs between garnet and phengite; therefore, Mg isotopes may become an effective indicator for partial melting of eclogites.
文摘The multiple atmospheric equilibria are studied by using a barotropic vorticity equation with thermal forcing and dissipative effects. Different low-spectral models are used to discuss the variations of theequilibrium states, with the results that the multiple features of equilibrium states depend heavily on thetruncations of the spectra, and the low-spectral model has obvious shortcomings in solving non-linear equations,suggesting that one has to be very Careful to employ highly truncated low-spectral model in approximating partial differential equations.
文摘技术性贸易壁垒是最难以量化的非关税壁垒之一,到目前为止对技术性贸易壁垒进行定量分析的实证研究较少。本文在Larson、Larson et al.和Larson&Scatasta等人的研究基础上,构建了局部均衡模型,运用在全国17省市开展的问卷调查对技术性贸易壁垒对我国水产品出口的影响进行了定量分析。分析发现,当日本、美国、欧盟和韩国等水产品进口国检验检疫标准每提升1%,我国对这四个市场的水产品出口将分别下降0.5689、0.5094、0.9436和0.6574个百分点。
